JP2007233508A - Auxiliary sheet for ic tag and wireless ic tag sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an auxiliary sheet for an IC tag, which enables the use of the same IC tag for general use and for metal-responding use, and a wireless IC tag sheet including the sheet installed to the IC tag. <P>SOLUTION: The auxiliary sheet for IC tag 1 to be superposed on an electromagnetic induction type IC tag 20 which has a specific resonance frequency and performs communications in the vicinity of this resonance frequency has a laminated structure of a soft magnetic layer 11 and a conductor layer 12 with a planar shape substantially equal to or larger than the IC tag 20. The sheet 1 is installed to one side of the IC tag 20 so that the soft magnetic layer 11 is interposed between the one side of the IC tag 20 and the conductor layer 12, and the resonance frequency of the installed auxiliary sheet for IC tag is set to be equal to the specific resonance frequency or within a communicable fluctuating range. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an auxiliary sheet for an IC tag that is attached to an IC tag that operates by an electromagnetic induction method such as 13.56 MHz and has a structure corresponding to a metal (conductor), and a wireless IC tag sheet that is attached to the IC tag. .

  In recent years, wireless communication systems using RFID (Radio Frequency Identification) technology have attracted attention. This communication system is generally composed of a data carrier capable of storing various data, and a reader / writer that reads and writes (reads / writes) information without contact with the data carrier. The data carrier is called an RFID tag (wireless IC tag), a non-contact IC card, or the like according to its shape, size, etc. (hereinafter collectively referred to as an IC tag). The radio frequency band used for the IC tag includes a band of 135 kHz or less, a 13.56 MHz band, a 2.45 GHz band, and the like. Since the IC tag is easy to handle for the user, it has recently been used for various entrance / exit management such as an automatic ticket gate for transportation. In addition, applications to electronic money and article management are also being studied.

  Of these, IC tags and reader / writers used in the 13.56 MHz band generally have a built-in loop antenna, and power is supplied to the IC tag by electromagnetic induction via the magnetic field generated by the reader / writer antenna. The data is read / written.

  When the periphery of the antenna is made of a good conductor such as metal (for example, when an IC tag is attached to a metal article), the influence of eddy currents or the like that a part of the communication power is generated on the surface of the good conductor There was a problem that the communication distance was shortened.

  As a countermeasure against this, Patent Document 1 below proposes to improve antenna characteristics by inserting a soft magnetic member such as a composite magnetic body between an antenna and an article.

JP 2002-290131 A

  By the way, if a magnetic body or metal is disposed in the vicinity of a loop antenna of an IC tag such as a non-contact IC card, the resonance frequency of the antenna greatly fluctuates. Therefore, to design an antenna, design is performed by setting a loop-shaped antenna pattern and a capacitor so that a desired resonance frequency is obtained in the presence of the loop-shaped antenna, a nearby magnetic body, and surrounding metal. . For example, it is described in Patent Document 1 and Non-Patent Document 1 below.

"RFID Handbook", 86 pages, published by Nikkan Kogyo Shimbun, February 26, 2001

  In other words, because the design differs between IC tags that are normally used (no metal) and metal-compatible IC tags, it is necessary for tag manufacturers to produce two types of IC tags: normal (no metal) and metal-compatible. The user also needs to purchase two types according to the usage conditions and use them separately, which is inconvenient in terms of cost and convenience.

  In order to solve the above-mentioned problems, the present invention provides an IC tag auxiliary sheet that can use the same IC tag for normal use and for metal use, and a wireless IC tag sheet that is mounted on the IC tag. Objective.

  Other objects and novel features of the present invention will be clarified in embodiments described later.

In order to achieve the above object, the auxiliary sheet for an IC tag according to the present invention is used to overlap an electromagnetic induction type IC tag having a specific resonance frequency and communicating in the vicinity of the resonance frequency. And
It has a laminated structure of at least a soft magnetic layer and a conductor layer, has substantially the same planar shape as the IC tag or a larger planar shape than the IC tag, and the gap between one surface of the IC tag and the conductor layer The IC tag is mounted on one side of the IC tag so that a soft magnetic layer is interposed, and the resonance frequency when the auxiliary sheet for IC tag is mounted is equal to the specific resonance frequency or within a communicable variation range. Yes.

  In the IC tag auxiliary sheet, a first dielectric layer may be provided between the soft magnetic layer and the conductor layer.

  In the IC tag auxiliary sheet, a second dielectric layer may be provided on a surface of the soft magnetic layer on which the conductor layer is not mounted.

  In the IC tag auxiliary sheet, the dielectric layer may have adhesiveness or adhesiveness.

  In the IC tag auxiliary sheet, the resonance frequency of the IC tag when the IC tag auxiliary sheet is mounted may be adjusted by the thickness of the dielectric layer.

In the IC tag auxiliary sheet, an adhesive layer may be provided on a surface of the conductor layer on which the magnetic layer is not attached.

The wireless IC tag sheet according to the present invention is characterized in that the IC tag auxiliary sheet is attached to the IC tag.

  According to the auxiliary sheet for IC tag according to the present invention, the resonance frequency when the auxiliary sheet for IC tag is attached to the IC tag communicating with the specific resonance frequency is the specific resonance frequency of the IC tag itself. It is set to be equal or within a fluctuation range in which communication is possible, and it is possible to use the same IC tag for normal use and for metal use. In other words, when using an IC tag in a place where no metal (conductor) is arranged around it, when using an ordinary IC tag as it is, for example, pasting it on an article made of metal (conductor) By mounting the IC tag auxiliary sheet according to the present invention between the IC tag and the article, the normal IC tag can be used as it is without changing the design (without changing the design of the built-in antenna). It becomes.

  Further, by attaching the IC tag auxiliary sheet to the IC tag, a wireless IC tag sheet that can be attached to a metal (conductor) article can be realized.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an IC tag auxiliary sheet and a wireless IC tag sheet will be described with reference to the drawings as the best mode for carrying out the present invention.

  FIG. 1 shows Embodiment 1 of an auxiliary sheet for an IC tag and a wireless IC tag sheet according to the present invention. As shown in FIG. 1, the IC tag auxiliary sheet 1 includes a soft magnetic layer 11 and a conductor layer 12 laminated and integrated therewith. The IC tag auxiliary sheet 1 is a sheet that is used as an auxiliary to the sheet-like IC tag 20 that operates alone using the electromagnetic induction method, and is substantially the same as the sheet-like IC tag 20 to be mounted. Coplanar shape.

  The sheet-like IC tag 20 to be mounted has a function as a thin card-shaped RFID tag having an outer shape of 86 mm × 54 mm, for example, has a built-in loop antenna, and communicates in the MHz band, for example, 13.56 MHz. (The resonance frequency of the IC tag itself is set to 13.56 MHz).

  As shown in FIG. 1, the IC tag auxiliary sheet 1 is mounted and used on one side of the IC tag 20 so that the soft magnetic layer 11 is interposed between one side of the IC tag and the conductor layer 12. The soft magnetic layer 11 has an appropriate magnetic permeability and thickness so that the resonance frequency becomes a frequency (near 13.56 MHz) at which the resonance frequency can be satisfactorily communicated in the mounted state (laminated state). The conductor layer 12 is laminated. As the soft magnetic layer 11, for example, a soft magnetic ferrite or a composite magnetic material in which soft magnetic ferrite or soft magnetic metal powder is dispersed in a binder such as rubber is used. The magnetic material used for the soft magnetic layer 11 desirably has a large real part of complex relative permeability, a small imaginary part, and a low conductivity. The conductor layer 12 preferably has a low resistance, for example, in order to suppress loss due to eddy current. These conductor layers are preferably metal foils having a thickness approximately equal to or greater than the skin depth of a good conductor such as aluminum or copper.

The product of the real part and the thickness of the complex relative permeability of the soft magnetic layer 11 is such that the larger the value of the product, the lower the resonance frequency due to the action of increasing the inductance of the loop antenna incorporated in the IC tag 20, When the product value decreases, the inductance of the loop antenna is reduced due to the influence of the conductor layer 12, and the resonance frequency increases.

The influence of the soft magnetic layer and the conductor layer on the resonance frequency of the antenna of the IC tag varies depending on the pattern shape of the antenna, the thickness structure of the entire tag, etc. Therefore, the magnetic permeability of the soft magnetic layer for each type of IC tag, Use an appropriate thickness.

  As a method of attaching the auxiliary sheet 1 of the present embodiment to the IC tag 20, the soft magnetic layer 11 is made sticky or adhesive, or the IC tag 20 and the auxiliary sheet 1 are integrated using a laminator or the like. A wireless IC tag sheet that can be attached to an article made of metal (conductor) is obtained by attaching the auxiliary sheet 1 to the IC tag 20.

  According to the first embodiment, the resonance frequency of the IC tag 20 when the IC tag auxiliary sheet 1 is attached to the IC tag 20 is equal to the specific resonance frequency (for example, 13.56 MHz) of the IC tag itself, or communication. By setting to be within a possible variation range, it is possible to use the same IC tag for normal use and for metal use. Specifically, if the decrease in reception sensitivity when the IC tag auxiliary sheet 1 is attached is within 50% compared to the reception sensitivity (magnetic field strength) when the IC tag 20 is used alone, it is designed to be within a communication fluctuation range. can do. In the case of causing a decrease in reception sensitivity exceeding 50%, it is not preferable because communication becomes impossible depending on the application.

  Accordingly, when the IC tag 20 is used in a place where no metal (conductor) is disposed around it, the normal IC tag 20 is used as it is, for example, when it is attached to a metal (conductor) product. The IC tag auxiliary sheet 1 is mounted between the IC tag 20 and the article, so that the normal IC tag 20 can be used as it is without changing the design (without changing the design of the built-in antenna). It becomes possible. As a result, it is not necessary for the user to purchase two types of IC tags in accordance with the use conditions, and this is advantageous in terms of cost and convenience.

  FIG. 2 is a second embodiment of an IC tag auxiliary sheet and a wireless IC tag sheet according to the present invention. The IC tag auxiliary sheet 1A includes a soft magnetic layer 11, a dielectric layer (nonmagnetic insulating layer) 13, and The conductor layers 12 are sequentially laminated and integrated. That is, the dielectric layer 13 is interposed between the soft magnetic layer 11 and the conductor layer 12. Other configurations are the same as those of the first embodiment.

  For the dielectric layer 13, for example, a dielectric having a low dielectric constant (relative dielectric constant of 5 or less) such as PET or acrylic, or an adhesive material such as a double-sided adhesive tape (also a low dielectric constant material) is used. .

  As the magnetic permeability and thickness of the soft magnetic layer 11 and the thickness of the dielectric layer 13, those suitable for each IC tag 20 to be mounted can be used.

  The method for attaching the auxiliary sheet 1A of the present embodiment to the IC tag 20 can employ the same method as that of the first embodiment.

  The operational effects of the second embodiment are substantially the same as those of the first embodiment. However, since the dielectric layer 13 is provided, the distance between the conductor layer 12 and the IC tag 20 is increased. Can be reduced as compared with the first embodiment.

  FIG. 3 is a third embodiment of an IC tag auxiliary sheet and a wireless IC tag sheet according to the present invention. The IC tag auxiliary sheet 1B includes a dielectric layer (nonmagnetic insulating layer) 14, a soft magnetic layer 11, and The conductor layers 12 are sequentially laminated and integrated. That is, the dielectric layer 14 is laminated on the surface of the soft magnetic layer 11 on the IC tag 20 mounting side. Other configurations are the same as those of the first embodiment.

  For the dielectric layer 14, for example, a low dielectric constant dielectric such as PET or acrylic, or an adhesive such as a double-sided adhesive tape is used.

  As the magnetic permeability and thickness of the soft magnetic layer 11 and the thickness of the dielectric layer 14, those suitable for each IC tag 20 to be mounted can be used.

  As a method of attaching the auxiliary sheet 1B of the present embodiment to the IC tag 20, the dielectric layer 14 is made sticky or adhesive, or the IC tag 20 and the auxiliary sheet 1B are integrated using a laminator or the like. A wireless IC tag sheet that can be attached to an article made of metal (conductor) is obtained by attaching the auxiliary sheet 1B to the IC tag 20.

  The operational effects of the third embodiment are substantially the same as those of the first embodiment. However, since the distance between the soft magnetic layer 11 and the IC tag 20 is increased by providing the dielectric layer 14, the soft magnetic layer 11 In addition, the influence of the conductor layer 12 can be reduced as compared with the first embodiment.

  Further, the configurations of the second embodiment and the third embodiment may be combined, and this case is shown in FIG. That is, as shown in FIG. 4, the IC tag auxiliary sheet 1 </ b> C has a configuration in which the dielectric layer 13 is laminated on one surface of the soft magnetic layer 11 and the dielectric layer 14 is laminated on the other surface. Other configurations are the same as those of the first embodiment. By changing the thickness of one or both of these dielectric layers 13 and 14, the resonance frequency when the IC tag auxiliary sheet 1 </ b> C is attached to the IC tag 20 can be finely adjusted.

  Moreover, the dielectric layers 13 and 14 may have adhesiveness or adhesiveness. In particular, in the case of the third and fourth embodiments, it is possible to directly attach the IC tag auxiliary sheet of the present invention to the IC tag by making the dielectric layer sticky or adhesive.

  Furthermore, as an example, an adhesive layer 15 for attaching an auxiliary sheet for an IC tag may be provided on the surface of the conductor layer 12 on which the soft magnetic layer is not mounted as in the fifth embodiment of FIG. Other configurations are the same as those of the fourth embodiment. In this way, the IC tag with the IC tag auxiliary sheet 1D of the fifth embodiment can be directly mounted on an adherend such as a packaging box.

  In each embodiment, the planar shape (outer contour) of the IC tag auxiliary sheet is substantially the same as the planar shape of the IC tag 20, but in terms of operation principle, it is more than the loop antenna built in the IC tag 20. The planar shape of the IC tag auxiliary sheet may be larger than the planar shape of the IC tag 20 depending on the application.

  Hereinafter, the auxiliary sheet for an IC tag according to the present invention will be described in detail in Examples.

IC tag (RFID tag)
RFID tag V720S-D13P30 manufactured by OMRON Software Co., Ltd. is used (outer dimensions 86mm x 54mm)

Resonance frequency measurement method A 50 mm x 40 mm sense coil is attached to the measurement port of a network analyzer (8753E manufactured by Agilent Technologies, Inc.) via a coaxial cable 1 m. The antenna to be measured (built in the IC tag) is placed on the sense coil, and the frequency with the maximum real part of the impedance observed on the network analyzer is set as the resonance frequency.

  Various magnetic materials as soft magnetic layers (see sample Nos. 1 to 11 in Table 1 below) 86 mm x 54 mm with aluminum foil tape (No. 8060-00 manufactured by Slion Tech Co., Ltd.) as a conductor layer pasted Was used as an auxiliary sheet for an IC tag, and the auxiliary sheet was attached to the IC tag via a double-sided adhesive tape (707N manufactured by Teraoka Seisakusho Co., Ltd.). The pasting was performed such that a magnetic material was interposed between one surface of the IC tag and the aluminum foil tape.

In addition, Example 1 is the form of FIG. 1 when not including the adhesive layer of the aluminum foil tape and the double-sided adhesive tape, and the form of FIG. 4 when both are taken into consideration.

  Regarding the IC tag auxiliary sheet of Example 1, the resonance frequency before and after the auxiliary sheet was attached was measured, and the effect of the IC tag auxiliary sheet of Example 1 was confirmed.

Result 1
The evaluation results of the resonance frequency are shown in Table 2 below. FIG. 6 shows a graph in which the horizontal axis represents the product of the complex relative permeability real part of the magnetic material and the thickness (mm), and the measurement result of the resonance frequency is plotted on the vertical axis.

  In Table 2, sample No. The IC tag with an auxiliary sheet for IC tag 1 is sample No. 1 in Table 1. 1 is used, and so on.

  From Table 2 and FIG. 6, by appropriately selecting the real part and thickness of the complex relative permeability of the magnetic material as the soft magnetic layer, by creating an auxiliary sheet of this example and pasting it to the IC tag, It was confirmed that even if the metal-compatible configuration is used, it is possible to produce an IC tag that can be satisfactorily communicated with little change in the resonance frequency.

For example, when the thickness of the magnetic material is t (mm) and the real part of the complex relative permeability at 13.56 MHz is μ1, sample No. 2 (product value 6.25), sample no. 7 (product value 4.5), and sample no. 11 (product value 4.8) falls within a frequency variation within 10% of the upper and lower of 13.56 MHz, and is preferable when communicating in the vicinity of 13.56 MHz. As far as Example 1, it can be said that the value of the product is preferably set to about 4-7.

  Other commercially available IC tags have different antenna patterns and thickness configurations. Therefore, in an IC tag different from the IC tag used in the present embodiment, the relationship between the complex relative permeability real part × thickness and the resonance frequency is not the same as in FIG. 6 (the tendency is the same). Therefore, the present invention is made by selecting an optimal magnetic material for each IC tag.

  Sample No. 1 in Table 1 as the soft magnetic layer. 11 and 86 mm × 54 mm, a 0.5 mm or 1 mm thick PET sheet having a low dielectric constant is applied as a dielectric layer with the double-sided tape described in Example 1, and an aluminum foil tape as a conductor layer is further applied. This was used as an IC tag auxiliary sheet, and the soft magnetic layer side of the auxiliary sheet was attached to the IC tag via a double-sided adhesive tape.

In addition, Example 2 is the form of FIG. 2 when not including the adhesive layer of the aluminum foil tape and the double-sided adhesive tape, and is the form of FIG. 4 when both are considered.

  Regarding the auxiliary sheet for IC tag of Example 2, the resonance frequency before and after the auxiliary sheet was attached was measured, and the effect of the auxiliary sheet for IC tag of Example 2 was confirmed.

Result 2
A graph showing the dielectric thickness on the horizontal axis and the resonance frequency on the vertical axis is shown in FIG. In addition, the thickness of 0 mm in the figure is a case where a dielectric layer is not attached.

  From FIG. 7, it is confirmed that the resonant frequency shifts to the low frequency side by mounting the dielectric layer between the soft magnetic layer and the conductor layer, and the resonant frequency is adjusted by adjusting the thickness of the dielectric layer. Can be adjusted.

  Sample No. 6 in Table 1 as a soft magnetic layer, 86 mm × 54 mm, an aluminum foil tape as a conductor layer, and a low dielectric constant as a dielectric layer on the IC tag mounting side of the soft magnetic layer A PET sheet having a thickness of 0.5 mm or 1 mm was used as an auxiliary sheet for an IC tag, and was attached to the IC tag via a double-sided adhesive tape.

In addition, Example 3 is the form of FIG. 3 when not including the adhesive layer of the aluminum foil tape and the double-sided adhesive tape, and is the form of FIG. 4 when both are considered.

  With respect to the IC tag auxiliary sheet of Example 3, the resonance frequency before and after the auxiliary sheet was attached was measured, and the effect of the IC tag auxiliary sheet of Example 3 was confirmed.

Result 3
FIG. 8 is a graph showing the dielectric thickness on the horizontal axis and the resonance frequency on the vertical axis. In addition, the thickness of 0 mm in the figure is a case where a dielectric layer is not attached.

  From FIG. 8, it is confirmed that the resonant frequency shifts to the high frequency side by mounting the dielectric layer between the IC tag and the soft magnetic layer, and by adjusting the thickness of the dielectric layer, It is possible to adjust the resonance frequency.

  Although the embodiments and examples of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited thereto and various modifications and changes can be made within the scope of the claims. I will.

It is an expanded sectional view which shows Embodiment 1 of the auxiliary sheet for IC tags and radio | wireless IC tag sheet which concern on this invention. It is an expanded sectional view which shows Embodiment 2 of this invention. It is an expanded sectional view which shows Embodiment 3 of this invention. It is an expanded sectional view which shows Embodiment 4 which combined Embodiment 2 and Embodiment 3 of this invention. FIG. 11 is an enlarged cross-sectional view showing a fifth embodiment in which an adhesive layer is added to the surface of the conductor layer on which the magnetic layer is not mounted, although the second and third embodiments of the present invention are combined. It is a graph which shows the relationship between the product of the complex relative magnetic permeability real part and thickness (mm), and the resonant frequency (MHz) in Example 1 of this invention. It is a graph which shows the relationship between the thickness of a dielectric material layer, and the resonant frequency (MHz) in Example 2 of this invention. It is a graph which shows the relationship between the thickness of a dielectric material layer, and the resonant frequency (MHz) in Example 3 of this invention.

Explanation of symbols

1, 1A, 1B, 1C, 1D IC tag auxiliary sheet 11 Soft magnetic layer 12 Conductor layer 13, 14 Dielectric layer 15 Adhesive layer 20 IC tag

Claims (7)

An IC tag auxiliary sheet that is used in an overlapping manner with respect to an electromagnetic induction type IC tag that has a specific resonance frequency and communicates in the vicinity of the resonance frequency,
It has a laminated structure of at least a soft magnetic layer and a conductor layer, has substantially the same planar shape as the IC tag or a larger planar shape than the IC tag, and the gap between one surface of the IC tag and the conductor layer The IC tag is attached to one side of the IC tag so that a soft magnetic layer is interposed, and the resonance frequency when the auxiliary sheet for IC tag is attached is equal to the specific resonance frequency or within a variable range in which communication is possible. A supplementary sheet for IC tags.   The auxiliary sheet for an IC tag according to claim 1, wherein a first dielectric layer is provided between the soft magnetic layer and the conductor layer.   The auxiliary sheet for an IC tag according to claim 1, wherein a second dielectric layer is provided on a surface of the soft magnetic layer on which the conductor layer is not mounted.   The auxiliary sheet for an IC tag according to claim 2 or 3, wherein the dielectric layer has adhesiveness or adhesiveness.   The auxiliary sheet for IC tag according to claim 2, 3 or 4, wherein the resonance frequency of the IC tag when the auxiliary sheet for IC tag is mounted is adjusted by the thickness of the dielectric layer. The auxiliary sheet for an IC tag according to claim 1, 2, 3, 4, or 5, wherein an adhesive layer is provided on a surface of the conductor layer on which the soft magnetic layer is not attached. A wireless IC tag sheet, wherein the IC tag auxiliary sheet according to claim 1, 2, 3, 4, 5, or 6 is attached to the IC tag.

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