JP2012104985A - Ic tag operating on metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable communication of an IC tag operating on a metal and reduce the size of the IC tag by eliminating a metal protector.SOLUTION: In an IC tag, a partial antenna composed of a radiation element and a matching circuit and an IC chip joined to the partial antenna are formed on one surface of an insulation base material. A spacer is formed on the partial antenna, and the one surface of a film is adhered to a metal housing to operate the IC tag. The radiation element creates electromagnetic continuity with the metal housing, and the partial antenna and the metal housing form a dipole antenna.

Description

  INDUSTRIAL APPLICABILITY The present invention is used for a cylinder, a mold, a metal pallet, and a bobbin case that require compatibility between miniaturization and ensuring mechanical strength, which cannot be handled by a normal RFID tag having a half-wavelength antenna in the microwave or UHF band. The present invention relates to a metal-compatible IC tag.

  In general, an RFID tag has an IC chip in which identification information such as an ID number is incorporated in an integrated circuit / an antenna connected to the IC chip / an inlet composed of the IC chip and a substrate on which the antenna is integrally mounted, The inlet is provided with utilities such as a protective transparent film and an adhesive for mounting, and the information is read from the outside by wireless means from the outside via an antenna connected to the IC chip ( Patent Document 1).

  When this general RFID tag is affixed to the surface of a metal body and operated, reflection / absorption occurs due to a metal surface attached to electromagnetic waves for communication, which causes a problem that communication becomes difficult. In the prior art, as a countermeasure against this, a resin or ferrite that prevents the signal from being consumed as an eddy current or an induced current on the surface of the metal or the supporting metal surface of the metal-compatible RFID tag itself, which reduces the influence, is used. A metal-compatible tag in which the inlet is incorporated in ceramic has been put into practical use. Furthermore, in applications that require mechanical strength, a proposal has been made to protect the entire metal-compatible RFID with a strong metal fitting (Patent Document 2).

  In small metal RFID tags, there is a need to increase the size and robustness of metal-compatible IC tags, and proposals have been made to use protective metal fittings as antennas to increase the robustness. However, since a protective metal fitting is required, there is a limit to downsizing as a result.

  In addition, when the IC tag is used close to a metal body, it is necessary to design impedance matching in consideration of the influence of the metal. A typical configuration is a dipole antenna type having a matching circuit and a radiating element. When the tag is made to function alone, there is a limit to downsizing the tag, which is an obstacle to lowering the price.

  In order to realize miniaturization, there is a patch antenna type tag instead of a dipole antenna, but it is generally known that the gain is higher than that of the dipole antenna but the directivity is low. There are metal molds, cylinders, metal pallets, etc. for the metal objects to be pasted, which are often different in shape and size, and there are restrictions on the space to be pasted. A corresponding tag is required.

JP 2001-283171 A JP 2008-090813 A

A patch antenna type of the same size by miniaturizing a dipole antenna type IC tag that has high directivity but difficult to miniaturize in an IC tag that is used by being attached to a metal housing. Provided is a metal-compatible IC tag that has higher performance than an IC tag, is low in price by reducing material costs, and can be used for applications that cannot be used due to space limitations.

As means for solving the above-mentioned problems, the invention according to claim 1 is characterized in that a partial antenna composed of a radiating element and a matching circuit and an IC chip bonded to the partial antenna are formed on one side of an insulating substrate. The IC tag has a spacer formed on the partial antenna, and is operated by attaching the one surface of the insulating base material to the metal casing, and the radiating element is electromagnetically connected to the metal casing to be the partial antenna. A metal-compatible IC tag characterized in that a dipole antenna is formed by a metal casing.

  The invention according to claim 2 is characterized in that the spacer electromagnetically insulates the matching circuit and the metal casing, and the dipole antenna and the IC chip are impedance-matched by the matching circuit. It is a metal corresponding | compatible IC tag of description.

  According to a third aspect of the present invention, there is provided an IC tag in which a partial antenna composed of a radiating element and a matching circuit and an IC chip bonded to the partial antenna are formed on one side of an insulating base material. The insulating substrate is operated with the matching circuit attached to the inside of the opening so that the matching circuit fits inside the opening, and the radiating element is electromagnetically connected to the metal housing. A metal-compatible IC tag characterized by forming a dipole antenna.

  The invention according to claim 4 is characterized in that the matching circuit fitted in the opening and the metal casing are electromagnetically insulated, and the dipole antenna and the IC chip are impedance-matched by the matching circuit. The metal-compatible IC tag according to claim 3.

  The invention according to claim 5 is characterized in that the planar shape of the metal casing is long and short, and the longitudinal direction of the metal casing and the plane of polarization of the antenna are parallel to each other. The metal-compatible IC tag according to claim 1.

  The invention according to claim 6 is characterized in that the length of the metal casing along the plane of polarization of the antenna is ½ or more of the wavelength of the radio wave transmitted to and received from the antenna. The metal-compatible IC tag according to any one of the items.

  A dipole antenna having higher directivity than a patch antenna is used for an IC tag of a type attached to a metal housing surface. The metal case to be attached is used as a part of the radiating element of the tag antenna. In the case of a UHF band IC tag, it is particularly effective when the longitudinal direction of the metal case is about 15 cm or more. The antenna matching circuit has a configuration in which the antenna matching circuit of the IC tag is floated from the metal surface using a spacer, thereby improving the communication distance.

  Whereas a conventional IC tag has an antenna, the present invention uses a metal casing to which an IC tag is attached as an antenna, so that it is smaller than an antenna used in a conventional IC tag. A radiating element is used, and miniaturization is possible.

  Further, the present invention is a dipole antenna type with high directivity, and has higher directivity than a conventional patch antenna type IC tag, and has higher performance when compared with the same size. Furthermore, since the number of constituent materials can be reduced, it is possible to provide an inexpensive IC tag, which can be used for applications that could not be used due to the pasting space.

It is the conceptual diagram which showed the structural example of embodiment of the metal corresponding | compatible IC tag which concerns on this invention. It is the conceptual diagram for description which emphasized the part concerned in the impedance matching of the metal corresponding | compatible IC tag which concerns on this invention. It is the conceptual diagram which showed the cross-sectional example of embodiment of the metal corresponding | compatible IC tag which concerns on this invention. It is the conceptual diagram which showed the structural example which made the matching circuit of one Embodiment of the other metal corresponding | compatible IC tag which concerns on this invention into one.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 shows a metal-compatible IC tag 11 of the present invention affixed to a metal housing 6, and a radiating element 2 and a matching circuit 3 formed by patterning a metal thin film or foil on an insulating substrate 4. And an IC chip 1 bonded to the antenna.

  The radiating element of the present invention functions as an electromagnetic conduction terminal 2 with the metal housing 6 in addition to the function as an antenna.

  FIG. 2 emphasizes the part involved in impedance matching of the metal-compatible IC tag 11 of the present invention. Matching is performed by controlling the area of the part shown in black. A metal foil attached to the four materials is formed by pattern etching. Although it is possible to adjust the area by flying the copper foil with a laser after patterning, it is generally not necessary.

FIG. 3 shows a cross section of the metal-compatible IC tag 11 of the present invention, in which the IC chip 1 is bonded to the matching circuit 3 and the matching circuit 3 and the metal housing 6 are made of a non-metallic insulating base material. Spacers 9 are arranged. An adhesive layer 5 is provided on the matching circuit 3 and the surface of the radiation element 2 connected to the matching circuit 3. The pressure-sensitive adhesive layer 5 on the surface of the radiating element 2 is formed over the entire surface, and a non-coated surface may be provided and the exposed portion may not be formed.
FIG. 4 shows a single matching circuit 3 that adjusts the matching with the metal casing according to the area and shape.

  In the present invention, the size of the matching circuit 3 depends on the thickness of the insulating base material serving as the spacer 9 and hardly depends on the material. Therefore, the same tag can be used for different non-metallic materials. The same antenna design can be used for IC tags that use hard materials for spacers and mold management, and IC tags that use soft materials and are attached to curved surfaces such as cylinders, if only the thickness up to the metal is specified. it can.

  Accordingly, standardization of the product is possible, and it is possible to provide an inexpensive metal-compatible IC tag 11 due to the mass production effect. In addition, the presence of the spacer 9 in the metal-compatible IC tag 11 improves the communication distance compared to the case where it does not exist, so the industry (manufacturer, distributor, use, etc.) that requires management of products made of metal. This is particularly effective when the management is operated by an IC tag at an operator).

A copper foil is pasted on a film 4 having a film size of 50 × 50 mm to form a radiating element 2 having an outer shape of 46.0 mm and an inner diameter of 26.5 mm and a matching circuit 3 having an outer shape of 18.5 mm and an inner diameter of 17.0 mm shown in FIG. The ring pattern was patterned by etching. The radiating element 2 and the matching circuit 3 are conductive from the wiring pattern, and the direction connecting the conductive pattern and the IC chip is the polarization plane 8. An IC chip 1 was set on the wiring pattern, an adhesive layer 5 was further provided, and a metal-compatible IC tag 11 in which a 4 mm spacer 9 was added with a foamed base made of acrylic resin was manufactured as a prototype.

  In order to affix the prototype metal-compatible IC tag 11 to a metal of copper, SUS, and aluminum having a size of 200 × 200 mm, the communication distance was measured. The results are shown in Table 1. When the spacer 9 is not provided between the matching circuit 3 and the metal housing 6, communication cannot be obtained if the spacer 9 is pasted on the metal housing 6, but the thickness of 4 mm is between the matching circuit 3 and the metal housing 6. When the spacer 9 was used, the communication distance was improved as compared with the case where the metal-compatible IC tag 11 was not attached to the metal, and the communication distance increased in the order of SUS, Cu, and Al.

  This IC tag antenna is designed so that the resonance frequency is around 960 MHz when the matching circuit 3 is 4 mm or more from the metal housing 6 or does not exist, and the metal housing 6 is attached to the radiating element 2. It is. At this time, the bare antenna and the metal to be attached were brought into contact with each other so that conduction was possible. The R / W used was a stationary type, circularly polarized wave, and an output of about 22 dBm.

The metal-compatible IC tag 11 of Example 1 alone had a communication distance characteristic of 195 mm, and its communication characteristics changed when it was attached to a copper plate, a SUS plate, or an aluminum plate. Communication was not possible when the spacer 9 was not present around the matching circuit 3, but the communication distance was improved to 500 mm or more by the presence of the spacer 9 as compared with the case of the single tag. In addition, the dependence on the material as the metal housing 6 was not found, and the error range.

  From this result, it is considered that the metal casing 6 to be attached is capable of communication without depending on the metal material. Further, if the matching circuit of the IC tag and the metal are brought close to each other, impedance matching is shifted and the communication distance is reduced.

The length of the copper tape having a width of 50 mm was changed to 200 mm, 150 mm, 100 mm, and 70 mm, and the metal-compatible IC tag 11 made on the copper tape was attached to measure the communication distance. The results are shown in Table 2. It can be seen that the longer the metal object case to be attached, which is the length of the radiating element, the longer the communication distance, and it is preferable that the distance is approximately λ / 2 (about 150 mm in the UHF band).

  If the metal housing 6 is not used as an antenna and only the radiating element of the metal-compatible IC tag is used, λ / 2 (about 150 mm in the UHF band) is required. By using the film, the size of the film 4 may be 50 × 50 mm, the antenna size may be 46.0 mm × 46.0 mm, and the size can be reduced.

The prototype metal-compatible IC tag 11 is attached to a 150 mm × 30 mm metal housing 6, and the polarization plane 8 of the metal-compatible IC tag 11 is attached parallel and perpendicular to the metal housing longitudinal direction 7, and its communication distance is measured. The results are shown in 3. As a result, the difference was 660 mm when pasted parallel to the metal casing longitudinal direction 7 and 250 mm when pasted vertically.

  This is because the length of the radiating element 2 is 150 mm when pasted in the metal casing longitudinal direction 7, and the length of the radiating element 2 is 30 mm when stretched perpendicular to the metal casing longitudinal direction 7. There was a difference in (distance). Therefore, it can be seen that it is desirable to apply the tape to the metal housing 6 in parallel with the metal housing longitudinal direction 7. That is, by sticking the IC tag to the metal casing 6 of FIG. 1, the length of the metal casing 6 to be pasted becomes the combined radiating element length.

  Moreover, since the existing tag has the radiating element 2, the present invention has only a part of the radiating element 2, so that the size can be reduced. Since the metal-compatible IC tag 11 with less constituent material can be obtained, an inexpensive IC tag can be provided.

  Since the metal-compatible IC tag 11 of the present invention is a dipole antenna, it has higher directivity than a patch antenna-type metal-compatible IC tag of the same size. Since the size of the matching circuit depends on the thickness of the insulating base material serving as the spacer 9 and does not depend on the material, the same tag can be used for different non-metallic materials. Therefore, when using a hard material for the spacer 9 and managing the die, it can be used by being attached to a curved surface such as a cylinder.

  The same antenna design can be used for the metal-compatible IC tag 11 of the present invention by defining only the thickness up to the metal. Therefore, standardization of products is possible, and an inexpensive IC tag can be provided due to mass production effects.

1 ... IC chip 2 ... Radiation element (conduction terminal)
DESCRIPTION OF SYMBOLS 3 ... Matching circuit 4 ... Insulating base material 5 ... Adhesive layer 6 ... Metal housing 7 ... Metal housing longitudinal direction 8 ... Polarization surface 9 ... Spacer 10 ... -Electromagnetic conduction part 11 with metal casing ... Metal-compatible IC tag

Claims (6)

  An IC tag in which a partial antenna composed of a radiating element and a matching circuit and an IC chip bonded to the partial antenna are formed on one side of an insulating substrate, and a spacer is formed on the partial antenna, and a metal housing A metal-compatible IC tag characterized in that a dipole antenna is formed by a partial antenna and a metal casing, wherein the radiating element is electromagnetically connected to the metal casing and the one side of the insulating base material is attached to the metal casing. .   The metal-compatible IC tag according to claim 1, wherein the spacer electromagnetically insulates the matching circuit and the metal casing, and the dipole antenna and the IC chip are impedance-matched by the matching circuit.   An IC tag in which a partial antenna composed of a radiating element and a matching circuit and an IC chip bonded to the partial antenna are formed on one side of an insulating substrate, and the one side of the film is attached to a metal housing having an opening A metal-compatible IC, characterized in that the matching circuit is attached and operated so as to fit inside the opening, and the radiating element is electromagnetically connected to the metal casing to form a dipole antenna with the partial antenna and the metal casing. tag.   4. The metal-compatible IC tag according to claim 3, wherein the matching circuit and the metal housing fitted inside the opening are electromagnetically insulated, and the dipole antenna and the IC chip are impedance-matched by the matching circuit. .   5. The metal-compatible IC tag according to claim 1, wherein the planar shape of the metal casing is long and short, and the longitudinal direction of the metal casing is parallel to the plane of polarization of the antenna.   The metal-compatible IC tag according to any one of claims 1 to 5, wherein the length of the metal casing along the plane of polarization of the antenna is ½ or more of the wavelength of radio waves transmitted to and received from the antenna. .