Novel automatic PCB inspection technique based on connectivity

This paper presents a novel technique for PCB inspection based on the comparison of the Connected Table of a Reference and a Test Image. The method is based on connected component analysis, which is a natural way to extract the connectivity information of the conductors of a PCB. The registration of the PCB holes, which is a common problem related to referential model techniques, is solved by the concept of zone of influence of each hole. This paper describes the method and its implementation using standard Morphology Image Processing techniques. A result of applying the technique to real images is shown