The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 08, 1987
Filed:
Dec. 24, 1984
Yasuhiko Hara, Machida, JP;
Koichi Karasaki, Hadano, JP;
Noriaki Ujiie, Katsuta, JP;
Akira Sase, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A pattern detecting apparatus for inspecting a printed wiring board is disclosed in which a fluorescent image formed by the fluorescent light from the substrate of the printed wiring board and an image formed by the reflected light from the wiring pattern of the printed wiring board are both used because a wiring material which is left on an undesired portion of the substrate and has low reflectivity, is detected only at the fluorescent image and a defective portion of the wiring pattern where a surface layer thereof peels off, is detected only at the image formed by the reflected light, the image used for detecting the above defective portion is preferably formed by the reflected infrared light from the wiring pattern for the reason that infrared light is insensitive to a shallow flaw in the surface of the wiring pattern, and the fluorescent image and the infrared image are processed by a detection circuit, and then compared with each other to detect a pattern defect on the basis of a difference between the images thus processed.