Optics: measuring and testing – Inspection of flaws or impurities – Having predetermined light transmission regions
Patent
1985-12-27
1987-08-25
Willis, Davis L.
Optics: measuring and testing
Inspection of flaws or impurities
Having predetermined light transmission regions
250562, 250572, 358106, G01N 2188
Patent
active
046889396
ABSTRACT:
Automated inspection of solder bumps (18--18) on a major surface (14) of a chip carrier (10) is accomplished by placing the chip carrier on a platform (22) beneath a ring light (28) which is in registration with a television camera (30). Light from the ring light, which is directed at an angle towards all sides (12--12) of the chip carrier, is only reflected upwardly into the television camera by the solder bumps. The output signal of the television camera, which varies with the intensity of the light reflected from the solder bumps, is processed by a vision system (32) to obtain a one-dimensional plot of the light intensity. The one-dimensional intensity plot is analyzed automatically by the vision system to detect for missing, bridged or excessive solder bumps on the chip carrier.
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AT&T - Technologies, Inc.
Koren Matthew W.
Levy R. B.
Willis Davis L.
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