극저온 마이크로 핀 휜 히트싱크 설계 및 열성능 평가

Abstract

Nowadays, electronic devices play a significant role in interconnecting through digitization and are rapidly advancing in various industry fields. The desire for more powerful computational performance has led to the miniaturization of electronics; consequently, this generates more heat. Conventional cooling solutions, such as air and water cooling, are insufficient for the thermal management of high- power electronics. Hence, a more efficient cooling solution should be proposed for the reliability of devices. This study explored several correlations for two-phase flow boiling in tubes and micro pin fin heat sinks. Experimental results were compared with correlation results for cryogenic flow boiling conditions. This study also conducted a comparative analysis of the thermal performance of micro pin fin heat sinks under different working fluid conditions, specifically water and liquid nitrogen. It was observed that liquid nitrogen flow boiling has better thermal performance than water flow boiling. Finally, the previous study for micro gap and micro pin fin cooler was compared with experimental results to analyze differences. Proposed micro pin fin heat sinks were configured in a staggered circular pin fins array to explore differences with a previous study, and they were manufactured using a silicon wafer with MEMS. The deposited film heater was employed to reduce contact resistance between the micro pin fin array and the heater. The test rig for evaluating thermal performance was designed with the intention of accommodating further research. This design has the advantage of facilitating the investigation of thermal performances and parametric effects of micro pin fin heat sinks using the same test rig. Finally, cryogenic thermal performance evaluation was conducted under saturated flow boiling conditions. The results of the evaluation show that the thermal resistance of micro pin fin heat sinks decreases as the heat flux increases at low exit quality. This study is meaningful as it observes the cryogenic thermal performance of staggered micro pin fin heat sinks, serving as a feasibility study. Additionally, it can provide insights for the design of micro pin fin heat sinks and test rigs for future work.