18 August 1997 Computer vision techniques for IC wire-bond height inspection
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Proceedings Volume 3185, Automatic Inspection and Novel Instrumentation; (1997) https://doi.org/10.1117/12.284035
Event: ISMA '97 International Symposium on Microelectronics and Assembly, 1997, Singapore, Singapore
The mechanical integrity of the wire-bond connections in an integrated circuit governs the electrical integrity of the IC chip. Good quality control of bonding operation requires the wire-bond ball size on the aluminum pad of the silicon chip to be within certain specified range of diameters and heights. This paper describes the problems associated with the inspection of wire bonding balls height using 2D images. Two methods of inspecting the bonding ball height were described. The first method uses structure lighting approach to gauge the height and the second method estimates the height by computing the focus indices of a series of the 2D wire-bond images. Fourier energy spectral density of the gradient image is used as a basis for computing the focus index of the image. A simple and effective differential method was used to compute the gradient image. Both methods are able to achieve an accuracy of +/- 1 micrometers for wire- bond ball height measurement.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Liang Mong Koh, Liang Mong Koh, Han-Ooi Lim, Han-Ooi Lim, } "Computer vision techniques for IC wire-bond height inspection", Proc. SPIE 3185, Automatic Inspection and Novel Instrumentation, (18 August 1997); doi: 10.1117/12.284035; https://doi.org/10.1117/12.284035


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