Microstructure, thermo-physical and mechanical properties of spray-deposited Si-30Al alloy for electronic packaging application

In this study, Si-30Al alloy was synthesized by the spray atomization and deposition technique. The microstructure and properties of the alloy were studied using optical microscopy, scanning electron microscopy, coefficient of thermal expansion (CTE) and thermal conductivity (TC) measurements, and 3-point bending tests. It was found that the microstructure of the alloy after hot pressing is composed of a continuous network of globular primary Si and interpenetrating secondary Al-rich phase. The property measurements results indicate that the spray-deposited 70Si30Al alloy has advantageous physical and mechanical characteristics, including low coefficient of thermal expansion (6.8 x 10-6/K), high thermal conductivity (118 W/mK), low density (2.42 g cm-3), high ultimate flexural strength (180 MPa) and Brinell hardness (261)