Issue link: https://iconnect007.uberflip.com/i/972396
46 FLEX007 MAGAZINE I APRIL 2018 by Kelly Dack, CID+ EPTAC I've been designing PCBs and flexible circuits for decades now. I've heard a lot of advice over the years, but what really sticks in my mind are the wise words of a mechanical engineer I worked with back in the '80s. He was an older guy named Clarence. One day, Clarence and I were doing a design review, and he gave me some sage advice: "Kelly, never design some- thing that can't be built." I got a chuckle out of his statement. Well, duh! Of course, it must be manufacturable. Every designer knows that, right? But as the years went by, I engaged with more designers, design teams and manufactur- ing stakeholders. (In my view, the stakeholders are anyone with "skin in the game." We don't want to let down any of our fellow stakehold- ers.) I soon realized that Clarence's words were a prophetic warning for my future career path as a PCB designer. While I was thinking "duh," I had only begun to start reaching out to sup- pliers and manufacturers in the PCB industry. As I spoke with these manufacturing stake- holders about what they need from a designer to make successful circuit boards, I heard woe- ful tales of PCB designs that were unmanufac- turable. Some designs had lines that would etch away, or via pads that would be obliterated if over-drilled to allow for plating. Multilayer PCB stack-ups would often need to be a quarter- inch thick to achieve the specified impedance requirements. It was as if these PCB designers had never set foot inside a fabrication facility before. And that turns out to be the case more often than you might think; many designers have never visited a board shop. After many years, I'm still designing rigid PCBs and "flexitos," and I'm still reaching out to PCB manufacturing suppliers and making queries to find out what designers can do to help our manufacturing counterparts be suc- cessful. And you know what? I'm am hearing Clarence's words echoing from an entire indus- try of fabricators: "Never design something that can't be built." If you are a PCB designer, are you surprised? Maybe you are responding "Duh," as I did 30