On-Line Quality Detection of Coating Film by Line-Scan Dynamic Spectral Domain Optical Coherence Tomography

• Main Authors: Ying-Chi Hsu, 徐英綺
• Other Authors: An-Bang Wang
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/70654434351046593270

碩士 === 國立臺灣大學 === 應用力學研究所 === 102 === The purposes of coating process are modifying the surface properties and adding the product value. Since wet coating process has the advantages of low cost, fast production and high material utilization rate, it has been widely used in the industry. Moreover, the trend of coating process includes thinner, multilayer, patterned or specially structured coating; however, the product defects are generally detected after the whole fabrication process due to the lack of on-line measuring system that leads to the increase of material waste and cost. Therefore, the goal of this research is to develop an on-line detecting system, which can be applied for the real-time measurement of precision coating film. The spectral-domain optical coherence tomography (SD-OCT) technique was used since SD-OCT has the advantages of non-contact, obtaining depth information without scanning and continuous measurement, and has great potential for on-line detecting method. We further proposed a prototype of line-scanning method, instead of the traditional point-scanning method, in order that the on-line fast measurement of the whole coating film could be achieved for the real applications. The specifications of this line-scan SD-OCT are: 5.3 mm width of scanning line with resolution of 100 μm (that could be further enhanced by adopting lens with higher magnification), the depth direction measurement range of ± 250 μm with resolution of 2.78 μm, and the measuring frequency of 30 Hz, (that is limited by the frame rate of charge couple device (CCD)). Real coating films on the plastic subtract and three-dimensional structures were measured to prove its use. It is expected to bring a new impact on the on-line precision measurement for industries in the future.