Electromagnetic shielding film

Abstract

The utility model provides an electromagnetic shielding film, which comprises an insulating layer, and a conductive layer, a conductive adhesive layer and a protective layer which are sequentially arranged on one surface of the insulating layer, the first reflecting layer is arranged between the conductive layer and the conductive adhesive layer, the material of the first reflecting layer is different from that of the protective layer, and the absolute value of the difference value between the dielectric constant of the first reflecting layer and the dielectric constant of the protective layer is larger than 1. According to the embodiment of the utility model, the material of the first reflecting layer is different from that of the protective layer, and the absolute value of the difference between the dielectric constant of the first reflecting layer and the dielectric constant of the protective layer is greater than 1, so that electromagnetic waves can be better reflected, and the reflection efficiency of the electromagnetic shielding film to the electromagnetic waves is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electromagnetic shielding films, in particular to an electromagnetic shielding film. Background Art

[0002] In electronic equipment products, electronic components generate electromagnetic waves when in operation, which cause electromagnetic interference to them and other electronic components. If the electromagnetic interference exceeds the limit of the electronic components, it will affect the normal operation of the electronic components. Electromagnetic shielding is an important way to limit the electromagnetic interference generated or received by electronic components and protect the normal operation of electronic components.

[0003] Electromagnetic shielding film is an electromagnetic shielding material. It is an electronic material film made of polyester film as the main raw material, through mixing, coating, slitting and baking, vacuum sputtering, electroplating, gluing and other processes. It can effectively block electromagnetic interference and is widely used in flexible circuit boards required by electronic products such as smart phones, tablets, smart watches, etc., providing electromagnetic shielding for flexible circuit boards. However, the current electromagnetic shielding film has a low reflection efficiency for electromagnetic waves. Utility Model Content

[0004] In view of this, an object of the embodiments of the present utility model is to provide an electromagnetic shielding film to solve the technical problem of low reflection efficiency of electromagnetic waves of the electromagnetic shielding film in the prior art.

[0005] In order to achieve the above-mentioned purpose, an embodiment of the utility model provides an electromagnetic shielding film, which includes: an insulating layer, and a conductive layer, a conductive adhesive layer and a protective layer arranged in sequence on one surface of the insulating layer; and a first reflective layer arranged between the conductive layer and the conductive adhesive layer, wherein the material of the first reflective layer is different from the material of the protective layer, and the absolute value of the difference between the dielectric constant of the first reflective layer and the dielectric constant of the protective layer is greater than 1.

[0006] In some possible implementations, the bonding force between the conductive layer and the insulating layer is greater than the sum of the mass of the protective layer, the mass of the conductive adhesive layer, and the mass of the first reflective layer.

[0007] In some possible implementations, the bonding force between the conductive layer and the insulating layer is greater than 120 N / m;

[0008] The conductive layer is a metal layer, which is deposited on one surface of the insulating layer by vacuum coating, and the metal layer is metal copper or metal aluminum.

[0009] In some possible implementations, the thickness of the insulating layer is 3 um to 8 um.

[0010] In some possible implementations, the insulating layer is made of polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene terephthalate, polyethylene naphthalate, poly(p-phenylene terephthalamide), acrylonitrile-butadiene-styrene copolymer, poly(p-phenylene terephthalamide), polypropylene, polyoxymethylene, epoxy resin, phenolic resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber or polycarbonate;

[0011] The thickness of the first reflective layer is 1 um to 1.5 um.

[0012] In some possible implementations, the thickness of the conductive layer may be 50 nm to 3 um.

[0013] In some possible implementations, the conductive adhesive layer is made of conductive glue containing metal particles, and the dielectric constant of the conductive adhesive layer is adjusted according to the metal type and content of the metal particles.

[0014] In some possible implementations, the thickness of the conductive adhesive layer is 100 nm to 1 um.

[0015] In some possible embodiments, the material of the protective layer is any one of polyethylene, polypropylene, ethylene propylene copolymer, polyethylene terephthalate, polyethylene naphthalate, poly(p-phenylene terephthalamide), acrylonitrile-butadiene-styrene copolymer, poly(p-phenylene terephthalamide), polypropylene, polyoxymethylene, epoxy resin, phenolic resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber and polycarbonate.

[0016] In some possible implementations, the thickness of the protective layer may be 1 um to 8 um.

[0017] The beneficial technical effects of the above technical solution are:

[0018] An electromagnetic shielding film provided by an embodiment of the utility model comprises: an insulating layer, and a conductive layer, a conductive adhesive layer and a protective layer sequentially arranged on a surface of the insulating layer; and a first reflective layer arranged between the conductive adhesive layer and the protective layer, wherein the material of the first reflective layer is different from that of the protective layer, and the absolute value of the difference between the dielectric constant of the first reflective layer and that of the protective layer is greater than 1. In the embodiment of the utility model, the material of the first reflective layer is different from that of the protective layer, and the absolute value of the difference between the dielectric constant of the first reflective layer and that of the protective layer is greater than 1, so that electromagnetic waves can be better reflected, thereby improving the reflection efficiency of the electromagnetic shielding film to electromagnetic waves. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of the overall structure of an electromagnetic shielding film according to an embodiment of the utility model.

[0021] Description of Figure Numbers:

[0022] 10. Insulating layer; 11. Conductive layer; 12. Conductive adhesive layer; 13. Protective layer; 14. First reflective film. DETAILED DESCRIPTION

[0023] The features and exemplary embodiments of various aspects of the utility model will be described in detail below. In the detailed description below, many specific details are proposed in order to provide a comprehensive understanding of the utility model. However, it is obvious to those skilled in the art that the utility model can be implemented without the need for some of these specific details. The following description of the embodiment is only to provide a better understanding of the utility model by illustrating an example of the utility model. In the drawings and the following description, at least part of the known structures and technologies are not shown in order to avoid unnecessary ambiguity to the utility model; and, for clarity, the size of some structures may be exaggerated. In addition, the features, structures or characteristics described below may be combined in one or more embodiments in any suitable manner.

[0024] Figure 1 Schematic diagram of the structure of an electromagnetic shielding film according to an embodiment of the utility model. Figure 1 As shown, the electromagnetic shielding film includes: an insulating layer 10, and a conductive layer 11, a conductive adhesive layer 12 and a protective layer 13 arranged in sequence on a surface of the insulating layer 10; and a first reflective layer 14 arranged between the conductive layer and the conductive adhesive layer, wherein the material of the first reflective layer 14 is different from the material of the protective layer 13, for example, when the material of the first reflective layer 14 is polypropylene with a dielectric constant of 2.1, and the material of the protective layer 13 is acrylonitrile styrene acrylate with a dielectric constant of 3.3; or conversely, the material of the first reflective layer 14 is polyethylene with a dielectric constant of 2.30, and the material of the protective layer 13 is polyethylene terephthalate with a dielectric constant of 4.0, so that the absolute value of the difference between the dielectric constant of the first reflective layer 14 and the dielectric constant of the protective layer is greater than 1.

[0025] Because when the dielectric constants of the incident medium (protective layer 13) and the reflective medium (first reflective layer 14) are equal, the reflection coefficient is zero, that is, there is no reflection at all, and when there is a difference in the dielectric constants of the two, the reflection coefficient is not zero, that is, there is a reflection phenomenon. When the reflection coefficient is greater than 1, the reflection effect is the best. Therefore, the embodiment of the utility model can better reflect electromagnetic waves and improve the reflection efficiency of the electromagnetic shielding film to electromagnetic waves by making the absolute value of the difference between the dielectric constant of the first reflective layer and the dielectric constant of the protective layer greater than 1.

[0026] Of course, in some embodiments, a second reflective layer or more reflective layers may be provided. The second reflective layer or more reflective layers are provided above the conductive layer 11. The thickness of the second reflective layer may be greater than the thickness of the first reflective layer, so as to further achieve reflection of electromagnetic waves.

[0027] In some embodiments, the bonding force between the conductive layer 11 and the insulating layer 10 is greater than the sum of the mass of the protective layer 13, the mass of the conductive adhesive layer 12, and the mass of the first reflective layer 14. For example, the mass of the protective layer 13 is M1, the mass of the conductive adhesive layer 12 is M2, the mass of the first reflective layer 14 is M3, and the bonding force between the conductive layer 11 and the insulating layer 10 is F1, then F1>M2+M1+M3, at this time, the electromagnetic shielding film in this embodiment will not curl and affect the use and transportation. At the same time, the metal layer will not fall off over time. Because the electromagnetic shielding film in this embodiment is a 4-layer structure of the insulating layer 10, the conductive layer 11, the conductive adhesive layer 12 and the protective layer 13, the mass of the outer two layers, that is, the protective layer 13 and the conductive adhesive layer 12 is too high, which will cause the electromagnetic shielding film to curl toward the conductive adhesive layer 12 side. At the same time, if the mass of the conductive adhesive layer 12 side is large, the conductive layer 11 will be removed.

[0028] In some embodiments, the bonding force between the conductive layer 11 and the insulating layer 10 is greater than 120 N / m; the conductive layer 11 is a metal layer, which is deposited on one surface of the insulating layer 10 by vacuum coating, and the metal layer is copper or aluminum. In this way, the metal layer is not easy to fall off in subsequent use.

[0029] In some embodiments, the thickness of the insulating layer 10 is 3um to 8um. In this embodiment, the thickness of the insulating layer 10 is mainly considered by the formation method of the metal layer. For example, if the metal layer is formed by magnetron sputtering, the insulating layer 10 needs to move in a vacuum device. If the thickness is too small, it is easy to break, and if the thickness is too large, it is easy to increase the quality and cost.

[0030] In some embodiments, the material of the insulating layer 10 is polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene terephthalate, polyethylene naphthalate, poly(p-phenylene terephthalamide), acrylonitrile-butadiene-styrene copolymer, poly(p-phenylene terephthalamide), polypropylene, polyoxymethylene, epoxy resin, phenolic resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber or polycarbonate.

[0031] In some embodiments, the thickness of the conductive layer 11 may be 50nm to 3um. In this embodiment, the conductive layer 11 is made of metal, that is, the thickness of the metal layer mainly plays a role in color reflection, and the reflection and conductivity effects are better when the thickness is in the range of 50nm to 3um.

[0032] In some embodiments, the conductive adhesive layer 12 is made of conductive glue containing metal particles, and the dielectric constant of the conductive adhesive layer 12 is adjusted according to the metal type and content of the metal particles. In this embodiment, the conductive adhesive layer 12 can be prepared by coating the conductive glue containing metal particles on the metal layer, the metal particles are generally nickel, and can also be other metals, and the dielectric constant of the conductive glue can be adjusted according to the type or content of the conductive particles.

[0033] In some embodiments, the thickness of the conductive adhesive layer 12 is 100nm to 1um. In this embodiment, the conductive adhesive layer 12 mainly plays a bonding role, and this thickness has good bonding strength, and can cooperate with the thickness of the metal layer and the insulating layer 10 to prevent the electromagnetic shielding film from curling.

[0034] In some embodiments, the material of the protective layer 13 is any one of polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene terephthalate, polyethylene naphthalate, poly(p-phenylene terephthalamide), acrylonitrile-butadiene-styrene copolymer, poly(p-phenylene terephthalamide), polypropylene, polyoxymethylene, epoxy resin, phenolic resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber and polycarbonate.

[0035] In some embodiments, in order to better exert the protective effect of the protective layer 13 on the electromagnetic shielding film and improve the service life of the electromagnetic shielding film, the thickness of the protective layer 13 in this embodiment can be 1 um to 8 um.

[0036] In the description of the embodiments of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present utility model. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0037] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An electromagnetic shielding film, characterized in that: The electromagnetic shielding film comprises: an insulating layer (10), and a conductive layer (11), a conductive adhesive layer (12) and a protective layer (13) arranged in sequence on a surface of the insulating layer (10), and a first reflective layer (14) arranged between the conductive layer (11) and the conductive adhesive layer (12), wherein the material of the first reflective layer (14) is different from that of the protective layer (13), and the absolute value of the difference between the dielectric constant of the first reflective layer (14) and the dielectric constant of the protective layer (13) is greater than 1.

2. The electromagnetic shielding film according to claim 1, characterized in that: The material of the first reflective layer (14) is any one of polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene terephthalate, polyethylene naphthalate, poly(p-phenylene terephthalamide), acrylonitrile-butadiene-styrene copolymer, polypropylene, polyoxymethylene, epoxy resin, phenolic resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber, polycarbonate and acrylonitrile-styrene-acrylate; The thickness of the first reflective layer (14) is 1 um to 1.5 um.

3. The electromagnetic shielding film according to claim 1, characterized in that: The bonding force between the conductive layer (11) and the insulating layer (10) is greater than the sum of the mass of the protective layer (13), the mass of the conductive adhesive layer (12) and the mass of the first reflective layer (14).

4. The electromagnetic shielding film according to claim 1, characterized in that: The bonding force between the conductive layer (11) and the insulating layer (10) is greater than 120 N / m; The conductive layer (11) is a metal layer, which is deposited on a surface of the insulating layer (10) by vacuum coating, and the metal layer is metal copper or metal aluminum.

5. The electromagnetic shielding film according to claim 1, characterized in that: The material of the insulating layer (10) is any one of polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene terephthalate, polyethylene naphthalate, poly(p-phenylene terephthalamide), acrylonitrile-butadiene-styrene copolymer, polypropylene, polyoxymethylene, epoxy resin, phenolic resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber and polycarbonate; The thickness of the insulating layer (10) is 3 um to 8 um.

6. The electromagnetic shielding film according to claim 1, characterized in that: The thickness of the conductive layer (11) is 50 nm to 3 um.

7. The electromagnetic shielding film according to claim 1, characterized in that: The conductive adhesive layer (12) is made of conductive adhesive containing metal particles, and the dielectric constant of the conductive adhesive layer (12) is adjusted according to the metal type and content of the metal particles.

8. The electromagnetic shielding film according to claim 1, characterized in that: The thickness of the conductive adhesive layer (12) is 100 nm to 1 um.

9. The electromagnetic shielding film according to claim 1, characterized in that: The material of the protective layer (13) is any one of polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene terephthalate, polyethylene naphthalate, poly(p-phenylene terephthalamide), acrylonitrile-butadiene-styrene copolymer, poly(p-phenylene terephthalamide), polypropylene, polyoxymethylene, epoxy resin, phenolic resin, polytetrafluoroethylene, polyvinylidene fluoride, silicone rubber and polycarbonate.

10. The electromagnetic shielding film according to claim 1, characterized in that: The thickness of the protective layer (13) may be 1 um to 8 um.

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