Issue link: https://iconnect007.uberflip.com/i/1467185
14 DESIGN007 MAGAZINE I MAY 2022 that's easy. Many of our customers, however, want to be that interface. ey want to be the one who passes the data back and forth, and thus things get lost in translation, and that can add a lot of time. We've found that can be a real barrier if the designer isn't able to directly talk to the manufacturer, even if we're trying to. Our best practice is that our designers always verify information with the fab manager in advance. Andy Shaughnessy: Everyone talks about DFM and the need for communication, but in the end, there's almost no communication with the fabricator because they don't know where the board will be built. So, instead of telling designers to talk to your manufacturer, maybe we should just embrace reality and call it "designing in a vacuum?" Cory Grunwald: If I'm working with a customer and I don't know which fab shop I'm going to, I must make a lot of assumptions. I must work over what I expect a minimum trace and space or minimum via sizes will be. I'll start with a capability sheet from a known supplier that we'll go through. But then I must add a little bit to what I expect for those tolerances, because I don't know if they're going to a shop that can do 3-mil trace and space, or if a shop has to go to 5 mils. Matties: When you're designing like that, what's the downside? Grunwald: e downside is you can't be on the cutting edge. You can't be working on the smallest parts and the thinnest traces and spaces because you don't know who it's going to and who can handle it. Matties: But is the design that you're allowing some tolerance for still a successful design? Grunwald: Yes. It can be a successful design, but as you know, projects are getting smaller and faster, and those requirements usually require a top-end board shop. Without talking to your shop directly, you can't assume that you're going to a place that can do it. Matties: at makes it tough to do your job. Kolar: It can add a lot of churn. It can be, "Hey, you design the best with the information you have." en the customer takes it through DFM. ey come back and say, "We have a fundamental issue. We need 2-ounce copper on this outer layer, but we can't support this trace and space with that." It could lead to a full redesign because we've assumed we can do stacked vias and they won't do that. ere are several things that can lead to redesigns, and it's even more fun when the customer wants to work with multiple vendors at once. Matties: But the reality, Jen, is designers are designing in a vacuum all the time, right? is isn't an isolated case. Kolar: I would say that the more complex the board, getting into motherboard scale, the more likely you're getting to have multiple reviews by Jen Kolar