JP2002298116A - Tag for use in rfid - Google Patents

Abstract

(57) [Summary] An RFID tag which secures tightness between an IC chip and an antenna coil and is extremely thin and can be bent in accordance with the curved outer surface of an article is obtained. An RFID tag includes an IC chip and an antenna coil. The IC chip 13 and the antenna coil 14 are integrally surrounded by the resin 16 by injection molding or casting. A magnetic core member 14a in which the antenna coil 14 is formed in a flat plate shape from a magnetic material;
a having a coil body 14b spirally wound around an axis extending in the plane of the magnetic core member 14a.
The C chip 13 is adhered to the surface of the magnetic core member 14a or provided near the magnetic core member 14a. Magnetic core member 14
a is formed of a composite material of a powder or flake and a plastic made of a magnetic material, and the composite material is made of a magnetic material of 10 to 56% by volume and a plastic of 90 to 44% by volume.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an RFID tag using RFID (Radio Frequency Identification) technology.

[0002]

2. Description of the Related Art Conventionally, an antenna coil in which a coil body is spirally wound around a magnetic core member formed in a rod shape by ferrite or the like around the axis of the magnetic core member, and an electric coil is electrically connected to the coil body of the antenna coil. And an IC chip which is connected to an IC chip and stores information on an article to be managed. This tag is covered with a special exterior material that protects against external force caused by contact with atmospheric humidity, dust and surroundings, and is attached to the flat part of the article to be identified or monitored. The tag attached to the flat part of the article in this manner can identify or monitor the article by reading information stored in the IC chip or by resonating with radio waves of a specific frequency. Be composed.

[0003]

However, the conventional exterior material is generally composed of a container for accommodating the tag and a lid for sealing the container, so that the tightness of the joint between the container and the lid is ensured. It is difficult to secure the tag, and if the hermeticity is not secured, there is a problem that the tag cannot be effectively protected from humidity and dust in the air. Also, in the case of tags attached to frequently moved articles, it is necessary to avoid the tags from protruding significantly from the articles to be managed and to avoid the tags coming into contact with surrounding objects when transporting the articles. There is also. Furthermore, in the above-described conventional tag, the tag itself cannot be bent because a magnetic core member made of ferrite or the like is used. However, in recent years, tags are often attached to the curved outer surface of a disk-shaped article or the curved outer surface of a cylindrical pipe, so that the tag itself is made flexible and the tag is bent. It would be convenient if it could be curved in accordance with the outer surface and directly attached to the article in that state.

[0004] A first object of the present invention is to provide an RFID tag capable of ensuring the hermeticity of an IC chip and an antenna coil. A second object of the present invention is to provide an RFID tag capable of preventing a tag attached to an article from coming into contact with a surrounding object while the article is being transported, by forming the tag to be extremely thin. A third object of the present invention is to provide an RFID tag that can be bent in accordance with a curved outer surface of an article.

[0005]

The invention according to claim 1 is
As shown in FIGS. 1 and 2, an IC chip 13 attached to an article 11 and storing unique information different for each article 11, and an antenna attached to the article 11 and electrically connected to the IC chip 13 RFI with coil 14
It is an improvement of the tag for D. The characteristic configuration is that the IC chip 13 and the antenna coil 14 are integrally surrounded by the resin 16 by injection molding or casting. In the RFID tag according to the first aspect, since the IC chip 13 and the antenna coil 14 are reliably surrounded and sealed by the resin, the IC chip 13 and the antenna coil 1 are not sealed.
4 is reliably isolated from the outside air, and can be effectively protected from humidity and dust in the atmosphere. Here, when the resin 16 is injection-molded, the productivity of the RFID tag can be improved. However, when the IC chip 13 and the antenna coil 14 are relatively fragile, the IC chip 13 and the antenna coil 14 are surrounded by the resin 16 by casting to prevent damage due to pressure during injection molding. Is preferred.

The invention according to claim 2 is the invention according to claim 1, wherein the antenna coil 14 is formed of a magnetic material in a flat plate shape, and the magnetic core member 14a is attached to the magnetic core member 14a. And a coil main body 14b spirally wound around an axis extending in the plane of the above, and the IC chip 13 is adhered to the surface of the magnetic core member 14a or provided near the magnetic core member 14a. This is an RFID tag. In the RFID tag according to the second aspect, when radio waves are transmitted toward the tag 12, the tag 12 resonates,
Since the IC chip 13 is activated, the unique information stored in the IC chip 13 is transmitted again from the antenna coil 14. Further, since the antenna coil 14 can be formed extremely thin, the tag 12 itself becomes thin and the amount of protrusion from the surface of the attached article 11 is reduced, and the tag 12 comes into contact with surrounding objects during the transport of the article 11. Can be prevented.

A third aspect of the present invention is the invention according to the first aspect, wherein, as shown in FIGS. 5 and 6, a magnetic core member 6 in which the antenna coil 64 is formed of a magnetic material in a flat plate shape.
4a and a coil body 64b spirally wound on the same plane as the magnetic core member 64a so as to surround the outer peripheral edge of the magnetic core member 64a, and the IC chip 13 is bonded to the surface of the magnetic core member 64a. This is the RFID tag that has been used. In the RFID tag according to the third aspect, the antenna coil 64 can be formed thinner, and the tag 62 itself can be further thinned. When a radio wave is transmitted toward the tag 62, even if the distance between the radio wave transmission source and the antenna coil 64 is relatively large, the coil body 64b is formed by the magnetic core member 64a.
(The magnetic flux is generated by the radio wave) increases. As a result, the amplitude of the resonance of the resonance circuit including the antenna coil 64 increases, so that the tag 62
Can be sufficiently activated, and the unique information stored in the IC chip 13 is transmitted again from the antenna coil 64.

The invention according to claim 4 is the invention according to claim 2 or 3, wherein the magnetic core members 14a and 64a are formed of a composite material of powder or flake and a plastic made of a magnetic material, and the composite material is RFID comprising 10-56% by volume of magnetic material and 90-44% by volume of plastic
Tag. In the RFID tag according to the fourth aspect, the magnetic core members 14a and 64a having flexibility can be obtained by mixing the magnetic material and the plastic in the above ratio, and the RFID tag itself is curved. Thus, even if the attached portion of the article 11 has a curved surface, the tag can be attached in a curved state.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. As shown in FIG. 1 and FIG.
The RFID tag 12 is attached to the front surface of the device. The tag 12 includes an IC chip 13 in which unique information different for each article 11 is stored, and an antenna coil 14 electrically connected to the IC chip 13. In this embodiment, the article 11 is a repair part stored in a warehouse, and is formed of a non-magnetic and non-conductive material such as plastic. The antenna coil 14 includes a magnetic core member 14a formed of a magnetic material in a flat plate shape, and a coil body 14b spirally wound around the magnetic core member 14a around an axis extending in the plane of the magnetic core member 14a. Have.

The magnetic core member 14a is formed in a rectangular plate shape by a composite material of powder or flake and plastic made of a magnetic material, or is made of Fe (METGLAS2605S-2 manufactured by Allied Chemical) or Co (Allied Chemical). It is formed in a rectangular plate shape by a laminated material of an amorphous foil such as METGLAS2714A). Examples of the magnetic material include soft magnetic ferrite and soft magnetic metal. As the plastic, a thermoplastic plastic having good workability or a thermosetting plastic having good heat resistance can be used. Examples of the powder made of the magnetic material include carbonyl iron powder, atomized powder such as iron-permalloy, and reduced iron powder. On the other hand, as flakes made of a magnetic material, flakes obtained by pulverizing the above powder with a ball mill or the like to form a powder, and then mechanically flattening the powder, or molten iron particles of an iron-based or cobalt-based amorphous alloy are used. Flakes obtained by colliding with water-cooled copper.

When the magnetic core member 14a is formed of a composite material, the magnetic core member 14a is made up of 10 to 56% by volume of a magnetic material and 9
It is preferably formed of a composite material of 0 to 44% by volume of plastic. If the amount of powder or flakes made of a magnetic material is less than 10 volumes, the obtained magnetic core member 14
The magnetic permeability of “a” becomes low, and in order to obtain the required magnetic permeability, the magnetic core member 14a itself needs to be large, and the antenna coil 14 itself cannot be reduced in size. On the other hand, if the amount of the powder or flakes made of a magnetic material is 56% by volume or more, the obtained magnetic core member 14a may not have flexibility. The particularly preferred range of the powder or flake made of a magnetic material is 25% by volume to 45% by volume.

When the magnetic core member 14a is formed from a composite material, it is preferable to form the magnetic core member 14a by injection molding or compression molding of the composite material. However, tag 12
When it is particularly necessary to apply a thin material to the film or sheet having flexibility, the core material 14a is formed from the film or sheet and the composite material applied to the film or sheet by applying and drying the composite material. It may be formed with a coating film. The magnetic core member 14a thus formed
Is more flexible than a magnetic core member made of fragile ferrite, so that it is less likely to break even when thin. Further, since the powder or flakes made of a magnetic material is dispersed in plastic, that is, the magnetic powder or flakes are insulated from each other by plastic, the magnetic core member 14a does not have conductivity as a whole, No eddy currents are generated even if it is subjected. The coil body 14b is a copper wire, and is spirally wound around the magnetic core member 14a around the axis of the magnetic core member 14a. The 1C chip 13 is electrically connected to the copper wire of the antenna coil 14.

As shown in FIG. 4, the IC chip 13 has a power supply circuit 13a, a radio frequency (RF) circuit 13b, a modulation circuit 13c, a demodulation circuit 13d, a CPU 13e, and is connected to the CPU 13e. And a memory 13f in which the information is stored. The power supply circuit 13a has a built-in capacitor (not shown), and this capacitor forms a resonance circuit with the antenna coil 14. When the antenna coil 14 receives a radio wave of a specific frequency (frequency at which the resonance circuit resonates), the capacitor is charged with electric power generated by the mutual induction action. Power supply circuit 13a
Rectifies and stabilizes this power and supplies it to the CPU 13e.
Activate the IC chip 13. Memory 13f is ROM
(Read only memory), RAM (ramdom-access memor)
y) and EEPROM (electrically erasable program)
and reads stored data in response to a read command by radio wave data communication from the identification means 17 under the control of the CPU 13e, and reads data stored in response to a write command from the identification means 17. Is written.

Referring back to FIGS. 1 and 2, the IC chip 13 is adhered to the surface of the magnetic core member 14a while being electrically connected to the copper wire of the antenna coil 14, and the IC chip 13 and the antenna coil 14 are The resin 16 is integrally surrounded by the molding. The casting in this embodiment is shown in FIG.
This is performed using a mold 21 that can be divided into two parts as shown in FIG. 1A, and the upper mold 22 having the resin injection port 22a formed thereon is removably attached to the lower mold 23 with small screws 26. Pins 22b and 23b are formed in the upper mold 22 and the lower mold 23, respectively, for supporting the magnetic core member 14a having the IC chip 13 adhered to the surface at the center thereof. When the resin is actually cast, as shown in FIG. 3B, the magnetic core member 14 having the IC chip 13 adhered to the surface thereof is used.
a is floated and supported inside the mold 21 by the pins 22b and 23b, and in this state, a resin is injected from the injection hole 22a and molded. As the resin to be injected, for example, polypropylene (PP), polyethylene terephthalate (PE)
T), polyethylene (PE), synthetic high-molecular polyamide (trade name “Nylon”), urethane, silicone, and the like.

After the resin injected into the mold 21 is cured, the upper mold 22 is removed from the lower mold 23, and the resin molded product 24 is taken out from the lower mold 23 as shown in FIG. In this resin molded product 24, the IC chip 13 and the antenna coil 14 are integrally surrounded by the resin, and small holes 24a corresponding to the pins 22b and 23b supporting the magnetic core member 14a are formed. The small holes 24a are sealed with resin as required, and the RFID tag 12 of the present invention shown in FIG. 3D in which the IC chip 13 and the antenna coil 14 are integrally surrounded by the resin 16 is obtained. Further, the small holes 24a may be closed by covering them with an exterior seal (not shown) covering the upper surface, or a double-sided adhesive tape described later.

The RFID tag 12 constructed as described above
In this case, the IC chip 13 and the antenna coil 14 are reliably surrounded and sealed by the resin.
3 and the antenna coil 14 are reliably isolated from the outside air,
It can be effectively protected from humidity and dust in the atmosphere.
Further, the RFID tag 12 of the present invention is attached to the surface of the article 11 via an adhesive (not shown) or a double-sided adhesive tape, and is used for managing the article 11. The RFID tag 12 according to this embodiment is a coil body 1 spirally wound around a magnetic core member 14a formed in a flat shape.
Since the antenna coil 14 made of 4b is used,
Since the thickness can be made relatively thin, it is possible to prevent the tag 12 from protruding from the article 11 in a state where the tag 12 is attached to the article 11. As a result, it is possible to prevent the tag 12 from contacting surrounding objects when the article 11 is transported.

Further, the magnetic core member 1 in this embodiment
4a is made of a composite material so as to have flexibility, so that the resin 16 surrounding the IC chip 13 and the antenna coil 14 is made of flexible synthetic polymer polyamide (trade name "nylon"), urethane or In the case of silicone or the like, the flexibility of the RFID tag 12 itself is ensured, and even if the outer surface on which the tag 12 is mounted is curved, the tag 12 itself can correspond to the outer surface of the article 11. The tag 12 can be attached to the outer surface of the article 11 by such a curve.

The article 11 having the RFID tag 12 attached thereto is managed by a manager of the article 11 using a portable identification means 17 which is portable. Specifically, as shown in FIG.
a is approached to the tag 12, and the interrogation signal is transmitted from the transmitting / receiving antenna 17a to the antenna coil 14 of the tag 12 by radio waves of a specific frequency. The transmitted radio wave of the interrogation signal is received by the antenna coil 14 of the tag 12. CP of IC chip 13 electrically connected to antenna coil 14
U13e transmits the information on the article 11 written in the memory 13f based on the inquiry signal. The transmitted data is transmitted and received by the transmitting / receiving antenna 17a of the identification unit 17.
And displays the information unique to the article 11 on the display unit 17 b of the identification unit 17. The administrator manages the article 11 by looking at the information displayed on the display unit 17b.

In the above embodiment, the tag 12 is attached to the article 11 made of a non-magnetic and non-conductive material such as plastic.
When the portion to be attached of the article 11 to which the tag 2 is to be attached is made of metal, it is preferable to interpose a conductive plate made of a conductive material between the tag 12 and the metal portion to which the tag 12 is attached. In this case, the thickness of the conductive plate is 0.01 to 2 mm, preferably 0.05 to 0.5 mm. RFID tag 1
2 is attached to the metal part of the article via the conductive plate, and when a radio wave is transmitted from the transmitting / receiving antenna 17a of the identification means 17 toward the antenna coil 14 of the tag 12, the conductive plate
No eddy current is generated in the metal portion of the article 11 to block the passage of radio waves to the article 11. As a result, the tag 12 resonates, so that the IC chip 13 is activated and the IC chip 13 is activated.
Is transmitted from the antenna coil 14 again. As a result, the identification means 17 becomes the IC chip 1
3 can reliably read the information stored in the memory.

Further, in the above-described embodiment, the example in which the IC chip 13 is adhered to the surface of the magnetic core member 14a has been described, but as long as the IC chip 13 and the antenna coil 14 are integrally surrounded by the resin 16, , The IC chip 13 and the magnetic core member 1
It may be provided near the magnetic core member 14a without bonding to the magnetic core member 14a. Further, in the above-described embodiment, the IC chip 13 and the antenna coil 14 are surrounded by the resin 16 by casting, but the strength of the IC chip 13 and the antenna coil 14 is relatively high and can sufficiently withstand the pressure due to injection molding. In the case of, the IC chip 1 is made of resin 16 by injection molding.
3 and the antenna coil 14 may be surrounded. When the resin 16 is molded by injection molding, the productivity of the RFID tag can be improved as compared with the case where the resin 16 is molded by casting.

FIGS. 5 and 6 show a second embodiment of the present invention. 5 and 6, the same reference numerals as those in FIGS. 1 and 2 indicate the same parts. In this embodiment, the article 11 is formed of a non-magnetic and non-conductive material such as plastic, and the antenna coil 64 includes a magnetic core member 64a formed of a magnetic material in a flat plate shape, and an outer peripheral edge of the magnetic core member 64a. And a coil main body 64b spirally wound on the same plane as the magnetic core member 64a so as to surround the coil core 64a. The magnetic core member 64a is made of a metal or ferrite powder or a composite material of flakes and plastic, and is formed in a disk shape, or is made of an Fe-based material (METGLAS2605S- manufactured by Allied Chemical Co., Ltd.).
2) or Co-based (METGLAS manufactured by Allied Chemical Company)
It is formed in a disk shape from a laminated material of an amorphous foil such as 2714A).

The coil body 64b is formed by etching a copper foil or an aluminum foil adhered to the surface of the resin film 64c, and the magnetic core member 64a is adhered to the resin film 64c so as to be located at the center of the coil body 64b. When the magnetic core member 64a is formed of a composite material, a method of injection molding or compression molding the composite material into a disk before bonding to the resin film 64c, and a method of applying a liquid composite material to the coil body 64b. There is a method of pouring and solidifying. The IC chip 13 is adhered to the surface of the magnetic core member 64a, and the IC chip 13 and the antenna coil 64 are integrally surrounded by resin by injection molding or casting. Except for the above, the configuration is the same as that of the first embodiment.

The RFID tag 62 thus configured
The antenna coil 64 is attached to the article 11 via an adhesive or a double-sided adhesive tape. The antenna coil 64 is formed of a magnetic core member 64a and a coil body 64b spirally wound on the same plane, and is extremely thin. For this reason, the tag 62 is also extremely thin and does not protrude very little from the article 11, so that its attachment strength can be sufficiently secured. In addition, the antenna coil 6
When a radio wave is transmitted toward the magnetic core member 4, the magnetic core member 6 can be transmitted even if the distance between the transmitting / receiving antenna and the antenna coil 64 is relatively large.
Due to the presence of 4a, the magnetic flux density passing through the center of the coil body 64b (this magnetic flux is generated by the radio wave) increases. As a result, the tag 62 resonates, so that the IC chip 1
3 is activated, and the unique information stored in the IC chip 13 is transmitted again from the antenna coil 64 to the transmitting / receiving antenna. Thus, the identification means can read the information stored in the memory of the IC chip 13.

[0024]

As described above, according to the present invention, I
The C chip and the antenna coil are integrally surrounded by resin by injection molding or cast molding, and the IC chip and the antenna coil are sealed with the resin, so that the IC chip and the antenna coil are reliably isolated from the outside air, and It can be effectively protected from humidity and dust. in this case,
An antenna coil is constituted by a magnetic core member formed in a plate shape from a magnetic material, and a coil body spirally wound around the magnetic core member around an axis extending in the plane of the magnetic core member, and an IC chip is formed. If the antenna coil is bonded to the surface of the magnetic core member or provided near the magnetic core member, the antenna coil can be formed extremely thin, and the tag itself can be thinned.

An antenna coil is formed by a magnetic core member formed of a magnetic material in a flat plate shape and a coil body spirally wound on the same plane as the magnetic core member so as to surround the outer peripheral edge of the magnetic core member. The antenna coil can be formed thinner if it is configured and the IC chip is adhered to the surface of the magnetic core member. As a result, the amount of protrusion of the RFID tag from the surface of the article is reduced, and the tag can be prevented from coming into contact with surrounding objects during the transport of the article. Further, if the magnetic core member is formed of a composite material of powder or flake and a plastic made of a magnetic material, and the composite material is blended with 10 to 56% by volume of the magnetic material and 90 to 44% by volume of the plastic, the flexibility is improved. It is possible to obtain a magnetic core member having the property, to be able to curve the RFID tag itself, and to mount the tag in a curved state even if the attached portion of the article has a curved surface.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line AA of FIG. 2 showing an RFID tag according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line BB of FIG. 1 showing the configuration of the tag.

FIG. 3 is a view showing a manufacturing process for obtaining the tag by casting.

FIG. 4 is a configuration diagram showing a state in which a transmission / reception antenna of an identification unit faces the tag.

FIG. 5 is a sectional view taken along line EE of FIG. 6, showing a second embodiment of the present invention.

FIG. 6 is a cross-sectional view taken along line FF of FIG. 5 showing the configuration of the tag. .

[Explanation of symbols]

 11 Article 12, 62 RFID tag 13 IC chip 14, 64 Antenna coil 14a, 64a Magnetic core member 14b, 64b Coil body 16 Resin

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01Q 7/06 G06K 19/00 H (72) Inventor Takashi Tsuchida 1-12-1 Koishikawa, Bunkyo-ku, Tokyo Mitsubishi Materials Corporation Mobile Business Development Center (72) Inventor Seiro Yawata 1-12-14 Koishikawa, Bunkyo-ku, Tokyo Intellectual Property Service Corporation F-term (reference) 2C005 MA15 MA40 MB10 NA08 NB37 5B035 BA01 BA03 BB09 CA01 CA23 5J046 AA07 AA09 AA14 AA15 AB11 AB12 QA02 5J047 AA07 AA09 AA14 AA15 AB11 AB12 FC06

Claims (4)

[Claims] 1. An article (11) attached to an article (11) and said article (11)
An IC chip (13) in which unique information different for each is stored;
An antenna coil (14, 64) attached to the article (11) and electrically connected to the IC chip (13).
An RFID tag, wherein the IC chip (13) and the antenna coil (14, 64) are integrally surrounded by a resin (16) by injection molding or casting. 2. An antenna coil (14) comprising a magnetic core member (14a) formed of a magnetic material in a flat plate shape, and a magnetic core member (14).
a) has a coil body (14b) spirally wound around an axis extending in the plane of the magnetic core member (14a), and an IC chip (13) is formed of the magnetic core member (14a). The RFID tag according to claim 1, wherein the RFID tag is adhered to a surface or provided near the magnetic core member (14a). 3. A magnetic core member (64a) in which an antenna coil (64) is formed in a flat plate shape from a magnetic material, and said magnetic core member (64a).
And a coil body (64b) spirally wound on the same plane as the magnetic core member (64a) so as to surround the outer peripheral edge of the magnetic core member (64a). An RFID tag adhered to a surface. 4. The magnetic core member (14a, 64a) is formed of a composite material of powder or flake and plastic made of a magnetic material, wherein the composite material contains 10 to 56% by volume of a magnetic material and 90% by volume.
The RFID tag according to claim 2, wherein the RFID tag is made of plastic by up to 44% by volume.