Substrate and preparation method thereof, and touch panel

Abstract

The application discloses a substrate, a preparation method thereof and a touch panel. The substrate comprises a substrate, which is divided into a touch area and a frame area arranged along the periphery of the touch area. The frame area comprises a signal trace layer arranged on the substrate, an insulating layer arranged on the signal trace layer and a conductive layer arranged on the insulating layer for releasing static electricity. The conductive layer and the signal trace layer are arranged on different layers, so that the signal trace does not affect the width of the conductive layer, and the width of the conductive layer can be made as large as possible. When the conductive layer is used as a ground wire for releasing static electricity, the width of the conductive layer is large, so that the conductive layer can quickly release static electricity, and accumulation of static electricity and static breakdown damage caused by the accumulation of static electricity are avoided.

Description

TECHNICAL FIELD

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

[0002] In the production process of the touch panel, the wiring, bridge point and even the functional area in the panel are often broken down due to the accumulation of static electricity, which eventually leads to the loss of function of the touch panel, reduces the product yield and affects the consumer experience. In the prior art, in order to reduce the damage caused by the accumulation of static electricity, a ring-shaped ground wire is usually arranged in the peripheral frame of the functional area of the touch panel, which is connected to the whole machine system through a flexible circuit board, and then the static electricity is discharged through the ground power line.

[0003] However, as the frame of the touch panel becomes narrower and narrower, the width of the ground wire arranged in the frame becomes smaller and smaller, which leads to the decrease of the anti-static breakdown capability of the ground wire. Therefore, in the actual production process, part of the accumulated static electricity cannot be discharged in time, resulting in a large number of finished products being scrapped. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a substrate, a preparation method thereof and a touch panel to improve the static discharge capability of the touch panel.

[0005] In order to solve the above technical problems, the present application provides a substrate, which comprises a substrate, the substrate is divided into a touch area and a frame area arranged around the touch area, the frame area comprises a signal wiring layer arranged on the substrate, an insulating layer arranged on the signal wiring layer and a conductive layer arranged on the insulating layer for discharging static electricity.

[0006] Optionally, the thickness of the insulating layer is 5um-15um.

[0007] Optionally, the width of the conductive layer is greater than or equal to 2mm.

[0008] Optionally, the conductive layer is in the form of a ring surrounding the touch area, and a fracture for dividing the conductive layer into a plurality of sub-conductive segments is arranged in the extension direction of the conductive layer.

[0009] Optionally, the conductive layer comprises a lead pad.

[0010] Optionally, the conductive layer has a preset distance between the outer edge of the conductive layer and the outer edge of the insulating layer.

[0011] Optionally, the conductive layer comprises a plurality of spaced hollow parts.

[0012] Optionally, the substrate further comprises an outer coating layer arranged between the signal wiring layer and the insulating layer.

[0013] To solve the above technical problems, the embodiment of the present application also provides a substrate preparation method, comprising:

[0014] A substrate is provided, which is divided into a touch area and a frame area arranged along the periphery of the touch area;

[0015] A signal trace layer is formed in the frame area;

[0016] An insulating layer is formed on the signal trace layer by using a screen printing process;

[0017] A conductive layer is formed on the insulating layer by using a screen silk printing process.

[0018] To solve the above technical problems, the embodiment of the present application also provides a touch panel, comprising the above-mentioned substrate, the conductive layer is electrically connected with a ground power line of the touch panel, or the conductive layer is electrically connected with a shell of the touch panel through a conductive adhesive tape.

[0019] The substrate provided by the embodiment of the present application has the insulating layer arranged on the signal trace layer in the frame area, and the conductive layer for releasing static electricity is arranged on the insulating layer. Since the conductive layer and the signal trace layer are arranged in different layers, the signal trace does not affect the width of the conductive layer, and thus the width of the conductive layer can be made as large as possible. When the conductive layer is used as a ground wire for releasing static electricity, since the width of the conductive layer is large, the conductive layer can quickly release static electricity, avoiding the accumulation of static electricity and the static breakdown damage caused thereby. At the same time, the arrangement of the insulating layer avoids the interference of the conductive layer on the signal trace layer.

[0020] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be achieved and obtained by means of the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the technical solutions of the present application, and constitute a part of the specification, and are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute a limitation on the technical solutions of the present application.

[0022] Figure 1 It is a top view structural schematic diagram of the substrate of the first embodiment of the present application;

[0023] Figure 2 It is a top view structural schematic diagram of the substrate of the first embodiment of the present application; Figure 1

[0024] Figure 3 It is a top view structural schematic diagram of the substrate of the first embodiment of the present application; Figure 1 ​Enlarged structural schematic view of the middle B part;

[0025] Figure 4 Side view structural schematic view of a touch panel according to a second embodiment of the present application.

[0026] Legend:

[0027] 1 - substrate; 10 - touch area; 20 - frame area;

[0028] 21 - substrate; 22 - signal trace layer; 23 - insulating layer;

[0029] 24 - conductive layer; 25 - first outer coating layer; 26 - black matrix;

[0030] 27 - second outer coating layer; 30 - flexible circuit board; 241 - break;

[0031] 242 - lead pad; 243 - hollow part; 244 - first sub-conductive segment;

[0032] 245 - second sub-conductive segment. DETAILED DESCRIPTION

[0033] To make the objects, technical solutions, and advantages of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other in any manner without conflict.

[0034] In the existing market, in order to meet the needs of users, the frame of touch products becomes narrower and narrower. Although the narrow frame product meets the fashion demand, the narrow frame also leads to the decline of the electrostatic protection ability of the product. The main reasons are as follows: when the touch position is in the edge area of the product, static electricity may be generated, and this part of static electricity is easy to be attracted to jump over the edge of the product and enter the edge area wiring on the back of the touch product, and then the wiring in the edge area on the back is easy to be impacted by static electricity; in addition, with the narrowing of the frame, the width of the ground wire in the frame becomes narrower, usually less than 0.4mm, and the anti-static breakdown ability of this width of ground wire is general, and the accumulated static electricity cannot be discharged in time, and at the same time, with the thinning of the width of the functional wiring, the functional wiring is more likely to be broken down by static electricity, so that the touch product is damaged by static electricity, resulting in that the product cannot be used continuously.

[0035] In the related art, in order to avoid the damage of the product caused by static electricity breakdown, the method of pasting conductive tape or adding an anti-explosion film in the touch panel is generally used to avoid the risk of static damage. However, the addition of the anti-explosion film cannot protect the wiring in the frame area, and with the narrowing of the frame area, the attachable width of the conductive tape is narrowed, which greatly increases the attachment difficulty of the conductive tape and reduces the electrostatic protection effect of the product.

[0036] In the following embodiments, "width" refers to the dimension along the width direction of the paper; "height" refers to the dimension along the height direction of the paper.

[0037] The technical content of the present invention will be described in detail below through specific embodiments.

[0038] First embodiment:

[0039] Figure 1 This is a top view of the substrate according to the first embodiment of the present invention. Figure 2 for Figure 1 A schematic diagram of the AA section structure. From Figure 1 and Figure 2 As can be seen, the touch panel includes a substrate 21, which is divided into a touch area 10 and a border area 20. The border area 20 is disposed along the periphery of the touch area 10. The border area 20 includes a signal routing layer 22 disposed on the substrate 21, as well as an insulating layer 23 and a conductive layer 24 for discharging static electricity. The insulating layer 23 is disposed on the signal routing layer 22, and the conductive layer 24 is disposed on the insulating layer 23.

[0040] The substrate proposed in this embodiment of the invention has an insulating layer disposed on the signal trace layer within the frame area. A conductive layer for static electricity discharge is disposed on the insulating layer. Since the conductive layer and the signal trace layer are disposed on different layers, the signal traces do not affect the width of the conductive layer. Therefore, the width of the conductive layer can be maximized. When the conductive layer is used as a ground wire for static electricity discharge, its larger width allows for rapid discharge of static electricity, preventing static accumulation and resulting electrostatic breakdown damage. Simultaneously, the insulating layer prevents interference from the conductive layer to the signal trace layer.

[0041] In this embodiment, as Figure 2 As shown, the thickness H of the insulating layer 23 is 5µm to 15µm. If the thickness of the insulating layer 23 is less than 5µm, the coupling capacitance between the signal trace layer and the conductive layer will be too large, generating background noise. If the thickness of the insulating layer 23 is greater than 15µm, the adhesive thickness required for bonding the substrate to other modules will be correspondingly smaller, affecting the bonding process. Setting the thickness of the insulating layer 23 to 5µm to 15µm not only achieves good bonding between the substrate and other modules, but also reduces the coupling capacitance between the conductive layer 24 and the signal trace layer, avoiding interference from the conductive layer 24 to the signal trace layer. Experiments show that the insulating layer 23 controls the signal variation in the signal trace layer caused by the conductive layer 24 to within 1.5%.

[0042] from Figure 2As can also be seen, the substrate of this embodiment, within the frame region 20, also includes a first overcoat 25 disposed between the signal trace layer 22 and the insulating layer 23. It is easily understood that the signal trace layer 22 typically includes metal bridges, metal traces, etc., therefore the first overcoat 25 can effectively protect the signal trace layer 22. Furthermore, the provision of the first overcoat 25 facilitates the fabrication of the insulating layer 23. In this embodiment, to achieve a thickness of 5µm to 15µm for the insulating layer 23, a screen printing process can be used to print the insulating layer 23 on the first overcoat 25 to achieve an insulating layer thickness of 5µm to 15µm.

[0043] In this embodiment, the conductive layer 24 is used to release static electricity. Therefore, the precision requirements for the conductive layer 24 are greatly reduced. To improve the preparation efficiency and reduce the cost of the conductive layer 24, a screen printing process can be used to form the conductive layer 24 on the insulating layer 23 in this embodiment. The conductive layer 24 is a conductive ink. The conductive layer 24 can be one or more of gold-based conductive ink, silver-based conductive ink, copper-based conductive ink, and carbon-based conductive ink. Silver-based conductive inks include conductive silver paste, etc.

[0044] In this embodiment, as Figure 2 As shown, the width of the conductive layer 24 is greater than or equal to 1 mm, which allows for rapid static discharge. Furthermore, the width of the conductive layer 24 is greater than or equal to 2 mm, thereby further reducing the impedance of the conductive layer to less than 2 K ohms and further improving the static discharge rate of the conductive layer.

[0045] In order to release static electricity from the conductive layer 24, the conductive layer 24 includes lead pads 242, such as Figure 1 As shown. From Figure 2 It can also be seen that there is a preset distance between the outer edge of the conductive layer 24 and the outer edge of the insulating layer 23. Therefore, when using the substrate of this embodiment to manufacture a touch panel, the lead pad 242 can be electrically connected to the conductive tape disposed around the panel. The conductive tape is connected to the overall casing of the touch panel or the liquid crystal module (LCM). Thus, static electricity on the conductive layer 24 is conducted to the casing through the lead pad 242 and the conductive tape and released, preventing static electricity from accumulating on the conductive layer. Typically, the border area 20 of the substrate has different widths. To increase the area of ​​the lead pad 242, it can be placed within the wider border, for example, in... Figure 1 In the middle, the width of the top and bottom borders is wider than the width of the left and right borders. Therefore, the lead pad 242 is set inside the top or bottom border.

[0046] from Figure 1As can be seen, the conductive layer 24 is annularly arranged around the touch area 10. A break 241 is provided in the extending direction of the conductive layer 24, which breaks the conductive layer in the extending direction, thereby dividing the conductive layer 24 into multiple sub-conductive segments. Figure 1 In this design, two breaks 241 divide the conductive layer into two sub-conductive segments: a first sub-conductive segment 244 and a second sub-conductive segment 245. Each sub-conductive segment has a corresponding lead pad, allowing each segment to be electrically connected to the conductive tape via the lead pad. When static electricity accumulates on the conductive layer, since the sub-conductive segments are disconnected from each other, the accumulated static electricity is discharged along the corresponding sub-conductive segment, shortening the discharge path and increasing the discharge speed. For example, if the first and second sub-conductive segments 244 are not disconnected, the static electricity at point C on the first sub-conductive segment 244 might be discharged along the direction towards the second sub-conductive segment, lengthening the discharge path and potentially causing substrate breakdown. However, since the first and second sub-conductive segments 244 and 245 are disconnected, the static electricity at point C will only be discharged along the first sub-conductive segment 244, shortening the discharge path and increasing the discharge speed. In specific implementations, the number and width of the breaks 241 can be set as needed.

[0047] When there are multiple breaks, the breaks divide the conductive layer into multiple sub-conductive segments. In order for the static electricity on each sub-conductive segment to be released through the conductive tape, each sub-conductive segment needs to be equipped with a corresponding lead pad. The lead pad is electrically connected to the conductive tape, so that the static electricity on each sub-conductive segment can be conducted to the whole machine casing through the conductive tape and released.

[0048] Figure 3 for Figure 1 A magnified structural diagram of section B. Figure 3 As can be seen, the conductive layer 24 includes multiple hollow portions 243. The hollow portions 243 can increase the adhesion of the conductive layer 24 and prevent the conductive layer from peeling off from the insulating layer 23. At the same time, the hollow portions can also appropriately increase the width of the conductive layer, reduce the resistance of the conductive layer, and further improve the electrostatic discharge speed of the conductive layer.

[0049] The cutouts 243 are spaced apart along the extension direction of the conductive layer. The shape of the cutouts 243 can be any shape, such as polygonal, circular, or elliptical.

[0050] from Figure 2 It can also be seen that the touch panel of this embodiment is provided with a black matrix 26 and a second outer layer 27 in the frame area 20, wherein the black matrix 26 and the second outer layer 27 are disposed between the substrate 21 and the signal trace layer 22 in sequence.

[0051] The second embodiment of the present application provides a method for manufacturing a substrate.

[0052] The second embodiment of the present application provides a method for manufacturing a substrate. Figure 2 The method for manufacturing the substrate comprises the following steps:

[0053] A substrate 21 is provided, which is divided into a touch area and a frame area arranged along the periphery of the touch area;

[0054] A signal trace layer 22 is formed in the frame area;

[0055] An insulating layer 23 is formed on the signal trace layer 22 by using a screen printing process;

[0056] A conductive layer 24 is formed on the insulating layer 23 by using a screen silk printing process.

[0057] Before the insulating layer 23 is formed, the method further comprises the step of forming a first overcoat layer 25 on the signal trace layer 22.

[0058] The method for manufacturing the substrate of the embodiment further comprises the steps of sequentially forming a black matrix 26 and a second overcoat layer 27 in the frame area of the substrate 21 before the signal trace layer 22 is formed.

[0059] In the embodiment, the methods for forming the black matrix, the second overcoat layer, the signal trace layer and the first overcoat layer are known methods in the prior art, which are not described herein.

[0060] Generally, the manufacturing process of the substrate can be divided into a 5-mask process and a 6-mask process. The 5-mask process route is: forming a black matrix → forming an ITO pattern → forming a second overcoat layer → forming a signal trace layer → forming a first overcoat layer → forming an insulating layer by using a screen printing process → forming a conductive layer by using a screen silk printing process, wherein the signal trace layer comprises signal connecting lines in the frame area, and the signal trace layer further comprises metal bridges and metal connecting lines in the touch area. The 6-mask process route is: forming a black matrix → forming an ITO bridge → forming a second overcoat layer → forming an ITO pattern → forming a signal trace layer → forming a first overcoat layer → forming an insulating layer by using a screen printing process → forming a conductive layer by using a screen silk printing process, wherein the signal trace layer comprises signal connecting lines and GND lines in the frame area, and the signal trace layer further comprises metal connecting lines in the touch area. Regardless of whether the 5-mask process or the 6-mask process is used, the cross-sectional view of the frame area of the obtained substrate is as shown in FIG. 4. Figure 2

[0061] The third embodiment of the present application provides a substrate.

[0062] ​Based on the inventive concept of the foregoing embodiments, this invention also provides a touch panel, which includes the substrate of the foregoing embodiments. The touch panel can be any product or component with display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigator.

[0063] Figure 4 This is a side view of the touch panel according to a third embodiment of the present invention. The touch panel includes the substrate 1, the liquid crystal module (LCM), and the casing as described in the previous embodiments, and also includes conductive tape. The conductive tape is electrically connected to the lead pads 242 of the conductive layer and to the casing. In other words, the lead pads of the conductive layer are connected to the casing via the conductive tape, thereby releasing static electricity on the conductive layer through the lead pads and conductive tape, preventing static electricity accumulation on the conductive layer. In other embodiments, the conductive tape can also be connected to the liquid crystal module (LCM), so that the conductive layer is electrically connected to the casing via the conductive tape and the liquid crystal module, achieving the release of static electricity on the conductive layer.

[0064] It is easy to understand that the touch panel also includes a flexible circuit board 30. The conductive layer can also be electrically connected to the flexible circuit board 30 of the touch panel, such as... Figure 4 As shown, the conductive layer is electrically connected to the whole system through the flexible circuit board 30, and the conductive layer can release static electricity through the grounding power line of the whole system.

[0065] Experiments show that the electrostatic discharge capability of conventional touch panels is ±8.5KV, while the electrostatic discharge capability of the touch panel in this embodiment of the invention can reach 17.2KV. Compared with conventional touch panels, the electrostatic discharge capability of the touch panel in this embodiment of the invention is greatly improved, by more than 80%, avoiding the accumulation of static electricity, improving product yield, and reducing production costs. Moreover, the signal change of this touch panel is less than 1.5%.

[0066] In the description of the embodiments of the present invention, it should be understood that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0067] In the description of the embodiments of the present application, it should be noted that unless specifically stated and limited otherwise, the terms "mounting", "connected", "connecting" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, can be indirectly connected through an intermediate medium, or can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0068] Although the embodiments of the present application are disclosed as above, the content described is only the embodiments adopted for the purpose of facilitating the understanding of the present application, and is not intended to limit the present application. Any modification and change in the form and details can be made by those skilled in the art without departing from the spirit and scope of the present application. The patent protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A substrate, characterized in that, The substrate includes a touch area and a border area surrounding the touch area. The border area includes a signal trace layer on the substrate, an outer layer on the signal trace layer, an insulating layer printed on the outer layer using screen printing, and a conductive layer on the insulating layer for static discharge. The conductive layer includes lead pads for static discharge, which are electrically connected to an outer conductive tape. The lead pads are located within the upper or lower border of the border area. The insulating layer has a thickness of 5µm to 15µm, ensuring that the signal variation in the signal trace layer caused by the conductive layer is less than 1.5%. The conductive layer has a width greater than or equal to 2mm, ensuring that its impedance is less than 2K ohms. The substrate's electrostatic discharge capability can reach 17.2KV.

2. The substrate according to claim 1, characterized in that, The conductive layer is in the form of a ring surrounding the touch area, and there are breaks in the extending direction of the conductive layer to divide the conductive layer into multiple sub-conductive segments.

3. The substrate according to claim 1, characterized in that, There is a predetermined distance between the outer edge of the conductive layer and the outer edge of the insulating layer.

4. The substrate according to claim 1, characterized in that, The conductive layer includes multiple spaced-apart cutouts.

5. A method for preparing a substrate, characterized in that, include: A substrate is provided, the substrate being divided into a touch area and a border area disposed around the periphery of the touch area; A signal routing layer is formed within the border area; An outer layer is formed on the signal trace layer; An insulating layer is formed on the outer layer using a screen printing process; the thickness of the insulating layer is 5µm to 15µm, so that the signal variation of the signal trace layer caused by the conductive layer is less than 1.5%; A conductive layer is formed on the insulating layer using a screen printing process. The conductive layer includes lead pads that discharge static electricity from the conductive layer. The lead pads are electrically connected to the surrounding conductive tape. The lead pads are disposed within the upper or lower border of the border area. The width of the conductive layer is greater than or equal to 2 mm, making the impedance of the conductive layer less than 2 kΩ. The electrostatic discharge capability of the substrate can reach 17.2 kV.

6. A touch panel, characterized in that, The substrate includes any one of claims 1 to 4, wherein the conductive layer is electrically connected to the ground power line of the touch panel, or the conductive layer is electrically connected to the housing of the touch panel via conductive tape.

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