Characterization on the performance of a fractal-shaped microchannel network for microelectronic cooling

Abstract

Previous theoretical and analytical studies have shown that microchannel heat sinks with a fractal-shaped network have many advantages over traditional parallel microchannels with respect to thermal resistance, temperature uniformity and pressure drop. However, to the best knowledge of the authors, no experimental investigations on fractal-shaped microchannel network heat sinks have been conducted so far to verify their performance. In this paper, we designed and fabricated a silicon-based microchannel heat sink with a single-layered fractal-shaped microchannel network using MEMS technology, and experimentally studied its pressure drop and thermal resistance characteristics under different mass flow rate and heat flux conditions. Numerical simulations are performed to predict the heat sink performance under the same experimental conditions. It is found that the experimentally measured pressure drop in the heat sink has a nonlinear relationship with the mass flow rate, which agrees very well with the numerical simulation result. It is also found that the experimentally measured thermal resistance is also in reasonably good agreement with the numerical simulation, and therefore indirectly verifies the conclusion of previous numerical simulations that the performance of the fractal-shaped microchannel network is better than that of traditional parallel microchannels.