Multi-layered SiC microchannel heat sinks - modeling and experiment

Abstract

This work describes the heat transfer in a novel class of multi-layered microchannel heat sinks manufactured from SiC using an extrusion freeform fabrication (EFF) technique. EFF permits the fabrication of geometrically complex, three-dimensional structures in non-traditional materials. In this paper, experimental data is compared with a closed-form analytical solution for single and multi-layered channels. It is found that multi-layer heat sinks have lower thermal resistance compared to single layer samples, and this improvement in performance increases with thermal conductivity of the heat sink material. Additionally, for fixed overall flow rate, increasing the number of layers has the benefit of reducing the overall pressure drop, despite the reduction in the per-channel flow rate. The analytical solution shows that unit thermal resistance R" (/spl deg/C/(W/cm/sup 2/)) of order 0.05 can be achieved with two layers of channels with diameter of order 100 /spl mu/m.