A novel composite pinfin heat sink for hotspot mitigation

Abstract

A power-efficient composite pinfin heat sink has been introduced to mitigate the temperature non-uniformity in a microprocessor with heterogeneous heat flux distribution. The proposed composite design was evaluated numerically, and its performance was compared with a non-composite design. The concept utilizes the difference in thermal conductivities of different metals to develop an efficient cooling solution. The heat sink was divided into two zones (hotspot zone and background zone) according to the heat flux distribution. Copper and aluminum were selected for the hotspot and background zones, respectively. The non-composite heat sink was designed with exactly the same geometric parameters, however, aluminum was used for the background as well as the hotspot zone. Both designs (composite and non-composite) were analyzed at different flow rates and heating conditions. The temperature non-uniformity, temperature rise, thermal resistance, and pumping power were evaluated to compare their thermohydraulic performances. The composite heat sink showed substantial enhancement in the thermal performance without any change in the pumping power.