Issue link: https://iconnect007.uberflip.com/i/899995
12 The PCB Design Magazine • November 2017 by the I-Connect007 Team For this month's issue, our editorial team interviewed some of the top HDI experts in the PCB supply chain. Joining us on the confer- ence call were Steve Bird, PCB/flex technology manager at Finisar , and Tony Torres of APCT. Also on the call were several technologists from MC Assembly: Vince Burns, quality engineer; Steve Jervey, director of Test Engineering; Mike Smyth, SMT engineer; and Paul Petty, prod- uct engineer. This wide-ranging conversation covered the latest technology developments, manufacturing challenges, and HDI strategies, from the design, fabrication, and assembly per- spectives. Andy Shaughnessy: Why don't we start with de- sign? Steve, you're an HDI technology manager, so you're driving this whole thing. Why don't you tell us where you guys are with HDI? Steve Bird: Sure. I'm wearing two hats. One is technical lead for the EEs and the CAD design- ers here at Finisar, and the second one is organic substrate roadmapping and development. May- be 18 months or two years ago, we were work- ing with a fabricator. We started cheating on the FR-4 design rules, and to their credit they built over 1,500 of these over a period of a year or so and finally gave it up and said, "No bid." So of course, the upper management team came to my group saying, "You're violating the de- sign rules." And I said, "Yes, but not without an engineer sitting next to the CAD designer. And yeah, we did, but what we have here really is not a design rule violation, but a technology limitation." That spun off an effort to find a substrate that could support the design rules that we're cheating to. Our PCB technology team was tasked with the effort. We got one new substrate developed and released, but now those new de- sign rules are being violated; we have to contin- ue development. For that previous generation, once we got off FR-4 and onto alternate materi- als, we were still in the subtractive process. Now we're looking very heavily at the semi-additive process. Our trace with normal FR-4 is going from 4 mil trace and space down to say, 3.5 mil, FEATURE INTERVIEW