Abstract: A transducer driver signal acquisition system is developed. The voltage and current signal of the transducer are acquired during the ultrasonic heavy aluminum wedge bonding. The input power and output impedance signal are calculated. Under different conditions, 1 000 times bonding tests are carried through, and driver signals are recorded. According to the test results, the time-domain characters of the input power and output signals are proposed, the relationship between bonding strength and the average value of input power or output impedance are obtained. The results show that the bonding strength and input power of transducer system has an obvious relationship like a parabola with downward open side. Phase P1 and P2 are the main phases effecting the bonding strength, and have the same important functions. Although phase P3 has no effect on the bonding strength, its average power indicated the bonding strength in a certain extent. But the relationship between output impedance and bonding strength is not clear, and not fit to indicate bonding strength.

Key words: Input power, Output impedance, Transducer system, Wire bonding