Issue link: https://iconnect007.uberflip.com/i/1392944
JULY 2021 I PCB007 MAGAZINE 43 spaces, like I just mentioned, where there's an inconsistency between how much space you have in area A vs. area B. It would be design- ing outside of what would be normal manufac- turing. For example, they're asking for 1.5 mils of copper, and I have a 6-mil drill hole. You just don't have enough room to get copper through that area. ose would be common design for manufacturability things we might see. Johnson: WUS does some complex work. Can you characterize that for me? What's the WUS sweet spot? Link: We have four different facilities, and each one has its own sweet spot, which is the way it should be. Our automotive plant is going to be six- or eight-layer board, with HDI/hybrid, possibly RF materials. ey're usually smaller platforms. e Taiwan facility is a high degree of HDI, usually smaller platforms as well, and generally not the ultra-low loss materials— more like Megtron 6 or equivalent, and higher loss materials e C3 facility is our most advanced facility, and the sweet spot would be 24-32 layers, HDI, backdrill. at generally makes six or greater materials. e C4 facility sweet spot is 10- to 12-layer board range of different materials with panel sizes that don't go past a 21x24 working panel size. Johnson: at's four different facilities, four different sweet spots and setups, and four dif- ferent rule decks, if you will. You must char- acterize each of your facilities uniquely with- in the design for manufacturability tool envi- ronment. Link: Right. For most customers, we either only use one facility, or we know well in advance which facility it's going to go through. So, cus- tomer N might say, "Here's a 14-layer PCIE card," and we already know that's going to go into the C4 facility. If they talk about a 26-lay- er, HDI build, it's going to go in the C3 facility. Johnson: Okay, so how do you assist your cus- tomers in doing that? Or are they even inter- ested? Link: ey definitely are. With customers like that, we have periodic meetings with them to talk about details so it doesn't come up as a surprise. We are able to keep them aware of the types of technology available in the fa- cilities. We do pretty good work from front- end engineering, working with the customer before boards are designed to completely be able to talk through issues that will eventual- ly show up. We try to get them before it starts, basically. Johnson: is can be time-intensive. Link: It can be, yes. Johnson: You're still working on a very manu- al process here for putting that information to- gether. For example, there is no use of AI at this point to help with the process of thinking through manufacturability decisions? Link: at's correct, and we want it that way. We give our customers a set of rules that say, "ese are the rules that we want to be bound by," and then our competitor comes up with a different set of rules. Now maybe they're okay with 94% yield, and we were targeting a 95% yield. Suddenly, their rules look better than ours because they're willing to accept a little bit more loss in yield, or more risk to reliabil- ity. Because all suppliers don't have the same standards, they're gauged against it on paper: "Can WUS do this? Can XYZ do that? Oh, XYZ can do it, but WUS can't. Okay, we'll give them the work." We like to have some of those discussions as well: "is is the way it is, but we can do it your way, and it's not black and white, because PCBs aren't black and white, right?" Reliabili- ty is parts per million, yield is in percentages, and unless everybody's held to the same stan-