IBM gives chips a cooling rinse

Someday, you may hose off your microprocessor with water to keep it from overheating.

Researchers at IBM's Zurich labs have developed a "chip cap" filled with a network of channels that can help capture the heat generated by microprocessors and other semiconductors and transport it somewhere else. The design of the hierarchical channels was inspired by similar branching systems found in nature, said IBM, which disclosed details about the project at the Power and Cooling for Data Centres Summit taking place in London this week.

So far, the researchers have demonstrated how the cap can help spread thermal grease more evenly. Thermal grease is a particle-filled substance that conducts heat from the chip to another component, called a heat sink. The idea is to make the layer of grease as thin as possible.

But the team also plans to experiment with ways of squirting water through the channels, using a technique called "direct jet impingement." In this system, the squirted water would be prevented from touching the electronics by the channels and be sucked out quickly. Some server chips have included liquid-filled pipes placed near microprocessors to cool off chips.

In initial laboratory tests of the water system, the Zurich team has demonstrated cooling power densities of up to 370 watts per square centimeter. Conventional air cooling technologies are effective on 75-watt surfaces.

Chips generate a lot of heat, and even though semiconductor makers are developing new transistors and other technologies to curb it, temperatures will continue to climb. Every two years, manufacturers increase the number of transistors they can put into chips (and shrink them) through the magic of Moore's Law. Moreover, smaller transistors increase the energy density of the surface of chips.

Hot chips can melt computers, as well as limit the number of servers that can be squeezed into rack or computer room. That increases real estate costs for big server farms. Heat also forces computer owners to invest heavily in energy-sucking air conditioning systems.

IBM estimates that some chips may have energy densities equivalent to the surface of the sun, when left uncooled. That's 6,000 degrees Celsius.

[Commander_Spock]

Why "WATER COOLED"....

... when "AIR COOLING" or some other form of "LIQUID COOLANT" might be even better. With Water - Think about "corrosion"! Now you will see the best of Cammander_Spock! Where "EAGLES" dare!!!

Best Regards.

[Commander_Spock]

Oops!

"Commander" not "C.mmm......

[No_Man]

other coolants

Air cooling is the least efficient means of cooling a surface. Gases in general have an extremely low cooling density, and plain air is useless. Why do you think they use heat sinks on the processor, rather than just sticking a fan on it?

Purified water is actually not all that corrosive when used with the right metals. Many forms of water corrosion are the result of reactions with salts dissolved in the water. Some metals will still oxidize in water regardless, but I suspect they've already considered this and will plan the chip surface accordingly.

Another liquid coolant would be feasible and could be much more effective. However, since we're already talking about a level of cooling that is beyond our current needs, I suspect they're going to go for the simple and cheap solution before looking into a complex and expensive solution that's overkill.

[tonynaz]

Why not use that energy to heat buildings?

There are certainly many out there much smarter than I am, so that is why I?m surprised to see an absence of technologies to redistribute the heat generated by datacenters to things that can use it, such as office buildings. Ok. That doesn?t work well in the summer, but during winter months that could offset gas and electrical costs. What else can we do with this heat? Maybe I?m stretching the concept a little, but why can?t all this heat be somehow channeled to create steam (or something along those lines) to generate power again.

[willdryden]

Water cooling nothing new

Water cooling PCs has been around since the first Pentium processor was intoduced. Instead of the big heat sink, you mount a water jacket on the chip and run it to a radiator mounted on the back of the case. This is good for noise reduction, but more expensive than a good set of ear plugs. The only new thing seams to be that they are putting the water channels IN the chip.