Automatic extraction of component inspection regions from Printed Circuit Board

The inspection machine in PCB(Printed Circuit Board) assembly line checks for assembly errors by examining the images inside the component inspection region. The component inspection region consists of a component package region and a soldering region. The regions need to be extracted automatically so the auto-teaching system of the inspection machine can work. An image segmentation method was proposed to extract the component inspection regions automatically from the images of the PCB. The acquired image was transformed to HSI color model, and then segmented by several regions by a clustering method. A modified K-means algorithm was developed to increase the accuracy of extraction. The heuristics generating the initial clusters and merging the final clusters were newly proposed. The vertical and horizontal projection was also developed to distinguish the region of the component package and the region of soldering. The experimental results are presented to highlight the utility of the proposed method.