Dual-layer cylindrical array of pin–fin microchannels with heat dissipation capacity up to 1200 W/cm2

With the advancement of miniaturization and highly integrated microelectronic systems, the increasing heat flux in hotspot areas elevates the risk of thermal failure in chips. In light of this, a novel alternating cylindrical pin–fin array has been embedded in a double-layer cross-flow microchannel heat sink to enhance heat transfer. The research objectives of this study are to ensure that the hotspot temperature does not exceed the safe operating temperature of the chip under high heat flux conditions, while achieving optimal temperature uniformity and minimized pressure drop. To this end, the study first investigates the effects of different boundary conditions on the thermal performance of cross-flow microchannel heat sinks, and compares the heat transfer performance between cylindrical pin–fin microchannel heat sinks and conventional double-layer microchannel heat sinks. The results demonstrate that a cylindrical pin–fin array double-layer cross-flow microchannel heat sink using deionized water as coolant successfully removes a heat flux of 1200 W/cm² from a 2 × 2 mm² hotspot area. Notably, the arrangement of counter-flow in the upper and lower layers resolves the temperature gradient along the flow direction observed in unidirectional flow systems. Compared to co-flow microchannel heat sinks, the cross-flow configuration improves temperature uniformity by 1.15 %, and enhances the heat transfer coefficient to 35.56 kW/m²·K. Furthermore, a strong positive correlation exists between the heat transfer coefficient and Reynolds number. Variations in Re values induce a maximum pressure drop of 6.5 kPa while reducing the total thermal resistance to 0.44 K·cm²/W (conductive resistance: 0.238 K·cm²/W; convective resistance: 0.123 K·cm²/W).