JP2014239185A - Method for forming sintered magnetic laminate and electromagnetic wave shield sheet for mounting on non-contact communication equipment - Google Patents

Abstract

An electromagnetic wave shielding sheet that can communicate at 13.56 MHz even when the magnetic sheet is made thin, and can always obtain stable communication characteristics in any metallic environment. provide. The real part μ ′ of the relative permeability when excited at an AC frequency of 13.56 MHz is 100 H / m or more, the imaginary part μ ″ of the relative permeability is 10 or less, and the relative permittivity is 15 or less. By bonding a metal foil to one surface of the magnetically bonded sheet through an insulating adhesive layer having a relative dielectric constant of 10 or less, a sintered magnetic sheet having a thickness of about 50 to 200 μm is obtained. By using a low dielectric constant material for the sintered magnetic sheet and the adhesive layer, it is possible to obtain stable communication characteristics in a metal environment. It can be obtained by inserting a sintered magnetic sheet between a flexible long protective film that moves continuously or intermittently simultaneously and a flexible long metal foil.

Description

The present invention provides an electromagnetic wave shielding sheet for mounting on a non-contact communication device such as a mobile phone, a smartphone, a tablet, and the like, which can obtain stable communication characteristics with respect to an applied magnetic field without being affected by the use environment. It relates to a forming method.

In recent years, non-contact short-range information communication means used in RFID (Radio Frequency IDentification) systems such as Osaifu-Keitai and IC cards have become widespread. Electronic components such as an insulating base, a magnetic body, an antenna coil, and an IC chip are indispensable for the module used for such non-contact communication means. RFID performs information communication with readers and writers using a change in magnetic field due to a frequency of 13.56 MHz. If a conductor such as a metal is present close to the back surface of the antenna, the communication magnetic field is generated by the metal. There is a problem that communication is hindered by generating a demagnetizing field opposite to the communication magnetic field caused by the induced current (eddy current) inside. Therefore, a magnetic material is disposed between the metal or the like and the antenna coil, the magnetic flux is focused, the demagnetizing field of the metal is relaxed, and a desired communication distance is obtained.

However, as the cellular phone and the like become thinner, the distance from the metal such as the circuit board and the battery pack becomes closer, and the magnetic material thickness is required to be reduced. If the thickness of the magnetic material is reduced, the communication magnetic field at the time of communication cannot be sufficiently focused by the magnetic material layer alone, and the problem arises that the influence of the eddy current due to the metallic environment as described above deteriorates the communication characteristics. It will end up. As a means for shielding a penetrating magnetic field, Patent Document 1 discloses an electromagnetic wave shielding sheet having a magnetic layer and a metal layer. According to this, the electromagnetic wave which leaks can be suppressed in a wide range.

JP 2012-79806 A

However, in communication using 13.56 MHz, if an electromagnetic wave shield sheet having a polymer type magnetic layer as thin as 200 μm or less and a metal layer is used as in Patent Document 1, the magnetic permeability of the magnetic layer is too low. Therefore, the eddy current generated in the metal layer also increases. And the magnetic field required for communication cannot be obtained by the demagnetizing field generated by the eddy current, and communication becomes impossible. Therefore, an object of the present invention is to provide an electromagnetic wave shielding sheet that can communicate at 13.56 MHz even if it is thinned, and to provide a method for forming the electromagnetic wave shielding sheet.

Moreover, the electromagnetic wave shielding sheet is used by being mounted on various mobile phones. Depending on the type of mobile phone, the metal parts used in it vary, so the communication characteristics change under the influence of the metal environment, so communication is possible with one mobile phone, but communication with the other mobile phone. This will cause problems such as inability to do so. Therefore, an object of the present invention is to provide an electromagnetic wave shielding sheet that can obtain stable communication characteristics in any metal environment.

As a result of intensive studies to achieve the above object, the present inventors can communicate at 13.56 MHz even if the magnetic sheet is thinned by adopting the following embodiment and manufacturing method. Furthermore, the present inventors have found that an electromagnetic wave shielding sheet that can always obtain stable communication characteristics can be provided regardless of the metal environment.

In a method of forming a sintered magnetic laminate in which a flexible metal foil is attached to the back surface of a sintered magnetic sheet having a flexible protective film attached to the surface, continuously or intermittently A method for forming a sintered magnetic laminate, comprising: pressing and fixing a flexible long metal foil that moves simultaneously to a sintered magnetic sheet.

In a method of forming a sintered magnetic laminate in which a flexible metal foil is attached to the back surface of a sintered magnetic sheet having a flexible protective film attached to the surface, continuously or intermittently A method of forming a sintered magnetic laminate, wherein a sintered magnetic sheet is interposed between a flexible long protective film and a flexible long metal foil that move simultaneously.

  The sintered magnetic sheet is composed of a plurality of partitions having a predetermined shape and size, and the partitions are spaced from each other between the flexible long protective film and the flexible long metal foil. A method for forming a sintered magnetic layered body interposed between the two.

  A method for forming a sintered magnetic laminate in which the sintered magnetic sheet is narrower than the width of a flexible long protective film and a flexible long metal foil.

In a method of forming a sintered magnetic laminate in which a flexible metal foil is attached to the back surface of a sintered magnetic sheet having a flexible protective film attached to the surface, the method is continuously or intermittently performed simultaneously. While interposing a sintered magnetic sheet between the moving flexible long protective film and the flexible long metal foil, the obtained sintered magnetic laminate is bonded to the flexible long protective film. A method for forming a sintered magnetic laminate, characterized by forming a fixed-length sintered magnetic laminate by shearing to a predetermined length at a location where a flexible long metal foil is directly joined.

A sintered magnetic sheet having a real part μ ′ of a relative permeability of 100 H / m or more, an imaginary part μ ″ of a relative permeability of 10 or less, and a relative permittivity of 15 or less when the AC frequency is excited at 13.56 MHz. By adhering a metal foil to one surface of this through an insulating adhesive layer having a relative dielectric constant of 10 or less, the transmitted magnetic field is reduced and the influence of the metal environment is also reduced.

A sintered magnetic sheet having a real part μ ′ of a relative permeability of 100 H / m or more, an imaginary part μ ″ of a relative permeability of 10 or less, and a relative permittivity of 15 or less when the AC frequency is excited at 13.56 MHz. A metal foil is bonded to one surface of the sintered magnetic sheet via an insulating adhesive layer having a relative dielectric constant of 10 or less, and a protective film is bonded to the other surface of the sintered magnetic sheet via the insulating adhesive layer. Adhesion reduces the transmitted magnetic field and reduces the influence of the metal environment.

By forming an insulating film or an adhesive layer on the surface of the metal foil, the metal foil can be protected or an electromagnetic wave shielding sheet can be directly attached to a mobile phone.

The thickness can be reduced by setting the thickness of the sintered magnetic sheet to 50 to 200 μm.

When the thickness of the metal foil is 5 to 30 μm, a shielding effect can be obtained without unnecessarily increasing the thickness of the electromagnetic wave shielding sheet.

Q value (Q1) when a spiral antenna coil conductor is disposed on the other surface of the sintered magnetic sheet, and Q value when a metal is further disposed on the metal foil side in addition to the antenna coil conductor ( When the ratio to Q2) is 1.0 <(Q2) / (Q1) <1.1 and (Q2)> 30, stable communication characteristics can be obtained in any metal environment. be able to.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the electromagnetic wave shielding sheet which can acquire the stable communication characteristic, without being influenced by metal environment.

Sectional drawing of the electromagnetic wave shielding sheet which concerns on one Embodiment of this invention. Sectional drawing of the electromagnetic wave shielding sheet which concerns on other embodiment similarly. The figure which showed the process of the crimping | fixing fixation of this invention. The top view of the electromagnetic wave shielding sheet after pressure fixing. AA arrow sectional drawing in Fig.4 (a). The figure which showed the process of the crimping | fixing fixation of this invention. Schematic diagram showing the magnetic field when metal foil is not used The schematic diagram which showed the mode of the magnetic field in a metal environment. The schematic diagram which showed the mode of the magnetic field when using a polymer-type magnetic body. The schematic diagram which showed the mode of the magnetic field when using the electromagnetic wave shielding sheet of this invention. The schematic diagram which showed the mode of the magnetic field in a metal environment. Sectional drawing when an antenna coil conductor is installed in the electromagnetic wave shielding sheet of the present invention. The schematic diagram which showed the electric current which flows through an antenna coil conductor. The schematic diagram which showed the electric current which flows through the antenna coil conductor in a metal environment. FIG. 11B is a partial equivalent circuit diagram of FIG. The schematic diagram which showed the electric current in a metal environment when an antenna coil conductor is installed in the electromagnetic wave shielding sheet of this invention. FIG. 11D is a partial equivalent circuit diagram of FIG.

Embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the sintered magnetic laminate of the present invention is obtained by laminating a sintered magnetic sheet 2, an adhesive layer 3, and a metal foil 4 in this order. And the electromagnetic wave shielding sheet 1 for non-contact communication equipment mounting can be obtained by processing the obtained sintered magnetic laminated body into a desired shape.

The sintered magnetic sheet 2 can be obtained according to the following procedure. A slurry obtained by mixing a soft magnetic powder such as a Ni—Zn system with a solvent, a binder, a dispersant and the like is formed into a sheet shape by a technique such as a doctor blade. By sintering the obtained magnetic green sheet at 800 to 1300 ° C., the sintered magnetic sheet 2 can be obtained. If a split groove is formed in advance on at least one surface of the magnetic green sheet, the sintered magnetic sheet 2 is easily broken along the split groove, and the sintered magnetic sheet 2 is given flexibility. can do.

When the thickness of the sintered magnetic sheet 2 is 200 μm or less, the real part μ ′ of the magnetic permeability is preferably 100 or more and 180 or less. If it is less than 100, when a perpendicular magnetic field is applied to the sintered magnetic sheet, the rate of transmission of the magnetic flux is large, the eddy current generated in the metal foil is large, the demagnetizing field is large, the magnetic flux is canceled and communication is performed. There arises a problem that a necessary induced current value cannot be obtained. If the real part μ ′ of the magnetic permeability is made larger than 180, the imaginary part μ ″ of the magnetic permeability, which is a loss component, becomes higher than 10 and the induced current value necessary for communication cannot be obtained. Arise.

The thickness of the sintered magnetic sheet 2 is preferably 50 to 200 μm. If the thickness is less than 50 μm, the magnetic field cannot be sufficiently focused, the transmitted magnetic field becomes large, and there is a problem that it is canceled out by the demagnetizing field as described above. When it is thicker than 200 μm, the magnetic field can be sufficiently focused only by the sintered magnetic sheet 2, so that it is not necessary to install the metal foil 4.

The adhesive layer 3 is for bonding the sintered magnetic material sheet 2 and the metal foil 4, and the material thereof is not particularly limited, but acrylic, silicon, epoxy, urethane, or the like is used. be able to.

The thickness of the pressure-sensitive adhesive layer 3 is the distance between the magnetic sheet 2 and the metal foil 4, and the smaller this distance is and the higher the conductivity of the metal foil is, the larger the induced current (eddy current) generated inside the metal foil. When this distance is small, only the adhesive layer may be used, but when this distance is increased, the adhesive layers 3a and 3b are provided on both surfaces of the substrate 5 having a predetermined thickness as shown in FIG. It is preferable. As the base material 5, a resin sheet of polyethylene, polycarbonate, polyimide, acrylic, urethane, or the like can be used, but polyethylene terephthalate is preferable.

The metal foil 4 is suitably made of copper, aluminum, nickel, tin, alloys thereof. In particular, copper is desirable because it has the highest conductivity and is inexpensive. The thickness is preferably 5 to 30 μm. When the thickness is less than 5 μm, a sufficient shielding effect cannot be obtained. When the thickness is more than 30 μm, there are problems of reduced workability and high cost, and the design is contrary to thinning.

Next, a method for laminating the above-described sintered magnetic sheet 2, adhesive layer 3, and metal foil 4 will be described. There are various lamination methods. For example, lamination can be performed using a laminating machine.

As shown in FIG. 3, a roll-like flexible long metal foil 6 laminated in the order of a metal foil 4, an adhesive layer 3 adjusted to a predetermined thickness, and a release paper 7 is set on a roll 8a of a laminating machine. . When the release paper 7 is peeled therefrom and the release paper 7 is taken up by the roll 8 b of the laminating machine, the adhesive layer 3 is exposed on one surface of the metal foil 4. At this time, if an appropriate tension is applied in the width direction of the metal foil 4 to keep the metal foil 4 in a stretched state, lamination can be performed without generating wrinkles.

And the division body of the sintered magnetic material sheet 2 processed beforehand by the predetermined magnitude | size is installed on the conveyor 9. FIG. At this time, if a plurality of the sintered magnetic sheets 2 are arranged at a predetermined interval, a large amount can be efficiently produced. Therefore, it is desirable that the partition of the sintered magnetic sheet be narrower than the width of the flexible long metal foil. And while moving the metal foil 4 which exposed the adhesion layer 3 mentioned above continuously or intermittently, it presses against the sintered magnetic material sheet 2 with the rolls 8c and 8d, and one surface of the sintered magnetic material sheet A metal foil 4 with an adhesive layer is attached to the substrate. Although not shown, an adhesive sheet or the like can be similarly attached to the other surface of the sintered magnetic sheet. Furthermore, the metal foil can be protected by attaching an insulating film or an adhesive layer to the surface where the metal foil 4 is exposed, or the metal foil surface can be directly attached to a battery or the like.

In this way, the electromagnetic wave shielding sheet 1 as shown in FIG. 4A can be obtained. And if it processes to a desired shape by punching, shearing, pressing, etc., the electromagnetic wave shielding sheet of this invention as shown in FIG.4 (b) can be obtained.

Further, when the protective film is bonded to the other surface of the sintered magnetic sheet, the protective film 10, the adhesive layer 3 adjusted to a predetermined thickness, and the release paper 7 are laminated in this order as shown in FIG. A roll-shaped flexible long protective film 11 is set on a roll 8e of a laminating machine. When the release paper 7 is peeled therefrom and the release paper 7 is wound up by the roll 8f of the laminating machine, the adhesive layer 3 is exposed on one surface of the protective film. When the metal foil 4 is pressed with the roll 8 c and the protective film 10 is pressed with the roll 8 d, the sintered magnetic sheet 2 can be interposed between the metal foil 4 and the protective film 10.

Next, the effect of the electromagnetic wave shielding sheet 1 will be described. First, the effect of the prior art that does not use the electromagnetic wave shielding sheet of the present invention will be described. FIG. 6A shows the state of the magnetic field when the magnetic field (H1) is applied to the sintered magnetic sheet 2, but the magnetic field (H1) is sufficiently reduced when the sintered magnetic sheet is thinned. It cannot be focused and generates a transmitted magnetic field (H2). FIG. 6B shows a magnetic field when the sintered magnetic sheet 2 is brought close to a metal environment installed in a mobile phone or the like, for example, the battery 12. When the battery 12 is brought closer, a demagnetizing field (H3) due to the eddy current 13 is generated by the transmitted magnetic field (H2). Since the sintered magnetic sheet 2 completely focuses the magnetic flux against the applied magnetic field (H1) and cannot shield any further magnetic field, the demagnetizing field (H3) due to the transmitted magnetic field (H2) is sintered. The applied magnetic field (H1) is canceled through the magnetic sheet 2. That is, the magnetic field (H5) that can be used for communication is (H5) = (H1) − (H3), and the magnetic field that can be used for communication is reduced due to the influence of the metal environment, which causes communication failure. is there.

Next, FIG. 7 shows a state of a magnetic field when a magnetic body having a magnetic permeability smaller than 100, for example, an electromagnetic wave shielding shield in which a polymer type magnetic body 14 disclosed in Patent Document 1 and a metal foil 4 are laminated is used. Show. A polymer type magnetic body having a thickness of 200 μm or less has a low permeability, so that the transmission ratio of the applied magnetic field (H1) is large, and the transmission magnetic field (H2) is larger than when a sintered magnetic sheet is used. The eddy current 13 and the demagnetizing field (H3) generated in the foil are too large, and the magnetic field (H5) that can be used for communication becomes very small, causing a communication failure.

Next, FIG. 8A shows the state of the magnetic field when the electromagnetic wave shielding sheet 1 of the present invention is used. An eddy current 13 and a demagnetizing field (H3) are generated in the metal foil 4 by the penetrating magnetic field (H2) slightly transmitted through the applied magnetic field (H1), and the magnetic field used for communication is canceled by the applied magnetic field (H1). H5). FIG. 8B shows a magnetic field when the sintered magnetic sheet 2 is brought close to a metal environment installed in a mobile phone or the like, for example, the battery 12. When the battery 12 is brought closer, a further demagnetizing field (H4) against the eddy current generated in the metal foil 4 is generated in the battery 12. Therefore, since an eddy current is generated in the battery in a direction in which the eddy current inside the metal foil is canceled, the magnetic field (H5) used for communication does not decrease even in a metal environment. That is, (H5) in FIG. 8 (a) and (H5) in FIG. 8 (b) are almost the same, and stable communication characteristics can always be obtained without being affected by the metal environment. .

Therefore, by setting the magnetic sheet thickness, magnetic permeability, magnetic loss, metal foil thickness, and distance between the magnetic sheet and the metal foil to a predetermined design in advance, which magnetic field (H5) can be used for communication is determined. Even in such a metal environment, it is always almost constant.

Next, the effect when the electromagnetic wave shielding sheet 1 of the present invention is mounted on a mobile phone for antenna communication will be described. As shown in FIG. 9, the applied magnetic field (H 1) applied from the reader / writer 15 is canceled by the demagnetizing field (H 3) due to the eddy current generated in the metal foil 4 and becomes (H 5). The antenna coil conductor 16 installed on the sintered magnetic material sheet side of the electromagnetic wave shielding sheet 1 causes a current to flow through (H5), and communication is performed by this current. The communication characteristic Q at this time is expressed by Q = 2πfL / R, f is an AC frequency of 13.56 MHz, and the inductance L and the resistance R depend on μ ′ and μ ″ of the magnetic sheet and the material of the antenna coil conductor. An approximate value is determined, and Q required for stable communication is 30 or more.

When the electromagnetic wave shielding sheet 1 is mounted on a mobile phone, there is a problem in that the communication characteristics change due to the influence of the metal environment such as a battery or other metal parts. Since the metallic environment varies depending on the type of mobile phone, an electromagnetic wave shielding sheet that can maintain a constant Q regardless of the metallic environment is required. That is, an electromagnetic wave shielding sheet is required in which the ratio of Q (Q1) when there is no metallic environment to Q (Q2) under the metallic environment is always 1.0 <(Q2) / (Q1) <1.1. is there.

Here, the difference between Q1 and Q2 will be described with respect to the resistance R. As shown in FIG. 10A, in a state where there is no metal environment, the current 17 flowing through the antenna coil conductor 16 flows on the entire cross section of the antenna coil conductor 16 on average, and the current distribution is almost free from bias. . On the other hand, as shown in FIG. 10B, in a metal environment, a capacitor due to a potential difference between the antenna coil conductor 16 and the metal environment, for example, the battery 12 is parasitic and the current distribution is biased. Further, the cross-sectional area of the antenna coil conductor 16 decreases, and the resistance R increases, so that Q decreases. FIG. 10C shows a partial equivalent circuit at that time. However, as shown in FIG. 10 (d), the electromagnetic wave shielding sheet 1 on which the metal foil 4 is previously installed is already a capacitor between the antenna coil conductor 16 and the metal foil 4 even in the absence of a metal environment such as a battery. Is parasitic. When placed in a metal environment such as the battery 12, a capacitor is further parasitic between the metal foil 4 and the battery 12, so that the capacitor is connected in series. It becomes smaller than the state without metal environment. Therefore, the bias of the current distribution in the antenna coil conductor 16 is alleviated, the apparent cross-sectional area of the antenna coil conductor 16 is increased, and the resistance R is decreased, thereby increasing Q. FIG. 10E shows a partial equivalent circuit at that time.

The smaller the dielectric constant between the antenna coil conductor 16 and the metal foil 4, the smaller the rate of change of R. Therefore, it is desirable that the sintered magnetic material sheet 2 and the adhesive layer 3 have a smaller dielectric constant. It is desirable that the sintered magnetic sheet 2 is 15 or less and the dielectric constant of the adhesive layer 3 is 10 or less.

Next, the difference between Q1 and Q2 will be described with respect to the inductance L. As for the inductance L, the metal foil 4 is preliminarily placed on the sintered magnetic sheet 2, so that the parasitic capacitance value between the antenna coil conductors is added to the potential difference generated between the metal foil 4 and the antenna coil conductor 16. The parasitic capacitance increases in parallel between the start and end of the antenna coil conductor 16, and the inductance L value is lowered and stabilized at a predetermined rate. Therefore, even if it is installed in a metal environment such as a battery, the change in the L value is small. Therefore, when the resonance frequency (13.56 MHz) fo = 1 / 2π (√LC) is set in combination with the resonance capacitor Further, the fluctuation of the resonance frequency due to the further change of the metal environment can be minimized.

Therefore, by adopting the configuration requirements of the present invention, it is possible to achieve communication characteristics of 1.0 <(Q2) / (Q1) <1.1 and (Q2)> 30.

Although the details of the present invention have been described above, what has been described here is a specific embodiment of the present invention. Based on the technical idea, the above-described implementation has been made to the extent that the effects of the invention are not significantly impaired. It should be understood that a part of the form can be modified and implemented.

INDUSTRIAL APPLICABILITY According to the present invention, it can be widely used in the field of mobile phones that perform wireless communication such as smartphones.

1: Electromagnetic wave shielding sheet 2: Sintered magnetic material sheet 3: Adhesive layer 4: Metal foil 5: Base material 6: Flexible long metal foil 7: Release paper 8: Roll 9: Conveyor 10: Protective film 11: Possible Flexible long protective film 12: battery 13: eddy current 14: polymer type magnetic body 15: reader / writer 16: antenna coil conductor 17: current H1: applied magnetic field H2: penetrating magnetic field H3: demagnetizing field H4: against eddy current Demagnetizing field H5: Magnetic field after cancellation (magnetic field that can be used for communication)

Claims (11)

In a method of forming a sintered magnetic laminate in which a flexible metal foil is attached to the back surface of a sintered magnetic sheet having a flexible protective film attached to the surface, continuously or intermittently A method for forming a sintered magnetic laminate, comprising: pressing and fixing a flexible long metal foil that moves simultaneously to a sintered magnetic sheet. In a method of forming a sintered magnetic laminate in which a flexible metal foil is attached to the back surface of a sintered magnetic sheet having a flexible protective film attached to the surface, continuously or intermittently A method of forming a sintered magnetic laminate, wherein a sintered magnetic sheet is interposed between a flexible long protective film and a flexible long metal foil that move simultaneously.   The sintered magnetic sheet is composed of a plurality of partitions having a predetermined shape and size, and the partitions are spaced from each other between the flexible long protective film and the flexible long metal foil. The method for forming a sintered magnetic laminate according to claim 1 or 2, wherein the sintered magnetic laminate is inserted into the sintered magnetic laminate.   The method for forming a sintered magnetic laminate according to any one of claims 1 to 3, wherein the sintered magnetic sheet is narrower than a width of the flexible long protective film and the flexible long metal foil. In a method of forming a sintered magnetic laminate in which a flexible metal foil is attached to the back surface of a sintered magnetic sheet having a flexible protective film attached to the surface, the method is continuously or intermittently performed simultaneously. While interposing a sintered magnetic sheet between the moving flexible long protective film and the flexible long metal foil, the obtained sintered magnetic laminate is bonded to the flexible long protective film. A method for forming a sintered magnetic laminate, characterized by forming a fixed-length sintered magnetic laminate by shearing to a predetermined length at a location where a flexible long metal foil is directly joined. A sintered magnetic sheet having a real part μ ′ of a relative permeability of 100 H / m or more, an imaginary part μ ″ of a relative permeability of 10 or less, and a relative permittivity of 15 or less when the AC frequency is excited at 13.56 MHz. An electromagnetic wave shielding sheet for mounting on a non-contact communication device, wherein a metal foil is bonded to one surface of the metal foil via an insulating adhesive layer having a relative dielectric constant of 10 or less. A sintered magnetic sheet having a real part μ ′ of a relative permeability of 100 H / m or more, an imaginary part μ ″ of a relative permeability of 10 or less, and a relative permittivity of 15 or less when the AC frequency is excited at 13.56 MHz. A metal foil is bonded to one surface of the sintered magnetic sheet via an insulating adhesive layer having a relative dielectric constant of 10 or less, and a protective film is bonded to the other surface of the sintered magnetic sheet via the insulating adhesive layer. Electromagnetic wave shielding sheet for mounting non-contact communication equipment. The electromagnetic wave shielding sheet for mounting a non-contact communication device according to claim 6 or 7, wherein an insulating film or an adhesive layer is formed on a surface of the metal foil. The electromagnetic shielding sheet for mounting a non-contact communication device according to any one of claims 6 to 8, wherein the sintered magnetic material sheet has a thickness of 50 to 200 µm. The electromagnetic shielding sheet for mounting a non-contact communication device according to any one of claims 6 to 9, wherein the metal foil has a thickness of 5 to 30 µm. Q value when a spiral antenna coil conductor is disposed on the other surface of the sintered magnetic sheet (Q1), and Q value when a metal is further disposed on the metal foil side in addition to the antenna copper wire ( The non-contact communication device according to any one of claims 6 to 10, wherein a ratio to Q2) satisfies 1.0 <(Q2) / (Q1) <1.1 and satisfies (Q2)> 30. Electromagnetic wave shielding sheet for mounting.

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