Silver-migration-preventing conductive film and manufacturing method of silver-migration-preventing conductive film

Abstract

The invention relates to an anti-silver-migration conducting film and a manufacturing method thereof, the anti-silver-migration conducting film comprises a moisture absorption layer, a silver paste electrode, a super-hydrophobic coating and a protective layer, the silver paste electrode comprises a grounding wire and a plurality of signal wires, the thickness of the silver paste electrode is smaller than that of the moisture absorption layer, and the thickness of the super-hydrophobic coating is larger than that of the moisture absorption layer. The thickness of the super-hydrophobic coating is smaller than that of the moisture absorption layer; on the sensor substrate, a moisture absorption layer is arranged between the grounding wire and the signal wire, a moisture absorption layer is arranged between the signal wires, a super-hydrophobic coating is arranged above the silver paste electrode, and a protective layer is arranged above the super-hydrophobic coating. According to the invention, the problem of silver migration of the touch screen is solved.

Description

Technical Field

[0001] This application relates to the technical field of touch screens, and particularly to an anti-silver migration conductive film and a method for manufacturing the anti-silver migration conductive film. Background Art

[0002] At present, for touch screens with a film structure solution, due to cost and sheet resistance reasons, more and more of the film materials used have been changed from the original ITO to nano-silver materials. For large sizes (over 55 inches), due to the requirements of the touch screen for resistance and transmittance, currently only nano-silver film materials can be selected. As the conductive lines become thinner and thinner, the probability of silver migration occurring is getting higher and higher. The problems of silver anodic oxidation and silver migration are the main obstacles for the current nano-silver film materials not to be widely promoted on a large scale.

[0003] Silver migration refers to the situation in a humid environment with a DC voltage gradient. Water molecules penetrate into the surface of the silver-containing conductor and electrolyze to form hydrogen ions and hydroxide ions. Under the action of the electric field, silver ions migrate from a high potential to a low potential and form a flocculent or dendritic expansion, forming black silver oxide at the boundary where the high and low positions are connected, ultimately leading to short-circuit failure. And the nano-silver conductive film material is to uniformly coat a conductive film material in the form of a nano-scale silver wire mesh on a transparent film material; for a touch screen, the touch pattern we need is etched on the surface of this conductive film, and the induction magnetic field required for the channel formation is formed; for products made of nano-silver film materials, if the environment is humid, silver migration is likely to occur during power-on operation, resulting in poor touch screen function. Currently, nano-silver film material manufacturers overcome this by adjusting their nano-silver coating formula, trying to solidify the nano-silver on the surface of the film material as much as possible, but the migration of silver ions is still likely to cause problems due to the influence of the use environment.

[0004] Currently, mainly a ultra-thin and transparent insulating layer is coated on the surface of the nano-silver wire transparent conductive film to isolate the surface of the nano-silver wire conductive film from the external environment. However, by the method of coating the insulating layer, since there are height differences between each electrode of the nano-silver, water vapor can enter along the height differences, resulting in silver migration.

[0005] Regarding the problem of silver migration in touch screens in the related art, no effective solution has been proposed yet. Summary of the Invention

[0006] In this embodiment, an anti-silver migration conductive film and a method for manufacturing the anti-silver migration conductive film are provided to solve the problem of silver migration in touch screens in the related art.

[0007] In the first aspect, in this embodiment, an anti-silver migration conductive film is provided, including: a moisture absorption layer, a silver paste electrode, a superhydrophobic coating, and a protective layer, wherein,

[0008] The silver paste electrode includes a ground wire and a plurality of signal wires. The thickness of the silver paste electrode is less than that of the moisture absorption layer, and the thickness of the superhydrophobic coating is greater than that of the moisture absorption layer;

[0009] On the sensor substrate, a moisture absorption layer is provided between the ground wire and the signal wires, a moisture absorption layer is provided between the signal wires, a superhydrophobic coating is provided above the silver paste electrode, and a protective layer is provided above the superhydrophobic coating.

[0010] In some embodiments, the moisture absorption layer is a metal oxide coating, and the metal oxide coating includes a magnetron sputtered alumina coating, a magnetron sputtered calcium oxide coating, and a magnetron sputtered magnesium oxide coating.

[0011] In some embodiments, the superhydrophobic coating is a fluorine-containing superhydrophobic coating, a nano-silica coating, or a titanium dioxide coating.

[0012] In some embodiments, the thickness of the moisture absorption layer is 200 nanometers to 400 nanometers.

[0013] In some embodiments, the thickness of the silver paste electrode is 100 nanometers to 200 nanometers.

[0014] In some embodiments, the thickness of the superhydrophobic coating is 1 micrometer to 5 micrometers.

[0015] In a second aspect, a mobile device is provided in this embodiment. The mobile device includes the anti-silver migration conductive film described in the first aspect above.

[0016] In a third aspect, a method for manufacturing an anti-silver migration conductive film is provided in this embodiment. The method is applied to the anti-silver migration conductive film described in the first aspect above, and the manufacturing method includes:

[0017] Obtain a sensor substrate and perform ultrasonic cleaning on the sensor substrate;

[0018] Deposit a moisture absorption layer on the surface of the sensor substrate;

[0019] Print a silver paste electrode between the moisture absorption layers; the thickness of the silver paste electrode is less than that of the moisture absorption layer;

[0020] Coat a superhydrophobic coating on the upper surface of the silver paste electrode, and the thickness of the superhydrophobic coating is greater than that of the moisture absorption layer;

[0021] Coat a protective layer on the superhydrophobic coating, and the protective layer uses a superhydrophobic coating;

[0022] Obtain the target anti-silver migration conductive film.

[0023] In some embodiments, before depositing a moisture absorption layer on the surface of the sensor substrate, it further includes:

[0024] Bond the sensor substrate to the glass. On the sensor substrate, perform a hollowing process on the areas that need to be magnetron - sputtered and a masking process on the conductive silver paste areas.

[0025] Introduce an inert gas at a preset gas flow rate, apply a magnetic field at a preset magnetron - sputtering power, and set the temperature of the sensor substrate at a preset temperature.

[0026] In some of these embodiments, printing silver paste electrodes between the moisture - absorbing layers includes:

[0027] Obtain a preset number of silver nanowires;

[0028] Stir the silver nanowires in a preset container to obtain a silver nanowire dispersion;

[0029] Add a preset amount of polyethylene oxide to the silver nanowire dispersion and stir for a preset period of time to obtain silver nanowire ink, and print the silver nanowire ink between the moisture - absorbing layers to form silver paste electrodes.

[0030] Compared with the related art, the anti - silver - migration conductive film provided in this embodiment includes: a moisture - absorbing layer, silver paste electrodes, a super - hydrophobic coating, and a protective layer. Among them, the silver paste electrodes include a ground wire and a number of signal lines. The thickness of the silver paste electrodes is less than the thickness of the moisture - absorbing layer, and the thickness of the super - hydrophobic coating is greater than the thickness of the moisture - absorbing layer; on the sensor substrate, a moisture - absorbing layer is provided between the ground wire and the signal lines, a moisture - absorbing layer is provided between the signal lines, a super - hydrophobic coating is provided above the silver paste electrodes, and a protective layer is provided above the super - hydrophobic coating. The problem of silver migration in the touch screen is solved.

[0031] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects, and advantages of this application more concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of this application and form a part of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0033] Figure 1 is a schematic structural diagram of the anti - silver - migration conductive film of this embodiment.

[0034] Figure 2 is a flowchart of the manufacturing method of the anti - silver - migration conductive film of this embodiment.

[0035] Figure 3 is a flowchart of another manufacturing method of the anti - silver - migration conductive film of this embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To more clearly understand the purpose, technical solution and advantages of the present application, the present application will be described and explained below with reference to the accompanying drawings and embodiments.

[0037] Unless otherwise defined, the technical terms or scientific terms involved in the present application shall have the general meanings understood by those with ordinary skills in the technical field to which the present application belongs. In the present application, words such as "a", "one", "kind", "the", "these" and the like do not indicate a limitation in quantity, and they can be singular or plural. The terms "including", "comprising", "having" and any variants thereof involved in the present application are intended to cover non-exclusive inclusion; for example, a process, method, system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent in these processes, methods, products or devices. The words such as "connected", "coupled" and "joined" involved in the present application are not limited to physical or mechanical connections, but may include electrical connections, whether directly or indirectly. The "plurality" involved in the present application means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" may represent: A exists alone, A and B exist simultaneously, and B exists alone. Usually, the character " / " indicates that the objects associated before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in the present application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0038] In this embodiment, a silver migration-proof conductive film is provided, which includes: a protective layer, a superhydrophobic coating, a silver paste electrode and a moisture absorption layer. Among them, the silver paste electrode includes a ground wire and a plurality of signal lines. The thickness of the silver paste electrode is less than the thickness of the moisture absorption layer, and the thickness of the superhydrophobic coating is greater than the thickness of the moisture absorption layer; on the sensor substrate, a moisture absorption layer is provided between the ground wire and the signal lines, a moisture absorption layer is provided between the signal lines, a superhydrophobic coating is provided above the silver paste electrode, and a protective layer is provided above the superhydrophobic coating.

[0039] Specifically, in today's information age, touchscreens have become an indispensable part of daily life. From smartphones, tablets to ATMs, electronic guide systems, and even future smart homes and driverless cars, touchscreens play an important role. The core components of touchscreens are ITO (Indium Tin Oxide) glass and silver paste lines. ITO, namely indium tin oxide, is a transparent conductive oxide. When it is coated on the glass surface, ITO glass is formed. This special glass has excellent electrical conductivity and light transmittance. In a touchscreen, ITO glass is used as the conductive layer. When a user's finger or stylus touches the screen, a tiny current is generated, and this current is conducted through the ITO glass to the electrodes at all corners of the screen. Silver paste lines play the role of current channels in the touchscreen. They are printed on the ITO glass to connect all the electrodes and form a complete circuit network. During the preparation process, the silver paste lines are precisely printed on the ITO glass to form hair-thin lines. The combined use of ITO glass and silver paste lines jointly completes the touch sensing task. When a user touches the screen, the ITO glass is responsible for sensing the change in current and conducting these changes to the silver paste lines, and then the silver paste lines transmit these current signals to the controller of the touchscreen. After a series of processing and analysis, the position of the touch point is finally determined.

[0040] However, when designing silver paste lines, there is a problem of silver migration. Two important influencing factors of silver migration are the entry of water vapor and the increase in temperature. High temperature and high humidity will increase the speed of silver migration. To prevent silver migration, an anti-silver-migration conductive film is provided in this embodiment. Figure 1 It is a schematic structural diagram of the anti-silver-migration conductive film of this embodiment, as Figure 1As shown in the figure, a conductive film is provided on the sensor substrate 11. The silver migration prevention conductive film includes, from bottom to top, a moisture absorption layer 12, a silver paste electrode 13, a superhydrophobic coating 14, and a protective layer 15. Among them, the silver paste electrode 13 includes a ground wire 131 and a plurality of signal lines 132. In order to prevent moisture from entering between the ground wire 131 and the signal lines 132 of the silver paste electrode 13 and between the signal lines 132, resulting in silver migration, in this embodiment, the silver migration prevention conductive film first sets a moisture absorption layer between the silver paste channels. Among them, in order to ensure that the moisture absorption layer can completely cover the silver paste electrode, the thickness of the silver paste electrode is set to be less than the thickness of the moisture absorption layer. Through the good moisture absorption and insulation properties of the moisture absorption layer, the moisture entering between the silver paste electrodes 13 is absorbed, and at the same time, the conductivity between the silver paste lines is not affected. Secondly, in order to prevent moisture from entering from the surface of the silver paste electrode, a superhydrophobic coating is provided on the upper surface of the silver paste electrode. Among them, the thickness of the superhydrophobic coating is greater than the thickness of the moisture absorption layer. The superhydrophobic coating is a coating with special surface wetting properties, and its contact angle with water is greater than 150°, and the rolling angle is less than 10°. The superhydrophobic coating can be prepared by etching method, layer-by-layer self-assembly method, sol-gel method, hydrothermal synthesis method, electrochemical deposition method, spraying method, etc. In this embodiment, the preparation method of the superhydrophobic coating is not specifically limited, and it can be selected according to the actual situation. By setting the superhydrophobic coating, it is possible to prevent moisture from focusing on the upper surface of the silver paste electrode, so that moisture can only accumulate from both sides. Since moisture absorption layers are provided on both sides, when the moisture flows through both sides, it is absorbed by the moisture absorption layer, protecting the reliability of the silver paste electrode and preventing silver migration of the silver paste electrode. Finally, after a superhydrophobic coating is provided above each silver paste electrode, a protective layer covering all the silver paste electrodes and the moisture absorption layer is further provided above all the superhydrophobic coatings. The protective layer can also be a superhydrophobic coating to further prevent the entry of moisture, thereby preventing silver migration of the silver paste electrode.

[0041] The silver migration prevention conductive film set in this embodiment includes: a moisture absorption layer, a silver paste electrode, a superhydrophobic coating, and a protective layer. Among them, the silver paste electrode includes a ground wire and a plurality of signal lines. The thickness of the silver paste electrode is less than the thickness of the moisture absorption layer, and the thickness of the superhydrophobic coating is greater than the thickness of the moisture absorption layer; on the sensor substrate, a moisture absorption layer is provided between the ground wire and the signal lines, a moisture absorption layer is provided between the signal lines, a superhydrophobic coating is provided above the silver paste electrode, and a protective layer is provided above the superhydrophobic coating. Compared with the current method of coating a thin and transparent insulating layer on the surface of the nano-silver wire transparent conductive film to isolate the surface of the nano-silver wire conductive film from the external environment, in this embodiment, a moisture absorption layer is provided between the silver paste electrodes to absorb the moisture entering between the electrodes, and a superhydrophobic coating is provided on the upper surface of the silver paste electrode to prevent moisture from entering from the upper surface of the silver paste electrode, thereby comprehensively preventing silver migration of the silver paste electrode and solving the problem of silver migration of the touch screen.

[0042] In some of these embodiments, the moisture absorption layer employs a metal oxide coating, and the metal oxide coating includes a magnetron sputtered alumina coating, a magnetron sputtered calcium oxide coating, and a magnetron sputtered magnesium oxide coating. Among them, the thickness of the moisture absorption layer is 200 nanometers to 400 nanometers, and the thickness of the silver paste electrode is 100 nanometers to 200 nanometers.

[0043] Specifically, in the moisture absorption layer, in order to ensure both moisture absorption and insulation simultaneously, a metal oxide coating is used in this embodiment, which includes a magnetron sputtered alumina coating (Al2O3), a magnetron sputtered calcium oxide coating (CaO), and a magnetron sputtered magnesium oxide coating (MgO). The magnetron sputtered alumina coating forms an alumina layer on the aluminum surface through magnetron sputtering technology, which can improve the corrosion resistance of the material, and also increase its wear resistance and hardness. The magnetron sputtered calcium oxide coating can provide good moisture absorption, helping the material maintain stable performance in a humid environment. This coating can be prepared by chemical vapor deposition (CVD) or physical vapor deposition (PVD) technology. The magnetron sputtered magnesium oxide coating has good chemical corrosion resistance and electrical insulation, and can also provide a certain degree of moisture absorption performance. This coating can be formed by thermal spraying or electrochemical deposition methods. There is a certain void structure and surface activity among the metal oxides. When water vapor enters, it will adsorb water molecules; at the same time, the metal oxides have a very high resistivity, which can play a good insulating and protective role; in addition, the metal oxides have good thermal conductivity, which can timely conduct the heat of the silver paste line and dissipate heat from the silver paste line, thereby further preventing high temperature from accelerating the speed of silver migration. In this embodiment, the thickness of the moisture absorption layer can be set to 200 nanometers to 400 nanometers, and the thickness of the silver paste electrode is 100 nanometers to 200 nanometers. The thickness of the silver paste electrode is set to be 100 nanometers - 200 nanometers smaller than the thickness of the absorption layer to ensure that the absorption layer can completely cover the silver paste electrode. The specific thicknesses of the absorption layer and the silver paste electrode can also be set according to the actual situation.

[0044] In another embodiment, the superhydrophobic coating is a fluorine-containing superhydrophobic coating, a nano-silica coating, or a titanium dioxide coating. Among them, the thickness of the superhydrophobic coating is 1 micrometer to 5 micrometers.

[0045] Specifically, in order to prevent water vapor from entering the upper surface of the silver paste electrode, a superhydrophobic layer is provided on the upper surface of the silver paste electrode. The superhydrophobic coating uses a fluorine-containing superhydrophobic coating, such as polytetrafluoroethylene (PTFE), to reduce the surface energy, thereby achieving superhydrophobicity. Among them, fluoropolymers have extremely low surface energy and can effectively repel water molecules. Or the superhydrophobic coating uses a silica coating. This coating forms a rough surface structure by coating nanoscale silica particles on the substrate surface, increasing the surface roughness, thereby improving the hydrophobicity. The nano-silica coating can be prepared by the sol-gel method. This method is convenient to operate and has low preparation cost, but the controllability of the coating structure is poor. For example, fluorosilane (FAS) is added to an ethanol solution containing ammonia water, and then a clean glass sheet is immersed in the solution and dried to obtain a transparent superhydrophobic coating. Or the superhydrophobic coating uses a titanium dioxide coating (TiO2). Titanium dioxide is a semiconductor material with photocatalytic activity and can decompose organic pollutants. By coating titanium dioxide on the substrate surface, a superhydrophobic coating can be formed, and at the same time, its photocatalytic properties can be used to achieve self-cleaning. For example, using Ti(OC3H7)4 as a precursor, a TiO2 thin film is deposited on the surface of tin oxide by CVD method, and then the film is coated and modified with a fluoroalkyl methacrylate copolymer to prepare a superhydrophobic anatase TiO2 coating with a water contact angle of 166.1° and a contact angle hysteresis of 6°, and good stability. Among them, in this embodiment, the thickness of the superhydrophobic coating is 1 to 5 microns, and the thickness of the superhydrophobic coating is greater than the thickness of the moisture absorption layer. The specific thickness can also be determined according to the actual situation.

[0046] In this embodiment, a mobile device is provided, and the mobile device includes the anti-silver migration conductive film in the above embodiment. The mobile device can be a smart phone, a tablet computer, an ATM, an electronic guide system, a smart home, a driverless car, or other devices using a touch screen.

[0047] In this embodiment, a method for manufacturing an anti-silver migration conductive film is provided, Figure 2 which is a flowchart of the method for manufacturing the anti-silver migration conductive film in this embodiment, as Figure 2 shown, and the process includes the following steps:

[0048] Step S201, obtain a sensor substrate and perform ultrasonic cleaning on the sensor substrate.

[0049] Specifically, select a suitable substrate material according to application requirements, such as glass, PET (polyethylene terephthalate) film, etc. The selected substrate material is ultrasonically cleaned to remove dust, grease, and other contaminants on the surface. The cleaned substrate is dried by hot air drying, infrared drying, or natural air drying to remove residual moisture.

[0050] Step S202, deposit a moisture-absorbing layer on the surface of the sensor substrate.

[0051] Specifically, grow a moisture-absorbing layer on the surface of the substrate after cleaning and drying. The moisture-absorbing layer can be: a magnetron sputtered alumina (Al2O3) coating, a magnetron sputtered calcium oxide coating (CaO), or a magnetron sputtered magnesium oxide coating (MgO). Since there are certain void structures and surface activities between metal oxides, when water vapor enters, it will adsorb water molecules. At the same time, metal oxides have a very high resistivity, which can provide good insulation protection. In addition, metal oxides have good thermal conductivity, which can timely conduct the heat of the silver paste lines, achieving a heat dissipation effect, thereby preventing high temperature from accelerating the speed of silver migration and improving performance reliability. Among them, the thickness of the moisture-absorbing layer is set to: 200 nanometers to 400 nanometers.

[0052] Step S203, print silver paste electrodes between the moisture-absorbing layers; the thickness of the silver paste electrodes is less than the thickness of the moisture-absorbing layer.

[0053] Specifically, after growing a moisture-absorbing layer on the surface of the sensor substrate, between the moisture-absorbing layers, print silver paste electrodes by inkjet printing. The thickness of the silver paste electrodes is controlled within 100 nanometers to 200 nanometers. The thickness of the silver paste electrodes is less than the thickness of the moisture-absorbing layer, 100 nanometers - 200 nanometers lower than the moisture-absorbing layer, to ensure good contact and electrical connection between the electrodes and the moisture-absorbing layer, and at the same time avoid performance degradation caused by too thick electrodes. After printing the silver paste electrodes, perform a curing treatment to ensure the stability and conductivity of the electrodes. Among them, the curing treatment can be achieved through heat treatment, ultraviolet light irradiation or other means.

[0054] Step S204, coat a superhydrophobic coating on the upper surface of the silver paste electrodes, and the thickness of the superhydrophobic coating is greater than the thickness of the moisture-absorbing layer.

[0055] Specifically, coat a superhydrophobic coating on the surface of the silver paste electrodes. The superhydrophobic coating can be an F-containing superhydrophobic coating. After the coating is cured, the thickness of the superhydrophobic layer is lower than the thickness of the moisture-absorbing layer, and the thickness of the superhydrophobic layer is controlled within 1 micrometer to 5 micrometers. Coatings such as nano-silica and titanium dioxide can also be used.

[0056] Step S205, coat a protective layer on the superhydrophobic coating, and the protective layer uses a superhydrophobic coating; obtain the target anti-silver migration conductive film.

[0057] Specifically, after coating the above-mentioned superhydrophobic coating, add another protective layer. The protective layer can use the same material as the superhydrophobic coating. The protective layer covers the moisture-absorbing layer, completely isolating the silver wire electrodes from the outside world. After coating the protective film, obtain the target anti-silver migration conductive film.

[0058] Through the above steps S201 to S205, a sensor substrate is obtained, and the sensor substrate is ultrasonically cleaned; a moisture absorption layer is plated on the surface of the sensor substrate; silver paste electrodes are printed between the moisture absorption layers; the thickness of the silver paste electrodes is less than the thickness of the moisture absorption layer; a superhydrophobic coating is coated on the upper surface of the silver paste electrodes, and the thickness of the superhydrophobic coating is greater than the thickness of the moisture absorption layer; a protective layer is coated on the superhydrophobic coating, and the protective layer uses a superhydrophobic coating; a target anti-silver migration conductive film is obtained. Compared with the current method of coating a thin and transparent insulating layer on the surface of a silver nanowire transparent conductive film to isolate the surface of the silver nanowire conductive film from the external environment, by adding a protective layer and a superhydrophobic coating on the surface of the silver paste electrodes to isolate water vapor from entering the surface of the silver paste electrodes; through the moisture absorption layer, the relevant water vapor between the silver paste electrodes is absorbed, thereby preventing silver ionization and avoiding silver migration.

[0059] In some of these embodiments, before plating a moisture absorption layer on the surface of the sensor substrate, it further includes:

[0060] The sensor substrate is bonded to the glass, on the sensor substrate, the area to be magnetron sputtered is hollowed out, and the area of the conductive silver paste is shielded; an inert gas is introduced according to a preset gas flow rate, a magnetic field is applied according to a preset magnetron power, and the temperature of the sensor substrate is set according to a preset temperature.

[0061] Specifically, before growing a moisture absorption layer on the surface of the sensor substrate, the sensor substrate is first designed, the area of the substrate to be magnetron sputtered is in a hollow state, and the area of the conductive silver paste is shielded; to prevent the silver paste from being covered by the sputtering material, the designed sensor substrate and the glass are installed and bonded using a tooling to ensure that the magnetron area is aligned with the silver paste area. The glass bonded well is placed in the magnetron sputtering cavity, the cavity is closed, and vacuum pumping is carried out until the vacuum degree in the cavity is above 10 3 Pa, where the high-vacuum environment helps to reduce the interference of gas molecules on the sputtering process and improve the quality and uniformity of the conductive film; an inert gas, such as argon, is introduced, and the gas flow rate is controlled to be 10 - 40 ml / min. Among them, the inert gas plays an ionization role in the sputtering process and helps the target atoms or molecules to be sputtered out from the surface of the target; a magnetic field is applied: the power of the magnetron sputtering is controlled within the range of 100 - 150 w to control the sputtering rate and the deposition rate of the conductive film; the temperature of the sample stage is set between 220 - 450 °C to improve the adhesion and crystallization quality of the film, and at the same time, it also helps to reduce the moisture and organic substances on the surface of the substrate. The magnetron sputtering process is started, and the target atoms or molecules are sputtered out under the action of the magnetic field and the electric field and deposited on the surface of the substrate to form a moisture absorption layer.

[0062] In another embodiment, printing silver paste electrodes between the moisture absorption layers includes:

[0063] Obtain a preset number of silver nanowires; stir the silver nanowires in a preset container to obtain a silver nanowire dispersion; add a preset number of polyethylene oxides to the silver nanowire dispersion and stir for a preset duration to obtain silver nanowire ink, and print the silver nanowire ink between the moisture absorption layers to form a silver paste electrode.

[0064] Specifically, after magnetron sputtering is completed, slowly reduce the chamber temperature to avoid film stress and potential film damage caused by sudden temperature changes; take out the sensor substrate for ultrasonic cleaning to remove possible residual sputtering materials or impurities, and thoroughly dry the cleaned sensor substrate.

[0065] Accurately weigh a certain amount of silver nanowires and add them to a mixed solution of deionized water and absolute ethanol. Use a magnetic stirrer to stir for 10 - 30 minutes to ensure that the silver nanowires are evenly dispersed in the solution;

[0066] Add a certain amount of PEO (polyethylene oxide) as a dispersant to the silver nanowire dispersion, with the mass ratio controlled at 1% - 5%, and stir for 15 - 60 minutes to form a stable silver nanowire ink. The viscosity of the ink should be controlled at 1 - 20 mPa·s, and the surface tension should be between 10 - 50 mN / m.

[0067] Treat the prepared silver nanowire ink in ultrasonic waves for 5 minutes to further disperse and stabilize the ink and prevent the aggregation of silver nanowires.

[0068] Use a special spraying device to spray the silver nanowire ink onto the sensor substrate that has been ultrasonically cleaned. During the spraying process, set the nozzle pressure between 5 - 35 V to ensure that the ink can be evenly sprayed and form the required thickness (100 nanometers to 200 nanometers). Control the spraying distance, spraying speed, and number of spraying times during the spraying process to obtain a uniform coating. After spraying is completed, the silver nanowire ink is subjected to a curing treatment to form a stable silver paste electrode.

[0069] In this embodiment, a method for manufacturing an anti - silver - migration conductive film is also provided. Figure 3 It is a flowchart of another method for manufacturing an anti - silver - migration conductive film in this embodiment, as Figure 3 shown, and this process includes the following steps:

[0070] Step S301, obtain a sensor substrate and perform ultrasonic cleaning on the sensor substrate;

[0071] Step S302, bond the sensor substrate to the glass, on the sensor substrate, perform a hollowing - out treatment on the area to be magnetron - sputtered, and perform a masking treatment on the conductive silver paste area; introduce an inert gas according to a preset gas flow rate, apply a magnetic field according to a preset magnetron power, and set the temperature of the sensor substrate according to a preset temperature; deposit a moisture absorption layer on the surface of the sensor substrate.

[0072] Step S303: Obtain a preset number of silver nanowires; stir the silver nanowires in a preset container to obtain a silver nanowire dispersion; add a preset amount of polyethylene oxide to the silver nanowire dispersion and stir for a preset duration to obtain silver nanowire ink, and print the silver nanowire ink between the moisture absorption layers to form a silver paste electrode; the thickness of the silver paste electrode is less than the thickness of the moisture absorption layer;

[0073] Step S304: Coat a superhydrophobic coating on the upper surface of the silver paste electrode, and the thickness of the superhydrophobic coating is greater than the thickness of the moisture absorption layer;

[0074] Step S305: Coat a protective layer on the superhydrophobic coating, and the protective layer uses the superhydrophobic coating to obtain the target silver migration-proof conductive film.

[0075] Specifically, the manufacturing method of the silver migration-proof conductive film is as follows:

[0076] 1. Take ordinary glass and a design template, perform ultrasonic cleaning for 10 - 20 minutes, and let it stand for surface drying;

[0077] 2. Design a sensor substrate, use a tooling installation to bond it to the glass, make the area of the substrate that needs to be magnetron sputtered in a hollow state, and mask the conductive silver paste area;

[0078] 3. Place the glass bonded in step 2 in the magnetron cavity, evacuate, and pump to a vacuum degree of more than 10 3 Pa;

[0079] 4. Introduce an inert gas, such as argon, and control the gas flow rate to be 10 - 40 ml / min;

[0080] 5. Apply a magnetic field: set the magnetron power to be 100 - 150 w; control the sample stage temperature to be 220 - 450 °C;

[0081] 6. Perform magnetron sputtering coating to obtain a moisture absorption layer: according to requirements, control the thickness of the magnetron aluminum oxide coating of the moisture absorption layer to be 200 nanometers to 400 nanometers;

[0082] 7. After the magnetron sputtering is completed, perform cooling;

[0083] 8. Take out the sample for ultrasonic cleaning and set it aside for use;

[0084] 9. Take a certain amount of silver nanowires, add them to a mixed solution of deionized water and absolute ethanol, and use a magnetic stirrer to stir for 10 - 30 minutes to obtain a silver nanowire dispersion;

[0085] 10. Add a certain amount of PEO (polyethylene oxide) as a dispersant to the silver nanowire dispersion, with the mass ratio controlled at 1%-5%, and stir for 15-60 minutes to form a stable silver nanowire ink; the viscosity is 1-20 mPa·s, and the surface tension is 10-50 mN / m;

[0086] 11. Treat the prepared silver nanowire ink in ultrasonic for 5 minutes;

[0087] 12. Spray the silver nanowire conductive ink prepared in step 11 onto the sample in step 8 through a special spraying device, control the spraying thickness to be 100 nanometers to 200 nanometers, and set the nozzle pressure between 5-35 V;

[0088] 13. Dry the above sample at 100-160 °C for 30-120 minutes;

[0089] 14. Spray a silica superhydrophobic coating on the surface of the above sample, with a thickness of 1 to 5 microns, and the thickness of the superhydrophobic coating is greater than the thickness of the electrode and the moisture absorption layer; then carry out curing treatment;

[0090] 15. Spray a protective layer on the surface of the above sample, and the protective layer uses a silica superhydrophobic coating; prepare to achieve the target silver migration conductive film.

[0091] Through the above steps S301 to S305, compared with currently coating a thin and transparent insulating layer on the surface of the silver nanowire transparent conductive film to isolate the surface of the silver nanowire conductive film from the external environment, by adding a protective layer and a superhydrophobic coating on the surface of the silver paste electrode to isolate water vapor from entering the surface of the silver paste electrode; through the moisture absorption layer, absorb the relevant water vapor between the silver paste electrodes, thereby preventing silver ionization and avoiding silver migration.

[0092] It should be understood that the specific embodiments described here are only used to explain this application, rather than to limit it. According to the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0093] Obviously, the drawings are only some examples or embodiments of this application. For those of ordinary skill in the art, this application can also be applied to other similar situations according to these drawings without creative efforts. In addition, it can be understood that although the work done during this development process may be complex and time-consuming, for those of ordinary skill in the art, some design, manufacturing or production changes based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient disclosure of this application.

[0094] As used in this application, the term "embodiment" means that the specific features, structures, or characteristics described in connection with an embodiment may be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily mean the same embodiment, nor does it mean being independent or alternative to other embodiments and mutually exclusive. What can be clearly or implicitly understood by those of ordinary skill in the art is that the embodiments described in this application can be combined with other embodiments without conflict.

[0095] The above-described embodiments merely represent several implementation manners of this application. Their descriptions are relatively specific and detailed, but they should not be construed as limitations on the scope of patent protection. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the appended claims.

Claims

1. A silver migration-proof conductive film, characterized in that, Comprising: a moisture absorption layer, silver paste electrodes, a superhydrophobic coating, and a protective layer, wherein, the silver paste electrodes include a ground wire and a plurality of signal lines, the thickness of the silver paste electrodes is less than the thickness of the moisture absorption layer, and the thickness of the superhydrophobic coating is greater than the thickness of the moisture absorption layer; on the sensor substrate, the moisture absorption layer is disposed between the ground wire and the signal lines, the moisture absorption layer is disposed between the signal lines, the superhydrophobic coating is disposed above the silver paste electrodes, and the protective layer is disposed above the superhydrophobic coating.

2. The anti-silver migration conductive film according to claim 1, wherein The moisture absorption layer adopts a metal oxide coating, and the metal oxide coating includes a magnetron sputtered alumina coating, a magnetron sputtered calcium oxide coating, and a magnetron sputtered magnesium oxide coating.

3. The anti-silver migration conductive film according to claim 1, wherein The superhydrophobic coating is a fluorine-containing superhydrophobic coating, a nano-silica coating, or a titanium dioxide coating.

4. The anti-silver migration conductive film according to claim 1, wherein The thickness of the moisture absorption layer is 200 nanometers to 400 nanometers.

5. The anti-silver migration conductive film according to claim 1, wherein The thickness of the silver paste electrodes is 100 nanometers to 200 nanometers.

6. The anti-silver migration conductive film according to claim 1, wherein The thickness of the superhydrophobic coating is 1 micrometer to 5 micrometers.

7. A mobile device, characterized in that, Comprising the anti-silver migration conductive film according to any one of claims 1 to 6.

8. A method for manufacturing a silver migration-proof conductive film, which is applied to the silver migration-proof conductive film described in any one of claims 1 to 6, and is characterized in that, The manufacturing method includes: obtaining a sensor substrate and performing ultrasonic cleaning on the sensor substrate; depositing a moisture absorption layer on the surface of the sensor substrate; printing silver paste electrodes between the moisture absorption layers; the thickness of the silver paste electrodes is less than the thickness of the moisture absorption layer; coating a superhydrophobic coating on the upper surface of the silver paste electrodes, the thickness of the superhydrophobic coating is greater than the thickness of the moisture absorption layer; coating a protective layer on the superhydrophobic coating, and the protective layer adopts a superhydrophobic coating; obtaining the target anti-silver migration conductive film.

9. The method for manufacturing a silver migration-proof conductive film according to claim 8, wherein Before depositing a moisture absorption layer on the surface of the sensor substrate, the method further includes: bonding the sensor substrate to glass, performing a hollowing-out treatment on the area to be magnetron sputtered on the sensor substrate, and performing a shielding treatment on the conductive silver paste area; introducing an inert gas according to a preset gas flow rate, applying a magnetic field according to a preset magnetron sputtering power, and setting the temperature of the sensor substrate according to a preset temperature.

10. The method for manufacturing a silver migration-proof conductive film according to claim 8, characterized in that, The printing of the silver paste electrodes between the moisture absorption layers includes: obtaining a preset number of silver nanowires; stirring the silver nanowires in a preset container to obtain a silver nanowire dispersion; adding a preset amount of polyethylene oxide to the silver nanowire dispersion and stirring for a preset period of time to obtain silver nanowire ink, and printing the silver nanowire ink between the moisture absorption layers into silver paste electrodes.

Images