Issue link: https://iconnect007.uberflip.com/i/1481368
18 DESIGN007 MAGAZINE I OCTOBER 2022 Snogren: Yes. And when Apple decided it needed UHDI, the company didn't just throw designs over the fence and get somebody to build it. ey went to companies like AT&S and Multek, and said, "Here's where we need to go. Here's our roadmap. Start developing capabilities to get there." ey started doing that in factories that were already pretty spe- cific to a certain capability anyway. I have friends who worked at a Multek HDI factory in Zhuhai. ey said Apple and Samsung were migrating from 50-micron line and space to 40 and 35, then saying, "We've hit the wall in this factory. We're having to build a factory some- where else that's going to do mSAP." Johnson: Well, that's a fundamental shi for thinking in North America, for sure, and Europe as well. Snogren: You can't be all things to all people. at's the thing. Multek is a good example. On their campus in Zhuhai, they have an HDI fac- tory, a flex factory, a daughter board factory, and a back panel factory, and they're very seg- regated for a very specific type of printed cir- cuit board. Shaughnessy: Are there any good resources to learn more about ultra HDI, maybe in the form of websites, books, or instructors? Snogren: Yes, there are a few resources, but not many. I learned about semi-additive process- ing when I first started. Shaughnessy: How did you get into ultra HDI? Your father, Richard, wrote for me years ago. Snogren: My father owned a circuit board fac- tory, Reliable Circuits in Clearwater, Florida, when I was in high school. I worked there dur- ing college. Aer college, I worked at a couple of circuit board shops in Denver. en my dad and I decided to start a shop in Colorado back in the mid-'80s, and we ran that for 16 years. I went to Coretec for a while, and then got hired as a consultant by Viasystems. I was in China for four years at the Guangzhou factory and the Zhongshan factory. I got to see another side of things. It's just ridiculously high volume. I've been working with smaller compa- nies recently, like Royal Circuits, which was acquired by Summit. I helped Royal Circuits develop its HDI capability several years ago. But the migration into ultra HDI really came through my work with the DoD and the PCB executive agent. I'm on the IPC-1791 com- mittee, and we were talking about whether we should include IC substrates into IPC-1791. We found out there really aren't any industry design or quality standards for substrates. I started researching it a little bit and educated myself about IC packaging. I realized that not much happens in the U.S., certainly none of the fabrication of the substrates. is led to the creation of the IPC-D -33-AP committee to develop design and product performance stan- dards for UHDI PCBs. Shaughnessy: What does your roadmap look like for UHDI? Snogren: We developed a roadmap at Royal Cir- cuits last year. It's interesting because I came in originally about eight years ago when Royal was doing mostly 2, 4, and 6 layers. I worked with them to develop the capabilities to build HDI. I le for a while, then I approached Milan, Royal's owner, last year. I said, "Look, you're proficient now at HDI. You can do an eight- and 10-layer buildup board with five lam cycles and stacked microvias. You're good at it, but you are limited to 3-mil line and space. Let's put a roadmap together, get you down to You can't be all things to all people. That's the thing.