KR20100127377A - Liquid crystal display and method of manufacturing the same - Google Patents

Abstract

PURPOSE: A liquid crystal display device and a manufacturing method thereof are provided to prevent an image from being distorted due to external shock, thereby improving a display feature. CONSTITUTION: A liquid crystal layer is interposed between a first display panel and a second display panel. A plurality of spacers(45) is located between the first display panel and the second display panel. The spacers maintain an interval between the first and second display panels. A polymer wall(50) surrounds the spacers.

Description

Liquid crystal display device and its manufacturing method {LIQUID CRYSTAL DISPLAY AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to a liquid crystal display device and a manufacturing method thereof.

As the Internet becomes more popular and the amount of information communicated explosively, the future will create an environment of 'ubiquitous display' where people can access information anytime and anywhere. And the role of portable displays such as PDAs have become important. In order to implement such a ubiquitous display environment, the portability of the display is required to directly access information at a desired time and place, and a large screen characteristic for displaying various multimedia information is required.

Accordingly, in order to simultaneously satisfy such portability and large screen characteristics, there is a need to develop a display in a form that can be expanded and used when functioning as a display by giving flexibility to the display and folded and stored when carrying.

Meanwhile, a typical liquid crystal display (LCD) among flat panel display devices that are widely used currently includes two glass substrates on which electrodes are formed and a liquid crystal layer interposed therebetween, and applies a voltage to the electrodes. The mainstream is to control the amount of light transmitted by rearranging the liquid crystal molecules of the liquid crystal layer.

By the way, since such a liquid crystal display uses a heavy and fragile glass substrate, portability and large screen display are limited.

Therefore, in recent years, a flexible liquid crystal display device using a plastic substrate that is light in weight, strong in impact, and has a flexible property has been developed. The flexible liquid crystal display device is light and excellent in portability, and can be manufactured by a method such as a roll-to-roll process, thereby mass-producing a large area display device.

However, the flexible liquid crystal display may distort the displayed image when an external shock such as bending or pressing is applied, and in severe cases, the display itself may be damaged.

Therefore, the problem to be solved in the present invention is to improve the stability against external impact in the flexible liquid crystal display.

The liquid crystal display according to the exemplary embodiment of the present invention includes a first display panel and a second display panel facing each other, a liquid crystal layer interposed between the first display panel and the second display panel, and between the first display panel and the second display panel. And a plurality of spacers disposed in the spacer to maintain a gap between the first display panel and the second display panel, wherein the spacer includes a columnar spacer, a polymer wall surrounding the columnar spacer, and a neighbor. It comprises a polymer connecting portion connecting between the polymer walls.

The polymer wall and the polymer connection portion may be formed from a monomer having affinity with the columnar spacer.

The monomer may include one selected from thiol compounds, allyl ether compounds, isocyanate ester compounds, mercaptopropionate compounds, (meth) acrylate compounds, and combinations thereof.

The monomer is trimethylopropane tristhiol, trimethylopropane diallyl ether, isophorone diisocyanate ester, pentaerythritol tetramercaptopropionate, hexane Dithiol, isobornyl methacrylate, isobornyl methacrylate, hexane diacrylate, and combinations thereof.

The monomer may have photocurable or heat curable properties.

Adjacent columnar spacers may be formed at intervals of 10 to 100 μm.

The liquid crystal layer may include a plurality of liquid crystal isolation regions partitioned by the polymer connection portion.

At least one of the first display panel and the second display panel may include a flexible substrate.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, the method comprising: forming a first display panel and a second display panel, respectively, forming a columnar spacer on at least one of the first display panel and the second display panel; Bonding the first display panel and the second display panel to each other, injecting a mixture of a liquid crystal and a monomer between the first display panel and the second display panel, separating the liquid crystal and the monomer, and curing the monomer. Forming a polymer connection portion connecting the polymer wall surrounding the columnar spacer and the polymer wall adjacent to each other.

Separating the liquid crystal and the monomer may include cooling.

The cooling may be performed at a lower temperature than the step of injecting a mixture of the liquid crystal and the monomer.

The monomer may have affinity with the columnar spacer.

The monomer may include one selected from thiol compounds, allyl ether compounds, isocyanate ester compounds, mercaptopropionate compounds, (meth) acrylate compounds, and combinations thereof.

The monomers include trimethyllopropane tristyol, trimethyllopropane diallyl ether, isophorone diisocyanate ester, pentaerythritol tetramercaptopropionate, hexane dithiol, isobornyl methacrylate, hexane diacrylate® and combinations thereof It may include one selected from.

Curing the monomer may be cured by heat or light.

The forming of the first display panel and the second display panel may include forming an electric field generating electrode on the flexible substrate.

The liquid crystal display according to the present invention can reduce damage or deformation of the liquid crystal layer and the display panel including the same when an external shock such as bending or pressing of the display panel is applied in the flexible liquid crystal display, thereby preventing damage to the display device itself. In addition to preventing, the displayed image can be improved by preventing the displayed image from being distorted by an external impact. In addition, since the monomer remaining in the liquid crystal layer is hardly left, an increase in driving voltage or a decrease in the contrast ratio due to the remaining monomer can be prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. Whenever a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Next, a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1 to 3.

1 is a cross-sectional view schematically illustrating a liquid crystal display according to an exemplary embodiment of the present invention, FIG. 2 is a plan view schematically showing the liquid crystal display of FIG. 1, and FIG. 3 is an image of the liquid crystal display of FIG. 2. Is a picture showing.

First, referring to FIGS. 1 and 2, the liquid crystal display 500 according to the exemplary embodiment of the present invention may include the first display panel 100, the second display panel 200, and the first display panel 100 facing each other. The liquid crystal layer 300 is interposed between the second display panel 200.

In the first display panel 100, a thin film transistor (TFT) (not shown) and an electric field generating electrode (not shown) connected to the thin film transistor are formed on the substrate 110.

The second display panel 200 includes a color filter (not shown) and an electric field generating electrode (not shown) on the substrate 210.

The substrates 110 and 210 may be made of a flexible material, for example, one selected from polyacrylate, polyethylene ether phthalate, polyethylene naphthalate, polycarbonate, polyarylate, polyetherimide, polyether sulfone, polyimide, and the like. Or it may be made of two or more plastic materials.

A substrate protective film (not shown) made of an inorganic material such as silicon oxide (SiO ₂ ) or silicon nitride (SiN _x ) or an organic material may be formed on at least one of the lower and upper portions of the substrates 110 and 210.

The liquid crystal layer 300 may include a plurality of liquid crystals 30, and the liquid crystal 30 may have positive dielectric anisotropy or negative dielectric anisotropy.

A plurality of spacers 45 are formed between the first display panel 100 and the second display panel 200. The spacer 45 maintains a cell gap between the first display panel 100 and the second display panel 200.

The spacer 45 is a polymer that connects between the column spacer 40, the polymer wall 50 surrounding the column spacer 40, and the neighboring polymer wall 50. It includes a connector 60.

The columnar spacer 40 may be formed to have a height substantially equal to or lower than a gap between the first display panel 100 and the second display panel 200. The column spacer 40 may be made in a circular or polygonal shape, and may be arranged side by side or randomly arranged along the column and / or row direction.

The columnar spacer 40 may be made of a photosensitive material and may be formed from monomers having functional groups capable of photopolymerization. The monomers may include, but are not limited to, for example, thiol compounds, allyl ether compounds, isocyanate ester compounds, mercaptopropionate compounds, (meth) acrylate compounds, and combinations thereof.

The polymer wall 50 surrounds at least a portion of the columnar spacer 40. The polymer wall 50 may be made of a polymer formed from monomers that are chemically compatible with the column spacer 40.

Here, the monomer having affinity with the column spacer 40 includes, for example, one selected from a thiol compound, an allyl ether compound, an isocyanate ester compound, a mercaptopropionate compound, a (meth) acrylate compound, and a combination thereof. can do. However, the monomer is not particularly limited when the monomer has a chemical affinity with the column spacer 40.

Specifically, the monomers include, for example, trimethyllopropane tristyol, trimethyllopropane diallyl ether, isophorone diisocyanate ester, pentaerythritol tetramercaptopropionate, hexane dithiol, isobornyl methacrylate, hexane diacrylate 아크릴 and It may include one selected from a combination thereof.

The monomer may have photocurable or thermosetting.

The polymer connector 60 connects the neighboring polymer walls 50, as shown in FIG. In the drawings, the polymer connection part 60 is shown as an example in which the structure extends in the vertical direction and the horizontal direction, but is not limited thereto and may be a structure extending in various directions.

The polymer connector 60 may form a plurality of small regions partitioned by the polymer connector 60 by connecting neighboring polymer walls 50. These small regions are filled with liquid crystal molecules, which can form a plurality of liquid crystal isolation regions.

As described above, the liquid crystal display according to the present invention includes a columnar spacer 40, a polymer wall 50 surrounding the columnar spacer 40, and a polymer connector 60 connecting the polymer wall 50. The spacer may be evenly distributed between the first display panel 100 and the second display panel 200. Accordingly, in the case of the display panel including the flexible substrate, when the external impact such as bending or pressing of the display panel is applied, the liquid crystal layer and the display panel including the same may be reduced or reduced. Therefore, not only the display device itself may be damaged but also the displayed image may be prevented from being distorted due to an external impact, thereby improving display characteristics.

In addition, by forming the polymer wall 50 and the polymer connecting portion 60 by using a monomer having a chemical affinity to the columnar spacer 40, the monomers phase separated from the liquid crystal spontaneously columnar spacer 40 By gathering to the side and hardening it, the monomer remaining in the liquid crystal layer is hardly left, so that the display voltage may be improved by preventing the increase of the driving voltage or the decrease of the contrast ratio due to the remaining monomer.

Hereinafter, a method of manufacturing the above-described liquid crystal display will be described with reference to FIGS. 4A to 7.

4A, 5, 6A, and 7 are cross-sectional views sequentially illustrating a method of manufacturing a liquid crystal display according to another exemplary embodiment of the present invention, and FIGS. 4B and 4C are views illustrating the shape and arrangement of columnar spacers. FIG. 6B is a photograph showing a result of phase separation of a liquid crystal and a monomer.

First, the first display panel 100 in which the thin film transistor and the field generating electrode are formed on the substrate 110 made of plastic material, and the second display panel in which the color filter and the field generating electrode are formed on the substrate 210 made of plastic material. 200) respectively.

Next, referring to FIG. 4A, the spacer 40 is formed on the first display panel 100. However, the present invention is not limited thereto, and the spacer 40 may be formed on the second display panel 200. The columnar spacer 40 may be formed by, for example, applying a photosensitive material and exposing and developing the photosensitive material.

4B and 4C are plan views illustrating the shape and arrangement of the columnar spacer 40 by way of example.

The columnar spacers 40 may be evenly arranged, for example, in a quadrangular shape as shown in FIG. 4B, where the spacing d1 between neighboring columnar spacers 40 may be about 10 to 100 μm.

In addition, the column spacer 40 may be arranged evenly along columns and rows in a diamond shape as shown in FIG. 4C, where the distance d2 between neighboring column spacers 40 is about 10 to 100. May be μm.

However, the shape and size of the column spacer 40 and the arrangement of the column spacer 40 may be variously modified, but is not limited thereto.

Next, referring to FIG. 5, the first display panel 100 and the second display panel are bonded to each other.

Subsequently, a mixture of the liquid crystal 30 and the monomer 50a is injected between the first display panel 100 and the second display panel 200. However, the present invention is not limited thereto, and after the mixture of the liquid crystal 30 and the monomer 50a is formed on the first display panel 100 or the second display panel 200, the first display panel 100 and the second display panel 200 are bonded to each other. You may. At this time, the mixture of the liquid crystal 30 and the monomer 50a may be present at room temperature or higher.

At this time, the monomer 50a can be selected as a kind having affinity with the columnar spacer 40, for example, a thiol compound, allyl ether compound, isocyanate ester compound, mercaptopropionate compound, (meth) acrylate compound And combinations thereof.

Specifically, the monomer 50a is, for example, trimethyllopropane tristilol, trimethyllopropane diallyl ether, isophorone diisocyanate ester, pentaerythritol tetramercaptopropionate, hexane dithiol, isobornyl methacrylate, hexane Diacrylate and combinations thereof.

The monomer 50a may have photocurability or thermosetting.

The liquid crystal 30 and the monomer 50a are then phase separated. In this case, the phase separation may be performed by cooling the mixture of the liquid crystal 30 and the monomer 50a, and the cooling may be performed at a temperature lower than the mixing temperature of the liquid crystal 30 and the monomer 50a. Specifically, the mixture of the liquid crystal 30 and the monomer 50a exists in a state where they are mixed with each other by thermal energy when the temperature is high, but at a temperature lower than the mixing temperature of the liquid crystal 30 and the monomer 50a, the liquid crystal 30 ) And the miscibility of the monomer 50a is lowered, resulting in phase separation.

Next, referring to FIG. 6A, when the liquid crystal 30 and the monomer 50a are phase separated as described above, the monomers 50a are collected around the columnar spacer 40 having affinity. Accordingly, the region in which the liquid crystal 30 exists and the region in which the monomer 50a exists may be separated.

6b is a photograph showing the result of phase separation of such a liquid crystal and a monomer. Referring to FIG. 6B, the columnar spacers 40 and the monomers 50a gathered around the columnar spacers 40 may be identified, and some of the monomers 50a may have the columnar spacers 40. Surrounding and some of the monomers 50a are lined up between the adjacent columnar spacers 40.

Next, referring to FIG. 7, light is irradiated or heat is applied to the monomer 50a to cure the same. Accordingly, as shown in FIGS. 1 and 2, a polymer connection part 60 is formed to connect the polymer wall 50 surrounding the columnar spacer 40 and the neighboring polymer wall 50.

As described above, in the present invention, by using a monomer having a chemical affinity with the columnar spacer 40, the liquid crystal and the monomer can be easily separated by phase separation, thereby reducing the amount of monomer remaining in the liquid crystal layer. At the same time, the spacers evenly distributed between the first display panel 100 and the second display panel 200 may be formed.

Therefore, the liquid crystal display according to the present invention can reduce the damage or deformation of the liquid crystal layer and the display panel including the same when an external impact such as bending or pressing of the display panel is applied, thereby preventing damage to the display device itself. The display characteristic can be improved by preventing the displayed image from being distorted by an external impact. In addition, since the monomer remaining in the liquid crystal layer is hardly left, the display voltage may be improved by preventing the increase of the driving voltage or the decrease of the contrast ratio due to the remaining monomer.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the invention.

1 is a cross-sectional view schematically illustrating a liquid crystal display according to an exemplary embodiment of the present invention, FIG. 2 is a plan view schematically showing the liquid crystal display of FIG. 1, and FIG. 3 is an image of the liquid crystal display of FIG. 2. Is a picture showing.

4A, 5, 6A, and 7 are cross-sectional views sequentially illustrating a method of manufacturing a liquid crystal display according to another exemplary embodiment of the present invention.

 4B and 4C are plan views illustratively showing the shape and arrangement of the column spacer;

6b is a photograph showing the result of phase separation of a liquid crystal and a monomer.

Claims (17)

A first display panel and a second display panel facing each other, A liquid crystal layer interposed between the first display panel and the second display panel, A plurality of spacers disposed between the first display panel and the second display panel and maintaining a gap between the first display panel and the second display panel. Including, The spacer is Column spacer, A polymer wall surrounding the column spacer, and A polymer connector connecting between neighboring polymer walls Liquid crystal display comprising a. In claim 1, And the polymer wall and the polymer connection portion are formed from a monomer chemically compatible with the columnar spacer. In claim 2, And said monomer comprises one selected from thiol compounds, allyl ether compounds, isocyanate ester compounds, mercaptopropionate compounds, (meth) acrylate compounds, and combinations thereof. 4. The method of claim 3, The monomers include trimethyllopropane tristyol, trimethyllopropane diallyl ether, isophorone diisocyanate ester, pentaerythritol tetramercaptopropionate, hexane dithiol, isobornyl methacrylate, hexane diacrylate and combinations thereof Liquid crystal display comprising one selected from. In claim 2, The monomer has a photocurable or thermosetting liquid crystal display device. In claim 1, Adjacent columnar spacers are formed at intervals of 10 to 100 μm. In claim 1, The liquid crystal layer includes a plurality of liquid crystal isolation regions partitioned by the polymer connection portion. In claim 1, And at least one of the first display panel and the second display panel includes a flexible substrate. Forming a first display panel and a second display panel, respectively; Forming a columnar spacer on at least one of the first display panel and the second display panel; Bonding the first display panel and the second display panel to each other; Injecting a mixture of a liquid crystal and a monomer between the first display panel and the second display panel; Separating the liquid crystal and the monomer, and Curing the monomer to form a polymer connection portion connecting the polymer wall surrounding the columnar spacer and the neighboring polymer wall; Method of manufacturing a liquid crystal display comprising a. The method of claim 9, The separating of the liquid crystal and the monomer may include cooling the liquid crystal display. In claim 10, The cooling may be performed at a temperature lower than a mixing temperature of the liquid crystal and the monomer. In claim 10, The separating of the liquid crystal and the monomer may include collecting the monomer around the columnar spacer in the cooling step. The method of claim 9, And said monomer has a chemical affinity with said columnar spacer. The method of claim 13, And said monomer comprises one selected from thiol compounds, allyl ether compounds, isocyanate ester compounds, mercaptopropionate compounds, (meth) acrylate compounds, and combinations thereof. The method of claim 14, The monomers are trimethyllopropane tristyol, trimethyllopropane diallyl ether, isophorone diisocyanate ester, pentaerythritol tetramercaptopropionate, hexane dithiol, isobornyl methacrylate, hexane diacrylate 아크릴 and combinations thereof Method of manufacturing a liquid crystal display device comprising one selected from. The method of claim 9, Curing the monomer is a method of manufacturing a liquid crystal display device that is cured by heat or light. The method of claim 9, The forming of the first display panel and the second display panel, respectively, includes forming an electric field generating electrode on the flexible substrate.

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