Application of novel color composite fringe projection profilometry technology for the flip-chip solder bump height measurement system

• Main Authors: Han-Cheng Wu, 吳翰承
• Other Authors: Chung-Feng Jeffrey Kuo
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/72ae2f

博士 === 國立臺灣科技大學 === 自動化及控制研究所 === 107 === This study developed a flip-chip solder bump height measurement system based on fringe projection profilometry technology. First, this study proposed a novel method of homography fringe generation, using the planar homography relationship between the coordinates of the projected image and the camera-captured coordinates to generate a fringe image on the captured image plane. The image was then converted and projected onto the projection plane to obtain a corrected fringe image of periodic consistency, thus effectively reducing phase errors caused by an inconsistent period. Second, the study used the color crosstalk coefficient correction technique to suppress the color cross-talk effect in the color 3CCD camera. Third, this study proposed fringes with different base values and modulation intensities in color channels, in order to produce a color composite fringe with robustness, and set up a multi-channel composite phase unwrapping algorithm that uses fringe modulation weights of different channels to recombine the phase information for better measurement accuracy and stability. The experimental results showed that the average measurement accuracy is 0.43 μm and the standard deviation is 1.38 µm. The results thus proved that the proposed height measurement system is effective in measuring a plane with a height of 50 μm. In the flip-chip solder bump measuring experiment, different fringe parameter-based values and amplitude intensity parameters were analyzed to overcome the problem of the reflective coefficient between the flip-chip baseboard and the solder bump. The proposed system presents good measurement results and robust stability in the solder bump measurement and can be used for the measurement of height information for micron flip-chip solder bump application.