Detecting PCB Defects Using Image Processing Major : Measurement

Printed 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 progress of industry, electronic devices are prone to be more portable, thinner, shorter, and smaller. This trend has made the technique of PCB to higher density. It is always a challenge to testing high density PCB for researchers in the high automatic manufacture field. At present, the measurement methods are sparse, efficiency is low, operation is difficult, and cost of error is high. In order to improve the status, developing a more efficient, stable, accurate and automatic PCB testing system has become an emergent and significant task.The former researcher has confirmed the project that identifies the various PCB defects automatically with optic photographic system and image analysis technique. He has developed an automatic testing system to detect the bypass defects and broken defects. The system is precise and automatic, and has been proved to be a feasible method in the PCB online testing.In this paper, many techniques in image processing and analyzing are utilized to implement the function detecting the spur defects and flaw defects automatically. In the processing, many novel methods based on the geometric straightness of objects themselves differing from the old one based on the global topologic connectivity between objects are used. The experiments explain that this change is suit to detect the spur defects and flaw defects. It compensates the shortcoming of the current testing system and makes it to be a complete PCB online testing system in function.