Key Techniques Of Automatic Flexible Printed Circuit Board Production Equipment

Flexible Printed Circuit (FPC) board industry has developed for more than60years.Nowadays, led by the new material and new technology, FPC becomes more and more criticalin national industrial system. Especially when chip manufacturing industry uses FPC as ICsubstrate, it becomes a strategic pillar industry. The main purpose of the research work in thispaper is to improve the automation level of the FPC industry and improve productionefficiency, reduce defects rate as well.This paper analyses the cutting-edge technology and equipment used in FPC industry.And summaries four bottleneck processes for improving automation. The problems in thesefour processes are abstracted into two basic theoretical issues—the image registration andsurface defects inspection problems. By comparing the human and the existing machinevision algorithm in solving these two problems, this paper reveals that human uses selectiveattention mechanism and information extraction step by step way to reduce the amount of datafor visual task. And we design four human experiments to prove the related theory andhypothesis.Inspired by human vision system, we try to solve these two problems by using selectiveattention and effective information extraction. First of all, we construct mechanic model andpropose novel―A-B‖parallel mode. In this mode, there are two cameras capture a picture andb picture at once. And this two pictures are designed to imaged roughly the same parts of twoproducts. In this way, the image gets reference for each other and doubles the throughput.Saliency map is used to simulate human selective attention. And by this concept we put imageregistration and surface defects detection problem into one computational framework.For saliency computation, we propose a main edge abstraction method. Scale spaceanalysis is used to abstract main edges in a FPC image. And Gestalt theory are simulated toimprove the main edge map. This method is very good in abstract main edge in FPC imageand X-ray image and has not affection to defect image.We discuss three kinds of saliency computation. The first one is saliency map based onfrequency domain method. We propose using phase-only Fourier transform to calculatefrequency domain saliency map. The different resolution frequency domain saliency maps arediscussed to illustrated how to used them as index of special signals. The second one issaliency map based on object and color. We propose a novel method based on objectsegmentation-merge and object priori knowledge. The third one is saliency map based ondefect feature. We propose three defect saliency maps: the color defect saliency map, the edge density saliency map and edge regularity saliency map.After discussing of saliency map, we propose a novel image registration method base onsaliency man and MSERs. The low resolution saliency map is used for selective attentionclues and sub windows are abstracted around the saliency extreme points. Then the MSERsare searched in the sub windows. By this way, we reduce the amount of the feature andmismatching possibility.After registration of two―A-B‖mode images，we transform the local extreme points ofhigh resolution saliency map to inspect the candidates of defects. And the defect of platedgold surface is discussed specially. We propose a novel method based on saliency map andShannon entropy ratio to detect defects on plated gold surface. And this method is alsosimulation of human vision.