White Paper
Processing and Reliability Issues for Eutectic AuSn Solder Joints
By Dr. John C. McNulty
Eutectic AuSn solder is increasingly used in high reliability and/or high temperature applications where conventional SnPb and Pb-free solders exhibit insufficient strength, creep resistance, and other issues. These applications include hybrid microelectronics (particularly flip chips), microelectromechanical systems (MEMS), optical switches, LEDs, laser diodes, radiofrequency (RF) devices, and hermetic packaging for commercial, industrial, military, and telecommunications applications. For most of these applications, AuSn provides the additional benefit of not requiring flux during reflow, significantly reducing the potential for contamination and pad corrosion.