RFID tag and tag manufacturing method

Abstract

An RFID tag (100) comprises: a tag base material (1) in which an antenna (2) is provided on a plate-shaped base material surface (1a) that faces one side (D1a) in the thickness direction (D1) of the RFID tag; an IC chip (30) in which at least a portion thereof is disposed further to the one side (D1a) in the thickness direction (D1) than the antenna (2), and that is connected to the antenna (2); and a cover member (4) provided around the IC chip (30) on the base material surface (1a). An end on the one side (D1a) in the thickness direction (D1) of the cover member (4) is located at the same position as an end on one side (D1a) in the thickness direction (D1) of the IC chip (30), or further to the one side (D1a) in the thickness direction (D1) than the end on the one side (D1a) in the thickness direction (D1) of the IC chip (30).

Description

RFID tag and tag manufacturing method

[0001] The present invention relates to an RFID tag and a method for manufacturing the tag.

[0002] A technology called RFID (Radio Frequency Identification) that wirelessly reads and writes data using radio waves has been known. Currently, this type of technology is used in a variety of situations, one example of which is to significantly reduce the labor required for inventory management of products and checkouts using automated registers. RFID tags with predetermined information written on them are attached to products, and the information on the RFID tags is read by a dedicated reader.

[0003] RFID tags come in three types: active tags that are equipped with a battery; passive tags that are battery-free and have an IC chip mounted on the tag that is powered by radio waves from a reader; and semi-active tags that combine active and passive types. Passive tags do not require maintenance such as battery replacement, can be made smaller, and can be made more affordable. For this reason, passive tags have been increasingly used in logistics sites such as inventory management in recent years. Among these, tags that use radio waves in the UHF band (860 to 960 MHz) are attracting particular attention because of their long communication distances and low cost.

[0004] This type of RFID tag is described, for example, in Patent Document 1, and is configured by mounting an IC chip on a tag substrate having an antenna formed on its surface.

[0005] JP 2013-92972 A

[0006] In conventional RFID tags such as those disclosed in Patent Document 1, an inlay with an IC chip about 100 μm thick mounted on the surface of a base material is inserted into a tag or label made of paper or film, so that a protrusion of about 100 μm from the IC portion is always present on the outside. Therefore, when an RFID tag is attached to a pallet, returnable box, or the like at a logistics site, for example, and this protrusion collides with another pallet, a compressive load acts concentratedly on the IC chip, which can easily be damaged.

[0007] Therefore, the present invention provides an RFID tag that can avoid concentrated loads on the IC chip and improve durability, and a tag manufacturing method for manufacturing the RFID tag.

[0008] An RFID tag according to one embodiment of the present invention is an RFID tag that is attached to an object and enables the object to be identified by wireless data communication, and comprises: a plate-shaped tag substrate having an antenna on the substrate surface facing one side in the thickness direction of the tag substrate; an IC chip that is connected to the antenna and at least a portion of which is positioned on one side in the thickness direction of the antenna; and a cover member that is provided around the IC chip on the surface of the substrate, wherein the end of the cover member on one side in the thickness direction is either at the same position as the end of the IC chip on one side in the thickness direction or is located on one side in the thickness direction of the end of the IC chip on one side in the thickness direction.

[0009] In the above RFID tag, the cover member is plate-shaped, and the entire cover surface facing one side in the thickness direction of the cover member may be located at the same position as the end of the IC chip on one side in the thickness direction, or may be located on one side in the thickness direction of the IC chip.

[0010] In the above RFID tag, the cover member has a first cover portion arranged on one side of the IC chip in a first horizontal direction along the surface direction of the substrate surface, and a second cover portion arranged away from the first cover portion on the other side of the IC chip in the first horizontal direction, and a slit-shaped portion may be formed between the first cover portion and the second cover portion, extending in a second horizontal direction along the surface direction and intersecting the first horizontal direction, to position the IC chip.

[0011] In the RFID tag, the cover member may be formed with a chip placement hole that penetrates the cover member in the thickness direction and in which the IC chip is placed.

[0012] The RFID tag further comprises a chip holding member that holds the IC chip from one side in the thickness direction, and a chip-antenna connection member that is provided on a surface of the chip holding member facing the other side in the thickness direction, connected to the IC chip from one side in the thickness direction, and connected to the antenna from one side in the thickness direction, and the end of the cover member on one side in the thickness direction may be located at the same position as the end of the chip holding member on one side in the thickness direction, or on one side in the thickness direction of the end of the chip holding member on one side in the thickness direction.

[0013] In the above RFID tag, the chip-antenna connecting member has an antenna connection portion that extends in the planar direction of the substrate surface and faces the antenna, the chip holding member has a connection portion overlapping portion that is stacked on one side of the antenna connection portion in the thickness direction and extends in the planar direction of the substrate surface, and the cover member may be arranged to sandwich the antenna connection portion and the connection portion overlapping portion between it and the antenna.

[0014] The RFID tag may further include an adhesive layer laminated to the tag substrate on the back surface of the substrate opposite to the front surface, the tag substrate being formed from a flexible material that can be elastically bent and deformed at least in the thickness direction, and capable of attaching the tag substrate to an object.

[0015] A tag manufacturing method according to one aspect of the present invention is a tag manufacturing method for manufacturing the above-mentioned RFID tag, and includes the steps of unwinding cover member material from a roll containing sheet-like cover member material that serves as the basis for the cover member; cutting the unwound cover member material along the unwinding direction; attaching one side portion and the other side portion of the cut cover member material to a group of tag substrates in which a plurality of tag substrates each having an IC chip provided thereon are arranged in a line in the conveying direction, in a conveying cross direction that intersects the conveying direction so as to avoid the IC chips; and, after the cover member material has been attached, separating each tag substrate in the group of tag substrates in the conveying direction, thereby forming the first cover portion and the second cover portion on each tag substrate.

[0016] According to the above RFID tag, it is possible to prevent concentrated loads on the IC chip and improve durability. Furthermore, according to the above tag manufacturing method, it is possible to manufacture an RFID tag that can prevent concentrated loads on the IC chip and improve durability.

[0017] FIG. 1 is a plan view of an RFID tag according to an embodiment of the present invention, as seen from the IC chip side. FIG. 2 is a longitudinal cross-sectional view of the RFID tag, showing the II cross-section of FIG. 1. FIG. 3 is a plan view of the RFID tag as seen from the IC chip side, showing the cover member exposed by removing the front outer layer part. FIG. 4 is a schematic diagram showing a method for manufacturing the RFID tag. FIG. 5 is a plan view of an RFID tag according to a first modified embodiment of the present invention, as seen from the IC chip side, showing the cover member exposed by removing the front outer layer part. FIG. 6 is a longitudinal cross-sectional view of an RFID tag according to a second modified embodiment of the present invention.

[0018] An RFID tag 100 according to an embodiment of the present invention will now be described. As shown in FIG. 1 , the RFID tag 100 is a rectangular plate (sheet) having a thickness that is, for example, 50 μm or more greater than the thickness of an IC chip 30 (described later). The RFID tag 100 is a device that is attached to an object (not shown) and performs wireless data communication with a dedicated reader / writer, thereby enabling the identification, management, etc. of the object. In this embodiment, the RFID tag 100 is a passive tag. The RFID tag 100 is flexible enough to be elastically deformed at least in the thickness direction of its own plate, and is also robust (shock resistant).

[0019] Furthermore, the RFID tag 100 of this embodiment has a larger dimension in the width direction, which is perpendicular to its thickness direction, than in the depth direction, which is perpendicular to (intersects with) the thickness direction and the width direction. Hereinafter, the width direction of the RFID tag 100 will be referred to as the first horizontal direction Dx, and the depth direction will be referred to as the second horizontal direction Dy.

[0020] (Overall structure) Specifically, as shown in FIG. 2, the RFID tag 100 comprises a plate-shaped (sheet-shaped) inlay 110, a front outer layer 111 laminated on one side of the inlay 110, and a back outer layer 112 laminated on the other side of the inlay 110.

[0021] (Inlay) The inlay 110 has a plate-shaped (sheet-shaped) tag substrate 1 , and a chip unit 3 and a cover member 4 provided on the tag substrate 1 .

[0022] The tag substrate 1 is formed from a flexible material that can be elastically bent and deformed at least in the thickness direction D1 of the tag substrate 1. Resins such as polyimide, PET, PP, and PVC, which have excellent flexibility, heat resistance, and electrical insulation, are preferably used as the material for the tag substrate 1. An antenna 2 is provided on a substrate surface 1a facing one side D1a in the thickness direction D1 of the tag substrate 1.

[0023] The antenna 2 is formed, for example, by printing conductive ink on the surface 1a of the substrate, but can also be formed using various methods such as etching, attaching metal foil, vapor deposition, etc. The pattern of the antenna 2 is not particularly limited.

[0024] The chip unit 3 has an IC chip 30 , a chip holding member 31 that holds the IC chip 30 , and a chip-antenna connecting member 32 provided between the IC chip 30 and the chip holding member 31 .

[0025] Terminals 30a of the IC chip 30 are provided on a surface facing one side D1a in the thickness direction D1 of the IC chip 30. The IC chip 30 is configured to operate by receiving radio waves from a reader / writer. In this embodiment, at least a portion of the IC chip 30 is located closer to the one side D1a in the thickness direction D1 than the antenna 2.

[0026] The chip holding member 31 mounts the IC chip 30, is formed of a resin film such as polyimide or PET, and is sheet-shaped, and holds the IC chip 30 from one side D1a in the thickness direction D1. In this embodiment, when viewed from the cross section shown in FIG. 2 (a cross section perpendicular to the second horizontal direction Dy), the chip holding member 31 has a chip facing portion 31a that extends in a plane direction D2 of the substrate surface 1a of the tag substrate 1 on one side D1a in the thickness direction D1 relative to the IC chip 30, a pair of side portions 31b that extend from the chip facing portion 31a toward the other side D1b in the thickness direction D1 along both side surfaces facing the width direction of the IC chip 30, which is the first horizontal direction Dx, and a connection portion overlapping portion 31c that extends from each side portion 31b in the plane direction D2 toward the side away from the IC chip 30 and is arranged on the antenna 2.

[0027] The chip-antenna connection member 32 is provided on a surface 31h facing the other side D1b in the thickness direction D1 of the chip holding member 31, and is electrically connected to the terminal 30a of the IC chip 30 from one side D1a in the thickness direction D1. The chip-antenna connection member 32, like the antenna 2, is formed on the surface 31h of the chip holding member 31 by various methods such as printing conductive ink, etching, attaching metal foil, and vapor deposition. The chip-antenna connection member 32 is provided across the entire surface 31h of the chip holding member 31, and has an antenna connection portion 32a laminated on one side D1a in the thickness direction D1 of the connection portion overlapping portion 31c of the chip holding member 31. The antenna connection portion 32a extends in the planar direction D2 of the substrate surface 1a of the tag substrate 1 and is positioned opposite the antenna 2. In this embodiment, an insulating adhesive 119 is interposed between the antenna connection portion 32a and the antenna 2, and they are magnetically coupled, thereby enabling communication between the IC chip 30 and the reader / writer through the antenna 2. The antenna connection portion 32a and the antenna 2 may be electrically connected and conductive with a conductive adhesive.

[0028] The cover member 4 is preferably thicker than the IC chip 30, having a thickness of 60 μm to 200 μm (for example, if the thickness of the IC chip 30 is 100 μm), and is formed in a plate (sheet) shape with a thickness of preferably 150 μm. The cover member 4 is provided around the IC chip 30 on the substrate surface 1a. The cover member 4 is formed, for example, from a resin such as polyimide, PET, PP, or PVC that has excellent flexibility, heat resistance, and electrical insulation, and covers substantially the entire substrate surface 1a of the tag substrate 1. The entire cover surface 4a of the cover member 4 facing one side D1a in the thickness direction D1 is located closer to the one side D1a in the thickness direction D1 than the IC chip 30. Furthermore, the entire cover surface 4a is located closer to the one side D1a in the thickness direction D1 than the chip holding member 31. In other words, the protruding height of the cover member 4 toward the one side D1a in the thickness direction D1, based on the substrate surface 1a of the tag substrate 1, is greater than the protruding height of the IC chip 30. Between the cover member 4 and the antenna 2, there is interposed an adhesive 120, for example, of a silicone type, which has waterproof, heat-resistant, elastic, and electrically insulating properties.

[0029] Here, the cover member 4 has a first cover part 41 arranged on one side Dxa of the first horizontal direction Dx relative to the IC chip 30, and a second cover part 42 arranged on the other side Dxb of the first horizontal direction Dx relative to the IC chip 30.

[0030] The first cover portion 41 sandwiches the antenna connection portion 32a of the chip-antenna connection member 32 and the connection portion overlap portion 31c of the chip holding member 31 between the antenna 2 and the first cover portion 41 on one side Dxa of the first horizontal direction Dx relative to the IC chip 30.

[0031] The second cover part 42 is disposed at a position spaced apart in the first horizontal direction Dx from the first cover part 41. Furthermore, the second cover part 42 sandwiches the antenna connection part 32a of the chip-antenna connection member 32 and the connection part overlap part 31c of the chip holding member 31 between itself and the antenna 2 on the other side Dxb in the first horizontal direction Dx from the IC chip 30. Therefore, as shown in FIG. 3 , a slit-shaped part 40 extending in the second horizontal direction Dy and in which the IC chip 30 is disposed is formed between the first cover part 41 and the second cover part 42.

[0032] 2 , the front outer layer portion 111 is plate-shaped (sheet-shaped) and is laminated on one side of the cover member 4 in the thickness direction D1. The front outer layer portion 111 has an outermost layer 121 formed from a flexible material that can be elastically bent and deformed at least in the thickness direction D1, and an adhesive layer 122 made of an adhesive interposed between the outermost layer 121 and the cover surface 4a of the cover member 4. A composite material made of paper and resin, for example, is suitably used as the material for the outermost layer 121.

[0033] (Back-Side Outer Layer) The back-side outer layer 112 is plate-shaped (sheet-shaped) and is laminated on the tag substrate 1 on the substrate back surface 1b side opposite the substrate front surface 1a of the tag substrate 1. The back-side outer layer 112 has an adhesive layer 123 provided on the substrate back surface 1b and enabling the tag substrate 1 to be attached to an object, and a release paper 124 that protects the adhesive layer 123. Therefore, the RFID tag 100 of this embodiment is used by being attached to an object.

[0034] 4, a method for manufacturing the RFID tag 100 will be described. First, a step of unwinding the cover member material 400 from a roll R containing the sheet-like cover member material 400 that will be the base of the cover member 4 is performed. Then, a step of cutting the unwound cover member material 400 by a slitter S along the unwinding direction D10 is performed.

[0035] Then, while a group 410 of tag substrates, each having a tag substrate 1 provided with an antenna 2 and a chip unit 3 arranged in a conveying direction D11, is being conveyed by a conveying device T, one side portion 400a and the other side portion 400b of the cover member material 400 cut and separated by a slitter S are lined up in a conveying cross direction D12 that intersects with the conveying direction D11, and a process is executed in which they are attached so as to avoid the IC chip 30 of the chip unit 3.

[0036] After the cover member material 400 is attached to the tag substrate group 410, a front outer layer portion 111 and a back outer layer portion 112 (see FIG. 2) are attached to the tag substrate group 410, and a process is performed in which each tag substrate 1 in the tag substrate group 410 is separated in the transport direction D11. In this way, an RFID tag 100 is manufactured in which a first cover portion 41 and a second cover portion 42 (see FIG. 3) are provided on each tag substrate 1.

[0037] (Effects) According to the RFID tag 100 of the present embodiment described above, the cover member 4 is provided on the base material surface 1a around the IC chip 30, with the cover surface 4a positioned closer to one side D1a in the thickness direction D1 than the IC chip 30. Therefore, even if an object comes into contact with the RFID tag 100 from one side D1a in the thickness direction D1, the compressive load from the object can be borne by the cover surface 4a of the cover member 4. Therefore, the entire load from the object is not concentratedly applied to the IC chip 30, and damage to the IC chip 30 can be avoided.

[0038] In particular, in this embodiment, the cover surface 4a of the cover member 4 is disposed on one side D1a in the thickness direction D1 further than the chip holding member 31. This prevents the entire load from the object from being concentrated on the chip holding member 31, and therefore prevents damage to the entire chip unit 3.

[0039] Furthermore, by forming the slit-shaped portion 40 in the cover member 4 and arranging the IC chip 30 in the slit-shaped portion 40 , the cover member 4 can be easily provided around the IC chip 30 .

[0040] Furthermore, because the cover member 4 sandwiches the antenna connection portion 32a of the chip-antenna connection member 32 and the connection portion overlap portion 31a of the chip holding member 31 between itself and the antenna 2, when a compressive load in the thickness direction D1 acts on the RFID tag 100, a force acts in the direction in which the cover member 4 presses the chip-antenna connection member 32 against the antenna 2. As a result, even if a compressive load acts on the RFID tag 100, damage that would result in a disconnection between the IC chip 30 and the antenna 2 can be avoided.

[0041] Furthermore, since RFID tag 100 has adhesive layer 122, it is used by being attached to an object. Therefore, for example, when RFID tag 100 is attached to the side of a pallet or returnable container at a logistics site, there is a possibility that other pallets or returnable containers or work machines such as forklifts may accidentally come into contact with RFID tag 100. However, even in such a case, cover member 4 can prevent damage to IC chip 30.

[0042] Furthermore, the RFID tag 100 having the above-described configuration can be manufactured by stacking layers of paper or resin film rather than by a method such as resin molding, thereby enabling high-speed manufacturing of the RFID tag 100. This provides many advantages, such as mass production and cost reductions due to mass production.

[0043] The present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit and scope of the present invention. For example, as shown in Fig. 5, the cover member 4 may be an integrated unit, rather than being separated into the first cover portion 41 and the second cover portion 42. In this case, the cover member 4 is formed with a chip placement hole 4h that penetrates in the thickness direction D1 and into which the IC chip 30 is placed.

[0044] As shown in Figure 6, the RFID tag 100 does not necessarily have to have a chip unit 3, and the terminal 30a of the IC chip 30 may be arranged on the surface of the IC chip 30 facing the other side D1b in the thickness direction D1, and this terminal 30a may be directly connected to the antenna 2.

[0045] Furthermore, it is not necessary that the entire cover surface 4a of the cover member 4 is disposed on the one side D1a in the thickness direction D1 of the IC chip 30; it is sufficient that at least a portion of the cover member 4, i.e., the end of the cover member 4 on the one side D1a in the thickness direction D1, is disposed on the one side D1a in the thickness direction D1 of the IC chip 30 and the chip holding member 31. Furthermore, the entire cover surface 4a of the cover member 4 may be disposed in the same position as the end of the IC chip 30 and the chip holding member 31 on the one side D1a in the thickness direction D1, or the end of the cover member 4 on the one side D1a in the thickness direction D1 may be disposed in the same position as the end of the IC chip 30 and the chip holding member 31 on the one side D1a in the thickness direction D1. Even in this case, it is possible to avoid concentrated load on the IC chip 30.

[0046] The back outer layer 112 does not necessarily have to have the adhesive layer 123 and the release paper 124. In this case, the RFID tag 100 may be attached to an object by screwing. The RFID tag 100 may also be attached to an object by using both the adhesive layer 123 and the release paper 124 and by screwing.

[0047] According to the RFID tag of the present invention, it is possible to avoid concentrated loads on the IC chip and improve durability. Also, according to the tag manufacturing method of the present invention, it is possible to manufacture an RFID tag that can avoid concentrated loads on the IC chip and improve durability.

[0048] DESCRIPTION OF SYMBOLS 1...Tag substrate 1a...Substrate surface 1b...Substrate back surface 2...Antenna 3...Chip unit 4...Cover member 4a...Cover surface 4h...Chip placement hole 30...IC chip 30a...Terminal 31...Chip holding member 31c...Connection portion overlapping portion 32...Chip-antenna connecting member 32a...Antenna connecting portion 40...Slit-shaped portion 41...First cover portion 42...Second cover portion 100...RFID tag 110...Inlay 122...Adhesive layer 400...Cover member material 410...Tag substrate group D1...Thickness direction D1a...One side D1b...Other side D2...Face direction D10...Unwinding direction D11...Conveying direction D12...Cross-conveying direction Dx...First lateral direction Dy...Second lateral direction

Claims

1. An RFID tag that is attached to an object and enables the object to be identified by wireless data communication, comprising: a plate-shaped tag substrate having an antenna on the surface of the substrate facing one side in the thickness direction of the tag substrate; an IC chip that is connected to the antenna and at least a portion of which is located on one side in the thickness direction of the antenna; and a cover member that is located around the IC chip on the surface of the substrate, wherein the end of the cover member on one side in the thickness direction is either in the same position as the end of the IC chip on one side in the thickness direction, or is located on one side in the thickness direction of the end of the IC chip on one side in the thickness direction.

2. An RFID tag as described in claim 1, wherein the cover member is plate-shaped, and the entire cover surface facing one side in the thickness direction of the cover member is located at the same position as the end of the IC chip on one side in the thickness direction, or on one side in the thickness direction of the end of the IC chip on one side in the thickness direction.

3. An RFID tag as described in claim 1 or 2, wherein the cover member has a first cover portion arranged on one side of the IC chip in a first horizontal direction along the surface direction of the substrate surface, and a second cover portion arranged apart from the first cover portion on the other side of the IC chip in the first horizontal direction, and wherein a slit-shaped portion is formed between the first cover portion and the second cover portion, extending in a second horizontal direction that intersects the first horizontal direction and along the surface direction, and in which the IC chip is positioned.

4. The RFID tag according to claim 1 or 2, wherein the cover member has a chip placement hole formed therein that penetrates the cover member in the thickness direction and in which the IC chip is placed.

5. An RFID tag as described in claim 1 or 2, further comprising: a chip holding member that holds the IC chip from one side in the thickness direction; and a chip-antenna connection member that is provided on a surface of the chip holding member facing the other side in the thickness direction, connected to the IC chip from one side in the thickness direction, and connected to the antenna from one side in the thickness direction, wherein the end of the cover member on one side in the thickness direction is located at the same position as the end of the chip holding member on one side in the thickness direction, or is located on one side in the thickness direction of the end of the chip holding member on one side in the thickness direction.

6. An RFID tag as described in claim 5, wherein the chip-antenna connecting member has an antenna connecting portion that extends in the planar direction of the substrate surface and faces the antenna, the chip holding member has a connecting portion overlapping portion that is stacked on one side of the antenna connecting portion in the thickness direction and extends in the planar direction of the substrate surface, and the cover member is arranged to sandwich the antenna connecting portion and the connecting portion overlapping portion between it and the antenna.

7. An RFID tag as claimed in claim 1 or 2, wherein the tag substrate is formed from a flexible material that can be elastically bent and deformed at least in the thickness direction, and further comprises an adhesive layer laminated to the tag substrate on the back surface of the substrate opposite the front surface, and capable of attaching the tag substrate to an object.

8. A tag manufacturing method for manufacturing the RFID tag described in claim 3, comprising the steps of: unwinding cover member material from a roll containing sheet-like cover member material that serves as the basis for the cover member; cutting the unwound cover member material along the unwinding direction; attaching one side portion and the other side portion of the cut cover member material to a tag substrate group in which a plurality of tag substrates, each having an IC chip provided thereon, are arranged in a line in the conveying direction, in a cross-conveyance direction that intersects with the conveying direction, so as to avoid the IC chips; and after the cover member material has been attached, separating each tag substrate in the tag substrate group in the conveying direction, thereby forming the first cover portion and the second cover portion on each tag substrate.

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