Electromagnetic shielding multifunctional composite film of embedded metal mesh

Abstract

The utility model discloses an electromagnetic shielding multifunctional composite film of an embedded metal mesh, and belongs to the technical field of optical antireflection films. The high-refractive-index conductive film is formed by alternating a base material, a metal mesh, a high-refractive-index conductive film layer and a low-refractive-index film layer, the metal mesh is embedded in the base material, the high-refractive-index conductive film layer and the low-refractive-index film layer are sequentially and alternately arranged above the base material, the outermost layer is the high-refractive-index conductive film layer, the low-refractive-index film layer is subjected to graphical processing, and the high-refractive-index conductive film layer and the low-refractive-index film layer are sequentially and alternately arranged on the base material. The projection area of the low-refractive-index film layer is smaller than that of the high-refractive-index conductive film layers, and the multiple high-refractive-index conductive film layers are communicated outside the low-refractive-index film layer; the metal mesh embedded structure and the material selection of the high-refractive-index conductive film layer and the low-refractive-index film layer increase the mechanical strength of the composite film, have a protection function, can be used as an electric heating film without additional electrodes, and enable the composite film to have a better shielding effect through the parallel structure and the microwave resonant cavity structure.

Description

Technical Field

[0001] The electromagnetic shielding multifunctional composite film with embedded metal mesh of this invention belongs to the field of optical antireflection film technology. Background Technology

[0002] Radar stealth window structures involve fabricating periodic arrays or randomly arranged metal meshes on the surface of an optical window substrate, and then preparing an anti-reflection protective layer on the mesh surface. The thickness of the mesh and anti-reflection protective layer in this structure is generally in the micrometer or submicrometer range. However, the lattice constant and expansion coefficient of the metal mesh differ from those of the substrate material, which is detrimental to the adhesion, thermal shock resistance, and laser damage resistance of the coated metal mesh. Under service conditions such as wind, sand, and rain, the film layer is easily damaged, resulting in a shorter lifespan for radar stealth windows of this structure.

[0003] To address the aforementioned issues, the invention patent application No. 2023118601539, "A Multi-band Radar Stealth Composite Structure Optical Window and Its Preparation Method," provides a solution. This multi-band radar stealth composite structure optical window, from bottom to top, consists of an optical window substrate, a metal mesh, a protective layer, and an anti-reflective protective film. The metal mesh is periodically distributed on the upper surface of the optical window substrate. The protective layer is made of the same material as the optical window substrate. The anti-reflective film is multi-layered, and the distance between adjacent anti-reflective films gradually decreases as it extends outwards. Compared to traditional optical windows, this multi-band radar stealth composite structure optical window has higher light transmittance and mechanical strength, thus able to withstand harsh environments such as high and low temperatures, humidity, salt spray, mold, and sandstorms. Analyzing the manufacturing process of this technical solution, it is equivalent to processing the metal mesh on the window surface and then wrapping it with an anti-reflective film, achieving isolation between the mesh and the external environment.

[0004] Furthermore, the invention patent application No. 2023106557395, entitled "A Method for Manufacturing an Embedded Electromagnetic Shielding Metal Mesh", involves the following steps in sequence: fabricating a reverse mask on an optical substrate, etching metal mesh grooves with a plasma beam, depositing a metal thin film, depositing a bottom thin film, removing adhesive and cleaning, and depositing an optical antireflective film with environmental corrosion resistance. This manufacturing process involves etching grooves on the window surface, processing the metal mesh inside the grooves, and then sealing the grooves with an antireflective film, thereby isolating the mesh from the external environment and enabling the optical window to simultaneously achieve multiple functions such as electromagnetic shielding, good optical transmittance, and resistance to environmental corrosion.

[0005] It is evident that using multilayer composite films to isolate metal mesh from the external environment is an effective means of improving the optical performance and environmental tolerance of loaded metal mesh windows. Summary of the Invention

[0006] Based on our invention patent "Visible Light Range Optical Anti-reflection Protection Electromagnetic Shielding Functional Composite Film" (application number 2024116448543), we designed an embedded metal mesh electromagnetic shielding multifunctional composite film. This film not only achieves the same technical objective of isolating the metal mesh from the external environment, but also has a simple structure and rich functions.

[0007] The objective of this invention is achieved as follows:

[0008] An electromagnetic shielding multifunctional composite film with an embedded metal mesh is composed of a substrate, a metal mesh, a high-refractive-index conductive film layer, and a low-refractive-index film layer, which are alternately arranged. The metal mesh is embedded in the substrate. On the substrate, the high-refractive-index conductive film layer and the low-refractive-index film layer are alternately arranged in sequence, with the outermost layer being the high-refractive-index conductive film layer. The low-refractive-index film layer is patterned, and its projected area is smaller than that of the high-refractive-index conductive film layer. Multiple high-refractive-index conductive film layers are connected outside the low-refractive-index film layer.

[0009] The beneficial effects of the electromagnetic shielding multifunctional composite film with embedded metal mesh of the present invention are as follows:

[0010] First, the metal mesh is embedded in the substrate, which allows the metal mesh to be isolated from the external environment, so as to achieve the technical purpose of higher mechanical strength and the ability to withstand harsh environments.

[0011] Second, the high refractive index conductive film layer is made of ITO and the low refractive index film layer is made of magnesium fluoride. Both materials have high hardness, which enables the composite film of the present invention to serve as a protective film and improve the environmental tolerance of optical devices.

[0012] Third, the high refractive index conductive film has conductive properties, and multiple high refractive index conductive films are connected outside the low refractive index film, so that the high refractive index conductive film itself can be used as an electrode. Without the need for an external electrode, the composite film can be used as an electric heating film.

[0013] Fourth, the low refractive index film layer is patterned, which enables the composite film of the present invention to also have electromagnetic shielding function; in addition, multiple high refractive index conductive film layers are connected outside the low refractive index film layer, so that the high refractive index conductive film layers form a parallel structure. The resistivity of this parallel structure is much lower than that of a single high refractive index conductive film layer, thus greatly improving the shielding effectiveness.

[0014] Fifth, a microwave resonant cavity is formed between the metal mesh and the closest high-refractive-index conductive film. By adjusting the embedding depth of the metal mesh, i.e., changing the distance between the metal mesh and the closest high-refractive-index conductive film, a better shielding effect can be achieved at a specific distance for a specific spectral band based on the principle of resonant absorption. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the electromagnetic shielding multifunctional composite film of the embedded metal mesh grid of the present invention.

[0016] In the figure: 1. Substrate, 2. Metal mesh, 3. High refractive index conductive film, 4. Low refractive index film. Detailed Implementation

[0017] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0018] Method 1

[0019] The following are specific embodiments of the electromagnetic shielding multifunctional composite film with embedded metal mesh of the present invention.

[0020] The electromagnetic shielding multifunctional composite film with embedded metal mesh in this specific embodiment is shown in the schematic diagram below. Figure 1 As shown, the structure is composed of a substrate 1, a metal mesh 2, a high-refractive-index conductive film layer 3, and a low-refractive-index film layer 4, which are alternately arranged. The metal mesh 2 is embedded in the substrate 1. Above the substrate 1, the high-refractive-index conductive film layer 3 and the low-refractive-index film layer 4 are alternately arranged, with the outermost layer being the high-refractive-index conductive film layer 3. The low-refractive-index film layer 4 is patterned, and its projected area is smaller than that of the high-refractive-index conductive film layer 3. Multiple high-refractive-index conductive film layers 3 are connected outside the low-refractive-index film layer 4.

[0021] The high-refractive-index conductive film layer 3 is ITO or indium oxide; the low-refractive-index film layer 4 is magnesium fluoride.

[0022] Method 2

[0023] The following is a detailed implementation of the method for preparing the electromagnetic shielding multifunctional composite film of the embedded metal mesh grid of the present invention.

[0024] The method for preparing the electromagnetic shielding multifunctional composite film with embedded metal mesh according to this specific embodiment includes the following steps:

[0025] Step a: Embed the metal mesh 2 into the substrate 1;

[0026] Step b: A low-refractive-index film layer 4 and a high-refractive-index conductive film layer 3 are sequentially prepared on substrate 1 to form a multilayer structure;

[0027] Step c: On the periphery of the multilayer structure, the same material as the high refractive index conductive film layer 3 is used to cover the multilayer structure, so that the high refractive index conductive film layer 3 is connected to the outside of the low refractive index film layer 4.

Claims

1. An electromagnetic shielding multifunctional composite film with embedded metal mesh, characterized in that, It is composed of a substrate (1), a metal mesh (2), a high refractive index conductive film layer (3) and a low refractive index film layer (4) alternatingly. The metal mesh (2) is embedded in the substrate (1). Above the substrate (1), the high refractive index conductive film layer (3) and the low refractive index film layer (4) alternately in sequence, and the outermost layer is the high refractive index conductive film layer (3). The low refractive index film layer (4) is patterned, and the projected area of ​​the low refractive index film layer (4) is smaller than that of the high refractive index conductive film layer (3). Multiple high refractive index conductive film layers (3) are connected outside the low refractive index film layer (4).

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