DEFECT DECTION FOR FLEXIBLE PCB BY USING DIAGONALWISE DWT WITH DATA PERIODIC EXTENSION

• Main Authors: Tao-Ching Yu, 禹道青
• Other Authors: Chau-Yun Hsu
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/02799913747703918012

碩士 === 大同大學 === 通訊工程研究所 === 96 === Wavelet transform applied to frequency and time domain characteristics. Due to wavelet transformation has multi-resolution analytical characteristic, which can use wavelet transform to analyze defects of structural texture possible. The FPCB board is constructed from three structural textures: vertical, horizontal or oblique in degrees of 45 or 135 diagonal. In the method, the inspection is mainly divided into two parts. First part mainly aims at defects inspection of the horizontal and vertical circuit lines. The part makes wavelet transform in accordance with the original image, and reconstructions of the defect parts existing. The other part will spread the original image to become the new rhombus, and use the DWT transform to detect the defects. 　　This thesis aims mainly at the defects inspection of the oblique circuit lines on FPCB. Using period Extension to lower observed time to improve defect can be found precisely, and raise the efficiency accuracy and realization possibility of the hardware to reach the goal of automatic defects inspection.