Cooler on a Chip

As computer chips become faster and smaller, they also get hotter, and the fans used to cool PCs and keep their chips from slowing or failing can’t keep up.

To solve this problem, Thar Technologies in Pittsburgh, PA, has developed a microrefrigeration system that uses carbon dioxide to rapidly and effectively cool chips.

Thar’s key innovation is a microcompressor only 1.25 centimeters by 5 centimeters by 5 centimeters that compresses gaseous carbon dioxide into a “supercritical” state, where its properties hover between those of a liquid and a gas.

The system cools the carbon dioxide through expansion and pipes it through an ultrathin heat exchanger. Just 125 micrometers thick, the exchanger sits directly on the microchip, drawing heat through the chip’s packaging and cooling the electronics inside. This converts the carbon dioxide back into a gas; the gas is recirculated to the microcompressor, and the heat bleeds off by convection in a second heat exchanger.

Lalit Chordia, Thar’s founder and CEO, says the system can cool chips to lower temperatures than other technologies that use water or liquid metal; these lower temperatures translate into longer chip life.

And the system is small enough to be used not only in desktop computers but also in laptops.

Thar is now working to scale up manufacturing to produce the microrefrigerators reliably and cheaply enough for the computing industry.