RFID electronic tag embedded body and environment-friendly RFID room card

Abstract

The utility model discloses a radio frequency identification (RFID) electronic tag embedded body and an environment-friendly RFID room card. The RFID electronic tag embedded body comprises a chip, a main coil antenna, a paper base material and a gap bridge antenna; the main coil antenna is arranged on one side of the paper base material, and the gap bridge antenna is arranged on the other side of the paper base material; the two faces of the paper base material are coated with waterproof wear-resistant coatings. The main coil antenna and the gap bridge antenna are formed through a metal etching process; and the main coil antenna and the gap bridge antenna form loop conduction in a physical riveting manner, and are electrically connected with the chip. According to the utility model, the paper base material coated with the waterproof wear-resistant coatings on the two surfaces is adopted, so that the paper weakness is overcome and the etching process is adapted. The main coil and the gap bridge coil are arranged on the two sides of the base material respectively and are formed through low-direct-current-resistance etching metal, and the electrical performance is improved. Physical riveting connection is reliable and stable, and the problem that paper base materials are prone to breakage during connection is solved. The embedded body is environment-friendly, good in process adaptability and excellent in electrical performance, and can be reliably embedded in a hard shell.

Description

Technical Field

[0001] This utility model relates to the field of radio frequency identification (RFID) technology, and more specifically, to an RFID electronic tag embedding and an environmentally friendly RFID room key. Background Technology

[0002] Traditional RFID cards, especially IC cards used in access control and room key applications, typically use PET (polyethylene terephthalate) or similar plastic materials as the antenna substrate for their core functional component—the electronic tag (inlay). PET substrates have high mechanical strength and good processing adaptability, making them suitable for card manufacturing processes and everyday use environments. However, PET materials are difficult to degrade naturally, causing long-term environmental pollution after disposal, which contradicts the current global advocacy for low-carbon, environmentally friendly, and sustainable development concepts.

[0003] The industry has begun exploring the use of more environmentally friendly biodegradable materials to replace PET substrates in the manufacture of RFID electronic tags. Paper materials have attracted attention due to their ease of acquisition, relatively low cost, and biodegradability. However, paper materials themselves have inherent drawbacks such as low strength, sensitivity to moisture, poor dimensional stability, and poor weather resistance. When using paper materials as antenna substrates in card products, especially in scenarios where they need to be embedded in rigid shells (such as wooden room keys), traditional electronic tag manufacturing processes (such as etching, connection of antennas to chips and bridges) can easily damage the paper substrate, resulting in a low yield rate during antenna manufacturing. More significantly, after the cards are manufactured and put into use, fluctuations in environmental humidity and temperature, or external forces such as bending and squeezing, can easily cause deformation or even tearing of the paper substrate. In particular, the connection points between the antenna lines and bridges are prone to unreliable connections, increased contact resistance, or even complete open circuits, seriously affecting the functional stability, card reading performance, and product lifespan of the electronic tags. Furthermore, the dielectric environment of paper and the final product is quite different from that of PET-based materials. If traditional antenna designs are used directly, the antenna's radio frequency performance (such as resonant frequency and impedance) will be significantly deviated, making it impossible to resonate precisely at the target operating frequency, thus affecting the read / write distance and communication reliability.

[0004] While wood is used as a card substrate due to its environmental friendliness and natural texture, existing wooden electronic tag cards typically embed standard, plastic-based electronic tags into a wooden casing. Although this product form is environmentally friendly in terms of the card substrate material, the core electronic tag component is usually still plastic, failing to fundamentally solve the problem. Furthermore, current technologies lack suitable solutions for ensuring the long-term reliability of embedded electronic tags (especially paper-based tags) in the specific composite material environment of a wooden casing, and for optimizing antenna design to adapt to this composite dielectric environment.

[0005] Therefore, how to provide an RFID room card paper electronic tag embedding that can be embedded in a wooden card base, overcome the inherent defects of paper substrate, and has reliable connection and excellent radio frequency performance, while ensuring environmental protection and biodegradability, as well as an environmentally friendly RFID room card containing the embedding and its manufacturing method, has become an urgent technical problem to be solved. Utility Model Content

[0006] The purpose of this utility model is to provide an RFID room card paper electronic tag embedding that, while ensuring environmental protection and biodegradability, can be embedded in a wooden card base, overcomes the inherent defects of paper substrates, and has reliable connection and excellent radio frequency performance, as well as an environmentally friendly RFID room card containing the embedding and its manufacturing method.

[0007] This utility model provides an RFID electronic tag embedding, including a chip, a main coil antenna, a paper substrate, and a bridge antenna;

[0008] The main coil antenna is located on one side of the paper substrate, and the bridge antenna is located on the other side of the paper substrate.

[0009] The paper substrate is coated with a waterproof and wear-resistant coating on both sides;

[0010] Both the main coil antenna and the bridge antenna are formed using a metal etching process; and

[0011] The main coil antenna and the bridge antenna are physically riveted together to form a circuit and are electrically connected to the chip.

[0012] Preferably, the paper substrate is pure wood pulp coated paper, such as 60-80g pure wood pulp coated paper.

[0013] Preferably, the thickness of the paper substrate is 50–70 μm.

[0014] Preferably, the waterproof and wear-resistant coating is a water-based polyurethane coating.

[0015] Preferably, the main coil antenna is a wide-body coil design.

[0016] Preferably, the etched metal is etched aluminum.

[0017] Preferably, the physical riveting method achieves electrical connection between the main coil antenna and the bridge antenna through the bridge riveting point. The physical riveting pressure is 4-8N and the time is 0.5-1.5 seconds.

[0018] This utility model also provides an environmentally friendly RFID room card, including a wooden shell and an RFID electronic tag inlay. The RFID electronic tag inlay is embedded in the wooden shell. The RFID electronic tag inlay is the RFID electronic tag inlay of any one of the first aspects of this utility model. The antenna design of the RFID electronic tag inlay is optimized according to the dielectric constant of the wooden shell and the paper substrate, so that the environmentally friendly RFID room card resonates in the range of 13.56MHz±7KHz.

[0019] Based on the technical content disclosed in this utility model, the following beneficial effects are achieved:

[0020] This utility model provides an environmentally friendly RFID room card paper electronic tag embedding. By using a paper substrate with a double-sided waterproof and wear-resistant coating, it overcomes the shortcomings of paper's low strength and susceptibility to moisture, making it suitable for the manufacturing process of etched metal antennas. The main coil antenna is located on one side of the paper substrate, and the bridge antenna is located on the other side, both formed by metal etching. Compared to printing silver paste, this process results in a lower DC resistance. For example, the DC resistance of an etched aluminum antenna can be as low as 3-5Ω, while that of a printed conductive silver paste antenna is typically 10-20Ω, significantly improving resistance. The electrical performance has been improved, such as increasing the Q value of the antenna, thereby increasing the card reading distance by about 100%. The main coil antenna and the bridge antenna are connected by physical riveting, ensuring the reliability and stability of the connection. For example, the contact resistance is generally ≤0.2 ohms. It has also passed the stringent environmental reliability test of 168 hours of double 85 aging test, overcoming the technical problem of easy breakage at the connection point of the paper substrate. The combination of these features makes the inlay have good environmental protection, manufacturing process adaptability and electrical performance, and has the reliability to be used when embedded in a rigid shell.

[0021] Other features and advantages of the present invention will become clear from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present invention and, together with their description, serve to explain the principles of the present invention.

[0023] Figure 1 This is a schematic diagram of the RFID electronic tag of this utility model after omitting the paper substrate.

[0024] Figure 2 This is a schematic diagram of the front of the RFID electronic tag embedded body of this utility model.

[0025] Figure 3 This is a schematic diagram of the back of the RFID electronic tag embedded in this utility model.

[0026] Figure 4 The figure shows the HFSS simulation results of the antenna design of this utility model.

[0027] Figure 5 The measured resonant frequency diagram of the finished environmentally friendly RFID room card of this utility model.

[0028] Explanation of reference numerals in the attached diagram: 1. Chip; 2. Main coil antenna; 3. Paper substrate; 4. Bridge antenna; 41. First bridge riveting point; 42. Second bridge riveting point; 43. Third bridge riveting point; 44. Fourth bridge riveting point. Detailed Implementation

[0029] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0030] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0031] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0032] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0033] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0034] This invention overcomes the difficulties of paper substrate application by applying a specific waterproof and wear-resistant coating to the paper substrate, using etched metal antennas and physical riveting connections, and conducting radio frequency optimization design for the composite material environment composed of a wooden shell and a paper inlay. Ultimately, it provides an environmentally friendly RFID room card solution that is different from existing technologies.

[0035] The environmentally friendly RFID room key of this invention comprises two main parts: an outer wooden shell and an RFID inlay (i.e., an embedded paper electronic tag for the environmentally friendly RFID room key) embedded within the wooden shell. The wooden shell provides the room key with the required shape, feel, and physical protection. The wooden shell can be formed from wood using processing methods commonly used in the art, such as cutting and carving. The RFID inlay is the key component for realizing RFID functionality, carrying the chip and antenna. The wooden shell and the RFID inlay can be combined using conventional assembly processes in the art, such as bonding and fixing with environmentally friendly adhesives, or encapsulating the inlay between the wooden materials using a lamination process.

[0036] In some embodiments, the wooden shell is pre-fabricated to house a fixed cavity for the inlay. In other embodiments, the wooden shell is not pre-fabricated to house a fixed cavity for the inlay, but rather the inlay is laminated or bonded together with layers of wooden material, and the thickness of the inlay itself or the pressure during the lamination process can naturally create a space between the layers of wooden material to house the inlay.

[0037] The environmentally friendly RFID room key paper electronic tag embedding is an environmentally friendly electronic tag inlay based on paper substrate 3. For example... Figures 1 to 3 As shown, the embedded body mainly includes: a paper substrate 3, a main coil antenna 2 and a bridge antenna 4 made based on the substrate, and an RFID chip 1 connected to the antenna.

[0038] The paper substrate 3 is made of pure wood pulp paper. Preferably, the paper substrate 3 is 60-80g pure wood pulp coated paper, typically with a thickness of 50-70µm. For example, all-wood pulp coated paper from UPM can be used. The use of pure wood pulp paper reflects its environmental friendliness and biodegradability.

[0039] To overcome the inherent drawbacks of the paper substrate 3, such as low strength, susceptibility to moisture, sensitivity to humidity, and susceptibility to contamination, and to enable it to adapt to the subsequent precision manufacturing processes of the RFID inlay (such as etching and physical riveting) and the usage environment of the final product (a room card embedded in a wooden shell), a waterproof and wear-resistant coating is applied to both sides of the paper substrate 3. Preferably, the waterproof and wear-resistant coating is a water-based polyurethane coating. For example, water-based polyurethane coatings with similar properties can be used.

[0040] The application process of this waterproof and wear-resistant coating mainly includes three steps: coating, drying, and curing. Coating needs to be controlled to be uniform, with a typical application rate of 5-8 g / m². During the drying process, good ventilation is essential, and the temperature should be maintained at 60℃±5℃, for example, around 60℃, for 20-40 minutes (e.g., 30 minutes). Curing requires a low temperature and a long time to release paper stress; the temperature should be maintained at 50℃±5℃, for example, around 50℃, for 6-8 days (e.g., 7 days).

[0041] The pure wood pulp coated paper substrate treated with this coating has good waterproof and wear-resistant properties and the necessary mechanical strength (such as a certain stiffness and toughness). It can withstand the immersion and rinsing of subsequent antenna etching process conditions (e.g., etching solution is acidic copper chloride solution, time 3-5 minutes; etching film removal conditions 5-10% sodium hydroxide solution 3-5 minutes) without damage. At the same time, it provides a stable base for subsequent physical riveting, which significantly improves the yield.

[0042] The main coil antenna 2 is disposed on one surface (e.g., the front) of the paper substrate 3. Figure 1 As shown), the bridge antenna 4 is disposed on the other side of the paper substrate 3 (e.g., the back side, as shown). Figure 2 (As shown).

[0043] Both the main coil antenna 2 and the bridge antenna 4 are formed on a coated paper substrate 3 using a metal etching process. Preferably, the etched metal is etched aluminum. Aluminum is relatively inexpensive and has good electrical conductivity.

[0044] The main coil antenna 2 is preferably a wide-body coil design. For example... Figures 1 to 3 The antenna structure shown features a coil composed of multiple tightly packed turns of wire. For example, the antenna structure has external dimensions of approximately 60x30mm, with 11 turns of wire, a wire width of approximately 0.42mm, a wire spacing of approximately 0.5mm, and an internal cavity size of approximately a rounded rectangle with radius R2.5. This wide-body coil design helps reduce the antenna's DC resistance. For example, the DC resistance of an etched aluminum antenna is as low as 3-5Ω, far lower than that of a paper-based antenna using printed conductive silver paste (whose DC resistance is typically 10-20Ω). This significantly improves the antenna's Q value and electrical performance; for example, the reading distance can be increased by approximately double.

[0045] Bridge antenna 4 (e.g.) Figure 2 and Figure 4 (As shown) is used to connect the two ends of the main coil antenna 2 to form a complete radio frequency circuit.

[0046] The main coil antenna 2 and the bridge antenna 4 are connected by physical riveting, forming a conductive antenna circuit. For example... Figure 1 and Figure 2 As shown, the main coil antenna 2 has areas for riveting (e.g., labeled "first bridge riveting point 41" and "second bridge riveting point 42"), and the bridge antenna 4 also has corresponding areas (e.g., labeled "third bridge riveting point 43" and "fourth bridge riveting point 44"). During the riveting process, metal rivets are used to physically impact and pressurize the riveting points of the main coil antenna 2 and the corresponding riveting points of the bridge antenna 4 to form a stable electrical conductivity path (e.g., ...). Figure 2 The first bridge riveting point 41 shown is... Figure 3The third bridge riveting point 43 shown is connected to connect the bridge. Figure 2 The second bridge riveting point 42 shown is... Figure 3 The fourth bridge riveting point 44 is shown. Physical riveting is a commonly used connection technique in this field, requiring no additional riveting material. When performing physical riveting on paper substrates treated with a specific waterproof and wear-resistant coating, it is necessary to precisely control the riveting process parameters, such as controlling the riveting pressure at 4-8N and the time at 0.5-1.5 seconds (e.g., 1 second). The specific parameters are fine-tuned according to the actual situation to ensure that the aluminum layer is firmly connected and not damaged (neither under-riveting nor over-riveting). This physical riveting connection has the advantages of low contact resistance (generally ≤0.2 ohms) and extremely high stability, and can pass harsh environmental reliability tests (such as the double 85 aging test, with no problems after 168 hours), effectively ensuring the long-term reliability of the antenna connection point and overcoming the technical problem of easy breakage of connection points on paper substrates.

[0047] The RFID chip 1 is electrically connected to the main coil antenna 2, for example, through a bonding process. Chip 1 is responsible for storing and processing information and communicating wirelessly with the reader.

[0048] Example of an environmentally friendly RFID room key:

[0049] The environmentally friendly RFID room key consists of a wooden shell with an embedded paper electronic tag (RFID inlay) for the aforementioned environmentally friendly RFID room key.

[0050] The antenna design (including the shape, size, and number of turns of the main coil antenna 2 and the bridge antenna 4) of the paper electronic tag embedded in the environmentally friendly RFID room card is optimized based on the dielectric constant of the composite dielectric environment formed by the wooden shell of the room card and the paper substrate 3 (including the coating) used in the RFID inlay. This ensures that the finished environmentally friendly RFID room card resonates accurately around the target operating frequency of 13.56MHz. The dielectric constant of the materials affects the electromagnetic performance of the antenna, especially the resonant frequency and impedance. After embedding the paper inlay into the wooden shell, the dielectric environment of the entire room card is a complex composite environment composed of various materials such as wood, paper substrate, coating, and adhesive. To enable the antenna to resonate accurately within the range of 13.56MHz±7KHz in this specific environment, targeted design optimization is required.

[0051] like Figure 4As shown, the antenna design optimization process can be performed using electromagnetic simulation software (such as HFSS). In the simulation, a detailed model is established, including the wooden shell and paper inlay, along with their respective material layers (paper, coating, aluminum, chip 1, and connection points). Parameters such as the dielectric constant of each material at a frequency of 13.56MHz are input (the dielectric constant of the selected coated paper substrate is approximately 3.3F / m; for comparison, the dielectric constant of a typical PET substrate is approximately 2.2F / m). The antenna's geometric parameters (e.g., external coil dimensions, internal window dimensions, line width, line spacing, number of turns, feed point location, etc.) are iteratively adjusted through simulation analysis until the antenna achieves impedance matching the selected chip 1 in the simulated composite dielectric environment and resonates near the target frequency. Considering that factors such as human intervention in actual use may cause the resonant frequency to shift downwards, the target frequency is usually designed to be slightly higher. This design sets the resonant frequency of the finished tag at 13.6MHz. Figure 5 As shown, the measured resonant frequency of the finished room key (e.g., model T8200) reached 13.658MHz, with an attenuation of -6.707dB and a Q value of 13.376, which basically matches the simulation results, proving the effectiveness of the design. This optimized design for composite dielectric environments ensures that the RFID inlay based on paper substrate 3 still maintains excellent radio frequency performance even within a wooden casing.

[0052] Example of a method for producing environmentally friendly RFID room cards:

[0053] The method for producing environmentally friendly RFID room cards includes providing a wooden outer shell and preparing a paper electronic tag embedded for the environmentally friendly RFID room card, and then combining the prepared embedded with the wooden outer shell.

[0054] A method for preparing an embedded paper electronic tag for environmentally friendly RFID room cards includes: providing a paper substrate 3 (preferably pure wood pulp paper, more preferably 60-80g pure wood pulp coated paper, 50-70µm thick), and applying a waterproof and wear-resistant coating (e.g., water-based polyurethane coating) to both sides. This coating process includes coating, drying, and curing (e.g., coating amount 5-8g / m², drying at 60℃±5℃ for approximately 30 minutes, and curing at 50℃±5℃ for approximately 7 days). A main coil antenna 2 (preferably wide-body design) and a bridge antenna 4 are fabricated on the front and back sides of the treated paper substrate using a metal etching process (e.g., aluminum etching). A chip 1 is electrically connected to the main coil antenna 2. Then, the main coil antenna 2 and the bridge antenna 4 are connected and connected by physical riveting (e.g., controlling the riveting pressure to 4-8N for approximately 1 second). The antenna design was optimized based on the dielectric constants of the wooden shell and the coated paper substrate to ensure that the final product (embedded in the wooden shell) resonates within the range of 13.56MHz ± 7KHz.

[0055] The prepared environmentally friendly RFID room card is combined with a paper electronic tag embedded in a wooden shell, for example, through lamination or bonding processes. In some embodiments, the wooden shell is composed of layers of wood material, and the embedded is directly laminated or bonded to the wood material layers. The thickness of the embedded or the pressure during the lamination process can naturally create a space between the wood material layers to accommodate the embedded.

[0056] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. An RFID electronic tag embedding, characterized in that, include: Chip, main coil antenna, paper substrate and bridge antenna; The main coil antenna is disposed on one side of the paper substrate, and the bridge antenna is disposed on the other side of the paper substrate; The paper substrate is coated with a waterproof and wear-resistant coating on both sides; Both the main coil antenna and the bridge antenna are formed using a metal etching process; and The main coil antenna and the bridge antenna are connected in a loop by physical riveting and are electrically connected to the chip.

2. The RFID electronic tag embedding according to claim 1, characterized in that, The paper substrate is pure wood pulp coated paper.

3. The RFID electronic tag embedding according to claim 2, characterized in that, The thickness of the paper substrate is 50–70 μm.

4. The RFID electronic tag embedding according to any one of claims 1 to 3, characterized in that, The waterproof and wear-resistant coating is a water-based polyurethane coating.

5. The RFID electronic tag embedding according to any one of claims 1 to 3, characterized in that, The main coil antenna is a wide-body coil design.

6. The RFID electronic tag embedding according to any one of claims 1 to 3, characterized in that, The etched metal is etched aluminum.

7. The RFID electronic tag embedding according to any one of claims 1 to 3, characterized in that, The physical riveting method achieves electrical connection between the main coil antenna and the bridge antenna through the bridge riveting point.

8. An environmentally friendly RFID room card, characterized in that, It includes a wooden outer shell and an RFID electronic tag inlay, wherein the RFID electronic tag inlay is embedded in the wooden outer shell, and the RFID electronic tag inlay is the RFID electronic tag inlay according to any one of claims 1 to 7.

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