INSPECTION APPARATUS FOR WIRING PATTERN

PURPOSE:To reduce a false report and to inspect a wiring pattern stably by a method wherein the feature of the wiring pattern extracted from a binary-coded image is compared with reference data which has been extracted from a good board in advance. CONSTITUTION:A shading image obtained by sensing 103 the image of a printed-circuit board 101 as an object under test is converted 105 into a binary-coded image. Feature information on a wiring pattern is extracted 106 from a skelton image obtained by processing all picture elements into fine elements, and it is compared 109 with feature information (reference data) extracted 106 from a good board in advance. When they are compared and judged, a first arbitray judgment region is set around a noticeable feature point tn on a board under test. When a feature point rn on the good board does not correspond, the distance sl between the feature point tn and one or more feature points tn-i whose correspondence has been finished is found. A second judgment region is set around the point of the distance sl from a feature point rn-i whose correspondence has been finished, the existence of the corresponding feature point rn is judged, a plurality of existing coordinate points are made to correspond surely, and only an intrinsic flaw is extracted and registered in an information memory 112.