Instrumentation of vibration distribution along capillary for wire bonder based on new SM-LD vibration measurement method

A new optical vibrometer employing a self-mixing laser diode (SM-LD) is described, which can measure a vibration amplitude less than a half of optical wavelength 785 nm. An ultrasonic vibration distribution ranging 20-200 nm/sub p-p/ is measured along a capillary for wire bonder. The proposed SM-LD vibrometer has a fair accuracy 4.5% to detect an abnormal vibration of the capillary.