KR100987719B1 - Array substrate with improved aperture ratio, manufacturing method thereof and liquid crystal display device including the same - Google Patents

Abstract

The array substrate according to the present invention includes a transparent substrate, a plurality of pixel electrodes, a switching element, a data line, a gate line, and a storage electrode. The plurality of pixel electrodes are formed to be spaced apart from each other by a first distance between the transparent substrate and the transparent substrate. The data line is spaced apart from the transparent substrate by a second distance above the transparent substrate. In addition, the data line is disposed between the pixel electrodes and electrically connected to the source electrode so as to have a width of a first length in order to apply the pixel voltage to the pixel electrode. The gate line is electrically connected to the gate electrode to transmit an electrical signal for turning on / off a switching device. The storage electrode is formed to be spaced apart by a third distance from the transparent substrate and the transparent substrate. In addition, the storage electrode is disposed between the pixel electrodes. In addition, the storage electrode overlaps the storage electrode and two neighboring pixel electrodes by a second length and a third length, respectively, to block light leakage.

Description

ARRAY SUBSTRATE HAVING ENHANCED OPENING RATIO, METHOD OF MANUFACTURING THE SAME AND LIQUID CRYSTAL DISPLAY APPARATUS HAVING THE SAME}

1A is a layout of a conventional array substrate.

FIG. 1B is a schematic cross-sectional view of FIG. 1A.

2 is a schematic diagram illustrating a driving principle of a liquid crystal display device.

3A is a layout of an array substrate according to a first exemplary embodiment of the present invention.

3B is a schematic cross-sectional view of FIG. 3A.

4A is a layout of an array substrate according to a second exemplary embodiment of the present invention.

4B is a schematic cross-sectional view of FIG. 4A.

5A and 5B are schematic plan views illustrating the shape of a window formed in the data line of FIG. 4A, respectively.

6 is a schematic cross-sectional view of a liquid crystal display.

<Brief description of the main parts of the drawing>

101: pixel electrode 102: data line                 

103a, 103b, 103c: storage electrode 104: thin film transistor

105: gate line 106: opening

107: light blocking film 108: transparent substrate

109: window 201: liquid crystal capacitor

201: storage capacitor 501: first substrate

502: second substrate 503: second transparent substrate

504: color filter 506: liquid crystal layer

508: first insulating film 509: second insulating film

511: first transparent substrate 512: common electrode

The present invention relates to an array substrate, a method for manufacturing the same, and a liquid crystal display including the same, and more particularly, to an array substrate having an improved aperture ratio, a method for manufacturing the same, and a liquid crystal display including the same.

A liquid crystal display device is a device that displays an image using a liquid crystal. Liquid crystal displays are light and thin, and their range of use is gradually expanding.

The liquid crystal display largely includes a liquid crystal display panel and a backlight assembly. The backlight assembly is disposed under the liquid crystal display panel to supply light to the liquid crystal display panel.                         

The liquid crystal display panel includes a color filter substrate, an array substrate, and a liquid crystal layer interposed between the color filter substrate and the array substrate. The color filter substrate includes a color filter including a red color filter, a green color filter, and a blue color filter in a matrix form. The color filter is disposed on the pixel electrode of the array substrate to filter light passing through the pixel electrode to pass only light having a specific wavelength. Hereinafter, a conventional array substrate will be described.

FIG. 1A is a layout of a conventional array substrate, and FIG. 1B is a schematic cross-sectional view of FIG. 1A.

The array substrate includes a thin film transistor 104, a storage electrode 103a and a pixel electrode 101. The thin film transistor 104, the storage electrode 103a, and the pixel electrode 101 face the color filter (not shown) of the color filter substrate.

The array substrate also includes a data line 102 and a gate line 105. The data line 102 and the gate line 105 face the interface of the color filter.

The data line 102 is electrically connected to the source S of the thin film transistor 104, and the gate line 105 is electrically connected to the gate G of the thin film transistor 104. The drain D of the thin film transistor 104 is electrically connected to the pixel electrode 101.

When a voltage is applied to the gate line 105, the thin film transistor 104 electrically connected to the gate line 105 is turned on, and the voltage of the data line 102 is applied to the pixel electrode 101. . When a pixel voltage is applied to the pixel electrode 101, an electric field is formed between the pixel electrode 101 of the array substrate and the common electrode (not shown) of the color filter substrate, and the electric field is formed between the array substrate and the color filter substrate. The arrangement of liquid crystal molecules in the positioned liquid crystal layer (not shown) is changed, thereby changing the optical properties of the liquid crystal molecules.

The image is displayed by the light passing through the changed liquid crystal.

The storage electrode 103a assists the capacitance of the liquid crystal capacitor formed between the pixel electrode 101 and the common electrode (not shown) of the color filter substrate. That is, the function of preventing the pixel voltage of the pixel electrode 101 from being changed by the coupling when the peripheral voltage changes after the data is inputted. The storage electrode 103a is formed at an edge portion of the pixel electrode 101.

However, in the conventional array substrate having such a structure, since light leaks through the opening 106 formed between the storage electrode 103a and the data line 102, the light blocking film (or black matrix) is applied to the color filter substrate. Prevent light leakage

This light blocking film 107 leaves a constant margin around the opening 106.

In FIG. 1B, the light blocking film 107 has a left margin of 5 μm, a right margin of 6 μm, a width of the data line 102 of 5 μm, and a width of the opening 106 of 2.5 μm, respectively, so that the width of the light blocking film is 22 μm. As described above, the aperture ratio of the conventional array substrate may be lowered due to the wider barrier layer.

Light passing through the opening 107 propagates (diffuses). Therefore, when the light blocking film 107 is moved away from the opening 106 (that is, when the separation distance between the array substrate and the color filter substrate increases), the width of the light blocking film 107 must also be increased to block such light. do. However, the separation distance between the array substrate and the color filter substrate is limited due to the limitation of the thickness of the liquid crystal layer. Therefore, there is a limit in improving the aperture ratio by reducing the width of the light blocking film 107.

Further, the light blocking film 107 is formed on the color filter substrate. The liquid crystal display device forms an array substrate and a color filter substrate, and then combines the two substrates by an assembly process to form a liquid crystal display panel. However, it is virtually impossible to align correctly during the alignment process, so there is a slight margin to align. For this reason, the left right margin of the light shielding film 107 is required.

Accordingly, a first object of the present invention is to provide an array substrate having an improved aperture ratio.

A second object of the present invention is to provide a method of manufacturing an array substrate having an improved aperture ratio.

Another object of the present invention is to provide a liquid crystal display device having an improved aperture ratio.

The array substrate according to the present invention includes a transparent substrate, a plurality of pixel electrodes, a switching element, a data line, a gate line, and a storage electrode. The plurality of pixel electrodes are formed to be spaced apart by a first distance from the transparent substrate and the transparent substrate, and are arranged in a matrix form. The switching element includes a gate electrode, a drain electrode and a source electrode, and the drain electrode is electrically connected to each of the pixel electrodes. The data line is spaced apart from the transparent substrate by a second distance above the transparent substrate. In addition, the data line is disposed between the pixel electrodes. In addition, the data line is electrically connected to the source electrode and is formed to have a width of a first length to apply a pixel voltage to the pixel electrode. The gate line is electrically connected to the gate electrode to transmit an electrical signal for turning on and off the switching device. The storage electrode is formed spaced apart by a third distance from the transparent substrate and the transparent substrate. In addition, the storage electrode is disposed between the pixel electrode. In addition, the storage electrode overlaps the storage electrode and the two pixel electrodes neighboring each other by a second length and a third length, respectively. Preferably the storage electrode comprises a window having a width of a fourth length and the fourth length is formed to be smaller than the first length so that the window is formed with an inner edge of the storage electrode and an outer edge of the data line. Overlap.

In addition, the method of manufacturing an array substrate according to the present invention may include forming a plurality of pixel electrodes spaced apart by a first distance from a transparent substrate and an upper portion of the transparent substrate and arranged in a matrix, and forming a gate electrode, a drain electrode, and a source electrode. Forming a plurality of switching elements electrically connected to the respective pixel electrodes, the drain electrodes being spaced apart from each other by a second distance between the transparent substrate and the transparent substrate, and disposed between the pixel electrodes; Forming a gate line electrically connected to the gate electrode to transmit an electrical signal for turning on and off the switching element, and electrically connected to the source electrode to apply a pixel voltage to the pixel electrode; Forming a data line having a width of one length, and the transparent substrate and the transparent substrate A plurality of storage electrodes formed to be spaced apart from each other by a third distance, and disposed between the pixel electrodes, wherein the storage electrode and the two neighboring pixel electrodes overlap each other by a second length and a third length, respectively. Forming the storage electrode.

In addition, the liquid crystal display according to the present invention includes a first substrate, a second substrate, and a liquid crystal layer. The first substrate may include: (I) a first transparent substrate, ii) a plurality of pixel electrodes formed in a matrix shape spaced apart by a first distance from the first transparent substrate and the first transparent substrate, and iii) a gate electrode; A plurality of switching elements electrically connected to the respective pixel electrodes, respectively, iv) spaced apart from each other by a second distance above the first transparent substrate and the first transparent substrate; A data line disposed between the pixel electrodes and electrically connected to the source electrode, the data line having a width of a first length to apply a pixel voltage to the pixel electrode, and v) electrically connected to the gate electrode to turn on the switching element. And a gate line transferring an electrical signal for turning off, and vi) spaced apart by a third distance from the first transparent substrate and the first transparent substrate. And a plurality of storage electrodes disposed between the pixel electrodes. The storage electrode and the two neighboring pixel electrodes overlap each other by a second length and a third length, respectively. The second substrate is formed to face the first substrate. The liquid crystal layer is interposed between the first substrate and the second substrate.

The present invention prevents light from leaking by shielding the opening between the pixel electrodes using the storage electrode. Since the storage electrode is close to the opening between the pixel electrodes, the width of overlapping between the electrode and the pixel electrode can be reduced. Furthermore, since the storage electrode is formed on the same substrate as the pixel electrode, it is not necessary to consider a misalign margin, so that the width at which the pixel electrode and the storage electrode overlap can be reduced. Therefore, the aperture ratio increases.

Hereinafter, the present invention will be described in detail with reference to the drawings.

2 is a schematic diagram illustrating a driving principle of a liquid crystal display device.

Referring to FIG. 2, a plurality of data lines 102 are formed on the array substrate to be spaced apart by a predetermined distance in a first direction, and the plurality of gate lines 203 are a predetermined distance in a second direction perpendicular to the first direction. It is formed by spaced apart. The data line 102 and the gate line 203 are formed at different heights from the array substrate.

One pixel is defined by an area surrounded by each data line 102 and each gate line 203. One pixel includes a thin film transistor 104, a storage capacitor 202, and a liquid crystal capacitor (capacitor 201 formed between a pixel electrode and a common electrode). The thin film transistor 104 includes a drain electrode D, a gate electrode G, and a source electrode S.

The gate electrode D of the thin film transistor 104 is electrically connected to the gate line 105. The source electrode S of the thin film transistor 104 is electrically connected to the data line 102. In addition, the drain electrode D of the thin film transistor 104 is electrically connected to the storage capacitor 202 and the liquid crystal capacitor electrode 201.

When a gate voltage is applied to the gate electrode G, the thin film transistor 104 is turned on. When the thin film transistor 104 is turned on, the pixel voltage of the data line 102 is applied to the storage capacitor 202 and the liquid crystal capacitor 201 through the thin film transistor 104. When the pixel voltage is applied to the liquid crystal capacitor 201, the arrangement of the liquid crystal placed between the common electrode and the pixel electrode constituting the liquid crystal capacitor is changed to change the optical characteristics. The image is represented by such a change in optical characteristics.

The storage capacitor 202 prevents the pixel voltage applied to the pixel electrode of the liquid crystal capacitor 201 from changing when the voltage around the data ends.

The pixel electrode of the liquid crystal capacitor 201 includes indium tin oxide (ITO) or indium zinc oxide. Indium tin oxide and indium zinc oxide have good conductivity as transparent materials.

3A is a layout of an array substrate according to a first exemplary embodiment of the present invention, and FIG. 3B is a schematic cross-sectional view of FIG. 3A.

3A and 3B, the array substrate according to the first embodiment of the present invention is a transparent substrate 108, a plurality of pixel electrodes 101, a switching element 104, a data line 102, a gate line 105. ) And storage electrode 103b.

The plurality of pixel electrodes 101 are formed to be spaced apart from each other by the first distance d1 on the transparent substrate 108 and the transparent substrate 108. In addition, the plurality of pixel electrodes 101 are arranged in a matrix. The pixel electrode includes indium tin oxide (ITO) or indium zinc oxide. Indium tin oxide and indium zinc oxide have good conductivity as transparent materials.

The switching element 104 includes a gate electrode G, a drain electrode D, and a source electrode S, and the drain electrode D is electrically connected to each of the pixel electrodes 101, respectively. The data line 102 is spaced apart from the transparent substrate 108 and the transparent substrate 108 by a second distance d2. In addition, the data line is disposed between the pixel electrodes.

The data line 102 is electrically connected to the source electrode S and is formed to have a width of a first length W1 to apply a pixel voltage to the pixel electrode 101. About 3.0 micrometers-4.0 micrometers are suitable for the range of 1st length W1, Preferably 3.5 micrometers is preferable. According to the first embodiment of the present invention, the data line 102 may overlap with the storage electrode 103b to generate parasitic capacitance. Therefore, the smaller the width of the data line 102 is, the better. However, when the width of the data line 102 becomes smaller than 3.0 μm, the probability of disconnection of the data line 102 increases. In particular, there is a high possibility of disconnection at the part having a step in the lower part.

The gate line 105 protrudes from the gate electrode G. That is, the gate line 105 is electrically connected to transmit an electrical signal for turning on and off the switching element 104.

The storage electrode 103b is formed to be spaced apart from the transparent substrate 108 and the transparent substrate 108 by a third distance d3. In addition, the storage electrode 103b is disposed between the pixel electrodes 101. In addition, the storage electrode 103b overlaps the storage electrode 103b with the two pixel electrodes 101 adjacent to each other by a second length W2 and a third length W3, respectively.

The second length W2 is in the range of about 2.5 μm to 3.5 μm, with a range of approximately 3 μm being appropriate. The third length W3 ranges from about 4.5 μm to 5.5 μm, with a range of approximately 5 μm being appropriate.

Since the pretilt angle of the liquid crystal of the pixel electrode or the arrangement of the liquid crystals is not symmetrical, the second length W2 and the third length W3 are different from each other.

The storage electrode 103b is formed on the same substrate as the data line 102 and the pixel electrode 101. Therefore, when the opening 106 is shielded using the storage electrode 103a, since the misaligned margin does not need to be considered as in the related art, the width of the margin can be reduced. In addition, since the distance between the storage electrode 103a and the opening 106 is close, less light is spread. Therefore, the width of the second length W2 and the third length W3, which is the length at which the storage electrode 103a and the data line 102 overlap, is reduced.

As a result, the aperture ratio is improved.

4A is a layout of an array substrate according to a second exemplary embodiment of the present invention, and FIG. 4B is a schematic cross-sectional view of FIG. 4A.

4A and 4B are the same as FIGS. 3A and 3B except for the shape of the storage electrode. Therefore, the same reference numeral is used for the same component, and the description of the same component is omitted.

4A and 4B, an array substrate according to a second embodiment of the present invention may include a transparent substrate 108, a plurality of pixel electrodes 101, a switching element 104, a data line 102, and a gate line 105. ) And storage electrode 103c.

The storage electrode 103c includes a window 109 having a width of a fourth length W4, and the fourth length W4 is formed to be smaller than the first length W1 to define the window as an inner edge of the storage electrode and the data. The outer edges of the line overlap.

Thus, light passing through the window 109 is blocked by the data line 102. In addition, the opening 109 is blocked by the storage electrode 103c so that light does not leak.

As such, when the storage electrode 103c includes the window 109, parasitic capacitance generated between the data line 102 and the storage electrode 103c may be reduced.

When parasitic capacitance occurs, power consumption increases. Therefore, when the window 109 is formed inside the storage electrode to reduce the overlapping area with the data line 102, power consumption is reduced.

5A and 5B are schematic plan views illustrating the shape of a window formed in the data line of FIG. 4A, respectively.

5A and 5B, the shape of the window 109 may be variously modified. The shape of the window 109 included in the storage electrode is not limited to the window 109 illustrated in FIGS. 5A and 5B.                     

That is, various modifications are possible as long as the area overlapping with the data line is reduced.

6 is a schematic cross-sectional view of a liquid crystal display.

Referring to FIG. 6, the liquid crystal display includes a first substrate (array substrate) 502, a second substrate (color filter substrate) 501, and a liquid crystal layer 506. The liquid crystal layer 506 is disposed between the first substrate 502 and the second substrate 501.

The first substrate 502 includes a storage electrode 103b and a pixel electrode 101.

The storage electrode 103b is formed on the first transparent substrate 511. A second insulating layer 509 is formed on the storage electrode 103b to cover the entire first transparent substrate 511. The data line 102 is formed on the second insulating layer 509 and is positioned above the storage electrode 103b. The first insulating layer 508 is again formed on the storage electrode 103b to cover the entire second insulating layer 509.

The plurality of pixel electrodes 101 are formed on the first insulating film 508. The plurality of pixel electrodes 101 are arranged in a matrix shape. Each pixel electrode 101 is shielded by the storage electrode 103b so that light does not leak.

The second substrate 501 includes a color filter 504 and a common electrode 512.

The color filter 504 is formed on the second transparent substrate 503. The color filter 504 includes a red color filter R, a green color filter G, and a blue color B filter.

The planarization layer 505 is coated on the color filter 504, and the common electrode 512 is formed on the planarization layer 505. Like the pixel electrode 101, the common electrode 512 includes indium tin oxide (ITO) or indium zinc oxide (Indium Zinc Oxide). The common electrode 512 is formed to face the pixel electrode 101. The common electrode 512 is applied with a reference potential. The pixel voltage is applied to the pixel electrode 101. Therefore, an electric field is formed between the pixel electrode 101 and the common electrode 512, and the arrangement of liquid crystal molecules of the liquid crystal layer 506 having dielectric anisotropy is changed. Liquid crystals also have refractive index anisotropy, so when the arrangement is changed, the transmittance of light passing through the corresponding pixel is changed to adjust the amount of light, and the light passes through the color filter to display a specific color.

The image is displayed by the combination of these pixels.

In the above, a typical twisted nematic liquid crystal display has been described as an example. However, it is a matter of course that the present invention is applicable to a liquid crystal display device having a storage electrode.

The present invention prevents light from leaking by shielding the opening between the pixel electrodes using the storage electrode. Since the storage electrode is close to the opening between the pixel electrodes, the width of overlapping between the electrode and the pixel electrode can be reduced. Furthermore, since the storage electrode is formed on the same substrate as the pixel electrode, it is not necessary to consider a misalign margin, so that the width at which the pixel electrode and the storage electrode overlap can be reduced. Therefore, the aperture ratio increases.

While the above has been described with reference to the preferred embodiments of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated that it can be changed.

Claims (18)

Transparent substrate; A plurality of pixel electrodes spaced apart by a first distance from the transparent substrate and an upper portion of the transparent substrate, and arranged in a matrix; A plurality of switching elements including a gate electrode, a drain electrode formed on the gate electrode, and a source electrode spaced apart from the drain electrode, wherein the drain electrode is electrically connected to each of the pixel electrodes; A data line spaced apart by a second distance from the transparent substrate to an upper portion of the transparent substrate, disposed between the pixel electrodes, electrically connected to the source electrode, and formed to have a width of a first length to apply a pixel voltage to the pixel electrode; ; A gate line electrically connected to the gate electrode to transfer an electrical signal for turning on and off the switching device; And A light blocking layer formed to be spaced apart by a third distance from the transparent substrate and an upper portion of the transparent substrate, and formed to overlap with the data lines adjacent to each other; And the light blocking layer overlaps adjacent pixel electrodes with different lengths. The array substrate of claim 1, wherein the light blocking layer is a storage wiring. delete Transparent substrate; A plurality of pixel electrodes spaced apart by a first distance from the transparent substrate and an upper portion of the transparent substrate, and arranged in a matrix; A plurality of switching elements including a gate electrode, a drain electrode formed on the gate electrode, and a source electrode spaced apart from the drain electrode, wherein the drain electrode is electrically connected to each of the pixel electrodes; A data line spaced apart by a second distance from the transparent substrate to an upper portion of the transparent substrate, disposed between the pixel electrodes, electrically connected to the source electrode, and formed to have a width of a first length to apply a pixel voltage to the pixel electrode; ; A gate line electrically connected to the gate electrode to transfer an electrical signal for turning on and off the switching device; And A plurality of storage electrodes disposed on the transparent substrate and spaced apart from each other by a third distance, and including a plurality of storage electrodes disposed between the pixel electrodes, wherein the storage electrodes and the two neighboring pixel electrodes each have a second length. And overlap by a third length, And the second length and the third length are each different from each other. The array substrate of claim 4, wherein the second distance is smaller than the first distance. The array substrate of claim 4, wherein the third distance is smaller than the second distance. delete The storage device of claim 4, wherein the storage electrode comprises a window having a width of a fourth length, and the fourth length is formed to be smaller than the first length, so that an inner edge of the storage electrode of the window and the data line are formed. Array substrate, characterized in that the outer edge overlap. Forming a plurality of pixel electrodes spaced apart from each other by a first distance between the transparent substrate and the transparent substrate and arranged in a matrix; Forming a plurality of switching elements including a gate electrode, a drain electrode formed on the gate electrode, and a source electrode spaced apart from the drain electrode, wherein the drain electrode is electrically connected to each of the pixel electrodes; A gate line spaced apart from the transparent substrate by a second distance, disposed between the pixel electrodes, and electrically connected to the gate electrode to form a gate line for transmitting an electrical signal for turning on and off the switching element; Doing; Forming a data line electrically connected to the source electrode, the data line having a width of a first length to apply a pixel voltage to the pixel electrode; And A plurality of storage electrodes formed on the transparent substrate and spaced apart from each other by a third distance, and disposed between the pixel electrodes, wherein the storage electrodes and the two neighboring pixel electrodes each have a second length. And forming a storage electrode overlapped by a third length; And the second length and the third length are each different from each other. 10. The method of claim 9, wherein said second distance is less than said first distance. 10. The method of claim 9, wherein said third distance is less than said second distance. delete 10. The method of claim 9, wherein the storage electrode comprises a window having a width of a fourth length, the fourth length is formed to be smaller than the first length to the inner edge of the storage electrode of the window and the data line Array substrate manufacturing method characterized in that the outer edge overlap. I) a first transparent substrate, ii) a plurality of pixel electrodes formed spaced apart by a first distance from the first transparent substrate and the first transparent substrate, and arranged in a matrix, iii) a gate electrode, and an upper portion of the gate electrode A plurality of switching elements including a drain electrode formed on the first electrode and a source electrode spaced apart from the drain electrode, wherein the drain electrode is electrically connected to each of the pixel electrodes, respectively, iv) on the first transparent substrate and the first transparent substrate. A data line spaced apart by a second distance, disposed between the pixel electrodes, electrically connected to the source electrode, and formed to have a width of a first length to apply a pixel voltage to the pixel electrode; A gate line connected to the gate line for transmitting an electrical signal for turning on and off the switching element, and vi) the first transparent substrate; A plurality of storage electrodes formed on the first transparent substrate and spaced apart from each other by a third distance, and disposed between the pixel electrodes, wherein the storage electrodes and the two neighboring pixel electrodes each have a second length and a second length; A first substrate overlapped by three lengths; A second substrate including a second transparent substrate and formed to face the first substrate; And A liquid crystal layer interposed between the first substrate and the second substrate, And the second length and the third length are different from each other. The liquid crystal display of claim 14, wherein the second distance is smaller than the first distance. The liquid crystal display of claim 14, wherein the third distance is smaller than the second distance. delete 15. The storage device of claim 14, wherein the storage electrode comprises a window having a width of a fourth length, wherein the fourth length is formed to be smaller than the first length, the inner edge of the storage electrode of the window and the data line. A liquid crystal display device, wherein the outer edges overlap.

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