Causes and Solutions of Common Wire Defects in TFT LCD Displays

In TFT LCD display module, according to different causes and different positions and shapes, line defects can be divided into line defects such as line break in the screen, line defects such as short circuit in the screen, line defects such as short circuit between terminals, and abnormal driving. See the following table for the phenomenon and causes of each type of line defect.

Broken wires and short circuits in the screen are usually caused by dust pollution and other factors in the production process of the screen itself. Abnormal drive line defects are problems of the drive circuit. Other types of line defects are related to the process of the display terminal. These types of line defects can be repaired by adjusting the drive circuit, replacing COF/COG and other methods.

LCD line defect is the most common defect. Line break defects are mainly data line breaks. Introducing the design countermeasures of line break repair in the display screen design can greatly improve the product qualification rate.


The repair methods are mainly divided into two design strategies: off screen repair and on screen repair.


1. Off screen repair design for broken wires. Through wiring outside the screen, the data signal is synchronously transmitted to the broken line that cannot be displayed normally, so as to realize the normal operation of the display screen.


2. On screen repair design for broken wires. It can be realized by pixel design. Through the path on the pixel, the upper and lower parts of the data line break can be connected, which can save the power amplifier OP commonly used in the off screen repair design and reduce the product development cost. Different display modes, different bypass paths, and different pixel structures lead to different repair designs.