A transparent electromagnetic shielding film with high transmittance and low reflectance

Abstract

The utility model relates to the field of transparent electromagnetic shielding, disclose a kind of antireflection transparent electromagnetic shielding film of antireflection, by transparent base film and the metal mesh grid of surface setting;The metal mesh grid is composed of intersecting metal wire, and the cross section of metal wire is triangle;There is tackifying layer between the metal mesh grid and transparent base film, and the top of metal mesh grid has covering layer.The utility model has the advantages of compared with prior art, solve the problem of the deficiency that the current metal mesh grid electromagnetic shielding film has high shielding efficiency while cannot have high transmittance.

Description

Technical Field

[0001] This utility model relates to the field of transparent electromagnetic shielding technology, specifically to an anti-reflective transparent electromagnetic shielding film. Background Technology

[0002] Electromagnetic shielding films are thin-film materials with dual military and civilian applications, serving to protect electronic circuits and other sensitive devices from electromagnetic interference. Transparent electromagnetic shielding films are required for critical viewing areas in aircraft, automobiles, and ships. Common electromagnetic shielding films include ITO films and metal mesh films. ITO films, made by sputtering indium tin oxide onto a substrate, typically achieve transmittance of over 88%. However, ITO films have a disadvantage: generally high resistance (above 10Ω), resulting in shielding effectiveness below 40dB in the low-to-mid-frequency range, which inhibits their effectiveness in complex electromagnetic environments. In contrast, metal mesh films exhibit significantly lower resistance (below 0.5Ω), resulting in superior shielding effectiveness across the entire frequency range, reaching up to 60dB. However, traditional metal mesh films have rectangular or trapezoidal cross-sections with flat tops, leading to strong light reflection and a transmittance reduction of 20%–30%, severely impacting visual perception and posing a significant safety hazard for drivers. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to overcome the above-mentioned technical difficulties and provide an anti-reflective transparent electromagnetic shielding film, which solves the problem that the existing metal mesh electromagnetic shielding film has high shielding efficiency but cannot have high transmittance.

[0004] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows: an anti-reflective transparent electromagnetic shielding film, which is composed of a transparent base film and a metal mesh grid disposed on the surface; the metal mesh grid is composed of intersecting metal wires, and the cross-section of the metal wires is triangular; there is an adhesive layer between the metal mesh grid and the transparent base film, and a covering layer on the top of the metal mesh grid.

[0005] As an improvement, the metal wire is made of one of the metals silver, copper, nickel, iron, aluminum, stainless steel, or a metal alloy composed of the above metals.

[0006] As an improvement, the metal mesh is composed of one of the following shapes: circular, square, rhomboid, or wavy.

[0007] As an improvement, the metal or metal alloy surface of the metal mesh is covered with metal oxides or sulfides.

[0008] As an improvement, the triangular cross-section of the metal wire includes a first side and a second side other than the bottom side that contacts the transparent base film, and the angle between the first side and the second side and the bottom side is adjustable.

[0009] As an improvement, the transparent base film is composed of one or more transparent materials such as PET, glass, and PU.

[0010] As an improvement, the width of the base of the triangular cross-section of the metal wire is 0.1μm-100μm.

[0011] As an improvement, the cross-section of the metal mesh can be multiple sets of triangles connected in parallel, and the triangular cross-sections can overlap.

[0012] The advantages of this utility model compared with the prior art are as follows: (1) The cross-section of the metal mesh was changed to a triangular structure, which suppressed the light reflection at the top of the cross-section. By adjusting the angles of the first and second sides of the triangle with respect to the base, the reflection angle of the light on the sides was changed, and the reflected light was changed to transmitted light that penetrated the mesh, thereby further improving the transmittance.

[0013] (2) A protective layer and a covering layer are set at the top of the triangular cross section, which can effectively prevent the traditional metal mesh electromagnetic shielding film from being corroded and failing in complex environments. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a transparent electromagnetic shielding film structure that enhances transparency and reduces reflection according to this utility model.

[0015] Figure 2 This is a schematic diagram of the shape of a transparent electromagnetic shielding film with anti-reflection and anti-reflection properties.

[0016] Figure 3 This is a schematic diagram of the triangular cross-sectional structure of a transparent electromagnetic shielding film for enhancing transparency and reducing reflection, according to this utility model.

[0017] As shown in the figure: 11. Substrate; 12. Adhesive layer; 13. Metal mesh; 14. Protective layer; 15. Covering layer; 21. Bottom edge; 22. First side edge; 23. Second side edge. Detailed Implementation

[0018] This utility model provides an anti-reflection and anti-reflection electromagnetic shielding film, the structural schematic diagram of which is shown below. Figure 1 As shown, a metal mesh 13 is disposed on the substrate 11. The metal mesh 13 is composed of intersecting metal wires, such as... Figure 2The metal mesh shown can be circular, square, rhomboid, or wavy. To achieve a transmittance of over 90%, the aperture of the mesh generally needs to be set to 200μm or larger. An adhesion-enhancing layer 12 is provided between the metal mesh 13 and the transparent base film 11, as needed. The purpose of the adhesion-enhancing layer 12 is to effectively improve the adhesion of the metal mesh to the transparent substrate, meeting the reliability requirements for long-term use, preventing peeling, flaking, and cracking. Generally, the adhesion achieved after using the adhesion-enhancing layer is greater than 2.74 N / cm². If the metal mesh is manufactured on a glass substrate by sputtering, the adhesion-enhancing layer 12 can be omitted because the sputtered metal layer and glass naturally have good adhesion. A protective layer 14 is provided on the surface of the metal mesh 13 to provide corrosion resistance for long-term use under complex conditions. The materials generally selected can be metal oxides or sulfides, achieved by directly performing relevant chemical reactions on the surface of the completed metal mesh 12. A cover layer 15 may be provided on the upper part of the tackifying layer 12 and the protective layer 14 as needed. The cover layer 15 is generally an optical resin adhesive that matches the refractive index of the transparent substrate, such as acrylic resin adhesive, epoxy resin adhesive, phenolic resin adhesive, etc.

[0019] The refractive index is typically selected in the range of 1.5 to 1.9, and the thickness is typically 5-10 μm.

[0020] The metal wire cross-section of the metal mesh 12 is triangular, consisting of a base 21, a first side 22, and a second side 23. The base 21 preferably has a line width of 5 μm. The angle θ1 between the first side 22 and the base needs to be greater than 45°, and the angle θ2 between the second side 23 and the base needs to be greater than 45°. θ1 and θ2 can be unequal, allowing independent control of the anti-reflection effect at each angle. With this configuration, all light rays incident perpendicular to the transparent substrate, reflected light occurring at the first and second sides, will completely penetrate the mesh and be converted into transmitted light. Simultaneously, the triangular cross-section reduces the top edge of traditional trapezoidal or rectangular cross-sections, thus suppressing all reflections caused by the top edge. Generally, a traditional 80% transmittance metal mesh transparent electromagnetic shielding film has a metal mesh itself causing 13% reflection; however, this method achieves over 10% anti-reflection, bringing the total transmittance of the transparent electromagnetic shielding film to 89.2%.

[0021] In summary, this invention changes the cross-section of the metal mesh grid to a triangular structure, suppressing light reflection at the top of the cross-section. By adjusting the angles of the first and second sides of the triangle with respect to the base, the reflection angle of light at the sides is changed, transforming reflected light into transmitted light that penetrates the mesh grid, further improving transmittance. Furthermore, the protective and covering layers at the top of the triangular cross-section effectively prevent the corrosion and failure of traditional metal mesh electromagnetic shielding films in complex environments.

[0022] It should be understood that the application of this utility model is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

[0025] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. An antireflective and transparent electromagnetic shielding film, characterized in that: It consists of a transparent base film and a metal mesh set on the surface; The metal mesh is composed of intersecting metal wires with triangular cross-sections; there is an adhesive layer between the metal mesh and the transparent base film, and a covering layer on top of the metal mesh.

2. The transparent electromagnetic interference shielding film of claim 1, wherein: The metal mesh is composed of one of the following shapes: circular, square, diamond, or wavy.

3. The transparent electromagnetic interference shielding film of claim 2, wherein: The metal or metal alloy surface of the metal mesh is covered with metal oxides or sulfides.

4. The transparent electromagnetic interference shielding film of claim 1, wherein: The triangular cross-section of the metal wire includes a first side and a second side other than the bottom side that contacts the transparent base film, and the angle between the first side and the second side and the bottom side is adjustable.

5. The transparent electromagnetic interference shielding film of claim 4, wherein: The width of the base of the triangular cross-section of the metal wire is 0.1μm-100μm.

6. The transparent electromagnetic interference shielding film of claim 1, wherein: The cross-section of the metal mesh can be multiple sets of triangles connected in parallel, and the triangular cross-sections can overlap.

Images