JP2005327939A - Magnetic shielding sheet for tag, and the tag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic shielding sheet and an electronic component using it, which can shield the electronic component from magnetic field, without causing loss in the energy of the magnetic field. <P>SOLUTION: The magnetic shield sheet 10 is constituted of the laminate of a shielding layer 11 and adhesive agent layers 12. Since the shielding layer 11 is made of a material, having a large real part μ' of a complex relative permeability μ, the lines of magnetic field come to pass through the shielding layer in a concentrative way when disposing the shielding layer 11 in a magnetic field. Thus, the magnetic field of one region partitioned by the magnetic shielding sheet 10 can be prevented from leaking to the other partitioned region by using the magnetic shield sheet 10, because the regions are shielded mutually from the magnetic fields by using the magnetic shielding sheet 10. Further, since the shielding layer 11 is made of the material, having a small imaginary part μ'' of the complex relative permeability μ, the loss in the energy of the magnetic field which is caused by the disposal of the shield layer 11 can be suppressed to be small, even if the shielding layer 11 is disposed in the magnetic field. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnetic shield sheet for shielding a magnetic field and an electronic component using the same.

  As RFID (Radio Frequency Identification), there are an RFID tag and a non-contact IC card. In addition to this, the practical use of a mobile terminal having an RFID function is being studied. There are the following two types of communication means for RFID tags. One is an electromagnetic induction method in which power is supplied by communication between a coil and a coil to communicate, and a frequency of 135 kHz or 13.56 MHz is used. The other is a radio wave system, and frequencies of 433 MHz, 900 MHz, 2.8 GHz, and 5.8 GHz are used. The frequency mainly used for the non-contact IC card is 4.91 MHz for the contact type and 13.56 MHz for the proximity type. By using the 13.56 MHz band, wireless communication within a few centimeters to 1 m is possible, and practical use is being made mainly by using this band.

  FIG. 11 is a cross-sectional view schematically showing a tag 1 which is a conventional technique. The tag 1 includes an antenna 2 that transmits and receives an electromagnetic wave signal, and an integrated circuit (IC) 3 that processes a signal transmitted and received by the antenna 2. When the tag 1 receives the request signal from the reading device, the tag 1 transmits the information stored in the IC 3, in other words, the information held in the tag 1 can be read by the reading device. Configured. This tag 1 is provided by being attached to a product, for example, and is used for product management such as prevention of product theft and grasping of inventory status.

  When the tag 1 is used by being attached to a metal product, and the metal member 4 is present in the vicinity of the antenna 2, the magnetic field lines of the magnetic field formed by the electromagnetic wave signal transmitted and received by the antenna 2 are made of the metal member. 4, and an eddy current is generated in the metal member 4. When eddy currents are generated in this way, the energy of electromagnetic waves is converted into heat energy and absorbed. If energy is absorbed in this way, the electromagnetic wave signal is greatly attenuated and cannot be transmitted or received. Therefore, such a tag 1 cannot be used in the vicinity of the metal member 4.

  FIG. 12 is a cross-sectional view schematically showing a tag 1A which is another conventional technique. The tag 1A shown in FIG. 12 is similar to the tag 1 of FIG. 11, and the same reference numerals are given to corresponding portions, and only different configurations will be described. In order to solve the problem of the tag 1 of FIG. 11, the tag 1 </ b> A of FIG. 12 includes a magnetic absorption plate 7 provided so as to be disposed between the member 4 that is an article to be attached and the antenna 2. Configured as follows. The magnetic absorption plate 7 is made of a material having a high magnetic permeability such as sendust, ferrite and carbonyl iron, and thus a material having a high complex relative permeability.

  The complex relative permeability has a real part and an imaginary part, and the complex relative permeability increases as the real part increases. In other words, a material having a high complex relative permeability has a high real part in the complex relative permeability. When a material having a high real part in the complex relative permeability exists in the magnetic field, the magnetic field lines are concentrated in the member. Therefore, by providing the magnetic absorption plate 7, the magnetic field is prevented from leaking, and information can be read even if the metal member 4 is present in the vicinity. Such a tag 1A is disclosed in, for example, Patent Document 1.

JP 2000-113142 A

  In the tag 1A shown in FIG. 12, the magnetic absorption plate 7 made of a material having a high complex relative permeability is provided to prevent the magnetic field from leaking. Sendust, ferrite, carbonyl iron and the like are used as materials having a high complex relative permeability. When these materials are filled in a binder such as a polymer, the real part in the complex relative permeability of the sheet as an insulating sheet can be increased, the magnetic field can be shielded, and magnetic field leakage can be prevented. The imaginary part of the complex relative permeability is also high. This is because the real part of the complex relative permeability at a specific frequency is designed to be high, but at the same time, the imaginary part of the complex relative permeability is not designed to be low. A material having a high imaginary part of complex relative permeability loses energy of the magnetic field, specifically, converts the magnetic field energy into thermal energy and absorbs it. If a magnetic absorption plate made of a material having a high complex relative permeability is used as described above, loss of electromagnetic wave energy in the magnetic absorption plate is caused even if loss in the metal member 4 can be prevented. There's a problem. In actual use, not only the use of a magnetic shield material but also the influence of the metal surface is avoided by widening the distance between the antennas from the metal surface as much as possible (1-2 mm). In other words, when these materials are used, even if they are used as a magnetic shield material for RFID tags (also called a magnetic yoke), a considerable thickness is required including the space.

  Accordingly, an object of the present invention is to provide a magnetic shield sheet that can shield a magnetic field without losing the energy of the magnetic field and that is thinner than the conventional one, and an electronic component using the same. A mobile terminal (for example, a mobile phone) having an RFID function is shielded on the inner surface of the casing. In addition, since the space for the antenna is very narrow and the environment is easily affected by the metal surface due to the thinning, a high-performance magnetic shield sheet corresponding to this is provided. Further, by using this sheet, an unprecedented thin RFID tag antenna can be installed in a mobile terminal, and these thin systems (electronic parts) including a magnetic shield sheet are provided.

  Furthermore, in the present invention, by having a magnetic shielding property with respect to the above-mentioned specific frequency, it contributes to be useful as a metal-compatible RFID tag, and at other frequencies (for example, 100 MHz to 6 GHz), the real part of the complex relative permeability and An imaginary part becomes high, and for example, a magnetic shield sheet that also serves to suppress unwanted radiation noise and the like and an electronic component using the same are provided. That is, the present invention provides an intelligent sheet that suitably converts and functions the magnetic permeability and dielectric constant at two or more frequencies.

The present invention includes a shield layer comprising a shield layer made of a material having a large real part μ _γ ′ of a complex relative permeability μ _{γ with} respect to a specific frequency and a small imaginary part μ _γ ″ of the complex relative permeability μ _γ. It is a sheet.

According to the present invention, the magnetic shield sheet is provided with a shield layer. Since the shield layer is made of a material having a large real part μ _γ ′ of the complex relative permeability μ _γ , when this shield layer is provided in a magnetic field, the magnetic field lines concentrate on the shield layer. Therefore, by using a magnetic shield sheet, it is possible to shield the magnetic field and prevent the magnetic field of one region partitioned by the magnetic shield sheet from leaking to the other region. Furthermore, since the shield layer is made of a material having a small imaginary part μ _γ ″ of the complex relative permeability μ _γ , even if this shield layer is provided in the magnetic field, the loss of magnetic field energy due to the provision of the shield layer is kept small. be able to.

  Such a magnetic shield sheet may be used by interposing between an antenna and a metal member, for example, when the antenna is disposed in the vicinity of a metal member and used for wireless communication. In this case, the energy of the magnetic field of the transmitted / received electromagnetic wave signal is prevented from being absorbed by the metal member. Moreover, the magnetic shield sheet itself for preventing the influence of such a metal member has a small magnetic loss. Therefore, even an antenna close to a metal surface (surface having conductivity) can be suitably transmitted and received for wireless communication.

In the invention, it is preferable that the shield layer is made of a material having a small imaginary part ε _γ ″ of the complex relative dielectric constant ε _γ with respect to a specific frequency.

According to the present invention, the imaginary part of the complex relative permittivity _ε γ ε γ "is small. Imaginary part of the complex relative permittivity _ε γ ε γ" becomes conductive measure of shielding layers, the imaginary part epsilon _gamma "is If it is large, conductivity will be developed, and if conductivity is developed, eddy current will be generated when the magnetic flux passes through the shield layer. When it is used to improve the above, it becomes an obstacle to wireless communication by attenuating the magnetic flux. On the other hand, by reducing the imaginary part ε _γ ″ of the complex relative dielectric constant ε _γ , the occurrence of the above problem is prevented. Therefore, it is possible to prevent the wireless communication from becoming an obstacle and to realize a preferable wireless communication environment.

Further, the present invention is characterized in that the specific frequency is 13.56 MHz.
According to the present invention, for example, the above-described effect can be achieved with respect to 13.56 MHz mainly used for communication of an RFID (Radio Frequency IDentification) tag, and suitable wireless communication using the RFID tag can be achieved. it can.

The present invention, the real part of the complex relative permeability mu _gamma real part mu _gamma 'is 30 or more and the imaginary part mu _gamma "of the complex relative magnetic permeability mu _gamma complex relative magnetic permeability mu _gamma of at 13.56MHz electromagnetic mu A value tanδμ divided by _γ ′ is 0.2 or less.

  According to the present invention, the magnetic flux concentrates on the shield layer and the attenuation in the magnetic flux decreases because of such a numerical relationship. Therefore, by using the magnetic shield sheet, wireless communication can be satisfactorily performed near the metal surface, for example.

The present invention, the real part of the complex relative permeability mu _gamma real part mu _gamma 'is 50 or more and the imaginary part mu _gamma "of the complex relative magnetic permeability mu _gamma complex relative magnetic permeability mu _gamma of at 13.56MHz electromagnetic mu A value tanδμ divided by _γ ′ is 0.1 or less.

  According to the present invention, such a numerical relationship causes the magnetic flux to flow more concentratedly in the shield layer and further reduce the attenuation therein. Therefore, by using the magnetic shield sheet, wireless communication can be performed better, for example, in the vicinity of the metal surface. Therefore, for example, even an RFID tag close to a metal surface can secure a better communication environment and can provide a shield layer that is thinner (for example, 100 μm) than a conventional product.

Further, the present invention is characterized in that a volume resistivity value is 10 ⁶ Ωcm or more.
According to the present invention, the volume specific resistance value is 10 ⁶ Ωcm or more to ensure insulation, thereby suppressing the generation of eddy currents and not providing electromagnetic shielding properties that reflect radiation noise.

According to the present invention, the shield layer is characterized in that an imaginary part ε _γ ″ of a complex dielectric constant ε _γ in an electromagnetic wave of 13.56 MHz is 500 or less.

  According to the present invention, attenuation due to eddy current can be suppressed as much as possible in other words.

The present invention, in the electromagnetic wave of a specific frequency, the imaginary part of the real part mu _gamma 'is large and complex relative magnetic permeability mu _gamma of the complex relative permeability _μ γ μ γ "is small, the electromagnetic wave of a frequency other than the specific frequency is a imaginary part mu _gamma "is greater and the characteristics of the real part mu _gamma 'is large and complex relative magnetic permeability mu _gamma of the complex relative permeability mu _gamma.

  According to the present invention, a magnetic shield sheet that achieves the above-described magnetic shielding effect for electromagnetic waves of a specific frequency and has an effect of suppressing (absorbing) unnecessary radiation noise at frequencies other than the specific frequency is realized. be able to. For example, it is possible to realize a magnetic shield sheet that functions as a metal-compatible magnetic shield sheet of an RFID tag that uses an electromagnetic wave of 13.56 MHz and that achieves an effect of suppressing (absorbing) unnecessary radiation noise at other frequencies.

The present invention, the specific frequency is other than 1GHz, the imaginary part mu _gamma "a complex relative magnetic permeability real part mu _gamma 'is 7 or more and the complex relative permeability mu _gamma of the complex relative permeability mu _gamma in electromagnetic wave 1GHz value tanδμ divided by the real part of μ γ μ γ _'is equal to or not less than 0.5.

  According to the present invention, a magnetic shield sheet that functions as a metal-compatible magnetic shield sheet of an RFID tag that uses an electromagnetic wave of 13.56 MHz, and that achieves an effect of suppressing (absorbing) unnecessary radiation noise at other frequencies (1 GHz). Can be realized.

In the present invention, the specific frequency is other than 100 MHz to 1 GHz, the real part μ _γ ′ of the complex relative permeability μ _γ at 100 MHz to 1 GHz is 10 or more, and the imaginary part μ _γ ″ of the complex relative permeability μ _γ is the complex ratio. The value tan δμ divided by the real part μ _γ ′ of the magnetic permeability μ _γ is 0.5 or more.

  According to the present invention, it functions as a metal-compatible magnetic shield sheet for an RFID tag that uses an electromagnetic wave of 13.56 MHz, and has an effect of suppressing (absorbing) high unnecessary radiation noise at other wide frequencies (100 MHz to 1 GHz). The magnetic shield sheet to be achieved can be realized.

The present invention is characterized by having flexibility.
According to the present invention, since the magnetic shield sheet has flexibility, it can be freely deformed. Thereby, there are few restrictions on an installation place and it can be used for a wide use. For example, when it is used by being attached to an article, it can be provided following the shape of the article.

Further, the present invention is characterized in that flame retardancy is imparted.
According to the present invention, the magnetic shield sheet has flame retardancy. Electronic devices such as mobile phones may also be required to have flame retardancy for the polymer material that is used in the interior. The magnetic shield sheet can be suitably used as a material constituting such an article or by being attached to the article.

  The present invention is characterized in that thermal conductivity is imparted. An IC substrate or a power supply unit that becomes a heat source may be close to each other, and excellent thermal conductivity leads to suppression of temperature rise and prevention of performance degradation due to exposure to high temperature.

  In addition, the present invention is a magnetic shield sheet characterized in that at least one surface portion is provided with adhesiveness.

  According to the present invention, since the magnetic shield sheet is provided with adhesiveness on at least one surface portion, when attached to an article, the magnetic shield sheet can be attached to the article using the adhesiveness. . Thus, the magnetic shield sheet can be easily attached to the article. Therefore, the work for using the magnetic shield sheet can be facilitated.

The present invention also provides antenna means for transmitting and receiving electromagnetic wave signals;
It is an electronic component characterized by including the magnetic shielding sheet as described in any one of Claims 1-14 provided in the opposite side to a transmission / reception direction with respect to an antenna means.

  According to the present invention, the electronic component is provided with an antenna means and a magnetic shield sheet. The magnetic shield sheet is provided on the side opposite to the transmission / reception direction with respect to the antenna means. As a result, even if the electronic component is provided in the vicinity of the metal member, the energy of the electromagnetic wave is made of metal by disposing the magnetic shield sheet between the metal member and the antenna means. Without being absorbed by the member, it can be suitably transmitted and received by the antenna means. Thus, even if it is provided in the vicinity of a metal member, an electronic component that can be suitably transmitted and received by the antenna means can be realized.

  According to the present invention, by using the magnetic shield sheet, the energy loss of the magnetic field is suppressed to be small, the magnetic field is shielded, and the magnetic field of one region partitioned by the magnetic shield sheet leaks to the other region. Can be prevented. Therefore, it is possible to achieve a magnetic shield sheet that shields electromagnetic waves having a specific frequency without being attenuated.

Further, according to the present invention, by reducing the imaginary part ε _γ ″ of the complex relative dielectric constant ε _γ , it is possible to prevent the occurrence of the above-described problem and prevent a wireless communication from becoming an obstacle. Can be realized.

  Further, according to the present invention, for example, the above-described effect can be achieved with respect to 13.56 MHz mainly used for communication of an RFID tag, and suitable wireless communication using the RFID tag can be achieved.

  Further, according to the present invention, by using the magnetic shield sheet, wireless communication can be satisfactorily performed near the metal surface, for example.

  Further, according to the present invention, by using the magnetic shield sheet, wireless communication can be performed better in the vicinity of, for example, a metal surface. Therefore, for example, even in the case of an RFID tag close to a metal surface, it is possible to secure a better communication environment and to provide a shield layer that is thinner (for example, 100 μm) than a conventional product.

In addition, according to the present invention, by ensuring electrical insulation, generation of eddy current can be suppressed and reflection of radiation noise can be prevented.
Further, according to the present invention, it is possible to suppress attenuation due to eddy current as much as possible.

  In addition, according to the present invention, the above-described magnetic shielding effect is achieved for electromagnetic waves of a specific frequency (for example, 13.56 MHz), and an effect of suppressing (absorbing) unnecessary radiation noise and the like is achieved at frequencies other than the specific frequency. It is possible to realize a magnetic shield sheet having the same.

  Further, according to the present invention, a magnetic shield that functions as a metal-compatible magnetic shield sheet for an RFID tag that uses an electromagnetic wave of 13.56 MHz and achieves an effect of suppressing (absorbing) unnecessary radiation noise at other frequencies (1 GHz). A sheet can be realized.

  In addition, according to the present invention, it functions as a metal-compatible magnetic shield sheet for an RFID tag that uses an electromagnetic wave of 13.56 MHz, and is effective in suppressing (absorbing) high unnecessary radiation noise at other wide frequency ranges (100 MHz to 1 GHz). It is possible to realize a magnetic shield sheet that achieves the above.

  Further, according to the present invention, it is possible to realize a magnetic shield sheet that can be used in a wide range of applications with few restrictions on the installation location.

  According to the present invention, it is possible to realize a magnetic shield sheet that has high thermal conductivity and can be used in the vicinity of a heat source.

  Further, according to the present invention, the magnetic shield sheet can be suitably used as a material constituting the flame retardant article or attached to the article.

  Further, according to the present invention, when used by being attached to an article, it can be attached to the article by using adhesiveness, and the magnetic shield sheet can be easily attached to the article.

  Further, according to the present invention, it is possible to realize an electronic component that can be suitably transmitted and received by the antenna means even when provided in the vicinity of a metal member.

  FIG. 1 is a simplified cross-sectional view showing a magnetic shield sheet 10 according to an embodiment of the present invention. The magnetic shield sheet 10 is a sheet used to shield at least a magnetic field. In the present embodiment, the magnetic shield sheet 10 is used to shield an electromagnetic field formed by, for example, an electromagnetic wave. In other words, in the present embodiment, the magnetic shield sheet 10 is used to shield electromagnetic waves. The electromagnetic wave to be shielded may be, for example, 13.56 MHz or 900 MHz, but is 13.56 MHz in the present embodiment.

  The magnetic shield sheet 10 is configured in a laminate in which a shield layer 11 and an adhesive layer 12 are laminated. The shield layer 11 is a layer for shielding at least a magnetic field, in this embodiment, an electromagnetic field and shielding an electromagnetic wave. The pressure-sensitive adhesive layer 12 is a layer for sticking the magnetic shield sheet 10 including the shield layer 11 to an article using the sticking force.

Shielding layer 11 is made of a real part mu _gamma 'is large and the imaginary part mu _gamma "is less material of the complex relative permeability mu _gamma of the complex relative permeability mu _gamma. Specifically, the complex relative the shield layer 11 The real part μ _γ ′ of the magnetic permeability μ _γ is 30 or more, preferably 60 or more, the imaginary part μ _γ ″ of the complex relative permeability is 6 or less, and the permeability loss term tan δμ (= μ _γ ″). / Μ _γ ′) is 0.2 or less The larger the real part μ _γ ′ of the complex relative permeability μ _γ of the shield layer 11, the more preferable, and the real part μ _γ ′ of the complex relative permeability is just an upper limit. However, the imaginary part μ _γ ″ of the complex relative permeability μ _γ does not exceed the value and cannot exceed 1, so that 1 is the upper limit value. The imaginary part μ _γ ″ of the complex relative permeability μ _γ and the permeability loss term tan δμ are preferably as small as possible and are equal to no lower limit, but cannot be a value less than 0, so 0 is the lower limit value.

The shield layer 11 is made of a material having a small imaginary part ε _γ ″ of the complex relative dielectric constant ε _γ . Specifically, the imaginary part ε _γ ″ of the complex relative dielectric constant ε _γ of the shield layer 11 is 500 or less. is there. The imaginary part ε _γ ″ of the complex relative dielectric constant ε _γ is preferably as small as possible. There is no lower limit, but it cannot be a value less than 0, so 0 is the lower limit.

Specifically, such a shield layer 11 is filled with a flat soft magnetic metal powder using, for example, a non-halogen polymer or a non-halogen mixed material obtained by mixing a non-halogen polymer and another polymer as a binder. It is obtained by dispersing and orienting. In this embodiment, HNBR (hydrogenated NBR) is used, but the present invention is not limited to this. A halogen-based polymer may also be used. The material used to form these shield layers 11 is hereinafter referred to as “the present material”. When this material is compared with a sheet (hereinafter referred to as “conventional material”) in which a binder such as a polymer filled with Sendust, ferrite, and carbonyl iron used in the prior art is compared, the 13.56 MHz electromagnetic wave of this material The real part μ _γ ′ of the complex relative permeability μ _γ is a large value that is equal to or greater than the real part of the complex relative permeability of the conventional material, and the complex relative permeability of the present material in the 13.56 MHz electromagnetic wave. The imaginary part μ _γ ″ of the magnetic permeability μ _γ is a small value that is less than the imaginary part of the complex relative permeability of the conventional material. Also, the imaginary part ε _γ ″ of the complex relative permittivity ε _γ of the present material is It is a small value that is about the same as or lower than the real part of the complex relative dielectric constant, and is a sufficiently low value that does not exhibit conductivity.

Here, the material constants of the present material and the conventional material with respect to electromagnetic waves having a frequency of 1 MHz to 10 GHz are compared. Material constant, the real part of the complex relative permeability μ _γ μ _γ ', the imaginary part mu _gamma of the complex relative permeability mu _gamma ", the real part of the complex relative permittivity ε _γ ε _γ' and the complex relative permittivity epsilon of _gamma Includes an imaginary part ε _γ ″. The measurement was carried out by ring processing (φ7 × φ3) of the material and the coaxial tube method.

  FIG. 2 shows the measurement of a sheet (Example 1) formed to a thickness of 100 μm using, as the material, HNBR filled with 40 vol.% Of JEM powder (Fe—Ni—Cr—Si alloy) manufactured by Mitsubishi Materials. It is a graph which shows a result. FIG. 3 shows the measurement results of a sheet (Example 2) formed to a thickness of 100 μm using a material filled with 50 vol.% Of sendust (Fe—Si—Al alloy) resin-coated on HNBR as the present material. It is a graph. FIG. 4 is a graph showing the measurement results of a sheet (Example 3) having a thickness of 100 μm using a material in which 57 vol.% Of Sendust (Fe—Si—Al alloy) is filled in HNBR as the present material.

  FIG. 5 is a graph showing the measurement results of a sheet (Comparative Example 1) formed to a thickness of 500 μm using a material in which 50 vol.% Of ferrite is filled in chlorinated polyethylene as a conventional material. FIG. 6 is a graph showing measurement results of a sheet (Comparative Example 2) formed to a thickness of 500 μm using a material obtained by filling chlorinated polyethylene with 50 vol.% Of carbonyl iron as a conventional material. FIG. 7 is a graph showing the measurement results of a noise suppression sheet (commercial product; Comparative Example 3) formed to a thickness of 100 μm using Sendust (Fe—Si—Al alloy) as a conventional material.

In each of Examples 1 to 3 shown in FIGS. 2 to 4, and the real part of the complex relative permeability μ γ μ γ _'is 30 or more at 13.56 MHz, and the imaginary part of the complex relative permeability _μ γ μ γ " the real part mu _gamma "'is a value obtained by dividing the permeability loss term _{tanδ (= μ γ" / μ} γ' of the complex relative magnetic permeability mu _gamma) of 0.2 or less. in particular examples 1, 13 The real part μ _γ ′ of the complex relative permeability μ _γ at .56 MHz is 61 and the imaginary part μ _γ ″ of the complex relative permeability μ _γ is 0.05 as tan δ = μ _γ ″ / μ _γ ′.

On the other hand, in Comparative Example 1 and Comparative Example 2 shown in FIGS. 5 and 6, the lower limit frequency is 100 MHz, but the real part μ _γ ′ of the complex relative permeability μ _γ is less than 10, and the frequency is lower than that. The behavior of the real part μ _γ ′ of the complex relative permeability μ _γ does not increase even on the side. In Comparative Example 3 shown in FIG. 7, the real part μ _γ ′ of the complex relative permeability μ _γ at 13.56 MHz is as large as 69, but the imaginary part μ _γ ″ of the complex permeability μ _γ is 33, and the permeability loss. The term tan δ (= μ _γ ″ / μ _γ ′) is as large as 0.48. In each of these Comparative Examples 1 to 3, the magnetic shield sheet in the present invention, specifically, a magnetic shield material for a metal-compatible RFID tag (also called a magnetic yoke) is insufficient.

The difference in performance between Examples 1 to 3 and Comparative Examples 1 to 3 is due to the following reason. The first reason is that each of Examples 1 to 3 differs from Comparative Examples 1 and 2 in that a flat soft magnetic metal (JEM powder or Sendust) is used. The second reason is that in each of Examples 1 to 3, the flat soft magnetic metal shape was not dispersed (distorted, bent, etc.), and was closely dispersed and oriented. This is because it is different from 3. The third reason is that in each of the first to third embodiments, the frequency at which the real part μ _γ ′ of the complex relative permeability μ _γ of the sheet decreases is increased (100 MHz or higher) to be a complex of 13.56 MHz. This is because it is different from Comparative Example 3 in that the imaginary part μ _γ ″ of the relative magnetic permeability μ _γ is lowered (realized by examining the blending method and the metal composition ratio).

In Examples 1 to 3 using the present material in combination with the above three reasons, preferable specific material constants μ _γ ′, μ _γ ″, ε _γ ′, ε _γ ″ can be obtained. The general noise suppression sheet is devoted to 1 and 2 above, and is designed to increase both the real part μ _γ ′ and imaginary part μ _γ ″ of the complex relative permeability μ _γ at each frequency. It clearly distinguishes from the technology, and at a specific frequency (13.56 MHz), the real part μ _γ ′ of the complex relative permeability μ _γ is high but the imaginary part μ _γ ″ is low. . In particular, the results of Example 1 are not easily obtained from conventional materials.

  The pressure-sensitive adhesive layer 12 is made of an adhesive material such as No. Nitto Denko Corporation. It consists of giving 500. By providing this pressure-sensitive adhesive layer 12, adhesiveness is imparted to at least one surface portion of the magnetic shield sheet 10. Such a pressure-sensitive adhesive layer 12 is laminated on one side in the thickness direction of the shield layer 11 to constitute the magnetic shield sheet 10.

  The magnetic shield sheet 10 has an overall thickness dimension T10 of 10 μm or more and 500 μm or less. Thus, the magnetic shield sheet 10 is formed with a small thickness dimension T10, and the shield layer 11 and the pressure-sensitive adhesive layer 12 (hereinafter, these layers are collectively referred to as “each layer 11, 12”) as described above. Made of material and flexible. Therefore, the magnetic shield sheet 10 can be freely deformed.

  In addition, in the magnetic shield sheet 10, for example, a flame retardant or a flame retardant aid is added to at least one of the layers 11 and 12. This imparts flame retardancy to the magnetic shield sheet 10. For example, an electronic device such as a mobile phone may be required to have flame retardancy for an interior polymer material.

  The flame retardant for obtaining such flame retardancy is not particularly limited. For example, phosphorus compounds, boron compounds, bromine flame retardants, zinc flame retardants, nitrogen flame retardants, hydroxide series Flame retardants, metal compound flame retardants, and the like can be used as appropriate. Examples of phosphorus compounds include phosphate esters and titanium phosphate. Examples of the boron compound include zinc borate. Examples of brominated flame retardants include hexabromobenzene, hexabromocyclododecane, decabromobenzyl phenyl ether, decabromobenzyl phenyl oxide, tetrabromobisphenol, ammonium bromide and the like. Examples of the zinc-based flame retardant include zinc carbonate, zinc oxide, and zinc borate. Examples of nitrogen-based flame retardants include triazine compounds, hindered amine compounds, or melamine compounds such as melamine cyanurate and melamine anidine compounds. Examples of the hydroxide flame retardant include magnesium hydroxide and aluminum hydroxide. Examples of the metal compound flame retardant include antimony trioxide, molybdenum oxide, manganese oxide, chromium oxide, and iron oxide.

  In this example, a flame retardant chemical in which decabromodiphenyl oxide and antimony trioxide are mixed, for example, the trade name “Polysafe FCT-5” sold by Ajinomoto Fine Technology Co., Ltd. is used for the polymer material 100. The evaluation of UL94V0 was achieved by adding 30 chemicals (weight ratio). The magnetic shield sheet 10 can be suitably used as a material constituting such an article or mounted on the article. For example, it can be suitably used by being mounted on an article used in a space where it is desired to prevent combustion and generation of gas accompanying it, such as an apparatus in an aircraft, a ship, and a vehicle.

Moreover, the magnetic shield sheet 10 has electrical insulation. Specifically, when each of the layers 11 and 12 is made of the material as described above, the volume specific resistance value of the magnetic shield sheet 10 is 10 ⁶ Ωcm or more. The volume specific resistance value of the shield layer 11 is preferably as large as possible. Therefore, the maximum value that can be realized is the upper limit value of the volume resistivity. In this way, it has a high volume resistivity and electrical insulation.

  The magnetic shield sheet 10 has heat resistance. Specifically, the heat-resistant temperature of the magnetic shield sheet 10 when a crosslinking agent is added to rubber or a resin material is 150 ° C., and the magnetic shield sheet 10 has characteristics until the temperature exceeds at least 150 ° C. Does not change.

  FIG. 8 is a cross-sectional view showing the tag 15 including the magnetic shield sheet 10 in a simplified manner. The tag 15, which is an electronic component, includes an antenna element 16 for transmitting and receiving an electromagnetic wave signal (sometimes referred to as an “electromagnetic wave signal”) and an integrated circuit (IC) 17 electrically connected to the antenna element 16. The magnetic shield sheet 10 is further provided on the tag.

  The antenna element 16 serving as an antenna means is a loop antenna formed in a loop shape along the virtual plane 18. The virtual surface 18 may be a flat surface or a curved surface, but is a flat surface in the present embodiment. The antenna element 16 can transmit at least an electromagnetic wave signal toward one side with respect to the virtual plane 18 and can receive an electromagnetic wave signal coming from one side with respect to the virtual plane 18. Specifically, the antenna element 16 transmits an electromagnetic wave signal in a transmission / reception direction A that is perpendicular to the virtual surface 18 and faces one side of the virtual surface 18, and receives an electromagnetic wave signal that arrives from the transmission / reception direction A. Can do.

  The IC 17 has at least a storage unit and a control unit. Information can be stored in the storage unit, and the control unit can store information in the storage unit or read information from the storage unit. In response to a command represented by the electromagnetic wave signal received by the antenna element 16, the IC 17 stores information in the storage unit or reads information stored in the storage unit and outputs a signal representing the information to the antenna element 16. To give.

  For example, an electromagnetic wave signal representing information to be stored in advance (hereinafter referred to as “main information”) and information instructing to store the main information (hereinafter referred to as “storage command information”) from the information management device, When received by the antenna element 16, an electrical signal representing main information and storage command information is provided from the antenna element 16 to the IC 17. The IC tag 17 causes the control unit to store main information in the storage unit based on the storage command information.

  An electromagnetic wave signal representing information (hereinafter referred to as “transmission command information”) for instructing to transmit information (hereinafter referred to as “storage information”) stored in the storage unit is received by the antenna element 16 from the information management device. Then, an electric signal representing transmission command information is given from the antenna element 16 to the IC 17. As for IC tag 17, a control part reads the information (memory | storage information) memorize | stored in a memory | storage part based on transmission command information, and gives the electrical signal showing the memory | storage information to the antenna element 16. FIG. As a result, an electromagnetic wave signal representing stored information is transmitted from the antenna element 16.

  Thus, the tag 15 is an electronic component that transmits and receives an electromagnetic wave signal using the antenna element 16. The tag 15 may be a battery-driven tag that is driven by a built-in battery, or may be a batteryless tag that returns an electromagnetic wave signal using the energy of the received electromagnetic wave signal.

  The magnetic shield sheet 10 is used so that such a tag 15 can be used in the vicinity of the metal member 19. The magnetic shield sheet 10 is provided on the side opposite to the transmission / reception direction A with respect to the antenna element 16, and thus on the other side with respect to the virtual surface 18. The magnetic shield sheet 10 is provided with the adhesive layer 12 disposed on the opposite side of the antenna element 16 and the IC 17 from the shield layer 11.

  Although simplified in FIG. 8, the antenna element 16 and the IC 17 are packaged by being mounted on a flexible tape, and the magnetic shield sheet 10 is attached thereto. Are stacked. In attaching the magnetic shield sheet 10 to the package on which the antenna element 16 and the IC 17 are mounted, for example, an adhesive is used.

  The tag 15 including the magnetic shield sheet 10 is used by being mounted on, for example, a metal member 19. The tag 15 is provided so that the magnetic shield sheet 10 is disposed closer to the metal member 19 than the antenna element 16 so that the magnetic shield sheet 10 is interposed between the antenna element 16 and the metal member 19. It is done. The pressure-sensitive adhesive layer 12 of the magnetic shield sheet 10 faces the metal member 19, and the pressure-sensitive adhesive layer 12 is attached and attached to the metal member 19.

  The magnetic shield sheet 10 has the shield layer 11 as described above. The electromagnetic field is shielded by the shield layer 11 and the electromagnetic field of one of the two regions partitioned by the magnetic shield sheet 10 is used. Can be prevented from leaking to the other region, and the energy of the electromagnetic field in one region can be prevented from being transmitted to the other region. The electromagnetic field that can be shielded includes, of course, an electromagnetic field formed by an electromagnetic wave, and therefore the electromagnetic wave that forms this electromagnetic field can be shielded.

Specifically, since the shield layer 11 is made of a material having a large real part μ _γ ′ of the complex relative permeability μ _γ , when the shield layer 11 is provided in a magnetic field, for example, transmission from the antenna element 16 in FIG. As shown in the example of the electric field generated by the electromagnetic wave, the magnetic field lines 20 concentrate on the shield layer 11 and do not pass through or difficult to pass through the metal member 19 existing in the vicinity. Thus, the magnetic shield sheet 10 is used to shield the magnetic field, and the magnetic field in the region where the antenna element 16 which is one region partitioned by the magnetic shield sheet 10 is provided is the metal member which is the other region. It can prevent leaking to the area | region in which 19 is provided.

  When the antenna element 16 is provided at a position similar to the position shown in FIG. 8, if the magnetic shield sheet 10 is not provided, the magnetic field lines of the magnetic field due to the transmitted electromagnetic waves are, for example, as shown by the imaginary line 21 in FIG. In addition, it passes through the metal member 19. When the magnetic lines of force pass through the metal member 19 in this way, an eddy current is generated in the metal member 19 with the change of the magnetic field, and heat is generated. Thus, the energy of the magnetic field is converted into heat energy, and the energy of the magnetic field is absorbed. On the other hand, by shielding the magnetic field using the magnetic shield sheet 10, the energy of the magnetic field opposite to the metal member 19 with respect to the magnetic shield sheet 10 is prevented from being absorbed by the metal member 19. Can be removed. Therefore, the magnetic member 19 absorbs the energy of the magnetic field formed by the electromagnetic wave transmitted and received by the antenna element 16 on the side of the antenna element 16 that is opposite to the metal member 19 with respect to the magnetic shield sheet 10. It is prevented.

Further, since the shield layer 11 is made of a material having a small imaginary part μ _γ ″ of the complex relative permeability μ _γ , energy loss in the shield layer 11 accompanying the passage of the magnetic flux even though the shield layer 11 passes through the shield layer 11. As a result, even if the magnetic lines of force pass through the shield layer 11 in a concentrated manner, it is possible to prevent the shield layer 11 itself from losing the energy of the magnetic field. 11 prevents absorption of magnetic field energy by the metallic member 19 existing in the vicinity, suppresses loss by itself, and minimizes attenuation of magnetic field energy as much as possible.

  By interposing such a magnetic shield sheet 10 between the antenna element 16 and the metal member 19 as described above, the energy of the electromagnetic field due to the electromagnetic wave signal transmitted and received by the antenna element 16 is made of metal. Absorption by the member 19 is prevented. In addition, the magnetic shield sheet 10 itself for preventing the influence of the metal member 19 has a small magnetic loss and dielectric loss. Therefore, the antenna element 16 can transmit and receive a long distance suitably. Accordingly, even when the tag 15 is provided in the vicinity of the metal member 19, information can be wirelessly communicated between the information management device and the tag 15, and the electromagnetic wave signal transmitted from the information management device can be transmitted. The information to be represented can be stored in the tag 15, and the information stored in the tag 15 can be read out by the information management device.

  Thus, by using the magnetic shield sheet 10, an electronic component using the antenna element 16 is attached to the metal member 19, for example, and is provided in the vicinity of the metal member 19. An electronic component can be used in a state where transmission and reception can be realized. Therefore, for example, the tag 15 as described above is attached to a beverage 22 containing a beverage in a metal container which is a metal member 19 as shown in FIG. Can be used. Further, the tag 15 is incorporated in an electronic device 23 such as a mobile phone device in which many metal members 19 such as a substrate as shown in FIG. 10 are used, for example, for the purpose of merchandise management or user authentication. Can be used. Thus, the wide use of the tag 15 can be secured, and the highly convenient tag 15 can be realized.

  As shown in FIG. 2, according to the present invention, it functions as an RFID metal-compatible magnetic shield sheet at 13.56 MHz, and has an effect of suppressing (absorbing) unnecessary radiation noise and the like at other frequencies (1 GHz).

In the present invention, the real part μ _γ ′ of the complex relative permeability μ _γ at 100 MHz and 1 GHz is 10 or more, and the imaginary part μ _γ ″ of the complex relative permeability μ _γ is 0 as tan δ = μ _γ ″ / μ _γ ′. It is 5 or more.

According to the present invention, it functions as an RFID metal-compatible magnetic shield sheet at 13.56 MHz, and has a high suppression effect (absorption) of unwanted radiation noise at other wide frequency ranges (100 MHz to 1 GHz). Specifically, the real part μ _γ ′ of the complex relative permeability μ _γ at 100 MHz of Example 1 is 35, the imaginary part μ _γ ″ is 19, and tan δ = 0.54, and the complex relative permeability μ _{γ at 1} GHz. The real part μ _γ ′ is 12.4, the imaginary part μ _γ ″ is 14, and tan δ = 1.13.

  Moreover, since the magnetic shield sheet 10 has flexibility as described above, it can be freely deformed. Thereby, there are few restrictions on an installation place and it can be used for a wide use. For example, when it is used by being attached to an article, it can be provided following the shape of the article. For example, as shown in FIG. 9, it can be attached to the surface of a cylindrical container (corresponding to the metal member 19) in accordance with the shape of the surface. Can be reduced, and the mounting operation can be facilitated. When used as the tag 15, the material of the other configuration can be appropriately selected so that the tag 15 has a flexible configuration as a whole, so that the tag 15 can be attached following the cylindrical surface. It becomes like this.

  In addition, since the magnetic shield sheet 10 is provided with adhesiveness on at least one surface portion, when attached to an article, the magnetic shield sheet 10 can be attached to the article using the adhesiveness. Thus, the magnetic shield sheet 10 can be easily attached to the article. Therefore, the operation | work for utilizing the magnetic shielding sheet 10 and an electronic component provided with it can be made easy.

The magnetic shield sheet 10 has heat resistance and electrical insulation as described above. With regard to heat resistance, it may be used at 120 ° C. or 130 ° C. particularly in automobile applications, and it is required that it can be used without degradation of performance even at that temperature. The heat resistance can be realized by adding a crosslinking material and crosslinking the binder. In this case, it is of course possible to realize heat resistance at a higher temperature (for example, 200 ° C.) by appropriately combining the kind of the binder used and the crosslinking material. Further, by covering the soft magnetic metal powder with an organic and inorganic insulating material as a binder, the electrical insulation of the magnetic shield sheet 10 can be improved without direct contact with the soft magnetic metal dispersed in the sheet. Can do. If electricity is conducted, an eddy current is generated in itself and the magnetic energy is attenuated. Furthermore, since the circuit and the plating casing (ground) are arranged in close proximity, if the magnetic shield sheet 10 has conductivity, it will be conducted through it, which will hinder the operation. In order to prevent these, the magnetic shield sheet 10 achieves a volume resistivity of 10 ⁶ Ωcm or more.

  The above-described embodiment is merely an example of the present invention, and the configuration can be changed. For example, the stacked configuration may be changed. Specifically, as shown by a virtual line in FIG. 1, the second pressure-sensitive adhesive layer 30 may be provided on the side opposite to the pressure-sensitive adhesive layer 12 with respect to the shield layer 11. When such a magnetic shield sheet 10 is used for the tag 15, when the magnetic shield sheet 10 is attached to a package on which the antenna element 16 and the IC 17 are mounted to configure the tag 15, a separate adhesive is used. Even if it does not use, it becomes possible to stick using the second adhesive material layer 30, and the work becomes easy. Thus, the installation and mounting work of the magnetic shield sheet 10 can be facilitated such that the magnetic shield sheet 10 can be easily incorporated into an electronic component.

  Further, the adhesive layer 12 may be used for attaching the magnetic shield sheet 10 to a package on which the antenna element 16 and the IC 17 are mounted when the adhesive layer 12 is incorporated into the tag 15. In this case, as long as the second pressure-sensitive adhesive layer 30 is provided, the second pressure-sensitive adhesive layer 30 may be attached to the article, or the second pressure-sensitive adhesive layer 30 is not provided. For example, it may be attached to the article using an adhesive. Moreover, the structure which adds an adhesive to the shield layer 11, and provides adhesiveness to the surface may be sufficient, without forming the adhesive layers 12 and 30.

  Further, the means for imparting flame retardancy may be another configuration instead of the configuration in which the flame retardant is added. Further, the minimum performance required for the magnetic shield sheet 10 is a performance for shielding a magnetic field, and the other performance is not an essential requirement and may not have a configuration.

The use of the magnetic shield sheet 10 is not limited to electronic components, and can be widely used in applications where there is a requirement to shield at least a magnetic field. Of course, the electronic component is not limited to the tag 15. Further, the tag 15 may be used for an article having a metal member 19 other than the aforementioned article. For example, the electronic device is not limited to a mobile phone device, but may be a PDA, a notebook personal computer, or the like.
Configuration changes other than these examples may be used.

It is sectional drawing which simplifies and shows the magnetic shielding sheet 10 of one Embodiment of this invention. 4 is a graph showing measurement results of material constants (ε _γ ′, ε _γ ″, μ _γ ′, μ _γ ″) of Example 1. 10 is a graph showing measurement results of material constants (ε _γ ′, ε _γ ″, μ _γ ′, μ _γ ″) of Example 2. 10 is a graph showing measurement results of material constants (ε _γ ′, ε _γ ″, μ _γ ′, μ _γ ″) of Example 3. 6 is a graph showing measurement results of material constants (ε _γ ′, ε _γ ″, μ _γ ′, μ _γ ″) of Comparative Example 1. 6 is a graph showing measurement results of material constants (ε _γ ′, ε _γ ″, μ _γ ′, μ _γ ″) of Comparative Example 2. 14 is a graph showing measurement results of material constants (ε _γ ′, ε _γ ″, μ _γ ′, μ _γ ″) of Comparative Example 3. It is sectional drawing which simplifies and shows the tag 15 provided with the magnetic shielding sheet 10. FIG. It is a perspective view which shows the beverage 22 with which the tag 15 is mounted | worn. It is a perspective view which shows the electronic apparatus with which the tag 15 is incorporated. It is sectional drawing which simplifies and shows the tag 1 which is a prior art. It is sectional drawing which simplifies and shows the tag 1A which is another prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic shield sheet 11 Shield layer 12 Adhesive layer 15 Tag 16 Antenna element 17 IC
19 Metal Member 20 Magnetic Field Line 22 Beverage 23 Electronic Device

The present invention is characterized in that the surface resistivity is 10 ⁶ Ω or more.
According to the present invention, the surface resistivity is 10 ⁶ Ω or more to ensure insulation, thereby suppressing the generation of eddy currents and not providing electromagnetic shielding properties that reflect radiation noise.

Moreover, the magnetic shield sheet 10 has electrical insulation. Specifically, the surface resistivity (ASTM-D257) of the magnetic shield sheet 10 is 10 ⁶ Ω or more because each of the layers 11 and 12 is made of the material as described above. The surface resistivity (ASTM-D257) of the shield layer 11 is preferably as large as possible. Therefore, the maximum value that can be realized is the upper limit value of the surface resistivity (ASTM-D257). Thus, it has a high surface resistivity (ASTM-D257) and has electrical insulation.

The magnetic shield sheet 10 has heat resistance and electrical insulation as described above. With regard to heat resistance, it may be used at 120 ° C. or 130 ° C. particularly in automobile applications, and it is required that it can be used without degradation of performance even at that temperature. The heat resistance can be realized by adding a crosslinking material and crosslinking the binder. In this case, it is of course possible to realize heat resistance at a higher temperature (for example, 200 ° C.) by appropriately combining the kind of the binder used and the crosslinking material. Further, by covering the soft magnetic metal powder with an organic and inorganic insulating material as a binder, the electrical insulation of the magnetic shield sheet 10 can be improved without direct contact with the soft magnetic metal dispersed in the sheet. Can do. If electricity is conducted, an eddy current is generated in itself and the magnetic energy is attenuated. Furthermore, since the circuit and the plating casing (ground) are arranged in close proximity, if the magnetic shield sheet 10 has conductivity, it will be conducted through it, which will hinder the operation. In order to prevent these, the magnetic shield sheet 10 achieves a surface resistivity (ASTM-D257) of 10 ⁶ Ω or more.

  The present invention relates to a magnetic shield sheet for shielding a magnetic field and an electronic component using the same.

  As RFID (Radio Frequency Identification), there are an RFID tag and a non-contact IC card. In addition to this, the practical use of a mobile terminal having an RFID function is being studied. There are the following two types of communication means for RFID tags. One is an electromagnetic induction method in which power is supplied by communication between a coil and a coil to communicate, and a frequency of 135 kHz or 13.56 MHz is used. The other one is a radio wave system, and frequencies of 433 MHz, 900 MHz, 2.8 GHz, and 5.8 GHz are used. The frequency mainly used for the non-contact IC card is 4.91 MHz for the contact type and 13.56 MHz for the proximity type. By using the 13.56 MHz band, wireless communication within a range of several centimeters to 1 m is possible, and practical use has been attempted mainly using this band.

  FIG. 11 is a cross-sectional view schematically showing a tag 1 which is a conventional technique. The tag 1 includes an antenna 2 that transmits and receives an electromagnetic wave signal, and an integrated circuit (IC) 3 that processes a signal transmitted and received by the antenna 2. When the tag 1 receives the request signal from the reading device, the tag 1 transmits the information stored in the IC 3, in other words, the information held in the tag 1 can be read by the reading device. Configured. This tag 1 is provided by being attached to a product, for example, and is used for product management such as prevention of product theft and grasping of inventory status.

  When the tag 1 is used by being attached to a metal product, and the metal member 4 is present in the vicinity of the antenna 2, the magnetic field lines of the magnetic field formed by the electromagnetic wave signal transmitted and received by the antenna 2 are made of the metal member. 4, and an eddy current is generated in the metal member 4. When eddy currents are generated in this way, the energy of electromagnetic waves is converted into heat energy and absorbed. If energy is absorbed in this way, the electromagnetic wave signal is greatly attenuated and cannot be transmitted or received. Therefore, such a tag 1 cannot be used in the vicinity of the metal member 4.

  FIG. 12 is a cross-sectional view schematically showing a tag 1A which is another conventional technique. The tag 1A shown in FIG. 12 is similar to the tag 1 of FIG. 11, and the same reference numerals are given to corresponding portions, and only different configurations will be described. In order to solve the problem of the tag 1 of FIG. 11, the tag 1 </ b> A of FIG. 12 includes a magnetic absorption plate 7 provided so as to be disposed between the member 4 that is an article to be attached and the antenna 2. Configured as follows. The magnetic absorption plate 7 is made of a material having a high magnetic permeability such as sendust, ferrite and carbonyl iron, and thus a material having a high complex relative permeability.

  The complex relative permeability has a real part and an imaginary part, and the complex relative permeability increases as the real part increases. In other words, a material having a high complex relative permeability has a high real part in the complex relative permeability. When a material having a high real part in the complex relative permeability exists in the magnetic field, the magnetic field lines are concentrated in the member. Therefore, by providing the magnetic absorption plate 7, the magnetic field is prevented from leaking, and information can be read even if the metal member 4 is present in the vicinity. Such a tag 1A is disclosed in, for example, Patent Document 1.

JP 2000-113142 A

  In the tag 1A shown in FIG. 12, the magnetic absorption plate 7 made of a material having a high complex relative permeability is provided to prevent the magnetic field from leaking. Sendust, ferrite, carbonyl iron and the like are used as materials having a high complex relative permeability. When these materials are filled in a binder such as a polymer, the real part in the complex relative permeability of the sheet as an insulating sheet can be increased, the magnetic field can be shielded, and magnetic field leakage can be prevented. The imaginary part of the complex relative permeability is also high. This is because the real part of the complex relative permeability at a specific frequency is designed to be high, but at the same time, the imaginary part of the complex relative permeability is not designed to be low. A material having a high imaginary part of complex relative permeability loses energy of the magnetic field, specifically, converts the magnetic field energy into thermal energy and absorbs it. If a magnetic absorption plate made of a material having a high complex relative permeability is used as described above, loss of electromagnetic wave energy in the magnetic absorption plate is caused even if loss in the metal member 4 can be prevented. There's a problem. In actual use, not only the use of a magnetic shield material but also the influence of the metal surface is avoided by widening the distance between the antennas from the metal surface as much as possible (1-2 mm). In other words, when these materials are used, even if they are used as a magnetic shield material for RFID tags (also called a magnetic yoke), a considerable thickness is required including the space.

  Accordingly, an object of the present invention is to provide a magnetic shield sheet that can shield a magnetic field without losing the energy of the magnetic field and that is thinner than the conventional one, and an electronic component using the same. A mobile terminal (for example, a mobile phone) having an RFID function is shielded on the inner surface of the casing. In addition, since the space for the antenna is very narrow and the environment is easily affected by the metal surface due to the thinning, a high-performance magnetic shield sheet corresponding to this is provided. Further, by using this sheet, an unprecedented thin RFID tag antenna can be installed in a mobile terminal, and these thin systems (electronic parts) including a magnetic shield sheet are provided.

  Furthermore, in the present invention, by having a magnetic shielding property with respect to the above-mentioned specific frequency, it contributes to be useful as a metal-compatible RFID tag, and at other frequencies (for example, 100 MHz to 6 GHz), the real part of the complex relative permeability and An imaginary part becomes high, and for example, a magnetic shield sheet that also serves to suppress unwanted radiation noise and the like and an electronic component using the same are provided. That is, the present invention provides an intelligent sheet that suitably converts and functions the magnetic permeability and dielectric constant at two or more frequencies.

In the present invention, the real part μ ′ of the complex relative permeability μ in an electromagnetic wave having a frequency of 13.56 MHz is 30 or more, and the imaginary part μ ″ of the complex relative permeability μ is 6 or less,
A magnetic shield comprising a shield layer having a real part μ ′ of a complex relative permeability μ of 7 or more and an imaginary part μ ″ of a complex relative permeability μ of 7 or more in an electromagnetic wave having a frequency of 100 MHz to 1 GHz. It is a sheet.

According to the present invention, the magnetic shield sheet is provided with a shield layer. In the shield layer, the larger the real part μ ′ of the complex relative permeability μ is, the more the magnetic lines of force (magnetic flux) pass. The smaller the real part μ ′ of the complex relative permeability μ is, the more the magnetic line of force (magnetic flux) is. It becomes composition that is hard to pass. The shield layer is configured such that the larger the imaginary part μ ″ of the complex relative permeability μ, the more the magnetic field energy is lost, and the smaller the imaginary part μ ″ of the complex relative permeability μ, the less likely the magnetic field energy is lost.

With respect to the electromagnetic wave of 13.56 MHz, the shield layer has a real part μ ′ of the complex relative permeability μ as large as 30 or more and an imaginary part μ ″ of the complex relative permeability μ as small as 6 or less. With respect to a magnetic field formed by an electromagnetic wave of 56 MHz, it is possible to make it easy for magnetic lines of force (magnetic flux) to pass through the shield layer and to prevent loss of magnetic field energy on the magnetic shield sheet. By using it, the 13.56 MHz electromagnetic wave can be shielded so as not to leak while suppressing the loss of energy.

Furthermore, the shield layer has an actual part μ ′ of the complex relative permeability μ of 7 or more and is never too small for an electromagnetic wave of 100 MHz to 1 GHz, and an imaginary part μ ″ of the complex relative permeability μ is 7 or more. This allows the magnetic field lines (magnetic flux) to pass through the shield layer with respect to the magnetic field formed by the electromagnetic waves of 100 MHz to 1 GHz, thereby losing the energy of the magnetic field. An electromagnetic wave of 100 MHz to 1 GHz can be absorbed.

Such a magnetic shield sheet is provided between an antenna and a metal member when, for example, when a wireless member uses 13.56 MHz electromagnetic waves and a metal member exists in the vicinity of the antenna. Used. This prevents the 13.56 MHz electromagnetic wave from leaking to the metal member side, and prevents the 13.56 MHz electromagnetic wave energy from being absorbed by the metal object. In addition, the magnetic shield sheet itself has a reduced magnetic loss. Therefore, even in a state where a metal member is present in the vicinity of the antenna, wireless communication can be suitably performed using an electromagnetic wave of 13.56 MHz. The electromagnetic wave of 13.56 MHz is mainly used for communication of an RFID (Radio Frequency IDentification) tag, for example. Therefore, communication can be suitably performed using the RFID tag.

Moreover, since the magnetic shield sheet can absorb electromagnetic waves of 100 MHz to 1 GHz, unnecessary radiation noise and the like can be suppressed with respect to electromagnetic waves of 100 MHz to 1 GHz. Therefore, the loss can be suppressed small with respect to the 13.56 MHz electromagnetic wave used for communication, and the unnecessary 100 MHz to 1 GHz electromagnetic wave can be absorbed, and communication can be performed more suitably.

In the present invention, the shield layer is made of a material in which a flat soft magnetic metal powder is mixed with a polymer,
The soft magnetic metal powder is characterized in that it is densely dispersed in an oriented state without causing shape deformation including distortion and bending .

According to the present invention, the flat soft magnetic metal powder is densely dispersed in the polymer in an oriented state without causing shape deformation including distortion and bending, thereby forming a shield layer. With such a configuration, with respect to an electromagnetic wave of 13.56 MHz, the real part μ ′ of the complex relative permeability μ is as large as 30 or more and the imaginary part μ ″ of the complex relative permeability μ is as small as 6 or less. However, for electromagnetic waves of 100 MHz to 1 GHz, the real part μ ′ of the complex relative permeability μ is never too small as 7 and the imaginary part μ ″ of the complex relative permeability μ is as large as 7 or more. The shield layer can be formed. Therefore, a magnetic shield sheet that achieves the above-described excellent effect can be realized.

According to the present invention, the shield layer is characterized in that an imaginary part ε ″ of a complex relative dielectric constant ε in an electromagnetic wave having a frequency of 13.56 MHz is 500 or less.

According to the present invention, for an electromagnetic wave of 13.56 MHz, the imaginary part ε ″ of the complex dielectric constant ε is as small as 500 or less. The imaginary part ε ″ of the complex dielectric constant ε is the conductivity of the shield layer. If the imaginary part ε ″ of the complex relative permittivity ε is large, conductivity is manifested. When conductivity is manifested, eddy currents are generated when the magnetic flux passes through the shield layer. When the eddy current is generated in this way, for example, when used for improving the wireless communication environment, the magnetic communication is hindered by attenuating the magnetic flux. By reducing the portion ε ″, it is possible to prevent the occurrence of the above-described problem and prevent a wireless communication failure, thereby realizing a suitable wireless communication environment.

The present invention, the volume resistivity is equal to or is more than 10 ⁶ Ω cm.
According to the present invention, by ensuring that the volume resistivity value is 10 ⁶ Ωcm or more and ensuring insulation, generation of eddy currents is suppressed, and electromagnetic wave shielding properties that reflect radiation noise are not imparted.

The present invention is characterized by having flexibility.
According to the present invention, since the magnetic shield sheet has flexibility, it can be freely deformed. Thereby, there are few restrictions on an installation place and it can be used for a wide use. For example, when it is used by being attached to an article, it can be provided following the shape of the article.

The present invention is characterized in that thermal conductivity is imparted. An IC substrate or a power supply unit that becomes a heat source may be close to each other, and excellent thermal conductivity leads to suppression of temperature rise and prevention of performance degradation due to exposure to high temperature.

Further, the present invention is characterized in that flame retardancy is imparted.
According to the present invention, the magnetic shield sheet has flame retardancy. Electronic devices such as mobile phones may also be required to have flame retardancy for the polymer material that is used in the interior. The magnetic shield sheet can be suitably used as a material constituting such an article or by being attached to the article.

  In addition, the present invention is a magnetic shield sheet characterized in that at least one surface portion is provided with adhesiveness.

  According to the present invention, since the magnetic shield sheet is provided with adhesiveness on at least one surface portion, when attached to an article, the magnetic shield sheet can be attached to the article using the adhesiveness. . Thus, the magnetic shield sheet can be easily attached to the article. Therefore, the work for using the magnetic shield sheet can be facilitated.

The present invention also provides antenna means for transmitting and receiving electromagnetic wave signals;
It is an electronic component characterized by including the magnetic shielding sheet as described in any one of Claims 1-8 provided in the opposite side to a transmission / reception direction with respect to an antenna means.

  According to the present invention, the electronic component is provided with an antenna means and a magnetic shield sheet. The magnetic shield sheet is provided on the side opposite to the transmission / reception direction with respect to the antenna means. As a result, even if the electronic component is provided in the vicinity of the metal member, the energy of the electromagnetic wave is made of metal by disposing the magnetic shield sheet between the metal member and the antenna means. Without being absorbed by the member, it can be suitably transmitted and received by the antenna means. Thus, even if it is provided in the vicinity of a metal member, an electronic component that can be suitably transmitted and received by the antenna means can be realized.

According to the present invention, by using a magnetic shield sheet, 13.56 MHz electromagnetic waves can be shielded without being attenuated. Therefore, when performing wireless communication using an electromagnetic wave of 13.56 MHz, even if a metal member exists in the vicinity of the antenna, wireless communication can be suitably performed. The 13.56 MHz electromagnetic wave is, for example, RFID (
It is mainly used for communication of (Radio Frequency IDentification) tags, and communication can be suitably performed using RFID tags. Furthermore, by using a magnetic shield sheet, electromagnetic waves of 100 MHz to 1 GHz can be absorbed, so unnecessary radiation noise and the like can be suppressed with respect to electromagnetic waves of 100 MHz to 1 GHz. Therefore, the loss can be suppressed small with respect to the 13.56 MHz electromagnetic wave used for communication, and the unnecessary 100 MHz to 1 GHz electromagnetic wave can be absorbed, and communication can be performed more suitably.

Further, according to the present invention, the flat soft magnetic metal powder is densely dispersed in the polymer in an oriented state without causing shape deformation including distortion and bending, thereby forming a shield layer. Therefore, a magnetic shield sheet that achieves the above-described excellent effect can be realized.

Further, according to the present invention, the imaginary part ε ″ of the complex relative permittivity ε is small, and an eddy current is generated when the magnetic flux passes through the shield layer. Therefore, it is possible to prevent the wireless communication from becoming an obstacle and to realize a preferable wireless communication environment.

In addition, according to the present invention, by ensuring insulation with a volume resistivity value of 10 ⁶ Ωcm or more, generation of eddy currents is suppressed, and electromagnetic wave shielding properties that reflect radiation noise are not imparted. Thus, a suitable magnetic shield sheet can be realized.

  Further, according to the present invention, it is possible to realize a magnetic shield sheet that can be used in a wide range of applications with few restrictions on installation locations.

  According to the present invention, it is possible to realize a magnetic shield sheet that has high thermal conductivity and can be used in the vicinity of a heat source.

  Further, according to the present invention, the magnetic shield sheet can be suitably used as a material constituting the flame retardant article or attached to the article.

  Moreover, according to the present invention, when used by being attached to an article, it can be attached to the article using the adhesiveness, and the magnetic shield sheet can be easily attached to the article.

  In addition, according to the present invention, it is possible to realize an electronic component that can be suitably transmitted and received by the antenna means even when provided in the vicinity of a metal member.

  FIG. 1 is a simplified cross-sectional view showing a magnetic shield sheet 10 according to an embodiment of the present invention. The magnetic shield sheet 10 is a sheet used to shield at least a magnetic field. In the present embodiment, the magnetic shield sheet 10 is used to shield an electromagnetic field formed by, for example, an electromagnetic wave. In other words, in the present embodiment, the magnetic shield sheet 10 is used to shield electromagnetic waves. The electromagnetic wave to be shielded may be, for example, 13.56 MHz or 900 MHz, but is 13.56 MHz in the present embodiment.

  The magnetic shield sheet 10 is configured in a laminate in which a shield layer 11 and an adhesive layer 12 are laminated. The shield layer 11 is a layer for shielding at least a magnetic field, in this embodiment, an electromagnetic field and shielding an electromagnetic wave. The pressure-sensitive adhesive layer 12 is a layer for sticking the magnetic shield sheet 10 including the shield layer 11 to an article using the sticking force.

Shielding layer 11, the real part of the complex relative permeability mu mu 'is made of a large and the imaginary part mu "is less material of the complex relative permeability mu. Specifically, the real of the complex relative permeability mu of the shield layer 11 The part μ ′ is 30 or more, preferably 60 or more, the imaginary part μ ″ of the complex relative permeability is 6 or less, and the permeability loss term tan δ ( = μ ″ / μ ′ ) is 0. .2 or less. the real part of the complex relative permeability mu of the shield layer 11 mu 'is not preferable larger. imaginary part of the complex relative permeability mu mu "and permeability loss term tan δ (= μ" / mu ') is smaller preferably, the lower limit is equal to no, it is not a name that can be a value of 0 or less.

The shield layer 11 is made of a material having a small imaginary part ε ″ of the complex relative dielectric constant ε . Specifically, the imaginary part ε ″ of the complex relative dielectric constant ε of the shield layer 11 is 500 or less. Imaginary part of the complex relative permittivity epsilon epsilon "is smaller preferably, but just the lower limit is not, it is not a name that can be a value of 0 or less.

Specifically, such a shield layer 11 is filled with a flat soft magnetic metal powder using, for example, a non-halogen polymer or a non-halogen mixed material obtained by mixing a non-halogen polymer and another polymer as a binder. It is obtained by dispersing and orienting. In this embodiment, HNBR (hydrogenated NBR) is used, but the present invention is not limited to this. A halogen-based polymer may also be used. The material used to form these shield layers 11 is hereinafter referred to as “the present material”. When this material is compared with a sheet (hereinafter referred to as “conventional material”) in which a binder such as a polymer filled with Sendust, ferrite, and carbonyl iron used in the prior art is compared, the 13.56 MHz electromagnetic wave of this material The real part μ ′ of the complex relative permeability μ is a large value equal to or higher than the real part of the complex relative permeability of the conventional material, and the complex relative permeability μ of the present material in an electromagnetic wave of 13.56 MHz. The imaginary part μ ″ of the conventional material is a small value that is less than the imaginary part of the complex relative permeability of the conventional material. Also , the imaginary part ε ″ of the complex relative dielectric constant ε of the present material is the actual complex relative dielectric constant of the conventional material. It is a small value that is the same as or less than that of the part, and is a sufficiently low value that does not exhibit conductivity.

Here, the material constants of the present material and the conventional material with respect to electromagnetic waves having a frequency of 1 MHz to 10 GHz are compared. The material constant includes a real part μ ′ of the complex relative permeability μ, an imaginary part μ ″ of the complex relative permeability μ, a real part ε ′ of the complex relative permittivity ε, and an imaginary part ε ″ of the complex relative permittivity ε . The measurement was carried out by ring processing (φ7 × φ3) of the material and the coaxial tube method.

  FIG. 2 shows the measurement of a sheet (Example 1) formed to a thickness of 100 μm using, as the material, HNBR filled with 40 vol.% Of JEM powder (Fe—Ni—Cr—Si alloy) manufactured by Mitsubishi Materials. It is a graph which shows a result. FIG. 3 shows the measurement results of a sheet (Example 2) formed to a thickness of 100 μm using a material filled with 50 vol.% Of sendust (Fe—Si—Al alloy) resin-coated on HNBR as the present material. It is a graph. FIG. 4 is a graph showing the measurement results of a sheet (Example 3) having a thickness of 100 μm using a material in which 57 vol.% Of Sendust (Fe—Si—Al alloy) is filled in HNBR as the present material.

  FIG. 5 is a graph showing the measurement results of a sheet (Comparative Example 1) formed to a thickness of 500 μm using a material in which 50 vol.% Of ferrite is filled in chlorinated polyethylene as a conventional material. FIG. 6 is a graph showing measurement results of a sheet (Comparative Example 2) formed to a thickness of 500 μm using a material obtained by filling chlorinated polyethylene with 50 vol.% Of carbonyl iron as a conventional material. FIG. 7 is a graph showing the measurement results of a noise suppression sheet (commercial product; Comparative Example 3) formed to a thickness of 100 μm using Sendust (Fe—Si—Al alloy) as a conventional material.

2 to 4, the real part μ ′ of the complex relative permeability μ at 13.56 MHz is 30 or more, and the imaginary part μ ″ of the complex relative permeability μ is the complex relative permeability. The permeability loss term tan δ (= μ ″ / μ ′ ), which is a value divided by the real part μ ′ of the magnetic permeability μ, is 0.2 or less. Particularly, in Example 1, the real part μ ′ of the complex relative permeability μ at 61.56 MHz is 61 and the imaginary part μ ″ of the complex relative permeability μ is 3, and tan δ ( = μ ” / μ ′) is 0. .05.

On the other hand, in Comparative Example 1 and Comparative Example 2 shown in FIGS. 5 and 6, the lower limit frequency is 100 MHz, but the real part μ ′ of the complex relative permeability μ is less than 10, and lower than that. However, the behavior is shown in which the real part μ ′ of the complex relative permeability μ does not increase. In Comparative Example 3 shown in FIG. 7, the real part μ ′ of the complex relative permeability μ at 13.56 MHz is as large as 69, but the imaginary part μ ″ of the complex permeability μ is 33 and the permeability loss term tan δ ( = Μ ″ / μ ′ ) is a large value of 0.48. In each of these Comparative Examples 1 to 3, the magnetic shield sheet in the present invention, specifically, a magnetic shield material for a metal-compatible RFID tag (also called a magnetic yoke) is insufficient.

The difference in performance between Examples 1 to 3 and Comparative Examples 1 to 3 is due to the following reason. The first reason is that each of Examples 1 to 3 differs from Comparative Examples 1 and 2 in that a flat soft magnetic metal (JEM powder or Sendust) is used. The second reason is that in each of Examples 1 to 3, the flat soft magnetic metal shape was not dispersed (distorted, bent, etc.), and was closely dispersed and oriented. This is because it is different from 3. The third reason is that in each of the first to third embodiments, the frequency at which the real part μ ′ of the complex relative permeability μ of the sheet decreases is increased (100 MHz or more) to increase the complex relative permeability of 13.56 MHz. This is because it is different from Comparative Example 3 in that the imaginary part μ ″ of the magnetic susceptibility μ is lowered (realized by examining the blending method and the metal composition ratio).

In each of Examples 1 to 3 using the present material in combination of the above three reasons, preferable specific material constants μ ′, μ ″, ε ′, ε ″ can be obtained. The general noise suppression sheet is devoted to 1 and 2 above, and is designed to increase both the real part μ ′ and the imaginary part μ ″ of the complex relative permeability μ at each frequency. In particular, at a specific frequency (13.56 MHz) , the real part μ ′ of the complex relative permeability μ is high but the imaginary part μ ″ is low. In particular, the results of Example 1 are not easily obtained from conventional materials.

  The pressure-sensitive adhesive layer 12 is made of an adhesive material such as No. Nitto Denko Corporation. It consists of giving 500. By providing this pressure-sensitive adhesive layer 12, adhesiveness is imparted to at least one surface portion of the magnetic shield sheet 10. Such a pressure-sensitive adhesive layer 12 is laminated on one side in the thickness direction of the shield layer 11 to constitute the magnetic shield sheet 10.

  The magnetic shield sheet 10 has an overall thickness dimension T10 of 10 μm or more and 500 μm or less. Thus, the magnetic shield sheet 10 is formed with a small thickness dimension T10, and the shield layer 11 and the pressure-sensitive adhesive layer 12 (hereinafter, these layers are collectively referred to as “each layer 11, 12”) as described above. Made of material and flexible. Therefore, the magnetic shield sheet 10 can be freely deformed.

  In addition, in the magnetic shield sheet 10, for example, a flame retardant or a flame retardant aid is added to at least one of the layers 11 and 12. This imparts flame retardancy to the magnetic shield sheet 10. For example, an electronic device such as a mobile phone may be required to have flame retardancy for an interior polymer material.

  The flame retardant for obtaining such flame retardancy is not particularly limited. For example, phosphorus compounds, boron compounds, bromine flame retardants, zinc flame retardants, nitrogen flame retardants, hydroxide series Flame retardants, metal compound flame retardants, and the like can be used as appropriate. Examples of phosphorus compounds include phosphate esters and titanium phosphate. Examples of the boron compound include zinc borate. Examples of brominated flame retardants include hexabromobenzene, hexabromocyclododecane, decabromobenzyl phenyl ether, decabromobenzyl phenyl oxide, tetrabromobisphenol, ammonium bromide and the like. Examples of the zinc-based flame retardant include zinc carbonate, zinc oxide, and zinc borate. Examples of nitrogen-based flame retardants include triazine compounds, hindered amine compounds, or melamine compounds such as melamine cyanurate and melamine anidine compounds. Examples of the hydroxide flame retardant include magnesium hydroxide and aluminum hydroxide. Examples of the metal compound flame retardant include antimony trioxide, molybdenum oxide, manganese oxide, chromium oxide, and iron oxide.

  In this example, a flame retardant chemical in which decabromodiphenyl oxide and antimony trioxide are mixed, for example, the trade name “Polysafe FCT-5” sold by Ajinomoto Fine Technology Co., Ltd. is used for the polymer material 100. The evaluation of UL94V0 was achieved by adding 30 chemicals (weight ratio). The magnetic shield sheet 10 can be suitably used as a material constituting such an article or mounted on the article. For example, it can be suitably used by being mounted on an article used in a space where it is desired to prevent combustion and generation of gas accompanying it, such as an apparatus in an aircraft, a ship, and a vehicle.

Moreover, the magnetic shield sheet 10 has electrical insulation. Specifically, the volume specific resistance value of the magnetic shield sheet 10 is 10 ⁶ Ωcm or more because each of the layers 11 and 12 is made of the material as described above. The volume specific resistance value of the shield layer 11 is preferably as large as possible. Therefore, the maximum value that can be realized is the upper limit value of the volume resistivity. Thus has high volume resistivity, it has an electrical insulating property.

  The magnetic shield sheet 10 has heat resistance. Specifically, the heat-resistant temperature of the magnetic shield sheet 10 when a crosslinking agent is added to rubber or a resin material is 150 ° C., and the magnetic shield sheet 10 has characteristics until the temperature exceeds at least 150 ° C. Does not change.

  FIG. 8 is a cross-sectional view showing the tag 15 including the magnetic shield sheet 10 in a simplified manner. The tag 15, which is an electronic component, includes an antenna element 16 for transmitting and receiving an electromagnetic wave signal (sometimes referred to as an “electromagnetic wave signal”) and an integrated circuit (IC) 17 electrically connected to the antenna element 16. The magnetic shield sheet 10 is further provided on the tag.

  The antenna element 16 serving as an antenna means is a loop antenna formed in a loop shape along the virtual plane 18. The virtual surface 18 may be a flat surface or a curved surface, but is a flat surface in the present embodiment. The antenna element 16 can transmit at least an electromagnetic wave signal toward one side with respect to the virtual plane 18 and can receive an electromagnetic wave signal coming from one side with respect to the virtual plane 18. Specifically, the antenna element 16 transmits an electromagnetic wave signal in a transmission / reception direction A that is perpendicular to the virtual surface 18 and faces one side of the virtual surface 18, and receives an electromagnetic wave signal that arrives from the transmission / reception direction A. Can do.

  The IC 17 has at least a storage unit and a control unit. Information can be stored in the storage unit, and the control unit can store information in the storage unit or read information from the storage unit. In response to a command represented by the electromagnetic wave signal received by the antenna element 16, the IC 17 stores information in the storage unit or reads information stored in the storage unit and outputs a signal representing the information to the antenna element 16. To give.

  For example, an electromagnetic wave signal representing information to be stored in advance (hereinafter referred to as “main information”) and information instructing to store the main information (hereinafter referred to as “storage command information”) from the information management device, When received by the antenna element 16, an electrical signal representing main information and storage command information is provided from the antenna element 16 to the IC 17. The IC tag 17 causes the control unit to store main information in the storage unit based on the storage command information.

  An electromagnetic wave signal representing information (hereinafter referred to as “transmission command information”) for instructing to transmit information (hereinafter referred to as “storage information”) stored in the storage unit is received by the antenna element 16 from the information management device. Then, an electric signal representing transmission command information is given from the antenna element 16 to the IC 17. As for IC tag 17, a control part reads the information (memory | storage information) memorize | stored in a memory | storage part based on transmission command information, and gives the electrical signal showing the memory | storage information to the antenna element 16. FIG. As a result, an electromagnetic wave signal representing stored information is transmitted from the antenna element 16.

  Thus, the tag 15 is an electronic component that transmits and receives an electromagnetic wave signal using the antenna element 16. The tag 15 may be a battery-driven tag that is driven by a built-in battery, or may be a batteryless tag that returns an electromagnetic wave signal using the energy of the received electromagnetic wave signal.

  The magnetic shield sheet 10 is used so that such a tag 15 can be used in the vicinity of the metal member 19. The magnetic shield sheet 10 is provided on the side opposite to the transmission / reception direction A with respect to the antenna element 16, and thus on the other side with respect to the virtual surface 18. The magnetic shield sheet 10 is provided with the adhesive layer 12 disposed on the opposite side of the antenna element 16 and the IC 17 from the shield layer 11.

  Although simplified in FIG. 8, the antenna element 16 and the IC 17 are packaged by being mounted on a flexible tape, and the magnetic shield sheet 10 is attached thereto. Are stacked. In attaching the magnetic shield sheet 10 to the package on which the antenna element 16 and the IC 17 are mounted, for example, an adhesive is used.

  The tag 15 including the magnetic shield sheet 10 is used by being mounted on, for example, a metal member 19. The tag 15 is provided so that the magnetic shield sheet 10 is disposed closer to the metal member 19 than the antenna element 16 so that the magnetic shield sheet 10 is interposed between the antenna element 16 and the metal member 19. It is done. The pressure-sensitive adhesive layer 12 of the magnetic shield sheet 10 faces the metal member 19, and the pressure-sensitive adhesive layer 12 is attached and attached to the metal member 19.

  The magnetic shield sheet 10 has the shield layer 11 as described above. The electromagnetic field is shielded by the shield layer 11 and the electromagnetic field of one of the two regions partitioned by the magnetic shield sheet 10 is used. Can be prevented from leaking to the other region, and the energy of the electromagnetic field in one region can be prevented from being transmitted to the other region. The electromagnetic field that can be shielded includes, of course, an electromagnetic field formed by an electromagnetic wave, and therefore the electromagnetic wave that forms this electromagnetic field can be shielded.

To be specific, the shield layer 11, since made of a real part mu 'is large material of the complex relative magnetic permeability mu, the provision of the shield layer 11 in the magnetic field is transmitted from the antenna element 16 in FIG. 8 for example As shown in the example of the electric field due to electromagnetic waves, the magnetic lines of force 20 pass through the shield layer 11 in a concentrated manner, and do not pass through or difficult to pass through the metal member 19 existing in the vicinity. Thus, the magnetic shield sheet 10 is used to shield the magnetic field, and the magnetic field in the region where the antenna element 16 which is one region partitioned by the magnetic shield sheet 10 is provided is the metal member which is the other region. It can prevent leaking to the area | region in which 19 is provided.

  When the antenna element 16 is provided at a position similar to the position shown in FIG. 8, if the magnetic shield sheet 10 is not provided, the magnetic field lines of the magnetic field due to the transmitted electromagnetic waves are, for example, as shown by the imaginary line 21 in FIG. In addition, it passes through the metal member 19. When the magnetic lines of force pass through the metal member 19 in this way, an eddy current is generated in the metal member 19 with the change of the magnetic field, and heat is generated. Thus, the energy of the magnetic field is converted into heat energy, and the energy of the magnetic field is absorbed. On the other hand, by shielding the magnetic field using the magnetic shield sheet 10, the energy of the magnetic field opposite to the metal member 19 with respect to the magnetic shield sheet 10 is prevented from being absorbed by the metal member 19. Can be removed. Therefore, the magnetic member 19 absorbs the energy of the magnetic field formed by the electromagnetic wave transmitted and received by the antenna element 16 on the side of the antenna element 16 that is opposite to the metal member 19 with respect to the magnetic shield sheet 10. It is prevented.

Further, since the shield layer 11 is made of a material having a small imaginary part μ ″ of the complex relative permeability μ, even if magnetic flux passes through the shield layer 11, energy loss in the shield layer 11 due to the passage is reduced. As a result, even if the magnetic lines of force pass through the shield layer 11 in a concentrated manner, the shield layer 11 itself is prevented from losing energy of the magnetic field. Further, absorption of magnetic field energy by the metallic member 19 existing in the vicinity can be prevented, loss by the self can be suppressed to be small, and attenuation of magnetic field energy can be made as small as possible.

  By interposing such a magnetic shield sheet 10 between the antenna element 16 and the metal member 19 as described above, the energy of the electromagnetic field due to the electromagnetic wave signal transmitted and received by the antenna element 16 is made of metal. Absorption by the member 19 is prevented. In addition, the magnetic shield sheet 10 itself for preventing the influence of the metal member 19 has a small magnetic loss and dielectric loss. Therefore, the antenna element 16 can transmit and receive a long distance suitably. Accordingly, even when the tag 15 is provided in the vicinity of the metal member 19, information can be wirelessly communicated between the information management device and the tag 15, and the electromagnetic wave signal transmitted from the information management device can be transmitted. The information to be represented can be stored in the tag 15, and the information stored in the tag 15 can be read out by the information management device.

  Thus, by using the magnetic shield sheet 10, an electronic component using the antenna element 16 is attached to the metal member 19, for example, and is provided in the vicinity of the metal member 19. An electronic component can be used in a state where transmission and reception can be realized. Therefore, for example, the tag 15 as described above is attached to a beverage 22 containing a beverage in a metal container which is a metal member 19 as shown in FIG. Can be used. Further, the tag 15 is incorporated in an electronic device 23 such as a mobile phone device in which many metal members 19 such as a substrate as shown in FIG. 10 are used, for example, for the purpose of merchandise management or user authentication. Can be used. Thus, the wide use of the tag 15 can be secured, and the highly convenient tag 15 can be realized.

As shown in FIG. 8 , according to the present invention, it functions as an RFID metal-compatible magnetic shield sheet at 13.56 MHz, and has an effect of suppressing (absorbing) unnecessary radiation noise and the like at other frequencies (1 GHz).

Further, the present invention is characterized in that the real part μ ′ of the complex relative permeability μ from 100 MHz to 1 GHz is 7 or more and the imaginary part μ ″ of the complex relative permeability μ is 7 or more.

According to the present invention, it functions as an RFID metal-compatible magnetic shield sheet at 13.56 MHz, and has a high suppression effect (absorption) of unwanted radiation noise at other wide frequency ranges (100 MHz to 1 GHz). Specifically, the real part μ ′ of the complex relative permeability μ at 100 MHz in Example 1 is 35, the imaginary part μ ″ is 19, and the real part μ ′ of the complex relative permeability μ at 1 GHz is 12. 4 and the imaginary part μ ″ is 14 , indicating that the noise suppression effect is used together.

  Moreover, since the magnetic shield sheet 10 has flexibility as described above, it can be freely deformed. Thereby, there are few restrictions on an installation place and it can be used for a wide use. For example, when it is used by being attached to an article, it can be provided following the shape of the article. For example, as shown in FIG. 9, it can be attached to the surface of a cylindrical container (corresponding to the metal member 19) in accordance with the shape of the surface. Can be reduced, and the mounting operation can be facilitated. When used as the tag 15, the material of the other configuration can be appropriately selected so that the tag 15 has a flexible configuration as a whole, so that the tag 15 can be attached following the cylindrical surface. It becomes like this.

  In addition, since the magnetic shield sheet 10 is provided with adhesiveness on at least one surface portion, when attached to an article, the magnetic shield sheet 10 can be attached to the article using the adhesiveness. Thus, the magnetic shield sheet 10 can be easily attached to the article. Therefore, the operation | work for utilizing the magnetic shielding sheet 10 and an electronic component provided with it can be made easy.

The magnetic shield sheet 10 has heat resistance and electrical insulation as described above. With regard to heat resistance, it may be used at 120 ° C. or 130 ° C. particularly in automobile applications, and it is required that it can be used without degradation of performance even at that temperature. The heat resistance can be realized by adding a crosslinking material and crosslinking the binder. In this case, it is of course possible to realize heat resistance at a higher temperature (for example, 200 ° C.) by appropriately combining the kind of the binder used and the crosslinking material. Further, by covering the soft magnetic metal powder with an organic and inorganic insulating material as a binder, the electrical insulation of the magnetic shield sheet 10 can be improved without direct contact with the soft magnetic metal dispersed in the sheet. Can do. If electricity is conducted, an eddy current is generated in itself and the magnetic energy is attenuated. Furthermore, since the circuit and the plating casing (ground) are arranged in close proximity, if the magnetic shield sheet 10 has conductivity, it will be conducted through it, which will hinder the operation. And the volume resistivity of the magnetic shield sheet 10 in order to prevent these have achieved more than 10 ⁶ Omega cm.

  The above-described embodiment is merely an example of the present invention, and the configuration can be changed. For example, the stacked configuration may be changed. Specifically, as shown by a virtual line in FIG. 1, the second pressure-sensitive adhesive layer 30 may be provided on the side opposite to the pressure-sensitive adhesive layer 12 with respect to the shield layer 11. When such a magnetic shield sheet 10 is used for the tag 15, when the magnetic shield sheet 10 is attached to a package on which the antenna element 16 and the IC 17 are mounted to configure the tag 15, a separate adhesive is used. Even if it does not use, it becomes possible to stick using the second adhesive material layer 30, and the work becomes easy. Thus, the installation and mounting work of the magnetic shield sheet 10 can be facilitated such that the magnetic shield sheet 10 can be easily incorporated into an electronic component.

  Further, the adhesive layer 12 may be used for attaching the magnetic shield sheet 10 to a package on which the antenna element 16 and the IC 17 are mounted when the adhesive layer 12 is incorporated into the tag 15. In this case, as long as the second pressure-sensitive adhesive layer 30 is provided, the second pressure-sensitive adhesive layer 30 may be attached to the article, or the second pressure-sensitive adhesive layer 30 is not provided. For example, it may be attached to the article using an adhesive. Moreover, the structure which adds an adhesive to the shield layer 11, and provides adhesiveness to the surface may be sufficient, without forming the adhesive layers 12 and 30.

  Further, the means for imparting flame retardancy may be another configuration instead of the configuration in which the flame retardant is added. Further, the minimum performance required for the magnetic shield sheet 10 is a performance for shielding a magnetic field, and the other performance is not an essential requirement and may not have a configuration.

The use of the magnetic shield sheet 10 is not limited to electronic components, and can be widely used in applications where there is a requirement to shield at least a magnetic field. Of course, the electronic component is not limited to the tag 15. Further, the tag 15 may be used for an article having a metal member 19 other than the aforementioned article. For example, the electronic device is not limited to a mobile phone device, but may be a PDA, a notebook personal computer, or the like.
Configuration changes other than these examples may be used.

It is sectional drawing which simplifies and shows the magnetic shielding sheet 10 of one Embodiment of this invention. 4 is a graph showing measurement results of material constants ( ε ′, ε ″, μ ′, μ ″ ) of Example 1. 6 is a graph showing measurement results of material constants ( ε ′, ε ″, μ ′, μ ″ ) of Example 2. 10 is a graph showing measurement results of material constants ( ε ′, ε ″, μ ′, μ ″ ) of Example 3. 6 is a graph showing measurement results of material constants ( ε ′, ε ″, μ ′, μ ″ ) of Comparative Example 1. 10 is a graph showing measurement results of material constants ( ε ′, ε ″, μ ′, μ ″ ) of Comparative Example 2. 10 is a graph showing measurement results of material constants ( ε ′, ε ″, μ ′, μ ″ ) of Comparative Example 3. It is sectional drawing which simplifies and shows the tag 15 provided with the magnetic shielding sheet 10. FIG. It is a perspective view which shows the beverage 22 with which the tag 15 is mounted | worn. It is a perspective view which shows the electronic apparatus with which the tag 15 is incorporated. It is sectional drawing which simplifies and shows the tag 1 which is a prior art. It is sectional drawing which simplifies and shows the tag 1A which is another prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Magnetic shield sheet 11 Shield layer 12 Adhesive layer 15 Tag 16 Antenna element 17 IC
19 Metal Member 20 Magnetic Field Line 22 Beverage 23 Electronic Device

The present invention relates to a tag using this magnetic shield sheet and tag for shielding magnetic field.

Therefore, an object of the present invention, without loss of energy of the magnetic field, it is possible to shield the magnetic field is to provide a further tag using the magnetic shield sheet and this tag is made thin than before. A mobile terminal (for example, a mobile phone) having an RFID function is shielded on the inner surface of the casing. Further, since the space for the antenna is very narrow due to the reduction in thickness and the environment is easily affected by the metal surface, a magnetic shield sheet for a high-performance tag corresponding to this is provided. Furthermore, by using this sheet, an unprecedented thin RFID tag antenna can be installed in a mobile terminal, and these thin systems ( tags ) including a magnetic shield sheet for tags are provided.

Furthermore, in the present invention, by having a magnetic shielding property with respect to the above-mentioned specific frequency, it contributes to be useful as a metal-compatible RFID tag, and at other frequencies (for example, 100 MHz to 6 GHz), the real part of the complex relative permeability and even as high as the imaginary part, for example, to provide a tag using the same magnetic shield sheet and tag, characterized in that also serves as an inhibitory effect of such unwanted radiation noise. That is, the present invention provides an intelligent sheet that suitably converts and functions the magnetic permeability and dielectric constant at two or more frequencies.

The present invention has an antenna element for transmitting and receiving an electromagnetic wave signal having a frequency of 13.56 MHz, and is electrically connected to the antenna element and transmits a signal from the antenna element in response to a signal received by the antenna element. When using a tag including an integrated circuit in the vicinity of a metal member, a tag magnetic shield sheet provided between the antenna element and the metal member,
Frequency Ri imaginary part mu "is 6 der following real part mu 'is not less than 30 and the complex relative permeability mu of the complex relative permeability mu at 13.56MHz electromagnetic waves,
The imaginary part ε ″ of the complex relative dielectric constant ε in an electromagnetic wave having a frequency of 13.56 MHz is 500 or less,
For a tag comprising a shield layer having a real part μ ′ of a complex relative permeability μ of 7 or more and an imaginary part μ ″ of a complex relative permeability μ of 7 or more in an electromagnetic wave having a frequency of 100 MHz to 1 GHz It is a magnetic shield sheet.

According to the present invention, the magnetic shield sheet for tags is provided with a shield layer. In the shield layer, the larger the real part μ ′ of the complex relative permeability μ is, the more the magnetic lines of force (magnetic flux) pass. The smaller the real part μ ′ of the complex relative permeability μ is, the more the magnetic line of force (magnetic flux) is. It becomes composition that is hard to pass. The shield layer is configured such that the larger the imaginary part μ ″ of the complex relative permeability μ, the more the magnetic field energy is lost, and the smaller the imaginary part μ ″ of the complex relative permeability μ, the less likely the magnetic field energy is lost.

With respect to the electromagnetic wave of 13.56 MHz, the shield layer has a real part μ ′ of the complex relative permeability μ as large as 30 or more and an imaginary part μ ″ of the complex relative permeability μ as small as 6 or less. to the magnetic field formed by electromagnetic waves 56 MHz, the magnetic force lines (magnetic flux) is liable as to concentrate the shield layer, it is possible to make on not lost the energy of the magnetic field at that. Therefore the magnetic shielding tag By using the sheet, 13.56 MHz electromagnetic waves can be shielded from leaking while suppressing energy loss to a small level.
Further, for electromagnetic waves of 13.56 MHz, the imaginary part ε ″ of the complex dielectric constant ε is as small as 500 or less. The imaginary part ε ″ of the complex dielectric constant ε is a measure of the conductivity of the shield layer. When the imaginary part ε ″ of the complex relative dielectric constant ε is large, the conductivity is developed. When the conductivity is developed, an eddy current is generated when the magnetic flux passes through the shield layer. When the eddy current is generated as described above, for example, when used for improving the wireless communication environment, the magnetic flux is attenuated to hinder wireless communication. On the other hand, the imaginary part ε ″ of the complex relative dielectric constant ε is By reducing the size, it is possible to prevent the occurrence of the above problem and prevent a wireless communication failure, thereby realizing a suitable wireless communication environment.

Furthermore, the shield layer has an actual part μ ′ of the complex relative permeability μ of 7 or more and is never too small for an electromagnetic wave of 100 MHz to 1 GHz, and an imaginary part μ ″ of the complex relative permeability μ is 7 or more. large. This respect to the magnetic field formed by electromagnetic waves of 100 MHz to 1 GHz, the magnetic field lines (magnetic flux) is arranged to pass shield layer, it is possible to lose energy of the magnetic field. Therefore the use of the magnetic shield sheet tag Can absorb electromagnetic waves of 100 MHz to 1 GHz.

The magnetic shield sheet for such tags, in the case of using the tag for wireless communication using electromagnetic waves of 1 3.56MHz in the vicinity of the metallic member, disposed between the antenna element and a metal member Used. This prevents the 13.56 MHz electromagnetic wave from leaking to the metal member side, and prevents the 13.56 MHz electromagnetic wave energy from being absorbed by the metal object. Moreover, the magnetic loss sheet for the tag itself has a small magnetic loss. Therefore , even if the tag is used in the vicinity of a metal member , radio communication can be suitably performed using 13.56 MHz electromagnetic waves. The electromagnetic wave of 13.56 MHz is mainly used for communication of an RFID (Radio Frequency IDentification) tag, for example. Therefore, communication can be suitably performed using the RFID tag.

Moreover , since the magnetic shield sheet for tags can absorb electromagnetic waves of 100 MHz to 1 GHz, unnecessary radiation noise and the like can be suppressed with respect to electromagnetic waves of 100 MHz to 1 GHz. Therefore, the loss can be suppressed small with respect to the 13.56 MHz electromagnetic wave used for communication by the tag, and the unnecessary 100 MHz to 1 GHz electromagnetic wave can be absorbed, and communication can be performed more suitably.

According to the present invention, the flat soft magnetic metal powder is densely dispersed in the polymer in an oriented state without causing shape deformation including distortion and bending, thereby forming a shield layer. With such a configuration, with respect to an electromagnetic wave of 13.56 MHz, the real part μ ′ of the complex relative permeability μ is as large as 30 or more and the imaginary part μ ″ of the complex relative permeability μ is as small as 6 or less. However, for electromagnetic waves of 100 MHz to 1 GHz, the real part μ ′ of the complex relative permeability μ is never too small as 7 and the imaginary part μ ″ of the complex relative permeability μ is as large as 7 or more. The shield layer can be formed. Therefore , a magnetic shield sheet for tags that achieves the above-described excellent effects can be realized.

The present invention is characterized by having flexibility.
According to the present invention, the magnetic shield sheet for tags has flexibility and can be freely deformed. Thereby, there are few restrictions on an installation place and it can be used for a wide use. For example, when it is used by being attached to an article, it can be provided following the shape of the article.

Further, the present invention is characterized in that thermal conductivity is imparted.
According to the present invention, an IC substrate or a power supply unit serving as a heat source may be close to each other, and excellent thermal conductivity leads to suppression of temperature rise and prevention of performance degradation due to exposure to high temperature.

Further, the present invention is characterized in that flame retardancy is imparted.
According to the present invention, the magnetic shield sheet for tags can obtain flame retardancy. Electronic devices such as mobile phones may also be required to have flame retardancy for the polymer material that is used in the interior. The magnetic shield sheet for tags can be suitably used as a material constituting such an article or attached to the article.

Further the invention features that the adhesive is applied to at least one surface portion.

According to the present invention, the tag magnetic shield sheet is provided with adhesiveness on at least one surface portion. Therefore, when attached to an article, the tag magnetic shield sheet is attached to the article using the adhesiveness. Can do. Thus, the tag magnetic shield sheet can be easily attached to the article. Therefore, the work for using the tag magnetic shield sheet can be facilitated.

The present invention includes an antenna element for frequency to transmit and receive electromagnetic signals 13.56 MHz,
An integrated circuit electrically connected to the antenna element and transmitting a signal from the antenna element in response to a signal received by the antenna element;
It is a tag characterized by including the magnetic shield sheet for tags as described in any one of Claims 1-7 .

According to the present invention, the magnetic shield sheet tag is provided between the antenna element and the metal member. Thus, tags can also be provided in the vicinity of the metallic member, without the energy of electromagnetic wave is absorbed by a metal member, it can be suitably received by the antenna elements. Thus, even if it is provided in the vicinity of a metal member, a tag that can be suitably transmitted and received by the antenna element can be realized.

According to the present invention, an electromagnetic wave of 13.56 MHz can be shielded without being attenuated. Therefore, when wireless communication is performed using an electromagnetic wave of 13.56 MHz, even if a metal member exists in the vicinity of the antenna element , wireless communication can be suitably performed. An electromagnetic wave of 13.56 MHz is mainly used for communication of an RFID (Radio Frequency IDentification) tag, for example, and can be suitably communicated using the RFID tag in the vicinity of a metal member . Moreover, the imaginary part ε ″ of the complex dielectric constant ε is small, and eddy currents are generated when the magnetic flux passes through the shield layer, thereby preventing the occurrence of problems that interfere with wireless communication. to prevent becomes enough, it is possible to realize a suitable wireless communication environment. it is possible to absorb electromagnetic waves of 1 00MHz～1GHz Furthermore, with respect to electromagnetic waves of 100 MHz to 1 GHz, unnecessary radiation noise or the like Therefore, the loss of the 13.56 MHz electromagnetic wave used for communication can be reduced, and the unnecessary 100 MHz to 1 GHz electromagnetic wave can be absorbed and more appropriately communicated.

Further, according to the present invention, the flat soft magnetic metal powder is densely dispersed in the polymer in an oriented state without causing shape deformation including distortion and bending, thereby forming a shield layer. Therefore , a magnetic shield sheet for tags that achieves the above-described excellent effects can be realized.

In addition, according to the present invention, by ensuring insulation with a volume resistivity value of 10 ⁶ Ωcm or more, generation of eddy currents is suppressed, and electromagnetic wave shielding properties that reflect radiation noise are not imparted. Thus, a suitable tag magnetic shield sheet can be realized.

In addition, according to the present invention, it is possible to realize a magnetic shield sheet for tags that can be used in a wide range of applications with few restrictions on installation locations.

According to the present invention, it is possible to realize a tag magnetic shield sheet that has high thermal conductivity and can be used in the vicinity of a heat source.

Further, according to the present invention, the magnetic shield sheet for tags can be suitably used as a material constituting the flame retardant article or attached to the article.

Further, according to the present invention, when used by being attached to an article, the tag can be attached and attached to the article using the adhesiveness, and the tag magnetic shield sheet can be easily attached to the article.

In addition, according to the present invention, it is possible to realize a tag that can be suitably transmitted and received by an antenna element even when provided in the vicinity of a metal member.

FIG. 1 is a simplified cross-sectional view showing a tag magnetic shield sheet (hereinafter simply referred to as “magnetic shield sheet”) 10 according to an embodiment of the present invention. The magnetic shield sheet 10 is a sheet used to shield at least a magnetic field. In the present embodiment, the magnetic shield sheet 10 is used to shield an electromagnetic field formed by, for example, an electromagnetic wave. In other words, in the present embodiment, the magnetic shield sheet 10 is used to shield electromagnetic waves. The electromagnetic wave to be shielded may be, for example, 13.56 MHz or 900 MHz, but is 13.56 MHz in the present embodiment.

It is sectional drawing which simplifies and shows the magnetic shielding sheet 10 for tags of one Embodiment of this invention. 6 is a graph showing measurement results of material constants (ε ′, ε ″, μ ′, μ ″) of Example 1. 10 is a graph showing measurement results of material constants (ε ′, ε ″, μ ′, μ ″) of Example 2. 10 is a graph showing measurement results of material constants (ε ′, ε ″, μ ′, μ ″) of Example 3. 6 is a graph showing measurement results of material constants (ε ′, ε ″, μ ′, μ ″) of Comparative Example 1. 10 is a graph showing measurement results of material constants (ε ′, ε ″, μ ′, μ ″) of Comparative Example 2. 10 is a graph showing measurement results of material constants (ε ′, ε ″, μ ′, μ ″) of Comparative Example 3. It is sectional drawing which simplifies and shows the tag 15 provided with the magnetic shielding sheet 10. FIG. It is a perspective view which shows the beverage 22 with which the tag 15 is mounted | worn. It is a perspective view which shows the electronic apparatus with which the tag 15 is incorporated. It is sectional drawing which simplifies and shows the tag 1 which is a prior art. It is sectional drawing which simplifies and shows the tag 1A which is another prior art.

Claims (15)

A magnetic shield sheet comprising a shield layer made of a material having a large real part μ _γ ′ of a complex relative permeability μ _{γ and} a small imaginary part μ _γ ″ of a complex relative permeability μ _γ in an electromagnetic wave having a specific frequency. The magnetic shield sheet according to claim 1, wherein the shield layer is made of a material having a small imaginary part ε _γ ″ of a complex dielectric constant ε _γ in an electromagnetic wave having a specific frequency.   The magnetic shield sheet according to claim 1 or 2, wherein the specific frequency is 13.56 MHz. Complex relative permeability mu real part of the _gamma mu _gamma in 13.56MHz electromagnetic waves 'is 30 or more and the imaginary part mu _gamma "of the complex relative permeability mu _gamma real part mu _gamma of the complex relative permeability mu _gamma' divided by The magnetic shield sheet according to claim 3, wherein the value tan δμ is 0.2 or less. Complex relative permeability mu real part of the _gamma mu _gamma in 13.56MHz electromagnetic waves 'is an imaginary part mu _gamma "of 50 or more and the complex relative permeability mu _gamma real part mu _gamma of the complex relative permeability mu _gamma' divided by The magnetic shield sheet according to claim 3, wherein the value tan δμ is 0.1 or less. ^6. The magnetic shield sheet according to claim 1, wherein the volume resistivity value is 10 ⁶ Ωcm or more. The magnetic shield sheet according to claim 3, wherein the shield layer has an imaginary part ε _γ ″ of a complex dielectric constant ε _γ in an electromagnetic wave of 13.56 MHz of 500 or less. In the electromagnetic wave of a specific frequency, the real part of the complex relative permeability μ γ μ γ _'is large and the imaginary part of the complex relative permeability _μ γ μ γ "is small, the electromagnetic wave of a frequency other than the specific frequency, the complex relative magnetic shield sheet according to any one of claims 1 to 7 real part mu _gamma 'is to be large and the imaginary part mu _gamma "is greater and the characteristics of the complex relative permeability mu _gamma of permeability mu _gamma. Specific frequency is other than 1GHz, the real part of the imaginary part mu _gamma "of the real part mu _gamma 'is 7 or more and the complex relative permeability mu _gamma of the complex relative permeability mu _gamma in the electromagnetic complex relative magnetic permeability mu _gamma of 1GHz magnetic shield sheet according to claim 8, wherein the value tanδμ divided by mu _gamma 'is equal to or not less than 0.5. Specific frequency is other than 100 MHz to 1 GHz, the imaginary part mu _gamma "of the real part mu _gamma 'is 10 or more and the complex relative permeability mu _gamma of the complex relative permeability mu _gamma in 100 MHz to 1 GHz of the complex relative permeability mu _gamma 9. The magnetic shield sheet according to claim 8, wherein a value tan δμ divided by the real part μ _γ ′ is 0.5 or more.   It has flexibility, The magnetic shielding sheet of Claims 1-10 characterized by the above-mentioned.   The magnetic shield sheet according to claim 1, wherein thermal conductivity is imparted.   The magnetic shield sheet according to any one of claims 1 to 12, wherein flame retardancy is imparted.   The magnetic shield sheet according to any one of claims 1 to 12, wherein at least one surface portion is provided with adhesiveness. Antenna means for transmitting and receiving electromagnetic wave signals;
An electronic component comprising the magnetic shield sheet according to claim 1, which is provided on the opposite side of the transmitting / receiving direction with respect to the antenna means.

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