Manufacturing method of conductive film, conductive film and electronic equipment

Abstract

The invention provides a manufacturing method of a conductive film, the conductive film and electronic equipment. The method comprises the following steps: providing a substrate; taking the first surface of the substrate as a bearing surface, and manufacturing a conductive function layer on the bearing surface; wherein the step of manufacturing the conductive functional layer on the bearing surface comprises the following steps of: arranging a first optical adhesive layer on the bearing surface; a second optical adhesive layer is arranged on the surface, away from the bearing surface, of the first optical adhesive layer; stamping a groove with a preset pattern on the second optical adhesive layer, wherein the groove penetrates through the second optical adhesive layer and goes deep into the first optical adhesive layer; scraping and filling conductive slurry into the groove, and curing; and removing the second optical adhesive layer to form the conductive function layer. According to the manufacturing method of the conductive film, the number of times of scraping and filling the conductive slurry can be reduced, so that the appearance reject ratio caused by repeated scraping and filling is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of conductive films, and in particular to a method for manufacturing a conductive film, a conductive film and an electronic device. Background Art

[0002] A touch screen is a sensing device that can receive input signals such as touch. When a graphic button on the screen is touched, the tactile feedback system on the touch screen can drive various connection devices according to a pre-programmed program. It can be used to replace mechanical button panels and create vivid audio and video effects through liquid crystal display screens. The touch screen has given information interaction a brand new look and is a very attractive new information interaction device.

[0003] Conductive film is a vital component of touch screens. Generally, imprinting technology (such as nanoimprinting) is used to press grooves of preset patterns in the optical adhesive layer. Conductive paste is filled into the grooves using a scraper and filling tool. The conductive paste is heated and cured to form a conductive structure, thereby forming a conductive film.

[0004] However, due to the surface tension effect of the nanoparticles and groove structure in the slurry at a microscopic scale, as well as the volatilization of the solvent in the slurry, the conductive material in the groove cannot be filled in one go. Usually, it takes three scraping passes to fill it. This not only has low production efficiency, but also increases the appearance defect rate during multiple scraping processes, such as scraper lines and scratches. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a method for manufacturing a conductive film, by introducing a second optical adhesive layer stacked on a first optical adhesive layer used to generate a conductive functional layer, thereby increasing the filling rate of the groove achieved by a single conductive paste scraping, thereby reducing the number of times the conductive paste is scraped.

[0006] The present invention provides a method for manufacturing a conductive film, the method comprising:

[0007] providing a substrate;

[0008] Using the first surface of the substrate as a bearing surface, and manufacturing a conductive functional layer on the bearing surface;

[0009] Wherein, the step of manufacturing a conductive functional layer on the bearing surface comprises:

[0010] Disposing a first optical adhesive layer on the carrying surface;

[0011] Disposing a second optical adhesive layer on a surface of the first optical adhesive layer away from the bearing surface;

[0012] Imprinting a groove with a preset pattern on the second optical adhesive layer, wherein the groove penetrates the second optical adhesive layer and extends into the first optical adhesive layer;

[0013] Scrape and fill the conductive paste into the groove, and solidify it;

[0014] The second optical adhesive layer is removed to form the conductive functional layer.

[0015] Specifically, the thickness of the first optical adhesive layer is: 0.4N+M, and the thickness of the second optical adhesive layer is 0.6N, wherein N is the width of the groove, and the value of M is 1um-10um.

[0016] Specifically, the thickness of the first optical adhesive layer is 1.4um-22um.

[0017] Specifically, the thickness of the second optical adhesive layer is 0.6um-18um.

[0018] Specifically, the first optical adhesive layer is a thermosetting embossing adhesive or an ultraviolet light curing embossing adhesive.

[0019] Specifically, the second optical adhesive layer is a thermoplastic embossed adhesive.

[0020] Specifically, before the second optical adhesive layer is provided on the surface of the first optical adhesive layer away from the bearing surface, the method further includes:

[0021] A release treatment is performed on a surface of the first optical adhesive layer away from the bearing surface to increase a release force of the surface.

[0022] Specifically, it also includes: using the second surface of the substrate as a bearing surface, and manufacturing a conductive functional layer on the bearing surface, wherein the second surface is an opposite surface to the first surface of the substrate.

[0023] Specifically, it also includes: using the third surface as a bearing surface, manufacturing a conductive functional layer on the bearing surface, wherein the third surface is a surface away from the substrate and the conductive functional layer is manufactured using the first surface as a bearing surface.

[0024] The present invention also provides a conductive film, which is made by any of the methods described above.

[0025] The present invention also provides an electronic device, comprising the conductive film as described above.

[0026] To summarize, in the process of manufacturing the conductive functional layer of the conductive film in the embodiment of the present invention, a second optical adhesive layer is introduced and stacked on the first optical adhesive layer used to generate the conductive functional layer, and the second optical adhesive layer is removed after the conductive slurry is scraped into the groove and cured to form a conductive circuit. This can reduce the height difference between the upper surface of the conductive slurry after a single scraping and the upper surface of the first optical adhesive layer, increase the filling rate of the groove achieved by a single scraping of the conductive slurry, and thus reduce the number of scraping and filling times. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 FIG. 4 is a schematic flow chart of a method for manufacturing a conductive film according to an embodiment of the present invention.

[0029] Figure 2 for Figure 1 Schematic diagram of the process of step S2 in FIG.

[0030] Figure 3 FIG. 4 is a schematic diagram of a process for manufacturing a conductive film according to an embodiment of the present invention.

[0031] Figure 4 It is a schematic diagram of the scraping effect of conductive slurry in the prior art.

[0032] Figure 5 FIG. 4 is a schematic flow chart of a method for manufacturing a conductive film in another embodiment of the present invention.

[0033] Figure 6 FIG. 4 is a schematic flow chart of a method for manufacturing a conductive film in yet another embodiment of the present invention.

[0034] Figure 7 FIG. 1 is a schematic structural diagram of a conductive film according to an embodiment of the present invention.

[0035] Figure 8 FIG. 4 is a schematic structural diagram of a conductive film according to another embodiment of the present invention.

[0036] Fig. 9 FIG. 4 is a schematic structural diagram of a conductive film according to another embodiment of the present invention.

[0037] The reference numerals of the embodiments of the present invention in the above drawings are as follows:

[0038] 1. substrate; 11. first surface; 2. conductive functional layer; 21. first optical adhesive layer; 22. second optical adhesive layer; 23. groove; 24. conductive circuit. DETAILED DESCRIPTION

[0039] The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the description of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0041] The directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front”, “back”, “top”, “bottom”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of description and simplified description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0042] The terms "first", "second", "third" and the like are merely used to distinguish elements of similar nature, and do not indicate or imply relative importance or a particular order.

[0043] The terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of the elements listed and may also include additional elements not expressly listed.

[0044] The following is a detailed description through specific embodiments.

[0045] like Figure 1 As shown, an embodiment of the present invention provides a method for manufacturing a conductive film, which is used to manufacture a conductive film. The method includes the following steps:

[0046] Step S1: providing a substrate 1.

[0047] Step S2: Using the first surface 11 of the substrate 1 as a carrying surface, a conductive functional layer 2 is formed on the carrying surface.

[0048] Among them, Figure 2 and Figure 3 As shown, the above step S2 includes the following steps:

[0049] Step S21: disposing a first optical adhesive layer 21 on the carrying surface;

[0050] Step S23: disposing a second optical adhesive layer 22 on the surface of the first optical adhesive layer 21 away from the bearing surface;

[0051] Step S24: printing a groove 23 with a preset pattern on the second optical adhesive layer 22 , wherein the groove 23 penetrates the second optical adhesive layer 22 and extends into the first optical adhesive layer 21 ;

[0052] Step S25: scraping the conductive paste into the groove 23 and curing it;

[0053] Step S26: removing the second optical adhesive layer 22 to form the conductive functional layer 2.

[0054] In the above step S24, the groove 23 can be formed by embossing on the second optical adhesive layer 22 by an embossing template. According to the needs of practical applications, the groove 23 can be deep into the preset position of the first optical adhesive layer 21. Specifically, the ratio of the thickness of the groove 23 deep into the first optical adhesive layer 21 to the thickness of the first optical adhesive layer 21 is a preset ratio, such as 1 / 3, 3 / 8, 1 / 2, 5 / 8, 7 / 8, etc. Alternatively, the thickness of the groove 23 deep into the first optical adhesive layer 21 is a preset thickness, such as 3um, 5um, 8um, 10um, etc.

[0055] In the above step S25, the conductive paste is scraped into the groove 23, which can be specifically scraped into the groove 23 by a scraping tool (such as a scraper). Specifically, the scraper can be manually controlled or automatically controlled by an automated tool (such as a robot arm, a scraping device, etc.) to scrape the conductive paste into the groove 23.

[0056] In this embodiment, the conductive paste can be a material with conductive properties such as low-temperature silver paste, nano silver wire, carbon nanotube, etc. After the conductive paste in the groove 23 is cured by heating and curing, a conductive circuit 24 with a preset pattern is formed. Accordingly, the first optical adhesive layer 21 and the conductive circuit 24 constitute the conductive functional layer 2.

[0057] In a specific embodiment, the heating curing temperature of the conductive paste is 100-160 degrees Celsius, and the heating curing time of the conductive paste is 15-90 minutes.

[0058] In the above step S26, the method for removing the second optical adhesive layer 22 may be: heating the second optical adhesive layer 22 to a softened state and then peeling it off. Specifically, a single-sided adhesive may be used to adhere the surface of the second optical adhesive layer 22 away from the first optical adhesive layer 21, and the second optical adhesive layer 22 may be peeled off from the first optical adhesive layer 21 by utilizing the adhesive force of the single-sided adhesive.

[0059] In the prior art, when manufacturing the conductive functional layer of the conductive film, a scraper or the like is used to scrape the conductive slurry into the groove, such as Figure 4 As shown, the upper surface of the conductive paste undergoes an extrusion effect under the action of pressure, and the scraper will take away part of the conductive paste, resulting in the upper surface of the conductive paste being a concave arc with a low middle and high ends, so that there is a height difference Δh between the upper surface of the conductive circuit formed in the end and the upper surface of the optical adhesive layer in which it is embedded, and as the width of the groove increases, the conductive paste taken away by the scraper will increase, and the height difference between the upper surface of the corresponding conductive circuit and the upper surface of the optical adhesive layer will increase accordingly. Therefore, when using a scraper or the like to scrape the conductive paste into the groove, it is necessary to scrape and fill multiple times to reduce the height difference and improve the performance of the conductive film. Experiments show that when the width of the groove is 5um, the height difference between the upper surface of the conductive circuit and the upper surface of the optical adhesive layer in which it is embedded is generally 1.0um-1.5um; when the width of the groove is 15um, the height difference between the upper surface of the conductive circuit and the upper surface of the optical adhesive layer in which it is embedded will reach 2um.

[0060] Based on the above problems existing in the prior art, in the process of manufacturing the conductive functional layer of the conductive film, this embodiment introduces a second optical adhesive layer stacked on the first optical adhesive layer used to generate the conductive functional layer, and removes the second optical adhesive layer after scraping the conductive slurry into the groove and curing to form a conductive circuit. This can reduce the height difference between the upper surface of the conductive slurry after a single scraping and the upper surface of the first optical adhesive layer, thereby increasing the filling rate of the groove in a single scraping, thereby reducing the number of scraping times.

[0061] In one embodiment, the thickness of the first optical adhesive layer 21 is: 0.4N+M, and the thickness of the second optical adhesive layer 22 is 0.6N, wherein N is the width of the groove 23, the value of N is 3um-30um, and the value of M is 1um-10um. Specifically, according to the needs of actual applications, N can be 5um, 7um, 10um, 15um, 20um, 25um, etc., and M can be 3um, 5um, 7um, etc., and this application does not limit this.

[0062] In this embodiment, by reasonably setting the thickness of the first optical adhesive layer, the thickness of the second optical adhesive layer and the width of the groove, the conductive slurry can be scraped and filled in place at one time, reducing the appearance defect rate caused by multiple scraping, such as scraper lines, scratches, etc.; at the same time, it can also ensure the consistency of the filling quality of the conductive slurry, thereby improving the stability of the conductive film.

[0063] In one embodiment, the first optical adhesive layer 21 is a thermosetting or UV-curable embossed adhesive. The thickness of the first optical adhesive layer 21 is 1.4um-22um, and the thickness of the first optical adhesive layer 21 can be 2um, 5um, 10um, 15um, 20um. In one embodiment, the second optical adhesive layer 22 is a thermoplastic embossed adhesive, and the material of the second optical adhesive layer 22 is selected from one of polymethacrylate, polystyrene, polycarbonate, polymethacrylate aromatic ester, and polymethacrylate aromatic ester. The thickness of the second optical adhesive layer 22 is 0.6um-18um, and the thickness of the second optical adhesive layer 22 can be 1.8um, 5um, 10um, 15um.

[0064] In this embodiment, if Figure 2 As shown, after the second optical adhesive layer 22 is provided, a composite multilayer structure is formed between the substrate 1, the first optical adhesive layer 21 and the second optical adhesive layer 22. In this embodiment, before the above step S23, it also includes:

[0065] Step S22: performing a release treatment on the surface of the first adhesive layer away from the bearing surface to increase the release force of the surface. In this embodiment, the release treatment may be a treatment process such as plasma, fluorine coating or silicon coating, so that an ultra-light and stable release force is formed between the first optical adhesive layer 21 and the second optical adhesive layer 22, which is convenient for subsequent separation.

[0066] In another embodiment, Figure 5 As shown, the method for making the conductive film also includes the steps of:

[0067] S3: Using the second surface of the substrate 1 as a bearing surface, a conductive functional layer 2 is formed on the bearing surface, wherein the second surface is the opposite surface of the first surface 11 of the substrate 1 .

[0068] In yet another embodiment, Figure 6 As shown, the method for making the conductive film also includes the steps of:

[0069] S4: Using the third surface as a bearing surface, a conductive functional layer 2 is fabricated on the bearing surface, wherein the third surface is a surface of the conductive functional layer 2 fabricated using the first surface 11 as a bearing surface and away from the substrate 1 .

[0070] Exemplarily, the following is a detailed parameter of a specific example to better illustrate the manufacturing process of the conductive film, which includes the following steps:

[0071] Step A: A 2.1 um thick acrylic resin layer (equivalent to the first optical adhesive layer 21) is disposed on the upper surface of polyethylene terephthalate (equivalent to the substrate 1), a layer of silicone release agent is coated on the upper surface of the acrylic resin layer, and then a 3.2 um thick polymethyl methacrylate layer (equivalent to the second optical adhesive layer 22) is disposed.

[0072] Step B: After heating until the second optical adhesive layer 22 is softened, a groove 23 with a preset pattern is embossed on the upper surface of the second optical adhesive layer 22 using an embossing template, and the groove 23 penetrates the second optical adhesive layer 22 and penetrates into the first optical adhesive layer 21, thereby preparing a composite multilayer structure with a groove 23 with a preset pattern. Here, the depth of the groove 23 is 4.8um and the width is 4.8um.

[0073] Step C: Use a scraper to fill the low-temperature silver paste once, and heat it at 130 degrees Celsius for 30 minutes to cure the low-temperature silver paste. The filling height of the low-temperature silver paste is about 2.1um.

[0074] Step D: heating at 160 degrees Celsius for 20 minutes, peeling off the second optical adhesive layer 22, and obtaining a conductive film in which the conductive circuit 24 is substantially flush with the upper surface of the substrate 1.

[0075] An embodiment of the present invention further provides a conductive film, which is manufactured by the conductive film manufacturing method of any of the above embodiments.

[0076] For example, Figure 7 As shown, the conductive film includes a substrate 1 and a conductive functional layer 2 disposed on one side surface of the substrate 1. The conductive functional layer 2 includes: a first optical adhesive layer 21, and a conductive circuit 24 formed of a conductive paste is disposed on the surface of the first optical adhesive layer 21 away from the substrate 1, and the surface of the conductive circuit 24 is flush with or slightly higher than the surface of the first optical adhesive layer 21. The conductive film is a sensing device for receiving input signals such as touch, and can be used in electronic devices.

[0077] like Figure 8 As shown, the conductive film includes a substrate 1 and two conductive functional layers 2 respectively arranged on both side surfaces of the substrate 1 .

[0078] like Fig. 9 As shown, the conductive film includes a substrate 1 and two conductive functional layers 2 stacked on one side surface of the substrate 1 .

[0079] An embodiment of the present invention further provides an electronic device, wherein the electronic device comprises the conductive film manufactured according to any one of the above embodiments.

[0080] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A method for manufacturing a conductive film, characterized in that: The method includes: providing a substrate; Using the first surface of the substrate as a bearing surface, and manufacturing a conductive functional layer on the bearing surface; Wherein, the step of manufacturing a conductive functional layer on the bearing surface comprises: Disposing a first optical adhesive layer on the carrying surface; Disposing a second optical adhesive layer on a surface of the first optical adhesive layer away from the bearing surface; Imprinting a groove with a preset pattern on the second optical adhesive layer, wherein the groove penetrates the second optical adhesive layer and extends into the first optical adhesive layer; Scrape and fill the conductive paste into the groove, and solidify it; The second optical adhesive layer is removed to form the conductive functional layer.

2. The method for manufacturing a conductive film according to claim 1, wherein: The thickness of the first optical adhesive layer is: 0.4N+M, and the thickness of the second optical adhesive layer is 0.6N, wherein N is the width of the groove, and the value of M is 1um-10um.

3. The method for manufacturing a conductive film according to claim 1, wherein: The thickness of the first optical adhesive layer is 1.4um-22um.

4. The method for manufacturing a conductive film according to claim 1, wherein: The thickness of the second optical adhesive layer is 0.6um-18um.

5. The method for manufacturing a conductive film according to claim 1, wherein: The first optical adhesive layer is a thermosetting embossing adhesive or an ultraviolet light curing embossing adhesive.

6. The method for manufacturing a conductive film according to claim 1, wherein: The second optical adhesive layer is a thermoplastic embossed adhesive.

7. The method for manufacturing a conductive film according to claim 1, wherein: Before the second optical adhesive layer is provided on the surface of the first optical adhesive layer away from the bearing surface, the method further comprises: A release treatment is performed on a surface of the first optical adhesive layer away from the bearing surface to increase a release force of the surface.

8. The method for manufacturing a conductive film according to any one of claims 1 to 7, characterized in that: Also includes: The second surface of the substrate is used as a bearing surface, and a conductive functional layer is manufactured on the bearing surface. The second surface is the opposite surface of the first surface of the substrate.

9. The method for manufacturing a conductive film according to any one of claims 1 to 7, characterized in that: Also includes: The third surface is used as a bearing surface, and a conductive functional layer is manufactured on the bearing surface. The third surface is a surface away from the substrate of the conductive functional layer manufactured using the first surface as a bearing surface.

10. A conductive film, characterized in that: The conductive film is manufactured by the method according to any one of claims 1 to 9.

11. An electronic device, characterized in that: Comprising the conductive film as claimed in claim 10.

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