The characteristics of ultrasonic vibration transmission and coupling in bonding technology

Ultrasonic vibration transmission is a very critical and complex problem in bonding equipment. In this paper, the transmitting model of ultrasonic vibration in ultrasonic transducer and capillary have been given out by utilizing the propagating mechanism of ultrasonic wave in elastic body. The ultrasonic vibration displacement and velocity of high frequency were measured by using the laser doppler vibrometer PSV-400-M2(1.5MHz), then the conclusion in theory have been proven. Ultrasonic vibration displacement (or velocity) and energy density increase with decreasing section in the transmitting process. The coupling characteristics of ultrasonic longitudinal-complex transverse vibration system are simulated by Matlab software. Vibration locus shapes driven simultaneously by the same frequency and different frequencies are elliptical (or circular) loci and rectangular (or square) loci respectively. Microstructure characteristics at bonding interface were observed by using scanning electron microscope (KYKY2800), and would be improved by coupling loci, thus bond strength and quality would be enhanced. An advanced bond pattern would be indicated. And we draw some conclusions that have important theoretical and practical significance for further research about thermosonic bond technology.