Touch substrate, manufacturing method thereof and display device

Abstract

The application provides a touch substrate, a manufacturing method thereof and a display device, and belongs to the technical field of display. The touch substrate comprises a substrate and a plurality of mutually independent touch electrodes on the substrate. The touch electrode comprises a first metal pattern and a second metal pattern which are arranged in layers. The first orthographic projection of the first metal pattern on the substrate covers the second orthographic projection of the second metal pattern on the substrate. The second metal pattern is between the first metal pattern and the substrate. The technical scheme of the application can improve the horizontal stripe defect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a touch substrate, a manufacturing method thereof and a display device. BACKGROUND

[0002] The capacitive touch screen is divided into self-capacitance touch screen and mutual capacitance touch screen, the mutual capacitance touch screen uses the change of the capacitance value formed between two electrodes as the touch sensing signal, the mutual capacitance is the capacitance generated when the X-axis and Y-axis sensing electrodes intersect each other, wherein TX is the Y-axis transmitting electrode and RX is the X-axis receiving electrode.

[0003] At present, when the capacitive touch screen detects the surface horizontal stripe, the external light is incident on the capacitive touch screen, and reflection occurs on the side surface and the upper surface of the electrode, and the human eye appears as a horizontal black and white stripe. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a touch substrate, a manufacturing method thereof and a display device, which can improve the horizontal stripe defect.

[0005] To solve the above technical problems, the embodiments of the present application provide the technical solutions as follows:

[0006] In one aspect, a touch substrate is provided, comprising a substrate and a plurality of mutually independent touch electrodes located on the substrate, the touch electrode comprising a first metal pattern and a second metal pattern arranged in layers, the first metal pattern covering the second metal pattern on the substrate in a first orthographic projection, and the second metal pattern being located between the first metal pattern and the substrate.

[0007] In some embodiments, the touch electrode further comprises a third metal pattern located between the second metal pattern and the substrate, the third metal pattern covering the second metal pattern on the substrate in a third orthographic projection.

[0008] In some embodiments, the minimum distance between the boundary of the first orthographic projection and the boundary of the second orthographic projection is greater than 2um.

[0009] In some embodiments, the surface of the first metal pattern away from the substrate is uneven.

[0010] In some embodiments, the touch substrate further comprises:

[0011] An insulating layer located on the substrate and covering the gap between the touch electrode and the adjacent touch electrode, the thickness of the insulating layer being greater than the thickness of the touch electrode.

[0012] The embodiment of the present application further provides a display device comprising the touch substrate as described above.

[0013] The embodiment of the present application further provides a manufacturing method of a touch substrate, comprising a substrate and a plurality of mutually independent touch electrodes on the substrate, and the forming of the touch electrodes comprises:

[0014] forming a first metal pattern and a second metal pattern in a stacked manner, wherein a first orthographic projection of the first metal pattern on the substrate covers a second orthographic projection of the second metal pattern on the substrate, and the second metal pattern is located between the first metal pattern and the substrate.

[0015] In some embodiments, the forming of the touch electrodes further comprises:

[0016] forming a third metal pattern between the second metal pattern and the substrate, wherein a third orthographic projection of the third metal pattern on the substrate covers the second orthographic projection of the second metal pattern on the substrate.

[0017] In some embodiments, after the forming of the first metal pattern, the method further comprises:

[0018] dry etching the first metal pattern by using a gas, so that a surface of the first metal pattern away from the substrate is uneven.

[0019] In some embodiments, after the forming of the touch electrodes, the method further comprises:

[0020] forming an insulating layer covering a gap between the touch electrode and an adjacent touch electrode, wherein a thickness of the insulating layer is greater than a thickness of the touch electrode.

[0021] The embodiment of the present application has the following beneficial effects:

[0022] In the above scheme, the touch electrode comprises a first metal pattern and a second metal pattern in a stacked manner, a first orthographic projection of the first metal pattern on the substrate covers a second orthographic projection of the second metal pattern on the substrate, the light reflected after the external light incident to the side surface of the second metal pattern can be blocked by the first metal pattern, or the side surface of the second metal pattern is blocked to avoid the external light incident to the side surface of the second metal pattern, the propagation path of the light reflected by the side surface of the second metal pattern is changed, the light reflection is reduced, and the horizontal stripe defect is improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic plan view of the touch substrate;

[0024] Figure 2 is a schematic cross-sectional view of the touch electrode;

[0025] Figure 3 This is a cross-sectional schematic diagram of the touch electrode according to an embodiment of the present invention.

[0026] Figure Labels

[0027] 01 Touch electrode bridging

[0028] 02 Touch electrodes

[0029] 021 First Metal Graphic

[0030] 022 Second Metal Graphic

[0031] 023 Third Metal Graphic

[0032] 03 Base

[0033] 04 Insulation layer Detailed Implementation

[0034] To make the technical problems, technical solutions and advantages of the embodiments of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0035] Capacitive touchscreens are divided into self-capacitance touchscreens and mutual-capacitance touchscreens. Mutual-capacitance touchscreens use the change in capacitance between two electrodes as the touch sensing signal. For example... Figure 1 As shown, the mutual capacitance touch substrate includes multiple arrayed touch electrodes 02, and adjacent touch electrodes 02 in the same row or column are connected by touch electrode bridges 01. Figure 2 for Figure 1 A schematic diagram of the cross-section in the AA direction, as shown below. Figure 2 As shown, the touch electrode 02 is generally made of metal material and has a strong reflectivity. When external light shines on the side surface and top surface of the touch electrode 02, it will be reflected by the touch electrode 02, and the human eye will see it as horizontal black and white stripes at an angle.

[0036] Embodiments of the present invention provide a touch substrate and a method for manufacturing the same, as well as a display device, which can improve the defects of horizontal stripes.

[0037] Embodiments of the present invention provide a touch substrate, such as Figure 3 As shown, the device includes a substrate 03 and a plurality of independent touch electrodes 02 located on the substrate 03. The touch electrodes 02 include a first metal pattern 021 and a second metal pattern 022 stacked together. The first orthographic projection of the first metal pattern 021 on the substrate 03 covers the second orthographic projection of the second metal pattern 022 on the substrate 03. The second metal pattern 022 is located between the first metal pattern 021 and the substrate 03.

[0038] In this embodiment, the touch electrode includes a first metal pattern 021 and a second metal pattern 022 stacked together. The first orthographic projection of the first metal pattern 021 on the substrate covers the second orthographic projection of the second metal pattern 022 on the substrate. The light rays incident on the side surface of the second metal pattern 022 can be blocked by the first metal pattern 021 after being reflected. Alternatively, the first metal pattern 021 can block the side surface of the second metal pattern 022 to prevent external light rays from incident on the side surface of the second metal pattern 022, thereby changing the propagation path of the light rays reflected by the side surface of the second metal pattern 022, reducing light reflection, and improving horizontal stripe defects.

[0039] The first metal pattern 021 can be made of Ti, and the second metal pattern 022 can be made of Al. Of course, the first metal pattern 021 is not limited to Ti, and the second metal pattern 022 is not limited to Al; other metal materials can also be used.

[0040] The greater the difference in area between the first orthographic projection and the second orthographic projection, the more light the first metal pattern 021 can block from reaching the side surface of the second metal pattern 022. Simultaneously, it can block reflected light from the outside light incident on the side surface of the second metal pattern 022. Therefore, the minimum distance between the boundaries of the first and second orthographic projections can be greater than 2µm. However, if the area of ​​the first orthographic projection increases, the upper surface of the first metal pattern 021 will also increase. Since the first metal pattern 021 is also made of metal, it will reflect incident light. To reduce the reflection of incident light by the first metal pattern 021, its surface can be made uneven, such as... Figure 3 As shown, the first metal pattern 021 diffusely reflects incident light, improving horizontal stripe defects. Specifically, after forming a smooth first metal pattern, gas can be used to etch the smooth surface of the first metal pattern 021. By controlling the gas etching time, it is ensured that the first metal pattern 021 will not be etched through, while the surface of the first metal pattern 021 is uneven.

[0041] In some embodiments, such as Figure 3 As shown, the touch electrode also includes a third metal pattern 023 located between the second metal pattern 022 and the substrate 03, the third orthographic projection of the third metal pattern 023 on the substrate 03 covering the second orthographic projection of the second metal pattern 022 on the substrate 03. Figure 3As shown, even if external light is irradiated to the side surface of the second metal pattern 022 and is reflected by the side surface of the second metal pattern 022, the part of the light irradiated to the third metal pattern 023 can change the light path of the light reflected by the side surface of the second metal pattern 022, and can avoid a large amount of light directly exiting the touch substrate, thereby reducing the horizontal stripe defect.

[0042] The third metal pattern 023 can be made of Ti, and when the second metal pattern 022 is made of Al with good conductivity, the first metal pattern 021 and the third metal pattern 023 can protect the second metal pattern 022 from being oxidized.

[0043] In some embodiments, as shown in FIG. 1, the touch substrate further comprises: Figure 3 As shown, the touch substrate further comprises:

[0044] An insulating layer 04 is located on the substrate 03 and covers the gap between the touch electrode 02 and the adjacent touch electrode, and the thickness of the insulating layer 04 is greater than the thickness of the touch electrode 02. There is a difference in refractive index between the insulating layer 04 and the air, and the light will be refracted when passing through the interface between the air and the insulating layer 04, irradiating the surface of the first metal pattern 021 to form diffuse reflection and reduce the horizontal stripe defect. In addition, the light reflected by the touch electrode 02 will be refracted when passing through the interface between the air and the insulating layer 04, changing the light path of the light and avoiding a large amount of light directly exiting the touch substrate, thereby reducing the horizontal stripe defect.

[0045] The insulating layer 04 can be made of an inorganic insulating layer or an organic insulating layer, such as silicon nitride, silicon oxynitride, or silicon oxide.

[0046] Embodiments of the present application also provide a display device comprising the touch substrate as described above. The touch substrate of the present embodiment can avoid the horizontal stripe defect of the display device.

[0047] The display device includes, but is not limited to, a radio frequency unit, a network module, an audio output unit, an input unit, a sensor, a display unit, a user input unit, an interface unit, a memory, a processor, and a power supply, etc. Those skilled in the art can understand that the structure of the display device described above does not constitute a limitation on the display device, and the display device can include more or fewer components described above, or combine certain components, or different component arrangements. In the embodiments of the present application, the display device includes, but is not limited to, a display, a mobile phone, a tablet computer, a television, a wearable electronic device, a navigation display device, etc.

[0048] The display device can be a television, a display, a digital photo frame, a mobile phone, a tablet computer, or any product or component with display function, wherein the display device further comprises a flexible circuit board, a printed circuit board, and a back plate.

[0049] Embodiments of the present application also provide a method for manufacturing a touch substrate, including a substrate and a plurality of mutually independent touch electrodes on the substrate, forming the touch electrodes includes:

[0050] forming a first metal pattern and a second metal pattern in a stacked manner, a first orthographic projection of the first metal pattern on the substrate covers a second orthographic projection of the second metal pattern on the substrate, and the second metal pattern is between the first metal pattern and the substrate.

[0051] As shown in Figure 3 In this embodiment, the touch electrode includes a first metal pattern 021 and a second metal pattern 022 in a stacked manner, a first orthographic projection of the first metal pattern 021 on the substrate covers a second orthographic projection of the second metal pattern 022 on the substrate, and the light reflected after being incident on the side surface of the second metal pattern 022 can be blocked by the first metal pattern 021, or the first metal pattern 021 blocks the side surface of the second metal pattern 022 to avoid external light from being incident on the side surface of the second metal pattern 022, changes the propagation path of the light reflected by the side surface of the second metal pattern 022, reduces light reflection, and improves horizontal stripe defects.

[0052] The first metal pattern 021 can be made of metal Ti, and the second metal pattern 022 can be made of metal Al. Of course, the first metal pattern 021 is not limited to metal Ti, and the second metal pattern 022 is not limited to metal Al, but can also be made of other metal materials.

[0053] In some embodiments, forming the touch electrode further includes:

[0054] forming a third metal pattern between the second metal pattern and the substrate, a third orthographic projection of the third metal pattern on the substrate covers the second orthographic projection of the second metal pattern on the substrate. As shown in Figure 3 Even if external light is incident on the side surface of the second metal pattern 022 and reflected by the side surface of the second metal pattern 022, this part of light can change the light path of the light reflected by the side surface of the second metal pattern 022 after being incident on the third metal pattern 023, which can avoid a large amount of light directly exiting the touch substrate and reduce horizontal stripe defects.

[0055] The greater the difference in area between the first orthographic projection and the second orthographic projection, the more light the first metal pattern 021 can block from reaching the side surface of the second metal pattern 022. Simultaneously, it can block reflected light from the outside light incident on the side surface of the second metal pattern 022. Therefore, the minimum distance between the boundaries of the first and second orthographic projections can be greater than 2µm. However, if the area of ​​the first orthographic projection increases, the upper surface of the first metal pattern 021 will also increase. Since the first metal pattern 021 is also made of metal, it will reflect incident light. To reduce the reflection of incident light by the first metal pattern 021, its surface can be made uneven, such as... Figure 3 As shown, the first metal pattern 021 diffusely reflects incident light, improving horizontal stripe defects. Specifically, after forming a smooth first metal pattern, gas can be used to etch the smooth surface of the first metal pattern 021. By controlling the gas etching time, it is ensured that the first metal pattern 021 will not be etched through, while the surface of the first metal pattern 021 is uneven.

[0056] In some embodiments, after forming the first metal pattern, the method further includes:

[0057] The first metal pattern is dry etched using gas, resulting in an uneven surface on the side of the first metal pattern away from the substrate.

[0058] In some embodiments, after forming the touch electrode, the method further includes:

[0059] An insulating layer is formed to cover the gap between the touch electrode and the adjacent touch electrode, the thickness of the insulating layer being greater than the thickness of the touch electrode.

[0060] like Figure 3 As shown, there is a refractive index difference between the insulating layer 04 and the air. When light passes through the interface between the air and the insulating layer 04, it is refracted and shines on the surface of the first metal pattern 021, forming diffuse reflection and reducing horizontal stripe defects. In addition, the light reflected by the touch electrode 02 is refracted when it passes through the interface between the air and the insulating layer 04, changing the light path and preventing a large amount of light from directly escaping from the touch substrate, thus reducing horizontal stripe defects.

[0061] The method for manufacturing the touch substrate in this embodiment specifically includes the following steps:

[0062] Step 1: Provide a substrate and form a pattern of touch electrode bridges on the substrate;

[0063] The substrate can be a glass substrate or a quartz substrate. Specifically, a thickness of approximately [thickness missing] can be deposited on the substrate using sputtering or thermal evaporation methods. A metal layer, which can be Cu, Al, Ag, Mo, Cr, Nd, Ni, Mn, Ti, Ta, W and the like, and alloys of these metals, can be a single layer or a multi-layer structure, such as Cu\Mo, Ti\Cu\Ti, Mo\Al\Mo, etc. A photoresist is coated on the metal layer, and the photoresist is exposed to light using a mask plate to form a photoresist non-retained area and a photoresist retained area. After developing, the photoresist in the photoresist non-retained area is completely removed, and the thickness of the photoresist in the photoresist retained area remains unchanged. The metal layer in the photoresist non-retained area is completely etched away by an etching process, and the remaining photoresist is stripped to form a pattern of the touch electrode bridge.

[0064] Step 2, forming an interlayer insulating layer on the substrate completed in step 1;

[0065] Specifically, a plasma enhanced chemical vapor deposition (PECVD) method can be used to deposit an interlayer insulating layer with a thickness of 1000-2000 nm on the substrate completed in step 1. The interlayer insulating layer can be an oxide, a nitride or an oxynitride, and the corresponding reaction gas is SiH4, NH3, N2 or SiH2Cl2, NH3, N2.

[0066] Step 3, sequentially forming a third metal layer, a second metal layer and a first metal layer on the substrate completed in step 2, and etching the third metal layer, the second metal layer and the first metal layer to form a first metal pattern, a second metal pattern and a third metal pattern, which constitute a touch electrode. Adjacent touch electrodes in the same row or column are connected by a touch electrode bridge.

[0067] Specifically, the first metal layer can be Ti, the second metal layer can be Al, and the third metal layer can be Ti. A photoresist is coated on the first metal layer, and the photoresist is exposed to light using a mask plate to form a photoresist non-retained area and a photoresist completely retained area. After developing, the photoresist in the photoresist non-retained area is completely removed, and the thickness of the photoresist in the photoresist completely retained area remains unchanged. The third metal layer, the second metal layer and the first metal layer are etched by an etching liquid to form a first metal pattern, a second metal pattern and a third metal pattern. By selecting the etching liquid, the etching speed of the etching liquid on the second metal layer is greater than that on the first metal layer and the second metal layer, and a notch is formed on the side surface of the touch electrode, such as Figure 3 ​As shown, the first orthographic projection of the first metal pattern 021 on the substrate 03 covers the second orthographic projection of the second metal pattern 022 on the substrate 03, and the third orthographic projection of the third metal pattern 023 on the substrate 03 covers the second orthographic projection of the second metal pattern 022 on the substrate 03. The remaining photoresist is stripped.

[0068] Step 4, forming an insulating layer 04 on the substrate completed in step 3;

[0069] Specifically, a plasma enhanced chemical vapor deposition (PECVD) method can be used to deposit the insulating layer 04 on the substrate completed in step 3, with a thickness of 100-1000nm. The insulating layer can be made of oxide, nitride or oxynitride, and the corresponding reaction gas is SiH4, NH3, N2 or SiH2Cl2, NH3, N2.

[0070] Step 5, forming a planar layer.

[0071] Specifically, an organic resin layer with a thickness of 100-1000nm can be coated on the insulating layer 04 to form the planar layer. Of course, if the surface of the insulating layer 04 is flat, the planar layer can be omitted.

[0072] In the method embodiments of the present application, the serial numbers of the steps cannot be used to limit the sequence of the steps, and for those skilled in the art, the sequence of the steps can be changed without creative labor, which is within the protection scope of the present application.

[0073] It should be noted that each embodiment in the present specification is described in a progressive manner, and the same or similar parts between each embodiment can be referred to each other, and each embodiment mainly describes the difference from other embodiments. Especially, for the embodiment, since it is basically similar to the product embodiment, the description is relatively simple, and the related parts can be referred to the part of the product embodiment.

[0074] ​​Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first", "second", and the like, as used in the present disclosure, do not imply any order, quantity, or importance, but are used to distinguish different components. The terms "include", "comprise", and the like, mean to encompass the elements listed after such terms and their equivalents, and do not exclude other elements. The terms "connected", "coupled", and the like, do not necessarily mean physically or mechanically connected, but can include electrical connection, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like, are used only to indicate relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships can also be changed accordingly.

[0075] It can be understood that when an element such as a layer, a film, a region, or a substrate is referred to as being "on" or "under" another element, it can be "directly" on or under the other element, or an intervening element can also be present.

[0076] In the description of the above-described embodiments, specific features, structures, materials, or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0077] The above description is merely illustrative of the disclosure and does not limit the scope of the disclosure. Any modifications made within the scope of the disclosure disclosed herein should be encompassed by the scope of the disclosure. Therefore, the scope of the disclosure should be based on the scope of the claims.

Claims

1. A touch substrate, comprising a substrate and a plurality of mutually independent touch electrodes on the substrate, characterized in that, The touch electrode includes a first metal pattern and a second metal pattern stacked, a first orthographic projection of the first metal pattern on the substrate covers a second orthographic projection of the second metal pattern on the substrate, the second metal pattern is between the first metal pattern and the substrate, a surface of the first metal pattern away from the substrate is uneven, the first metal pattern covers a surface of the second metal pattern away from the substrate, the first metal pattern does not cover a side surface of the second metal pattern, and the first metal pattern shields the side surface of the second metal pattern. 2.The touch substrate of claim 1, wherein, The touch electrode further includes a third metal pattern between the second metal pattern and the substrate, a third orthographic projection of the third metal pattern on the substrate covers the second orthographic projection of the second metal pattern on the substrate. 3.The touch substrate of claim 1, wherein, A minimum distance between a boundary of the first orthographic projection and a boundary of the second orthographic projection is greater than 2 um.

4. The touch substrate according to any one of claims 1-3, wherein, The touch substrate further includes: An insulating layer on the substrate covering a gap between the touch electrode and an adjacent touch electrode, a thickness of the insulating layer is greater than a thickness of the touch electrode.

5. A display device, characterized by comprising: A touch substrate including any one of claims 1-4. 6.A method for manufacturing a touch substrate, comprising a substrate and a plurality of mutually independent touch electrodes on the substrate, characterized in that, Forming the touch electrode includes: Forming a first metal pattern and a second metal pattern stacked, a first orthographic projection of the first metal pattern on the substrate covers a second orthographic projection of the second metal pattern on the substrate, the second metal pattern is between the first metal pattern and the substrate, a surface of the first metal pattern away from the substrate is uneven, the first metal pattern covers a surface of the second metal pattern away from the substrate, the first metal pattern does not cover a side surface of the second metal pattern, and the first metal pattern shields the side surface of the second metal pattern.

7. The method of manufacturing the touch substrate according to claim 6, wherein, Forming the touch electrode further includes: Forming a third metal pattern between the second metal pattern and the substrate, a third orthographic projection of the third metal pattern on the substrate covers the second orthographic projection of the second metal pattern on the substrate. 8.The method of manufacturing the touch substrate according to claim 6, characterized in that, After forming the first metal pattern, the method further includes: Dry etching the first metal pattern with a gas, so that a surface of the first metal pattern away from the substrate is uneven. 9.The method of manufacturing the touch substrate according to claim 6, characterized in that, After forming the touch electrode, the method further includes: Forming an insulating layer covering a gap between the touch electrode and an adjacent touch electrode, a thickness of the insulating layer is greater than a thickness of the touch electrode.

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