Comparative study of Au-Sn and Sn-Ag-Cu as die-attach materials for power electronics applications

A comparative study of Sn–3.0Ag–0.5Cu (SAC305) and Au–20Sn solders as die‐attach materials for high‐temperature power electronic applications was performed. The solid‐state interfacial reactions of SAC305 and Au–20Sn solders with a Ni‐plated Si chip and a direct‐bonded‐copper substrate, as well as the growth of interfacial intermetallic compound layers and interfacial stability, were investigated and compared during aging at 150 and 200 °C for up to 2000 h. The SAC305 solder exhibited a higher interfacial intermetallic compound growth rate and a higher consumption rate of the Ni layer than the Au–20Sn solder. The Au–20Sn solder had a superior interfacial stability for high‐temperature power electronic applications. Copyright © 2016 John Wiley & Sons, Ltd.