Microstructure, Mechanical and High-Temperature Electrical Properties of Cyanide-Free Au-Coated Ag Wire (ACA)

Abstract

An efficient and environmental-friendly method, featuring a cyanide-free plating process was established for Au-coated Ag wire (ACA). This new Ag wires can meet the reliability standards of wire bonding. The proposed ACA wire was studied to ensure compatibility with electrical properties; mechanical properties and free air ball characterization. Tensile tests showed that ACA wire was stronger than pure Ag wire. The Au coated layer has excellent an bonded interface with the Ag wire. Electrical properties at high temperature demonstrate that the ACA wire maintains outstanding electrical resistance. Further, the Au layer coating the Ag prevents wire oxidation and corrosion during the packaging process. ACA wire formed by the cyanide-free plating method can be used for IC and LED packaging processes.