IBM researchers develop next-generation chip-cooling technologies

October 26, 2006
IBM researchers develop next-generation chip-cooling technologies

Enlarge

The image shows a cross-sectional schematic of the cooling architecture using the high thermal conductivity interface. A highly viscous paste is brought between the chip cap and the hot chip in order to reduce the thermal resistance. Thanks to its tree-like branched channels, the architecture allows the paste to spread very homogenously and attains a thickness of less than 10 micrometers. With this technique, two times less pressure is needed to apply the paste and a twofold increase in cooling performance can be achieved. Credit: IBM

At the BroadGroup Power and Cooling Summit in London, IBM researchers presented an innovative approach for improving the cooling of computer chips, an increasingly urgent need given the large amount of heat released by today's more powerful processors and the additional energy required for removing that heat.

The technique, called "high thermal conductivity interface technology," allows a twofold improvement in heat removal over current methods. This paves the way for continued development of creative electronic products through the use of more powerful chips without complex and costly systems simply to cool them.

As chip performance continues to progress according to Moore's Law, efficient chip cooling has become one of the most vexing problems for designers of electronic products. The IBM technique outlined today is one of several being explored by scientists from the IBM Zurich Research Laboratory to address the issue.

IBM researchers develop next-generation chip-cooling technologies

Close-up of the micrometer-sized tree-like hierarchical channel design. Credit: IBM

"Electronic products are capable of amazing things, largely because of the more powerful chips at their heart," said Bruno Michel, manager of the Advanced Thermal Packaging research group at IBM's Zurich lab. "We want to help electronics makers keep the innovations coming. Our chip-cooling technology is just one tool at our disposal to help them do that."

The approach used by IBM addresses the connection point between the hot chip and the various cooling components used today to draw the heat away, including heat sinks. Special particle-filled viscous pastes are typically applied to this interface to guarantee that chips can expand and contract owing to the thermal cycling. This paste is kept as thin as possible in order to transport heat from chip to the cooling components efficiently. Yet, squeezing these pastes too thin between the cooling components and chip would damage or even crack the chip if the conventional technologies are used.

Using sophisticated micro-technology, the IBM researchers developed a chip cap with a network of tree-like branched channels on its surface. The pattern is designed such that when pressure is applied, the paste spreads much more evenly and the pressure remains uniform across the chip. This allows the right uniformity to be obtained with nearly two times less pressure, and a ten times better heat transport through the interface.

This unique and extremely powerful design for chip cooling is borrowed from biology. Systems of hierarchical channels can be found manifold in nature, e.g. tree leaves, roots, or the human circulatory system. They can serve very large volumes with little energy, which is crucial in all organisms larger than a few millimeters. Ancient water irrigation systems also used the same approach.

The demonstrated prototype is part of a large effort within IBM's Research and Development organizations to improve cooling performance of next and future generations of computer systems.

The cooling bottleneck results from the demand for ever more powerful computer chips and becomes one of the most severe constraints of overall chip performance. Today's high-performance chips already generate a power density of 100 Watts per square centimeter — one order of magnitude more than that of a typical hotplate. Tomorrow's chips may attain even higher power densities, which would create surface temperatures close to that of the sun when not cooled (approx. 6000 °C). Current cooling technologies, mainly based on forced air convection (fans) blowing across heat sinks with densely spaced fins, have essentially reached their limits with the current generation of electronic products. To make matters worse, energy needed to cool computer systems is rapidly approaching the power used for calculations, thus almost doubling the overall power budget.

"Cooling is a holistic challenge from the individual transistor to the datacenter. Powerful techniques, brought as close as possible to the chip right where the cooling is needed, will be crucial for tackling the power and cooling issues," states Michel.

IBM researchers develop next-generation chip-cooling technologies

A scanning electron microscope image showing a cross section through the jets and four hierarchical layers of manifolds (jets). Blue arrows indicate the water flow. Credit: IBM

Looking beyond the limits of air-cooling systems, Zurich researchers are taking their concept of branched channel design even further and are developing a novel and promising approach for water-cooling. Called direct jet impingement, it squirts water onto the back of the chip and sucks it off again in a perfectly closed system using an array of up to 50,000 tiny nozzles and a complicated tree-like branched return architecture.

By developing a perfectly closed system, there is also no fear of coolant getting into the electronics on the chips. What's more, the IBM team was able to enhance the cooling capabilities of the system by devising ways to apply it directly to the back of the chip and thereby avoiding the resistive thermal interfaces in between the cooling system and the silicon.

First lab results are impressive. The team has demonstrated cooling power densities of up to 370 Watts per square centimeter with water as coolant. This is more than six times beyond the current limits of air-cooling techniques at about 75 Watts per square centimeter. Yet, the system uses much less energy for pumping than other cooling systems do.

Source: IBM


Rank 4 /5 (61 votes)
Tags

Relevant PhysicsForums posts
  • Force free body diagram problem on gym equipment
    created1 hour ago
  • Empirical data regarding shower heads and water
    created9 hours ago
  • feed hold button on CNC lathe
    createdFeb 09, 2012
  • RFAC in Fortran
    createdFeb 09, 2012
  • dynamics 2/32
    createdFeb 08, 2012
  • dynamics
    createdFeb 08, 2012
  • More from Physics Forums - General Engineering

More news stories

Netflix light on flicks as viewers soak up TV shows

Like most fresh faces that arrive in Hollywood, Netflix wanted to be a movie star. But now it's learning what many in Tinseltown have known for decades: Movies are sexy, but the real money is in television.

Technology / Business

created 6 minutes ago | popularity not rated yet | comments 0

Sony's Hirai refuses to abandon dire TV business

Struggling Japanese entertainment giant Sony will not abandon its cash-bleeding television business, its incoming CEO says, but he acknowledges tough decisions lie ahead including over redundancies.

Technology / Business

created 36 minutes ago | popularity not rated yet | comments 0

New error-correcting codes guarantee the fastest possible rate of data transmission

Error-correcting codes are one of the triumphs of the digital age. They’re a way of encoding information so that it can be transmitted across a communication channel — such as an optical fiber o ...

Technology / Computer Sciences

created 3 hours ago | popularity 5 / 5 (3) | comments 2 | with audio podcast

Small modular reactor design could be a 'SUPERSTAR'

(PhysOrg.com) -- Though most of today's nuclear reactors are cooled by water, we've long known that there are alternatives; in fact, the world's first nuclear-powered electricity in 1951 came from a reactor ...

Technology / Energy & Green Tech

created 2 hours ago | popularity 5 / 5 (4) | comments 9 | with audio podcast

Advanced power-grid model finds low-cost, low-carbon future in West

(PhysOrg.com) -- The least expensive way for the Western U.S. to reduce greenhouse gas emissions enough to help prevent the worst consequences of global warming is to replace coal with renewable and other ...

Technology / Energy & Green Tech

created 2 hours ago | popularity 5 / 5 (1) | comments 3 | with audio podcast


Experts reveal how plants don't get sunburn

(PhysOrg.com) -- Experts at the University of Glasgow have discovered how plants survive the harmful rays of the sun.

Fool's gold may prove an unlikely alternative to overexploited catalytic materials

Catalytic materials, which lower the energy barriers for chemical reactions, are used in everything from the commercial production of chemicals to catalytic converters in car engines. However, with current catalytic materials ...

Curry spice component may help slow prostate tumor growth

Curcumin, an active component of the Indian curry spice turmeric, may help slow down tumor growth in castration-resistant prostate cancer patients on androgen deprivation therapy (ADT), a study from researchers ...

Unpicking HIV’s invisibility cloak

Drug researchers hunting for alternative ways to treat human immunodeficiency virus (HIV) infections may soon have a novel target—its camouflage coat. HIV hides inside a cloak unusually rich in a sugar ...

What lies beneath: Mapping hidden nanostructures

The ability to diagnose and predict the properties of materials is vital, particularly in the expanding field of nanotechnology. Electron and atom-probe microscopy can categorize atoms in thin sheets of material, ...

To avoid early labor and delivery, weight and diet changes not the answer

One of the strongest known risk factors for spontaneous or unexpected preterm birth – any birth that occurs before the 37th week of pregnancy, most often without a known cause – is already having had one. For women ...