Issue link: https://iconnect007.uberflip.com/i/1481368
12 DESIGN007 MAGAZINE I OCTOBER 2022 SLP (substrate-like PCB) because printed cir- cuit boards, at least in Asia for small form-fac- tor products, are being produced with manu- facturing techniques similar to IC substrates. IC substrates now have line widths and spaces down to 6 and 8 microns, and that's where we're going. When you look at some of the Apple and Samsung products, they're in the 20- to 25-micron line and space range in high volumes. Shaughnessy: For years, we've been hearing that the convergence of IC and PCB processes was on the horizon. It seems like we're finally there now. Snogren: We are. Historically, IC substrates were made with semi-additive or modified semi-additive processing, and now printed cir- cuit boards are being made with semi-additive and modified semi-additive processing. It is really happening. Shaughnessy: Is Asia the center of ultra HDI? Snogren: Yes. It really started with Apple work- ing with their suppliers in Asia to get their line widths and spaces down. ey did it in a big way, but because of that, other companies are taking advantage of the capability that's been established. ere are companies in other parts of the world that can do that. ere may be one or two in Israel and Europe, but more than 95% of the volume is being done in Asia, with most of it in China. Shaughnessy: What segments are driving the development of ultra HDI? Snogren: It's anything that has a small form fac- tor. It started with the cellphone, just trying to pack more capability into a small space. You see it in medical devices that need to be small, such as in-ear devices or hearing aids. We need to do implantable devices that must be small and innocuous. With heterogeneous integration and cramming more transistors into a square inch through heterogeneous packaging, there are more I/Os on the device. e I/O density increases, so your pitch decreases, and that's driving this as well. Shaughnessy: Are design engineers from the PCB side studying IC laminate design pro- cesses, and vice versa? Snogren: Product designers need to under- stand there is a manufacturing process capable of producing these finer features, and they can employ those in their products to reduce the size of the product or reduce layer count. e problem is you can't get it in the United States, so if they design it, they don't have a place to buy it here. You must go to Asia. Right now, companies are trying to develop it. Averatek has some licensees who can do this. Winonics (Additive Circuits Technologies) has a similar technology it is developing. But I don't know if anyone is doing anything in a meaningful way or volume. Certainly not in any kind of volume at this point. Shaughnessy: UHDI seems to be uncharted ter- ritory. What's the biggest hurdle for fabricators Herb Snogren