Automatic Inspection System For PCB Based On Computer Vision

Print Circuit Board (PCB) is an information carrier integrating various electronic components. It has been applied in different fields widely. With the continuous development of technology and improvement of the level of technics , PCB are prone to be more layers and more density . It is always a challenge to testing automatically high density PCB for researchers in the high automatic manufacture field. This paper has confirmed the project of inspecting PCB' s defect automatically with optic photographic technique, computer control technique and image process technique, and has been proved to the a feasible method in the automatic testing of PCB.This paper was processing on the base of previous researcher , their research focus on how to seek for arithmetic of image process to inspect the defect of PCB , according to the result of their research , they pick out the part of defect from PCB , for example Short ,Cut , Burr, Mousebite and so on. But testing the defect adopting to image process is only a part of automatic inspection system for PCB. except that , many problem can' t be solved , such as the conflict of CCD' s high resolving power and big vision field , how to control the automatic gathering of PCB' s image using master and slave computer parallel structure , how to inspect the defect of PCB such as width of circuit ,distance of circuit ,losing circuit and so on. The research aim at how to combine computer vision , precise machine , automatic control with image process , at how to resolve the contradiction between high resolving power of image gathering and wide vision field , at how to realize automatic mosaic of image , at how to realize precise orientation of two dimension worktable , at how to realize communication between master computer and slave computer , and at how to inspect the defect of line width , line distance and losing . later experimentation proved that the research solved above-mentioned problems successfully , compensates the shortcoming of the current testing system and makes it to be a complete PCB automatic testing system in function .