[MICRO] On-demand Mobile CPU Cooling with Thin-Film Thermoelectric Arr…

​Abstract​

On-demand cooling is inevitable to maximize the processor’s performance, while fulfilling thermal constraints - this holds more in advanced technologies, where localized hotspots change during run-time. In this work, we propose to adopt an array of thin-film thermoelectric (TE) devices, that is integrated within the chip packaging, for both cooling and energy-harvesting purposes. Each TE-device within the array can be during the run-time enabled either for energy harvesting or on-demand cooling. Our approach is implemented and evaluated using a mature Finite Elements Analysis (FEA) tool in which a commercial multi-core mobile chip is modeled after careful calibrations together with state-of-the-art TE-devices. Results demonstrate that our approach reduces the peak temperature by up to 24 ◦C and the average temperature by 10 ◦C across various benchmarks with the cost of 67.5 mW. Additionally, the harvested energy from the array of TE-devices compensates for 89% of the required cooling energy.