Low-Cost Energy-Efficient On-Chip Hotspot Targeted Microjet Cooling for High- Power Electronics

This article presents the design, fabrication, experimental characterization, and modeling analysis of the chip-level hotspot targeted liquid impingement jet cooling for high-power electronics. The hotspot targeted jet impingement cooling concept is successfully demonstrated with a chip-level jet impingement cooler with a 1-mm nozzle pitch and 300-μm nozzle diameter fabricated using high-resolution stereolithography (additive manufacturing). The computational fluid dynamics (CFD) modeling and experimental analysis show that the improved hotspot targeted cooler design with fully open outlets can reduce the on-chip temperature difference by 70% compared with the full array cooler at the same pumping power of 0.03 W. The local heat transfer coefficient can achieve 15 × 104W/m2K with a local flow rate per nozzle of 40 mL/min, requiring a pump power of 0.6 W. The benchmarking study proves that the hotspot targeted cooling is much more energy-efficient than uniform array cooling, with lower temperature difference and lower pump power.