Research on the Image Multilayer Matching Comparison Method in PCB Defects Inspection

摘要

In the real-time inspection technology of the printed circuit board (PCB), the matching comparison method is widely used with its simple and easy algorithm to implement. However it has kinds of flaws such as high rate of false report and mutually disturbs among different patterns in comparing process. Therefore this research improved the conventional matching comparison method, proposed the multilayer matching comparison method that based on the multi-threshold values partition image, enhanced the PCB inspection accuracy and reduced the phenomenon of false report. This technique is especially suitable for the inspection of PCB image that has complex gray-levels and multimodal histogram, and can also preliminarily classify the defects according to the partition layers processing.