Optics: measuring and testing – By configuration comparison – With photosensitive film or plate
Patent
1991-11-22
1993-05-18
Rosenberger, Richard A.
Optics: measuring and testing
By configuration comparison
With photosensitive film or plate
G01B 1106
Patent
active
052125408
ABSTRACT:
The invention relates to a method for measuring a thickness of a printed circuit board having a plating portion provided on a core portion. The method includes directing a laser beam to the core portion of the printed circuit board, whereby the laser beam at least partially reflects from the core portion. The reflected laser beam is monitored and a thickness of the core portion is determined based upon the reflected laser beam. The plating portion of the printed circuit board is then heated by transferring a selected amount of energy thereto. The thermal characteristics of the heated plating are monitored and a thickness of the plating portion is determined based upon these thermal characteristics.
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Micro)n Technology, Inc.
Pham Hoa Q.
Rosenberger Richard A.
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