| This paper is about the study of aluminum wire bonding machine. Feature of the transducer system when the capillary tightness and the bonding pressure change are analyzed. Based on the normal analysis in time domain, a new time-frequency method was used, the problem of the interface formation is explained with the signal feature. This article's task mainly includes:(1) Builds the basic structures of ultrasonic bonding process monitoring system. Such as monitoring the electrical driving signal, monitoring speed signal, monitoring the bonding pressure and the offline measurement of the bonding quality. The feasibility of monitoring system is validated by experiment.(2) Apply signal-processing means to analysis two experiments include the experiment on bonding pressure and the experiment on capillary tightness. The optimal pressure window and the window for optimal tightness appeared in the experiment are explained and use the basic statistical time-domain methods to interpret the experimental results.(3) With the limitation of the time-domain methods, Imports the time-frequency analysis to analyze the system. Take a contrast of some time-frequency analysis method, the feasibility of the wavelet analysis is proved, Selected the optimal wavelet, and with the characteristics of the bonding system a new method of time- frequency transform is used.(4) Use the new method of time-frequency transform to analysis the bonding system, the characteristics of the current, voltage and the velocity in time-frequency domain is found. The formation of interface in bonding process is analyzed with these characteristics.All the studies could supply some basic technique for the ultrasonic bonding mechanism and the manufacture of the monitoring system for ultrasonic bonding process. |
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