RFID label and method of manufacturing the same

Abstract

To provide an RFID label configured to suppress reduction in communication performance, and a method of manufacturing the RFID label.SOLUTION: An RFID label 10 includes an inlet 2, a conductive layer body 4 having conductivity, and a bonding layer 3. The inlet 2 includes an IC chip 21, and an antenna electrically connected to the IC chip 21. The conductive layer body 4 has conductivity. The bonding layer 3 is arranged between the inlet 2 and the conductive layer body 4 to bond the inlet 2 and the conductive layer body 4. The bonding layer 3 contains at least one of a non-polar olefin resin and a non-polar synthetic rubber resin. A thickness of the bonding layer 3 is 200 to 800 μm. An overall thickness of the RFID label 10 is 300 to 1200 μm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an RFID label and a method for manufacturing an RFID label. [Background technology]

[0002] In recent years, RFID (Radio Frequency Identification) tags have been used for the purpose of distribution management, etc. RFID tags are capable of short-range wireless communication with a reader / writer. The RFID tag described in Patent Document 1 is constructed by stacking a conductive sheet, a spacer member made of polystyrene foam or the like, and an IC tag. The spacer member is interposed between the conductive sheet and the IC tag. Because this RFID tag includes the spacer member, it can also be attached to metal objects. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-90621 Summary of the Invention [Problem to be solved by the invention]

[0004] The RFID tag described above may have its communication performance, such as communication distance and frequency characteristics, affected by changes in the thickness of the spacer member due to pressure or other factors.

[0005] An object of one aspect of the present invention is to provide an RFID label and a method for manufacturing an RFID label that can suppress a decrease in communication performance. [Means for solving the problem]

[0006] One aspect of the present invention provides an RFID label comprising: an inlet having an IC chip and an antenna electrically connected to the IC chip; a conductive layer having electrical conductivity; and an adhesive layer interposed between the inlet and the conductive layer and adhering the inlet and the conductive layer, the adhesive layer containing at least one of a non-polar olefin-based resin and a non-polar synthetic rubber-based resin, the adhesive layer having a thickness of 200 μm to 800 μm, and the overall thickness being 300 μm to 1200 μm.

[0007] The conductive layer preferably includes a metal layer and a resin layer laminated on the metal layer.

[0008] The conductive layer may have a thickness of 10 μm to 100 μm.

[0009] Another aspect of the present invention provides a method for manufacturing an RFID label, comprising the steps of: preparing an inlet having an IC chip and an antenna electrically connected to the IC chip; and a conductive layer having conductivity; applying an adhesive to at least one of the inlet and the conductive layer; and bonding the inlet and the conductive layer with the adhesive to obtain an RFID label having an overall thickness of 300 μm to 1200 μm, wherein the adhesive contains at least one of a non-polar olefin-based resin and a non-polar synthetic rubber-based resin, and the thickness of the adhesive layer formed by the adhesive is 200 μm to 800 μm. [Effects of the Invention]

[0010] According to one aspect of the present invention, it is possible to provide an RFID label and a method for manufacturing an RFID label that can suppress a decrease in communication performance. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of an RFID label according to a first embodiment. [Figure 2] FIG. 1 is a plan view of an RFID label according to a first embodiment. [Figure 3] FIG. 2 is a cross-sectional view of a first example of a conductive layer body. [Figure 4] 2A to 2C are process diagrams illustrating a method for manufacturing an RFID label according to the first embodiment. [Figure 5] This is a process diagram following the previous figure. [Figure 6] This is a process diagram following the previous figure. [Figure 7] 3A to 3C are diagrams illustrating how to use the RFID label according to the first embodiment. [Figure 8] FIG. 2 is a cross-sectional view of a second example of a conductive layer body. [Figure 9] FIG. 10 is a cross-sectional view of a third example of a conductive layer body. [Figure 10] FIG. 2 is a plan view of a portion of a first example of an antenna. [Figure 11] FIG. 10 is a plan view of a portion of a second example of an antenna. [Figure 12] FIG. 10 is a cross-sectional view of an RFID label according to a second embodiment in use. [Figure 13] FIG. 10 is a plan view of a modified example of the inlet. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, RFID labels according to embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below are specifically described to facilitate a better understanding of the gist of the present invention, and are not intended to limit the scope of the present invention. In the drawings referred to below, the dimensions of each component are appropriately changed as necessary to facilitate understanding.

[0013] [RFID Label] (First Embodiment) Fig. 1 is a cross-sectional view of an RFID label 10 according to the first embodiment. Fig. 2 is a plan view of the RFID label 10. Fig. 1 is a cross-sectional view taken along line II in Fig. 2. Hereinafter, the posture of the RFID label 10 will be tentatively determined based on Fig. 1. For example, the inlet 2 is positioned above the conductive layer 4. The positional relationship determined here does not limit the posture of the RFID label 10 during use. A plan view refers to a view from the thickness direction of the RFID label 10.

[0014] As shown in Fig. 1, the RFID label 10 includes a surface substrate 1, an inlet 2, an adhesive layer 3, a conductive layer 4, a pressure-sensitive adhesive layer 5, and a release sheet 6. The RFID label 10 has the surface substrate 1, the inlet 2, the adhesive layer 3, the conductive layer 4, the pressure-sensitive adhesive layer 5, and the release sheet 6 laminated together in this order. The RFID label 10 is an example of a "contactless data transmitter / receiver (RFID tag)."

[0015] Information is displayed on the surface (top surface) of the surface substrate 1 using characters, figures, symbols, etc. The information display is formed by printing or the like. The surface substrate 1 is formed from, for example, paper, resin, etc. The surface substrate 1 is formed in a sheet shape. The surface substrate 1 is attached to the top surface of the inlet 2 with an adhesive or the like.

[0016] 2, the surface substrate 1 has a rectangular shape in plan view. The shape of the surface substrate 1 in plan view is the same as the shape of the inlet 2 in plan view. The entire surface of the surface substrate 1 is overlapped on the upper surface of the inlet 2.

[0017] The inlet 2 includes a substrate 20, an IC chip 21, a circuit 22, and an antenna 23. The substrate 20 is plate-shaped. For example, the substrate 20 may be made of a resin. Examples of resins that form the substrate 20 include polyethylene terephthalate (PET) and polyimide. The substrate 20 may be made of glass fiber cloth impregnated with epoxy resin and then thermoset. The substrate 20 may be a paper substrate, a ceramic substrate, or the like. The substrate 20 is, for example, a rigid substrate. The substrate 20 has a rectangular shape (more specifically, a rectangular shape) in plan view.

[0018] The IC chip 21 is, for example, a semiconductor integrated circuit that writes and reads information contactlessly by wirelessly communicating with the outside via the circuit 22 and the antenna 23. The IC chip 21 operates, for example, by power supplied contactlessly from the outside via the circuit 22 and the antenna 23. The IC chip 21 is plate-shaped or rectangular parallelepiped-shaped. The IC chip 21 is rectangular in plan view.

[0019] As shown in FIG. 1, the IC chip 21 is formed on the lower surface of the base material 20 (the surface on which the adhesive layer 3 is formed). The IC chip 21 protrudes downward from the lower surface of the base material 20. The thickness of the IC chip 21 is, for example, 100 μm to 300 μm. The IC chip 21 is embedded in the adhesive layer 3. The lower surface 21a and four side surfaces 21b of the IC chip 21 are covered with the adhesive layer 3. The lower surface 21a and four side surfaces 21b of the IC chip 21 are each in contact with the adhesive layer 3 over their entirety and are adhered to the adhesive layer 3.

[0020] Since the IC chip 21 is formed on the lower surface of the base material 20, it is difficult for external forces to be applied to it. For example, when a pressing force (external force) is applied to the RFID label 10 from above in the thickness direction, the force is dispersed by the base material 20, and the force acting on the IC chip 21 is reduced. Therefore, the IC chip 21 can be protected and its normal function can be ensured.

[0021] 2, the circuit 22 is formed in a layer on one surface of the substrate 20. The circuit 22 is preferably formed on the lower surface of the substrate 20. The circuit 22 is electrically connected to the IC chip 21. The circuit 22 may be in a loop shape (annular shape).

[0022] The antenna 23 is an antenna for the booster. The antenna 23 is formed in a layer on one surface of the substrate 20. The antenna 23 is preferably formed on the lower surface of the substrate 20. The antenna 23 includes, for example, a central portion 23A and a pair of radiating portions 323B, 23B. The pair of radiating portions 23B, 23B extend from the central portion 23A toward one end and the other end of the substrate 20, respectively. The inner edge of the central portion 23A and the inner edges of the radiating portions 23B, 23B are close to the outer edge of the circuit 22. The antenna 23 can be electromagnetically coupled to the circuit 22. Therefore, the antenna 23 is electrically connected to the circuit 22.

[0023] The circuit 22 and the antenna 23 are formed, for example, from a metal foil, a metal thin film, a metal plate, or the like. The metal thin film is formed, for example, by plating. The metal thin film is formed, for example, by a thin film formation method such as metal vapor deposition. The metal constituting the circuit 22 and the antenna 23 is, for example, copper, silver, gold, platinum, aluminum, or the like. The circuit 22 and the antenna 23 may be formed from a conductive ink such as a polymer-type conductive ink or a silver ink composition. The conductive ink may contain conductive particles formed from a metal, a carbon material, or the like.

[0024] 1, the adhesive layer 3 is interposed between the inlet 2 and the conductive layer 4 to bond the inlet 2 and the conductive layer 4. The adhesive layer 3 is formed, for example, from a liquid or semi-solid curable adhesive material.

[0025] The adhesive layer 3 contains at least one of a non-polar olefin resin and a non-polar synthetic rubber. A non-polar olefin resin is an olefin resin that does not have polarity, specifically, an olefin resin in which electronic polarization does not occur within the molecule. A non-polar olefin resin does not have, for example, a polar functional group. A non-polar olefin resin does not have, for example, a permanent dipole. A non-polar olefin resin may be, for example, an unsaturated hydrocarbon consisting only of carbon atoms and hydrogen atoms.

[0026] The term "non-polar" as used herein does not strictly mean that there is no polarity. In other words, non-polar olefin resins also include olefin resins with low polarity (specifically, olefin resins with low intramolecular electronic polarization). Non-polar olefin resins, for example, have few polar functional groups.

[0027] Examples of non-polar olefin-based resins include polyethylene, polypropylene, polybutene, polyisobutylene, polystyrene, and cycloolefin. Examples of non-polar olefin-based resins include ethylene-vinyl acetate copolymers. Although ethylene-vinyl acetate copolymers have polarity, their polarity is low, so they can be included in the non-polar olefin-based resins. These olefin resins may be used alone or in combination of two or more.

[0028] Non-polar olefin resins have a solubility parameter (SP value) of 6 to 10 (cal / cm 3 ) 1 / 2 The SP value is preferably 7 to 9 (cal / cm 3 ) 1 / 2 The SP value can be calculated, for example, by the following formula. SP=(ΔH / V) 1 / 2 (ΔH is the molar heat of vaporization (cal / mol). V is the molar volume (cm 3 / mol).

[0029] The SP value can be measured, for example, by using the Fedors method (see SP Value Basics, Applications and Calculations, March 31, 2005, 1st Edition, published by Akitoshi Taniguchi, published by Johokki Co., Ltd., pages 66 and 67).

[0030] The non-polar olefin resin preferably has a dielectric loss tangent (see, for example, JIS C2138) of 0.001 or less, and a dielectric constant (see, for example, JIS K6911 or ASTM D150) of 3 or less.

[0031] Non-polar synthetic rubber is a synthetic rubber that does not have polarity, specifically, a synthetic rubber that does not have electronic polarization in its molecules. For example, non-polar synthetic rubber does not have a polar functional group. For example, non-polar synthetic rubber does not have a permanent dipole.

[0032] Regarding synthetic rubber, "non-polar" does not strictly mean that it is not polar. In other words, non-polar synthetic rubber also includes synthetic rubber with low polarity (specifically, synthetic rubber with low electronic polarization within the molecule). Non-polar synthetic rubber has, for example, few polar functional groups.

[0033] Examples of non-polar synthetic rubbers include ethylene propylene rubber, ethylene propylene diene rubber, isobutylene rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, silicone rubber, etc. These synthetic rubbers may be used alone or in combination of two or more.

[0034] Non-polar synthetic rubber has an SP value of 6 to 10 (cal / cm 3 ) 1 / 2 The SP value is preferably 7 to 9 (cal / cm 3 ) 1 / 2 The non-polar synthetic rubber preferably has a dielectric loss tangent of 0.001 or less and a dielectric constant of 3 or less.

[0035] The adhesive layer 3 may contain only one of a non-polar olefin resin and a non-polar synthetic rubber, or may contain both. The content ratio (mass ratio) of the olefin resin to the synthetic rubber in the adhesive layer 3 may be, for example, 1:9 to 9:1 (olefin resin:synthetic rubber).

[0036] The adhesive layer 3 contains at least one of a non-polar olefin resin and a non-polar synthetic rubber, so the dielectric tangent of the adhesive layer 3 is small. This prevents a decrease in communication distance due to dielectric loss. This allows the RFID label 10 to achieve electrical characteristics suitable for the communication characteristics (communication distance, frequency band) required. On the other hand, if the adhesive layer 3 is made of a polar material, the dielectric loss tangent of the adhesive layer 3 increases due to the influence of polarization. As a result, the electrical energy that would otherwise be used for communication is converted into thermal energy, resulting in a loss, which may degrade the communication characteristics of the RFID label 10. For example, the communication distance may become shorter.

[0037] The inlet 2 and the adhesive layer 3 are directly bonded to each other, and therefore there is no adhesive layer, sticky layer, or the like between the inlet 2 and the adhesive layer 3 to bond them together. Therefore, the inlet 2 and the adhesive layer 3 are in direct contact over the entire surface. The conductive layer 4 and the adhesive layer 3 are directly bonded to each other, and therefore there is no adhesive layer, sticky layer, or the like between the conductive layer 4 and the adhesive layer 3 to bond them together. Therefore, the conductive layer 4 and the adhesive layer 3 are in direct contact over the entire surface.

[0038] Because the inlet 2 and the adhesive layer 3 are bonded together, the peel strength P1 between the inlet 2 and the adhesive layer 3 is higher than the peel strength between other layers. For example, the peel strength P1 is higher than the peel strength between the surface substrate 1 and the inlet 2. The peel strength P1 is higher than the peel strength between the conductive layer 4 and the adhesive layer 5.

[0039] Because the conductive layer 4 and the adhesive layer 3 are bonded together, the peel strength P2 between the conductive layer 4 and the adhesive layer 3 is higher than the peel strength between other layers. For example, the peel strength P2 is higher than the peel strength between the surface substrate 1 and the inlet 2. The peel strength P2 is higher than the peel strength between the conductive layer 4 and the adhesive layer 5. Methods for measuring the peel strength include the 90-degree peel test method and the 180-degree peel test method specified in JIS Z0237:2009.

[0040] The thickness of the adhesive layer 3 is 200 μm to 800 μm. By making the thickness of the adhesive layer 3 200 μm or more, a sufficient distance can be secured between the inlet 2 and the conductive layer 4, improving the communication performance of the RFID label 10. By making the thickness of the adhesive layer 3 800 μm or less, the overall thickness of the RFID label 10 can be reduced. This makes the RFID label 10 more suitable for use with a label printer that prints on the surface base material 1. By making the thickness of the adhesive layer 3 800 μm or less, the overall thickness of the RFID label 10 can be reduced and the flexibility of the RFID label 10 can be increased. This makes it easier to attach the RFID label 10 to an object even if the surface is uneven.

[0041] Fig. 3 is a cross-sectional view of a first example of the conductive layer 4. As shown in Fig. 3, the conductive layer 4 includes a metal layer 4B and a resin layer 4A. The resin layer 4A is laminated on the upper surface of the metal layer 4B. The conductive layer 4 has conductivity due to the inclusion of the metal layer 4B.

[0042] Examples of resins that can be used to form the resin layer 4A include polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyamide resins such as nylon 6 and nylon 66; and polyolefin resins such as polyethylene and polypropylene.

[0043] The metal layer 4B is formed of a metal such as aluminum, an aluminum alloy, stainless steel, copper, gold, silver, or silver-palladium. The metal layer 4B is formed of a metal foil, a metal thin film, a metal plate, or the like. The metal thin film is formed by, for example, plating. The metal thin film is formed by various thin film formation methods such as metal vapor deposition. The metal layer 4B is a conductive layer. Instead of the metal layer 4B, a conductive layer containing a conductive ink such as a polymer-type conductive ink or a silver ink composition may be used.

[0044] The thickness of the conductive layer 4 is, for example, 10 μm to 100 μm. When the thickness of the conductive layer 4 is 10 μm or more, the function as a conductive layer can be improved and the communication performance of the RFID label 10 can be improved. When the thickness of the conductive layer 4 is 100 μm or less, the overall thickness of the RFID label 10 can be reduced.

[0045] The resin layer 4A has a thickness of, for example, 5 μm to 50 μm, and the metal layer 4B has a thickness of, for example, 5 μm to 50 μm.

[0046] In the conductive layer 4, the resin layer 4A is provided above the metal layer 4B, and therefore the adhesive layer 3 is in contact with the resin layer 4A. This makes it easier to optimize the adhesive strength between the adhesive layer 3 and the conductive layer 4. The conductive layer 4 has resin layer 4A, which increases the tensile strength, making metal layer 4B less likely to break when a tensile force is applied to conductive layer 4 during processing.

[0047] As shown in FIG. 1, adhesive layer 5 can be made of an adhesive that is generally used for labels. The release sheet 6 is formed of, for example, paper or a resin sheet.

[0048] The adhesive layer 3, the conductive layer 4, and the adhesive layer 5 have a rectangular shape in plan view. The adhesive layer 3, the conductive layer 4, and the adhesive layer 5 have the same shapes in plan view as the inlet 2. The adhesive layer 3, the conductive layer 4, and the adhesive layer 5 overlap with the inlet 2 in plan view.

[0049] The overall thickness T1 of the RFID label 10 (thickness from the surface substrate 1 to the adhesive layer 5) is 300 μm to 1200 μm. By making the overall thickness of the RFID label 10 300 μm or more, a sufficient distance can be secured between the inlet 2 and the conductive layer 4, improving the communication performance of the RFID label 10. By making the overall thickness of the RFID label 10 1200 μm or less, the RFID label 10 can be more easily used with a label printer that prints on the surface base material 1. By making the overall thickness of the RFID label 10 1200 μm or less, the flexibility of the RFID label 10 can be increased. Therefore, the RFID label 10 can be easily attached to an object even if the surface is uneven.

[0050] [RFID Label Manufacturing Method] (First Embodiment) Next, a method for manufacturing the RFID label 10 will be described.

[0051] (1st process: Preparation process) As shown in FIG. 4, the inlet 2 and the conductive layer 4 are prepared.

[0052] (Second process: Adhesive application process) As shown in FIG. 5, adhesive 7 is applied to at least one of the lower surface of the inlet 2 and the upper surface of the conductive layer 4. The adhesive 7 is, for example, an uncured liquid curing adhesive. The adhesive 7 may also be a semi-solid curing adhesive. In this embodiment, the adhesive 7 is applied to the upper surface of the conductive layer 4. The adhesive 7 contains at least one of a non-polar olefin resin and a non-polar synthetic rubber resin.

[0053] (3rd process: adhesion process) As shown in FIG. 6 , adhesive 7 is brought into contact with the bottom surface of inlet 2, and inlet 2 and conductive layer 4 are bonded together via adhesive 7. This results in a laminate 8 in which inlet 2, adhesive 7, and conductive layer 4 are laminated together. At this time, IC chip 21 of inlet 2 is embedded in adhesive 7. The bottom surface 21a and four side surfaces 21b of IC chip 21 are covered with adhesive 7. The bottom surface 21a and four side surfaces 21b of IC chip 21 are in contact with adhesive 7 over their entire surfaces.

[0054] The adhesive 7 is cured by cooling, drying, heating, energy ray radiation, or the like to form the adhesive layer 3 (see FIG. 1). The adhesive layer 3 is a cured product of the adhesive 7. The adhesive layer 3 bonds the inlet 2 and the conductive layer 4 together.

[0055] As shown in FIG. 1 , a surface substrate 1 is formed on the upper surface of an inlet 2. An adhesive layer 5 is formed on the lower surface of a conductive layer 4, and a release sheet 6 is attached to the adhesive layer 5. The surface substrate 1 may be formed on the upper surface of the inlet 2 before bonding the inlet 2 and the conductive layer 4 together via an adhesive material 7. The adhesive layer 5 and release sheet 6 may be formed on the lower surface of the conductive layer 4 before bonding the inlet 2 and the conductive layer 4 together via the adhesive material 7. As a result, the RFID label 10 shown in FIG. 1 is obtained.

[0056] [How to use RFID labels] The RFID label 10 can be used, for example, as follows. The release sheet 6 is peeled off from the adhesive layer 5. As shown in Fig. 7, the RFID label 10 with the adhesive layer 5 exposed is attached to the surface of the target article 30. At least the surface of the target article 30 may be made of metal.

[0057] [Effects of the RFID label of the first embodiment] 1 has an adhesive layer 3 provided between the inlet 2 and the conductive layer 4, which makes it difficult for the distance between the inlet 2 and the conductive layer 4 to fluctuate. This reduces radio wave attenuation and changes in frequency characteristics, ensuring good communication performance. For example, fluctuations in communication distance can be suppressed. The RFID label 10 has an adhesive layer 3 between the inlet 2 and the conductive layer 4, ensuring good communication performance even when the surface of the target article 30 is made of metal. Therefore, the RFID label 10 is a "metal article compatible label" that can be used with metal articles.

[0058] In the RFID label 10, an adhesive layer 3 is provided between the inlet 2 and the conductive layer 4 to bond them together. The adhesive layer 3 functions as a spacer that separates the inlet 2 from the conductive layer 4. Therefore, the adhesive layer 3 has both the function of bonding the inlet 2 and the conductive layer 4 together and the function of acting as a spacer that separates them.

[0059] The RFID label 10 has a simpler structure than conventional RFID tags in which a plate-shaped spacer is placed between an inlet and a conductive layer and bonded to the inlet and the conductive layer, respectively. Therefore, the manufacturing process for the RFID label 10 is simpler and easier to manufacture than RFID tags with conventional structures.

[0060] Since the conductive layer 4 has the metal layer 4B and the resin layer 4A, it has higher mechanical strength (e.g., tensile strength) than a conductive layer consisting only of a metal layer, which makes the conductive layer 4 easier to handle.

[0061] [Advantages of the RFID label manufacturing method according to the first embodiment] 4 to 6, the method for manufacturing the RFID label 10 provides the adhesive layer 3 between the inlet 2 and the conductive layer 4, thereby making it possible to manufacture an RFID label 10 in which the distance between the inlet 2 and the conductive layer 4 is less likely to fluctuate. This makes it possible to manufacture an RFID label 10 with good communication performance.

[0062] According to the manufacturing method, an adhesive layer 3 is provided between the inlet 2 and the conductive layer 4, and therefore the manufacturing process is simpler and easier than when manufacturing an RFID tag with a conventional structure in which plate-shaped spacers are adhered to the inlet and the conductive layer, respectively.

[0063] The manufacturing method includes a step of applying adhesive 7 to at least one of the inlet 2 and the conductive layer 4. According to this manufacturing method, the thickness of the adhesive layer 3 can be easily adjusted by adjusting the thickness of the adhesive 7 applied when applying the adhesive 7. Therefore, RFID labels with communication characteristics suited to the application can be manufactured.

[0064] [Conductive layer] (Second example) FIG. 8 is a cross-sectional view of a conductive layer 14, which is a second example of the conductive layer. As shown in Fig. 8, the conductive layer 14 includes a metal layer 4B and a resin layer 4A. The conductive layer 14 differs from the conductive layer 4 shown in Fig. 3 in that the resin layer 4A is laminated on the lower surface of the metal layer 4B. The conductive layer 14 has conductivity due to the inclusion of the metal layer 4B.

[0065] In the conductive layer 14, the metal layer 4B is provided above the resin layer 4A, so the adhesive layer 3 is in contact with the metal layer 4B. This may make it easier to optimize the adhesive strength between the adhesive layer 3 and the conductive layer 14. The conductive layer 14 has resin layer 4A, which increases the tensile strength, making the metal layer 4B less likely to break when a tensile force is applied to the conductive layer 14 during processing.

[0066] [Conductive layer] (Third example) FIG. 9 is a cross-sectional view of a conductive layer 24, which is a third example of the conductive layer. 9, the conductive layer 24 is made up of only the metal layer 4B. Because the conductive layer 24 is made up of only the metal layer 4B, this is advantageous in making the RFID label 10 thinner.

[0067] [Antenna] (First example) FIG. 10 is a plan view of a part (for example, a part of the radiating portion) of an antenna 123 which is a first example of the antenna 23 shown in FIG. As shown in Fig. 10, the antenna 123 is formed in a layer on one surface of the substrate 20. The antenna 123 has no holes and is formed uniformly over the entire surface. The antenna 123 is formed of, for example, a metal foil, a metal thin film, a metal plate, or the like. The antenna 123 has a large area and is therefore excellent in terms of radiation characteristics.

[0068] [Antenna] (Second example) FIG. 11 is a plan view of a part (for example, a part of the radiating portion) of an antenna 223 which is a second example of the antenna 23 shown in FIG. As shown in FIG. 11, the antenna 223 is formed in a layer on one surface of the substrate 20. The antenna 223 is formed of, for example, a metal foil, a metal thin film, or a metal plate. A plurality of holes 25 are formed in the antenna 223. The holes 25 are rectangular (for example, diamond-shaped). Since the plurality of holes 25 are formed aligned vertically and horizontally, the antenna 223 has a mesh-like pattern in which a plurality of metal wirings intersect. More specifically, in FIG. 11, the antenna 223 has a mesh-like pattern in which a plurality of parallel oblique wirings 26 slanting upward to the right and a plurality of parallel oblique wirings 27 slanting upward to the left intersect with each other.

[0069] The left-right direction in Fig. 11 is referred to as the X direction. The up-down direction in Fig. 11 is referred to as the Y direction. In a plan view, hole 25 is a rhombus with two diagonals aligned along the X and Y directions, respectively. Although hole 25 shown in Fig. 11 has a larger dimension in the X direction than the dimension in the Y direction, hole 25 may have the same dimension in the X and Y directions.

[0070] Since the antenna 223 has a plurality of holes 25 formed therein, it has lower bending rigidity than the antenna 123 (see FIG. 10) which does not have holes. This increases the flexibility of the RFID label 10. This makes it easier to attach the RFID label 10 to an object even if the object has an uneven surface.

[0071] [RFID Label] (Second Embodiment) 12 is a cross-sectional view of the RFID label 110 according to the second embodiment in use. Note that the same components as those in the first embodiment are denoted by the same reference numerals and will not be described. 12, an RFID label 110 differs from the RFID label 10 of the first embodiment shown in Fig. 1 in that a surface base material 101 is used instead of the surface base material 1. The laminate from the inlet 2 to the adhesive layer 5 is called a laminate 9. RFID label 110 is an example of a "contactless data transmitter / receiver (RFID tag)."

[0072] The surface substrate 101 has a larger area in plan view than the surface substrate 1 shown in Fig. 1. A rectangular frame-shaped portion (peripheral portion 102) including the outer peripheral edge 101a of the surface substrate 101 protrudes outward from the outer peripheral edge of the laminate 9 in plan view. The outer peripheral portion 102 is attached to the surface of the target article 30 with an adhesive or the like.

[0073] If the surface of the target article 30 is uneven, part of the RFID label is likely to peel off from the surface of the target article 30, but with the RFID label 110, the surface base material 101 can press the laminate 9 against the target article 30. Therefore, the RFID label 110 can be installed so that the laminate 9 comes into contact with the target article 30 over a wide area.

[0074] [Inlet] (Variation) FIG. 13 is a plan view of an inlet 302 which is a modification of the inlet 2. As shown in FIG. 13, the inlet 302 includes a substrate 20, an IC chip 21, a circuit 322, and an antenna 323. The circuit 322 has a power feeding portion 324. The antenna 323 has a plurality of radiating portions 325. The circuit 322 and the antenna 323 are formed on one surface of the substrate 20 using metal foil or the like. The circuit 322 and the antenna 323 are integrally formed.

[0075] Although the embodiments of the present invention have been described above, the configurations and combinations thereof in the embodiments are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments. 1, in the RFID label 10 of the first embodiment, the IC chip 21 is formed on the lower surface of the base material 20, but the surface of the base material 20 on which the IC chip 21 is formed is not particularly limited. The IC chip 21 may also be formed on the upper surface of the base material 20.

[0076] 2, the RFID label 10 has a rectangular shape in plan view, but the shape of the RFID label in plan view is not particularly limited. The shape of the RFID label in plan view may be a circle, an ellipse, a polygon, or the like. 1 includes a surface substrate 1, an inlet 2, an adhesive layer 3, a conductive layer 4, a pressure-sensitive adhesive layer 5, and a release sheet 6, but the layer configuration of the RFID label is not limited to this. For example, another layer may be formed between the surface substrate 1 and the inlet 2. Another layer may be formed between the conductive layer 4 and the pressure-sensitive adhesive layer 5. [Explanation of symbols]

[0077] 2,302...inlet, 3...adhesive layer, 4...conductive layer, 4A...resin layer, 4B...metal layer, 7...adhesive, 10,110...RFID label, 21...IC chip, 23,123,223,323...antenna, T1...total thickness.

Claims

1. an inlet having an IC chip and an antenna electrically connected to the IC chip; a conductive layer having conductivity; an adhesive layer interposed between the inlet and the conductive layer to bond the inlet and the conductive layer; Equipped with the adhesive layer contains at least one of a non-polar olefin-based resin and a non-polar synthetic rubber-based resin, The thickness of the adhesive layer is 200 μm to 800 μm, The RFID label has a total thickness of 300 μm to 1200 μm.

2. The RFID label according to claim 1 , wherein the conductive layer comprises a metal layer and a resin layer laminated on the metal layer.

3. 3. The RFID label according to claim 2, wherein the conductive layer has a thickness of 10 μm to 100 μm.

4. A step of preparing an inlet having an IC chip and an antenna electrically connected to the IC chip, and a conductive layer having conductivity; applying an adhesive to at least one of the inlet and the conductive layer; a step of bonding the inlet and the conductive layer with the adhesive to obtain an RFID label having an overall thickness of 300 μm to 1200 μm; and the adhesive material includes at least one of a non-polar olefin-based resin and a non-polar synthetic rubber-based resin, The method for manufacturing an RFID label, wherein the adhesive layer formed by the adhesive material has a thickness of 200 μm to 800 μm.

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