KR20050068178A - Liquid crystal display divice comprising line type siver dot and fabrication method therefor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having a common voltage applying line, and a method of manufacturing the same, wherein the seal line is composed of two parallel seal lines, and a silver contact for applying a common voltage to the common electrode therebetween. Is configured in a line shape. In addition, the common electrode applying line and the seal line are formed at the same time by a dispensing method to reduce silver contact defects, and do not have to devote a separate space for silver contact formation and to reduce a separate silver contact forming process.

Description

Liquid crystal display device including line type silver contact and manufacturing method therefor {LIQUID CRYSTAL DISPLAY DIVICE COMPRISING LINE TYPE SIVER DOT AND FABRICATION METHOD THEREFOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device including silver contacts (Ag dots), and more particularly, to a structure of a liquid crystal display device in which a structure of a silver contact for supplying voltage to a common electrode is changed into a line shape, and a manufacturing method thereof.

In today's information society, display is more important as a visual information transmission medium, and in order to gain a major position in the future, it is necessary to satisfy requirements such as low power consumption, thinness, light weight, and high definition. Liquid Crystal Display (LCD), the flagship product of Flat Panel Display (FPD), has not only the ability to satisfy these conditions of the display but also mass production. It has been established as a core parts industry that can gradually replace the existing cathode ray tube (CRT).

BACKGROUND ART In general, a liquid crystal display device is a display device in which data signals according to image information are individually supplied to pixels arranged in a matrix form so that a desired image can be displayed by adjusting light transmittance of the pixels.

To this end, the liquid crystal display device is a liquid crystal display panel which largely injects liquid crystal between a color filter substrate and an array substrate to output an image, and is installed on a rear surface of the liquid crystal display panel to provide light over the entire surface of the panel. The backlight unit may include a lower cover, a top case, and the like, which securely support each corner portion of the liquid crystal display panel and the backlight unit.

In particular, the liquid crystal display panel includes a color filter substrate and an array substrate and a liquid crystal layer formed between the color filter substrate and the array substrate.

The color filter substrate may include a black matrix that distinguishes between a color filter including a sub-color filter (red, green, blue) that implements color and the sub-color filter, and blocks light passing through the liquid crystal layer. It consists of a transparent common electrode for applying a voltage to the liquid crystal layer.

In addition, the array substrate is a thin film transistor (TFT) which is a switching element formed in a cross-section of the gate line and the data line, the plurality of gate lines and data lines, which are arranged vertically and horizontally on the substrate to define a plurality of pixel areas. ) And a pixel electrode formed on the pixel region.

The color filter substrate and the array substrate configured as described above are provided with a cell gap so as to be uniformly spaced apart by a spacer, and are united by a seal pattern formed on the outside of the image display area. The display panel is formed. At this time, the bonding of the two substrates is made through a bonding key formed on the color filter substrate or the array substrate.

On the other hand, an silver paste dot pattern having both conductivity and adhesion characteristics is formed outside the array substrate screen display to apply a common voltage to the color filter substrate.

Hereinafter, a liquid crystal display panel in which silver contacts are formed will be described with reference to FIG. 1.

1 is a plan view schematically illustrating a structure of a general liquid crystal display panel.

As shown in the figure, the liquid crystal display panel is largely a liquid crystal layer (not shown) filled between the color filter substrate 105 and the thin film transistor array substrate 110 and the color filter substrate 105 and the array substrate 110. )

The thin film transistor array substrate 110 is formed on a cross region of the plurality of gate lines 116 and data lines 117 and the gate lines 116 and data lines 117 that are arranged vertically and horizontally on the substrate 110. A thin film transistor (not shown), which is a switching element, and a screen display unit on which a pixel electrode (not shown) for applying an electric field to the liquid crystal is formed.

In addition, one long side and one end side of the array substrate 110 protrude relative to the color filter substrate 105 so that a driving circuit unit for driving the liquid crystal display panel is positioned. The gate pad part 124 is formed at one protruding short side of the 110, and the data pad part 123 is formed at one protruding one side of the protruding side.

In this case, the gate pad unit 124 supplies a scanning signal supplied from the gate driving circuit unit (not shown) to the gate line 116 of each pixel region of the screen display unit, which is the image display region 125. The data pad unit 123 supplies the image information supplied from the data driving circuit unit (not shown) to the data line 117 of the pixel region.

Although not shown in the drawing, the screen display unit 125 of the color filter substrate 105 includes a common filter serving as a counter electrode between the color filter for implementing color and the pixel electrode formed on the array substrate 110.

The color filter substrate 105 and the array substrate 110 configured as described above are provided with a cell gap so as to be uniformly spaced apart by a spacer (not shown), and formed on the outside of the screen display unit 125. The seal patterns 140 may be bonded to each other to form a unit liquid crystal display panel. At this time, the bonding of the two substrates 105 and 110 is performed through a bonding key (not shown) formed in the color filter substrate 105 and the array substrate 110. In addition, the common voltage formed on the color filter substrate 105 is applied by the silver contact 170.

A liquid crystal display device displays an image using a liquid crystal having an array direction controlled by an electric field and having refractive index anisotropy. A pixel electrode is formed on a thin film transistor array substrate to apply an electric field to the liquid crystal, and a common electrode on an upper substrate. In this manner, a voltage starting from the thin film transistor array substrate is applied to the upper common electrode via a silver contact by applying a voltage to the common electrode.

Referring to FIG. 2, the voltage is applied to the common electrode through the silver contact.

2 is a cross-sectional view of a liquid crystal display panel, in which a thin film transistor array substrate 201 is formed as a lower substrate and a color filter substrate 202 is formed as an upper substrate, and a liquid crystal 205 is filled therebetween. It is formed.

An alignment layer 207 for initial alignment of liquid crystals is formed on the thin film transistor array substrate and the color filter substrate, respectively.

Meanwhile, a common electrode 206 for applying an electric field to the liquid crystal is formed on the color filter substrate 202, and a silver contact 203 is formed outside the screen display unit to apply an electric field to the common electrode 206. .

In addition, a seal line 204 is formed outside the screen display unit to prevent the liquid crystal 205 formed between the color filter substrate 202 and the thin film transistor array substrate 201 from leaking out.

The silver contacts 203 may be formed outside the screen display unit of the thin film transistor array substrate by a dispensing method, and the silver contacts 203 are connected to each other by a common electrode line, so that the same common electrode voltage is applied.

However, the Ag contact is sprayed by a dispenser in the form of a solution containing silver as a conductor and volatilizes a solvent containing silver to form a silver contact. In addition, the silver contact point is formed outside the seal line with a size of several thousand μm to increase the size of the liquid crystal display panel. In addition, the silver contact solution containing a volatile solvent and silver is stored in a storage container and then sprayed and volatilized through a dispense to form a silver contact. The silver contact solution stored in the storage container is formed by the precipitation of silver and Different concentrations of the bottoms can occur. For this reason, when silver contacts are formed by spraying, silver contacts may be formed at different concentrations, in which case, a shot of the silver contacts may occur. As a result, normal common electrode voltage cannot be applied, causing pixel defects.

The present invention is to change the form of the silver contact to a line type to solve the problem that the common voltage is not applied smoothly due to the poor formation of the silver contact when forming a silver contact for applying a voltage to the common electrode due to the poor formation of the silver contact It aims at improving the occurrence of a short circuit.

In addition, in the development of a liquid crystal display device in which the enlargement trend is progressing, another purpose is to reduce the size of the liquid crystal display device by forming silver contacts without dedicating a separate space for forming silver contacts.

In order to achieve the above object, the present invention provides a display unit comprising a plurality of unit pixels; Two seal lines formed outside the screen display unit; And a common electrode voltage application line formed between the two seal lines. In addition, the common electrode applying line is characterized in that formed by curing the solvent containing silver. The seal line and the common electrode applying line may be formed by a dispensing method.

A liquid crystal display device is an image display device that displays an image using liquid crystals whose array direction is changed by refractive index anisotropy and an electric field. In order to apply an electric field to the liquid crystal, two electrodes are required. As two electrodes for applying an electric field to the liquid crystal, a pixel electrode and a common electrode are used. In the TN mode, a pixel electrode is formed on an array substrate, and a color filter substrate is opposed to the color filter substrate. The common electrode is formed on the. The common electrode voltage was applied by forming a silver contact on one side of the thin film transistor array substrate by connecting the common electrode to a common electrode formed on the color filter substrate. However, since the silver contact is formed by a method of dropping and volatizing while contacting the common electrode in the form of a dot and mixed with a volatile solvent, it may cause a problem in bonding to the common electrode.

The present invention has been made to solve the above problems, and forms a common voltage application line in a line shape without using a contact method by applying a common electrode voltage to the common electrode.

In addition, in forming the common electrode applying line, a method of forming by dispensing so as to be formed simultaneously with the seal line is employed.

In addition, the common electrode applying line of the present invention is formed together with the seal line while dividing the seal line into two seal lines, and forming a common electrode applying line between the seal lines so as to be common with the seal line within the range of one conventional seal line. It is possible to form all of the electrode application lines. By this method, the space required for forming the silver contact can be reduced.

Hereinafter, a detailed description of the present invention will be described with reference to FIG. 3.

The liquid crystal display panel includes a thin film transistor array substrate 301 having a plurality of switching elements arranged in a matrix, and a color filter substrate 302 formed to face the thin film transistor array substrate 301, and the color filter substrate 302 and a thin film. It is formed with a liquid crystal 305 filled in the cell gap between the transistor array substrate.

The thin film transistor array substrate 301 may be further divided into a screen display unit 320 in which a plurality of unit pixels are arranged in a matrix, and a pad unit formed outside the screen display unit.

The thin film transistor array substrate 301 and the color filter substrate 302 are bonded to each other to form a liquid crystal display panel. The means for joining and bonding the two substrates is a seal line 304. Therefore, the seal line 304 is formed in a line shape on the outside of the screen display unit 320 to bond the upper color filter substrate 302 and the thin film transistor array substrate 301.

As the liquid crystal display becomes larger, the width of the seal line reaches about 1 mm. The seal line also serves to support the color filter substrate and the thin film transistor array substrate.

The present invention is formed by separating the seal line into two seal lines 304 to allow the combined color filter substrate and the thin film transistor array substrate to be sufficiently supported.

In addition, in forming the two seal lines 304, the present invention forms two seal lines having a width of about 250㎛. When the space between the seal lines is about 500 μm, the seal lines may be configured to have two seal lines within a width of 1 mm.

Since the seal line is formed by being separated into two seal lines, a single seal line effect can be obtained by dispersing the force.

In addition, the present invention is formed in a line shape by a dispensing method using a silver mixed solution that has conventionally used a silver contact to apply a common voltage to the common electrode 306 formed on the color filter substrate.

Since the silver contact solution is a paste in which silver and a volatile solvent are mixed as a conductor, the paste may be sprayed by a dispenser to form a line-shaped common voltage application line 303.

When the common voltage application line 303 is used in a line shape, the area where the common electrode 306 and the common voltage application line 303 are in contact with each other can be further widened, so that stable common voltage can be applied.

In addition, the common voltage application line 303 having the line shape is formed between the seal lines 304 separated by the two seal lines, thereby eliminating the need for a separate space for forming a silver contact. The application line 303 and the seal line 304 can be formed within the conventional seal line formation range.

In addition, as a method of forming a seal line, a screen printing method of printing a seal line using a mask and a dispensing method of drawing a seal line using a dispense may be applied. The common electrode applying line 303 of the present invention may be a dispense method. Since the common voltage applying line 303 and the seal line 304 are simultaneously formed by the dispensing method, the process of forming the silver contact can be reduced. However, the present invention is not limited to forming the common voltage applying line and the seal line at the same time, and may form the seal line first and then the common voltage applying line, and vice versa to form the seal line and the common voltage applying line. You may.

4 is a schematic diagram of forming the seal line 304 and the common voltage application line 303 of the present invention by the dispenser 401, each dispenser being connected to a sealant supply tank and a solution storage tank including a silver contact, respectively. And and are supplied with the sprayed contact mixture solution to form a seal line and a common voltage application line.

Hereinafter, a method of forming a liquid crystal display device by the above technique of simultaneously forming a seal line and a common voltage application line will be described.

As shown in FIG. 5, the method of manufacturing a liquid crystal display device according to the present invention includes forming a TFT array substrate as a lower substrate (S501), forming a color filter substrate as an upper substrate (S510), and an upper substrate. Bonding the lower substrate (S506), cutting the bonded substrate by unit cell (S507), and injecting liquid crystal into the cut unit cell (S508).

First, the step of forming a TFT array substrate (S501)), the TFT array substrate is a step of preparing a transparent mother substrate on which a plurality of unit cells can be formed, forming a plurality of gate lines parallel to each other on the substrate Forming a gate insulating film on the substrate on which the gate line is formed, forming a semiconductor layer on the gate insulating film, forming a data line, a source electrode and a drain electrode on the semiconductor layer, the data line, Forming a protective film on the substrate on which the source electrode and the drain electrode are formed; and forming a pixel electrode on the protective film.

In addition, the alignment film forming process for the initial alignment of the liquid crystal is carried out on the TFT array substrate formed through the above process.

The alignment film forming process may be largely classified into an alignment film applying process, a rubbing process, and a cleaning process. Application of the alignment film is formed by a spin coating method or a printing method. When the alignment film is formed by the above method, a rubbing process is performed in which the alignment film is rubbed with a rubbing cloth or the like so that the alignment film has a certain orientation. Next, the alignment film forming step is completed by washing the alignment film.

Next, the seal line and the common voltage application line are formed outside the pixel region of the TFT array substrate on which the alignment film is formed. The seal line and the common voltage applying line form a dispensing spraying silver contact mixed solution in the center, and dispose a seal line forming dispense to the left and right sides of the silver contact dispensing mixed solution to simultaneously form the seal line and the common voltage applying line. .

 The seal line divided into two maintains a cell gap when the upper substrate and the lower substrate are bonded, and prevents the liquid crystal injected into the space between the bonded upper and lower substrates from leaking out, and is formed between the two seal lines. The voltage application line applies a common voltage to the common electrode formed on the color filter substrate.

However, in the forming of the seal line, the seal line may be formed first, and a common voltage applying line may be formed therebetween.

After the seal line and the common voltage application line are formed outside the screen display unit of the liquid crystal display device, a process of bonding the color filter substrate formed through a separate process is performed.

The bonding process heats the seal line to a predetermined temperature to bond the color filter substrate and the thin film transistor array substrate. At this time, the common voltage application line is completed as the volatile solvent of the common voltage application line formed between the two seal lines is volatilized.

After the bonding process by the seal line is completed, a unit liquid crystal display panel is formed through a cutting process of cutting the bonded color filter substrate and the thin film transistor array substrate into a unit liquid crystal display panel.

Subsequently, the unit liquid crystal display panel undergoes a liquid crystal injection process to obtain a complete unit liquid crystal display panel.

As described above, a stable common voltage without short circuit failure can be applied by forming a silver contact for applying a common voltage to a common electrode formed on a color filter substrate in a line shape, and applying the common voltage. By forming the common voltage application line by the dispenser method, the common voltage application line can be formed at the same time as the seal line, and the process of forming the silver contact can be shortened. In addition, since the common voltage application line is formed between two separate seal lines, it is not necessary to separately provide a space for forming a silver contact, thereby reducing the size of the liquid crystal display panel.

1 is a plan view showing the structure of a general liquid crystal display panel.

2 is a cross-sectional view and a perspective view showing a structure of a general liquid crystal display panel.

3 is a cross-sectional view and a perspective view showing the structure of a liquid crystal display panel of the present invention.

4 is a schematic diagram for forming a seal line and a common voltage application line of the present invention.

5 is a flow chart showing a manufacturing process of the liquid crystal display panel of the present invention.

********* Description of the symbols for the main parts of the drawings ***********

301: thin film transistor array substrate 302: color filter substrate

306: common electrode 305: liquid crystal

303: common voltage application line 304: seal line

320: display unit

Claims (8)

A screen display unit on which a plurality of unit pixels are arranged; Two seal lines formed outside the screen display unit; And a common voltage application line formed between the two seal lines. The liquid crystal display device of claim 1, wherein the common electrode voltage application line comprises silver. The liquid crystal display device of claim 1, wherein the seal line and the common voltage application line are parallel to each other. The liquid crystal display device according to claim 1, wherein a width at which the seal line is formed is within 1 µm. The liquid crystal display of claim 1, wherein the two seal lines and the common voltage applying line are formed by a dispenser at the same time. Forming a screen display on the substrate; and Forming a thin film transistor array substrate including forming two parallel seal lines spaced apart from the screen display unit by a predetermined distance and a common voltage applying line between the two seal lines; Forming a color filter substrate facing the thin film transistor array substrate; Bonding the thin film transistor array substrate to the color filter substrate; And cutting the bonded thin film transistor array substrate and the color filter substrate into a unit liquid crystal display panel. The method of claim 6, wherein the solvent included in the common voltage applying line is removed and the common voltage applying line is formed in the bonding of the thin film transistor array substrate and the color filter substrate. The method of claim 6, wherein the seal line and the common voltage application line are dispensed by a dispenser.