An intelligent robotic vision system for inspection of surface mount PCBs

The authors present techniques used for defect inspection on surface-mount printed circuit boards (PCBs). The focus is on five different types of defects, namely, missing components, misalignment, wrong orientation of IC chips, wrong parts, and poor solder joints. Five separate algorithms have been developed to detect these faults. The technique of windowing was used to reduce the amount of redundant data to be processed. Preprocessing functions like convolution as well as all image processing tasks are performed on the window regions only, saving a tremendous amount of computation time. Experimental results showed that these algorithms are reliable, fast and cost-effective