A film and a circuit board

Abstract

Embodiments of the present invention disclose a film and a circuit board. The film includes: a first film layer; a metal layer located on one side of the first film layer; wherein, the gray value of the color of the first film layer is less than the gray value of the color of the metal layer. The technical solution of the embodiments of the present invention can achieve a relatively obvious contrast in brightness, thereby broadening the application range of the film.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of identification code production, and particularly to a film and a circuit board. Background Art

[0002] With the rapid development of the electronics industry, electronic products are further developing towards miniaturization, light weight, and high-density assembly, which greatly promotes the development of flexible circuit boards, thereby realizing the integration of various components and wires.

[0003] Various components are integrated inside electronic products. In order to better trace the electronic product or a certain device inside it, identification codes are often set inside the electronic products. By scanning the identification codes, the information of the product or a certain component can be traced.

[0004] Currently, in the prior art, the identification code (such as a two-dimensional code) is set on a steel plate. However, due to the thinness and lightness of electronic products, the size of the steel plate is limited, resulting in the inability to print the two-dimensional code on the steel plate. Subsequently, the identification code is printed on the flexible board by printing. However, due to the small size of the flexible board, the printed identification code is not clear, the resolution is small, and there is also a situation where the identification code cannot be printed. Summary of the Invention

[0005] The embodiments of the present invention provide a film and a circuit board to achieve a more obvious contrast between light and dark brightness, thereby broadening the application range of the film.

[0006] In a first aspect, the embodiments of the present invention provide a film, which includes:

[0007] A first film layer;

[0008] A metal layer located on one side of the first film layer;

[0009] Wherein, the gray value of the color of the first film layer is less than the gray value of the color of the metal layer.

[0010] Optionally, the film further includes an adhesive layer;

[0011] The adhesive layer is disposed on the side of the metal layer away from the first film layer;

[0012] Optionally, the metal layer includes a first metal layer and a second metal layer;

[0013] The first metal layer is disposed on the side close to the first film layer; the second metal layer is disposed on the side of the first metal layer away from the first film layer.

[0014] Optionally, the first metal layer includes a first sputtered metal layer and a second sputtered metal layer;

[0015] The first sputtered metal layer is disposed on a side close to the first film layer; the second sputtered metal layer is disposed on a side of the first sputtered metal layer away from the first film layer.

[0016] Optionally, the material of the first metal layer is at least one single element among nickel, silver, platinum, gold, titanium, aluminum, cobalt, and chromium; or, the material of the first metal layer is an alloy formed by at least two of nickel, silver, platinum, gold, titanium, aluminum, cobalt, and chromium; the material of the second metal layer is at least one single element among nickel, silver, platinum, aluminum, titanium, aluminum, cobalt, and chromium; or, the material of the second metal layer is an alloy formed by at least two of nickel, silver, platinum, aluminum, titanium, aluminum, cobalt, and chromium; or, the material of the second metal layer is a combination among alloys formed by at least two of nickel, silver, platinum, aluminum, titanium, aluminum, cobalt, and chromium.

[0017] Optionally, the thickness range of the first film layer is 0.5 - 40 μm, the thickness range of the metal layer is 0.05 - 10 μm, and the thickness range of the adhesive layer is 1 - 30 μm.

[0018] Optionally, a side of the metal layer away from the first film layer is roughened to form a plurality of convex structures.

[0019] Optionally, the roughness range of the surface of the metal layer away from the first film layer is 0.5 - 30 μm.

[0020] Optionally, the difference between the gray value of the color of the first film layer and the gray value of the color of the metal layer is less than or equal to a first gray threshold, and the first gray threshold is greater than or equal to 10.

[0021] Optionally, the first gray threshold is 50.

[0022] Optionally, the first gray threshold is 100.

[0023] In a second aspect, an embodiment of the present invention further provides a film, which includes:

[0024] A first film layer;

[0025] A metal layer located on one side of the first film layer;

[0026] An adhesive layer disposed on a side of the metal layer away from the first film layer;

[0027] Wherein, the gray value of the color of the first film layer is less than the gray value of the color of the metal layer, and the first film layer forms a hollowed - out graphic of an identification code.

[0028] Optionally, a groove pattern is formed on one side of the metal layer close to the first film layer, and the vertical projection of the hollow pattern on the plane where the metal layer is located completely coincides with the groove pattern. Fourthly, an embodiment of the present invention further provides a circuit board, which includes a circuit board body, a shielding film, and the film according to any one of the embodiments of the present invention, and the shielding film is provided on the circuit board body, and the film is provided on the shielding film.

[0029] Fifthly, an embodiment of the present invention further provides a circuit board, which includes a circuit board body and the film according to any one of the embodiments of the present invention, and the shielding film is provided on the circuit board body, and the film is provided on the shielding film.

[0030] The technical solution of the embodiment of the present invention, the film includes: a first film layer; a metal layer located on one side of the first film layer; wherein, the gray value of the color of the first film layer is less than the gray value of the color of the metal layer. It solves the problems that the steel plate size limit in the prior art cannot print identification codes, and the clarity of the identification codes printed in the flexible board is not high, so as to realize that the film has a relatively obvious contrast between light and dark brightness, and further broaden the application range of the film. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of a film provided by an embodiment of the present invention;

[0032] Figure 2 is a schematic structural diagram of another film provided by an embodiment of the present invention;

[0033] Figure 3 is a schematic structural diagram of another film provided by an embodiment of the present invention;

[0034] Figure 4 is a schematic structural diagram of yet another film provided by an embodiment of the present invention;

[0035] Figure 5 is a schematic structural diagram of a circuit board provided by an embodiment of the present invention;

[0036] Figure 6 is a schematic structural diagram of another circuit board provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention.

[0038] It should also be noted that, for ease of description, only parts related to the present invention rather than all content are shown in the drawings. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of the operations can be implemented in parallel, concurrently, or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operations are completed, but it can also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, and so on.

[0039] An embodiment of the present invention provides a film, which can be applied to set identification codes for various components integrated inside electronic products. Figure 1 The following is a schematic structural diagram of a film provided by an embodiment of the present invention. Refer to Figure 1 The specific structure of this film includes:

[0040] A first film layer 110;

[0041] A metal layer 120 located on one side of the first film layer 110;

[0042] Among them, the gray value of the color of the first film layer 110 is less than the gray value of the color of the metal layer 120.

[0043] Among them, the first film layer 110 is used to insulate and support the metal layer 120, and to form a relatively obvious contrast in brightness between light and dark with the metal layer 120 to a certain extent. The first film layer 110 can be black, or a color closer to black such as dark blue. The specific color of the first film layer 110 is not limited in this embodiment.

[0044] Optionally, the first film layer 110 may include a PPS thin film layer, a PEN thin film layer, a polyester thin film layer, a polyimide thin film layer, a film layer formed after curing epoxy resin ink, a film layer formed after curing polyurethane ink, a film layer formed after curing modified acrylic resin, or a film layer formed after curing polyimide resin.

[0045] In order to adapt to the trend of thinning of electronic products, the thickness range of the first film layer 110 can be 2 μm to 15 μm, so as to minimize the thickness of the first film layer 110. Optionally, the thickness of the first film layer 110 can be selected as 4 μm to achieve the thinning of the first film layer 110 on the premise of having good insulation and protection performance.

[0046] The metal layer 120 is used to form an obvious color or brightness difference with the first film layer 110, and the gray value of the metal layer 120 is greater than the gray value of the first film layer 110.

[0047] In this embodiment, grayscale parameters are used to convert a color into a high-quality grayscale gradient to detect the contrast in brightness between the metal layer 120 and the first film layer 110. Grayscale uses black tones to represent various colors, that is, black is used as the reference color, and different colors are displayed as black with different saturations. The range between white and black is divided into 0 to 255 grayscale levels, with the grayscale value of white being 255 and the grayscale value of black being 0.

[0048] Exemplarily, in this embodiment, it is defined that the grayscale value of the metal layer 120 is greater than the grayscale value of the first film layer 110, which means that the difference in the grayscale values of the colors of the metal layer 120 and the first film layer 110 is relatively large. For example, if the color of the metal layer 120 is silver and the grayscale value of silver is relatively large, then the silver color of the metal layer 120 forms a sharp contrast with the dark color of the first film layer 110.

[0049] Furthermore, the difference between the grayscale value of the color of the metal layer 120 and the grayscale value of the color of the first film layer 110 is greater than or equal to the first grayscale threshold; the first grayscale threshold is greater than or equal to 10, so the difference between the grayscale value of the color of the metal layer 120 and the grayscale value of the color of the first film layer 110 is at least 10, making the difference in brightness between the metal layer 120 and the first film layer 110 more obvious, and improving the recognition accuracy of the identification code formed by the metal layer 120 and the first film layer 110 by the identification code recognition device.

[0050] To further increase the brightness difference between the metal layer 120 and the first film layer 110, the first grayscale threshold can be defined as 50. Then, the difference between the grayscale value of the color of the metal layer 120 and the grayscale value of the color of the first film layer 110 is at least 50. The color brightness of the metal layer 120 is stronger, and the color brightness of the first film layer 110 is smaller, further increasing the contrast in brightness between the metal layer 120 and the first film layer 110, and improving the recognition accuracy and precision of the identification code.

[0051] Based on the above embodiment, in this embodiment, the first grayscale threshold can be further defined as 100. Then, the difference between the grayscale value of the color of the metal layer 120 and the grayscale value of the color of the first film layer 110 is at least 100. For example, if the grayscale value of the color of the first film layer 110 is 0, the difference between the grayscale value of the color of the metal layer 120 and the grayscale value of the color of the first film layer 110 is at least 100, and even 255. Then, the grayscale value of the metal layer 120 can be selected to be greater than or equal to 100. The situation where the grayscale values differ by 255 is that one of the metal layer 120 and the first film layer 110 is pure black and the other is pure white, that is, one of their grayscale values is 255 and the other is 0, with a large difference in brightness or color, further enhancing the clarity of the identification code.

[0052] The technical solution of the embodiment of the present invention, the film includes: a first film layer; a metal layer located on one side of the first film layer; wherein, the gray value of the color of the first film layer is less than the gray value of the color of the metal layer. It solves the problems in the prior art that the steel plate size limit cannot print identification codes, and the clarity of the identification codes printed on the flexible board is not high, so as to achieve a relatively obvious light and dark brightness contrast through the film, and further broaden the application range of the film.

[0053] Figure 2 It is a schematic structural diagram of another film provided by the embodiment of the present invention. Refer to Figure 2 , on the basis of the above embodiment, the film further includes an adhesive layer 130; the adhesive layer 130 is disposed on the side of the metal layer 120 away from the first film layer 110. Wherein, the adhesive layer 130 plays a connecting role.

[0054] Figure 3 It is a schematic structural diagram of another film provided by the embodiment of the present invention. Refer to Figure 3 , on the basis of the above embodiment, the metal layer 120 includes a first metal layer 121 and a second metal layer 122; the first metal layer 121 is disposed on the side close to the first film layer 110; the second metal layer 122 is disposed on the side of the first metal layer 121 away from the first film layer 110.

[0055] Specifically, the first metal layer 121 is sputtered on the first film layer 110 by a sputtering process. The first metal layer 121 can be understood as a sputtered metal layer in this embodiment. Of course, the first metal layer 121 can also be formed by other processes, such as electroless plating, physical vapor deposition, chemical vapor deposition, evaporation plating, electroplating, and hybrid plating, etc. In this embodiment, the preparation process of the first metal layer 121 is not specifically limited.

[0056] The purpose of the first metal layer 121 and the second metal layer 122 is to form a relatively strong color difference with the first film layer 110, with an obvious black and white contrast ratio, so as to improve the recognition rate of the formed identification code.

[0057] The second metal layer 122 is formed on the first metal layer 121 by an electroplating process. The second metal layer 122 can be understood as an electroplated metal layer. Of course, the second metal layer 122 can also be formed by other processes, such as electroless plating, physical vapor deposition, chemical vapor deposition, evaporation plating, sputtering plating, and hybrid plating, etc. In this embodiment, the preparation process of the second metal layer 122 is not specifically limited.

[0058] In this embodiment, the first metal layer 121 and the second metal layer 122 are both made of white or silvery white or other lighter metals. The material of the first metal layer is at least one element selected from nickel, silver, platinum, gold, titanium, aluminum, cobalt and chromium; or, the material of the first metal layer is an alloy formed by at least two of nickel, silver, platinum, gold, titanium, aluminum, cobalt and chromium; the material of the second metal layer is at least one element selected from nickel, silver, platinum, aluminum, titanium, aluminum, cobalt and chromium; or, the material of the second metal layer is an alloy formed by at least two of nickel, silver, platinum, aluminum, titanium, aluminum, cobalt and chromium; or, the material of the second metal layer is a combination of alloys formed by at least two of nickel, silver, platinum, aluminum, titanium, aluminum, cobalt and chromium. Optionally, the first metal layer 121 and the second metal layer 122 are both made of nickel.

[0059] It can be understood that when ablation is to be performed to form an identification code, the laser energy forms a hollow pattern on the first film layer 110, thereby exposing the color of the first metal layer 121. Therefore, the grayscale value corresponding to the color of the first metal layer 121 is preferably greater than the grayscale value corresponding to the color of the second metal layer 122. For example, the first metal layer 121 can be selected to be silver, and the second metal layer 122 can be selected to be nickel.

[0060] Furthermore, when the thickness of the first metal layer 121 is relatively thin, when the identification code is formed by ablation, the first metal layer 121 is completely burned through due to the larger laser energy, thereby exposing the color of the second metal layer 122. At this time, the grayscale value corresponding to the color of the first metal layer 121 and the grayscale value corresponding to the color of the second metal layer can be selected without any restrictions.

[0061] Figure 4 is a schematic diagram of the structure of another membrane provided by an embodiment of the present invention, see Figure 4 , based on the above embodiment, the first metal layer 121 includes a first sputtered metal layer 1211 and a second sputtered metal layer 1212;

[0062] The first sputtered metal layer 1211 is disposed on a side close to the first film layer 110 ; the second sputtered metal layer 1212 is disposed on a side of the first sputtered metal layer 1211 away from the first film layer 110 .

[0063] Based on the above embodiments, the material of the first sputtered metal layer 1211 is at least one single element among nickel, silver, platinum, gold, titanium, aluminum, cobalt, and chromium; or, the material of the first sputtered metal layer 1211 is an alloy formed by at least two of nickel, silver, platinum, gold, titanium, aluminum, cobalt, and chromium; the material of the second sputtered metal layer 1212 is at least one single element among nickel, silver, platinum, titanium, aluminum, cobalt, and chromium; or, the material of the second sputtered metal layer 1212 is an alloy formed by at least two of nickel, silver, platinum, titanium, aluminum, cobalt, and chromium; the material of the second metal layer 122 is at least one single element among nickel, silver, platinum, aluminum, titanium, aluminum, cobalt, and chromium; or, the material of the second metal layer 122 is an alloy formed by at least two of nickel, silver, platinum, aluminum, titanium, aluminum, cobalt, and chromium; or, the material of the second metal layer 122 is a combination between alloys formed by at least two of nickel, silver, platinum, aluminum, titanium, aluminum, cobalt, and chromium.

[0064] It can be understood that in this embodiment, two sputtered metal layers can be provided. Since during the actual process of ablating the first film layer 110 to form the hollowed-out pattern of the identification code, the laser energy may penetrate the first sputtered metal layer 1211, the second sputtered metal layer 1212 can be used to increase the safeguard and keep the hollowed-out pattern exposing a sputtered metal layer with a relatively high flatness.

[0065] Furthermore, the gray value of the color of the first sputtered metal layer 1211 can be set to be greater than the gray value of the color of the second sputtered metal layer 1212. For example, the first sputtered metal layer 1211 can be set to silver, and the second sputtered metal layer 1212 can be set to nickel. Then, the metal surface of silver can form a distinct color contrast with the dark first film layer 110, improving the clarity of the identification code.

[0066] Based on the above embodiments, the thickness range of the first film layer is 0.5 - 40 μm, the thickness range of the metal layer is 0.05 - 10 μm, and the thickness range of the adhesive layer is 1 - 30 μm.

[0067] Among them, the thickness range of the metal layer is 0.05 - 10 μm, that is, the total thickness range of the superposition of the first metal layer 120 and the second metal layer 130 can be 0.05 - 10 μm.

[0068] Based on the above embodiments, the side of the metal layer away from the first film layer is roughened to form a plurality of convex structures.

[0069] In this embodiment, the convex structures enhance the bonding force and adhesiveness between the metal layer 120 and the adhesive layer 130, and further realize the function of preventing the board from bursting. Specifically, when this film is laminated on the shielding film of the circuit board,

[0070] The overflow glue that can push up the convex structure is extruded to the concave part of the metal layer, increasing the glue capacity between the metal layer and the printed circuit board and avoiding the peeling between the film and the printed circuit board. Due to the setting of the convex structure, when the film is pressed against the circuit board, the glue at the convex part can be extruded into the concave part, thereby increasing the glue capacity and avoiding the occurrence of the phenomenon of board explosion.

[0071] Based on the above embodiments, the roughness range of the surface of the metal layer away from the first film layer is 0.5 - 30 μm.

[0072] Optionally, the material for micro-roughening treatment between the metal layer 120 and the glue layer 130 can be copper. An embodiment of the present invention provides a film, which can be applicable to setting identification codes for various components integrated inside electronic products. Continuing to refer to Figure 2 , the specific structure of the film includes:

[0073] A first film layer 110;

[0074] A metal layer 120 located on one side of the first film layer 110;

[0075] A glue layer provided on the side of the metal layer 120 away from the first film layer 110;

[0076] Among them, the gray value of the color of the first film layer 110 is less than the gray value of the color of the metal layer 120, and the first film layer 110 forms a hollowed-out pattern for the identification code.

[0077] Among them, the identification code formed by the first film layer 110 can increase the recognition rate of the identification code through the obvious contrast of light and dark brightness between the first film layer 110 and the metal layer 120.

[0078] Specifically, the metal layer 120 is provided on one side of the first film layer 110, and a hollowed-out pattern for the identification code is formed on the first film layer 110. Through the metal layer 120, a strong color difference contrast can be generated with the gray value of the first film layer 110, thereby making the identification code have a better recognition rate.

[0079] Optionally, the above hollowed-out pattern can be formed by laser ablation.

[0080] It should be noted that when ablating the above hollowed-out pattern, there are two situations:

[0081] The first one is that only the first film layer 110 is burned through to form a hollowed-out pattern for the identification code, and the metal layer 120 is not ablated. That is, the ablation depth of the hollowed-out pattern is the thickness of the first film layer 110. Then the hollowed-out pattern just exposes the unablated metal layer 120, that is, the first film layer 110 and the metal layer 120 form the identification code.

[0082] Second, while forming the hollowed-out pattern of the identification code by burning through the first film layer 110, a part of the metal layer 120 is also ablated, that is, the metal layer 120 is partially ablated without being completely ablated. Therefore, after the ablation of the identification code is completed, the hollowed-out pattern can also expose the metal layer 120, so that the first film layer 110 and the metal layer 120 form the identification code. Specifically, the first film layer 110 is burned through to form a hollowed-out pattern, and a groove pattern (not marked in the figure) is formed on the side of the metal layer 120 close to the first film layer 110. The vertical projection of the hollowed-out pattern on the plane where the metal layer 120 is located completely coincides with the groove pattern. The side of the metal layer 120 close to the first film layer 110 is ablated to form a groove pattern, and because the above groove pattern and the hollowed-out pattern are formed through one process, the vertical projection of the hollowed-out pattern on the plane where the metal layer 120 is located completely coincides with the groove pattern.

[0083] The identification code is a unique corresponding identification mark for identifying components or electronic products. The identification code can include character graphics such as numbers and letters, and can also be a bar code or a two-dimensional code. The film in this embodiment can include at least one of the above bar codes, two-dimensional codes, and characters to identify the corresponding components or electronic products.

[0084] It can be understood that the film provided in this embodiment can be used to set the identification code to better trace the electronic product corresponding to the identification code or a certain component inside the electronic product. This film can be used together with the shielding film and is arranged on the circuit board. This film can be directly attached to the shielding film or the component through an adhesive layer. Further, the circuit board is arranged in the corresponding electronic device, and the electronic device can include electronic products such as mobile phones and computers. This embodiment does not make special limitations on this.

[0085] On the basis of the above embodiment, the thickness of the first film layer is H1, the thickness of the identification code is h, and the thickness of the metal layer is H2, where H1 ≤ h < H2.

[0086] On the basis of the above embodiment, the embodiment of the present invention also provides a circuit board, as Figure 5 shown, Figure 5 is a schematic structural diagram of a circuit board provided by the embodiment of the present invention. The circuit board includes a circuit board body 2, a shielding film 3, and the film 1 provided in any one of the embodiments of the present invention; and the shielding film 3 is arranged on the circuit board body 2, and the film 1 is arranged on the shielding film 3. The circuit board in this embodiment includes the technical features of the film provided in any embodiment of the present invention and has the beneficial effects of the film provided in any embodiment of the present invention.

[0087] The circuit board body 2 integrates a large number of components with different functions. In this embodiment, the identification codes of the components can be set at the positions corresponding to the components on the film 1. The shielding film 3 can cover the above-mentioned circuit board body 2 entirely to achieve overall electromagnetic shielding. The shielding film 3 can also include multiple sub-shielding films with smaller sizes, and each sub-shielding film is used to cover the corresponding area of the printed circuit board. This embodiment does not limit this. In addition, the shielding film 3 can be attached to the circuit board first, and then the film 1 provided in the above embodiment can be attached. Exemplarily, the identification code corresponding to the electronic device formed on the film 1 can be set in the edge area of the shielding film 3.

[0088] It can be understood that the embodiments of the present invention also provide an electronic device, which includes a circuit board provided in the above embodiments. The electronic devices provided in the embodiments of the present invention can be computers, televisions, smart wearable devices, etc. The embodiments of the present invention do not make special limitations on this.

[0089] On the basis of the above embodiments, the embodiments of the present invention also provide a circuit board, as Figure 6 shown, Figure 6 is a schematic structural diagram of a circuit board provided by an embodiment of the present invention. The circuit board includes a circuit board body 2 and the film 1 described in any one of the embodiments of the present invention. The film 1 is attached to the circuit board body 2 through the adhesive layer. The circuit board in this embodiment includes the technical features of the film provided in any embodiment of the present invention and has the beneficial effects of the film provided in any embodiment of the present invention.

[0090] The circuit board body 2 integrates a large number of components with different functions. In this embodiment, the identification codes of the components can be set at the positions corresponding to the components on the film 1.

[0091] It can be understood that the embodiments of the present invention also provide an electronic device, which includes a circuit board provided in the above embodiments. The electronic devices provided in the embodiments of the present invention can be computers, televisions, smart wearable devices, etc. The embodiments of the present invention do not make special limitations on this.

[0092] Note that the above is only the preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described here. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, it can also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A membrane, characterized in that, include: The first film layer; a metal layer located on one side of the first film layer; Adhesive layer; Disposed on a side of the metal layer away from the first film layer; Wherein, the gray value of the color of the first film layer is smaller than the gray value of the color of the metal layer, and the first film layer forms a hollow pattern of the identification code; The metal layer includes a first metal layer and a second metal layer; The first metal layer is disposed on a side close to the first film layer; the second metal layer is disposed on a side of the first metal layer away from the first film layer; The first metal layer includes a first sputtered metal layer and a second sputtered metal layer; the first sputtered metal layer is arranged on a side close to the first film layer; The second sputtered metal layer is disposed on a side of the first sputtered metal layer away from the first film layer.

2. The membrane according to claim 1, wherein The material of the first metal layer is at least one element selected from the group consisting of nickel, silver, platinum, gold, titanium, aluminum, cobalt and chromium; or, the material of the first metal layer is an alloy formed by at least two of nickel, silver, platinum, gold, titanium, aluminum, cobalt and chromium; the material of the second metal layer is at least one element selected from the group consisting of nickel, silver, platinum, aluminum, titanium, aluminum, cobalt and chromium; or, the material of the second metal layer is an alloy formed by at least two of nickel, silver, platinum, aluminum, titanium, aluminum, cobalt and chromium; or, the material of the second metal layer is a combination of alloys formed by at least two of nickel, silver, platinum, aluminum, titanium, aluminum, cobalt and chromium.

3. The membrane according to claim 2, characterized in that, The thickness of the first film layer is in the range of 0.5-40 μm, the thickness of the metal layer is in the range of 0.05-10 μm, and the thickness of the adhesive layer is in the range of 1-30 μm.

4. The membrane according to claim 1, wherein A side of the metal layer away from the first film layer is roughened to form a plurality of protrusion structures.

5. The membrane according to claim 1 or 4, characterized in that, The roughness of the surface of the metal layer away from the first film layer is in the range of 0.5-30 μm.

6. The membrane according to claim 1, wherein A difference between a grayscale value of a color of the first film layer and a grayscale value of a color of the metal layer is less than or equal to a first grayscale threshold, and the first grayscale threshold is greater than or equal to 10.

7. The membrane according to claim 6, wherein, The first grayscale threshold is 50.

8. The membrane according to claim 6, wherein The first grayscale threshold is 100.

9. The film according to claim 1, characterized in that, A groove pattern is formed on one side of the metal layer close to the first film layer, and a vertical projection of the hollow pattern on the plane where the metal layer is located completely overlaps with the groove pattern.

10. A circuit board, characterized in that, It comprises a circuit board body, a shielding film and a film as described in any one of claims 1 to 9, wherein the shielding film is arranged on the circuit board body, and the film is arranged on the shielding film.

11. A circuit board, characterized in that, It comprises a circuit board body and the film as described in any one of claims 1 to 9, wherein the film is adhered to the circuit board body through the adhesive layer.

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