Analytical Assessment of the Effect of Thermal Interface Layer Voids on Temperature in Lid-Integral Microchannel Coldplate Cooling

In the thermal management of electronics, the voids in the thermal interface materials (TIMs), especially metal welding, are an important factor affecting the peak temperature of the chip. In this article, a model that can be used to describe the heat conduction of lid-integral microchannel coldplate cooling was proposed. According to the model, an analytical expression for calculating the peak temperature difference is derived based on the analysis of heat conduction characteristics. By comparison with the finite element method (FEM) simulation results and experimental results, the proposed model and analytical expression are proved to be simple, fast, and effective for microchannel coldplate cooling. The effects of material parameters, structural parameters, and void location were studied based on the analytical expression and FEM simulation. Increasing the thermal conductivity and thickness of the chip and the convective heat transfer coefficient of the heat sink or reducing the radius of the void can significantly reduce the peak temperature difference. The variation in chip size, void distance, and chip location does not necessarily affect the peak temperature difference. For the void distribution in the vertical direction of TIM, the temperature difference in through void and bottom void is larger than middle void and top void.