Flexible circuit board structure for high-temperature environment

Abstract

The utility model belongs to the technical field of flexible circuit boards, in particular to a flexible circuit board structure used in a high-temperature environment, which comprises a polyimide substrate layer 1, a copper foil layer 2, a covering layer and a protective layer 6, the copper foil layer 2 is a rolled copper foil layer 2 so as to have better bending resistance, an anti-oxidation layer 3 is covered on the copper foil layer 2, and the anti-oxidation layer 3 is covered on the protective layer 6. The covering layer comprises a first covering layer 4 and a second covering layer 5, the first covering layer 4 and the second covering layer 5 are PI films, the surfaces of the PI films are coated with epoxy adhesive films, and one side of the outer surface of the second covering layer 5 is provided with a protective layer 6 which is used for protecting the FPC from being influenced by the external environment. And the high temperature resistance is excellent, and the copper foil layer 2 is not easily influenced by the external environment.

Description

Technical Field

[0001] The utility model relates to the technical field of flexible circuit boards, in particular to a flexible circuit board structure used in a high-temperature environment. Background Art

[0002] Flexible circuit boards, also known as soft boards, are printed circuits made of flexible insulating substrates. Flexible circuits provide excellent electrical performance, can meet the design needs of smaller and higher-density installations, and also help reduce assembly processes and enhance reliability. Flexible circuit boards are the only solution to meet the miniaturization and mobility requirements of electronic products. However, existing flexible circuit boards are not ideally resistant to high temperatures, making them inconvenient for people to use. In addition, the copper foil layer is easily oxidized in high-temperature environments, affecting normal use.

[0003] Therefore, it is necessary to design a flexible circuit board that is more adaptable to high temperature environments. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a flexible circuit board structure for high temperature environment, which has excellent bending resistance, and the copper foil layer is more resistant to oxidation in high temperature environment and has better high temperature resistance.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A flexible circuit board structure for high-temperature environments includes a polyimide substrate layer, a copper foil layer, a covering layer, and a protective layer. The copper foil layer is a rolled copper foil layer to have better bending resistance. The copper foil layer is covered with an anti-oxidation layer. The covering layer includes a first covering layer and a second covering layer. The first covering layer is a liquid crystal polymer layer, and the second covering layer is a PI film. The surface of the PI film is coated with an epoxy film. A protective layer is provided on one side of the outer surface of the second covering layer to protect the FPC from the influence of the external environment.

[0007] Optionally, in an embodiment of the present invention, the copper foil layer is a rolled copper foil layer.

[0008] Optionally, in an embodiment of the present invention, the thickness of the copper foil layer is 20 μm-80 μm.

[0009] Optionally, in one embodiment of the present invention, the anti-oxidation layer is a nickel plating layer.

[0010] Optionally, in one embodiment of the present invention, the thickness of the second covering layer is 0.025 mm-0.05 mm.

[0011] Optionally, in an embodiment of the present invention, the thickness of the first covering layer is 10 μm-30 μm.

[0012] Optionally, in one embodiment of the present invention, the protective layer is any one of a silicone coating and a fluoride coating.

[0013] Beneficial effects of the utility model

[0014] The utility model discloses a flexible circuit board structure for use in high-temperature environments. The structure adopts polyimide as the base material layer and the copper foil layer adopts rolled copper foil, so that the structure has excellent ductility, bending resistance and conductivity. The copper foil layer is provided with a nickel plating layer to protect the copper foil layer and prevent the copper foil layer from high-temperature oxidation. The nickel plating layer is provided with a double covering layer to provide double high-temperature protection for the circuit board and can buffer part of the impact force for the copper foil layer to avoid damage. The outermost layer of the circuit board is also provided with a protective coating to improve the weather resistance of the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art.

[0016] Figure 1 This is a schematic diagram of the circuit board structure of Example 1 of the present utility model;

[0017] Description of reference numerals: polyimide base material layer 1 , copper foil layer 2 , anti-oxidation layer 3 , first covering layer 4 , second covering layer 5 , protective layer 6 . DETAILED DESCRIPTION

[0018] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the utility model, the following is a detailed description of the specific implementation method, structure, characteristics and effects of the present invention in combination with the accompanying drawings and preferred embodiments. Example 1

[0019] In order to improve the service life of flexible circuit boards, a flexible circuit board structure for high temperature environments is designed. The specific solution is as follows:

[0020] like Figure 1 As shown, a flexible circuit board structure for high-temperature environments includes a polyimide substrate layer 1, a copper foil layer 2, a covering layer and a protective layer 6. The copper foil layer 2 is a rolled copper foil layer 2 to have better bending resistance. The copper foil layer 2 is covered with an anti-oxidation layer 3. The covering layer includes a first covering layer 4 and a second covering layer 5. The first covering layer 4 is a liquid crystal polymer layer, and the second covering layer 5 is a PI film. The surface of the PI film is coated with an epoxy film. A protective layer 6 is provided on one side of the outer surface of the second covering layer 5 to protect the FPC from the influence of the external environment.

[0021] A laying groove is opened on the polyimide substrate layer 1 for setting the copper foil layer 2, and the edge of the polyimide substrate layer 1 can block the edge of the copper foil layer 2. Together with the anti-oxidation layer 3, it can provide a closed environment for the copper foil layer 2 to reduce the possibility of oxidation.

[0022] The copper foil layer 2 is a rolled copper foil layer 2 to improve the conductivity and mechanical strength of the circuit.

[0023] The thickness of the copper foil layer 2 is 20 μm-80 μm. In this embodiment, the thickness of the copper foil layer 2 is 50 μm.

[0024] The anti-oxidation layer 3 is a nickel plating layer, which can effectively protect the copper foil from the influence of high temperature oxidation. The nickel plating layer has a strong bonding force with the copper foil and can be deposited on the surface of the copper foil by electroplating or chemical plating.

[0025] The thickness of the second covering layer 5 is 0.025mm-0.05mm. The PI film has excellent flexibility and can withstand the bending and folding of the circuit board. It is very suitable for the covering layer of the flexible circuit board. It also has good high temperature resistance and can maintain stable physical and chemical properties under high temperature conditions. The surface of the PI film is wear-resistant and can protect the internal conductive circuit layer from friction and wear.

[0026] The thickness of the first covering layer 4 is 10μm-30μm. Liquid crystal polymer has extremely high heat resistance and can maintain stable performance in high temperature environment. LCP has high strength, high modulus and good impact resistance, which can effectively protect the flexible circuit board from physical damage.

[0027] The protective layer 6 is either a silicone coating or a fluoride coating. In this embodiment, the protective layer 6 is a silicone coating, which can maintain stability in a high temperature environment and effectively resist corrosive environments such as humid, acidic or alkaline conditions, thereby protecting the circuit board from damage. The good insulation performance protects the circuit board from external electromagnetic interference, improves the stability and reliability of the circuit board, and has a certain flexibility to meet the bending requirements of the flexible circuit board.

[0028] The flexible circuit board of this solution uses rolled copper foil, which has excellent ductility, bending resistance and conductivity. A nickel plating layer is provided on the copper foil layer 2 to enhance the high temperature and oxidation resistance of the copper foil layer 2. A double covering layer is provided on the nickel plating layer to provide double high-temperature protection for the circuit board and can buffer part of the impact force for the copper foil layer 2 to avoid damage. A protective coating is also provided on the outermost layer of the circuit board to improve the weather resistance of the circuit board.

[0029] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0030] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A flexible circuit board structure for high temperature environment, characterized in that: It includes a polyimide substrate layer, a copper foil layer, a covering layer and a protective layer. The copper foil layer is a rolled copper foil layer to have better bending resistance. The copper foil layer is covered with an anti-oxidation layer. The covering layer includes a first covering layer and a second covering layer. The first covering layer is a liquid crystal polymer layer, and the second covering layer is a PI film. The surface of the PI film is coated with an epoxy film. A protective layer is provided on one side of the outer surface of the second covering layer to protect the FPC from the influence of the external environment.

2. The flexible circuit board structure for use in a high temperature environment according to claim 1, characterized in that: The copper foil layer is a rolled copper foil layer.

3. The flexible circuit board structure for use in a high temperature environment according to claim 1, characterized in that: The thickness of the copper foil layer is 20 μm-80 μm.

4. The flexible circuit board structure for use in a high temperature environment according to claim 1, characterized in that: The anti-oxidation layer is a nickel plating layer.

5. The flexible circuit board structure for use in a high temperature environment according to claim 1, characterized in that: The second covering layer has a thickness of 0.025 mm to 0.05 mm.

6. The flexible circuit board structure for use in a high temperature environment according to claim 1, characterized in that: The thickness of the first covering layer is 10 μm-30 μm.

7. The flexible circuit board structure for use in a high temperature environment according to claim 1, characterized in that: The protective layer is any one of an organic silicon coating and a fluoride coating.

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