KR20060130431A - Liquid crystal display device and fabrication method thereof - Google Patents

Abstract

An LCD and a method for manufacturing the same are provided to sufficiently fill an outer region of an LCD panel with liquid crystals, by disposing more column spacers in the outer region than a center region of the LCD panel. A plurality of pixels are defined on first and second substrates(103,105). A liquid crystal layer is formed between the first and second substrates. Column spacers(130) are configured to maintain a cell gap between the first and second substrates. A density of column spacer in a center region(C) of an LCD panel is higher than a density of column spacer in an outer region(E) of the LCD panel. The column spacer is capable of having a circle shape.

Description

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

1 is a cross-sectional view of a general liquid crystal display device.

2 is a flowchart showing a conventional method for manufacturing a liquid crystal display device.

3 is a view showing liquid crystal injection of a conventional liquid crystal display device.

4 is a view showing a method of manufacturing a liquid crystal display device by the liquid crystal dropping method.

5 is a view showing a liquid crystal display device of the present invention.

FIG. 6 is a diagram illustrating a distribution of column spacers disposed in the central region C of FIG. 5.

FIG. 7 is a diagram illustrating a distribution of column spacers disposed in an outer region E of FIG. 5.

*** Explanation of symbols for main parts of drawing ***

103: lower substrate 105: upper substrate

108: gate line 109: data line

116: seal pattern 118: color filter

121: black matrix 130: column spacer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device using a dropping method, and more particularly, to a liquid crystal display device and a method for manufacturing the same, which can prevent liquid crystals from being swept.

Recently, with the development of various portable electronic devices such as mobile phones, PDAs, and notebook computers, there is a growing demand for flat panel display devices for light and thin applications. Such flat panel displays are being actively researched, such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), FED (Field Emission Display), and VFD (Vacuum Fluorescent Display). Liquid crystal display devices (LCDs) are in the spotlight for their implementation.

1 schematically illustrates a cross section of a general liquid crystal display device. As shown in the figure, the liquid crystal display device 1 is composed of a lower substrate 5 and an upper substrate 3 and a liquid crystal layer 7 formed between the lower substrate 5 and the upper substrate 3. . Although the lower substrate 5 is a driving element array substrate, although not shown in the drawing, a plurality of pixels are formed on the lower substrate 5, and each pixel is driven such as a thin film transistor. An element is formed. The upper substrate 3 is a color filter substrate, and a color filter layer for real color is formed. In addition, a pixel electrode and a common electrode are formed on the lower substrate 5 and the upper substrate 3, respectively, and an alignment film for aligning liquid crystal molecules of the liquid crystal layer 7 is coated.

The lower substrate 5 and the upper substrate 3 are bonded by a sealing material 9, and the amount of light that penetrates the liquid crystal layer by driving the liquid crystal molecules by a driving element formed on the lower substrate 5. Information is displayed by controlling.

The manufacturing process of the liquid crystal display device can be largely divided into a driving element array substrate process of forming a driving element on the lower substrate 5, a color filter substrate process of forming a color filter on the upper substrate 3, and a cell process. However, the process of the liquid crystal display will be described with reference to FIG. 2.

First, a plurality of gate lines and data lines which are arranged on the lower substrate 5 to define a pixel region are formed by a driving element array process, and the gate line and the data are formed in each of the pixel regions. A thin film transistor which is a driving element connected to the line is formed (S101). In addition, the pixel electrode is connected to the thin film transistor through the driving element array process to drive the liquid crystal layer as a signal is applied through the thin film transistor.

In addition, the upper substrate 3 is formed with a color filter layer and a common electrode of R, G, B to implement the color by the color filter process (S104).

Subsequently, an alignment layer is applied to the upper substrate 3 and the lower substrate 5, respectively, and then the alignment control force or surface fixing force (ie, the liquid crystal molecules of the liquid crystal layer formed between the upper substrate 3 and the lower substrate 5). In order to provide a pretilt angle and an orientation direction, the alignment layer is rubbed (S102 and S105). Subsequently, a spacer is disposed on the lower substrate 5 to maintain a constant cell gap, and a sealing material is applied to an outer portion of the upper substrate 3. Then, the lower substrate 5 and the upper substrate are dispersed. Pressure is applied to (3), and it adheres (S103, S106, S107).

On the other hand, the lower substrate 5 and the upper substrate 3 is made of a large area glass substrate. In other words, a plurality of panel regions are formed on a large area glass substrate, and a TFT and a color filter layer, which are driving elements, are formed in each of the panel regions. Must be processed (S108). Thereafter, the liquid crystal is injected into the liquid crystal panel processed as described above through the liquid crystal inlet, and the liquid crystal inlet is encapsulated to form a liquid crystal layer. Then, the liquid crystal display is manufactured by inspecting each liquid crystal panel (S109 and S110). .

At this time, the liquid crystal injection is performed by the following process. That is, as shown in FIG. 3, nitrogen (N ₂ ) gas is supplied into the vacuum chamber 10 in a state where the injection port 16 of the liquid crystal panel 1 is in contact with the liquid crystal 14 to provide the chamber 10. When the degree of vacuum is lowered, the liquid crystal 14 is injected into the panel 1 through the injection hole 16 by the pressure difference between the pressure inside the liquid crystal panel 1 and the vacuum chamber 10, and the liquid crystal is introduced into the panel 1. The liquid crystal layer is formed by encapsulating the injection hole 16 with a sealing material after it is completely filled in (). This method is called vacuum injection of liquid crystal).

However, since the liquid crystal is injected through the injection hole 16 of the liquid crystal panel 1 in the vacuum chamber 10 as described above, the liquid crystal injection time takes a long time. That is, since the distance between the drive element array substrate and the color filter substrate of the liquid crystal panel is very narrow, such as several micrometers, only a very small amount of liquid crystal per unit time is injected into the liquid crystal panel. For example, when manufacturing a liquid crystal panel of about 15 inches takes about 8 hours to completely inject the liquid crystal, the liquid crystal panel manufacturing process is lengthened by the long-term liquid crystal injection has a problem that the manufacturing efficiency is lowered. . In particular, the vacuum injection method as described above is not suitable for large area, since the liquid crystal injection time becomes longer as the liquid crystal panel is enlarged.

Accordingly, the present invention has been made to solve the above problems, and the present invention is to provide a method of manufacturing a liquid crystal display device that can improve the process efficiency of the liquid crystal display device by forming a liquid crystal layer through a dropping method.

Another object of the present invention is to provide a liquid crystal display device and a method for manufacturing the same, by which the liquid crystal is spread out to the outside of the liquid crystal panel, thereby preventing the gravity failure of the liquid crystal due to the liquid crystal slid.

The liquid crystal display device of the present invention for achieving the above object includes a first substrate and a second substrate in which a plurality of pixels are defined; A liquid crystal layer formed between the first and second substrates; And a column spacer for maintaining a cell gap between the first and second substrates, wherein the column spacers have a higher density of formation in the outer region than the center region of the substrate. In this case, the column spacer is formed in a circular shape, one column spacer formed at the center portion is formed for every six pixels, and one column spacer formed at the outer portion is formed for each one of the two pixels.

The first substrate may further include a plurality of gate lines arranged in a first direction on a transparent substrate; A plurality of data lines crossing the gate lines vertically to define a plurality of pixels; A switching element formed between the gate line and the data line to switch the pixel; And a pixel electrode formed in the pixel region, wherein the second substrate comprises: a black matrix formed on a transparent substrate; A color filter formed on the black matrix; And a common electrode formed on the color filter.

In this case, the column spacer is formed in a region corresponding to the black matrix, and does not affect the opening ratio.

In addition, the method of manufacturing a liquid crystal display device according to the present invention comprises the steps of preparing a first and a second substrate; Forming a column spacer having a higher density in the outer region than the center region on the first substrate; Forming a seal pattern on the second substrate; Dropping liquid crystal on the first substrate; And bonding the first and second substrates to each other by the seal pattern.

According to the present invention as described above, since the density of the spacer is formed on the outer side of the liquid crystal panel where the unfilled region of the liquid crystal is generated, a liquid crystal layer having a uniform thickness can be formed over the entire liquid crystal panel.

In addition, the liquid crystal layer of the present invention is formed by the liquid crystal dropping method, the liquid crystal dropping method is a dropping and dispensing the liquid crystal directly on the substrate (drip) and the liquid crystal dropped by the bonding pressure of the panel uniform across the panel The liquid crystal layer is formed by distribution. Since the liquid crystal dropping method directly drops the liquid crystal onto the substrate for a short time, the liquid crystal layer formation of the large area liquid crystal display device proceeds very quickly, thereby shortening the process time of the liquid crystal display device and improving productivity. Has the advantage that

On the other hand, in the liquid crystal dropping method, since the seal pattern is formed in a curved line along the outer edge of the panel, when the dropping amount of the liquid crystal falls below or exceeds the reference value, an unfilled area or an overfilled area of the liquid crystal is generated. As such, the cell gap of the liquid crystal panel is uneven due to the unfilled or overfilled liquid crystal, and the transmittance of the liquid crystal is changed so that the screen display characteristics are deteriorated. (This is called gravity defect.)

Accordingly, in the present invention, in particular, to solve this problem, by forming a density of the spacer formed in the outer portion of the liquid crystal panel higher than the central portion, the liquid crystal is easily spread to the outer portion so that the unfilled region of the liquid crystal is not generated Do not That is, the spacer induces the liquid crystal to easily spread to the outer side of the liquid crystal panel so that the unfilled region of the liquid crystal does not occur.

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

FIG. 4 is a view schematically illustrating the basic concept of the liquid crystal dropping method. As shown in the drawing, the lower substrate 105 and the upper substrate 103 having the TFT and the color filter formed therein, respectively, in the liquid crystal dropping method. Before bonding, the liquid crystal 107 is dropped on the lower substrate 105 in a drop shape. The liquid crystal 107 may be dropped on the substrate 103 on which the color filter is formed. In other words, the liquid crystal dropping substrate in the liquid crystal dropping method may be a thin film transistor array substrate or a color filter substrate. However, when the substrates are bonded, the substrate on which the liquid crystal is dropped must be placed at the bottom.

In this case, a seal pattern 116 is applied to an outer region of the upper substrate 103, and the upper substrate 103 is formed by the seal pattern 116 as pressure is applied to the upper substrate 103 and the lower substrate 105. 103 and the lower substrate 105 are bonded together. At the same time, a drop of the liquid crystal 107 is spread out by the pressure to form a liquid crystal layer between the upper substrate 103 and the lower substrate 105. In other words, the biggest feature of the liquid crystal dropping method is that the liquid crystal 107 is dropped on the lower substrate in advance before the panel 101 is bonded, and then the panel is bonded by the seal pattern 116.

The method of manufacturing a liquid crystal display device using the liquid crystal dropping method has the following difference from the manufacturing method of the conventional liquid crystal injection method. In the conventional liquid crystal injection method, a glass substrate having a large area in which a plurality of panels are formed is separated into panel units, and liquid crystal is injected. Processing can be separated in units. This process difference provides many advantages when manufacturing an actual liquid crystal display device. Of course, there is an advantage of the liquid crystal dropping method itself (that is, the advantage of the rapid generation of the liquid crystal layer), but there is also an advantage resulting from forming the liquid crystal layer by the glass substrate unit formed with a plurality of panels. For example, when four liquid crystal panels are formed on a glass substrate, in the process of forming the liquid crystal layer by the liquid crystal injection method, the same conditions (the same liquid crystal container, the same injection) are injected when the liquid crystal is injected into each of the processed four liquid crystal panels at once The liquid crystal panel having the same cell gap can be formed by a pressure or the like, but in the liquid crystal dropping method, a liquid crystal panel having different cell gaps can be formed by controlling the amount of liquid crystal dropped on the four liquid crystal panels by one drop. It becomes.

On the other hand, in the liquid crystal dropping method, the liquid crystal is dropped onto the substrate through liquid crystal dropping. When the cell gaps of the liquid crystal panels formed on the same substrate are different from each other, the amount of liquid crystal dropped on each liquid crystal panel must be accurately controlled. This will occur. Further, in the liquid crystal dropping system, the amount of liquid crystal dropped on the liquid crystal panel falls short of or exceeds the set reference value. In particular, an unfilled region occurs in the outer region (corner region) of the liquid crystal panel. Here, the set reference value of the liquid crystal amount means the amount of liquid crystal that can be filled in the cell gap region of the liquid crystal panel.

On the other hand, in the liquid crystal dropping method, the seal pattern is formed in the shape of a closed curve along the periphery of the liquid crystal panel, and the liquid crystal panel is bonded after the liquid crystal is dropped, so that the liquid crystal is added even if the amount of liquid crystal falls short of the set reference value. Cannot be injected into the film, and the image quality deteriorates due to the unfilled area of the liquid crystal.

Therefore, the present invention has been made in particular to solve this problem, and by increasing the density of the spacer formed in the outer portion of the liquid crystal panel, the liquid crystal is easily spread, thereby preventing the liquid crystal from filling in the outer region.

5 shows a liquid crystal display device according to the present invention. As shown in the drawing, the liquid crystal display device 100 according to the present invention includes an upper substrate 103 and a lower substrate 105, and the two substrates 103 and 105. ) And a liquid crystal layer (not shown) formed therebetween.

The lower substrate 105 is divided into an image display unit 113 which displays liquid images by arranging liquid crystal cells in a matrix form, and gate / data pad units 114 and 115 which transmit external signals to the image display unit 113. . A gate line 108 and a data line 109 are arranged in the image display unit 113 to define liquid crystal cells arranged vertically and horizontally, and a liquid crystal cell is formed at an intersection of the gate line 108 and the data line 109. Thin film transistors for switching them and a pixel electrode connected to the thin film transistors to drive the liquid crystal cell are formed.

The upper substrate 103 is formed with a black matrix for preventing light leakage and a color filter applied separately for each cell region. A common electrode for applying a signal to the liquid crystal layer together with a pixel electrode is formed on the color filter. .

The upper substrate 103 and the lower substrate 105 configured as described above are bonded by the seal pattern 116 formed along the outer side thereof, and therein to maintain a constant cell gap between the two substrates 103 and 105 therein. The column spacer 130 is formed, and the column spacer 130 has different densities in the central region C and the outer region E of the liquid crystal panel.

That is, the column spacer 130 formed in the outer region E is arranged more densely than the center region C, and this is to prevent the unfilled region of the liquid crystal from occurring in the outer portion, particularly the corner portion. .

The column spacer 130 may be formed on the lower substrate 105 or the upper substrate 103. When the column spacer 130 is formed on the lower substrate 105, the column spacer 130 may not cover the pixel region, that is, the gate line 108 or the data. Lines 109 or intersections thereof. Even when the spacer is formed on the upper substrate 103, the spacer is formed in the black matrix area that does not cover the pixel area.

6 and 7 illustrate an upper substrate (color filter substrate) on which the column spacer 130 is formed, and FIG. 6 shows a part of the central region C of FIG. 5, and FIG. 7 shows the outer region of FIG. 5. E) In particular, the corner regions of the lower substrate are shown respectively.

As shown in FIG. 6, the upper substrate 103 includes a color filter 118 and a black matrix 121 formed of R, G, and B colors, and the color filter 118 is disposed on the gate line and the data line. The black matrix 121 is formed in a region corresponding to the gate line, the data line, and the switching element. In addition, the column spacer 130 is formed on the black matrix 121. Since the region in which the black matrix 121 is formed is a region through which light is not actually transmitted, the column spacer 130 is formed in this region. This does not affect the aperture ratio characteristics at all. In this case, one column spacer 130 may be disposed per six pixels, but the number of column spacers 130 in the center area is not limited.

As illustrated in FIG. 7B, in the outer region E, one column spacer 130 is formed per two pixels, but the number of column spacers 130 is not limited. The basic concept of the present invention is to vary the density of the spacers disposed in the central region C and the outer region E of the liquid crystal panel, but the number is not limited thereto. However, the number of column spacers 130 disposed in the outer region E should be larger than that of the central region C.

When the liquid crystal layer is formed through the dropping method, the liquid crystal layer is formed in the outer region E so that the liquid crystal is not filled in the liquid crystal droplets. The column spacer 130 maintains the cell gap and allows the liquid crystal to spread to the corner region.

On the other hand, the column spacer 130 may have a variety of shapes, for example, may have a rhombus shape or a circular shape. The column spacer 130 is instantaneously deformed due to the pressure applied when the column spacer 130 is bonded. Since the column spacer 130 has a circular shape, since the restoring force is excellent, the column spacer 130 may prevent defects due to deformation of the spacer. have.

As described above, the present invention increases the number of arrangement of the column spacers in the outer region of the liquid crystal panel in which the liquid crystal does not normally spread, thereby inducing the liquid crystal to be easily spread, so that an unfilled region of the liquid crystal does not occur.

According to the present invention, in the liquid crystal display device in which the liquid crystal layer is formed in a dropping manner, the number of column spacers arranged in the center region and the outer region of the liquid crystal display device is differently designed, but the filling of the outer region, that is, the liquid crystal is well performed. By arranging more column spacers in an area which is not made, the number of column spacers arranged in the center region and the outer region should be designed according to the size of the liquid crystal display device.

As described above, according to the present invention, in the liquid crystal display device formed in the liquid crystal dropping method, by forming more column spacers in the outer region than in the center region, the liquid crystal is prevented from being filled in the outer region, thereby improving image quality. There is a number.

Claims (9)

A first substrate and a second substrate on which a plurality of pixels are defined; A liquid crystal layer formed between the first and second substrates; And And a column spacer maintaining a cell gap between the first and second substrates, wherein the column spacers have a higher density of formation in the outer region than the center region of the substrate. The method of claim 1, And said column spacer is circular. The method of claim 1, And one column spacer formed at each of the six center pixels. The method of claim 1, And one column spacer formed at each outer portion of each pixel. The method of claim 1, And the outer area is a corner area. The method of claim 1, The first substrate, A plurality of gate lines arranged in a first direction on a transparent substrate; A plurality of data lines crossing the gate lines vertically to define a plurality of pixels; A switching element formed between the gate line and the data line to switch the pixel; And And a pixel electrode formed in the pixel region. The method of claim 1, The second substrate, A black matrix formed on the transparent substrate; A color filter formed on the black matrix; And And a common electrode formed on the color filter. The method of claim 7, wherein And the column spacer is formed in a region corresponding to the black matrix. Preparing first and second substrates; Forming a column spacer having a higher density in the outer region than the center region on the first substrate; Forming a seal pattern on the second substrate; Dropping liquid crystal on the first substrate; And And bonding the first and second substrates to each other by the seal pattern.

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