Secondary bending copper wire antenna-coupled type radio frequency tag and manufacturing method

Abstract

Disclosed in the present invention are a secondary bending copper wire antenna-coupled type radio frequency tag in the technical field of radio frequency tags and a manufacturing method. The radio frequency tag comprises a radio frequency antenna and a radio frequency resonant cavity assembly, the radio frequency antenna itself is corrugated, the whole radio frequency antenna is bent to form a sinusoidal wave shape, and the radio frequency resonant cavity assembly is coupled with the radio frequency antenna. The manufacturing method comprises the steps: preparing a bare copper wire to be processed, performing primary processing to form a corrugated shape, performing secondary processing to form a sinusoidal wave-shaped radio frequency antenna, coupling the radio frequency antenna with a tag semi-finished product to form a coupled type radio frequency tag, and the like. In the present invention, the radio frequency antenna is in coupling contact with the radio frequency resonant cavity assembly and a conductive adhesive is not required to be used, so that the radio frequency resonant cavity assembly is convenient to separate, the waste of cost is reduced, and the present invention involves a smaller size of the whole product and can be applied to a small radio frequency tag.

Description

A secondary bent copper wire antenna coupled radio frequency tag and its manufacturing method Technical Field

[0001] The present invention relates to the technical field of radio frequency tags, and in particular to a secondary bent copper wire antenna coupled radio frequency tag and a manufacturing method thereof. Background Art

[0002] Radio frequency tags are the foundation of the Internet of Things. The development and application of the Internet of Things is about to approach an annual usage of 100 billion radio frequency tags. The cost of radio frequency tags has affected the promotion of the Internet of Things. Therefore, it is urgent to reduce the cost of radio frequency tags and reduce the environmental pollution caused by electronic waste.

[0003] The cost of radio frequency tags consists of three parts: chip, antenna and label paper. The cost of chips has been greatly reduced, with the unit price dropping from 0.12 yuan to 0.065 yuan, a decrease of nearly 50%. There is little room for further price reduction, and there is also little room for price reduction of label paper.

[0004] The express delivery and logistics industry urgently needs to upgrade from barcode express labels to radio frequency (RF) express labels to enhance information technology, reduce manual operations, and improve efficiency. However, the express delivery and logistics industry is a low-profit industry. The current structure and process of chemically etched antenna-integrated RF labels add an additional 0.15 yuan to the price of each label, restricting their use. The industry is in urgent need of low-cost RF tags.

[0005] The mainstream "PET aluminum film chemical etching process RF antenna" on the market has many defects:

[0006] (1) Complex production process

[0007] ① PET film and aluminum foil are laminated with solvent glue to form PET aluminum foil film. Then, a photosensitive agent is applied to the aluminum foil surface. The pattern is exposed. The film is developed. The film is fixed. Chemical etching is performed to remove the aluminum foil outside the antenna pattern. The film is then washed and dried. The RF chip is then encapsulated on the surface to form the traditional INLAY film.

[0008] ② The chip is mounted on the chemically etched antenna using anisotropic conductive resin. The conductive resin solidifies and becomes an inseparable INLAY with the antenna.

[0009] ③Then apply pressure-sensitive adhesive on INLAY --- laminate release paper --- die-cut --- waste discharge --- wet INLAY (INLAY label).

[0010] ④ Transfer the wet INLAY to the back of the label paper --- apply pressure-sensitive adhesive again --- laminate the release paper --- die-cut again --- discharge waste --- to become a radio frequency self-adhesive label (commonly known as sandwich process).

[0011] (2) Pollution of the environment

[0012] A large amount of waste liquid and waste water are generated during the preparation process, polluting the environment. At the same time, the INLAY composed of PET film, aluminum foil and chip is stably combined together. After the RFID tag is used, the PET film is difficult to decompose under normal conditions, causing pollution.

[0013] In addition, airline luggage tags and express logistics labels are all single-use and generate a large amount of electronic waste.

[0014] (3) High cost

[0015] Affected by the production process and raw materials, the production cost of the finished product is high; at the same time, the chip on the PET aluminum foil film chemical etching antenna integrated RFID tag cannot be removed from the tag for secondary use, resulting in a waste of raw materials and increased raw material costs.

[0016] (4) Low production efficiency

[0017] When using INLAY to make RFID tags, the surface of the INLAY must be coated with glue to form "wet INLAY", which is then pasted between the face paper and the backing paper of the RFID tag. This is commonly known as the "sandwich-style RFID tag packaging process", and the tag production efficiency is low.

[0018] However, the structure of forming the RF antenna by ordinary bending of antenna materials cannot be applied to small RF tags, and is affected by the bending structure, resulting in a rapid decline in RF performance.

[0019] The above defects are worth solving. Summary of the Invention

[0020] In order to overcome the defects of traditional PET aluminum film chemical etching process RF antenna such as high production cost and easy pollution, the ordinary bent antenna cannot cope with small tags and has poor RF performance, the present invention provides a double-bent copper wire antenna coupled RF tag and its production method.

[0021] The technical solution of the present invention is as follows:

[0022] A double-bent copper wire antenna-coupled radio frequency tag comprises a label face paper, a label backing paper, a radio frequency antenna, and a radio frequency resonant cavity assembly located between the label face paper and the label backing paper. The radio frequency antenna and the radio frequency resonant cavity assembly are coupled and connected. Pressure-sensitive adhesive is also filled between the label face paper and the label backing paper.

[0023] The length of the RF antenna in a corrugated shape after one bend is about 104 mm. After one bend, the RF antenna forms a sinusoidal period after two bends; the RF antenna can also form two sinusoidal periods after being bent.

[0024] The RF resonant cavity assembly includes an RF resonant cavity and an RF chip, which is connected to the opening of the coil in the RF resonant cavity. For relatively large RF tags, a single-coil RF resonant cavity (RCA) can be used as the RF resonant cavity assembly, coupled to a single-sine-period RF antenna. For relatively small RF tags, a dual-coil RF resonant cavity (MRS) can be used as the RF resonant cavity assembly, coupled to two sinusoidal-period RF antennas.

[0025] In addition, the manufacturing process of the double-bent copper wire antenna coupled radio frequency tag includes the following steps:

[0026] (1) Prepare the bare copper wire to be processed.

[0027] (2) Bend the bare copper wire into a corrugated shape once. During the bending process, double gears can be used for rolling.

[0028] (3) The bare copper wire after the first bending is bent a second time to form a radio frequency antenna, so that the entire radio frequency antenna is in the shape of a sine wave. During the second bending process, a forward thrust and a left-right extrusion force are simultaneously applied to the bare copper wire after the first bending, so that the second bending under the action of the combined force forms an overall sine wave shape.

[0029] (4) Connect the processed RF antenna to the semi-finished tag to form a coupled RF tag.

[0030] The present invention according to the above scheme has the beneficial effect that no resistive electrical contact is required between the RF antenna and the RF resonant cavity assembly in the present invention, and direct coupling contact can be used, and there is no need to use conductive glue, which makes the installation and separation of the RF antenna and the RF resonant cavity assembly very convenient, and the RF resonant cavity assembly can be recycled, reducing the waste of the RF resonant cavity assembly and saving related costs.

[0031] In addition, the radio frequency antenna in the present invention is formed by bending the copper wire twice, which reduces the overall length of the radio frequency antenna while ensuring the total length of the copper wire, and can be applied to small radio frequency tags. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1a is a schematic diagram of the structure of a conventional PET aluminum foil composite film chemically etched antenna radio frequency tag;

[0033] Figure 1b is a side cross-sectional view of a conventional PET aluminum foil composite film chemically etched antenna radio frequency tag structure;

[0034] FIG2a is a schematic diagram of the structure of the radio frequency tag of the present invention;

[0035] FIG2 b is a side cross-sectional view of the radio frequency tag of the present invention;

[0036] FIG3a is a schematic diagram of a single-coil radio frequency resonant cavity RCA;

[0037] FIG3 b is a schematic diagram of a single-coil radio frequency resonant cavity RCA from another perspective;

[0038] FIG4 a is a schematic diagram of a dual-coil radio frequency resonant cavity MRS;

[0039] FIG4 b is a schematic diagram of a dual-coil radio frequency resonant cavity MRS from another perspective;

[0040] FIG5 is a schematic diagram of a single-bend copper wire antenna;

[0041] FIG6 is a schematic diagram of a quadratic bent copper wire antenna with a sinusoidal period;

[0042] FIG7 is a schematic diagram of a quadratic bent copper wire antenna with two sinusoidal periods;

[0043] FIG8 is a schematic diagram of an RFID tag with a sinusoidal quadratic bent copper wire antenna coupled to a single-coil RF resonant cavity RCA;

[0044] FIG9 is a schematic diagram of an RFID tag with two sinusoidal periods of quadratic bent copper wire antenna coupled to a dual-coil RF resonant cavity MRS;

[0045] Figure 10 is a flowchart for manufacturing a double-bent copper wire antenna coupled RFID tag.

[0046] In the figure, the labels are:

[0047] 1. PET base film; 2. Aluminum foil antenna; 3. RF chip; 4. Label backing paper; 5. Label cover paper; 6. Double-bend copper wire antenna;

[0048] 7. Single-coil RF resonant cavity RCA; 71. PET base film of RCA; 72. Aluminum foil coil of RCA; 72', RF coupling end; 8. Double-coil RF resonant cavity MRS; 81. PET base film of MRS; 82. Aluminum foil coil of MRS; 82', RF coupling end; 82'', outer coil; 82''', inner coil. DETAILED DESCRIPTION

[0049] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0050] As shown in Figures 1a and 1b, when the traditional PET aluminum film chemical etching process RF antenna is applied to the RF tag, the aluminum foil antenna 2 is first etched on the PET base film 1, and then the RF chip 3 is installed on the aluminum foil antenna 2, and the entire structure is encapsulated between the label base paper 4 and the label face paper 5, and pressure-sensitive adhesive is applied between the label base paper 4 and the label face paper 5 to form the RF tag structure.

[0051] Since the process of etching the aluminum foil antenna 2 on the PET base film 1 requires the steps of "coating the aluminum foil surface with a photosensitive agent - exposing the pattern - developing - fixing - chemically etching to remove the aluminum foil outside the antenna pattern - washing - drying", the above process is complicated and has a high production cost. In addition, a large amount of waste liquid and wastewater are generated during the etching process, which pollutes the environment.

[0052] To address the high cost, complex manufacturing process, and propensity to generate pollutants associated with chemically etching PET aluminum film radio frequency antennas, some technologies use single-bend copper wire as radio frequency antennas to create radio frequency tags. However, single-bend copper wire antennas also have numerous drawbacks:

[0053] (1) Although the manufacturing process of the single-bend copper wire antenna is simple and can shorten the length of the half-wave array antenna, it is subject to the limitations of the single-bend forming process. The height of the bent waveform cannot be too large, so the effectiveness of reducing the antenna length is limited. When the bending height of the single-bend copper wire antenna, that is, the antenna length, is less than 90mm, the RF performance drops rapidly.

[0054] (2) The application of copper wire antennas formed by single bending is limited. Single bending copper wire antennas are suitable for RFID tags with a length greater than 104 mm, such as furniture tags, airline luggage tags, logistics tags, etc., but they cannot be used for RFID tags less than 90 mm in length, such as clothing tags, warehouse tags, book tags, etc.

[0055] (3) The single-bend copper wire antenna is limited by the height of the bending waveform, and the width of the tag is only 5-10mm, so the sensitivity of the RFID tag is about 3dB lower.

[0056] Therefore, in order to overcome the defects of the traditional "PET aluminum film chemical etching process radio frequency antenna" and "single-bending copper wire antenna", the present invention provides a coupled radio frequency tag prepared by a secondary-bending copper wire antenna.

[0057] As shown in Figures 2a to 9, the secondary bent copper wire antenna coupled type RF tag includes: a label face paper 5, a label backing paper 4, and an RF antenna and RF resonant cavity assembly located therebetween. Pressure-sensitive adhesive is also filled between the label face paper 5 and the label backing paper 4.

[0058] The radio frequency antenna of the present invention is the core focus. It is formed by bending a copper wire once to form a corrugated body. This corrugated copper wire antenna is then bent a second time to form an overall sinusoidal shape. In other embodiments, the corrugated copper wire antenna can be bent to form two connected sinusoidal waveforms.

[0059] In specific applications, the RF antenna is bent twice to form a sinusoidal period. The length of the RF antenna is selected between 60 mm and 85 mm. The RF antenna can also be bent twice to form two interconnected sinusoidal periods. The width of the two sinusoidal periods is selected between 45 mm and 65 mm.

[0060] The RF resonant cavity assembly of the present invention includes a RF resonant cavity and a RF chip 3. The RF chip 3 is connected to the opening of the coil in the RF resonant cavity. Specifically, a single-coil RF resonant cavity RCA7 or a dual-coil RF resonant cavity MRS8 can be selected depending on the application.

[0061] As shown in Figures 3a and 3b, the single-coil RF resonant cavity RCA7 includes an RCA PET base film 71 and an RCA aluminum foil coil 72, with the RF chip 3 located at the opening of the RCA aluminum foil coil 72. The RCA aluminum foil coil 72 is a single-turn coil located on the surface of the RCA PET base film 71. The single-coil RF resonant cavity RCA7 is less than 0.1 mm from the RF antenna via the RF coupling end 72', eliminating the need for a conductive medium (such as solder or conductive resin) to connect to the RF antenna and form an RF tag. This also facilitates separation from the RF antenna, allowing the RF resonant cavity to be recycled for multiple uses.

[0062] The outer dimensions of the single-coil RF resonant cavity RCA7 are 20mm×20mm. In a specific application example, the lateral dimensions of the single-coil RF resonant cavity RCA7 can be 18mm×16mm. The single-coil RF resonant cavity RCA7 can be square or circular.

[0063] As shown in Figures 4a and 4b, the dual-coil RF resonant cavity MRS8 includes an MRS PET base film 81 and an MRS aluminum foil coil 82, and the RF chip 3 is located at the opening of the MRS aluminum foil coil 82. The MRS aluminum foil coil 82 includes two inner and outer coils (outer coil wire 82'' and inner coil wire 82''), which are located on the surface of the MRS PET base film 81. The maximum outer dimension of the dual-coil RF resonant cavity MRS is 8mm×9mm, which has a lower cost and is more convenient to separate from the straight copper wire antenna through the RF coupling end 82' and recycle for multiple uses. In a specific application example, the lateral dimension of the dual-coil RF resonant cavity MRS can be selected to be 7mm×7mm. The dual-coil RF resonant cavity MRS8 can be square or circular.

[0064] The RF resonant cavity assembly and RF antenna do not require resistive electrical contact for coupling, and performance is stable when the distance between them is less than 0.05mm. No conductive adhesive is required for coupling, so the RF resonant cavity assembly can be installed with the aluminum foil facing up or down, with no restrictions on its orientation. Furthermore, since there is no conductive adhesive bonding, separation is very easy, making the RF resonant cavity assembly easy to recycle and the RCA chip reusable multiple times.

[0065] As shown in FIG10 , the present invention also provides a method for manufacturing a double-bent copper wire antenna coupled radio frequency tag, which is used to prepare the above-mentioned double-bent copper wire antenna coupled radio frequency tag. The specific manufacturing steps include:

[0066] (1) Prepare the bare copper wire to be processed.

[0067] According to the needs, the bare copper wire can be cut into the required size first, or the rolled bare copper wire can be directly processed into the required shape and then cut.

[0068] (2) Bend the bare copper wire once to form a corrugated shape.

[0069] As shown in Figure 5, during the single-bending process of bare copper wire, dual gears are used for rolling. The number of corrugations is related to the amplitude. When using a gear module of 1 or 1.5 during the single-bending process, the extremely fine copper wire is compressed during rolling, resulting in an optimal length, L, of approximately 104 mm.

[0070] (3) The bare copper wire after the first bending is bent a second time to form a radio frequency antenna, so that the entire radio frequency antenna is in the shape of a sine wave, as shown in Figures 6 and 7.

[0071] During the secondary bending process, a forward thrust and left-right squeezing force are simultaneously applied to the bare copper wire after the primary bend, causing it to bend again under the combined force to form an overall sinusoidal wave shape. In other words, the corrugated copper wire after the primary bend is subjected to left-right forces as it moves forward. The combined force of these two forces transforms the primary bent copper wire into a sinusoidal wave shape, which is called a "secondary bent copper wire RF antenna."

[0072] The copper wire is bent to form a sinusoidal RF antenna, depending on the needs. Specifically, the copper wire experiences a periodic left-right thrust as it moves forward. These two perpendicular forces create a sinusoidal shape. Adjusting the magnitude of the left-right thrust adjusts the height and width of the secondary bend. The length of a sinusoidal RF antenna can range from 85mm to 60mm.

[0073] If needed, you can also choose to bend the copper wire to form a two-sine-wave RF antenna. This means that the single-bent copper wire antenna experiences two cycles of left and right thrust as it moves forward. By adjusting the amplitude of these thrusts, the height and width of the two connected sinusoidal curves can be adjusted. The length of the two-sine-wave RF antenna can range from 65mm to 45mm.

[0074] (4) Connect the processed RF antenna to the semi-finished tag to form a coupled RF tag.

[0075] As shown in FIG8 , when a sine-periodic RF antenna is formed by secondary bending, the single-coil RF resonant cavity RCA is coupled to the middle position of the RF antenna to form a coupled RF tag.

[0076] As shown in FIG9 , when the secondary bend forms a radio frequency antenna with two sinusoidal periods, the dual-coil radio frequency resonant cavity MRS is coupled to the two sinusoidal wave connection positions of the radio frequency antenna to form a coupled radio frequency tag.

[0077] Application of the double-bent copper wire antenna coupled radio frequency tag in the present invention:

[0078] (1) The length of the RF antenna with a secondary bend of a sinusoidal cycle is 80mm to 65mm. The RF tags produced include aviation luggage RF tags, express RF tags, logistics RF tags, clothing RF tags, commodity RF tags, water-washable RF tags, laundry RF tags, etc.

[0079] (2) The length of the RF antenna with two secondary bends of two sinusoidal periods is selected between 65mm and 45mm. The RF tag combined with the micro dual-coil RF sensor (i.e., dual-coil RF resonant cavity MRS) not only has a long reading distance in various RF identification scenarios, but also has an anti-counterfeiting function that can detect the authenticity at a glance due to the unique pattern of the "micro dual-coil RF sensor". It is used for the anti-counterfeiting needs of industries such as food, medicine, tobacco, alcohol, shoes and clothing, and electronic products, as well as for the automatic information management of warehousing and logistics.

[0080] The double-bent copper wire antenna coupled radio frequency tag of the present invention has excellent environmental benefits:

[0081] The traditional chemical etching process for RFID tag antennas (INLAY) saves 360 tons of PET film, 144 tons of PET aluminum foil glue, and 300 tons of aluminum foil for every 2 billion tags. However, the double-bent copper wire antenna of the present invention and the coupled RFID tag it produces do not require PET film etching, generating no waste liquid or wastewater. This is safe and environmentally friendly, reducing the use of 72 tons of volatile solvents, 300 tons of chemical etching solution, and a significant amount of wastewater.

[0082] The double-bent copper wire antenna coupled radio frequency tag of the present invention has excellent economic benefits:

[0083] (1) The average unit cost of the traditional chemically etched antenna (INLAY) of the RFID tag is more than RMB 0.025, while the cost of the double-bent copper wire antenna in the present invention is only RMB 0.0015, saving RMB 0.0235 per antenna. The cost of 100 million RFID tags is reduced by RMB 2.35 million.

[0084] The biggest barrier to upgrading RFID tags in the express delivery industry is their cost. Given the 100 billion tags used annually by the express delivery industry, double-bent copper wire antennas save 2.35 billion RMB compared to traditional PET aluminum foil chemically etched antennas. These double-bent copper wire antennas are helping to expand RFID tag adoption in the express delivery, logistics, and commercial sectors.

[0085] (2) Recycling radio frequency resonant cavity RCA and micro dual-coil radio frequency sensor MRS can increase the economic benefits of recycling chips for multiple uses.

[0086] Excluding the costs of recycling and secondary label production, the secondary use of RF chips can save the cost of chips and packaging binding by 50% of the chip price. The label cost of the secondary used RF chip will be reduced by RMB 0.05, and a total of RMB 100 million can be saved for 2 billion RF labels.

Claims

1. A secondary bent copper wire antenna coupled type radio frequency tag, characterized in that: include: A corrugated radio frequency antenna, wherein the radio frequency antenna is bent to form a sine wave shape; A radio frequency resonant cavity assembly is coupled to the radio frequency antenna.

2. The double-bent copper wire antenna coupling type radio frequency tag according to claim 1, characterized in that: The radio frequency resonant cavity assembly comprises a radio frequency resonant cavity and a radio frequency chip, and the radio frequency chip is connected to the opening of the coil in the radio frequency resonant cavity.

3. The double-bent copper wire antenna coupling type radio frequency tag according to claim 1, characterized in that: It also includes label face paper and label base paper, and the radio frequency antenna and the radio frequency resonant cavity assembly are located between the label face paper and the label base paper.

4. The twice-bent copper wire antenna coupled radio frequency tag according to any one of claims 1 to 3, characterized in that: The radio frequency antenna forms a sinusoidal period after being bent.

5. The twice-bent copper wire antenna coupled radio frequency tag according to any one of claims 1 to 3, characterized in that: The radio frequency antenna forms two sinusoidal periods after being bent.

6. A method for manufacturing a secondary-bending copper wire antenna coupled radio frequency tag, characterized in that: The following steps are involved: (1) Prepare bare copper wire to be processed; (2) Bend the bare copper wire once to form a corrugated shape; (3) The bare copper wire after the first bending is bent for a second time to form a radio frequency antenna, so that the entire radio frequency antenna is in a sinusoidal wave shape; (4) Connect the processed RF antenna to the semi-finished tag to form a coupled RF tag.

7. The method for manufacturing a double-bent copper wire antenna coupled radio frequency tag according to claim 6, characterized in that: During the primary bending process of the bare copper wire, double gears are used for rolling.

8. The method for manufacturing a double-bent copper wire antenna coupled radio frequency tag according to claim 6, characterized in that: During the secondary bending process, a forward thrust and a left-right extrusion force are simultaneously applied to the bare copper wire after the primary bending, so that the secondary bending under the action of the combined force forms an overall sinusoidal wave shape.

9. The method for manufacturing a double-bent copper wire antenna coupled radio frequency tag according to any one of claims 6 to 8, characterized in that: When a sine-period RF antenna is formed by secondary bending, the middle position of the RF antenna is connected to the single-coil RF resonant cavity RCA to form a coupled RF tag.

10. The method for manufacturing a double-bent copper wire antenna coupled radio frequency tag according to any one of claims 6 to 8, characterized in that: When the secondary bend forms a radio frequency antenna with two sinusoidal periods, the two sinusoidal wave connection positions of the radio frequency antenna are connected to the double-coil radio frequency resonant cavity MRS to form a coupled radio frequency tag.

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