Research On Detection System Of PCB Based On Image Processing

The continuous adjustment and upgrading of industries put forward higher requirements for the overall quality of the product.But the phenomenon is commonly seen in the manufacture of overall Printed Circuit Board(Printed Circuit Board,PCB)that the PCBs of general level are surplus,while these owning high quality and are in short supply.As the common defect methods of PCB,the artificial detection after defect occurring make it possible that the situation of missing or wrong detection and cannot solve the problem existed in time,so a precision-guaranteed quality online testing equipment for PCB is necessary.The online detection process based on the image recognition of PCB bare board in the background of WK company was researched in the thesis.The on-line detection system based on the image recognition was designed according to the experience of related products and algorithms at home and abroad in this thesis to detect the PCB bare board on line by means of image recognizing and building the hardware system for image acquisition.The purpose was to recognize most accurately the images and judge whether the PCB bare board meet the processing requirements based on the high-quality images collected.The system is consisted of two parts:the hardware part of the system is as the basic support,composed of the image acquisition system,which utilizes the linear array camera of CCD(industrial camera),motion control system and lighting system The hardware part is controlled by the other core part,the software system,the main function of which is to processing and judging these images after collecting them.The camera auto-focus algorithm,image splicing algorithm,image preprocessing algorithm and round hole image recognition algorithm are revolved as the main algorithms in this thesis.On-line monitoring system platform of the PCB bare board based on image recognition is build by choosing the most suitable algorithm combined with the conditions of the hardware itself.The auto focus of the camera is realized Through the testing of the main functions of the system.The accuracy of the image splicing is improved and the efficiency of the image recognition get guaranteed after the algorithm being optimized.The adoption of high precision image positioning makes positioning function more accurate.Whether the products to be tested are qualified can be intuitively determined through the matching data displayed.Compared with other PCB detection equipment on the market,the hardware cost of the system is relatively small and the effect of collecting images is relatively stable.And the software interface is simple and its operation is convenient for the first-line workers to operate,which meets greatly the actual demand of market in China.