Study of the hot-pressing sintering process of diamond/copper composites and their thermal conductivity

Abstract

Diamond/copper composites have been widely studied as high thermal conductivity (TC) materials for heat dissipation in electronic integrated devices. In this study, diamond/copper composites with fin structures were prepared by hot-pressing sintering. The relative density and TC of the composites were analyzed for different diamond particle sizes, diamond volume fractions, sintering temperatures and sintering pressures. The relative density of the composites decreases significantly with increasing diamond particle size and volume fraction. The TC of the composite was found to be a maximum of 564.2 W/m·K at 1400 N sintering pressure and 900 °C sintering temperature when the diamond particle size was 230 µm and the volume fraction was 60%. In addition, the coefficient of thermal expansion (CTE) of the diamond/copper composite was 7.01 × 10−6 K−1 at 1400 N sintering pressure and 900 °C sintering temperature, which meets the packaging requirements for electronic integrated devices. The heat dissipation experiment of the diamond/Cu microchannel heat sink (MCHS) showed that the surface temperature of the heat source can be controlled at 59.9 °C when the inlet velocity was 0.4 m/s, achieving a cooling of 40.1 °C.