18 September 1996 Time-averaged speckle-interferometry for investigation and optimizing for electronic bond tools
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Proceedings Volume 2782, Optical Inspection and Micromeasurements; (1996) https://doi.org/10.1117/12.250802
Event: Lasers, Optics, and Vision for Productivity in Manufacturing I, 1996, Besancon, France
For the purpose of investigation and optimizing of micro- mechanical and harmonic vibrating devices a measuring setup was developed. The goal was to determine vibrational mode structures as well as the magnitude of the amplitudes in dependence on the surface position at the observed object. Frequencies up to 100 kHz cause typical low amplitudes in the order of microns. To prevent any influence of the measurement on the vibration an interferometric system with a rough, speckled object wave seemed to be appropriate. A number of phase-shifted and -modulated speckle- interferograms are detected with a CCD-camera, digitized and transferred to a computer. A suitable algorithm compensates phase fluctuations partially occurring between the image snaps and calculates the amplitudes. To assess the errors investigations of the setup and algorithm used were carried out. It was found that a part from speckle noise mainly the low dynamics and noise of the CCD-camera limit the accuracy to about 0.5 percent of peak-amplitude. The setup was used to analyze the electronic ultrasonic bonding. The measured amplitude distributions of the bond-tool showed a high sensitivity in the clamp-in-conditions and were the base for a statement of an optimized clamp-in-length and a new developed tool.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Volker Kirschner, Wolfgang Schreiber, Gunther Notni, Richard M. Kowarschik, "Time-averaged speckle-interferometry for investigation and optimizing for electronic bond tools", Proc. SPIE 2782, Optical Inspection and Micromeasurements, (18 September 1996); doi: 10.1117/12.250802; https://doi.org/10.1117/12.250802

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