Vision system for printed circuit board inspection

The Vision System is used for the inspection of Printed Circuit Boards (PCBs) of different sizes. It detects the presence or absence of mounted components in a PCB. An automatic conveyor transports these boards to the imaging area. The image of the PCB is captured by a camera interfaced to a computer through a frame grabber circuit. The captured image has a resolution of 256 x 240 pixels with 64 gray levels. A library of image processing tools was implemented for the development of applications. From this library, a program for PCB inspection was developed. The inspection process is accomplished through template matching. The matching operation is done by comparing a stored template with an image of the PCB to be inspected. When a match is detected, the PCB is declared acceptable. A report of the status of the boards inspected is generated at the same time