Issue link: https://iconnect007.uberflip.com/i/1509257
12 DESIGN007 MAGAZINE I OCTOBER 2023 IPC standards are the drivers of the fabrica- tion process. ey guide designers and explain what they should be doing. When I ask these designers why they don't use them, oen they'll say, "I want to reinvent the wheel." I'll tell them, "Do you know how difficult that is? You have an entire system and structure here of standards that have been developed through experts in the industry, and you want to ignore them?" Barry Matties: At the very least, that unnecessarily elevates risk. at's right. You're asking a fab house to build a board not based on any guidelines. If you don't aim for anything, you're bound to hit it. at's what can hap- pen if you don't have a guideline to direct you when you're designing the PCB. It's a recipe for failure. Matties: Why aren't these designers following the standards? Do they see them as being too expen- sive, or maybe they don't know how to access what they need? Pricing may be an issue, but it doesn't explain the whole problem. We must do a better job of exposing new designers to IPC standards. When I started my PCB design career 25 years ago, I took a course at Palomar College (where I'm now teaching), and the very first thing my fantastic instruc- tor Bill Brooks did was hand us IPC standards. It was my introduction to the whole area of standards, and everything developed from there. Let's be honest: IPC standards are not excit- ing reading. It's not like you curl up on the sofa with a glass of wine and an IPC standard, but it is important reference material; designers must understand what's in there and where to find what they need. e standards will guide you. When a designer says he's going to reinvent the wheel and not follow standards, I ask, "Do you understand that the fab house is following that standard? at's their guideline for build- ing your board and you need to understand those standards, so you know what the board shops are expecting." If we help new design- ers understand these standards early on, that would be a big step. Matties: Essentially, they're trying to create their own standard. ey may get their design fabricated, but that doesn't make it right. I was talking to a com- pany recently who told me, "We don't really have a standard that we fol- low. We tried IPC standards, but it's not our thing." Shaughnessy: Where should a new designer start with IPC standards? What's the "starter pack," so to speak? Start with IPC T-50, which covers terms and defini- tions, because you must understand the termi- nology involved. It's vital that everyone is on the same page about terms we're using and what those definitions are. Next is IPC-2221, the basic PCB design standards. en I would loop in IPC-7351 for libraries and IPC-7251 for foot- prints. ey're both vital, but I would lean toward implementing IPC-7351 because the library is everything. I learned this years ago when I set up a library and didn't follow any standards. If I had followed IPC-7351, I could have avoided a lot of problems. It gave me the answers I needed and explained how I should have done things in the first place. We must do a better job of exposing new designers to IPC standards.