KR101157231B1 - Liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device including a plastic substrate and a manufacturing method thereof.

In the liquid crystal display device of the present invention, at least one of the substrates made of a plastic substrate is used to manufacture the liquid crystal display device, so that the plastic substrate is not bent by the vacuum pressure used to form the liquid crystal layer by injection or dropping. A liquid crystal display device manufacturing method for attaching a polarizing plate before forming a liquid crystal layer and a liquid crystal display device using the manufacturing method are provided.

LCD, Plastic Substrate, Pattern, Spacer, Vacuum

Description

Liquid crystal display and its manufacturing method {LIQUID CRYSTAL DISPLAY DEVICE AND MANUFACTURING METHOD THEREOF}

1 is a plan view of a liquid crystal display device according to the prior art.

2A to 2D are manufacturing process diagrams of a liquid crystal display device according to the prior art.

3A and 3B are cross-sectional views of a liquid crystal display device using a conventional liquid crystal injection method.

4A to 4F are cross-sectional views of a liquid crystal display device according to a first embodiment of the present invention.

5A to 5C are cross-sectional views of a liquid crystal display device according to a second embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

200: first substrate 220: first alignment layer

210: spacer 240: photoresist

250: pattern mask 250: first polarizing plate

300: second substrate 320: second alignment layer

350: second polarizing plate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, various protections including a polarizing plate or a polarizing plate on a back surface of a plastic substrate before bonding using a patterned spacer and pressure when using a plastic material as a substrate. The present invention relates to a liquid crystal display device and a method of manufacturing the same, which keep the cell gap constant by preventing the plastic substrate from being bent by providing the film together.

In general, a liquid crystal display device displays a desired image by separately supplying data signals according to image information to liquid crystal cells arranged in a matrix, and adjusting light transmittance of the liquid crystal cells. to be.

Such a liquid crystal display device may be broadly divided into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel, wherein the liquid crystal panel includes first and second substrates bonded to each other with a predetermined space; It consists of a liquid crystal layer injected between said first and second substrates.

1 is a plan view of a liquid crystal display according to the prior art.

As shown in FIG. 1, a conventional liquid crystal display device includes a first substrate 100 having a thin film transistor formed thereon and a spacer dispersed therein, and an outer black matrix 130 outside the active area 120. The second substrate 150 coated with the thermosetting sealant 110 is bonded to the portion.

After bonding, heat is applied to cure the thermosetting sealant 110. After the panel bonding, the liquid crystal is injected by the vacuum injection method.

Here, the thermosetting sealant 110 shows that it is applied under the second substrate 150. This method is used when the line width of the black matrix 130 outside the panel, such as a monitor, is large.

2A to 2D are manufacturing process diagrams of a liquid crystal display device according to the prior art.

As shown in FIG. 2A, a thin film transistor and a pixel electrode are formed in the active region 120 on the first substrate 100, and the first alignment layer 101 is formed.

Meanwhile, the second alignment layer 151 is formed on the second substrate 150 on which the color filter pattern in which the active region 120 is defined is formed.

As shown in FIG. 2B, the spacer 102 is dispersed on the first alignment layer 101, and the thermosetting sealant 110 is printed on the second alignment layer 151 as a sealant.

The thermosetting sealant 110 prints on the second substrate 150 corresponding to the outer region of the spacer 102 scattered on the first substrate 100.

As illustrated in FIG. 2C, the second substrate 150 on which the second alignment layer 151 is formed is aligned with the first substrate 100 on which the first alignment layer 101 is formed and then bonded to each other, and the heater 170 is used. To harden.

As shown in FIG. 2D, when the thermosetting sealant 110 of the liquid crystal panel is cured by the heater 170, the liquid crystal 103a is vacuum-injected between the bonded first and second substrates 100 and 150. .

The liquid crystal injection uses a vacuum injection method using a pressure difference between the inside and the outside of the liquid crystal panel in the chamber.

The liquid crystal injection hole for the liquid crystal injection is sealed after the liquid crystal injection is completed (End Seal).                         

When the polarizing plates are attached to the first and second substrates 100 and 150 of the encapsulated liquid crystal panel, the liquid crystal panel is completed.

The substrate is formed of a large area glass substrate, and a plurality of unit liquid crystal panel regions are formed on the glass substrate.

However, as consumer requirements vary, such as high-definition, high-volume information processing, light weight, and prevention of breakage of glass substrates due to dropping during movement, various technologies are studied. For example, in order to solve the problem of breakage of the glass substrate due to the drop during movement, the substrate material of the mobile terminal has been changed from glass to plastic.

3A and 3B are cross-sectional views of a liquid crystal display using a conventional liquid crystal injection method.

3A and 3B, when the plastic substrate is applied to the second substrate 150 and the spherical spacers 102 are injected, the plastic substrate is flexible. In connection with the characteristics, the plastic substrate may be bent or curled like a paper when a vacuum is applied in the liquid crystal 103a injection process.

At this time, the second substrate 150, which is the plastic substrate, may not be bent to maintain a constant cell gap, and the spherical spacer 102 may be moved to an arbitrary position as well as agglomeration of spacers in the active region.

Therefore, the liquid crystal display has a problem that luminance unevenness occurs at a specific gray level when driving grayscale.

The present invention provides a liquid crystal display device which can maintain the constant cell gap by preventing the plastic substrate from bending when applying the plastic substrate to the liquid crystal display device, and can prevent occurrence of luminance unevenness due to movement and aggregation of the spherical spacers. Has its purpose.

In the liquid crystal display device of the present invention, at least one of the substrates made of a plastic substrate is used to manufacture the liquid crystal display device, so that the plastic substrate is not bent by the vacuum pressure used to form the liquid crystal layer by injection or dropping. A liquid crystal display device manufacturing method for attaching a polarizing plate before forming a liquid crystal layer and a liquid crystal display device using the manufacturing method are provided.

A liquid crystal display device according to a first embodiment of the present invention includes a first substrate including a thin film transistor, a second substrate including a color filter, a liquid crystal layer sandwiched between the first substrate and the second substrate, and the first substrate. A sealing material for bonding the second substrate and a spacer for maintaining a thickness of the liquid crystal layer held between the first substrate and the second substrate at a predetermined value, wherein the second substrate is made of a thin plastic material. .

In addition, the photosensitive agent is included in the spacer to form a line with the substrate using a photomask, and before the liquid crystal is injected using osmotic pressure, a protective film including a polarizing plate or a polarizing plate is formed on the second substrate made of the plastic material. To place.

As a result, the second substrate of the plastic material including the polarizing plate or the protective film including the polarizing plate can be prevented from being bent by the vacuum pressure acting upon the liquid crystal injection, and the line-shaped pattern spacer is fixed to the substrate, Even after the formation of the conventional liquid crystal layer, the spacer is not moved to an arbitrary position like the spherical spacer, or agglomeration of the spacer does not occur in the cell gap, so that luminance unevenness does not occur.

A liquid crystal display device according to a second embodiment of the present invention includes a first substrate including a thin film transistor, a second substrate including a color filter, a liquid crystal layer sandwiched between the first substrate and the second substrate, and the first substrate. A sealing material for bonding the second substrate and a spacer for maintaining a thickness of the liquid crystal layer held between the first substrate and the second substrate at a predetermined value, wherein the second substrate is made of a thin plastic material. .

In addition, the photosensitive agent is included in the spacer to form a line shape integrally with the substrate using a photomask, and a protective film including the polarizing plate or the polarizing plate is disposed on the second substrate made of the plastic material before dropping the liquid crystal. .

As a result, the second substrate of the plastic material including the polarizing plate or the protective film including the polarizing plate can be prevented from being bent due to the vacuum pressure acting upon the liquid crystal dropping, and the line-shaped pattern spacer is formed even after the conventional liquid crystal layer is formed. Like a spherical spacer, the spacer is not moved to an arbitrary position or agglomeration of spacers in the cell gap does not occur, so that luminance unevenness does not occur.                     

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4A to 4F are cross-sectional views of a liquid crystal display device according to a first embodiment of the present invention.

As shown in FIG. 4A, an alignment layer 220 is formed on the first substrate 200 on which the thin film transistor is formed by a thin film process.

The alignment layer 220 is rubbed in a required direction by a roller surrounded by a soft cloth made of rayon or the like.

A material used as the spacer 210 is coated on the rubbed first substrate 200 to a predetermined thickness.

The spacer 210 is not easily deformed by a subsequent process, it is preferable to use an insulating glass, ceramic and plastic material.

The spacer is set at a height of 1 to 10 mu m and a width of 1 to 30 mu m.

In order to form the spacer 210 material formed on the first substrate 200 in a predetermined form by a photolithography process, a photoresist 240 is coated on the surface of the spacer 210 material. .

As shown in FIG. 4B, the line pattern mask 260 is formed on the surface of the photosensitive resin 240 to form the spacer 210 in a line shape.                     

The photoresist layer 240 is patterned using the pattern mask 260, and the spacer 210 on the first substrate 200 is patterned using the patterned photoresist.

After such a patterning process, as shown in FIG. 4C, a plurality of line-shaped pattern spacers 210 are formed on the first substrate 200.

In addition, the pattern spacer 210 may be formed in a rectangular shape, and in addition, the pattern spacer 210 may be formed in any one shape selected from trapezoidal, cylindrical, and hemispherical.

The pattern spacer 210 is preferably formed in a region where light does not leak.

That is, when the first substrate 200 including the thin film transistor is provided as the pattern spacer 210 substrate as in the first embodiment of the present invention, the pattern spacer 210 may be a gate bus line (not shown) or It is formed on a data bus line (not shown).

In addition, unlike the embodiment of the present invention, when the substrate including the color filter is provided as a pattern spacer substrate, the pattern spacer 210 may be formed under a black matrix (not shown).

In addition, by forming the pattern spacer 210 in a line shape at regular intervals, it is possible to prevent the loss and damage of the spherical spacer, which may occur in the case of the conventional spherical spacer, and to maintain a uniform cell gap so that the liquid crystal display The deterioration of the screen quality of the device can be prevented.

As shown in FIG. 4D, a sealing process of enclosing the peripheral portion of the first substrate 200 is performed.

That is, by forming the partition wall 230 surrounding the periphery of the first substrate 200, the liquid crystal 400 is dropped out of the substrate 200 by the process of dropping the liquid crystal 400 to be performed later Can be prevented.

As shown in FIG. 4E, the first substrate 200 coated with the pattern spacer 210 and the second substrate 300 made of plastic are bonded together, and the first and second polarizing plates 250 and 350 are bonded to each other. It is attached to the back surface of the first substrate and the second substrate 200.

The polarizing plates 250 and 350 may include a protective film, and the protective film may be a diffusion plate, polyethylene terephthalate, or an acrylic film.

In addition, although not specifically described in the embodiment of the present invention, the step of attaching the first and second polarizing plates 250 and 350 to the back surface of the first substrate and the second substrate 200, 300 is injected into the liquid crystal It is irrelevant to the process order before doing it. That is, the first polarizers 250 and 350 may be attached to the rear surfaces of the first and second substrates 200 and 300, respectively, and then the first and second substrates 200 and 300 may be bonded to each other.

In order to be in a vacuum state between the second substrate 200, which is a substrate made of a plastic material to which the second polarizing plate 350 is attached, and the two substrates 200 and 300 of the liquid crystal display device to which the pattern space in the form of a line is applied. Even if the second substrate 200 made of the plastic substrate is not bent, and because it is not a conventional spherical spacer, the spacer is not moved to an arbitrary position or agglomeration of spacers in the cell gap does not occur.                     

Here, the plastic substrate material may include carbon such as polyester, polyethylene, polystyrene, polypropylene, ABS resin (Acrylonitrile Butadiene Styrene Copolymer) or polyethylene terephthalate (Polyethyleneterephthalate). It is made of a polymeric material.

In addition, the thermally acceptable temperature of the plastic polymer materials is about 150 ~ 500 ℃.

As shown in FIG. 4F, the liquid crystal display of the present invention attaches a polarizing plate and various protective films 350 on the second substrate 300, which is a plastic substrate, and the first substrate, which is the second substrate 300 and the glass substrate. The liquid crystal 400 is injected using an osmotic pressure between the spacers for maintaining the cell gap between the substrates 200 and the patterned spacers 210 having a line shape and sealed with the sealant 280.

The sealant 230 may be a thermosetting resin that is cured when exposed to heat or an ultraviolet curable resin that is cured when exposed to ultraviolet rays.

In the case of the thermosetting resin, there are an epoxy resin, a urethane resin, a phenol resin and the like.

Epoxy resins are used the most because it is described as an example of the epoxy resin as follows.

The epoxy resin is opened by amines, amides, and the like, in which an epoxy ring is a curing agent, and the open ring becomes a reaction site to open another epoxy ring in series to form a polymer chain.

This chemical reaction is referred to as curing, and the epoxy resin is thermosetting, which is cured in 30 minutes to 1 hour when heated at 120 to 140 ° C. in a room temperature curing type that reacts immediately at room temperature.

Many methods of heating are used to complete the reaction.

The cured epoxy compound adheres well to both glass substrates. And the cured epoxy compound is excellent in bearing capacity and hard.

In addition, the UV-curable sealant may be used by mixing a monomer or oligomer having an acrylic group bonded to both ends with an initiator, or using a monomer or oligomer having an acrylic group bonded to the other end thereof with an initiator. desirable.

When irradiated with ultraviolet rays, the first substrate and the second substrate are adhered by polymerizing a monomer or oligomer activated by an initiator constituting the ultraviolet curable seal material by polymerizing.

The liquid crystal display device manufactured as described above includes a first and second substrates 200 made of a plastic material to which the polarizers 250 and 350 are attached, and a pattern space in the form of lines. Even if the two substrates 200 and 300 are in a vacuum state, the second substrate 200 made of the plastic substrate does not bend, and after the liquid crystal injection, a pattern spacer in the form of a line is used instead of a spherical spacer. There is no shift in position or agglomeration of spacers within the cell gap.

However, a method for forming a liquid crystal layer between a first substrate including the thin film transistor array and a second substrate including a color filter is performed by bonding the first substrate and the second substrate as described above, and then capillary phenomenon and pressure. Since the vacuum injection method of injecting liquid crystal between both substrates using a difference takes a long time to inject the liquid crystal, when the substrate becomes large in size, there is a problem in that productivity decreases.

Therefore, in the present invention, a liquid crystal display device in which a liquid crystal is dropped by a method of forming a liquid crystal layer between the two substrates will be described as another embodiment (second embodiment) of the present invention.

Since the process of forming the pattern spacer of the liquid crystal display device dropping the liquid crystal in the form of lines at regular intervals is formed by the same method as the liquid crystal display panel injecting the liquid crystal described above, a description thereof will be omitted.

5A to 5C are cross-sectional views of a liquid crystal display device according to a second embodiment of the present invention.

As shown in FIG. 5A, the pattern spacer 210 is formed on the first substrate 200 in a line shape at regular intervals, and the sealant 230 is coated.

As shown in FIG. 5B, the liquid crystal 400 is uniformly dropped in the active region on the first substrate 200. At this time, the step of dropping the liquid crystal 400 is preferably carried out at a temperature of 100 ~ 150 ℃.

As shown in FIG. 5C, when the dropping of the liquid crystal 400 is completed, the polarizing plate 350 is attached to the second substrate 300, which is a plastic substrate, and the first substrate 200 and the color filter are included. The liquid crystal display is completed by aligning the second substrate 300 made of plastic at high temperature.                     

The polarizing plate 350 may include a protective film, and the protective film may be a diffusion plate, polyethylene terephthalate, or an acrylic film.

In addition, although not specifically described in the embodiment of the present invention, the step of attaching the first and second polarizing plates 250 and 350 to the back of the first substrate and the second substrate 200, 300 dropping the liquid crystal May be performed before. That is, after the first and second polarizing plates 250 and 350 are attached to the rear surfaces of the first and second substrates 200 and 300, the liquid crystal may be dropped onto the first substrate 200. Thereafter, the first and second substrates 200 and 300 may be bonded together.

At this time, the second substrate 300, which is the thin plastic substrate, is provided with a polarizing plate and various protective films on the top even in the pressing process for bonding, and the pattern spacer 230 is arranged in a line shape on the first substrate, In addition to preventing bending of the plastic substrate, the use of a patterned spacer in the form of a line rather than a conventional spherical spacer does not cause the spacer to move to an arbitrary position or to cause agglomeration of spacers in the cell gap.

The liquid crystal display device according to the present invention as described above has the following effects.

First, the plastic substrate is bent due to the protective film including the polarizing plate on the plastic substrate and the pattern spacer formed in the form of a line with the substrate even when the two substrates are in vacuum or pressurized state for bonding in the liquid crystal display device of the substrate of the present invention. There is no effect.

Secondly, in the liquid crystal display of the present invention, the patterned spacer having the line shape does not generate luminance unevenness because the spacer does not move to an arbitrary position or do not generate agglomeration of spacers within the cell gap even after the conventional liquid crystal layer is formed. There is.

In addition, the present invention is not limited to the embodiments, and various changes can be made by those skilled in the art without departing from the gist of the present invention as claimed in the following claims.

Claims (31)

Preparing at least one of the first and second substrates made of a plastic material; Forming a pattern spacer and a sealant between the first substrate and the second substrate; Bonding the first substrate and the second substrate to each other; Forming a polarizer on a bottom surface of the bonded first substrate and the second substrate; And injecting a liquid crystal between the bonded first substrate and the second substrate by a liquid crystal injection method. Preparing at least one of the first and second substrates made of a plastic material; Forming a pattern spacer and a sealant between the first substrate and the second substrate; Forming a polarizing plate on the back surface of the first and second substrates; Bonding the first substrate and the second substrate to each other; And injecting a liquid crystal between the bonded first substrate and the second substrate by a liquid crystal injection method. The method according to claim 1 or 2, And the pattern spacer is patterned on only one of the first substrate and the second substrate, or is patterned on the first substrate and the second substrate. The method according to claim 1 or 2, And a height of 1 to 10 µm and a width of 1 to 30 µm. The method according to claim 1 or 2, The pattern spacer is formed in a rectangular shape, or a liquid crystal display device, characterized in that formed in any one shape selected from trapezoidal, cylindrical and hemispherical. The method according to claim 1 or 2, And the pattern spacers are formed using a photolithography process. The method according to claim 1 or 2, And the pattern spacers are arranged at regular intervals. The method according to claim 1 or 2, And the pattern spacer uses any one or two or more of glass, ceramic, and plastic materials. The method according to claim 1 or 2, And the pattern spacers are formed in a line shape. The method according to claim 1 or 2, As the plastic material, a polymer material including carbon of polyester, polyethylene, polystyrene, polypropylene, ABS resin (Acrylonitrile Butadiene Styrene Copolymer) or polyethylene terephthalate is used. Method of manufacturing a liquid crystal display device characterized in that. 11. The method of claim 10, The thermally acceptable temperature of the plastic materials is 150 ~ 500 ℃ manufacturing method of the liquid crystal display device. The method according to claim 1 or 2, And said sealant is a thermosetting resin or an ultraviolet curable resin. 13. The method of claim 12, The thermosetting sealant is an epoxy resin, a urethane resin or a phenol resin manufacturing method of a liquid crystal display device. The method according to claim 1 or 2, The polarizing plate is a manufacturing method of the liquid crystal display device comprising a protective film. The method of claim 14, The protective film is a method of manufacturing a liquid crystal display device, characterized in that the polyethylene terephthalate (PolyEthylene Terephthalate) or acrylic (Acryl) film. Preparing at least one of the first and second substrates made of a plastic material; Forming a polarizing plate on the back surface of the first substrate and the second substrate; Forming a pattern spacer and a sealant on the first substrate or the second substrate; Dropping liquid crystal onto the first substrate or the second substrate by a liquid crystal dropping method; And bonding the first substrate and the second substrate to each other. Preparing at least one of the first and second substrates made of a plastic material; Forming a pattern spacer and a sealant on the first substrate or the second substrate; Dropping liquid crystal onto the first substrate or the second substrate by a liquid crystal dropping method; Forming a polarizing plate on the back surface of the first substrate and the second substrate; And bonding the first substrate and the second substrate to each other. The method according to claim 16 or 17, And the pattern spacer is patterned on only one of the first substrate and the second substrate, or is patterned on the first substrate and the second substrate. The method according to claim 16 or 17, And a height of 1 to 10 µm and a width of 1 to 30 µm. The method according to claim 16 or 17, The pattern spacer is formed in a rectangular shape, or a liquid crystal display device, characterized in that formed in any one shape selected from trapezoidal, cylindrical and hemispherical. The method according to claim 16 or 17, And the pattern spacers are formed using a photolithography process. The method according to claim 16 or 17, And the pattern spacers are arranged at regular intervals. The method according to claim 16 or 17, And the pattern spacer uses any one or two or more of glass, ceramic, and plastic materials. The method according to claim 16 or 17, And the pattern spacers are formed in a line shape. The method according to claim 16 or 17, As the plastic material, a polymer material including carbon of polyester, polyethylene, polystyrene, polypropylene, ABS resin (Acrylonitrile Butadiene Styrene Copolymer) or polyethylene terephthalate is used. Method of manufacturing a liquid crystal display device characterized in that. The method of claim 25, The thermally acceptable temperature of the plastic materials is 150 ~ 500 ℃ manufacturing method of the liquid crystal display device. The method according to claim 16 or 17, And said sealant is a thermosetting resin or an ultraviolet curable resin. 28. The method of claim 27, The thermosetting sealant is an epoxy resin, a urethane resin or a phenol resin manufacturing method of a liquid crystal display device. The method according to claim 16 or 17, The polarizing plate comprises a protective film, characterized in that the manufacturing method of the liquid crystal display device. 30. The method of claim 29, The protective film is a method of manufacturing a liquid crystal display device, characterized in that the polyethylene terephthalate (PolyEthylene Terephthalate) or acrylic (Acryl) film. The method according to any one of claims 1, 2, 16 and 17, A liquid crystal display device manufactured using the method for manufacturing the liquid crystal display device.

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