This article reported a simple method for preparing diamond/SiC composites by polymer impregnation and pyrolysis (PIP) process, and the advantages of this method were discussed. Only diamond and SiC were contained in the diamond/SiC composite prepared by PIP process, and the diamond particles remained thermally stable up until the pyrolysis temperature was increased to 1600 °C. The pyrolysis temperature has a significant impact on the thermal conductivity and dielectric properties of composites. The thermal conductivity of the composite reaches a maximum value of 63.9 W/mK when the pyrolysis temperature is 1600 °C, and the minimum values of the real and imaginary part of the complex permittivity are 19.5 and 0.77, respectively. The PIP process is a quick and easy method to prepare diamond/SiC composites without needing expensive equipment, and it is of importance for promoting its application in the field of electric packaging substrate.

Diamond reinforced silicon carbide matrix composites (diamond/SiC) with high thermal conductivity were prepared by tape casting combined with Si vapor infiltration for thermal management application. The effects of the mixing mode of bimodal diamond particles on the microstructure, thermal and mechanical properties of the composites were analyzed. The results reveal that the thermal conductivity of composites is affected significantly by mixing mode of diamond. In general, when the content of large diamond remains constant, adding a slight amount of small diamond was found to be effective in improving the thermal conductivity of the composite. However, excess small diamonds added will decrease thermal conductivity due to its high interfacial thermal resistance. The maximum thermal conductivity of obtained diamond/SiC is 469 W/(m K) when 38 vol% large diamond and 4 vol% small diamond were added. Such a result can be attributed to the formation of efficient heat transfer channels within the composite and sound interfacial bonding between diamond and SiC phase. Diamond/SiC with high thermal conductivity are expected to be the next generation of electronic packaging substrate.