IC tag

Abstract

This IC tag comprises: a base material having a first surface and a second surface; an IC chip disposed on the first surface of the base material; a dipole antenna that is disposed on the first surface of the base material and electrically transmits and receives information stored in the IC chip; a cover joined to the first surface of the base material so as to cover the IC chip and the antenna; a first resin layer laminated on at least a portion of a surface of the cover on the opposite side from a surface joined to the first surface of the base material; and a second resin layer laminated on at least a portion of the second surface of the base material. The first resin layer and the second resin layer each have a tensile elastic modulus of 2.0 GPa or less.

Description

IC tag

[0001] The present invention relates to an IC tag.

[0002] In recent years, a type of IC tag has been proposed, which is a structure in which an antenna for radio wave communication and an IC chip are mounted on a base sheet made of plastic or paper, called an inlet. Such an inlet is sealed with, for example, resin and is used to manage goods by attaching it to or embedding it in goods.

[0003] International Publication No. 2009 / 011041

[0004] The IC tag described above may be used in harsh environments where it is subjected to external forces such as bending, which may cause the IC chip to peel off from the antenna or the antenna to break. If the IC chip peels off from the antenna or the antenna breaks, the communication function may deteriorate, and communication may become impossible.

[0005] An object of the present invention is to provide an IC tag that can reduce the risk of its communication function being degraded even when an external force such as bending is applied to the IC tag.

[0006] An IC tag according to a first aspect of the present invention comprises a substrate having a first surface and a second surface, an IC chip arranged on the first surface of the substrate, a dipole antenna arranged on the first surface of the substrate and electrically transmitting and receiving information stored in the IC chip, a cover joined to the first surface of the substrate so as to cover the IC chip and the antenna, a first resin layer laminated on at least a portion of the surface of the cover opposite to the surface joined to the first surface of the substrate, and a second resin layer laminated on at least a portion of the second surface of the substrate, wherein the first resin layer and the second resin layer have a tensile modulus of elasticity of 2.0 GPa or less.

[0007] An IC tag according to a second aspect of the present invention is the IC tag according to the first aspect, wherein the ratio of the tensile modulus of elasticity of the first resin layer to the tensile modulus of elasticity of the cover is 0.5 or less.

[0008] An IC tag according to a third aspect of the present invention is the IC tag according to the first or second aspect, wherein the thickness of the first resin layer is greater than the thickness of the cover.

[0009] An IC tag according to a fourth aspect of the present invention is the IC tag according to the third aspect, wherein the ratio of the thickness of the first resin layer to the thickness of the cover is 1.0 or greater.

[0010] An IC tag according to a fifth aspect of the present invention is an IC tag according to any one of the first to fourth aspects, wherein the ratio of the tensile modulus of elasticity of the second resin layer to the tensile modulus of elasticity of the substrate is 0.5 or less.

[0011] An IC tag according to a sixth aspect of the present invention is the IC tag according to any one of the first to fifth aspects, wherein the thickness of the second resin layer is greater than the thickness of the substrate.

[0012] An IC tag according to a seventh aspect of the present invention is the IC tag according to the sixth aspect, wherein the ratio of the thickness of the second resin layer to the thickness of the base material is 1.0 or more.

[0013] An IC tag according to an eighth aspect of the present invention is the IC tag according to any one of the first to seventh aspects, and has a bending load of 2.0 N or less.

[0014] According to the IC tag of the present invention, even when an external force such as bending is applied, the risk of the communication function being deteriorated can be reduced.

[0015] Fig. 2 is a cross-sectional view of an IC tag of an embodiment. Fig. 3 is a plan view of the IC tag of Fig. 1 with a first resin layer and a cover removed. Fig. 4 is a cross-sectional view of a virtual IC tag. Fig. 5 is a table relating to the specifications of IC tags of Examples and Comparative Examples. Fig. 6 is a cross-sectional view of an IC tag of Comparative Example 1. Fig. 7 is a table relating to test results.

[0016] An IC tag according to one embodiment of the present invention will be described below with reference to the drawings.

[0017] 1. Overview of IC Tag An embodiment of an IC tag according to the present invention will now be described with reference to the drawings. FIG. 1 is a cross-sectional view of an IC tag 10 according to this embodiment. FIG. 2 is a plan view of the IC tag 10 of FIG. 1 , with the first resin layer 6 and the cover 4 removed. As shown in FIGS. 1 and 2 , the IC tag according to this embodiment includes a rectangular substrate 1 having a first surface 11 (top surface) and a second surface 12 (bottom surface), an IC chip 2 and a dipole antenna 3 disposed on the top surface of the substrate 1, and a rectangular cover 4 covering the IC chip 2 and the dipole antenna 3. The cover 4 is fixed to the first surface 11 of the substrate 1 with an adhesive 5. Each of these components will now be described in detail.

[0018] The material constituting the substrate 1 is not particularly limited, but may be, for example, a polyester-based resin such as low-density polyethylene, high-density polyethylene, polypropylene, polyethylene naphthalate, polyamide 6, polyamide 66, polyvinyl chloride, or polyethylene terephthalate, or a polyimide-based resin. The thickness of the substrate 1 is also not particularly limited, but is preferably, for example, 25 μm to 200 μm, and more preferably 50 μm to 150 μm.

[0019] For ease of explanation, the longitudinal sides of the substrate 1 will be referred to as a first side 101 and a second side 102, and the lateral sides will be referred to as a third side 103 and a fourth side 104, as shown in Fig. 2. These sides are connected in the order of the first side 101, the third side 103, the second side 102, and the fourth side 104.

[0020] The IC chip 2 is a known device having a memory function, and is electrically connected to a dipole antenna 3 made of a conductor.

[0021] In this embodiment, a dipole antenna 3 as shown in FIG. 2 is used as an example. The dipole antenna 3 includes an impedance matching section 31 disposed near the center of the substrate 1 in the longitudinal direction, and a pair of dipole sections 32 extending from the impedance matching section 31 in the longitudinal direction of the substrate 1. The impedance matching section 31 is formed in the shape of a rectangular frame having first to fourth sides. More specifically, the first side 311 of the impedance matching section 31 is disposed slightly away from the first side 101 of the substrate 1, and the second side 312 is disposed along the second side 102 of the substrate 1. That is, the impedance matching section 31 has the first side 311, third side 313, second side 312, and fourth side 314 connected in this order. The IC chip 2 is disposed near the center of the first side 311 of the impedance matching section 31.

[0022] The dipole section 32 has a bilaterally symmetrical shape, and therefore only the left side of Fig. 2 will be described. The dipole section 32 extends from the first side 311 of the impedance matching section 31 toward the first side 101 of the substrate 1, then extends along the first side 101 of the substrate 1, and further extends along the third side 103 and the second side 102, repeating this pattern. The thickness of the dipole antenna 3 is not particularly limited, but may be, for example, 5 µm or more and 20 µm or less.

[0023] The material constituting the dipole antenna 3 is not particularly limited, but can be formed from a conductive material such as silver, copper, or aluminum. When silver is used, the dipole antenna 3 can be formed by applying a silver paste containing silver to the substrate 1 by screen printing. On the other hand, when copper or aluminum is used, the dipole antenna 3 can be formed by, for example, etching. The IC chip 2 may also be fixed to the dipole antenna 3 with, for example, a conductive adhesive. Alternatively, the IC chip 2 can be fixed to the dipole antenna 3 by known flip-chip mounting for electronic components. The thickness of the IC chip 2 is not particularly limited, but can be 100 μm or more and 150 μm or less.

[0024] The dipole antenna 3 as described above can transmit and receive information stored in the IC chip 2 by radio waves in the UHF band, for example.

[0025] The material constituting the cover 4 is not particularly limited, but is preferably a material that is deformable by heat. The material constituting the cover 4 may be, for example, the same material as the base material 1. The thickness of the cover 4 is not particularly limited, but is preferably, for example, 25 μm or more and 250 μm or less, and more preferably 50 μm or more and 150 μm or less.

[0026] The adhesive 5 can be made of a material whose main component is, for example, an acrylic thermosetting resin, an ester thermosetting resin, an epoxy thermosetting resin, or a polyimide thermosetting resin. A thermoplastic adhesive can also be used as the adhesive 5.

[0027] The IC tag 10 may be used in harsh environments where it is subjected to external forces such as bending. In a typical example, the IC tag 10 is attached to clothing. Therefore, when clothing to which the IC tag 10 is attached is washed in a washing machine, the IC tag 10 is subjected to a large external force in the bending direction. The IC tag 10 of this embodiment further includes a first resin layer 6 and a second resin layer 7 to prevent the IC chip 2 from peeling off from the dipole antenna 3 and the dipole antenna 3 from breaking (hereinafter, these may be collectively referred to as "a decrease in the communication function of the IC tag 10") even when the IC tag 10 is subjected to a large external force in the bending direction.

[0028] The first resin layer 6 suppresses large plastic deformation of the cover 4 even when a large external force is applied in a bending direction. The first resin layer 6 is laminated on at least a portion of the surface of the cover 4 opposite to the surface that is joined to the first surface 11 of the base material 1. In this embodiment, the first resin layer 6 is laminated on almost the entire surface of the cover 4 opposite to the surface that is joined to the first surface 11 of the base material 1.

[0029] The material constituting the first resin layer 6 is not particularly limited as long as it has a tensile modulus of elasticity of 2.0 GPa or less. The material constituting the first resin layer 6 may be an adhesive, a bonding sheet containing an adhesive, or a coating material. The adhesive may be, for example, an epoxy-based adhesive. The coating material may be an elastomer such as rubber. The rubber is not particularly limited, and examples thereof include nitrile rubber, chloroprene rubber, chlorosulfonated polyethylene, polybutadiene rubber, natural rubber, ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), hydrogenated nitrile rubber (H-NBR), millable urethane, acrylic rubber, silicone rubber, fluororubber, and carboxylated nitrile rubber. These rubbers may be used alone or in combination. These rubbers may also be used in combination with at least one of the adhesive and the bonding sheet. The tensile modulus of elasticity of the first resin layer 6 is measured based on IPC-TM-650 "Reliability test for electronic components and printed wiring boards" or JIS K7127 1999 "Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets."

[0030] In order to prevent the cover 4 from undergoing large plastic deformation, the first resin layer 6 preferably has a tensile modulus of elasticity of 1.0 GPa or less, and more preferably 0.5 GPa or less.

[0031] In order to prevent the cover 4 from undergoing large plastic deformation, the ratio of the tensile modulus of the first resin layer 6 to the tensile modulus of the cover 4 is preferably 0.5 or less, more preferably 0.25 or less, and even more preferably 0.125 or less.

[0032] The thickness of the first resin layer 6 is not particularly limited. From the viewpoint of suppressing large plastic deformation of the cover 4, the thickness of the first resin layer 6 is preferably 25 μm or more, more preferably 50 μm or more, and even more preferably 100 μm or more. From the viewpoint of increasing the flexibility of the IC tag 10, the thickness of the first resin layer 6 is preferably 300 μm or less, more preferably 250 μm or less, and even more preferably 200 μm or less. Preferred ranges for the thickness of the first resin layer 6 are 25 μm or more and 300 μm or less, 25 μm or more and 250 μm, 25 μm or more and 200 μm, 50 μm or more and 300 μm or less, 50 μm or more and 250 μm, 50 μm or more and 200 μm, 100 μm or more and 300 μm or less, or 100 μm or more and 250 μm, and 100 μm or more and 200 μm or less.

[0033] In order to prevent the cover 4 from undergoing large plastic deformation, the thickness of the first resin layer 6 is preferably greater than the thickness of the cover 4 .

[0034] From the standpoint of suppressing large plastic deformation of the cover 4, the ratio of the thickness of the first resin layer 6 to the thickness of the cover 4 is preferably 1.0 or greater, more preferably 1.5 or greater, and even more preferably 2.0 or greater.

[0035] The second resin layer 7 prevents the substrate 1 from undergoing large plastic deformation even when a large external force is applied in the bending direction. The second resin layer 7 is laminated on at least a portion of the second surface 12 of the substrate 1. In this embodiment, the second resin layer 7 is laminated on almost the entire second surface 12 of the substrate 1.

[0036] The material constituting the second resin layer 7 is not particularly limited as long as it has a tensile modulus of elasticity of 2.0 GPa or less. The material constituting the second resin layer 7 may be an adhesive, a bonding sheet containing an adhesive, or a coating material. The adhesive may be, for example, an epoxy-based adhesive. The coating material may be an elastomer such as rubber. The rubber is not particularly limited, and examples thereof include nitrile rubber, chloroprene rubber, chlorosulfonated polyethylene, polybutadiene rubber, natural rubber, ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM), hydrogenated nitrile rubber (H-NBR), millable urethane, acrylic rubber, silicone rubber, fluororubber, and carboxylated nitrile rubber. These rubbers may be used alone or in combination. These rubbers may also be used in combination with at least one of the adhesive and the bonding sheet. The tensile modulus of the second resin layer 7 is measured using the same method as for the first resin layer 6.

[0037] From the viewpoint of suppressing large plastic deformation of the substrate 1, the tensile modulus of elasticity of the second resin layer 7 is preferably 1.0 GPa or less, and more preferably 0.5 GPa or less.

[0038] The thickness of the second resin layer 7 is not particularly limited. From the viewpoint of suppressing large plastic deformation of the substrate 1, the thickness of the second resin layer 7 is preferably 25 μm or more, more preferably 50 μm or more, and even more preferably 100 μm or more. From the viewpoint of increasing the flexibility of the IC tag 10, the thickness of the second resin layer 7 is preferably 300 μm or less, more preferably 250 μm or less, and even more preferably 200 μm or less. Preferred ranges for the thickness of the second resin layer 7 are 25 μm or more and 300 μm or less, 25 μm or more and 250 μm, 25 μm or more and 200 μm, 50 μm or more and 300 μm or less, 50 μm or more and 250 μm, 50 μm or more and 200 μm, 100 μm or more and 300 μm or less, or 100 μm or more and 250 μm, and 100 μm or more and 200 μm or less.

[0039] From the viewpoint of suppressing large plastic deformation of the substrate 1 , the thickness of the second resin layer 7 is preferably greater than the thickness of the substrate 1 .

[0040] From the viewpoint of preventing the substrate 1 from undergoing large plastic deformation, the ratio of the thickness of the second resin layer 7 to the thickness of the substrate 1 is preferably 1.0 or more, more preferably 1.5 or more, and even more preferably 2.0 or more.

[0041] From the viewpoint of preventing the substrate 1 from undergoing large plastic deformation, the ratio of the tensile modulus of the second resin layer 7 to the tensile modulus of the substrate 1 is preferably 0.5 or less, more preferably 0.25 or less, and even more preferably 0.125 or less.

[0042] From the viewpoint of increasing the flexibility of the IC tag 10, the bending load of the IC tag 10 is preferably 2.0 N or less, more preferably 1.5 N or less, and even more preferably 1.0 N or less. When the bending load of the IC tag 10 is 2.0 N or less, the clothing to which the IC tag 10 is attached is less likely to be damaged when washed in a washing machine.

[0043] The bending load of the IC tag 10 is measured using a bending load measuring device (Force Gauge ZTS-200N manufactured by Imada Corporation). In measuring the bending load of the IC tag 10, a jig is sandwiched between a pair of support bases, and the distance between the pair of support bases is set to 16 mm. Next, the IC tag 10 is placed so as to straddle the pair of support bases. Next, the portion of the IC tag 10 between the pair of support bases is pressed down with an attachment of the bending load measuring device at a speed of 10 mm / min, and the load when the attachment is lowered by 5 mm is taken as the bending load of the IC tag 10.

[0044] 3 is a cross-sectional view of a hypothetical IC tag 10X (hereinafter referred to as "IC tag 10X") that does not have a first resin layer 6 or a second resin layer 7. The IC tag 10X includes a rectangular substrate 1X having a first surface 11X and a second surface 12X, an IC chip 2X and a dipole antenna 3X disposed on the upper surface of the substrate 1X, and a rectangular cover 4X that covers the IC chip 2X and the dipole antenna 3X. The cover 4X is fixed to the first surface 11X of the substrate 1X with an adhesive 5X. The IC tag 10X has the same configuration as the IC tag 10 of this embodiment, except that it does not have the first resin layer 6 or the second resin layer 7.

[0045] The IC tag 10X is highly flexible because no materials are laminated on the outside of the cover 4 or on the second surface 12X of the base material 1. Therefore, when an external force acts on the IC tag 10X such that it bends at a position XA near the center in the longitudinal direction, as shown by the arrow in Fig. 3, the cover 4X undergoes large plastic deformation in the elongated direction.

[0046] When the external force is no longer applied, the IC tag 10X attempts to return to its original shape. Although the adhesive 5X returns to its original length, the stretched portion of the cover 4X does not return to its original length, causing wrinkles to form in the cover 4X. This repeated bending and unbending of the IC tag 10X causes the wrinkles in the cover 4X to become larger. If large wrinkles form in the portion of the cover 4X that covers the IC chip 2X, a space is formed above the IC chip 2X, making the IC chip 2X more likely to peel off from the dipole antenna 3X.

[0047] In the IC tag 10 of this embodiment, a first resin layer 6 having a tensile modulus of elasticity of 2 GPa or less is laminated on the cover 4. The first resin layer 6 prevents the cover 4 from undergoing large plastic deformation in the extension direction, thereby suppressing the formation of wrinkles on the cover 4. This prevents the IC chip 2 from peeling off from the dipole antenna 3.

[0048] Furthermore, when the IC tag 10X is bent back, a force acts on the cover 4X in a direction that peels it off from the adhesive 5X. For this reason, the cover 4X of the IC tag 10X may peel off from the adhesive 5X. If the IC tag 10X is bent in a state in which the cover 4X has peeled off from the adhesive 5X, stress will concentrate at the boundary between the portion of the cover 4X that is joined to the base material 1X by the adhesive 5X and the peeled portion, which may cause the dipole antenna 3X to break.

[0049] In the IC tag 10 of this embodiment, the first resin layer 6 prevents the cover 4 from undergoing large plastic deformation in the direction of extension, so that when the IC tag 10 is bent back, the force acting on the cover 4 in the direction of peeling it off from the adhesive 5 is weak. Because the cover 4 is less likely to peel off from the adhesive 5, breakage of the dipole antenna 3 is suppressed.

[0050] When the IC tag 10X is bent back, a force acts on the substrate 1X in a direction that causes the substrate 1X to peel away from the dipole antenna 3X, which can result in the substrate 1X peeling away from the dipole antenna 3X. If the IC tag 10X is bent in a state in which the substrate 1X has peeled away from the dipole antenna 3X, stress will concentrate at the boundary between the portion of the substrate 1X that is joined to the dipole antenna 3X and the peeled portion, which could result in the dipole antenna 3X breaking.

[0051] In the IC tag 10 of this embodiment, a second resin layer 7 having a tensile modulus of elasticity of 2 GPa or less is laminated on the second surface 12 of the substrate 1. In the IC tag 10 of this embodiment, the second resin layer 7 prevents the substrate 1 from undergoing large plastic deformation in the direction of contraction, and therefore, when the IC tag 10 is bent back, the force acting on the substrate 1 in the direction of peeling it off from the dipole antenna 3 is weak. Therefore, the substrate 1 is less likely to peel off from the dipole antenna 3, and breakage of the dipole antenna 3 is suppressed.

[0052] <3. Modifications> The above-described embodiments are examples of possible forms of the IC tag according to the present invention, and are not intended to limit the forms. The IC tag according to the present invention may take forms different from those exemplified in the embodiments. Examples include forms in which part of the configuration of the embodiment is replaced, changed, or omitted, or forms in which a new configuration is added to the embodiment. Some examples of modifications of the embodiments are shown below. Note that the following modifications can be combined with each other to the extent that they do not cause technical contradictions.

[0053] <3-1. First Modification> The shape of the dipole antenna 3 in the embodiment is one example, and can be modified into various shapes. Furthermore, the position of the IC chip 2 on the dipole antenna 3 is not particularly limited. Furthermore, various types of dipole antennas 3 can be used, and in addition to the dipole antenna 3 used in the embodiment, a patch antenna may also be used. In other words, the shape, etc. of the dipole antenna 3 are not particularly limited, and various forms are possible.

[0054] <3-2. Second Modification> The shape of the IC tag 10, that is, the shapes of the substrate 1, cover 4, first resin layer 6, and second resin layer 7, is not particularly limited, and in addition to the elongated shape described above, various shapes such as rectangular, circular, polygonal, etc. may be used depending on the application. Furthermore, the substrate 1 and the cover 4 do not necessarily have to have the same shape, as long as at least the IC chip 2 and dipole antenna 3 are disposed between the substrate 1 and the cover 4.

[0055] 4. Examples The inventors of the present application manufactured IC tags of Examples 1 and 2 and Comparative Examples 1 to 4 and conducted tests to confirm their durability and flexibility. For the sake of convenience, the following description will be given with the same reference numerals as in the embodiment to designate elements constituting the IC tags of Examples 1 and 2 and Comparative Examples 1 to 4 that are the same as in the embodiment.

[0056] FIG. 4 is a table showing the specifications of the IC tags of Examples 1 and 2 and Comparative Examples 1 to 4. The IC tags of Examples 1 and 2 are IC tags of the embodiment. The material constituting the substrate 1 and cover 4 of the IC tags of Examples 1 and 2 is polyethylene terephthalate. The tensile modulus of elasticity of polyethylene terephthalate is 3.9 GPa. The material constituting the adhesive 5 of the IC tags of Examples 1 and 2 is an epoxy-based thermosetting resin. The material constituting the first resin layer 6 and second resin layer 7 of the IC tags of Examples 1 and 2 is a bonding sheet containing an epoxy-based adhesive. The elastic modulus of the bonding sheet is 0.3 GPa.

[0057] 5 is a cross-sectional view of an IC tag of Comparative Example 1. The IC tag of Comparative Example 1 includes a rectangular substrate 1Y having a first surface 11Y and a second surface 12Y, an IC chip 2Y and a dipole antenna 3Y disposed on the upper surface of the substrate 1Y, and a rectangular cover 4Y covering the IC chip 2Y and the dipole antenna 3Y. The cover 4Y is fixed to the first surface 11Y of the substrate 1Y with an adhesive 5Y. The IC tag of Comparative Example 1 includes a laminate material 6Y laminated on the cover 4Y. The laminate material 6Y is bonded to the cover 4Y with an adhesive material 8Y. The IC tag of Comparative Example 1 includes a laminate material 7Y laminated on the second surface 12Y of the substrate 1Y. The laminate material 7Y is bonded to the substrate 1Y with an adhesive material 9Y.

[0058] The material constituting the substrate 1Y and cover 4Y of the IC tag of Comparative Example 1 is polyethylene terephthalate. The tensile modulus of the polyethylene terephthalate constituting the substrate 1Y and cover 4Y is 3.9 GPa. The material constituting the adhesive 5Y of the IC tag of Comparative Example 1 is an epoxy-based thermosetting resin. The material constituting the laminating material 6Y and laminating material 7Y of the IC tag of Comparative Example 1 is polyethylene terephthalate. The tensile modulus of the polyethylene terephthalate constituting the laminating materials 6Y and 7Y is 3.9 GPa. The material constituting the adhesive materials 8Y and 9Y of the IC tag of Comparative Example 1 is an acrylic adhesive tape (No. 5000NS manufactured by Nitto Denko Corporation).

[0059] The IC tags of Comparative Examples 2 to 4 are IC tags related to the hypothetical IC tag 10X shown in Figure 3. The material constituting the substrate 1X and cover 4X of the IC tags of Comparative Examples 2 to 4 is polyethylene terephthalate. The tensile modulus of elasticity of polyethylene terephthalate is 3.9 GPa. The material constituting the adhesive 5X of the IC tags of Comparative Examples 2 to 4 is an epoxy-based thermosetting resin.

[0060] In the test, the IC tags of Examples 1 and 2 and Comparative Examples 2 to 4 were attached to cotton T-shirts using name labels (manufactured by NLC Corporation), and the T-shirts with the attached IC tags were washed and dried in a washer / dryer. The capacity of the washer / dryer used in the test was 20 kg, the washing time was 40 minutes, and the drying time was 120 minutes. The drying temperature was 90°C. In the test, 30 T-shirts each with the IC tags of Examples 1 and 2 and Comparative Examples 2 to 4 attached were prepared, and all T-shirts were washed and dried 100 times. The read distance of each IC tag was then measured, and IC tags with a read distance retention rate of 50% or more were determined to be faulty, and IC tags with a read distance retention rate of less than 50% were determined to be faulty. In addition, in the test, the bending load of the IC tags of Examples 1 and 2 and Comparative Examples 2 to 4 was measured using the method described in the embodiment.

[0061] Figure 6 is a table showing the test results. It was confirmed that the IC tags of Examples 1 and 2 did not fail. Therefore, it was confirmed that the communication function of the IC tags of Examples 1 and 2 is unlikely to be impaired even when subjected to external forces such as bending. It was also confirmed that the bending load of the IC tags of Examples 1 and 2 was 2.0 N or less, i.e., that they are highly flexible. Therefore, it was confirmed that the IC tags of Examples 1 and 2 are unlikely to damage clothing when washed, etc., even when attached to clothing.

[0062] Although no failures occurred in the IC tag of Comparative Example 1, it was confirmed that the bending load was high. Therefore, it was confirmed that the IC tag of Comparative Example 1 is highly likely to damage clothing when attached to the clothing during washing or the like.

[0063] It was confirmed that failures occurred in the IC tags of Comparative Examples 2 to 4. This is thought to be because the IC tags of Comparative Examples 2 to 4 did not have the first resin layer 6 and the second resin layer 7, and therefore had low durability.

[0064] 1: Base material 2: IC chip 3: Dipole antenna 4: Cover 6: First resin layer 7: Second resin layer 11: First surface 12: Second surface

Claims

1. An IC tag comprising: a substrate having a first surface and a second surface; an IC chip disposed on the first surface of the substrate; a dipole antenna disposed on the first surface of the substrate and electrically transmitting and receiving information stored in the IC chip; a cover joined to the first surface of the substrate so as to cover the IC chip and the dipole antenna; a first resin layer laminated on at least a portion of the surface of the cover opposite to the surface joined to the first surface of the substrate; and a second resin layer laminated on at least a portion of the second surface of the substrate, wherein the first resin layer and the second resin layer have a tensile modulus of elasticity of 2.0 GPa or less.

2. The IC tag according to claim 1, wherein the ratio of the tensile modulus of elasticity of the first resin layer to that of the cover is 0.5 or less.

3. An IC tag according to claim 1 or 2, wherein the thickness of the first resin layer is greater than the thickness of the cover.

4. The IC tag according to claim 1 or 2, wherein the ratio of the thickness of said first resin layer to the thickness of said cover is 1.0 or more.

5. An IC tag according to claim 1 or 2, wherein the ratio of the tensile modulus of elasticity of the second resin layer to the tensile modulus of elasticity of the substrate is 0.5 or less.

6. An IC tag according to claim 1 or 2, wherein the thickness of the second resin layer is greater than the thickness of the substrate.

7. An IC tag according to claim 1 or 2, wherein the ratio of the thickness of said second resin layer to the thickness of said base material is 1.0 or more.

8. The IC tag according to claim 1 or 2, wherein the bending load is 2.0 N or less.

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