KR20060059481A - Array substrate having enhanced aperture ratio, method of manufacturing the same and liquid crystal display apparatus having 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 to form 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 or off the switching element.

The storage electrode is spaced apart by a third distance from the transparent substrate to the upper portion of the transparent substrate, and a window is formed in the center to reduce parasitic capacitance with the data line. In addition, in order to prevent electric field distortion that may occur between the storage electrode and the pixel electrode, the distance between the data line and the neighboring pixel electrode is formed to be different, and the light blocking film of the corresponding color filter substrate is asymmetric about the data line. It forms as an enemy and effectively blocks light leakage.

Story electrode, data line, pixel electrode, light blocking film, aperture ratio, light leakage

Description

Array substrate with improved aperture ratio, manufacturing method thereof, and liquid crystal display device including the same {ARRAY SUBSTRATE HAVING ENHANCED APERTURE 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 cross-sectional view taken along the line II 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 cross-sectional view taken along the line II-II 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.

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

6A to 6E are layout views according to a method of manufacturing a liquid crystal display according to the present invention.

<Description of the symbols for the main parts of the drawings>

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

202: storage capacitor 501: first substrate

502: second substrate 503: second transparent substrate

504: color filter 505: planarization film

506 liquid crystal layer 508 first insulating film

509: second insulating film 510: active layer

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 display devices 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 cross-sectional view taken along the line I-I 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 a 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 electrode of the thin film transistor 104, and the gate line 105 is electrically connected to the gate electrode of the thin film transistor 104. The drain electrode 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. do. 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 a 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 liquid crystal layer (not shown) positioned is changed, so that the optical properties of the liquid crystal molecules are changed.

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 the edge portion or the center portion of the pixel electrode 101.

However, in the conventional array substrate having such a structure, an opening 106 is formed between the storage electrode 103a and the data line 102 so that light passing through the opening 106 is diffracted and leaks. In addition, since the light blocking film 107 is formed in the color filter substrate at a predetermined distance away from the opening 106 through which light leaks, the opening 106 has a light blocking film 107 having a predetermined width to prevent light leakage. Form with a margin of margin around it. As described above, in the case of the conventional array substrate, the aperture ratio is lowered due to the width of the light blocking film 107 widened to prevent light leakage.

Further, the light blocking film 107 is formed on the color filter substrate. In the liquid crystal display, an array substrate and a color filter substrate are formed, and then the two substrates are joined 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 some margin to align. For this reason, the left and right margins of the light shielding film 107 are 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 so as to have a first gap and a second gap with the neighboring pixel electrode, and are electrically connected to the source electrode to apply a pixel voltage to the pixel electrode. The first interval and the second interval may vary from each other depending on the rubbing direction of the array substrate. The gate line is electrically connected to the gate electrode to transmit an electrical signal for turning on or off the switching element. The storage electrode is formed spaced apart by a third distance from the transparent substrate and the transparent substrate. The storage electrode may include a plurality of storage electrodes disposed to overlap the neighboring pixel electrode by a first length and a second length. An opening may be formed in the storage electrode, for example.

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. And forming a plurality of switching elements electrically connected to the respective pixel electrodes, the drain electrodes being spaced apart by a second distance from the transparent substrate to an upper portion of the transparent substrate, and disposed between the pixel electrodes. Forming a data line electrically connected to the source electrode at first and second intervals of the pixel electrode, the data line being formed to apply a pixel voltage to the pixel electrode, and electrically connected to the gate electrode; Forming a gate line transferring an electrical signal for turning on or off the switching element And forming a plurality of storage electrodes spaced apart by a third distance from the transparent substrate and an upper portion of the transparent substrate, and arranged to overlap the neighboring pixel electrode by a first length and a second length. .

An opening may be formed in the storage electrode, for example.                     

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 to form a pixel voltage to the pixel electrode, and v) an electrical line electrically connected to the gate electrode to turn on or off the switching element. A gate line for transmitting a signal, and vi) a third distance between the first transparent substrate and the first transparent substrate, the gate line being spaced apart from each other by a third distance, A plurality of storage electrodes are formed to have a right side and are disposed to overlap at least a portion of the neighboring pixel electrodes.

The storage electrode and the two pixel electrodes neighboring each other overlap each other by a first length and a second length, respectively.

An opening may be formed in the storage electrode, for example.

The second substrate may include a light blocking layer that faces the first substrate and is disposed to correspond to the neighboring pixel electrode and is asymmetrical about the data line.

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. 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. In addition, a parasitic capacitance with a data line can be reduced by forming a window in the center of the streak electrode, and a strong electric field distortion can be prevented by adjusting a gap width between the data line and a neighboring pixel electrode.

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 105 is 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 105 are formed at different heights from the array substrate to the insulating film.

One pixel is defined by an area surrounded by each data line 102 and each gate line 105. 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, a gate electrode, and a source electrode.

The gate electrode G 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, 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 surrounding voltage changes after the image data is input.

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 cross-sectional view taken along the line II-II of FIG. 3A.

3A and 3B, an array substrate according to a first embodiment of the present invention may include a plurality of pixel electrodes 101, a switching element 104, a data line 102, a gate line 105, and a 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, a drain electrode and a source electrode, and the drain electrode 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 102 is disposed between the pixel electrodes.

The data line 102 is electrically connected to the source electrode and formed to apply a pixel voltage to the pixel electrode 101. 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 width of the data line 102 in the overlapping area is preferably smaller than the width of the data line 102 in the non-overlapping area.

Gate line 105 protrudes from the gate electrode. That is, the gate line 105 is electrically connected to the gate line 105 to transmit an electrical signal for turning on or 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 first length W2 and a second length W3, respectively.

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

In addition, in order to prevent light leakage caused by a change in the liquid crystal array which may be caused by strong electric field distortion between the storage electrode 103b and the pixel electrode 101, the first interval W4 and the second of the neighboring pixel electrode and the data line. The intervals W5 are formed to be different from each other. The light blocking film 107 of the color filter substrate corresponding thereto is also formed to be asymmetrical about the data line 102 in order to prevent leakage light that may occur non-uniformly according to the rubbing direction of the liquid crystal with a minimum width.

In addition, 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. Therefore, the distance between the storage electrode 103b and the opening 106 is close, so that light is spread less. 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 numerals are used for the same components, and descriptions of the same components will be omitted.

4A and 4B, the array substrate according to the second 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 103c.

The storage electrode 103c forms a window 109 in the center to reduce parasitic capacitance that may occur between the data line 102.

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.

In addition, strong electric field distortion occurs due to a high voltage between the storage electrode 103c and the pixel electrode 101, so that the arrangement of the liquid crystals may vary. For example, when the rubbing direction of the array substrate proceeds from left to right, the arrangement of liquid crystals in the right pixel electrode in the neighboring pixel electrode is particularly affected by the electric field distortion. In order to prevent the electric field distortion, the widths of the intervals W4 and W5 are differently formed between the neighboring pixel electrodes 106 and the data lines 102. Preferably, the width of W5 is made wider than the width of W4.

In addition, the widths of the regions W2 and W3 where the storage electrode 103c and the pixel electrode 106 overlap each other are formed differently. Preferably, the width of W3 is made wider than the width of W2.

The leakage light due to the width change is formed by blocking the light blocking layer 107 so as to be asymmetric about the data line 102.

Therefore, light leakage is blocked by the storage electrode 103c and the light blocking film 107 of the color filter substrate.

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

Referring to FIG. 5, 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 is formed on the first insulating layer 508. The plurality of pixel electrodes 101 are arranged in a matrix shape. The opening between each pixel electrode 101 is shielded by the storage electrode 103b and the light blocking film 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. 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.

Referring to FIGS. 6A to 6E, a layout view according to a manufacturing method of a liquid crystal display device is described. First, in FIG. 6A, a conductive material is deposited on the insulating first substrate 511 to a predetermined thickness, and then a photosensitive film is coated thereon. The photoresist is patterned to form a photolithography mask, and the gate material 105 and the storage electrode 103b are formed by etching the conductive material by applying the photolithography mask. In addition, the storage electrode 103b in an area overlapping the data line may form a window 109 inside the storage electrode 130b to reduce parasitic capacitance occurring between the data line and the storage electrode 103b. have. The storage electrode 103b has a U-shaped structure as shown in the figure.

In FIG. 6B, after the gate line 105 is formed, an insulating material is coated on the entire surface of the resultant to form a gate insulating film (not shown), and then an amorphous silicon or polycrystalline silicon is coated on the gate insulating film to a predetermined thickness. After forming a predetermined photolithography mask on the silicon layer as shown in FIG. 6a and applying the same to the silicon layer to form an active layer 510 on the gate insulating layer in the gate line 105 region. do.

In FIG. 6C, after forming the active layer 510, a conductive material is deposited and a data line 102 is formed by patterning the deposited conductive material layer by applying a predetermined photo-etch mask.

6D and 6E, after forming the data line 102, an insulating material is deposited on the entire surface of the resultant to form a first insulating film 508, and a transparent electrode is deposited on the first insulating film 508. The transparent electrode is patterned by applying a predetermined photolithography mask to form the pixel electrode 101.

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 at which the storage electrode and the pixel electrode overlap 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.

In addition, in order to prevent electric field distortion generated between the storage electrode and the pixel electrode, the width of the gap between the data line and the pixel electrode is different from each other, and a light blocking film of the curly filter substrate is formed asymmetrically around the data line. To effectively block light leakage. Therefore, the aperture ratio increases.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. I can understand that you can.

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 and a source electrode, the drain electrodes being electrically connected to the respective pixel electrodes, respectively; The substrate is spaced apart from the transparent substrate by a second distance, and is disposed between the pixel electrodes and is electrically connected to the source electrode at first and second intervals with the neighboring pixel electrode. A data line formed to apply a pixel voltage; A gate line electrically connected to the gate electrode and transferring an electrical signal to turn on or off the switching device; And And a plurality of storage electrodes formed to be spaced apart by a third distance from the transparent substrate and an upper portion of the transparent substrate, and disposed to overlap the neighboring pixel electrode by a first length and a second length. The array substrate of claim 1, wherein the second distance is smaller than the first distance. The array substrate of claim 1, wherein the third distance is smaller than the second distance. The array substrate of claim 1, wherein the first and second intervals are different from each other. The array substrate of claim 1, wherein the first length and the second length are different from each other. The array substrate of claim 1, wherein a window is formed at a central portion of each of the plurality of storage electrodes. Forming a transparent substrate; Forming 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 shape; Forming a plurality of switching elements including a gate electrode, a drain electrode, and a source electrode, each of the drain electrodes being electrically connected to the respective pixel electrodes; The substrate is spaced apart from the transparent substrate by a second distance, and is disposed between the pixel electrodes and is electrically connected to the source electrode at first and second intervals with the neighboring pixel electrode. Forming a data line applying a pixel voltage; Forming a gate line electrically connected to the gate electrode to transmit an electrical signal for turning on or off the switching device; And And forming a plurality of storage electrodes spaced apart from each other by a third distance from the transparent substrate and above the transparent substrate, and arranged to overlap the neighboring pixel electrode by a first length and a second length. . 8. The method of claim 7, wherein said second distance is less than said first distance. 8. The method of claim 7, wherein said third distance is less than said second distance. 8. The method of claim 7, wherein the first and second intervals are different. 8. The array substrate of claim 7, wherein the first length and the second length are different from each other. 8. The method of claim 7, wherein a window is formed at a central portion of each of the plurality of storage electrodes. I) a first transparent substrate, ii) a plurality of pixel electrodes formed to be 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, a drain electrode and a source electrode A plurality of switching elements electrically connected to the respective pixel electrodes, respectively, iv) spaced apart from each other by a second distance between the first transparent substrate and the first transparent substrate and disposed between the pixel electrodes; And a data line electrically connected to the source electrode to apply a pixel voltage to the pixel electrode, and v) a gate electrically connected to the gate electrode to transfer an electrical signal to turn on or off the switching element. And vi) a third distance above the first transparent substrate and the first transparent substrate, the third transparent substrate being spaced apart from the neighboring pixel electrode. Fig first substrate including a plurality of storage electrodes arranged such that partly overlap; A second substrate facing the first substrate and including a second transparent substrate, the second substrate including a light blocking layer disposed to correspond to the neighboring pixel electrode and extending asymmetrically about the data line; And And a liquid crystal layer interposed between the first substrate and the second substrate. The liquid crystal display of claim 13, wherein the second distance is smaller than the first distance. The liquid crystal display of claim 13, wherein the third distance is smaller than the second distance. The liquid crystal display of claim 13, wherein the second length and the third length are different from each other. The liquid crystal display of claim 13, wherein the second length and the third length are different from each other. The liquid crystal display of claim 13, wherein a window is formed in a central portion of each of the plurality of storage electrodes.

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