IPC International Community magazine an association member publication
Issue link: https://iconnect007.uberflip.com/i/1544398
APRIL 2026 I I-CONNECT007 MAGAZINE 59 on-silicon (SoC) applications, developers can avoid discarding significant portions of the silicon-based product. So, instead of getting 50% yield, maybe you get close to 95+% yield. You've been in the design game a long time. So, you believe that the new PCB designer will be in- volved in the design of substrates or interposers? Absolutely. As I mentioned, it's a matter of scaling. PCB designers have been connecting parts for de- cades, and they will get the same data you would use for a packaged component, but now they're shown as bare dies with preformed terminals. You simply have to adapt the existing CAD tools to assist in developing a new component library and establish the design criteria for circuit routing. The design engineer may still be using multiple layers but with significantly different materials—maybe silicon or glass as a base. Folks at Georgia Tech, for example, have been working on developing the process for using glass as an interposer base for over 20 years. Although silicon remains a primary base material for interposer applications, the poly- mer glass materials are evolving technology that is just beginning to hit the mainstream, much like we saw with the transition to SMT back in the 1980s. In bringing up the next generation of PCB design- ers, we talk about them needing to know more than just the electronic design piece. How much do today's PCB designers need to know about the engineering disciplines, even if they aren't experts in them? The design engineer will certainly need to under- stand base materials and how they impact product performance. We have a lot of good materials today and new ones being developed for higher operating temperatures, less flexing, and less loss. The problem with circuit boards has always been that the materials they are made with are not physically compatible with the uncased silicon they are being mounted to. When it comes to material properties, there is quite a disparity between the behavior of the silicon and the epoxy-glass based circuit board. But material manufacturers (primar- ily in Japan) have created new formulations where the materials coefficient of thermal expansion (CTE) rate is very close to the silicon itself. When employing semi-additive circuit forming technolo- gy, the commercial PCB fabricators will be a viable supply source for UHDI package substrates. You do a lot on the education front, working with young engineers. What do you tell young people these days? I tell them not to rush it just because somebody's putting pressure on them; do the best they can to make it right the first time. Rushing almost always leads to redesigns which cost companies a lot of money. Sometimes it cannot be helped, of course. There will always be revisions that may have noth- ing to do with the design engineer, so patience is part of it. And I always tell them to remember that some- body has to manufacture their design. You're going to design it once, then you can watch the company churn hundreds, or even thousands of your design off the production line. There is quite a lot of satis- faction in seeing that. Vern, it's good to catch up with you. Thank you. Thank you, Marcy. I-CONNECT007