TFT LCD光配向制程对低灰阶画面抖动的影响

Influence of TFT-LCD photo alignment process on low gray image jitter

为了改善光配向产品画质,提高产品良率,针对光配向产品在低灰阶出现画面抖动不良现象进行系统研究,发现了画面抖动异常发生机理并找到有效的改善措施。首先,通过盒厚量测仪对异常区域进行预倾角比对,确定异常位置预倾角变化。接着通过光配向原理与预倾角角度进行关联分析,对画面抖动机理提出合理解释,确认由外部静电电场造成局部光配向电压异常。最后,通过排查机构确认静电发生单元,提出有效的改善措施。画面抖动是基板在制程中受到静电累积,造成基板背面积累一定电荷。在光配向制程中,受外部静电场的影响,像素内的电压未达到预定值,造成预倾角异常,点灯成像为画面抖动。通过改善在制程中的静电累积,防止静电累积在基板背面造成光配向电压异常,改善画面抖动不良。

In order to improve the image quality and product yield of photo alignment products,this paper systematically studies the bad phenomenon of image jitter in low gray scale of photo alignment products,finds out the mechanism of abnormal image jitter,and finds effective improvement measures.Firstly,the abnormal position pre-tilt angle is determined by comparing the pre-tilt angle of the abnormal area with the box thickness gauge.Secondly,through the correlation analysis of photo alignment principle and pre-tilt angle,the mechanism of image jitter is reasonably explained,and the local optical orientation voltage anomaly caused by external electrostatic field is confirmed.Finally,the electrostatic generating unit is confirmed by the investigation mechanism,and effective improvement measures are proposed.The image jitter is the static electricity in the process of the base plate.Accumulation results in a certain charge accumulated on the back of the substrate.Under the influence of the external electrostatic field,the voltage in the pixel does not reach the predetermined value,resulting in an abnormal pre-tilt angle and image jitter.By improving the electrostatic accumulation in the process,the abnormal light orientation voltage caused by electrostatic accumulation on the back of the substrate can be prevented,improving poor image jitter.