Ultrasonic bonding method controlled by the characteristic waveform of ultrasonic propagation

The vibration propagated in polymer components is related to the interfacial fusion in ultrasonic bonding process, which can be employed to be reference variables to control the ultrasonic energy. In this paper, an ultrasonic precise bonding method controlled by characteristic waveform from the wavelet decomposition of the ultrasonic propagation is proposed. The vibration propagated from ultrasonic horn, through polymer components, to the anvil finally is analysed by wavelet packet decomposition. The node signal in the frequency band of 109,375-125,000 Hz, which contains more information related to the interfacial fusion behaviour, is reconstructed as the characteristic waveform. The ultrasonic bonding control procedure is designed by the recognition of two characteristic points on the characteristic waveform. Results indicate that, at the second characteristic point, high-quality interfacial fusion bonding is achieved without overflow out of the edge.