Toward extremely low thermal resistance with extremely low pumping power consumption for ultra-high heat flux removal on chip size scale

As artificial intelligence grows, electronic devices are constantly being upgraded to improve performance to meet the surging demand in data computation. Efficient thermal management is critical to ensure devices operate stably. Manifold microchannels are used extensively as an excellent method of high heat flux cooling with low pumping power consumption. In this study, porous microchannel heat sinks with different manifold covers, named MMC-1 (50 % covering area) and MMC-2 (80 % covering area), were proposed for large-area heat flux removal to examine the influence of manifold covers on thermal performance and pumping power consumption. The inner wall surface of the manifold microchannel heat sinks was sintered with 1 μm copper powder to promote the occurrence of coolant nucleate boiling and enhance turbulent heat transfer. Water, HFE-7100, and a non-azeotropic immiscible binary mixture (HFE-7100/water) were compared as coolant in the manifold microchannel heat sinks, respectively. The flow rates were ranged from 50 to 150 L/h, and the total heat loads ranged from 250 to 2000 W over 5 cm2 heating area. The results showed that the thermal performance of MMC-2 was superior to that of MMC-1, which suggested that the larger manifold covering area will enhance heat transfer but also increase pressure loss. The MMC-2 heat sink can dissipating heat load up to 1700 W from 5 cm2 heating area (corresponding to q = 360 W/cm2) while maintaining the chip junction temperature Ths below 85 °C with an extremely low pumping power below 0.32 W, which indicating a coefficient of performance as high as 5695.