The performance test and analysis of silicon-based microchannel heat sink

First, a micro cross flow heat sink made of (110)-orientated silicon is fabricated by bulk micromachining, and wafers with hundreds of high aspect ratio channels are bonded together by diffusion bonding with aluminum as medium layers. The core of the micro heat sink is about 0.918cm(3), and the density of the heat transfer area is 15,294 m(2)/m(3). Using pure water as the working fluid, as the maximum pressure drop reaches 2.47 bar, the flow rate is greater than 4.5 1/min., and that makes the overall heat transfer coefficient up to 24.7 kW/m(2)K, corresponds to a volumetric heat transfer coefficient of 188.5 MW/m(3)K. Second, we fabricate a series of 40 mu m wide and 30 mm long micro channels with different aspect ratio in 12 cm(2) (110) silicon wafer area. The silicon is anodic bonded with #7740 Pyrex glass to form the micro channel structure. Using pure water as the working fluid, hydraulic resistance and thermal performance of the micro channel structure are evaluated experimentally. As the maximum pressure drop reaches 3.3 bar, the flow rate is 0.3 1/min, and that make the heat transfer coefficient up to 32,598 W/m(2)K.