Thermal conductivity of copper-diamond composite materials produced by electrodeposition and the effect of TiC coatings on diamond particles

Copper matrix composite materials with diamond particles are considered to be among the leading candidates as the heat sink materials for future electronic devices. However, today, these materials are mostly produced by high temperature-high pressure (HTHP) processes, which can be very costly. In order to explore an economically more viable approach of producing copper-diamond composite materials, we used electrodeposition to synthesize such materials and measured their thermal conductivities. The maximum thermal conductivity observed was 454 W/mK at 68.2 vol % diamond. In an attempt to improve the thermal conductivity further, titanium carbide (TiC) coatings were implemented on the diamond particles. The TiC coated diamond particles embedded in the electrodeposited copper matrix improved the thermal conductivity to 557 W/mK at 34.7 vol %, which is similar to 40 % higher than 400 W/mK for pure copper. This value is comparable to currently available commercial HTHP heat sink materials. These results show that there is a potential of using electrodeposition an alternative synthesis method for producing copper-diamond composite materials for thermal managements. However, the formation of the microstructure at different electrodeposition current densities suggests that a careful process optimization is required to obtain a void-free Cu matrix between the embedded diamond particles.