Hotspot thermal management using a microchannel-pinfin hybrid heat sink

An energy-efficient micro heat sink is presented for the thermal management of microprocessors with heterogeneous power distributions. The performance of the proposed microchannel-pinfin hybrid heat sink was evaluated numerically and compared with that of a simple microchannel heat sink. The hybrid heat sink was designed with two separate zones: rectangular microchannels were used over the low-heat-flux zone (background area), and an array of cylindrical pinfins were incorporated over the high-heat-flux zone (hotspot area) of the heat sink. Conjugate heat transfer analysis was performed by solving the three-dimensional Navier-Stokes and energy equations with the temperature-dependent thermophysical properties of the fluid. The thermal resistance, pumping power, temperature non-uniformity, and maximum temperature rise at the hotspot were selected as the performance parameters. The hybrid heat sink exhibited remarkable improvement in the thermal performance compared to the non-hybrid heat sink with a reasonable increase in the pumping power.