Numerical Analysis of Deformation and Thermal Behavior during Ultrasonic Al Ribbon Bonding

Ultrasonic bonding process for wiring an Al ribbon to electric pads on substrate is affected by ribbon deformation and thermal behavior, i.e., (temperature rise of the materials during bonding). In the present study, the deformation and thermal behavior are analyzed. Numerical simulations of temperature rise and the deformation of the ribbon (wiring materials) were carried out by finite difference and element methods, respectively. As a result, the temperature rise and deformation processes were visualized by graphic images. It was suggested that the temperature of ribbon rose up to greater than 373 K during bonding. The ribbon deformation and the frictional slip behaviors influenced each other. Ultrasonic vibration enhances the equivalent stress in the Al ribbon very largely.