KR100950519B1 - Apparatus And Method Of rubbing in Liquid Crystal Display Panel - Google Patents

Abstract

The present invention relates to a rubbing apparatus and method for a liquid crystal display panel that can shorten the rubbing process time and increase orientation uniformity and rubbing density.

A rubbing apparatus for a liquid crystal display panel according to the present invention includes: a plurality of rubbing portions for rubbing an alignment film formed on a substrate; And a control unit for controlling the plurality of rubbing units.

Description

Rubbing device and method of liquid crystal display panel {Apparatus And Method Of rubbing in Liquid Crystal Display Panel}             

1 is a cross-sectional view of a general liquid crystal display panel.

2 is a flowchart illustrating a manufacturing process of a general liquid crystal cell.

3 is a view showing a rubbing device of a liquid crystal display panel generally used.

4 is a view showing a rubbing device for a liquid crystal display panel according to a first embodiment of the present invention.

5 is a view illustrating a process in which a rubbing process is performed by a rubbing device of the liquid crystal display panel shown in FIG. 4.

6 is a view showing a rubbing device for a liquid crystal display panel according to a second embodiment of the present invention.

FIG. 7 illustrates a process in which a rubbing process is performed by a rubbing device of the liquid crystal display panel shown in FIG. 6 when rubbing a first model substrate. FIG.

FIG. 8 illustrates a process in which a rubbing process is performed by a rubbing device of the LCD panel shown in FIG. 6 when rubbing a second model substrate; FIG.

<Description of Symbols for Main Parts of Drawings>

10,110: first and second substrate 21: gate electrode

30 insulating film 41 active layer

51, 52: ohmic contact layer 61: source electrode

62 drain electrode 70 protective layer

71: contact hole 81: pixel electrode

91,150: first and second alignment layers 120: black matrix

130: color filter 140: common electrode

212,412,712: alignment layer 213,513,813 support

214,514,814: Loving Roll 215,515,815: Loving Can

216,416,716: Stage 217,417,717: Driving roller

300, 400, 700: substrate 700a, 700b: first and second model substrate

500,800: rubbing part 800a, 800b: first and second model rubbing part

600,900: control unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more particularly, to a rubbing device and a method of a liquid crystal display panel which can shorten the rubbing process time and increase orientation uniformity and rubbing density.

Recently, with the rapid development of the information society, there is a need for a flat panel display having excellent characteristics such as thinning, light weight, and low power consumption. Among them, a liquid crystal display panel having excellent color reproducibility is emerging. display panel) is actively developed.

In general, a liquid crystal display panel has two substrates each having electrodes formed thereon so that the surfaces on which the two electrodes are formed face each other, a liquid crystal material is injected between the two substrates, and a voltage is applied to the two electrodes. By moving the liquid crystal molecules, the image is represented by the transmittance of light that varies accordingly.

1 is a cross-sectional view of a general liquid crystal display panel.

Referring to FIG. 1, in a general liquid crystal display panel, a gate electrode 21 made of a conductive material such as a metal is formed on a transparent first substrate 10, and a silicon nitride film (SiN _x ) or a silicon oxide film (SiO ₂ ) is formed thereon. The gate insulating film 30 made of) covers the gate electrode 21. An active layer 41 made of amorphous silicon is formed on the gate insulating layer 30 on the gate electrode 21, and ohmic contact layers 51 and 52 made of amorphous silicon doped with impurities are formed thereon.

Source and drain electrodes 61 and 62 made of a conductive material such as a metal are formed on the ohmic contact layers 51 and 52, and the source and drain electrodes 61 and 62 together with the gate electrode 21 are thin film transistors. (T).                         

Although not shown, the gate electrode 21 is connected to the gate wiring, the source electrode 61 is connected to the data wiring, and the gate wiring and the data wiring are orthogonal to each other to define the pixel region.

Subsequently, a passivation layer 70 made of a silicon nitride film, a silicon oxide film, or an organic insulating layer is formed on the source and drain electrodes 61 and 62, and the passivation layer 70 has a contact hole 71 exposing the drain electrode 62. Has

A pixel electrode 81 made of a transparent conductive material is formed in the pixel area above the passivation layer 70, and the pixel electrode 81 is connected to the drain electrode 62 through the contact hole 71.

The first alignment layer 91 formed of a material such as polyimide and having a predetermined direction is formed on the pixel electrode 81.

Meanwhile, the second substrate 110 is disposed on the first substrate 10 and spaced apart from the first substrate 10 at a predetermined interval.

The black matrix 120 is formed at a portion of the second substrate 110 that corresponds to the thin film transistor T. Although not illustrated, the black matrix 120 covers portions other than the pixel electrode 81. The color filter 130 is formed under the black matrix 120, and the color filter 130 sequentially repeats three colors of red (R), green (G), and blue (B). The color corresponds to one pixel area. Next, a common electrode 140 made of a transparent conductive material is formed below the color filter 130, and a second electrode formed of a material such as polyimide and having a predetermined direction under the common electrode 140 is formed. The alignment film 150 is formed. The liquid crystal layer 200 is injected between the first alignment layer 91 and the second alignment layer 150.

The liquid crystal display panel includes an array substrate manufacturing process for forming a thin film transistor and a pixel electrode, a color filter substrate manufacturing process for forming a color filter and a common electrode, an arrangement of two manufactured substrates, an injection and encapsulation of a liquid crystal material, and a polarizing plate attached. It is formed by a liquid crystal cell process consisting of.

2 is a flowchart illustrating a general liquid crystal cell manufacturing process.

Referring to FIG. 2, in a general liquid crystal cell manufacturing process, a thin film transistor substrate including a thin film transistor and a color filter substrate including a color filter are prepared (st1).

The thin film transistor substrate is formed by repeating a process of depositing and patterning a thin film several times. The number of masks used in patterning of thin films is representative of the number of processes, and research is being actively conducted to reduce manufacturing costs by reducing the number of masks. have.

The color filter substrate is formed by sequentially forming a black matrix, a color filter of red (R), green (G), and blue (B) and a common electrode to prevent light leakage from occurring in portions other than the pixel region.

Subsequently, an alignment film for determining an initial arrangement direction of liquid crystal molecules is formed on each substrate (st2).

Formation of the alignment film consists of applying a polymer thin film and arranging the alignment film in a constant direction. In general, a polyimide-based organic material is mainly used for the alignment layer, and a rubbing method is used as a method of arranging the alignment layer. The rubbing method rubs an alignment layer in a predetermined direction using a rubbing cloth, and has an advantage of easy alignment processing, which is suitable for mass production, stable alignment, and easy control of the pretilt angle.

Next, a seal pattern is formed on one of the two substrates (st3), and the seal pattern is located outside the region where the image is represented, and forms a gap for injecting the liquid crystal and leaks the injected liquid crystal. Serves to prevent.

The seal pattern is formed by forming a thermosetting resin in a predetermined pattern, and a seal pattern forming method includes a screen printing method using a screen mask and a seal dispenser method using a dispenser.

Subsequently, in order to maintain a precise and uniform gap between the thin film transistor substrate and the color filter substrate, a spacer having a predetermined size is scattered on one of the two substrates (st4). The scattering method of the spacer can be divided into a wet spreading method in which the spacer is mixed by spraying alcohol and the like, and a dry spreading method in which only the spacers are scattered.

Next, two substrates of the liquid crystal display panel, that is, the thin film transistor substrate and the color filter substrate are disposed, and the seal patterns are pressed and cured (st5). At this time, the alignment films of the substrates face each other, and the pixel electrodes and the color filters are disposed so as to correspond one-to-one.                         

Next, the two substrates are cut into respective cells and separated (st6). In general, by forming a plurality of cells to be one liquid crystal display panel on a single substrate and separating the cells into cells, the liquid crystal display panel can improve manufacturing efficiency and reduce manufacturing cost.

The cell cutting process includes a scribe process of forming a cutting line on the surface of the glass substrate using a diamond pen having a hardness higher than that of the glass substrate, and a break process of applying a force to cut the glass substrate.

Next, the liquid crystal is injected between the alignment layers of the two substrates (st7). As the injection of the liquid crystal, a vacuum injection method using a pressure difference inside and outside the cell is mainly used. Here, when the liquid crystal is injected into the cell, bubbles may be formed inside the cell by minute air bubbles in the liquid crystal, which may cause a defect. Therefore, in order to prevent this, a defoaming process of removing bubbles by leaving the liquid crystal in vacuum for a long time is necessary.

When the injection of the liquid crystal is completed, the injection hole is sealed so that the liquid crystal does not flow out of the injection hole of the cell. In general, after applying the ultraviolet curable resin to the inlet using a dispenser, the inlet is prevented by irradiating with ultraviolet rays to cure.

Next, the polarizing plates are attached to the outside of the liquid crystal cell formed in this manner, and then the driving circuit is connected to complete the liquid crystal display panel (st8).

Such a liquid crystal display panel includes a color filter substrate having a color filter and a common electrode, a thin film transistor substrate having a thin film transistor and a pixel electrode formed thereon, and a liquid crystal layer formed between the two substrates. The liquid crystal molecules of should be oriented in a specific direction.                         

Therefore, in order to align the liquid crystal molecules in a specific direction, an organic polymer film called an alignment film must be artificially formed on the substrate and subjected to rubbing to impart anisotropy.

That is, polyamic acid, soluble polyimide, and the like are applied to the upper surface of the substrate, and then cured at a temperature of about 60 ° C. to about 80 ° C. and about 80 ° C. to about 200 ° C., and then polyimidized. Various alignment patterns are formed on the surface of the polyimide film.

Here, the rubbing process is performed by rotating a cylindrical rubbing roll wound with a rubbing cloth such as rayon or nylon and rubbing while applying physical friction to the surface of the polyimide film.

The rubbing method currently used is a technology that attaches a rubbing cloth to the rubbing roll and then rotates the rubbing roll to leave a uniform groove on the alignment layer.The rubbing roll rotates and moves without moving the rubbing stage on which the substrate is mounted for each type. And a rubbing head moving method for rubbing the alignment film, and a rubbing stage moving method for rubbing the alignment film by rotating the rubbing roll in place.

3 is a view showing a rubbing device commonly used.

Referring to FIG. 3, a rubbing device commonly used includes a rubbing roll 314 having a cylindrical shape, a rubbing cloth 315 attached to the outer circumferential surface of the rubbing roll 314 using double-sided tape, and a rubbing roll 314. Is connected to the central axis of the support is provided with a support (313) for supporting the rubbing roll.

Referring to the driving method of the rubbing device, first, the substrate 300 on which the alignment layer 312 is formed is mounted on the upper surface of the stage 316, and the driving roller 317 is rotated by the power of the driving motor (not shown). The substrate 300 is moved by advancing the stage 316. At this time, the rubbing roll 314 connected to the support 313 contacts the alignment film 312 of the substrate 300 advancing at the bottom thereof, and then rotates to leave grooves on the surface of the alignment film 312.

On the other hand, in order to have a uniform display characteristics, it is important to form a groove uniformly in a large area, which is possible by aligning the polymer chain on the alignment film surface in a certain direction by rubbing the surface of the alignment film with a rubbing cloth at a uniform pressure and speed. .

However, such a rubbing device is a failure of the rubbing roll 314 or rubbing cloth 315 when rubbing the alignment film 312 with a single rubbing roll 314, for example, rubbing roll 314 or rubbing cloth 315 wear When the orientation nonuniformity occurs, there is a problem that the production is stopped while replacing the rubbing roll 314 or rubbing cloth 315. In addition, this rubbing device has a problem that it is difficult to immediately respond because the rubbing roll 314 should be changed when the model of the substrate 300 to be rubbed changes. In addition, such a rubbing device has a limitation in increasing the rubbing density because the rubbing of the alignment layer 312 only once with a single rubbing roll 314.

Accordingly, it is an object of the present invention to provide a rubbing apparatus and method for a liquid crystal display panel which can shorten the rubbing process time and increase the orientation uniformity and rubbing density.

In order to achieve the above object, a rubbing device for a liquid crystal display panel according to an embodiment of the present invention includes a plurality of rubbing portions for rubbing an alignment film formed on a substrate, and a control portion for controlling the plurality of rubbing portions.

In the rubbing device of the liquid crystal display panel, each of the plurality of rubbing portions includes a cylindrical rubbing roll, a rubbing cloth attached to an outer circumferential surface of the rubbing roll, and a support connected to a central axis of the rubbing roll to support the rubbing roll. Equipped.

In the rubbing device of the liquid crystal display panel, rubbing cloth of the same material and type may be used for each of the plurality of rubbing parts, and the plurality of rubbing parts may be applied to a substrate of the same model.

In the rubbing device of the liquid crystal display panel, rubbing cloths of different materials and types are used for at least one of the plurality of rubbing parts, and the plurality of rubbing parts may be applied to substrates of different models.

In the rubbing device of the liquid crystal display panel, the controller controls the at least one rubbing unit to rub in contact with an alignment layer formed on the substrate.

A rubbing cloth of the same material and type may be used for at least one rubbing portion in contact with the substrate in the rubbing device of the liquid crystal display panel.

A rubbing method of a liquid crystal display panel according to an exemplary embodiment of the present invention includes providing a plurality of rubbing portions controlled by a controller, and rubbing the at least one rubbing portion in contact with an alignment layer formed on a substrate.

Other objects and features of the present invention in addition to the above object will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 4 to 8.

4 is a view showing a rubbing device for a liquid crystal display panel according to a first embodiment of the present invention.

It is assumed that the rubbing device according to the first embodiment of the present invention performs a rubbing process on the substrates 400 of the same model on which the alignment layer 412 is formed.

Referring to FIG. 4, the rubbing device according to the first embodiment of the present invention includes a plurality of rubbing parts 500 and a controller 600 for controlling the plurality of rubbing parts 500.

Each of the plurality of rubbing portions 500 has a cylindrical rubbing roll 514, a rubbing cloth 515 attached to the outer circumferential surface of the rubbing roll 514 using double-sided tape, and a central axis of the rubbing roll 514. It is provided with a support 513 connected to support the rubbing roll. The plurality of rubbing parts 500 move up and down to perform a rubbing process on the substrate 400 on which the alignment layer 412 mounted on the upper surface of the stage 416 is formed. Meanwhile, a rubbing cloth 515 having the same type and the same material is used for each of the plurality of rubbing parts 500.

The controller 600 is connected to each of the plurality of rubbing units 500 and serves to control each of the plurality of rubbing units 500. The controller 600 controls the at least one rubbing unit 500 to perform a rubbing process on the substrate 400 on which the alignment layer 412 is formed. At this time, the control unit 600 controls the at least one rubbing unit 500 manually or automatically to create a desired rubbing density during the rubbing process of the substrate 400 on which the alignment layer 412 is formed.

Referring to the rubbing process according to the first embodiment of the present invention in detail, first, the substrate 400 on which the alignment layer 412 is formed is mounted on the upper surface of the stage 416, and driven by the power of a driving motor (not shown). The substrate 400 is moved by rotating the roller 417 to advance the stage 416. At this time, as shown in FIG. 5, at least two or more rubbing parts 500 of the plurality of rubbing parts 500 come into contact with the stage 416 moving forward under the control of the controller 600 to perform a rubbing process. . That is, the rubbing roll 514 connected to the support 513 of the at least two rubbing portions 500 is in contact with the alignment film 412 of the substrate 400 advancing at the bottom thereof, and then rotates to allow the surface of the alignment film 412 to rotate. Leaves home. Therefore, since the rubbing process is performed at least twice, the desired rubbing density can be made, thereby minimizing rubbing defects by reducing orientation unevenness, thereby improving yield. In addition, when the rubbing portion 500 is rubbing the substrate 400 on which the alignment layer 412 is formed, another rubbing portion 500 may be directly applied, so that the rubbing process may be speeded up.

6 is a view showing a rubbing device for a liquid crystal display panel according to a second embodiment of the present invention.

It is assumed that the rubbing device according to the second embodiment of the present invention performs a rubbing process on the substrates 700 of various models on which the alignment layer 712 is formed.

Referring to FIG. 6, the rubbing device according to the second embodiment of the present invention includes a plurality of rubbing parts 800 and a controller 900 for controlling the plurality of rubbing parts 800.

Each of the plurality of rubbing portions 800 has a cylindrical rubbing roll 814, a rubbing cloth 815 attached to the outer circumferential surface of the rubbing roll 814 using double-sided tape, and a central axis of the rubbing roll 814. It is provided with a support 813 connected to support the rubbing roll. The plurality of rubbing parts 800 are moved up and down to perform a rubbing process on the substrate 700 on which the alignment layer 712 is mounted on the upper surface of the stage 716. Meanwhile, the plurality of rubbing parts 800 may be applied to various types of rubbing parts 800 that may be applied to various types of substrates 700 so as to immediately respond to a model change of the substrate 700 on which the alignment layer 712 is formed. It is provided.

The controller 900 is connected to each of the plurality of rubbing units 800 and serves to control each of the plurality of rubbing units 800. The controller 900 controls the at least one rubbing unit 800 to perform a rubbing process on the substrate 700 on which the alignment layer 712 is formed. At this time, the control unit 900 controls the at least one rubbing unit 800 manually or automatically to create a desired rubbing density during the rubbing process of the substrate 700 on which the alignment layer 712 is formed. In addition, the rubbing portion 800 may be controlled in various forms so as to immediately respond to a model change of the substrate 700 on which the alignment layer 712 is formed.

Referring to the rubbing process according to the second embodiment of the present invention in detail, first, the first model substrate 700a on which the alignment layer 712 is formed is mounted on the upper surface of the stage 716, and the driving motor (not shown) The first model substrate 700a is moved by rotating the driving roller 717 by the power to advance the stage 716. At this time, as shown in FIG. 7, the first model rubbing part 800a used in the rubbing process of the first model substrate 700a among the plurality of rubbing parts 800 may move forward under the control of the controller 900. In contact with the stage 716 to perform a rubbing process. That is, the rubbing roll 814 connected to the support 813 of the first model rubbing portion 800a contacts the alignment layer 712 of the first model substrate 700a advancing from the bottom thereof, and then rotates the alignment layer 712. Leave a groove on the surface. At this time, the remaining rubbing portions except for the first model rubbing portion 800a are not used to rub the first model substrate 700a. Meanwhile, the rubbing process is performed at least two times by simultaneously rubbing the first model substrate 700a using two or more first model rubbing parts 800a of the same shape, thereby making it possible to make a desired rubbing mill, resulting in uneven alignment. The reduction of can minimize the rubbing defects to improve the yield.

Thereafter, the second model substrate 700b, which is a different model from the first model substrate 700a, is mounted on the upper surface of the stage 716, and the driving roller 717 is rotated by the power of a driving motor (not shown) to rotate the stage ( The second model substrate 700b is moved by advancing 716. At this time, as shown in FIG. 8, the second model rubbing part 800b used in the rubbing process of the second model substrate 700b among the plurality of rubbing parts 800 may move forward under the control of the controller 900. In contact with the stage 716 to perform a rubbing process. That is, the rubbing roll 814 connected to the support 813 of the second model rubbing portion 800b comes in contact with the alignment layer 712 of the second model substrate 800b moving forward from the bottom thereof, and then rotates, and the alignment layer 712 rotates. Leave a groove on the surface. At this time, the remaining rubbing portions except for the second model rubbing portion 800b are not used to rub the second model substrate 700b. Meanwhile, the rubbing process is performed at least two times by simultaneously rubbing the second model substrate 700b by using two or more second model rubbing parts 800b of the same shape, so that a desired rubbing density can be made. The reduction of can minimize the rubbing defects to improve the yield. As such, even if the model of the substrate 700 is changed, the rubbing unit 800 corresponding to the model can be quickly responded by the control unit 900 so that the production of the rubbing unit 800 can be prevented from being stopped. do.

As described above, the rubbing device and method of the liquid crystal display panel according to the present invention can increase the number of rubbing by rubbing the alignment film formed on the substrate using a plurality of rubbing parts to increase the uniformity of the alignment and the rubbing density. In addition, by applying a plurality of rubbing portion can be quickly responded to the model change of the substrate it is possible to shorten the rubbing process time.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

Claims (9)

A plurality of rubbing portions for rubbing the alignment films formed on at least two different models of substrates, respectively; And a control unit for controlling the plurality of rubbing units, respectively. The method of claim 1, The plurality of rubbing parts may have shapes corresponding to the substrates of the different models, respectively, and are respectively operated by the controller to rub the alignment layers formed on the substrates of the different models, respectively. Each of the plurality of rubbing parts A cylindrical rubbing roll, A rubbing cloth attached to an outer circumferential surface of the rubbing roll, And a supporter connected to the central axis of the rubbing roll to support the rubbing roll. The method of claim 2, And a rubbing cloth of the same material and type is used for each of the plurality of rubbing parts. The method of claim 2, And a rubbing cloth of a different material and type is used for each of the plurality of rubbing parts. delete delete Providing a plurality of rubbing portions controlled by the controller, And rubbing the alignment layers, respectively, by contacting the alignment layers formed on the substrates of different models, respectively. delete delete

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