KR101397447B1 - Liquid Crystal Display device and method for fabricating the same - Google Patents

Abstract

The present invention relates to a liquid crystal display device and a method of manufacturing the same, and a liquid crystal display device according to the present invention is formed on a substrate and includes gate lines, common electrode lines and data line; A thin film transistor formed at a portion where the gate line and the data line cross each other; An opaque insulating film formed to overlap the thin film transistor and the data line; And a transparent electrode line electrically connected to the thin film transistor and composed of a plurality of branched pixel electrodes and a transparent electrode line electrically connected to the common electrode line and composed of a plurality of branched transparent electrodes .

Opaque insulating film, pixel electrode line, transparent electrode line, common electrode line

Description

[0001] The present invention relates to a liquid crystal display device and a manufacturing method thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a liquid crystal display device and a method of manufacturing the same, and more particularly, to a liquid crystal display device capable of improving an aperture ratio by removing a viewing angle cross-talk (VAC) .

Generally, the driving principle of a liquid crystal display device utilizes the optical anisotropy and polarization properties of a liquid crystal. Since the liquid crystal is thin and long in structure, it has directionality in the arrangement of molecules, and the direction of the molecular arrangement can be controlled by artificially applying voltage to the liquid crystal.

At present, an active matrix type liquid crystal display device in which a thin film transistor (TFT) and a pixel electrode connected to the thin film transistor are arranged in a matrix manner has been receiving the most attention because of its excellent resolution and moving picture implementation capability.

The structure of such a conventional liquid crystal display will be described with reference to FIGS. 1 and 2. FIG.

1 is a schematic cross-sectional view of a conventional liquid crystal display device, and is a schematic cross-sectional view showing a case where light leakage occurs in a region other than a liquid crystal driving region.

2 is a schematic cross-sectional view of a conventional liquid crystal display device, and is a schematic cross-sectional view showing a case where light leakage occurs in a data line region.

1 and 2, the liquid crystal display of the IPS (In-Plane Switching) mode according to the related art has a pixel electrode 23 formed on a pixel region and a pixel region, a pixel electrode 23, A lower substrate 11 on which array wiring lines and alignment layers 25 including a common electrode 13 (Vcom) formed on the same plane or another layer and a thin film transistor (not shown) (Not shown) including a black matrix 43 (Black Matrix) and sub color filters (not shown) (R, G and B) and an overcoat layer And a liquid crystal 51 is filled between the lower substrate 11 and the upper substrate 41.

 The lower substrate 11 is also referred to as an array substrate. A thin film transistor (not shown) as a switching element is disposed in a matrix form. A gate line (not shown) passing through the plurality of thin film transistors crosses the data line 21, .

In addition, since the IPS mode liquid crystal display device drives the liquid crystal in the transverse electric field, the black matrix 43 uses an organic material (i.e., resin) rather than a metal in order to prevent the electric field from being distorted.

The lower array substrate of the liquid crystal display according to the related art has a display area, i.e., a drive area, which is an area where an image is actually transmitted through a light beam, and a non-display area where the light beam is blocked by the black matrix, , I.e., a non-driving region.

Although not shown in the drawing, the array substrate 11 in the display area is formed in parallel with a gate line (not shown) and a common electrode line (not shown) in the horizontal direction, and the data lines 21 Are formed perpendicular to the gate line (not shown) and the common electrode line (not shown).

A gate electrode (not shown) is formed on one side of the gate line (not shown), and a source electrode (not shown) is formed on the data line 21 in the vicinity of the gate electrode And a drain electrode (not shown) is formed at a position corresponding to the source electrode (not shown) with a gap therebetween.

A plurality of common electrodes 13 branched from the common electrode line are formed in the common electrode line (not shown), and contact holes (not shown) formed in the passivation layer 25 are formed in the drain electrodes (not shown) And a plurality of pixel electrodes 23 branched from the pixel electrode lines are formed in the pixel electrode lines (not shown).

In this configuration, the common electrode 13 and the pixel electrode 23 are staggered from each other, and the common electrode 13 formed in the pixel region is in a state in which a common voltage input from the common electrode line is always applied.

In addition, image signals of various levels are applied to the pixel electrode through the data line 21 according to the level of the gate voltage applied to the gate electrode.

Accordingly, in the pixel region, a horizontal electric field is distributed by the voltage applied to the pixel electrode 23 and the common electrode 13, and the degree of the liquid crystal arrangement is changed according to the intensity of the electric field.

On the other hand, the black matrix 43 formed on the upper substrate 41 serves to block light leakage through portions other than the liquid crystal driving region. Here, when the light leakage can not form a desired electric field, it means that the liquid crystal can not be controlled and the unwanted light is transmitted.

The liquid crystal display according to the related art having the above-described configuration has the following problems.

Since the transparent insulating layer, that is, the protective layer is formed on the lower substrate, the light leakage to the portion other than the liquid crystal driving region is blocked by the black matrix provided on the upper substrate. As shown in Figs. 1 and 2, light leakage occurs, and the contrast ratio is reduced.

Further, when the width of the black matrix is increased to prevent the light leakage, the aperture ratio is reduced and the trade off is broken.

Therefore, when the conventional technique can not form a desired electric field, the liquid crystal can not be controlled and the undesired light is transmitted. Due to the structure of the liquid crystal display device according to the prior art, .

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a semiconductor device capable of preventing a light leakage by removing a viewing angle cross-talk (VAC) by applying an opaque insulating film, And a method of manufacturing the same.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a gate line, a common electrode line, and a data line formed on a substrate and arranged in a direction perpendicular to each other to define pixel regions; A thin film transistor formed at a portion where the gate line and the data line cross each other; An opaque insulating film formed to overlap the thin film transistor and the data line; And a transparent electrode line electrically connected to the thin film transistor and composed of a plurality of branched pixel electrodes and a transparent electrode line electrically connected to the common electrode line and composed of a plurality of branched transparent electrodes .

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device including forming a gate line on a substrate defined by a pixel region and a non-pixel region, a gate electrode branched from the gate line, and a common electrode line; Forming a gate insulating film and an active layer on the gate electrode; Forming a data line vertically aligned with the gate line on the active layer, a source electrode branched from the data line, and a drain electrode spaced apart from the source electrode; Forming an opaque insulating film on the drain electrode, the source electrode, and the data line excluding the pixel region and exposing a portion of the drain electrode; And a pixel electrode line electrically connected to the drain electrode on the opaque insulating film, a plurality of pixel electrodes branched from the pixel electrode line, and the transparent electrode line.

The liquid crystal display device and the manufacturing method thereof according to the present invention have the following effects.

The liquid crystal display device and the method of manufacturing the same according to the present invention can improve the aperture ratio by removing the viewing angle cross-talk (VAC) by forming an opaque insulating film on the data line and the common electrodes on both sides adjacent to the data line, . Particularly, the present invention can remove the viewing angle cross-talk (VAC), thereby increasing the aperture, thereby improving the aperture ratio.

In addition, the present invention can improve the contrast ratio by removing a viewing angle cross-talk (VAC) by applying an opaque insulating film.

In addition, since the present invention can be applied to all parts where a viewing angle cross-talk (VAC) is generated, it is possible to provide a wide range of viewing modes such as an IPS mode (In-Plane Switching mode), a TN mode (Twisted Nematic mode) Applicable.

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

3 is a plan view of a liquid crystal display device according to the present invention.

4 is a cross-sectional view of the liquid crystal display device taken along the line IV-IV of Fig.

5A to 5E are cross-sectional views illustrating a manufacturing process of a liquid crystal display device according to the present invention.

3 and 4, the liquid crystal display according to the present invention includes a pixel electrode line 117 formed on a pixel region and a pixel region, and a pixel electrode line 117 formed on the pixel electrode line 117 at a position spaced apart from the pixel electrode line 117 by a predetermined distance A lower substrate 101 on which array wiring lines and alignment films (not shown) including a common electrode line 103 (Vcom) and a thin film transistor (not shown) as a switching device are formed, a black matrix 143 (Black Matrix) And an upper substrate 141 including a color filter 145 including sub color filters (not shown) (R, G and B) and an overcoat layer (not shown) for protecting the color filters 145, A liquid crystal (not shown in FIG. 5F) 151 is filled between the lower substrate 101 and the upper substrate 141.

 The lower substrate 101 is also referred to as an array substrate. A thin film transistor (not shown) as a switching element is disposed in a matrix form. A gate line 102 and a data line 111 passing through the plurality of thin film transistors cross each other. Respectively.

The pixel region is defined by intersecting the gate line 102 and the data line 111. The pixel electrode line 117 formed on the pixel region uses a transparent conductive metal having a relatively high light transmittance such as indium-tin-oxide (ITO).

In addition, since the IPS mode liquid crystal display device drives the liquid crystal by the transverse electric field, the black matrix 143 uses an organic material (i.e., resin) rather than a metal in order to prevent the electric field from being distorted.

The lower array substrate of the liquid crystal display according to the present invention includes a display area, i.e., a drive area, which is an area where an image is actually transmitted through a light beam, and a display area where a light beam is blocked by the black matrix 143, Non-display region, that is, a non-driving region.

A gate line 102 and a common electrode line 103 are formed in parallel in the horizontal direction on the lower substrate 101 in the display region and a data line 111 is formed in a vertical direction And is perpendicular to the gate line 102 and the common electrode line 103.

A gate electrode 102a is formed on one side of the gate line 102. A source electrode 111a is formed on the data line 111 in the vicinity of the gate electrode 102a, And a drain electrode 111b is formed at a position corresponding to the source electrode 111a with a gap therebetween.

A plurality of common electrodes 103a branched from the common electrode line are formed in the common electrode line 103. A drain contact hole (not shown) formed in the opaque insulating film 113 is formed in the drain electrode 111b. And a pixel electrode line 117 is connected to the pixel electrode line 117. A plurality of pixel electrodes 117a branched from the pixel electrode line are formed in the pixel electrode line 117. [

The opaque insulating film 113 overlaps the data line 111 and the common electrode 103a branched from the common electrode line 103. [ The opaque insulating film 113 is preferably formed of an insulating material having a low dielectric constant, a low transmittance, and a high light absorptivity. Therefore, the opaque insulating film 113 may be made of any insulating material having such characteristics.

In addition, the common electrode line 103 is formed simultaneously with the gate line 103, and is formed of an opaque metal material.

A transparent electrode line 119 overlaps and is electrically connected to the common electrode line 103. A plurality of transparent electrodes 119a branched from the transparent electrode line are formed in the transparent electrode line 119 . The transparent electrode 119a positioned at the outermost one of the plurality of transparent electrodes 119a overlaps with the common electrode 103a branched from the common electrode line 103. [

In this structure, the transparent electrode 119a and the pixel electrode 117a are shifted from each other, and the transparent electrode 119a formed in the pixel region is in a state in which a common voltage input from the common electrode line 103 is always applied to be.

In addition, image signals of various levels are applied to the pixel electrode 117a through the data line 111 according to the level of the gate voltage applied to the gate electrode 102a.

Accordingly, a transverse electric field is distributed in the pixel region due to the voltage applied to the pixel electrode 117a and the transparent electrode 119a, and the degree of the liquid crystal alignment is changed according to the intensity of the electric field.

The black matrix 143 formed on the upper substrate 141 serves to block light leakage through portions other than the liquid crystal driving region. In addition to the black matrix 143, the black matrix 143 is formed on the lower substrate 101, The light leakage is also shielded by the common electrode 103a and the opaque insulating film 113 located at the outermost portion of the region. At this time, when the light leakage can not form a desired electric field, it means that the liquid crystal can not be controlled and the unwanted light is transmitted.

Therefore, in the liquid crystal display device according to the present invention, the light leakage is blocked by the opaque insulating film 113 overlapping the data line 111 and the common electrode 103a, thereby reducing viewing angle cross-talk (VAC) The aperture ratio can be improved and light leakage can be prevented. Particularly, in the present invention, viewing angle cross-talk (VAC) can be removed through the opaque insulating film without increasing the margin of the black matrix in order to prevent the light leakage, .

In addition, the present invention can improve the contrast ratio by removing a viewing angle cross-talk (VAC) by applying an opaque insulating film.

A method of manufacturing a liquid crystal display device according to the present invention will be described with reference to FIGS. 5A to 5E.

5A to 5E are cross-sectional views illustrating a manufacturing process of a liquid crystal display device according to the present invention.

5A, a metal film (not shown) is first deposited on a lower substrate 101 made of transparent glass or the like by a sputtering method, and then the metal film (not shown) is formed by a photolithography process and an etching process A gate electrode 102a branched from the gate line, a common electrode line 103, and a plurality of branch lines (not shown) extending from the common electrode line 103. In addition, The common electrode 103a is formed.

At this time, as the metal film material for forming the gate line, Al-based metal such as Al and Al alloy, Ag-based metal such as Ag and Ag alloy, Mo-based metal such as Mo and Mo alloy, Cr, Ti and Ta use.

In addition, they may comprise two membranes of different material properties, namely a bottom membrane and a top membrane thereon. Here, the upper film is made of a metal having a low resistivity, for example, an Al-based metal or an Ag-based metal so as to reduce signal delay and voltage drop of the gate line.

Alternatively, the lower film may be made of a material having excellent physical, chemical and electrical contact properties with other materials, particularly indium tin oxide (ITO) or indium zinc oxide (IZO), such as Ti, Ta, Cr, , Or an example of a combination of the lower film and the upper film is Cr / Al-Nd alloy.

Next, a gate insulating film made of an inorganic insulating material such as silicon nitride (SiNx) is formed on the entire surface of the lower substrate 101 including the gate line 102, the gate electrode 102a, the common electrode line 103 and the common electrode 103a 105 are formed.

A semiconductor layer (not shown) made of a hydrogenated amorphous silicon or the like and a silicide or an n + hydrogenated amorphous silicon layer having a high concentration of a silicide or n-type impurity are formed on the gate insulating layer 105, (Not shown) are formed in this order.

Then, the impurity layer and the semiconductor layer are selectively removed through a photolithography process and an etching process to form the semiconductor pattern 107 and the ohmic contact layer 109. At this time, the semiconductor pattern 107 and the ohmic contact layer 109 are used as an active layer.

5B, a metal material for forming a data line is deposited on the lower substrate 101 including the semiconductor pattern 107 and the ohmic contact layer 109 by a sputtering method, (Not shown in FIG. 3), a source electrode 111a branched from the data line 111, and a source electrode 111a spaced apart from the source electrode 111a by a predetermined distance Drain electrodes 111b are formed.

As the metal material for forming the data line 111, an Al-based metal, an Ag-based metal, a Mo-based metal, Cr, Ti, Ta, or the like may be used.

The data line 111 is formed so as to intersect with the gate line 102. The source electrode 111a and the drain electrode 111b are formed under the semiconductor pattern 107 and the gate electrode 102a, And constitutes a thin film transistor which is a switching element.

The channel of the thin film transistor is formed in the semiconductor pattern 107 between the source electrode 111a and the drain electrode 111b.

Next, as shown in FIG. 5C, an opaque insulating layer 113 is formed on the entire surface of the lower substrate 101 including the data line 111 and the source / drain electrodes 111a and 111b. At this time, the opaque insulating layer 113 is selected from an insulating material having excellent planarization characteristics, low dielectric constant characteristics, and excellent light absorptivity.

5D, the opaque insulating film 113 is selectively patterned through a photolithography process and an etching process to expose a portion of the drain electrode 111b in the opaque insulating film 113 (Not shown). At this time, the opaque insulating layer 113 is patterned to overlap the data line 111 and the common electrode 103a together with the thin film transistor region. In particular, the opaque insulating film 113 is not present in the pixel region except the thin film transistor T and the data line 111, and is removed.

Next, a metal material layer (not shown) made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is deposited on the opaque insulating film 113 including the contact hole (not shown) by a sputtering method And then selectively removed by a photolithography process and an etching process to form a pixel electrode line 117 and a transparent electrode line 119. A plurality of pixel electrodes 117a are formed on the pixel electrode line 117 and a plurality of transparent electrodes 119a are formed on the transparent electrode line 119. The transparent electrodes 119a are divided into transparent electrodes 119a. The transparent electrode 119a positioned at the outermost one of the plurality of transparent electrodes 119a overlaps with the common electrode 103a branched from the common electrode line 103. [

The transparent electrode 119a and the pixel electrode 117a are staggered from each other and the transparent electrode 119a formed in the pixel region is in a state in which the common voltage input from the common electrode line 103 is always applied .

In addition, image signals of various levels are applied to the pixel electrode 117a through the data line 111 according to the level of the gate voltage applied to the gate electrode 102a.

At this time, when the data voltage is applied to the pixel electrode 119, an electric field is generated together with the transparent electrode 119a to which a common voltage is applied, so that the liquid crystal layer between the pixel electrode 117a and the transparent electrode 119a The liquid crystal molecules of the liquid crystal layer 151 are arranged in a predetermined direction.

Subsequently, a process of forming a lower alignment layer (not shown) for aligning liquid crystal molecules in a predetermined direction is performed on the opaque insulating layer 113 including the pixel electrode 117a, thereby completing the fabrication of the thin film transistor array substrate.

Meanwhile, as shown in FIG. 5E, an opaque film (not shown) is formed on the upper substrate 141 to form a black matrix for preventing light leakage. At this time, as the material of the opaque film (not shown), opaque metal or opaque resin containing chromium (Cr) is used.

Then, the opaque film (not shown) is selectively removed through an exposure and etching process using a photolithography process technique to form a black matrix 143.

Next, a photosensitive color resin is deposited on the entire surface of the upper substrate 141 including the black matrix 143, and patterning is performed through a photolithography process and an etching process to form red, green, and blue color filters 145 do. At this time, each of the red, green, and blue color filters 145 uses a photolithography process and an etching process.

A process of forming each of the red, green, and blue color filters 145 using the photolithography process and the etching process will now be described.

First, red (R) photosensitive color resin is entirely deposited on an upper substrate 141 on which a black matrix 143 is formed, and then a photolithography process and an etching process for a photosensitive color resin of red (R) To form a red (R) color filter.

Next, a green (G) photosensitive color resin is entirely deposited on the upper substrate 141 on which a red color filter is formed, and then a photolithography process and an etching process are performed on the photosensitive color resin of green (G) And a green (G) color filter is formed by performing patterning.

Next, a blue (B) photosensitive color resin is entirely deposited on an upper substrate 141 on which a red color filter and a green color filter are formed, and then a photolithography process for a photosensitive color resin of blue (B) And patterning through the etching process is performed to form the blue (B) color filter to finally complete the color filter 145.

Then, an overcoat layer (not shown) is formed on the color filter 145 to planarize the upper substrate 141 using an organic insulating material.

Next, an upper alignment film (not shown) for aligning the liquid crystal in a predetermined direction is formed on the overcoat layer (not shown).

Then, a spacer (not shown) for holding the cell gap between the thin film transistor and the color filter substrate is formed on the alignment film (not shown) to complete the fabrication of the color filter array substrate.

After the liquid crystal layer 151 is formed between the thin film transistor array substrate and the color filter array substrate thus manufactured, the both substrates are bonded together to complete the liquid crystal display device manufacturing process.

Therefore, in the liquid crystal display according to the present invention, the light leakage is blocked by the opaque insulating layer 113 overlapping the data line 111 and the common electrode 103a, thereby forming a viewing angle cross-talk (VAC) The aperture ratio can be improved and light leakage can be prevented. Particularly, in the present invention, viewing angle cross-talk (VAC) can be removed through the opaque insulating film without increasing the margin of the black matrix in order to prevent the light leakage, .

In addition, the present invention can improve the contrast ratio by removing a viewing angle cross-talk (VAC) by applying an opaque insulating film.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

Therefore, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also within the scope of the present invention.

1 is a schematic cross-sectional view of a conventional liquid crystal display device, and is a schematic cross-sectional view showing a case where light leakage occurs in a region other than a liquid crystal driving region.

2 is a schematic cross-sectional view of a conventional liquid crystal display device, and is a schematic cross-sectional view showing a case where light leakage occurs in a data line region.

3 is a plan view of a liquid crystal display device according to the present invention.

4 is a cross-sectional view of the liquid crystal display device taken along the line IV-IV of Fig.

5A to 5E are cross-sectional views illustrating a manufacturing process of a liquid crystal display device according to the present invention.

Claims (13)

A plurality of gate lines and a plurality of data lines formed on the substrate, the gate lines and the data lines being arranged in a direction perpendicular to each other to define pixel regions; A common electrode line arranged parallel to the gate line and having a plurality of common electrodes branched adjacent to the data line; A thin film transistor formed at a portion where the gate line and the data line cross each other; An opaque insulating film formed on the thin film transistor and the data line so as to overlap the thin film transistor and the data line; A pixel electrode line electrically connected to the thin film transistor and composed of a plurality of branched pixel electrodes; And And a plurality of branched transparent electrodes electrically connected to the common electrode line and spaced apart from the plurality of branched pixel electrodes, The transparent electrodes positioned at the outermost of the plurality of transparent electrodes branched from the transparent electrode line are disposed on the opaque insulating film so as to overlap with the common electrodes of the common electrode line; Wherein the opaque insulating film overlaps the data line and a common electrode adjacent to the data line and branched from the common electrode line. The liquid crystal display device according to claim 1, wherein the opaque insulating film is made of an insulating material having a low dielectric constant, a low transmittance, and a light absorbing property. delete delete delete The liquid crystal display of claim 1, wherein the thin film transistor comprises a gate electrode, a gate insulating film formed on the gate electrode, an active layer, and a source electrode and a drain electrode formed between the channel region of the active layer. The liquid crystal display device according to claim 1, further comprising: a color filter substrate bonded to the substrate and having a black matrix, a color filter layer and an overcoat layer laminated; And a liquid crystal layer formed between the color filter substrate and the substrate. Forming a plurality of common electrodes branched from the common electrode line together with a gate line and a gate electrode and a common electrode line branched from the gate line on a substrate defined by a pixel region and a non-pixel region; Forming a gate insulating film and an active layer on the gate electrode; Forming a data line adjacent to the plurality of common electrodes on the active layer and perpendicular to the gate line, a source electrode branched from the data line, and a drain electrode spaced apart from the source electrode; Forming an opaque insulating layer on the drain electrode, the source electrode, and the data line excluding the pixel region, the opaque insulating layer being formed to overlap the drain electrode, the source electrode, and the data line and exposing a part of the drain electrode; And A pixel electrode line electrically connected to the drain electrode in the pixel region, a plurality of pixel electrodes branched in the pixel electrode line, and a plurality of transparent electrodes branched from the plurality of pixel electrodes, The method comprising the steps of: The transparent electrodes positioned at the outermost of the plurality of transparent electrodes branched from the transparent electrode line are disposed on the opaque insulating film so as to overlap with the common electrodes of the common electrode line; Wherein the opaque insulating film overlaps the data line and a common electrode adjacent to the data line and branched from the common electrode line. The method of claim 8, wherein the opaque insulating film is made of an insulating material having a low dielectric constant, a low transmittance, and a light absorbing property. delete delete delete 9. The method of claim 8, further comprising: providing a color filter substrate bonded to the substrate; Stacking a black matrix, a color filter layer and an overcoat layer on the color filter substrate; And And forming a liquid crystal layer between the color filter substrate and the substrate.

Images