Double-sided readable-writable NFC (Near Field Communication) card with metal texture and manufacturing method thereof

Abstract

The invention belongs to the technical field of NFC chip structures, and particularly relates to a double-sided readable-writable NFC card with metal texture, which comprises an NFC main body and a decorative layer, and is characterized in that the NFC main body is configured to be a complete radio frequency circuit formed by welding a basic radio frequency antenna and a metal extension antenna, the basic radio frequency antenna is located in a placement groove formed in the metal extension antenna, an induction coil, a capacitor module and a chip module are configured on the basic radio frequency antenna, and the metal extension antenna is configured to be a series integration of a plurality of coils formed by a plurality of layers of gullies surrounding the center of the metal extension antenna. The multiple layers of gullies are filled with insulators, the two faces of the NFC main body are of plane structures after filling, and the decoration layers are attached to the two faces of the NFC main body. In practical application, the NFC card has the weight of a metal card, and meanwhile, the read-write distance and normal use of the card are not influenced. Meanwhile, the invention further discloses a manufacturing method of the NFC card.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of NFC card structure, and particularly relates to a double-sided readable and writable NFC card with metal texture and a manufacturing method thereof. BACKGROUND

[0002] Near Field Communication (NFC) is a technology that enables devices (such as mobile phones) to exchange data when brought into close proximity. It is derived from the integration and evolution of contactless RF identification and interconnection technologies. By integrating inductive card readers, inductive cards, and point-to-point communication functions on a single chip, mobile terminals can be used for mobile payments, electronic ticketing, access control, mobile identity recognition, anti-counterfeiting, and other applications. The matching degree between the material selection and the function implementation of such cards has always been a key consideration for industry designers. Currently, the base materials of such cards are mostly non-metallic materials. These materials are easy to process and form, have controllable costs, are light in weight, and are not prone to rust, thus meeting the basic structural support and daily use requirements of the cards, and have become the main choice in the industry.

[0003] As users' requirements for card function use experience and appearance texture continue to improve, the existing non-metallic material cards gradually show two key technical problems. In terms of functional performance, if the structural strength, wear resistance, or appearance grade of the card is to be improved, using metal materials as the base material or surface decoration layer of the card will encounter serious radio frequency signal interference problems, and in actual use, the card often needs to be tightly attached to the surface of the read-write device to complete the identification. Sometimes, even multiple attempts cannot successfully read or write data, which seriously affects the convenience of user use.

[0004] In terms of texture, the existing cards that generally use non-metallic materials are light in weight, resulting in a virtual touch and a lack of sufficient stability and feedback when holding, which affects the long-term hand feel experience. This texture is difficult to meet the aesthetic needs of some users for high-end cards. With the continuous advancement of the consumption upgrading trend, users pay more and more attention to the texture of cards as daily carrying items while focusing on the practicality of card functions. There is an urgent need for a solution to solve the above problems. SUMMARY

[0005] One of the purposes of the present application is to provide a double-sided readable and writable NFC card with metal texture to address the deficiencies of the prior art. In actual application, the card has the weight of a metal card while not affecting the read-write distance and normal use of the card.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] A double-sided readable and writable NFC card with a metallic texture includes an NFC body and a decorative layer. The NFC body is configured as a complete radio frequency circuit consisting of a base radio frequency antenna and a metal extension antenna welded together. The base radio frequency antenna is located in a placement groove opened in the metal extension antenna. An induction coil, a capacitor module, and a chip module are disposed on the base radio frequency antenna. The metal extension antenna is configured as a series integration of multiple coils formed by multiple layers of trenches around its center. Each of the multiple trenches is filled with an insulator, and both sides of the filled NFC body are set as planar structures. The decorative layer is attached to both sides of the NFC body.

[0008] As an improvement to the metallic double-sided readable and writable NFC card described in this application, the placement groove is offset from the groove and is located at the center of the inner circle formed by multiple layers of the groove. The basic radio frequency antenna is fixedly attached to the placement groove by double-sided adhesive, and the decorative layer is attached to the NFC body by the first adhesive layer.

[0009] As an improvement to the metallic double-sided readable and writable NFC card described in this application, the basic radio frequency antenna includes a radio frequency body and soldering points extending from the radio frequency body to both sides. The soldering points are used to solder to the metal extension antenna. The capacitor module and the chip module are located on the radio frequency body.

[0010] As an improvement to the metallic double-sided readable and writable NFC card described in this application, the inner wall of the groove has a protrusion, the insulator has a reinforcing groove that matches the protrusion, and / or, the inner wall of the groove is provided with a reinforcing groove, and the insulator extends with a protrusion that matches the reinforcing groove.

[0011] As an improvement to the metallic double-sided readable and writable NFC card described in this application, the NFC body further includes a first adhesive film layer, which covers both sides of the metal extension antenna and is in contact with the first adhesive layer.

[0012] As an improvement to the metallic double-sided readable and writable NFC card described in this application, the decorative layer includes a protective layer, a transparent base layer, an optical processing layer, and a first adhesive layer stacked sequentially from the direction away from the NFC body to the direction closer to the NFC body. The transparent base layer has an ink pattern on the side away from the protective layer, and the ink pattern has a metallic texture through the optical processing layer. The optical processing layer includes a stacked texture layer and an electroplating layer, and the texture layer is disposed close to the transparent base layer.

[0013] As an improvement to the metallic double-sided readable and writable NFC card described in this application, the optical process layer further includes a second adhesive film layer, which is disposed on the side of the electroplated layer away from the texture layer. A second adhesive layer is disposed between the optical process layer and the transparent base layer, and the second adhesive layer is disposed close to the texture layer.

[0014] As an improvement to the metallic double-sided readable and writable NFC card described in this application, the decorative layer is configured as a fabric structure.

[0015] As an improvement to the metallic double-sided readable and writable NFC card described in this application, the decorative layer includes a coating and a pattern layer disposed on the surface of the coating, wherein the pattern layer is configured as a thermal transfer film structure.

[0016] The second objective of this application is to provide a method for manufacturing a double-sided readable and writable NFC card with a metallic texture as described above, comprising the following steps:

[0017] Step 1: Use laser cutting and etching to create grooves and placement slots on the metal sheet to form a metal extension antenna;

[0018] Step 2: Match and install the induction coil, capacitor module, and chip module onto the basic radio frequency antenna;

[0019] Step 3: The basic radio frequency antenna is installed in the placement groove and welded to the metal extension antenna to form a complete radio frequency circuit, thus forming the NFC main body;

[0020] Step 4: The trenches of the metal extension antenna are filled with an insulator, and the front and back of the NFC body are processed into a planar structure using a grinding and polishing process.

[0021] Step 5: Apply the decorative layer to both sides of the NFC body using hot pressing or rolling.

[0022] As an improvement to the method for manufacturing a double-sided readable and writable NFC card with a metallic texture as described in this application, step five, the crushing method includes the following steps:

[0023] Step 6: Apply glue to both sides of the NFC body and place the decorative layer on the NFC body;

[0024] Step 7: After rolling the semi-finished product from Step 6, put it into an oven to dry and obtain the finished product.

[0025] The beneficial effects of this application are as follows: In actual use, the NFC card of this application is equipped with a layered structure and a metal extension antenna of the same size as the decorative layer. That is, a large-area metal sheet is used as a combination of radio frequency antenna and basic radio frequency antenna, which enables the NFC card of this application to have sufficient stability and feedback when held, improve the tactile experience of long-term use, and make its card swiping distance comparable to that of non-metallic NFC cards, without affecting the normal use of double-sided reading and writing function; In addition, the structure of the groove in the metal extension antenna filled with insulator in this application enables the NFC body to have a planar structure on both sides, which facilitates the hot pressing of the decorative layer and does not affect the overall visual effect of the NFC card. Attached Figure Description

[0026] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0027] Figure 1 This is a structural schematic diagram of Embodiment 1 of this application.

[0028] Figure 2 This is an exploded view of the NFC subject in Embodiment 1 of this application.

[0029] Figure 3 This is an exploded view of the NFC subject in Embodiment 2 of this application.

[0030] Figure 4 This is a schematic diagram of the structure of the decorative layer in Embodiment 1 of this application.

[0031] Figure 5 This is a schematic diagram of the structure of the decorative layer in Embodiment 3 of this application.

[0032] Figure 6 This is a schematic diagram of the structure of the decorative layer in Embodiment 4 of this application.

[0033] The reference numerals in the attached figures are explained as follows:

[0034] 1. NFC main body; 11. Basic RF antenna; 111. RF main body; 112. Soldering point; 12. Metal extension antenna; 121. Placement groove; 122. Trench; 123. Insulator; 13. Capacitor module; 14. Chip module; 15. Double-sided adhesive; 16. First adhesive film layer; 17. Induction coil;

[0035] 2. Decorative layer; 21. Protective layer; 22. Transparent base layer; 23. Optical processing layer; 231. Texture layer; 232. Electroplating layer; 233. Second adhesive film layer; 24. First adhesive layer; 25. Second adhesive layer; 26. Coating layer; 27. Pattern layer;

[0036] 31. Reinforced groove; 32. Protrusion. Detailed Implementation

[0037] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "including but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error. Furthermore, terms such as "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0038] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0040] The following is in conjunction with the appendix Figures 1-6 The present application will be further described in detail with reference to specific implementation methods, but this is not intended to limit the present application.

[0041] Implementation Method 1

[0042] The following is in conjunction with the appendix Figure 1 , 2 Description of Implementation Method 1 (section 4)

[0043] A double-sided readable and writable NFC card with a metallic texture includes an NFC body 1 and a decorative layer 2. The NFC body 1 is configured as a complete radio frequency circuit formed by welding a basic radio frequency antenna 11 and a metal extension antenna 12. The basic radio frequency antenna 11 is located in a placement groove 121 opened in the metal extension antenna 12. An induction coil 17, a capacitor module 13 and a chip module 14 are arranged on the basic radio frequency antenna 11. The metal extension antenna 12 is configured as a series integration of multiple coils formed by multiple layers of trenches 122 around its center. Each of the multiple trenches 122 is filled with an insulator 123 and both sides of the filled NFC body 1 are set as planar structures. The decorative layer 2 is attached to both sides of the NFC body 1 through a first adhesive layer 24.

[0044] In this embodiment, a large area of ​​metal sheet material is divided into a series of coils through laser cutting and etching processes, up to the outermost coil, to obtain a metal extension antenna 12. This increases the sensing area, and the outermost coil is also part of the coil, ensuring that the metal extension antenna 12 in this embodiment does not generate additional interference to electromagnetic waves. In actual use, the chip module 14 and capacitor module 13 are bonded to the basic RF antenna 11 using an inverted welding method, and then glued to the metal extension antenna 12 with double-sided adhesive 15. A complete RF circuit is formed by welding, and then the decorative layer 2 is hot-pressed to obtain the NFC card in this embodiment. The inductance is adjusted by adjusting the number of turns of the sensing coil 17 on the basic RF antenna 11 according to the specific application. In conjunction with the capacitor module 13, the inductive reactance is adjusted to be equal to or close to the capacitive reactance, minimizing the reflection back to the source. By optimizing the reading distance, the normal use of the double-sided reading and writing function of the NFC card is ensured, achieving a swiping distance comparable to that of non-metallic NFC cards, thus improving the user's swiping experience. Simultaneously, the weight of the NFC card exceeds 16g, providing sufficient stability and tactile feedback when held, enhancing the long-term tactile experience. Furthermore, the structure of the grooves 122 in the metal extension antenna 12 filled with an insulator 123 allows the NFC body 1 to have a planar structure on both sides, facilitating the hot-pressing bonding of the decorative layer 2 and preventing bending of the NFC body 1, which could leave bending marks on the decorative layer 2 after bonding. It should be noted that the NFC card is relatively thin, and the bending angle of the NFC body 1 is small, which could significantly impact the overall aesthetics. This technical solution avoids these issues, thus preserving the overall visual appeal of the NFC card.

[0045] Specifically, the placement groove 121 is staggered from the trench 122 and is located at the center of the inner circle formed by the multiple trenches 122. The basic radio frequency antenna 11 is fixedly attached to the placement groove 121 by double-sided adhesive 15. The basic radio frequency antenna 11 includes a radio frequency body 111 and welding points 112 extending from the radio frequency body 111 to both sides. The welding points 112 are used for welding with the metal extension antenna 12. The capacitor module 13 and the chip module 14 are located on the radio frequency body 111. The capacitor module 13 and the chip module 14 are invertedly welded to the radio frequency body 111. The inverted welding can further reduce the thickness of the NFC body. The placement groove 121 can ensure the flatness of the NFC body 1, facilitate the welding of the basic radio frequency antenna 11 and the metal extension antenna 12 and the subsequent bonding of the decorative layer 2, and ensure the overall aesthetics of the NFC card.

[0046] Specifically, the inner wall of the groove 122 has a protrusion 32, and the insulator 123 has a reinforcing groove 31 that matches the protrusion 32. Alternatively, the inner wall of the groove 122 has a reinforcing groove 31, and the insulator 123 extends with a protrusion 32 that matches the reinforcing groove 31. The groove 122 is filled with the insulator 123 to ensure the flatness of the NFC body 1. In this embodiment, the height of the basic radio frequency antenna 11 is less than the depth of the placement groove 121. Therefore, to ensure flatness, the insulator 123 is also filled within the placement groove 121. The inner wall of the groove 122 has a protrusion 32, and the insulator 123 has a reinforcing groove 31 that matches the protrusion 32. It is understood that in other technical solutions, the following can also be used: the inner wall of the groove 122 has a reinforcing groove 31, and the insulator 123 extends with a protrusion 32 that matches the reinforcing groove 31. The matching protrusion 32 and the reinforcing groove 31 can increase the robustness of the NFC body 1.

[0047] In this embodiment, the insulator 123 is formed by filling the metal extension antenna 12 with the base radio frequency antenna 11 installed by processes such as dispensing, potting or injection molding, and then using a grinding and polishing process to make the front and back surfaces flat to ensure flatness.

[0048] Specifically, the NFC body 1 also includes a first adhesive film layer 16, which covers both sides of the metal extension antenna 12 and is in contact with the first adhesive layer 24. The first adhesive film layer 16 is made of a material of the same type or similar properties as the decorative layer 2, which can achieve a strong bonding force during the subsequent hot pressing process of the decorative layer 2, thereby improving the overall firmness of the NFC card.

[0049] Specifically, the decorative layer 2 includes a protective layer 21, a transparent base layer 22, an optical process layer 23, a first adhesive layer 24, and a second adhesive film layer 233, which are stacked sequentially from the direction away from the NFC subject 1 to the direction closer to the NFC subject 1. The second adhesive film layer 233 is disposed on the side of the electroplated layer 232 away from the texture layer 231. A second adhesive layer 25 is disposed between the optical process layer 23 and the transparent base layer 22, and the second adhesive layer 25 is disposed close to the texture layer 231. The protective layer 21 adopts an anti-fingerprint coating process, which utilizes chemical materials with extremely low surface energy. This material gives the protective layer 21 extremely strong water-repellent and oil-repellent properties, which can better protect the NFC card and provide a longer service life. The optical process layer 23 includes a stacked texture layer 231 and an electroplated layer 232. The texture layer 231 is disposed close to the transparent base layer 22. The side of the transparent base layer 22 away from the protective layer 21 is provided with an ink pattern, and the ink pattern has a metallic texture through the optical process layer 23. The electroplated layer 232 includes multiple transparent thin film materials with different refractive indices, which achieve a metallic texture by utilizing the principle of light interference.

[0050] Implementation Method 2

[0051] like Figure 3 As shown, in this embodiment, the first adhesive film layer 16 is not included in the NFC body 1, which is mainly determined by the different manufacturing methods.

[0052] The other structures are the same as in Implementation Method 1, and will not be described again here.

[0053] Implementation Method 3

[0054] like Figure 5 As shown, in this embodiment, the decorative layer 2 is set as a fabric structure, which can bring different tactile experiences to users and increase the diversity of NFC card faces to meet the needs of different users.

[0055] The other structures are the same as in Implementation Method 1 or Implementation Method 2, and will not be described again here.

[0056] Implementation Method 4

[0057] like Figure 6 As shown, in this embodiment, the decorative layer 2 includes a coating layer 26 and a pattern layer 27 disposed on the surface of the coating layer 26. The pattern layer 27 is configured as a heat transfer film structure. In practical applications, this embodiment uses a heat transfer process to transfer the pattern onto the coating layer 26 to form the pattern layer 27. The pattern of the pattern layer 27 can be customized according to the actual situation to increase aesthetics.

[0058] The other structures are the same as in Implementation Method 1 or Implementation Method 2, and will not be described again here.

[0059] Implementation Method 5

[0060] A method for manufacturing a double-sided readable and writable NFC card with a metallic texture, as described in any one of embodiments one, three, or four, includes the following steps:

[0061] Step 1: Use laser cutting and etching to create grooves 122 and placement recesses 121 on the metal sheet to form a metal extension antenna 12;

[0062] Step 2: Install the induction coil 17, capacitor module 13 and chip module 14 onto the base RF antenna 11.

[0063] Step 3: The basic radio frequency antenna 11 is installed in the placement groove 121 and welded to the metal extension antenna 12 to form a complete radio frequency circuit, forming the NFC main body 1;

[0064] Step 4: Fill the grooves 122 of the metal extension antenna 12 with insulator 123, and use a grinding and polishing process to process the front and back of the NFC body 1 into a planar structure.

[0065] Step 5: Apply the decorative layer 2 to both sides of the NFC body 1 using a hot-pressing method.

[0066] Implementation Method Six

[0067] A method for manufacturing a double-sided readable and writable NFC card with a metallic texture, as described in any of embodiments two, three, and four, includes the following steps:

[0068] Step 1: Use laser cutting and etching to create grooves 122 and placement recesses 121 on the metal sheet to form a metal extension antenna 12;

[0069] Step 2: Install the induction coil 17, capacitor module 13 and chip module 14 onto the base RF antenna 11.

[0070] Step 3: The basic radio frequency antenna 11 is installed in the placement groove 121 and welded to the metal extension antenna 12 to form a complete radio frequency circuit, forming the NFC main body 1;

[0071] Step 4: Fill the grooves 122 of the metal extension antenna 12 with insulator 123, and use a grinding and polishing process to process the front and back of the NFC body 1 into a planar structure.

[0072] Step 5: Apply the decorative layer 2 to both sides of the NFC body 1 by rolling.

[0073] The compaction method in step five includes the following steps:

[0074] Step 6: Apply glue to both sides of the NFC body 1, and place the decorative layer 2 on the NFC body 1;

[0075] Step 7: After rolling the semi-finished product from Step 6, place it in an oven to dry and obtain the finished product. Rolling can remove the air between the NFC body 1 and the decorative layer 2 in the semi-finished product, further ensuring the surface flatness of the finished NFC card and the adhesion between the NFC body 1 and the decorative layer 2.

[0076] In this embodiment, the metal sheet is divided into coils connected in series until the outermost metal extension antenna 12 is welded to the basic radio frequency antenna 11, all of which become part of the coil. This avoids additional electromagnetic interference from the metal, allowing the NFC card in this embodiment to have the weight of metal while maintaining the same swiping distance as non-metallic NFC cards, without affecting the normal use of the double-sided read / write function. In addition, the structure of filling the grooves 122 in the metal extension antenna 12 with an insulator 123 makes the two sides of the NFC body 1 planar, which facilitates the hot-pressing of the decorative layer 2 and avoids bending of the NFC body 1, which would leave bending marks after the decorative layer 2 is bonded. It is understood that the hot-pressing method is existing technology and will not be described in detail here. It should be noted that the NFC card is relatively thin, and the bending angle of the NFC body 1 is relatively small, which can still have a significant impact on the overall aesthetics. This technical solution avoids the above situation and thus does not affect the overall visual effect of the NFC card.

[0077] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0078] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this application is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on this application are within the scope of protection of this application. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this application.

Claims

1. A double-sided readable and writable NFC card with a metallic texture, characterized in that, The NFC body (1) includes an NFC main body (1) and a decorative layer (2). The NFC main body (1) is configured as a complete radio frequency circuit formed by welding a basic radio frequency antenna (11) and a metal extension antenna (12). The basic radio frequency antenna (11) is located in a placement groove (121) opened in the metal extension antenna (12). The basic radio frequency antenna (11) is equipped with an induction coil (17), a capacitor module (13) and a chip module (14). The metal extension antenna (12) is configured as a series integration of multiple coils formed by multiple trenches (122) around its center. Each of the multiple trenches (122) is filled with an insulator (123), and both sides of the filled NFC main body (1) are set as planar structures. The decorative layer (2) is attached to both sides of the NFC main body (1).

2. A double-sided readable and writable NFC card with a metallic texture as described in claim 1, characterized in that, The placement groove (121) is offset from the groove (122) and is located at the center of the inner circle formed by the multiple layers of the groove (122). The basic radio frequency antenna (11) is fixedly attached to the placement groove (121) by double-sided adhesive (15). The decorative layer (2) is attached to the NFC body (1) by the first adhesive layer (24).

3. A double-sided readable and writable NFC card with a metallic texture as described in claim 1, characterized in that, The basic radio frequency antenna (11) includes a radio frequency body (111) and welding points (112) extending from the radio frequency body (111) to both sides. The welding points (112) are used to weld to the metal extension antenna (12). The capacitor module (13) and the chip module (14) are located on the radio frequency body (111).

4. A double-sided readable and writable NFC card with a metallic texture as described in claim 1, characterized in that, The inner wall of the groove (122) has a protrusion (32), the insulator (123) has a reinforcing groove (31) that matches the protrusion (32), and / or, the inner wall of the groove (122) is provided with a reinforcing groove (31), and the insulator (123) extends with a protrusion (32) that matches the reinforcing groove (31).

5. A double-sided readable and writable NFC card with a metallic texture as described in claim 1, characterized in that, The decorative layer (2) includes a protective layer (21), a transparent base layer (22), an optical process layer (23), and a first adhesive layer (24) stacked sequentially from the direction away from the NFC body (1) to the direction close to the NFC body (1). The transparent base layer (22) has an ink pattern on the side away from the protective layer (21), and the ink pattern has a metallic texture through the optical process layer (23). The optical process layer (23) includes a texture layer (231) and an electroplating layer (232) stacked together. The texture layer (231) is disposed close to the transparent base layer (22).

6. A double-sided readable and writable NFC card with a metallic texture as described in claim 5, characterized in that, The optical process layer (23) further includes a second adhesive film layer (233), which is disposed on the side of the electroplated layer (232) away from the texture layer (231). A second adhesive layer (25) is provided between the optical process layer (23) and the transparent base layer (22), which is disposed close to the texture layer (231).

7. A double-sided readable and writable NFC card with a metallic texture as described in claim 1, characterized in that, The decorative layer (2) is configured as a fabric structure.

8. A double-sided readable and writable NFC card with a metallic texture as described in claim 1, characterized in that, The decorative layer (2) includes a coating (26) and a pattern layer (27) disposed on the surface of the coating (26), wherein the pattern layer (27) is configured as a heat transfer film structure.

9. A method for manufacturing a double-sided readable and writable NFC card with a metallic texture as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Use laser cutting and etching to create grooves (122) and placement slots (121) on the metal sheet to form a metal extension antenna (12). Step 2: Match and install the induction coil (17), capacitor module (13) and chip module (14) onto the basic radio frequency antenna (11). Step 3: The basic radio frequency antenna (11) is installed in the placement groove (121) and welded with the metal extension antenna (12) to form a complete radio frequency circuit, forming the NFC body (1). Step 4: The trenches (122) of the metal extension antenna (12) are filled with an insulator (123), and the front and back sides of the NFC body (1) are processed into a planar structure using a grinding and polishing process; Step 5: Apply the decorative layer (2) to both sides of the NFC body (1) by hot pressing or rolling.

10. The method for manufacturing a double-sided readable and writable NFC card with a metallic texture as described in claim 9, characterized in that, In step five, the compaction method includes the following steps: Step 6: Apply glue to both sides of the NFC body (1) and place the decorative layer (2) on the NFC body (1); Step 7: After rolling the semi-finished product from Step 6, put it into an oven to dry and obtain the finished product.

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