Thermal management system for high, dense, and compact power electronics

Modern microelectronics requires more sophisticated and uniform thermal management practices to sustain the device's reliability and performance. The current work reports a new heat sink configuration that manipulates the heat by dividing the microchannel heat sink into four distinct symmetrical areas and multi-bifurcation channels. Additionally, cutting-edge carbon-based thermal interface materials (TIM) with high thermal conductivity anisotropy were applied. Two inlet and outlet cases (In case 1, the channel width is decreased with the flow stream and versa; in Case 2) were studied for water and Ethanol. Computational Fluid Dynamics (CFD) modeling and experimental setup were conducted to investigate the proposed heat sink. A multi-objective genetic algorithm and new user-defined functions (UDF) are utilized to determine the TIM's optimum thermal conductivity anisotropy values. The results show that the numerical and experimental results match with an average deviation less than 1% under the same conditions. Furthermore, the heat sink's geometry significantly influenced the device's non-uniformity. Comparing Case 1 to Case 2, at the highest flow rate, Case 1 showed 55% and 42% better uniform cooling for Ethanol and water, respectively. Water showed about 3% enhancement on the average wall temperature for both Case1 and 2. However, Ethanol offered better temperature uniformity, where the moderate enhancement in temperature uniformity was about 3.6% in Case 1 compared to water. Involving the TIM broke up any potential for creating local hotspots. Finally, the optimization shows that the optimum in-plane and through-plane thermal conductivity values were about 1170 W/m k and 1 W/m k, respectively.