KR20050037788A - Liquid crystal display device and method for manufacturing thereof - Google Patents

Abstract

The present invention provides a first substrate including a plurality of thin film transistors and pixel electrodes, a second substrate including a black matrix layer, a color filter layer, and a common electrode, and a plurality of parallel guide walls protruding along an active region of the second substrate. And it provides a liquid crystal display device comprising a liquid crystal filled between each guide wall.

Description

Liquid crystal display device and method for manufacturing thereof

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a more economical and high productivity structure.

As the information society develops, the demand for display devices is increasing in various forms, and in recent years, the LCD (Lipuid Crystal Display Device), PDP (Plasma Display Panel), ELD (Electro Luminescent Display), and VFD (Vacuum Fluorescent) Various flat panel display devices such as displays have been studied, and some of them are already used as display devices in various devices. Among them, LCDs are being used a lot while replacing CRTs (Cathode Ray Tubes) for mobile image display devices due to the advantages of excellent image quality, light weight, thinness, and low power consumption.

As described above, although various technical advances have been made in the liquid crystal display panel to serve as a screen display device in many fields, the task of improving the image quality as the screen display device is often arranged with the above characteristics and advantages. .

Therefore, in order for a liquid crystal display device to be used in various parts as a general screen display device, the key to development is how much high definition images such as high definition, high brightness, and large area can be realized while maintaining the characteristics of light weight, thinness, and low power consumption. It can be said.

Such a liquid crystal display device is largely divided into a liquid crystal display panel for displaying an image and a circuit unit for driving the liquid crystal display panel. A device including a liquid crystal display device, a system outer case, a power supply unit, and the like to implement a desired image is called a liquid crystal display device.

The liquid crystal display panel includes a first substrate on which a thin film transistor array is formed, a second substrate on which a color filter array is formed, and a liquid crystal layer formed between the two substrates.

The first substrate on which the thin film transistor array is formed includes a plurality of gate lines arranged in one direction at a predetermined interval, a plurality of data lines arranged in a direction perpendicular to the gate lines to define a pixel region, A plurality of pixel electrodes formed in the pixel region to display an image, and formed in a pixel region of a portion where each of the gate lines and the data lines intersect, and are turned on / off by a driving signal of the gate lines, so that the image signals of the data lines A plurality of thin film transistors for transmitting the to each pixel electrode is provided.

In addition, the second substrate on which the color filter array is formed includes a black matrix layer that blocks light in portions other than the pixel region, and R, G, and B colors that are formed in portions corresponding to the pixel regions to implement color. A filter layer and a common electrode formed on the front surface including the color filter layer are provided. Of course, in the liquid crystal display of the IPS mode, the common electrode may be formed on the first substrate.

After the first and second substrates are aligned in order to ensure the orientation of liquid crystal molecules, a seal pattern is applied along an outer portion of the upper surface of the second substrate, and a liquid crystal is dropped or injected into the seal pattern. . In addition, spacers are scattered to maintain a constant gap (hereinafter, referred to as "Cell Gap") of the liquid crystal layer when the first substrate and the second substrate are bonded. Thereafter, the first and second substrates are bonded to have a predetermined space, and a liquid crystal layer is formed between the first substrate and the second substrate.

As a method of encapsulating liquid crystal between the first and second substrates, a conventional liquid crystal injection method of injecting a liquid crystal through an injection hole of a sealing agent after bonding a substrate in vacuum, and Japanese Patent Application Laid-Open No. 11-089612 ( Liquid crystals and seal materials proposed in Japanese Patent Application Laid-Open No. 2000-284295, Japanese Patent Application Laid-Open No. 4-142054 (Japanese Patent Laid-Open No. 5-346561), and Japanese Patent Application Publication No. 11-172903 (Japanese Patent Laid-Open No. 2000-005405). It can be largely divided into a liquid crystal dropping method and the like to bond any one of the substrate dropping the other substrate and vacuum.

1 is a view showing a bonding method of a liquid crystal display panel by a liquid crystal injection method of the prior art.

As shown in FIG. 1, a process of filling the liquid crystal 31 between the substrates 10 by a conventional liquid crystal injection method is performed in the vacuum chamber 20. Here, the liquid crystal storage 30 in which the liquid crystal 31 is stored is provided at the inner lower portion of the vacuum chamber 20.

The inside of the vacuum chamber 20 is in a vacuum state by the pumping action of the vacuum pump 25 connected by a pipe, in the vacuum state to face the two substrates 10 to one end of the liquid crystal storage 30 It comes into contact with the stored liquid crystal 31. At this time, the liquid crystal 31 flows in between the substrate 10 by a capillary phenomenon in a vacuum state. One end of the substrate is brought into contact with the liquid crystal 31, and at the same time, nitrogen gas (N ₂ ), which is an inert gas, is injected into the vacuum chamber 20 to allow the inside of the chamber 20 to reach an atmospheric pressure state. It is left to stand for more than time to complete the injection of the liquid crystal 31.

2 schematically illustrates a substrate bonding structure to which a liquid crystal dropping method is applied in a conventional liquid crystal display panel manufacturing method.

As shown in FIG. 2, the substrate according to the prior art is bonded in a vacuum chamber in which a vacuum state is formed.

The substrates 10a and 10b fixed to the stages 40 and 41 are bonded together in a vacuum state.

The first and second substrates 10a and 10b that are externally loaded after the liquid crystal 31 is dropped in a plurality of places on the upper surface of the second substrate 10b to be fixed to the lower stage 41. When the stages 40 and 41 are fixed to each stage, the inside of the vacuum chamber 21 is in a vacuum state by driving a vacuum pump (not shown). Since the upper stage 40 moves downward by the support 42, the first substrate 10a and the second substrate 10b are bonded together.

Here, the substrates 10a and 10b carried into the vacuum chamber 21 may include a plurality of electric static chucks (not shown) mounted on the bottom surface of the upper stage 40 and the upper surface of the lower stage 41. It is fixed by). That is, the substrates 10a and 10b are fixed to the stages 40 and 41 by the electrostatic force provided by the electrostatic chuck.

The reason why the bonding process according to the prior art is performed in a vacuum state is to increase the fluidity of the dropped liquid crystal 31 to be uniformly distributed on the upper surface of the second substrate 10b. If the liquid crystals 31 are not evenly distributed on the substrate, bubbles are generated in the liquid crystals 31 after the first and second substrates 10a and 10b are bonded together, such as distortion of the screen of the liquid crystal display panel. It can be caused.

However, the conventional bonding structure of the substrate for a liquid crystal display device as described above has the following problems.

First, according to the prior art, since the bonding process of the first and second substrates must be performed in a vacuum, additional components such as a vacuum chamber and a vacuum pump are required in the bonding device, and the configuration of the bonding device is complicated.

Second, according to the prior art, the spacers are irregularly distributed to maintain the cell gap, but the spacers interfere with the uniform path of light, thereby preventing the correct spherical shape of the image.

Third, there is a problem in that productivity takes a long time to achieve a vacuum state inside the vacuum chamber for bonding the substrate according to the prior art.

In order to achieve the above object, the present invention includes a first substrate on which a plurality of thin film transistors and pixel electrodes are formed, a second substrate on which a black matrix layer, a color filter layer, and a common electrode are formed, and protrude along an active region of the second substrate. It provides a plurality of parallel guide walls, and a liquid crystal display device comprising a liquid crystal filled between each of the guide walls.

The liquid crystal display device of the present invention forms a plurality of guide walls having a small size on the upper surface of the substrate, which is a main component thereof, so that the substrate bonding process can be directly performed at normal pressure without the need to create a vacuum state during the bonding process of the substrate. do.

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

3A is a schematic plan view of a substrate for manufacturing a liquid crystal display device with a guide wall according to the present invention, and FIG. 3B is a schematic side cross-sectional view of the substrate.

The liquid crystal display of the present invention includes a first substrate 110a, a second substrate 110b, and a plurality of guide walls 160 provided on the second substrate 110b.

Here, the first substrate 110a is a TFT substrate including a plurality of transistors and pixel electrodes, and the second substrate 110b is a color filter substrate including a black matrix layer, a color filter layer, and a common electrode. In general, the liquid crystal is filled between the substrates 110a and 110b and then bonded to form a liquid crystal display panel.

The edge portion of the liquid crystal display panel is a dead space that is coupled to the outer case and is a dead space that does not display an image. The portion displaying the image inside the dead space is called an active area, and the state of the liquid crystal located in the active area has an important effect on the image quality characteristics of the liquid crystal display device. Therefore, the liquid crystal provided in the active region should not contain bubbles or foreign substances.

As shown in FIG. 3A, a portion corresponding to the active region of the second substrate 110b is provided with a plurality of guide walls 160 in a long side direction or a short side direction. The guide wall 160 is made of a transparent solid, extending in the longitudinal direction are provided in parallel with each other.

Referring to FIG. 3B, the guide wall 160 protrudes from an upper surface of the second substrate 110b. The guide wall 160 is preferably configured to protrude to a height capable of performing a function of maintaining a cell gap between the first substrate 110a and the second substrate 110b when the substrate is bonded after the liquid crystal is filled. Therefore, the guide wall 160 may serve as a spacer according to the prior art.

4 is a diagram illustrating an arrangement structure of guide walls formed on the second substrate.

Referring to FIG. 4, the guide wall 160 is formed to have a predetermined interval in units of pixel regions 150a of the second substrate 110b. The color filter substrate of the liquid crystal display device includes a black matrix layer 150b that blocks light in portions except the pixel region 150a. R (Red), G (Green), and B (Blue) color filter layers for implementing color are formed in a portion corresponding to each pixel region 150a, and a common electrode is provided on the entire surface of the color filter layer.

The inside of each lattice region partitioned by the black matrix layer 150b is referred to as a pixel region 150a or a pixel, and the guide walls 160 are provided with a plurality of intervals equal to the size of each pixel region 150a. do.

Meanwhile, the guide wall 160 is formed along one longitudinal direction of the grating formed on the black matrix layer 150b.

As shown in FIG. 4, a black matrix layer 150b is formed on the second substrate 110b to distinguish each pixel region 150a which is repeated in the order of R, G, and B. FIG. The black matrix layer 150b is formed of a lattice having a predetermined shape in portions except the pixel region 150a and is a region through which light does not pass. That is, the liquid crystal inside the pixel region 150a selectively transmits the light to the outside due to the change in the molecular arrangement, thereby realizing a desired image, but the portion covered by the black matrix layer 150b is blocked.

Therefore, the guide wall 160 is preferably formed along the grid of the black matrix layer 150b so as not to obstruct the path of light for displaying an image. Therefore, the guide wall 160 solves the problem that the conventional spacers are irregularly distributed so that a part thereof is located in the pixel region 150a to partially obstruct the path of light.

The guide wall 160 may be provided in the vertical direction, but is not limited thereto, and may be provided in the horizontal direction. In addition, the guide wall 160 may have the same shape as the grid of the black matrix layer 150b and may be provided in both the horizontal direction and the vertical direction.

The size of the pixel region 150a is very small, and the guide wall 160 formed at the interval accommodates the liquid crystal dropped therebetween. Here, the surface tension of the liquid crystal is generated by the cohesive force of the liquid crystal molecules, and the force acting between the guide wall 160 and the liquid crystal molecules is an adhesive force. When the cohesive force is greater than the cohesive force, the liquid crystal is filled in a convex upward shape between the guide walls 160 by the surface tension.

5 is a view showing a bonding structure of a substrate for manufacturing a liquid crystal display device of the present invention.

As shown in FIG. 5, of the substrates loaded into the combiner for bonding, the first substrate 110a is fixed to the upper stage 140, and the second substrate 110b in which the liquid crystal is dropped is the lower stage ( 141). The liquid crystal 131 accommodated in the gap between the plurality of guide walls 160 formed on the second substrate 110b is convexly protruded upward between the guide walls 160 due to its surface tension. It is filled. When the first stage 141 and the second substrate 140 is bonded while the upper stage 140 moves downward by the driving of the stage moving means 142, the convexly protruding portion is covered on the upper surface. The occurrence of bubbles is prevented while being in close contact with the lower surface of the first substrate 110a. Accordingly, the present invention prevents a problem caused by bubbles remaining inside the liquid crystal 131 even when the bonding process is performed at atmospheric pressure using the guide wall 160.

That is, the guide wall 160 is installed to prevent the liquid crystal 131 from including bubbles even when the substrate is bonded at normal pressure, and at the same time serves as a spacer for maintaining the cell gap.

In addition, since the bonding process is not performed in a vacuum state, the vacuum suction force without the need for using an electrostatic chuck having a complicated structure in order to fix the first and second substrates 110a and 110b to the upper and lower stages 140 and 141, respectively. Can be fixed by That is, a plurality of vacuum holes connected to a vacuum pump are formed on the lower surface of the upper stage 140 and the upper surface of the lower stage 141, and the substrates 110a and 110b are formed by the vacuum suction force generated in the vacuum holes. Can be fixed respectively.

On the other hand, the guide wall 160 is preferably made of an acrylic material. The acrylic material may be provided on the substrate in a desired shape by a photolithography method or a printing method, and may be made of a transparent material having excellent light transmittance, thereby satisfying desired characteristics of the guide wall 160. In addition, the adhesive property between the acrylic material and the liquid crystal also satisfies the desired conditions. However, the present invention is not limited thereto, and any material that satisfies the characteristics of the guide wall 160 disclosed in the present invention may be used.

On the other hand, unlike the above-described embodiment, the guide wall may be formed on the thin film transistor substrate instead of the color filter substrate, and the liquid crystal may be dropped. That is, the thin film transistor substrate may be used as the second substrate, and the color filter substrate may be used as the first substrate. In this case, the surface on which the liquid crystal is dropped on the thin film transistor substrate must have a flatness of a predetermined level or higher so as to form the guide wall, and the guide wall corresponds to the lattice of the black matrix layer 150b formed on the color filter substrate. It should be formed at the position.

Hereinafter, a manufacturing method of the liquid crystal display device will be described in detail with reference to the accompanying drawings.

6 shows a schematic process of forming the guide wall of the present invention on a substrate on which liquid crystal is to be dropped.

As shown in FIG. 6, the method of manufacturing a liquid crystal display of the present invention includes a first step of attaching a transparent synthetic resin to an upper surface of a second substrate on which liquid crystals are dropped, a second step of applying a photoresist to an upper surface of the synthetic resin, and A third step of covering and exposing a mask on which a plurality of parallel etching planes extending along the active region of the second substrate is over the photoresist; a fourth step of developing and etching to form a plurality of guide walls; and the guide wall And a fifth step of dropping the liquid crystal onto the upper surface of the formed second substrate, and a sixth step of bonding the second substrate and the first substrate.

The photolithography process using the photoresist to display the etched surface and make the desired shape as described above is obtained by using a principle of changing the properties by causing a chemical reaction when the photoresist receives light as a specific chemical. It is a process of forming a desired pattern by selectively irradiating light to the photoresist using a mask of a desired pattern.

The process includes an application step of applying a photoresist corresponding to a film of a photograph, an exposure step of selectively irradiating light such as ultraviolet rays using a mask, and then a photoresist of a portion receiving light using a developer. It consists of a developing process of removing and forming a pattern. Here, the pattern is formed along a portion where the guide wall is to be formed, and the pattern is formed in a shape that is elongated at intervals of each pixel of the second substrate.

When the pattern is formed as described above, a process of etching a portion to be etched to form the guide wall is performed. The etching method may use a phenomenon in which a reactive material such as an atom or a radical formed from a gas plasma formed under three conditions of vacuum, gas, and RF power reacts with a material deposited on a substrate to change into a volatile material. .

All the above process steps are very vulnerable to various dust particles, and because of this, wrong pattern formation causes defects of the entire liquid crystal display panel, and therefore, should be performed in a clean environment, and precise management of materials and equipment is important.

The transparent synthetic resin is preferably made of an acrylic material in consideration of adhesive properties with liquid crystals. In addition, a color filter substrate having a black matrix layer is used as the second substrate, and the guide wall is formed to extend in one direction of the black matrix grating so as not to obstruct the path of light in the pixel area to implement an image. Do not

As described above, the present invention provides a liquid crystal display device and a method of manufacturing the same, in which a liquid crystal is dropped onto a substrate on which a guide wall is formed to ensure that the substrate is stable at normal pressure.

As described above, the substrate bonding apparatus for the liquid crystal display device manufacturing process of the present invention has the following effects.

First, according to the present invention, since the liquid crystal of the first substrate and the second substrate is dropped between the guide walls, bubbles are prevented even when the bonding process is performed at normal pressure, so that no additional parts such as a vacuum chamber and a vacuum pump are needed, and the bonding apparatus is unnecessary. The configuration of can be simplified.

Secondly, according to the present invention, the guide wall is regularly arranged in the black matrix lattice area that does not display an image so as to maintain the cell gap so that the path of the light may not be obstructed as much as possible.

Third, according to the present invention, since it is possible to bond the substrate at normal pressure, the time required for achieving the vacuum state can be increased, thereby significantly increasing the productivity.

1 is a block diagram showing a substrate bonding structure by a conventional liquid crystal injection method

2 is a configuration diagram showing a substrate bonding structure by a conventional liquid crystal dropping method

3A is a cross-sectional view of a substrate for manufacturing a liquid crystal display device having a guide wall of the present invention.

3B is a front view of a substrate for manufacturing a liquid crystal display device having a guide wall of the present invention.

4 is a view of the arrangement structure of the guide wall in the present invention;

5 is a view schematically showing a bonding process of a substrate for manufacturing a liquid crystal display device of the present invention.

6 is a flowchart illustrating a method of manufacturing a liquid crystal display device according to the present invention.

<Description of Signs of Major Parts of Drawings>

110a: first substrate 110b: second substrate

131: liquid crystal 140: upper stage

141: lower stage 150a: pixel area

150b: Black Matrix Layer 160: Guide Wall

Claims (9)

A first substrate on which a plurality of thin film transistors and pixel electrodes are formed; A second substrate on which a black matrix layer, a color filter layer, and a common electrode are formed; A plurality of parallel guide walls protruding along the active region of the second substrate; And And a liquid crystal filled between the guide walls. The method of claim 1, And the guide wall is formed to have a predetermined interval in units of pixels of the second substrate. The method of claim 1, And the guide wall extends in one direction along the black matrix grid. The method of claim 1, And the guide wall is formed in the same shape as the black matrix lattice. The method of claim 1, And the guide wall is made of an acrylic material. Attaching a transparent synthetic resin to the upper surface of the second substrate on which the liquid crystal is to be dropped; A second step of applying a photoresist to an upper surface of the synthetic resin; A third step of covering and exposing a mask on which a plurality of parallel etching surfaces extending along an active region of the second substrate is displayed on the photoresist; Developing and etching to form a plurality of guide walls; A fifth step of dropping liquid crystal onto an upper surface of the second substrate on which the guide wall is formed; And And a sixth step of attaching the second substrate and the first substrate to each other. The method of claim 6, The synthetic resin is a method of manufacturing a liquid crystal display device, characterized in that the acrylic material. The method of claim 6, And in the fourth step, the photoresist is formed to have a predetermined interval in units of pixels of the second substrate after development. The method of claim 6, And the second substrate is a substrate on which a black matrix layer is formed, and the guide wall extends in one direction of the black matrix grid.