Development of a sectorial laser beam scanning measuring system assisted with an image processing system

• Main Authors: Ya-wen Deng, 鄧雅文
• Other Authors: Fang-jung Shiou
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/hwegy2

碩士 === 國立臺灣科技大學 === 機械工程系 === 94 === A sectorial laser beam scanning measuring system based on the triangulation principle was developed in this study, to measure the surface roughness and the workpiece profile after a suitable calibration. The developed system mainly consists of a micro-focus sectorial line laser, an image processing system, a PC-based 3-axis machine, and a PC. According to the scattering theorem, a correlation was investigated between the surface roughness of the workpiece measured with a precision stylus instrument and the average fringe line width projected onto the workpiece surface. The height value of the object can be calculated, based on the offset between the position projected onto the object and the position projected onto platform after carrying out the calibration with gauge blocks. For a workpiece with flat surface, its surface roughness and flatness can be determined simultaneously. The developed system was applied to measure the surface roughness and flatness of a plastic sheet. The surface roughness deviation between the measurement using the developed system and that of a stylus surface roughness measurement instrument was about 0.033 μm. The flatness error deviation between the measurement using the developed system and that of a coordinate measuring machine was about 7 μm. The co-planarity of a BGA socket can also be measured by the developed system, the measured result was about 0.1274 mm. In addition, the position related to the lack of the solder ball could also be detected by the developed system.