随着高分辨率TFT-LCD HADS产品的开发, 一种与像素ITO图形密切相关、有明暗(黑白)亮度差异、不同视角观察下存在黑白反转现象的Mura不良高发。经过对不良产品的参数测量和模拟分析, 确定发生该不良的原因是在邻近区域内, 像素开口区内的像素电极ITO(1ITO)图形和公共电极ITO(2ITO)图形发生了不同程度的相对偏移, 电场分布存在差异, 因此亮度发生明显差异; 而且由于图形间的相对偏移导致电极间的电场发生偏移, 形成像素左右两侧的一侧为强电场, 一侧为弱电场, 因而会出现从一侧观察发亮而从另一侧观察发暗、左右视角观察的黑白反转现象。Mura区与相邻OK区1ITO2ITO 对位差异为0.5 μm。通过1ITO和2ITO的线宽设计优化, 可提高产品对此偏移不均一的容忍度。最终采用最佳1ITO、2ITO 线宽条件生产, 配合1ITO和2ITO共用设备及TP非线性补正等条件并举, 此不良由高发时的14.2%降至0.2%以下。本文研究成果对于高分辨率 HADS产品的设计和性能改善, 有着重要的指导和参考意义。

With the development of high resolution TFT-LCD HADS products, a kind of Mura which is closely related to the pattern of ITO, occurred frequently. The Mura has bright and dark (black and white) brightness differences, and there is a black and white reversal phenomenon in different viewing angles. After measuring and simulating the parameters of the unaccepted products, the reason is concluded that the pixel electrode ITO (1ITO) pattern and the common electrode ITO (2ITO) figure in the pixel open area have different relative shift in the adjacent area, and the distribution of the electric field different, so the brightness difference is obviously different. Because of the relative shift between the patterns, the electric field between the electrodes is offset, which results in the strong electric field on one side of the pixel and the weak electric field on the other side. Therefore, the black and white reversal phenomenon is observed from opposite sides. The overlay’s difference of 1ITO to 2ITO between Mura and OK areas is 0.5 μm. Through the optimization of dimension design of 1ITO and 2ITO, the tolerance of the product to offset can be improved. Finally, using the best 1ITO, 2ITO dimension design, as well as combined with 1ITO and 2ITO common equipment and TP nonlinear correction and other conditions, the ratio of Mura occurrence is decreased from 14.2% to less than 0.2%. The research achievement in this paper has the important guidance and reference significance for the design and performance improvement of high resolution HADS products.