Transient Active Cooling of Microscale Hot Spots Using Thermoelectric Devices

Thermal management of microprocessors suffers from transient local hot spot induced by circuits such as clock generator. Embedded thermoelectric devices (TEDs) are promising to remove heat from local hot spots with passive cooling by the Fourier law and active cooling by thermoelectric effect with transient electrical power supplied. In this work, we introduce an analytical model to describe the temperature response of a periodically heated hot spot, which is actively cooled by a thermoelectric cooler operating at the same frequency. The analytical result is experimentally validated with frequency domain thermal reflectance (FDTR) measurements made directly on an actively cooled Si TED where the transient local hot spot is replicated by laser. We further demonstrate a practical and energy efficient method to actively cancel the TED’s surface temperature variations based on our model’s analytical result. We then apply this method to cancel the transient temperature variation of 2.35 ± 0.26K at 10 kHz on the Si TED’s hot side surface. Our model’s result and the active cooling method is promising for analysis and optimization of cooling systems for transient localized hot spots in integrated circuits.