Patent ID: 7248355

Claim:
A method for locating errors in component placement on a printed circuit board comprising the steps of: utilizing a computer-aided visual inspection machine to determine the placement and orientation of components on the printed circuit board; enhancing contrast of visual images as sensed by the computer-aided visual inspection machine between components and the printed circuit board by disposing special visibility material on the printed circuit board at least in regions surrounding the components; comparing the enhanced contrast visual images of a printed circuit board being evaluated to stored enhanced contrast visual images of a reference printed circuit board having previously determined correct component placement and orientation; generating scores reflecting the difference between the compared images of the printed circuit board being evaluated and images associated with the reference printed circuit board; determining that a first component on the evaluated board has a placement or orientation error if a first score corresponding to the difference between the image of the first component on the printed circuit board being evaluated and image of the first component on the reference printed circuit board exceeds a predetermined threshold value.