New Chip Cooling Technology

by : Pattrick Savarna

According to Moore's law the density of chips in microprocessors keep doubling every two years. With the increasing density and effectiveness of the current chips the amount of heat generated by these chips is also increasing. To cope with the enormous heat, new technologies will be needed in future to cool the that produces much more heat than the current microprocessors.

Such a new technology has been developed at Purdue University that uses "microjets" to deposit liquid into tiny channels. This technology is able to remove five times more heat than other experimental high-performance chip-cooling methods.

The conventional computer chips usually generate about 100 watts per square centimeter. The chips are air-cooled with finned metal plates called heat sinks and often a small . Most of the liquid-cooling techniques are limited to a cooling capacity of about 200 watts per square centimeter. However the new microjet technology is able to cool chips that generate more than 1,000 watts of heat per square centimeter. With its help new doors in the advancement of chips technology can be opened.

This technology is a combination of two cooling methods, the microjets and microchannels, hence called a hybrid system. The microjets cools uniformly because the liquid is supplied in the form of jets everywhere along the length of each channel. It helps to prevent any part of chips from overheating. The coolant is collected at either ends of the channels and is circulated back through the system.

The channels in this cooling system is narrower than a millimeter, or thousandth of a meter wide. They are formed on top of a chip and covered with a metal plate. This metallic plate has tiny holes through which the coolant is pumped in microjets, and then the liquid flows along channels to cool the chip. When the coolant gets heated by the hot chip inside the channels, it bubbles and becomes a vapor, easing the cooling process.

This new technology uses a hydrofluorocarbon as the cooling liquid. It is a dielectric and will not conduct electricity or cause short circuits. However hydroflurocarbons are not very efficient coolants and their heat conductivity is far lower than water. But they avoid electrical short circuits and are environmentally better than other coolants. They have low global-warming effects and are not harmful to the ozone layer in the earth's atmosphere.