Paste Don’t Plate! People are doing 90 layer multilayers with paste interconnects. Want to learn more? Find out about paste sintering from Chris Hunrath to learn more about its applications and benefits to PCB designers. What must designers consider and what are the advantages of Ormet’s products? Listen in for insights from the expert in this week’s episode.
- New material developments make paste interconnect technology more feasible
- Ormet’s paste sinters at one temperature forming a new alloy with higher melting point
- Paste interconnects allow for changing build sequence in which vias are formed i.e. drill, add paste, and then laminate - giving you interconnects inside a double-sided core with no visible vias
- Multilayer PCBs: Can split up a 32-layer board to two 16-layers (even as many as 4 x 18 layer multilayers - which is much easier to build
- Also reduces risk depending on design - electrically test each half and only use the good ones
- Ormet process/paste interconnect process eliminates traditional drawbacks i.e. excess copper on surface features
- Eliminate backdrilling with paste interconnect process without extra copper in the via
- Ormet paste eliminates electrolysis and plating process
- Signal integrity benefits
- Applications: RF, high-layer multi cap, avoid secondary remelt, downhole assembly etc
- Design considerations: Where to split up layers for best design benefit; Via at 1:1 or less aspect ratio - only in 1 B stage layer and correct size via for applying paste; Size of receptor pad for laser drill via must be correct to prevent paste from running - spread glass is good for B-stage; annular ring around the via to register laser drilling; with many paste interconnects - don't paste to the edge.
- Paste melts and forms alloy with inter layer copper creating a permanent metallurgical joint
- People are doing 90 layer multilayers with paste interconnects.
- HDPUG (HDP User Group) is creating HDI test vehicles with paste interconnects and HDPUG members will have access to reliability data for breaking up big PCBs
- Paste don’t plate!
- Future topics: Many ways to use conductive inks in electronics, copper foil, integrity issues and printed electronics. Material science behind electronics, new design tools, various versions of conductive inks
Links and Resources:
Chris Hunrath on Linkedin