Al-50 wt%Si Alloy by Spark Plasma Sintering (SPS) for Electronic Packaging Materials

A hypereutectic Al-50 wt%Si alloy for electronic packaging was prepared by spark plasma sintering (SPS) technology using gas-atomized Al-50 wt%Si powder. The effect of sintering parameters on alloy phase composition, microstructure, thermal performance and the tensile strength at different temperatures was investigated. The experimental results show that the alloy can obey the diffraction peaks of silicon and aluminum without other peaks appearing. The primary silicon in the prepared alloy can be evenly distributed in the aluminum matrix. The coefficient of thermal expansion (CTE) and thermal conductivity (TC) of the alloy will improve with the increase of sintering temperature, but they will decrease after sintering for a long time, which is caused by the large difference of coefficient of thermal expansion between silicon and aluminum. The tensile properties of the alloy at room temperature will increase with the increase of sintering temperature, but higher test temperatures will inhibit the tensile properties except the elongation. The morphology and fracture mode of the tensile fracture are also analyzed to determine the good bonding strength of the alloy.