In this study, interfacial feature and bonding strength of ultrasonic bonded Al-Cu joints was investigated. A pure aluminum A1050-H24 and an oxygen-free copper C1020 were used. These dimensions were the width of 9mm, the length of 30mm and the thickness of 1mm. Several kinds of Al-Cu joints were produced using an ultrasonic metal bonder with different bonding condition, such as the order of laminating Al and Cu, and the indentation of the horn. The bonding strength by the peer testing, the cross-sectional microstructures and the interfacial features exposed by the chemical treatment were investigated. It was found that the bonding state differs depending on the position at the interface.
