KR101087510B1 - Liquid crystal display panel and method of fabricating the same - Google Patents

Abstract

The liquid crystal display panel of the present invention and a method of manufacturing the same are to maintain a uniform cell gap by fixing the column spacer using a protrusion to improve the bonding force between the column spacer and the substrate, forming a column spacer on the first substrate ; Forming a pixel electrode on the second substrate using a transparent conductive material; Forming at least one protrusion by patterning the transparent conductive material in a predetermined region of the second substrate facing the column spacer; And bonding the first substrate and the second substrate so that the protrusion is embedded in the bottom surface of the column spacer.

Description

Liquid crystal display panel and its manufacturing method {LIQUID CRYSTAL DISPLAY PANEL AND METHOD OF FABRICATING THE SAME}

1 is an exploded perspective view schematically illustrating a structure of a general liquid crystal display panel.

2 is a plan view schematically illustrating a portion of an array substrate of a liquid crystal display panel according to an exemplary embodiment of the present invention.

3 is an exemplary view illustrating a cross section taken along line II-II ′ of the liquid crystal display panel illustrated in FIG. 2.

4A to 4D are exemplary views illustrating protrusions according to embodiments of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

105: color filter substrate 110: array substrate

116: gate line 117: data line

150: column spacer 160,260A ~ 260D: protrusion

The present invention relates to a liquid crystal display panel and a method for manufacturing the same, and more particularly, to a liquid crystal display panel and a method for manufacturing the same to prevent gravity defects by maintaining a uniform cell gap.

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

To this end, the liquid crystal display includes a liquid crystal display panel in which pixels are arranged in a matrix and a driving unit for driving the pixels.

The liquid crystal display panel is bonded to an array substrate on which a thin film transistor array is formed and a color filter substrate on which a color filter is formed to maintain a uniform cell gap, and the array substrate and the color filter substrate. The liquid crystal layer is formed in the cell gap therebetween.

In this case, an alignment layer is formed on the surface of the array substrate and the color filter substrate facing each other, and rubbing is performed to arrange the liquid crystals of the liquid crystal layer in a predetermined direction.

In addition, the array substrate and the color filter substrate are bonded by a seal pattern formed along the outer edge of the image display unit, and the polarized plate and the phase difference plate are provided on the outer surfaces of the bonded array substrate and the color filter substrate. By selectively configuring such a plurality of components, a liquid crystal display device having high luminance and contrast characteristics by changing the light traveling state or the refractive index is constructed.

Hereinafter, the liquid crystal display panel configured as described above will be described in detail with reference to the accompanying drawings.                         

1 is an exploded perspective view schematically illustrating a structure of a general liquid crystal display panel.

As shown in the figure, the liquid crystal display panel is largely composed of a color filter substrate 5 and an array substrate 10 and a liquid crystal layer 40 formed between the color filter substrate 5 and the array substrate 10.

At this time, the color filter substrate 5 and the color filter (C) consisting of a sub-color filter (7) for realizing the colors (Red, Green, G, Blue; B) and A black matrix 6 that separates the sub-color filters 7 and blocks light passing through the liquid crystal layer 40, and a transparent common electrode 8 that applies a voltage to the liquid crystal layer 40. )

In addition, the array substrate 10 is arranged such that the data lines 17 to which image information is applied and the gate lines 16 to which a scan signal is applied cross each other, and the data lines 17 and the gate lines 16 are intersected with each other. In each pixel region P defined by the plurality of pixels, a thin film transistor T and a pixel electrode 18, which are switching elements, are formed.

The pixel region P is a sub pixel corresponding to one sub color filter 7 of the color filter substrate 5. The color image is a sub-color filter 7 of the red, green, and blue colors. It is obtained by combining. That is, three subpixels of red, green, and blue are gathered to form one pixel, and the thin film transistor T is connected to the red and green subpixels, respectively.

In this case, although not shown in detail, the thin film transistor T includes a gate electrode connected to the gate line 16, a source electrode and a drain electrode connected to the data line 17. In addition, the thin film transistor T forms a conductive channel between the source electrode and the drain electrode by an insulating film for insulating the gate electrode and the source / drain electrode and a gate voltage supplied to the gate electrode. Layer.

The array substrate 10 and the color filter substrate 5 configured as described above are maintained with a constant cell gap by spacers (not shown), and are bonded by a seal pattern (not shown) formed along the periphery of the image display unit. do.

In this case, a method of randomly dispersing ball spacers, such as glass beads or plastic beads, has been used. However, as the liquid crystal display panel is gradually enlarged in recent years, precise cell gap is maintained due to agglomeration of ball spacers. Is difficult, and poor image quality occurs.

Therefore, in the case of a large liquid crystal display panel, a column spacer (or a patterned spacer) in which a spacer is fixed to an array substrate or a color filter substrate is used instead of a ball spacer.

At this time, the thickness of the liquid crystal layer, that is, the cell gap between the array substrate and the color filter substrate is one of the most important items in the design of the liquid crystal display panel. That is, when the thickness of the liquid crystal layer is changed according to each sub-pixel of the panel, a serious problem that the color or the luminance is changed accordingly occurs.

However, in a general liquid crystal display panel, only a spacer generates a bearing force against external pressure to maintain a cell gap, and thus there is a problem in that the bonding force between the spacer and the substrate is not so large. Therefore, when the pressure is generated due to temperature rise or gravity inside the liquid crystal display panel and the cell gap is increased, the spacer may not play a large role.

This problem is a bigger problem in the current trend of larger panels, because the larger the panel, the larger the substrate, the more the warpage of the substrate occurs, and the greater the amount of liquid crystal added. to be.

SUMMARY OF THE INVENTION 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 panel and a method of manufacturing the same, which can maintain a uniform cell gap by improving the bonding force between the column spacer and the substrate.

In addition, another object of the present invention is to provide a liquid crystal display panel and a method of manufacturing the light leakage is prevented by maintaining a uniform cell gap.

Other objects and features of the present invention will be described in the configuration and claims of the invention described below.

In order to achieve the above object, the liquid crystal display panel of the present invention comprises a column spacer formed on the first substrate to form a cell gap between the first substrate and the second substrate; A pixel electrode formed of a transparent conductive material on the second substrate; At least one protrusion formed in a predetermined region of the second substrate opposite to the column spacer and made of the transparent conductive material and embedded in a lower surface of the column spacer; And a liquid crystal layer formed in a cell gap between the first substrate and the second substrate.

In addition, the manufacturing method of the liquid crystal display panel of the present invention comprises the steps of forming a column spacer on the first substrate; Forming a pixel electrode on the second substrate using a transparent conductive material; Forming at least one protrusion by patterning the transparent conductive material in a predetermined region of the second substrate facing the column spacer; And bonding the first substrate and the second substrate so that the protrusion is embedded in the bottom surface of the column spacer.

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

2 is a plan view schematically illustrating a portion of an array substrate of a liquid crystal display panel according to an exemplary embodiment of the present invention.

In this case, the present embodiment shows a case in which the column spacer is formed on the color filter substrate, and the protrusions for coupling with the column spacer are formed on the array substrate facing the column spacer, but the present invention is not limited thereto. Column spacers may be formed on the array substrate, and protrusions may be formed on the color filter substrate.

As shown in the drawing, the liquid crystal display panel according to the present exemplary embodiment is arranged in the vertical direction at regular distances from the gate lines 116 which are regularly spaced apart and arranged in the horizontal direction, and intersects with the gate lines 116. 117 and the pixel area P, which is an image display area defined by the gate line 116 and the data line 117 intersecting with each other.

In this case, although N gate lines 116 and M data lines 117 cross each other in the actual array substrate, there are N × M pixel regions P. However, for convenience of description, one pixel region P is illustrated in the drawing. ).

Switching such as a thin film transistor for selectively supplying the image signal applied through the data line 117 to the pixel region P by the scan signal applied through the gate line 116 in the pixel region P. FIG. A device (not shown) is provided, and a pixel electrode (not shown) for driving the liquid crystal layer by an image signal applied through the thin film transistor is provided.

Although not shown in the drawing, the thin film transistor includes a gate electrode connected to the gate line 116, a source electrode and a drain electrode connected to the data line 117. The thin film transistor may include an insulating layer for insulating the gate electrode and a source / drain electrode, and a channel layer forming a conductive channel between the source electrode and the drain electrode by a gate voltage supplied to the gate electrode.

In this case, a column spacer 150 maintaining a cell gap of the liquid crystal display panel is positioned on the gate line 116, and a protrusion 160 of the present invention is formed in a region where the column spacer 150 is in contact with the lower array substrate. It is formed and coupled to the bottom surface of the column spacer 150. In this case, the protrusion 160 is formed to have a cross-sectional area smaller than the area formed by the column spacer 150.

That is, the column spacer 150 is formed on the upper color filter substrate (not shown) of the panel, and at least one protrusion 160 is disposed on the lower array substrate to face the column spacer 150. When it is made smaller and formed, when the color filter substrate and the array substrate are bonded, the protrusions 160 are embedded in the column spacer 150 to increase the bonding force between the column spacer 150 and the lower array substrate. It becomes possible.

In this way, by fixing the protrusions 160 to the column spacers 150, it is possible to counter the tension as well as the external compressive force to some extent, thereby maintaining the cell gap uniformly. In particular, in a large panel, it is possible to prevent the cell gap caused by the temperature rise and gravity and the resulting light leakage phenomenon.

In this case, any material may be used as long as the material of the protrusion 160 is larger than the material of the column spacer 150 so as to be embedded in the column spacer 150.

In this case, the protrusion 160 may be formed of a transparent conductive material constituting the pixel electrode of the lower array substrate. In this case, the protrusion 160 may be formed without an additional process. In other words, when forming a pixel electrode in the pixel region P of the array substrate, a transparent conductive material such as indium tin oxide (ITO) constituting the pixel electrode is formed and patterned to form a pixel electrode without any additional process. The protrusions 160 may be formed.

FIG. 3 is an exemplary view illustrating a cross section taken along line II-II ′ of the liquid crystal display panel illustrated in FIG. 2, illustrating an example in which a column spacer is formed integrally with a color filter substrate, which is an upper substrate.

As shown in the figure, the liquid crystal display panel according to the present embodiment includes an array substrate 110 having a thin film transistor array, a color filter formed thereon, and a color filter substrate 105 bonded to the array substrate 110. A column spacer 150 formed on the filter substrate 105 to uniformly maintain a cell gap between the array substrate 110 and the color filter substrate 105, and a cell gap between the array substrate 110 and the color filter substrate 105. It consists of a liquid crystal layer (not shown) formed in.

In this case, the gate line 116, the first insulating film 115A, and the second insulating film 115B are sequentially formed on the array substrate 110, and the color filter substrate 105 is disposed on the second insulating film 115B. Protrusions 160 are formed to engage with the column spacer 150 formed in the).

As described above, the protrusion 160 may be formed by patterning and using a transparent conductive material constituting the pixel electrode of the array substrate 110. Alternatively, the protrusion 160 may be formed of a metallic material having a high hardness by using an additional process. You may.

In addition, the color filter substrate 105 is partitioned by the black matrix 106 and the black matrix 106 formed on the substrate 105 and arranged in a matrix so as to correspond to the pixel region P. A color filter (not shown) and a common electrode 108 formed on the entire surface of the substrate 105.

In this case, an overcoat layer may be further formed below the common electrode 108 to planarize the surface of the red, green, and blue color filters and the black matrix 106.

A column spacer 150 patterned with an organic layer is formed on the common electrode 108. The width of the column spacer 150 is made as large as possible. This is to prevent the bonding margin between the color filter substrate and the array substrate from decreasing.

That is, when the width of the column spacer 150 decreases to become similar to the width of the lower protrusions 160, the column spacers 150 and the protrusions 160 must be accurately aligned when the color filter substrate and the array substrate are bonded together. Since this means that the bonding margin is small, it is preferable to form the width of the column spacer 160 as large as described above.

On the other hand, the drawing shows a case of forming two lower protrusions 160, for example, the present invention is not limited to this, and the number of the lower plate protrusions 160 is not limited.

In addition, the present embodiment shows a conical protrusion 160 having a pointed tip, for example, but the present invention is not limited thereto. When the color filter substrate and the array substrate are attached to each other with a sharp end, the protrusion 160 may be attached thereto. The nail can be formed into various shapes just by being nailed to the bottom surface of the column spacer 150 like a nail.

4A to 4D are exemplary views illustrating protrusions according to embodiments of the present invention.

At this time, the lower part of each figure shows a cross-sectional view of the projection from the side, and the upper part shows a plan view of the projection from above.

The protrusion may be any shape as long as it can be embedded in the lower surface of the spacer, but as shown, a conical shape (260A), pyramidal shape (260B), and wedge shape (260C) are easily pointed to be embedded in the column spacer. Or the like.

Also, as shown in FIG. 4D, a narrow hexahedron shape 260D may be formed.                     

At this time, the pyramidal shape 260B and the conical shape 260A may be formed using a slit mask, and the hexahedral shape 260D may be manufactured by a general exposure method.

The manufacturing method of the liquid crystal display panel according to the present embodiment configured as described above is largely an array process for forming an array substrate, a color filter process for forming a color filter substrate, and a unit liquid crystal display panel by combining the array substrate and the color filter substrate. It is made of a cell process to form a, looking at this in more detail as follows.

First, a thin film transistor which is a switching element which is arranged vertically and horizontally on a transparent insulating substrate such as glass to define a plurality of pixel regions and is connected to the gate line and the data line in each pixel region. To form. In addition, the pixel electrode is connected to the thin film transistor through the array process and drives the liquid crystal layer as a signal is applied through the thin film transistor. In the transverse electric field mode, the pixel electrode and the common electrode forming the horizontal electric field are formed together in the liquid crystal layer through the array process.

In addition, the color filter substrate includes a black matrix that distinguishes between a color filter composed of red, green, and blue subcolor filters that implement color by a color filter process, and the subcolor filter, and blocks light transmitted through the liquid crystal layer; A common electrode, which is a counter electrode of the pixel electrode, is formed.

In this case, a spacer is formed on the color filter substrate using an organic layer, and the array substrate is formed by making at least one protrusion smaller than the spacer on a portion facing the spacer.                     

In this case, as the liquid crystal display panel is gradually enlarged, a column spacer (or a patterned spacer) of a type fixed to an array substrate or a color filter substrate is used.

In the present embodiment, a case in which the column spacer is formed in a form fixed to the color filter substrate has been described as an example. However, the present invention is not limited thereto, and the column spacer may be formed on the array substrate. It is formed on the color filter substrate facing the column spacer.

Subsequently, an alignment layer is applied to the array substrate and the color filter substrate, respectively, and then the alignment layer is provided to provide alignment control force or surface fixation force (ie, pretilt angle and alignment direction) to the liquid crystal molecules of the liquid crystal layer formed between the two substrates. Orientation treatment. In this case, a rubbing or photoalignment method may be applied as the alignment treatment method.

Next, the sealant and the silver paste are applied to the outer portion of the color filter substrate and a liquid crystal layer is formed on the array substrate.

The seal pattern may be formed by printing with a screen mask or by forming a seal pattern having a desired shape using a movable sealant dispenser.

In addition, the method of forming the liquid crystal layer is largely divided into a vacuum injection method and a dropping method. Unlike the vacuum injection method, the liquid crystal display panel to which the dropping method is applied separates the unit liquid crystal panel from the large area mother substrate after the liquid crystal layer is formed. The process proceeds.

Although many details are set forth in the foregoing description, it should be construed as an illustration of preferred embodiments rather than to limit the scope of the invention. Therefore, the invention should not be defined by the described embodiments, but should be defined by the claims and their equivalents.

As described above, the liquid crystal display panel and the method of manufacturing the same according to the present invention can maintain the cell gap of the panel even when the pressure inside the liquid crystal display panel is increased due to gravity or temperature change. As a result, cell gaps in large panels and light leakage can be prevented in advance.

In addition, because the alignment margin can be made quite large, it is excellent in mass production.

Claims (13)

Forming a column spacer on the first substrate; Forming a pixel electrode on the second substrate using a transparent conductive material; Forming at least one protrusion by patterning the transparent conductive material in a predetermined region of the second substrate facing the column spacer; And And bonding the first substrate and the second substrate to the protrusion to be embedded in the bottom surface of the column spacer. The method of claim 1, further comprising forming a black matrix and a color filter on the first substrate, and forming a switching element on the second substrate. The method of claim 2, further comprising forming a common electrode on the black matrix and the color filter. delete delete The method of claim 1, wherein the protrusion is formed of a conductive material having a hardness greater than that of the column spacer. The method of claim 1, wherein the protrusion is formed in a pointed shape such as a conical shape, a pyramid shape, or a wedge shape. The method of claim 1, wherein the protrusion is formed in a hexahedron having a narrower width than a bottom surface of the column spacer. delete A column spacer formed on a first substrate to form a cell gap between the first substrate and the second substrate; A pixel electrode formed of a transparent conductive material on the second substrate; At least one protrusion formed in a predetermined region of the second substrate opposite to the column spacer and made of the transparent conductive material and embedded in a lower surface of the column spacer; And A liquid crystal display panel comprising a liquid crystal layer formed in a cell gap between the first substrate and the second substrate. The liquid crystal display panel of claim 10, wherein the first substrate is a color filter substrate and the second substrate is an array substrate. The liquid crystal display panel of claim 10, wherein the protrusion is formed of a conductive material having a hardness greater than that of the column spacer. The liquid crystal display panel of claim 10, wherein the protrusion has a sharp cone shape, a pyramid shape, a wedge shape, or a hexahedron having a narrow width compared to a lower surface of the column spacer.

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