SILICON PARTICLE REINFORCED ALUMINUM MATRIX COMPOSITES FOR ELECTRONIC PACKAGING

摘要

Liquid phase sintering (LPS) method has been innovated in fabricating Si/Al composites with high volume fraction which have potential applications in thermal management of electronic packaging. Density, microstructure, and coefficient of thermal expansion (CTE) of Si/Al composites effected by the fabricating parameters were examined. The results show that void content of composites decreases with increasing silicon particle size, compacting pressure, and LPS temperature. The 70 Si/30 Al composite with a void content 6 vol.% can be obtained by optimizing the fabricating parameters. Voids in 70 Si/ 30 Al composite resulted from the gas kept inside the compact, but the larger amount of voids in the 80 Si/20 Al and 90 Si/10 Al composites arised from the low packing density of the irregular silicon particles. Metallographic study confirms the typical behavior of LPS in the sintering period. CTE measurement shows that CTEs of the composites are insensitive to the void content and reduced remarkably as silicon volume fraction increases. This demonstrates that CTE could be adjusted to fit the various requirements of electronic packaging.