Lightweight diamond/Cu interface tuning for outstanding heat conduction

Abstract With rapid developments in the field of very large‐scale integrated circuits, heat dissipation has emerged as a significant factor that restricts the high‐density integration of chips. Due to their high thermal conductivity and low thermal expansion coefficient, diamond/Cu composites have attracted considerable attention as a promising thermal management material. In this study, a surface tungsten carbide gradient layer coating of diamond particles has been realized using comprehensive magnetron sputtering technology and a heat treatment process. Diamond/Cu composites were prepared using high‐temperature and high‐pressure technology. The results show that, by adjusting the heat treatment process, tungsten carbide and di‐tungsten carbide are generated by an in situ reaction at the tungsten–diamond interface, and W–WC–W 2 C gradient layer‐coated diamond particles were obtained. The diamond/Cu composites were sintered by high‐temperature and high‐pressure technology, and the density of surface‐modified diamond/Cu composites was less than 4 g cm −3 . The W–WC–W 2 C@diamond/Cu composites have a thermal diffusivity as high as 331 mm 2 s −1 , and their thermal expansion coefficient is as low as 1.76 × 10 −6 K −1 . The interface coherent structure of the gradient layer‐coated diamond/copper composite can effectively improve the interface heat transport efficiency.