Thermal performance and heat transfer mechanism of EGa-In-Sn/W composite thermal interface materials

Liquid metal-based thermal interface materials (TIMs) have garnered attention in the field of microelectronics due to their flowability and high thermal conductivity. In this study, Composite TIMs were developed using EGa-In-Sn (eutectic gallium-indium-tin) alloy and tungsten particles through a stirred grinding method. The effect of tungsten particle content on the thermal performance of the TIMs was investigated. Finite element analysis was employed to analyze the internal heat transfer behavior. Results demonstrated that the thermal conductivity of the composite TIMs initially increased and then decreased with increasing tungsten particle content, reaching a peak at nearly twice that of EGa-In-Sn alloy. The established two-dimensional model aligned with experimental data, facilitating predictions for the thermal conductivity of composite TIMs. Interconnected tungsten particles formed the primary heat flux channel, while voids impeded the heat flux. Particle spacing, contact mode and void size are the main factors affecting the heat conduction between tungsten particles.