Research On Quality Testing Technology Of PCB Based On Image Processing

With the high-speed growth of IC industry,Printed Circuit Board(Printed Circuit Board,PCB),as the common electronic unit in our life,is expanding towards the direction of higher and higher integration,smaller area and more layers.With the increasing requirement of PCB production,PCB is faced with the problem of rapid and accurate detection of production quality.The traditional PCB defect detection methods include manual visual test,electric test and infrared detection,but they all have some shortcomings such as slow speed and accuracy.In order to make up for the traditional PCB defect detection methods weakness and meet the needs of industrial assembly line detection,people have developed the AOI detection system based on machine vision technology,this system is to integrate machine vision software and hardware,but the focus of the system is still defect detection algorithm.The main research contents of this paper is to design the system based on digital image processing and using FPGA technology to achieve high speed and efficient detection of PCB board defects.PCB may be some defects in the manufacturing process,so the PCB defects need to be identified.In order to achieve the system,the main work is as follows:1.The application of digital image processing technology is studied,which can be divided into four parts: image acquisition,image preprocessing,image recognition and image display.Among them,the core part is image preprocessing and image recognition.2.The PCB defect detection system is deeply studied,and based on this,the design framework of PCB defect detection system based on FPGA is proposed,which is mainly composed of image acquisition module,image preprocessing module,image cache module,defect detection module and image display module.However,this paper mainly uses FPGA technology to design the key modules.3.The design idea and main functions of image preprocessing module,image cache module and defect detection module in PCB defect detection system are analyzed by FPGA technology,and the logic design of each module is carried out on this basis.4.In the PCB defect detection system,histogram equalization module,median filter module,edge detection module and PCB defect detection module are simulated and verified by Matlab and Modelsim simulation software,respectively.The simulation results show that the effect of FPGA hardware processing is significant as that of Matlab software processing,but the hardware processing is more efficient and fast.