KR101888446B1 - Liquid crystal display device and method of fabricating the same - Google Patents

Abstract

The present invention relates to a liquid crystal display device capable of compensating for a viewing angle color deviation and reducing a field distortion region to improve an aperture ratio and a transmittance and a method of manufacturing the same. A gate wiring formed; A data line crossing the gate line; And a unit pixel including a plurality of sub-pixels formed in each region provided at an intersection of the gate wiring and the data wiring, wherein the unit pixel is located on the left side with respect to the data wiring located between the unit pixels connected to the same gate wiring The data lines located in the first unit pixel are formed to be inclined in the first direction and the data lines located in the second unit pixel located on the right of the data line are formed to be inclined in the second direction, The first direction and the second direction are symmetrical with respect to the data line.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal display device and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of compensating for a viewing angle color deviation and reducing a field distortion region and a manufacturing method thereof.

(PDP), Electro Luminescent Display (ELD), Vacuum Fluorescent (VFD), and the like have been developed in recent years in response to the demand for display devices. Display) have been studied, and some of them have already been used as display devices in various devices.

Among them, liquid crystal display devices are mostly used in place of CRT (Cathode Ray Tube) for the purpose of portable image display devices because of their excellent image quality, light weight, thinness and low power consumption, But also various kinds of monitors such as a television and a computer monitor receiving and displaying a broadcast signal in addition to the use of the same mobile type.

Such a liquid crystal display device includes a lower substrate on which a thin film transistor array is formed, an upper substrate on which a color filter array is formed, and a liquid crystal layer formed between the lower and upper substrates. A gate line and a data line intersecting the lower substrate define a plurality of sub-pixels, and a thin film transistor is formed in each sub-pixel to drive a plurality of pixel electrodes and pixel electrodes individually supplied with data signals individually . A color filter formed on each sub-pixel, a black matrix for preventing light leakage, and a column spacer for maintaining a gap between the lower substrate and the upper substrate are formed on the upper substrate.

A typical driving mode most commonly used in the above-described liquid crystal display device is a TN (Twisted Nematic) mode in which a liquid crystal director is arranged to be twisted by 90 degrees and then a voltage is applied to control the liquid crystal director, And an in-plane switching mode in which the liquid crystal is driven by a horizontal electric field between the arranged pixel electrodes and the common electrode.

In particular, in the transverse electric field mode, the pixel electrode and the common electrode are alternately formed on the lower substrate so that the liquid crystal is aligned by the transverse electric field generated between the pixel electrode and the common electrode. However, a liquid crystal display device of a fringe field switching (FFS) mode has been proposed since the transverse electric field mode liquid crystal display device has a wide viewing angle but low aperture ratio and transmittance.

In the fringe field-mode liquid crystal display device, a pixel electrode and a common electrode form a fringing electric field with an insulating film interposed therebetween to operate the liquid crystal molecules, thereby precisely controlling the liquid crystal molecules to obtain a high contrast ratio, It is possible to realize a higher screen quality than the transverse electric field mode liquid crystal display device.

Hereinafter, a general liquid crystal display device will be described with reference to the accompanying drawings.

FIG. 1A is a plan view of a general liquid crystal display device, and FIG. 1B is a plan view showing an electric field distortion region of a general liquid crystal display device.

1A, a typical liquid crystal display device includes a plurality of gate wirings GL and data wirings DL intersecting each other on a substrate to define a plurality of sub-pixels, an intersection of the gate wirings GL and data wirings DL, And a thin film transistor (TFT) formed in the region. The thin film transistor TFT includes a gate electrode 10, source and drain electrodes 13a and 13b, and a semiconductor layer 12. In particular, in the fringe field-mode liquid crystal display device, a pixel electrode 15 in the form of a tubular electrode and a common electrode 16 in the form of a slit form a fringing field with an insulating film (not shown) therebetween.

At this time, the fringe field liquid crystal display device can compensate the viewing angle color deviation by forming the pixel electrode 15 and the common electrode 16 to be inclined. In this case, as shown in Fig. 1B, an electric field distortion region A where the liquid crystal is abnormally driven by the difference in angles between the data line DL and the pixel electrode 15 is generated, and the transmittance of the liquid crystal display device .

Specifically, since the data line DL is perpendicular to the gate line GL but is formed so that only the pixel electrode 15 and the common electrode 16 are inclined, the pixel electrode 15 and the common electrode 16 in the sub- The electric field is distorted at the non-formed region, that is, at the edge of the pixel region. In particular, since the pixel electrode 15 and the common electrode 16 of the adjacent sub-pixel are formed symmetrically with respect to the data line DL, each sub-pixel has at least two electric field distortion regions A, When the sub-pixels constitute one unit pixel, each unit pixel has at least six electric field distortion regions (A).

SUMMARY OF THE INVENTION The present invention has been conceived in order to solve the above problems, and it is an object of the present invention to provide a liquid crystal display device, in which data lines arranged in a unit pixel positioned on the left side and data lines arranged in a unit pixel positioned on the right side are symmetrical And to provide a liquid crystal display device and a method of manufacturing the same that can reduce an electric field distortion region.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a gate wiring formed on a substrate; A data line crossing the gate line; And a unit pixel including a plurality of sub-pixels formed in each region provided at an intersection of the gate wiring and the data wiring, wherein the unit pixel is located on the left side with respect to the data wiring located between the unit pixels connected to the same gate wiring The data lines located in the first unit pixel are formed to be inclined in the first direction and the data lines located in the second unit pixel located on the right of the data line are formed to be inclined in the second direction, The first direction and the second direction are symmetrical with respect to the data line.

The data line between the first unit pixel and the second unit pixel is perpendicular to the gate line.

The sub-pixel includes a thin film transistor formed on the substrate; A first insulating layer formed to cover the thin film transistor; A pixel electrode formed on the first insulating film and connected to the thin film transistor; A second insulating layer formed on the pixel electrode; And a common electrode which forms a fringe electric field with the pixel electrode through the second insulating film.

The pixel electrode and the common electrode are inclined in a direction parallel to the data line.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, including: forming a gate wiring on a substrate; Forming a data line crossing the gate line; And a unit pixel including a plurality of sub-pixels formed in each region provided at an intersection of the gate line and the data line, wherein the unit pixel includes a plurality of unit pixels connected to the same gate line, The data lines located in the first unit pixel positioned on the left side are inclined in the first direction and the data lines located in the second unit pixel positioned on the right side of the data line are inclined in the second direction And the first direction and the second direction are symmetrical with respect to the data line.

A data line between the first unit pixel and the second unit pixel is formed in a direction perpendicular to the gate line.

Forming a thin film transistor on the substrate; Forming a first insulating film to cover the thin film transistor; Forming a pixel electrode connected to the thin film transistor on the first insulating film; Forming a second insulating layer on the pixel electrode; And forming a common electrode having a fringing electric field with the pixel electrode through the second insulating film.

The pixel electrode and the common electrode are formed to be inclined in a direction parallel to the data line.

The liquid crystal display device and the method of manufacturing the same of the present invention as described above are formed such that the pixel electrode, the common electrode, and the data line of the unit pixel are inclined. In particular, the pixel electrode, the common electrode, and the data line of the unit pixel located on the left side are tilted in the first direction on the basis of the data line, the pixel electrode, the common electrode, and the data line of the unit pixel located on the right side are aligned in the second direction The first direction and the second direction are symmetrical with respect to the data line, and the field distortion region can be reduced. Accordingly, the aperture ratio and transmittance of the liquid crystal display device can be improved.

1A is a plan view of a typical liquid crystal display device.
FIG. 1B is a plan view showing an electric field distortion region of a general liquid crystal display device. FIG.
2A is a plan view of a liquid crystal display device of the present invention.
FIG. 2B is a cross-sectional view taken along the line I-I 'in FIG. 2A. FIG.
3 is a plan view showing a field distortion region of the liquid crystal display device of the present invention.
FIGS. 4A to 4F are cross-sectional views showing the manufacturing steps of the liquid crystal display device of the present invention, and FIGS. 5A and 5F are process plan views showing the manufacturing steps of the liquid crystal display device of the present invention.

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

2A is a plan view of a liquid crystal display device of the present invention, and FIG. 2B is a cross-sectional view taken along the line I-I 'of FIG. 2A.

2A and 2B, the liquid crystal display of the present invention includes a gate wiring GL formed on a substrate 100, a data wiring DL intersecting with the gate wiring GL, a gate wiring GL, Sub-pixels are formed in each region provided at the intersection of the wirings DL, and a plurality of sub-pixels constitute one unit pixel. At this time, the data lines DL located in the first unit pixel located on the left side with respect to the data line DL located between the unit pixels connected to the same gate line GL are formed to be inclined in the first direction The data lines DL located in the second unit pixel located on the right side of the data line DL are formed to be inclined in the second direction and the first direction and the second direction are connected to the data line DL It is symmetric by reference.

Specifically, the gate line GL supplies a scan signal from a gate driver (not shown), and the data line DL supplies a video signal from a data driver (not shown). The gate line GL and the data line DL intersect each other with the gate insulating film 111 interposed therebetween to define each sub-pixel. In the intersecting region of the gate line GL and the data line DL of each sub-pixel, A transistor TFT is formed.

The thin film transistor TFT causes the pixel electrode 150 to be filled with a video signal of the data line DL in response to a scan signal of the gate line GL. The thin film transistor (TFT) has a structure in which a gate electrode 110, a source electrode 130a and a drain electrode 130b spaced apart from each other, and an active layer 120a and an ohmic contact layer 120b are sequentially stacked. (120). At this time, the gate electrode 110 may protrude from the gate line GL, and may be defined as a part of the gate line GL, as shown in the figure.

The active layer 120a overlaps the gate electrode 110 with the gate insulating film 111 formed of an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx) or the like interposed therebetween. The ohmic contact layer 120b formed on the active layer 120a reduces electrical contact resistance between the source and drain electrodes 130a and 130b and the active layer 120a and reduces the contact resistance between the source and drain electrodes 130a and 130b, The ohmic contact layer 120b corresponding to the separated interval of the ohmic contact layer 120b is removed to form a channel. The source electrode 130a is connected to the data line DL to receive the pixel signal of the data line DL and the drain electrode 130b is formed to face the source electrode 130a do.

First and second protective films 140a and 140b are sequentially formed on the entire surface of the gate insulating film 111 to cover the thin film transistor (TFT). In this case, it is preferable that the first protective film 140a is an inorganic protective film and the second protective film 140b is an organic protective film. The drain contact hole 140h formed by selectively removing the first and second protective films 140a and 140b exposes the drain electrode 130b and is electrically connected to the drain electrode 130b along the drain contact hole 140h. The pixel electrode 150 to be connected is formed. The pixel electrode 150 is formed of a transparent conductive material such as Tin Oxide (ITO), Indium Tin Oxide (ITO), Indium Zinc Oxide (ITO), Indium Tin Zinc Oxide (ITZO)

An insulating layer 160 is formed to cover the pixel electrode 150 and a common electrode 170 is formed on the insulating layer 160 as a transparent conductive material as described above. The common electrode 170 is formed in a plurality of slit shapes to form a fringe electric field with the pixel electrode 150 with the insulating film 160 interposed therebetween. The liquid crystal molecules are rotated by dielectric anisotropy by the fringe electric field, and the light transmittance through the sub pixels is changed according to the degree of rotation of the liquid crystal molecules, thereby realizing an image.

Although not shown, a common electrode 170 in the form of a tubular electrode may be formed on the second protective film 140b, and a plurality of slit-shaped pixel electrodes 150 may be formed on the insulating film 160. In this case, the drain contact hole 140h is formed by selectively removing the first and second protective films 140a and 140b and the insulating film 160. [

When the pixel electrode 150 and the common electrode 170 are formed to be inclined so as to compensate for the viewing angle color deviation as in a general liquid crystal display device, the data line DL, the pixel electrode 150, An electric field distortion region in which the liquid crystal is abnormally driven at the corner of the sub-pixel occurs. As a result, the transmittance and the aperture ratio of the liquid crystal display device are lowered.

Accordingly, in the liquid crystal display device of the present invention, not only the pixel electrode 150 and the common electrode 170 but also the data line DL are inclined so that the electric field distortion region can be reduced.

Specifically, in the liquid crystal display device of the present invention, when a plurality of sub-pixels connected to the same gate line GL constitute one unit pixel, the data line DL between adjacent unit pixels is connected to the gate line GL It is vertical. The data line DL in the first unit pixel located on the left side with respect to the data line DL is formed to be inclined in the first direction and the second unit pixel The data lines DL in the second direction are formed to be inclined in the second direction.

In particular, it is preferable that a plurality of sub-pixels constituting one unit pixel are R, G, and B sub-pixels, and that an arrangement of sub-pixels includes a G sub-pixel located between the R sub-pixel and the B sub-pixel. That is, the G sub-pixel has a parallelogram shape, and the R sub-pixel and the B sub-pixel have a trapezoidal shape.

The pixel electrode 150 and the common electrode 170 of the plurality of sub-pixels constituting the first unit pixel are also formed to be inclined in the first direction like the data line DL, and a plurality of The pixel electrode 150 and the common electrode 160 of the sub-pixels are also formed to be inclined in the second direction. In this case, the first direction and the second direction are symmetrical with respect to the data line DL for dividing the unit pixel, and the first direction and the second direction are substantially parallel to the data line DL, 7 degrees.

3 is a plan view showing a field distortion region of the liquid crystal display device of the present invention.

As shown in FIG. 3, since the pixel electrode 150 and the common electrode 170 of the G sub-pixel are formed in a direction parallel to the adjacent data line DL, the electric field distortion does not occur in the G sub-pixel. Since the R sub pixel and the B sub pixel are adjacent to the data line DL perpendicular to the gate line GL, the R pixel and the B sub pixel do not form the pixel electrode 150 and the common electrode 170 The electric field is distorted in the region adjacent to the data line DL that divides the unit pixel.

That is, in the liquid crystal display device of the present invention, the pixel electrode 150 and the common electrode 170 in the unit pixel are formed in a direction parallel to the data line DL. Therefore, the pixel electrode 150 and the common electrode 170 of the G sub-pixel most contributing to the improvement in luminance compared to the middle sub-pixel of the unit pixel, that is, generally the R sub-pixel and the B sub- The data line DL is formed in a direction parallel to the data line DL on the side of the data line DL. Since the electric field distortion region A occurs only at the edges of the sub-pixels on both sides of the unit pixel, that is, the edge of the R and B sub-pixels, only one electric field distortion region is provided in one unit pixel.

Accordingly, the liquid crystal display device of the present invention can reduce the field-distortion region A and prevent the aperture ratio and the transmittance of the liquid crystal display device from being reduced due to the electric-field-distorted region A.

Particularly, in a general liquid crystal display device having a resolution of 312 ppi (Pixel Per Inch), the R, G, and B sub-pixels all have two electric field distortion regions. However, in the liquid crystal display of the present invention having a resolution of 312 ppi, the transmittance of R, G, and B sub-pixels is higher than that of general R, G, and B sub-pixels of a liquid crystal display device. This is because in the liquid crystal display device of the present invention, the G sub-pixel does not have an electric field distortion region, and only R sub-pixel and B sub-pixel have one electric field distortion region.

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

FIGS. 4A to 4F are cross-sectional views illustrating a manufacturing process of a liquid crystal display device of the present invention, and FIGS. 5A and 5F are process plan views illustrating a manufacturing process of the liquid crystal display device of the present invention.

As shown in FIGS. 4A and 5A, a gate line GL and a gate electrode 110 are formed on a substrate 100. The gate electrode 110 is protruded from the gate line GL or defined as a part of the gate line GL. 4B and 5B, a gate insulating film 111 is formed on the entire surface of the substrate 100 including the gate wiring GL and the gate electrode 110, and an active layer 120a is formed on the gate insulating film 111, And the ohmic contact layer 120b are stacked in this order.

4C and 5C, a data metal layer is formed on the entire surface of the gate insulating film 111 including the semiconductor layer 120 and the data metal layer is patterned to form a data line DL and a data line DL connected to the data line DL The source electrode 130a and the drain electrode 130b are spaced apart from the source electrode 130a by a predetermined distance and the ohmic contact layer 120b corresponding to the interval between the source electrode 130a and the drain electrode 130b is formed. To form a channel. Although not shown, the semiconductor layer 120, the data line DL, the source electrode 130a, and the drain electrode 130b may be formed using a single mask.

The data line DL is formed so as to cross the gate line GL with the gate insulating film 111 interposed therebetween so that sub pixels are formed at each intersection of the gate line GL and the data line DL. Thus, a thin film transistor (TFT) including a gate electrode 110, a gate insulating film 111, a semiconductor layer 120, a source electrode 130a and a drain electrode 130b is formed in each sub pixel.

Particularly, a plurality of sub-pixels connected to the same gate line GL constitute one unit pixel, and a data line DL between adjacent unit pixels is formed so as to cross the gate line GL. The data line DL in the first unit pixel located on the left side of the data line DL is formed to be inclined in the first direction and the data line DL of the second unit pixel Is formed to be inclined in the second direction. In this case, it is preferable that the first direction and the second direction are symmetrical with respect to the data line DL perpendicular to the gate line GL.

Next, as shown in FIGS. 4D and 5D, the first and second protective films 140a and 140b are sequentially formed so as to cover the TFTs. In this case, it is preferable that the first protective film 140a is an inorganic protective film and the second protective film 140b is an organic protective film. The first and second protective films 140a and 140b are selectively removed to form a drain contact hole 140h exposing the drain electrode 130b.

A transparent conductive material such as tin oxide (ITO), indium tin oxide (ITO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO) is formed on the entire surface of the second passivation layer 140b as shown in FIGS. 4E and 5E And a transparent conductive material is patterned to form the pixel electrode 150 connected to the drain electrode 130b through the drain contact hole 140h. The pixel electrode 150 is formed in the shape of a tubular electrode and the pixel electrode 150 in the first unit pixel is formed to be inclined in the first direction like the data line DL of the first unit pixel, The pixel electrode 150 is formed to be inclined in the second direction like the data line DL.

4F and 5F, an insulating layer 160 is formed to cover the pixel electrode 150, and a plurality of slit-shaped common electrodes 170 overlapping the pixel electrodes 150 are formed on the insulating layer 160, . At this time, the common electrode 170 in the first unit pixel is formed to be inclined in the first direction like the data line DL of the first unit pixel, and the common electrode 170 in the second unit pixel is also formed in the data line DL in the second direction.

The common electrode 170 forms a fringe electric field with the pixel electrode 150 with the insulating film 160 interposed therebetween. The liquid crystal molecules are rotated by dielectric anisotropy by the fringe electric field, and the light transmittance through the sub pixels is changed according to the degree of rotation of the liquid crystal molecules, thereby realizing an image. Although not shown, a common electrode 170 in the form of a tubular electrode may be formed on the second protective film 140b, and a plurality of slit-shaped pixel electrodes 150 may be formed on the insulating film 160.

In the liquid crystal display of the present invention, the pixel electrode 150 and the common electrode 170 in the unit pixel are formed in a direction parallel to the data line DL. Therefore, since the pixel electrode 150 and the common electrode 170 of the middle sub-pixel of the unit pixel are formed in a direction parallel to the data lines DL on both the sub-pixels, the unit pixel 150 does not have a field- Since the sub-pixels on both sides of the pixel are adjacent to the data line DL perpendicular to the gate line GL, an electric field distortion region A is generated at the edge.

That is, the liquid crystal display device of the present invention has only two field-distortion regions in one unit pixel. Accordingly, the liquid crystal display device of the present invention can reduce the field-distortion region A and prevent the aperture ratio and the transmittance of the liquid crystal display device from being reduced due to the electric-field-distorted region A.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

DL: Data line GL: Gate line
100: substrate 110: gate electrode
111: gate insulating film 120: semiconductor layer
120a: active layer 120b: ohmic contact layer
130a: source electrode 130b: drain electrode
140a: first protective film 140b: second protective film
140h: drain contact hole 150: pixel electrode
160: insulating film 170: common electrode

Claims (8)

A gate wiring formed on the substrate;
A data line crossing the gate line; And
And a unit pixel formed of a plurality of sub-pixels formed in each region provided at an intersection of the gate wiring and the data wiring,
The data lines between the sub-pixels located in the odd-numbered unit pixel connected to the same gate line are formed to be inclined in the first direction,
The data lines between the sub-pixels located in the odd-numbered unit pixel are formed to be inclined in the second direction,
Wherein the first direction and the second direction are symmetrical with respect to a data line that divides the odd-numbered unit pixel and the even-numbered unit pixel. The method according to claim 1,
And the data line dividing the odd-numbered unit pixel and the even-numbered unit pixel is perpendicular to the gate line. The method according to claim 1,
The sub-pixel includes a thin film transistor formed on the substrate;
A first insulating layer formed to cover the thin film transistor;
A pixel electrode formed on the first insulating film and connected to the thin film transistor;
A second insulating layer formed on the pixel electrode; And
And a common electrode which forms a fringing electric field with the pixel electrode through the second insulating film. The method of claim 3,
Wherein the pixel electrode and the common electrode are inclined in a direction parallel to the data line between the sub-pixels. Forming a gate wiring on the substrate;
Forming a data line crossing the gate line; And
And a unit pixel including a plurality of sub-pixels formed in each region provided at an intersection of the gate wiring and the data wiring,
The data lines between the sub-pixels located in the odd-numbered unit pixel connected to the same gate line are formed to be inclined in the first direction,
The data lines between the sub-pixels located in the odd-numbered unit pixel are inclined in the second direction,
Wherein the first direction and the second direction are symmetrical with respect to a data line for dividing the odd-numbered unit pixel and the even-numbered unit pixel. 6. The method of claim 5,
And a data line for dividing the odd-numbered unit pixel and the even-numbered unit pixel is formed in a direction perpendicular to the gate wiring. 6. The method of claim 5,
Forming a thin film transistor on the substrate;
Forming a first insulating film to cover the thin film transistor;
Forming a pixel electrode connected to the thin film transistor on the first insulating film;
Forming a second insulating layer on the pixel electrode; And
And forming a common electrode having a fringing electric field with the pixel electrode with the second insulating film interposed therebetween. 8. The method of claim 7,
Wherein the pixel electrode and the common electrode are formed to be inclined in a direction parallel to the data line between the sub-pixels.

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