KR20020056113A - method for fabricating a black matrix of a LCD - Google Patents

Abstract

PURPOSE: A method of forming a black matrix of a liquid crystal display is provided to simplify a black matrix fabrication process, reduce processing time, improve production yield and decrease manufacturing cost. CONSTITUTION: A gate line(113) and a gate line(115) are formed on a substrate(100), intersecting each other to define a pixel region. A thin film transistor consists of a gate electrode(125) connected to the gate line, source and drain electrodes(121,123) connected to the data line, and an active layer. A pixel electrode(117) is placed in the pixel region and connected to the drain electrode. A resin black matrix(126) is formed by an ink jet method on the gate line, the data line and the thin film transistor. The black matrix blocks the region between the data line and the pixel electrode. The black matrix is made of opaque resin and serves as a spacer.

Description

Method for fabricating a black matrix of a LCD

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a method of forming a black matrix constituting a liquid crystal display device.

1 is a view schematically showing a general liquid crystal panel.

As shown, the liquid crystal display includes a color filter 7 including a black matrix 6 and a sub-color filter (red, green, blue) 8 and an upper substrate on which a transparent common electrode 18 is formed on the color filter. And a lower substrate 22 having an array wiring including a pixel region P and a pixel electrode 17 formed on the pixel region, and a switching element T. The upper substrate 5 and the lower substrate are formed of the lower substrate 22. The liquid crystal 14 is filled between the substrates 22.

The lower substrate 22 is also referred to as an array substrate, and 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 15 passing through the plurality of thin film transistors cross each other. Is formed.

The pixel area P is an area defined by the gate line 13 and the data line 15 intersecting each other. The pixel electrode 17 formed on the pixel region P uses a transparent conductive metal having relatively high light transmittance, such as indium-tin-oxide (ITO).

In the above-described configuration, the first method of forming the black matrix is a method of depositing and patterning an opaque metal having a low reflection characteristic such as chromium, and forming the second matrix. It is formed through the process of etching.

The color filter is configured in an etched region of the patterned black matrix.

The color filter may be formed by a printing method, a dyeing method, a polymer electrodeposition method, or a pigment dispersion method.

For example, the pigment dispersion method described above may be repeated by applying, exposing, and patterning a resist, which is prepared by using a pigment prepared in advance, to a substrate, thereby producing red, green, and blue colors. It is a method of forming a color filter.

At this time, an acrylic resin or the like may be used as a material of the color filter. In order to pattern the resin, pre-bake, exposure, development, post-bake Can be patterned through the process.

As described above, the upper substrate and the lower substrate, which have undergone respective processes, are bonded to each other in the assembling process to form a liquid crystal display device.

In this manner, a color liquid crystal display device can be manufactured.

However, the method of forming the black matrix according to the first method and the second method has a disadvantage in that the process is complicated and the required time increases.

In particular, when the opaque resin is formed of a black matrix, there is a disadvantage that the material is limited to the photosensitive material.

In addition, since a large area substrate is formed on the substrate through spin coating, there is a limitation that uniformity cannot be guaranteed.

Accordingly, an object of the present invention is to propose a method of forming a new black matrix, which aims to simplify the process and to reduce the time, thereby improving the yield of the product and reducing the manufacturing cost.

1 is an exploded perspective view showing a conventional color liquid crystal display device;

2 is a plan view showing some pixels of an array substrate for a liquid crystal display device according to a first embodiment of the present invention;

3 is a cross-sectional view taken along line III-III ′ of FIG. 2;

4 is a plan view showing some pixels of an array substrate for a liquid crystal display according to a second embodiment of the present invention;

5A through 5D are cross-sectional views taken along the line VV ′ of FIG. 4 and shown in a process sequence.

<Brief description of symbols for the main parts of the drawings>

100: array substrate 113: gate wiring

115: data wiring 117: pixel electrode

119 active layer 121 source electrode

123: drain electrode 125: gate electrode

126: Resin Black Matrix 127: Contact Hole

An array substrate for a liquid crystal display device according to the present invention for achieving the above object is a substrate; A gate wiring and a data wiring on the substrate to vertically intersect to define a pixel region; A thin film transistor comprising a gate electrode connected to the gate wiring, a source electrode and a drain electrode connected to the data wiring, and an active layer; A pixel electrode connected to the drain electrode and positioned in the pixel region; And a resin black matrix formed on the gate line, the data line, and the thin film transistor by an inkjet method.

The black matrix is formed of an opaque resin and is configured to block an area between the data line and the pixel electrode.

An array substrate manufacturing method for a liquid crystal display device according to an aspect of the present invention includes the steps of preparing a substrate; Forming a gate line and a data line on the substrate, the gate line and the data line interposing the insulating layer and vertically crossing each other to define a pixel area; Forming a thin film transistor comprising a gate electrode connected to the gate wiring, a source electrode and a drain electrode connected to the data wiring, and an active layer; Forming a pixel electrode connected to the drain electrode and positioned in the pixel region; Forming a black matrix on the gate line, the data line, and the thin film transistor by an inkjet method.

According to another aspect of the present invention, a method of manufacturing an array substrate for a liquid crystal display device includes preparing a substrate; Forming a filter on a plurality of sub color filters formed on a predetermined area on the substrate; Forming a planarization layer on the plurality of sub color filters; Forming a gate wiring and a data wiring on the planarization film and interposing the insulating film and vertically intersecting the insulating film to define a pixel area; Forming a thin film transistor comprising a gate electrode connected to the gate wiring, a source electrode and a drain electrode connected to the data wiring, and an active layer; Forming a pixel electrode connected to the drain electrode and positioned in the pixel region; Spraying black resin on the thin film transistor by an inkjet method to form an island-like black matrix.

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

First Embodiment

The first embodiment of the present invention proposes a structure in which a black matrix is directly formed on a lower array substrate by using the inkjet method as described above.

2 and 3 are plan views showing some pixels of an array substrate for a liquid crystal display device according to a first embodiment of the present invention, and sectional views taken along the line III-III`.

As shown in the drawing, the gate wiring 113 and the data wiring 115 are formed to cross each other in a matrix form on the substrate 100, and at the intersection of the gate wiring 113 and the data wiring 115. The thin film transistor T is formed. The thin film transistor T includes a gate electrode 125, an active layer 119, a source electrode 121, and a drain electrode 123.

The pixel electrode 117 is formed on the entire surface of the area defined by the gate wiring 113 and the data wiring 115 intersecting, and the pixel electrode 117 is connected to the drain electrode 123 through the contact hole 127. Configure to contact.

In this configuration, the resin black is extended on the gate wiring 113, the data wiring 115, and the thin film transistor T to the region K between the wirings 113 and 115 and the pixel electrode 117. The matrix 126 is formed.

Therefore, since the area between each of the wirings 113 and 115 and the pixel electrode 117, which are areas where light leakage occurs, is already blocked by the black matrix 126, the black matrix is usually patterned including the bonding margin. The aperture ratio can be further secured as compared with the conventional liquid crystal display device having the?.

Since the black matrix 126 is formed by an inkjet method, the black matrix 126 is not limited to a photosensitive material and may be an opaque resin that can be sprayed.

Hereinafter, the manufacturing process of the array substrate as described above will be briefly described.

First, the first metal layer is formed and patterned on the substrate 100 to form the gate wiring 113 and the gate electrode 125. In this case, the first metal layer is formed by selecting one of conductive metal groups including aluminum (Al), aluminum alloy, copper (Cu), tungsten (W), molybdenum (Mo), and chromium (Cr).

Next, silicon nitride (SiN _x ) or silicon oxide (SiO ₂ ) is deposited on the entire surface of the substrate 100 including the gate wiring 113 to form a gate insulating layer 130.

Next, the active layer 119 formed of pure amorphous silicon (a-Si: H) and the impurity amorphous silicon (n + a-Si: H) are formed on the gate insulating layer 130 on the gate electrode 125. One ohmic contact layer 120 is formed.

Next, a second metal layer is formed and patterned on the entire surface of the substrate 100 on which the ohmic contact layer 120 is formed to form a data wiring 115 that intersects the gate wiring 113, and the data wiring ( A source electrode 121 extending from 115 and a drain electrode 123 spaced apart from each other are formed.

Next, a contact hole exposing an entire surface of the substrate 100 on which the source and drain electrodes 121 and 123 are formed to form a protective layer 132 and patterning the portion, thereby exposing a portion of the drain electrode 123. 127).

Next, a transparent conductive metal is deposited and patterned on the passivation layer 132 to form the pixel electrode 117 in contact with the drain electrode 123.

Next, the black matrix 126 is formed by spraying an opaque resin on the gate wiring 113, the data wiring 115, and the thin film transistor T by an inkjet method.

In this case, the black matrix 126 may be formed under the protective layer by changing the process order.

In addition, the black matrix 126 can be applied to a structure in which only the upper portion of the TFT and the upper portion of the gate wiring 113 are formed, and a structure applied only to the upper portion of the TFT.

In the case of an island-like black matrix, the height can be designed in accordance with the thickness of the liquid crystal layer, thereby serving as a spacer.

According to the above-described process, an array substrate for a liquid crystal display device according to a first embodiment of the present invention can be manufactured.

Hereinafter, the second embodiment of the present invention is a structure in which a black matrix is formed in the method according to the present invention on an array substrate having a color filter disposed below.

Example 2

A second embodiment of the present invention proposes an array substrate for a liquid crystal display device having a TFT on color filter (TOC) structure in which a color filter is formed under a thin film transistor.

4 is an enlarged plan view schematically showing a part of a TOC structure array substrate according to a second embodiment of the present invention.

As illustrated, the array substrate 100 has a thin film transistor T, which is a switching device that applies a signal voltage to the pixel P and the pixel, and a data line 115 and a gate intersecting while being connected to the thin film transistor. The wiring 113 is formed.

The pixel electrode 117 of the pixel P is formed in a region defined by the orthogonality of the gate wiring 113 and the data wiring 115, wherein one side of the pixel electrode 117 is a drain of the thin film transistor. The electrode 123 and the contact hole 127 are connected to each other.

An organic resin is printed on the top of the thin film transistor by an inkjet method to form an island-like black matrix.

Each sub-color filter showing red, green, and blue colors is formed under each pixel electrode, and a data wiring or a gate wiring is positioned above the boundary formed by each sub-color.

Therefore, unlike the first embodiment, the black matrix is not formed under each of the wirings. In this configuration, each pixel electrode 117 is planarized with the data wiring 115 and the gate wiring 113 in plan view. Configure so that they overlap slightly.

The black matrix 126 formed on the thin film transistor T may be configured only in a desired region by an inkjet method.

As described above, the structure in which the black matrix 126 is patterned only on the upper portion of the thin film transistor T is more cost effective when the inkjet method according to the present invention is used.

This is because, when the black matrix is formed according to the conventional method, the same amount of photoresist is used regardless of whether the pattern is large or small, and the smaller the pattern of the black matrix, the greater the waste of material cost.

Hereinafter, a method of manufacturing a TOC structure array substrate according to a second embodiment of the present invention will be described with reference to FIGS. 5A to 5D.

5A through 5D are cross-sectional views taken along the line VV ′ of FIG. 4 and shown in a process sequence.

First, FIG. 5A is a cross-sectional view illustrating a process of forming the color filter 129.

As shown, the red (R), green (G), and blue (B) subcolor filters 124 are formed on the substrate 100 by a predetermined method. Each sub-color filter has the same shape, and a mosaic array in which a sub-color filter having the same color is arranged in one direction and a mosaic array in which the sub-color filters (red, green, blue) are repeatedly arranged. It can be configured as.

The transparent pixel electrode 117 of FIG. 4, which is formed in a subsequent process, is positioned on the sub-color filter 124.

Next, one selected from the group of organic insulating materials including benzocyclobutene and acryl-based resin is coated on the substrate 100 on which each sub-color filter 124 is formed. In addition, the planarization film 128 is formed to planarize the surface of the substrate 100 on which the color filter 124 is formed.

Next, silicon nitride (SiN _X ) or silicon oxide (SiO ₂ ) is deposited on the planarization layer 128 to form a buffer layer 130.

Next, as shown in FIG. 5B, aluminum (Al), aluminum alloy (AlNd), chromium (Cr), tungsten (W), molybdenum (Mo), copper (Cu), and the like are formed on the buffer layer 130. A selected one of the included conductive metal groups is deposited and patterned to form a plurality of gate lines (113 in FIG. 4) configured in one direction and a plurality of gate electrodes 125 protruding from the gate lines.

Next, an inorganic insulating material group in which a silicon oxide film (SiO ₂ ) and a silicon nitride film (SiN _x ) are formed on the entire surface of the substrate 100 including the gate wiring (113 in FIG. 4), and in some cases, benzocyclobutene One selected from an organic insulating material group consisting of (Benzocyclobutene) and an acrylic resin (resin) is deposited or coated to form a gate insulating film 141 which is a first insulating film.

Next, as shown in FIG. 5C, an amorphous silicon (a-Si: H) layer and an impurity amorphous silicon (n + a-Si :) layer are formed on the gate insulating film 141 on the gate wiring 113 (in FIG. 4). The semiconductor layer 119 is formed by stacking the H) layers.

In the stacked structure, the lower pure amorphous silicon layer is later an active layer 119a, and the impurity amorphous silicon layer is an ohmic contact layer for lowering the resistance between the active layer and the subsequent metal wiring. layer) 119b.

Next, a selected one of the conductive metals is deposited and patterned on the entire surface of the substrate 100 on which the semiconductor layer 119 is formed, and vertically intersects the gate wiring (113 in FIG. 4) to form a pixel region ( A data line 115 defining P), a source electrode 121 protruding from one side of the gate electrode 125 on the data line 115, and a drain spaced apart from the source electrode 121 at a predetermined interval. The electrode 123 is formed.

In such a configuration, the data wiring and the gate wiring are configured on the boundary formed by each of the sub-color filters, so that not only means for transmitting a signal but also serves as a black matrix.

Next, as shown in FIG. 5D, one of the above-described organic insulating material group and optionally an inorganic insulating material group is selected on the entire surface of the substrate 100 on which the data wiring 115 and the like are formed. This is applied or deposited to form a protective layer 142, which is a second insulating film.

Next, the protective layer 142 is patterned to form a drain contact hole 127 disposed on the drain electrode 123 and exposing a part of the drain electrode 123.

Next, one of the transparent conductive metal group consisting of indium tin oxide (ITO) and indium zinc oxide (IZO) is deposited on the entire surface of the substrate 100 on which the patterned protective layer 142 is formed, and the pattern is formed. The pixel electrode 117 is formed in contact with the exposed drain electrode 123. In this case, the pixel electrode 117 extends above the gate wiring (113 in FIG. 4) or the data wiring (115 in FIG. 4) to overlap each wiring with a small gap.

Next, an island-like black matrix 144 is formed on the thin film transistor by an inkjet method. Since the black matrix 144 is an organic resin, the black matrix 144 may be formed by spraying the black matrix 144 in the inkjet device 146 to form only a specific region.

The island-like black matrix can be designed to match the thickness of the liquid crystal layer to serve as a spacer.

In this manner, a liquid crystal display device having a TFT on color filter (TOC) structure according to a second embodiment of the present invention can be manufactured.

Therefore, the method of forming the black matrix according to the present invention as described above has the following effects.

First, it is not limited to the photosensitive material because it uses an opaque resin sprayable by the inkjet method.

Second, since the process of forming the black matrix only in the desired area by a single spraying process is possible, the process can be simplified, thereby reducing the time required and reducing material costs.

Third, since the light leakage region is already blocked by the method of configuring the black matrix on the lower substrate, the process margin does not need to be considered separately, thereby securing the aperture ratio of the liquid crystal panel.

Fourth, the structure of the color filter on the lower substrate has no defect due to the bonding error, thereby improving the yield of the liquid crystal display device.

Fifth, even if the substrate becomes large, the uniform black matrix is formed, thereby increasing the use area of the substrate.

Sixth, the function as a black matrix and the function of a spacer can be simultaneously implemented.

Claims (13)

A substrate; A gate wiring and a data wiring on the substrate to vertically intersect to define a pixel region; A thin film transistor comprising a gate electrode connected to the gate wiring, a source electrode and a drain electrode connected to the data wiring, and an active layer; A pixel electrode connected to the drain electrode and positioned in the pixel region; Resin black matrix formed by inkjet method on the gate wiring, data wiring and thin film transistor Array substrate for a liquid crystal display device comprising a. The method of claim 1, And the black matrix is configured to block an area between the data line and the pixel electrode. The method of claim 1, The black matrix is an opaque resin array substrate for a liquid crystal display device. The method of claim 1, An array substrate for a liquid crystal display device, wherein the black matrix also functions as a spacer. Preparing a substrate; Forming a gate line and a data line on the substrate, the gate line and the data line interposing the insulating layer and vertically crossing each other to define a pixel area; Forming a thin film transistor comprising a gate electrode connected to the gate wiring, a source electrode and a drain electrode connected to the data wiring, and an active layer; Forming a pixel electrode connected to the drain electrode and positioned in the pixel region; Forming a black matrix on the gate line, the data line, and the thin film transistor by an inkjet method Array substrate manufacturing method for a liquid crystal display device comprising a. The method of claim 5, And the black matrix extends to block an area between the gate wiring and the pixel electrode. The method of claim 5, The black matrix is an opaque resin array substrate manufacturing method for a liquid crystal display device. The method of claim 5, An array substrate for a liquid crystal display device, wherein the black matrix also functions as a spacer. Preparing a substrate; Forming a plurality of sub color filters formed on a predetermined area on the substrate; Forming a planarization layer on the plurality of sub color filters; Forming a gate wiring and a data wiring on the planarization film and interposing the insulating film and vertically intersecting the insulating film to define a pixel area; Forming a thin film transistor comprising a gate electrode connected to the gate wiring, a source electrode and a drain electrode connected to the data wiring, and an active layer; Forming a pixel electrode connected to the drain electrode and positioned in the pixel region; Forming an island-shaped black matrix by spraying black resin on the thin film transistor by an inkjet method; Array substrate manufacturing method for a liquid crystal display device comprising a. The method of claim 9, And forming the gate wirings and the data wirings above the boundary formed by the sub-color filters. The method of claim 9, And the pixel electrode extends from the pixel area and overlaps a predetermined area with a gate wiring and a data wiring. The method of claim 9, The black matrix is an opaque resin array substrate manufacturing method for a liquid crystal display device. The method of claim 9, An array substrate for a liquid crystal display device, wherein the black matrix also functions as a spacer.