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Apparatus-for-checking-patterns-on-printed-circuit-boards

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Apparatus for checking patterns on printed circuit boards

Details

Inventors: Sase, Akira; Nagata, Takeo; Fukunaga, Masao; Sakurai, Yutaka; Satomi, deceased, Yoshikatsu;
Assignee: Hitachi, Ltd. (Tokyo, JP)
Primary Examiner: Britton; Howard W.
Assistant Examiner:
Attorney, Agent or Firm: Antonelli, Terry & Wands

In an apparatus for checking patterns on printed circuit boards by comparing two patterns formed on two printed circuit boards, registration patterns each including orthogonal straight line segments and respectively formed on the two printed circuit boards are imaged by two imagers, and registration images from the imagers are matched by means of a registration unit to accurately match an image of a pattern to be checked on one printed circuit board with an image of a reference pattern on the other printed circuit board.

DETAILED DESCRIPTION An object of this invention is to provide an apparatus for checking patterns formed on printed circuit boards which can accurately match an image of a pattern on a printed circuit board with an image of a corresponding pattern on another printed circuit board which is compared to the former board.
This invention is grounded on the fact that if patterns on respective printed circuit boards are of a two-dimensional pattern which has orthogonal straight line portions, images of the patterns can be matched accurately by utilizing these orthogonal straight line portions.
Thus, in a pattern checking apparatus according to the invention, registration patterns each including orthogonal straight line segments and respectively formed on two printed circuit boards compared to each other are imaged by two imagers, and registration images from the imagers are matched by means of a registration unit to accurately match an image of a pattern to be checked on one printed circuit board with an image of a reference pattern on the other printed circuit board, thereby making it possible to accurately compare the pattern to be checked with the reference pattern.

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