KR100685912B1 - Method for fabricating liquid crystal display panel - Google Patents

Abstract

The present invention is to provide a method for manufacturing a liquid crystal panel which can shorten the process time and improve the alignment characteristics, the method of manufacturing a liquid crystal panel of the present invention is to manufacture a liquid crystal panel in which a liquid crystal is injected between two substrates And a step of bonding the two substrates together, a step of forming a liquid crystal layer between the two substrates, and a step of performing an alignment treatment by simultaneously irradiating ultraviolet rays to the outer surface of each of the substrates. It is done.

Orientation, liquid crystal

Description

Manufacturing method of liquid crystal panel {Method for fabricating liquid crystal display panel}

1A to 1C are flowcharts illustrating a method of manufacturing a liquid crystal panel according to the related art.

2a to 2c is a process chart for explaining the manufacturing method of the liquid crystal panel according to the present invention.

Explanation of symbols for main parts of the drawings

21: first substrate 22: first alignment layer

23: second substrate 24: second alignment layer

25: spacer 27: sealant

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a method for manufacturing a liquid crystal panel.

One of the display devices, CRT (Cathode Ray Tube), has been mainly used for monitors such as TVs, measuring devices, information terminal devices, etc., but due to the weight and size of the CRT itself, Could not respond positively.

In order to replace the CRT, liquid crystal display devices (LCDs), which have advantages of light and thin, have been actively developed. In recent years, they have been sufficiently developed to perform a role as flat panel display devices. The demand is on the rise.

In general, low-cost and high-performance TFT-LCDs use amorphous silicon thin-film transistors as switching elements. Currently, LCDs have a VGA (Video Graphic Array; maximum resolution of 640 × 480 pixels). ), SVGA (800 × 600) and XVGA (1024 × 768) are aimed at high resolution.

The liquid crystal display device uses the electro-optic properties of the liquid crystal injected into the panel. Unlike PDP (PDP) and FED (Field Emission Display), the liquid crystal display device does not emit light by itself, so To view the displayed image, a backlight, which is a separate light source that uniformly irradiates the image display surface, is required.

Hereinafter, a method of manufacturing a liquid crystal panel according to the prior art will be described with reference to the accompanying drawings.

1A to 1C are process diagrams for explaining a method of manufacturing a liquid crystal panel according to the prior art.

Liquid crystal panels can be roughly divided into substrate manufacturing and cell manufacturing.

As shown in FIG. 1A, the organic polymer resin is coated on the first substrate 11 on which the pattern is formed to have a function of an alignment film and an insulating film, thereby forming a first alignment film 12, and in a predetermined direction thereon. The alignment direction of the liquid crystal is determined by irradiating rubbed or polarized ultraviolet (UV).

Subsequently, as shown in FIG. 1B, similarly to the formation of the first alignment layer 12 on the patterned second substrate 13, an organic polymer resin is applied to form the second alignment layer 14, followed by rubbing. Alternatively, ultraviolet light is irradiated to determine the alignment direction of the liquid crystal.

In the alignment film forming process, the most important thing is to form the alignment film uniformly and uniformly over a large area. Usually, the thickness of the alignment film is about 500 to 1000 GPa, and defects such as spots may occur due to the thickness difference of about 100 GPa on the same substrate. Control of the thickness of the alignment film is a very important management item.

Thereafter, as shown in FIG. 1C, after the sealant 17 is printed and dried on the inner peripheral portion of the second substrate 13 to sufficiently blow off the solvent, the front of the first substrate 11 surrounding the sealant is transferred. The spacers 15 for controlling the thickness of the liquid crystal cell are scattered in the area, and the two substrates are bonded to each other to face each other. In this step, it is necessary to pay special attention so that moisture or the like does not remain in the liquid crystal cell only.

Subsequently, after curing the sealant 17, the original substrate is subjected to a scribe process of forming a cutting line on the surface of the substrate with a diamond pen having a high hardness, and a break process of applying a force to cut the disc substrate. Cut to product size. Then, the liquid crystal is injected into the cell container cut into the product size, there is a method using a capillary phenomenon, a method using a pressure difference, a method of making a vacuum and injecting. Finally, when the injection hole injecting the liquid crystal is sealed with the adhesive, the manufacturing process of the liquid crystal panel is completed.

In such a method of manufacturing a liquid crystal panel, it is essential to form an alignment film as described above on the inner wall of the substrate in contact with the liquid crystal because a desired molecular arrangement state cannot be obtained by simply forming a liquid crystal material between the substrates. After forming a thin film of an organic polymer on a substrate by a heavy printing coating method and curing, a rubbing method for controlling the orientation direction of liquid crystal molecules is typical, and avoids physical contact such as rubbing, As a method for preventing static electricity, there is a photo alignment method, in which an alignment layer that is photoreactive should be used.

However, the conventional method of manufacturing a liquid crystal panel has the following problems.

First, after rubbing or irradiating the alignment layer and then irradiating the two substrates, the two layers are bonded to each other. Thus, the surface of the alignment layer formed on the substrate is exposed to heat or light during the bonding process, thereby preventing contamination of the substrate and inflow of particles. This lowers the orientation characteristic, which lowers the process yield.

Second, when the alignment process by rubbing, it is difficult to finely control the degree of orientation, the static electricity generated during rubbing to destroy the thin film transistor, and the adsorption of dust and the formation of scratch (scratch) to reduce the performance and yield of the device.

The present invention has been made to solve the above problems of the prior art, and an object thereof is to provide a method for manufacturing a liquid crystal panel which can shorten the alignment process time and improve the alignment characteristics.

The method of manufacturing a liquid crystal panel of the present invention for achieving the above object is a process of bonding the two substrates in the manufacture of a liquid crystal panel in which a liquid crystal is injected between two substrates, and a liquid crystal layer between the two substrates And forming an alignment process by irradiating ultraviolet rays simultaneously to the outer surface of each of the substrates.

More specifically, the step of forming a first alignment film on the patterned first substrate, the step of forming a second alignment film on the patterned second substrate, the first substrate and the second substrate is bonded And injecting and encapsulating a liquid crystal between the first substrate and the second substrate, and simultaneously irradiating ultraviolet rays from the outer surfaces of the first substrate and the second substrate to perform alignment treatment on the first and second alignment layers. It comprises a process to implement.

Such a liquid crystal panel manufacturing method of the present invention is characterized in that the alignment process using ultraviolet rays in a state in which the two substrates are bonded to each other and completed until the injection and encapsulation of the liquid crystal in order to shorten the process time and improve the alignment characteristics.

Hereinafter, an embodiment of a method of manufacturing a liquid crystal panel according to the present invention will be described with reference to the accompanying drawings.

2A to 2C are process drawings for explaining a method for manufacturing a liquid crystal panel according to the present invention.                     

As shown in FIG. 2A, patterns are formed on the first substrate 21. That is, thin film transistors are formed on the first substrate 21 on the first substrate 21 by repeating deposition, exposure, and etching, and at the intersections thereof, and a thin film transistor is electrically connected to the drain electrode of the thin film transistor. A pixel electrode to be connected is formed.

The thin film transistor includes a gate electrode extending from a gate wiring, a gate insulating film formed on the gate electrode, a semiconductor layer formed on the gate insulating film, and a source electrode and a drain electrode formed on the semiconductor layer. Is formed of a silicon nitride film (SiN _X ) or a silicon oxide film (SiO _X ).

After forming the patterns as described above, a protective film is formed on the entire surface, and a first alignment layer 22 is formed on the protective film. At this time, the thickness of the first alignment layer 22 is about 500 to 1000 GPa. The first alignment layer 22 may be formed of an inorganic material, an organic material, and a quantum material. A polyimide polymer compound is used for the organic alignment film in consideration of stability, durability, and productivity of the alignment.

Next, as shown in FIG. 2B, the second alignment layer 24 is formed on the second substrate 23 on which the pattern is formed to have a thickness of 500 to 1000 GPa similarly to the first alignment layer 22.

As the first and second alignment layers, any material suitable for an optical alignment layer can be used, and most of them are cinnamate-based polyvinyl cinnamate, polysiloxane cinnamate, cellulose cinnamate, and cellulose. cinnamate) and the like are mainly used.

Here, the pattern formed on the second substrate 23 is located between the R, G, B color filter layers for expressing color and the respective color filter layers, and the pixel electrode formed on the first substrate 21 is formed. It is composed of a black matrix layer that blocks light from being transmitted to the excluded region, and a common electrode formed on the front surface including the black matrix layer and the color filter layer.

In this case, the common electrode includes a transparent conductive material, that is, an indium tin oxide (ITO) film containing tin oxide and a tin oxide film (SnO ₂ ), and the indium oxide film (hereinafter referred to as “ITO”). Is a transparent electrode material having the highest conductivity, and has chemical stability and thermal stability, and because of the good workability of the electrode pattern, the transparent electrode of many liquid crystal displays regardless of segment display or matrix display. Used as

Thus, after forming the 1st alignment film 22 and the 2nd alignment film 24 on the 1st board | substrate 21 and the 2nd board | substrate 23, respectively, after wash | cleaning, as shown in FIG. 2C, After the sealing agent 27 is printed and dried around the inner side of the second substrate 23 to sufficiently blow off the solvent, the thickness of the liquid crystal cell in the entire region of the first substrate 21 surrounding the sealing agent 27. To distribute the spacers 25 for controlling them uniformly.

Thereafter, the first substrate 21 and the second substrate 23 are adhered to each other, and then, between the first substrate 21 and the second substrate 23 through a liquid crystal injection hole by using a capillary phenomenon and a pressure difference. The liquid crystal is injected, and the liquid crystal injection hole is sealed so that the liquid crystal does not flow out.                     

Subsequently, when the ultraviolet rays (UV) are irradiated to the first alignment layer 22 and the second alignment layer 24 at the same time on the outer surfaces of the first substrate 21 and the second substrate 23, the alignment treatment is performed simultaneously. The manufacturing process of the liquid crystal panel according to this is completed.

In this case, the ultraviolet rays irradiated from the outer surface of each substrate should have a wavelength band that does not pass through the liquid crystal so as not to affect the alignment layers facing each other.

As described above, in the method of manufacturing the liquid crystal panel of the present invention, the first substrate and the second substrate on which the alignment layer is formed are treated by a sealant printing process and a spacer dispersing process, and each substrate in a state where bonding and liquid crystal are injected and liquid crystal injection opening is completed. Ultraviolet rays are simultaneously irradiated onto the alignment film formed on the substrate, and the alignment process is performed at the same time.

As mentioned above, the manufacturing method of the liquid crystal panel of this invention has the following effects.

First, the overall process time can be shortened by reducing the alignment treatment time due to ultraviolet irradiation to 1/2.

Second, by performing the alignment treatment by irradiating ultraviolet rays in the wavelength band that does not pass through the liquid crystal layer, the alignment treatment is possible without affecting the alignment layer on the opposite side in the state of completing the injection and encapsulation of the liquid crystal. Irradiation of ultraviolet rays in the state of completion of injection and encapsulation can prevent the alignment film from being damaged by heat or light in the bonding process, thereby obtaining an alignment film having uniform and good alignment characteristics.

Claims (3)

In the manufacture of a liquid crystal panel in which a liquid crystal is injected between two substrates, Bonding the two substrates together; Forming a liquid crystal layer between the two substrates; And irradiating ultraviolet rays in the wavelength band that do not pass through the liquid crystal layer to outer surfaces of the substrates to perform alignment treatment. The method of manufacturing a liquid crystal panel according to claim 1, further comprising the step of forming an alignment film on each substrate. The method of claim 1, wherein the step of performing alignment treatment by irradiating ultraviolet rays to the outer surfaces of the two substrates is performed at the same time.

Images