KR20060074554A - Thin film transistor array panel - Google Patents

Abstract

According to an exemplary embodiment of the present invention, a thin film transistor array panel includes an insulating substrate, a gate line formed on the insulating substrate, a capacitive auxiliary electrode separated from the gate line, a data line insulated from and intersecting the gate line, respective gate lines and data lines; A thin film transistor having a drain electrode, a capacitive coupling electrode overlapping the capacitive auxiliary electrode and connected to the drain electrode, and a first pixel electrode and a capacitive auxiliary electrode connected to the drain electrode. And a pixel electrode having two pixel electrodes. One of the capacitive auxiliary electrode or the capacitive coupling electrode has a groove passing through the boundary line of the capacitive auxiliary electrode or the capacitive coupling electrode.

Capacitive coupling, pixel defect, capacitive coupling electrode, capacitive auxiliary electrode

Description

Thin Film Transistor Display Panels {THIN FILM TRANSISTOR ARRAY PANEL}

1 is a layout view illustrating a structure of a thin film transistor array panel for a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 is a layout view illustrating a structure of a common electrode display panel of a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a layout view illustrating a structure of a liquid crystal display according to an exemplary embodiment including the two display panels of FIGS. 1 and 2.

4 and 5 are cross-sectional views of the liquid crystal display of FIG. 3 taken along lines IV-IV 'and V-V', respectively;

6 is a circuit diagram of a liquid crystal display according to an exemplary embodiment of the present invention.

7 is a layout view illustrating a structure of a liquid crystal display according to another exemplary embodiment of the present invention.

8 and 9 are cross-sectional views of the liquid crystal display of FIG. 7 taken along the lines VIII-VIII 'and IX-IX', respectively.

Explanation of reference numbers

11, 21: alignment film 12, 22: polarizing plate

81, 82: contact auxiliary member                 

100, 200: display panel 110, 210: insulating substrate

121: gate line 124: gate electrode

131a and 131b: sustain electrode line 135a and 135b: sustain electrode

136: capacitive auxiliary electrode 140: gate insulating film

151 and 154: semiconductors 161, 163 and 165: ohmic contact members

171 and 179: data line 173: source electrode

175a and 175b: drain electrodes 176a and 176b: capacitive coupling electrodes

180: protective film 181, 182, 185a, 185b, 186: contact hole

190: pixel electrode 220: light blocking member

250: overcoat 270: common electrode

91, 92, 93a, 93b, 94a, 94b, 95a, 95b: cutout of the pixel electrode

71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b: cutout of common electrode

3: liquid crystal layer 310: liquid crystal molecules

The present invention relates to a thin film transistor array panel, and more particularly, to a thin film transistor array panel used in a liquid crystal display device in which pixels are divided into multiple domains.

The liquid crystal display is one of the most widely used flat panel display devices. The liquid crystal display includes two display panels on which field generating electrodes, such as a pixel electrode and a common electrode, are formed, and a liquid crystal layer interposed therebetween. Is applied to generate an electric field in the liquid crystal layer, thereby determining the orientation of liquid crystal molecules in the liquid crystal layer and controlling the polarization of incident light to display an image.

Among them, the vertical alignment mode liquid crystal display in which the long axis of the liquid crystal molecules are arranged perpendicular to the upper and lower display panels without an electric field applied to the display panel is high in contrast ratio and easy to implement a wide viewing angle.

Means for implementing a wide viewing angle in a vertical alignment mode liquid crystal display include a method of forming a cutout in the field generating electrode and a method of forming a protrusion on the field generating electrode. Since the direction in which the liquid crystal molecules are inclined by the cutout and the protrusion can be determined, the wide viewing angle can be secured by dispersing the inclination directions of the liquid crystal molecules in various directions.

However, the liquid crystal display of the vertical alignment type has a problem in that the side visibility is inferior to the front visibility.

In addition, one of the causes of the increase in manufacturing cost in the process of manufacturing a liquid crystal display is pixel defects. Among them, white defects, in which pixels are always bright, are easily noticeable. It is desirable to repair by replacing black defects where the pixels are always dark so that they are not possible.

 SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a thin film transistor array panel capable of stably securing visibility.

Another object of the present invention is to provide a thin film transistor array panel which can easily repair pixel defects.

In order to solve this problem, the present invention divides the pixel electrode into at least two or more sub pixel electrodes and combines the sub pixel electrodes in a capacitive manner so that different potentials are applied. In this case, the capacitive coupling electrode and the capacitive auxiliary electrode forming the capacitive coupling have two boundary lines that cross each other, and have portions that do not overlap each other, thereby repairing pixel defects.

According to an exemplary embodiment of the present invention, a thin film transistor array panel includes an insulating substrate, a gate line formed on the insulating substrate, a capacitive auxiliary electrode separated from the gate line, a data line insulated from and intersecting the gate line, respective gate lines and data lines; A thin film transistor having a drain electrode, overlapping the capacitive auxiliary electrode, a capacitive coupling electrode connected to the drain electrode, and a first pixel electrode and a capacitive auxiliary electrode connected to the drain electrode. And a pixel electrode including a second pixel electrode. One of the capacitive auxiliary electrode or the capacitive coupling electrode has a groove passing through the boundary line of the capacitive auxiliary electrode or the capacitive coupling electrode.

The capacitive auxiliary electrode and the capacitive coupling electrode preferably have grooves facing each other.                     

Preferably, the capacitive coupling electrode has an opening that exposes the gate insulating layer on the capacitive auxiliary electrode, and a contact hole connecting the capacitive auxiliary electrode and the second pixel electrode is preferably disposed in the opening. And the grooves of the capacitive auxiliary electrode are preferably arranged at both sides of the opening, respectively.

The drain electrode is disposed above and below the capacitive coupling electrode, and preferably includes an extension part connected to the capacitive coupling electrode through the connection part, and the first pixel electrode is divided into at least two parts. The portions are preferably connected to the two extensions, respectively.

The storage electrode line may further include a storage electrode line having a storage electrode overlapping the drain electrode, and the storage electrode lines may be formed in pairs so that the storage electrodes overlap the two extensions.

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Next, a thin film transistor array panel and a liquid crystal display including the same according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

First, a liquid crystal display according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6.

FIG. 1 is a layout view illustrating a structure of a thin film transistor array panel for a liquid crystal display according to an exemplary embodiment. FIG. 2 is a layout view illustrating a structure of a common electrode display panel for a liquid crystal display according to an exemplary embodiment. 3 is a layout view illustrating a structure of a liquid crystal display device including the thin film transistor array panel of FIG. 1 and the thin film transistor array panel of FIG. 2, and FIGS. 4 and 5 are IV-IV ′ lines of the liquid crystal display of FIG. 6 is a cross-sectional view taken along the line VV ′, and FIG. 6 is a circuit diagram illustrating the configuration of one pixel in the liquid crystal display according to the exemplary embodiment of the present invention.

The liquid crystal display according to the present exemplary embodiment includes a thin film transistor array panel 100, a common electrode panel 200 facing the thin film transistor array panel 100, and a liquid crystal layer 3 interposed between the two display panels 100 and 200.

First, the thin film transistor array panel 100 will be described in detail with reference to FIGS. 1 and 3 to 5.

A plurality of gate lines 121, a plurality of storage electrode lines 131a and 131b, and a plurality of capacitive auxiliary electrodes 136 are formed on the insulating substrate 110.                     

The gate lines 121 mainly extend in the horizontal direction and are separated from each other, and transmit gate signals. Each gate line 121 includes a plurality of protrusions constituting the plurality of gate electrodes 124 and an end portion 129 having a large area for connecting another layer or an external device.

Each of the storage electrode lines 131a and 131b mainly extends in the horizontal direction and is disposed in pairs between the adjacent gate lines 121. Each of the storage electrode lines 131a and 131b is positioned near the gate lines 121 adjacent to each other, and includes a plurality of protrusions forming the storage electrodes 135a and 135b, respectively. The two storage electrodes 135a and 135b extend in a wider width than the other portions, and the two storage electrode lines 131a and 131b are centerlines of the first and second pixel electrodes 190a and 190b parallel to the gate line 121. It is symmetrical with respect to. A predetermined voltage such as a common voltage applied to the common electrode 270 of the common electrode display panel 200 of the liquid crystal display is applied to the storage electrode lines 131a and 131b.

Each capacitive auxiliary electrode 136 mainly extends in a horizontal direction to form a rectangular shape, and is disposed at a center between two adjacent gate lines 121 and separated from each other. In this case, each of the capacitive auxiliary electrodes 136 has grooves 136a and 136b disposed on both sides of the longitudinal center line, respectively. The width of the capacitive auxiliary electrode 136 in which the grooves 136a and 136b are located is, of course, narrower than other portions, and is preferably 8 μm or more.

The gate line 121, the storage electrode lines 131a and 131b, and the capacitive auxiliary electrode 136 are preferably made of aluminum-based metal, silver-based metal, copper-based metal, molybdenum-based metal, chromium, titanium, and tantalum. It may have a single film structure or a multilayer film structure. The multilayer film may include, for example, two conductive films having different physical properties, that is, a lower film and an upper film thereon. One conductive film is a low resistivity metal such as aluminum (Al) or an aluminum alloy such as aluminum (Ag) or a silver alloy such as silver (Ag) or silver alloy to reduce signal delay or voltage drop. It may be made of a copper-based metal such as copper (Cu) or a copper alloy. In contrast, other conductive films have excellent contact properties with other materials, particularly indium tin oxide (ITO) and indium zinc oxide (IZO), such as chromium, molybdenum (Mo), molybdenum alloys, tantalum (Ta), or titanium (Ti). ) And the like. Good examples of the two conductive films include chromium / aluminum-neodymium (Nd) alloys or molybdenum or molybdenum alloys / aluminum alloys.

In addition, side surfaces of the gate line 121, the storage electrode lines 131a and 131b, and the capacitive auxiliary electrode 136 are inclined with respect to the surface of the substrate 110, and the inclination angle is preferably about 30-80 °.

A gate insulating layer 140 made of silicon nitride (SiN _x ) is formed on the gate line 121, the storage electrode lines 131a and 131b, and the capacitive auxiliary electrode 136.

A plurality of island-like semiconductors 154 made of hydrogenated amorphous silicon (amorphous silicon is abbreviated a-Si) and the like are formed on the gate insulating layer 140. Each island-like semiconductor 154 is mainly located above the gate electrode 124 and extends to the top of the gate line 121 through which the data line 171 will pass. A buffer layer may be added to the upper portion of the storage electrode lines 131a and 131b through which the data line 171 passes through the same layer as the island-type semiconductor 154.

On the semiconductor 154, a plurality of island-like ohmic contacts 163 and 165 made of a material such as n + hydrogenated amorphous silicon doped with a high concentration of n-type impurities such as silicide or phosphorus are formed. It is. The two islands of ohmic contact 163 and 165 are paired and disposed on the semiconductor 154, facing each other with respect to the gate electrode 124.

Sides of the island-like semiconductor 154 and the ohmic contacts 163 and 165 are also inclined with respect to the surface of the substrate 110, and the inclination angle is preferably 30-80 °.

A plurality of data lines 171 and a plurality of drain electrodes 175 separated therefrom are formed on the ohmic contacts 163 and 165 and the gate insulating layer 140, respectively.

The data line 171 mainly extends in the vertical direction and crosses the gate line 121 and the storage electrode lines 131a and 131b and transmits a data voltage. Each data line 171 has a wide end portion 179 for connection with another layer or an external device.

Each of the drain electrodes 175 is positioned at the top and the bottom of the region surrounded by the gate line 121 and the data line 171 to overlap the storage electrodes 135a and 135b, respectively. ). Sides of the extended portions 175a and 175b of each of the drain electrodes 175 are substantially parallel to the sides of the sustain electrodes 135a and 135b and are parallel to the gate lines 121. The first and second pixel electrodes 190a and 190b are parallel to each other. Symmetrical with respect to the centerline of Each of the data lines 171 includes a plurality of protrusions, and the protrusions form a source electrode 173 partially surrounding one end of the drain electrode 175 positioned on the semiconductor 154. One gate electrode 124, one source electrode 173, and one drain electrode 175 together with the semiconductor 154 form one thin film transistor (TFT), and a channel of the thin film transistor. ) Is formed in the semiconductor 154 between the source electrode 173 and the drain electrode 175.

In addition, the drain electrode 175 is positioned at the center of the region surrounded by the gate line 121 and the data line 171, overlaps the capacitive auxiliary electrode 136, and is parallel to the side of the capacitive auxiliary electrode 136. And a capacitive coupling electrode having sides. The capacitive coupling electrode 176 also has grooves 176a and 176b corresponding to the grooves 136a and 136b of the capacitor auxiliary electrode 136. In this case, the grooves 176a and 176b of the capacitive coupling electrode 176 and the grooves 136a and 136b of the capacitive auxiliary electrode 136 cross each other so that at least the capacitive coupling electrode 176 and the capacitive auxiliary electrode 136 are Some of the grooves 136a, 136b, 176a, and 176b do not overlap each other, and some of the grooves 136a, 136b, 176a, and 176b overlap. Such a structure can easily repair the pixel defect, which will be described in detail later. In addition, each of the capacitive coupling electrodes 176 has an opening 76 positioned between the two grooves 176a and 176b and exposing the gate insulating layer 140 on the capacitive auxiliary electrode 136.

In addition, the drain electrode 175 connects the two extension parts 175a and 175b and the capacitive coupling electrode 176 to each other, and the connection parts 177a and 177b extending in parallel with the neighboring data lines 171 on both sides. Has

Meanwhile, in such a structure, the drain electrode 175 and the capacitive auxiliary electrode 136 have a symmetrical structure with respect to the center line of the first and second pixel electrodes 190a and 190b parallel to the neighboring gate lines 121. Have

The data line 171 and the drain electrode 175 also preferably include refractory metals such as chromium or molybdenum-based metals, tantalum and titanium, and a single film structure or a conductive film such as molybdenum, molybdenum alloy, and chromium (not shown). ) And a conductive film (not shown), which is an aluminum-based metal located above or below the structure, may have a multilayer structure.

Similar to the gate line 121 and the storage electrode lines 131a and 131b, the data line 171 and the drain electrode 175 are inclined at an angle of about 30 to 80 degrees, respectively.

The ohmic contacts 163 and 165 exist between the lower semiconductor 154 and the upper data line 171 and the drain electrode 175 and lower the contact resistance. The island-like semiconductor 154 has a portion exposed between the source electrode 173 and the drain electrode 175 and not covered by the data line 171 and the drain electrode 175.

A passivation layer 180 is formed on the data line 171 and the drain electrode 175 and the portion of the semiconductor 154 that is not covered by them. The passivation layer 180 is a-Si: C: O, a-Si: O: F formed by plasma enhanced chemical vapor deposition (PECVD), an organic material having excellent planarization characteristics, and having photosensitivity. The low dielectric constant insulating material of 4.0 or less, or an inorganic material, such as silicon nitride and silicon oxide, is preferable.

The passivation layer 180 includes a plurality of contact holes 182, 185a, and 185b respectively exposing the extension portions 175a and 175b of the pair of drain electrodes 175 and the end portions 179 of the data line 171. ) And a plurality of contact holes 181 and 186 exposing a portion of the capacitive auxiliary electrode 136 and an end portion 129 of the gate line 121 together with the gate insulating layer 140. The contact holes 181, 182, 185a, 185b, and 186 may be made in various shapes such as polygons or circles. The side walls of the contact holes 181, 182, 185a, 185b, and 186 are inclined at an angle of 30 ° to 85 °, and are preferably stepped.

In this case, the contact holes 186 exposing the capacitive auxiliary electrode 136 are positioned in the openings 76 of the capacitive coupling electrode 176, respectively, and thus the liquid crystal molecules are separated due to the step generated by the sidewall of the contact hole 186. Even if the arrangement is distorted and light leaks from this portion, it is blocked by the capacitive coupling electrode 176. Therefore, it is possible to block the occurrence of the discretization while ensuring the aperture ratio of the pixel. In order to place the contact hole 186 exposing the capacitive auxiliary electrode 136 outside the capacitive coupling electrode 176, the capacitive auxiliary electrode 136 is extended to block the alignment distortion of the liquid crystal molecules caused by the step difference. And the width must be widened in consideration of the process margin, thereby reducing the aperture ratio of the pixel.

A plurality of first and second pixel electrodes 190a and 190b, a shielding electrode 88, and a plurality of contact assistants 81 formed of ITO or IZO are disposed on the passivation layer 180. , 82) are formed. Alternatively, the first / second pixel electrodes 190a and 190b may be made of a transparent conductive polymer, and in the case of a reflective liquid crystal display device, the first / second pixel electrodes 190a and 190b may be an opaque reflective metal. It can also be made. In this case, the contact assistants 81 and 82 may be made of a material different from the first and second pixel electrodes 190a and 190b, for example, ITO or IZO.

The first pixel electrode 190a is physically and electrically connected to the drain electrode 175 through the contact holes 185a and 185b to receive a data voltage from the drain electrode 175. The second pixel electrode 190b is connected to the capacitive auxiliary electrode 136 through the contact hole 186, and the capacitive auxiliary electrode 136 overlaps the capacitive coupling electrode 176 of the drain electrode 175. . Accordingly, the second pixel electrode 190b is electromagnetically coupled (capacitive) to the first pixel electrode 190a to indirectly apply a data voltage.

The first and second pixel electrodes 190a and 190b and the common electrode 270 form a capacitor (hereinafter, referred to as a “liquid crystal capacitor”) to maintain an applied voltage even after the thin film transistor is turned off. In order to enhance the voltage holding capability, there is another capacitor connected in parallel with the liquid crystal capacitor, which is called a storage capacitor. The storage capacitor is formed by overlapping the first / second pixel electrodes 190a and 190b and the storage electrode lines 131a and 131b and the capacitive auxiliary electrode 136, and increases the capacitance of the storage capacitor. For this purpose, the storage electrodes 135a and 135b are disposed on the storage electrode lines 131a and 131b, and the extension portions 175a and 175b of the drain electrode 175 connected to the first pixel electrode 190a are extended, extended and overlapped between the terminals. Close the distance and increase the overlap area.

The pair of first and second pixel electrodes 190a and 190b substantially exist in an area surrounded by the data line 171 and the gate line 121, and most of the boundary is formed between the gate line 121 and the data line 171. Parallel to form a rectangle. The first and second pixel electrodes 190a and 190b are separated from each other, and the first pixel electrode 190a is separated from each other and is composed of two parts positioned at an upper portion and a lower portion with respect to the second pixel electrode 190b. The second pixel electrode 190b is sandwiched between two portions of the first pixel electrode 190a. Two portions of the first pixel electrode 190a and the second pixel electrode 190b have sides that are inclined by ± 45 ° with respect to the gate line 121, so that the first and second pixel electrodes 190a and 190b may have gates. The center line of the first and second pixel electrodes 190a and 190b parallel to the line 121 has a symmetrical structure.

Each of the first and second pixel electrodes 190a and 190b is chamfered at a corner, and the chamfered hypotenuse forms an angle of about 45 degrees with respect to the gate line 121.

The first and second pixel electrodes 190a and 190b have a central cutout 91 and 92, lower cutouts 93a, 94a and 95a and upper cutouts 93b, 94b and 95b. The two pixel electrodes 190a and 190b are divided into a plurality of regions by these cutouts 91, 92, 93a, 93b, 94a, 94b, 95a, 95b. The cutouts 91, 92, 93a, 93b, 94a, 94b, 95a, and 95b may have first and second pixel electrodes 190a and 190b parallel to the horizontal center line or gate line 121 of the capacitive coupling electrode 176. The center line is substantially symmetrical with respect to the center line, and two parts of the first pixel electrode 190a and the second pixel electrode 190b are separated through a gap formed by two incisions 93a and 93b facing each other.

The lower and upper cutouts 93a, 93b, 94a, 94b, 95a, and 95b extend approximately obliquely from the left side of the first / second pixel electrodes 190a and 190b to the right side, and the first / second pixel. The electrodes 190a and 190b are positioned on the lower half and the upper half, respectively, which are divided into a center line that is bisected in the horizontal direction. The lower and upper incisions 93a, 93b, 94a, 94b, 95a, and 95b extend perpendicular to each other at an angle of about 45 degrees with respect to the gate line 121, and the central incisions 91 and 92 are lower incisions. It consists of a pair of branches substantially parallel to 93a, 94a, 95a and upper incisions 93b, 94b, 95b, respectively. The central cutouts 91 and 92 have horizontal sections extending in the transverse direction from the center.

Accordingly, the upper and lower half surfaces of the first and second pixel electrodes 190a and 190b are divided into six regions by the cutouts 91, 92, 93a, 93b, 94a, 94b, 95a, and 95b, respectively. These regions have a symmetrical structure with respect to a bisector dividing the first and second pixel electrodes 190a and 190b up and down. In addition, an area that does not have a thin film, such as the drain electrode 175, the storage electrode lines 131a and 131b, and the capacitor auxiliary electrode 136, is also provided for the bisector that divides the first and second pixel electrodes 190a and 190b up and down. It has a symmetrical structure. At this time, the number of regions or the number of cutout portions varies depending on the design elements such as the size of the pixel, the ratio of the length of the horizontal side to the vertical side of the pixel electrode, the type and characteristics of the liquid crystal layer 3, and the like.

The first and second pixel electrodes 190a and 190b also overlap the neighboring gate line 121 or the data line 171 to increase the aperture ratio.

The contact auxiliary members 81 and 82 are connected to the end portion 129 of the gate line 121 and the end portion 179 of the data line 171 through the contact holes 181 and 182, respectively. The contact auxiliary members 81 and 82 complement and protect the exposed end portions 129 of the gate lines 121 and the exposed end portions 179 of the data lines 171 and external devices and protect them. To do. The contact auxiliary members 81 and 82 are connected to the external device through an anisotropic conductive film (not shown) or the like.

When the gate driving circuit is integrated in the thin film transistor array panel 100, the contact auxiliary member 81 may serve to connect the metal layer of the gate driving circuit and the gate line 121. Similarly, when the data driving circuit is integrated in the thin film transistor array panel 100, the contact auxiliary member 82 may serve to connect the metal layer and the data line 171 of the data driving circuit.

The shielding electrode 88 extends along the data line 171 and the gate line 121, and a portion located above the data line 171 completely covers the data line 171 and is positioned above the gate line 121. The portion having a width smaller than the width of the gate line 121 is located within the boundary line of the gate line 121. However, the width may be adjusted to be smaller than the data line 171, and may have a boundary line positioned outside the boundary line of the gate line 121. A common voltage is applied to the shielding electrode 88, and is connected to the storage electrode lines 131a and 131b through contact holes (not shown) of the passivation layer 180 and the gate insulating layer 140, or the common voltage is applied to the thin film transistor. The display panel 100 may be connected to a short point (not shown) that passes from the display panel 100 to the common electrode display panel 200. At this time, it is preferable to minimize the distance between the shielding electrode 88 and the first and second pixel electrodes 190a and 190b to minimize the reduction of the aperture ratio.

As such, when the shielding electrode 88 to which the common voltage is applied is disposed on the data line 171, the shielding electrode 88 is disposed between the data line 171 and the first and second pixel electrodes 190a and 190b and the data line. By blocking the electric field formed between the 171 and the common electrode 270, the voltage distortion of the first and second pixel electrodes 190a and 190b and the signal delay of the data voltage transmitted by the data line 171 are reduced.

Also, in order to prevent a short circuit between the first and second pixel electrodes 190a and 190b and the shielding electrode 88, a distance is required between the first and second pixel electrodes 190a and 190b so that the first and second pixel electrodes 190a and 190b may have a data line ( Further away from 171, the parasitic capacity between them is reduced. Furthermore, since the permittivity of the liquid crystal layer 3 is higher than that of the passivation layer 180, the parasitic capacitance between the data line 171 and the shielding electrode 88 is absent when the shielding electrode 88 is absent. It is smaller than the parasitic capacitance between 171 and the common electrode 270.

In addition, since the first and second pixel electrodes 190a and 190b and the shielding electrode 88 are made of the same layer, the distance between them is kept constant so that the parasitic capacitance between them is constant.

Next, the common electrode display panel 200 will be described with reference to FIGS. 2 to 5.

A light blocking member 220 is formed on an insulating substrate 210 made of transparent glass, and the light blocking member 220 faces the first / second pixel electrodes 190a and 190b and faces the first / second pixel electrode. It has a plurality of openings having almost the same shape as 190a and 190b. Alternatively, the light blocking member 220 may include a portion corresponding to the data line 171 and a portion corresponding to the thin film transistor.

A plurality of color filters 230 are also formed on the substrate 210 and are mostly located in an area surrounded by the light blocking member 220. The color filter 230 may extend in the vertical direction along the first and second pixel electrodes 190a and 190b. The color filter 230 may display one of primary colors such as red, green, and blue.

An overcoat 250 is formed on the color filter 230.

The common electrode 270 formed of a transparent conductor such as ITO or IZO is formed on the overcoat 250.

The common electrode 270 has a plurality of sets of cutouts 71, 72, 73, 73a, 73b, 74a, 74b, 75a, 75b, 76a, and 76b.

A pair of cutouts 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b face the first and second pixel electrodes 190a, 190b and have a central cutout 71, 72, 73), lower incisions 74a, 75a, 76a and upper incisions 74b, 75b, 76b. The cutouts 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b each have cutouts 91, 92, 93a, 93b, 94a, of the adjacent first / second pixel electrodes 190a, 190b. It is disposed between 94b, 95a, and 95b or between the hypotenuses of the edge cutouts 95a and 95b and the first and second pixel electrodes 190a and 190b. In addition, each of the cutouts 71, 72, 73, 74a, 74b, 75a, 75b, 76a, and 76b may have cutouts 91, 92, 93a, 93b, and 94a of the first and second pixel electrodes 190a and 190b. 94b, 95a, 95b) and at least one diagonal line.

The lower and upper cutouts 74a, 74b, 75a, 75b, 76a, and 76b each have an oblique line extending from the right side of the first and second pixel electrodes 190a and 190b toward the lower or upper side, and the diagonal line portion. A horizontal portion and a vertical portion extending from the ends and overlapping sides along the sides of the first and second pixel electrodes 190a and 190b and forming an obtuse angle with the oblique portion.

The central cutouts 71, 72, and 73 have a central horizontal portion extending from the left side of the first and second pixel electrodes 190a and 190b to the horizontal portion, and the first horizontal portion has an oblique angle with the central horizontal portion at the end of the central horizontal portion. A pair of diagonal portions extending toward the left sides of the second pixel electrodes 190a and 190b, and overlapping with the left side along the left sides of the first / second pixel electrodes 190a and 190b from each end of the diagonal portion. A longitudinal longitudinal portion extending and obtuse the oblique portion.

The number of cutouts 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b may vary depending on design elements, and the light shielding member 220 may have cutouts 71, 72, 73, 74a, 74b. , 75a, 75b, 76a, and 76b may be overlapped to block light leakage near the cut portions 71, 72, 73, 74a, 74b, 75a, 75b, 76a, and 76b.

Vertical alignment layers 11 and 21 are coated on the inner surfaces of the display panels 100 and 200, and polarizing plates 12 and 22 are provided on the outer surfaces thereof.

The transmission axes of the two polarizing plates 12 and 22 are orthogonal, and one transmission axis is parallel to the gate line 121. In the case of a reflective liquid crystal display, one of the two polarizing plates 12 and 22 may be omitted.

The alignment layers 11 and 21 may be horizontal alignment layers.

A phase retardation film may be interposed between the display panels 100 and 200 and the polarizers 12 and 22 to compensate for the delay value of the liquid crystal layer 3, respectively. The phase retardation film has birefringence and serves to reversely compensate for the birefringence of the liquid crystal layer 3. As the retardation film, a uniaxial or biaxial optical film can be used, and in particular, a negative uniaxial optical film can be used.

The liquid crystal display may also include a polarizer 12 and 22, a phase retardation film, display panels 100 and 200, and a backlight unit for supplying light to the liquid crystal layer 3.

The liquid crystal layer 3 has negative dielectric anisotropy, and the liquid crystal molecules 310 of the liquid crystal layer 3 are aligned such that their major axes are perpendicular to the surfaces of the two display panels in the absence of an electric field. Therefore, incident light does not pass through the quadrature polarizers 12 and 22 and is blocked.

When a common voltage is applied to the common electrode 270 and a data voltage is applied to the first and second pixel electrodes 190a and 190b, an electric field substantially perpendicular to the surface of the display panel is generated. The liquid crystal molecules 310 try to change the direction of the long axis perpendicular to the direction of the electric field in response to the electric field. Meanwhile, the cutouts 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b, 91, 92, 93a, 93b, of the common electrode 270 and the first and second pixel electrodes 190a and 190b. The sides of 94a, 94b, 95a, and 95b and the first and second pixel electrodes 190a and 190b distort the electric field to produce horizontal components that determine the inclination direction of the liquid crystal molecules. The horizontal components of the electric field are the first and second sides of the incisions 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b, 91, 92, 93a, 93b, 94a, 94b, 95a, 95b It is perpendicular to the sides of the pixel electrodes 190a and 190b. Also, the horizontal component of the main electric field at the two opposite sides of the incisions 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b, 91, 92, 93a, 93b, 94a, 94b, 95a, 95b Are in opposite directions.

Through these electric fields, the incisions 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b, 91, 92, 93a, 93b, 94a, 94b, 95a, 95b form liquid crystal molecules of the liquid crystal layer 3. Controls the tilt direction. Incisions 76a, 76b defined or defined by adjacent incisions 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b, 91, 92, 93a, 93b, 94a, 94b, 95a, 95b And the liquid crystal molecules in each domain defined by the right hypotenuse of the first and second pixel electrodes 190a and 190b are incisions 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b, 91, 92, 93a, 93b, 94a, 94b, 95a, 95b are inclined in a direction perpendicular to the longitudinal direction. The two longest sides of each domain are almost parallel to each other, and form approximately ± 45 degrees with the gate line 121. Most of the liquid crystal molecules in the domain are inclined in four directions, thereby extending the viewing angle.

The width of the incisions 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b, 91, 92, 93a, 93b, 94a, 94b, 95a, 95b is preferably about 9 μm to about 12 μm.

At least one incision 71, 72, 73, 74a, 74b, 75a, 75b, 76a, 76b, 91, 92, 93a, 93b, 94a, 94b, 95a, 95b is a protrusion (not shown) Or may be replaced by a depression (not shown). The protrusions may be made of organic or inorganic materials and may be disposed above or below the field generating electrodes 190 and 270, and the width thereof is preferably about 5 μm to about 10 μm.                     

In addition, since the same common voltage is applied to the common electrode 270 and the shielding electrode 88, there is almost no electric field between the two. Accordingly, since the liquid crystal molecules 310 positioned between the common electrode 270 and the shielding electrode 88 maintain their initial vertical alignment, light incident on the portion is not transmitted and is blocked.

Meanwhile, when the inclination direction of the liquid crystal molecules 310 and the transmission axis of the polarizers 12 and 22 are 45 degrees, the highest luminance can be obtained. In the present embodiment, the inclination direction of the liquid crystal molecules 310 in all domains is the gate line. The gate line 121 is perpendicular or horizontal to the edges of the display panels 100 and 200 at an angle of 45 ° with the 121. Therefore, in the present exemplary embodiment, when the transmission axes of the polarizers 12 and 22 are attached to be perpendicular or parallel to the edges of the display panels 100 and 200, the highest luminance can be obtained and the polarizers 12 and 22 can be manufactured at low cost. Can be.

In the liquid crystal display according to the exemplary embodiment of the present invention, as described above, the second pixel electrode 190b is electromagnetically coupled (capacitively coupled) to the first pixel electrode 190a. Referring to FIG. 6, two portions of the first pixel electrode 190a are directly connected to the thin film transistor Q through the drain electrode 175 and transferred through the data line 171 through the thin film transistor Q. The voltage of the second pixel electrode 190b is changed by capacitive coupling with the first pixel electrode 190a as opposed to receiving the image signal voltage. In this embodiment, the voltage of the second pixel electrode 190b is always lower than the voltage of the first pixel electrode 190a, and the reason thereof will be described in detail.

In FIG. 5, Clca represents a liquid crystal capacitor formed between the first pixel electrode 190a and the common electrode 270, and Csta represents a storage capacitor formed between the first pixel electrode 190a and the storage electrode line 131. . Clcb represents the liquid crystal capacitance formed between the second pixel electrode 190b and the common electrode 270, Cstb represents the storage capacitance formed between the second pixel electrode 190b and the storage electrode line 131, and Ccp represents A coupling capacitor formed between the second pixel electrode 190b and the first pixel electrode 190a is shown.

When the voltage of the first pixel electrode 190a with respect to the voltage of the common electrode 270 is called Va, and the voltage of the second pixel electrode 190b is called Vb, according to the voltage division law,

Vb = Va × [Ccp / (Ccp + Clcb + Cstb)]

Since Ccp / (Ccp + Clcb + Cstb) cannot always be greater than 1, Vb is always smaller than Va. At this time, the voltage of the common electrode 270 for Clca and Clcb and the voltages of the sustain electrode lines 131a and 131b for Csta and Cstb may be different. In this case, the voltage of the common electrode 270 applied to Clca and Clcb is the same. The absolute value of the image signal voltage Va applied to Clca always has a value greater than the absolute value of the image signal voltage Vb applied to Clcb. As such, when two pixel electrodes having different voltages are disposed in one pixel, the liquid crystal molecules may be driven at different voltages to be inclined at different tilt angles, thereby improving side visibility.

Further, in the liquid crystal display according to the exemplary embodiment of the present invention, the opaque film and the cutouts 71, 72, 73, and 74a such as the capacitive auxiliary electrode 136, the storage electrode lines 131a and 131b, and the drain electrode 175 may be used. , 74b, 75a, 75b, 76a, 76b, 91, 92, 93a, 93b, 94a, 94b, 95a, 95b, the first and second pixel electrodes 190a in which the domains defined by the gate line 121 are parallel to each other. , 190b) has a symmetrical structure with respect to the centerline. Therefore, the capacitive auxiliary electrode 136, the capacitive coupling electrode 176a, and 176b and the storage electrode line with respect to the vertical bisectoral center lines of the first and second pixel electrodes 190a and 190b among four kinds of domains inclined in different directions. Opaque films such as 131a and 131b and the drain electrode 175 are disposed in the same manner. Therefore, by designing the transmissive areas to have the same area in the four kinds of domains, it is possible to ensure uniform visibility at various viewing angles.

By adjusting Ccp, the ratio of Vb to Va can be adjusted. The adjustment of Ccp is possible by adjusting the overlapping area and distance of the capacitive coupling electrodes 176a and 176b and the second pixel electrode 190b. The overlap area can be easily adjusted by changing the width of the capacitive coupling electrode 176, and the distance can be adjusted by changing the formation position of the capacitive coupling electrode 176. That is, in the exemplary embodiment of the present invention, the capacitive coupling electrode 176 is formed on the same layer as the data line 171, but the capacitive coupling electrode 176 and the second pixel are formed on the same layer as the gate line 121. The distance between the electrodes 190b may be increased. At this time, it is preferable that Vb is 0.6 to 0.8 times with respect to Va.

Meanwhile, in another embodiment, a voltage whose absolute value is always higher than the voltage of the first pixel electrode 190a may be applied to the second pixel electrode 190b, which may be applied to the second pixel electrode 190b such as a common voltage. This is achieved by capacitively coupling the first pixel electrode 190a while an arbitrary voltage is applied.

The area ratio of the second pixel electrode 190b through which the high or low pixel voltage is transmitted relative to the first pixel electrode 190a through which the image signal is directly transmitted is preferably in the range of 1: 0.85-1: 1.15. Two or more second pixel electrodes 190b may be disposed to be capacitively coupled to the pixel electrodes 190a.

A method of manufacturing the thin film transistor array panel shown in FIGS. 1 to 4 according to an embodiment of the present invention will be described in detail.

A conductive film made of chromium, molybdenum or molybdenum alloy, aluminum-based metal or silver-based metal is sputter deposited on the insulating substrate 110 and wet or dry etched to form a gate including a plurality of gate electrodes 124 and end portions 129. A line 121, a plurality of pair of storage electrode lines 131a and 131b, and a capacitive auxiliary electrode 136 are formed.

A three-layer film of a gate insulating film 140 of about 1,500-5,000 kPa thick, an intrinsic amorphous silicon layer of about 500-2,000 kPa thick, and an impurity amorphous silicon layer of about 300-600 kPa thick A plurality of linear impurity semiconductors and a plurality of intrinsic semiconductors 154 are formed on the gate insulating layer 140 by photolithography of the impurity amorphous silicon layer and the intrinsic amorphous silicon layer.

Subsequently, a conductive film is deposited to a thickness of 1,500 mV to 3,000 mV by sputtering or the like, and then patterned to form a plurality of data lines 171 and openings 76 including a plurality of source electrodes 173 and end portions 179. The branches form a plurality of drain electrodes 175 including a plurality of capacitive coupling electrodes 176.

Subsequently, the plurality of island-type ohmic contacts 163 and 165 are completed by removing the exposed impurity semiconductor portions that are not covered by the data line 171 and the drain electrode 175, while the portions of the intrinsic semiconductor 154 thereunder. Expose Oxygen plasma is preferably followed by stabilization of the surface of the exposed intrinsic semiconductor 154 portion.

A protective film 180 made of a positive photosensitive organic insulator is applied, and then exposed and developed through a photomask (not shown) to expose the end portion 179 of the data line 171 and a part of the drain electrode 175. Forming a plurality of contact holes 182, 185a, and 185b, and disposed on the capacitive auxiliary electrode 136 and the end portion 129 of the gate line 121 in the opening 76 of the capacitive coupling electrode 176. A plurality of contact holes 181 and 186 exposing portions of the gate insulating layer 140 are formed. In this case, the sidewalls of the contact holes 181, 182, 185a, 185b, and 186 may have a stepped profile by partially adjusting the transmittance of light.

When the protective film 180 is formed as a negative photosensitive film, the light blocking area and the transmissive area of the mask are reversed as compared with the case where the positive photosensitive film is used.

When the upper conductive film of aluminum is exposed through the contact holes 181, 182, 185a, 185b, and 186, the exposed portion of the gate insulating layer 140 is removed and the end of the gate line 121 positioned below it. After exposing the portion 129 and the portion of the capacitive auxiliary electrode 136, a process may be added to remove the top layer comprising aluminum.

Finally, an IZO film or an ITO film having a thickness of about 400-500 Å is deposited by sputtering and photo-etched to form a passivation layer 180, a drain electrode 175, a capacitive auxiliary electrode 136, and an end portion 179 of the data line 171. ) And a plurality of first / second pixel electrodes 190a and 190b, a plurality of contact auxiliary members 81 and 82, and a plurality of shielding electrodes 88 on the exposed portion of the end portion 129 of the gate line 121. ).                     

In the liquid crystal display, when the capacitive coupling electrode 176 and the capacitive auxiliary electrode 136 are short-circuited with each other at the point “S1” or “S2”, the second pixel electrode 190b may have a first pixel electrode 190a. A high voltage equal to) is transmitted, which is brighter than the surrounding pixels, resulting in a defect. In the repairing method of the liquid crystal display according to the exemplary embodiment of the present invention, in order to repair the white defect, when the capacitive coupling electrode 176 and the capacitive auxiliary electrode 136 are short-circuited with each other at a point “S1”, A portion of the capacitive auxiliary electrode 136 of the portion where the short circuit occurs by irradiating a laser to the point “L1” of the capacitive auxiliary electrode 136 exposed through the groove 176a of the coupling electrode 176 is connected to the capacitive auxiliary electrode ( 136). As a result, a defect that is displayed brighter than the surrounding pixels may be repaired, and a voltage corresponding to a varying coupling capacitance is transmitted to the second pixel electrode 190b. As described above, in the thin film transistor array panel according to the exemplary embodiment of the present invention, the grooves 176a and 176b of the capacitive coupling electrode 176 and the grooves 136a and 136b of the capacitive auxiliary electrode 136 intersect with each other and at least the capacitive coupling electrode. Since the 176 and the capacitor auxiliary electrode 136 have portions that do not overlap each other in the grooves 136a, 136b, 176a, and 176b, the defective pixel can be more easily repaired.

A liquid crystal display according to another exemplary embodiment of the present invention will be described in detail with reference to FIGS. 7 to 9.

7 is a layout view illustrating a structure of a liquid crystal display according to another exemplary embodiment. FIGS. 8 and 9 are cross-sectional views illustrating the liquid crystal display of FIG. 7 taken along the line VIII-VIII ′.                     

7 to 9, the liquid crystal display according to the present exemplary embodiment also includes a thin film transistor array panel 100, a common electrode display panel 200, and a liquid crystal layer 3 inserted between the two display panels 100 and 200. And a pair of polarizers 12 and 22 attached to outer surfaces of the two display panels 100 and 200.

The layered structures of the display panels 100 and 200 according to the present exemplary embodiment are substantially the same as those of FIGS. 1 to 4.

Referring to the thin film transistor array panel 100, the plurality of gate lines 121 including the gate electrode 124, the plurality of storage electrode lines 131a and 131b including the storage electrodes 135a and 135b, respectively, and capacitive properties The auxiliary electrode 136 is formed on the substrate 110, and the gate insulating layer 140, the semiconductor 154, and the ohmic contacts 163 and 165 are sequentially formed thereon. The plurality of data lines 171 including the source electrode 173, the plurality of capacitive coupling electrodes 176, and the plurality of drain electrodes 175 including the plurality of extension parts 175a and 175b may include the gate insulating layer 140. ), A passivation layer 180 is formed thereon, and a plurality of contact holes 181, 182, 185a, 185b, and 186 are formed in the passivation layer 180 and the gate insulating layer 140. A plurality of first and second pixel electrodes 190a and 190b, a plurality of shielding electrodes 88, and a plurality of contact auxiliary members 81 and 82 are formed on the passivation layer 180, and an alignment layer 11 is formed thereon. It is applied.

Referring to the common electrode display panel 200, the light blocking member 220, the plurality of color filters 230, the overcoat 250, the common electrode 270, and the alignment layer 21 are formed on the insulating substrate 210. have.                     

Unlike the liquid crystal display of FIGS. 1 to 5, the semiconductor 154 is a protrusion of the linear semiconductor 151 extending to the lower portion of the data line 171 and the drain electrode 175, and has an island-type ohmic contact 165. A resistive contact member 163 facing away) is also a protrusion of the linear resistive contact member 161. At this time, the linear semiconductor 151 has substantially the same shape as the data line 171, the drain electrode 175, and the ohmic contacts 161 and 165 thereunder. However, the protrusion 154 of the linear semiconductor 151 has a portion not covered by the data line 171 and the drain electrode 175, such as a portion between the source electrode 173 and the drain electrode 175. The semiconductor 151 and the island-shaped ohmic contact 165 extend in the same shape to the lower portion of the capacitive coupling electrode 176.

In the method of manufacturing the thin film transistor array panel according to the exemplary embodiment of the present invention, the data line 171, the drain electrode 175, the semiconductor 151, and the ohmic contacts 161 and 165 are formed in one photo process. .

The photosensitive film pattern used in such a photo process differs in thickness according to a position, and especially includes a 1st part and a 2nd part in order of decreasing thickness. The first part is located in the wiring area occupied by the data line and the drain electrode, and the second part is located in the channel area of the thin film transistor.

There may be various methods of varying the thickness of the photoresist pattern according to the position. For example, a method of providing a translucent area in addition to the transparent area and the light blocking area in the photomask is possible. have. The translucent region is provided with a slit pattern, a lattice pattern, or a thin film having a medium transmittance or a medium thickness. When using the slit pattern, it is preferable that the width of the slits and the interval between the slits are smaller than the resolution of the exposure machine used for the photographic process. Another example is to use a photoresist film that can be reflowed. That is, a thin portion is formed by forming a reflowable photoresist pattern with a normal exposure mask having only a transparent region and a light shielding region and then reflowing to allow the photoresist film to flow down into a region where no residue is left.

In this way, a one-time photographic process can be reduced, thereby simplifying the manufacturing method.

As described above, by dividing the pixel electrode and applying different voltages, the side visibility of the liquid crystal display may be improved, and thereby the viewing angle may be extended.

In addition, by arranging the grooves so as not to partially overlap the capacitive coupling electrode and the capacitive auxiliary electrode, pixel defects can be easily repaired, and process yield can be improved.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights. In particular, the arrangement of the cutouts formed in the pixel electrode and the common electrode may be variously modified.

Claims (9)

Insulation board, A gate line formed on the insulating substrate, A capacitive auxiliary electrode separated from the gate line, A data line insulated from and intersecting the gate line; A thin film transistor connected to each of the gate lines and the data lines and having a drain electrode, A capacitive coupling electrode overlapping the capacitive auxiliary electrode and connected to the drain electrode, and A pixel electrode having a first pixel electrode connected to the drain electrode and a second pixel electrode connected to the capacitive auxiliary electrode, One of the capacitive auxiliary electrode or the capacitive coupling electrode has a groove passing through a boundary line of the capacitive auxiliary electrode or the capacitive coupling electrode. In claim 1, And the capacitive auxiliary electrode and the capacitive coupling electrode each have a groove facing each other. In claim 2, The capacitive coupling electrode has an opening that exposes the gate insulating layer on the capacitive auxiliary electrode. In claim 3, And a contact hole connecting the capacitive auxiliary electrode and the second pixel electrode in the opening. In claim 4, And the grooves of the capacitive coupling electrode and the capacitive auxiliary electrode are respectively disposed on both sides of the opening. In claim 1, The drain electrode is disposed above and below the capacitive coupling electrode and includes an extension part connected to the capacitive coupling electrode through a connection part. In claim 6, And a storage electrode line having a storage electrode overlapping the drain electrode. In claim 7, The first pixel electrode is divided into at least two parts, Two portions of the first pixel electrode are connected to the two extensions, respectively. In claim 8, The sustain electrode line is formed in a pair, and the sustain electrode overlaps the two extensions, respectively.

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