KR100687335B1 - Liquid crystal display and manufacturing method therefor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method of manufacturing the same; a subcolor filter and a black matrix formed on an upper portion of a first insulating substrate; A first substrate formed on the first planarization film and having a common electrode for applying a voltage to the liquid crystal layer on one side thereof, and a first alignment film having an embossed surface; A second substrate disposed opposite the first substrate, the switching element formed on the second insulating substrate, a pixel electrode connected to the switching element to apply a voltage to the liquid crystal layer on the other side, and the switching element And a second planarization film covering and planarizing the pixel electrode, and a second substrate including a second alignment film having an embossed surface; And a liquid crystal layer sealed between the first substrate and the second substrate by sealants provided at edges of the first substrate and the second substrate, wherein the first alignment layer and the second alignment layer have the liquid crystal at their edges. It is characterized in that it is formed only before the sealant forming region so as not to overlap with the sealant for sealing the layer.

Description

Liquid crystal display and manufacturing method therefor {Liquid crystal display and manufacturing method therefor}             

1 is a cross-sectional view for explaining a liquid crystal display device according to the prior art.

Figure 2 is a process cross-sectional view for explaining a liquid crystal display device and a manufacturing method according to the present invention.

(Code description of main parts of drawing)

100: lower plate 120: lower glass substrate

140: thin film transistor 160: pixel electrode

180 planarization layer 190 alignment layer

200: top plate 220: upper glass substrate

240: sub-color filter 260: planarization layer

280: common electrode 290: alignment layer

300: sealant 400: liquid crystal layer

The present invention relates to a liquid crystal display device and a method for manufacturing the same, and more particularly, to a liquid crystal display device and a method for manufacturing the same for preventing the display display defect or degradation thereof due to the ion ions in the liquid crystal layer.

Referring to FIG. 1, a conventional liquid crystal display device will be described.

In the liquid crystal display shown in FIG. 1, two substrates 10 and 20 on which various kinds of elements are formed are arranged to correspond to each other, and a liquid crystal layer 40 is disposed between the two substrates 10 and 20. It is located in a fitted form.

The lower glass substrate 10 of the liquid crystal display element serves as a thin film transistor 14 which serves as a switching role, and the other electrode which receives a signal from the thin film transistor 14 and applies a voltage to the liquid crystal layer 40. And a planarization film 18 and a lower alignment film 19 covering the thin film transistor 14 and the pixel electrode 16.

In addition, the upper glass substrate 20 is formed with a sub color filter 24 and a black matrix 25 for implementing colors, and to planarize a surface on the sub color filter 24 and the black matrix 25. The planarization film 26 for this is formed. The common electrode 28 and the upper alignment layer 29, which serve as one electrode for applying a voltage to the liquid crystal layer 40, are sequentially formed on the planarization layer 26.

Here, a low stepped portion A in which the sealant 30 is formed is formed at the edge of the upper alignment layer 29.

In order to prevent leakage of the liquid crystal 40 injected between the upper substrate 20 and the lower substrate 10, a sealant 30 is formed at the edge thereof and sealed.

The upper and lower alignment layers 29 and 19 and the sealant 30 overlap each other at the edges of the upper substrate 20 and the lower substrate 10.

However, in such a conventional liquid crystal display device, impurity ions remain on the surface or inside of the alignment layer to lower the hold ratio of the liquid crystal layer, which changes the liquid crystal array, thereby causing Mura, that is, a screen display defect. There is this.

In addition, the resin thermosetting silicone binder extracted from the sealant used to seal the liquid crystal inlet does not completely react with the glass substrate, so that impurity ions generated are diffused into the active region, thereby lowering the retention of the liquid crystal layer. There is a problem that occurs.

In addition, the impurity ions are concentrated at the edge of the upper alignment layer, which is a low stepped portion where the sealant is formed, thereby lowering the retention of the liquid crystal layer, which causes a problem of changing the liquid crystal array.

Accordingly, the present invention has been made to solve the above problems of the prior art, and to provide a liquid crystal display device and a method of manufacturing the same that can prevent screen display defects by preventing impurity ions from remaining on or inside the alignment layer. The purpose is.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a subcolor filter and a black matrix formed on an upper portion of a first insulating substrate, a first planarization film covering and planarizing an upper portion of the subcolor filter and a black matrix; A first substrate formed on the first planarization film and having a common electrode for applying a voltage to the liquid crystal layer on one side thereof, and a first alignment film having an embossed surface; A second substrate disposed opposite the first substrate, the switching element formed on the second insulating substrate, a pixel electrode connected to the switching element to apply a voltage to the liquid crystal layer on the other side, and the switching element And a second planarization film covering and planarizing the pixel electrode, and a second substrate including a second alignment film having an embossed surface; And a liquid crystal layer sealed between the first substrate and the second substrate by sealants provided at edges of the first substrate and the second substrate, wherein the first alignment layer and the second alignment layer have the liquid crystal at their edges. It is characterized in that it is formed only before the sealant forming region so as not to overlap with the sealant for sealing the layer.

In addition, the manufacturing method of the liquid crystal display device according to the present invention comprises the steps of forming a sub-color filter and a black matrix on the first insulating substrate; Forming a first planarization layer on the sub-color filter and the black matrix; Forming a common electrode on one side of the first planarization layer to apply a voltage to the liquid crystal layer; Forming a first alignment layer on the common electrode, the first alignment layer having an embossed surface until the sealant forming region so as not to overlap with the sealant; Forming a switching device on an upper portion of the second insulating substrate disposed to face the first insulating substrate; Forming a pixel electrode connected to the switching element to apply a voltage to the liquid crystal layer on the other side; Forming a second planarization layer on the switching element and the pixel electrode; Forming a conductive second alignment layer having an embossed surface before the sealant forming region so as not to overlap with the sealant on the second planarization film; And injecting a liquid crystal layer between the first insulating substrate and the second insulating substrate using a sealant provided at edges of the first insulating substrate and the second insulating substrate as an encapsulant.

(Example)

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

2 is a cross-sectional view illustrating a liquid crystal display device and a method of manufacturing the same according to the present invention.

Referring to FIG. 2, a liquid crystal display and a method of manufacturing the same according to the present invention will be described.

In the liquid crystal display according to the present invention, two upper and lower substrates 200 and 100 having various kinds of elements are arranged to correspond to each other, and the liquid crystal layer 400 is disposed between the two substrates 100 and 200. It is located in a fitted form.

The upper substrate 200 is a color filter substrate composed of a color filter and a black matrix, and the lower substrate 100 is an array substrate composed of a thin film transistor and a pixel electrode.

First, referring to the array substrate 100, the thin film transistor 140 is formed on the lower insulating substrate 120, and the pixel electrode 160 connected to the drain electrode (not shown) of the thin film transistor 140 is formed. After that, a planarization layer 180 is formed by applying a transparent organic material to planarize the surface of the resultant.

In this case, the pixel electrode 160 uses a transparent conductive metal having a relatively high transmittance of light, such as indium tin oxide (ITO).

In addition, the planarization film 180 has an embossed surface having a depth of 1 μm or more at an interface with a subsequent alignment film. Here, the depth of the embossed shape represents the height difference between the vertex of the concave portion and the convex portion of the embossed portion, the same expression used below all have the same meaning.

Next, an alignment layer 190 is formed by coating a transparent polymer material such as polyimide on the planarization layer 180. As illustrated, the alignment layer 190 is formed only before the sealant 300 so as not to overlap with the sealant 300 for sealing the liquid crystal layer, and a rubbing direction is defined in a predetermined direction so that the alignment layer 190 The orientation characteristic is determined.

In this case, the alignment layer 190 has an embossed surface having a depth of 1 μm or more at the interface with the liquid crystal layer and the interface of the alignment layer 190. Since the alignment layer 190 is conductive, impurity ions in the liquid crystal are captured to prevent floating in the liquid crystal. Here, the alignment film 190 can exhibit conductive properties by containing a conductive dopant such as an alkali metal ion in the polymer film constituting the alignment film.

In addition, before the alignment layer 190 is formed, a cleaning process using ultraviolet rays may be further performed, and an electrical cleaning process may be performed after the rubbing of the alignment layer 190.

Here, the sum of the thicknesses of the alignment layer 190, the planarization layer 180, and the pixel electrode 160 is formed to have a thin thickness of 700 μm or less, thereby facilitating the capture of impurity ions.

Next, a lower polarizer (not shown) is formed under the transparent lower insulating substrate 120 on which the alignment layer 190 is formed.

Next, referring to the color filter substrate 200, a sub color filter (red, green, blue) 240 is formed on the upper insulating substrate 220 to correspond to the pixel electrode 160, and the pixel electrode 160 is formed. After forming the black matrix 250 in the region corresponding to the ()) to form a planarization film (over coating film) 260 by applying a transparent organic material on the top of the resultant to planarize the surface.

The black matrix has an embossed surface having a depth of 1 μm or more.

Next, after forming the common electrode 280 on the planarization layer 260, an alignment layer 290 is formed by coating a transparent polymer material such as polyimide. The alignment layer 290 has a rubbing direction defined in a predetermined direction to determine the alignment characteristic of the liquid crystal.

In this case, the alignment layer 290 has an embossed surface having a depth of 1 μm or more at an interface in contact with the liquid crystal layer, and does not overlap with the sealant 300 for sealing the liquid crystal layer at the edge of the alignment layer 290. By only forming the sealant 300 before the sealant 300, the possibility of concentration of impurity ions during the cleaning process, which is caused by the edge of the alignment layer, which is a relatively low level of the conventional step, is prevented.

delete

In addition, since the alignment layer 290 and the black matrix 250 are conductive, the common electrode 280 and the alignment layer 290 electrically contact each other and capture impurity ions in the liquid crystal layer to prevent floating in the liquid crystal. Will be improved. In this case, the alignment film 290 exhibits conductive properties by containing a conductive dopant such as an alkali metal ion in the polymer film constituting the alignment film.

Here, the sum of the thicknesses of the alignment layer 290, the planarization layer 260, and the common electrode 280 is formed to have a thin thickness of 700 μm or less, thereby smoothly capturing impurity ions.

In addition, before the alignment layer 290 is formed, a cleaning process using ultraviolet rays may be further performed, and an electrical cleaning process may be performed after the rubbing of the alignment layer 290.

Subsequently, an upper polarizer (not shown) is formed on the upper insulating substrate 220 on which the alignment layer 290 is formed.

Next, a liquid crystal is injected between the upper substrate 200 and the lower substrate 100 to form the liquid crystal layer 400 and then sealant 300 is formed to seal the liquid crystal layer 400.

In this case, when the injection hole using the thermosetting resin is sealed, the liquid crystal may be injected and then sealed by UV irradiation of the thermosetting resin injection hole of the upper and lower substrates.

As described above, the present invention forms the upper and lower alignment layers with a conductive material, but forms the upper and lower alignment layers only before the sealant so as not to overlap with the sealant for sealing the liquid crystal layer, thereby concentrating impurities in the region in the overlap between the sealant and the alignment layer. It is possible to improve display defects by preventing impurities and remaining impurity ions on the surface or inside of the alignment layer.

Further, by directly contacting or applying a portion of the electrode to the alignment film, there is an effect that the screen defect (mura) can be suppressed more than when the electrode is insulated from the alignment film with the insulating film.

In addition, there is an effect that the screen defect can be suppressed by reducing impurity ions by curing the resin by ultraviolet irradiation and sealing the liquid crystal inlet.                     

On the other hand, the present invention is not limited to the above-described specific preferred embodiments, and various changes can be made by those skilled in the art without departing from the gist of the invention claimed in the claims. will be.

Claims (25)

A sub-color filter and a black matrix formed on the first insulating substrate, a first planarization film covering and flattening the sub-color filter and the black matrix, and a voltage formed on the liquid crystal layer from one side of the first planarization film. A first substrate having a common electrode to be applied and a first alignment film having an embossed surface; A second substrate disposed opposite the first substrate, the switching element formed on the second insulating substrate, a pixel electrode connected to the switching element to apply a voltage to the liquid crystal layer on the other side, and the switching element And a second planarization film covering and planarizing the pixel electrode, and a second substrate including a second alignment film having an embossed surface; And And a liquid crystal layer sealed between the first substrate and the second substrate by sealants provided at edges of the first substrate and the second substrate. And the first alignment layer and the second alignment layer are formed only before the sealant forming region so as not to overlap the sealant for sealing the liquid crystal layer at the edge thereof. delete delete The liquid crystal display device of claim 1, wherein the first and second alignment layers are formed of a conductive material. The liquid crystal display device according to claim 1, wherein the embossed shape of the first alignment layer is formed at an interface with the liquid crystal layer. The liquid crystal display device according to claim 1, wherein the embossed shape of the second alignment layer is formed at an interface with the liquid crystal layer and at an interface with the second planarization film. The liquid crystal display device of claim 1, wherein the black matrix of the first substrate is formed of a conductive material. The liquid crystal display device according to claim 1, wherein the black matrix has an embossed surface. The liquid crystal display device according to claim 1 or 8, wherein the embossed shape has a height difference of at least 1 µm between a vertex of a concave portion of the embossed portion and a vertex of the convex portion. The liquid crystal display device according to claim 1, wherein the second planarization film has an embossed shape at an interface with the second alignment film. The liquid crystal display device according to claim 1, wherein the sum of the thicknesses of the first alignment layer, the first planarization layer, and the common electrode is a thin thickness of 700 GPa or less. The liquid crystal display device according to claim 1, wherein the sum of the thicknesses of the second alignment film, the second planarization film, and the pixel electrode is a thin thickness of 700 m or less. Forming a sub-color filter and a black matrix on the first insulating substrate; Forming a first planarization layer on the sub-color filter and the black matrix; Forming a common electrode on one side of the first planarization layer to apply a voltage to the liquid crystal layer; Forming a first alignment layer on the common electrode, the first alignment layer having an embossed surface until the sealant forming region so as not to overlap with the sealant; Forming a switching device on an upper portion of the second insulating substrate disposed to face the first insulating substrate; Forming a pixel electrode connected to the switching element to apply a voltage to the liquid crystal layer on the other side; Forming a second planarization layer on the switching element and the pixel electrode; Forming a second alignment layer on the second planarization layer, the second alignment layer having an embossed surface until the sealant forming region so as not to overlap with the sealant; And Injecting a liquid crystal layer between the first insulating substrate and the second insulating substrate using a sealant provided at edges of the first insulating substrate and the second insulating substrate as an encapsulant; Method of manufacturing the device. The method of claim 13, further comprising performing a cleaning process using ultraviolet rays before forming the first and second alignment layers. The method of claim 13, further comprising performing an electrical cleaning process after rubbing the first and second alignment layers. delete The method of claim 13, wherein the first and second alignment layers are formed of a conductive material. The method of claim 13, wherein the embossed shape of the first alignment layer is formed on an interface with the liquid crystal layer. The method of claim 13, wherein the embossed shape of the second alignment layer is formed at an interface with the liquid crystal layer and at an interface with the second planarization film. The method of claim 13, wherein the black matrix of the first insulating substrate is formed of a conductive material. The method of claim 13, wherein the black matrix has an embossed surface. 22. The liquid crystal display method according to claim 13 or 21, wherein the embossed shape has a height difference of at least 1 [mu] m between the vertex of the concave portion and the convex portion of the embossed portion. The method of claim 13, wherein the second planarization film has an embossed shape at an interface with the second alignment film. The method of claim 13, wherein the sum of the thicknesses of the first alignment layer, the first planarization layer, and the common electrode is a thin thickness of 700 m3 or less. The method of claim 13, wherein the sum of the thicknesses of the second alignment layer, the second planarization layer, and the pixel electrode is a thin thickness of 700 m3 or less.

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