X-bit labs

New Chip-Cooling Technology Promises a Revolution.

Category: Coolers

by Ilya Gavrichenkov

[ 08/15/2007 | 02:13 PM ]

The Purdue University researchers, in work funded by Intel, have shown that the technology increased the "heat-transfer coefficient," which describes the cooling rate, by as much as 250 percent. Other experimental technologies that may be applied to cool down future chips promise only 40%-50% cooling efficiency improvement.  When used in combination with a conventional fan, the experimental device enhanced the fan's effectiveness by increasing airflow to the surface of a mock computer chip. The new technology could help engineers design thinner laptop computers that run cooler than today's machines.

The experimental cooling device, which was fabricated on top of a mock computer chip, works by generating ions - or electrically charged atoms - using electrodes placed near one another. The device contained a positively charged wire, or anode, and negatively charged electrodes, called cathodes. The anode was positioned about 10 millimeters above the cathodes. When voltage was passed through the device, the negatively charged electrodes discharged electrons toward the positively charged anode. Along the way, the electrons collided with air molecules, producing positively charged ions, which were then attracted back toward the negatively charged electrodes, creating an "ionic wind." This breeze increased the airflow on the surface of the experimental chip.

Conventional cooling technologies are limited by a principle called the "no-slip" effect - as air flows over an object, the air molecules nearest the surface remain stationary. The molecules farther away from the surface move progressively faster. This phenomenon hinders computer cooling because it restricts airflow where it is most needed, directly on the chip's hot surface.

The new approach potentially solves this problem by using the ionic wind effect in combination with a conventional fan to create airflow immediately adjacent to the chip's surface.

The next step in the research will be to reduce the size of components within the device from the scale of millimeters to microns, or millionths of a meter. Miniaturizing the technology will be critical to applying the method to computers and consumer electronics, allowing the device to operate at lower voltage and to cool small hot spots.

The new cooling technology could be introduced in computers within three years if researchers are able to miniaturize it and make the system rugged enough. As the technology is further developed, such cooling devices might be integrated into portable consumer electronics products, including cell phones.