Joint Strength of Transient Liquid Phase Bonding Using Cu-SAC Molded Sheet

This paper describes a transient liquid phase (TLP) bonding technology using a Cu-SAC molded sheet fabricated by uniaxial pressing for a mixture of Cu and SAC particles for power semiconductors die attach applications. The Cu-SAC molded sheet had little internal voids with a smooth surface. This Cu-SAC molded sheet was utilized for TLP bonding process in a formic acid atmosphere at 300°C with a bonding pressure of 5 MPa for 20 min. A microstructure composed of Cu particles connected by intermetallic compounds, Cu <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Sn, was observed. The average shear strength was 50.5 MPa. The Cu-SAC molded sheet showed its potential as a high-temperature die attach material.