Page 27 - EE Times Europe Magazine | June2020

EE|Times EUROPE 27

PACKAGING
Wanted: Process Engineers Versed in Packaging

By Junko Yoshida

he new frontier of leading-edge IC design is Others are notably taking similar approaches for
packaging, according to Arijit Raychowdhury, package-level integration. “Apple, Qualcomm are
an expert in digital and mixed-signal design all pursuing this, and they are at different levels of
T who teaches VLSI courses at the Georgia maturity,” said Raychowdhury. Put simply, leading
Institute of Technology and who received the 2018 CPU vendors looking to the future are “all about
IEEE/ACM “Innovator Under 40 Award” at that year’s heterogeneous integration of the package.”
Design Automation Conference. The emphasis on leading-edge IC design is shift-
Integration is the holy grail of VLSI design. ing from the process to the packaging. The problem
Next-generation IC design lives or dies on the next is that “there is very little understanding, at least
feasible advance in integration. Historically, the VLSI in the U.S., about how this transition is going to
community has depended on progress in process node happen,” according to Raychowdhury. He singled out
technology to overcome the next fast-approaching TSMC as a company “doing a better job” of letting
bump on the road toward higher integration. But the industry know “what is on-die versus what is
times are changing. Georgia Tech’s Arijit Raychowdhury on-package.”
The chip industry understands that scaling in (Image: University of Notre Dame) During our interview, Raychowdhury stressed the
accordance with Moore’s Law has been slowing. The importance of “connecting the dots” in the engi-
industry appears reluctant to confront an imminent neering world. Linking theories learned at school
upheaval in chip integration — an unmistakable transition from process with designs in the real world is one obvious example. Knowing how
to packaging technologies. the business of technologies connects with Wall Street valuation is
Raychowdhury is one of a rarified few who have zeroed in on this another. While technical papers submitted at ISSCC or VLSI Symposia
trend. Citing Advanced Micro Devices’ Zen and Intel’s Lakefield pro- inform engineers about cutting-edge technology, there is a huge mid-
cessors, he told EE Times Europe that packaging is an area that process dle ground that must be explained between advanced tech papers and
engineers must understand. Intel is using an advanced package inte- books that teach engineering basics.
gration technology called Foveros for its Lakefield chips, Raychowdhury Our conversation covered challenges in teaching EE courses in the
noted. “AMD is using similar integration technology to combine 7-nm pandemic era, transistor scaling, new fields of expertise for next-
CPU with 10-nm I/O using package-level integration. It helps improve generation VLSI designers to master, and what sort of engineering
system yield for them. Their flagship product for this is Zen 2.” students are most likely to succeed in the real world.

TEACHING IN THE PANDEMIC ERA suffered some damage and power outages. of] on what the industry is doing and whether
EE TIMES EUROPE: I see you’re at home. Is It’s just a mess. they can get jobs. Then there are some courses
school still in session? that are fundamental; we can’t stop teaching
Arijit Raychowdhury: We just got done EETE: So despite all the advances in them Laplace or Fourier transform.
[for the semester] a day before yesterday. technology, we are still at the mercy of
We moved to online classes in the middle of nature. Is that right? EETE: So these must be taught.
March; it’s been almost six weeks of online Raychowdhury: In all sorts of ways. Yes. Raychowdhury: Right. But [students]
classes. We have students from all over the sometimes find it hard to connect them to real-
place — you know, from China, from Vietnam INFORMATION GAP world applications. They are always looking for
— so it’s crazy to hear from a student from the EETE: Over here at AspenCore, we are how the theory connects to practice.
West Coast saying, “Oh, it’s a lot of work.” on a mission to discern a gap between You asked me about my connections with
what our readers thought they’d already [EE Times sister site] EDN. I’ve been reading
EETE: How do you teach online? learned in school and what they have to EDN since, I don’t know, 2001. I used to work
Raychowdhury: We video-record the lectures do on the job. From your viewpoint as at Texas Instruments long back before I went
ahead of time and post them online. Then an instructor, are you getting feedback to grad school. So, the first design that I did at
during normal class hours, we just log into from students such as, “Gosh, I wish I’d TI actually got this EDN Innovation Award. It
Blue Jeans, Microsoft Teams, or some other learned that in school”? was back in 2003. It wasn’t just me; our whole
video conference system. Then we do a little Raychowdhury: That’s one thing students team got that award. Because it was the first
more of a Q&A. I answer students’ questions always mention, and this can be very specific award I actually got in my life, that was cool.
and all that, as opposed to going through to certain instructors as well. Students are
the entire lecture. It has been OK. I mean, I always interested in understanding how things SETUP AND HOLD
wouldn’t say it’s that bad, but it’s been OK. they’ve learned in class apply to the real world EETE: Speaking of EDN stories, one of the
But I think now you’re seeing lots of — which products use which fundamental most popular articles is about “setup
students who don’t have proper internet con- techniques and [apply] what they’ve been and hold time.” Consistently, the basics
nections. This could be a struggle even within taught. This is what we hear often in academia. of setup and hold time have been very
this country right here. There are students Some academics have moved to academia popular. So where could we get more of
in rural areas, and they don’t have a stable from the industry. They have a better under- that kind of stuff out there?
internet. And you know, we already had torna- standing of what’s going on. I think students Raychowdhury: I think that’s a perfect ques-
does a couple of weeks back. And there were — undergraduates particularly — enjoy taking tion. I agree. These days, in our VLSI course, I
students in southern Georgia whose houses courses that have more implications [in terms spend about 20% of my time just talking about

www.eetimes.eu | JUNE 2020