JP4053519B2 - Fringe field switching mode liquid crystal display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having a high transmittance and a high aperture ratio and a method for manufacturing the same.

  Recently, liquid crystal display devices have been spotlighted as elements of next-generation advanced display devices with low power consumption, excellent portability, technology-intensive, and high added value. The liquid crystal display device is formed by injecting liquid crystal between two substrates on which transparent electrodes are formed, and by positioning an upper polarizing plate and a lower polarizing plate outside the upper substrate and the lower substrate, so that the liquid crystal molecules differ. This is a non-light-emitting element that changes the polarization characteristics of light depending on the directionality and obtains an image effect.

  Currently, an active matrix type liquid crystal display device in which a thin film transistor, which is a switching element that opens and closes each pixel, is arranged for each pixel is excellent in resolution and moving image display capability. Widely used in application fields such as high information monitors.

  However, a TN (Twisted Nematic) display mode, which is a typical liquid crystal display device, has fundamental problems such as a narrow viewing angle and a slow response characteristic.

  In order to solve such problems, a novel and diverse concept of liquid crystal display elements has been proposed. For example, there are a method using a multi-domain TN structure in which one pixel is separated into a number of sub-pixels and a method using an OCB (Optically Compensated Birefringence) mode.

  In the multi-domain method, the process of forming the multi-domain is complicated, and there is a limit to improving the viewing angle. The OCB mode method is excellent in electro-optical performance in terms of viewing angle characteristics and response speed. However, it is difficult to stably adjust and maintain the liquid crystal by the bias voltage.

  Recently, as a part of a new display mode, a lateral electric field mode in which electrodes for driving liquid crystal molecules and the like are all formed on the same substrate has been proposed.

FIG. 1 is a diagram for explaining a driving principle of a general horizontal electric field type liquid crystal display device.
As illustrated, an upper substrate 10 that is a color filter substrate and a lower substrate 20 that is an array substrate are spaced apart from each other, and a liquid crystal layer 30 is interposed between the upper substrate 10 and the lower substrate 20. The common electrode 22 and the pixel electrode 24 are formed on the inner surface of the lower substrate 20.

  The liquid crystal layer 30 is operated by the horizontal electric field 26 of the common electrode 22 and the pixel electrode 24, and the liquid crystal molecules in the liquid crystal layer 30 are moved by the horizontal electric field, so that the viewing angle is widened.

  For example, when the horizontal electric field type liquid crystal display device is viewed from the front, it can be viewed in the direction of about 80o-85o up / down / left / right.

Hereinafter, it will be described in detail with reference to the drawing of the electrode arrangement structure of a general array substrate for a horizontal electric field type liquid crystal display.
FIG. 2 is a schematic plan view of an array substrate for a general horizontal electric field type liquid crystal display device.
As shown in the figure, the gate wiring 40 and the data wiring 42 are formed so as to cross each other, and a thin film transistor T is formed at the intersection of the gate wiring 40 and the data wiring 42. An intersection region between the gate line 40 and the data line 42 is defined by a pixel region.

  A common wiring 44 is formed so as to be spaced apart from the gate wiring 40 by a certain distance. In the common wiring 44 located in the pixel region P, a large number of common electrodes 46 are branched in parallel with the data wiring 42. In addition, a first pixel connection line 48 is formed connected to the thin film transistor T. In the first pixel connection line 48, a large number of pixel electrodes 50 are branched alternately with the common electrode 46 in the interval between the common electrodes 46. Has been.

  A second pixel connection line 52 is formed at a position where one end of the pixel electrode 50 or the like is connected and overlaps the common line 44. A region where the common line 44 and the second pixel connection line 52 overlap each other constitutes a storage capacitor Cst with an insulator (not shown) interposed therebetween.

  The separation section between the common electrode 46 and the pixel electrode 50 corresponds to a substantial opening area A in which the liquid crystal is driven by a horizontal electric field. In the drawing, a four-block structure having four opening areas A is shown as an example. That is, a structure in which three common electrodes 46 and two pixel electrodes 50 are alternately arranged for each pixel region P is shown.

  For convenience of explanation, the common electrode 46 positioned adjacent to the data line 42 is referred to as a first common electrode 46a, and the common electrode 46 positioned inside the pixel region P is referred to as a second common electrode 46b. Of the first common electrode 46a and the second common electrode 46b, the first common electrode 46a located on the outer surface minimizes crosstalk, which is a phenomenon of poor image quality that occurs between the data wiring 42 and the pixel electrode 50, and reduces light In order to prevent the leakage phenomenon, it must be formed with a width wider than that of the second common electrode 46b.

  In order to improve the transmittance and aperture ratio of the horizontal electric field type liquid crystal display device, a fringe field switching mode (hereinafter referred to as FFS mode) liquid crystal display device has been proposed.

  The FFS mode liquid crystal display device has a slit shape corresponding to a structure in which a plurality of rectangular common electrodes corresponding to a kind of island pattern structure corresponding to a pixel region and a plurality of rod-shaped patterns are formed to be spaced apart from each other. The pixel electrodes are arranged so as to overlap with an insulator interposed therebetween. Compared with the IPS mode, the horizontal electric field is formed at intervals of several A, so the horizontal electric field is strong, There is an advantage that the liquid crystal molecules above the electrodes can be aligned by a transverse electric field. Moreover, since both electrodes are formed of indium-tin-oxide ITO, there is a feature that the brightness in the white state is increased and the aperture ratio is increased.

Hereinafter, the electrode arrangement structure of a general FFS mode liquid crystal display device will be described in detail with reference to the drawings.
3 and 4 are diagrams of a general FFS mode liquid crystal display device.
3 is a plan view, and FIG. 4 is a cross-sectional view showing a section taken along the line IIIB-IIIB in FIG. 3. For convenience of explanation, FIG. 3 is for an FFS mode liquid crystal display device. FIG. 4 mainly shows a cross-sectional structure of a liquid crystal display device including a liquid crystal layer with reference to the corresponding cut region, centering on a plan view of the array substrate.

  In FIG. 3, the gate wiring 62 and the data wiring 78 are formed so as to cross each other, and a thin film transistor T is formed at the intersection of the gate wiring 62 and the data wiring 78. The intersecting region of the wiring 78 is defined by the pixel region P. In the pixel region P, a large number of pixel electrodes 82 that are connected to the thin film transistor T and are spaced apart from each other, and a common electrode 68 are extended to a lower portion of the large number of pixel electrodes 82.

  More specifically, the thin film transistor T includes a gate electrode 64, a semiconductor layer 72, a source electrode 74, and a drain electrode 76, and is connected to the drain electrode 76 to form a first pixel connection line 84. In the one-pixel connection wiring 84, the many pixel electrodes 82 described above are branched, and one ends of the pixel electrodes 82 and the like are connected by the second pixel connection wiring 86.

  Further, the common electrode 68 for each pixel region P is connected to a common wiring 66 formed so as to be spaced apart from each other in the same direction as the gate wiring 62. The common electrode 68 and the pixel electrode 82 are made of a transparent conductive material through different processes, and the common wire 66 is made of the same material through the same process as the gate wire 62. The common wiring 66 and the common electrode 68 are connected to each other without connecting an insulating film therebetween, and the pixel electrode 82 is disposed above the common electrode 68 with an insulator (not shown) interposed therebetween. Has a structured.

Hereinafter, the operational characteristics of the FFS mode liquid crystal display device will be described through presentation of the cross-sectional structure of FIG.
In FIG. 4, a square-shaped common electrode 68 is formed on the first substrate 60, and a first insulating layer 70 is formed in a region covering the common electrode 68.
A plurality of slit-shaped pixel electrodes 82 are formed on the first insulating layer 70 above the common electrode 68 so as to be separated from each other, and a first alignment film 88 is formed in a region covering the pixel electrode 82. Is formed.

  In addition, a second substrate 90 is disposed so as to face the first substrate 60, and a color filter layer 92 and a second alignment film 94 are sequentially formed below the second substrate 90, and the first alignment is performed. A liquid crystal layer 96 is interposed between the film 88 and the second alignment film 94.

  The operation principle of the FFS mode will be described in more detail. Initially, the liquid crystal between the electrodes is first rotated in parallel with the substrate by the side electric field, and after a certain time, the vertical and side electric fields are generated in the electrode portion. The liquid crystal molecules on the electrode rotate due to the elastic force of the liquid crystal. That is, since light is transmitted from all surfaces on the electrode, the transmittance is high. Furthermore, the degree of rotation of the liquid crystal within one pixel is different, and the color shift is reduced due to the self-compensation effect.

  When the horizontal electric field electrode is formed in a stripe pattern, the alignment direction is formed in a direction inclined about 60 ° with respect to the 0 ° direction to form a horizontal electric field when a voltage is applied. There is a problem that the viewing angle is inclined and the range of the viewing angle is not uniform, and in the case of a stripe pattern, the orientation direction is almost composed of 90 ° -270 ° direction. By being positioned so as to be orthogonal to each other in the polarization axis directions 0 ° and 90 °, the viewing angle characteristics are degraded in the 45 ° and 135 ° directions.

  In addition, since there is a difference in color shift for each angle in all directions, there is a problem in that the viewing angle characteristics deteriorate.

  In order to solve the above-described problems, an object of the present invention is to provide an FFS mode liquid crystal display device that minimizes a color shift phenomenon and improves a viewing angle, and a manufacturing method thereof.

  For this reason, in the present invention, a lateral direction using a first electrode formed in a square shape at a position corresponding to the pixel region and a second electrode formed in a circular structure at a position overlapping the first electrode. The liquid crystal is driven by an electric field.

  In order to achieve the above object, an FFS mode liquid crystal display device of the present invention defines a pixel region by crossing a first substrate, a gate wiring formed on the first substrate, and the gate wiring. A data line, a thin film transistor connected to the gate line and the data line, a common line spaced apart from the gate line and parallel to the gate line, and a branch from the common line substantially corresponding to the pixel region. A square-shaped common electrode, a ring-shaped pixel electrode connected to the thin film transistor and overlapping the common electrode, a second substrate disposed to face the first substrate, and the first substrate, A liquid crystal layer provided between the second substrate and the second substrate is included.

Here, a pixel connection line is further included between the thin film transistor and the pixel electrode, and the pixel electrode and the common electrode are formed of a transparent conductive material.
The liquid crystal molecules of the liquid crystal layer are driven by an electric field parallel to the first substrate and the second substrate in a region between the pixel electrode patterns and a region where the pixel electrode and the common electrode overlap.

  The pixel electrodes include circular and ring patterns, and the pixel electrode patterns are concentric. At this time, the pixel electrode includes a circular first pixel electrode pattern, a ring-shaped second pixel electrode pattern, and a third pixel electrode pattern, and the first pixel electrode pattern is formed inside the third pixel electrode pattern. The second pixel electrode pattern is positioned between the first pixel electrode pattern and the third pixel electrode pattern.

The overlapped common electrode and pixel electrode constitute a storage capacitor with an insulator interposed.
The second substrate further includes a black matrix having an opening exposing the pixel region and covering an end side of the common electrode on an inner surface of the second substrate. Here, the opening is configured in a circular shape.

The pixel region may have a regular square shape. At this time, the pixel region corresponds to one subpixel, and red, green, blue, and white subpixels constitute one pixel.
The capacitor further includes a capacitor electrode connected to the pixel region and overlapping the previous gate line to form a storage capacitor.

  The thin film transistor includes a gate electrode branched from the gate wiring, a semiconductor layer overlapping the gate electrode, a source electrode branched from the data wiring, and a drain electrode spaced apart from the source electrode.

  Another FFS mode liquid crystal display device according to the present invention includes a first substrate, a gate line formed on the first substrate, a data line that intersects the gate line and defines a pixel region, and the gate. A thin film transistor connected to a wiring and a data wiring, a thin film electrode connected to the thin film transistor, substantially separated from the pixel wiring, the gate wiring, and parallel to the gate wiring, and branched from the common wiring And a circular common electrode overlapping the pixel electrode, a second substrate disposed so as to face the first substrate, and a liquid crystal layer provided between the first substrate and the second substrate.

The pixel electrode and the common electrode are formed of a transparent conductive material.
The liquid crystal molecules of the liquid crystal layer are driven by an electric field parallel to the first substrate and the second substrate in a region corresponding to the opening of the common electrode and a region where the pixel electrode and the common electrode overlap.
The common electrode includes a first common electrode pattern having a circular opening and a ring-shaped second common electrode pattern positioned in the opening.
The overlapped common electrode and pixel electrode constitute a storage capacitor with an insulator interposed.

The second substrate further includes a black matrix having an opening exposing the pixel region and covering an end side of the common electrode on an inner surface of the second substrate. The opening is configured in a circular shape.
The pixel region may have a regular square shape. At this time, the pixel region corresponds to one subpixel, and red, green, blue, and white subpixels constitute one pixel.
The capacitor further includes a capacitor electrode connected to the pixel region and overlapping the previous gate line to form a storage capacitor.

  The thin film transistor includes a gate electrode branched from the gate wiring, a semiconductor layer overlapping the gate electrode, a source electrode branched from the data wiring, and a drain electrode spaced apart from the source electrode.

  Another FFS mode liquid crystal display device of the present invention includes a first substrate, a gate wiring formed on the first substrate, a data wiring defining a pixel region crossing the gate wiring, A thin film transistor connected to a gate line and a data line, a common line that is spaced apart from the gate line and is parallel to the gate line, and a branch from the common line, corresponding to the pixel region, has a substantially rectangular shape. Provided between a common electrode, a spiral pixel electrode connected to the thin film transistor and overlapping the common electrode, a second substrate disposed to face the first substrate, and the first substrate and the second substrate A liquid crystal layer.

  Another FFS mode liquid crystal display device of the present invention includes a first substrate, a gate wiring formed on the first substrate, a data wiring defining a pixel region crossing the gate wiring, A thin film transistor coupled to a gate wiring and a data wiring; a substantially rectangular pixel electrode coupled to the thin film transistor; spaced apart from the gate wiring; parallel to the gate wiring; and from the common wiring A common electrode that is branched and has a spiral opening and overlaps the pixel electrode, a second substrate that is disposed to face the first substrate, and a space between the first substrate and the second substrate. A liquid crystal layer.

  A method of manufacturing an FFS mode liquid crystal display device according to the present invention includes a step of forming a gate line on a substrate, a step of forming a data line defining a pixel region across the gate line, the gate line, Forming a thin film transistor connected to the data line; forming a common line spaced apart from the gate line and parallel to the gate line; and branching from the common line to form a substantially rectangular common Forming an electrode and forming a ring-shaped pixel electrode connected to the thin film transistor and overlapping the common electrode.

Here, the pixel electrode and the common electrode are formed of a transparent conductive material.
The step of forming the pixel electrode is performed after the step of forming the common electrode.
The pixel electrode includes a concentric circular or ring pattern.

  According to another aspect of the present invention, there is provided a method of manufacturing an FFS mode liquid crystal display device, comprising: forming a gate line on a substrate; forming a data line defining a pixel region across the gate line; Forming a thin film transistor connected to the wiring and the data wiring; forming a substantially rectangular pixel electrode connected to the thin film transistor; and being separated from the gate wiring and parallel to the gate wiring. Forming a wiring, and forming a circular common electrode branched from the common wiring and overlapping the pixel electrode.

Here, the pixel electrode and the common electrode are formed of a transparent conductive material.
The step of forming the common electrode is performed after the step of forming the pixel electrode.
The common wiring includes a first common wiring pattern having a circular opening and a ring-shaped second common wiring pattern located in the opening.

  According to another aspect of the present invention, there is provided a method of manufacturing an FFS mode liquid crystal display device, comprising: forming a gate line on a substrate; forming a data line defining a pixel region across the gate line; Forming a thin film transistor connected to the wiring and the data wiring; forming a common wiring spaced apart from the gate wiring and parallel to the gate wiring; and branching from the common wiring; Forming a common electrode; and forming a spiral pixel electrode connected to the thin film transistor and overlapping the common electrode.

  According to another aspect of the present invention, there is provided a method of manufacturing an FFS mode liquid crystal display device, comprising: forming a gate line on a substrate; forming a data line defining a pixel region across the gate line; Forming a thin film transistor connected to the wiring and the data wiring; forming a substantially rectangular pixel electrode connected to the thin film transistor; and being separated from the gate wiring and parallel to the gate wiring. Forming a wiring and forming a common electrode branched from the common wiring and overlapping the pixel electrode and having a spiral opening.

  Another FFS mode liquid crystal display device of the present invention includes a first substrate, a gate wiring on the first substrate, a data wiring crossing the gate wiring to define a pixel region, the gate wiring, A thin film transistor connected to the data line; a common line spaced in parallel to the gate line; a common electrode connected to the common line; a pixel electrode connected to the thin film transistor and overlapping the common electrode; A second substrate disposed to face the substrate, and a liquid crystal layer provided between the first substrate and the second substrate, wherein the pixel electrode and the common electrode have a potential between the pixel electrode and the common electrode. When the difference exists, the liquid crystals of the liquid crystal layer are arranged in a multi-domain structure arranged radially from the center of the pixel region.

At least one of the pixel electrode and the common electrode is bent, and at least one of the pixel electrode and the common electrode is substantially rectangular.
The electric field between the pixel electrode and the common electrode is independent and substantially constant with respect to the potential difference between the pixel electrode and the common electrode.

The pixel electrode and the common electrode have substantially different shapes.
At least one of the pixel electrode and the common electrode has a ring or the like, and a difference between radii or the like of successive rings or the like is substantially constant.
At least one of the pixel electrode and the common electrode has a spiral or the like, and the difference between the radii of the portions adjacent to the continuous side surfaces of the spiral or the like is substantially constant.
The pixel electrode and the common electrode overlap with another gate wiring.

  The liquid crystal display device further includes a black matrix having an opening that defines an aperture ratio of the pixel region. At this time, the opening is larger than the pixel electrode and smaller than the common electrode. A region where at least one of the pixel electrode and the common electrode overlaps with the black matrix is curved. The black matrix has a circular opening.

At least one of the pixel electrode and the common electrode is substantially symmetric with respect to all directions surrounding the center of the pixel electrode.
The common electrode is substantially square and has a substantially curved opening. At this time, the pixel electrode is smaller than the common electrode and larger than the opening of the common electrode.
At least one of the pixel electrode and the common electrode is elliptical.
The liquid crystal has no directionality.

At least one of the pixel electrode and the common electrode has a curved portion and a quadrangular portion.
One pixel of the display device includes a group of adjacent 2 ²ⁿ (n is an integer) pixel regions. At this time, the liquid crystal display device further includes color filters of different colors formed on the second substrate, and the group of adjacent pixel regions is 2 ^2m (m is smaller than n, or , The same integer) different color filters.

In the group of adjacent pixel regions, the pixel electrode and the common electrode of each pixel have the same shape.
In the group of adjacent pixel regions, at least one of the pixel electrode and the common electrode in the first pixel region is the pixel electrode formed in the second pixel region of the group of adjacent pixel regions or in common. The shape is different from the electrode.

  According to the FFS mode liquid crystal display device and the method of manufacturing the same according to the present invention, the electrode that forms the lateral electric field is positioned at the position where the first electrode that is formed so as to correspond to the pixel region and the first electrode overlap. Since it is composed of the second electrode having a circular electrode structure, the opening region between the first electrode and the second electrode has a circular structure, and the liquid crystal has no directivity and improves the viewing angle. In addition, the aperture ratio can be improved by applying a regular square pixel structure, the area where the black matrix overlaps is reduced, and the difference in brightness generated by products at the time of misalignment can be minimized. is there.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
5 and 6 are diagrams showing the pattern structure of the FFS mode circular electrode according to the present invention. FIG. 5 is a diagram showing the driving characteristics of the liquid crystal molecules by domain, and FIG. 6 is a diagram of a TV (Transmittance-Voltage) curve graph, in which the central part is the same, and from the inside. As an example, a structure in which lateral electric field electrodes (hereinafter abbreviated as circular electrodes) having a ring structure are arranged in this order can be presented.

  According to the circular electrode (CE) structure shown in FIG. 5, a multi-domain composed of four domains D1, D2, D3, and D4 defined by regions of the arrangement structure of different liquid crystal molecules 110 from each other. The domain-specific liquid crystal molecules 110 are arranged in the rubbing direction without being distinguished from one another when no voltage is applied, for example, in a 90 ° -270 ° direction, and then when a voltage is applied, Are arranged in a radial structure, generally perpendicular to the circular electrode CE.

  As shown in FIG. 6, the TV characteristic is characterized by the fact that the effect for each rubbing direction in the horizontal electric field electrode having the conventional stripe pattern structure is shown by one curve.

  Hereinafter, specific embodiments of the FFS mode liquid crystal display device having a circular electrode structure according to the present invention will be described in detail with reference to the drawings.

FIG. 7 is a plan view of the substrate for the FFS mode liquid crystal display device according to the first embodiment of the present invention.
As shown in the figure, the gate wiring 112 is formed in the first direction, the data wiring 128 is formed in the second direction intersecting the first direction, and corresponds to the gate wiring 112 in the first direction. Thus, the common wiring 142 is formed, and the intersection region of the gate wiring 112 and the data wiring 128 is defined by the pixel region P.
In the common wiring 142, a rectangular common electrode 144 corresponding to the pixel region P is formed for each pixel region P.

  A thin film transistor T is formed at the intersection of the gate line 112 and the data line 128, and a first pixel connection line 140 is formed connected to the thin film transistor T. In the first pixel connection line 140, a second pixel connection is formed. The wiring 141 is extended, and in the second pixel connection wiring 141, pixel electrodes 138 configured by a large number of circular patterns are branched.

  The pixel electrodes 138 have the same central portion, and are composed of a large number of patterns arranged in order from the inner side to the outer side. The first pixel electrode pattern 138a and the second pixel electrode pattern are formed from the central portion to the outer side. 138b and the third pixel electrode pattern 138c form a structure in order.

In the FFS mode according to the present embodiment, not only the separation region between the pixel electrode 138 patterns but also the region where the pixel electrode 138 and the common electrode 144 overlap is used as the opening region. Therefore, the pixel electrode 138 and the common electrode 144 are An example is indium-tin-oxide ITO selected from transparent conductive materials.
In the case of the FFS mode according to the present invention, a region where the pixel electrode 138 and the common electrode 144 are overlapped with an insulator (not shown) can be stored without an additional storage capacitor. A capacitor Cst is formed.

  The shaded area in the drawing is the black matrix forming area BA, and the black matrix (not shown) is located on the opposite substrate or the same substrate and serves to block light in the area where the liquid crystal is not driven. To do. The black matrix formation area BA includes an open portion 146 that exposes a main area of the pixel area, and is formed in an area including a non-pixel area and a frame portion of the common electrode 144, and is larger than, for example, the third pixel electrode pattern 138c. The size can be formed in a circular structure.

FIGS. 8 to 13 are diagrams illustrating a manufacturing process of an FFS mode liquid crystal display device substrate according to a six mask process according to the first embodiment of the present invention.
A brief description will be given focusing on circular electrodes. The mask process described above is a process for patterning by a photo-etching process using a photosensitive material.

  FIG. 8 is a stage in which a gate wiring 112 having a gate electrode 116 is formed on the substrate 110 in the first direction by a first mask process.

  9 shows a step of forming a gate insulating film (not shown) in a region covering the gate wiring 112 and a step of forming a semiconductor layer 122 in a region covering the gate electrode 116 by a second mask process. FIG. 10 illustrates an island pattern that is separated from the data line 128, the source electrode 130 branched from the data line 128, and the source electrode 130 in a second direction intersecting the first direction by a third mask process. This is the step of forming the drain electrode 132 constituted by

A region where the gate line 112 and the data line 128 intersect is defined by a pixel region P.
The source electrode 130 and the drain electrode 132 are positioned to overlap both sides of the semiconductor layer 122.
Through this stage, the gate electrode 116, the semiconductor layer 122, the source electrode 130, and the drain electrode 132 constitute a thin film transistor T.

  Exposing the intrinsic semiconductor material of the semiconductor layer 122 located in the separation between the source electrode 130 and the drain electrode 132 and configuring the exposed intrinsic semiconductor material region as a channel Ch.

  FIG. 11 includes a step of forming a protective layer (not shown) on the entire surface of the substrate including the thin film transistor T, and is separated from the gate wiring 112 in the first direction on the protective layer by a fourth mask process. In this step, the common wiring 134 positioned so as to form a common electrode 136 that branches into a rectangular pattern corresponding to the pixel region P in units of the pixel region P by the common wiring 134.

  FIG. 12 shows a step of forming an insulating layer (not shown) on the entire surface of the substrate covering the common wiring 134 and the common electrode 136, and the drain electrode 132 is formed on the insulating layer and the protective layer by a fifth mask process. This is a step of forming a drain contact hole 138 to be partially exposed.

  FIG. 13 illustrates a first pixel connection line 140 connected to the drain electrode 132 through the drain contact hole 138 and a first pixel connection line 140 on the insulating layer including the drain contact hole 138 by a sixth mask process. The second pixel connection line 142 extended in the second direction and the pixel electrode 144 branched from the second pixel connection line 142 are formed.

The pixel electrodes 144 are configured by a number of patterns having a circular structure formed in order so as to be spaced apart from each other from the inside to the outside at the same central portion.
More specifically, a first pixel electrode pattern 144a configured in a circular pattern at the center, a second pixel electrode pattern 144b configured in a ring shape on the outer periphery of the first pixel electrode pattern 144a, and a second pixel electrode The outer periphery of the pattern 144b includes a third pixel electrode pattern 144c configured in a ring shape.
It is important that the common electrode 136 and the pixel electrode 144 are located in an overlapping region.

  Hereinafter, a process of manufacturing the FFS mode liquid crystal display device by a low mask process in which the number of masks is reduced from the manufacturing process according to the first embodiment will be described.

FIGS. 14 to 18 are plan views showing the manufacturing process of the FFS mode liquid crystal display device with five masks according to the second embodiment of the present invention in stages, and the description of the steps overlapping with the five mask processes according to the first embodiment. Keep it simple.
FIG. 14 is a step of forming the gate wiring 212 and the gate electrode 216 on the substrate 210 by the first mask process by the same method as in FIG.

  FIG. 15 shows a step of forming a gate insulating film (not shown) in a region covering the gate wiring 212 and the gate electrode 216, and a diffractive exposure after sequentially laminating a semiconductor material and a metal material on the gate insulating film. A data mask 228, a source electrode 230, and a drain electrode 232 are formed using the metal material by a second mask process including a method, and a pattern structure corresponding to the data wire 228, the source electrode 230, and the drain electrode 232 is formed. The semiconductor material layer 225 is formed from a semiconductor material. The semiconductor material layer 225 includes an interval between the source electrode 230 and the drain electrode 232, and the semiconductor material layer 225 at a position corresponding to the source electrode 230 and the drain electrode 232 includes a semiconductor region (SC; semiconductor). area).

The gate electrode 216, the semiconductor region SC of the semiconductor material layer 225, the source electrode 230, and the drain electrode 232 form a thin film transistor T.
In this step, a channel Ch is formed by exposing a pure semiconductor region of the semiconductor material layer 225 located in a distance between the source electrode 230 and the drain electrode 232 by a diffraction exposure method.

  For example, when using a positive type photosensitive material that removes the exposed part, a mask with a slit part is placed at a position corresponding to the channel part, and the pattern part is to be formed in the channel part. As a method of forming a thin photosensitive material layer, a semiconductor process and a source / drain process can be performed simultaneously in one mask process.

  FIG. 16 shows a step of forming a protective layer (not shown) on the entire surface of the substrate covering the thin film transistor T, and a step of forming a common wiring 234 and a common electrode 236 on the protective layer by a third mask process. is there.

  The material constituting the common wiring 234 and the common electrode 236 is selected from transparent conductive materials, and an example is indium-tin-oxide ITO.

  FIG. 17 shows a step of forming an insulating layer (not shown) in a region covering the common wiring 234 and the common electrode 236, and partially exposing the drain electrode 232 to the insulating layer and the protective layer by a fourth mask process. In this step, the drain contact hole 238 is formed.

  FIG. 18 illustrates a first pixel connection line 240 connected to the drain electrode 232 through the drain contact hole 238 by a fifth mask process on the insulating layer including the drain contact hole 238, and the first pixel connection line. In this step, the second pixel connection line 242 extended at 240 and the circular pixel electrode 244 branched from the second pixel connection line 242 are formed.

The pixel electrode 244 includes a plurality of patterns, and the structure described above with reference to FIG. 12 can be applied as a specific pattern structure.
That is, the pixel electrode 244 includes a first pixel electrode pattern 244a, a second pixel electrode pattern 244b, and a third pixel electrode pattern 244c.
The material constituting the pixel electrode 244 is selected from a transparent conductive material, like the common electrode 236, such as indium-tin-oxide ITO.

  Hereinafter, in another embodiment of the present invention, a spiral electrode structure is presented as another pattern structure of a circular electrode structure.

  FIG. 19 is a plan view of a substrate for an FFS mode liquid crystal display device according to a third embodiment of the present invention, and shows a spiral electrode structure. Since the part except Example 1 and the circular electrode structure can be applied in the same manner, the description regarding the overlapping part is omitted.

  As shown in the drawing, a square-shaped common electrode 344 is formed in the pixel region P connected to the common wiring 342, and a first pixel connection wiring 340 is formed connected to the thin film transistor T. A pixel electrode 338 having a spiral structure is formed in a region extending from the wiring 340 and overlapping the common electrode 344.

  In the case of the first embodiment, assuming that the pixel electrode is configured by a combination of a large number of ring structures configured by closed curves, in the present embodiment, one pixel electrode does not have a separate second pixel connection wiring, and the inner side from the outside. It is characterized in that it is formed in a spiral shape while maintaining a constant interval from the inside to the outside.

  This structure is also characterized in that the liquid crystal is driven by a lateral electric field in the separation region between the spiral patterns of the pixel electrode 338 and the overlapping region of the pixel electrode 338 and the common electrode 344. The pixel electrode 338 and the common electrode 344 are selected from transparent conductive materials, and an example is indium-tin-oxide ITO.

The region where the pixel electrode 338 and the common electrode 344 overlap constitutes a storage capacitor Cst with an insulator (not shown) interposed therebetween.
A region shown by hatching in the drawing corresponds to a black matrix area (BA) having a circular open portion 346 exposing the pixel electrode 338.

  FIGS. 20 to 22 are plan views showing the steps of manufacturing the FFS mode lateral electric field type liquid crystal display substrate of the spiral structure by the six mask process according to the third embodiment of the present invention. Since the mask process through the fourth mask process can be applied in the same manner as in the first embodiment, they are shown in one drawing.

  FIG. 20 shows a step of forming the gate wiring 312 and the gate electrode 316 by the first mask process, a step of forming the semiconductor layer 322 by the second mask process, and the data wiring 388, the source electrode 330, the drain by the third mask process. Forming a thin film transistor T including the gate electrode 316, the semiconductor layer 322, the source electrode 330, and the drain electrode 332 by forming an electrode 332; and using the mask for the source electrode 330 and the drain electrode 332 Forming a channel Ch composed of an intrinsic semiconductor material region.

  A step of forming a protective layer (not shown) on the entire surface of the substrate including the thin film transistor T, and a top portion of the protective layer (not shown) are positioned in parallel with the gate wiring 312 by a fourth mask process, The method includes a step of forming a common wiring 334 having a square-shaped common electrode 336 corresponding to the pixel region P.

  FIG. 21 shows a step of forming an insulating layer (not shown) on the entire surface of the substrate including the common wiring 334 and the common electrode 336, and the drain electrode 332 is formed on the insulating layer and the protective layer by a fifth mask process. This is a step of forming a drain contact hole 338 to be partially exposed.

  FIG. 22 illustrates a pixel connection line 340 connected to the drain electrode 332 through the drain contact hole 338 and an extension of the pixel connection line 340 on the insulating layer including the drain contact hole 338 by a sixth mask process. The pixel electrode 344 having a spiral structure is formed.

  Hereinafter, a process of manufacturing a substrate for an FFS mode liquid crystal display device having a spiral electrode structure according to a process in which the number of mask processes is reduced from the manufacturing process according to the third embodiment will be described.

23 to 25 are plan views showing a process of manufacturing a substrate for an FFS mode liquid crystal display device according to the five mask process according to the fourth embodiment of the present invention.
23 shows a step of forming the gate wiring 412 and the gate electrode 416 by the first mask process, and the data wiring 428, the source electrode 430, and the drain electrode 432 by the second mask process, and the data wiring 428, the source electrode 430, and the drain. A step of forming a semiconductor material layer 425 having a semiconductor region SC in a pattern structure corresponding to the electrode 432 and corresponding to the source electrode 430 and the drain electrode 432 is included.

  The gate electrode 416, the semiconductor region SC of the semiconductor material layer 425, the source electrode 430, and the drain electrode 432 constitute a thin film transistor T, including the step of forming a channel Ch by a diffraction exposure method in the same mask process. A step of forming a protective layer (not shown) on the entire surface of the substrate in a region covering the thin film transistor T, and a third mask process on the protective layer (not shown) in parallel with the gate wiring 412. It is a step of forming a common wiring 434 located and having a square-shaped common electrode 436 corresponding to the pixel region P.

  FIG. 24 shows a step of forming an insulating layer (not shown) on the entire surface of the substrate including the common wiring 434 and the common electrode 436, and the drain electrode 432 is formed on the insulating layer and the protective layer by a fourth mask process. This is a step of forming a drain contact hole 438 to be partially exposed.

  25, a pixel connection line 440 connected to the drain electrode 432 through the drain contact hole 438 and the pixel connection line 440 are formed on the insulating layer including the drain contact hole 438 by a fifth mask process. Forming a pixel electrode 444 having a spiral structure.

  FIG. 26 and FIG. 27 are diagrams for explaining the degree of decrease in aperture ratio at the time of misalignment due to the pattern structure of the horizontal electric field electrode. FIG. 26 is a diagram of a conventional stripe pattern type lateral field electrode, and FIG. 27 is a diagram of a circular pattern type lateral field electrode according to the present invention.

  As shown in the figure, misalignment occurs in the bonding process of the substrates 450 and 470 on which the horizontal electric field electrodes (IE1, IE2; In-plane Electrode) are formed and the substrates 460 and 480 on which the black matrices BM1 and BM2 are formed. In this case, the black matrixes BM1 and BM2 exceed the design value, and the area where the horizontal electric field electrodes IE1 and IE2 overlap is enlarged, and such misalignment causes a reduction in the opening area.

In the case of FIG. 26, the region R1 where the black matrix BM1 and the horizontal electric field electrode IE1 overlap is entirely overlapped in the length direction of the horizontal electric field electrode IE1 due to the pattern structure of the horizontal electric field electrode IE1, but in the case of FIG. Since the horizontal electric field electrode IE2 according to the present invention has a circular electrode structure, the region R2 where the black matrix BM2 and the horizontal electric field electrode IE2 overlap is greatly reduced as compared with FIG.
Therefore, according to the circular electrode structure according to the present invention, the bonding process margin is increased, so that the difference in brightness between products is reduced.

  Hereinafter, another embodiment of the present invention provides an improved structure of a storage capacitor.

FIG. 28 is a plan view of the FFS mode liquid crystal display device according to the fifth embodiment of the present invention, and the features that are distinguished from the first embodiment will be mainly described.
As illustrated, in the third pixel electrode pattern 538 c that is the outermost corner pattern of the pixel electrode 538, the capacitor electrode 540 is extended so as to overlap the previous-stage gate wiring 512.

  That is, the storage capacitor Cst 1 is the sum of the first storage capacitor Cst1 in the region where the pixel electrode 538 and the common electrode 520 overlap and the second storage capacitor Cst2 in the region where the capacitor electrode 540 and the gate wiring overlap. By being configured, the liquid crystal is stably driven with an increase in the storage capacitor Cst than the structure according to the first and third embodiments.

  Hereinafter, in another embodiment of the present invention, in order to improve the aperture ratio, a red-red, green-green, blue-blue, and white-white subpixel having a regular square structure is a four-color pixel structure that constitutes one pixel. An FFS mode liquid crystal display device with a circular electrode structure is presented.

FIG. 29 is a plan view of an FFS mode liquid crystal display device according to a sixth embodiment of the present invention, and relates to a red, green, blue, and white four-color pixel structure formed of a regular square.
In general, in the three-color pixel structure of red, green, and blue, subpixels are formed in a rectangular shape, and the shortened width in the pixel region determines the radius of the circular electrode, and the dummy region other than the circular electrode is considerably large. By occupying a large specific gravity, there was a limit to improving the aperture ratio.

However, in the regular rectangular pixel structure, since the distance from the center to the four sides of the pixel region is the same, there is no problem in determining the radius of the circular electrode, and the specific gravity occupied by the dummy region other than the circular electrode is greatly reduced. As a result, the aperture ratio can be effectively improved.
As shown in the drawing, four subpixels of red 602, green 604, blue 606, and white 608 formed by regular squares form a FPS mode liquid crystal display having a circular electrode structure of a four-color pixel structure forming one pixel PX. When the device is applied, the utilization efficiency of the pixel region can be increased and the aperture ratio can be effectively increased.

  Hereinafter, an embodiment in which the pixel electrode is formed in a square shape and the common electrode has a circular structure will be presented.

  30 and 31 are plan views of an FFS mode liquid crystal display device according to a seventh embodiment of the present invention, in which FIG. 30 is a ring structure and FIG. 31 is an FFS mode liquid crystal display device including a common electrode having a spiral structure. Therefore, the characteristic part which is distinguished from the first embodiment will be mainly described.

  In this embodiment, the pixel electrodes 738 and 838 are formed in a square shape at a position corresponding to the pixel region P, and the common electrodes 744 and 844 are formed in a circular structure at a position where the pixel electrodes 738 and 838 overlap. It is characterized by.

  Also in this structure, the region where the pixel electrodes 738 and 838 overlap with the common electrodes 744 and 844 constitutes the storage capacitor Cst with an insulator (not shown) interposed therebetween, and the pixel electrodes 738 and 838 and the common electrode The material constituting 744 and 844 is selected from transparent conductive materials. For example, the material is formed of indium-tin-oxide ITO, and a separation section between the common electrodes 744 and 844 and a region where both electrodes overlap each other are openings. By configuring the region and forming the opening region in a circular structure as in the first embodiment, the viewing angle characteristics are improved.

  The common electrode 744 according to FIG. 30 has a ring structure, and the common electrode 844 according to FIG. 31 has a spiral structure.

  More specifically, the common electrode 744 according to FIG. 30 has a circular open portion 746, and a first common electrode pattern 744a and a first common electrode pattern 744a located in a region covering the frame portion of the pixel region P. And a second common electrode pattern 744b positioned in a ring structure. In addition, the pixel electrode 738 is larger in size than the open portion 746 inside the first common electrode pattern 744a.

  The common electrode 844 according to FIG. 31 has a spiral open portion 846 and is located in a region surrounding the frame portion of the pixel region P. The pixel electrode 838 is larger than the open portion 846 inside the common electrode 844. Size.

Further, the structure and manufacturing process according to the first to sixth embodiments can be applied, including the characteristic structure according to the present embodiment.
However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the circular electrode structure according to the present invention corresponds to a structure including an elliptical structure.

It is a figure for demonstrating the drive principle of a general horizontal electric field type liquid crystal display device. It is a schematic plan view of an array substrate for a general horizontal electric field type liquid crystal display device. It is a top view of a common FFS mode liquid crystal display device. FIG. 4 is a cross-sectional view showing a cross section taken along the line IIIB-IIIB in FIG. 3. FIG. 4 is a diagram of a pattern structure of an FFS mode circular electrode according to the present invention, showing characteristics of driving liquid crystal molecules by domain. FIG. 4 is a diagram of a pattern structure of an FFS mode circular electrode according to the present invention, and is a curve graph of transmittance-voltage (TV) characteristics. It is a top view of the board | substrate for FFS mode liquid crystal display devices by Example 1 of this invention. It is the figure which showed the manufacturing process of the board | substrate for FFS mode liquid crystal display devices by Example 1 of this invention according to the step. FIG. 9 is a plan view illustrating a process following the process in FIG. 8. FIG. 10 is a plan view illustrating a process following the process in FIG. 9. FIG. 11 is a plan view illustrating a process following FIG. 10. FIG. 12 is a plan view illustrating a process following the process in FIG. 11. FIG. 13 is a plan view illustrating a process following the process in FIG. 12. It is the top view which showed the manufacturing process of the board | substrate for FFS mode liquid crystal display devices by Example 2 of this invention according to the step. FIG. 15 is a plan view illustrating a process following the process in FIG. 14. FIG. 16 is a plan view illustrating a process following the process in FIG. 15. FIG. 17 is a plan view illustrating a process following the process in FIG. 16. FIG. 18 is a plan view illustrating a process following the process in FIG. 17. It is a top view of the board | substrate for FFS mode liquid crystal display devices by Example 3 of this invention. It is the top view which showed the manufacturing process of the board | substrate for liquid crystal display devices of the horizontal electric field type of a spiral FFS mode by Example 3 of this invention according to the step. FIG. 21 is a plan view illustrating a process following the process in FIG. 20. FIG. 22 is a plan view illustrating a process following the process in FIG. 21. It is the top view which showed the manufacturing process of the board | substrate for FFS mode liquid crystal display devices by Example 4 of this invention according to the step. FIG. 24 is a plan view illustrating a process following the process in FIG. 23. FIG. 25 is a plan view illustrating a process following the process in FIG. 24. It is a figure for demonstrating the grade of the reduction | decrease of the aperture ratio at the time of the joining misalignment by a horizontal electric field type pattern structure, Comprising: It is a figure of the horizontal electric field electrode of the conventional stripe pattern type. It is a figure for demonstrating the grade of the reduction | decrease of the aperture ratio at the time of the joint misalignment by a horizontal electric field type pattern structure, Comprising: It is a figure of the circular pattern type horizontal electric field electrode by this invention. It is a top view of the FFS mode liquid crystal display device by Example 5 of this invention. It is a top view of the FFS mode liquid crystal display device by Example 6 of this invention. It is a top view of the FFS mode liquid crystal display device by Example 7 of this invention. It is a top view of the FFS mode liquid crystal display device by Example 7 of this invention.

Explanation of symbols

112: Gate wiring 128: Data wiring 138a: First pixel electrode pattern 138b: Second pixel electrode pattern 138c: Third pixel electrode pattern 138: Pixel electrode
140: first pixel connection wiring 141: second pixel connection wiring 142: common wiring 144: common electrode 146: open portion
BA: Black matrix formation region Cst: Storage capacitor P: Pixel region T: Thin film transistor

Claims (44)

A first substrate;
A gate wiring formed on the first substrate;
Data wiring crossing the gate wiring to define a pixel region;
A thin film transistor connected to the gate line and the data line;
A common wiring separated from the gate wiring and parallel to the gate wiring;
A common electrode branched from the common wiring and substantially formed in a rectangular shape corresponding to the pixel region;
A ring-shaped pixel electrode connected to the thin film transistor and overlapping the common electrode;
A second substrate disposed to face the first substrate;
An FFS mode liquid crystal display device including a liquid crystal layer provided between the first substrate and the second substrate. 2. The FFS mode liquid crystal display device according to claim 1, further comprising a pixel connection line between the thin film transistor and the pixel electrode. 2. The FFS mode liquid crystal display device according to claim 1, wherein the pixel electrode and the common electrode are made of a transparent conductive material. The liquid crystal molecules of the liquid crystal layer are driven by an electric field parallel to the first substrate and the second substrate in a region between the pixel electrode patterns and a region where the pixel electrode and the common electrode overlap. The FFS mode liquid crystal display device according to claim 1. The FFS mode liquid crystal display device according to claim 1, wherein the pixel electrode includes a circular pattern and a ring-shaped pattern. 6. The FFS mode liquid crystal display device according to claim 5, wherein the pattern of the pixel electrodes is concentric. The pixel electrode includes a circular first pixel electrode pattern, a ring-shaped second pixel electrode pattern, and a third pixel electrode pattern, and the first pixel electrode pattern is located inside the third pixel electrode pattern. 7. The FFS mode liquid crystal display device according to claim 6, wherein the second pixel electrode pattern is located between the first pixel electrode pattern and the third pixel electrode pattern. 2. The FFS mode liquid crystal display device according to claim 1, wherein the overlapped common electrode and pixel electrode constitute a storage capacitor in a state where an insulator is interposed. 2. The FFS mode liquid crystal display device according to claim 1, further comprising a black matrix having an opening exposing the pixel region on an inner surface of the second substrate and covering an end side of the common electrode. . The FFS mode liquid crystal display device according to claim 9, wherein the opening is circular. 2. The FFS mode liquid crystal display device according to claim 1, wherein the pixel region has a regular square shape. 12. The FFS mode liquid crystal display device according to claim 11, wherein in the pixel area, red, green, blue, and white subpixels constitute one pixel corresponding to one subpixel. The FFS mode liquid crystal display device according to claim 1, further comprising a capacitor electrode connected to the pixel region and overlapping the previous gate line to form a storage capacitor. The thin film transistor includes a gate electrode branched from the gate wiring, a semiconductor layer overlapping with the gate electrode, a source electrode branched from the data wiring, and a drain electrode separated from the source electrode. The FFS mode liquid crystal display device according to claim 1. A first substrate;
A gate wiring formed on the first substrate;
Data wiring crossing the gate wiring to define a pixel region;
A thin film transistor connected to the gate line and the data line;
A substantially rectangular pixel electrode coupled to the thin film transistor;
A common wiring separated from the gate wiring and parallel to the gate wiring;
A circular common electrode branched from the common wiring and overlapping the pixel electrode;
A second substrate disposed to face the first substrate;
An FFS mode liquid crystal display device including a liquid crystal layer provided between the first substrate and the second substrate. 16. The FFS mode liquid crystal display device according to claim 15, wherein the pixel electrode and the common electrode are made of a transparent conductive material. The liquid crystal molecules of the liquid crystal layer are driven by a parallel electric field on the first substrate and the second substrate in a region corresponding to the opening of the common electrode and a region where the pixel electrode and the common electrode overlap. The FFS mode liquid crystal display device according to claim 15. 16. The FFS mode liquid crystal according to claim 15, wherein the common electrode includes a first common electrode pattern having a circular opening, and a ring-shaped second common electrode pattern positioned in the opening. Display device. 16. The FFS mode liquid crystal display device according to claim 15, wherein the overlapped common electrode and pixel electrode constitute a storage capacitor with an insulator interposed therebetween. 16. The FFS mode liquid crystal display device according to claim 15, further comprising a black matrix having an opening for exposing the pixel region on an inner surface of the second substrate and covering an end side of the common electrode. . 21. The FFS mode liquid crystal display device according to claim 20, wherein the opening is circular. 16. The FFS mode liquid crystal display device according to claim 15, wherein the pixel region has a regular square shape. 23. The FFS mode liquid crystal display device according to claim 22, wherein in the pixel area, red, green, blue, and white subpixels constitute one pixel corresponding to one subpixel. 16. The FFS mode liquid crystal display device according to claim 15, further comprising a capacitor electrode connected to the pixel region and overlapping the previous gate line to form a storage capacitor. The thin film transistor includes a gate electrode branched from the gate wiring, a semiconductor layer overlapping with the gate electrode, a source electrode branched from the data wiring, and a drain electrode separated from the source electrode. The FFS mode liquid crystal display device according to claim 15. A first substrate;
A gate wiring formed on the first substrate;
Data wiring crossing the gate wiring to define a pixel region;
A thin film transistor connected to the gate line and the data line;
A common wiring separated from the gate wiring and parallel to the gate wiring;
A substantially quadrangular common electrode branched from the common wiring and corresponding to the pixel region;
A spiral pixel electrode connected to the thin film transistor and overlapping the common electrode;
A second substrate disposed to face the first substrate;
An FFS mode liquid crystal display device including a liquid crystal layer provided between the first substrate and the second substrate. A first substrate;
A gate wiring formed on the first substrate;
Data wiring crossing the gate wiring to define a pixel region;
A thin film transistor connected to the gate line and the data line;
A substantially rectangular pixel electrode coupled to the thin film transistor;
A common wiring separated from the gate wiring and parallel to the gate wiring;
A common electrode branched from the common wiring, having a spiral opening, and overlapping the pixel electrode;
A second substrate disposed to face the first substrate;
An FFS mode liquid crystal display device including a liquid crystal layer provided between the first substrate and the second substrate. Forming a gate wiring on the substrate;
Forming a data line defining a pixel region crossing the gate line;
Forming a thin film transistor connected to the gate line and the data line;
Forming a common wiring spaced apart from the gate wiring and parallel to the gate wiring;
An FFS mode liquid crystal display device comprising: a step of forming a substantially rectangular common electrode branched from the common line; and a step of forming a ring-shaped pixel electrode connected to the thin film transistor and overlapping the common electrode Manufacturing method. The pixel electrode and the common electrode, the manufacturing method of the FFS mode liquid crystal display device according to claim 28, characterized in that it is formed of a transparent conductive material. 29. The method of manufacturing an FFS mode liquid crystal display device according to claim 28, wherein the step of forming the pixel electrode is performed after the step of forming the common electrode. 29. The method of manufacturing an FFS mode liquid crystal display device according to claim 28, wherein the pixel electrode includes concentric circular and ring patterns. Forming a gate wiring on the substrate;
Forming a data line defining a pixel region crossing the gate line;
Forming a thin film transistor connected to the gate line and the data line;
Forming a substantially rectangular pixel electrode connected to the thin film transistor;
A method of manufacturing an FFS mode liquid crystal display device, comprising: forming a common line that is separated from the gate line and parallel to the gate line; and forming a circular common electrode that is branched from the common line and overlaps the pixel electrode . The pixel electrode and the common electrode, the manufacturing method of the FFS mode liquid crystal display device according to claim 32, characterized in that it is formed of a transparent conductive material. The method of manufacturing an FFS mode liquid crystal display device according to claim 32, wherein the step of forming the common electrode is performed after the step of forming the pixel electrode. The FFS mode liquid crystal according to claim 32, wherein the common wiring includes a first common wiring pattern having a circular opening and a ring-shaped second common wiring pattern located in the opening. Manufacturing method of display device. Forming a gate wiring on the substrate;
Forming a data line defining a pixel region crossing the gate line;
Forming a thin film transistor connected to the gate line and the data line;
Forming a common wiring spaced apart from the gate wiring and parallel to the gate wiring;
An FFS mode liquid crystal display device, comprising: a step of forming a substantially rectangular common electrode branched from the common line; and a step of forming a spiral pixel electrode connected to the thin film transistor and overlapping the common electrode. Production method. Forming a gate wiring on the substrate;
Forming a data line defining a pixel region crossing the gate line;
Forming a thin film transistor connected to the gate line and the data line;
Forming a substantially rectangular pixel electrode connected to the thin film transistor;
An FFS mode including a step of forming a common wire that is spaced apart from the gate wire and parallel to the gate wire; and a step of forming a common electrode that is branched from the common wire and overlaps the pixel electrode and has a spiral opening. A method for manufacturing a liquid crystal display device. A first substrate;
A gate wiring formed on the first substrate;
Data wiring crossing the gate wiring to define a pixel region;
A thin film transistor connected to the gate line and the data line;
A common wiring separated from the gate wiring and parallel to the gate wiring;
A common electrode extended from the common wiring;
A pixel electrode connected to the thin film transistor;
A second substrate disposed to face the first substrate;
A liquid crystal layer provided between the first substrate and the second substrate;
A liquid crystal display device in which one of the common electrode and the pixel electrode has a substantially rectangular shape, the other has a curved shape, and the pixel electrode and the common electrode overlap each other.   The liquid crystal display device according to claim 38, wherein the curved electrode has a ring shape.   The liquid crystal display device according to claim 38, wherein the curved electrode has a spiral shape.   40. The liquid crystal display device according to claim 38, wherein the substantially rectangular electrode is substantially square.   The liquid crystal display device according to claim 38, wherein the common electrode is substantially rectangular.   The liquid crystal display device according to claim 38, wherein the pixel electrode has a curved shape. 39. The liquid crystal display device according to claim 38, wherein the overlapping pixel electrode and common electrode constitute an accumulation procedure with an insulating layer interposed therebetween.

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