Fabrication of liquid metal/diamond hybrid thermal interface materials with high thermal conductivity and low flowability

In this work, liquid metal-based hybrid thermal interface materials were fabricated using chromium-coated diamond particles (CCDPs) and eutectic gallium-indium-tin low melting temperature alloy (EGa-In-Sn LMTA), and the changes in material thermal conductivity and viscosity with the volume mixing ratio of liquid metal and diamond were investigated. The thermal conductivity of TIMs shows a bell-shaped trend of first increasing and then decreasing with the increase of CCDP content, reaching the highest value of 126 & PLUSMN; 6 W/m & BULL;K at a 50% CCDP volume mixing ratio. When the CCDP content reaches the critical value (40%), the CCDPs formed a chain-like structure connected by LMTA, greatly enhancing heat transfer. The flowability of the LMTA/CCDP composite TIMs shows a decreasing trend with the increase of diamond content. The formation of liquid bridges and the presence of capillary forces cause the TIM to exhibit different flow characteristics from liquid to solid states.