Issue link: https://iconnect007.uberflip.com/i/1529411
16 PCB007 MAGAZINE I NOVEMBER 2024 corresponding trace for the power that went through it got hot and literally burned away. at was my profile picture on Microso Teams for quite some time. ICAPE Group is a manufacturer that engages across the PCB technology spectrum. What are your customers most challenged by? Usually only the very special situations end up on my table. But more commonly, I've seen requests for standard layout stackups to meet their requirements, customers asking for something that has already been proven based on their impedance requirements, etc. ey may be running into the danger of need- ing exotic materials because nowadays, even if you look at just a USB port 3.0, it's a high-fre- quency connection. You need to think about the impedance of your USB connector. That makes sense. I've encountered it enough that I created a webinar all about impedance, and that exam- ple is part of my introduction. I had a cus- tomer who was unaware he had an imped- ance-controlled connection on his PCB when he switched the build to us. He didn't pro- vide any documenta- tion regarding layer stackup or impedance. So, of course, our man- ufacturer used the most standard, cost-effec- tive stackup. Now, the trick about USB con- trollers is they are so well designed they will detect a misconfigura- tion on the impedance and throttle down or fall back to an earlier version's performance standards so the drivers and transistors don't get damaged. That's smart technology. You wouldn't necessarily think of a USB connection port as smart. I haven't read the full standard yet, but they think a lot about backward compatibility and whether you need to support it. In this case, the customer really needed the USB 3.0 function- ality, so we took a microsection. e photos of these two PCBs are not of the same position, but you can see that the layer stackups are dif- ferent. You can see a differential signal in there and it's probably connected to the USB port. That's how you figured out that you weren't building the board correctly? Based on the provided documentation, our PCB was built correctly. We compared our cross-section to a working board from the other fabricator, which enabled us to adjust the layer stackup to the competition. For some issues, I have started to use the term "draw- ing board engineer." Sometimes, you get PCB layouts with mechanical tolerances where you realize this person has never done any solder- ing in his life, never seen the machines, and probably has not touched the product he is building. He knows how to make a drawing, Figure 1: Cross-section of a stackup.