KR20030088645A - Liquid crystal display panel having a black sealant - Google Patents

Abstract

PURPOSE: A liquid crystal display panel having a black sealant is provided to interrupt pollution of a liquid crystal display due to imperfect curing of a sealant and normally execute functions of black matrices by replacing a transparent material of the sealant by a black material. CONSTITUTION: A plurality of data lines and a plurality of gate lines crossing the data lines are formed on an array substrate for defining a plurality of pixels. A color filter substrate(110) includes black matrices(120) corresponding to the pixels. A liquid crystal layer is injected into a certain gap between the color filter substrate and the array substrate. A black sealant(300) is applied on a certain area to define a liquid crystal display panel by the combination of the color filter substrate and the array substrate for sealing up the liquid crystal layer. The black sealant is applied to minimize an area where the black sealant is overlapped with the utmost outline black matrix(125), and is completely cured by UV(Ultra Violet) light or heat, and prevents loss of light due to a backlight unit installed under the array substrate.

Description

Liquid crystal display panel having black sealant {LIQUID CRYSTAL DISPLAY PANEL HAVING A BLACK SEALANT}

TECHNICAL FIELD The present invention relates to a liquid crystal display panel having a black sealant, and more particularly, to a liquid crystal display panel having a black sealant that is completely cured and has a black matrix function.

A general liquid crystal display (LCD) forms a liquid crystal display panel through liquid crystal injected between an upper substrate (color filter substrate) and a lower substrate (array substrate), and between the common electrode and the pixel electrode formed on the plate surface of the lower substrate for each pixel. It is a device that composes a screen by applying an electric field to the liquid crystal to change the arrangement of the liquid passing through or blocking the light.

The configuration of the liquid crystal display panel will be briefly described with reference to FIG. 1.

1 is an exploded perspective view illustrating a general color liquid crystal display panel.

Referring to FIG. 1, a general liquid crystal display panel includes a color filter 25 including a black matrix 24, a color filter substrate 20 having a transparent common electrode 22 formed on the color filter, and a pixel region P. Referring to FIG. And an array substrate 12 having a pixel electrode 15 formed on the pixel region, a switching element T, and array wiring, and a liquid crystal 40 between the color filter substrate 20 and the array substrate 10. It is filled.

The array substrate 10 is also referred to as an array substrate. The thin film transistor T, which is a switching element, is positioned in a matrix type, and the gate wiring 13 and the data wiring 14 passing through the plurality of thin film transistors cross each other. Is formed. In this case, the pixel region P is a region in which the gate wiring 13 and the data wiring 14 cross each other, and a transparent pixel electrode 15 is formed on the pixel region.

Hereinafter, the manufacturing process of the liquid crystal display panel will be briefly described.

First, a plurality of TFTs are arranged on the array substrate 10 as switching elements, and pixel electrodes are formed in one-to-one correspondence with TFTs.

Next, an alignment film is formed on the array substrate 10. Such alignment film formation includes the application and rubbing of the polymer thin film. The polymer thin film is generally referred to as an alignment film, and must be deposited with a uniform thickness over the entire array substrate, and the rubbing should be uniform.

In addition, rubbing is a main process of determining the initial alignment direction of the liquid crystal. The rubbing of the alignment layer enables normal driving of the liquid crystal and has uniform display characteristics. In particular, in general, an alignment layer is mainly used in an organic polyimide series.

Subsequently, a seal pattern is printed. The seal pattern in the liquid crystal cell performs two functions of forming a gap for injecting the liquid crystal and not leaking the injected liquid crystal. Such a seal pattern is a process of forming a thermosetting resin in a desired pattern constantly, and the screen printing method is mainstream.

Subsequently, a spacer of a predetermined size is applied to maintain a precise and uniform gap between the color filter substrate and the array substrate in the process of manufacturing the liquid crystal cell. In particular, when dispersing the spacer, it should be distributed at a uniform density with respect to the array substrate. The dispersing method can be largely divided into a wet dispersing method in which a spacer is mixed with an alcohol and sprayed and a dry dispersing method in which only a spacer is dispersed.

After the spacer spreading process is completed, the upper substrate, which is a color filter substrate, and the array substrate, which is a thin film transistor array substrate, are bonded to each other. The joining of the upper substrate and the array substrate is determined by the margin given in the design of each substrate, which usually requires a precision of several μm. If the two substrates are out of the bonding error range, light leaks out, and thus the desired image quality characteristics cannot be expected when the liquid crystal cell is driven.

Next, the liquid crystal cell produced above is cut into a unit cell. In general, a liquid crystal cell undergoes a process of forming a plurality of liquid crystal cells on a large area glass substrate and then separating them into one liquid crystal cell, which is a cell cutting process. The cell cutting process includes a scribing process of forming a cutting line on a surface of a substrate using a diamond pen having a hardness higher than that of a glass substrate, and a break process of applying a force to cut the cutting line.

Next, the liquid crystal is injected into the liquid crystal cell cut into each unit cell to complete the unit liquid crystal cell. In particular, the unit liquid crystal cell has a gap of several μm in an area of several hundred cm 2. Therefore, the vacuum injection method using the pressure difference between the inside and outside of the cell is most widely used as a method of effectively injecting the liquid crystal into the cell of such a structure.

In the initial manufacturing process of the liquid crystal display panel, the liquid crystal was injected into several cells at the same time and then cut into unit cells (called an integrated type). However, as the cell size increases, the liquid crystal is injected after cutting into unit cells. The method (called the filling method) is used.

2 is a perspective view illustrating a screen printing method used in a seal pattern process.

Referring to FIG. 2, screen printing includes a screen 34 having a predetermined pattern and a rubber squeegee 36 for printing.

The seal pattern 30 on the substrate 12 has two functions of forming a gap for liquid crystal injection in the liquid crystal display panel and preventing the injected liquid crystal from leaking out. Accordingly, the seal pattern 30 is formed along the edge of the substrate 12, and the liquid crystal injection hole 32 is formed at one edge.

Formation of the seal pattern 30 through the screen printing method is a process of printing a thermosetting sealant including a spacer (SPACER) for maintaining the cell gap on the substrate 12 through the screen (Screen 34), It consists of a drying process that evaporates the solvent contained in the sealant for leveling.

In practice, in the seal pattern 30, the uniformity of thickness and height becomes a very important process control item. This is because if the seal pattern 30 is unevenly formed, the cell gap is not constant after curing of the seal pattern.

The seal material used for the seal pattern 30 generally uses a thermosetting or UV (ultraviolet) curable epoxy resin or the like. However, the epoxy resin itself is harmless to the liquid crystal, but amines contained in the thermosetting agent may decompose the liquid crystal material.

Therefore, when forming the thermosetting epoxy resin seal pattern 30, it is necessary to sufficiently prebak while changing the temperature at which the sealant is baked after screen printing in stages.

In addition, the seal pattern may be configured in various ways.

3 is a plan view of the liquid crystal display panel showing the seal pattern 30 printed on the array substrate 10 by a screen printing method or the like. Here, the seal pattern 20 can be largely divided into a main seal line 30a and an auxiliary seal line 30b.

The main seal line 30a is to prevent the liquid crystal from leaking to the outside and to maintain the cell gap. In addition, the auxiliary seal line 30b bonds the substrate 10 and a substrate (not shown) corresponding thereto, and prevents damage of the main seal line 30a by the cleaning liquid and the etching liquid during the cleaning and etching of the bonded substrate. To do this. The sealant forming such a seal pattern is cured by UV light irradiated from the outside to bond the substrate to the substrate.

However, in the sealant curing method using UV light used for bonding between substrates, as shown in FIG. 4, an area directly exposed to UV light and an area not directly exposed to UV light are generated by the outer black matrix 24. do.

This is because the black matrix composed of the CrOx / Cr double layer blocks UV light transmission, and since the UV sealant is not directly exposed to the UV light, the UV sealant portion at the bottom of the outer black matrix becomes uncured to contaminate the liquid crystal. There is a problem that acts as a cause.

In addition, as shown in FIG. 5, when the black matrix width is reduced by a dotted line to completely cure the sealant 30, the light provided from the backlight unit B / L is not blocked and passes through. Therefore, the function of the black matrix is deteriorated, and there is a problem as the liquid crystal display panel itself.

Therefore, the technical and problem of the present invention are to solve such a conventional problem, and an object of the present invention is to completely cure by UV light or heat to block contamination of the liquid crystal layer, and to prevent light leakage of light emitted from the backlight unit. There is provided a liquid crystal display panel having a black sealant.

1 is an exploded perspective view illustrating a general color liquid crystal display panel.

2 is a perspective view illustrating a screen printing method used in a seal pattern process.

3 is a plan view of a liquid crystal display panel showing a seal pattern printed on a substrate by a screen printing method or the like.

4 is a view for explaining a sealant region that is uncured by the outer black matrix.

5 is a view for explaining a light leakage phenomenon according to the reduction of the width of the black matrix.

6 is a view for explaining a color filter substrate according to an embodiment of the present invention.

7A to 7C are views for explaining a partially cut surface of the liquid crystal display panel including the color filter substrate of FIG. 6 described above.

<Description of the symbols for the main parts of the drawings>

100: color filter substrate 110: glass substrate

120: black matrix layer 125: outermost black matrix layer

130R, 130G, 130B: color filter pattern 200: array substrate

300: black sealant

According to one aspect of the present invention, a liquid crystal display panel having a black sealant includes an array substrate including a plurality of data lines and a plurality of gate lines intersecting the data lines to define a plurality of pixels. ; A color filter substrate having a black matrix corresponding to the pixel; A liquid crystal layer injected into a predetermined gap formed between the color filter substrate and the array substrate; And a black sealant applied to a predetermined area to enclose the liquid crystal layer so as to define a liquid crystal display panel by incorporation of the color filter substrate and the array substrate.

The black sealant is applied to minimize the area overlapping with the outermost black matrix of the black matrix and is completely cured by UV light or heat radiated from the outside, and prevents light leakage by the backlight unit provided under the array substrate. Characterized in that.

According to the liquid crystal display panel having the black sealant, the sealant is uncured by replacing the sealant which prevents the separation of the liquid crystal layer incorporated by combining the array substrate and the color filter substrate with a black material and a material that is completely cured by heat or UV light. In addition to blocking contamination caused by the liquid crystal layer, the light leakage phenomenon of the light emitted from the backlight unit may be prevented to perform the function of the black matrix normally.

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

FIG. 6 is a view for explaining a color filter substrate according to an exemplary embodiment of the present invention. In particular, FIG. 6 is a plan view illustrating an outer portion of a color filter substrate coated with a black sealant having a black matrix function.

Referring to FIG. 6, a color filter substrate according to an embodiment of the present invention includes various colored layers constituting a filter portion of a color filter on the surface of a transparent substrate 110 such as glass, that is, a black matrix 120 and R. Each of the color filter patterns 130R, 130G, and 130B is formed. It is preferable that these colored layers consist of resin containing coloring materials, such as a pigment and dye.

More specifically, a black matrix (shading film or black mask) 120 is applied on the transparent substrate 110 to define the pixel region for the display. Of course, in the drawings, a grid type having a predetermined interval between the horizontal and vertical intervals has been described as an example, but various types of black matrices such as a honeycomb type may be applied.

The R color filter pattern 130R is applied to each of the specific pixel regions defined by the black matrix 120, and the G color filter pattern 130G is applied to each of the specific pixel regions defined by the black matrix 120, The B color filter pattern 130B is applied to each of the specific pixel regions defined by the black matrix 120.

Since a series of processes for manufacturing the respective color filter patterns 130R, 130G, and 130B of the R, G, and B may be manufactured through well-known methods, detailed description thereof will be omitted.

Meanwhile, the black sealant 300 is coated on the outer region of the predetermined region defining the liquid crystal panel among the black matrix 120 applied on the surface of the color filter substrate, that is, the outermost black matrix 125, so that the array substrate may be applied in the future. The liquid crystal layer will be embedded in a predetermined void formed through the combination with.

Here, the material of the black sealant 300 applied to the outermost part of the color filter substrate is preferably a material that is completely cured by irradiation of UV light or heat, and thus, the liquid crystal layer embedded through the completely cured material is contaminated. I can solve it.

In addition, the black material of the sealant 300 is preferably manufactured by dispersing a black material such as carbon in a transparent UV curable sealant, and the black sealant formed by applying the black material is a back light that is a lower part of the array substrate in the future. It is possible to solve the problem of light leakage caused by passing light emitted from the unit. Here, the characteristics of the medium to be used as the black sealant should have an optical density of 3 or more, that is, transmittance (T) of 0.1% or less after curing by UV light or curing by heat or the like. Where the optical density (OD) is Obtained by

Although not shown in the drawings, a surface protective layer made of a transparent resin or the like is formed on the black matrix 120 and the color filter patterns 130R, 130G, and 130B of R, G, and B, respectively. The surface protection layer is to prevent the invasion of the chemical solution when forming another layer (for example, a transparent electrode pattern, etc.) on the color filter to protect the colored layer and at the same time to ensure the flatness of the color filter surface.

Although not shown in the drawing, a transparent electrode made of a transparent conductor such as indium tin oxide (ITO) is formed on the surface of the color filter. In general, however, since the surface protection layer (not shown) and the transparent electrode (not shown) have poor adhesion to each other, when the transparent electrode is directly formed on the color filter, the pattern precision of the electrode pattern cannot be secured. It is preferable to form an insulating film (or intermediate layer) made of SiO 2 on the surface of the surface protective layer of the film by sputtering or the like, and to form a transparent electrode on the formed insulating film.

Next, the color filter substrate coupled to the array substrate by the black sealant according to the present invention will be described in more detail with reference to FIGS. 7A to 7C.

7A to 7C are views for explaining a partially cut surface of the liquid crystal display panel including the color filter substrate of FIG. 6 described above.

FIG. 7A is a view for explaining a partial cut surface of the color filter substrate of FIG. 6 cut out from II ′, in particular, a cut surface of a liquid crystal display panel including a color filter substrate and an array substrate bonded by a black sealant. do.

Referring to FIG. 7A, the black sealant 300 is coated so that the outermost black matrix 125 provided on the transparent substrate 110 of the color filter substrate is not exposed, and the color is applied through the applied black sealant 300. The filter substrate and the array substrate 200 are combined to form a liquid crystal display panel.

More specifically, the inner surface of the color filter substrate, that is, the R color filter pattern 130R and the G color filter pattern 130G, the G color filter pattern 130G and the B color filter pattern 130B, and the B color filter pattern ( The black matrix 120 is coated between the 130B) and the G color filter pattern 130G, and the liquid crystal layer in which the black sealant 300 is applied to the outer side of the liquid crystal display panel is overlapped with the outermost black matrix 125. Block the departure of 400.

As shown, even if the outermost black matrix 125 is not exposed, the black sealant 300 may perform the function of a normal black matrix.

FIG. 7B is a view for explaining a partial cut surface of the color filter substrate of FIG. 6 cut out from II-II ', and particularly, a cut surface of a liquid crystal display panel including a color filter substrate and an array substrate bonded by a black sealant. do.

Referring to FIG. 7B, the inner black matrix 120 among the black matrix layers provided on the transparent substrate 110 of the color filter substrate blocks the transmission of light passing through the liquid crystal layer to perform a normal black matrix function. The outermost black matrix 125 is coated so that the black sealant 300 is overlapped so that the outermost black matrix 125 is not exposed, and the color filter substrate and the array substrate 200 are applied through the coated black sealant 300. This coalesces to form a liquid crystal display panel.

FIG. 7C is a view for explaining a partial cut surface of the color filter substrate of FIG. 6 cut through III-III ′, and particularly, a cut surface of a liquid crystal display panel including a color filter substrate and an array substrate bonded by a black sealant. do.

Referring to FIG. 7C, the black sealant 300 is coated so that the outermost black matrix 125 is not exposed among the black matrices provided on the transparent substrate 110 of the color filter substrate, and the applied black sealant 300 is mediated. As a result, the color filter substrate and the array substrate 200 are combined to form a liquid crystal display panel. Of course, the inner black matrix 120 of the black matrix provided in the transparent substrate 110 blocks the transmission of light passing through the liquid crystal layer to perform a normal black matrix function.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

As described above, according to the present invention, a liquid crystal caused by uncuring the sealant by replacing the sealant that blocks the separation of the liquid crystal layer incorporated by combining the array substrate and the color filter substrate with a material that is completely cured by irradiation of UV light or heat. It can block the contamination of the layer.

In addition, according to the present invention, the function of the black matrix can be normally performed by replacing the sealant material which blocks the separation of the liquid crystal layer embedded by combining the array substrate and the color filter substrate from the transparent material to the black material.

Claims (3)

An array substrate having a plurality of data lines and a plurality of gate lines crossing the data lines to define a plurality of pixels; A color filter substrate having a black matrix corresponding to the pixel; A liquid crystal layer injected into a predetermined gap formed between the color filter substrate and the array substrate; And A black sealant applied to a predetermined area to define a liquid crystal display panel by incorporation of the color filter substrate and the array substrate to encapsulate the liquid crystal layer, The black sealant is applied to minimize the area overlapping with the outermost black matrix of the black matrix and is completely cured by UV light or heat radiated from the outside, and prevents light leakage by the backlight unit provided under the array substrate. A liquid crystal display panel having a black sealant. The liquid crystal display panel of claim 1, wherein the black sealant has dispersed carbon. The liquid crystal display panel of claim 1, wherein the black sealant cured by UV light irradiation or heat satisfies an optical density of 3.0 or more.