CN111399292B - Array substrate, preparation method thereof and touch liquid crystal display device - Google Patents

Abstract

The invention provides an array substrate and a preparation method thereof, wherein the array substrate comprises a plurality of sub-pixels which are arranged in an array manner, each sub-pixel comprises a display pixel area and a photosensitive pixel area, a switch thin film transistor and a pixel electrode which are electrically connected are arranged in the display pixel area, and a photosensitive thin film transistor is arranged in the photosensitive pixel area. The invention provides a touch liquid crystal display device which comprises the array substrate. According to the array substrate, the preparation method thereof and the touch liquid crystal display device provided by the invention, the switch thin film transistor and the pixel electrode which are electrically connected are formed in the display pixel area of the array substrate, and the photosensitive thin film transistor is formed in the photosensitive pixel area of the array substrate, so that the manufacturing process of the photosensitive thin film transistor is compatible with that of the switch thin film transistor, and the cost is reduced while the remote sensing is realized.

Description

Array substrate and preparation method thereof, and touch liquid crystal display device

technical field

The present invention relates to the field of display technology, and in particular, to an array substrate, a preparation method thereof, and a touch-control liquid crystal display device.

Background technique

Thin film transistors are widely used in the display field, and new technologies such as oxide thin film transistors and low temperature polysilicon thin film transistors are constantly updated. In recent years, hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) technology has been widely used in switching elements of LCDs. At present, a-Si:H TFT technology is simple and suitable for large-area electronic devices, which is of great help to the development of the display industry.

In addition, the high photosensitivity properties of a-Si:H TFTs also provide development potential for the application of optical sensors. Using the electro-optical properties of a-Si:H thin films, a-Si:H TFTs can realize various value-added functions such as X-ray image sensing, fingerprint and optical touch display. Among these new TFT technologies, oversized interactive screens with remote touch capability are highly valued in meeting rooms and conference room applications, where LEDs or laser pointers are typically used to provide multi-point optical input Function. How to embed the photosensitive thin film transistor in the touch liquid crystal display device and be compatible with the TFT switching process of the touch liquid crystal display device is an urgent problem to be solved.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an array substrate, a preparation method thereof, and a touch-control liquid crystal display device, so as to solve the problem that the photosensitive thin film transistor of the existing touch-control liquid crystal device realizes remote touch control and the process of the touch-control liquid crystal display device cannot be compatible. .

The present invention solves its technical problems by adopting the following technical solutions.

The present invention provides an array substrate, the array substrate includes a plurality of sub-pixels arranged in an array, each sub-pixel includes a display pixel area and a photosensitive pixel area, and the display pixel area is provided with a switching thin film transistor and a pixel electrode that are electrically connected , a photosensitive thin film transistor is arranged in the photosensitive pixel area.

In one embodiment of the present invention, the array substrate includes a first data line and a first scan line electrically connected to the switching thin film transistor, and a second data line and a second scan line electrically connected to the photosensitive thin film transistor Wire.

The present invention also provides a touch-control liquid crystal display device, comprising the above-mentioned array substrate.

In one embodiment of the present invention, the touch-control liquid crystal display device includes a color filter substrate disposed opposite to the array substrate, and the color filter substrate includes a first color blocking area, a second color blocking area and a third color blocking area Resist regions, each color resist region corresponding to a sub-pixel on the array substrate.

The present invention also provides a method for preparing an array substrate, comprising:

A switching thin film transistor and a photosensitive thin film transistor are formed synchronously in the display pixel area and the photosensitive pixel area on the base of the array substrate;

A pixel electrode and a common electrode that are insulated from each other are formed on the switching thin film transistor, and the pixel electrode is electrically connected to the switching thin film transistor;

In one embodiment of the present invention, the step of synchronously forming the switching thin film transistor and the photosensitive thin film transistor in the display pixel area and the photosensitive pixel area on the base of the array substrate includes:

A first gate electrode and a second gate electrode are respectively formed on the display pixel region and the photosensitive pixel region of the substrate, and on the substrate on which the first gate electrode and the second gate electrode are formed Insulation.

In an embodiment of the present invention, the step of forming an insulating layer on the substrate on which the first gate electrode and the second gate electrode are formed includes:

After forming a second channel layer on the second gate where the insulating layer is formed, a first channel layer is formed on the first gate where the insulating layer is formed.

In an embodiment of the present invention, the step after forming a first channel layer on the first gate electrode where the insulating layer is formed further includes: forming a photoresist layer on the first channel layer, A source-drain metal layer is formed on the second channel layer and the first channel layer on which the photoresist layer is formed.

In one embodiment of the present invention, the source-drain metal layer above the second channel layer is etched to form the second source electrode and the second drain electrode of the photosensitive thin film transistor.

In an embodiment of the present invention, after the photoresist layer above the first channel layer is peeled off by a lift-off process, the source-drain metal layer above the first channel layer forms the switching film The first source electrode and the first drain electrode of the transistor; the distance between the first source electrode and the first drain electrode is less than or equal to the distance between the second source electrode and the second drain electrode.

In an embodiment of the present invention, the switching thin film transistor is an oxide thin film transistor, and the photosensitive thin film transistor is a hydrogenated amorphous silicon thin film transistor.

The array substrate provided by the present invention and the preparation method thereof, by forming electrically connected switching thin film transistors and pixel electrodes in the display pixel area of the array substrate, and forming photosensitive thin film transistors in the photosensitive pixel area of the array substrate, can make the manufacturing process of the photosensitive thin film transistor and the photosensitive thin film transistor compatible. The switching thin-film transistors are process-compatible, enabling remote sensing while reducing cost.

Description of drawings

FIG. 1 is a cross-sectional view of a liquid crystal touch display device according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view of the color filter substrate in the first embodiment of the present invention.

FIG. 3 is a schematic plan view of the array substrate in the first embodiment of the present invention.

4a to 4m are flow charts of the fabrication process of the array substrate according to the first embodiment of the present invention.

5 is a cross-sectional view of an array substrate according to a second embodiment of the present invention.

Detailed ways

In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific embodiments, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and examples.

[First Embodiment]

1 is a cross-sectional view of a liquid crystal touch display device in a first embodiment of the present invention, FIG. 2 is a schematic plan view of a color filter substrate in a first embodiment of the present invention, and FIG. 3 is an array substrate in the first embodiment of the present invention Schematic diagram of the plane structure. Referring to FIGS. 1 to 3 , an embodiment of the present invention provides a liquid crystal touch display device, the liquid crystal touch display device includes an array substrate 100 , and the array substrate 100 includes a plurality of sub-pixels SP (sub-pixels) arranged in an array , the first data line 41, the first scan line 51, the second data line 42 and the second scan line 52, each sub-pixel SP includes a display pixel area SP1 and a photosensitive pixel area SP2, and the display pixel area SP1 is provided with an electrically connected The switching thin film transistor 10 and the pixel electrode 31 are provided with the photosensitive thin film transistor 20 in the photosensitive pixel area SP2; the first data line 41 and the first scanning line 51 are respectively electrically connected to the switching thin film transistor 10, and the second data line 42 and the second scanning The lines 52 are electrically connected to the photosensitive thin film transistors 20, respectively. In this embodiment, the sub-pixels SP are, for example, red R, green G, or blue B sub-pixels, and a plurality of adjacent sub-pixels SP constitute a display pixel (pixel). For example, one display pixel may include three sub-pixels SP of red R, green G and blue B.

Please refer to FIG. 1 to FIG. 3 , the first data lines 41 and the second data lines 42 are arranged adjacent to and parallel to each other, and the first scan lines 51 and the second scan lines 52 are arranged adjacent to and parallel to each other. The switching thin film transistor 10 includes a first gate electrode 11 , a first channel layer 13 , a first source electrode 14 and a first drain electrode 15 , the first gate electrode 11 is connected to the first scan line 51 , and the first channel layer 13 is provided Above the first gate 11 and electrically connected to the first source 14 and the first drain 15 respectively, one of the first source 14 and the first drain 15 is electrically connected to the first data line 41 , and the first source The other of the first drain electrode 14 and the first drain electrode 15 is connected to the pixel electrode 31 . For example, the first source electrode 14 is connected to the first data line 41 , and the first drain electrode 15 is connected to the pixel electrode 31 .

The photosensitive thin film transistor 20 includes a second gate electrode 21 , a second channel layer 23 , a second source electrode 24 and a second drain electrode 25 , the second gate electrode 21 is connected to the second scan line 52 , and the second channel layer 23 is provided Above the second gate electrode 21 and electrically connected to the second source electrode 24 and the second drain electrode 25 respectively. One of the second source electrode 24 and the second drain electrode 25 is connected to the second data line 42, and the other one of the second source electrode 24 and the second drain electrode 25 is connected to the second scan line 52 through a contact hole, for example, the second The source electrode 24 is connected to the second data line 42, and the second drain electrode 25 is connected to the second scan line 52 through the contact hole. In this embodiment, the first scan line 51 and the second scan line 52 can be connected to the same signal terminal to receive the same electrical signal.

Please refer to FIG. 1 to FIG. 3 , the liquid crystal touch display device further includes a color filter substrate 200 disposed opposite to the array substrate 100 , and the color filter substrate 200 includes a first color resist region 201 , a second color resist region 202 and a third color filter substrate 200 . The color resist region 203, for example, the first color resist region 201 is a red color resist region, the second color resist region is a green color resist region, and the third color resist region 203 is a blue color resist region. Each color resist region is disposed corresponding to a sub-pixel SP on the array substrate 100 .

When the LED light or laser is irradiated on the liquid crystal touch display device, the LED light or laser is irradiated onto the array substrate 100 through the color filter substrate 200, and the photosensitive thin film transistor 20 of the array substrate 100 can convert the light intensity into an electrical signal, Thereby, a non-contact remote touch can be realized.

In this embodiment, the distance between the first source electrode 14 and the first drain electrode 15 is equal to the distance between the second source electrode 24 and the second drain electrode 25 .

4a to 4m are flowcharts of the manufacturing process of the array substrate according to the first embodiment of the present invention. Please refer to FIG. 4a to FIG. 4m. An embodiment of the present invention provides a method for preparing an array substrate, including:

The display pixel area SP1 and the photosensitive pixel area SP2 on the base 110 of the array substrate 100 are synchronously formed with the switching thin film transistor 10 and the photosensitive thin film transistor 20;

A pixel electrode 31 and a common electrode 32 that are insulated from each other are formed on the switching thin film transistor 10 , and the pixel electrode 31 is electrically connected to the switching thin film transistor 10 .

The switching thin film transistor 10 is an oxide thin film transistor, and the photosensitive thin film transistor 20 is a hydrogenated amorphous silicon thin film transistor.

The manufacturing process of the array substrate 100 will be described in detail below.

Referring to FIG. 4a, a substrate 110 is provided, and a first gate 11 and a second gate 21 are formed on the substrate 110 simultaneously, wherein the first gate 11 is located in the display pixel region SP1, and the second gate 21 is located in the photosensitive pixel region SP2. Then, a gate insulating layer 101 and an insulating layer 12 are sequentially formed on the substrate 110 on which the first gate 11 and the second gate 21 are formed. The insulating layer 12 is made of, for example, silicon oxide.

Referring to FIG. 4 b , a second channel layer 23 is formed on the second gate electrode 21 where the insulating layer 12 is formed. The second channel layer 23 is an a-Si:H thin film layer.

Referring to FIG. 4c, a first channel layer 13 is formed on the first gate 11 on which the insulating layer 12 is formed, and the first channel layer 13 and the second channel layer 23 are disposed in the same layer. Then, a photoresist layer 102 is formed on the first channel layer 13 . In this embodiment, the material of the first channel layer 13 is indium gallium zinc oxide (IGZO). Using IGZO as the material of the first channel layer 13 can effectively reduce the use of traditional silicon oxide. transistor leakage current overheating problem. Forming the photoresist layer 102 on the first channel layer 13 can improve the liquid corrosion resistance of the IGZO thin film transistor and improve the stability of the device.

Referring to FIG. 4d, after the photoresist layer 102 is formed on the first channel layer 13, the source-drain metal layer 16 is formed on the second channel layer 23 and the first channel layer 13 on which the photoresist layer is formed.

Referring to FIG. 4 e , the source-drain metal layer 16 above the second channel layer 23 is etched to form the second source electrode 24 and the second drain electrode 25 of the photosensitive thin film transistor 20 .

Referring to FIG. 4f , after the photoresist layer 102 above the first channel layer 13 is peeled off by a lift-off process, the photoresist layer 102 is peeled off together with part of the metal of the source-drain metal layer 16 , and the source layer 102 above the first channel layer 13 is peeled off. The drain metal layer 16 forms the first source electrode 14 and the first drain electrode 15 of the switching thin film transistor 10 . Among them, the lift-off process is to first apply glue on the substrate and photolithography, and then prepare a metal thin film. Where there is photoresist, the metal thin film is formed on the photoresist, and there is no photoresist. where the metal thin film is formed directly on the substrate. When a solvent is used to remove the photoresist on the substrate, the unwanted metal is shed in the solvent as the photoresist dissolves, while the metal part formed directly on the substrate remains to form a pattern. Lift-off is commonly used for patterning of platinum, gold, silicides and refractory metals.

Referring to FIG. 4g, a first protective layer 103 is formed on the substrate 110 on which the first source electrode 14 and the first drain electrode 15 and the second source electrode 24 and the second drain electrode 25 are formed. The first protective layer 103 Cover the display pixel area SP1 and the photosensitive pixel area SP2.

Referring to FIGS. 4h to 4j, an organic flat layer 104 is formed on the substrate 110 on which the first protective layer 103 is formed, and the organic flat layer 104 covers the display pixel area SP1 and the photosensitive pixel area SP2. A first contact hole 106 is formed after etching the organic flat layer 104 so that the first protective layer 103 is partially exposed, and then a common electrode 32 is formed on the first protective layer 103 . The common electrode 32 is only formed in the display pixel region SP1.

Referring to FIG. 4k , a second protective layer 105 is formed on the substrate 110 on which the common electrode 32 is formed, and the second protective layer 105 is in contact with the first protective layer 103 at the first contact hole 106 . The second protective layer 105 covers the display pixel area SP1 and the photosensitive pixel area SP2.

4l to 4m, the second protective layer 105 is etched to expose the first source electrode 14, and then a pixel electrode 31 is formed on the second protective layer 105, and the pixel electrode 31 is in contact with the first source electrode 14. . The pixel electrode 31 is only formed above the display pixel region SP1.

In the array substrate and the manufacturing method thereof provided by the present invention, by forming the switch thin film transistor 10 and the pixel electrode 31 electrically connected in the display pixel area SP1 of the array substrate 100, the photosensitive thin film transistor 20 is formed in the photosensitive pixel area SP2 of the array substrate 100, and at the same time A second data line and a second scan line are added on the array substrate, and the touch sensing of the photosensitive thin film transistor 20 is optimized through the second data line and the second scan line; in addition, the switching thin film transistor 10 is an oxide thin film transistor, using IGZO As the material of the first channel layer 13, the photosensitive thin film transistor 20 is a hydrogenated amorphous silicon thin film transistor, and a-Si is used as the material of the second channel layer 23; the present invention innovatively combines the process of the photosensitive thin film transistor 20 with the The switching thin film transistor 10 is process compatible, so that the cost can be reduced while realizing remote sensing.

[Second Embodiment]

5 is a cross-sectional view of an array substrate according to a second embodiment of the present invention. Each sub-pixel SP of the array substrate 100 includes a display pixel area SP1 and a photosensitive pixel area SP2, the display pixel area SP1 is provided with a switching thin film transistor and a pixel electrode 31 that are electrically connected, and also includes a common electrode 32, the common electrode 32 and the pixel electrode 31 is insulated by the second protective layer 105, and a photosensitive thin film transistor is provided in the photosensitive pixel region SP2. The first gate 11 is located in the display pixel region SP1, and the second gate 21 is located in the photosensitive pixel region SP2. The second source electrode 24 and the second drain electrode 25 of the photosensitive thin film transistor are formed over the second channel layer 23 . A first source electrode 14 and a first drain electrode 15 of the switching thin film transistor are formed over the first channel layer 13 .

The difference between this embodiment and the first embodiment is that the distance between the first source electrode 14 and the first drain electrode 15 is smaller than the distance between the second source electrode 24 and the second drain electrode 25 . Such a design can increase the exposed area of the second channel layer 23 of the photosensitive thin film transistor 20 , so that the second channel layer 23 can more easily sense light, thereby improving the sensitivity of the photosensitive thin film transistor 20 .

As used herein, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion, in addition to those elements listed, but also other elements not expressly listed.

In this document, the related terms such as front, rear, upper and lower are defined by the positions of the components in the drawings and the positions between the components, which are only for the clarity and convenience of expressing the technical solution. It should be understood that the use of the locative words should not limit the scope of protection claimed in this application.

The above-described embodiments and features of the embodiments herein may be combined with each other without conflict.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (8)

1. A method for preparing an array substrate is characterized by comprising the following steps:

synchronously forming a switching thin film transistor (10) and a photosensitive thin film transistor (20) in a display pixel region (SP1) and a photosensitive pixel region (SP2) on a substrate (110) of an array substrate (100);

forming a pixel electrode (31) and a common electrode (32) which are insulated from each other on the switching thin film transistor (10), wherein the pixel electrode (31) is electrically connected with the switching thin film transistor (10);

wherein the step of forming the switching thin film transistor (10) and the light sensitive thin film transistor (20) in synchronization with the display pixel region (SP1) and the light sensitive pixel region (SP2) on the base (110) of the array substrate (100) comprises:

forming a first gate electrode (11) and a second gate electrode (21) in the display pixel region (SP1) and the photosensitive pixel region (SP2) of the substrate (110), respectively, and forming an insulating layer (12) on the substrate (110) where the first gate electrode (11) and the second gate electrode (21) are formed;

forming a first channel layer (13) on the first gate (11) on which the insulating layer (12) is formed after forming a second channel layer (23) on the second gate (21) on which the insulating layer (12) is formed;

and forming a light resistance layer (102) on the first channel layer (13), and forming a source-drain metal layer (16) on the second channel layer (23) and the first channel layer (13) formed with the light resistance layer (102).

2. The method of fabricating the array substrate according to claim 1, wherein the source-drain metal layer (16) above the second channel layer (23) is etched to form a second source electrode (24) and a second drain electrode (25) of the photosensitive thin film transistor (20).

3. The method for manufacturing the array substrate according to claim 2, wherein the source drain metal layer (16) above the first channel layer (13) forms a first source electrode (14) and a first drain electrode (15) of the switching thin film transistor (10) after the photoresist layer (102) above the first channel layer (13) is stripped through a stripping process; the distance between the first source (14) and the first drain (15) is smaller than or equal to the distance between the second source (24) and the second drain (25).

4. The method of fabricating an array substrate of claim 1, wherein the switching thin film transistor (10) is an oxide thin film transistor and the photosensitive thin film transistor (20) is a hydrogenated amorphous silicon thin film transistor.

5. An array substrate (100) manufactured by the method for manufacturing an array substrate according to any one of claims 1 to 4, wherein the array substrate (100) comprises a plurality of sub-pixels (SP) arranged in an array, each sub-pixel (SP) comprises a display pixel region (SP1) and a photosensitive pixel region (SP2), the display pixel region (SP1) is provided with a switching thin film transistor (10) and a pixel electrode (31) which are electrically connected, and the photosensitive pixel region (SP2) is provided with a photosensitive thin film transistor (20).

6. The array substrate (100) of claim 5, wherein the array substrate (100) comprises a first data line (41) and a first scan line (51) electrically connected to the switching thin film transistor (10) and a second data line (42) and a second scan line (52) electrically connected to the photosensitive thin film transistor (20).

7. A touch-sensitive liquid crystal display device, comprising the array substrate (100) according to any one of claims 5 to 6.

8. The touch-sensitive liquid crystal display device according to claim 7, further comprising a color filter substrate (200) disposed opposite to the array substrate (100), wherein the color filter substrate (200) comprises a first color-resist region (201), a second color-resist region (202), and a third color-resist region (203), each color-resist region being disposed corresponding to a sub-pixel (SP) on the array substrate (100).

Images