Interface regulation of diamond-doped GaInSn composites

Diamond-doped GaInSn thermal interface materials have broad application prospects in the field of electronic thermal management. However, the poor wettability of diamond and liquid metal makes the fabrication of composites through simple mechanical agitation difficult. In this study, the wettability between GaInSn and diamond was improved by reducing the surface tension of liquid metal and improving the anisotropy of the diamond surface. The diamond/liquid metal (Dia/LM) interface structure was regulated by controlling the gallium oxide content. Ga2O3 was enriched in the GaInSn and diamond contact surface, which can reduce the surface tension of the liquid metal, improve the wettability of GaInSn to diamond, produce a mechanical locking force with the diamond surface, strengthen the bonding between the liquid metal and the diamond, and reduce the thermal resistance of the liquid metal/diamond interface. The Dia/LM interface structure was controlled by using crushed diamond. Result shows that the wettability of the surface (111) of the diamond was the best. The (100) and (110) planes with poor wettability were cut by the crushed diamond cleavage step, and the area of the crystal plane with poor wettability was reduced, thus improving the wettability of the liquid metal. The improvement of the crushed diamonds' wettability was verified by molecular dynamics calculation. The composite preparation technology of diamond and the GaInSn liquid metal was optimized, and the high-performance Dia/LM thermal interface material was prepared by ultrasonic-assisted and micro-oxidation methods.