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The Shaughnessy Report: Let’s Get Small

Comedian Steve Martin could have been talking about the October 2022 issue of Design007 Magazine when he released his album “Let’s Get Small” in 1977—or maybe not. Well, as Steve would say, excuuuuse me! (You may have to explain that reference to any young people in your company.)

But it is tough to get much smaller than ultra HDI. This is a whole new level of miniaturization for most PCB designers and fabricators. UHDI folks speak in terms of microns, not mils. Everything changes when you start working with 15-micron lines and spaces.

The IPC D-33-AP Subcommittee is working hard at updating standards for UHDI because standards can barely keep up with UHDI processing. Cleanliness becomes all-important at that level, as a speck of dust can wreak havoc on UHDI circuitry. We’re talking about near-cleanroom quality.

When we started planning this issue of Design007 Magazine, we quickly discovered that there aren’t that many UHDI experts in North America; the overwhelming majority of UHDI technologists and facilities are in Asia. As a designer half-jokingly told me recently, “Most of the world’s experts in UHDI speak Mandarin.” (I only know about 10 words in Mandarin, and half of those are slang, so that could be a problem.)

The DoD has begun to recognize that the United States is behind the rest of the world in critical electronics manufacturing, and UHDI is a perfect example. But it’s no easy feat for a fabricator to jump into UHDI; a direct imaging machine alone runs close to $1 million.

Even as the use of UHDI continues to grow with processes such as A-SAP and mSAP, there’s a dearth of information available in English. Very few instructors in our industry teach UHDI design or fabrication curriculum, and there are not many UHDI resources online or elsewhere. We realized this was a great chance for Design007 Magazine to help fill that void by focusing on UHDI processes.

So, we asked some of the top UHDI experts to share their knowledge about designing and fabricating these tiny features. In this issue, we cover the challenges and opportunities in UHDI design, and the level of commitment required to become one of these top-level designers. Our goal is that you understand the critical points in the UHDI fabrication process to advance your capabilities of UHDI design.

In our conversation with Royal Circuits’ UHDI expert Herb Snogren, he explains exactly what constitutes ultra HDI, where the current cutting edge lies, and the hurdles facing anyone who wants to design or manufacture boards at the 20-micron level or below. Instructor Cherie Litson breaks down the semi-additive manufacturing process and shares some of her tips and tricks for designing A-SAP and mSAP circuits. Columnist Tara Dunn explains how to speed up the “learning curve” for UHDI circuits, and she answers common questions from new UHDI technologists.

Columnist Vern Solberg discusses how to conduct an interconnect capacity analysis to determine whether a design should utilize HDI or UHDI features. Jan Pedersen of NCAB, co-chair of the IPC D-33-AP Subcommittee, details their efforts to form UHDI standards. Kelly Dack then describes how he suddenly found himself working on designs with 15-micron lines and offers some advice for working on these tiny features.

We bring you columns from Barry Olney, Matt Stevenson, John Coonrod, Istvan Novak, Saskia Hogan, Matt Walsh, and Joe Fjelstad. In our flex space, we have an article by Stan Farnsworth and the concluding installment of our printed electronics roundtable with Kevin Miller, Mike Wagner, John Voultos, and Tom Bianchi.

There’s a real need for information about UHDI. As you move forward into the world of microns, I hope you will consider this month’s Design007 Magazine as a reference. One final note, if you haven’t already, be sure to follow us on LinkedIn and Twitter. There you’ll find updates and links to many of our most popular features. Let’s have a conversation online, and get small!

This column appears in the October 2022 issue of Design007 Magazine.