Influence of wire deformation behavior on bondability

Investigation on Cu wire stitch bonding (Report 2)

Abstract

For the direct bonding between Cu wire and Cu alloy lead frame, the wire deformation behavior and the temperature rise at the interface between a wire and a lead terminal are very significant. In this report, the operation of the load on the bondability and the correlation between the wire deformation behavior and bondability are clarified. The wire deformation is controlled by load control, and the plastic flow and the temperature rise at the interface are depended by the equilibrium of the load and the ultrasonic vibration. By setting the higher value of the initial load, the working load can be settled the smaller value, and so the wire deformation becomes smaller and bondability is superior than that in bonding by applying the constant load.