A method for preparing a metal copper mesh electromagnetic shielding transparent conductive film
By employing conductive mesh templates and metal particle mesh fabrication methods, the problems of low efficiency and high cost in the preparation of electromagnetic shielding transparent conductive films in existing technologies have been solved, achieving efficient and low-cost preparation of electromagnetic shielding transparent conductive films suitable for flexible electronic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TAIYUAN UNIVERSITY OF TECHNOLOGY
- Filing Date
- 2026-02-02
- Publication Date
- 2026-06-05
AI Technical Summary
Existing technologies for preparing electromagnetic shielding transparent conductive films suffer from problems such as complex processes, high material costs, low processing efficiency, easy template wear, poor adaptability, and concentrated electromagnetic wave diffraction, making efficient preparation particularly difficult in flexible electronic devices.
A method using conductive mesh templates and metal particle meshes is employed to prepare a sacrificial crack template, coat it with conductive ink or metal paste, and then form a transparent conductive film with electromagnetic shielding of a copper mesh through electroplating or high-temperature sintering. This method achieves efficient preparation using low-cost materials and general-purpose equipment.
It has achieved efficient and low-cost preparation of electromagnetic shielding transparent conductive films, which are suitable for mass production, have high pattern precision, low material and equipment costs, and excellent flexibility compatibility, making them suitable for flexible electronic devices.
Smart Images
Figure CN122158260A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electromagnetic shielding transparent conductive film technology, and particularly relates to a method for preparing a metal copper mesh electromagnetic shielding transparent conductive film. Background Technology
[0002] Electromagnetic interference (EMI) refers to the phenomenon of mutual interference between electrical or electronic devices. With the rapid iteration of industries such as 5G communication, smart terminals, new energy vehicle electronics, aerospace electronics, and medical equipment, electronic devices are rapidly developing towards higher frequencies, greater integration, miniaturization, and flexibility. While this trend is driving leaps in device performance, it also brings the dual challenges of electromagnetic compatibility (EMC) and transparent functionality requirements, becoming a key bottleneck restricting the development of related industries.
[0003] Electromagnetic shielding transparent conductive films are a type of functional thin film that combines "high light transmittance" and "electromagnetic shielding capability." Their core value lies in solving the pain point of traditional metal shielding materials (such as metal plates and meshes) where "shielding and transparency cannot be simultaneously achieved." Essentially, they use a "transparent conductive layer" to "reflect, absorb, and dissipate" electromagnetic waves, while simultaneously ensuring light transmittance through structural design. Copper's low cost, high ductility, and high conductivity give copper mesh-type electromagnetic shielding transparent conductive films a natural advantage in applications requiring electromagnetic shielding, especially suitable for "thin and flexible" scenarios such as foldable screen phones and flexible wearable devices.
[0004] Currently, the main methods for preparing regular metal meshes include photolithography (including ultraviolet lithography and electron beam lithography), laser direct writing, and nanoimprint lithography. These methods suffer from drawbacks such as complex processes, high material costs, stringent production environment requirements, low processing efficiency, easy template wear, and poor adaptability. Furthermore, regular metal meshes are prone to electromagnetic wave diffraction concentration and electromagnetic leakage at specific frequencies. Existing irregular metal meshes are mostly prepared using the crack template method, which suffers from low preparation efficiency, expensive equipment, complex processes, and difficulty in transferring patterns onto ordinary glass. Summary of the Invention
[0005] The purpose of this invention is to provide a method for preparing a transparent conductive film with electromagnetic shielding of copper mesh, in order to solve the problems existing in the background art.
[0006] This invention is achieved as follows: a method for preparing a transparent conductive film with electromagnetic shielding using a copper mesh, wherein the transparent conductive film with electromagnetic shielding using a copper mesh is obtained through a conductive mesh template and a metal particle mesh, specifically: 1. Select a substrate, and prepare a sacrificial crack template by matching the amount of crack manufacturing material proportionally according to the substrate size; match the amount of conductive ink proportionally according to the substrate size, coat the sacrificial crack template with conductive ink and dry it, then remove the sacrificial crack template to obtain a conductive mesh template; prepare a copper sulfate electroplating solution, immerse the conductive mesh template as the cathode and the pure copper sheet as the anode in the copper sulfate electroplating solution for electroplating, clean it after electroplating, and obtain a transparent conductive film for electromagnetic shielding of metallic copper mesh.
[0007] 2. Select a substrate, and prepare a sacrificial crack template by matching the amount of crack manufacturing material proportionally according to the size of the substrate; match the amount of metal paste proportionally according to the size of the substrate, coat the sacrificial crack template with metal paste and preliminarily dry it, then remove the sacrificial crack template to obtain a preliminary metal particle mesh; sinter the preliminary metal particle mesh at high temperature, and obtain a transparent conductive film for electromagnetic shielding of copper metal mesh after cooling.
[0008] Preferably, the material used to prepare the sacrificial crack template can be selected from water-based crackle paint, protein, TiO2, ZnO, SiO2, or crack gel, etc. The crack gel can be prepared by compounding raw materials such as methyl methacrylate, butyl acrylate, acrylic acid, hydroxypropyl acrylate, ammonium persulfate, sodium dodecyl sulfonate, OP-10, and sodium bicarbonate.
[0009] Preferably, when preparing the sacrificial crack template, the crack manufacturing material with controlled concentration can be coated onto the treated substrate by spin coating, drop coating, blade coating, dip coating or spray coating, and then dried and cured.
[0010] Preferably, in the method for preparing a transparent conductive film for electromagnetic shielding of a copper mesh through a conductive mesh template, the conductive ink can be a composite coating liquid based on PEDOT:PSS. Before coating, the template can be cleaned with plasma to improve the filling performance. After coating, the template is heated and dried, and the sacrificial template is removed using a specific chemical solution (such as a mixed solution of potassium hydroxide and acetone).
[0011] Preferably, the copper sulfate electroplating solution may contain copper sulfate pentahydrate, sulfuric acid, sodium polydithiopropane sulfonate, and polyethylene glycol, and the electroplating parameters such as current density and deposition time can be adjusted according to the required copper layer thickness.
[0012] Preferably, in the method for preparing a transparent conductive film for electromagnetic shielding of copper mesh through a metal particle grid, the metal paste can be copper paste or silver paste. After coating, it is initially dried, and then sintered at high temperature to fuse and connect the metal particles to form a conductive network. The sintering temperature and time can be selected according to the type of metal.
[0013] The present invention provides a method for preparing a transparent conductive film for electromagnetic shielding of copper mesh, which has the following beneficial effects: High preparation efficiency, suitable for large-scale production: The formation of sacrificial crack templates relies on the stress induction of the material itself, without the need for complex design or operation, and the preparation time of a single batch of templates can be shortened to the hour level; conductive ink or metal paste can quickly cover the template through efficient coating technology such as spin coating, and the sacrificial template can be removed by chemical dissolution. The process is short and can be adapted to large-area continuous production. With high pattern precision and controllable dimensions, it is suitable for the fabrication of micro-nano scale copper meshes: the crack size of the sacrificial crack template can be precisely controlled by the preparation conditions such as spin coating rate, drying temperature, and crack paint concentration. Conductive ink or metal paste can fully fill the crack gaps, replicating the crack template structure with high fidelity, and the line width and spacing uniformity deviation is <5%. Low material and equipment costs, resulting in significant economic benefits: The raw materials for sacrificial template preparation are low-cost materials such as commercial crackle paint, protein, and nanoparticles, while the cost of conductive ink and metal paste is far lower than that of materials such as photoresist; the required equipment consists of general-purpose equipment such as spin coaters, electroplating tanks, and sintering furnaces, with investment far lower than that of high-precision equipment such as photolithography machines and electron beam etching systems, and the material utilization rate is high. Excellent flexibility and compatibility, suitable for flexible electronic devices: The thin film and metal paste formed after the conductive ink dries have good flexibility and adaptability to flexible substrates. The electroplated copper layer can achieve flexible matching by controlling the thickness. The sintered metal mesh has excellent ductility and can be directly attached to flexible substrates and irregularly shaped substrates. It is not easy to crack when bent or stretched and can maintain conductivity continuity. Attached Figure Description
[0014] Figure 1 A template image of a crack on ordinary glass after drying, prepared for selective copper electroplating; Figure 2 Image of a crack template after drying, prepared by spin-coating conductive ink onto the crack template for selective copper plating; Figure 3 A diagram of the conductive mesh template remaining after removing the cracked template for selective copper electroplating; Figure 4 A copper metal image on a conductive mesh template prepared for selective copper electroplating; Figure 5 A template image of a crack after drying on ordinary glass where metal paste is directly filled; Figure 6 A preliminary drying diagram of copper paste spin-coated onto a crack template for direct metal filling; Figure 7 A preliminary copper mesh diagram of the remaining metal particles after removing the cracked template for direct filling with metal slurry; Figure 8A diagram of a sintered conductive copper mesh directly filled with metal paste. Detailed Implementation
[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0016] The specific implementation of the present invention will be described in detail below with reference to specific embodiments. Example
[0017] Preparation method based on conductive mesh fabrication using sacrificial crack templates + selective copper electroplating This embodiment corresponds to the preparation method of a transparent conductive film for electromagnetic shielding using a copper mesh. The specific steps are as follows: S1: Preparation of sacrificial crack template The base is made of 8cm*8cm ordinary glass; The amount of crack-making material and conductive ink used is matched according to the size of the substrate, ranging from 50ul to 3ml / cm². In this example, 6.4ml is extracted from an 8cm*8cm ordinary glass. Purchase water-based crackle paint; By adding deionized water to the original crackle paint and stirring for 1-3 hours or heating the original crackle paint in a water bath for a certain time (2-5 hours), the crackle paint solvent is evaporated to obtain crackle paint of different concentrations, which can be used to prepare different mesh sizes and line widths. Use a pipette to extract 6.4 ml of the adjusted crackle paint and spin coat it onto an 8cm*8cm ordinary glass substrate that has been cleaned and hydrophilically treated (spray coater speed set to 300~1000 rpm, time 15~60s). The substrate was then placed in a vacuum drying oven and dried at 40℃~80℃ for 30min~60min to obtain a preliminary crack template; The preliminary crack template is placed in an 80℃ oven for 1-3 hours to further cure the crack paint and ensure that it adheres tightly to the glass substrate, forming the final sacrificial crack template.
[0018] like Figure 1 As shown, Figure 1 It is a template for cracks on ordinary glass after drying.
[0019] S2: Fabrication of conductive mesh template Purchase conductive ink (composition: PEDOT:PSS based compound coating solution). The cured sacrificial crack template is cleaned using a plasma cleaner (Plasma, power setting 5~10W, processing time 10~30s) to improve the hydrophilicity of the crack gaps and ensure that the conductive ink is fully filled. Use a pipette to extract 6.4 ml of conductive ink and spin coat it onto the sacrificial crack template (spin coater speed 500~1000 rpm, time 10~30 s). Then it was placed in a 120°C oven and dried for 15 minutes to allow the conductive ink to solidify into a film; Prepare a mixed solution of potassium hydroxide (KOH) and acetone (preparation ratio: 1g KOH is dissolved in 20ml deionized water, and after it is completely dissolved, 40ml acetone is added and stirred evenly). Immerse the dried template in the solution for 3-10 minutes, remove the sacrificial crack template, and the remaining part is the conductive mesh template (the crack shape is completely complementary to that of the sacrificial crack template).
[0020] like Figure 2 As shown, Figure 2 This is the state after the conductive ink has been spin-coated onto the cracked template and dried; such as... Figure 3 As shown, Figure 3 The conductive mesh template remaining after removing the cracked template.
[0021] S3: Preparation of transparent conductive film for electromagnetic shielding of copper mesh Prepare copper sulfate electroplating solution: Add 70 g / L (10-100 g / L) copper sulfate pentahydrate (CuSO4・5H2O), 240 g / L (150-320 g / L) sulfuric acid (H2SO4), 5 mg / L (0.1-20 mg / L) sodium polydithiopropane sulfonate (SPS), and 50 mg / L (10-200 mg / L) polyethylene glycol (PEG) sequentially to deionized water, and stir at room temperature for 1-3 hours to ensure that all components are completely dissolved; The conductive mesh template is used as the cathode and the pure copper sheet is used as the anode. The plate is immersed in the above electroplating solution. The current density of the electroplating power supply is set to 20mA・cm⁻² (5-30mA / cm²), and the deposition time is 10-120s (corresponding to a copper layer thickness of 33-400nm), so that Cu²⁺ is deposited in the conductive mesh area in a directional manner. Remove the electroplated template and rinse the surface with deionized water 3-5 times (each rinse lasts 10-20 seconds) to remove residual electroplating solution, finally obtaining a transparent conductive film for electromagnetic shielding of copper mesh.
[0022] like Figure 4 As shown, Figure 4 A transparent conductive film for electromagnetic shielding of a copper mesh after electroplating copper metal onto a conductive mesh template. Example
[0023] Preparation method based on sacrificial crack template + direct filling of metal slurry This embodiment corresponds to the preparation method of a transparent conductive film for electromagnetic shielding using a copper mesh. The specific steps are as follows: S1: Preparation of sacrificial crack template The base size is selected as 8cm*8cm ordinary glass; The amount of crack-forming materials and metal paste (taking copper paste as an example) should be matched according to the size of the substrate, ranging from 50ul to 3ml / cm². In this example, 6.4ml is extracted from an 8cm*8cm ordinary glass. Purchase water-based crackle paint; By adding deionized water to the original crackle paint and stirring for 1-3 hours or heating the original crackle paint in a water bath for a certain time (2-5 hours), the crackle paint solvent is evaporated to obtain crackle paint of different concentrations, which can be used to prepare different mesh sizes and line widths. Use a pipette to extract 6.4 ml of the adjusted crackle paint and spin coat it onto an 8cm*8cm ordinary glass substrate that has been cleaned and hydrophilically treated (spray coater speed set to 300~1000 rpm, time 15~60s). The substrate was then placed in a vacuum drying oven and dried at 40℃~80℃ for 30min~60min to obtain a preliminary crack template; The preliminary crack template is placed in an 80℃ oven for 1-3 hours to further cure the crack paint and ensure that it adheres tightly to the glass substrate, forming the final sacrificial crack template.
[0024] like Figure 5 As shown, Figure 5 This is a crack template dried on ordinary glass (corresponding to the final sacrificial crack template prepared in this step).
[0025] S2: Preparation of preliminary metal particle mesh The purchased metal paste (copper, silver, etc.) is applied to the sacrificial crack template by spin coating (300~2000rpm, 10~60s); After initial drying (40℃~120℃, 5~30min), the sacrificial crack template is removed to obtain a preliminary metal particle mesh.
[0026] like Figure 6 As shown, Figure 6 This is the state after the copper paste has been spin-coated onto the crack template and partially dried; such as... Figure 7 As shown, Figure 7 The copper mesh is the initial metal particle residue remaining after removing the cracked template.
[0027] S3: Fabrication of conductive metal mesh (copper mesh electromagnetic shielding transparent conductive film) The preliminary metal particle mesh is sintered at high temperature (copper mesh sintering temperature 200~450℃, holding time 10~60min; silver mesh sintering temperature 150~350℃, holding time 5~30min), and after cooling, a conductive metal mesh is obtained, namely a transparent conductive film for electromagnetic shielding of metal copper mesh.
[0028] like Figure 8 As shown, Figure 8 It is a sintered conductive copper mesh.
[0029] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a transparent conductive film for electromagnetic shielding using a copper mesh, characterized in that, The method for preparing the transparent conductive film with electromagnetic shielding of the copper mesh includes: S1. Select a substrate and, based on the size of the substrate, match the amount of crack manufacturing material at a ratio of 50ul~3ml / cm² to prepare a sacrificial crack template. S2. According to the size of the substrate, the amount of conductive ink is matched at a ratio of 50ul~3ml / cm², the conductive ink is coated on the sacrificial crack template and dried, and then the sacrificial crack template is removed to obtain a conductive mesh template; S3. Prepare a copper sulfate electroplating solution, immerse the conductive mesh template as the cathode and the pure copper sheet as the anode in the copper sulfate electroplating solution for electroplating, and rinse with deionized water after electroplating to obtain a transparent conductive film for electromagnetic shielding of metallic copper mesh.
2. A method for preparing a transparent conductive film for electromagnetic shielding using a copper mesh, characterized in that, The method for preparing the transparent conductive film with electromagnetic shielding of the copper mesh includes: S1. Select a substrate and, based on the size of the substrate, match the amount of crack manufacturing material at a ratio of 50ul~3ml / cm² to prepare a sacrificial crack template. S2. According to the size of the substrate, the amount of metal paste is matched at a ratio of 50ul~3ml / cm². The metal paste is coated on the sacrificial crack template and pre-dried. Then the sacrificial crack template is removed to obtain a preliminary metal particle mesh. S3. The preliminary metal particle mesh is sintered at high temperature and cooled to obtain a transparent conductive film with electromagnetic shielding of metal copper mesh.
3. The method for preparing a transparent conductive film with electromagnetic shielding of copper mesh according to claim 1 or 2, characterized in that, The sacrificial crack template described in S1 is prepared from one of the following materials: water-based crackle paint, protein, TiO2, ZnO, SiO2, or crack gel. The crack gel is prepared by compounding methyl methacrylate (30-300g), butyl acrylate (10-100g), acrylic acid (1.5-15g), hydroxypropyl acrylate (3-30g), ammonium persulfate (0.2-2g), sodium dodecyl sulfonate (0.8-8g), OP-10 (1.2-12g), and sodium bicarbonate (0.5-5g).
4. The method for preparing a transparent conductive film with electromagnetic shielding of copper mesh according to claim 1 or 2, characterized in that, The specific process for preparing the sacrificial crack template in S1 is as follows: After adjusting the concentration of the crack-forming material, it was spin-coated onto a cleaned and hydrophilically treated substrate. The spin coater speed was set to 300~1000 rpm for 15~60 seconds. Subsequently, the substrate was placed in a vacuum drying oven and dried at 40℃~80℃ for 30min~60min to obtain a preliminary crack template. The preliminary crack template is placed in an 80℃ oven and kept at that temperature for 1-3 hours. After curing, the final sacrificial crack template is formed.
5. The method for preparing a transparent conductive film for electromagnetic shielding of copper mesh according to claim 1, characterized in that, The conductive ink described in S2 is based on PEDOT: The PSS compound coating liquid is coated by spin coating, with a spin coater speed of 500~1000 rpm and a time of 10~30s; Before coating, use a plasma cleaner to clean the cured sacrificial crack template. Set the plasma cleaner power to 5~10W and the processing time to 10~30s. The drying method is to place it in a 120℃ oven and dry it for 15 minutes; The method for removing the sacrificial crack template is to immerse the dried template in a mixed solution of potassium hydroxide and acetone for 3-10 minutes. The ratio of the mixed solution is 1g KOH dissolved in 20ml deionized water. After complete dissolution, 40ml acetone is added and stirred evenly.
6. The method for preparing a transparent conductive film with electromagnetic shielding of copper mesh according to claim 1, characterized in that, The composition and concentration of the copper sulfate electroplating solution described in S3 are as follows: Copper sulfate pentahydrate CuSO4・5H2O, 10-100 g / L; sulfuric acid H2SO4, 150-320 g / L; sodium polydisulfide dipropane sulfonate SPS, 0.1-20 mg / L; polyethylene glycol PEG, 10-200 mg / L. During preparation, add each component to deionized water in sequence and stir at room temperature for 1-3 hours until completely dissolved; During electroplating, the current density of the electroplating power supply is set to 5-30 mA / cm², and the deposition time is 10-120 s; the number of rinsing cycles is 3-5, and the rinsing time for each cycle is 10-20 s.
7. The method for preparing a transparent conductive film with electromagnetic shielding of copper mesh according to claim 2, characterized in that, The metal paste mentioned in S2 is a copper paste or a silver paste, and the coating method is spin coating. The spin coating speed is 300~2000 rpm and the time is 10~60s. The initial drying temperature is 40℃~120℃ and the time is 5~30min.
8. The method for preparing a transparent conductive film with electromagnetic shielding of copper mesh according to claim 2, characterized in that, The high-temperature sintering conditions described in S3 are as follows: when the metal paste is copper paste, the sintering temperature is 200~450℃ and the holding time is 10~60min; when the metal paste is silver paste, the sintering temperature is 150~350℃ and the holding time is 5~30min.