Research On Line Width And Line Distance Of High Speed PCB And Defect Detection Method Based On CCD

As the basis of automobile manufacturing,communication industry,computer field and other fields,the quality of PCB directly affects the quality of various products,and the line width and line distance of PCB affect the yield of the finished board.With the continuous development of linear array CCD,in order to detect PCB quickly and accurately and at a low cost,this paper studies the methods of line width and line distance measurement and defect detection using linear array CCD camera.Firstly,the structure and working principle of CCD are introduced.The advantages of using linear CCD to detect PCB defects and measure line width and line distance are analyzed.According to the working characteristics of linear CCD,the matching problem between linear CCD and worktable is analyzed.The relationship between linear CCD imaging and speed is pointed out,and the image scanning and acquisition system based on CCD is designed.Secondly,the shortcomings of real-time and detection accuracy of traditional PCB line width and line distance detection are analyzed.Based on this,a PCB line width and line distance measurement algorithm based on CCD image fast filtering and adaptive fitting is designed,and online detection is completed.In order to improve the speed and accuracy of detection,improve and use part of the fast guide filtering method.In order to improve the real-time performance,the image enhancement,binary processing and fitting line are optimized adaptively.In order to highlight the effectiveness of this method,this method is compared with the results after model training.Thirdly,as a supplementary detection of line width and line distance measurement,PCB defects are detected from the image by using structure similarity algorithm,image rolling splicing is completed by using linear CCD,and defect detection is carried out on the scanned image after splicing.PCB defect detection algorithm based on CCD image high-speed rolling recombination and structure similarity algorithm is designed to complete online detection.The rolling image is transferred to the detection system after reorganization,and the structural similarity algorithm is used for defect detection.For the false detection caused by the structural similarity algorithm,the self-tuning module is used for correction,and the image information is completed,which corrects the shortcomings of the structural similarity algorithm.Finally,a real-time line width and line distance measurement and defect detection system for PCB is designed and completed in this paper.The upper computer program is used to control the photolithography motion platform and specific detection operation.The method and system described in this paper are verified by many experiments,and good detection results are obtained.Compared with the traditional detection method,the difference of the detection method described in this paper is that under a certain speed disturbance,the detection of line width and line distance has better robustness.Using the characteristics of linear array CCD camera,the detection is carried out in parts synchronously,which improves the efficiency and reduces the cost of detection.