& cplSiteName &

Infineon's Chip Sandwich

Light Reading
Out of the Lab
Light Reading
8/14/2002
50%
50%

Yesterday, Infineon Technologies AG (NYSE/Frankfurt: IFX) announced what it claims is a breakthrough in chip packaging technology: a technique that allows two electronic ICs (integrated circuits) to be squeezed into the space formerly occupied by one (see Infineon Intros 'Sandwich' Chip System).

Put simply, the German chipmaker has come up with a way to solder two chips together, one above the other, using a layer of copper in which chip-to-chip interconnections can be formed.

Infineon claims that its technology offers "a way out of the wiring crisis" -- referring to the fact that the number of pin-outs on a chip, and the number of traces on a printed circuit board, are starting to limit the functionality that can be put inside the chip itself. Reducing those wires to short copper links inside a "sandwich" allows chips to run faster, take up less space, and could reduce costs by up to 30 percent, the company contends.

Clever though it is, the idea of using stacked chips is not unique to Infineon. Others, including Sharp Foundry Services (part of Japanese electronics giant Sharp Ltd.) and Intel Corp. (Nasdaq: INTC), have developed so-called chip scale packages (CSPs) with up to four chips stacked on top of each other.

The different lies in the interconnects, says Reiner Schönrock, spokesperson at Infineon's worldwide headquarters in Munich. Stacked CSPs from other companies make connections using standard wire-bonding around the edges of the silicon die, rather than the copper sandwich developed by Infineon. "This [copper sandwich] is true 3D integration," Schönrock claims.

All stacked CSPs save on space and the costs associated with packaging, an approach that has turned out to be a big hit with manufacturers of mobile handsets. But Infineon's approach has several additional advantages over technologies from the likes of Sharp and Intel, which will open up other applications, says Schönrock.

For starters, the connections between chips are much shorter, so they can support faster speeds. The company claims that clock speeds of up to 200 GHz should be possible with its chips -- roughly 100 times faster than the fastest microprocessor today. This figure is a little hard to believe, but clearly this process has implications for fast communications technologies, including mobile and broadband networking.

The other key advantage is in heat dissipation. Since 80 percent of the chip's surface is covered by copper, which is a good conductor, the chip maintains an even temperature and can dissipate excess heat more easily. Furthermore, since the chip-to-chip interconnects are so short, they generate less heat in the first place than their wirebond counterparts.

The above image, taken with a microscope, shows how the chips are melded together. Infineon uses a diffusion soldering process, called SOLID, for "solid liquid interdiffusion."

First, a layer of copper is applied to the two surfaces to be bonded. Patterns are created in the copper using standard photolithography techniques to define where the interconnections will go. Then a thin layer (3 microns) of solder is applied, and the surfaces are pressed together at 3 bar of pressure and 270 degrees C, creating a permanent bond. The backsides of the two silicon wafers have been pre-polished, so that when they are bonded together, their combined thickness is almost the same as an original single slice of silicon.

In the image, places where current is flowing appear bright. Copper, which shows up pink, forms a channel from the top chip to the bottom chip. The grey areas at the top and bottom of the image are cross-sections of plain silicon -- the electronics are only found in the surface layer of the wafer.

Infineon's first prototype 3D IC, produced for an unnamed smart-card vendor, integrates a memory chip with the smart-card controller, increasing the available memory from the usual maximum of 32 kbytes to 160 kbytes.

Proving that it works is the first step, says Schönrock, and now the company will look at partnering with other chipmakers to produce products that meet their needs. There is also an obvious opportunity to apply this technique to products that Infineon makes itself, such as VDSL gear. The company also "hasn't ruled out the possibility" of licensing its technology to other foundries, he adds.

— Pauline Rigby, Senior Editor, Light Reading
http://www.lightreading.com Want to know more? The big cheeses of the optical networking industry will be discussing this very topic at Opticon 2002, Light Reading’s annual conference, being held in San Jose, California, August 19-22. Check it out at Opticon 2002.

Register now and save $500 off the registration fee. Just use the VIP Code C2PT1LHT on your registration form, and deduct $500 from the published conference fee. It's that simple!

(0)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View        ADD A COMMENT
Educational Resources
sponsor supplied content
Educational Resources Archive
More Blogs from Out of the Lab
The US goverment has funded two projects to develop an optical packet router capable of scaling to 100 Tbit/s
BlazePhotonics has slashed losses in hollow fiber, according to research it presented at OFC
Intel's silicon modulator could turn out to be a bit of a letdown – because it's not all that fast
Xilinx is funding research that could lead to FPGAs replacing network processors in future optical networks
U. of Kansas researchers think they're close to multiwavelength all-optical clock recovery
Light Reading’s Upskill U is a FREE, interactive, online educational resource that delivers must-have education on themes that relate to the overall business transformation taking place in the communications industry.
NEXT COURSE
Wednesday, October 5, 1:00PM EDT
Gigabit & Smart Cities
Joe Kochan, COO & Co-Founder, US Ignite
UPCOMING COURSE SCHEDULE
Friday, October 7, 1:00PM EDT
Gigabit & DOCSIS 3.1
Ty Pearman, Director, Access Architecture, Comcast
Wednesday, October 19, 1:00PM EDT
Securing a Virtual World
Rita Marty, Executive Director, Mobility and Cloud Security, Chief Security Office, AT&T
Friday, October 21, 1:00PM EDT
Security: Evolving the Data Center
Rasool Kareem Irfan, Head, Telecom & Infrastructure Security Practice, Tata Communications Transformation Services Ltd (TCTS)
in association with:
From The Founder
Light Reading today starts a new voyage as part of a larger Enterprise.
Flash Poll
Live Streaming Video
Charting the CSP's Future
Six different communications service providers join to debate their visions of the future CSP, following a landmark presentation from AT&T on its massive virtualization efforts and a look back on where the telecom industry has been and where it's going from two industry veterans.
LRTV Documentaries
From Philly, With Love

9|30|16   |     |   (5) comments


Join Alan Breznick, cable's answer to the Italian Stallion, as he runs through the highlights of SCTE Cable-Tec Expo, lumbers along in Rocky Balboa's footsteps and searches for the perfect Philadelphia cheesesteak.
LRTV Interviews
CenturyLink: SD-WAN Customers Looking for Value Not Cost Savings

9|30|16   |   5:31   |   (0) comments


At NFV & Carrier SDN in Denver, CenturyLink's Eric Nowak told Light Reading that when customers launch SD-WAN, they aren't necessary looking to save money, but instead they are looking for more value from what they're spending. He also shared some unique case studies and lessons learned from launching SD-WAN services.
LRTV Custom TV
Flexible Deployment Approaches for the Gigabit Services Evolution

9|29|16   |     |   (0) comments


For many operators, the gigabit evolution begins with the shift from DOCSIS 3.0 to DOCSIS 3.1. But that move represents a change not only in the protocol itself, but in the approach to architecting their entire DOCSIS delivery chain -- from the headend to the outside plant and home gateway components.

Jonathan Ruff, senior director of global technical ...

LRTV Interviews
Level 3 VP: Enterprises Need More for Less

9|29|16   |   05:27   |   (0) comments


Andrew Dugan, Level 3 group vice president of global technology and IT, says enterprises need more bandwidth and they need it faster and with greater security, but they want to spend less, if possible. They are looking to carriers to reduce their network complexity and help protect them from cyberattacks as well.
LRTV Interviews
CenturyLink: SDN/NFV Pose New Interconnection Possibilities

9|28|16   |   04:37   |   (0) comments


Network operators should develop new APIs and business processes for reselling virtual assets to each other, says CenturyLink's Bill Walker. That will enable them to build digital business portfolios that help them avoid becoming commodity transport providers.
LRTV Interviews
Level 3: Overcoming Terror of Being Supplier, Integrator & Developer

9|28|16   |     |   (0) comments


At Light Reading's NFV & Carrier SDN event in Denver, Travis Ewert of Level 3 Communications said there is terror in becoming supplier, integrator and developer, but it can be overcome and be cost effective.
LRTV Custom TV
Introducing IoT World News

9|27|16   |   01:43   |   (0) comments


Self-driving cars, medical sensors, smart cities... and refrigerators. In order to address the huge scope of IoT, KNect365 has created a unique online community that will help businesses to understand and monetize the opportunities that live within the IoT market. We look forward to welcoming you to IoT World News -- your gateway to a better connected future.
LRTV Interviews
AT&T: Reusable Functions Next NFV Key

9|27|16   |   06:03   |   (0) comments


The next generation of NFV has to break functions down into reusable software chunks, making everything much more cloud-like.
LRTV Interviews
Masergy on Security: Attackers Gaining Upper Hand

9|27|16   |   5:10   |   (2) comments


At Light Reading's NFV & Carrier SDN event in Denver, Ray Watson, vice president of Global Technology at Masergy, says that because of the growth in virtualization, the threat landscape is shifting in favor of the attackers. As a result, service providers need to think beyond just defending the perimeter and take a more holistic approach to security.
LRTV Interviews
Verizon Takes Next Step on Biz Virtualization Journey

9|26|16   |   4:38   |   (2) comments


At September's NFV & Carrier SDN event in Denver, Light Reading sat down with Victoria Lonker, director of Product and New Business Innovation at Verizon, to chat about where the carrier is with delivering virtualized services to business customers.
LRTV Interviews
Global Services: The $40B Face-Off

9|26|16   |   05:53   |   (1) comment


More service providers than ever before are battling it out to win a slice of what is now a $40 billion global communications services pie, explains Ovum Principal Analyst David Molony.
LRTV Documentaries
MEC Congress: The Key Takeaways

9|22|16   |   03:25   |   (3) comments


Three key takeaways from the Mobile Edge Computing (MEC) Congress in Munich, Germany.
Upcoming Live Events
November 3, 2016, The Montcalm Marble Arch, London
November 30, 2016, The Westin Times Square, New York City
December 1, 2016, The Westin Times Square, New York, NY
December 6-8, 2016, The Westin Excelsior, Rome
May 16-17, 2017, Austin Convention Center, Austin, TX
All Upcoming Live Events
Infographics
Hot Topics
AT&T CEO Backs Black Lives Matter
Dan Jones, Mobile Editor, 9/30/2016
Eurobites: Telefónica Taps Juniper for Network Security
Paul Rainford, Assistant Editor, Europe, 9/26/2016
Powell Kills the Cable Show
Mari Silbey, Senior Editor, Cable/Video, 9/29/2016
Telstra Sees Quadrupled Data Capacity by 2020
Carol Wilson, Editor-at-large, 9/28/2016
From Philly, With Love
Alan Breznick, Cable/Video Practice Leader, Light Reading, 9/30/2016
Like Us on Facebook
Twitter Feed
BETWEEN THE CEOs - Executive Interviews
Light Reading CEO Steve Saunders and UXP Systems CEO Gemini Waghmare discuss the strategic importance of digital identity for operators in the midst of transformation.
Join us for an in-depth interview between Steve Saunders of Light Reading and Alexis Black Bjorlin of Intel as they discuss the release of the company's Silicon Photonics platform, its performance, long-term prospects, customer expectations and much more.
Animals with Phones
There's Nothing Like Missing a Full Minute of Pokémon Go Click Here
Live Digital Audio

A vital part of increasing the number of women in comms is transforming the ways companies can support and empower women. While progressive company policies that support both men and women in achieving work-life balance are a step in the right direction, creating a company culture that supports those policies can at times be more challenging.

During this show, we'll talk to Lynn Comp, Senior Director of Industry and Sales Enabling (ISE) in the Network Platforms Group at Intel, about why those challenges exist and how companies can overcome them. She'll provide insight into how Intel has worked to create a culture that supports work-life balance, and provide steps and guidance for other companies wishing to do the same. We will also leave plenty of time to get your questions answered live on the air.