IC tag

Abstract

This provides an IC tag that can easily maintain a contactless communication state for a long period of time, even after the attached clothing has been repeatedly washed. [Solution] The IC tag 1D comprises a flexible substrate 10 made of an insulator, an antenna 30 made of a conductor on the substrate, an IC chip 20 connected to the antenna, and a protective material 40 attached to the substrate so as to overlap the entire IC chip in a plan view of the substrate.

Description

Technical Field

[0001] The present invention relates to an IC tag, more specifically, an IC tag having high washing durability and being suitably applicable to clothing and the like.

Background Art

[0002] An IC tag capable of non-contact communication including an IC chip connected to an antenna is also called an RFID (Radio Frequency IDentification) tag or an NFC (Near Field Communication) tag and is widely used for authenticity determination of articles, logistics management, and the like.

[0003] When applying an IC tag to clothing, in order to use it for a long period of time, it is necessary to maintain a state where non-contact communication is possible even when the attached clothing is washed. Regarding this problem, Patent Document 1 discloses a configuration in which a chip reinforcement is disposed on a part of an IC chip and an antenna, and the whole is covered with a flexible coating.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, the disconnection of the antenna due to deformation of the clothing to which the IC tag is applied is regarded as a major factor causing communication failure, and the above configuration is adopted. However, as will be described in detail later, when the inventors washed a large number of clothes to which the IC tag was attached and examined them, it became clear that the major factor causing the IC tag to become incommunicable during washing was different from the above. Based on the above findings, the inventors completed the present invention.

[0006] In view of the above circumstances, the present invention aims to provide an IC tag that can easily maintain a contactless communication state for a long period of time even when the attached clothing is repeatedly washed. [Means for solving the problem]

[0007] The present invention relates to an IC tag comprising a flexible substrate formed of an insulator, an antenna formed of a conductor on the substrate, an IC chip connected to the antenna, and a protective material attached to the substrate so as to overlap the entire IC chip in a plan view of the substrate. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an IC tag that can easily maintain a contactless communication state for a long period of time, even when the attached clothing is repeatedly washed. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic plan view showing an IC tag according to the first embodiment of the present invention. [Figure 2] This is a schematic bottom view of the IC tag. [Figure 3] This is a schematic bottom view showing a modified version of the IC tag. [Figure 4] This is a schematic bottom view showing a modified version of the IC tag. [Figure 5] This is a schematic bottom view showing a modified version of the IC tag. [Figure 6] This is a schematic bottom view showing a modified version of the IC tag. [Figure 7] This is a schematic bottom view showing a modified version of the IC tag. [Figure 8] This is a schematic plan view showing an IC tag according to a second embodiment of the present invention. [Figure 9] This is a schematic plan view showing a modified version of the IC tag. [Figure 10] This is a schematic plan view showing a modified version of the IC tag. [Figure 11] This is a schematic plan view showing a modified version of the IC tag. [Figure 12] It is a schematic bottom view showing an IC tag according to the third embodiment of the present invention. [Figure 13] It is a schematic cross-sectional view showing an IC tag according to a modified example of the present invention. [Figure 14] It is a schematic cross-sectional view showing an IC tag according to a modified example of the present invention.

Mode for Carrying Out the Invention

[0010] Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIG. 1 is a schematic plan view showing an IC tag 1 according to this embodiment, and FIG. 2 is a schematic bottom view of the IC tag. The IC tag 1 has a substrate 10 made of an insulator, an IC chip 20, an antenna 30, and a protective material 40 formed on the substrate 10.

[0011] The substrate 10 is formed in a rectangular shape in plan view using a resin material such as polyimide (Pi), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN). The thickness of the substrate 10 is, for example, about 50 to 150 μm and has flexibility that allows it to be easily curved.

[0012] The IC chip 20 is disposed on the upper surface of the substrate 10, and both ends of the antenna 30 are connected to form a closed circuit. There is no particular limitation on the mounting mode of the IC chip 20, and various methods such as wire bonding and flip chip can be selected. The entire IC chip 20 including the connection portion with the antenna 30 is covered and protected by a mold 21. The mold 21 can be formed, for example, by dropping a material such as resin onto the IC chip 20 and curing it.

[0013] The antenna 30 of this embodiment is an antenna for non-contact communication. Starting from the IC chip 20 located at the central part of the substrate 10 in plan view, it extends a certain length and then forms a plurality of loops toward the periphery and reaches the upper surface side end point 31. The antenna 30 continues from the upper surface side end point 31 to the lower surface side of the substrate 10, forms a plurality of loops toward the central part, and then comes out to the upper surface side again near the IC chip 20 and is connected to the IC chip 20. Such an antenna can be formed by etching a metal layer, drawing a metal wire, etc. From the perspective of reducing the discomfort of the wearer when attached to clothes, formation by etching with excellent flatness and flexibility is suitable. In the antenna 30, the connection between the upper surface pattern and the lower surface pattern can be performed by, for example, caulking.

[0014] The protective material 40 is attached to the lower surface of the substrate 10. In the plan view of the IC tag 1, the protective material 40 overlaps the entire mold 21 covering the IC chip 20. That is, the entire IC chip 20 including the periphery of the mold 21 and the joining part between the IC chip 20 and the antenna 30 is within the range of the protective material 40. The protective material 40 of this embodiment is a sheet formed of a resin such as PET or polyimide, and is attached using an adhesive or the like to cover a part of the substrate 10 and the antenna 30 formed on the lower surface. The thickness of the protective material 40 is, for example, 0.1 mm, and it may be 0.8 times or more the thickness of the substrate 10. The material of the protective material 40 may be the same as or different from that of the substrate 10.

[0015] The inventors conducted studies on attaching IC tags with various configurations to clothes and performing washing by water. When 16 samples of each IC tag were washed 25 times with a commercial washing machine, communication failures occurred in at least one sample or more in all IC tags, and many IC tags with communication failures in the majority were also observed.

[0016] In the above-mentioned Patent Document 1, it is considered that the disconnection of the antenna due to the bending stress acting on the RFID tag is a major factor in communication failures. However, when the inventors examined the IC tags that exhibited communication failures in detail during the above study, they found that none of the tags had broken antennas. Instead, many tags showed that a portion of the periphery of the mold 21 had peeled away from the substrate 10. Based on the resonant frequency during communication attempts, it was concluded that this peeling was causing poor or complete disconnection of the connection between the IC chip 20 and the antenna 30.

[0017] Based on the above findings, the inventors considered that suppressing the deformation of the substrate 10 at the periphery of the mold 21 might prevent the occurrence of the aforementioned delamination, and thus conceived of a configuration in which a protective material 40 is attached to the substrate 10. In other words, since the protective material 40 overlaps with the entire mold 21 in a plan view of the IC tag 1, bending deformation of the substrate 10 always reaches the protective material 40 before it is transmitted to the mold 21, regardless of where it occurs.

[0018] In the IC tag 1, the area where the protective material 40 is provided is thicker, so the rigidity (susceptibility to bending deformation) of the IC tag 1 changes abruptly at the boundary between the area with and without the protective material 40. As a result, bending stress concentrates at this boundary, making bending deformation more likely to occur at the boundary, and the force acting on the periphery of the mold 21 to peel the mold 21 from the substrate 10 is significantly reduced or eliminated.

[0019] In this embodiment, the IC tag 1, through the protective material 40, suppresses connection failures between the IC chip and the antenna 30, which are a major cause of communication failures during washing, and thus significantly improves resistance to washing. Sixteen garment samples, each fitted with an IC tag having a configuration equivalent to the IC tag 1 shown in Figures 1 and 2, were washed 25 times in a commercial washing machine, as in the same study described above. None of the samples showed communication failures, confirming the usefulness of the structure according to this embodiment.

[0020] In the IC tag 1 according to this embodiment, the shapes of the substrate 10 and the protective material 40 can be changed as appropriate. Figures 3 to 7 are bottom views of modified IC tags according to this embodiment. Each IC tag is equipped with a circular substrate 10. In the following figures, the antenna 30 is not shown, but its arrangement is generally the same as that of IC tag 1, and it is formed in a circular loop shape around the periphery of the substrate 10. Also, since the IC chip and mold are not visible from the bottom, the area of ​​the mold 21 is indicated by a dashed line.

[0021] The IC tag 1A shown in Figure 3, like the IC tag 1, has a protective material 40 that is positioned across the entire circular substrate 10 in one direction (the vertical direction in the figure). The effects and benefits of the protective material 40 are also generally the same as those of the IC tag 1.

[0022] The protective material 40A of the IC tag 1B shown in Figure 4 is positioned across the entire substrate 10 in one direction, similar to Figure 3, and has protrusions 41 that protrude on both sides in a direction intersecting this direction (the up and down direction in the figure). The IC tag 1B is equipped with a protective material 40A having a protrusion 41. When viewed in the intersecting direction where the protrusion 41 protrudes, as shown in Figure 4, it has a configuration consisting of a first region R1 where there is a substrate 10 but no protective material 40A, a second region R2 where there is both a substrate 10 and protective material 40A but no areas without protective material, and a third region R3 located between the first region R1 and the second region R2, where there is both a portion with a substrate 10 but no protective material 40A, and a portion with both a substrate 10 and protective material 40A. This increases the number of boundaries where the rigidity changes, and deformation is absorbed at each boundary, thus further reducing the force acting on the periphery of the mold 21. Similar effects can be expected by providing a recess instead of a protrusion, or by providing both a protrusion and a recess.

[0023] The protective material 40B of the IC tag 1C shown in Figure 5 is triangular in plan view and does not cover the entire substrate 10 in any direction. In a configuration with protective material of this type, the periphery of the protective material is easily deformed in any direction, and the deformation is not directional. Therefore, while suitably protecting the periphery of the mold 21 as in the embodiments described above, it has the advantage of being able to deform well to follow the wearer's body movements when attached to clothing, and is less likely to cause discomfort to the wearer. In this embodiment, there are no restrictions on the plan view shape of the protective material 40B, and it may be a shape with rounded polygonal corners, as shown in Figure 6, or a shape without a straight periphery, as shown in Figure 7. Shapes with rounded corners or shapes without straight edges can also be applied to the embodiments shown in Figures 3 and 4.

[0024] A second embodiment of the present invention will be described with reference to Figures 8 to 11. In the following description, components that are common to those already described will be denoted by the same reference numerals, and redundant descriptions will be omitted. Figure 8 shows a plan view of the IC tag 101 according to this embodiment. The protective material 140 according to this embodiment is circular in shape when viewed from above, and is attached to the surface on which the mold 21 is located, surrounding the mold 21.

[0025] In the IC tag 101 as well, the deformation of the substrate 10 due to bending is first received by the outer edge of the protective material 140, so that a force that would peel the mold 21 away from the substrate 10 is less likely to act on it, thus producing the same effects as in each of the embodiments described above. There are no particular restrictions on the plan view shape of the frame-shaped protective material according to this embodiment; it may be a polygonal shape formed only by a straight periphery. Furthermore, if the protective material 140A shown in Figure 9 has a shape with irregularities on its periphery in plan view, similar to the protective material 40A, the boundary where the rigidity changes can be increased, and the force acting on the periphery of the mold 21 can be further reduced.

[0026] Furthermore, as shown in the modified IC tags 101A and 101B in Figures 10 and 11, instead of surrounding the mold with a frame-shaped protective material, two strip-shaped protective materials 140B extending in one direction across the substrate 10 may be arranged to sandwich the mold 21. Even with this configuration, the protective material can withstand the bending deformation of the substrate 10 approaching from the left and right directions in the figure, thereby preventing the mold 21 from peeling off the substrate 10. In this configuration, although there is no protective material in the vertical direction of the mold 21 as shown in the figure, the protective material 140B is arranged across the vertical direction of the substrate 10, so that the bending deformation of the substrate 10 approaching from above or below does not reach the periphery of the mold 21 to some extent. From the viewpoint of fully obtaining this effect, it is preferable that the width of the strip-shaped protective material 140B be 1 mm or more. The strip-shaped protective material 140B may be curved, as in the IC tag 101A, or straight, as in the IC tag 101B. Furthermore, the two protective materials may be symmetrical or asymmetrical with respect to the mold 21. The planar shape of the substrate 10 is not limited to the circular shape shown, but may be a polygon or the like. If it is a polygon, the direction in which the strip-shaped protective material extends can be set as appropriate and does not necessarily have to be parallel to the sides of the polygon.

[0027] In the second embodiment, additional protective material may be placed on the lower surface of the substrate 10. The protective material placed in this case may be the same as that shown in the first embodiment or the same as that shown in the second embodiment. If the protective material shown in the second embodiment is used, it may be the same as or different from that on the upper surface.

[0028] A third embodiment of the present invention will be described with reference to Figure 12. Figure 12 shows a bottom view of the IC tag 201 according to this embodiment. The mold 21 in this embodiment is located on the periphery of the substrate 10, and the protective material 240 is positioned such that, in a plan view, a portion of its own periphery coincides with the periphery of the substrate. In this embodiment, since there are no areas that are prone to bending deformation in the direction in which the periphery of the protective material 240 coincides with the periphery of the substrate 10, the direction in which bending deformation approaches the mold 21 can be limited, which has the advantage of further suppressing peeling of the mold 21. For the planar shape of the part of the periphery of the protective material 240 that does not coincide with the periphery of the substrate 10, the shapes of each embodiment described above can be appropriately selected and applied.

[0029] When attaching the IC tag according to the present invention to clothing, its position is not particularly limited. It may be directly sewn onto a desired location on the clothing or attached using an adhesive. However, attaching it to a so-called "woven label," which is attached to clothing and bears a brand logo or care label, is preferable in terms of clothing manufacturing efficiency because it allows for the mass production of woven labels with the IC tag attached in advance.

[0030] Although each embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and combinations of the configuration are also included without departing from the spirit of the present invention.

[0031] For example, the shape of the antenna is not limited to the coil shape shown in the embodiment, and other antenna shapes such as a dipole antenna may be used depending on the intended form of contactless communication.

[0032] Furthermore, in the IC tag according to the present invention, a mold covering the entire IC chip is not essential. While a mold covering the entire IC chip has the advantage of protecting the IC chip from external impacts, the aforementioned resistance to washing is basically provided by the protective material. Therefore, as shown in the modified example in Figure 13, a part of the IC chip 20 may be exposed from the mold 21, or as shown in the modified example in Figure 14, there may be no mold, and the IC chip 20 and antenna 30 may be arranged on one side of the substrate 10. In the modified example shown in Figure 13, similar to the embodiment, the protective material 40 should be attached so that it overlaps with the entire mold 21 in a plan view of the substrate 10. In the modified example shown in Figure 14, since no force acts from the mold to peel the IC chip 20 away from the antenna 30, the same washing resistance can be provided by attaching the protective material 40 so that it overlaps with the entire IC chip 20 in a plan view of the substrate 10. [Explanation of symbols]

[0033] 1, 1A, 1B, 1C, 1D, 1E, 101, 101A, 101B, 201 IC tags 10 circuit boards 20 IC chips 21 molds 30 Antennas 40, 40A, 140, 140A, 140B, 240 Protective material

Claims

1. A flexible substrate formed of an insulator, An antenna formed on the substrate with a conductor, The IC chip connected to the aforementioned antenna, In a plan view of the substrate, a protective material is attached to the substrate so as to overlap the entire IC chip, Equipped with, IC tag.

2. A flexible substrate formed of an insulator, An antenna formed on the substrate with a conductor, The IC chip connected to the aforementioned antenna, In a plan view of the aforementioned substrate, a protective material is attached to the substrate so as to surround the IC chip, Equipped with, IC tag.

3. A flexible substrate formed of an insulator, An antenna formed on the aforementioned substrate using a conductor, The IC chip connected to the aforementioned antenna, In a plan view of the substrate, two strip-shaped protective materials are attached to the substrate so as to sandwich the IC chip, Equipped with, IC tag.

4. The protective material is attached to the substrate on the side opposite to the side on which the IC chip is provided. The IC tag according to any one of claims 1 to 3.

5. The thickness of the protective material is 0.8 times or more the thickness of the substrate. The IC tag according to any one of claims 1 to 3.

6. In a plan view of the substrate, a portion of the periphery of the protective material coincides with a portion of the periphery of the substrate. The IC tag according to claim 1.

7. The substrate further comprises a mold that is placed on the substrate and covers the IC chip, The protective material is attached to the substrate so as to overlap the entire mold in a plan view of the substrate. The IC tag according to claim 1.

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