고정밀 머신 비전을 위한 정확한 PCB 윤곽선과 코너 검출

Accurate PCB Outline Extraction and Corner Detection for High Precision Machine Vision

  • 고동민 (한국기술교육대학교 창의융합공학협동과정) ;
  • 최강선 (한국기술교육대학교 창의융합공학협동과정)
  • Ko, Dong-Min (Interdisciplinary Program in Creative Engineering, KOREATECH) ;
  • Choi, Kang-Sun (Interdisciplinary Program in Creative Engineering, KOREATECH)
  • 투고 : 2017.08.23
  • 심사 : 2017.09.19
  • 발행 : 2017.09.30

초록

Recently, advance in technology have increased the importance of visual inspection in semiconductor inspection areas. In PCB visual inspection, accurate line estimation is critical to the accuracy of the entire process, since it is utilized in preprocessing steps such as calibration and alignment. We propose a line estimation method that is differently weighted for the line candidates using a histogram of gradient information, when the position of the initial approximate corner points is known. Using the obtained line equation of the outline, corner points can be calculated accurately. The proposed method is compared with the existing method in terms of the accuracy of the detected corner points. The proposed method accurately detects corner points even when the existing method fails. For high-resolution frames of 3.5mega-pixels, the proposed method is performed in 89.01ms.

키워드

참고문헌

  1. Choi, K.-S., Byun, J.-Y., Kim, N.-H., Choi, B.-D., and Ko, S.-J., "Real-time Inspection System for Printed Circuit Boards," Lecture Notes in Computer Science, vol. 2781, pp. 458-465, Sep. 2003.
  2. Ko, J.-S., Rheem, J.-Y., Oh, K.-W., and Choi, K.-S., "Micro-crack Detection in Heterogeneously Textured Surface of Polycrystalline Solar Cell," Journal of the Semiconductor & Display Technology, vol. 14, no. 3, Sep. 2015.
  3. Berng, D.-B., Lee, S.-M., and Chou, C.-C., "Automated Bonding Position Inspection of Multi-layered Wire IC Using Machine Vision," International Journal of Production Research, vol. 48, issue 23, 2010.
  4. Duda, R. and Hart, P. E., "Use of the Hough Transformation to Detect Lines and Curves in Pictures," Communications of the ACM, 1972.
  5. Harris, C. and Stephens, M., "A Combined Corner and Edge Detector," Alvey Vision Conference, 1988.