The Development of an Automatic Desktop Phase-Shifting Shadow Moire System

• Main Authors: Shih-Hsien Wu, 吳時賢
• Other Authors: Yi-Hong Lin
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/88242747420796797909

碩士 === 國立屏東科技大學 === 機械工程系 === 93 === One of the main factors makes the warpage of the BGA electronic packages is the difference of thermal expansion coefficient between materials. A laser point-to-point measuring method is primary used to measure the warpage now by off-line sampling inspection. Nevertheless, we can’t control the product’s quality very well in the manufacturing process. Therefore, it is important to establish an on-line inspect system to measure the warpage of the BGA. The purpose of the thesis is to develop a desktop on-line auto-inspection warpage system for BGA electronic packages. A shadow moiré technique combined with self-designed illuminate module to reduce the error of the system, and used four-step phase shifting technology to improve the resolution of the shadow moiré pattern. Then, the uncontinued phase field was restored by unwrapping technology based on the digital image processes. The digital image unwrapping technology unwrap a noise phase map effectively by the following steps. The processing sequences are Segmentation, Image Preprocessing, Pattern Recognition and Decision. Finally, the developed system can provide a high-speed, easy-setup, easy-use and high-stability mechanism for applying in on-line production processes.