Microstructure and properties of Al/Si/SiC composites for electronic packaging

The Al/Si/SiC composites with medium volume fraction for electronic packaging were fabricated by gas pressure infiltration. On the premise of keeping the machinability of the composites, the silicon carbide particles, which have the similar size with silicon particles (average 13 μm), were added to replace silicon particles of same volume fraction, and microstructure and properties of the composites were investigated. The results show that reinforcing particles are distributed uniformly and no apparent pores are observed in the composites. It is also observed that higher thermal conductivity (TC) and flexural strength will be obtained with the addition of SiC particles. Meanwhile, coefficient of thermal expansion (CTE) changes smaller than TC. Models for predicting thermal properties were also discussed. Equivalent effective conductivity (EEC) was proposed to make H-J model suitable for hybrid particles and multimodal particle size distribution.