| Title |
Wavelet Transform Based Defect Detection for PCB Inspection Machines |
| Authors |
연승근(Youn, Seung-Geun) ; 김영규(Kim, Young-Gyu) ; 박태형(Park, Tae-Hyung) |
| DOI |
https://doi.org/10.5370/KIEE.2017.66.10.1508 |
| Keywords |
PCB inspection machine ; Wavelet transform ; Defect detection ; Image compression |
| Abstract |
This paper proposes the defect detection method for automatic inspection machines in printed circuit boards (PCBs) manufacturing system. The defects of PCB such as open, short, pin hole and scratch can be detected by comparing the standard image and the target image. The standard image is obtained from CAD file such as ODB++ format, and the target image is obtained by arranging, filtering and binarization of captured PCB image. Since the PCB size is too large and image resolution is too high, the image processing requires a lot of memory and computational time. The wavelet transform is applied to compress the standard and target images, which results in reducing the memory and computational time. To increase the inspection accuracy, we utilize the he HH-domain as well as LL-domain of the transformed images. Experimental results are finally presented to show the performance improvement of the proposed method. |