TFT-LCD面板在屏幕上有斑点或波浪状Mura, 影响液晶显示器的品质, 经过图形匹配, 缺陷与曝光机机台形貌匹配。通过对异常区域特性分析, 发现异常区域的BM CD、BM 像素间距存在异常。对原因进行模型分析: 玻璃在曝光机基台上局部区域发生弯曲, 曝光距离变短, 致使BM PR受光区域变小, BM CD会偏小, 进而导致区域性透过光不均一产生Mura; 玻璃弯曲后BM 像素间距相对于设计位置也会发生变化, 从而导致漏光产生Mura。经过实验验证, BM CD和像素间距的偏差主要由机台凸起导致glass弯曲引起, 可以通过降低吸附压力和研磨机台, 来改善CD差异和像素间距偏移, 同时像素间距偏移漏光, 也可以通过增加CD来改善。最终通过BM CD增加、研磨机台和降低吸附压力措施, Stage Mura不良率由10.05%下降至0.11%。

The spotted and striped Mura on TFT-LCD Panel degraded product quality. The defect pattern matched the exposure stage by analyzing. It was found that the BM CD and Pixel Pitch are abnormal through researching the abnormal area characteristic parameter. Model analysis based on Stage Mura indicated that the bending of glass on stage shorted the Exposure gap, which shrank the Exposure area, and minified CD and formed transmittance difference. The bending of glass also shifted the Pixel Pitch, which resulted in light leak and Mura. The experiment showed that the difference of BM CD and Pixel Pitch were caused by Stage flatness, which could be improved by polishing stage and decreasing vacuum adsorption pressure. The light leak of Pixel Pitch could be also improved by extending CD. Finally, the CF BM stage Mura was improved greatly by CD increasing, stage polishing, and vacuum adsorption pressure decreasing, and the Stage Mura defect ratio decreased from 105% to 0.11%.