Preparation Of SiCp/Al Composites And Electronic Device Fabrication

SiC_p/Al composites have become the hotspot of the research of electronic packaging materials due to its low density, high thermal conductivity (TC) and low and adjustable coefficient of thermal expansion (CTE).At present, the methods for fabrication of SiC_p/Al composites are mainly Powder Metallurgy (PM) and Infiltration. However, both of them have limitations. PM has a limitation on SiC content: ex. the content of SiC can't exceed 55vol%, which will restrict the further decline of CTEs; the high temperature during infiltration process results in interface reaction and produce brittle phase which is adverse to the properties of composites. Also, the residual pores and agglomerant exert an influence on TCs of composites.According to the limitations of the above-mentioned methods, Spark Plasma Sintering (SPS) has been applied in the present study.Firstly, we considered the feasibility of this method to fabricate SiC_p/Al composites with low content of SiC particles, and primarily explored the effects of temperature, pressure and heating-rate on the fabrication.As our method was similar to traditional powder metallurgy, how to improve the SiC content was still a key problem. In order to overcome it, particle-match method was introduced, and proper proportion among the various particles size was found out. As a result, 65vol% SiC_p/Al composites with 99% relative density were successfully obtained. The test of thermal properties showed that TCs in our study were all higher than 200w/m.K which was well match the demand of electronic packaging materials. But CTEs were a little higher than those samples of other methods. Meanwhile, we had found that the large size SiC particles played a more important role in the decline of CTEs than the small ones. TCs increased with the increasing of the size of SiC particles, but the fracture strength were a little lower compared with other methods which may be attributed to the large size of the SiC particles.What's more, to decline CTEs, we brought in Si -as additive. By adjusting of...