本文研究了一款TFT-LCD HADS产品出现的21.4%横纹不良。通过分析和改善研究表明, 产生横纹的根本原因是Vcom 反馈信号与CLK1、CLK2、CLK3信号产生耦合效应及Vcom补偿电路共同作用下, 导致Vcom在栅压关闭前存在三上三下的周期性波动, 形成三行暗三行亮水平粗纹; 根据原理分析进行不良改善实验验证, 最终通过调整降低Vcom补偿电路倍数, 将该不良降低至0%。

In this paper, we explore a kind of horizontal stripes defect which happened 21.4% in TFT-LCD HADS product. Through analysis and improvement study, the main reason for horizontal stripes defect was the coupling effect of Vcom Feedback signal and CLK1, CLK2, CLK3 signal, and Vcom compensation circuit. As a result, there are three periodic fluctuations of Vcom before Gate closing, which form three lines of dark and three lines of bright horizontal rough lines. According to the principle analysis, the defect improvement experiment is verified. Finally, by adjusting the Vcom compensation circuit multiple, the defect is reduced to 0%.