Thermal conductivity of SPS consolidated Cu/diamond composites with Cr-coated diamond particles

Cu/diamond composites have been considered as a next generation of thermal management material for electronic packages and heat sinks applications. The major challenge in the development of these composites is to obtain a well bonded interface between the copper and the diamond. In this study, an effective way to apply a vapor deposited chromium coating onto diamond particles was used to overcome this interface problem. The Cu/diamond composites were produced by spark plasma sintering (SPS) technique. The results showed that the densification, interfacial bonding and thermal conductivity of coated composites were evidently enhanced compared to that of uncoated composites. A maximum thermal conductivity of 284 W/m K, 31% increase with that of uncoated composite was obtained in the coated composite containing 50 vol.% particles sintered at 920 °C. However, the thermal conductivity of coated composites was still far below the theoretical value. The possible reasons for this deviation were discussed and the methods for further improvement in thermal conductivity of Cu/diamond composites were proposed.