Comparative thermal performance evaluation of graphite/epoxy fin heat sinks

Heat sinks constructed from natural graphite/epoxy composites are a high performance, lightweight alternative to traditional copper and aluminum designs. For applications where the heat source is the same size as the heat sink, laminated graphite/epoxy heat sinks have been shown to perform equivalently to copper heat sinks at a 75% lower weight. However, when the heat source is smaller than the heat sink, laminated graphite/epoxy heat sinks perform poorly. For this situation, a hybrid graphite epoxy heat sink has been developed. This hybrid construction incorporates graphite/epoxy fins bonded to a copper base. This paper examines the thermal performance of this heat sink and includes both computer models and experimental results. The effects of fin material and bonding techniques on thermal performance were examined. An optimized hybrid heatsink was found to have a thermal performance nearly equivalent to that of a copper heat sink combined with a 40% reduction in weight.