KR100487429B1 - Method For Repairing A Defect Of Liquid Crystal Display Device And Liquid Crystal Display Device - Google Patents

Abstract

The present invention relates to a method for repairing a defect of a liquid crystal display device, wherein a black pigment or a tape is formed on the upper C / F substrate of the bright coordinates after the automatic alignment by floating the coordinates of the bright spots in which the circuit found during the automatic probe inspection after the panel is completed. The defect repair method of the liquid crystal display device characterized in that the darkening and repairing.

Description

Method for Repairing A Defect Of Liquid Crystal Display Device And Liquid Crystal Display Device

The present invention relates to a defect repair method and a liquid crystal display device of the liquid crystal display device, and more particularly to a method for repairing point defects.

Liquid crystal display devices have various uses such as notebooks, personal digital assistants, TVs, and aviation monitors due to low voltage driving, full color implementation, and light and small size. In recent years, research into manufacturing large panels has been actively conducted in the industry of liquid crystal display devices.

Here, the liquid crystal display device is a display device that applies an operating voltage to tens of thousands of thin film transistors to activate the same number of pixel electrodes, and implements an image by using light transmittance according to the arrangement of liquid crystals between the pixel electrode and the common electrode. However, when manufacturing a liquid crystal display device, there are pixel electrodes which do not operate among tens of thousands of pixel electrodes. This defect includes predecessors that do not operate the entire line and point defects where only one coordinate does not work.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the cause of the non-operating pixel electrode and the method for repairing the point defect according to the prior art.

1 is a plan view showing a defect type in a TFT array of a general liquid crystal display device, and FIG. 2 is a process chart of a conventional point defect repair method.

As shown in FIG. 1, the point defects of the TFT array are shown. Here, G _1, G _{2, and} G ₃ are gate wirings and D _1, D _{2 and} D ₃ are data wirings.

First, there are no source / drain active layers, a case where the pixel electrode is not attached, and a contact between the drain and the pixel electrode are unstable or not. The types of point defects are as follows. There is a point defect 101 due to a source defect and a point defect 102 due to a short circuit between a source and a drain. There is a point defect 103 due to a gate defect, and a point defect 104 due to a short circuit between the pixel electrode and the pixel electrode. Short circuit here means short.

As shown in FIG. 2, in the conventional method for repairing a point defect, a defect coordinate is first detected through an automatic probe device (210). The bad coordinate detection method 210 uses a method of fixing a needle at an intersection point of a gate wiring line and a data wiring line by line, applying a voltage through an external signal, and then detecting a coordinate that cannot drive a signal. Point defects that cannot be driven have bright spots and dark spots. In this case, when the liquid crystal display is normally white (NW), coordinates that cannot drive a signal indicate a bright point. Here, a method of giving an external signal uses a personal computer or a pattern generator. Then, in order to clearly distinguish the bright spots, a gray is placed and the defective coordinates are found.

Find the defective coordinates and then do a laser repair (220). It is to darken the point of light with a laser. That is, the gate electrode and the storage electrode are welded with a laser to shorten them. Here, laser welding is as follows. When a laser is irradiated to a metal with a high energy artificial ray, the laser can be converted into thermal energy to melt (weld) the metal or to burn (remove) the metal if strong. Welding is when the laser power is weak, and the discharge slit size is small, and combustion (removal) is when the laser power is strong and the discharge slit size is large. Select the laser well to weld the gate and storage electrodes. When irradiated using a laser welding machine, the passivation of the gate electrode and the upper layer of the storage electrode is burned at a low temperature, so that the gate electrode and the storage electrode can be welded.

Then, it is checked whether the point defect is repaired successfully by using the automatic probe device (230). The method is the same as that described at 210.

After confirming that the point defects (bright spots) are successfully repaired, washing with distilled water and attaching a polarizing plate (240). After attaching the polarizer (240) Tab attached and inspected (250).

The defect repair method of the liquid crystal display device as described above has the following problems.

First, point defects that can cause predecessors during laser repair cannot be repaired.

In other words, when the data line and the storage electrode are incorrectly connected, when the gate electrode and the storage electrode are laser-welded (the gate line and the storage electrode are connected), a gate defect is connected to the data line connected to the storage electrode. Therefore, it is impossible to repair the point defect.

Second, if the defect is not detected and proceeds to the next step, the point defect cannot be repaired.

Third, the repair process of the bright spot is complicated.

Fourth, in order to repair the defect, the polarizer must be removed, which causes a high cost.

The present invention has been made to solve the above problems, and after the completion of the panel, the coordinates of the spots found during the automatic probe inspection floating the upper C / F substrate of the spots with a black pigment or tape on the coordinates after the automatic alignment before polarizing plate attachment The process of repairing the point defects by dark spots is simple, the process is simple, no side effects of the predefects occur, and repair is possible even if missed during the probe inspection. The object is to provide an element.

Defect repair method of the liquid crystal display device of the present invention for achieving the above object, the upper C / F of the coordinate coordinates after the automatic alignment by floating the coordinates of the bright spot that the circuit found during the automatic probe inspection after completion of the panel It is characterized by covering the substrate with black pigment or tape to darken and repair.

Hereinafter, a defect repairing method and a liquid crystal display device of a liquid crystal display device according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view of an automatic probe device for carrying out the present invention, FIG. 4 is a configuration diagram of the automatic probe device including FIG. 3 for carrying out the present invention, and FIG. 5 is a process diagram of a method for repairing point defects of the present invention. 6 is a cross-sectional view of the liquid crystal display device repaired by the present invention.

As shown in FIG. 3, the LCD substrate 300 is moved to a test position defined by the stage 318 and the suction table 317 using handling means such as a robot arm, and the substrate 300 is fixed by vacuum suction. . Then, the stage 318 is moved to the stage shaft 319. A backlight 301 on the stage 318, a diffuser plate 302 for diffusing an electric light on the backlight 302, and a lower plate polarizer 303 for transmitting light in one direction on the diffuser plate 302. Is installed. The adsorption table 317 is formed of a material capable of transmitting polarized light.

A light source 314 that will pass through the upper polarizing plate 312 is disposed in the illumination jig 311, and the illuminance of the light source 314 is adjusted through the dimming box 316. Here, the probe device is cut off from the outside by the light blocking box 315.

The lighting jig 311 is a device for mounting the light source 314 and is disposed in the base plate 313. The lighting jig 311 and the light source 314 are lighting devices that are turned on by a direct current so as to constantly emit the DC light 320 under the control of an illumination signal from the dimming box 316.

To check the point defect, the stage 318 and the stage shaft 319 are adjusted to raise the substrate 300 to the manipulator 313a, and the baseplate 313 and the manipulator 313a are moved. The substrate 300 is electrically inspected by directly contacting an intersection point of the gate line and the data line and applying a voltage. At this time, the adsorption table 317 adsorbs the substrate 300 to fix the substrate 300 so that the manipulator 313a can accurately contact the gate and drain terminals.

The bad coordinate detection method is as follows. The base plate 313 and the man plate 313a have probes having needle tips such as pogo pins or needles, and probes at intersections of gate and data lines line by line. Is fixed, voltage is applied through an external signal, and then a method of visually detecting a coordinate that cannot drive the signal is used. Point defects that cannot be driven have bright spots and dark spots. In this case, when the liquid crystal display is normally white (NW), coordinates that cannot drive a signal indicate a bright point. Here, a method of giving an external signal uses a personal computer or a pattern generator. Then, in order to clearly distinguish the bright spots, a gray is placed and the defective coordinates are found.

After detecting and displaying a defective coordinate of the substrate 300, the substrate 300 is lowered from the manipulator 313a.

Referring to the names and brief description of each part using the configuration diagram of the automatic probe device of Figure 4 as follows. The worktable 401 performs panel conveyance, contact with the needle after alignment, and the like. In the work table 401, a backlight, a diffusion plate, and a lower plate polarizer are sequentially formed from below. The alignment camera 402 photographs the alignment mark of the panel. The base plate 403 is a substrate on which the probe unit is mounted. The probe unit is composed of PCB, FPC, TAB IC, needle or film type.

The panel set position 404 is a portion for mounting and detaching the panel to be inspected. The CRT monitor 405 is a monitor on which alignment marks of panels are displayed. The microscope arm 406 is used for poor contact and contact state between the electrode and the needle. The operation panel 407 shows the current operating state. The testing panel 408 shows a backlight power supply, ionizer power switch. The main body power switch panel 409 performs equipment power on and off.

Mounting frame 410 is a built-in equipment control box and can adjust the inspection height. Emergency power switch 411 is a switch to stop the operation of the equipment in an emergency. The backlight adjustment switch 412 is a switch for adjusting the backlight brightness. The run model indicator 413 displays the model and thickness of the currently set panel.

And, as shown in Figure 5, in the point defect repair method according to the present invention, first, the defective coordinates are detected through the automatic probe device (510). The bad coordinate detection method 510 uses a method of fixing a needle at an intersection point of a gate wiring line and a data wiring line by line, applying a voltage through an external signal, and then detecting a coordinate that cannot drive a signal. Point defects that cannot be driven have bright spots and dark spots. In this case, when the liquid crystal display is normally white (NW), coordinates that cannot drive a signal indicate a bright point. Here, a method of giving an external signal uses a personal computer or a pattern generator. Then, in order to clearly distinguish the bright spots, a gray is placed and the defective coordinates are found.

The detected defective coordinates are displayed and washed with distilled water. After cleaning, the black pigment or tape is attached to the C / F on the top of the defective coordinates (bright spots) (520). In other words, the bright spot is darkened. Even if the incorrectly displayed coordinates are removed by attaching the black pigment or tape to the correct coordinates, the repair method is simple and can be quickly responded to a repair miss.

After repairing the point defect, the polarizing plate 530 is attached and then inspected after attaching the tab 540.

 FIG. 6 shows a first substrate including a light source 601 and a thin film transistor 602 formed at an intersection of a data line, a gate line, a data line and a data line and a pixel electrode 603 driven by the thin film transistor. There is a (600), a color filter 652 formed between the black matrix 651, the black matrix 651, and the common electrode 653 deposited on the front of the black matrix 651 and the color filter 652. 2 is a cross-sectional view of a liquid crystal display device including a second substrate 650 including a defect correction means 660 on a rear surface of the second substrate 650 corresponding to the defective thin film transistor 604. Here, the defect correcting means 660 includes attaching a black tape or black pigment to the upper C / F substrate of the bright coordinates, and the polarizing plate 670 is attached to the upper portion of the defect correcting means 660.

The defect repair method and the liquid crystal display device of the liquid crystal display device of the present invention as described above has the following effects.

First, since the black pigment or tape is attached to the C / F on the top of the bad coordinates, it is possible to repair the point defects that cannot be repaired because laser defects are not generated because side effects are not generated.

Second, they can respond quickly to repair misses.

Third, the point defect repair process is simple.

Fourth, the cost of repairing point defects is low.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

1 is a plan view showing a defect type in a TFT array of a general liquid crystal display device.

Figure 2 is a conventional process for repairing point defects.

3 is a cross-sectional view of an automatic probe device for practicing the present invention.

4 is a block diagram of an automatic probe device including FIG. 3 for practicing the present invention.

5 is a process diagram of the point defect repair method of the present invention.

6 is a cross-sectional view of a liquid crystal display device repaired by the present invention.

* Explanation of symbols for main parts of the drawings

510: automatic probe inspection, bad coordinate detection

520: Attach black pigment or tape to C / F on top of the coordinates after cleaning

530: polarizing plate attached

540: Inspection after attaching tab

Claims (4)

Detecting defective coordinates of the pixel through an automatic probe inspection after panel completion; Displaying and cleaning the detected defective coordinates; Attaching a black pigment or black tape onto the C / F substrate on top of the bad coordinates; Fixing a defect of the liquid crystal display device comprising the step of attaching a polarizing plate on the front surface of the C / F substrate including the pigment or black tape. Light source, A first substrate including a data line, a gate line, a thin film transistor formed at an intersection of the data line and the data line and a pixel electrode driven by the thin film transistor; A second substrate including a black matrix, a color filter formed between the black matrix, the black matrix and a common electrode deposited on the front surface of the color filter; Defect correction means formed on a rear surface of the second substrate so as to correspond to a defective thin film transistor among the thin film transistors; Liquid crystal display device comprising a polarizing plate formed on the defect correction means.        The liquid crystal display device according to claim 2, wherein the defect correction means attaches a black tape or a black pigment to the upper C / F substrate of the bright point coordinates. delete