横线Mura的分析与改善

Analysis and Improvement of Horizontal Line Mura

横线Mura是一种在TFT-LCD生产过程中产生的不良,对于画面品质有较大的影响。文中对横线Mura发生的原因进行分析,通过对金属膜层的应力测量及分析不良区域金属断面结构,认为横线Mura的发生是由于在栅电极成膜过程中,玻璃基板中心和边缘的Mo金属层的应力差异较大,造成在应力释放后Mo金属层与玻璃基板之间结合不紧密,从而影响到栅电极与源电极间的寄生电容参数发生变化和信号电平发生偏移。提出对栅电极膜层结构进行调整,将栅电极底层Mo金属膜去除可以有效地降低不良的发生比率,并进行了相关验证。

Horizontal Line Mura is one kind of defect during TFT-LCD manufacturing process.This defect will affect display quality seriously.After analyzing the profile of the metal layer and measuring the stress status of metal film,the root cause can be revealed.It shows that during deposition process of metal film on glass substrate,the stress of Mo layer between the center area and glass edge is different,and this caused the loose of Mo layer,which affect the capacitor between gate and source electrode,then cause display voltage shifting on the pixel.To solve this issue,by removing bottom Mo layer to adjust Gate layer stack ratio,the failure rate can be effectively reduced.And this is demonstrated by experiment.