Surface-ModifiedInVGr as a Thermal Interface Materialwith High Thermal Conductivity and Low Contact Thermal Resistance

Highly efficient thermal interface materials (TIMs) play an essential role for integrated devices and systems of high energy density such as AI and power semiconductor chips. Conventional polymer-based composite TIMs that have low thermal conductivity and large contact thermal resistance do not meet heat dissipation needs of rapidly developing modern high-power electronics. In this work, we report an indium/vertical graphite (InVGr) composite material, which exhibits thermal conductivity as high as 220.2 W/m·K. Moreover, by employing low-melting-point InBiSn liquid metal (LM) for contact surface optimization, the contact thermal resistance was reduced to 0.09 cm²·K/W under a pressure of 100 psi. Practical heat dissipation experiments demonstrate that with the LM/InVGr/LM composite, the heat source temperature was drastically decreased from 113.3 °C (when using commercial silicone pad SF 600G, 8 W/m·K) to 55.5 °C. Equivalent heat transfer coefficient analysis demonstrates that the cooling efficiency of LM/InVGr/LM outperforms those of commercial silicone pads and carbon fiber pads. These findings confirm that the surface-modified InVGr serves as a novel solution for the effective thermal management of state-of-the-art high-power electronic devices.