Research And Analysis Of Auto Inspection Of PCB's Defection

The Printed Circuit Board (PCB) is important to modern-day electronic equipment;its quality affects the performance of products. So PCB industries cry for on-line visual inspection. But if people do this work,it will be dull. People's energy is limited,so leaking will be happen easily.In this thesis first introduces the development present situation,then discusses the technology of inspection from three sides. If want to effective detect PCB defection,we first need accurate location of PCB image. In chapter two,the author uses the method of Wiener filter to accomplish the location of PCB image and gives the Wiener filter realize arithmetic. It resolves the problem from the point of image restoration. The experiments show the method of Wiener filter is effective. The efficiency and validity of inspection is based on the inspection arithmetic. Image edge denotes signal mutation of image. Detection of image edge is useful to image process. Wavelet transform has ability of detecting mutation point. In third chapter author uses this ability to detect the edge of image. Author hopes to detect PCB defection based on this method. The experiments testify validity of this method. In order to solve the problem of real time,the author discusses Digital Signal Processor (DSP). It researches the scheme of inspection system of PCB based on DSP. It is a new method of improving efficiency of the inspection system of PCB that uses DSP in the inspection system of PCB.