An additively manufactured manifold-microchannel heat sink for high-heat flux cooling

Abstract

Active liquid cooling technique with great efficiency not only reduces power consumption but also effectively dissipates high heat flux. In this study, a manifold-microchannel heat sink (MMCHS) was monolithically fabricated by additive manufacturing, and the thermal and hydraulic performance was investigated in a closed loop. Utilizing AlSi10Mg powder, the laser powder bed fusion process was used to fabricate the complex heat sink structure by directly putting a 3D liquid routing manifold structure on a typical microchannel. The MMCHS, with an overall size of 30 × 15 × 9 mm3, can support a heated area of 10 × 10 mm2 and features a tapered structure to facilitate uniform coolant flow. This system contains microchannels with a width and height of 0.2 mm and 2 mm, respectively, with an aspect ratio of AR = 21. Our results show that the MMCHS can dissipate effective heat flux up to 240 W/cm2 with a mass flow rate of 395 g/min with a considerably low-pressure drop of 1.7 kPa and low heated surface temperature of 100 °C. The corresponding total thermal resistance is as low as 0.21 K/W. In addition, numerical simulations showed detailed flow information as well as good agreement with experimental data. Finally, methods for structural improvement of the manifold microchannel were suggested based on the experimental and numerical results.