SMT007 Magazine

SMT007-Sept2020

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30 SMT007 MAGAZINE I SEPTEMBER 2020 all that information. There are a lot of things that I don't need to think about, as it's just sec- ond nature to me. But to some- one who does not possess all that experience, there's a lot of things to learn. Johnson: I'm thinking about the specific example you just used a few minutes ago—the well to allow for gases to escape, etc. With experience, that would become second nature, but that's not the sort of knowl- edge that's particularly obvious if you strictly design and haven't been exposed to what happens on the manufacturing side. Steiner: In the '80s, there was a lot of sur- face-mount development going on in some of the designer groups that I participated in, like SMTA and the IPC Designers Council. In the SMT fledgling period, when parts became widely available, we didn't really know what to expect in design as no one had that expe- rience. And we started putting surface mount parts on everything. A lot of that knowledge had come through trial and error because even in the IPC-type communities, SMT specific standards were being developed along with the industry learning. We started doing a lot of trial and error learning. There really wasn't very good information, so we were all learn- ing together. Johnson: You have a team of people that are doing design that you watch over. How do you bring them up to speed on what are the appro- priate manufacturability guidelines for your products? Steiner: I asked myself that same question, and I didn't have a good answer. I created a sys- tem where I use SharePoint, and I have a desk- top shortcut that I created and have pushed out to all of our engineers. Anything an engi- neer needs regarding a PCB design—from the design queue to the work logs and all the way through what acceptability requirements—will cific footprints to take care of specific conditions that you run into in manufacturing. For example, bottom-terminated components were a real chal- lenge to get acceptable solder joints and acceptable flux resi- dues when one does no-clean board assembly. Cleaning is an expensive thing, so we have weighed that at CASCO. For the last 10–12 years, I haven't been doing anything like mil- itary or avionics or anything that mandates thorough clean- ing. The commercial and automotive stuff that I've been focusing on is all no-clean. In the example of bottom-terminated compo- nents akin to QFNs, I include some things in our footprints like weeping wells for the flux so that, as the solder paste is reflowed and the part collapses, solder gases from the flux have a place to go and collect that's anywhere other than under the component. If you have the experience and knowledge and can anticipate things, cooking things like that into the foot- prints really helps. Johnson: If you look at the demographics of our industry, we have a lot of engineers, designers, and project managers who have been around for a long time. There's a large age gap. The next wave behind is in their 20s and early 30s. How do we keep that critical information around? Steiner: That's an interesting question because the entire ECAD/EDA industry has shifted to focus on that up-and-coming group of indi- viduals. Again, last fall, I was at AltiumLive, where they polled everyone to find out how many people were PCB designers using the Altium platform and how many engineers were doing their own circuit layout. It is inter- esting to see that each year, more and more are coming straight out of school and laying out their schematic and then doing their own PCB design. There is a loss of tribal knowledge from the more experienced people in getting Russ Steiner

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