CN103676246A - Method for repairing defect of liquid crystal display panel lines - Google Patents

Abstract

The invention discloses a liquid crystal panel line defect repairing method, which mainly connects the repairing line and COF through a zero-ohm resistance, and selects the repairing line according to the number and position of broken lines for repairing. The present invention improves the connection mode of the repair line and the COF input port on the PCB, thereby repairing the originally unrepairable liquid crystal panel, and at the same time does not need to set too many repair lines, so that the repair line can be fully utilized, and the liquid crystal The repair efficiency of the panel is effectively improved, and at the same time, the reject rate of the liquid crystal panel is effectively reduced.

Description

A method for repairing liquid crystal panel line defects

technical field

The invention belongs to the field of liquid crystal panel detection, and in particular relates to a method for repairing line defects of a liquid crystal panel.

Background technique

Thin-film transistor liquid crystal display (hereinafter referred to as TFT-LCD) is a kind of flat-panel display. Its display quality is closely related to resolution. The luminous point is called a pixel, and the resolution is generally expressed in the form of multiplication, such as the resolution of 1366*768, where 1366 is the number of pixels displayed in the horizontal direction of the effective display area, and 768 is the number of pixels displayed in the vertical direction. Each pixel is divided into three subpixels (Subpixel) of RGB. Generally, the three subpixels of RGB are arranged horizontally. For a 1366*768 resolution liquid crystal display, there will be 1366*3=4098 sub-pixels in the horizontal direction, and each sub-pixel in the horizontal direction is charged by a data line, so in 1366*768 In the case of resolution, there will be 4098 data lines, and in the case of higher resolution, the number of data lines will be more, for example, at 4k2k (resolution 3840*2160), the number of data lines will reach 3840*3 =11520 roots. If you consider solving the problem of insufficient charging and do double source (dual data lines), the number of data lines will be doubled. In the case of 4k2k, 3840*3*2=23040.

Every data line may be broken. If a data line is broken from the middle, the display will be abnormal below the break point. This situation is called a line defect. In order to solve such a situation, repair lines are generally set in the panel. to repair panels with wired defects. When a cable defect occurs, use laser to connect the upper and lower ends of the data line to the two ends of the repair line to complete the repair. the

At present, the repair line is mainly used to connect two repair lines on both sides of a COF (COF is a chip-on-chip film, referred to as COF in the lower order), so that when there are two broken lines in the area controlled by this COF, it can pass through these two lines. Repair line to fix. In this way, the maximum number of lines that can be repaired in theory is twice the number of S-COF particles, but considering the design of the in-plane array substrate, the number of repair lines in the plane will be limited, which will make the repair on the PCB The number of lines is much less than 2 times the number of COFs.

At present, more and more high-resolution panels are available, and the number of COF required is large. Due to the limitation in the plane, the number of repair lines cannot be too large. When the number of repair lines is less than that of COF, the current repair The problem of low repair efficiency will occur in the wire connection method. Because the number of repair lines is less than that of COF, it is inevitable that different COFs will be connected to the same repair line on the PCB, so when two broken lines appear in the area corresponding to a COF, after repairing with the repair line, share it with it If there is a disconnection in the area controlled by the COF of the repair line, it cannot be repaired. Even if there are repair lines reserved on the PCB at this time, the repair cannot be realized due to the limitation of the connection method, so that the LCD panel can no longer be used. The existing repair lines and COFs are connected in a fixed way, and when the number of COFs is greater than that of the repair lines, some repair lines cannot be fully utilized.

Contents of the invention

Purpose of the invention: The purpose of the present invention is to provide a liquid crystal panel repair method that can effectively reduce the reject rate and improve repair efficiency in view of the deficiencies in the prior art.

Technical solution: In order to achieve the above-mentioned purpose of the invention, the invention provides a method for repairing liquid crystal panel line defects, comprising the following steps:

Step 1: Set multiple repair lines on the PCB board in the liquid crystal display, connect the PCB board to the LCD panel through multiple COFs, and connect the two input ports in each COF to any two repair lines, if If the input ports in two or more COFs share one repair line, the input port in one COF is reserved to be directly connected to the repair line, and the input ports in the other COFs are connected to the repair line through a zero-ohm resistor; and Reserve a wiring port connected to the COF input port on each repair line;

Step 2: Detect the data lines in the LCD panel, and detect the number and location of broken data lines;

Step 3: Compare the detection results in step 2 with the number of repair lines, if the number of broken data lines in the LCD panel is greater than the number of repair lines, the LCD panel cannot be repaired; if the number of broken data lines in the LCD panel When the number of repair lines is not greater than that, the input end of the data line to be repaired is electrically connected to the output port of the corresponding COF through laser;

Step 4: If there are two or more COF input ports using the same repair line, keep one of the COF input ports connected to the repair line, and connect another or more COF input ports to the original repair line. After the zero-ohm resistor is disconnected, connect it to the free repair line through the zero-ohm resistor;

Step 5: Electrically connect the output end of the data line to be repaired with the corresponding repair line to form a repair loop.

In the step 1, the two input ports of each COF are connected to the repair line through a zero-ohm resistor, so that the input port of the COF can be flexibly connected to any repair line, thereby making the repair of the LCD panel more convenient and quick.

Beneficial effects: Compared with the prior art, the present invention improves the connection mode of the repair line and the COF input port on the PCB, thereby repairing the originally unrepairable LCD panel without setting too many repair lines, The repair line can be fully utilized, the repair efficiency of the liquid crystal panel is effectively improved, and the reject rate of the liquid crystal panel is effectively reduced. the

Description of drawings

Fig. 1 is the schematic diagram of the circuit structure of embodiment 1 of the present invention;

Fig. 2 is the connection schematic diagram of two input terminals and the repair line in COF4 before repairing in embodiment 1;

FIG. 3 is a schematic diagram of the connection between the two input terminals and the repair line in COF4 after repair in Example 1. FIG.

Detailed ways

The technical solutions of the present invention will be described in detail below, but the protection scope of the present invention is not limited to the embodiments.

Example 1:

A liquid crystal panel defect repairing method provided by the present invention comprises the following steps:

Step 1: Set 6 repair lines on the PCB, as shown in Figure 1, the 6 repair lines are divided into two groups on average, each group is 3 repair lines, one group on the left and one group on the right, the two groups have the same structure . Taking the left group as an example, the three repair lines defining the left group are R1, R2 and R3 respectively. The PCB board is connected to the LCD panel by 12 COFs, and the 12 COFs are equally divided into two groups, 6 COFs in each group, and the two input ports in each COF are respectively connected to any two repair lines through zero-ohm resistors. And reserve a connection port with the COF input port on each repair line.

In this embodiment, since there are only three repair lines in each group, but there are 6 COFs, there will be two COFs connected to the repair lines in the same way, wherein the two input ports of COF1 and COF4 are respectively connected to the repair lines R2 and The repair line R3 is connected, the two input ports of COF2 and COF5 are respectively connected with the repair line R1 and the repair line R2, and the two input ports of COF3 and COF6 are respectively connected with the repair line R1 and the repair line R3. At the same time, there are connection ports with COF1 and COF4 on the repair line R1, connection ports with COF3 and COF6 on the repair line R2, and connection ports with COF2 and COF5 on the repair line R3.

Step 2: Use a tester to detect the data lines in the LCD panel, and detect the number and location of broken data lines;

Step 3: Compare the detection result in step 2 with the number of repair lines. If the number of broken data lines in the LCD panel is greater than 3, the LCD panel cannot be repaired; if the number of broken data lines in the LCD panel is not greater than 3 , electrically connect the input end of the data line to be repaired to the corresponding output port of the COF;

In this embodiment, it is found that three data wires are disconnected after detection, and the two data wires controlled by COF1 and one data wire controlled by COF4 are disconnected. It is electrically connected with the corresponding output ends of COF1 and COF4. the

Step 4: Check the use of the repair line. If two or more COF input ports use the same repair line, keep one of the COF input ports connected to the repair line, and connect the other or more COF input ports After the zero-ohm resistor connected to the original repair line is disconnected, it is connected to the idle repair line through the zero-ohm resistor; since the two input ports of COF1 are respectively connected to the repair line R3 and the repair line R2, as shown in Figure 2, According to the initial preset repair line, the broken line in the COF4 control area is also repaired by the repair line R2, so the broken line cannot be repaired if the repair line R2 is reused. As shown in Figure 3, at this time, the zero-ohm resistor connected to the input port corresponding to the control disconnection in COF4 and the repair line R2 can be taken out, and the input port corresponding to the control disconnection in COF4 can be connected through the zero-ohm resistor. Connect with repair line R1.

Step 5: Electrically connect the output end of the data line to be repaired with the corresponding repair line to form a repair loop. In this embodiment, the output ends of the two data lines controlled by COF1 are electrically connected to the repair lines R3 and R2 respectively, and the output end of the disconnected data line controlled by COF4 is electrically connected to the repair line R1, thus forming repaired the circuit.

Claims (2)

1. a liquid crystal panel line defect restorative procedure, is characterized in that: comprise the following steps:

Step 1: many repair lines are set on the pcb board in liquid crystal display, pcb board is connected with liquid crystal panel by a plurality of COF, wherein two input ports in each COF are connected with any two repair lines respectively, if there is the input port in two or more COF to share a reparation repair line, retain an input port in COF and be directly connected with repair line, the input port in other COF is connected with repair line by zero Europe resistance; And in every repair line the reserved connection jaws being connected with COF input port;

Step 2: the data line in liquid crystal panel is detected, detect quantity and the position of broken data wire;

Step 3: the quantity of the testing result in step 2 and repair line is compared, if the quantity of broken data wire is greater than the quantity of repair line in liquid crystal panel, liquid crystal panel can not be repaired; When if in liquid crystal panel, the quantity of broken data wire is not more than the quantity of repair line, the input end of the data line that needs are repaired with the output port of corresponding COF by radium-shine electrical connection;

Step 4: if there is the input port of two or more COF to use same repair line, the input port that retains one of them COF is connected with reparation, after the input port of another or a plurality of COF and the zero Europe resistance between former repair line are disconnected, then be connected in idle repair line by zero Europe resistance;

Step 5: thus the output terminal of the data line that needs are repaired is electrically connected to formation reparation loop with corresponding repair line.

2. the first defect-restoration method therefor of liquid crystal panel according to claim 1, is characterized in that: two input ports in described step 1 in each COF are all connected with repair line by zero Europe resistance.

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