Net-shape forming process for diamond-copper composites with high thermal conductivity

High volume fraction diamond-copper composites were successfully prepared by the combination of metal injection molding for the preparation of diamond preforms with monosized particles and copper pressure infiltration technique. The effects of major processing parameters on the properties of diamond preforms and diamond-copper composites were investigated. The results show that the optimal conditions are as follows: loading of diamond powder 62%, infiltration temperature 1450 , infiltration pressure 30MPa, holding time 25min. Under the optimal conditions, the diamond-copper composites with diamond volume fraction of 62% can obtain the best performance, with the relative density of 99.7% the thermal conductivity of 530W/(m-K), and the coefficients of thermal expansion from 5.5 ppm/K to 7 ppm/K as the temperature from 50 to 400. All these properties can meet the demands of electronic packaging materials.