KR101117982B1 - Liquid Crystal Display Device And Method For Repairing Bright Spot Of The Same - Google Patents

Abstract

After the substrate bonding process of the liquid crystal display device, the present invention proposes a method for repairing bright spots caused by foreign matters inside the liquid crystal panel. The present invention relates to a liquid crystal display device and a method for repairing a bright spot by using a laser beam in which the bright spot defect is blackened by irradiating a laser beam to remove the spot defect caused by light leakage around the foreign matter. Forming a thin film transistor and a pixel electrode, forming a liquid crystal panel by opposing a second substrate with a liquid crystal layer interposed between the first substrate, and inspecting whether the liquid crystal panel has a bright point defect. And arranging a plurality of laser devices to focus on the spot where the bright point defect is confirmed. Irradiating a low beam to blacken the bright spot defect, further comprising forming a color filter layer on the second substrate, and forming an overcoat layer on the entire surface including the color filter layer. The laser beam is irradiated by focusing the plurality of laser devices on the overcoat layer or the color filter layer corresponding to the identified point.

Bright spots, foreign objects, laser repair

Description

Liquid Crystal Display Device And Method For Repairing Bright Spot Of The Same}

1 is a process cross-sectional view showing a bright point repair process according to a first embodiment of the present invention.

Figure 2 is a process cross-sectional view showing a bright point repair process according to a second embodiment of the present invention.

Figure 3 is a process cross-sectional view showing a bright point repair process according to a third embodiment of the present invention.

Figures 4a and 4b is a cross-sectional view showing a bright point repair process according to a fourth embodiment of the present invention.

* Explanation of symbols on the main parts of the drawings

11: first substrate 12: second substrate

13: liquid crystal layer 13a: liquid crystal molecules

21 black matrix 22 color filter layer

23: overcoat layer 30: foreign matter

50: blackening area L1, L2, L3: laser equipment

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device (LCD), and more particularly, to a liquid crystal display device and a bright point repair method for removing a bright spot caused by a foreign substance inside a liquid crystal cell.

Recently, a liquid crystal display device, which is one of the flat panel display devices that are attracting attention, is an element that changes the optical anisotropy by applying an electric field to a liquid crystal having the liquidity and the optical properties of the crystal, and has been applied to a conventional cathode ray tube. Compared with the low power consumption, small volume, large size, and high definition, it is widely used.

The liquid crystal display device having such characteristics is a structure in which a color filter substrate as an upper substrate and a TFT (Thin Film Transistor) array substrate as a lower substrate are bonded to face each other, and a liquid crystal layer having dielectric anisotropy is formed therebetween. And a thin film transistor (TFT) added to hundreds of thousands of pixels through a pixel selection address wiring to drive a voltage to the corresponding pixel.

In order to manufacture the liquid crystal display device as described above, a thin film transistor array substrate process, a color filter substrate process, a liquid crystal cell process, and the like should be largely performed.

The thin film transistor array substrate process is a process of forming a gate line, a data line, a thin film transistor and a pixel electrode on an organic substrate by repeating deposition, photolithography, and etching processes.

In the color filter substrate process, a color filter layer of red, green, and blue is formed on the organic substrate on which a black matrix is formed to realize colors. To form the common electrode ITO film.

In addition, the liquid crystal cell process is a process of forming a liquid crystal layer by bonding liquid crystal between the thin film transistor array substrate and the color filter array substrate so as to maintain a predetermined gap therebetween.

At this time, before the liquid crystal cell process, a test process is performed to test operation states of various circuit patterns on the thin film transistor array substrate and the color filter substrate and to detect defective pixels.

Pixel defects include line defects caused by point defects such as color defects by pixel area, bright spots always showing white, and dark spots always showing black, and short circuits between adjacent data lines. defects).

In this case, if a point defect is found, a repair process for darkening the unit pixel in which the point defect is found by performing a repair process by disconnecting the wiring by using a laser repair technology to produce a product.

That is, by short-circuiting and floating the wiring using laser equipment, the pixel is darkened by preventing the data signal from being applied to the pixel electrode.

If a defect occurs in one unit pixel, if the point is a dark point (black), it is inconspicuous when the surrounding pixel is white display, but if the point is a bright point (white), it is severe when the surrounding pixel is black display. As it stands out, it is advantageous to darken the defective pixels.

As a result, the darkened unit pixel does not play a role of displaying an image. However, since the darkened point of one unit pixel is spec-in, the next process may be continued.

However, in the liquid crystal display device according to the prior art, if foreign matter still exists after the test step, the printability during PI printing due to the foreign matter is poor, the pretilt angle and anchoring energy around the foreign matter. The energy is changed so that the regular arrangement of liquid crystal molecules is broken. Therefore, light leakage occurs around the foreign material.

In particular, the light level around the foreign material is relatively prominent toward the black level, and the black level is recognized as a bright spot. When liquid crystals are arranged by a horizontal electric field as in the IPS mode liquid crystal display device, such bright point defects are a major limitation in making a high quality liquid crystal display device.

In addition, when such a bright point defect is caused by a foreign matter formed inside the liquid crystal cell after the liquid crystal cell process, it is difficult to repair the defect because the opposing bonded substrate cannot be separated.

In addition, since the size of the bright point defect due to the foreign matter is about several tens of μm, it is not much easier to repair.

The present invention has been made in order to solve the above problems, when the foreign matter is confirmed inside the liquid crystal cell after the upper and lower substrate bonding process, the plurality of laser equipment is positioned at various angles in the region where the bright point is caused by the foreign matter It is an object of the present invention to provide a liquid crystal display device and a method for repairing a bright spot, which are intended to remove the bright spot caused by light leakage around a foreign material by blackening the spot defect by irradiating a laser beam by matching a focus to the laser beam.

The liquid crystal display device of the present invention for achieving the above object is a liquid crystal panel having a liquid crystal layer filled between the first and second substrates and the first and second substrates bonded at regular intervals, and the liquid crystal The blackening area may be included in the first substrate or the second substrate of the portion where the bright point defect occurs in the panel.

The first substrate on which the thin film transistor array is formed, the second substrate on which the color filter array including the color filter layer is formed to face the first substrate, the liquid crystal layer formed between the first and second substrates, and the bright point defect And a blackening area in the color filter layer of the generated portion.

In addition, a first substrate on which a thin film transistor array is formed, a second substrate on which a color filter array including an overcoat layer is formed to face the first substrate, a liquid crystal layer formed between the first and second substrates, and a bright point defect It characterized in that it comprises a blackening area in the overcoat layer of the generated portion.

As described above, the liquid crystal display device according to the present invention includes a blackening area on the substrate, the color filter layer, or the overcoat layer in order to repair a bright point defect. The blackening area is formed by a plurality of laser beam irradiation.

Meanwhile, a bright point repair method of a liquid crystal display device for achieving another object of the present invention comprises the steps of forming a gate wiring, a data wiring, a thin film transistor and a pixel electrode on a first substrate, and between the first substrate and the first substrate; Forming a liquid crystal panel by opposing the second substrate with the liquid crystal layer; inspecting whether the liquid crystal panel has a poor point of light, and arranging a plurality of laser devices so as to focus on the bright point; It characterized in that it comprises a step of irradiating the bright spot failure portion by irradiating.

That is, after the substrate bonding process of the liquid crystal display device, a method of repairing bright spots caused by a foreign substance inside the liquid crystal panel is proposed. A plurality of laser devices are placed at various angles and focused on a portion where the bright spots are caused by foreign substances. It is characterized by blackening the bright point defective part by irradiating a laser beam by matching. At this time, the focus of a plurality of laser equipment to focus on one portion to irradiate a laser beam of strong energy, it is possible to minimize the effect of blackening to adjacent pixels.

Meanwhile, the focusing portion of the plurality of laser devices may be a substrate, an overcoat layer, and a color filter layer so that the components are blackened or deformed to block light leakage. Laser beam irradiation may be directed to the upper substrate or to the lower substrate. However, the laser is not applied to the circuit pattern required for driving the liquid crystal display device.

As a result, laser repair can be performed on several low-cost laser devices without using high-power, expensive laser equipment, thereby reducing the cost of equipment investment.

On the other hand, as in the prior art, instead of darkening the entire pixel area, only a predetermined area within the pixel area is partially darkened, so there is no fear of dark spot detection in the white level luminance.

According to another aspect of the present invention, there is provided a bright point repair method for a liquid crystal display device, the method including: forming a gate wiring, a data wiring, a thin film transistor, and a pixel electrode on a first substrate; Forming a liquid crystal panel by opposing and bonding the second substrate with the liquid crystal layer; inspecting whether the liquid crystal panel has a bright point defect, and at least one of the first and second substrates where the bright point is confirmed. And irradiating the laser beam to locally etch the substrate to form an intaglio area, and filling an opaque material in the intaglio area.

That is, in addition to directly darkening the substrate to darken it, the substrate is etched to form a negative area, and then an opaque material such as ink is buried in the negative area to darken the bright spot defect.

Hereinafter, a liquid crystal display and a bright point repair method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

1, 2 and 3 are process cross-sectional views showing a bright spot repair process according to the first, second and third embodiments of the present invention, respectively, and FIGS. 4A and 4B are bright spots according to the fourth embodiment of the present invention. Process sectional view showing the repair process.

First, as shown in FIG. 1, the first and second substrates 11 and 12, on which various patterns for driving the elements are formed, are bonded to each other and a liquid crystal layer 13 is formed therebetween. The sealant (not shown) formed at the edges of the first and second substrates serves as an adhesive for completely bonding the two substrates so that the liquid crystal layer does not flow out.

In this case, the first substrate 11 is a thin film transistor array substrate, and includes a gate line and a data line defining a unit pixel region, a thin film transistor formed at an intersection point of the gate line and the data line, and a thin film transistor. Thus, patterns 29 of pixel electrodes for applying a voltage for driving the liquid crystal layer are formed in the unit pixel areas.

The second substrate 12 is a color filter layer array substrate, and includes a black matrix 21 for preventing light leakage, a color filter layer 22 for R, G, and B for realizing color on the black matrix. An overcoat layer 23 formed to planarize the surface of the color filter layer, or a common electrode (not shown) for applying a voltage for driving the liquid crystal layer to face the pixel electrode of the first substrate 11; It is.

Here, in the liquid crystal display of the IPS mode, not only the pixel electrode is formed in the unit pixel area of the first substrate 11, but the common electrode and the pixel electrode are formed to be parallel to each other at a constant interval. The common electrode is not formed on the second substrate 12, but only the overcoat layer 23 is formed.

In addition, an alignment layer (not shown) is formed on inner surfaces of the first and second substrates 11 and 12 having the above pattern to determine the initial alignment direction of the liquid crystal layer.

In the liquid crystal display device configured as described above, the liquid crystal molecules 13a are rearranged by a vertical electric field formed between the pixel electrode of the first substrate and the common electrode of the second substrate, thereby displaying an image of white or black.

The liquid crystal display device as described above has a Mass Production (MPS) test for defects such as line defects and point defects before opposing the first and second substrates 11 and 12. System) It goes through a test process, and performs a repair process that darkens the unit pixels in which defects are found.

However, after the first and second substrates are bonded to each other to complete the liquid crystal panel, there is a problem in that light leakage occurs due to foreign matter inside the liquid crystal panel. This is caused by the foreign matter remaining in the process of forming the pattern on the substrate, the printability during the alignment film printing by the foreign matter 30 is broken, the regular arrangement of the liquid crystal molecules 13a is broken around the foreign matter. Therefore, although black is to be displayed on the image, bright spots are generated around foreign matters in which the arrangement of the liquid crystals is broken, which is a great limitation in making a high quality liquid crystal display device.

Therefore, in order to eliminate the defect of the bright point in the liquid crystal display device in which the liquid crystal cell process is completed, the plurality of laser devices are arranged at various angles, and the bright spot is blackened or deformed by focusing on the bright spot and irradiating a laser beam. So that light can be blocked.

In detail, as illustrated in FIG. 1, a plurality of laser devices L1, L2, and L3 are disposed at various angles on the first substrate 11, and the first substrate corresponding to a portion where the foreign material 30 is formed. The laser beam is irradiated after setting the focus of the laser to (11).

Then, the first substrate in the portion irradiated with the laser by the plurality of laser beams is locally blackened or deformed locally by the strong energy of the plurality of laser beams, thereby forming a blackening region 50. Will fall. That is, in the state where the foreign matter is left as it is, the substrate of the region where the foreign matter is formed is locally blacked to block unwanted light leakage.

In this case, at least two laser devices may be prepared to perform a repair process by irradiating a laser beam toward a single focal point at various angles, and several laser devices having a lower cost than expensive laser devices where strong energy is radiated. It would be more desirable to lower the equipment investment cost by using it.

As described above, the color filter layer 22 and the overcoat layer 23 are not limited to blackening the first substrate 11 on which the patterns 29 such as thin film transistors are formed. ) May be blackened. That is, the blackening region 50 is formed by focusing all the laser equipment at a desired position inside the second substrate 12 and irradiating the laser beam locally to blacken it.

In the above, the method of darkening the substrate and darkening the bright point defect is described. However, as shown in FIG. 3, the color filter layer 22 or the overcoat layer 23 is blackened or deformed to make the color filter layer 22 or the overcoat layer black. (23) A blackening area may be formed inside to block light leakage.

That is, a plurality of laser devices (L1, L2, L3) are arranged at various angles and the focus is aligned with the color filter layer 22 or the overcoat layer 23 corresponding to the bright spot, and then irradiates the laser beam. The color filter layer or overcoat layer is locally discolored by the strong energy of the laser equipment and darkens.

At this time, the substrate, the color filter layer or the overcoat layer is blackened to correspond to the size (D) of the area requiring repair by the foreign matter.

However, the laser beam is not irradiated to circuit patterns such as wiring, electrodes, and thin film transistors required for driving the liquid crystal display.

In addition to darkening by changing and blackening the physical properties of the substrate, the color filter layer, and the overcoat layer, as described below, the substrate may be etched using laser equipment and filled with an opaque material in the etched intaglio area to darken it.

First, as shown in FIG. 4A, the first and second substrates 111 and 112 on which various patterns for driving the elements are formed are bonded to each other and a liquid crystal layer 113 is formed therebetween.

However, after bonding to the substrate, the bright spot may be caused by foreign matter remaining in the liquid crystal panel, and the substrate is etched by irradiating a laser beam on the spot where the bright spot has occurred using a laser device.

In this case, at least one laser device is used. When using a plurality of laser devices L1, L2, and L3, the laser devices are arranged at various angles, and the laser beam is focused by focusing on the spot defects. The intaglio region 150 is formed by etching the substrate.

In the method of irradiating a laser beam, the laser beam is irradiated within a range that does not completely penetrate the substrate while descending the focus of the laser beam from the substrate surface to a desired portion.

As shown in FIG. 4B, an opaque material is dropped into the etched substrate intaglio area 150, for example, by dropping the ink 145 to darken the spot where the bright spot is generated.

As such, when the substrate is etched and ink is filled in the engraved region, the region to be repaired becomes opaque by the ink, and the defect of bright spots around the foreign matter can be eliminated at the source. In addition, even after completion of the liquid crystal panel, it is possible to repair a bright point defect caused by a foreign substance inside the liquid crystal cell.

In this case, it is preferable that the liquid crystal display device is of a normally black type. This is because when the unit pixel becomes a dark spot, the peripheral pixel becomes inconspicuous when the white display is white, and thus the influence on the image quality is insufficient when displaying the image.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

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

First, place a plurality of laser equipment at various angles and focus on the spot where the spot defect occurs, and then irradiate the laser beam to blacken the spot defect, thereby eliminating the spot defect due to light transmission around the foreign material. Can be.

Second, since the bright point caused by the foreign matter inside the liquid crystal panel can be repaired after the substrate bonding process of the liquid crystal display device, the defective rate of the device can be minimized.

Third, since a plurality of laser devices are matched with one focal point to irradiate a laser beam of strong energy, the effect of blackening on adjacent pixels can be minimized.

Fourth, it is possible to reduce the cost of equipment investment because the laser repair can be performed by several low-cost laser equipments without using high-power expensive laser equipment.

Fifth, in the conventional repair process, bright spots are solved by darkening the entire unit pixel region. However, in the present invention, the darkened region can be minimized by partially darkening at least a region where foreign matter is located among the unit pixel regions.

Claims (16)

delete delete delete A first substrate on which a thin film transistor array is formed; A second substrate facing the first substrate and having a color filter array including a color filter layer; A liquid crystal layer formed between the first and second substrates; It includes a blackening area in the color filter layer of the portion where the bright point failure occurs, And the blackening area is formed by a plurality of laser beam irradiation. delete A first substrate on which a thin film transistor array is formed; A second substrate facing the first substrate and having a color filter array including an overcoat layer; A liquid crystal layer formed between the first and second substrates; And a blackening region in the overcoat layer of the portion where the bright point defect has occurred. 7. The liquid crystal display device according to claim 6, wherein the blackening area is formed by a plurality of laser beam irradiation. Forming a gate wiring, a data wiring, a thin film transistor, and a pixel electrode on the first substrate; Forming a liquid crystal panel by opposing and bonding a second substrate with a liquid crystal layer between the first substrate; Inspecting whether or not the bright point of the liquid crystal panel is defective; Arranging a plurality of laser apparatuses so as to focus on the spot where the spot defect is confirmed, and irradiating a laser beam to blacken the spot defect part; Forming a color filter layer on the second substrate; The method may further include forming an overcoat layer on the entire surface including the color filter layer. And focusing the plurality of laser devices on the overcoat layer or the color filter layer corresponding to the point where the bright point defect is confirmed, and irradiating a laser beam to the bright point repair method of the liquid crystal display device. delete delete delete delete delete delete delete delete

Images