Vibration Simulation of Transducer System in Thermosonic Wire bonding

The vibration simulation model of transducer system in wire bonding was established by mechanical finite element method and verified by electric sine sweeping exciting method. The results show that, transducer system of wire bonder works with its second combination vibration mode that includes three nodes axial vibration of concentrator and one node radial vibration of capillary. There are many other undesirable modes that may be excited because they are very close to working frequency. These undesirable modes would waste ultrasonic energy and badly influence to bonding quality between gold ball and substrate, so they should be well controlled in bonding. Good agreement between simulation and experimental result was obtained, where the computed error of working frequency is only 1.2%. The research result can be used in performance study and design of an ultrasonic transducer