| 摘要 |
PURPOSE:To decrease the number of times of erroneous detection by designating the terminal part of chip parts and the pad part of a printed circuit board as a check objective area with a compound mask pattern, comparing and collating obtained picture data with an error pattern decided beforehand, and recognizing a defect. CONSTITUTION:A figure shows a condition in which chip parts 3 are mounted at a pad part 5 on the printed circuit board, and the oblique line part of the figure is a check objective area 1. These oblique line parts are set by a program with the use of the compound mask pattern. In the figure, when the chip parts exceed a misregistration tolerance limit 2, they are regarded as the defects by the compound mask pattern. At the time of the lack of an article, since the picture data of a terminal part 4 of the chip parts image-picked-up by a television camera are omitted, they are recognized as the defects by the compound mask pattern in the same way. Thus, by limiting the check objective area 1 to the terminal part 4 of the chip parts 3 and to the pad part 5 of the printed circuit board, the number of times of erroneous detection can be decreased. |
