High heat flux, single-phase microchannel cooling

Microchannel heat sinks are a relevant thermal management technology because the combination of surface area enhancement and small length scales results in low thermal resistance. Previously, a thermal resistance of 0.09°C/W was achieved when a heat flux of 790 W/cm² was imposed on a 1 cm × 1 cm footprint portion of a 400 μm-thick Si test specimen utilizing single-phase microchannel cooling. Water was driven through the assembly with a 214 kPa pressure difference [1]. Under the same constraints, we report experimental results in which a heat flux of 1002 W/cm² and thermal resistance of 0.071°C/W have been achieved when water was the coolant. Preliminary results with a liquid metal minichannel heat sink are also reported and suggest that thermal resistances as low as 0.45°C/W may be achieved under the same constraints.