# Patent

## Title
Array substrate and manufacturing method thereof and liquid crystal display panel using the array substrate

## Abstract

A manufacturing method of an array substrate includes: providing a first substrate; forming a gate line, a data line, and a thin-film transistor array on the first substrate; forming a pixel electrode on the thin-film transistor array; depositing and forming a first passivation layer on the pixel electrode, the data line, and the thin-film transistor array; forming a black matrix on the first passivation layer; and forming a common electrode on the black matrix and the first passivation layer. The black matrix has a size that completely covers at least the data line such that when the common electrode is formed on the black matrix and the first passivation layer, a portion of the common electrode that corresponds exactly to the data line is completely spaced from the data line by the black matrix and the first passivation layer.

## Background
CROSS REFERENCE TO RELATED APPLICATIONS
This is a divisional application of co-pending U.S. patent application Ser. No. 14/236,867, filed on Feb. 3, 2014, which is a national stage of PCT application No. PCT/CN2013/091251, filed on Dec. 31, 2013, claiming foreign priority of Chinese Patent Application No. 201310670010.1, filed on Dec. 10, 2013.


BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of liquid crystal display technology, and in particular to an array substrate and a manufacturing method thereof and a display panel using the array substrate.
2. The Related Arts
Liquid crystal displays (LCDs) have a variety of advantages, such as thin device body, low power consumption, and being free of radiation, and are thus widely used. The development of the liquid crystal display industry brings in severer and severer performance requirements, such as performance related to high resolution, high brightness, wide view angle, and low power consumption, and associated techniques have been developed. Most of the liquid crystal displays that are currently available in the market are backlighting liquid crystal displays, which comprise a liquid crystal display panel and a backlight module. The operation principle of the liquid crystal display panel is that, with liquid crystal molecules interposed between two parallel glass substrates, application of electricity is selectively carried out to control the liquid crystal molecules to change direction in order to refract out light emitting from the backlight module for generating images.
The liquid crystal display panel comprises a color filter (CF) substrate, a thin-film transistor (TFT) substrate, liquid crystal (LC) interposed between the CF substrate and the TFT substrate, and a sealant and the manufacturing process generally comprises: a front stage of array process (including thin film, yellow light, etching, and film stripping), an intermediate stage of cell process (including laminating the TFT substrate and the CF substrate), and a rear stage of assembling process (including mounting of drive ICs and printed circuit board).
The liquid crystal display panels that are available in the mainstream market can be classified in three categories, including TN (twisted nematic)/STN (super twisted nematic), IPS (in-plane switching)/FFS (fringe field switching), and VA (Vertical Alignment). The FFS display panel is superior to the TN display panel in respect of view angle and is superior to the IPS display panel in respect of liquid crystal transmittance efficiency and thus, besides applications thereof in small-sized devices, is also getting a wider and wider applications medium- and large-sized monitors and televisions.
An FFS display panel uses a fringe electric field between a common electrode and a pixel electrode to drive liquid crystal. To eliminate after images caused by residues of direct current, it is a common practice to use an alternate current mode for driving. Such an alternate current is achieved with a voltage applied to the common electrode. Thus, the uniformity of the voltage on the common electrode directly affect the displaying quality of images. When the voltage of the common electrode is not uniform, the images on the screen may show phenomena of being greenish and flickering.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an array substrate, which takes advantage of a black matrix formed thereon to reduce a parasitic capacitance between a common electrode and gate lines and data lines in order to help enhance uniformity of voltage on the common electrode and improve the phenomena of being greenish and flickering of an image on a screen.
Another object of the present invention is to provide a manufacturing method of an array substrate, which enables easy and efficient manufacture and an array substrate manufactured with such a method helps improve the displaying quality of a liquid crystal display panel.
A further object of the present invention is to provide a liquid crystal display panel, which comprises a black matrix formed on an array substrate in order to reduce a parasitic capacitance between a common electrode and gate lines and data lines to help enhance uniformity of voltage on the common electrode and improve the phenomena of being greenish and flickering of an image on a screen.
To achieve the above objects, the present invention provides an array substrate, which comprises: a first substrate, a gate line formed on the first substrate, a data line formed on the first substrate, a thin-film transistor array formed on the first substrate, a pixel electrode formed on the thin-film transistor array, a first passivation layer formed on the pixel electrode, the data line, and the thin-film transistor array, a black matrix formed on the first passivation layer, and a common electrode formed on the black matrix and the first passivation layer.
The thin-film transistor array comprises: a gate terminal formed on the first substrate, a gate insulation layer formed on the first substrate and the gate terminal, a semiconductor layer formed on the gate insulation layer, and a source/drain terminal formed on the semiconductor layer. The gate terminal is made of a metal of chromium, molybdenum, aluminum, or copper. The gate insulation layer is formed by depositing silicon through plasma enhanced chemical vapor deposition. The semiconductor layer is formed by depositing hydrogenated amorphous silicon.
The pixel electrode and the common electrode are each a transparent conductive layer. The pixel electrode and the common electrode are both made of indium tin oxide or indium zinc oxide. The first substrate is a glass substrate or a plastic substrate.
The gate insulation layer has a thickness of 2000-5000 Å. The gate terminal has a thickness of 2000-5000 Å. The semiconductor layer has a thickness of 2000-4000 Å. The first passivation layer has a thickness of 100-6000 Å. The source/drain terminal has a thickness of 1000-6000 Å. The pixel electrode has a thickness of 100-1000 Å. The common electrode has a thickness of 100-1000 Å. The black matrix has a thickness of 0.2-1.0 um.
The present invention also provides a manufacturing method of an array substrate, which comprising the following steps:
(1) providing a first substrate;
(2) forming a gate line, a data line, and a thin-film transistor array on the first substrate;
(3) forming a pixel electrode on the thin-film transistor array;
(4) depositing and forming a first passivation layer on the pixel electrode, the data line, and the thin-film transistor array;
(5) forming a black matrix on the first passivation layer; and
(6) forming a common electrode on the black matrix and the first passivation layer.
Step (2) comprises the following steps:
(2.1) forming a first metal layer on the first substrate and subjecting the first metal layer to a first photolithographic process according to a predetermined pattern to form a gate terminal and the gate line;
(2.2) applying plasma enhanced chemical vapor deposition to deposit silicon on the first substrate and the gate terminal and the gate line to form a gate insulation layer;
(2.3) applying plasma enhanced chemical vapor deposition to deposit hydrogenated amorphous silicon on the gate insulation layer to form a semiconductor layer and subjecting the semiconductor layer 56 to a second photolithographic process according to a predetermined pattern; and
(2.4) forming a second metal layer on the semiconductor layer and the gate insulation layer and subjecting the second metal layer to a third photolithographic process according to a predetermined pattern to form a source/drain terminal and a data line, so as to form the thin-film transistor array.
In step (3), a transparent conductive layer is formed on the thin-film transistor array and the transparent conductive layer is subjected to a fourth photolithographic process according to a predetermined pattern in order to form the pixel electrode;
in step (4), plasma enhanced chemical vapor deposition is applied to deposit and form a protective film on the pixel electrode, the data line, and the thin-film transistor array and the protective film is subjected to a fifth photolithographic process according to a predetermined pattern in order to form the first passivation layer;
in step (5), a coating process is applied to form a black matrix of a predetermined thickness on the first passivation layer and the black matrix is subjected to a sixth photolithographic process; and
in step (6), a transparent conductive layer is formed on the black matrix and the first passivation layer and the transparent conductive layer is subjected to a seventh photolithographic process according to a predetermined pattern in order to form the common electrode.
The first substrate is a glass substrate or a plastic substrate. The gate insulation layer has a thickness of 2000-5000 Å. The gate terminal has a thickness of 2000-5000 Å. The semiconductor layer has a thickness of 2000-4000 Å. The first passivation layer has a thickness of 100-6000 Å. The source/drain terminal has a thickness of 1000-6000 Å. The pixel electrode has a thickness of 100-1000 Å. The common electrode has a thickness of 100-1000 Å. The black matrix has a thickness of 0.2-1.0 um.
The present invention further provides a liquid crystal display panel, which comprises: a array substrate, a color filter substrate, and a liquid crystal material hermetically sealed between the array substrate and the color filter substrate. The array substrate comprises: a first substrate, a gate line formed on the first substrate, a data line formed on the first substrate, a thin-film transistor array formed on the first substrate, a pixel electrode formed on the thin-film transistor array, a first passivation layer formed on the pixel electrode, the data line, and the thin-film transistor array, a black matrix formed on the first passivation layer, and a common electrode formed on the black matrix and the first passivation layer. The color filter substrate comprises: a second substrate, a color filter formed on the second substrate, a second passivation layer formed on the color filter and the second substrate, and a spacer layer formed on the second passivation layer.
The thin-film transistor array comprises: a gate terminal formed on the first substrate, a gate insulation layer formed on the first substrate and the gate terminal, a semiconductor layer formed on the gate insulation layer, and a source/drain terminal formed on the semiconductor layer, the gate terminal being made of a metal of chromium, molybdenum, aluminum, or copper, the gate insulation layer being formed by depositing silicon through plasma enhanced chemical vapor deposition, the semiconductor layer being formed by depositing hydrogenated amorphous silicon;
the pixel electrode and the common electrode are each a transparent conductive layer, the pixel electrode and the common electrode being both made of indium tin oxide or indium zinc oxide, the first substrate being a glass substrate or a plastic substrate;
the gate insulation layer has a thickness of 2000-5000 Å, the gate terminal having a thickness of 2000-5000 Å, the semiconductor layer having a thickness of 2000-4000 Å, the first passivation layer having a thickness of 100-6000 Å, the source/drain terminal having a thickness of 1000-6000 Å, the pixel electrode having a thickness of 100-1000 Å, the common electrode having a thickness of 100-1000 Å, the black matrix having a thickness of 0.2-1.0 um; and
the second substrate is a glass substrate or plastic substrate, the color filter comprising: a red filter, a blue filter, and a green filter.
The efficacy of the present invention is that the present invention provides an array substrate and a manufacturing method thereof and a liquid crystal display panel using the array substrate, in which a black matrix is formed on the array substrate to increase the distance between a common electrode and a data line and a gate line in order to reduce a parasitic capacitance between the common electrode and the gate line and the data line to help enhance uniformity of voltage on the common electrode and improve the phenomena of being greenish and flickering of a screen image. Further, the manufacturing method of the array substrate is simple.
For better understanding of the features and technical contents of the present invention, reference will be made to the following detailed description of the present invention and the attached drawings. However, the drawings are provided for the purposes of reference and illustration and are not intended to impose limitations to the present invention.



BRIEF DESCRIPTION OF THE DRAWINGS
The technical solution, as well as other beneficial advantages, of the present invention will be apparent from the following detailed description of embodiments of the present invention, with reference to the attached drawing. In the drawing:
FIG. 1 is a top plan view showing of an array substrate according to the present invention;
FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;
FIG. 3 is a cross-sectional view taken along line B-B of FIG. 1;
FIG. 4 is a flow chart illustrating a manufacturing method of an array substrate according to the present invention;
FIGS. 5-11 are schematic views illustrating the process of the manufacturing method of the array substrate according to the present invention; and
FIG. 12 is a schematic view illustrating the structure of a liquid crystal display panel according to the present invention.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
To further expound the technical solution adopted in the present invention and the advantages thereof, a detailed description is given to a preferred embodiment of the present invention and the attached drawings.
Referring to FIGS. 1-3, the present invention provides an array substrate. The array substrate is applicable to an FFS (Fringe Field Switching) display panel and comprises, specifically: a first substrate 32, a gate line (not shown) formed on the first substrate 32, a data line 34 formed on the first substrate 32, a thin-film transistor array (not labeled) formed on the first substrate 32, a pixel electrode 36 formed on the thin-film transistor array, a first passivation layer 38 formed on the pixel electrode 36, the data line 34, and the thin-film transistor array, a black matrix 42 formed on the first passivation layer 38, and a common electrode 44 formed on the black matrix 42 and the first passivation layer 38. The common electrode 44 is located above the data line 34 and the gate line and the black matrix 42 is arranged between the common electrode 44 and the data line 34 and the gate line to help increase the distance therebetween and thus reduce the parasitic capacitance between the common electrode 44 and the gate line and the data line 34 so as to help enhance uniformity of voltage on the common electrode 44.
Specifically, the thin-film transistor array comprises: a gate terminal 52 formed on the first substrate 32, a gate insulation layer 54 formed on the first substrate 32 and the gate terminal 52, a semiconductor layer 56 formed on the gate insulation layer 54, and a source/drain terminal 58 formed on the semiconductor layer 56. The gate terminal 52 has a thickness of 2000-5000 Å. The gate insulation layer 54 has a thickness of 2000-5000 Å. The gate terminal 52 is made of a metal of chromium (Cr), molybdenum (Mo), aluminum (Al), or copper (Cu). The gate insulation layer 54 is formed by depositing silicon (Si) through plasma enhanced chemical vapor deposition. The semiconductor layer 56 is formed by depositing hydrogenated amorphous silicon (a-Si:H).
The gate line is formed of a non-thin-film-transistor-array portion of a first metal layer. The data line 34 is formed of a non-thin-film-transistor-array portion of a second metal layer.
The pixel electrode 36 and the common electrode 44 are each a transparent conductive layer. In the instant embodiment, the pixel electrode 36 and the common electrode 44 are both made of indium tin oxide or indium zinc oxide. The first substrate 32 is a glass substrate or a plastic substrate and in the instant embodiment, is preferably a glass substrate.
In the instant embodiment, thicknesses of other film layers are specified as follows. The thickness of the first passivation layer 38 is 2000-5000 Å. The thickness of the semiconductor layer 56 is 100-6000 Å. The thickness of the source/drain terminal 58 is 1000-6000 Å. The thickness of the pixel electrode 36 is 100-1000 Å. The thickness of the common electrode 44 is 100-1000 Å. The thickness of the black matrix 42 is 0.2-1.0 um.
Referring to FIGS. 4-11, the present invention also provides a manufacturing method of an array substrate, which comprises the following steps:
Step 1: providing a first substrate 32.
The first substrate 32 is a glass substrate or a plastic substrate and in the instant embodiment, is preferably a glass substrate.
Step 2: forming a gate line (not shown), a data line 34, and a thin-film transistor array (not labeled) on the first substrate 42.
This step can be further divided as the following steps:
Step 2.1: forming a first metal layer on the first substrate 42 and subjecting the first metal layer to a first photolithographic process according to a predetermined pattern to form a gate terminal 52 and the gate line.
Specifically, the first photolithographic process comprises steps including: coating, exposure, development, etching, and peeling, wherein etching is mask based wet etching.
The gate terminal 52 has a thickness of 2000-5000 Å.
Step 2.2: applying plasma enhanced chemical vapor deposition (PECVD) to deposit silicon on the first substrate 32 and the gate terminal 52 and the gate line to form a gate insulation layer 54.
The gate insulation layer has a thickness of 2000-4000 Å.
Step 2.3: applying plasma enhanced chemical vapor deposition to deposit hydrogenated amorphous silicon on the gate insulation layer 54 to form a semiconductor layer 56 and subjecting the semiconductor layer 56 to a second photolithographic process according to a predetermined pattern.
The second photolithographic process comprises steps including: coating, exposure, development, etching, and peeling, wherein etching is dry etching.
The semiconductor layer 56 has a thickness of 100-6000 Å.
Step 2.4: forming a second metal layer on the semiconductor layer 56 and the gate insulation layer 54 and subjecting the second metal layer to a third photolithographic process according to a predetermined pattern to form a source/drain terminal 58 and a data line 34, so as to form the thin-film transistor array.
The third photolithographic process comprises steps including: coating, exposure, development, etching, and peeling, wherein etching is wet etching.
The source/drain terminal 58 has a thickness of 1000-6000 Å.
Step 3: forming a pixel electrode 36 on the thin-film transistor array.
A transparent conductive layer is formed on the thin-film transistor array (the source/drain terminal 58 and the gate insulation layer 54) and the transparent conductive layer is subjected to a fourth photolithographic process according to a predetermined pattern in order to form the pixel electrode 36. The fourth photolithographic process comprises steps including: coating, exposure, development, etching, and peeling, wherein etching is mask based wet etching.
The pixel electrode 36 has a thickness of 100-1000 Å.
Step 4: depositing and forming a first passivation layer 38 on the pixel electrode 36, the data line 34, and the thin-film transistor array.
Plasma enhanced chemical vapor deposition is applied to deposit and form a protective film on the pixel electrode 36, the data line 34, and the thin-film transistor array and the protective film is subjected to a fifth photolithographic process according to a predetermined pattern in order to form the first passivation layer 38. The fifth photolithographic process comprises steps including: coating, exposure, development, etching, and peeling, wherein etching is dry etching or wet etching.
The first passivation layer 38 has a thickness of 2000-5000 Å.
Step 5: forming a black matrix 42 on the first passivation layer 38.
A coating process is applied to form a black matrix 42 of a predetermined thickness on the first passivation layer 38 and the black matrix 42 is subjected to a sixth photolithographic process. The black matrix 42 has a thickness of 0.2-1.0 um.
Step 6: forming a common electrode 44 on the black matrix 42 and the first passivation layer 38.
A transparent conductive layer is formed on the black matrix 42 and the first passivation layer 38 and the transparent conductive layer is subjected to a seventh photolithographic process according to a predetermined pattern in order to form the common electrode 44. The common electrode 44 has a thickness of 100-1000 Å.
Referring to FIG. 12, the present invention further provides a liquid crystal display panel. The liquid crystal display panel is an FFS display panel and comprises, specifically: an array substrate 30, a color filter substrate 50, and a liquid crystal material 60 hermetically sealed between the array substrate 30 and the color filter substrate 50. The array substrate 30 comprises: a first substrate 32, a gate line (not shown) formed on the first substrate 32, a data line 34 formed on the first substrate 32, a thin-film transistor array (not labeled) formed on the first substrate 32, a pixel electrode 36 formed on the thin-film transistor array, a first passivation layer 38 formed on the pixel electrode 36, the data line 34, and the thin-film transistor array, a black matrix 42 formed on the first passivation layer 38, and a common electrode 44 formed on the black matrix 42 and the first passivation layer 38. The color filter substrate 50 comprises: a second substrate 61, a color filter 62 formed on the second substrate 61, a second passivation layer 67 formed on the color filter 62 and the second substrate 61, and a spacer layer 68 formed on the second passivation layer 67. The common electrode 44 is located above the data line 34 and the gate line and the black matrix 42 is arranged between the common electrode 44 and the data line 34 and the gate line to help increase the distance therebetween and thus reduce the parasitic capacitance between the common electrode 44 and the gate line and the data line 34 so as to help enhance uniformity of voltage on the common electrode 44.
Specifically, the thin-film transistor array comprises: a gate terminal 52 formed on the first substrate 32, a gate insulation layer 54 formed on the first substrate 32 and the gate terminal 52, a semiconductor layer 56 formed on the gate insulation layer 54, and a source/drain terminal 58 formed on the semiconductor layer 56. The gate terminal 52 has a thickness of 2000-5000 Å. The gate insulation layer 54 has a thickness of 2000-5000 Å. The gate terminal 52 is made of a metal of chromium, molybdenum, aluminum, or copper. The gate insulation layer 54 is formed by depositing silicon through plasma enhanced chemical vapor deposition. The semiconductor layer 56 is formed by depositing hydrogenated amorphous silicon.
The gate line is formed of a non-thin-film-transistor-array portion of the first metal layer. The data line 34 is formed of a non-thin-film-transistor-array portion of the second metal layer.
The pixel electrode 36 and the common electrode 44 are each a transparent conductive layer. In the instant embodiment, the pixel electrode 36 and the common electrode 44 are both made of indium tin oxide or indium zinc oxide. The first substrate 32 is a glass substrate or a plastic substrate and in the instant embodiment, is preferably a glass substrate.
In the instant embodiment, thicknesses of other film layers are specified as follows. The thickness of the first passivation layer 38 is 2000-5000 Å. The thickness of the semiconductor layer 56 is 100-6000 Å. The thickness of the source/drain terminal 58 is 1000-6000 Å. The thickness of the pixel electrode 36 is 100-1000 Å. The thickness of the common electrode 44 is 100-1000 Å. The thickness of the black matrix 42 is 0.2-1.0 um.
The second substrate 61 is a glass substrate or a plastic substrate. The color filter 62 comprises: a red filter 63, a blue filter 64, and a green filter 66.
In summary, the present invention provides an array substrate and a manufacturing method thereof and a liquid crystal display panel using the array substrate, in which a black matrix is formed on the array substrate to increase the distance between a common electrode and a data line and a gate line in order to reduce a parasitic capacitance between the common electrode and the gate line and the data line to help enhance uniformity of voltage on the common electrode and improve the phenomena of being greenish and flickering of a screen image. Further, the manufacturing method of the array substrate is simple.
Based on the description given above, those having ordinary skills of the art may easily contemplate various changes and modifications of the technical solution and technical ideas of the present invention and all these changes and modifications are considered within the protection scope of right for the present invention.

## Claims

1. A manufacturing method of an array substrate, comprising the following steps:
(1) providing a first substrate;
(2) forming a gate line, a data line, and a thin-film transistor array on the first substrate;
(3) forming a pixel electrode on the thin-film transistor array;
(4) depositing and forming a first passivation layer on the pixel electrode, the data line, and the thin-film transistor array;
(5) forming a black matrix on the first passivation layer; and
(6) forming a common electrode on the black matrix and the first passivation layer;
wherein the black matrix is formed on the first passivation layer that is deposited on the pixel electrode, the data line, and the thin-film transistor array such that the black matrix is in direct contact engagement with a surface of the first passivation layer, wherein the black matrix has a size that completely covers at least the data line; and
wherein the common electrode is formed on the back matrix and the first passivation layer such that the common electrode has a first portion that is in direct contact engagement with the surface of the first passivation layer and a second portion in direct contact engagement with a surface of the black matrix that is distant from the surface of the first passivation layer and exactly corresponding to at least the data line and completely spaced from the data line by the black matrix and the first passivation layer.

2. The manufacturing method of the array substrate as claimed in claim 1, wherein step (2) comprises the following steps:
(2.1) forming a first metal layer on the first substrate and subjecting the first metal layer to a first photolithographic process according to a predetermined pattern to form a gate terminal and the gate line;
(2.2) applying plasma enhanced chemical vapor deposition to deposit silicon on the first substrate and the gate terminal and the gate line to form a gate insulation layer;
(2.3) applying plasma enhanced chemical vapor deposition to deposit hydrogenated amorphous silicon on the gate insulation layer to form a semiconductor layer and subjecting the semiconductor layer 56 to a second photolithographic process according to a predetermined pattern; and
(2.4) forming a second metal layer on the semiconductor layer and the gate insulation layer and subjecting the second metal layer to a third photolithographic process according to a predetermined pattern to form a source/drain terminal and a data line, so as to form the thin-film transistor array.

3. The manufacturing method of the array substrate as claimed in claim 1, wherein in step (3), a transparent conductive layer is formed on the thin-film transistor array and the transparent conductive layer is subjected to a fourth photolithographic process according to a predetermined pattern in order to form the pixel electrode;
in step (4), plasma enhanced chemical vapor deposition is applied to deposit and form a protective film on the pixel electrode, the data line, and the thin-film transistor array and the protective film is subjected to a fifth photolithographic process according to a predetermined pattern in order to form the first passivation layer;
in step (5), a coating process is applied to form a black matrix of a predetermined thickness on the first passivation layer and the black matrix is subjected to a sixth photolithographic process; and
in step (6), a transparent conductive layer is formed on the black matrix and the first passivation layer and the transparent conductive layer is subjected to a seventh photolithographic process according to a predetermined pattern in order to form the common electrode.

4. The manufacturing method of the array substrate as claimed in claim 2, wherein the first substrate is a glass substrate or a plastic substrate, the gate insulation layer having a thickness of 2000-5000 Å, the gate terminal having a thickness of 2000-5000 Å, the semiconductor layer having a thickness of 2000-4000 Å, the first passivation layer having a thickness of 100-6000 Å, the source/drain terminal having a thickness of 1000-6000 Å, the pixel electrode having a thickness of 100-1000 Å, the common electrode having a thickness of 100-1000 Å, the black matrix having a thickness of 0.2-1.0 um.