KR100859470B1 - A Liquid Crystal Display Device And The Method For Manufacturing The Same - Google Patents

Abstract

To provide a liquid crystal display device and a method of manufacturing the same that can prevent the liquid crystal flows down the panel when the high temperature driving is reduced, the liquid crystal display device for achieving the above object is the active area and the cell margin area. Defined first and second substrates; A protective film formed on the first substrate and having a plurality of holes so that the liquid crystal stays in the cell margin area; And a black matrix and color filter layer formed on the second substrate and a second alignment layer formed on the color filter layer.

Overcoat layer, recessed part, protective film, hole, liquid crystal, column spacer

Description

Liquid Crystal Display Device And The Method For Manufacturing The Same

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

2 is a plan view of a bonded liquid crystal display device according to the present invention.

3A and 3B are structural cross-sectional views taken along the line II ′ and II-II ′ of FIG. 2.

4A and 4B are cross-sectional views of a process for forming a cell margin region of a lower substrate.

5A and 5B are cross-sectional views of a process for forming a cell margin region of an upper substrate;

Explanation of symbols on the main parts of the drawings

300: lower substrate 301: metal layer

302: protective film 303: first alignment film

310: upper substrate 311: black matrix

312a, 312b, 312c: color filter layer 313: overcoat layer

315: sealing material 316: liquid crystal layer

317: second alignment film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same that can prevent a liquid crystal from flowing down to a lower panel during high temperature driving.

As the information society develops, the demand for display devices is gradually increasing in various forms, and in recent years, liquid crystal display devices (LCDs), plasma display panels (PDPs), electro luminescent displays (ELDs), and VFDs (Vacuum) Various flat panel display devices such as fluorescent display have been studied, and some are already used as display devices in various devices.

Among them, LCD is the most used as a substitute for CRT (Cathode Ray Tube) for mobile image display device because of the excellent image quality, light weight, thinness, and low power consumption. In addition to mobile type such as notebook computer monitor, BACKGROUND ART Various developments have been made in televisions and computer monitors for receiving and displaying broadcast signals.

Such a liquid crystal display device may be classified into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel. The liquid crystal panel has a predetermined space and has an upper and lower substrates bonded to each other. It is composed of a liquid crystal layer formed between the lower substrate.

Here, the lower substrate (TFT array substrate) has a plurality of gate lines arranged in one direction at regular intervals, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, and each of the gate lines; A plurality of pixel electrodes formed in a matrix form in each pixel region defined by crossing data lines, and a plurality of thin film transistors switched by signals of the gate lines to transfer the signals of the data lines to the pixel electrodes. do.

In the upper substrate (color filter substrate), a black matrix layer for blocking light except for the pixel region, an R, G, and B color filter layer for expressing color colors, and a common electrode for implementing an image are formed. do.

The spacers are used to equalize the cell gap when the two substrates are bonded to each other. The spacers include ball spacers scattered on the substrates and column spacers fixed to the substrates.

However, the liquid crystal display device tends to move toward a large screen, and the ball spacer has a problem of changing a cell gap when applied to a large area. Therefore, a column spacer is mainly used for the large screen.

Hereinafter, a liquid crystal display device according to the related art will be described with reference to the accompanying drawings.

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

As shown in FIG. 1, the liquid crystal display according to the related art has a lower substrate 100 and a lower substrate 100 having a thin film transistor array including a gate line, a data line, a thin film transistor (TFT), and a pixel electrode. The upper and lower substrates may be maintained by maintaining a constant cell gap between the upper substrate 110 and the upper and lower substrates 110 and 100 having a color filter array including a black matrix, a color filter layer, a common electrode, and the like. And a liquid crystal layer (not shown) formed between the seal member 115 for adhering the 110 and 100 and the upper and lower substrates 110 and 100 bonded by the seal member 115. It is.

In addition, a spacer (not shown) is formed to maintain a cell gap between the bonded upper and lower substrates 110 and 100. In particular, a large sized column spacer is formed in which the spacer is fixed to the substrate.

Here, the upper and lower substrates 110 and 100 bonded by the seal member 115 have a cell margin (liquid crystal) between the active region 120 where the actual image is displayed and the active region 120 and the seal member 115. Margin) 150.

Although not shown in the figure of the upper substrate 110, the cell margin region is composed of a black matrix formed to act as a light blocking and a color filter layer of RGB (Red, Green, Blue).

When the above-described liquid crystal display device is applied to a large screen (17 ″ or larger), the column spacer (not shown) and the liquid crystal ( The cell gap is changed by the difference in the coefficient of thermal expansion of the liquid crystal (LC), which may cause the liquid crystal to be pushed down the panel.

That is, even if the liquid crystal flows down the panel because the cell gap is changed as described above, there is no structure to hold the liquid crystal in the cell margin area, so that the liquid crystal flows under the panel, resulting in unevenness in the liquid crystal display, thereby degrading image quality. Occurs.

 The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal display device and a method of manufacturing the same, which can prevent the liquid crystal from flowing down the panel and deteriorating the image quality during high temperature driving.

According to an aspect of the present invention, there is provided a liquid crystal display device including: first and second substrates in which an active region and a cell margin region are defined; A protective film formed on the first substrate and having a plurality of holes so that the liquid crystal stays in the cell margin area; And a black matrix and color filter layer formed on the second substrate, and a second alignment layer formed on the color filter layer.

In the method of manufacturing the liquid crystal display device of the present invention having the above configuration, a protective film having a plurality of holes is formed in the cell margin area of the first substrate among the first and second substrates in which the active area and the cell margin area are defined. step; And bonding the first and second substrates together.

According to the present invention, an overcoat layer having concave portions is formed in a cell margin region of an upper substrate, and a protective film having a plurality of holes is formed in a cell margin region of a lower substrate so that a liquid crystal is formed in the concave portion and a hole. This is to prevent the liquid crystal from flowing down to the lower part of the panel during high temperature driving in the future to prevent staining.

Hereinafter, a liquid crystal display device and a method of manufacturing the same according to exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a plan view of a bonded liquid crystal display device according to the present invention.

As shown in FIG. 2, the liquid crystal display device according to the present invention includes a lower substrate 300 and a lower substrate 300 on which a thin film transistor array including a gate line, a data line, a thin film transistor (TFT) and a pixel electrode is formed. In order to maintain a constant cell gap between the upper substrate 310 and the upper substrate 310, the color filter array having a black matrix, a color filter layer, a common electrode, etc. A liquid crystal layer 316 formed between the seal member 315 for adhering the substrates 310 and 300 and the upper and lower substrates 310 and 300 bonded by the seal member 315 (FIG. 3A, FIG. 3b).

The seal member 315 also serves to prevent liquid crystal leakage between the substrates 300 and 310.

In addition, the spacer 330 is formed to uniformly maintain the cell gap between the upper and lower substrates 310 and 300 bonded to the sealing material 315, and the spacer 330 on the large screen (17 화면 or larger). The column spacer 330 is used to fix the substrate to the substrate. At this time, the column spacer 330 is composed of a photosensitive organic resin.

Here, the bonded upper and lower substrates 310 and 300 may include an active region 320 in which an actual image is displayed, and a cell margin (liquid crystal margin) region 350 between the active region 320 and the seal member 315. ) And a pad margin area of the lower substrate 300 which is formed to extend from the upper substrate 310.

Hereinafter, the liquid crystal display device according to the exemplary embodiment of the present invention will be described by dividing the active area 320 and the cell margin area 350 of the upper and lower substrates 310 and 300.

3A and 3B are structural cross sectional views along the lines II ′ and II-II ′ of the cell margin regions.

Although not shown in the drawing, a thin film transistor is formed in each pixel region defined by the gate line and the data line intersected in the active region 320 of the lower substrate 300, and a protective film is formed on the thin film transistor. Pixel electrodes are formed in each pixel region.

3A and 3B, a metal layer 301 is formed in the cell margin area 350 of the lower substrate 300, and a protective film 302 having a plurality of holes is formed on the metal layer 301. It is.

In this case, a single layer metal layer 301 formed by extending the gate line or data line of the thin film transistor may be formed below the passivation layer 302, and the gate line and the data line may be formed instead of the single layer metal layer 301. All may be formed, or the same components as the active region 320 may be formed.

In the transverse electric field type liquid crystal display device, the metal layer 301 may be configured as a common line. In this structure, the pixel electrode and the common electrode are formed on the lower substrate 300 to form a parallel electric field.

In addition, the first alignment layer is formed on the front surface of the active region 320 and the cell margin region 350 of the lower substrate 300 to form a uniform alignment of liquid crystal molecules to enable normal liquid crystal driving and to have uniform display characteristics. 303 is formed.

Next, in the active region 320 and the cell margin (liquid crystal margin) region 350 of the upper substrate 310, a black matrix 311 that serves as light blocking and a color filter layer 312a of RGB (Red, Green, Blue) 212 formed on the overcoat layer 313 and overcoat layer 313 for protecting and planarizing the color filter layers 312a, 312b and 312c on the color filter layers 312a, 312b and 312c. The alignment film 317 is formed.

At this time, the overcoat layer 313 of the active region 320 is formed flat, and the overcoat layer 313 of the cell margin region 350 is formed with a plurality of concave portions.

In this case, the overcoat layer 313 may not be formed. In this case, the liquid crystal may stay by the hole formed in the passivation layer 302 of the lower substrate 300.

Although not shown in the drawing, in the TN mode, a common electrode may be formed on the color filter layers 312a, 312b, and 312c of the upper substrate 313.

In this case, the liquid crystal may stay by holes or recesses formed in the passivation layer 302 of the lower substrate 300.

The black matrix 311 is positioned between the region where the pixel electrode is not formed and the color filter layers 312a, 312b and 312c of RGB.

As described above, liquid crystal (LC) may remain in the plurality of holes formed in the passivation layer 302 and the recessed portion of the overcoat layer 313.

As a result, in the liquid crystal display device having a large screen, it is possible to prevent the liquid crystal from flowing down the panel even if the cell gap is changed by the difference in the coefficient of thermal expansion of the liquid crystal and the column spacer.

Although not shown in the drawing, a hole may be formed in the overcoat layer 313 of the cell margin area 350 of the upper substrate 310 instead of a recess, and the protective film 302 of the lower substrate 300 may be formed. The yaw part may be configured instead of the hole.

Next, a method of manufacturing a liquid crystal display device according to the present invention having the above structure will be described.

4A and 4B are cross-sectional views showing a cell margin area of a lower substrate, and FIGS. 5A and 5B are cross-sectional views showing a cell margin area of an upper substrate.

In the manufacturing method of the liquid crystal display device according to the present invention, in order to solve the problem of the liquid crystal flowing down the panel due to the difference in the thermal expansion coefficient of the column spacer and the liquid crystal, the cell margin between the active region 320 and the seal member 315 It is characterized by forming recesses or holes so that the liquid crystal remains in the region 350.

Before describing a process of forming recesses or holes in the cell margin region 350, a method of manufacturing a liquid crystal display device including an active region 320 and a seal material 315 having a cell array will be described.

A method of manufacturing a liquid crystal display device is divided into a vacuum injection method and a liquid crystal drop method according to a method of forming a liquid crystal layer between the lower substrate and the upper substrate.

First, a method of manufacturing a liquid crystal display device by a vacuum injection method will be described. A lower substrate 300 including a thin film transistor, a protective film 302 and a pixel electrode; The upper substrate 310 having the black matrix 311, the color filter layers 312a, 312b, and 312c and the overcoat layer 313 is prepared. Thereafter, a column spacer 330 is formed on the upper substrate 310.

After the first and second alignment layers 303 and 317 are formed on the lower substrate 300 and the upper substrate 310, respectively, the liquid crystals can be prevented from leaking out and the two substrates 300 and 310 can be bonded to each other. The thermosetting seal material 315 using an epoxy resin is applied to the substrate (mainly the upper substrate).

Both substrates 300 and 310 are bonded to each other and then heated to heat-cure the sealing material 315 to bond the two substrates 300 and 310.

Then, a scribing process and a cutting process are performed on both substrates 300 and 310 to be separated into a unit liquid crystal cell.

Then, the bonded liquid crystal cell is placed in a vacuum chamber to maintain the inside of the substrate in a vacuum state, and then the liquid crystal layer 316 is formed in the substrate immersed in the liquid crystal container.

Next, a method of manufacturing a liquid crystal display device according to a liquid crystal drop method includes preparing a lower substrate 300 on which a thin film transistor array is formed and an upper substrate 310 on which a color filter array is formed, applying a seal material 315; The process of forming the column spacer 330 is the same as the vacuum injection method.

If the liquid crystal dropping method differs from the vacuum injection method, the liquid crystal layer is not injected into the vacuum state after the two substrates are bonded, but the liquid crystal is deposited on the lower substrate 300 or the upper substrate 310 on which the seal member 315 is formed. After dripping, the bonding process of both substrates is performed.

As described above, since the liquid crystal dropping method performs the bonding process of both substrates after the liquid crystal is dropped, when the thermosetting seal material is used as the seal material 315, the liquid material is contaminated while the seal material 315 is heated. In the liquid crystal dropping method, the seal material 315 uses UV (ultra violet) -curable seal material or UV and thermosetting seal material using an acrylic resin or the like.

Therefore, after the bonding process of both substrates, UV is irradiated to bond both substrates.

Alternatively, in the case of UV and thermosetting seal materials, after UV irradiation, heat is applied and bonded.

When manufacturing the liquid crystal display device having the active region 320 and the seal member 315 as described above, the cell margin region 350 also forms the components by the same process, below, the upper substrate 310 and lower substrate Divided by (300) to explain in more detail.

First, as shown in FIG. 4A, the metal layer 301 is formed on the lower substrate 300.

In this case, the metal layer 301 may be a gate line or a data line formed in the pixel region of the active region 320 to extend to the cell margin region 350. Although not illustrated, the metal layer 301 may be formed in place of the metal layer 301. Both the gate line and the data line may be formed, or the same components as the pixel region of the active region 320 may be formed.

Thereafter, the protective film 302 is deposited on the metal layer 301 of the lower substrate 300. At this time, the protective film 302 uses an inorganic insulating film such as a silicon nitride film and a silicon oxide film, or an organic insulating film such as benzocyclobuten (BCB) or acrylic resin.

Then, the photoresist film 304 is coated on the protective film 302, and the photoresist film 304 is exposed and developed using a photomask to selectively pattern the photoresist film 304.

At this time, the photosensitive film 304 uses a positive photosensitive film to remove the exposed portion of the light by a developing process.

Instead of the positive photoresist layer, a negative photoresist layer may be used.                     

Thereafter, the protective layer 302 is etched to expose the lower substrate 300 using the selectively patterned photoresist layer 304 as a mask to form holes in the protective layer 302 as shown in FIG. 4B.

The first alignment layer 303 is coated on the entire surface of the passivation layer 302 and the lower substrate 300.

Next, as shown in FIG. 5A, a black matrix 311 and a color filter layer (312a, 312b and 312c in FIG. 3A) are formed on the upper substrate 310, and the black matrix 311 and the color filter layer are formed thereon. The overcoat layer 313 is coated to reduce the steps of 312a, 312b and 312c.

Thereafter, in order to form a plurality of recesses in the overcoat layer 313, the overcoat layer 313 is exposed and developed using a photomask capable of transmitting only a certain amount of light.

In this case, the photomask corresponds to a light shielding region in which a plurality of light shielding films having a predetermined width are formed for each region where the recess is formed.

The overcoat layer 313 is formed of a negative photoresist film, and the overcoat layer 313 under the region where 100% of light is transmitted remains as it is, and only a portion of the region where only a certain amount of light is transmitted is removed by the light diffraction process. Is formed.

That is, the overcoat layer 313 under the light shielding region is transmitted by the light diffusing process by a predetermined amount (approximately 'X')% and is transmitted to the overcoat layer 313 so that (100) of the overcoat layer 313 -'X ')% thickness is developed and removed.

For example, if light is transmitted approximately 60% by the exposure process, the overcoat layer 313 is developed by removing approximately 40% of the thickness.

As described above, a process of forming a plurality of recesses in the overcoat layer 313 as shown in FIG. 5B can be formed by only one photo process using a light diffraction process, and thus no additional etching process is required.

Although not shown in the drawing, a hole may be formed in the overcoat layer 313 of the cell margin area 350 of the upper substrate 310 instead of the recessed portion, and a protective film of the lower substrate 300 may be formed. A yaw portion may be formed in 302 instead of a hole.

The present invention is not limited to the above embodiments, and includes various forms that can be easily derived by those skilled in the art from the above embodiments.

As described above, the liquid crystal display device and the manufacturing method thereof according to the present invention have the following effects.

First, since the liquid crystal stays in the recess and the hole by forming recesses or holes in the overcoat layer and the protective film of the upper and lower substrates, the liquid crystal flows to the lower part of the panel during high temperature driving to prevent staining. Can be.

Accordingly, the image quality of the LCD screen can be improved.

Second, when forming a plurality of concave portions in the overcoat layer of the cell margin region, it is not necessary to perform a separate etching process can simplify the process.

Claims (13)

First and second substrates defining an active region and a cell margin region; A protective film formed on the first substrate and having a plurality of holes so that the liquid crystal stays in the cell margin area; A liquid crystal layer formed between the first and second substrates, A black matrix and color filter layer formed on the second substrate; And a second alignment layer formed on the color filter layer. The method of claim 1, And a sealing material is further provided between the first and second substrates. The method of claim 1, And a column spacer in the active regions of the first and second substrates. The method of claim 1, In the active region of the first substrate, a thin film transistor and a pixel electrode are provided in each pixel region defined by intersecting gate lines and data lines. And a first alignment layer in front of the active region and the cell margin region. delete The method of claim 1, An overcoat layer is further provided on the color filter layer. The method of claim 6, And said overcoat layer has a plurality of recesses in said cell margin region. The method of claim 6, And an overcoat layer formed in the active region of the second substrate is flat. Forming a protective film having a plurality of holes in the cell margin area of the first substrate among the first and second substrates in which the active area and the cell margin area are defined; And attaching the first and second substrates to each other. The method of claim 9, The protective film having a plurality of holes comprises the steps of depositing a protective film on the first substrate; Forming a plurality of photoresist patterns on the passivation layer; Etching the passivation layer using the photoresist pattern as a mask to form a plurality of holes; And removing the photosensitive film. The method of claim 10, The photosensitive film is a manufacturing method of a liquid crystal display device, characterized in that using any one of a positive photosensitive film and a negative photosensitive film. The method of claim 9, And forming an overcoat layer having a plurality of concave portions in the cell margin region of the second substrate. The method of claim 12, The overcoat layer having the plurality of recesses is Coating an overcoat layer on the second substrate; And exposing and developing the overcoat layer using a photomask.

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