JP4274867B2 - IC tag - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to an IC tag in which an enclosed electronic circuit is difficult to break.
[0002]
[Prior art]
In recent years, an IC tag is attached to an article such as a product, a stored item, or a luggage to manage the article. For example, an IC tag on which information such as manufacturing conditions, purchase status, price information, and usage status is recorded is attached to the product, and the recorded information is checked and managed by an interrogator (interrogator) as necessary. To be done.
As a conventional IC tag, an electronic circuit composed of circuit lines and an IC chip connected to the electronic circuit are provided on one surface of a base sheet having a high elastic modulus such as polyethylene terephthalate. A substrate adhesive sheet with an electronic circuit having a structure in which an adhesive layer to be covered is laminated is sandwiched between two sealing resin sheets, heat compression molded, and the substrate adhesive sheet with an electronic circuit is sealed with a resin A rare IC tag is known (see, for example, Patent Document 1).
However, this IC tag has a problem in that stress remains in the base sheet during heat compression molding, the stress is concentrated without being relaxed, and the electronic circuit in the stress concentration portion is broken.
Also, when an IC tag is attached to an article, there is a problem that stress is applied, the stress is concentrated without being relaxed, and the electronic circuit at the stress concentration portion is broken.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2003-68775
[Problems to be solved by the invention]
As a method for solving the above problems, it is required to accurately manage articles using an IC tag in which an enclosed electronic circuit is difficult to break.
[0005]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have found that even if the elastic modulus is low, if the stress relaxation rate is low beyond a certain region, internal stress accumulates, causing disconnection of the electronic circuit. End up. Moreover, even if the stress relaxation rate is high, it has been found that if the elastic modulus increases beyond a certain region, the electronic circuit is disconnected because it receives a strong stress when covered with the surface layer. As a result, the elastic modulus at 23 ° C. is 1 × 10 5 on both surfaces of the base sheet with an electronic circuit in which an electronic circuit composed of a circuit line and an IC chip connected to the circuit line is provided on one surface of the base sheet. ⁵ Pa or less, and the stress relaxation ratio after 1000 seconds at 23 ° C. via more than 60% of the buffer material, by covering the surface layer, found the above problems can be solved, and have completed the present invention.
[0006]
That is, according to the present invention, a base sheet with an electronic circuit in which an electronic circuit comprising a circuit line and an IC chip connected to the circuit line is provided on one surface of the base sheet has an elastic modulus at 23 ° C. on both sides. The present invention provides an IC tag characterized in that it is sequentially covered with a cushioning material and a surface layer having a stress relaxation rate after 1000 seconds at 23 ° C. of 60% or more at 1 × 10 ⁵ Pa or less.
Moreover, this invention provides the IC tag whose elastic modulus in 23 degreeC is 1 * 10 < ² > Pa or more and 1 * 10 < ⁵ > Pa or less in the said IC tag.
The present invention also provides an IC tag having an elastic modulus at 23 ° C. of 1 × 10 ³ Pa or more and 1 × 10 ⁵ Pa or less.
The present invention also provides an IC tag in which the buffer material is made of urethane resin.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The IC tag of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing a state in which each layer is laminated in the manufacturing process of one aspect of the IC tag of the present invention, and FIG. 2 is a schematic plan view of the electronic circuit of the same IC tag of the present invention. It is shown.
In the present invention, the base sheet with an electronic circuit is provided with an electronic circuit comprising a circuit line and an IC chip connected to the circuit line on one surface of the base sheet.
[0008]
The base sheet 1 is preferably a sheet made of a thermoplastic resin. Examples of the thermoplastic resin sheet include polyethylene resins such as high density polyethylene, medium density polyethylene, and low density polyethylene, polypropylene resins such as polypropylene, polymethyl-1-pentene / ethylene / cycloolefin copolymer, ethylene- Polyolefin resins such as vinyl acetate copolymer, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyvinyl chloride resin, polyvinyl alcohol resin, polycarbonate resin, polyamide resin, polyimide resin, fluorine resin, or Sheets made of various synthetic resins such as copolymers, polymer blends, and polymer alloys containing any of these can be used. In particular, sheets made of polyester resins are preferably used. It is. The base sheet 1 may be uniaxially stretched or biaxially stretched. The base sheet 1 may be a single layer or a multilayer of two or more layers of the same type or different types.
Although the thickness of the base material sheet 1 does not have a restriction | limiting in particular, Usually, what is necessary is just 30-300 micrometers, Preferably it is 50-200 micrometers.
[0009]
In the IC tag of the present invention, the electronic circuit 3 is provided on the surface of the base sheet 1.
The electronic circuit 3 is composed of circuit lines 4 made of a conductive material. As the conductive substance, for example, a metal simple substance such as a metal foil, a vapor deposition film, a thin film by sputtering, and the like are preferable. As the metal simple substance, gold, silver, nickel, copper, aluminum or the like, or a conductive paste in which particles of these metals are dispersed in a binder can be used.
1-15 micrometers is preferable and, as for the average particle diameter of a metal particle, 2-10 micrometers is especially preferable. Examples of the binder include an ultraviolet curable resin and a thermosetting resin, and examples thereof include an ultraviolet curable resin such as a polyester resin, a polyurethane resin, an epoxy resin, and a phenol resin, and a thermosetting resin.
The content of the metal particles is preferably 20 to 99% by mass, more preferably 50 to 99% by mass, and particularly preferably 70 to 99% by mass.
[0010]
The thickness of the circuit line 4 constituting the electronic circuit 3 is not particularly limited, but is 5 to 50 μm in the case of a metal foil, 0.01 to 1 μm in the case of a metal film by vapor deposition or sputtering, and 5 in the case of a conductive paste. It is preferable that it is 30 micrometers.
Although there is no restriction | limiting in particular in the width | variety of the circuit wire 4, 0.01-10 mm is preferable and 0.1-3 mm is especially preferable.
In order to form the circuit line 4 of the electronic circuit 3 on the surface of the base sheet 1, for example, a metal foil is bonded to the base sheet 1 with the adhesive layer 2, and the metal foil is etched to remove portions other than the circuit. For example, a method of forming the circuit line 4 of the electronic circuit 3 by removing it may be used. The etching process can be performed by a process similar to a normal etching process. In addition, the circuit lines 4 of the electronic circuit 3 are formed on the surface of the base sheet or on the surface of the adhesive layer 2 provided on the surface of the base sheet, and the electronic circuit 3 is formed by a means such as printing or applying a conductive paste. This can also be done by attaching the shape of the circuit line 4 to the shape of the circuit line 4.
[0011]
Examples of the shape of the circuit line of the electronic circuit 3 include the shape shown in FIG. In FIG. 3, an electronic circuit 3 serving as an antenna is formed by arranging circuit lines 4 made of a conductive material line in a quadruple spiral ring from the outer periphery to the inside of the circular base sheet 1 at a predetermined interval. Is forming. The electronic circuit 3 may be arranged in a quadruple spiral ring as shown in FIG. 3, but may be a single to triple spiral ring, or may be a five or more spiral ring.
[0012]
In order to increase the adhesive force between the base sheet 1 and the adhesive layer 2, the surface of the base sheet 1 may be surface-treated. Examples of the surface treatment method include corona discharge treatment, chemical treatment, and resin coating.
Examples of the adhesive used for the adhesive layer 2 include various adhesives such as a hot-melt adhesive, a thermoplastic adhesive, a pressure-sensitive adhesive, and a thermosetting adhesive. Examples of adhesive types include natural rubber adhesives, synthetic rubber adhesives, acrylic resin adhesives, polyester resin adhesives, polyvinyl ether resin adhesives, urethane resin adhesives, and silicone resin adhesives. Agents and the like.
[0013]
Specific examples of acrylic resin adhesives include homopolymers or copolymers of acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, etc. Etc. The polyester resin adhesive is a copolymer of a polyhydric alcohol and a polybasic acid. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, and butanediol. Polybasic acids include terephthalic acid and adipic acid. And maleic acid. Specific examples of the polyvinyl ether resin adhesive include polyvinyl ether and polyvinyl isobutyl ether. Specific examples of the silicone resin adhesive include dimethylpolysiloxane. These adhesives can be used individually by 1 type or in combination of 2 or more types.
Of these adhesives, polyester resin adhesives are preferred.
[0014]
The adhesive layer 2 may contain a colorant such as an adhesion-imparting agent, a plasticizer, a softening agent, an anti-aging agent, a filler, a dye or a pigment, if necessary.
The thickness of the adhesive layer 2 is not particularly limited, but is usually 1 to 100 μm, and preferably 3 to 50 μm.
The method for providing the adhesive layer 2 on the base sheet is not particularly limited, and various methods can be used. For example, an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a curtain coater, Examples of the method include coating and drying using a die coater, knife coater, screen coater, Mayer bar coater, kiss coater, and the like.
[0015]
An IC chip 5 is connected to the circuit line 4. The IC chip 5 may be provided inside the circuit line 4, may be provided outside the circuit line 4, or may be provided above the circuit line 4.
The IC chip 5 is preferably provided at the tip of the circuit line 4 of the electronic circuit 3.
[0016]
In order to connect the outermost and innermost circuit lines 4 of the electronic circuit 3 to the IC chip 5, the outermost or innermost circuit line 4 of the electronic circuit 3 is short-circuited with the intermediate ring-shaped circuit line 4 ( By connecting to the jumper wiring part 6 without conducting), the circuit line 4 is drawn out to the inside or outside and connected to the IC chip 5.
The thickness of the IC chip may be appropriately selected according to the use, but a thickness of 50 to 400 μm is usually used.
The jumper wiring portion 6 is a circuit provided so as to jump over the intermediate ring circuit line 4 so as not to be short-circuited so as to connect the innermost ring circuit line 4 and the outermost ring circuit line 4. For this purpose, an insulating layer 9 is usually provided between the jumper wiring portion 6 and the intermediate circuit line 4. The insulating layer 9 is made of an insulating material, and is preferably made of a cured product of a curable insulating material. The curable insulating material is preferably a curable insulating resin, and examples thereof include a photocurable insulating resin and a thermosetting insulating resin. A specific example of the insulating material is preferably an insulating ink, and a photocurable insulating ink such as an ultraviolet curable insulating ink is particularly preferable.
[0017]
The jumper wiring portion 6 is made of a conductive material similar to the circuit line 4, but is preferably made of a conductive resin. Examples of the conductive resin include the same ones as described above.
A preferred method for forming the jumper wiring portion 6 is screen printing of an insulating material made of an insulating resin from the outermost ring and the innermost ring circuit line 4 of the electronic circuit 3 across the ring circuit line 4 between them. After forming the insulating layer 9 by printing in a linear or planar manner by using a method such as drying or curing, a jumper wiring portion is formed by a method of printing a conductive paste on the surface of the insulating layer 9 in a linear manner by screen printing or the like. 6 or the like. The conductive paste is exemplified above.
The jumper wiring portion 6 may be formed after the circuit line 4 is formed on the surface of the adhesive layer 2, or after the jumper wiring portion 6 is formed on the surface of the adhesive layer 2 in advance, the jumper wiring portion The circuit line 4 may be formed so that the end of the circuit line 4 of the outermost ring and the innermost ring is arranged at the position 6.
[0018]
Examples of the method of connecting the IC chip 5 to the end of the circuit line 4 of the electronic circuit 3 include a method of connecting to the end surface of the circuit line 4 via an anisotropic conductive film by a flip chip bonding method. In the flip chip bonding method, wire bumps are provided on the electrode portions of the IC chip 5, and the surface on which the wire bumps of the IC chip 5 are pressed is pressed on the anisotropic conductive film coated on the end surface of the circuit line 4. In this method, wire bumps enter the isotropic conductive film, and the end of the circuit line 4 and the IC chip 5 are easily conducted.
[0019]
In this invention, the base material sheet with an electronic circuit is covered and sealed with the surface layer 8 via the buffer material 7 on both surfaces.
There are various methods for sealing the substrate sheet with electronic circuit by covering it with the surface layer 8, and the two surface layers 8 are interposed on both surfaces of the substrate sheet with electronic circuit via the buffer material 7. A method of sandwiching and enclosing the base sheet with electronic circuit is preferable.
The buffer material 7 has a property that the elastic modulus at 23 ° C. is 1 × 10 ⁵ Pa or less and the stress relaxation rate after 1000 seconds at 23 ° C. is 60% or more. The elastic modulus at 23 ° C. is preferably 8 × 10 ⁴ Pa or less, particularly preferably 7 × 10 ⁴ Pa or less. When the modulus of elasticity is 1 × 10 ⁵ Pa or more, a strong stress is applied when the surface layer is covered, causing disconnection of the electronic circuit. The lower limit of the elastic modulus at 23 ° C. is not particularly limited, but is preferably 1 × 10 ² Pa or more, and particularly preferably 1 × 10 ³ Pa or more. The stress relaxation rate after 1000 seconds at 23 ° C. is preferably 80% or more, and particularly preferably 85% or more. If the stress relaxation rate is 60% or less, the internal stress accumulates, causing disconnection of the electronic circuit.
[0020]
As a material of the buffer material 7, a material having the above properties may be selected as appropriate. A preferred specific example thereof is a polyurethane resin.
The buffer material 7 is preferably arranged so as to cover the entire surface of the base sheet 1.
The buffer material 7 preferably has the same shape and size as the base material sheet.
The thickness of the buffer material 7 is preferably 1 to 500 μm, particularly preferably 10 to 150 μm.
[0021]
Resin is mentioned as the surface layer 8 with which the base material sheet with an electronic circuit is covered via the buffer material 7, The thing similar to resin which comprises a base material sheet is mentioned. Of these resins, ABS resin and polyurethane resin are preferable.
The surface layer 8 is preferably hard against impact.
The thickness of the surface layer 8 is usually preferably about 1 to 5 mm, particularly preferably about 2 to 4 mm.
The shape of the surface layer 8 is preferably the same shape as the base sheet. Specifically, shapes such as a triangle, a quadrangle, a trapezoid, a pentagon or more polygon, an ellipse, and a circle are preferable.
The size of the surface layer 8 is preferably larger than the base sheet with electronic circuit, more preferably 1 to 15 mm, and particularly preferably 2 to 10 mm.
Examples of a method for sandwiching and enclosing the base sheet with electronic circuit between the two surface layers 8 include a method of sandwiching the base sheet with electronic circuit between the two surface layers 8 and performing heat compression molding.
[0022]
When a flat substrate sheet with an electronic circuit is sandwiched between two surface layers 8 larger than the substrate sheet with an electronic circuit via the buffer material 7, the edge of the surface layer 8, the substrate sheet with an electronic circuit, and the buffer A concave air gap 10 surrounded by the peripheral side surface of the material 7 is formed.
When the heat compression molding is performed, the end portion of the surface layer 8 is softened and enters the void portion 10, and the base sheet with electronic circuit can be contained (see FIG. 2). The temperature of the heat compression molding needs to be a temperature at which the surface layer 8 can be softened, and is preferably 30 ° C. or more lower than the heat resistance temperature of the substrate sheet of the substrate sheet with an electronic circuit, and 40 ° C. or more lower. Is particularly preferred. Specifically, 100 ° C. or lower is preferable, and 90 ° C. or lower is particularly preferable.
Further, the gap portion 10 may be filled with an adhesive to contain a base sheet with an electronic circuit.
The IC tag of the present invention can be used for various applications. For example, the IC tag can be used for managing an article by attaching the IC tag to an article such as a commodity, a stored item, or a luggage.
[0023]
【Example】
Next, the present invention will be specifically described with reference to examples. However, the present invention is not limited by these examples.
The elastic modulus at 23 ° C. and the stress relaxation rate after 1000 seconds at 23 ° C. were measured by the following methods.
(1) Using an elastic modulus measuring device (Rheometric, RDA II (twisting shear method)) or an automatic dynamic viscoelasticity measuring device (Toyo Baldwin, Leo Vibron DDV-II-EP V-1166) The elastic modulus at 23 ° C. at a frequency of 1 Hz was measured.
(2) Using a stress relaxation modulus elastic modulus measuring device (Rheometric, RDA II (twisting shear method)) or an automatic dynamic viscoelasticity measuring device (Toyo Baldwin, Leo Vibron DDV-II-EP V-1166) Then, a stress with a twist amount of 20% was applied at 23 ° C., and the ratio of the elastic modulus after 1000 seconds to the relaxation elastic modulus after 1 minute was measured.
[0024]
(Example 1)
A polyester-based thermoplastic adhesive (trade name “Byron 30SS”, manufactured by Toyobo Co., Ltd.) is applied to the surface of one side of a polyethylene terephthalate film (width 400 mm, height 400 mm, thickness 50 μm) as the base sheet 1. It dried with the gravure coater and apply | coated so that it might become thickness 5 micrometers, and the adhesive bond layer 2 was laminated | stacked. Further, an electrolytic copper foil having a thickness of 35 μm was thermocompression bonded to the surface of the adhesive layer 2 with a 100 ° C. heat seal roll. Next, as shown in FIG. 3, the surface of the electrolytic copper foil is screen-printed so that ten quadruple spiral circular circuit wires 4 (antennas) having an outer ring diameter of 25 mm are formed. Etching resist ink was printed (line width: 0.13 mm). This was etched with a ferric chloride solution to remove portions other than the circular spiral circuit wire 4. Thereafter, the etching resist ink was removed with an alkaline aqueous solution, and ten electronic circuits 3 (circuit line width: 0.13 mm) identical to those in FIG. 3 were formed.
[0025]
Next, in order to connect the terminal of the innermost ring circuit line 4 of the electronic circuit (antenna) 3 and the outermost ring circuit line 4 of the electronic circuit 3, ultraviolet curable ink is screen-printed between them. After printing in a rectangular planar shape, it is cured by irradiating with ultraviolet rays to form an insulating layer 9 made of a cured product of the ultraviolet curable ink, and a silver paste (average particle diameter of silver particles: 5 μm) is formed on the surface of the insulating layer 9. Silver particle content: 65% by mass, binder: thermosetting polyester resin) is printed in a wide line shape by screen printing, dried at 110 ° C., and jumper wiring portion 6 (length 3.7 mm, width 600 μm) , A thickness of 23 μm).
[0026]
Next, wire bumps are provided on the electrode part of the IC chip (manufactured by Philips, trade name “I / CODE”) 6 using a gold wire, and the IC chip 5 is made of an anisotropic conductive film (trade name “Sony Chemical Co., trade name“ 10 pieces of base sheets with electronic circuits were prepared by connecting to the end of the innermost circuit line 4 of the electronic circuit 3 using the flip chip bonding method through FP2322D ").
[0027]
Next, on both surfaces of the substrate sheet with an electronic circuit, a urethane resin (weight average molecular weight 5000) having an elastic modulus at 23 ° C. of 0.5 × 10 ⁵ Pa and a stress relaxation rate after 90 seconds at 23 ° C. of 90%. Buffer material 7 (comprising 50 parts by mass of a urethane oligomer having no reactive group (made by Arakawa Chemical Co., Ltd.), 10 parts by mass of a polyester oligomer as an adhesion improving agent, and 40 parts by mass of phenylhydroxypropyl acrylate) A disk having a diameter of 30 mm and a thickness of 60 μm are laminated, and further, a resin sheet made of ABS resin (a disk having a diameter of 35 mm, a thickness of 3 mm) as two surface layers 8 on the surface of the buffer material 7 and the surface of the adhesive layer, respectively. ) Was laminated. In this laminate, a concave gap 10 surrounded by the inner wall of the end portion of the surface layer 8, the base sheet with electronic circuit, and the end portion side surface of the buffer material 7 was formed.
Next, when this laminate was subjected to heat compression molding at 80 ° C., the end of the softened surface layer 8 entered the gap 10, the substrate sheet with electronic circuit was sealed, and 10 IC tags were created. did.
Ten IC tags obtained were placed in an environment in which a temperature change of −30 to 60 ° C. was repeated for 500 cycles, and then a non-contact transmission / reception test was performed.
[0028]
(Example 2)
As the buffer material 7, an acrylic adhesive (butyl acrylate / methyl methacrylate / 2-hydroxyethyl acrylate) having an elastic modulus at 23 ° C. of 9.8 × 10 ⁴ Pa and a stress relaxation rate of 64% after 1000 seconds at 23 ° C. Ten IC tags were prepared in the same manner as in Example 1 except that 100 parts of a copolymer and 4 parts of a diisocyanate-based curing agent were used.
Ten IC tags obtained were placed in an environment in which a temperature change of −30 to 60 ° C. was repeated for 500 cycles, and then a non-contact transmission / reception test was performed.
[0029]
(Comparative Example 1)
An IC tag was prepared in the same manner as in Example 1 except that the buffer material 7 was not provided.
After placing 10 obtained IC tags in an environment in which a temperature change of −30 to 60 ° C. was repeated for 500 cycles, a non-contact transmission / reception test was performed, and 4 out of 10 IC tags were normally transmitted / received. Could not do.
[0030]
(Comparative Example 2)
As buffer material 7, an adhesive (2-ethylhexyl acrylate / 2-hydroxyethyl acrylate copolymer having an elastic modulus at 23 ° C. of 5.8 × 10 ⁵ Pa and a stress relaxation rate of 59% after 1000 seconds at 23 ° C. An IC tag was prepared in the same manner as in Example 1 except that 100 parts of 1 part of a diisocyanate curing agent was used.
After placing 10 obtained IC tags in an environment in which a temperature change of −30 to 60 ° C. was repeated 500 cycles, a non-contact transmission / reception test was performed. As a result, 5 out of 10 IC tags successfully transmitted / received. Could not do.
[0031]
(Comparative Example 3)
As the buffer material 7, an adhesive having an elastic modulus at 23 ° C. of 1.32 × 10 ⁵ Pa and a stress relaxation rate of 97% after 1000 seconds at 23 ° C. (100 parts of butyl acrylate / acrylic acid copolymer with diisocyanate) An IC tag was prepared in the same manner as in Example 1 except that a mixture of 2 parts of a narto curing agent (trade name “PK” manufactured by Lintec Corporation) was used.
After placing 10 obtained IC tags in an environment in which a temperature change of −30 to 60 ° C. was repeated 500 cycles, a non-contact transmission / reception test was performed. As a result, 5 out of 10 IC tags successfully transmitted / received. Could not do.
[0032]
(Comparative Example 4)
As the cushioning material 7, a rubber sheet having a modulus of elasticity at 23 ° C. of 1 × 10 ³ Pa and a stress relaxation rate of 20% after 1000 seconds at 23 ° C. (trade name “Rubber Sheet MQ−, manufactured by NSC Japan”) 70 ”, a 30 mm diameter disc, 60 μm thick), and an IC tag was prepared in the same manner as in Example 1.
After placing 10 obtained IC tags in an environment in which a temperature change of -30 to 60 ° C. was repeated for 500 cycles, a non-contact transmission / reception test was conducted. Of the 10 IC tags, 6 were successfully transmitted / received. Could not do. When opened, the circuit line was cut.
[0033]
【The invention's effect】
The IC tag of the present invention has a characteristic that the encapsulated electronic circuit is not easily broken, and can transmit and receive normally.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view in the manufacturing process of an example of an IC tag of the present invention.
FIG. 2 is a schematic cross-sectional view of an example of an IC tag of the present invention.
FIG. 3 is a perspective plan view showing an electronic circuit of an example of an IC tag of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base material sheet 2 Adhesive layer 3 Electronic circuit 4 Circuit line 5 IC chip 6 Jumper wiring part 7 Buffer material 8 Surface layer 9 Insulating layer 10 Air gap part

Claims (4)

A base sheet with an electronic circuit in which an electronic circuit comprising a circuit line and an IC chip connected to the circuit line is provided on one surface of the base sheet has an elastic modulus at 23 ° C. on both surfaces of 1 × 10 ⁵ Pa. An IC tag characterized by being covered with a buffer material and a surface layer having a stress relaxation rate of 60% or more after 1000 seconds at 23 ° C.   Elastic modulus at 23 ° C. is 1 × 10 ² 1 × 10 at Pa or higher ⁵ The IC tag according to claim 1, which is Pa or less.   Elastic modulus at 23 ° C. is 1 × 10 ³ 1 × 10 at Pa or higher ⁵ The IC tag according to claim 1, which is Pa or less.   The IC tag according to claim 1, wherein the buffer material is made of urethane resin.

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