Flexible anti-metal RFID tag capable of being pasted and used on curved surface and preparation method of flexible anti-metal RFID tag

Abstract

The invention relates to a flexible anti-metal RFID tag capable of being pasted and used on a curved surface and a preparation method thereof.The tag comprises a flexible substrate, an antenna, a chip and a foam layer, the antenna is fixedly attached to the flexible substrate and is folded in half from the middle along with the flexible substrate to form an antenna top layer and an antenna bottom layer, and the antenna top layer and the antenna bottom layer are electrically connected through a bending part; the chip is electrically connected with the antenna top layer or the antenna bottom layer, and a plurality of notch grooves penetrating through the flexible substrate are correspondingly formed in the two opposite side edges of the antenna bottom layer at intervals. The label has the advantages that the notch grooves are formed in the bottom layer of the label, and when the label is pasted on a metal curved surface, the label can be better released at the notch grooves due to bending deformation without accumulation, so that wrinkles or closed bubbles are not easily generated when the label is pasted on the curved surface, and the performance of the pasted label can reach more than 80% of that of the label which is pasted on a plane; the performance is excellent; during preparation, various methods such as etching and die cutting are creatively and comprehensively applied, and the defect that the label with the notch groove cannot be formed only by using a traditional single etching method is overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of radio frequency tags, and in particular relates to a flexible anti-metal RFID tag that can be posted on a curved surface and a preparation method thereof. Background Art

[0002] When the anti-metal RFID tag is used on a metal surface, its special structural design can avoid the influence of the metal surface on the reading of the RFID tag signal. Since the flexible anti-metal RFID tag has a flexible substrate, an antenna formed on the flexible substrate, and a foam layer sandwiched between the upper and lower layers of the antenna, it has a certain ability to bend and deform. When it is necessary to post RFID tags on metal curved surfaces such as metal cylinders and elliptical cylinders, flexible anti-metal RFID tags are usually selected to ensure that the tags can fit relatively well with the metal curved surface.

[0003] However, in actual use, it is found that when the flexible anti-metal RFID tag is posted on a metal curved surface, its performance is often significantly reduced compared to when it is posted on a metal flat surface. For example, when the flexible anti-metal RFID tag is posted on a metal cylindrical surface, if the corresponding arc length central angle of the flexible anti-metal RFID tag after posting is above 60 degrees, the performance drops to less than 80%. Specifically, the same specification of flexible anti-metal RFID tags have an effective identification distance of more than 10m after being posted on a metal flat surface, but the effective identification distance after being posted on a metal curved surface is often less than 8m. After careful analysis, it was found that one of the main reasons for the performance degradation may be that the flexible substrate (usually PET) and the foam layer have different expansion and contraction properties when subjected to stress, and the flexible substrate is a continuous whole film material. When posted, the stress is not easy to release and the bubbles are easily sealed between the metal surface layer and the flexible substrate, resulting in the RFID tag finally posted on the metal curved surface having obvious wrinkles and unevenness, and the final performance of the tag is significantly reduced. Summary of the invention

[0004] The present invention provides a flexible anti-metal RFID tag that can be posted on a curved surface and a preparation method thereof, which solves the problem that the performance of a conventional flexible anti-metal RFID tag is significantly reduced when it is posted on a metal curved surface.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a flexible anti-metal RFID tag that can be posted on a curved surface, comprising a flexible substrate, an antenna, a chip and a foam layer, wherein the antenna is fixedly attached to the flexible substrate and is folded in half from the middle to form an antenna top layer and an antenna bottom layer electrically connected to each other by a bent portion, the chip is electrically connected to the antenna top layer or the antenna bottom layer, and the antenna bottom layer is provided with a plurality of notches formed by removing corresponding areas of the antenna bottom layer and the flexible substrate at corresponding intervals on two opposite sides perpendicular to the bent portion.

[0006] Based on the above technical solution, the present invention can also be improved as follows.

[0007] Furthermore, a printable surface layer is fixed to the upper surface of the top layer of the antenna by adhesive bonding.

[0008] Furthermore, glassine backing paper is fixed to the lower surface of the antenna bottom layer and the area of ​​the lower surface of the foam layer corresponding to the notch by adhesive bonding.

[0009] Furthermore, the foam layer is in the shape of a rectangular plate and its width is the same as the width of the bending portion, the depth of the notch groove is 1 / 4-1 / 3 of the width of the foam layer, the opening width of each notch groove at the side edge of the antenna bottom layer is 1 / 30-1 / 15 of the length of the foam layer, and the length of the foam layer is equivalent to the length of the antenna bottom layer or the antenna top layer.

[0010] Furthermore, there are multiple notches on the long sides of the antenna bottom layer, and the sum of the widths of all the notches on the long sides of the antenna bottom layer is 1 / 6-1 / 4 of the length of the antenna bottom layer.

[0011] Furthermore, the flexible substrate is a PET film or PI film with a thickness of 0.02-0.06 mm, the thickness of the antenna top layer and the antenna bottom layer are both 0.01-0.04 mm, and the thickness of the foam layer is 0.5-3 mm.

[0012] The present invention also provides a method for preparing the above-mentioned flexible anti-metal RFID tag that can be posted on a curved surface, which comprises the following steps:

[0013] S1. Printing a protective layer on the metal film layer composited on the upper surface of the flexible substrate;

[0014] S2. Etching and cleaning the metal film layer on the flexible substrate to form an antenna including an antenna top layer, an antenna bottom layer and a bending portion but not yet folded, and after passing the inspection, the antenna is set aside;

[0015] S3. Install the fixed chip in the GAP area of ​​the antenna and cut the waste to form each notch groove on the two opposite sides of the bottom of the antenna;

[0016] S4. Fold the antenna in half and composite the foam layer, fold the top layer of the antenna to the top of the bottom layer of the antenna, and fix the upper and lower surfaces of the foam layer to the top layer and the bottom layer of the antenna respectively by adhesive tape, and fix the printable surface layer on the upper surface of the top layer of the antenna by adhesive tape, and fix the glassine backing paper on the lower surface of the bottom layer of the antenna by adhesive tape;

[0017] S5. Die-cut and discard to form finished labels.

[0018] Based on the above preparation method, the present invention also has the following further specific options.

[0019] Specifically, in S3, the two opposite sides of the antenna bottom layer are first cut to form gap grooves, and then the fixed chip is installed at the GAP area of ​​the antenna.

[0020] Specifically, the metal film layer in S1 is an aluminum film or a copper film, and the metal film layer on the surface of the area corresponding to the notch is removed during etching in S2, and the cutting and waste removal in S3 is to cut through and remove the flexible substrate in the area corresponding to the notch using a laser cutting device.

[0021] Specifically, the cutting and waste removal in S3 is to use a die-cutting device to cut through and remove the metal film layer and the flexible substrate in the area corresponding to the notch groove.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] A plurality of notches are formed by cutting and removing at intervals on the two opposite sides of the antenna bottom layer together with the corresponding areas on both sides of the flexible substrate. After the notches are formed on the bottom layer of the obtained flexible anti-metal label, when it is pasted on a metal curved surface, the bending deformation can be better released at each notch without accumulation. Therefore, it is not easy to produce wrinkles or folds when pasted on the curved surface. At the same time, it can also effectively prevent the generation of closed bubbles between the metal curved surface and the label bottom layer during the pasting process. The performance of the flexible anti-metal label after pasting on the curved surface can reach more than 80% of that when it is pasted on a flat surface, which is significantly better than the same type of flexible anti-metal label with a complete bottom layer and no notches.

[0024] In the preparation method, the antenna forming method of the traditional RFID radio frequency tag is usually completed by etching the metal film layer on the flexible substrate. In order to make the antenna have a notch groove structure, the present invention combines etching forming with die cutting forming or laser cutting forming when forming the antenna, that is, a new combined antenna forming method is proposed. The antenna and the corresponding flexible anti-metal label prepared by this method have less performance attenuation when posted on a curved surface and have obvious advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a flexible anti-metal RFID tag that can be posted on a curved surface provided by the present invention;

[0026] Figure 2 for Figure 1 The bottom view of the flexible anti-metal RFID tag after the glassine backing paper is torn off;

[0027] Figure 3 for Figure 2 A cross-sectional view of the flexible anti-metal RFID tag along AA;

[0028] Figure 4 for Figure 1 The flexible anti-metal RFID tag is attached to the side of a metal cylinder in a top view;

[0029] Figure 5 for Figure 4 A schematic diagram of the portion marked with a number B and enclosed by a dotted circle after being enlarged;

[0030] Figure 6 This is a real-life effect diagram of a flexible anti-metal RFID tag without notches on the bottom layer in the prior art being affixed to a cylindrical surface (the left picture is before bonding, and the right picture is after bonding, and after bonding, there are usually obvious wrinkles);

[0031] Figure 7 The actual effect picture of the flexible anti-metal label provided by the present invention, which has various notches on the bottom layer and can be posted on the curved surface, is posted on the cylindrical curved surface (the left picture is before bonding, and the right picture is after bonding. After bonding, there are generally no wrinkles and it is relatively smooth);

[0032] Figure 8 This is a picture of the finished flexible anti-metal label that can be posted on a curved surface and is prepared by the present invention.

[0033] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0034] 1. Flexible substrate; 2. Chip; 3. Foam layer; 4. Antenna top layer; 5. Antenna bottom layer; 6. Printable surface layer; 7. Glassine backing paper; 8. Notch groove; 100. Flexible anti-metal RFID tag; 200. Metal cylinder. DETAILED DESCRIPTION

[0035] The principles and features of the present invention are described below in conjunction with the accompanying drawings and specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0036] In the description of the present invention, if terms indicating orientation such as "up", "down", "left", "right", "top", "bottom", "inside" and "outside" are used, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] like Figures 1 to 5As shown, the present invention provides a flexible anti-metal RFID tag that can be posted on a curved surface, comprising a flexible substrate 1, an antenna, a chip 2 and a foam layer 3. The antenna is fixedly attached to the flexible substrate 1 and is folded in half from the middle to form an antenna top layer 4 and an antenna bottom layer 5 electrically connected to each other by a bent portion. The chip 2 is electrically connected to the antenna top layer 4 or the antenna bottom layer 5. The antenna bottom layer 5 is provided with a plurality of notch grooves 8 formed by removing corresponding areas of the antenna bottom layer 5 and the flexible substrate 1 at corresponding intervals at two opposite sides perpendicular to the bent portion.

[0038] It should be noted that the notch is a blank slot left after the corresponding areas on both sides of the antenna bottom layer and the corresponding areas on both sides of the flexible substrate are cut or removed in other ways. The notch is different from the existing narrow gap opened for the resonance of the antenna. The notch is generally wider, and its width is significantly greater than the overall thickness of the label. In addition, since the antenna bottom layer and the flexible substrate are usually very thin, both below 0.1mm, even if there is no corresponding antenna bottom layer and flexible substrate at the notch, there will be no obvious unevenness when posting, and the self-adhesive can form a layer of adhesive film on the bottom layer of the label.

[0039] In one embodiment of the present invention, Figure 1 and Figure 3 As shown, the top surface of the antenna top layer 4 is fixed with a printable surface layer 6 by adhesive. The printable surface layer is used to print basic product information, which may be one or more of the information such as trademark, manufacturer name, and production date. The printable surface layer also plays a role in shielding and protecting the top layer of the antenna and the bending part of the antenna to a certain extent. When it is not necessary to print some information related to the product, the printable surface layer can also be replaced by other protective materials, such as PET film, PVC film, fluorocarbon coating, etc.

[0040] In one embodiment of the present invention, Figure 1 As shown, a glassine backing paper 7 is fixed to the lower surface of the antenna bottom layer 5 and the lower surface of the foam layer 3 in the area corresponding to the notch groove 8 by adhesive bonding.

[0041] It should be noted that the flexible anti-metal label produced by the present invention that can be posted on a curved surface should be fixed with a glassine backing paper by adhesive bonding at the bottom layer for convenience when leaving the factory. In this way, when using, the label can be posted on a metal curved surface or other target carrier by simply tearing off the glassine backing paper without applying glue separately. Figure 8 When the flexible anti-metal label 100 provided by the present invention can be pasted on a curved surface and is pasted on the cylindrical curved surface of a metal cylinder 200, Figure 4 and 5As shown, when posting, tear off the glassine backing paper first, and then post it directly on the metal cylindrical surface. When posting, the bent part of the label should be kept as parallel to the axis of the cylindrical surface as possible.

[0042] In one embodiment of the present invention, the foam layer 3 is in the shape of a rectangular plate and its width is the same as the width of the bending portion, the depth of the notch groove 8 is 1 / 4-1 / 3 of the width of the foam layer 3, and the opening width of each notch groove 8 at the side edge of the antenna bottom layer 5 is 1 / 30-1 / 15 of the length of the foam layer 3, and the length of the foam layer 3 is equivalent to the length of the antenna bottom layer 5 or the antenna top layer 4.

[0043] As mentioned above, the width and depth of the notch groove are both large, which ensures that the bottom layer has better flexibility and the bending deformation during pasting can be better released to the notch groove, thereby avoiding obvious wrinkles.

[0044] In one embodiment of the present invention, there are multiple notches 8 on the long sides of the antenna bottom layer 5 , and the sum of the widths of all the notches 8 on the long sides of the antenna bottom layer 5 is 1 / 6-1 / 4 of the length of the antenna bottom layer 5 .

[0045] It should be noted that when a plurality of notches are provided on each side of the antenna bottom layer and the notches occupy a total area of ​​one side of the antenna bottom layer that reaches the above degree, it can ensure that the label is smoother and less prone to wrinkles when posted on a curved surface.

[0046] In one embodiment of the present invention, the flexible substrate 1 is a PET film or PI film with a thickness of 0.02-0.06 mm, the thickness of the antenna top layer 4 and the antenna bottom layer 5 are both 0.01-0.04 mm, and the thickness of the foam layer 3 is 0.5-3 mm.

[0047] It should be noted that the material thickness in the above-mentioned value ranges can ensure that the corresponding flexible anti-metal label has better performance when affixed to a metal curved surface, and the effective recognition distance is not significantly attenuated.

[0048] The present invention also provides a method for preparing the above-mentioned flexible anti-metal RFID tag that can be posted on a curved surface, which comprises the following steps:

[0049] S1. Printing a protective layer on the composite metal film layer on the upper surface of the flexible substrate 1;

[0050] S2. Etching and cleaning the metal film layer on the flexible substrate 1 to form an antenna including an antenna top layer 4, an antenna bottom layer 5 and a bending portion but not yet folded, and after passing the inspection, the antenna is set aside;

[0051] S3. Install the fixed chip 2 in the GAP area of ​​the antenna and cut the waste to form each notch groove 8 on two opposite sides of the antenna bottom layer 5;

[0052] S4. Fold the antenna in half and compositely adhere the foam layer 3, fold the antenna top layer 4 to the top of the antenna bottom layer 5, and adhere the upper and lower surfaces of the foam layer 3 to the antenna top layer 4 and the antenna bottom layer 5 respectively by adhesive tape, and at the same time, adhere the printable surface layer 6 to the upper surface of the antenna top layer 4 by adhesive tape, and adhere the glassine backing paper 7 to the lower surface of the antenna bottom layer 5 by adhesive tape;

[0053] S5. Die-cut and discard to form finished labels.

[0054] It should be noted that the protective layer printed in S1 is acid-resistant but not alkali-resistant ink. After printing, acid etching is used in S2 etching. The acid etching dissolves and removes all the metal film layers in the unprotected areas. The remaining metal film layer constitutes the basic structure of the antenna circuit. When cleaning, the protective layer can be removed by alkali washing first, and then washed with water. After drying, defect detection can be carried out, and then the next step can be carried out.

[0055] In one embodiment of the present invention, in S3, the two opposite sides of the antenna bottom layer 5 are cut and removed to form the notches 8, and then the fixed chip 2 is installed at the GAP area of ​​the antenna. It can be understood that in S3, the chip can also be fixed and installed first, and then the notches are cut and removed to form the notches. The order is different, but the results are the same, and both should be included in the protection scope of the present invention.

[0056] In one embodiment of the present invention, the metal film layer in S1 is an aluminum film or a copper film, and the metal film layer on the surface of the area corresponding to the notch 8 is removed during etching in S2, and the cutting and waste removal in S3 is to cut through and remove the flexible substrate 1 in the area corresponding to the notch 8 using a laser cutting device. In other words, in this embodiment, the cutting and waste removal is only to cut off the PET film or PI film (flexible substrate) in the area corresponding to the notch, and the cutting of the plastic film can be completed by a laser cutting method.

[0057] In another embodiment of the present invention, the cutting and waste removal in S3 is to use a die-cutting device to cut through and remove the metal film layer and the flexible substrate 1 in the area corresponding to the notch 8. In other words, during etching, the metal film layer in the area corresponding to the notch is protected by the protective layer and is not etched away. Subsequently, during the notch cutting and forming, a die-cutting knife is used to directly cut off the metal film layer and the flexible substrate in the area corresponding to the notch to form the notch.

[0058] like Figure 6As shown in the figure, the antenna bottom layer and the flexible substrate of the existing flexible anti-metal label have complete edges without gaps. When it is posted on a cylindrical surface, the deformation cannot be well released during bending. The accumulated effect causes obvious wrinkles on the edge of the label after posting. There is also a large possibility of closed bubble area inside, which fails to fit well with the cylindrical surface, resulting in a decrease in label performance. Figure 6 The curved surface of the middle cylinder is made of plastic, and it is only used here to better illustrate the wrinkled area on the label after it is posted. In addition, the present invention also actually measures the performance change of the label when it is posted on the metal cylinder. After multiple tests, when it is posted on the side wall surface of the metal cylinder (such as the metal cylinder), the flexible anti-metal label, which originally had an average effective recognition distance of 10.5m after being posted on the flat metal surface, actually has an average effective recognition distance of only 7.3m, that is, the performance drops to less than 70%.

[0059] like Figure 7 As shown, the flexible anti-metal label with a notch groove on the bottom provided by the present invention is relatively smooth as a whole after being posted on a cylindrical curved surface, and no obvious wrinkles are observed. As above, the present invention has conducted a label performance test. After multiple tests, when posted on the side wall surface of a metal cylinder (such as a metal cylinder), the flexible anti-metal label, which originally had an effective recognition distance of 10.8m on average after being posted on a flat metal surface, actually measured an effective recognition distance of 8.9m on average, that is, the performance is maintained at more than 80% of the original flat surface.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A flexible anti-metal RFID tag that can be posted on a curved surface. It is characterized in that The invention comprises a flexible substrate (1), an antenna, a chip (2) and a foam layer (3); the antenna is fixedly attached to the flexible substrate (1) and is folded in half from the middle to form an antenna top layer (4) and an antenna bottom layer (5) which are electrically connected to each other by the folded portion; the chip (2) is electrically connected to the antenna top layer (4) or the antenna bottom layer (5); and the antenna bottom layer (5) is provided with a plurality of notches (8) formed by removing corresponding areas of the antenna bottom layer (5) and the flexible substrate (1) at corresponding intervals on two opposite side edges perpendicular to the folded portion.

2. According to claim 1, a flexible anti-metal RFID tag that can be posted on a curved surface, It is characterized in that A printable surface layer (6) is fixed to the upper surface of the antenna top layer (4) by adhesive bonding.

3. The flexible anti-metal RFID tag that can be posted on a curved surface according to claim 1, It is characterized in that Glassine backing paper (7) is fixed to the lower surface of the antenna bottom layer (5) and the area of ​​the lower surface of the foam layer (3) corresponding to the notch groove (8) by adhesive bonding.

4. The flexible anti-metal RFID tag that can be posted on a curved surface according to claim 1, It is characterized in that The foam layer (3) is in the shape of a rectangular plate and has a width that is the same as the width of the bent portion; the depth of the notch groove (8) is 1 / 4-1 / 3 of the width of the foam layer (3); the opening width of each notch groove (8) at the side edge of the antenna bottom layer (5) is 1 / 30-1 / 15 of the length of the foam layer (3); and the length of the foam layer (3) is equivalent to the length of the antenna bottom layer (5) or the antenna top layer (4).

5. The flexible anti-metal RFID tag that can be posted on a curved surface according to claim 4, It is characterized in that A plurality of the notches (8) are provided on the long sides of both sides of the antenna bottom layer (5), and the sum of the widths of all the notches (8) on the long sides of both sides of the antenna bottom layer (5) is 1 / 6 to 1 / 4 of the length of the antenna bottom layer (5).

6. A flexible anti-metal RFID tag that can be posted on a curved surface according to any one of claims 1 to 5, It is characterized in that The flexible substrate (1) is a PET film or a PI film with a thickness of 0.02-0.06 mm, the antenna top layer (4) and the antenna bottom layer (5) are both 0.01-0.04 mm thick, and the foam layer (3) is 0.5-3 mm thick.

7. A method for preparing a flexible anti-metal RFID tag that can be posted on a curved surface as claimed in any one of claims 1 to 6, It is characterized in that The steps include: S1. Printing a protective layer on the composite metal film layer on the upper surface of the flexible substrate (1); S2. Etching and cleaning the metal film layer on the flexible substrate (1) to form an antenna including an antenna top layer (4), an antenna bottom layer (5) and a bending portion but not yet folded, and after passing the inspection, the antenna is set aside; S3. Install the fixed chip (2) in the GAP area of ​​the antenna and cut the waste on the two opposite sides of the antenna bottom layer (5) to form each notch groove (8); S4. The antenna is folded in half to form a shape and the foam layer (3) is bonded to the antenna bottom layer (5), the top layer (4) of the antenna is folded to the top of the antenna bottom layer (5), the upper and lower surfaces of the foam layer (3) are respectively bonded to the antenna top layer (4) and the antenna bottom layer (5) by adhesive tape, and the printable surface layer (6) is bonded to the upper surface of the antenna top layer (4) by adhesive tape, and the glassine backing paper (7) is bonded to the lower surface of the antenna bottom layer (5) by adhesive tape; S5. Die-cut and discard to form finished labels.

8. A method for preparing a flexible anti-metal RFID tag that can be posted on a curved surface according to claim 7, It is characterized in that In S3, the two opposite sides of the antenna bottom layer (5) are cut to form notches (8), and then the fixed chip (2) is installed at the GAP area of ​​the antenna.

9. A method for preparing a flexible anti-metal RFID tag that can be posted on a curved surface according to claim 7 or 8, Features The metal film layer in S1 is an aluminum film or a copper film. When etching in S2, the metal film layer on the surface of the area corresponding to the notch groove (8) is removed together. The cutting and waste removal in S3 is to use a laser cutting device to cut through and remove the flexible substrate (1) in the area corresponding to the notch groove (8).

10. A method for preparing a flexible anti-metal RFID tag that can be posted on a curved surface according to claim 7 or 8, It is characterized in that The cutting and waste removal in S3 is to use a die-cutting device to cut through and remove the metal film layer and the flexible substrate (1) in the area corresponding to the notch groove (8).

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