Issue link: https://iconnect007.uberflip.com/i/1509257
34 DESIGN007 MAGAZINE I OCTOBER 2023 collect data, and then look at that data for our yields. If there's a defect, we can track it to see what has caused it. en if we buy new equip- ment to solve and bring that defect rate down, we can track it to see whether our investment is going through to work it out. COO Sean Pat- terson believes that we are a technology com- pany that owns board shops, so we want to use technology and the tools available to manage and do things in an intelligent manner. Traditionally, the board industry would just do another re-spin and not analyze what is working and what is not, what the yields are, etc. At times I'll get a very challenging design from a customer who didn't follow IPC rules, and we'll say, "No, this is not to the reliability that you require." ey'll reply, "We've been getting these boards built for years," and I'm thinking, "I understand what you're saying. You've been receiving good boards, but you do not know what is happening to make the quantity of your good boards." eir fabrica- tor may have had to throw away 50% or 75% of the boards that they produced to get that 100% deliverable. I said, "Let's redesign it, but let's follow the IPC design rules." Oen, people will say that the IPC rules are old and out of date, but they probably haven't read them recently, because the rules have been modified and updated. Every year, we work to improve all the stan- dards. If you follow them, and design it that way, you'll find that you get two things: a much more reliable product in the field, and the yields for the fabricator will probably be bet- ter too. In this instance, we simply followed the IPC rules. We looked at the challenges, how they wanted the boards built, and we changed certain things like the surface finish. We didn't move any components. We didn't change the number of laminations—I guess it was still five. At the end, their yield went from 25% to 88%. Of course, customers may not know about this, because a lot of the time fabricators don't share their struggles and pains. But this is real- ity for PCB manufacturers. If they drill down, they ask, "Why is the yield so bad?" at's where it becomes a problem within the fab- rication segment. Fabricators look at their processes for documenting collected data to analyze it, and when you do that, you can see, "e fallout is here, and it's because of your design." en the customer asks, "What can we do about the design? e cost is too high. What can we do?" Barry Matties: Do you have an example of a rule they weren't following that you did follow? Yes, here's one of my favorite rules to share with designers: removing the non-functional pads and routing the traces closer to the drilled hole where there's more room, because when they're routing it, they don't necessarily see the hole. ey remove the pad, and now there's all this room. Within IPC-2221 and IPC-2222, there's a rule that says, "Do not remove the pads to make more room." You route with the pads in and remove them aerward. It will take care of a lot of design problems. Some design guidelines from component manufactur- Gerry Partida