DocumentCode :
2598080
Title :
Improved monitoring of ultrasonic wire bonding via input electrical impedance
Author :
Zhang, Dong ; Ling, Shih-Fu ; Yi, Sung ; Foo, Say Wee
Author_Institution :
Sch. of Mech. & Production Eng., Nanyang Technol. Univ.
fYear :
2004
fDate :
8-10 Dec. 2004
Firstpage :
359
Lastpage :
363
Abstract :
The technology of using input electrical impedance to monitor a process of ultrasonic wire bonding has existed for a few decades. From literature it is seen that the waveforms of "impedance" in these methods were detected only approximately and much information was missing. In this paper, the method of detecting electrical impedance is improved so that the true waveforms of both the real and imaginary part of the input impedance of a wire bonder are detected and used to monitor bond quality and machine operation condition in-situ and real-time. In order to automate the monitoring, 25 features of the waveforms were selected and fed into a 3 layer back propagation artificial neural network which provides condition indicators after proper training. Since the input impedance characterizes the behavior of a dynamic system completely, once accurate measurement is made, it allows accurate prediction of bond strength. Comparison with results obtained from off-line standard shear tests well demonstrates this capability. When trained to identify operation conditions, the proposed system also identifies the drifting of operation parameters quite accurately
Keywords :
backpropagation; electric impedance measurement; lead bonding; process monitoring; ultrasonic bonding; back propagation artificial neural network; bond quality; bond strength; condition indicators; input electrical impedance; machine operation condition; process monitoring; shear tests; ultrasonic wire bonding; Bonding forces; Bonding processes; Computerized monitoring; Condition monitoring; Electric variables measurement; Impedance measurement; Phase locked loops; Piezoelectric materials; Voltage; Wire;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electronics Packaging Technology Conference, 2004. EPTC 2004. Proceedings of 6th
Conference_Location :
Singapore
Print_ISBN :
0-7803-8821-6
Type :
conf
DOI :
10.1109/EPTC.2004.1396634
Filename :
1396634
Link To Document :
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