Scientists say thermoelectric devices could solve overheating problems in shrinking transistors

The electronics industry is facing a new challenge. As the transistors in computer chips shrink, the heat they produce only increases. Overheating can reduce circuit performance, increase leakage power, or even completely damage the transistors.

A team of researchers from the University of Pittsburgh and Carnegie Mellon University have proposed locally embedded thermoelectric devices (TEDs) that can actively cool circuits. The research results are published in the journal Nature communication.

“Circuits such as clock generators and arithmetic and logic units (ALUs) produce high-frequency heat fluxes, and their peak hot spots occur on the microprocessor,” explained Feng Xiong, associate professor of electrical and computer engineering at Pitt’s Swanson School of Engineering. “Chip-sized cooling systems are being redesigned and a more targeted strategy is needed to dissipate heat at these hot spots.”

TED finds a hot spot

The only way to cool an object is to remove heat – or energy – from it. These circuits produce heat at a really high frequency. With TED, these high-frequency temperature fluctuations can be completely eliminated.

TEDs dissipate heat from hot spots inside circuits to colder areas throughout the device by using thermoelectric effects at the same frequency. The researchers proved their theory using experimental data from frequency-domain heat reflectance (FDTR) measurements made directly on an actively cooled thermoelectric device in which a pump laser replicates a transient hot spot. The team used materials with high thermal conductivity, which theoretically improves cooling efficiency by 100 times compared to conventional thermoelectric materials.

“We have demonstrated a practical method to actively eliminate transient temperature changes of circuit components using TED,” Feng said. “This result opens a new path for optimizing cooling system design for transient, localized hot spots in integrated circuits.”