Efficient thermal management of high-power electronics via jet-enhanced HU-type manifold microchannel

Abstract

To efficiently remove the increasingly higher heat fluxes from electronic chips, this numerical study presents an embedded single-phase water-cooled heat sink which consists of a microchannel layer and a jet-enhanced HU-type manifold layer. The manifold features two liquid inlet plenums symmetrically positioned on two opposite sides and some outlets arranged in the middle. In order to reduce the average thermal resistance, the fluid impinging velocity is boosted by narrowing the manifold channel inlet. However, narrower inlet also leads to flow maldistribution which increases the maximum thermal resistance. To address this problem, we demonstrate two approaches: either adding a flat plate at the manifold outlet or adjusting the manifold channel walls to form a tapered pathway. Further, the impact of the plenum and manifold channel inlet profiles on fluid flow and heat transfer is investigated. Negligible difference is found between rectangular and trapezoidal plenums. As to the manifold channel inlet, although similar heat transfer performance is obtained with different shapes, the total pressure drop can be substantially different. To reduce the large pressure drop at the inlet, a semicircular or triangular inlet profile is preferred, instead of a rectangular one. Quantitatively, we show that for a 3 × 3 mm2 heated area, our heat sink can dissipate fluxes up to 2000 W cm−2 with a maximum temperature rise of 65 K and a pressure drop below 40 kPa, which represents one of the highest performances and energy efficiencies reported to date.