A method for preparing a silver mesh transparent conductive film
By combining chemical silver plating with laser direct writing technology to prepare transparent conductive silver mesh films, the problems of complex processes and high costs in existing technologies have been solved, enabling low-cost, mass production and flexible pattern design, making it suitable for industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN INST OF TECH AT WEIHAI
- Filing Date
- 2024-09-02
- Publication Date
- 2026-07-14
AI Technical Summary
Existing technologies for preparing transparent conductive films with metal meshes suffer from complex processes, high costs, and are not suitable for mass production, especially due to the limitations of photolithography and electro-hydraulic inkjet printing technologies.
By combining chemical silver plating with laser direct writing technology, a silver mesh is prepared on a PET substrate through chemical silver plating, and then the pattern is etched using laser direct writing technology to realize the preparation of a transparent conductive film with a silver mesh, which simplifies the process and reduces costs.
It enables low-cost, high-volume production of silver mesh transparent conductive films, with fast laser direct writing speed, high pattern flexibility, no need for photomasks, low cost, and suitability for industrial production.
Smart Images
Figure CN118899124B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of conductive thin film technology, and specifically relates to a method for preparing a silver mesh transparent conductive thin film. Background Technology
[0002] With the rapid development of optoelectronic devices, such as transparent heaters, solar thin-film batteries, and smart windows, flexible transparent conductive films are becoming an important component of optoelectronic devices, and the requirements for optoelectronic performance are getting higher and higher. The traditional transparent conductive material is In2O3 (ITO), which has excellent optoelectronic performance. However, with the rapid economic development, due to the brittleness, high production cost, poor stability and shortage of indium, researchers are developing a new generation of transparent conductive materials to replace traditional ITO.
[0003] Current research directions for transparent conductive films mainly include transparent conductive oxides (TCOs), carbon-based materials, conductive polymers, metal nanowires, and metal meshes. The metal mesh lines form conductive pathways, while the interior of the mesh allows light to pass through. The size, linewidth, pattern, and other parameters of the metal mesh can be adjusted according to application requirements to regulate its photoelectric properties. As a new generation of transparent conductive films, metal meshes possess excellent comprehensive photoelectric properties while also exhibiting good flexibility, making them the most promising next-generation flexible transparent conductive films.
[0004] Methods for manufacturing metal meshes include photolithography, electro-hydraulic inkjet printing, laser direct writing, and nanoimprint lithography. Photolithography and nanoimprint lithography typically require pre-fabricated high-precision templates, and the overall process is complex, cumbersome, and costly, necessitating further processing using PVD methods such as magnetron sputtering or vapor deposition. Electro-hydraulic inkjet printing, which uses an electric field to drive droplet flow of nanoparticle ink to print meshes on a flexible substrate, often produces highly precise metal meshes, but the fabrication speed is slow, requiring subsequent processes such as annealing or low-temperature sintering, making it unsuitable for mass production of metal meshes.
[0005] Therefore, in view of the above-mentioned technical problems, it is necessary to provide a method for preparing a silver mesh transparent conductive film.
[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0007] The purpose of this invention is to provide a method for preparing a transparent conductive silver mesh film, which can prepare a metal mesh by combining chemical silver plating with laser direct writing technology. Chemical silver plating has low cost and can achieve mass production, while laser direct writing technology has the advantages of high speed and simple process, no need for mask, computer pattern drawing, and flexible design of metal mesh patterns.
[0008] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution:
[0009] A method for preparing a silver mesh transparent conductive film includes the following steps;
[0010] S1. Roughening treatment: Immerse the release PET in a roughening solution, and rinse with deionized water after roughening treatment;
[0011] S2. Sensitization treatment: Transfer the roughened release PET to the sensitization solution for immersion. After sensitization, rinse the silver-plated surface with deionized water and dry the silver-plated surface with an air compressor.
[0012] S3, Chemical Silver Plating: After the sensitized PET from step S2 is peeled off, the silver plating solution is prepared and mixed evenly. It is then poured into a plastic container containing PET. After the PET surface turns black, it is left to stand and then heated.
[0013] S4. Drying treatment: After the silver plating is completed, pour out the reaction solution, rinse with deionized water 2-3 times, and blow dry with an air compressor until the surface turns silvery-white, and then peel off the silver-plated PET.
[0014] S5. Laser Direct Writing: After drawing the grid pattern shape and array number in advance, the silver-plated PET is laser-written and etched to successfully obtain a silver grid flexible transparent conductive film.
[0015] In one or more embodiments of the present invention, step S3 specifically comprises:
[0016] S31, Peeling; Transfer the sensitized PET to a plastic container, peel off the back of the PET so that the tape adheres directly to the plastic container wall to prevent the PET from floating;
[0017] S32. Prepare the silver plating solution: First, add 1 ml of silver nitrate solution to a 10 ml centrifuge tube, then add diluted ammonia solution. Stop adding the solution when the mixture becomes clear. Next, add deionized water until the volume reaches 8 ml, then add 2 ml of glucose solution. Quickly shake the 10 ml centrifuge tube to obtain the silver plating solution.
[0018] S33. Heating: After mixing the silver plating solution evenly, pour it into a plastic container containing PET, and transfer the plastic container to the center of the heating platform. Shake the plastic container until the PET surface turns black and then let it stand still. Heat the container on the heating platform to react.
[0019] In one or more embodiments of the present invention, the temperature of the heating table in step S3 is set to 50°C, and the heating time of the heating table is 15-30 min.
[0020] In one or more embodiments of the present invention, the roughening solution in step S1 includes concentrated sulfuric acid.
[0021] In one or more embodiments of the present invention, the method for preparing the roughening solution is as follows: concentrated sulfuric acid is diluted in deionized water to obtain the roughening solution. The volume ratio of the concentrated sulfuric acid to the deionized water is 1:1.
[0022] In one or more embodiments of the present invention, the concentration of silver nitrate solution in step S32 is 17 g / L-20 g / L.
[0023] In one or more embodiments of the present invention, the method for preparing the diluted ammonia solution in step S32 is to dilute the concentrated ammonia solution in deionized water, wherein the volume ratio of the concentrated ammonia solution to the deionized water is 1:80.
[0024] In one or more embodiments of the present invention, the concentration of the glucose solution in step S32 is 80-160 g / L.
[0025] In one or more embodiments of the present invention, the soaking time in step S1 is 20-50 minutes. The soaking time in step S2 is 6-8 minutes.
[0026] In one or more embodiments of the present invention, the sensitizing solution in step S2 includes a stannous chloride solution with a concentration of 10-30 g / L.
[0027] Compared with the prior art, the method for preparing a silver mesh transparent conductive film of the present invention has the following advantages;
[0028] 1) The use of release PET film effectively prevents contamination of the back of PET during pretreatment and chemical silver plating, and the tape effectively adheres to the container, preventing PET from floating, thus enabling single-sided solution chemical silver plating of PET.
[0029] 2) The entire process is simple, requiring no complex operations. Laser direct writing is fast, offering high pattern flexibility and allowing for arbitrary adjustment of pattern parameters without being limited by masks. The fabrication cost is also low.
[0030] 3) Chemical silver plating: The silver layer is stacked in the form of silver nano-islands and silver nanoparticles. The surface of the silver nanoparticles has a plasma resonance effect, achieving a characteristic absorption peak in the 400-600nm blue-violet light wavelength range. This makes the silver mesh transparent conductive film a potential application in blue-violet light protection displays. Attached Figure Description
[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0032] Figure 1 This is a flowchart illustrating the silver mesh fabrication process in one embodiment of the present invention; Detailed Implementation
[0033] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.
[0034] like Figure 1 As shown, a method for preparing a silver mesh transparent conductive film in one embodiment of the present invention includes the following steps;
[0035] S1. Roughening treatment: Immerse the release PET in the roughening solution for 20-50 minutes. After roughening treatment, rinse with deionized water. Roughening treatment improves the wettability of the PET surface and generates hydrophilic groups, which is beneficial for sensitizing the complexation of stannous ions.
[0036] Furthermore, the roughening solution includes concentrated sulfuric acid. The roughening solution is prepared by diluting concentrated sulfuric acid in deionized water. The volume ratio of concentrated sulfuric acid to deionized water is 1:1.
[0037] Preferably, the PET is soaked in the roughening solution for 30 minutes.
[0038] S2. Sensitization treatment: Transfer the roughened release PET to the sensitization solution and immerse it for 6-8 minutes. After sensitization, rinse the silver-plated surface with deionized water and dry the silver-plated surface with an air compressor.
[0039] Furthermore, the sensitizing solution includes a stannous chloride solution with a concentration of 10-30 g / L, preferably 20 g / L.
[0040] Preferably, the time for immersing the roughened release PET in the sensitizing solution is 7 minutes.
[0041] S3, Chemical Silver Plating: After the sensitized PET from step S2 is peeled off, the silver plating solution is prepared and mixed evenly. It is then poured into a plastic container containing PET. After the PET surface turns black, it is left to stand and then heated.
[0042] S4. Drying treatment: After the silver plating is completed, pour out the reaction solution, rinse with deionized water 2-3 times, and blow dry with an air compressor until the surface turns silvery-white, and then peel off the silver-plated PET.
[0043] S5. Laser Direct Writing: After drawing the grid pattern shape and array number in advance, the silver-plated PET is laser-written and etched to successfully obtain a silver grid flexible transparent conductive film.
[0044] The specific steps in S3 are as follows:
[0045] S31, Peeling; Transfer the sensitized PET to a plastic container, peel off the back of the PET so that the tape adheres directly to the plastic container wall to prevent the PET from floating;
[0046] The preferred size for the plastic container is 54×54×20mm³.
[0047] S32. Prepare the silver plating solution: First, add 1 ml of silver nitrate solution to a 10 ml centrifuge tube, then add diluted ammonia solution. The mixture will initially become cloudy, then become clear with continued addition. Stop adding the solution once it becomes clear. Next, add deionized water until the volume reaches 8 ml, then add 2 ml of glucose solution. Quickly shake the 10 ml centrifuge tube to obtain the silver plating solution.
[0048] In step S32, the concentration of the silver nitrate solution is 17 g / L to 20 g / L. Preferably, the concentration of the silver nitrate solution is 17 g / L.
[0049] It is important to note that the concentration range of the electroless silver plating solution should be 17g / L-20g / L. If the concentration is too high, the silver layer will be thicker, and during the laser direct writing process, the spattering of nanoparticles due to phase explosion and plasma impact will be extremely large. If the concentration is too low, the silver layer will be thinner, the microscopic continuity will be poor, and it will not be conducive to improving conductivity. The method for preparing the diluted ammonia solution in step S32 is to dilute the concentrated ammonia solution in deionized water, with a volume ratio of concentrated ammonia solution to deionized water of 1:80.
[0050] The concentration of the glucose solution in step S32 is 80-160 g / L. Preferably, the concentration of the glucose solution is 100 g / L.
[0051] It is important to note that glucose, as a reducing agent, requires a moderate reaction rate. Other reducing agents, such as triethanolamine, have very slow reduction rates, preventing the silver layer from growing properly. Sodium borohydride and hydrazine hydrate have strong reducing properties, reacting immediately upon addition to the centrifuge tube, thus preventing silver plating on the PET surface. Formaldehyde and other reducing agents may have potential effects due to material controls, but these have not been investigated.
[0052] The concentration of glucose solution is critical. If the glucose solution concentration is too low, the reaction will be incomplete due to diffusion and other factors, resulting in a thin silver coating with poor continuity and high roughness, severely affecting the preparation of the silver mesh. If the glucose solution concentration is too high, the reaction will be too rapid, resulting in poor coating growth.
[0053] S33. Heating: After mixing the silver plating solution evenly, pour it into a plastic container containing PET, and transfer the plastic container to the center of the heating platform. Shake the plastic container until the PET surface turns black and then let it stand still. Heat the container on the heating platform to react.
[0054] Furthermore, in step S33, the heating table temperature is set to 50°C, and the heating time is 15-30 minutes. Preferably, the heating time is 20 minutes.
[0055] This application uses release PET film as the initial substrate, which effectively protects the back side of the silver-plated PET during the roughening and sensitization processes. The adhesive layer effectively prevents contamination of the back side of the silver-plated PET. As a key substrate material, release PET enables solution-based chemical silver plating processes.
[0056] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A method for preparing a silver mesh transparent conductive thin film, characterized in that, Includes the following steps; S1. Roughening treatment: Immerse the release PET in a roughening solution, and rinse with deionized water after roughening treatment; S2. Sensitization treatment: Transfer the roughened release PET to the sensitization solution for immersion. After sensitization, rinse the silver-plated surface with deionized water and dry the silver-plated surface with an air compressor. S3, Chemical Silver Plating: S31, Peeling; Transfer the sensitized PET to a plastic container, peel off the back of the PET so that the tape adheres directly to the plastic container wall to prevent the PET from floating; S32. Prepare the silver plating solution: First, add 1 ml of silver nitrate solution to a 10 ml centrifuge tube, then add the diluted ammonia solution. It can be observed that the mixture first becomes turbid and then becomes clear as the addition continues. Stop adding after it becomes clear. Then add deionized water until it rises to 8 ml, then add 2 ml of glucose solution. Quickly shake the 10 ml centrifuge tube to obtain the silver plating solution. S33. Heating: After mixing the silver plating solution evenly, pour it into a plastic container containing PET, and transfer the plastic container to the center of the heating table. Shake the plastic container until the PET surface turns black, then let it stand still and heat it on the heating table to react. S4. Drying treatment: After the silver plating is completed, pour out the reaction solution, rinse with deionized water 2-3 times, and blow dry with an air compressor until the surface turns silvery-white, and then peel off the silver-plated PET. S5. Laser Direct Writing: After drawing the grid pattern shape and array number in advance, the silver-plated PET is laser-written and etched to successfully obtain a silver grid flexible transparent conductive film.
2. The method for preparing a silver mesh transparent conductive film according to claim 1, characterized in that, The temperature of the heating table in step S3 is set to 50°C, and the heating time is 15-30 minutes.
3. The method for preparing a silver mesh transparent conductive film according to claim 2, characterized in that, The roughening solution in step S1 includes concentrated sulfuric acid.
4. The method for preparing a silver mesh transparent conductive film according to claim 3, characterized in that, The method for preparing the roughening solution is as follows: concentrated sulfuric acid is diluted in deionized water to obtain the roughening solution, wherein the volume ratio of concentrated sulfuric acid to deionized water is 1:
1.
5. The method for preparing a silver mesh transparent conductive film according to claim 4, characterized in that, The concentration of silver nitrate solution in step S32 is 17 g / L-20 g / L.
6. The method for preparing a silver mesh transparent conductive film according to claim 5, characterized in that, The method for preparing the diluted ammonia solution in step S32 is to dilute the concentrated ammonia solution in deionized water, wherein the volume ratio of the concentrated ammonia solution to the deionized water is 1:
80.
7. The method for preparing a silver mesh transparent conductive film according to claim 5, characterized in that, The concentration of the glucose solution in step S32 is 80-160 g / L.
8. The method for preparing a silver mesh transparent conductive film according to claim 1, characterized in that, The soaking time in step S1 is 20-50 minutes, and the soaking time in step S2 is 6-8 minutes.
9. The method for preparing a silver mesh transparent conductive film according to claim 1, characterized in that, The sensitizing solution in step S2 includes a stannous chloride solution with a concentration of 10-30 g / L.