Electromagnetic shielding film

Abstract

The utility model discloses an electromagnetic shielding film which comprises a protective layer, a 3D porous graphene layer and a foam metal layer. The 3D porous graphene layer is arranged between the protective layer and the foam metal layer, and a gum layer is arranged outside the foam metal layer. The foam metal layer has high conductivity and high magnetic conductivity and can provide conductivity loss and magnetic loss at the same time, in addition, the foam porous structure can reduce the density of the structure, and the porous structure is beneficial to multi-reflection dissipation of electromagnetic waves in the material; therefore, a very high shielding effectiveness value can be provided, and meanwhile, the 3D porous laser-induced graphene layer can enhance absorption of electromagnetic waves on the surface of the shielding film and improve impedance matching.

Description

Technical Field

[0001] The utility model belongs to the field of electromagnetic shielding, and in particular relates to an absorption-dominated high-performance electromagnetic shielding film. Background Art

[0002] With the rapid development of modern electronics and communications industries, electromagnetic radiation pollution has become a major pollution that is harmful to human production and life. Electromagnetic radiation pollution not only affects the normal operation of various electronic equipment, the stability of communication equipment and information security, but also has a huge impact on human health.

[0003] As a quasi-two-dimensional nanocarbon material, graphene has many excellent properties, such as high carrier mobility, high thermal conductivity, high mechanical strength, unique electrical and friction properties, etc. Porous graphene not only has some of these excellent properties, but also has a larger surface area due to its certain nanopore defects compared to intrinsic graphene. Laser-induced 3D porous graphene technology. It generates porous graphene in situ by laser irradiation on the polymer surface. This method is low-cost and can complete the graphene patterning in one step.

[0004] Existing electromagnetic shielding materials can be divided into metal electromagnetic shielding materials, magnetic dielectric electromagnetic shielding materials, carbon-based conductive electromagnetic shielding materials and polymer-based electromagnetic shielding materials. Traditional metal electromagnetic shielding materials and magnetic dielectric electromagnetic shielding materials have the characteristics of high density and difficulty in processing, but their excessive conductivity leads to impedance mismatch and excessive electromagnetic wave reflection, causing secondary pollution; the conductivity and shielding effectiveness of traditional carbon-based conductive electromagnetic shielding materials and traditional carbon materials compared with metal materials need to be improved. Utility Model Content

[0005] The main purpose of the utility model is to overcome the deficiencies of the prior art and provide an absorption-dominated high-performance electromagnetic shielding film.

[0006] In order to achieve the above-mentioned utility model purpose, the utility model adopts the following technical solutions:

[0007] An electromagnetic shielding film, comprising a protective layer, a 3D porous graphene layer and a foam metal layer;

[0008] The 3D porous graphene layer is arranged between the protective layer and the foam metal layer, and a back adhesive layer is arranged outside the foam metal layer.

[0009] Further technology of the utility model:

[0010] Preferably, the protective layer is a silicone layer.

[0011] Preferably, the thickness of the foam metal layer is 0.3-1 mm. The foam metal layer is one of foam nickel, foam iron, and foam iron-nickel.

[0012] Preferably, the adhesive layer is double-sided adhesive.

[0013] The 3D porous graphene layer is prepared by immersing the foam metal layer in a polymer solution, drying it in an oven at 80-100°C for 1-5 hours for curing, and then laser scanning it 2-4 times to generate uniform 3D porous graphene in situ on the foam metal electromagnetic shielding layer.

[0014] The beneficial effects of the utility model are:

[0015] In the electromagnetic shielding film designed by the utility model, the foam metal layer has high electrical conductivity and high magnetic permeability, and can provide electrical conduction loss and magnetic loss at the same time. In addition, the foam porous structure can reduce the density of the structure, and the porous structure is conducive to the multiple reflection dissipation of electromagnetic waves inside the material; therefore, it can provide a very high shielding effectiveness value. At the same time, the 3D porous laser-induced graphene layer can enhance the absorption of electromagnetic waves on the surface of the shielding film and improve impedance matching. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] Figure 2 Schematic diagram of curing PES on metal foam.

[0019] Figure 3 Schematic diagram of the graphene formation process.

[0020] Figure 4 This is a schematic diagram after the formation of graphene is completed.

[0021] The reference numerals are as follows: 1. protective layer; 2. 3D porous graphene layer; 3. foam metal layer; 4. adhesive layer; 5. polymer substrate; 6. laser. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be further described in detail below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model but not all. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0023] like Figure 1 As shown, the utility model provides an electromagnetic shielding film, comprising a protective layer 1, a 3D porous graphene layer 2 and a foam metal layer 3;

[0024] The 3D porous graphene layer 2 is arranged between the protection layer 1 and the foam metal layer 3 , and a backing layer 4 is arranged outside the foam metal layer 3 .

[0025] It should be noted that the protective layer in this embodiment is a silicone protective layer, and the back adhesive layer uses double-sided tape. The 3D porous graphene layer in this embodiment is: the foam metal layer is immersed in a polymer solution, placed in an oven at 80-100°C for 1-5 hours to cure, and then laser scanned 2-4 times to generate uniform 3D porous graphene in situ on the foam metal electromagnetic shielding layer.

[0026] Preparation method Figure 1-4 , including the following steps:

[0027] S1, immersing the foam metal layer 3 in a polymer solution, and forming a polymer substrate 5 on the surface of the foam metal after solidification.

[0028] S2. Scan the surface of the polymer substrate 5 with a laser 6 to generate a 3D porous graphene layer 2.

[0029] S3, applying liquid silicone on the surface of the 3D porous graphene layer 2, and waiting for the silicone to solidify to form a protective layer 1.

[0030] S4, attach adhesive layer 4.

[0031] In step S1, the polymer solution is one or more of polyethersulfone, polyimide, aromatic polyamide, polyamideimide, polybenzimidazole, polyetheretherketone, polyphenylene sulfide, chlorinated polyvinyl chloride, and epoxy resin.

[0032] In step S1, the curing temperature of the polymer solution is 80-100° C., and the curing time is 1-5 hours.

[0033] In step S1, the foam metal is one of foam nickel, foam iron and foam iron nickel, and has a thickness of 0.3-2 mm.

[0034] In step S2, the laser power is 4-10W, the scanning speed is 100-600mm / s, the air jump speed is 100-1000mm / s, the Q frequency is 2-10KHz, the scanning line spacing is 0.06-0.2mm, and the laser spot size is 60-200μm.

[0035] The light source of the laser irradiation is one of a solid laser source, a gas laser source, a liquid laser source and a semiconductor laser source.

[0036] The laser used for laser irradiation of polymer is CO2 laser with a wavelength of 10.6 μm or 9.3 μm.

[0037] According to the preferred preparation scheme, the foam metal layer 3 is immersed in a polymer solution, dried at 80-100°C for 1-5h and solidified to form a 5-100 micron polymer substrate 5 on the surface of the foam metal. The laser is controlled to irradiate the polymer substrate at a certain power and scanning speed to complete the growth of 3D porous graphene on the polymer substrate. Liquid silica gel is applied to the surface of the 3D porous graphene layer 2, and the silica gel is solidified to form a protective layer 1. Then the backing glue is attached.

[0038] Production example 1

[0039] In this example, the foam metal is 0.5 mm nickel foam, and the polymer substrate is polyethersulfone (PES). The specific steps are as follows:

[0040] Soak the nickel foam in the PES solution until the pores of the nickel foam are filled with the PES solution.

[0041] The nickel foam fully absorbed with the PES solution was placed in an oven and dried at 80°C for 2 hours to completely solidify the PES solution and form a PES film on the surface of the nickel foam.

[0042] The PES membrane surface was scanned twice using an infrared laser with a wavelength of 10.6 microns. The laser power was 5.5 W and the scanning speed was 200 mm / s. In-situ 3D porous graphene was generated.

[0043] A 0.5 mm thick layer of liquid silicone was applied on the graphene surface, and the silicone solidified to form a protective layer after 2 hours at room temperature.

[0044] Apply double-sided tape on the back.

[0045] Production example 2

[0046] In this example, the foam metal is 1 mm nickel foam and the polymer substrate is polyethersulfone (PES). The specific steps are as follows:

[0047] 1) Soak the nickel foam in the PES solution until the pores of the nickel foam are filled with the PES solution.

[0048] 2) The nickel foam fully absorbed with the PES solution is placed in an oven and dried at 90° C. for 3 h until the PES solution is completely solidified and a uniform PES film is formed on the surface of the nickel foam.

[0049] 3) Use an infrared laser with a wavelength of 10.6 microns to scan the surface of the PES membrane twice. The laser power is 6.5W and the scanning speed is 250mm / s. Generate in-situ 3D porous graphene.

[0050] 4) Apply a 0.5 mm thick layer of liquid silicone on the graphene surface. After 2 hours at room temperature, the silicone solidifies to form a protective layer.

[0051] 5) Apply double-sided tape on the back.

[0052] Production example 3

[0053] The foam metal of the example is 0.5 mm nickel foam, and the polymer substrate is polyimide (PI). The specific steps are as follows:

[0054] 1) Soak the nickel foam in the PI solution until the pores of the nickel foam are filled with the PI solution.

[0055] 2) The nickel foam that is fully absorbed with the PI solution is placed in an oven for solidification to form a uniform PI film on the surface of the nickel foam.

[0056] 3) Use an infrared laser with a wavelength of 10.6 microns to scan the surface of the PI film twice. The laser power is 6W and the scanning speed is 300mm / s. Generate in-situ 3D porous graphene.

[0057] 4) Apply a 0.5 mm thick layer of liquid silicone on the graphene surface. After 2 hours at room temperature, the silicone solidifies to form a protective layer.

[0058] 5) Apply double-sided tape on the back.

[0059] The above contents are merely examples and explanations of the structure of the utility model. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the utility model or exceed the scope defined in the claims, they should all fall within the protection scope of the utility model.

Claims

1. An electromagnetic shielding film, characterized in that: It comprises a protective layer (1), a 3D porous graphene layer (2) and a foam metal layer (3); The 3D porous graphene layer (2) is arranged between the protective layer (1) and the foam metal layer (3), and a backing layer (4) is arranged outside the foam metal layer (3).

2. The electromagnetic shielding film according to claim 1, characterized in that: The protective layer (1) is a silica gel layer.

3. The electromagnetic shielding film according to claim 1, characterized in that: The thickness of the foam metal layer (3) is 0.3-1 mm.

4. The electromagnetic shielding film according to claim 1, characterized in that: The back adhesive layer (4) is a double-sided adhesive.

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