Issue link: https://iconnect007.uberflip.com/i/1507822
SEPTEMBER 2023 I PCB007 MAGAZINE 9 Nolan Johnson is managing editor of SMT007 Magazine and co-managing editor of PCB007 Magazine. Nolan brings 30 years of career experience focused almost entirely on electronics design and manufacturing. To read other columns or to contact Johnson, click here. is the semiconductor fab's responsibility. But there are some on the semiconductor side who see these intra-package connectors as more PCB than IC, with the commensurate opinion that PCB fabs are better suited to manufacture them. ere's some truth to that opinion, but it overlooks a few uncomfortable facts, like the feature sizes that interposers and substrates require. Aer all, we're talking about fabricat- ing PCBs at semiconductor IC pad size dimen- sions or thereabouts. Can your fab do that today? Over in IC land, they see the dimen- sions needed for substrates as 20 years behind what they're capable of in their fabs; retro- tooling new facilities will be necessary to sup- port the advanced packaging capabilities. All this leaves the interposers and substrates in a bit of a lurch. Everybody will need them, yet they're all hesitant to invest. Some com- panies are dipping their toe in the proverbial water. Skywater, for example, is building out the capability, as are a few boutique shops who see a market opportunity. is kind of manu- facturing will require cleanrooms and reli- able processes for fabricating at feature sizes moving toward the single-digits in microns for trace and space—with via sizes to match, of course. By now, I'm sure you can start to see how ultra high density interconnect (UHDI) con- verges with the other two trends. To reach the dimensions we're heading toward, we reach a threshold of capability with the number of steps in fabrication: subtractive processes, copper smoothness, copper-to-substrate adhe- sion, management of CTE (coefficient of ther- mal expansion), and more. Of course, UHDI has found its early foothold in high-end, high- volume, cost-sensitive consumer products like cellphones, but it will be required for lower- volume, high-complexity work as we move forward. We can expect increased demand for this kind of ultra-small work from OEMs and designers—especially as the semiconductor companies force the issue with even smaller pad tolerances and larger package sizes to accommodate all the I/Os for these very com- plex chips. Which brings me full circle to materials: e specialization and the larger inventory of prod- ucts with specific characteristics is necessary to support this convergence. On the "innovation" side of the technology adoption bell curve, there is so much more convergence underway; this will only move steadily down the bell curve into mainstream adoption. is is why we're covering these three topics all at once. In this issue, we talk about materials with Darren Hitchcock, and UHDI fundamentals with Happy Holden and Anaya Vardya. PCB Technologies' Oved Shapira launches the con- vergence conversation in his interview. Brent Fischthal of Koh Young discusses how inspec- tion is tackling the additional challenges fur- ther down the chain in assembly. Finally, we bring you a video presentation by IPC's Matt Kelly to the U.S. Commerce Department, on behalf of the industry, regarding key parts of this convergence and how it should fit into the decision-making process for CHIPS Act fund- ing. is presentation is not only educational but provides an eyewitness view of how indus- try organizations such as IPC, PCBAA, and USPAE are raising government awareness. Another trend on the rise in the U.S. is cap- tive facilities. is month, our special coverage of Schweitzer Engineering Laboratories (SEL) includes six equipment suppliers who partic- ipated in SEL's $100 million captive facility build-out. Whether you're upgrading a depart- ment or building out a new facility yourself, these conversations provide insight into the process of standing up your facility too. PCB007