KR101213823B1 - liquid crystal display device and the fabrication method the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same, which can be driven in a reflective transmission type or a reflection type which prevents a short between neighboring pixels.

According to the present invention, by forming a concave-convex pattern on the periphery of the pixel region in the liquid crystal display device, it is possible to prevent the residue of the pattern in the periphery of the pixel region to prevent short between neighboring pixels.

Shot, flatness, irregularities, residue

Description

Liquid crystal display device and its manufacturing method {liquid crystal display device and the fabrication method the same}

1 is an exploded perspective view showing a general reflective transmissive liquid crystal display device.

2 is a cross-sectional view showing a general reflective transmissive liquid crystal display device.

3 is a plan view of a reflective transmissive liquid crystal display device having a conventional uneven reflective electrode.

4 is a plan view showing a portion of a transflective liquid crystal display device according to the present invention;

FIG. 5 is a cross-sectional view taken along the line II ′ of FIG. 4. FIG.

6A through 6H are cross-sectional views illustrating a process sequence of a lower substrate of the reflective liquid crystal display according to the present invention, cut along the cutting line II ′ of FIG. 4.

Description of the Related Art [0002]

111 capacitor electrode 122 gate wiring

132: gate electrode 138: gate insulating film

140: semiconductor layer 142: source electrode

144: drain electrode 146: data wiring

152: protective film 155: first photosensitive organic film

155b: Uneven pattern 158: Second photosensitive organic film

165: reflective electrode 167: pixel electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same, which can be driven in a reflective transmission type or a reflection type which prevents a short between neighboring pixels.

In general, the reflective transmissive liquid crystal display device has the functions of a transmissive liquid crystal display device and a reflective liquid crystal display device at the same time, and since it can use both back light and external natural light or artificial light source, it is restricted to the surrounding environment. Do not receive.

In addition to these advantages, there is an advantage that can reduce power consumption (power consumption).

1 is an exploded perspective view illustrating a general reflective transmissive liquid crystal display device.

As shown in the drawing, a general reflection-transmissive liquid crystal display device 29 includes an upper substrate 15 having a transparent common electrode 13 formed on a black matrix 19 and a sub color filter 17, a pixel region P, The reflective electrode 52 including the transmissive hole A and the transmissive electrode 64 are planar in the pixel region, and the remaining regions except the transmissive hole A are the pixel electrodes serving as the reflecting portions C, and the switching. The lower substrate 30 includes the device T and the array wirings 34 and 46, and the liquid crystal 23 is filled between the upper substrate 15 and the lower substrate 30.

2 is a cross-sectional view showing a general reflective transmissive liquid crystal display device.

As shown, the schematic reflection-transmissive liquid crystal display device 29 includes an upper substrate 15 having the common electrode 13 formed thereon, a reflection electrode 52 including a transmission hole (transmission portion) A, and the reflection electrode. A lower substrate 30 having a pixel electrode formed of a transparent electrode 64 on or below the liquid crystal 23, a liquid crystal 23 filled between the upper substrate 15 and the lower substrate 30, and the lower substrate ( It is composed of a backlight 41 located below the 30.

When the reflective liquid crystal display device 29 having such a configuration is used in the reflective mode, most of the light is used as an external natural light or an artificial light source.

The operation of the liquid crystal display device in the reflection mode and the transmission mode will be described with reference to the above-described configuration.

In the reflective mode, the liquid crystal display uses an external natural light or artificial light source, and the light B incident on the upper substrate 15 of the liquid crystal display is reflected by the reflective electrode 52. Passes through the liquid crystal 23 arranged by the electric field of the reflective electrode and the common electrode 13, the amount of light (B) passing through the liquid crystal is adjusted in accordance with the arrangement of the liquid crystal 23, the image (Image) Will be implemented.

On the contrary, when operating in the transmission mode, the light source uses the light F of the backlight 41 positioned below the lower substrate 21.

Light emitted from the backlight 41 is incident on the liquid crystal 23 through the transparent electrode 64, and is arranged by an electric field of the transparent electrode 64 and the common electrode 13 below the transmission hole. By adjusting the amount of light incident from the lower backlight 41 by the liquid crystal 23 is implemented an image.

In the conventional reflective transmissive liquid crystal display device fabricated as described above, the cell gap 2d of the transmissive portion is twice the cell gap d of the reflective portion, which is to improve the light efficiency of the reflective portion and the transmissive portion in the reflective transmissive liquid crystal display device. . That is, in the transflective liquid crystal display device, the cell gap of the transmissive part and the reflecting part is configured differently in order to increase the efficiency of the transmissive part.

However, in the conventional reflection-transmissive liquid crystal display device, the cell gap 2d of the transmissive part meets the requirement of twice the cell gap d of the reflecting part. However, since the reflection electrode is of a flat mirror type, in terms of reflection efficiency, there is a problem. In other words, if the reflective electrode is not a flat mirror shape but an uneven shape, the reflection efficiency at the reflector increases due to scattering phenomenon occurring on the surface of the reflective electrode. Therefore, in order to improve the reflection efficiency in the reflecting portion, it is preferable to fabricate the surface of the reflecting electrode corresponding to the reflecting portion in an uneven shape.

3 is a plan view of a reflective transmissive liquid crystal display device having a conventional uneven reflective electrode.

Referring to FIG. 3, the lower substrate 30 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 has a gate wiring passing through the plurality of thin film transistors T. 34 and data wiring 46 are formed.

In this case, the pixel area P is an area where the gate line 34 and the data line 46 cross each other.

A storage capacitor C is formed on a portion of the gate line 34, and is electrically connected in parallel with the reflective electrode 52 and the transmission electrode 67 (particularly, the pixel electrode) formed on the pixel region P. FIG. Connect.

A transmission hole h is formed in the pixel area, and the transmission hole h is formed by removing a portion of the reflective electrode 52.

The thin film transistor T includes a gate electrode 32, a source electrode 42, a drain electrode 44, and an active layer 40 formed on the gate electrode 32.

In addition, the uneven pattern 55b is randomly formed in the pixel region except for the through hole h. The uneven pattern 55b has a concave portion and a convex portion to induce diffuse reflection of light. .

By the way, the convex concave-convex pattern 55b has a general trend of forming a thickness of 2 μm or more in order to increase the diffuse reflection effect.

The concave-convex pattern 55b is also formed in the pixel region boundary region to maximize reflection efficiency.

However, such an uneven pattern 55b causes a patterning failure later in forming the pixel electrode 67.

That is, when the pixel electrode material is applied, the concave portion of the concave-convex pattern 55b tends to be thicker than the convex portion. Accordingly, when the pixel electrode material is patterned, a problem occurs that short (X) occurs between pixels adjacent to the pixel electrode material residue remaining between the pixel electrodes.

Such a problem of pattern residue between pixels may occur in the reflective electrode.

According to the present invention, a liquid crystal display having a reflection type or reflection type that densely forms concave-convex patterns between neighboring pixel electrodes in the liquid crystal display device to increase flatness, thereby preventing residue of the pixel electrode or the reflective electrode pattern and preventing shorting between pixels. It is an object to provide a display device and a method of manufacturing the same.

In order to achieve the above object, a liquid crystal display device according to the present invention includes: a gate wiring and a data wiring crossing vertically and horizontally on a first substrate and defining a plurality of pixel regions; A thin film transistor formed at an intersection of the gate wiring and the data wiring; An uneven pattern formed in the pixel area and having a different density according to a position; A reflective electrode formed on the uneven pattern; And a liquid crystal layer formed between the first substrate and the second substrate facing the first substrate.

In addition, in order to achieve the above object, the manufacturing method of the liquid crystal display device according to the present invention comprises the steps of: forming a gate wiring and a data wiring on the first substrate to cross each other longitudinally and define a pixel region; Forming a thin film transistor at an intersection point of the gate wiring and the data wiring; Forming an uneven pattern formed in the pixel area and having a different density according to a position; Forming a reflective electrode on the uneven pattern; And forming a liquid crystal layer between the first substrate and the second substrate facing the first substrate.

The uneven patterns formed at the periphery of the pixel area may be denser than the uneven patterns formed in the pixel area.

The uneven patterns are made of a photosensitive organic insulating film.

The pixel electrode may extend on the gate line to form a storage capacitor.

The pixel region may be formed of a reflecting unit and a transmitting unit.

The reflective electrode may form a through hole in the pixel area.

Concave-convex patterns formed around the pixel region are overlapped with each other.

Hereinafter, a reflective transmissive liquid crystal display device according to the present invention will be described with reference to the accompanying drawings.

FIG. 4 is a plan view showing a portion of a reflective liquid crystal display device according to the present invention, and FIG. 5 is a cross-sectional view taken along the line II ′ of FIG. 4.

As shown in FIGS. 4 and 5, as shown in FIG. 4, the gate wiring 122 formed in one direction, the gate electrode 132 connected thereto, and the gate wiring 122 are perpendicular to the lower substrate 130. The data lines 146 defining the pixel regions P are formed to cross each other.

In addition, a thin film transistor including a gate electrode 132, a semiconductor layer 140, and source and drain electrodes 142 and 144 formed on the semiconductor layer 140 at an intersection point of the two wirings 146 and 122. T) is formed.

In this case, the source electrode 142 of the thin film transistor T is connected to the data line 146, and the gate electrode 132 is connected to the gate line 122.

A storage capacitor C is formed on a portion of the gate line 122, and is electrically connected in parallel with the reflective electrode 165 and the transmissive electrode 167 (especially the pixel electrode) formed on the pixel region P. Connect.

In this case, since the pixel electrode 167 extends above the gate wiring 122 to form a storage capacitor, the pixel electrode 167 is adjacent to the neighboring pixel electrode 167.

Meanwhile, referring to FIG. 5, a gate insulating layer 138 is formed on the gate electrode 132.

Next, a semiconductor including an active layer 140a formed of pure amorphous silicon and an ohmic contact layer 140b formed of amorphous silicon containing impurities at a position corresponding to the gate electrode 132 on the gate insulating layer 138. Form layer 140.

Next, source and drain electrodes 142 and 144 are formed on the semiconductor layer 140. In this case, the source and drain electrodes 142 and 144 are spaced apart from each other by a predetermined interval.

An interlayer insulating layer 152 is formed on the entire surface of the lower substrate 130 on which the source and drain electrodes 142 and 144 are formed.

Next, an embossed concave-convex pattern 155b having a rounded upper surface of the convex portion using the first photosensitive organic layer 155 on the lower substrate 130 having the interlayer insulating layer 152 formed thereon is formed. Form.

On the other hand, the uneven pattern 155b formed on the pixel region P may have individual pattern intervals and overlapping levels adjusted.

In particular, the gap between the concave-convex pattern 155b is narrower and overlapped at the edge of the pixel region P than the center.

As described above, when the gap between the uneven pattern 155b is formed to be narrow and overlaps with each other, the height between the uneven pattern and the concave portion between the pattern and the convex portion of the pattern is reduced to some extent, thereby preventing residue during pixel electrode patterning. .

As described above, shortening between neighboring pixels can be prevented by increasing the density of the concave-convex pattern 155b formed in the peripheral portion K of the pixel electrode formed in the pixel region P.

The second photosensitive organic layer 158 is formed on the entire surface of the lower substrate 130 on which the embossed concave-convex pattern 155b is formed using a photosensitive organic material, preferably a photo acrylic resin.

In this case, it can be seen that the second photosensitive organic layer 158 formed on the embossed uneven pattern 155b of the first photosensitive organic layer 155 also has an uneven shape.

In addition, the flatness of the upper portion of the organic layer 158 on the uneven pattern formed on the peripheral portion K of the pixel electrode 167 becomes higher.

The drain contact hole 161 and the transmission hole h for the transmission part T are formed to be in electrical contact with the pixel electrode 167 formed after the drain electrode 144. That is, the second photosensitive organic layer 158 corresponding to the reflective part R is formed to be uneven along the shape of the uneven pattern 155b and at the same time the second photosensitive organic layer corresponding to the transmissive part T ( 158 is removed.

The uneven reflective electrode 165 is formed by depositing and patterning a metal material having excellent reflectivity such as aluminum (Al) on a portion of the reflective portion R corresponding to the uneven second photosensitive organic layer 158.

The pixel electrode 167 is formed on the uneven reflective electrode 165 using a transparent conductive metal material such as indium tin oxide (ITO).

In this case, the pixel electrode 167 is formed on the convex surface. At the edge of the pattern of the pixel electrode 167, the flatness is higher than the center, so that patterning is performed well without residue.

In addition, the lower substrate 130 formed as described above and formed to face each other at a predetermined interval apart from each other include a black matrix 119 at a position corresponding to the thin film transistor of the lower substrate 130 and the color thereunder. The upper substrate 115 including the filter 117 is included.

Hereinafter, a structure and a method of manufacturing the reflective transmissive liquid crystal display device according to the present invention will be described with reference to the accompanying drawings.

6A through 6H are cross-sectional views illustrating a process sequence of a lower substrate of the reflective liquid crystal display according to the present invention, cut along the cutting line I-I 'of FIG. 4.

First, as shown in FIG. 6A, a gate electrode 132 is formed by depositing and patterning a conductive metal material such as aluminum (Al), chromium (Cr), and molybdenum (Mo) on the transparent lower substrate 130. Although not shown, the gate line 122 connected to the gate electrode is also formed at the same time.

Subsequently, one of an inorganic insulating material group including silicon nitride (SiNx) and silicon oxide (SiO ₂ ) is deposited or coated to form a gate insulating layer 138.

Next, a semiconductor including an active layer 140a formed of pure amorphous silicon and an ohmic contact layer 140b formed of amorphous silicon containing impurities at a position corresponding to the gate electrode 132 on the gate insulating layer 138. Form layer 140.

Next, the source and drain electrodes 142 and 144 are formed on the semiconductor layer 140 using conductive metal materials such as aluminum (Al), chromium (Cr), and molybdenum (Mo).

The source and drain electrodes 142 and 144 are spaced apart from each other by a predetermined interval, and the source electrode 142 is electrically connected to the data line 146 of FIG. 4, and the gate electrode 132 is The gate wiring 122 is electrically connected to the above-described gate.

The capacitor electrode 111 is formed on the gate wiring 122.

Next, as shown in FIG. 6B, an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is used on the entire surface of the lower substrate 130 on which the source and drain electrodes 142 and 144 are formed. The interlayer insulating film 152 is formed.

Next, as shown in FIG. 6C, the first photosensitive organic layer 155 is formed on the entire surface of the substrate on which the interlayer insulating layer 152 is formed, using the photosensitive organic material, and the transmissive portion A and the blocking portion thereon. Place the mask 160 with (B).

The photosensitive organic material for the first photosensitive organic layer 155 may be a photo acrylic resin. The photosensitive organic material includes a positive type in which a portion irradiated with light is removed through a developing process and a negative type in which a portion not receiving light is removed. Here, the photosensitive organic material of a negative type will be described as an example.

Therefore, as can be seen in the drawing, the transmissive portion A of the mask 160 is formed in a rectangular pattern shape at a position corresponding to the reflecting portion R of the lower substrate 130. The blocking portion B of the mask 160 corresponds to other regions except for the transmissive portion T and the reflective portion R of the lower substrate 130.

In this case, the transmissive portion A of the mask 160 is more densely formed at the edge of the pixel region P, that is, the pixel electrode peripheral portion K.

The interlayer insulating layer illustrated in FIGS. 6B to 6C may be omitted. In this case, the first photosensitive organic layer 155 may be formed on the entire surface of the lower substrate 130 on which the source and drain electrodes 142 and 144 are formed. Will be.

Subsequently, as shown in FIG. 6D, when the photolithography process of irradiating light to the first photosensitive organic layer 155 is performed using the mask 160, the reflective portion R of the lower substrate 130 is formed. ), A rectangular photosensitive organic film pattern 155a is formed.

In this case, the quadrangular uneven photosensitive organic film pattern 155a is formed more densely at the edge portion of the lower region of the pixel region P of the lower substrate, that is, around the pixel electrode 167.

At the same time, it can be seen that the first photosensitive organic layer 155 of the portion corresponding to the transmission portion T of the lower substrate is also removed. In this case, the first photosensitive organic layer 155 corresponding to other regions on the substrate except for the transmissive part T and the reflective part R is also removed.

Subsequently, as shown in FIG. 6E, when the rectangular concave-convex photosensitive organic film pattern 155a is melted and cured, an embossed concave-convex pattern having a rounded upper surface of the convex portion ( 155b) is formed. However, the uneven pattern 155b may also be formed by exposing and developing the first photosensitive organic layer 155 using a mask having a plurality of slits.

When the rectangular concave-convex photosensitive organic layer pattern 155a is melted and cured, the concave-convex pattern 155b densely formed in the peripheral portion K of the pixel area overlaps each other or has a narrow gap therebetween. It is formed generally flat.

In addition, an uneven pattern 155b is randomly formed in the reflective region of the pixel region P.

Next, a second photosensitive organic layer 158 is formed on the entire surface of the substrate on which the embossed concave-convex pattern 155b is formed by using a photosensitive organic material, preferably a photo acrylic resin.

As shown in FIG. 6F, it can be seen that the second photosensitive organic layer 158 formed on the embossed concave-convex pattern 155b also has a concave-convex shape.

In addition, an upper surface of the concave-convex pattern 155b that is densely formed in the peripheral portion K of the pixel region is formed to be flatter.

In this step, it is important to coat an organic material having a thickness range capable of utilizing the concave-convex shape of the concave-convex pattern 155b formed through FIG. 6E, and the material forming the second photosensitive organic film is preferably a photo acrylic resin. Shall be.

In this step, a hole formed in a portion corresponding to the drain contact hole 161 in which the drain electrode 144 is in electrical contact with the pixel electrode 167 formed later, and a transmission hole h for the transmission part T. Is formed. That is, the second photosensitive organic film 158 corresponding to the reflective part R is formed to be uneven along the shape of the uneven pattern 155b and at the same time the second photosensitive organic film corresponding to the transmission part T. 158 is removed.

Although not shown, a storage contact hole and a gate pad exposing the storage electrode, the gate pad electrode and the data pad electrode to electrically contact the storage electrode and the pixel electrode, the gate pad electrode and the pixel electrode, and the data pad electrode and the pixel electrode. The second photosensitive organic layer 158 corresponding to the contact hole and the data pad contact hole is also simultaneously removed at this time.

Next, as shown in FIG. 6G, the interlayer insulating layer 152 is etched to partially expose the drain electrode 144 to complete the drain contact hole 161.

The uneven reflective electrode 165 is formed by depositing and patterning a metal material having excellent reflectivity such as aluminum (Al) on a portion of the reflective portion R corresponding to the uneven second photosensitive organic layer 158.

Next, as illustrated in FIG. 6H, the pixel electrode 167 is formed on the uneven reflective electrode 165 using a transparent conductive material such as indium tin oxide (ITO).

In this case, the pixel electrode 167 is formed around the pixel area P including the transmission part T, and the uneven pattern 155b is densely formed in the peripheral area K of the pixel area 155b. Since the upper surface is generally flat, the residue does not occur because the etching characteristics are good when the pixel electrode 167 and the reflective electrode 165 patterns are formed.

The present invention can be applied to a reflective liquid crystal display device as well as a reflective transmissive liquid crystal display device.

As mentioned above, although the present invention has been described in detail through specific embodiments, it is for explaining the present invention in detail, and the transverse electric field type liquid crystal display device and the manufacturing method thereof according to the present invention are not limited thereto, and the technical idea of the present invention. It is apparent that modifications and improvements are possible by those skilled in the art.

According to the present invention, the irregularities of the periphery of the pixel area are densely formed in the reflective or reflective liquid crystal display device, thereby preventing the residue of the pattern from the periphery of the pixel area, thereby preventing short between neighboring pixels.

Claims (19)

Gate wirings and data wirings intersecting longitudinally and horizontally on the first substrate and defining a plurality of pixel regions; A thin film transistor formed at an intersection of the gate wiring and the data wiring; An uneven pattern disposed on a front surface of the first substrate and having a different density according to a position; A reflective electrode formed on the uneven pattern; A liquid crystal layer formed between the first substrate and the second substrate facing the first substrate; And the concave-convex pattern is formed more densely in the periphery of the pixel region than in the pixel region. The method of claim 1, A gate electrode protruding from the gate wiring; A semiconductor layer formed on the gate electrode; Source and drain electrodes protruding from the data line and spaced apart from each other on the semiconductor layer by a predetermined distance; And a pixel electrode connected to the drain electrode. delete The method of claim 1, And the concave-convex patterns are formed of a photosensitive organic insulating layer. The method of claim 1, The uneven pattern is a photo acryl-based liquid crystal display device. The method of claim 1, And an insulating film on the uneven pattern. The method of claim 1, And a pixel electrode extending on the gate line to form a storage capacitor. The method of claim 1, And the concave-convex pattern is formed on the gate wiring and the data wiring. 3. The method of claim 2, And a concave-convex pattern is formed between the pixel electrode and a neighboring pixel electrode. The method of claim 1, And the reflective electrode has a through hole formed in the pixel area. The method of claim 1, The uneven patterns formed around the pixel area overlap each other. Forming a gate wiring and a data wiring on the first substrate, the gate wiring and the data wiring being vertically intersected with each other to define a pixel region; Forming a thin film transistor at an intersection point of the gate wiring and the data wiring; Forming a concave-convex pattern having a density different according to a position, disposed on a front surface of the first substrate; Forming a reflective electrode on the uneven pattern; Forming a liquid crystal layer between the first substrate and an opposing second substrate, And the concave-convex pattern is formed more densely in the periphery of the pixel region than in the pixel region. 13. The method of claim 12, The thin film transistor includes a gate electrode protruding from a gate wiring, a semiconductor layer, a source electrode and a drain electrode protruding from the data wiring. 13. The method of claim 12, In the step of forming the uneven pattern, Forming a photosensitive organic layer on the substrate; Exposing and developing the photosensitive organic layer to form first uneven patterns having different densities according to positions in the pixel region; And melting and curing the first concave-convex pattern to form an embossed second concave-convex pattern. delete 13. The method of claim 12, The uneven patterns formed in the periphery of the pixel region overlap each other. 13. The method of claim 12, And forming a pixel electrode connected to the thin film transistor. 13. The method of claim 12, And the pixel area is formed of a reflecting part and a transmitting part. 13. The method of claim 12, And the reflective electrode forms a transmission hole in the pixel region.

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