Wire bonding apparatus

An ultrasonic bonding apparatus including a piezoelectric element which transmit a vibration via the electric strain or magnetic strain effect to a capillary which is mounted to a non-resonant bonding arm, a microcomputer which outputs frequency data and amplitude data and an open-loop control circuit which includes a memory in which output waveform data is stored, a programmable frequency generator which varies the frequency according to the frequency data from the microcomputer and outputs a memory address switching signal, a first D/A converter which determines the amplitude in accordance with the amplitude data from the microcomputer, and a second D/A converter which applies output voltage or current to the piezoelectric element based upon the output waveform data at an address stored in the memory and selected by the address switching signal which is sent from the programmable frequency generator and upon the amplitude determined by the first D/A converter.