Effect of the secondary microcontact state induced by the all-factor thermal effect on bidirectional thermal contact performance

Abstract

Contact interfaces are widespread in electronic systems, and the heat dissipation problem caused by the thermal contact resistance (TCR) has seriously affected the overall performance. Previous studies often disregarded the effect of the secondary microcontact state induced by thermal effects such as thermal stress and thermal softening on thermal contact performance, such as TCR, contact interface temperature distribution nonuniformity (CITDN), and the thermal rectification effect. Therefore, this paper proposes a thermomechanical coupled numerical model that considers the secondary microcontact state induced by all-factor thermal effects, and the effect of the thermal effect on bidirectional thermal contact performance under different temperatures, thermal expansion coefficients and constraints is revealed. Furthermore, a method to control the thermal rectification coefficient by controlling the contact gap was proposed. The results show that the influence of thermal effects on TCR and CITDN at high temperatures, with high thermal expansion coefficients and under strong constraint conditions cannot be disregarded and that the influence of temperature and thermal expansion coefficient on the strong constraint side is greater than that on the weak constraint side. The thermal rectification effect is effectively enhanced by adjusting the initial contact gap determined by the thermal expansion coefficient, elastic modulus and temperature.