During SEMICON West, we arranged to interview as many technology leaders as possible through short video coverage — conversations really. One of those interviews was withb Eric Beyne, Ph.D., scientific director, Advanced Packaging and Interconnect Center, Interconnect, Packaging & Systems Integration at IMEC. IMEC is a Leuven, Belgium-based research institute that concentrates on microelectronics packaging and interconnect solutions. I had worked with Beyne during a webcast on MEMS quite a while back, so I knew what to expect.
Beyne was not intimidated by the videographer’s demands and talked in an animated way about areas that are hot right now in R&D. “Areas of research that are most productive for us currently are: 3D interconnect technology; integrated passives for radio frequency (RF) applications; flip chip scaling; textiles with stretchable, washable electronics; and MEMs, of course.” Stretchable electronics is a growing area, he punned. These textiles with built-in electronics replace the standard PCB in clothing or elsewhere, such as on the dashboard of a car. In fire-fighting uniforms it would be especially advantageous. One method of making the 3D interconnect is to cap wafers in MEMs and make the electrical interconnection with through silicon vias (TSVs). If you can do wafer-level bonding without punching through the cavity, TSVs can connect through the back. In Europe, scientists use a heterogeneous technology with MEMS, fan-outs, and TSVs. TSVs are already in cell phone cameras. “But 3D does not necessitate TSVs,” he adds. You can stack packages or stack dies and bump them. At the IC level you can change the design. You can use 3D interconnect with pMOS wafers connected to CMOS wafers.
One of the problems with 3D packaging today is that the overlay alignment isn’t quite there yet. Ten microns might be possible at a slow production pace, but at 1 µm, the precision and slow speed just isn’t there. If the vias are at 1 µm, what size would the landing pad be? “Then there’s the via-first, via-last approach,” he added. Right now 3D TSV interconnect is one of the most active areas for the future of packaging. Changes in technology must be possible in design.
After a few minutes of technology talk, we faded into other points of interest. “How often do you visit the U.S.?” I queried. “Perhaps too much lately,” Beyne responded. “This is my fifth visit, so almost once a month. I like the U.S.”
When this issue arrives, I’ll likely be in Leuven for IMEC’s research reviews. Since Leuven’s InBev just combined with St. Louis, Missouri-based Anheuser-Busch, we have more in common all the time. “Things go around,” he agreed. At the end of the interview, beer sounded like a pretty good suggestion. To view this interview with Eric Beyne as well as others, go to www.apmag.com.
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Gail Flower
Editor-in-Chief