Rfid / nfc device and method of manufacturing the same

Abstract

The application discloses an RFID / NFC device and a preparation method thereof. The preparation method of the RFID / NFC device comprises the following steps: providing a ferrite base material; adhering the ferrite base material and a film base material for bearing a wire to form a composite base material; implanting the wire into the surface of the composite base material in an ultrasonic winding mode by using an outer layer winding needle tube to form a coil on a bonding device with a bimodal ultrasonic tool head; after the winding is completed, performing low-temperature transient welding on the end point of the wire by using an inner core micro-welding electrode at the coaxial position of the bimodal ultrasonic tool head; performing electrical performance detection on the coil and the welding spot, and completing subsequent processing according to the detection result, so as to form the RFID / NFC device. The embodiment of the application can reduce the process complexity of preparing the RFID / NFC device.

Description

Technical Field

[0001] This application relates to the fields of radio frequency identification and near field communication technology, specifically to an RFID / NFC device and its fabrication method. Background Technology

[0002] RFID (Radio Frequency Identification) and NFC (Near Field Communication) devices are widely used in smart cards, electronic tags, IoT identification, and payment terminals. The core components of these devices typically consist of a planar antenna coil and an RF chip (IC). The antenna's shape, number of turns, wire diameter, and the environment (especially metallic environments) directly affect the device's read / write performance, coupling efficiency, and operating distance. To obtain the required electromagnetic performance and meet the requirements of flexible, thin, and low-cost products, flexible printed circuits (FPCs) or printed copper foil are traditionally used to fabricate the antenna structure, followed by bonding, soldering, and packaging processes to complete the finished product manufacturing.

[0003] Existing RFID / NFC antenna device manufacturing processes mostly employ flexible printed circuits or wire-wound and then glued assembly. These traditional processes typically involve multiple discrete steps, including patterning (such as electroplating, etching, or screen printing), lamination, die-cutting, aligning and gluing the antenna to the ferrite sheet / magnetic substrate, soldering the leads / pads, and final packaging, resulting in high process complexity. Summary of the Invention

[0004] This application provides an RFID / NFC device and a method for fabricating the same, which can reduce the complexity of the fabrication process for RFID / NFC devices.

[0005] In a first aspect, embodiments of this application provide a method for fabricating an RFID / NFC device, comprising:

[0006] Provide a ferrite substrate;

[0007] The ferrite substrate is bonded to a thin film substrate for carrying the conductor to form a composite substrate;

[0008] In a bonding device with a dual-mode ultrasonic tool head, a wire is implanted into the surface of the composite substrate to form a coil by ultrasonic winding using an outer winding needle tube.

[0009] After the winding is completed, the ends of the wire are subjected to low-temperature instantaneous welding using the inner core micro-welding electrode at the coaxial position of the dual-modal ultrasonic tool head.

[0010] The coil and solder joints are subjected to electrical performance testing, and subsequent processing is completed based on the test results to form an RFID / NFC device.

[0011] In the method for fabricating the RFID / NFC device provided in the embodiments of this application, the operating frequency of the outer winding needle tube is 20kHz-40kHz, and the amplitude is 2μm-10μm.

[0012] In the method for fabricating RFID / NFC devices provided in the embodiments of this application, the operating frequency of the inner core micro-welding electrode is 50kHz-80kHz, and the amplitude is 1μm-5μm.

[0013] In the method for preparing RFID / NFC devices provided in the embodiments of this application, the solder used for the low-temperature instantaneous welding is an alloy with a melting point in the range of 100℃-130℃.

[0014] In the method for fabricating RFID / NFC devices provided in this application embodiment, the welding time of the low-temperature instantaneous welding is ≤300ms.

[0015] In the method for preparing the RFID / NFC device provided in the embodiments of this application, the material of the thin film substrate is one or more of PET, PVC or PC.

[0016] In the method for fabricating RFID / NFC devices provided in the embodiments of this application, the conductors used are enameled copper wires or fine metal wires.

[0017] In the method for fabricating RFID / NFC devices provided in the embodiments of this application, the wire diameter is 20μm-200μm.

[0018] In the method for fabricating RFID / NFC devices provided in the embodiments of this application, the end of the outer winding needle tube is provided with a V-shaped guide groove or a recessed structure.

[0019] Secondly, embodiments of this application provide an RFID / NFC device, which is manufactured using the RFID / NFC device fabrication method described in any of the above-mentioned embodiments.

[0020] In summary, this application provides a method for fabricating an RFID / NFC device, including providing a ferrite substrate; bonding the ferrite substrate with a thin film substrate for carrying wires to form a composite substrate; using an outer winding needle tube on a bonding device with a dual-mode ultrasonic tool head to ultrasonically wind wires into the surface of the composite substrate to form a coil; after winding, using the inner core micro-welding electrode at the coaxial position of the dual-mode ultrasonic tool head to perform low-temperature instantaneous welding on the endpoints of the wires; performing electrical performance testing on the coil and the solder joint, and completing subsequent processing based on the test results, thereby forming an RFID / NFC device. This application, by bonding a ferrite substrate and a thin film substrate to form a composite substrate, and using a dual-mode ultrasonic tool head to directly implant wires into the surface of the composite substrate and instantly complete low-temperature instantaneous welding, replaces the traditional multiple processes such as FPC fabrication, electroplating / etching, bonding, and independent welding, thereby reducing the process complexity of fabricating RFID / NFC devices. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart illustrating the fabrication method of the RFID / NFC device provided in this application.

[0023] Figure 2 This is a schematic diagram of the structure of the RFID / NFC device provided in the embodiments of this application.

[0024] Figure 3 yes Figure 2 A schematic diagram of the cross-sectional structure along the AA direction. Detailed Implementation

[0025] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0026] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0027] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0028] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.

[0029] The following describes in detail the embodiments involved in this application. It should be noted that the order of description of the embodiments in this application is not intended to limit the priority of the embodiments.

[0030] The technical solutions shown in this application will be described in detail below through specific embodiments. It should be noted that the order of description of the following embodiments is not intended to limit the priority of the embodiments.

[0031] Existing RFID / NFC antenna device manufacturing processes mostly employ flexible printed circuits or wire-wound and then glued assembly. These traditional processes typically involve multiple discrete steps, including patterning (such as electroplating, etching, or screen printing), lamination, die-cutting, aligning and bonding the antenna to the ferrite sheet / magnetic substrate, soldering the leads / pads, and final packaging. These processes not only involve numerous steps, large equipment requirements, and long production cycles, but some critical steps (such as electroplating and etching) also require the use of chemical agents and high-temperature / vacuum treatments, leading to increased material and environmental compliance costs, as well as increased process complexity and the risk of yield fluctuations.

[0032] Furthermore, the step-by-step bonding and welding process between the antenna and the magnetic substrate is prone to assembly problems such as positioning errors, incomplete soldering, or short circuits, especially in small-sized, high-density coils or ultra-thin products, which in turn affects read / write performance and product consistency. As application scenarios increasingly demand higher requirements for device thickness, read distance, reliability, and low-cost mass production, there is an urgent need for a new manufacturing method that can reduce processes, decrease reliance on chemical treatments, improve assembly accuracy, and accommodate large-scale production capabilities, in order to meet the market's demand for high-performance, low-cost, and environmentally friendly RFID / NFC devices.

[0033] Based on this, embodiments of this application provide an RFID / NFC device and a method for its fabrication. Please refer to... Figure 1 , Figure 1 This is a flowchart illustrating the fabrication method of the RFID / NFC device provided in this application. The specific process of the fabrication method of the RFID / NFC device is as follows:

[0034] 101. Provide a ferrite substrate.

[0035] The ferrite substrate can be a sheet or roll of ferrite material, with the thickness depending on the application (e.g., 0.1mm-1.0mm).

[0036] In practical implementation, ferrite substrates can be formed in the following ways:

[0037] 1. Ball Milling: Weigh the ferrite raw material (powder) and necessary additives according to the formula, and add them to a ball mill jar for wet or dry ball milling to ensure thorough and uniform dispersion of the powder. The ball milling should be controlled until the powder particle size distribution is within the range of approximately 0.5μm-1μm to facilitate subsequent molding and densification. To improve the flowability and moldability of the slurry, dispersants, binders, plasticizers, and other additives (such as organic dispersants and polymer binders) can be added to the ball-milled slurry as needed, and the solid content and viscosity of the slurry should be controlled to meet casting requirements. The ball milling time, speed, and media selection can be optimized based on the characteristics of the raw materials.

[0038] 2. Tapecasting: A slurry with appropriate rheological properties obtained from ball milling is uniformly coated onto a carrier tape or substrate using a tape casting machine (or a blade / groove tape casting device). The slurry thickness and coating uniformity are controlled by adjusting the roller spacing and flow rate. The dry film thickness can be set from tens to hundreds of micrometers (e.g., 50 μm-500 μm), depending on the ferrite layer thickness requirements of the final device. After tape casting, the film can be dried in a ventilated box or constant temperature oven to remove the solvent, resulting in a transportable thin film.

[0039] 3. Slitting: The cast and dried film is wound up in the correct direction to form a roll for subsequent continuous production, suitable for roll-to-roll production lines or for easy storage and transportation. During slitting, it is important to control tension and ensure adequate drying to avoid curling, wrinkling, or surface contamination.

[0040] 4. Slitting / Cutting: Depending on the needs of subsequent processes, the cast film roll or large sheet can be cut into sheets or strips of specified sizes for positioning and processing on die-cutting, laminating, or bonding equipment. The order, size, and shape of slitting and rolling can be determined according to the production line layout and production requirements (e.g., width, single roll length, single sheet size, etc.).

[0041] 5. Sintering: The dried and shaped sheets or rolls are placed in a sintering furnace with a suitable atmosphere for high-temperature sintering. This removes organic additives and promotes particle bonding and densification of ferrite particles, forming a dense ferrite wafer. The sintering temperature and holding time can be determined according to the ferrite formulation (such as Ni-Zn, Mn-Zn systems, etc.) and the required density. For example, it can be 800℃-1300℃, and the holding time can be selected within the range of 1-4 hours depending on the thickness and formulation. It should be noted that the sintered ferrite substrate is usually highly brittle and prone to breakage or chipping. Therefore, appropriate clamping, support, or carrier tape (plate) protection should be used during subsequent handling, cutting, and bonding processes to avoid damage to the finished product.

[0042] Although sintered ferrite blanks have high density, they are brittle and not suitable for direct winding or die-cutting. Therefore, they can be crushed after being coated with adhesive to form uniform crushed magnetic material, which is convenient for subsequent winding and die-cutting.

[0043] Specifically, the sintered ferrite sheet can be placed on the worktable of a gluing machine. First, peelable adhesive tape or film is applied to both sides of the ferrite sheet (the tape used should balance adhesion and tearability; for example, it can be a thin polyolefin tape or a special protective film, with adhesion selected according to process requirements to ensure that fragments are adhered to the tape and do not scatter in large quantities). After gluing, a rolling device equipped with X and Y directional motion and pressure rollers is used to repeatedly roll the glued ferrite sheet, causing it to break into smaller particles in multiple directions under controlled stress. The size and shape of the fragments can be controlled by adjusting the roller spacing, roller diameter, roller surface morphology, and number of rolling cycles. In some embodiments, to obtain uniform particles, cross-directional (X / Y) rolling, multi-stage rolling with different gaps, or a combination of grooved pressure rollers can be used. Preferably, the risk of large unbroken pieces and excessive dust generation can be reduced by gradually decreasing the roller gap and performing multiple rolling cycles. The fragmentation process should be carried out under local dust collection and protection devices to control dust and protect the safety of operators.

[0044] After being crushed by rolling and pre-screened or dust-removed, the crushed magnetic material, along with the adhesive carrier tape, can be rolled or dry-packaged using a winding device. For scenarios employing a roll-to-roll continuous process, the crushed particles can be wound into rolls at specific intervals or with a uniform distribution for use in subsequent processes (such as reforming or die-cutting). Tension and layup uniformity should be controlled during winding to prevent particle aggregation or shedding. The finished rolled product should be labeled with batch number, particle size distribution, and processing date, and dried or moisture-proofed as needed before being stored.

[0045] Finally, the wound or packaged ferrite material (or a composite layer pre-laminated with a carrier tape according to a predetermined shape) can be placed on a die-cutting mold or die-cutting machine. The material is then cut into the final required ferrite substrate according to the desired product shape through die-cutting, punching, or laser cutting. During die-cutting, the die clearance and punching parameters should be appropriately selected to reduce edge chipping and ensure dimensional accuracy. For brittle materials, composite die-cutting with a support layer is preferred (e.g., bonding the ferrite material with the thin film carrier tape before die-cutting) to reduce chipping loss and improve the edge quality of the finished product. After die-cutting, deburring, edge trimming, and surface cleaning can be performed in preparation for subsequent lamination of the thin film substrate or entry into the next process (such as winding / embedding).

[0046] 102. A composite substrate is formed by bonding a ferrite substrate with a thin film substrate used to carry the conductor.

[0047] The film substrate can be one or more polymer film materials such as PET, PVC, and PC, and can be in sheet or roll form. The bonding method can employ hot pressing, adhesive bonding, or adhesive film lamination to ensure a secure bond and positional accuracy between the film substrate and the ferrite substrate. After bonding, it can be die-cut or segmented to obtain composite substrate workpieces or rolls suitable for subsequent winding.

[0048] 103. In a bonding device with a dual-mode ultrasonic tool head, a wire is implanted into the surface of a composite substrate to form a coil by means of ultrasonic winding using an outer winding needle tube.

[0049] The bonding device is equipped with a dual-mode ultrasonic tool head, which includes an outer winding needle tube and an inner core micro-welding electrode arranged coaxially; the outer winding needle tube is used to guide and embed / wrap the wire to the surface of the thin film substrate.

[0050] In this embodiment, the operating frequency of the outer winding needle tube is preferably 20kHz-40kHz, and the amplitude is preferably 2μm-10μm, so as to achieve high-precision embedding of the wire without damaging the thin film substrate.

[0051] To improve the positioning accuracy and embedding stability of the wire, a V-shaped guide groove or recess structure can be provided at the end of the outer winding needle tube. Through the synergistic effect of ultrasonic vibration and the guide groove, the enameled wire or fine metal wire is embedded into the film surface or the recess. The wire used can be enameled copper wire or other fine metal wire, with a preferred wire diameter of 20μm-200μm. The number of turns, wire spacing, and wiring shape (rectangular or other shapes) are designed according to the device specifications. Winding can be completed sequentially at a single station or in batches using a roll-to-roll continuous winding process.

[0052] 104. After the winding is completed, the ends of the wire are subjected to low-temperature instantaneous welding using the inner core micro-welding electrode at the coaxial position of the dual-mode ultrasonic tool head.

[0053] The inner core micro-welding electrode is coaxially arranged with the outer winding needle tube. After winding is completed, the inner core micro-welding electrode can extend to the end of the wire to perform the welding action, thereby realizing the integration of "winding-welding". The operating frequency of the inner core micro-welding electrode is preferably 50kHz-80kHz, and the amplitude is preferably 1μm-5μm, so as to realize local energy application and welding control in the welding area.

[0054] In this embodiment, the solder used for low-temperature instantaneous welding is an alloy with a melting point in the range of 100℃-130℃ (e.g., In-Sn alloy), or other low-temperature solders with similar melting points. The welding time is ≤300ms. Welding can achieve instantaneous melting and solidification of the solder through ultrasonic energy and / or residual heat of the wire, thereby obtaining a strong solder joint without causing thermal damage to the substrate. Low-temperature instantaneous welding can reduce thermal damage to the substrate and is suitable for flexible thin film and ferrite composite structures.

[0055] 105. Perform electrical performance testing on the coil and solder joints, and complete subsequent processing based on the test results to form an RFID / NFC device.

[0056] Electrical performance testing can be performed online on the same bonding device or switched to a dedicated testing station. Testing items include, but are not limited to: coil DC resistance measurement, AC impedance or resonant frequency measurement, Q-value testing, and read / write performance testing at 13.56MHz.

[0057] In some embodiments, a test current (e.g., 10mA) can be applied to measure the DC resistance of the coil, with a measurement accuracy of ±0.1Ω; when the measured value exceeds a preset threshold (e.g., exceeds the nominal value by ±X%), the system can automatically trigger a repair, rework, or rejection process.

[0058] The subsequent processing may include automatic soldering or local repair, mounting of radio frequency chips (ICs) (e.g., using conductive adhesive, anisotropic conductive film ACF, or crimping), resonant tuning (if matching capacitors are required), insulating / protective coating or encapsulation (e.g., UV-cured resin, epoxy coating or film), die-cutting / slitting, aging and reliability testing, functional programming (writing UID / EPC), final inspection and packaging, etc.

[0059] It should be noted that any of the above-mentioned subsequent processing steps can be used as optional or mandatory implementation steps in the embodiments of this application, and the specific steps can be determined according to the product design and production requirements.

[0060] This application embodiment directly replaces traditional FPC processing (electroplation, etching, coating, etc.) and subsequent assembly with ferrite using ultrasonic winding via a bonding machine. This significantly reduces chemical processing and consumable usage, lowers energy consumption and wastewater / waste gas generation, thus offering clear environmental and cost advantages. By directly embedding the wires into the thin-film substrate bonded to the ferrite, the separate preparation and alignment assembly steps of the FPC and ferrite are eliminated, avoiding cumulative displacement and poor contact problems during transportation, transposition, and assembly. This improves the yield of mass production and reduces rework and material loss. Furthermore, this application embodiment supports integrated punching of ferrite and winding, eliminating the need for separate punching of the ferrite before assembly. This facilitates the production of standardized sizes or standard sheets of ferrite, simplifying mold management, reducing specification complexity, and improving production consistency. Furthermore, the embodiments of this application employ a process improvement combining spatial integration (coaxial structure of the tool head and V-shaped guide groove, etc.) and temporal continuity (winding → instant welding → online detection), enabling high-precision embedding of micro-wires in complex three-dimensional paths. The typical positioning accuracy is preferably less than ±5μm, which is particularly important for miniaturized, high-density antenna structures. After the wire is completed at the winding station, it can be directly transferred to the welding state within the same tool head or device without intermediate handling, thereby avoiding displacement or contamination during transport and ensuring the relative positional accuracy of the structure before and after welding.

[0061] In summary, this application provides a method for fabricating an RFID / NFC device, including providing a ferrite substrate; bonding the ferrite substrate with a thin film substrate for carrying wires to form a composite substrate; using an outer winding needle tube to ultrasonically wind wires into the surface of the composite substrate to form a coil on a bonding device with a dual-mode ultrasonic tool head; after winding, using an inner core micro-welding electrode at the coaxial position of the dual-mode ultrasonic tool head to perform low-temperature instantaneous welding on the endpoints of the wires; performing electrical performance testing on the coil and the solder joint, and completing subsequent processing based on the test results, thereby forming an RFID / NFC device. This application integrates the ultrasonic winding technology of the bonding machine with processes such as ferrite substrate bonding, die-cutting, and instantaneous low-temperature welding, and executes them sequentially, replacing the traditional FPC process and step-by-step assembly. This simplifies the process flow, reduces manufacturing costs, and minimizes environmental impact, reducing the complexity of RFID / NFC device fabrication and significantly improving product yield and production efficiency.

[0062] This application also provides an RFID / NFC device; please refer to [link / reference]. Figures 2-3 , Figures 2-3 This is a schematic diagram of the RFID / NFC device provided in this application. The RFID / NFC device may include a ferrite substrate 11, a thin film substrate 12, and a coil 20.

[0063] The thin film substrate 12 and the ferrite substrate 11 are bonded together to form a composite substrate 10. Specifically, the thin film substrate 12 and the ferrite substrate 11 can be bonded together using an adhesive layer or by hot pressing to form the composite substrate 10. The thin film substrate 12 faces outward as the external surface of the device and is used to support the coil 20 and the pad 30; the ferrite substrate 11 is located below the thin film substrate 12 and is used to improve magnetic flux concentration and read / write performance.

[0064] The coil 20 is disposed on the surface of the thin film substrate 12 and embedded in the thin film substrate 12. The coil 20 is a rectangular or ring-shaped planar winding, and the coil 20 is composed of wires, which can be enameled wires or fine metal wires (such as enameled copper wires), with a wire diameter preferably of 20μm to 200μm, and the number of turns preferably of 3 to 12 turns (which can be adjusted according to the target reading distance and frequency).

[0065] The two ends of the coil 20 are connected to the pads 30 on the surface of the thin film substrate 12 through conductive paths. The pads 30 are used for electrical connection with radio frequency chips (ICs) or external connectors. The pads 30 can be metallized pads or formed through locally exposed conductive areas.

[0066] In some embodiments, the thin-film substrate 12 is provided with a groove or channel for accommodating the coil 20, which is embedded in the groove or channel to reduce device thickness and provide mechanical protection. Near the pad 30, the groove or channel may taper into a V-shape or have a guiding transition area to facilitate exposure of the pad 30 and to facilitate electrical connection to the radio frequency chip (IC) or external connectors.

[0067] In some embodiments, the coil 20 can be embedded into the film surface directly by ultrasonic fitting (ultrasonic pressing) without forming significant mechanical grooves, and the coil 20 wire surface is basically flush with the film surface after embedding.

[0068] The material of the film substrate 12 can be a thermoplastic film such as PET, PVC or PC; the film thickness can be 25μm to 200μm, preferably 50μm to 125μm;

[0069] The ferrite substrate 11 can be a continuous ferrite sheet, a composite layer of ferrite powder and binder, or a magnetic layer molded from ferrite sheets; the ferrite thickness and permeability can be designed according to the read distance / frequency requirements. The surface of the pad 30 can be metallized (e.g., Cu / Ni / Au or other metal layers suitable for low-temperature bonding) to accommodate conductive adhesives, anisotropic conductive films (ACF), or low-temperature soldering processes.

[0070] In summary, the RFID / NFC device provided in this application embodiment may include a ferrite substrate 11, a thin film substrate 12, and a coil 20. The thin film substrate 12 and the ferrite substrate 11 are bonded together to form a composite substrate 10. The coil 20 is disposed on the surface of the thin film substrate 12 and embedded within it. Both ends of the coil 20 are connected via conductive paths to pads 30 located on the surface of the thin film substrate 12. The pads 30 are used for electrical connection with an RF chip or external connector. The coil 20, pads 30, and composite substrate 10 together constitute the RFID / NFC device. By embedding the coil 20 into the thin film substrate 12 and bonding it to the ferrite substrate 11, this application embodiment can reduce the device thickness, improve the positioning accuracy of the coil 20, and enhance mechanical reliability and environmental tolerance. The ferrite substrate 11 can improve read distance and signal stability in environments containing metal.

[0071] The RFID / NFC device and its fabrication method provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method of manufacturing an RFID / NFC device, characterized by, The application relates to a preparation method of an RFID / NFC device. The preparation method comprises the following steps: providing a ferrite substrate, wherein the preparation of the ferrite substrate comprises the following steps: mixing ferrite raw materials and ball milling to form a slurry, performing flow casting and drying to obtain a flow casting film, performing sintering on the flow casting film to obtain a ferrite bare chip, performing glue sticking on the ferrite bare chip, performing roll crushing to form a crushed magnetic material, winding the crushed magnetic material and performing die cutting to obtain the ferrite substrate; attaching the ferrite substrate to a film substrate for carrying a wire to form a composite substrate; utilizing an outer layer winding needle tube to implant the wire on the surface of the composite substrate in an ultrasonic winding mode to form a coil on a bonding device with a bimodal ultrasonic tool head; the working frequency of the outer layer winding needle tube is 20 kHz-40 kHz, and the amplitude is 2 mu m-10 mu m; after the winding is completed, an inner core micro welding electrode at a coaxial position of the bimodal ultrasonic tool head is utilized to perform low-temperature transient welding on the end point of the wire; the working frequency of the inner core micro welding electrode is 50 kHz-80 kHz, and the amplitude is 1 mu m-5 mu m; the solder used in the low-temperature transient welding is an alloy with a melting point in the range of 100 DEG C-130 DEG C; the welding time of the low-temperature transient welding is less than or equal to 300 ms; the coil and the welding point are subjected to electrical performance detection, and subsequent processing is completed according to the detection result, so that the RFID / NFC device is formed.

2. The method of claim 1, wherein the RFID / NFC device is prepared by a method comprising: The material of the film substrate is one or more of PET, PVC or PC.

3. The method of claim 1, wherein the RFID / NFC device is prepared by a process comprising: The wire used is a lacquered copper wire or a fine metal wire.

4. The method of claim 3, wherein the RFID / NFC device is prepared by a method comprising: The wire diameter of the wire is 20 mu m-200 mu m.

5. The method of claim 1, wherein the RFID / NFC device is prepared by a process comprising: The end of the outer layer winding needle tube is provided with a V-shaped guide groove or groove structure.

6. An RFID / NFC device, characterized by The RFID / NFC device is prepared by the preparation method of the RFID / NFC device according to any one of claims 1-5.

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