Issue link: https://iconnect007.uberflip.com/i/1406534
52 SMT007 MAGAZINE I SEPTEMBER 2021 them in on a manufacturing line. If I need the 128K part, I set the configurations for that, but then none of the smaller versions work. How- ever, if I need the 32K bit part, and I set the con- figuration bits for 32K, the 64K, the 128K, any- thing more capable should drop right in with- out any soware changes—but they don't. You know how much heartache that would solve? Yet every single one of those microcontrollers can't mix and match on the line because they all must have those configuration bits set sepa- rately. Fix that problem. I beg you. Johnson: A big part of being able to design for manufacturability is extracting logic and rea- son out of the manufacturer's chip catalog. Benson: Even when we're in a normal supply chain situation, I've run across that. Some- times I design the little electronic handouts that we give out at trade shows, and I run into that exact situation. I need the 16K; they were fine for prototypes, but now when I want to build 600 of them, they're out of stock. Well, what about the 32K? Can't mix and match. Johnson: at's an interesting point. Design for manufacturability discussions oen stop by concluding the designer didn't get it right. When the designer may be working with component supply issues that they just can't work out. Benson: e other issue is with passives. I like to say there are engineered passives and there are passives that are just picked. I need some bypass capacitors. Okay, 0.01 microfarad 16 volt, whatever. Just give me some. Well, going to the assembly house, we don't know when something is picked or engineered. at's why we can't just say 0.01 microfarad 16 volt, there you go. We can't say that because we don't know if that's an engineered or a picked component. And if the industry could come up with a way of specifying that such that we know, that solves another headache, because the engineer is saying, "It's a bypass capacitor, it doesn't matter. Just pick one." Yet the engi- neer in the next cube over is saying, "Because of the particular frequency spectrum, the op- erations of my board, you had better pick the exact bypass capacitor that I specified, or this thing isn't going to work." Johnson: And yet, that same designer, that same engineer, on a different project, could see that bypass capacitor as critical. It's appli- cation specific. If a design team goes just a little bit further along to specify which ones are en- gineered in and which ones are easily swappa- ble, that eases the assembler's complex- ity. at makes it more manageable list, doesn't it? Benson: It really does. Johnson: As an assembler, do you have an ideal for the bill of material specifi- cation you are sent? Is there a set of col- umn headings that are just your depart- ment's dream for what a bill of materials will contain so that you can do your job as effectively as possible? Benson: Format used to be a big issue, but it's not so much anymore. e com- Parts in feeders.