A quarter-wave flexible UHF RFID electronic tag

Abstract

The present invention discloses a quarter-wave bending flexible ultra-high frequency RFID electronic tag, which includes a printable surface layer, an inlay layer, an insulating medium layer and an adhesive layer, wherein the inlay layer includes an inlay top surface portion, an inlay bottom surface portion and an inlay side portion connecting the inlay top surface portion and the inlay bottom surface portion, the inlay top surface portion is located between the printable surface layer and the insulating medium layer, the inlay bottom surface portion is located between the insulating medium layer and the adhesive layer, and an insulating auxiliary layer for increasing stiffness is also provided between the inlay top surface portion and the insulating medium layer. The product of the present invention is thin as a whole, has good flexibility, can be pasted on a curved surface object, can be printed and encoded by a commonly used RFID printer on the market, has a wider range of application, and has a long and stable reading distance.

Description

[Technical field]

[0001] The invention belongs to the technical field of electronic tags, and in particular relates to a quarter-wave bending flexible ultra-high frequency RFID electronic tag. [Background technology]

[0002] UHF RFID (ultra high frequency radio frequency identification) is an ultra high frequency wireless radio frequency tag. Ultra high frequency RFID technology has the characteristics of being able to read multiple tags at one time, strong penetration, multiple read and write, large data storage capacity, low cost, small size, easy to use, high reliability and life span. Ultra high frequency wireless radio frequency tags have been widely used in various industries, such as fixed asset management, management in warehousing and logistics transportation, and customs supervision and management of items or vehicles.

[0003] The application of ultra-high frequency electronic tags is very extensive, and the environment is changeable. Many managed items are metal objects, such as cars, containers, computers, metal shelves, etc. However, when ordinary wireless radio frequency tags are placed on metal surfaces, the reading distance of the wireless radio frequency tags will be greatly reduced or even cannot be read.

[0004] The demand for anti-metal radio frequency tags is increasing. Under the premise of large demand, the cost of radio frequency tags is particularly prominent. Existing flexible UHF RFID tags are all half-wave designs. The inlay of RFID tags is flat pressed onto substrates such as foam glue, PP, PET, and silicone, that is, the inlay is disconnected from the conductive layer at the bottom. It has the following disadvantages: 1) large product size; 2) short reading distance; 3) frequency deviation is easily caused by material differences during the production process, resulting in a decrease in reading distance, that is, the performance of RFID tags is unstable. [Summary of the invention]

[0005] The main purpose of the present invention is to provide a quarter-wave bending flexible ultra-high frequency RFID electronic tag with a long and stable reading distance.

[0006] The present invention achieves the above-mentioned purpose through the following technical scheme: a quarter-wave bent flexible ultra-high frequency RFID electronic tag, which includes a printable surface layer, an inlay layer, an insulating medium layer and an adhesive layer, the inlay layer includes an inlay top surface portion, an inlay bottom surface portion and an inlay side portion connecting the inlay top surface portion and the inlay bottom surface portion, the inlay top surface portion is located between the printable surface layer and the insulating medium layer, the inlay bottom surface portion is located between the insulating medium layer and the adhesive layer, and an insulating auxiliary layer for increasing stiffness is also arranged between the inlay top surface portion and the insulating medium layer.

[0007] Furthermore, the printable surface layer includes a printable surface material top surface portion, a printable surface material side surface portion covering the inlay side surface portion, and a printable surface material bottom surface portion bent and inserted between the inlay bottom surface portion and the adhesive layer.

[0008] Furthermore, the printable surface layer may be a flexible printable material layer such as a PET protective layer, a PP protective layer, a PC protective layer or a coated paper layer.

[0009] Furthermore, an antenna frequency modulation structure is provided on the top surface of the inlay.

[0010] Furthermore, the flexible insulating substrate layer may also be EVA foam, silica gel, PP, PET flexible coil or sheet.

[0011] Furthermore, a glue layer is provided on the surface of the insulating auxiliary layer facing the top surface of the inlay, so as to bond the insulating auxiliary layer and the inlay layer together.

[0012] Furthermore, the insulating auxiliary layer is a flexible insulating layer made of flexible PET material, paper, PC, ABS, or PP material.

[0013] Furthermore, the adhesive layer is industrial double-sided tape, foam tape, double-sided tape with a substrate, or silicone.

[0014] Furthermore, the inlay top portion is divided into an antenna portion, and the inlay bottom portion is divided into a ground portion of the antenna. The center frequency of the antenna is adjusted by adjusting the length of the antenna portion, that is, the bending position in the middle of the inlay top portion and the inlay bottom portion.

[0015] Furthermore, the antenna part includes an excitation feed ring composed of an L-shaped opening slot and a concave metal sheet, and a chip adhered to the inlay layer with conductive adhesive and powered by the excitation feed ring;

[0016] The grounding portion is designed on the bottom surface of the inlay, and includes a rectangular area surrounded by a plurality of spaced hollow grooves.

[0017] Compared with the prior art, the beneficial effect of the quarter-wave folded flexible ultra-high frequency RFID electronic tag of the present invention is that: the length of the Inlay is lengthened, the bottom conductive layer is made into a part of the Inlay, the bottom conductive layer is connected to the Inlay, and then the Inlay part is folded back onto the substrate of the RFID electronic tag through a bending process, that is, the quarter-wave design of the flexible RFID electronic tag is realized, so that under the condition of the same size, the reading distance is 1.5-2 times that of the ordinary half-wave flexible RFID electronic tag; in addition, the scheme can adjust the frequency of the RFID electronic tag by adjusting the bending position, thereby solving the problem of the problem of the material being different. The problem of frequency deviation and decreased reading distance caused by stability; a flexible printable surface layer will be used, and barcodes, numbers, text or images and other labels can be printed on the product surface by a printer, which improves the recognizability of the label and the availability of label information; the product is thin as a whole, has good flexibility, can be pasted on curved objects, and has a wider range of applications; this product can be printed and encoded by commonly used RFID printers on the market, and mass production can be achieved by using improved composite die-cutting equipment. The daily production capacity of each composite die-cutting equipment can reach 100,000 per day, which greatly improves production capacity and reduces production costs. The frequency modulation technology of the antenna solves the problem of frequency deviation caused by the thickness and density tolerance of each batch of the insulating medium layer.

Brief Description of the Drawings

[0018] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of the antenna chip layer in an embodiment of the present invention;

[0020] Figure 3 is a forward reading distance test curve diagram of the comparison antenna used in the embodiment of the present invention;

[0021] Figure 4 This is a forward reading distance test curve diagram of an embodiment of the present invention;

[0022] Figure 5 It is a reverse reading distance test curve diagram of an embodiment of the present invention;

[0023] The numbers in the figure represent:

[0024] 100 quarter-wave bending flexible ultra-high frequency RFID electronic tag; 1 printable surface layer, 11 printable surface material top surface portion, 12 printable surface material side portion, 13 printable surface material bottom surface portion; 2 inlay layer, 21 inlay top surface portion, 22 inlay bottom surface portion, 23 inlay side portion, 24 L-shaped opening groove, 25 concave metal sheet, 26 gap structure, 27 hollow groove, 28 chip; 3 insulating dielectric layer; 4 adhesive layer; 5 insulating auxiliary layer. [Specific implementation method]

[0025] Example:

[0026] Please refer to Figure 1-Figure 2 The present embodiment is a quarter-wave bending flexible ultra-high frequency RFID electronic tag 100, which includes a printable surface layer 1, an inlay layer 2, an insulating medium layer 3 and an adhesive layer 4, wherein the inlay layer 2 includes an inlay top surface portion 21, an inlay bottom surface portion 22 and an inlay side surface portion 23 connecting the inlay top surface portion 21 and the inlay bottom surface portion 22, the inlay top surface portion 21 is located between the printable surface layer 1 and the insulating medium layer 3, the inlay bottom surface portion 22 is located between the insulating medium layer 3 and the adhesive layer 4, and an insulating auxiliary layer 5 for increasing stiffness is also provided between the inlay top surface portion 21 and the insulating medium layer 3.

[0027] The printable surface layer 1 includes a printable surface material top surface portion 11, a printable surface material side portion 12 covering the inlay side portion 23, and a printable surface material bottom portion 13 bent and inserted between the inlay bottom portion 22 and the adhesive layer 4. The printable surface layer 1 can be a flexible printable material layer such as a PET protective layer, a PP protective layer, a PC protective layer or a coated paper layer. By designing the printable surface material side portion 12, the side of the inlay layer 2 is effectively protected, providing better protection for the inlay layer 2. The printable surface layer 1 can protect the inlay layer 2 and can also provide black and white and color printing of barcodes, text, numbers, images and other logos.

[0028] The inlay top surface 21 is provided with an antenna frequency modulation structure, and the inlay bottom surface 22 is a conductive part. The top surface and the bottom surface are connected through the side surface. The inlay is folded into a U shape through an automatic laminating machine and a bending process, and is attached to the non-conductive dielectric layer (i.e., the entire layer composed of the insulating dielectric layer 3 and the insulating auxiliary layer 5), thereby realizing a quarter-wave design. In this solution, the frequency of the RFID electronic tag can be adjusted by adjusting the length of the antenna on the top surface, thereby solving the problem of frequency offset caused by material instability affecting the decrease in reading distance.

[0029] The insulating medium layer 3 is a flexible insulating material, which separates the top surface of the inlay layer 2 from the bottom surface. At the same time, the inlay layer 2 is bent at the end surface of the insulating medium layer 3 to connect the top surface and the bottom surface of the inlay layer 2. The flexible insulating substrate layer 3 preferably uses a PE closed-cell foam layer, which is characterized by flexibility and convenient batch production of coils. The foam structure is a closed-cell structure with good waterproof performance, thereby avoiding the influence of water vapor and moisture on the reading distance and frequency of the wireless radio frequency tag. The PE closed-cell foam layer material is soft and can provide good protection for the chip and antenna. The flexible insulating substrate layer 3 can also be made of flexible coils or sheets such as EVA foam, silicone, PP, and PET.

[0030] The insulating auxiliary layer 5 is a flexible insulating material, and its purpose is to increase the stiffness of the flexible material of the insulating dielectric layer 3, and solve the problems of wrinkles and bubbles caused by the insulating dielectric layer 3 being too soft during the bending process. The surface of the insulating auxiliary layer 5 facing the inlay top surface portion 21 is provided with a glue layer, so as to bond the insulating auxiliary layer 5 to the inlay layer 2. The insulating auxiliary layer 5 preferably adopts a flexible PET material, which not only meets the requirements of increasing stiffness, but also meets the requirements of flexibility. The insulating auxiliary layer 5 can also be made of flexible materials such as paper, PC, ABS, PP, etc.

[0031] The adhesive layer 4 is an industrial double-sided tape, which can be used to stick the wireless radio frequency tag to the managed item. The material used in this embodiment is acrylic double-sided tape without a substrate, which has the advantage of high viscosity and can be applied to various surfaces; the adhesive layer 4 can also be made of foam glue, double-sided tape with a substrate, silicone and other sticky materials.

[0032] The inlay top surface portion 21 is the antenna portion, and the inlay bottom surface portion 22 is the grounding portion of the antenna, which eliminates the influence of most metals on the RFID electronic tag and makes the reading distance longer.

[0033] The antenna part includes an excitation feed ring composed of an L-shaped opening slot 24 and a concave metal sheet 25, and a chip 28 pasted on the inlay layer 2 with conductive glue and powered by the excitation feed ring; the L-shaped opening slot 24 is arranged around the concave metal sheet 25, and the chip 28 is pasted at the concave opening of the concave metal sheet 25 and is located on the long side of the L-shaped opening slot 24. By adjusting the size and position of the L-shaped opening slot 24 and the concave metal sheet 25, conjugate matching of the chip 28 and the antenna part on surfaces of different materials can be achieved, and the optimal reading distance has been achieved, which greatly improves the flexibility of the antenna design reading distance. This embodiment can also adapt to the influence of thickness and density tolerance of different batches of materials by adjusting the length of the inlay top surface part 21, that is, adjusting the bending position of the antenna part. The frequency decreases when the length of the bent antenna becomes longer, and vice versa. The frequency adjustment in the prior art is intelligently achieved by replacing materials or replacing antennas. Therefore, the electronic tag of this embodiment flexibly adjusts the antenna Inlay layer 2 for different batches of insulating medium layers 3 to ensure that the performance of each produced electronic tag is stable and reliable, and the reading distance meets the requirements.

[0034] A plurality of parallel slot structures 26 are also provided on one side of the concave metal sheet 25 .

[0035] The grounding portion is designed on the inlay bottom portion 22, and includes a rectangular area surrounded by a plurality of spaced hollow grooves 27, and the area is used to read the code of the RFID printer.

[0036] Please refer to Figure 3 , Figure 3 This is the forward reading distance measurement result of the tag with common antenna design. Its overall size is 60mm long, 25mm wide and 1.2mm thick. It uses Monza MR6P. The tag with common antenna design is pasted on the metal surface. The maximum reading distance of the fixed reader in the US area is 3-3.5 meters. Figure 3 The following table shows the reading distance measurement results of two common antenna tags. Figure 4-Figure 5 , Figure 4 This is a graph showing the forward reading distance test results of the product of this embodiment. Figure 5 This is a reverse reading distance test result diagram of the product of this embodiment. The overall dimensions of the quarter-wave bent flexible UHF RFID electronic tag 100 of this embodiment are 60 mm in length, 25 mm in width, and 1.2 mm in thickness. The chip 28 adopts Monza MR6P and is pasted on the metal surface. The maximum reading distance of the fixed reader in the US region reaches 6 meters, which is 1.7 times that of the ordinary design at the same size.

[0037] The quarter-wave folded flexible UHF RFID electronic tag 100 of this embodiment lengthens the length of the Inlay, makes the bottom conductive layer a part of the Inlay, makes the bottom conductive layer and the Inlay conductive, and then folds the Inlay part back onto the substrate of the RFID electronic tag through a bending process, thus realizing a quarter-wave design of the flexible RFID electronic tag, thereby realizing that under the condition of the same size, the reading distance is 1.5-2 times that of the ordinary half-wave flexible RFID electronic tag; in addition, this solution can adjust the frequency of the RFID electronic tag by adjusting the bending position, thereby solving the problems of frequency offset and reduced reading distance caused by unstable materials; and a flexible printable surface layer is adopted, and a printer can be used to print barcodes, numbers, text or images and other labels on the product surface, thereby improving the recognizability of the label and the availability of label information; this product is thin as a whole, has good flexibility, can be pasted on curved objects, and has a wider range of applications.

[0038] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A quarter-wave bending flexible UHF RFID electronic tag, characterized by: The invention comprises a printable surface layer, an inlay layer, an insulating medium layer and an adhesive layer, wherein the inlay layer comprises an inlay top surface portion, an inlay bottom surface portion and an inlay side surface portion connecting the inlay top surface portion and the inlay bottom surface portion, wherein the inlay top surface portion is located between the printable surface layer and the insulating medium layer, the inlay bottom surface portion is located between the insulating medium layer and the adhesive layer, and an insulating auxiliary layer for increasing stiffness is further arranged between the inlay top surface portion and the insulating medium layer; the inlay top surface portion is divided into an antenna portion, and the inlay bottom surface portion is divided into a grounding portion of the antenna, and by adjusting the The length of the antenna part, i.e., the bending position of the middle of the inlay top surface part and the inlay bottom surface part, realizes the adjustment of the antenna center frequency; the antenna part includes an excitation feed ring composed of an L-shaped opening groove and a concave metal sheet, and a chip that is attached to the inlay layer with conductive adhesive and powered by the excitation feed ring; the grounding part is designed on the inlay bottom surface part, which includes a rectangular area surrounded by a plurality of spaced hollow grooves; the printable surface layer includes a printable surface material top surface part, a printable surface material side surface part covering the inlay side surface part, and a printable surface material bottom surface part that is bent and inserted between the inlay bottom surface part and the adhesive layer.

2. The quarter-wave bending flexible UHF RFID electronic tag as claimed in claim 1, characterized in that: The printable surface layer is a flexible printable material layer made of a PET protective layer, a PP protective layer, a PC protective layer or a coated paper layer.

3. The quarter-wave bending flexible UHF RFID electronic tag as claimed in claim 1, characterized in that: The insulating medium layer is made of PE closed-cell foam cotton layer, EVA foam cotton, silica gel, PP, PET flexible coil or sheet.

4. The quarter-wave bending flexible UHF RFID electronic tag as claimed in claim 1, characterized in that: A glue layer is provided on the surface of the insulating auxiliary layer facing the top surface of the inlay, so as to bond the insulating auxiliary layer and the inlay layer together.

5. The quarter-wave bending flexible UHF RFID electronic tag as claimed in claim 1, characterized in that: The insulating auxiliary layer is a flexible insulating layer made of flexible PET material, paper, PC, ABS, or PP material.

6. The quarter-wave bending flexible UHF RFID electronic tag as claimed in claim 1, characterized in that: The adhesive layer is industrial double-sided adhesive, foam adhesive, double-sided adhesive with a substrate, or silica gel.

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