Abstract
A transverse ultrasonic vibration was employed to bond the Cu flip chip bump with Cu finished glass substrate. This study was focused on the atmospheric pressure plasma treatment conditions on the ultrasonic bonding strength between the Cu bump and Cu finished substrate because the cleanness and roughness of the bonding surface strongly affected the joint integrity. The optimized ultrasonic conditions greatly enhanced the joint strength bonded using ultrasonic energy, while the excessive plasma treatment degraded the joint integrity. In this study, the mechanisms why the joint strength was determined by the treatment conditions were examined and discussed using X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES).
