OnTrack: The PCB Design Podcast

In this OnTrack episode, we are very excited to bring you Tim Wang Lee, a Signal Integrity Application Scientist and the High-Speed Digital Application Product Manager at Keysight.

Tim will share his early days as a prodigy with Dr. Eric Bogatin. We will also discuss the importance of simulation and measurement to achieve signal integrity for your PCB design.

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Show Highlights:

• Tim Wang Lee Introduction
• Tim talks about Dr. Eric Bogatin as his mentor, the knowledge about simulation and signal integrity especially rule number nine
• A favorite phrase GIGO (garbage in garbage out) according to Tim is his way of understanding his intentions and asking questions before diving into a project
• Tim with Mike Russo, initiated simulation and measurement workflow seminars and webinars to help educate the importance of measurements and simulation to back it up
• What is a Virtual Prototype?
• Where to start with a system-level qualification in simulation?
• Tim explains what an EP Scan (Electrical Performance Scan) does
• Keysight is also now focusing on Power Integrity and Heidi Barnes is one of the leading experts in the Power Integrity ecosystem
• Next step for Keysight is to aid PCB designers in not only generating results but also fixing the issues

Links and Resources:

• Connect with Tim Wang Lee on LinkedIn

• Visit the Keysight Website

• Read Tim Wang Lee’s articles on SI Journal

• Watch Related Podcast Episode:

  • Pathological Design Features: Eric Bogatin on PCB Design

  • Power Integrity and Simulations with Heidi Barnes

  • Picotest’s Water-Cooled Probe with Steve Sandler

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In this episode, our guest Joe Dickson, tells us about the cutting-edge technology implemented in advanced packaging at Wus Printed Circuit International.  

Watch the episode here

Show Highlights:

• Joe Dickson talks about what they do at Wus, a printed circuit manufacturing company
  • He shares about their efforts to bring PCB technologies farther up by introducing advanced packaging options
  • He briefly describes what printed circuit-like materials are, also known as the vertical interposers or PCIe
• Zach explains how a pre-packaged chip can be mounted on a board
• What are the reliability and signal integrity challenges that come with assembling different packages on a board
  • Off-the-board solutions start to become more and more desirable 
• The flexibility of design and components is what driving the market to use more integrated packaging
• Speed is everything! When will the industry move on from copper and go to optical? 
• Knowing what's going on in simulations is very important; it opens opportunities to try new things
• Joe explains a way of using Faraday cages with cable connections on the surface
• Examples of the large market using the PCIe method are Xilinx and NVIDIA
• How far is silicon photonics from becoming mainstream as an interconnect technology?
• Standardazion versus innovation
• The future of PCB assembly is hybrid. Some will use the off-shelf, best-in-class products from Intel, AMB, NVIDIA, Xilinx, and get creative with them. 

Links and Resources:

• Connect with Joe Dickson on LinkedIn
• Visit Wus Printed Circuit International website
• Watch the related episode:
  • Eliminating Nuances in the PCB Manufacturing Processes with Amit Bahl of Sierra Circuits PCB
• Connect with Zach on LinkedIn
• Full OnTrack Podcast Library
• Altium Website

 

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I am very honored to have Bert Simonovich, a very well-known expert in the signal integrity community, in today’s episode. Bert developed the "Cannonball-Huray" model used for transmission line loss modeling, which has been adopted in several popular EDA tools.

 

We will be discussing several topics relating to copper roughness, including different approaches to ensure signal integrity in your PCB design.

 

Altium 365: Where the World Designs Electronics

Watch the video, click here.

 

Show Highlights:

• Bert shares his background and experience
  • He did his microprocessor systems back in the late '70s and later worked at Bell-Northern Research in Ottawa, Canada
  • In the 90s he transitioned to Nortel from where he specialized in backplane design and signal integrity
  • He founded Lamsim in 2009
• Bert retrospects using photo tools which is now the photo plotting with Gerbers. His experience helped him understand the mechanics of PCB construction
• A client’s demand led to extensive research involving dielectric material comparisons and foil roughness
• With various PCB surface roughness models, how to determine which process to move forward with?
  • Bert explains the Design Feedback Method
  • Cannonball technique is a roughness modeling approach which Bert also described as a heuristic method
  • Checkout Bert’s articles on SI Journal
• Bert gives a detailed explanation of how copper is being used in PCBs
• HDP user group international published a research paper Smooth Copper Signal Integrity in 2016
• Bert and Zach agree that PCB construction is complicated and it is highly recommended for PCB designers and SI engineers to learn more about the fabrication process
• What does reverse treated foil means, and how does it relate to the power layer?
• Read Bert’s DesignCon Paper: A Practical Method to Model Effective Permittivity and Phase Delay Due to Conductor Surface Roughness

Links and Resources:

Connect with Bert Simonovich on LinkedIn

Follow Lamsim Enterprises Inc. on LinkedIn

Visit Lamsim Enterprises Inc. website

Read Bert’s Articles on SI Journal

 

Full OnTrack Podcast Library

Altium Website

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Clearing up the confusion about the IPC 2152 with Mike Jouppi, the “Thermal Man''. Mike originally sat on one of the IPC task groups working on standards for thermal management. He will help us be enlightened about thermal management on PCB, which will be very useful to apply to your next PCB design project.

Altium 365: Where the World Designs Electronics
Watch the video, click here.

Show Highlights:

• Storytime! Mike's background in PCB design and involvement in IPC task groups
  • He worked in the Airforce as Missile Maintenance Specialist and later had an internship at Hughes Aircraft in Tucson, Arizona, where he did a thermal analysis
  • The TQM mindset—total quality management is what kept him moving forward
  • What does it mean when “Power was Negligible”; this led to Mike's first encounter with the IPC document
• How to take a vacuum environment into consideration? This is the question that leads Mike to start research and develop testing methods
  • Mikes received funding from Lockheed to do internal research and perform testing to understand trace heating
  • Mike shares his journey to seek funding for testing and how he ended up setting up his lab in his basement
  • He developed 68 different charts, 13 of those were raw data, and the remaining ones were all analytical creations with the thermal model
• Mike started working with IPC in 1999, IPC 2152 came out in 2009
• Mike wrote a chapter in Happy Holden’s Printed Circuits Handbook
• Clearing up confusion over what IPC 2221 and IPC 2152 represent, Mike emphasizes using the documentation as a baseline
• Another storytime! How did Mike come up with the name “Thermal Man”? The story involved measuring the thermal properties of an egg. Visit thermalman.com to check out Mike’s website
• More research was performed involving flex, heating vias, and microvias
• Discovery of the original data to the charts that are in IPC 2221 documented in the National Bureau of Standards report from 1955ish
• Mike has the data to prove that copper planes and copper pour affects thermal management
• The major players in terms of temperature response of the trace:
  • Influence of the copper planes
  • Mounting configuration
• Before the IPC took over the industry standards in electronic design, the National Bureau of Standards (the government) handled the management and documentations
• Check out more videos and courses about Thermal Management on Altium Academy Youtube Channel

Links and Resources:

Connect with Mike Jouppi on LinkedIn
Visit Mike Jouppi’s Electronics Thermal Management LLC website
OnTrack Episode with Isvan Novak: DesignCon 2020’s ‘Engineer of the Year’ Talks Power Integrity, Picosatellites, and Simulation Tools
Read Happy Holden’s Article on Altium Resource Hub
IPC Website
IPC 2221 and IPC 2152

Connect with Zack on LinkedIn
Full OnTrack Podcast Library
Altium Website
Download your Altium Designer Free Trial
Learn More about Altium Nexar

Altium 365: Where the World Designs Electronics

Dr. Eric Bogatin, Dean of Signal Integrity Academy, is back for some awesome discussion about bad PCB design guidelines. How to spot them to avoid ruining your design? This is going to be fun and insightful! Make sure to check the show notes and additional resources below. Watch until the end. Our favorite Dean has some perks for our listeners.

Altium 365: Where the World Designs Electronics

Watch the video, click here.

Show Highlights:

• Eric’s AltiumLive Presentation
  • Pathological Design Features
  • Demonstration of the 2D Field Solver built-in for free in Altium Designer
• Your intuition + PCB design tool can make or break your PCB design performance
• Most Common Sources of Noise
  • Ground bounce as an extreme case of crosstalk
  • Design structures that can strongly contribute to EMI failures
• Eric Explains “transparent interconnect”
• Best measurement practice and routing correctly
• Is an Arduino board really for beginners?
• EMI Problems caused by split planes—the trifecta, you get reflection noise, you get crosstalk noise, you get EMI noise out of it
• Eric Bogatin, Steve Sandler, and Larry Smith debunked PCB design myths and legends—the Myth of Three Capacitor Values
• Power integrity becoming Signal Integrity
  • What is Rad-hard?
  • Reliability concerns in aerospace technology and automotive systems
  • Fiber in vehicle and fiber base radar could be the solution
• Eric answers, What do you think about right-angle traces?
• 3 Month Signal Integrity Academy Subscription, use promo code ALT21
• AltiumLive Connect, register now!

Links and Resources:

• Article: The Myth of Three Capacitor Values 
• Signal Integrity Journal
• Laboratory for Atmospheric Space Physics
• Should You Worry About 90 Degree Bends in Circuit Board Traces?
• Previous Podcast Episode with Eric Bogatin
  • Why You Should Stop Hanging on to Legacy Design Rules
  • Eric Bogatin Debunks Common Misconceptions About Transmission Lines
  • Signal Integrity Expert Eric Bogatin on Best Measurement Practices
• AltiumLive 2022 Connect: Now open for registration
• Connect with Zach Peterson on LinkedIn
• Connect with Eric Bogatin on Linkedin
• Watch Zach’s latest Altium Academy courses on Youtube
• Read Zach’s articles on Altium’s resource hub

Full OnTrack Podcast Library
Altium Website
Download your Altium Designer Free Trial
Learn More about Altium Nexar

Altium 365: Where the World Designs Electronics

Everything that goes to making a board works against signal integrity...physics screw things up.
 -Bill Hargin

Avoid getting your design “skewed”! Today’s guest is Z-Zero’s Founder and CEO, Bill Hargin. Together we will dive into the cause of getting skews in your board. There are many details, and many questions answered, so make sure to watch through the end and check out the additional resources below.

Altium 365: Where the World Designs Electronics

Watch the video, click here.

Show Highlights:

• Introduction, a brief overview of Z-Zero and Bill’s background
  • Hardware Manager at Boeing (Electronic cooling and CAD design)
  • He became the Director of Sales and Marketing at Hyperlynx
  • High-speed marketing and five years in laminate space
  • Sharing his deep knowledge of signal integrity - travel around the world doing workshops
  • 2018 - full time at Z-Zero, a software company he founded. Z-Zero is an EDA start-up that offers solutions for stackup design, field solver, automation, library
• Bill presents every year at the PCB West on topics of stackup design and material selection
• Bill offers more resources through webinars and blog articles on z-zero.com
• What are Skews, and why is it’s a problem?
  • Comprehensive overview and solutions
    • Deterministic solutions
    • Stochastic Solutions
• What is a Glass-weave skew (GWS)?
• Prepreg glass types, what is spread glass?
• Bill’s deterministic solutions to avoid skew
  • Angled routing
  • Rotating artwork 10 degrees (waste about 15% of the material, higher cost)

Links and Resources:

Bill Hargin on LinkedIn
Z-Zero Website
Who Should Be Concerned about the Fiber-Weave Effect?

Read the blogs:
How to Avoid Getting Totally Skewed – Part 1
How to Avoid Getting Totally Skewed, Part 2
How to Avoid Getting Totally Skewed, Part 3
How to Avoid Getting Totally Skewed, Part 4

Watch the Webinars:
Glass-Weave Skew - Part 1 - Who Cares?
Glass-Weave Skew - Part 2 - Mitigation Methods  

 

Altium 365: Where the World Designs Electronics

The dean is in!

In this episode, Eric Bogatin, the Dean of Signal Integrity Academy is here to talk about empowering PCB  designers to become their own experts. Eric shares the inspiration behind his new book, PLUS you may have a say in what he will be writing next.

Watch now or listen on the go, and make sure to drop a comment on our YouTube channel here, to vote on which topic Eric should tackle in his next book.

Altium 365: Where the World Designs Electronics
Watch the video, click here.

Show Highlights:

• Out of this world (literally) storytime, Eric shares facts about the Crab Nebula Supernova
• Two Books from Artech, the inspiration behind Eric Bogatins “Practical Guide To...”
  • Bogatin’s Practical Guide to Transmission Line Design and Characterization for Signal Integrity Applications
  • Bogatin's Practical Guide to Prototype Breadboard and PCB Design
• What does it take to successfully build a prototype
• The important focus in Eric’s classes and books
  • the introduction to the signal integrity of switching noise
  • how do you design circuit boards for connectivity
• “I don’t like throwing rules” - Eric Bogatin
• Quick Poll, which book do you want Eric to write?
  • Compilation of All Eric's Rules of Thumb
  • Hacking interconnects using S-parameters
  • How to Use an Oscilloscope
• Check out more resources authored by Eric on Signal Integrity Academy and Signal Integrity Journal
• What is a Turbo Encabulator?
• OnTrack Virtual Bookclub
• News about AltiumLive 2021

Links and Resources:

Bogatin’s Practical Guide to Transmission Line Design and Characterization for Signal Integrity Applications
New Book (Pre-order): Bogatin's Practical Guide to Prototype Breadboard and PCB Design
Join our “Virtual” OnTrack community Book Club on Amazon!
Eric’s Author page on Amazon.com
Subscribe to Signal Integrity Journal

Full OnTrack Podcast Library
Altium Website
Download your Altium Designer Free Trial

 

Altium 365: Where the World Designs Electronics

The OnTrack Podcast welcomes Hans Klos, founder and CEO of Sintecs, a simulation service provider and developer of the HyperLynx® Connector tool. HyperLynx® Connector is a freeware application which seamlessly bridges the gap between Mentor Graphics’ HyperLynx and Altium Designer. 

Join us as Hans and Judy discuss the HyperLynx Connector tool, their upcoming webinar collaboration, and common signal integrity pitfalls.

 

Work from Anywhere. Connect with Anyone.
Share and Collaborate. Everything in One Place.

 

Watch the video, clickhere.

 

Show Highlights

• Hans Klos, founder and CEO of Sintec
• Rethinking Frequency and Rise and Fall times
• Common signal integrity pitfalls
• The problem with blindly trusting reference boards
• The Benefit of Simulation vs. Design & Measure
• The shift toward board level issues
• Why IoT devices are driving the need for simulation
• Sintecs’ HyperLynx Connector
• How design engineers can access Hyperlinx affordably
• Syntecs’ free training videos

Resources:

• Hans Klos on LinkedIn
• Signal Integrity Related Articles on AltiumⓇ Resource Hub
• Sintecs Website
• Hyperlynx SI/ALT Bundle Offer
• Hans Klos LinkedIn Profile

Work from Anywhere. Connect with Anyone.
Share and Collaborate. Everything in One Place.

On May 16, 1994, the Signal Integrity List (SI-List) was founded, with just 30 members on its charter email list. Today, there are more than 4,000 members worldwide, and the list includes Signal Integrity gurus like Istvan Novak, Todd Hubbing, Steve Weir, and Scott McMorrow. 

 

In this episode of the OnTrack Podcast, one of those world renown SI gurus, Scott McMorrow, CTO of Samtec Inc.’s Signal Integrity Group, connects with Judy Warner to discuss signal integrity concerns, and especially Samtec’s Webinar series, gEEk spEEk. 

Work from Anywhere. Connect with Anyone.

Watch the video, click here.

Show Highlights

• Scott McMorrow, CTO of Signal Integrity Group at Samtec Inc
• A quick overview of Samtec
• What is gEEk spEEk? 
• Learn something in 60 minutes; gEEk spEEk’s online content
• How to sign up for gEEk spEEk
• Using gEEk spEEk for internal training
• How Signal Integrity List got its start
• Judy’s big question: “When did you know you were gonna be an engineer?”

Resources:

• Scott McMorrow on LinkedIn
• gEEk spEEk Webinars (On-demand) 
• Samtec Website
• Making Connections! Scott McMorrow, on Building Relationship with Samtec as a Connector Supplier

Work from Anywhere. Connect with Anyone.

Signal integrity expert, Dr. Eric Bogatin, has a new book whose mission is to establish a solid educational foundation in the essential principles of signal interaction with transmission lines. The multimedia eBook, Bogatin’s Practical Guide to Transmission Line Design and Characterization for Signal Integrity Application, is currently available from Artech House and can also be found on Amazon. 

Dr. Bogatin is Signal Integrity Evangelist at Teledyne LeCroy, a leading provider of oscilloscopes, protocol analyzers, and test and measurement solutions. He joins the OnTrack Podcast to discuss his book and give us a sneak peak of his upcoming AltiumLive panel with Istvan Novak, Heidi Barnes of Keysight, and Steve Sandler of Picotest.

 

Altium 365 Podcast Listener Discount

 

Watch the video, click here.

 

Show Highlights:

 

• In addition to so much else, Eric Bogatin is a science fiction author! Check out his books Shadow Engineer, and S is for Space
• An overview of Eric’s new multimedia eBook, ‘Bogatin’s Practical Guide to Transmission Line Design and Characterization for Signal Integrity Application’
• ”I think the most confusing topic out there...is transmission lines”; how Eric’s book builds a solid foundation for anyone seeking clarification on transmission lines.
• Clarifying engineering’s most confusing issues 
• Teledyne LeCroy’s new TDR calculator
• The practical nature of transmission lines: common misconceptions among engineers
• Embedded videos, demos, and calculations: how Eric’s multimedia book provides an interactive experience 
• Hard copies, soft copies, ALL the copies: how and where to find Eric’s book(s)
• AltiumLive announcement
• The plain truth about split ground planes: Eric provides a sneak peak of his upcoming AltiumLive panel with Istvan Novak, Heidi Barnes of Keysight, and Steve Sandler of Picotest.
• ”There’s one case where you wanna use a split ground plane...”: Eric previews his upcoming demo on crosstalk reduction 

 

Links and Resources:

 

Eric Bogatin on LinkedIn
Bogatin’s Practical Guide to Transmission Line Design and Characterization for Signal Integrity Applications
Artech House Publishers
Eric Bogatin Author Page on Amazon
Shadow Engineer (Fiction Scifi book by Eric Bogatin)
S is for Space (2nd Scifi book by Eric Bogatin)
Teledyne LeCroy Website
Signal Integrity Journal
Podcast Episode: Signal Integrity Evangelist Eric Bogatin, our Expert Insider to DesignCon 2020

 

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Istvan Novak, Principal Signal and Power Integrity Engineer for Samtec Inc. and winner of the DesignCon 2020 Engineer of the Year Award joins the OnTrack podcast to talk picosatellites, simulation tools, and the rising importance of power integrity.

Altium 365 Podcast Listener Discount

Show Highlights

• Introduction to Istvan Novak 
• A brief look at Samtec Inc., the successful computer equipment manufacturing company headquartered in Indiana.
• Istvan’s path to becoming a Power Integrity expert
• CubeSats and the students who make them
• The challenges of dimensionality: has power integrity become more important than signal integrity?
• When Power Integrity is an afterthought
• The value of expert disagreement
• “Regardless of what we want to simulate, we can find good simulation tools to do it”: Good design and the challenges of modeling and simulation
• Closing thoughts; the first working Picosatellite; and the first electrosmog map of the globe 

Resources:

• Istvan Novak on LinkedIn
• Samtec: gEEk spEEk SI Webinars.
• Samtec Silicon-to-Silcon Solutions Website
• The SI-List Archives
• Istvan Novak: DesignCon 2020 Engineer of the Year Award 
• BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS Picosatellite
• Istvan Novak’s Electrical Integrity Website
• Picotest Website
• Signal Integrity Journal
• Design 007 Magazine, See pg. 38 Do You Really Need That Ferrite Bead in the PDN?
• First Electrosmog Map of the globe 

 

Altium 365 Podcast Listener Discount

Signal integrity expert, Dr. Eric Bogatin, shares why best measurement practices have become his go-to topic when speaking with PCB designers around the world. As Signal Integrity Evangelist at Teledyne LeCroy, a leading provider of oscilloscopes, protocol analyzers and related test and measurement solutions, Eric lectures around the world and he will be one of the keynote presenters at AltiumLive 2018: PCB Design Summit. Listen to Eric and Judy talk about the importance of best measurement practices and where to learn more — from webinars to conferences to the Signal Integrity Journal and Rule Number 9. Eric also has some real insights, so tune in and learn more in this episode of the OnTrack Podcast.

 

Show Highlights:

• The OnTrack Podcast is in 84 countries! Congrats to Daud Zoss who was the closest guess at 37 countries. He gets a free pass to AltiumLive as Judy’s guest.
• Dr Eric Bogatin will be a keynote speaker at AltiumLive in October 2018
• Best measurement practices - how do you get the answer to the performance, root cause, characterization, etc. as quickly as possible?
• How do you know what the performance of your instrument is, so that you know its capabilities and what the device is doing compared to your measurement instrument? It’s important to know what the properties of your scope in the probe is, to know the properties of the device you’re testing.
• Measurement data: Such as the rise time, frequency or figure of merit must be excavated to give you useful information. How do you get the information so it’s high quality and can be trusted, how do you turn it into information that you can turn into action?
• Eric is also the Editor of Signal Integrity Journal, working with Janine Love and Patrick Hindle.
• Expert content - if anyone is interested in writing a technical article for Signal Integrity Magazine, please write: Eric or Judy.
• Janine Love manages the EDI CON coming up in Santa Clara in October (a couple weeks after AltiumLive). Part of this is EDI CON University offering tutorials by industry experts.
• Industry Experts on the Editorial Advisory Board: Bert Simonovich, Yuriy Shlepnev, Larry Smith and Steve Sandler, Rula Bakleh, Jay Diepenbrock, Vladimir Dmitriev-Zdorov, Alfred Neves, Istvan Novak, Doug Smith, and Lisa Ward.
• Rule #9 - Before you do a measurement or simulation, think about what you expect to see ahead of time, and if it’s not what you expect, there’s always a reason for it. You need to identify the reason why it’s not what you expect.
• Hands on learning is a necessity for students. Eric and Mike Horowitz put together a five-week, standalone crash course on how to design a board.
• Designing for connectivity is just about driving the board to enable finding the parts and laying them out for assembly. Really simple.
• The lack of experience with Oscilloscopes is surprising because nobody has ever taught these students the correct method.
• Hands on experience is giving students an edge in the marketplace. There isn’t enough of the ‘real world’ activity in most Universities.

Links and Resources:

LeCroy webinars

Upcoming events at LeCroy

SI Journal webinars

Upcoming SI Webinars  

Hyperloop competition

AltiumLive 2018: Annual PCB Design Summit

 

 

If anyone is interested in writing a technical article, please write:

Eric Bogatin or Judy Warner

To see ALL show notes and watch the video recording please visit: 

https://resources.altium.com/altium-podcast/signal-integrity-expert-eric-bogatin-on-best-measurement-practices

 

 

Hi everyone, this is Judy Warner with Altium's OnTrack Podcast. Thanks for joining again, if you would please connect with me on LinkedIn I like to share lots of information relative to PCB designers and engineers who are laying out boards and on Twitter I'm @AltiumJudy and Altium is on all the usual places; Facebook, LinkedIn and Twitter.

So please let us know what you'd like to hear about on the podcast and we will do our best to get it done. So today I have a rock star with us and he needs no introduction . But before we get going with Dr. Eric Bogatin; I wanted to say that a few weeks back I had put a challenge out there to see if you guys could guess how many countries the On Track podcast has reached; and we have a winner! So congratulations to Daud Zoss. He's a Senior Staff Engineer at Dexcom; he guessed 37 countries and he was the closest one, unfortunately it was only about half, because we've actually reached 84 countries, I kid you not! So anyways, thank you for listening and engaging with us and all across the world. We really appreciate it.

So today, as I mentioned, we have Dr. Eric Bogatin with us who needs no introduction; who is a signal integrity guru. You might know him from many conferences in North America and I suppose around the world Eric has has presented, and I'm lucky enough to be here in California, where I've seen him present many times on Be The Signal and now the Be The Signal and Eric Bogatin brand is flying under the Teledyne LeCroy flag. So he has lots of lectures and demos and things and I'll let him tell you more about that. So Eric, welcome, we are glad to have you.

Hey thanks Judy, I'm happy to be here with you today and tell you about all the things I've got going on.

Well, we're super excited to have you as a keynote at AltiumLive, so we really appreciate you coming out for that and we've done some neat things together with students, so we'll talk about more about that. So why don't you start off by telling us a little bit about your day job at Teledyne LeCroy?

Sure yes, so many of you may know, and I know you - - I knew you back when I had my own company it was Bogatin Enterprises, and I literally went around the world and did training classes. And about seven years ago, my training company was acquired by LeCroy and we continued the training classes and then began to make a slight transition to, most of what I've done over the years has been best design practices.

How to get the design right the first time and LeCroy is in the measurement business; we are the third largest manufacturer of oscilloscopes and some of the highest end oscilloscopes; and our CTO Dave Graef, he likes to say that that in designing, the goal is to get it right the first time, but if you don't get it right the first time then the goal is to get it right the second time; and the way you get it right the second time is, you have to find the root cause of the problem and invariably that involves some measurements. So that's kind of the connection with LeCroy, is we're number three in the  scope world and have the highest end performance scopes out there.

We really specialize in the business of helping customers get it right the second time; kind of a faster time to insight. And so we started out when I joined them seven years ago, doing the same Best Design Practices presentations and classes I used to do, and then over the years since then, I've been working on this new area of Best Measurement Practices and so, with my day job at Teledyne LeCroy, I am still Signal Integrity Evangelist, but I spend more time now going around talking to folks about, and doing presentations on what are some of the best measurement practices. How do you kind of get the answer to either the performance, or the root cause, or the characterization, or get the Figure of Merit? How do you get that as quickly as possible?

And recently, in fact, I've got a couple of live events in the Bay Area coming up - actually next week - in last week in August, and then in Boston in September. And you can check the Teledyne LeCroy website for the events page to see where I'm coming next, but those presentations are really focused on, how do you - I call it kind of two aspects of in best measurement practice - one is situational awareness. How do you pay attention to - how do you know what the performance of your instrument is, so that you understand what its capabilities are, so what your device is doing, compared to your instruments. So you make sure that you are not seeing an artifact in the measurement.

Wow that's interesting.

Situational, because I find in talking a lot of folks about measurements; gosh there's a lot of confusion about what's the scope doing. And unfortunately there's no such thing as the ideal instrument; they're always - - or ideal probe, for that matter. There are always interactions of the probe and the scope with the device we're looking at, and it's important to understand what the properties of your scope in the probe are, to know how far away you are from the properties of the device you're testing so that you're getting good quality information about the device you care about and not an artifact of how you're doing the measurement. So that's the first piece of what we try to present and teach - those principles.

And the second piece is - and I see this with my students all the time - that they sometimes feel that just getting the data, just getting the measurement is enough. So they, push the right buttons and they get a screenshot and say: okay , here's my data. And I see a lot of engineers doing that as well, and the data is just the starting place. That's not - you're not done with the data - you need to take that data, the measurement and turn it into information. So you need to extract out, what's the few pieces of valuable information.

Like what's the rise time, or what's the frequency, or what's the jitter? It's a figure of merit that takes a lot of data and gives you one or two numbers that you can do something with. I was giving a talk at one of my events a couple weeks ago, and as I mentioned, that we have this huge amount of data in a scope. I mean, one acquisition can be we can take up to five Giga samples worth of data - but you know stupidly maybe - 10 - 20 mega samples but that's 10 or 20 million data points in one acquisition. It's a huge amount of data but you only want one or two numbers out of it. And so I used to call it data mining, and someone said: hey with all that data there it's not mining, it's excavating.

So it's kind of excavating the data for useful information, and then the third piece - once we have the information - is this: so what? It's how do you turn that information into action? How do you use the information you've got, to tell you is this good or bad? Should I, raise the line width or decrease the line width? What do I want to do with that information now? How am I going to use that to influence a decision? So it's those three steps that we talk about in our workshops; of how do you get the information, do you have high quality of confidence for the data, do you have high confidence in it? How do you turn that data into information, extract a couple of figures of merit, the nuggets of valuable information and how do you take that information and turn it into action?

So that's what I'm focusing on these days, the idea of best measurement practices. In addition to the stuff I've done forever, of best design practices. So that's kind of what I'm involved in now, spending a lot of time going around, doing live demonstrations, incorporating them in my workshops. Now we've got some really cool scopes and bring a lot of test vehicles and structures, so we can do live measurements of various signals. And so it's always a lot of fun when you can have...

A physical scope there, right.

-yeah a working device and the scope, and then people that come to these; you know I love working the crowd, and we talk about: well, if that's really what's going on, if you made the the rise time shorter, what what will you see? Or if I expanded the time base, what's the signal going to look like? And so we can do that as a live experiment in the group. So they're a lot of fun, very interactive activities. So that's that's what I do is my day job now.

Well, that's a lot, and it sounds - you make it sound really fun and engaging. So also, Teledyne LeCroy will have a table at AltiumLive, I hope we can talk you guys into bringing an oscilloscope so we'll let you work our crowd and I'm sure.

You know, another thing - oh by the way - I would encourage people that are listening to connect with Eric on LinkedIn, or connect with me I've been sharing those classes that Eric is teaching, so you'll be able to pick those up and see the different locations that he's teaching those courses. And we will also add those links below here in the show notes.

So if you're in those areas you can hop into one of Eric's classes, and he's super fun too it's a very plain spoken - and like I, can learn things from Eric Bogatin, and I am not, my technical prowess is limited, so I really appreciate that about Eric. The other thing you do, we have some friends in common which are Horizon House, the publishers of Microwave Journal, have published a new magazine called the SI Journal, which I am very excited about and you are also the editor of SI Journal, and we have friend in common Janine Love and Pat Hindle and the whole group. I used to write a blog for Microwave Journal that is put out by the same publishers on their website, talking about making RF boards and all the fun that goes along with that. And so now, Eric is editor of SI Journal, so you can also subscribe to that online. We will also share that link. So how's that been so far? Tell us about your job - how long has it been now? It hasn't been too terribly long?

You know what, I think it was about - - it's almost 2 years now, so I'm just going to...

Wow! I was gonna say a year and it's like two years. Wow.

So I think it was it'd be - - between Pat and Janine they kind of came up - they've been focusing on the Microwave Journal which has been around for 30-some years and this is one of the - I think it's the top...

I think it's like 60 years or something.

Is it 60 years?

I don't know I might be...

It's a long time - it's been around forever.

And it's been a real icon in the industry for good quality articles about microwave technology and with Janine's experience with the Design Con and in the signal integrity world; I think between she and Pat they realized: hey, the industry could really use another kind of curated source of high value information and so many of the magazines that we're used to getting have - - the print magazines have disappeared and they're all online, and so Pat and Janine decided to create this as an online journal initially. And they asked me to come on board as the editor; really the technical editor right at the beginning - about two years ago -

and so since then we've been kind of planning it out, putting together the editorial review board - of really some industry heavyweights and kind of creating a lot of new content, soliciting content from other experts in the industry, in fact, while I have a captive audience here, if anybody out there listening, is interested in writing technical articles for us, that'd be great.

Drop me an email or send it through Judy, and I'd be happy to take a look at what you like to do. We created this and our focus is to provide high value content that's curated. That there's so much information out there online right now. If you do a google search on Signal Integrity or Power Integrity it's not that you don't find anything, you find like 10 gazillion different sources.

You get flooded.

Yeah it's hard to know what's the good stuff and what the stuff is that I should waste my time with and so I think that's really the value of having an online publication or portal that is curated, and that's what we try to do is between myself and Janine and Pat and the editorial advisory board; we try to curate the content so that it's in our opinion what we would consider to be high-value content. And so we don't want to waste people's time or our own time and so there's, we think, a lot of really good valuable content. We've done the traditional stuff of short columns, of feature-length articles. Janine manages the annual conference EDI CON, which is now coming to the Santa Clara area in October. I think it's a couple weeks after AltiumLive.

Yah, it is, it's really close.

And part of that is now I think Janine's calling it the EDI CON University which is going to be tutorials by industry experts that are available for all the attendees. And then she also manages webinars, and if I can just plug a previous webinar. So we had Rick Hartley do a webinar...

Which we love and you know as I mentioned you and Rick are just so well respected and the SI field so I'm glad you snatched him up.

Yes we got him to do one a couple months ago and then that's recorded and posted on the...

Oh great!

-and then I did one a couple weeks ago that's also up there. So we have maybe it's 20 or 30 different webinars and they're all free and all available for anybody if you go to the SI Journal.com website, and you can look under videos and webinars, anybody can access all the content on the SI Journal is free as well.

So, there's some other people that are dear friends Bert Simonovich I know is on your team on the magazine who - - I think is Yuriy on that team as well?

Yeah Yuriy's been involved Istvan Novak has been on the Editorial Advisory Board. We just brought on Steve Sandler - - let's see; Larry Smith who is, he's my buddy, we worked on a book together that came out last year on Power Integrity and he now is at Micron; used to be at Qualcomm, he's maybe the one or two world expert on power integrity. So I learned a lot working with Larry. Let's see - - so yeah those are them.

They're all heavy hitters I mean, all really, they are the industry experts you really have, kudos to Horizon House for putting together such a crack team with you at the helm, which is just incredible, and like you said curating that content. Because there's so much noise out there. How do we bring the noise down and just cherry-pick, the best pieces? And I was kind of around before and as they were launching EDI CON and I was really glad to see them, as the high-speed digital and the RF world kind of moved together and some of the challenges were kind of overlapping to launch a show like EDI CON I think is really exciting and this magazine so, yay! Very excited about that so I can't... and again we'll put all these links below.

I'll even I'll see if I'll go pluck out some of those webinars and put those links in too if you didn't send those to me already.

So while I'm plugging webinars can I plug one other webinar too-

Yeah,

-that I should have mentioned. So I've been spending a lot of time, too much time, traveling doing these live events but also doing webinars; I mentioned the one with SI Journal. I've also been doing some through LeCroy, and we have a whole landing page on what LeCroy has done.

Yeah there's a lot there.

There's a lot of high value content that's all free. Anybody can view them and I'm hoping you'll put up a link to the webinar page from from LeCroy as well.

Okay.

I've put a series together on, a little bit about fundamentals of measurements, part of this best measurement practices series that I mentioned earlier they're one-hour webinars on various scope measurement principles and I'm doing them on a regular basis. I think we have two or three more scheduled for the rest of this year and then we'll have another series starting up in January.

Exciting, I like the idea of this best measurement practices, it's like really practical.

Yeah and it's the same thing with design practice. There are accepted practices that you want to follow unless you have a strong, compelling reason. Otherwise these are the right ways of doing things.

Right.

And same thing with measurement; there are just as many ways of screwing up a measurement as there is a design and so you've got to pay attention to both of them.

And there's a human in the loop too besides your probe and all that, so.

Oh absolutely.

So if the human isn't 'tuned up' -

Yeah

- now so one of the principles that I teach my graduate students and at University and also engineers I talk to, is I call it rule number nine and... have I talked to you about rule nine? Okay I'm definitely gonna be mentioning it at the at my keynote because I think it's one of the most important rules for any engineer and basically it says: before you do a measurement or simulation, you want to first anticipate. Think about what you expect to see and I have found that to be the most valuable kind of habit to get into, because just like you said, when there's a human involved it's easy to make a mistake. And how do you know that you don't have the connector connected where it should be, or how do you know: I think I'm looking on channel two, but I'm really going on channel three? Or I typed in 17 but I meant 71? How do you know?

You can check yourself but there's a limit to, how well you can check yourself and so, if you think about what you expect to see ahead of time, whether measurement or simulation and you look at the result and it's not what you expect, there's always a reason for it and you shouldn't proceed with that information until you've identified how come it's not what I expect. And when I do these live demos in front of groups, I'm constantly making mistakes because you know, it's under pressure. I get a screw in that connector and I'm not sure which demo am I on right now, and so I'm always looking at the screen to see, is it what I expect to see, and I can tell instantly when I've done something wrong because I use rule number nine. And I sometimes play a game with the audience, the engineers there, and say: okay, we expect to see this waveform go up and then down and it's flat - how come?

And it's good experience, good practice, that thinking of what could go wrong in the debugging process because that's what we all end up doing and the more experienced we can become at finding the root cause and why it's not what we expect I think, the quicker we can get to a good answer and move on to the next problem. So it's an incredibly powerful habit that I use all the time and I try to teach all my students.

This is what I love about your classes and things you teach Eric. I've sat in a few of them over the years is, that they're insanely practical and intuitive and memorable. Like rule number nine, I can remember that right, so I really have to say that about you.

Of course, don't forget I also reinforce good behavior with chocolate so that...

Oh yeah he does! He throws chocolate out at his classes so yeah it's like Pavlov's dog, yeah it's so true. Well I wanted to jump into the way that you and I started working together, is I think a month or two ago Iconnect007 came out with a magazine with an empty pair of shoes walking down the street, and it said, who's gonna fill your shoes? And everybody seems to get on this bandwagon about all the people that really, fundamentally understand PCB design in regards to, not just designing but manufacturing, assembly, the whole, all the stakeholders that are kind of implied in that process are greying and gonna retire, and so you know, there's been studies out by UP Media saying - by a pretty large sample - saying that in under 10 years half of PCB designers are going to be gone and so everyone has sort of gotten to this hysteria about it seems like the unanswerable question.

What I appreciate that you've done is I'm going to call you professor now - he wears lots of hats - professor Bogatin called me up and said, Judy, you know, I'm gonna do this program, he's used different tools right now that this - I think the students were sort of driving, or somebody was driving one at Altium Designer, so you kicked off this amazing semester-long course at the University of Colorado Boulder and you - I think co-teach that right Eric?

Yeah so I can give you the quick history.

Okay let's hear it.

So I've been teaching a graduate signal integrity class at CU Boulder for a number of years, based on my textbook and in talking to folks there, we realized that our students - so CU Boulder tends to be very project oriented very hands-on we believe in that, you know you learn from textbooks, you learn from studying, but you understand by doing. And it's the hands-on part that you really - everything comes together. And there were a number of classes that required building circuit boards and I would get called in as a consultant to help them in designing the circuit boards and there's relatively simple boards, two layer boards. But these kids had absolutely no idea. They could push the buttons on the tool, but they had absolutely no idea how the performance was influenced by it by what they do in the layout. And so it became really clear that, boy it sure would help if they had a little bit of guidance in how to design boards correctly. And so a number of us got together and realized: hey, we need this more formal training and a buddy of mine Mike Horowitz, who is an expert at design of circuit boards, we got together and put this course together which was - and it's kind of a funny organization too - we're also trying another experiment.

At CU you are semester based, and some courses are typically like 15 weeks or so. But we are experimenting with creating short five-week modules so it'll be the full regular course, that is a normal schedule of of 3 hours per week but it only lasts for five weeks. And so, Mike and I were tasked with putting a course on Printed Circuit Board Design and Manufacture together, that would have a five week beginning piece that could be a standalone so that most students, undergraduates, would take that and that'd be enough to get them going on their projects and then everybody else would continue for the rest of the ten weeks. And that would go into more detail so it gets them more experienced at circuit board design. And so that's how it got started, and Mike and I worked on it - it's every semester; so we did it twice last year and now. So that was kind of our joint development. And now Mike has gotten more involved in his CEO activities and so I'm gonna solo it this semester.

Oh okay.

So the format is basically a five-week crash course on how to design a board so you have a good chance of success when you build a two layer board. And then the other five weeks are more the same, more the technical detail about measurement technique - this idea the best measurement practices. How do you bring up a board? How do you design a board for simple tests and bring up? And then we'll do four layer boards, and then a little bit on the more high-performance systems. So it's a little bit more advanced and really you know, the way we've positioned it as: there are two levels of design. The first is if you can build a prototype and build it with a solderless breadboard and have wires going all over the place; if that works then designing the circuit board and having it work is really straightforward.

We call it designing just for connectivity you don't have to worry about performance, it's about, you want to be able to manufacture it, but performance isn't on; the interconnects don't matter, and and some of the student designs are just designed for connectivity. It's just about driving the board so you can find the parts of the library and build it in the schematic and then place them on the board and lay them out, so you can assemble it by hand - pretty straightforward.

But many of our student designs these days, are getting more sophisticated. They use a Wi-Fi connection, so you have RF on the board, they have sensitive analog to digital converters on the boards, they have components that sometimes -even BGA components - where the microcontrollers are using a really fine pitch; hard to design by hand, and some of these have a couple nanosecond edges where ground bounce is a tremendous problem. And so we're focusing our class on how to design a board. Not just for connectivity - that's the easy part - but for performance, so that you can designed so it's manufacturable, it's lower-cost reduce the - so much of it is risk management - and then kind of the basic performance issues to worry about.

And in my keynote, I'm thinking that I will probably present on what we have found to be the two most impactful design issues in designing a board, not for connectivity but for performance. If all you think about is connectivity you're gonna run into two significant problems. And so one of the topics is this idea of rethinking how signals propagate on interconnects and I've done this at PCB West and I did it at some of my other courses - and I had a couple people come up to me afterwards and tell me that it was a life-changing moment for them. Because I completely changed the way they've been working on boards for 20 years, and I completely changed how they thought about signals on boards. So I hope it will have a similar impact at AltiumLive, but it's going to be about how to rethink and how to train your intuition to think about how signals really propagate on interconnects.

I loved your Be the Signal....

so... and I'm sure this is a little bit more complex than what you're gonna present, but I remember the first time I ever sat in a course by Eric Bogatin, and he was talking about 'be the signal' and he's like: if this signal's moving from A to B what do you think is gonna happen to la-la-la... and I'm sitting there as a non-designer and he's like: no, be the signal. What would you do? And kind of helped us to frame, kind of this visual - and I'm a visual person - so I like to kind of visualize, what the things that were going on, in that signal path to create whatever it was. So I really loved that.

And that's basically what I'm going to be talking about, that Zen approach to thinking about signals propagating and and how to apply you know -  I'll probably mention it once, in my talk, about how to apply master's equations but in an intuitive way, to understand what's really going on in the interconnect.

So Eric's talk is called 'Living in the White Space' and that will be relative to signal propagation and I'm sure all of us, our brain will explode a little. I have these moments with Rick Hartley from time to time too where he says something and I'm like: nah! You know it could be that simple or whatever and I'm sure, you know Rick Hartley is a student of Eric Bogatin so, I'm sure it's more of the same.

So, well I really appreciate you Eric, taking on these students at university level. Here at Altium absolutely, I think I would do this part of my job for free; is to help students get equipped with not only tools - like I can give them free tools - but that's a really incomplete model, for them to learn. They're learning about electrical theory in school but really how to design a board, and how does - - I just finished a podcast today with Julie Ellis who's a Field Applications Engineer from TTM - what about stack-up? What about all these variables and how they come into play, that are not taught at university? But I love that you've brought them in at a university level because I think these are the kids - I think these are exactly who's going to fill some of those shoes, and they may be EEs laying out boards, they may end up like Rick Hartley did saying, I like just designing boards better than circuit design. Who knows? We don't know.

What has been some of your surprises by the way? What feedback from students?

So I think two things absolutely surprise me; one is, their lack of experience with oscilloscopes. That their way of using oscilloscope is first to push the autoscale button. And I slap their wrist if I catch them doing that, or pushing every button without knowing what it is until they see something, on the screen...

Until the light goes on, they're looking for the LED.

-and and so they, just the basic understanding of what an oscilloscope does and how to control the vertical/ horizontal and the trigger. You know the very basic things. A lot of these kids; nobody's ever sat them down and talked to them about it, so we focus on good - again - best measurement practices in the class as well as the design. The second thing is, there is a disconnect between what you learn in the textbook and what you see in the real world and it's the same thing, but you have to know how to apply what you learn in the textbook. And I don't think any university does enough of that hands-on, real-world activity. We try to do it a lot at CU, we have a lot of projects that students get involved in. Most of them are really about designing a little robot or designing some gadget that does something with the code that you write in there. So a lot of it is - some software, as well as the hardware.

But in our class we try to close the loop of the; here I do an estimate or calculation, and here I do a measurement. Like one of the first labs we do is blowing up traces.

That's fun! It is. Everybody likes blowing up something.

Everybody likes to blow shit up

[laughter].

And so the question, the first question I ask them is: okay, you're gonna lay out a board and you're gonna put some tracer - what line width should you use? You can select it to be anything you want.What line width should you use?

And so one of the things that surprised me is, when I asked the students is, they thought that a six mm wide line, just the narrowest that most fab shops will do. A six mm wide line, was too narrow because it's way too much resistance, or I can't put more than a couple milliamps of current through it. So I gotta use a twenty mm wide line, or fifty mm wide line. And it's the kind of thing that, the very first day in class, we calculate or we look at how do you calculate the resistance of a trace? How do you calculate what the maximum current handling it, using the IPC guidelines that Doug Brooks has been so heavily involved in.

And when you put in the numbers you realize: oh my gosh, it looks really narrow on this board it's only six mm wide but but gosh; it's resistance is going to be still in the tens hundreds of milli ohms for typical lengths. So it really isn't that high a resistance even though it looks really narrow because copper is an incredibly good conductor.

Exactly.

People don't have good calibration of that. And then, so I'll give you the number, and I hope none of my students are listening to this because they're gonna figure it out in class. But if you look in the IPC specs for maximum current handling for a six mm wide surface trace; it's like two amps or three amps and when we put two amps through, we have a test board with the different line widths on them. When you put six amp - - two amps through it, you find we can monitor the voltage across it with constant current and see the voltage increasing because it gets hotter, as you see the beginning of the runway, and RNDF around three amps, IPC's around two amps, around three amps, darned if it doesn't go to thermal runaway and we zap the trace and so, you can really get a good estimate by putting in the numbers ahead of time, of how some of these interconnects are going to behave.

But it's that habit of putting in the numbers doing simple estimates, applying what we learn in class to the real world, that the students don't have that good experience with and that's what we try to do in our class at CU.

Well to your point of hands-on, I feel like that's something that for whatever reason has left our education system too much right there's no shop at school anymore, there's no metal, there's no like just - and it's not just, what they would consider low labor skills or whatever. It's just hands-on learning the kinesthetics of it because I bet you dollars to doughnuts that kid, is gonna remember blowing up a three amp trace, more than if he read something about it in a book right?

Right, and sees the smoke and it pops and, there's this feedback well, what I was telling you about is, again one of my favorite parts of my job is, we just came back about three weeks ago from filming these kids that are doing the Hyperloop Competition -

Oh I'm gonna send you this video Eric - you're gonna die because what they do is so awesome and it's just because they get to do hands-on and they make a good - - there's no way they're not making, more mistakes per minute than everybody else in their field, but because of that and because the lack of constraints they have on them as far as businesses and law and whatever, you know this one team we sponsor is from Munich Germany, they just broke the world speed record inside the tube that Elon built at 290 miles per hour.

Crushing!

There's commercial  companies with venture capitalists that haven't hit that number. Because they're young and they're hungry and they're hands-on, and they're excited. But these are the kids who I think, there needs to be much more of what you're doing. I wish every University would, hopefully you'll set an example that others will follow. And by the way, I've cited your course to a group of six universities I was invited to speak at UCSD, UC Davis was there, five other universities and I put a screenshot of your course -

Oh that's great

-and so I, so if you start getting weird phone calls...

(laughter]

-because I'm like see what he's doing - you all need to do this you know, so hopefully the word will spread but until that happens things like the Hyperloop competition, the FSEA competition, where kids get to get their hands on it and blow stuff up and do it wrong, until they do it right, and learn how to use an oscilloscope in this really hands-on manner well these kids are coming out of college and the internships of these kids, one of these kids from University Wisconsin in the Hyperloop team he's a Qualcomm right now, the team lead is going to SpaceX on internship - companies are plucking them out because of the hands-on. So I think the more we sort of beat this drum and spread this message, I again, something I'm very passionate about - I know you are too - and thank you so much for doing that course and we cannot wait to hear from you and about Living in the White Space at AltiumLive.

Thank you so much for taking time out of your busy schedule.

Well I look forward to seeing you at AltiumLive and all the other viewers that you have and I hope folks come up in and say hi while I'm over there.

Okay will do, and make sure - well not make sure - see if we can get LeCroy and company to bring out an oscilloscope so you can - -

We will definitely have one at our table.

Okay good, good I think that would be something notable and something that people, the attendees would enjoy so thank you again Eric this has been...

Thank you Judy.

Thank you again, this has been Judy Warner with Altium's OnTrack podcast and Dr. Eric Bogatin of Teledyne LeCroy. We look forward to being with you next time. Until then, remember to always stay on track.

What do you do if you have an interference problem? Rick Hartley is an industry leader in the correct design of circuits and PC boards to prevent and solve noise, signal integrity and EMI problems. He consults and teaches internationally and he has taught seminars at numerous conferences, including the IEEE EMC Symposium, PCB West, IPC Apex/Expo and others. He is a past member of the Editorial Review Board of Printed Circuit Design Magazine and has written numerous technical papers and articles on methods to control noise, EMI and signal integrity.

Listen to this episode where Rick shares the worst ideas for a 4-layer and 6-layer stackups. He also offers a sneak peek of what to expect at his AltiumLive 2018 Keynote Presentation: The Extreme Importance of PC Board Stack-up.

Show Highlights:

• Contest - can you guess how many countries the OnTrack podcast has reached? You can win a Summit pass to be Judy’s personal guest at AltiumLive 2018! Just tag #OnTrackPodcast on Twitter with your best guess!
• Mid-80s - in digital domain things started to not work right and no one had answers. There was research to do (120 books later), learned what causes function vs. not function
• In the 90s, began to realize the problem wasn’t clock frequency, the problem is the frequency associated with the rising and falling edges of signals.
• Person who helped me the most - Ralph Morrison
• I didn’t learn what I needed in college, it had to come from experience.
• Energy and Fields and how they move - the energy is in the fields, not in the Voltage and current.

• Field dielectric / routing
• AltiumLive Keynote talk: The Extreme Importance of PC Board Stack-up
• If I’m contacted with an Interference problem, the question I ask is: “What is your printed circuit board stackup?”
• The most critical item is the board stackup, and it’s what people most often get wrong.
• Two or three voltage planes in a stackup with no grounds anywhere - a very serious problem e.g. high layer count board, 20 ground planes in board + signal routed on layer 1 and ground plane on layer 2 - return - 100% of signal on layer 1 would be in ground plane on layer 2. No current from that trace would be in any other ground layers, because energy is in the dielectric between layers 1 and 2
• With 2 or 3 signal layers, and then a plane - all signals try to reference one plane, all fields intermingling in the dielectric space, all coupling energy into one another and that’s one of the places where EMI comes from.
• It’s a matter of keeping fields isolated from one another for proper functioning.

• 4-Layer worst stack-up

• 6-Layer worst stack-up

• What to expect at AltiumLive (Early bird pricing - 10% off through end of July.)
• Setting the record straight: 15 years ago, Rick wrote a paper called ‘Board Stackup to Control EMI’ and “some ideas that I suggested in that paper, I have since learned are not good ideas.” Ignore this paper because the physics have changed. The speeds have become too fast.

Links and Resources:

PCB2Day Seminar

PCB West

RF Design Concepts

High Speed PCB Designer’s Guide, Martyn Gaudion

You can also read more articles featuring Rick Hartley in the OnTrack Newsletter here and here.

 

Hey everyone this is Judy Warner with Altium's OnTrack podcast. Thank you again for joining. We want to thank you so much for continuing to listen and we wanted to share with you that from May to June the listenership has doubled and absolutely exploded because I have amazing guests like I have today. Which is Rick Hartley.

But before we get going with Rick, I wanted to give a few of you a shout out. I wanted to say thank you for the notes and ideas for the show that you sent: To Daud Zoss, I'm sorry if I'm killing your name; Dave Rehack, Spencer Kelly gave us some really good ideas for our future shows. Enoch Sotello and also a nice sharp shout out from a LinkedIn group, the Arkansas Signal Integrity community and I'm sure you guys will enjoy hearing from Rick today.

So I thought I'd throw a fun thing out there since AltiumLive is going to be hosted in San Diego, October 3rd, 4th, and 5th. I thought I'd give you a little trivia question today. So can you guess how many countries the OnTrack Podcast has reached? If you guess close to the number, then I you will be my personal guest at AltiumLive and I'll give you a free ticket there. So how about that? So you can tweet your answers using the hashtag #ontrackpodcast.

So whoever is closest, and we will announce the winner on our next podcast. Thanks again for listening. So today we are talking to, in fact, one of our keynote speakers for AltiumLive, a dear friend and longtime associate, Rick Hartley and I'm sure for many of you, he is no stranger and he is a celebrated speaker. He's been a leader in IPC for many years and a very gifted designer. So Rick, welcome thank you so much for joining me today, it's a joy to have you.

Thank you Judy, it's a pleasure to be here.

So what I thought we'd talk about today Rick, well first let's queue up and tell people who may not know you - the six people on the planet that may not know Rick Hartley - a little bit about your education and your background and sort of how you became a signal integrity guru?

Oh, you want me to tell this?

Yes I do.

I'll try to make it brief.

Okay.

I basically started life in 1965 as a technician with a two-year tech degree and working for a large company in the east, and I spent a couple of years there and decided that wearing one hat a day for six to eight months wasn't what I wanted to do at the age of 20. That I really wanted to be able to wear five hats a day. And so I moved to a small company in Columbus Ohio - I'm still in Columbus - and basically joined an R&D group where I got to do just that. I would be testing boards one day and troubleshooting the next, and so on. Within a couple of years I moved to field service, and from field service I learned a lot about troubleshooting problems and field service as you can well imagine. From field service I moved into the engineering department in that company where I became a designer and as a designer - the designers back then designed everything but the circuit - they designed the circuit boards, the cabinets, the chassis, the wiring harnesses, the interconnects, everything except the actual circuit schematic and I spent a fair amount of time doing that.

And then, over time, with school in the evening I earned a degree in engineering became an EE and worked several years as a circuit designer around 1976, seven-ish time frame, the company - I had moved companies by then. The company I was working for asked me to; they said you have some background with printed circuit design? I said yes, we would like for you to help out doing part-time circuit design, part-time board layout. I said, sure no problem. After six months of that, I decided board design was really the thing I liked most.

And so I moved full-time into circuit board design, away from full-time circuit design. For a long time I was doing basically RF design, RF layout, which is a little more challenging, especially back then. Digital layout then wasn't too challenging. Anyway moved into board layout, spent a number of years there and along the way somewhere, about the mid eighties, things started to not work right in the digital domain, and frankly, most people didn't know why this was happening. They - most of the engineers I worked with, - were scratching their heads; I was certainly scratching mine. And over time, by doing a lot of reading; I purchased over 120 books since then, between the mid 80s and now, and read them all. Some of them, three or four times, and basically learned what causes things to function versus not function, what causes interference and so on, and probably the person that helped me the most to get to the understanding I have today, is Ralph Morrison, and I'm going to talk a little bit about Ralph as I go through this.

But anyway, by just getting my arms around why people have signal integrity problems, why there are interference issues, it's helped me over time to become I guess what people call a guru, I'm not sure I am, but you know whatever, whatever the title is.

A good guru will never say they're a guru Rick so it's okay, I'll call you a guru.

All right.

That's pretty much how I got there it was just a matter of, it was a matter of stumbling along frankly, for years and years - not fully knowing why, and little by little, gathering the knowledge, because sadly, I didn't learn in college, the stuff I really needed to know to take me to where I needed to be. I mean, it had to come through experience, it had to come through just hard-won, hands-on on the job experience. Because it didn't come from college, sadly. And that's kind of where, how I got to where I am today. And of course this all started in the mid-80s. By the mid-90s, I was really beginning to have a pretty good understanding of the issues and it's really all just built since then.

And I think, you and I had a talk and you were actually in our OnTrack newsletter a year or so ago, and I remember you saying around that time is, when you... didn't you talk about... oh I'm gonna forget the term now, because I'm not an engineer - rise times.

Yes oh absolutely.

Was that something, was it around that time that you started realizing that rise times were problematic?

That's exactly, it was actually in the 90s, when I started realizing that the problem wasn't clock frequency, the problem is the frequency associated with the rising and falling edges of signals. If you have a device on a circuit board, that is being clocked at a low frequency - two, three megahertz, but you have a rise time with two, three, four, five hundred picoseconds, you'll have energy in every transmission event that extends upwards to a gigahertz or beyond, even though you're only clocking at a low frequency. So it isn't the clock, the clock really sets the timing for the circuit. That's really why it's called a clock, it sets timing. The rise times are really the key element that drive signal integrity, and even worse; drive EMI issues and interference issues. It's really all about rise time, yes.

That's - I thought that was fascinating when you talked about that earlier. Now I've sat in a few of your classes and I've learned a couple, in my novice kind of way, a couple really key things that really impressed me when I sat in one of your classes at IPC, and in that room of say 50 people, you asked the people in that room: who in this room are EEs and also printed circuit board designers? And a handful of people raised their hand and you asked the question; which one's harder, the circuit design or the board design? And they all like guffawed at that and just said, duh, printed circuit board design.

To which someone like me went, wait - I thought the EE was the heavy lifter, the one that kind of got the creds for doing the hard work but you really taught me then, that - and I think this is a lot - because circuit boards have become so complex over time too but that probably wasn't always true - and I had just missed that, that it had become. So why is it that you asked that question, and what made you choose to go from EE to actual board design?

The, just frankly, the challenges. I found even in the late 70s, I found the challenges of board design to be more stimulating and more invigorating and it made me feel just more alive everyday to go to work than to be designing circuits and setting up test procedures and that sort of thing. And not that there's anything wrong with that, my god, I asked the question of those guys which is more challenging and most of them said board design. If you ask them which took them longer to learn, they would probably say circuit design took them longer, there's more to understand to become a good quality circuit designer, to really get what it takes to design circuits, to function properly. But once you have that knowledge, the actual effort and energy and time expended once you're there - once you're at that knowledge level - is actually greater to lay out a circuit board than it is to do a circuit design and that's why they all answered that way.

There is you're right.

There was a time when circuit board design was ridiculously easy. I have a circuit hanging on my wall, you can't see it from this camera but it's a two layer board that I designed in 1985. It has no planes and it's just routed power and ground and routed signals it's hideously complex because it's over 200 ICs, on a circuit board it's really packed, and that's why it's hanging there because it is such a complex, by the way hand taped, artwork. It's a very complex artwork and that makes people go 'oooh' when they walk in that's why it's there.

But the reality is, how that was laid out was immaterial, because its layout just almost didn't matter, you could do almost anything back then and the circuit would still work. I remember seeing a tape layout in the 1990s, of a guy from the aerospace world where I spent in the early 90s; a board this guy laid out in the 80s, that there was a corner powering ground pin IC for, like a 20 pin part, and there was a decoupling cap sitting above the IC, and he had a trace routed from the decoupling cap, all the way around the body of the IC and back up to the power pin of the device. It was probably an inch and a half long trace from it, and it was a skinny little, 10 mil trace, and the circuit worked. And it's because things were so slow back then compared to today. And it's about rise time not clock frequency. Rise times back then were measured in the tens, in some cases even hundreds, of nanoseconds.

Today they're measured in the hundreds of Picoseconds so they are at least a thousand times faster than then - a hundred to a thousand times faster than they were in the 80s and that's why, things today are harder to make work than they were in those days.

Well that just blows my mind to think of things - I mean, I know that it's happened it's just hard to get your head around those kind of numbers sometimes.The other thing you said, and then we're going to jump into what you're going to talk about at AltiumLive. The other thing I learned from you, which I've told you about this. A few times it just made my head explode was when you started talking about the energy in a circuit board is in the dielectric and it was like; wait what? No it's running like water through pipes on the traces, like that's how I pictured it and you explained it, and you showed a field you had and I all of a sudden, like well, I knew some energy moves through the dielectric, but not the way you explained and literally; it was like I felt embarrassed, and I remember walking up to you and going: okay don't tell anyone but I didn't know that. And you said...

People don't know that.

-then you said, it's okay judy EEs don't know that, and I'm like, okay all right I don't feel so bad. So why don't we know that Rick?

Because it's not talked about generally in college. Voltage and current are important parameters, they are - I just had a discussion very recently with Eric Bogatin on this exact subject. Voltage and current are extremely important parameters for identifying how transmission lines work, why signal integrity issues arise. These are all things that you need to know, but the reality is if - and if you're trying to track down signal integrity issues - probably best to talk about voltage and current more than the fields. But when you're trying to identify why an interference problem has occurred, why did energy move from circuit A to circuit B, how in the world did it get over to circuit B?

Where did that - because the voltage and current followed the traces that we routed in circuit A. So how did the energy...

The reason is that, as you just said, the energy is in the fields, not in the voltage and current and the fields travel through the dielectric space between the copper features. And that's the key element. When you route a trace you're routing half of a transmission line, the other half of the transmission line is the plane, usually in most boards today, a plane where the energy returns. So you have the forward current traveling down the trace that you've routed, and you have the return current traveling in the plane directly under the trace that's routing across the board. And that current is being established because there are fields with energy creating the voltage and current in the transmission line. And that's the key element to understand. If the energy weren't in the voltage IRAM, sorry, weren't in the fields; radio wouldn't work. Think about it, radio broadcasting of fields into free space, that get picked up by antenna that focused the energy into a radio. Anything that uses broadcast medium works in exactly that fashion. And the reason it works, is because the energy is in the fields. Now you can capture those fields with copper structures.

And when you do, then they will channel through the dielectric between the copper features; that's what an antenna does and an antenna focuses the fields into a center point, that focuses them to a transmission line, to the receiver and that's exactly what an antenna is. So bottom line, because the energy is in the fields, and the fields travel through the dielectric space, that's how things can sometimes spread. If we don't route traces properly, if we route, for example, two or three layers of traces above a plane; all of those trace layers are capable of coupling energy into one another, which causes the fields to then spread to places where they shouldn't be. Or, if you change layers improperly - that's something I'm going to talk about, at AltiumLive, is well - the main thing I want to talk about is board stackup.

Yeah so let's just jump in right there I think that's a good place to segue. So Rick is doing, han hour keynote at AltiumLive and the title of his talk is: 'The extreme importance of PC board stack up.' So let's just jump right off there. So you've already started to talk about energy and fields and how they move. Talk about that relative to stack up and why that can be problematic in not so obvious places?

Yeah I will, yes the main question that I ask people; if someone contacts me and says: Rick we've got an interference problem of some kind, be it EMI, be it interference between circuits, whatever. I've had, within the last year of it, people contact me to talk about op-amp circuits that were being interfered with by other things in a circuit board or inside a system. Why does this happen is the question that's often asked. The first question I ask them is, what is your printed circuit board stack up? Because the most critical item to get correct, to have correctly done, is the board stack up.

The most critical item is the board stack up and that's why I ask that question because what people often get wrong is the board stack. I will often see examples of people who have put two or three voltage planes next to each other in a board stack, with no grounds anywhere nearby. And that's one of the things I'm going to talk about at AltiumLive; why that's a problem. It's a very serious problem. For example, if you had a circuit board that was many layers thick, and you had, let's say twenty ground planes in the board. If you had a signal routed on layer 1, and there was a ground plane on layer 2, all 100% of the return current from that signal on layer 1 would be in the ground plane on layer 2, and there will be no current from that trace in any of the other ground layers because the energy is in the dielectric...

Yeah.

Between layers one and two, it establishes a forward current in the trace and a return current - a reverse current, in that. All the other planes, it's like they're not even there. They don't even get used because the energy focuses itself in that tight area, and as I said a minute ago, if you have two or three signal layers and then a plane, now all these signals are all trying to reference that one plane. So all of those fields are intermingling with one another, in that dielectric space and they're all coupling energy into one another, and that's where the interference factor comes from. That's where - it's one of the places where EMI comes from - there are many things that cause EMI, that's just one of the many problems. So it's a matter of keeping fields isolated from one another. That's what we have to do if we expect things to function properly.

Well I think, besides your prolific reading habits being an EE, I think, has obviously served you well and so, to understand how fields move and because, like I said, I have a very fundamental understanding of designs and certainly not of field theory and all of that, and how physics work but I think that's one reason why you've been such a popular speaker and consultant. You talked about - or you're going to talk about - and let's kind of tease it up a little bit; is the worst four layer stack up. What does that mean?

Well there are actually two four layer stack ups that I'm particularly not fond of. One of them is - and I see this a lot in the automotive and appliance industries - where they will put a single ground plane on, let's say layer three, and they'll put routing with routed power, on one, two, and four. And what we talked about a minute ago, having more than one routing layer referencing a single plane,in this case layers one and two; are both trying to reference the plane on layer three. And the result is the field, even if you route them in orthogonal directions, the traces, the fields will still inter-lead one another and we'll couple energy. And the energy that couples, won't be enough to cause a signal integrity problem if you do the stack - if you just do the routing correctly - but it will still be enough that it can cause EMI problems.

What a lot of people don't realize is that it takes as little as eight to ten microamps - microamps, millionths of an amp of common load current coupled into a balanced antenna to cause an FCC Class B, radiated admissions failure.

Wow.

So as it takes that little bit of current to cause an EMI problem, and it doesn't take much coupling of fields to create eight to ten, or even milliamps of noise current. So it's a problem that people need to pay attention to. So that's one of the four layers. The other four layer that's a problem, is the one everybody uses - and that's powering ground on two and three, and the reason that's a problem - if a circuit board is extremely thin - if a circuit board is say 10, 15, 20 mils thick; then those two power and ground planes on 2 & 3 are going to be very close together. And when you do that, when the power and ground planes are extremely tight - a few mils to maybe at most 10 mils away from one another, then you can get away with having power and ground on 2 & 3 or 4 layer. But if it's a 62 Milotic, a 1.6 millimeter thick board, and you have the planes on 2 & 3, they're going to be about a millimeter apart - and when planes are a millimeter apart, there's several things that go wrong.

One, we rely on the planes to help deliver power. The planes basically become the low impedance path for power delivery 2 and IC, if you asked a lot of people, a lot of Engineers, where does power come from in a circuit board? Their answer will be the power plane.

All right.

Of course we know that's not true. The energy comes from the dielectric space between the power plane and the ground plane.

See there it is again...

Exactly. If the dielectric space is tight, the capacitance will be fairly high but most of all the inductance of the planes will be very low, and when the inductance is low, now you have a low impedance delivery path for power. If the planes are far apart, as they are in a conventional 62 ml thick, four layer board, the impedance is so high it doesn't do a good job of delivering power, and you end up with large LD/IDT voltage drops across the power system that we can refer to as power bus switching noise, and that issue alone can cause signal integrity problems but mostly will cause EMI problems.

That's, again, it's like can't, my head's exploding again. Four layer board, 062 - standard thickness of your run-of-the-mill board, I mean this is not fancy, and you're saying this is a bad idea! And I'm like wait, what the earth does not flash? I mean it just that's what it sounds like to me like - it's crazy but it's fascinating and I can't wait to hear - I'm sure you'll dig into this more?

Well I'm gonna get into it more because there are routing implications with that four layer board as well.

Okay.

I mean it's worse than just - than just power delivery. If you have a trace routed on layer one referencing the power plane and you want to change layers to layer four, you're going to have to move the reference to the ground plane, which means the energy in the dielectric space between one and two has to somehow move through that board to the dielectric space between three and four. How is it going to get there? And there are people who will say, oh, it uses the decoupling capacitors. Well that's true, if the frequency is low enough. If rise times look low enough, then that's what will happen. That's why for years, we could get away with four layer boards with power and ground on two and three because rise times were so slow.

Gotcha.

But now all of a sudden, rise times are measured in the hundreds of Picoseconds and that four layer board just doesn't work well. But we're gonna get into that in more detail at AltiumLive.

Okay. You also talked about a six layer?

mm-hmm...

-please don't make my brain explode again Rick, but go ahead, tell me the six layer that's a bad idea?

The six layer board that everyone uses is signal, plane - like power ground, two signals, the other plane. If you put power into that, they'll put ground on five and then a signal and six. And this is a common six layer board that just about everybody on the planet uses and it's even worse than the four layer board with power and ground on two and three. And we're gonna get into intimate detail at AltiumLive about why. It's about, I mean, think about what we said about power delivery with the four layer board. If you have planes a millimeter apart and that's not good enough, what do you think putting them on two and five, of a six layer board where they're even further apart, is gonna do two power delivery?

And now, worse than that, you have the fields between two and five sharing the dielectric space with signals that are on three and four, and all of those fields are saying hello to each other; hey let's get together and party, and they do get together to party and they wreak havoc! And this is a bad board stack, and we're going to talk more about why it's a bad board stack, and then we're gonna get into exactly what to do to fix it. There is a solution. To be able to use that board stack and make it work, and we're gonna talk about how to do that.

Well I can't wait and I intentionally wanted to have you on today to tease that out because, for those of you that don't know already, Rick teaches all over North America, and sometimes out of the country as well. If you haven't seen it, we will share all these links in the show notes. But he's been teaching, he's been on, at least a North American tour, with a series put on by UP Media called 'PCB Today' and those are two days right, Rick?

It's a two day event, and then we go through everything we've discussed here and much, much, much, much more.

Right so two days; so I highly recommend UP Media's PCB2DAY with Rick Hartley. We will share that link for any of you that might want to get a full two days. At AltiumLive we're gonna have you drink from the fire hose and give you an hour of Rick Hartley talking as fast as he can. Rick also speaks at PCB West, which is in Santa Clara in September, I think it's September 12 this year, or that week of September.

It's September 11, 12, and 13 I believe -

It's a three-day event, again loaded with great content there's an exposition day but Rick teaches more than one class there and they're always packed, so.

I'm actually teaching six classes this year.

That's crazy and besides Rick, there's a lot of really other illustrious teachers. It's like good luck with that one; picking your courses because it's a really good show also put on by UP Media so...

I mean that show has Dan Beeker and Susy Webb, there's a host of people; Mike Creeden, I think is going to be there this year, there's just a boatload of people with talent talking about...

Such talent! And by the way, I want to boast just for five seconds, because I have the neatest friends in the whole wide world. And that is that Susy Webb will also be teaching at all AltiumLive, Mike Creeden will be there; I don't know if he's teaching yet, Eric Bogatin, who Rick mentioned, will also be a keynote speaker , and I think that conversation you were talking about having with Eric, was probably on an email feed that I was eavesdropping on.

It was actually just a direct email with Eric because yah, I think you were involved?

I got looped in there and, a significant portion went over my head, but it was just interesting to see you guys kind of bantering about your subject. So again, Eric will be one of the other keynote speakers so I'm very privileged to know some very bright, gifted people, and Altium is bringing all these wonderful folks together. So I hope you will join us and I hope this conversation has encouraged you to join us. And we do have early bird pricing, which is like ten percent off through the end of July. So please be my guest we will - - Rick has shared links with us to other resources. Oh! You wanted to mention something about a paper that's floating out there, that you no longer endorse. So why don't you mention something about that?

Yeah about 15 years ago, I wrote a paper called 'Board Stack Up to Control EMI,' and while the basic content of the paper is more or less correct, some of the board stacks that I I suggested in that paper; I have since learned were not good ideas, and in fact, the four layer and six layer that we just talked about, are two of them, that I recommended in that paper, because I believed at that time, that they were the right thing to do. I've since learned why they aren't, so if you happen to stumble across that paper again; it's called ' 'Board Stack Up to Control EMI,' ... or to help control EMI, something to that effect, and if you stumble across that, just ignore it.

Ignore it cause we're gonna get Rick Hartley 2.0 where things have gotten faster and he's, I don't know that you've gotten smarter; I think just the physics of the boards people are designing have changed.

The physics have changed and that's a key point. That's a very good point Judy, and that's partly why, I mean, it's possible that when I wrote that paper, that four and six layer boards were fine...

Yeah exactly but the speed...

-but they're not today.

And again that's why we always advocate here that you need to always be learning because technology does not stand still and what worked yesterday, is not going to work tomorrow. And so we we try our best to stay on top of it. Rick thank you so much for joining us. I also am going to put in a photo, hopefully it won't embarrass you Rick; of - -

You know, what I want to say about Rick Hartley and people like Susy Webb, Mike Creeden, Eric Bogatin; we are all - you all as designers and engineers are really standing on their shoulders and they used to do this stuff by hand. So I have the neatest photo ever of Rick Hartley with a big fat 70s tie I think, handling out the biggest board ever that I've seen - the biggest tape up I've ever seen.

That's actually the one hanging on my wall...

It is, that's the one? So I'm going to share that and the links too because you guys that just have snazzy racy tools and you started designing ten years ago won't believe the stuff these guys and gals did by hand. So, well Rick we totally and completely look forward to AltiumLive, thanks so much for agreeing to come and invest in the design community, and thanks again for doing this podcast you are a dear friend.

Judy, thank you so much for having me. Yeah and thank you so much for all that you do for the industry Rick, we really appreciate you.

It's a pleasure.

Again this has been Judy Warner with Altium's OnTrack Podcast and Rick Hartley of - how do you say that?

R Hartley Enterprises.

We look forward to seeing, or we look forward to you tuning in next time. Until then, remember to always stay on track.

When Lee Ritchey “got through launching things to the moon” his career took off (in Silicon Valley...before it was Silicon Valley!) and he is now widely regarded as one of the premier authorities on high speed PCB and system design. He is the founder of Leading Edge and author of Right the First Time.

Show Highlights:

• Lee started as a microwave engineer who designed chips that went up on the Apollo
• ICs and “faking” logic
• High Speed design courses first offered at Berkeley.
• He wrote the books to make the students happy and provide the coursework that didn’t exist.
• High speed signal path losses - how do we control skew? Where does it come from?
• And what’s the answer? Spread glass.

Links and Resources:

Lee Ritchey on Linkedin

Right the First Time

Lee’s Digital Library

Lee Ritchey’s Presentation at AltiumLive 2017 in Munich

 

SI forum - an email forum that is a very good resource for SI questions.

• All one needs to do is send an email to: si-list-freelists.org
• Type subscribe in the subject line to become a member.

Disclaimer: We respect the unique perspectives of all of our OnTrack podcasts guests. Therefore, we choose to offer their uncensored opinions in favor of full transparency. However, all opinions expressed are exclusively those of our guests and do not reflect the views of Altium or our employees.

 

Hi everyone, this is Judy Warner. Welcome back to the OnTrack Podcast. If you would please subscribe, and let us know what you'd like to hear more about here on OnTrack.

Today, another amazing guest Lee Ritchey, who truly needs no introduction. But if you haven't met Lee before - Lee is considered to be one of the industry's premier authorities on high-speed PCB and system design. He's the founder and president of Speeding Edge - an engineering consulting and training company, some of you have read his book. He's author of 'Right the First Time' and he has a very illustrious, amazing background, and we also had the privilege of having Lee speak last year at AltiumLive in Munich, so I'm delighted to have this conversation with Lee. Not too long after Design Con, so I know he'll have some great wisdom to share.

So, before Lee and I get started, also please connect with me on LinkedIn or on Twitter @AltiumJudy and Altium is also on LinkedIn, Twitter, and Facebook. Lee I'm going to start with a very high-level question. First of all, welcome. It's good to see you again.

Thanks for the invite.

Always my pleasure.

So, you're known as the high speed authority in our industry, but how did you get there? How did you, out of all the paths you could have taken sort of in your technology field, how did you end up kind of going down this rabbit hole?

I started out as a microwave engineer on the Apollo program, which as you probably know, was a long, long time ago. And the company I went to work for was in Silicon Valley, when it was not yet Silicon Valley. Well, after we got through launching things to the moon, NASA decided, well we're done with that, and lots of us - like sixty thousand of us - had to go find something else to do.

Wow.

Well I was in Silicon Valley and integrated circuits were starting to be a big play and the big jobs were designing things with integrated circuits digitally. And so I interviewed for a job designing equipment for testing digital integrated circuits, and got the job. And said, oh now I’ve got to go learn something about logic. So I went to bookstores and got books and I faked it, and that's how I got got my start. And of course, since I was already in the microwave end of things, transmission lines were already part of that, and that was what you had to be good at if you wanted to use ECL, and the high speed computers back then were ECL.

That's how I switched from microwave to what everybody called digital, and for a long time digital was slow enough so you could pretend it was digital, but I never did and always designed on transmission lines and so, as the speed went up all around the industry, everybody needed to learn how to do something with this high speed stuff. And I had a design company from '82 to '92 where we designed pretty much all the early work for Sun, Silicon Graphics, Cray - people like that, and invariably I would get a new client and the engineers knew nothing about high-speed design. So I'd spend two days teaching them the basics so that we could design their board. Out of which grew the courses that I do now. Which I first began to offer at UC Berkeley, and the complaint after every course was: there's no book, there's no textbook, and that's where the books that you mentioned, came from as I  had to write those to make the students happy at UC Berkeley. And in 1999, we decided that we didn't like working for companies so we started Speeding Edge.

Okay.

That's it, that's how I got here by - almost by accident.

Well I always say, most of us got here by accident. I mean some EEs take a nice, clean, straight path, but even they don't take that straight path., I know I didn't end up here on purpose either. But that's interesting, I didn't know that's how your book came to be. So the last time I saw you, you were actually speaking at DesignCon. And how often are you teaching these days actually ?

Most of my classes are private and I would guess about every two months or so.

Okay.

There are two-day, three, and day classes so, that's about as often as I want to do that. I don't know if you've lectured for 14 hours in a row, but it kind of wears out.

I don't think I know anything about anything enough to talk for 14 hours, maybe raising kids I don't know - like I don't think I know about anything to talk that long so now we - now we know for sure, you're way smarter than me.

Oh no, I just came from a different path that's all.

Well you and I were talking recently, preparing for this call and we sort of went down this path talking about PCI Express. So can you kind of talk a little bit about the evolution of speed and the extremely acute curve that we've taken in the last couple of years?

All right, well maybe let's start with PCI itself, which is the Bus architecture that is in - has been - in all the personal computers that you can buy, that's what PCI stands for: Personal Computer Interface, and it was a parallel Bus that you might have seven or eight plug-in cards, all on this Bus. That CPU could talk to any of those, any time, and then originally there was - it clocked at 33 megahertz, and it wasn't too long before the CPUs got faster than the Bus, and all of a sudden we were - what we call - IO-bound. We couldn't get any more performance out of a PC, because the Bus was too slow. So we upped the speed to 66 megahertz, and then a hundred, and for a lot of reasons they're too complicated for today, we couldn't go past 100 and that block limited how fast you could make a personal computer. And so we realized the architecture had to change. And the reason is that if the CPU can talk to any spot in the backplane at any time - to do that really fast, you have to have really, really short connections and that was not realistic. So we turned to an architecture that actually is old. The difference was signaling protocol, that is in PCI Express, has its origins way back with IBM. I was using it in '74, where we would connect two boxes to each other, where we couldn't do that with a parallel Bus, because the the noise in the background was too high. And so that's not a new technique adjust that early on, as you know, the guts of a computer is a parallel architecture meaning lots of bits switching in parallel, and the differential links that we're talking about here are serial.

So at each end, you had to go from a parallel Bus to a serial stream on the line, the other end - go back. And at that time, the serializers and deserializers were extremely complex and expensive. So the only reason you'd ever do that, is there were - if you were stuck, you couldn't do it any other way. Well as we'd gotten to where we have a billion transistors in an IC, these serializers and deserializers are what we call basically free. So all of a sudden it doesn't cost much to go from parallel to serial and back. And the advantage of that is, you can - you can drive... Well let me start from - in a parallel Bus were either series or parallel terminated - if you're lucky, you can drive that at 2 gigabits per second, that's very hard to do. With a serial Bus - we can drive them and we are right now driving them at 32 gigabits per second, which you could never do any other way, and this is how we're getting all the performance we need in the internet. Everyplace else is with these serial lengths and that's what PCI Express is. We switch from a parallel Bus to a serial Bus, to allow us to go faster.

Well, when you have serial links there, you can only have a driver and a CI receiver on the same net. So how is it the CPU's going to talk to six or seven devices like it was doing with the old parallel Bus? And the answer is, we have to have a switch chip somewhere so that we can switch between the CPU of whatever we want to talk to. Well early on, those were expensive chips, so we only use PCI Express in real high-end PCs like a gamer would buy. But we've now integrated those switch circuits right in the CPU so it's not an extra part to buy.

Oh okay.

So it's everywhere. So pretty much everywhere we've got PCI Express, well in itself it's not really all that big a deal because the early PCI Express was - well depends on your point of view - as fast as 500 megabits per second on the line and that's not special, to these terms. The rub is, we have started to go up the performance curve where we've got Gen 1, Gen 2, Gen 3, and so on. And Gen 3, which is it just about around the corner for everybody - it's 8 gigabit per second. That's not slow, and we start to see things that we could ignore at lower rates.

The one we're going to talk about today is not lost - it's the thing we called skew. Skew is the fact that the two sides of a differential pair don't arrive at the receiver at the same time - and some numbers on this, the most common until recently - most common data rate in switches and routers for the internet, was 10 gigabits per second. Where one bit is 100 picoseconds. And I did a test board in 2013 at DesignCon where we discovered 62 picoseconds of error in a path which is almost an entire data bit at 10 gigabits per second - which destroys the work. The link does not work and of course, we've got Gen 4 coming in at 16 gigabits and Gen 5 at 32 - where 32 of the bit period is only 30 picoseconds. So that error I just talked about, is two whole bits which means, nothing's gonna work right? So the question is, where does this skew come from?

So is that, Lee let me interrupt you for just a moment. Is that what you - the course a you taught this year at DesignCon, was that your focus?

Yes well the bootcamp, I call it 'Getting to 32 gigabits per second' which covers a number of things, skew being one of them.

Okay.

Of course the first worry almost everybody had, is loss. So we had this flurry of activity to make low loss materials and smooth Cochrane on and on like that. At the same time we were doing that, I see manufacturers figured out a way to improve their circuits so that loss is not a player anymore - not a big deal anymore. For example, the latest Vertex I guess their Vertex 8 or 9 from Xanax, at 28 gigabits per second, the Lincoln tolerates 38 GB of loss. Meaning that we start out with say a thousand millivolts and we wind up with four at the receiver, and it still works, so all the drive to have the world's best, lowest loss laminate is not a player anymore. Skew is, skew's killing everybody. All these laminates from people like Rogers and - you mentioned one earlier - I can't remember.

Taconic.

Taconic are simply not necessary - not necessary. At any rate, skew is just - and that was the theme of DesignCon this year. It is how do we control this bloody thing? So my impression - I guess that comes up next - is where's it come from?

Yeah, where does it come from Lee?

Well if the two sides were different to pair with different links, that would be, I think obviously, one way that can happen.

Right.

But pretty much everybody else had to design physical links to a few mills, so that tends not to be what the problem is. The problem is - and these are what we call micro defects or micro effects - the glass cloth in laminates you know, on average has a pitch between threads of about 16 mils - between 16 to 20 mils - Traces are 4 or 5 mils wide, so there's a huge difference between the width of a trace and the spacing of those glass fibers. Well, laminate is a mixture of glass and resin, and the dielectric constant of glass is on around 6 and the dielectric constant of resins is less than 3. That means that the lower the dielectric constant, the faster the signal is going to go.

That's right.

So if I had one side of a differential pair on the glass, and on the other one in between, there are two different speeds. That's where the problem comes from.

Now along those lines, I was just talking to Chris Hunrath from Insulectro, and he was talking about spread glass. What do you think?

That's what the answer is.

It is?

Okay cuz you know I've been here at Altium a little over a year and I guess I missed the spread glass thing, but I'm like, that actually sounds like it makes sense.

Well I and my colleagues have been the drivers of spread glass.

Really? Tell us about that.

Well so we found - I've got to confess - we found out by accident,

That's how all good inventions are found right?

Yes, and it had to do with - let me think about when that was - about 2005, we were trying to improve the uniform distribution of glass by using two plies of thin glass, hoping that they would sort of average out. And I had a fabricator in Oregon who says: you know, if you use a single ply of 33:13, you could save some money. So we built the test board and by chance that was really spread very nicely and so we had no skew problems. So all of a sudden, we thought we've solved all the world's problems by just using this glass. And then we built our test board from a different weaver.

So and this weaver spread the glass in one direction but not the other?

Yeah.

So, if you were to get that DesignCon paper you'd discover that we had really good skew one way.

One direction - - [laughter].

And so back to square one. Why aren't people spreading glass? So we got to digging around - and it was for laser drilling of blind vias.

Because, if you think about it, if you have like the classic 4 mil core was called 1080 glass. If you look at that, the glass bundles are round or not spread out, there are big voids between. Well so, if the guy drilling a laser drilled blind via wanted to get rid of the glass, he'd set the intensity to burn the glass and then go tear right through the backstop directly right, and so the laser drilling industry is the one responsible for spreading glass.

Like you said, complete accident.

It is, and they don't care about signal integrity, they care about laser drilling - so I and a guy named Scott 'Hindiga' of Cisco, started going to IPC's sessions on 'Standards for the Last Week' with the intention of getting some standards for how you spread the glass. Well it was got a whole lot like herding cats.

[laughter]

What an IPC committee being like herding cats? I don't know what you're talking about Lee [laughter]

Yeah, so around the table we had five or six weavers and they would not tell us how they wove their glass.

Because it was proprietary?

Yes, so he couldn't come up with the standard, and the only standard that the laser drilling people had was, you take the section of this cloth and they put it in the chamber and see how - put compressed air on one side and see how leaky it was. That's it - that's all there is today. If it was leaky, let's make it an X, and it was good. That would not be good enough for what we're doing here. So we are not done solving this problem, and there's about seven or eight different ways that people approach it. Now if you were at DesignCon this year, you'd discover two papers were presented by Cisco where, when they built the boards at five degrees to the weave, they got the best skew results. So that's how they're...

- Wow, yeah.

Can you imagine what that happens to you in a fab shop if you say pop this artwork on their at 5 degrees?

[Laughter]

-well I remember hearing about - from a colleague, he was an EE - they were actually at some point, because of the glass crossing and there being those bundles, they were actually starting to do it at - basically laying the prepreg at a diagonal. Do you follow what I'm saying?

Oh yes.

-do you remember that? That was kind of going on for a while to see if that would help, and I think it did help a little bit but again, the expense. There's so much loss of materials doing that, that it didn't make sense, or there was the trend of making that weave super, super tight so at least it was consistent, even if it was lossy. So, I feel like we've been going at this from a lot of angles - but hearing from Chris Hunrath, at Insulectro, it sounds like some people are really moving towards that spread glass and getting some good results.

Oh, that's my choice, but if you were to get the PCI Express Design Guide from Intel, they would tell you one of two things: you route all the signals at fifteen degrees through the X and Y-axis, or route them X and Y, and then you have the fabricator rotate the artwork 15 degrees on the panel.

Yeah.

That's in the standard for PCI Express.

I had no idea that was in the standard. I've heard about it, but that being - kind of anecdotally, but I didn't know it was actually written in the standard.

Yup it's in the standard from Intel, and you can - if you imagine a backplane where you have a regular array of pins for connectors and so forth - there is no way to route it at a 15 degree angle, because it's constrained by the pin array that's X and Y - so that's not a choice. So that leaves you with only the choice of popping the thing at an angle on the panel and then - you've been around enough to know the fab shop's gonna look at you like you have lost your mind.

Yeah.

Well we're not doing that, we're not doing that. We found some weaves that we know are well enough controlled that we're succeeding without that.

Okay good, that's good news. So this spread glass - so that's helping with the skew, you're saying, among other things?

It solves the problem.

It does?

Yeah.

That's amazing.

The rub is, you've got to be very careful who the weaver is.

Well can't you spec in a certain -

- What if I tell you that I had two weavers with the same stuff? That's the problem. When you say 33:13; there's no standard, that just means there's X in this direction Y in that direction, that's all that means.

Are there are prepreg providers that are - it sounds like there's prepreg providers that are doing it the way that you prefer. Or maybe other high speed...

There are, there are.

So do tell or can you tell?

Well the Doosan material I mentioned to you before we started this, is one of them.

Okay.

And a couple of Isola materials are okay but nothing else is.

That's a good hint, it's a good hint, look I mean I'm doing this podcast hoping to have a takeaway - so I don't just bring up all the problems and then say have a nice day thank you for sharing that. Right that's the goal like: yeah I found out what works, good luck! No.

So I have been seeing this word and this thing skews, so thanks for sharing that. One thing I could see as a potential problem - and tell me if I'm right or not - since that speed curve has risen so acutely, it seems like, the people who weren't previously doing high-speed design must be getting pulled into that space whether they want to go there or not right ? That - would that be a correct statement?

That's true yes.

When you and I were talking before this call about - let's talk about resources. About where these designers that are coming into this space I mean - speak just a moment about DesignCon, cuz I know you're pretty passionate about that show, and particularly giving out really good information?

DesignCon is the only conference I know where the level of information you need in this area exists. It's where everyone who has done research, or has studies and that sort of thing that are advancing the state of the art, that's where the papers get presented. It used to be - that was it. There were no tutorials, no education, that sort of thing. But over the last four or five years, we've added several things. This year we had three all-day boot camps on topics that matter to people who are trying to get on top of things. I did one title ‘Getting to 32 gigabits per second’ which dealt with all these topics. Intel did a three-hour on 'what is this PCI Express and what do you have to worry about' for people who have not seen it before and if it was five years ago, you might see there was nothing there for a board designer.

Now you would say it's the place you go for a board designer. There was a time when the PCB West was, but that has - I've been keeping track of that for a while - not offering the kinds of things you need for the these topics and I'm not sure why. I certainly have been talking to people who run it saying that you've got to offer tutorials, you used to do that. We used to offer stuff for engineers and they quit doing that because well, the guy who was running it was a board designer and he considered design an art, and their art dropped the stuff that appealed to engineering. Now, that stuff has to be learned by the designers.

It does, and as an old board designer person, I had to learn it from the board manufacturing side because I didn't realize - because I had left the industry for a while and come back, that things had sped up so much, that board designers all of a sudden weren't just dealing with: oh here's the specs, just adhere to the tolerances, do what the documentation says and have a nice day. There wasn't like now, high-speed board designers have to think about performance and all this wacky stuff. I mean the way we clean the board, the way we etch the board, the way we drill the board, everything can in a positive or negative way, affect the performance and it mortified me to think we got to a space where we could be completely IPC compliant and the board wouldn't perform as expected.

Yeah that's a good thing to observe and that is standards. By definition standards document the past by definition, and there are no standards group I can think of right now that has more behind the curve than IPC is, because they...

Why do you think that is? I have my suspicions, you're probably right actually, and you're more of an authority than me. But I'm just wondering why? What's caused that to happen?

Well who's driving it? Well, volunteers are driving it. Where do they come from? Well when IPC was at its prime, the standards committees were all staffed by engineers from aerospace companies.

Yeah true.

And the quality of the work was superb.

It's very true.

That's not true anymore - not true anymore, who goes to the IPC now? I don't, nothing there for me...

Why do you think the committee's aren't run by aerospace engineers anymore, or the Intels of the world, or Ciscos? Why why do you think it's not?

I wish I knew.

Yeah I really don't know either, I thought maybe you'd have some...

In the aerospace, that part of it, the aerospace contractors got out of the standards business and remember Jimmy Carter had a thing, The Commercial off-the-shelf Masters what... at any rate we're going.

Yeah - faster, cheaper...

Yes and the standards bodies that aerospace had, lost their money for example.

So they lost their funding to focus on that kind of thing.

I can see you probably heard of that. You know the last time it was updated? 1998.

[Laughter]

How outdated do you think that is?

And the update was to correct some spelling.

[laughter]

Oh my gosh, that's just plain sad, but they've come out with AS9100 and other things to replace it. I don't know the quality of those specs.

Well aerospace is on average about 15 years behind the industry now, it used to be the other way around.

Yeah, it's just really sad but I think that speaks to a lot of the way that politics have been run unfortunately, and the way things are getting funded.

Yes aerospace doesn't drive technology anymore.

Yeah, that's a crazy thing to think - to say out loud - I don't know, for you and I who have been around a little while. So, before we get too far off track, so DesignCon is definitely one place. Now because Design Con, if you pay to go to DesignCon, you can get all the proceedings. What can you do if you didn't go to DesignCon?

Well you can, for a hundred bucks, buy all the proceedings for a given year.

So someone could go on their website right now and for a hundred bucks buy...

All the papers that were presented this year correct.

That's amazing. Okay well that's a really good resource. Obviously your book which - because we were gonna talk - I went on your website and I noticed you're having some kind of fire sale on - I don't know if it's part one or something - but 'Right the First Time' - it looked like you were selling it and then it sounds like you now have a digital library of things you've published over the years?

That's true, and back on the topic of the books. We have two volumes and there was really gonna be one but - I don't know if you've written books or not - but you start out with great enthusiasm and this long list of topics. Then I had a deadline which was a Berkeley class, and I was only halfway through my list. And so I said: okay, this is volume one, next year we'll do volume two and what you probably don't know is, our books are printed in color. You have to have that in order to illustrate a lot of the things that matter. No technical publisher will publish in color, none of them.

Really, I didn't know about that I know it's expensive, but I didn't know that they wouldn't do it in color.

Yeah, so we were so focused, we formed our own publishing company and we went to a printer and said: we want to print this book. You see, there's a little secret about publishing.

Bonus material!

You have to give them a check for all the books before they turn the press on.

Oh boy that's expensive.

So for each of these two lines I wrote a check for $50,000.

Wow!

Crossed my fingers that someone would buy them, otherwise my garage would be full of books. Well, we sold out of volume 1 and volume 2 came along it sold faster than volume 1 did because it was a pull from volume 1. I am just debating, do I want to write another check for like $50,000 to get to print more volume one's, and the answer is no. So it became an eBook .

Oh ok.

So if you go on the website, when you buy you get them both, one's an e-book and the other is a hard copy.

Ok smart.

Then 200 books from now they'll both be eBook.

[laughter]

You got smarter.

My garage will be empty

[laughter].

I thought it essential that the books be in color.

That makes sense because some of those diagrams you can't distinguish between certain things without color being present.

No the color's for this industry. And so we are publishers and we sell our own books and people pay. I may be where I need to write volume through 3 and there needs to be a volume 3, to cover the things you and I just talked about. But I have told my friends - if I start talking about writing another book - their job is to slap me around until I get rid of the idea.

[laughter]

Well I'm not gonna slap you because this speed curve's going ahead now, we need to learn about skew and stuff. So - and who else Lee Ritchey, is gonna write that book?

I have actually written another book, working newsletters and articles that are on that - and someone should put them together but it's not me.

You know, we should get our friend Barry Matties to do that for you. Maybe he will.

You saw my distraction behind me which is the model railroad and that's more important.

Okay well I'm going to ask you about that, so I'm putting a hold on that subject, but let's cover a couple more quick things. One: you and I had an interesting conversation about circuit board manufacturers that are capable of doing good high-speed work and I made a comment and you corrected me right away because I said: well you know, board manufacturing hasn't changed that much in North America over ... blah, blah, blah. And you said, no that's not true. And I said except for places like TTM and you said which TTM?

Yes.

So tell me what you meant by that and fill our listeners in you know, of that conversation you and I had, cuz I thought it was very valuable actually.

Well when you say TTM, you're really talking about a dozen or so fab shops, which were acquired one by one. All have different capabilities for different markets, and if you're not careful and you get a bid from some - say TTM - they'll choose the fab shop that has the most capacity at the moment, which may not have the skills you need. And so I learned the hard way, you have to know what their capabilities are and when you give them the order, you say what plant is allowed to build the board.

And they'll accept that request and send it to the best location?

They won't get my business if they don't.

I am writing the check you will send it here.

Yes, yes and if you don't do that you won't get paid.

Yeah that totally makes sense. Well you and I talked about Stafford Springs which is a board shop, one of TTM's facilities I've always wanted to go through and it sounds like you've been through and that sounds like at least one of the locations that is capable of doing those high-speed designs?

That's right, and another one is in Hillsboro Oregon. It was originally called Merricks.

Oh yeah I remember Merricks.

Yeah and of course if I'm building small volumes it's my - my choice is a little place down in Orange called MEI.

It's not MEI anymore.

No it's got another name.

It's Summit Technologies which I agree they - I know Jerry Partita there - I hope to have him on this podcast actually because I think they've done a real good job there.

Yeah so you're sort of testing out something that we all say explicitly. If you're designing for this kind of space you need to be in direct conversation with the engineer at the fab shop, so that you don't make decisions that are not realistic. So I always have got that guy at the other end when I'm designing a new board.

I think that comes up again and again on this podcast by the way, people saying you have to talk to the key people at the board house which I totally agree with.

So let's talk about - I used to blog on Microwave Journal about what shops I thought - because I was working for Transline Technology, which is a really small board house in Orange County but they're quite good at RF and microwave. But I used to try, because I would see board houses say, sure yeah we do high-speed or the microwave because they've been built on say Rogers 4350 which processes much like FR4 -

- not really  

- well not exactly but close. It's pretty stable but then they would take an order for something that was PTFE because they built some 4350, and then they'd fail and say, sorry we tried to build three times and we failed. And I kept seeing this happen over and over again. So I started writing about what I thought people should know, what they should look for in a good board manufacturer, i.e. what percentage of their work is high speed.

So let's stop for just a second and clarify what high speed means.

Okay.

Because RF & microwave is not high speed with respect to the digital world.

Yes that's true.

Actually RF and microwave were simple compared to digital boards. I consider them to be trivial.

Yeah but some of the stuff you do on those for microwave boards are funky and weird.

That's not because they need to be like that. That's because RF engineers say things that are goofy

[laughter]

It is true because again why I started blogging is because RF engineers were starting to lay out their own boards which was not a good model.

Yeah, remember I'm an RF Engineer, and so most of the stuff you see people asking for on those RF and microwave boards is goofy; it's not good engineering, pure and simple. At any rate, so when we're talking about high-speed I'm talking about, cuz this is far away the majority, of things that must be digital.

Yes high speed digital, yeah.

Yeah and the people who can do that are good at laminating high layer type boards, and very rare in our microwave or high layer board count - almost never.

- Yeah this is true.

It is two different animals.

So if a guy says I'm a high speed fabricator and I make RF microwave boards, that's a different capability than what I need.

Yes it's true. So let's just talk about high-speed digital so you're right, somebody who can do high layer counts what would you look for laundry-list wise?

Well at the top of the list, is boards like mine. If you're not making boards like mine, you're gonna lean on me, and I'm not ready for that.

Yeah good point.

Yeah it really is, that's my first thing, you're making boards with the same class that I want you to builm, if the answer is no I'm gonna go someplace else.

And I would say, and how much of their work is like your work because if it's a really small percentage that would make me nervous too.

Yeah but it's my experience that if somebody's making high count boards, that's about all they're making.

Yeah it's true, they kind of - they kind of aim at that. And they're good at it, they're busy.

Yeah and they're busy and that's what makes them profitable actually. So and that also you will see in the equipment set.

There you go, exactly - exactly.

You won't see archaic… you'll see the most modern tools that gives them the precision and...

Yeah exactly, a really good vacuum lamination guy can supply and will build a twenty four layer board with ten mill vias and 12:1 aspect ratios.

Yeah. And so you've gotta go find fabricators who are in your sweet spot.

Yeah I agree with that.

And so - and of course - if you're in it for a little while you figure out there's about six choices in the US.

Yeah there's - it's true - there's not a lot and as you're speaking those are coming to mind I won't sell for anybody today but they are relatively easy to find.

Now - and now just before we finish that - six years ago, there were none in Asia because they were busy making consumer electronics.

Yeah I'm interested in your perspective on that, because I don't really know what that is - if it wasn't kind of cookie cutter consumer. So what's the state of the ability in China these days?

We've got as good a capability in Korea and China as there is in the US.

I guess that's good news from a price point standpoint?

Yeah and it's bad news for the American laminators though.

I know I'm an American and I feel whatever but we gotta - - it is what it is.

Don't forget not so long ago we made TVs.

I know we made a lot of stuff.

It's the nature of the business that we go where the low-cost labor is.

Yes that's true.

Okay, now back to your trains. So always at the end of the podcast here, which we are beginning to wrap up here, and thank you so much for your time. I always learn a lot from you Lee. You are working on - this part of the podcast I call 'designers after hours' because my observation has been, a lot of people that I know that are pretty smart engineers and designers, have neat hobbies after hours. So tell us about your after-hours fun?

Well the one that you can see in the background - there's a lot of railroad.

Let's see it, can you flip your screen that way without disrupting us?

Oh there it is.

Can you see it?

Yip I sure can.

And the one you can't see is I repair vacuum tube radios.

You do what?

Old, radios vacuum tube radios.

No way.

Yeah.

Just for fun - who still uses vacuum tube radios?

Well we're starting to get Wi-Fi guys who think that vacuum tubes are the way to go. But I started out making my spending money as a kid, fixing the radios. I've always been in there you just may know...

I know.

-so I'm just back to fixing old radios.

That's kind of a fun hobby, but vacuum tubes - like that cracks me up.

Yeah you probably didn't know you can buy new vacuum tubes?

I didn't - I didn't but I was talking to someone recently and I - it cracked me up because I remember doing this as a kid so, is - remember going to like the drugstore - the hardware store and you could test the vacuum tubes?

Yeah, come on over I've got a tester.

No way - somebody mentioned that

- I was like whoa! Like my childhood came flooding back going with my dad to the store and sticking in the vacuum tube testers that's funny.

[laughter]

Yeah, good times - good times.

Well we're about out of time Lee, so thank you again for your time. And I know we could go further and further but I will share the link to your information about your books, and I will also share the link you shared with me for the design concept people that download white papers, and if you think of anything else just let me know and we'll put it on the show notes here. So we don't leave people feeling hopeless. We get them registered for DesignCon and get some papers in their hand, and get some books in their hands so they could do their job better.

One last thing we talked about I oughta mention, if you can - if you do those - what do you call the thing we did in Munich?

Oh AltiumLIve.

Oh yeah if you keep doing those I would argue you should start offering these training courses.

Okay, all right you heard it here from the mouth of Lee Ritchey.

I have to go show this to the CEO later - proof!

It's been my pleasure.

Thanks so much Lee. And we will talk to you soon again. This has been Judy Warner with the OnTrack podcast. Thank you for joining us and thank you Lee Ritchey, have a good day. Have a good day. Bye.

 

Why is spread glass popular? What can you use instead of FR4? Listen and learn from industry veteran Chris Hunrath, who joins us from the San Jose Insulectro facility for a deep dive into what material sets are used in printed circuit board assembly and manufacturing. Get expert insights and learn about new materials on the market to help with your PCB design before going to fabrication and assembly.

 

Show Highlights:

• What is Insulectro? Operating for over 50 years, Insulectro provides materials for electronics, everything from laminates, prepregs, flex materials, copper foils, conductive inks, substrates, process chemistries, imaging materials and lamination materials. With 11 stocking locations, the newest in Toronto and 9 branches, Insulectro is a leader in providing electronic materials to industry.
• Prepregs - 175 different types to cut from in San Jose facility alone!
• Spread glass is becoming more popular - electrical and fabrication benefits because it is more electrically uniform. No open areas, the filaments are spread across (aka fanned out or mechanically spread) and this has signal benefits especially for differential pairs. Better from a drilling standpoint too.
• New materials are gaining traction - with low loss that laminate at normal temperatures
• Insulectro distributes for both Isola and DuPont
• Isola’s line-up of high-speed, low-loss material sets - Isola has a suite of laminates that are low loss, some of them with DKs close to the teflon range and they laminate at the normal temperatures which makes a composite build much simpler.
• Low-loss, low-Dk materials that can help with their signal integrity requirements
• I-Speed® - Low loss system, not as cheap as FR4 but its close and could be a good next step for people looking to upgrade material
• Having the right material set for a design is critical
• Challenges are more often in the fabrication than the design
• Copper is a really good moisture barrier, you have to bake the parts prior to assembly.
• I’ve seen people underestimate the baking and end up with scrap. Moisture is avoidable.
• Bonus Material: In Designer's After Hours, Chris Hunrath shares what kind of electric creatures lurk in La Jolla!!

  

Links and Resources:

Chris Hunrath on Linkedin

Insulectro

DuPont

Isola

HDPug Research on High Frequency Flex

Signal Integrity Journal

Understanding Glass Fabric by Isola Group

 

Hi this is Judy Warner with the OnTrack podcast. Thanks again for joining us. Once again I have another amazing guest for us who is the go-to guy in PCB laminates.

I am with Chris Hunrath today but before Chris and I get started I would like to please invite you to subscribe, or to favorite us on your RSS feed, or you can connect with me personally on LinkedIn. I share lots of stuff relative to engineers and PCB designers and on Altium I'm at @AltiumJudy and Altium is on Facebook Twitter and LinkedIn.

So please give us a subscribe and a connection and we’d love to interact with you and hear more about what you'd like to hear on this podcast but I'm sure you're going to enjoy today's guest.

Chris is the VP of technology at Insulectro and I'm gonna let Chris go ahead and tell you a little bit about Insulectro for those three people on the planet who might not know who Insulectro is. So, welcome Chris and tell us about Insulectro.

Okay thanks.

So yeah Insulectro has been around over 50 years. We supply materials to the circuit board industry - actually multiple industries - but mostly we've been focusing on electronic materials. Everything from laminates, prepregs, flex materials. copper foils, conductive inks. Different kinds of plastic substrates used with conductive inks, process chemistries, imaging materials, drilling materials, lamination materials. Also we have 11 stocking locations. We just opened one up in Toronto and we have nine branches. So I'm based in the San Jose branch in the Silicon Valley area so that's a little bit about Insulectro.

Yeah nothing going on there in San Jose?

Lots yeah, so since the San Jose facility is one of the four branches where we do fabrication on master sheets and master roles of prepreg and laminate we do cutting, tooling, vacuum packing, and will also do that on the lamination materials, the release films, and the press pads and things like that. So we do that in four branches…

I'm going to ask you more about that later  because you just told me about that yesterday and I had no idea you guys did that. Actually I saw you more as a distribution channel. But before I ask you about that, why don't you give us a little bit of background on your history in the industry and how you came to this? I always say no and no one does this on purpose, unless you're an EE right?

So yeah those printed circuit boards - those of us that got pulled into the industry ,, have been here a long time. So I started actually back in 1983, I was going to school for chemistry and one of the shops back east, actually in New Jersey, was looking for someone to work in plating on the night shift, and ,, the rest is history as they say. I got pulled into the business and the next thing I knew I was coming to California to to work with our sales team. So that's how I got started in this, and then I joined Insulectro in 2001 and it's been great being with this company. So many different materials we get to work with and so many different customers.

I think you're a familiar name and face - being the VP of Technology but you also do trade shows and stuff. You present a lot and are really articulate explaining the technology of laminates because it's gotten a lot more complicated than it used to be back in 1983. I started in ‘84 by the way, and it used to just be, we'll get some FR4 some, prepreg and you're off to the races.

Right yep, back then it was FR4 and polyimide. A little side note, actually the company I worked for made multi wire circuit boards so we also had an adhesive to embed the wires and that's a whole nother story for another time. Primarily it was FR4 and and polyimide and now there are so many different materials and then if you add the Flex materials on top. There's a lot to to work with, it's a lot of complexity but also a lot of opportunity. I mean electronics are going into everything and we're seeing that with our printed electronics products as well ,. A lot of interesting applications from wearables to medical to consumer electronics so that's been pretty cool to be a part of that as well.

Yeah so tell us about what you're seeing on the front lines of current technology and marketing trends that are having an impact on laminate suppliers - ultimately since our audience here is mostly engineers and PCB designers - how that's sort of flowing down and what the impact is?

Okay.

Yeah so big question  sorry.

Yeah that's okay, that's all right. It's become a bigger opportunity - a big part of our business - but if you look at  materials in general, everybody knows people are looking for higher speeds and high-speed digital and they're looking for lower loss in RF applications the Internet of Things also even data communications and those types of things; car electronics, radar, self-driving cars. All these things need low loss materials. One of our challenges - and again - it's an opportunity as a supplier to the industry; is having the right stuff available for customers and certainly the Bay Area. It's always been a quick turn market, but it's that the time window has shrunk and one of our challenges is supplying all these different materials to our customers, and of course with every laminate system, every resin system you have the different core thicknesses, the different copper weights and then you have the prepregs with different thicknesses, and resin contents. Add to that also spread glass. It’s becoming very popular I'm sure most of the people who watch this will be familiar with the spread glass systems. They have electrical and fabrication benefits but but again, it adds to the part numbers, the variety of materials we have to stock. So we we currently have here, just in San Jose, we have a hundred and seventy-five rolls of prepreg we cut from for customers. And ,, it always seems like our customers need something we don't have in stock.

Yeah.

It's the one thing they need for that application. But you know we try and up our game here and have the right things. And that comes from going to our customers and talking to the people in their design group, in their sales department and asking them; what do you see? You know, years ago we used to work on forecasts. Customers would have a very predictable usage on materials and they'd have forecasts out for some time. We would base our stock on that and we do forecasting today but it's not the same thing anymore. I mean customers may get an order and they have four days to turn it and they don't know what the build’s gonna be until the stackup’s done and and that creates those challenges. But you know, we try again, we try and improve what we stock and what we have here and get better and better at that. It's just never boring that's for sure.

Yeah right, you gotta have a big crystal ball…

Yeah just talk a little about spread glass.

Yeah spread glass now that kind of puzzles me in context of high speed so I'm curious. Teach us about spread glass?

So there's different kinds of glass, what they call standard E glass and then of course the low dielectric constant glass. I'll talk a little bit more about that in a few minutes. But the spread glass is basically that the the fibers, instead of having a crossover and a weave - like you would in a fabric for like clothing - the actual filaments and the weave are spread out, so you don't have open areas and crossover areas, or areas of higher density glass and that makes the system more electrically uniform. So when you have traces that go through the PCB they’re not either going through high resin content areas, or high glass content areas because they'll have different signal properties so you want to make it more uniform.

Are they more in glass spindles - are you saying it's not woven?

Well it is woven but instead of having a high concentration of glass with open areas of just pure resin, the filaments are spread across so you're filling in the open areas.

Okay so they're kind of fanned out you're saying?

Yes exactly there's different terminologies there’s mechanically spread, there's flat glass, but but basically what ends up happening is, the crossover areas where you would have what we call glass knuckles, they're thinner and of course, the open areas now have some glass. So again the system is more uniform it's a composite. So the composite’s more uniform and and like I said that has signal benefits, especially for differential pairs. If you had one trace and a diff pair running over mostly resin, and one running over mostly glass, they'll have different propagation velocities. So you'd have different electrical results, so the spring glass is better for that. It is better from a drilling standpoint, either laser or mechanical drilling. Because you're not going through high concentrations of glass where the crossovers are so there is a benefit there. There are some caveats though, to how it works with filling ground planes. Because the resin doesn't easily move through the glass fabric - you could have some problems filling, so we have to offer not just the spread version, we have to offer the standard versions as well because very often, designs - if they're strip line - you'll have a reference plane on either side of a signal and those reference planes could be heavy copper and they require a certain amount of fill. So you need the standard fabrics to use as well in a stack up. So you might have a mixture of those types of systems - so yeah it does add some complexity.

So now we're not only doing hybrid materials now we're doing hybrid prepreg you're saying?

Well there are different varieties I guess you have to do it that way anyways because if you're doing hybrid you're matching the materials to the bond ply that you're using anyways I suppose, but now you're adding in this kind of third layer almost.

Right.

And then we also have standard copper foil and then we have HVLP or VLP copper and low-profile coppers, so so yeah so it adds. And then of course, all the different copper weights - really everything from 5 micron through four or five/six ounces, so it's all over the place. But yeah actually going on the hybrid thing too we are seeing a lot of mixing the resin systems. In other words you would never mix B-stages in the same layer in other words you wouldn't have one kind of resin melt but you can mix cores so you could have one type of resin system as long as it's fully cured adjacent to another kind of resin system and we see that with RF, because very often what you do is, you have your low loss layer on the outside and then you would have your - whether it's high-speed digital or just DC - you would have that in the other layers and that system would be mixed and there are challenges there too even if you're not mixing the B-stages. Some materials require higher lamination temperatures and if you're not using a standard material that can withstand that, you would have issues or you would have to use a low loss material that has normal laminating  temperatures. And typically when we say normal laminating temperatures, we're talking in the 375 degrees Fahrenheit range. Whereas some of the more exotic PCB materials - the filled PTFE systems LCP FEP - they require much higher laminating temperatures more like 550 to 600 Fahrenheit.

For a while I was at an RF - it really never took took flight - but I'm sure you remember not too many years ago, we got on the fusion bonding bandwagon. We thought that was going to solve all our problems but I remember being at a shop where I think we were running our lamp press at like 700 - 800 degrees Fahrenheit for 12 hours with some crazy profile. That's not very sustainable but it was homogenous DK and it had some great performance benefits but it really never took flight. So my gosh let's talk about hybrid a little bit more because I left the industry for a while to raise kids, and when I came back it was like Rumpelstiltskin waking up to all this high speed stuff and I was like wow! And what I did see was an awful lot of hybrids. So can you talk a little bit about what you think - certainly RF and microwave is an obvious one - but talk about what is driving the demand of high-speed digital RF and hybrid technology overall?

Well it's - in very broad terms - it's about electronics, doing all kinds of different things from a design standpoint though it's about mixing, mixing proper material properties in composites that's what you do. You choose one material over another because of its properties and you separate those layers out to get what you need out of a design. So it's driven by cost, some of its also driven by how you would fabricate. In other words, if you had a material that was hard to laminate you could use that as a double-sided low loss layer and then bond the other layers. Conventionally that would run the DC or other signals you would have in the design. We do have some new materials, so one thing I didn't mention earlier is that we distribute for both Isola and DuPont.

Okay.

Isola does have a suite of laminates that are low loss, some of them even with DKs close to the Teflon range, and they laminate at normal temperatures. So making a composite build is a lot simpler. You don't have to do two separate laminations, unless you had buried micro vias. But you wouldn't do it because of the materials. You would do it because it's for the design but you can do it in one lamination cycle so that's one thing we're trying to bring to market and that's something that's been a growth item for us. Some of these new materials like Tera MT40 for example, the Astra MT77. Astra has the lower dielectric constant - a dielectric constant of just under three - that's for certain, for RF designs, whereas the I-Tera is for the mid-DK, what we call the 3.4 - 3.5 DK range but they're both low loss and they’re both laminated. Again at normal temperatures, so that seems to be getting some good traction.

How do they stand up cost-wise against some of the traditional high speed laminate providers?

Well as a resin system PTFE is expensive and then if you're reinforcing it with ceramic or fiberglass, that adds cost as well, so we actually stack up - no pun intended - pretty well with the PTFE-based product. It's not as well-known, many of the designers are familiar with the PTFE based laminates for RF applications so, they go with what they know very often, until they have a need and then they start looking at alternatives. And there's so many different, projects coming on with our customers, we're quite busy trying to keep that education process going.

So I'm putting myself in a designer's shoes today and I was talking to Lee Ritchie yesterday and he was talking about how the speed curve has gone up near vertical in the last five years and I think you and I would both agree that we've seen that trend. I'm putting myself in a designer's shoes, so how do I get educated fast enough to keep up with all these moving pieces? Because like I said, when I left the industry and came back it was completely like a waterfall as far as onboarding all the different laminate manufacturers and then learning about matching bond, prepregs and bonding systems and cover weights. And then, let's just throw in, that we might have this on an aluminum carrier or whatever. How can we do a good job other than hosting a podcast so I get people educated?

I think the IPC design councils are helpful for that. Some of our folks have presented, I presented, our other people presented. Certainly, if you're an OEM or a designer and you get boards from a board shop, reach out to the board shop and say, what are my options? The board shops have to live and breathe this stuff and certainly, folks like myself and folks at DuPont and Isola will also support the board shop in that effort. In fact that's becoming a bigger part of what I do. I travel with my customer to their customers and talk about their options and the pros and cons because you would think, in theory you would want the highest performance at the lowest cost but, it's not just single performance. It could be mechanical performance, it could be thermal performance, there are a lot of different attributes that you would need in the design and you don't know unless you talk, unless the designers were talking to the folks that have the materials background. You can't put all that together and I've seen projects where people have used the same old stuff and then they get unexpected results and so that's what we're trying to do. It's better for everybody if we hit it right the first time. So, that's what we do, we go in and we say, these are the options, this is when you use fired glass, this is when you use standard, this is when you go for the lowest loss possible, this is where you go for a better economy. We have a material called high speed that's very economical and it's pretty low loss, it's a 006 loss tangent and it's compact. It's not as cheap as FR4, but it's close to a lot of the other materials out there. So it's a nice scale of economy. Now it's not for every design but those who have been using FR4 for a long time and want to upgrade to a total low loss system, it might be a good next step. And that product has actually doing pretty well for us. The 4UIS has been growing pretty well and then the high-end products are growing pretty well. The products in between not so much, but, I think it's just a matter of what people need and the design.

All right, that makes sense. Does Insulectro and/or DuPont and Isola put out resources online that designers can get a hold of?

Yeah both companies, obviously all three of us actually, have websites with links to connect slash sheets, tech data sheets, and other things but I don't know if a website will ever be a good substitute for actually having a conversation with someone who's knowledgeable. Certainly that's a good place to start. The other thing too is sometimes a design will have some IPC slash sheet numbers on them, the specification sheets for different materials, and sometimes you're locked into that. So we've seen that with our customers, sometimes they're locked into a particular material set and it may not be the best. And again that goes back to having a conversation with the people involved. And sometimes they’re willing to change and sometimes not. Sometimes they have no choice. Certainly all old legacy military designs are examples where people are really stuck on very old old systems. And there's definitely a better mousetrap in those cases. But like I said, there's no substitute for having the conversation.

So Insulectro for instance, we were just at IPC Apex and I'm sure Chris, you were doing presentations there. I assume that going to trade shows also, there would be opportunities to have face-to-face conversations?

Yeah certainly, seek out - if you're buying boards - seek out your PCB shop. The folks at those trade shows, or sit in on some of the technical sessions, and then certainly, if Insulectro, Solar DuPont are there, great place to go get some information on materials.

Great.

Well I know I sound like I repeat myself often about this, but I've often said, and I used to blog on Microwave Journal to tell people, please go talk to your workshop, please go to your workshop because I think it kind of all ends and starts there and and because, like you said they have to deal with so many laminate and resin systems and all these things every day. A lot of times they could be helpful, it's just sometimes I think designers are so strapped for time. Sometimes they're doing the jobs of two people and so I'm always trying to help the designer get resources as best they can.

Yeah and it's something we appreciate, and what we see happening too, is they'll pick up a data sheet and they look at differences there - sometimes there are very minor differences between resin contents and electrical performance. You don't know the dielectric constant of a loss and they'll pick the lowest on the datasheet, but that might not be the best for the fabrication and having the right material to make the board come out right, yield well, do well after assembly, do well in the field. You're not really giving up anything even if the loss is very minor, higher in loss, but yet the board performs well it's definitely a good trade. So that's part of the problem, sometimes some of the designers who are pressed for time will pick a particular material set. Yeah it might have the lowest numbers, but it may not be the best fabrication. If you can't build it, or if the board shop doesn't yield well, it doesn't do anybody any good.

So I was just talking also to Kelly Dack, Chris.

You would probably recognize his face. Anyways we were just talking about this and it's like what looks good on paper is... First thing, it isn’t always this linear process when it comes to design and fabricating. So, back to the hybrid designs. What would you say for someone that's designing hybrids, some of the the challenges are of those boards and some of the benefits? Obviously performance is one of the benefits.

Yes performance and cost, because very often the very low loss materials, come at a premium, because of the resin systems - the cost of the resin systems - and the cost to make the materials and so on and so forth. So that is another benefit - it can be a challenge for the board shop and it really depends on the materials. The challenges are more often in fabrication than they are in the actual design part of it. Yeah, like I said before, it just varies so much, I mean one of the requirements usually for an RF design is to have a certain level of precision when it comes to forming the circuitry. When we say forming, it could be a plating and etching, it could be just print and etch, depending on the the technology used. And then you would laminate that into a standard FR4 system, and sometimes those materials aren't really compatible. So yeah, that goes back to being able to have materials that have the right CT properties, the right adhesion the right lamination properties.

But you look at some of these high speed materials and sometimes they can be more fragile. I mean they might for instance - and correct me if I'm wrong here - this is second-hand knowledge here, but they might survive the fab process, and lamination cycles, or even multiple lamination cycles, because then you introduce buried and blind vias. And then there's multiple thermal excursions and then you take it to assembly and you've got through-hole and surface mount part and they have to go through another two thermal excursions. And so that it all adds up and it it's not obvious at the outset right?

Yeah those are all good points, all things that have to be considered in the fabrication and use of the part and there's a lot there too. One of the things I'm seeing, is copper is a really good moisture barrier. So one of the things that we try and preach to our customers and their customers or the assemblers if it's a CM, is you have to bake the parts prior to assembly and you can't underestimate that. There was a really good paper put out around 2011 - 2012 at IPC that showed just how long it takes for the moisture to get around because if you have a strip line construction, or if you have a reference plane and RF design, that moisture has got to go around that copper plane. It can't go through it and I've seen people underestimate the baking and end up with with scrap. It's kind of a shame because if moisture is the only reason why you're doing the laminating and assembly it really is avoidable yeah sometimes it's a pain did it bake a board for two, four, six, sometimes 24 hours but, that's what it takes to yield well but it's it's still worth it and that’s something that comes up a lot.

Well I know that I worked for a smaller art shop and we had the case where we were doing kind of pre-production quantities and the board was cooking along, no problem, and then one day it wasn't working. Guess what, it had rained for a week and we didn't have them in an airtight storage or whatever, so we had to completely look the way we were storing and make sure we were baking this, because in California, it doesn't rain that much and it wasn't  first and foremost on our brains and when it came down to that, it was like what? Yeah didn't see that one coming at all.

I've seen that happen yeah, I've seen that it where customers or assemblers, they don't bake for years and think everything is great and they want to know what's changed and it's well material’s the same...

Had a heavy winter...

Yeah and it turns out it was something like that, it's always best practice to bake and it varies so much by design - ground planes are a problem. In fact there was a great study done recently with HD Paragon, I don't know if you if your listeners are familiar?

Maybe not, but we’ll put that link below in the show notes. Because they're an amazing asset to our industry.

So they did a great study on crosshatch ground planes on flex so there's some performance trade-offs to the crosshatch ground planes, but they do create a window. Moisture will get in more easily but it can get out more easily and when - as opposed to a solid plane - there is a frequency cut off where that is usable and one of the things the study looked at was diamond-shaped versus round openings in the ground plane. But I always like to put, or recommend putting, openings in the ground plane when you can afford it - just as a moisture egress.

Hmm, that’s new to me, so neat but it completely makes sense right? if you're locking in moisture inside of the laminate because you're capping it off, you're trapping it right?

Right, and a lot of the PCB processes are water based or aqueous based chemistries, even up to the surface finish. You know, Enog one of the most popular surface finishes, it sits in a hot bath for 30 minutes, actually two hot baths. The gold bath in the NIP and the nickel plating bath or high temperature what, 180 Fahrenheit - 190 Fahrenheit for 20 or 30 minutes in each bath. That's a big opportunity for the moisture uptake on the part, and if you can imagine, that's near when the part is finished. It usually gets routed and cleaned and electrical tests and a few other things. But then it goes out to the company that does the assembly some assemblers require the board shop to bake, which is okay if you put it in a moisture proof bag, but even that's not a guarantee because the workshop loses control over when it was opened and how long it stays in the atmosphere before it gets assembled and so on and so forth...

-or just before it gets bagged.

Yeah right.

And it may already be present and you're just vacuum sealing a moisture-laden board. It’s so many moving pieces, I always say, I wish my dear friends that were printed circuit board designers or engineers that are designing boards now understood the complexity of board manufacturing because you and I've been talking this whole time about just the laminates this is not drilling, laminating buried and blind vias, filling vias. There's so many moving pieces and I think sometimes copper bond treatments? Yeah all of that and I think in this day and age, a bare board is a line item on your bomb. It's not like pulling a component off the shelf and so I think the closer board fabricators and engineers can get together the better for both actually. Because sometimes I think the board fabricators also get exasperated with designers, but the technology is being driven in a certain way. And they're gonna be the first ones to see it and can actually help enable the board manufacturers in many cases so it kind of goes both ways

An experienced designer will know what the board shop needs and that's again - that comes from communication - things like minimum clearances, designed for manufacturability, those types of things, and in fact all the board fabricators I know are very good about working with their customers to try. And again it's in everyone's best interest to yield well and have a part that survives.

Absolutely, and back to Kelly Dack, we had a long conversation - actually two people here at Altium, all of our AEs and FEs here - are required to take the CID course and so two guys here recently took it and for the first time I got to look through the workbook. Holy cow this thing is like this thick and a huge percentage of that is the DFM things. It's understanding, so to hopefully save time and money and headache on the end of the designer.

Well Chris, I know we've only got started but we need to do this again clearly, because the other thing I want to talk with you about is flex, because flex is on the rise and I know you'll have a lot of insight there and I would love to ask you more about that. But before we go I always do this thing at the end of the podcast called ‘designers after hours’ because most people in our industry usually have some kind of interesting hobby. or a lot of us, even though we kind of act left brained, we have a pretty active right brain too actually, so sometimes we're creative or do something interesting. So do you have anything that you enjoy doing after hours, sort of unique?

Yeah so actually I've been I've been diving, gosh since the late 70s…

Diving? Oh scuba diving I thought you said dieting, okay!

Yeah so actually I started back east when I was living in New Jersey I actually did some shore diving and some wreck diving and that was a lot of fun. Now in California, when I was living in Southern California, it was Catalina Island and the Channel Islands and so on and so forth. But here in northern Cali the best place to go is Monterey. I've done some abalone diving up in Mendocino, but that's free diving that's not scuba. But, in fact, I've taken my sister my niece there. There's divers also and we've gone down to Monterey and I've done that so that's one of things I like to do. It's something I don't get to do as often as I like of course.

I know we're all so busy. Well speaking of free diving for abalone my mom and dad grew up here in San Diego - I grew up in in Orange County just about two hours north of here - but my mom, when she was a teenager used to free dive for abalone in La Jolla Cove. So about a year ago I moved down here and I'm itching to go get certified and do diving here because there's some really neat dive spots here. But we went to the area where my mom used to free dive and my daughter came up from snorkeling one day and pulled up two abalone shells, which is so rare.

Yeah

Well down here it's so picked over it's like there's divers out every weekend so it's really rare to find live abalone anymore. But anyway, she brought up a couple of shells.

Interesting fact about La Jolla, you can find electric rays down there so Rays are capable of delivering an electric shock.

Really?

Yeah well check it out they're pretty cool - but don't touch them - yeah, they're pretty cool.

Yes my interest in electronics and nature stops. Well thank you Chris, so much, this has been fascinating and I want to ask you 50 more questions but if you will say yes we'll do this again in a month or so and we'll talk about flex.

Sounds great.

Okay thanks so much Chris.

Again this has been Judy Warner and Chris Hunrath with the OnTrack podcast. Thanks for joining today, we look forward to you tuning in again and until then, remember to always stay OnTrack.

Bert Simonovich is founder of Lamsim Enterprises and an expert in innovative signal integrity and backplane solutions. He holds two patents and author of several publications. Anyone involved with the design and fabrication of high-speed circuit cards and backplanes or people who needs to estimate PCB transmission lines losses will find value in the paper Bert shared at DesignCon 2018, “A Causal Conductor Roughness Model and Its Effect on Transmission Line Characteristics”.  

Listen in to Join Judy Warner and Bert discuss copper roughness and the paper he presented at DesignCon 2018.

Copper roughness is located between the laminate and the copper

• From a manufacturing perspective, the rougher the copper the better
• But for high speed, the rougher the copper the higher the loss
• If you don’t model it correctly you cannot simulate it accurately
• The Huray model dilemma - where do you get the parameters to use for the model?
• Last year’s paper was about correcting the dielectric constant due to roughness
• New model is dubbed the Cannonball-Huray model
• The effort is collaborative, building on each others’ research i.e. Rogers, Polar
• As speed goes up, material properties are more important i.e. Fiber weave effect
• Accurate modeling is very important especially with new standards and tighter margins

 

Links and Resources:

Bert’s Whitepapers

Bert’s Articles on Signal Integrity Journal

Bert Simonovich’s Linkedin

Bert’s Twitter

Lamsim Enterprises, Inc.

 

Hi everyone this is Judy with the OnTrack podcast welcome back. If you are new to our podcast make sure to subscribe on your favorite RSS feed you can follow me on LinkedIn please.

Please. I love having friends on LinkedIn or at Twitter I'm @AltiumJudy and as far as Altium goes you can follow us on LinkedIn Twitter or Facebook.

So today I am at Design Con 2018 at the Santa Clara Convention Center and I'm delighted to have my dear friend Bert Simonovich who hails from Canada and so we're gonna chat with Bert today about the paper he submitted and all the things he's involved in. I also want to share with you about our fun history in Hobart and how we got to know each other. So Bert, welcome to our podcast and we only get to see each other maybe once or twice a year but I'm always so happy to see you.

Likewise, likewise Judy.

I'm glad you showed up this year and I'm glad I could get you. Last year I couldn't get you because you were so busy with your papers and everything; you were desperate, you were booked to the gunnels last year so I'm glad we got to run into each other.

So, to give you a little bit of background about Bert... well let me start from when Bert and I met. So what was it 2006 six or 2010?

Yeah 2010, something like that.

Yeah, so Bert was sort of in a transition period in his career and we met on LinkedIn and then we actually met at the show at Design Con and we connected through social media and we're old enough you know, and respectable enough in our careers that we didn't feel like that was creepy or anything. So we connected and we met upstairs; the top of the escalators here at Design Con, and we got acquainted and just networked and boy oh boy we didn't know the number of ways that our past would continue to cross over the years so, we hit it off immediately and Burt knew an awful lot about backplane and tell me again, you worked for a huge company up in Canada?

Okay so yeah we live in Ottawa area and I started my career at Bell Northern Research which was the research and development arm of Northern Telecom or eventually North Dell in Bell Canada.

There you go,

so it's essentially the same as like the AT&T; down here - researching, development and then that later got to fold it into the Nortel umbrella and I was there my entire career. It was 32 years until 2009 when they filed for bankruptcy and then my career ended…

Abruptly.

And that was kind of a shock. Then I was fortunate that I was able to you know - we weren't in bad shape financially - so it didn't hit us like it hit others. So I've considered myself fortunate, but what I missed was the day-to-day and and not knowing what the future was because at that time there was the downturn economy so it's hard for everybody and certainly harder for older ones and we were able to get out and fortunately got our pensions early and that kind of kept us going.

Yeah so that's right about the time I met you, not long after that right, and so you're like: mmm what am I gonna do now? I have all this knowledge and expertise how am I gonna apply it and so on your own dime you flew down here. We met and I was hoping that we were just networking to see how we could help one another professionally and whatnot, since that time - boy oh boy.

IMS came up from the UK to Montreal and we met again there.

That's right we met again there. We met at IMS so then, all of a sudden, our lives started weaving because I was in the RF and microwave space from the bare board side, and then I was doing the guest blogging for Microwave Journal and then you got to know all the folks - or you knew those folks in that space and then you got to know the Microwave Journal folks who have since launched the Signal Integrity Journal and now you're on that editorial review or review board for that magazine?

That's right.

And now, I think you just told me, this is your first year now that you're in the Technical Review Committee?

Technical Program Committee Yeah.

Right for Design Con so you actually reviewed the papers then that were being subpoenaed by some papers?

Yes.

Did they divvy them up?

Yes they basically divvy it up so there's quite a few reviewers for it to get the diversity and not just one person, several people review the same paper as well.

Right good. So, not only is he reviewing papers he's also submitting papers. So I want to say  congratulations that you are a finalist for best paper.

Oh thanks Judy.

Well I don't know that’s third time in a row now?

Actually five.

Five! You've been nominated that many times or you've submitted, but you've been nominated that many times. I see, so you are like a rockstar! So, tell us about the paper that you submitted this year.

Okay. This paper is actually a follow-up from last year's paper that I presented and last year after I presented it, there was a great discussion afterwards. It was the end of the day and people - there were no more papers after - and people that were interested stayed and we had a good little wrap of things and were discussing some of my results. And although I was close there was some doubt as to actually what it was, why there was still differences and my co-author Vladimir he had an idea that it's possibly due to causality of the metal.

Okay.

And Vladimir works for a mentor and so he had this idea and I had data and my technique and we decided to collaborate and see how well it would work. So he incorporated his algorithms into the tool and we checked it out and that brought the data exactly right on.

Wow! So this paper is kind of a wrap or closing the loop at the end of last year's paper basically?

That's correct, it's kind of a follow-up in a way and it kind of answers the question that we were suspecting. - the people who were discussing as a group were suspecting - so that was very satisfying when I had that. So we said, well we've got to publish this now so we'll do that.

So it was a copper roughness issue?

Well it's part of modeling called copper roughness, to model copper roughness properly and get the right model afterwards so you can do the simulations.

Isn’t that hard? I mean it seems like copper roughness, which is the roughness - for anyone that's not clear on this of our listeners - copper roughness is between the laminate and the copper. Not on the topside of them it's on the bottom side where it's being bonded to the laminate but it's not always the same?

No the thing is with roughness from a PCB manufacturing perspective, the rougher the better.

Right because there's adhesion.

Right peel strength. Nowadays, for high speed past 10 gigabit, now everything starts to matter and now people are talking 25 gigabit - 56 gigabit all the stuff lost, now becomes a factor. So it turns out the rougher the copper the higher the loss, so how do you model that? If you don't model that correctly you can't simulate it in advance.

Exactly.

So the bottling techniques in accuracy - so there's been different models out there one that's been very popular is the Hury model that was presented back in 2010 because I remember going to that presentation. Basically it was dubbed the ‘snowball model’ because when you look at the roughness profile under an electron scanning microscope, it looks like a stack of snowballs type of thing.

Okay.

Uh-huh and that's where it got coined the snowball model but it's the Hury model and it's very accurately  shown that you get very good results measured to simulation. The problem was where do you get the parameters to feed that model? Back then to get it, if you tuned the parameters you could get an excellent fit to the loss but that doesn't help for tools so how do I get that? Unless you're building a board or measuring the board to get the parameters so you can use those again if you're going to build that same geometry in a new design. So that's very time-consuming - pretty accurate - but not practical for smaller companies. If you need a good answer now, rather than a good answer later as Eric Bogatin always says, that never helps you. So, one of my early contract positions, because I started going in consultancy after Nortel. One of my clients they wanted to do some analysis on dielectrics but they also wanted to include their roughness and I knew nothing about roughness at that time. So I started to do my own research into this so that I could try and do the work, and found that it was all over the place in a way.

Anyway, I completed the analysis not even based on what I knew at the time and it was okay, but that seed sort of stuck. So I started in it and once you get an interest in something then try to go further and further. So it's been a pet project of mine so I decided to think about the Hury model and say: well, is there a way to get these parameters based on datasheet value only? If I know the roughness from a datasheet the, height of the roughness, can I get the radius though? So I thought about it and you know, I thought about: okay, this is the stack of spheres. If I stack them up can I determine the radius of the sphere from that stack? So you know it's basic geometry of things and eventually you can get that number if you know this height. So I thought - just out of curiosity - I'm gonna try it and when I did, I got reasonably good results, almost right off the bat. I'm not perfect, but I can tweak things a little bit more and I'm saying okay… That's how it kind of began so it's been over a few years, off and on. I did a paper earlier in 2015, when I first presented some of it, and that was quite successful and every year it's been kind of incremental and testing it against other data and then eventually other software came out like simBR and I started having success with the model there and that was great and so it kind of went. So lately, after that, then I started thinking about I never get the the actual delay property. So in order to model things, you need proper loss and then also the the delay property or the phase. So then I thought well, perhaps, how does the roughness come into it? Because I noticed the rough with the copper I get different phases for the same material. Anyway so I worked out some some things and that's what last year's paper was about, to correct the the dielectric constant due to roughness...

It was really last year's paper.

Uh-huh and so that that worked out very well and when I correct that, I get very good results with it so that's it in a nutshell how I got from there to here.

Wow. So I know you've worked also with Polar instruments. Tell us about how that came about?

Yes so last year Polar had introduced the Hurray model into their tool and I hadn't really met Martin but in his newsletters I always got it and he announced that they were going to come out with the remodel and a Polar tool so I emailed Martin and said; look let me check it out to see how well it works. So they gave me a trial thing just to check it out and I tested it out against my data and there was just a couple of hiccups, but we sorted them out and now the tool - it's a great tool - we can get the parameters now basically from data sheet to fill in. So we've dubbed the model really like a ‘cannonball’ Hury model because it's a combination of both.

Well Martin spoke, I think I shared this with you earlier that in October Martin Godean from Polar presented a talk at Altium Life in Munich and I was chairing the room he was in and he pulls up this stack of cannonballs - you and I hadn't talked about this - then he starts citing all this work by Bert Simonovich. I nearly fell out of chair, like my friend Bert? So I really love that Bert, you've like been such a collaborative force in this industry about these models and you know that you reached out to talk to Polar and really made it better. Not so much in a self-serving way but it's good for the industry really, it's good for designers right?

I think so.

And so I really appreciate that generosity of spirit that you have and it's what I liked about you when I first met you and here we are all these years later who knew.

That's right.

So, what's next Bert?  Tell us first of all, where can our listeners find your papers because I'm sure they'll want to get their hands on those?

Yes so I published papers that I have on my website at my company is http://lamsimenterprises.com.

Okay.

Well I'm sensing we'll try to put that in text somewhere I relate to this podcast so folks can find that and then they can find your consulting services there as well but then find all your papers there. Did Design Con aggregate the papers that come out of the show?

Oh yeah they have the proceedings.

But only the attendees get their proceedings right? So they can come to your website is the  bottom line, right?

Right, so anyways so for my papers, I have my papers that I published on my website and it's not just Design Con I’ve also done EDI Con papers and that's part of the signal integrity journal. There's an offshoot of that - is EDI Con - and I attended that the last two years, they were the first two. So there's Boston that was great time. Actually you went to the first one?

Yeah I went to the first one I can't believe how our lives have just crossed so many times. We just met each other here and went hi.

And you met and you met my wife.

Yeah I met  your wife on that trip.

Bert and I got to go to Fenway Park and have a private party at night and overlooking the fields and they brought out... what are those? I'm such a sports nut.

The trophies from the World Series.

- thank you the World Series trophies. They brought those out so we could you know take photo ops with and we had great food and we got to take over Fenway for a few hours and I met Bert's wife who's just a doll and we had a great time. So who knew when we met how our paths would cross?

But I think Design Con in general is about is networking, meeting new people, learning new things spreading the seed of papers. Like I was mentioning even last year's paper - Rogers took that and then confirmed the data or the theory part of it and then they presented results this year.

It’s such a great collaborative effort and I don't know I find it very refreshing because you know, like well I have a secret and if you give me a lot of money it might tell it to you. This is much more open handed and collaborative. I liked what you said earlier today - which was somebody will present something and then an offshoot will take off and then it'll take off and then someone will build on that and bring it back as something else. It's really the industry together - collaborating.

That's also for mine like 2010 with the snowball model, who knew? That room was packed to the rafters and out - that presentation from Paul Hury and Eric Bogaton’s and he presented that year and I was just dumbfounded and I'm going, well I don't understand it but that's cool, and that who knew that that would be the seed for my work, my research work.

And and then went into Polar and Rogers and it's just like an idea that sprung legs.

And that's just my example. One example of many you just look around - like Eric likes to say - come drink from the fire hose, that's the Design Con there’s just so much stuff and it's there and it's just a great place for that kind of thing.

It is a great show. So, a couple closing items. Number one what would you say for circuit board designers, are some of the kind of greatest challenges they're facing today? Looking forward into emerging technology is there any specific - one or two things maybe - that are sort of plaguing them at this point? Or things maybe they need to onboard and that they are not taking right now?

Just in general as the speeds are going up the actual material properties are really becoming a factor. A big thing is fiber - we've talked a lot about that - fiber weave effect and the industry is looking how to mitigate that effect. A lot of nice papers over the last few years, talking about that and again there's a lot of things on the roughness, getting good modeling because it's important now. And now with everything like the new Pam-4 standards, 56 gigabit. The margins are tighter, so fabricating boards is more demanding.

Yeah it ain't what it used to be I can tell you. I started in the board fabrication industry in 1984. Oh my gosh that seems like such easy stuff compared to today. I was just speaking with John Belushi from ASC and I said it used to be you just got your board, your fab drawing you had your sort of mechanical, here's the size of the footprint, this is the size of the trace plus or minus this, and off to the races you go. Now it's like a board fabricator has to think about everything they're doing and how that is going to impact. You can go to a board shop, make a board and be well within IPC standards and its’ still not performing to the designers intent.

I think it's not just the board shop, I think sort of the industry as well, you have to specify what you want properly in your fabrication notes.

What fabrication notes. What I'm saying is documentation, I think is an issue.

Yes and and the thing I'm seeing is if you want consistent results you have to nail down your design. Basically nail it down and not let the fabricator substitute material for different weaves. For instance if you have a stack up that you first designed it's got to be included verbatim on the fabrication notes. So you must use this material, this weave.You can’t substitute, and you can't play around with all the line widths and space to do things different. By specifying things on the notes that restricts what they can do you should end up getting what you want otherwise you may not.

And you had told me earlier in your consultancy business that you will talk about modeling certainly, but then you also give them the added benefits of giving them some guidelines of how to spec in these.

Yeah so typically a lot of my business is design reviewing boards before fabrication. After they do the design like Altium Board Designer would lay it out, so now there's a design review at the end so some of the clients they'd like to get some review over that visual review and I do that sort of thing for them. But as part of that, I review the stack up even from the board shop because the stack up people are human and could make an error. Typo or a lot of times they're just templates and they don't cut and paste properly or something, and it may not be correct. I haven't found anything that wasn't correct but I do that anyways, just check it, double check that the impedance is correct in things. But on top of that I also say that I'm going to review their fabrication notes to ensure there's consistency there and usually I find that a lot of these are smaller companies or startups. They're not aware of what's needed or they have one set of fab notes and they have the same design all over. They just use it over and over but that could add confusion in the shop.

Yeah absolutely.

At the end of the day part of the design review it's also part of a bit of educating as well to some clients so they realize some of the importance and they appreciate that as well.

Yeah and it is so sorely needed and people don't, like you said especially smaller companies, they don't always have the resources to go out and spend endless hours in a board shop getting educated or whatever the issue is. Or educated about signal integrity or whatever it is, so I think what you're offering in your business and in that niche is really valuable so that's great.

Well my friend I'm gonna let you get back out on the show floor. I'm sure you have a lot to do today I'm sure you're a busy guy so yeah I so appreciate you spending a little time with me and I'm so glad we got to connect I know you're getting so busy - such a big shot these days - it's been a delight thank you.

Actually, the reason I knew you were here, I saw something on LinkedIn and saw you were responding to somebody and I go: wait a minute is Judy here? So then I LinkedIn messaged you last night and I said, are you here? and yeah so let’s connect today.

See there's a lesson to everybody, LinkedIn really is useful. Gosh you and I've met a lot of friends through LinkedIn. I'm so glad to see my friends. I don't get to see you enough so I'm glad to see you whenever I get to see you, I'm not gonna complain. So best to you, congratulations on your nomination again.

Thank you Judy and the same to you.

And have a great show  and I look forward to catching up with you next time.

This has been Judy Warner with the OnTrack podcast please remember to subscribe on your favorite RSS feed and we look forward to talking with you next time and always remember to stay OnTrack.