Analysis of conjugate heat transfer in microchannel heat sinks

Heat transfer in a silicon substrate containing rectangular microchannels is investigated numerically. An exact model for a device that was fabricated using silicon [110] is developed. Equations governing the conservation of mass, momentum, and energy were solved in the fluid region (microchannels). Within the solid wafer, the heat conduction was solved. The effects of channel aspect ratio, Reynolds number, and number of channels on the thermal performance of the device was investigated. It was found that the Nusselt number is more for a system with a larger number of channels and larger Reynolds number. For Re = 673, the optimum channel depth that maximizes Nusselt number occurred at 300 mu m.