Liquid micro-cooling leads to sixty percent cooler fpga chips

Researchers at the Georgia Institute of Technology have developed a way to cool chips using microfluidics, namely by creating microchannels in the silicon of the fpga chips.

In this way it is possible to cool much more precisely in the places where it is needed. With the application of microfluidics, different chips can also be stacked. By combining the technique with certain connection techniques, it is possible to cool the stacked chips well everywhere. Ultimately, this allows smaller or more integrated circuits to be made that no longer require heat sinks or fans.

The Georgia Tech researchers were able to cool a 28nm fpga chip from Altera to more than sixty percent more than the same chip type in an air-cooled situation. More precisely, the researchers managed to cool the liquid-cooled chip to 24ºC, while the air-cooled version remained at 60ºC under comparable conditions.

To create the system, the researchers removed the heatsink and other heat-dissipating materials from the backs of standard Altera fpga chips. Cooling fluid channels were then etched into the chip, along with silicon cylinders approximately 100 microns in diameter, to improve heat conduction in the fluid. A layer of silicon was then placed over the channels and connections for the supply and discharge tubes were made. Demineralized water was used as coolant.

The test setup used water at about 20 ongeveerC on the inlet side, with a flow rate of 147 milliliters per minute. With this, the researchers managed to keep the chip at 24C. The researchers presented their findings at an IEEE conference under the banner ‘Emerging Technology, Power and Cooling’. A report of their research, which has not yet appeared as a paper, ended up on the Georgia Tec site.

Connection of the coolant supply to the channels etched in the back of the chip. Source: Rob Felt, Georgia Tech