根据超声引线键合实验平台结构,设计PZT(压电陶瓷)驱动信号传感电路,搭建键合力传感系统,集成多普勒振动测试系统,获得键合过程中的换能器驱动电压、电流、劈刀振动和键合压力信号。采用PCI6110数据采集卡,开发基于LabView8.2的采集软件,实现上述4路信号的同步采集、显示、频谱分析和保存。采用小波时频分析方法对电流信号进行分解,发掘电流信号中与键合质量相关联的一些特征。研究结果表明:信号采集系统能高速、同步采集键合过程中的多路信号;电流信号基频的频率、幅值及变化趋势都在一定程度上反映了键合质量;当电流信号频偏离正常值太大、均值太小和变化趋势异常时都表明键合失效。
According to the ultrasonic wire bonding circuit,sensing circuits were designed to detect the piezoelectric transducer(PZT) driver signal,a bonding force sensing system was constructed,and the laser doppler vibration measure system was used to measure the vibration of tool.Four signals,i.e.,driver voltage,current,tool vibration and bonding force during bonding process,were acquired,displayed and saved synchronously with data acquisition card PCI6110,which was programmed by LabView8.2.The current signals were analyzed by using the wavelet time-frequency method.Several characteristics were selected.The results indicate that this system is stable and four signals are acquired effectively at high speed during the bonding process.The frequency,amplitude and change tendency of current signals are related to the bonding quality in a certain extent.The fundamental resonance frequency deviation,very small current and exceptional current changing tendency all mean a failure of bonding.