Issue link: https://iconnect007.uberflip.com/i/1484263
30 PCB007 MAGAZINE I NOVEMBER 2022 on-chip boards that some of our customers are trying to do. Every layer seems sequentially drilled with 2-mil line and space, or 2-mil line with 1.5-mil spacing. We haven't done a lot of it, but we have seen some demand for it. Johnson: Where do you draw the line between UHDI and HDI? When does it become UHDI to you? Patel: For us, UHDI is when it becomes more than sub-drilling and sequential blind vias; it's a mixture of that, plus sub-3-mil lines/spaces, from my perspective. It becomes case-by-case specific on how to process these boards. I sup- pose that is the limitation of our equipment, but also our understanding of how things etch Feature Interview by Nolan Johnson I-CONNECT007 Candor Industries is a PCB fabricator invest- ing in UHDI fabrication capabilities in Canada. To support advanced packaging, as well as the current pace of IC process shrinks, PCB fab- rication capabilities must shrink to keep up. Sunny Patel, Candor's technical sales man- ager, brings us up to speed on what Candor has learned in their journey to add UHDI. What we gain from this interview is that, while certainly not insignificant, the stretch to add UHDI may be not as far as one might think. Nolan Johnson: Sunny, is Candor officially step- ping into the realm of UHDI? Sunny Patel: We're starting to get there. e first dabbling in UHDI has been these direct Candor: UHDI Under Development