| 摘要 |
PURPOSE:To inspect a clearance hole, etc., on an inner layer substrate of a through-hole part of a multi-layered substrate by counting the run length in one-scanning line units after labeling every connection component and detecting the defect based on the summation of the run length. CONSTITUTION:A wiring pattern formed on a substrate 101 is illuminated by a diffusion illuminator 104 and then, a graduation image is formed by an image inputting means 102 provided with a CCD camera, etc. The image is converted to a binary image after comparing with a threshold obtained by a density histogram, etc., by a binarizing means 105 in advance, and labeling processing for assigning different labels to each connection component is performed for the binary image by a labeling means 106. The run length of every connection component is counted in one-scanning line units by a run length counting means 107, and then, the means informs a judging means 112 of the effect. The summation is obtained at every connection component by the means 106 by performing software processing, and then, by comparing it with one or more optional thresholds fixed in advance so as to detect the defect. And in the case of the defect, the means 106 informs the outside of the kind and the coordinate of the defect. |
