Issue link: https://iconnect007.uberflip.com/i/1518649
36 DESIGN007 MAGAZINE I APRIL 2024 ey've never worked on any kind of complex RF boards or had one of their boards redone because they didn't have the correct part. It's really amazing when you're working with these young engineers, they see chip-on-board for the first time, and they say, "What on earth is that? I've never seen that." It's so much fun to show them what's going on here and how it works. ey're amazed. I ask them, "Do you want to learn more? Yes? Well, let me show you how to do these designs." For this course, I thought it would be cool to just have a wire-bond design that goes from beginning to end—a really easy one, nothing too difficult—but also throw in some control difficulty. I'm putting together a good sample design, and I'm sure by the end of the class, everybody will have a really good idea about how to place parts, set up your constraint man- agement, and a whole bunch of different things related to wire-bond design. It will be a fun class. That's great because it's fun for the students too. What are some of the biggest challenges that the students face when constraining the board? A lot of folks just don't put in the rules when they start a design; those constraints help you route faster and better, and route so that you don't have to redo the design repeatedly. By learning how to set constraints, and by keep- ing the design rule editor on, you can route and not make any mistakes. en, once you do the route, it's done. You don't have to clean it up later unless something really bad happens. By understanding better methods to set up your engineering constraints, it gives students a bet- ter idea of how they can be more productive and make their designs more engineered than ever before. at's what we're facing right now. We have to engineer our work a lot better than ever before. We also hear from designers who are trying to avoid over-constraining. Some high-speed designers throw the baby out with the bathwater and go with the most expensive materials every time. It's a challenge to find that fine line and not waver. I've been in some webinars where cer- tain soware packages can really over-con- strain things. at takes away the magic and the beauty of what we're doing. We're solv- ing a puzzle and making it correct engineer- ing-wise. But I'll lean toward over-constraint every now and then to engineer everything. Over-constraint can really hurt a design dur- ing assembly; we can really hurt ourselves by over-constraining. en we're back to rede- signing. One engineer said, "Don't show me how perfect you can make your design; show me the dirtiest signal I can have that still passes and makes the product work." Right. Like you mentioned, we can get over- constrained if we're trying to be too perfect. Sometimes EEs will try to constrain things too much. Every PCB design engineer should ask, "What speed are we at? Do we really need to match length to 1 mil? Will 10 mil work? Do we really need it?" A few friends say I ask too many questions, but I can't help it. I'm an engi- neer. Filbert Arzola