Concept and Analytical analysis of Silicon micro/nanopillars based 3-D stacked microchannel heat sink for advanced heat dissipation applications

In this paper, a concept of silicon micro/nanopillars based multilayer water cooled heat sink is presented. Heat dissipation rate of electronic devices can be significantly improved by the silicon micro/nanopillars, which are grown in the microchannels by utilizing the micromasking effect in deep reactive ion etching (DRIE). Due to the smaller diameter (0.5-2 mum) and larger height (~80 mum), the surface area of these silicon pillars is very high, which results in enhanced convective heat transfer rate, and thus improves thermal performance. Effects of etching mask type, mask thickness, platen power and substrate temperature on controlling the physical dimensions and the density of silicon pillars are presented. An analytical resistive network is presented to compare the heat dissipation characteristics of the heat sink, with and without the silicon pillars. This analytical analysis of this heat sink shows that the heat dissipation rate of the heat sink with silicon pillars can be increased by 22% as compared to one without silicon pillars. The effects of pillar diameter, height, and pillar density, on overall thermal resistance and the heat dissipation rate are also shown.