Computer Engineering and Applications ›› 2020, Vol. 56 ›› Issue (5): 227-233.DOI: 10.3778/j.issn.1002-8331.1812-0127

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Research on LED Defect Detection Method of Flexible Printed Circuit Board

LI Fei, FENG Kaiyong, YUAN Weiqi   

  1. School of Information Science and Engineering, Shenyang University of Technology, Shenyang 110870, China
  • Online:2020-03-01 Published:2020-03-06



  1. 沈阳工业大学 信息科学与工程学院,沈阳 110870


In order to solve the problem of leakage and stickiness in the production of flexible printed circuit board LED, a set of on-line inspection method of LED stickiness quality based on machine vision is proposed. A large plot of 8,192×70,000 pixels is firstly pre-treated, and the rectangular sieve of zone is used to retrieve the rectangular sieve of zone unless the pads area by using the stencil and traversing the idea to get the pad profile of a single pixel as the positioning template. As asynchronous scale of template matching positioning LED bonding pad area, wick region roundness is calculated by region projection, according to roundness patch of different contrast adaptive parameter Canny edge detection for getting wick edge, the wick edge is fitted to obtain wick coordinates. Lastly, LED defect is judged by wick coordinates, and LED stick deviation is judged by calculating pad coordinates deviation and lamp core coordinates. Field test results show that accuracy of LED leakage detection is 100%, accuracy of stick slant LED detection is 97.3%, and average detection time is 1,583?ms, which proves that the proposed detection method has practical value.

Key words: LED paste quality, moment, asynchronous zoom, adaptive parameters, projection



关键词: LED粘贴质量, 矩, 异步缩放, 自适应参数, 投影法