Electronic Packaging Diamond / Copper Composites

With the development of microelectronics and semiconductor, diamond/Cu compsoites as a new generation electronic packaging materials have received more and more attension. Diamond/Cu composites have more outstanding performance than the traditional electronic packaging materials.The have the most development potential to be the new generation electronic packaging. The research of diamond/Cu composite is of great theoretical and practical value.In this experiment, different diamond volume fraction (50vol.%,60vol.%,70 vol.%) of diamond/Cu were prepared by repressing and re-sintering technology of powder metallurgy under the condition of different fabrication process parameters, during the process, the diamond particle size of20μm,40μm,90μm was selected.The relative density of composites were measured and analyzed. The results showed that the relative density of composites elevated with increasing compacting pressure, but over 1500MPa, the compacting pressure didn't have so much influence on the relative density; At 890℃, the relative density of composites reached the maximum. but over 890℃, the relative density of composites began to decreasing with increasing sintering temperature due to the graphitization; Proper longer sintering time could contribute to improve the relative density; The relative density of composites heightened with the increasing of diamond particle size and reduced with the increasing of the volume fraction of diamond.The coefficient of thermal expansion of the composites were tested and analyzed. The study demonstrated that the coefficient of thermal expansion increased with the diamond particle size increased and the volume fraction of diamond reduced. At the same time, the coefficient of thermal expansion of the diamond/Cu composites was theoretical calculated according to the ROM model, Turner model and Kerner model.The thermal conductivityof the composites were tested and analyzed according to theoretical model. The results showed that the thermal conductivity elevated with the increasing of the relative density of composites,diamond particle size; the thermal conductivity decreased with the increasing of the volume fraction of diamond which were opposite to the theoretical calculation by using Geometric average model, Maxwell model and P.G. Klemens model. Due to the lower relaive density, The thermal conductivity of composite perared by the repressing and re-sintering technology was only 62.8 W/(m-K) which had some distance to the reported results of overseas referrence and expected goals.The diamond/Cu composites of 70vol.% diamond were prepared with optimized process, the relative density could be gained as 83% probably. and the coefficient of thermal expansion 6.4～7.5×10-6/K at 100℃.