Mechanical properties of thermosonic thin gold wire bonds

Among advanced chip interconnection technologies, wire bonding is still the most frequently used process. Thermosonic bonding provides a precious, fast, good quality and low heat-effect bonding method. Since the use of hybrid microelectronic circuits expanded, the need for zero-defect and more productive processes has grown. To improve productivity, mainly mechanical improvements of the bonders should be taken to reach higher speed. To avoid failures, head movement at loop formation, cleanliness of bonding pads and gold wire, the effect of heat on the microstructure of the ball bond are the most critical issues. Most frequent failures are detachment, crater formation in the pad, ball bond neck break, bond-to-bond and wire-to-wire shorts. In our research, causes of failures are revealed and methods will be improved to lower failure rates.