WO2019111848A1

WO2019111848A1 - Coil module

Info

Publication number: WO2019111848A1
Application number: PCT/JP2018/044365
Authority: WO
Inventors: 勝利平川; 中村　浩一
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2017-12-06
Filing date: 2018-12-03
Publication date: 2019-06-13
Also published as: JP2019102718A

Abstract

One aspect of the present invention relates to a coil module comprising: a flat coil used for power transmission for contactless charging; a magnetic sheet that is made of a first magnetic body forming a magnet path on the flat coil, that is 10-300 µm thick, and that has a hole in the center; and a diamagnetic section disposed adjacent to the hole.

Description

Coil module

The present invention is applied to an antenna module or a non-contact charging module equipped with wireless power supply such as Qi formulated by NFC (Near Field Communication) or WPC (Wireless Power Consortium) and Powermat formulated by PMA (Power Matters Alliance). The present invention relates to a coil module to be used.

The RFID (Rasio Frequency IDentification) supporting the ubiquitous society has been put to practical use in various fields, and one example is the installation of a noncontact IC card function on a portable terminal.

Currently, the movement to mount NFC in the 13.56 MHz band on mobile terminals is accelerating, but in recent years not only NFC but also non-contact charging modules have been mounted on mobile terminals, and charging of mobile terminals is non-contact charging It is also proposed to do. In this case, a transmitting coil is disposed on the charger side, and a receiving coil is disposed on the portable terminal. For example, in the case of WPC, electromagnetic induction is generated between both coils at a frequency of 100 kHz band (100 to 300 kHz). Technology to charge the

NFC is a short-distance wireless communication that communicates by electromagnetic induction using a frequency of 13.56 MHz band, while non-contact charging performs power transmission by electromagnetic induction of a coil using a frequency of 100 kHz band. is there. Therefore, when trying to configure the NFC antenna and the noncontact charging coil in the same module, the resonance frequency of the 13.56 MHz band of the NFC antenna and the resonance frequency of the 100 kHz band of the noncontact charging coil are different. A means has been proposed to improve both the communication efficiency of NFC and the power transfer efficiency of contactless charging by laminating two different types of magnetic materials. (For example, patent document 1).

Also, in the non-contact charging module, WPC generates electromagnetic induction between both coils at a frequency of 100 kHz band as described above to charge the portable terminal, but PMA needs to adjust the environment of special detection operation, Frequencies in the 200-400 kHz band are used.

As described above, since the frequency band is different depending on the type of wireless charging method, different modules have been used in the WPC module and the PMA module. However, recently, so-called combo type modules capable of supporting both WPC's Qi standard and PMA's Powermat standard are being developed.

As shown in FIG. 1, the combo type module currently being implemented includes a heat dissipation layer 5 (usually carbon such as graphite), an FPC (Flexible Printed Circuit) 6 composed of a coil 2 and a substrate 3, and high permeability ( It is known to be provided with a magnetic sheet 1 made of a magnetic material having μ ′) and a magnetic sheet 4 made of a magnetic material having a high saturation magnetic flux density (Bs).

However, in the case of employing a different metal such as amorphous as the magnetic material having a high magnetic permeability (μ ′) or a high saturation magnetic flux density (Bs), magnetic saturation may be accelerated to generate heat. Due to this heat generation, the transmission speed becomes slow, which causes a problem that the charging efficiency is deteriorated.

On the other hand, it is conceivable to use ferrite having a high permeability as the magnetic material, but the ferrite has a lower saturation magnetic flux density as compared with metal-based magnetic materials such as amorphous (noncrystalline metal) and nanocrystal metal. Therefore, when the thickness of the magnetic sheet is reduced, a good PMA detection operation can not be obtained, and there is a problem that the demand for thinning of a module used for a mobile phone can not be sufficiently satisfied.

In view of the above, it is an object of the present invention to provide a combo-type coil module that enables thin-walled power transmission in non-contact charging of both the PMA system and the WPC system.

JP 2013-121248 A

As a result of intensive studies, the present inventors have found that the above problems can be solved by the module having the following configuration, and completed the present invention by repeating studies based on such findings.

That is, the coil module according to one aspect of the present invention comprises a planar coil used for non-contact charge power transmission and a first magnetic body forming a magnetic path of the planar coil, and has a thickness of 10 to 300 μm, A magnetic sheet having a hole at a central portion, and a diamagnetic part disposed adjacent to the hole are characterized.

FIG. 1 is a schematic cross-sectional view showing an example of a conventional combo-type coil module. FIG. 2 is a schematic cross-sectional view showing an example of the coil module of the present embodiment. FIG. 3 is a schematic cross-sectional view showing still another example of the coil module of the present embodiment. FIG. 4 is a schematic plan view showing an example of the shape of the central portion of the magnetic sheet used in the coil module of the present embodiment. FIG. 5 is a schematic cross-sectional view showing an example of a conventional antenna module. FIG. 6 is a schematic cross-sectional view showing an example of the antenna module of the present embodiment.

According to the present invention, in order to enable stable PMA detection operation while being thin, a combo-type coil capable of supporting power transmission in both WPC (Qi) and PMA (Powermat) non-contact charging. It becomes possible to provide a module.

Hereinafter, although a coil module in an embodiment of the present invention is explained using a drawing etc., a coil module of the present invention is not necessarily limited to these. In each drawing, each symbol is:
1 Magnetic sheet (first magnetic body),
2 planar coils,
3 substrates,
4 Magnetic sheet different from the magnetic sheet made of the first magnetic material,
5 heat radiation layers,
6 FPC,
7 diamagnetic part,
8 holes,
9 Second magnetic body,
10 Indicates the periphery.

First, the coil module of the present embodiment will be described.

First Embodiment
FIG. 2 is a schematic cross-sectional view showing an example of the coil module of the present embodiment.

As shown in FIG. 2, in the coil module of this embodiment, a planar coil 2, a magnetic sheet 1 having a hole 8 at the center, and a diamagnetic part 7 disposed adjacent to the hole are included. At least equipped.

The planar coil 2 is disposed on the substrate 3. In addition, two or more layers may be stacked with the substrate 3 interposed therebetween. Furthermore, the coil module of the present embodiment may include two or more types of planar coils, and for example, is used for near-field wireless communication in addition to the planar coil used for non-contact charge power transmission. A planar coil may be provided.

An adhesive layer may be provided between the planar coil 2 and the magnetic sheet 1 as necessary.

The substrate 3 is not particularly limited as long as it is a relatively thin insulating layer, but materials having good heat resistance and mechanical properties are preferably used. In particular, a flexible substrate formed of a flexible insulating film (sheet) or the like is preferable. As a specific example of an insulating film, the film of a polyimide, PET, an epoxy resin composition type | system | group is mentioned. It may be an insulating substrate reinforced with a fiber base material such as glass cloth. It can also be used in the form of an FPC (flexible printed circuit board) in which a conductor circuit is formed as a planar coil on an insulating film (sheet). By using polyimide, PET, or the like as a substrate, a thin and flexible antenna module can be manufactured. In the embodiment, for example, it is preferable to use a polyimide film having a thickness of 10 to 200 μm.

The planar coil 2 of the present embodiment is a so-called charging coil that performs non-contact charge power transfer such as non-contact charge by electromagnetic induction using a frequency of about 100 to 400 kHz according to the standard such as WPC or PMA. The charging coil is formed, for example, by plating a copper foil having a line width of about 800 μm and a thickness of about 60 μm, using two terminals as a start and an end, and draws a vortex on the surface centering on the hollow portion. It is preferable that it is wound.

Furthermore, in the case of including a planar coil used for near-field wireless communication, the planar coil may be, for example, a coil that performs near-field wireless communication by electromagnetic induction using a specific frequency band called RFID. For example, in the case of NFC (Near Field Communication), a frequency of 13.56 MHz can be used. The NFC antenna is an antenna that communicates by electromagnetic induction using a frequency of 13.56 MHz band, and a seat antenna is generally used. In this case, since a single substrate has two types of planar coils, multifunctionality and miniaturization can be realized.

The planar coil 2 is usually wound on a substrate 3. Although a so-called α winding is mentioned as a specific example of the winding method of the planar coil 2, it is not limited to this winding method, and any shape such as a substantially rectangular shape including a substantially rectangular shape, a substantially square, an oval or a polygon It may be Moreover, in FIG. 2, although the number of turns of the planar coil 2 is 3 turns, it is not necessarily limited to this number of turns. There are no particular limitations on the material, height, and width of the conductors constituting the planar coil 2 and the gap between the adjacent conductors. For example, a metal foil such as copper foil can be used as the material of the conductor, and the height of the conductor, that is, the thickness of the planar coil 2 is preferably 30 to 150 μm, and about 70 to 80 μm. More preferable.

When two types of planar coils are provided, it is preferable that one of the planar coils be provided inside the other planar coil. From the viewpoint of less interference with communication, it is preferable that a flat coil for performing non-contact power transmission be provided inside, and a flat coil for performing near-field wireless communication be provided on the outside.

Assuming that the front and back of the substrate 3 are respectively a first surface and a second surface, planar coils 2 are provided on the first surface and the second surface of the substrate 3 respectively. The planar coil 2 may be electrically connected by a copper plating through hole.

In addition, a protective layer may be provided on the first surface and the second surface of the substrate to protect the planar coil 2 (not shown). As a specific example of a protective layer, the hardened | cured material of a liquid solder resist, a solder resist film, or a coverlay is mentioned. A protective layer may or may not be provided, and planar coil 2 may be provided on both the first surface and the second surface of substrate 3 (two-layer structure), the first surface of the substrate Alternatively, it may be provided on any one side of the second surface (one-layer structure).

The magnetic sheet 1 of the present embodiment is disposed to be in contact with the planar coil 2 (an adhesive layer may be present between them). The magnetic sheet 1 is made of a first magnetic material that forms the magnetic path of the planar coil 2, has a thickness of 10 to 300 μm, and has a hole 8 at its central portion.

As the first magnetic body used in the present embodiment, a ferrite sintered body, an amorphous, a silicon steel plate or the like can be used, and in particular, a ferrite sintered body is preferable. By forming the magnetic sheet 1 with a ferrite sintered body, in addition to supporting both the WPC (Qi) system and the PMA system, it is effective to reduce the thickness of the entire coil module. As the ferrite sintered body, specifically, Mn—Zn based ferrite and, depending on the application, magnetic materials such as Ni—Zn based ferrite, Mn—Ni based ferrite, Mg—Zn based ferrite and the like can be used.

When the thickness of the magnetic sheet 1 is less than 10 μm, the magnetic effect is reduced and it can not be an effective magnetic path. On the other hand, if it exceeds 300 μm, it may become an effective magnetic path, but it will go against thinning of the module. In recent years, there has been a strong demand for thinning modules, and the thickness of a more preferable magnetic sheet for meeting such needs is 10 to 150 μm.

The central portion in the magnetic sheet 1 of the present embodiment means the insulating layer portion of the substrate 3 which is the innermost diameter portion of the planar coil 2 and is not in contact with the conductor circuit of the innermost diameter.

Furthermore, in the magnetic sheet 1 of the present embodiment, as shown in FIG. 4, the saturation magnetic flux density is higher than that of the peripheral portion 10 in the peripheral portion 10 of the air hole 8 ′ (same as the air hole 8 in FIG. The height is preferably higher than that of the outer region, and preferably 1.1 times or more. Here, the peripheral portion 10 refers to a range of about 1 mm to 1 cm from the outer end of the hole 8 '.

In order to increase the saturation magnetic flux density in the peripheral portion 10, for example, it is conceivable to perform a break process on the peripheral portion of the first magnetic body (ferrite). The breaking process is a process of forming a protective layer of PET film on the upper and lower surfaces of the magnetic body when making the magnetic sheet, and pressing (breaking process) the cylindrical rigid body in the longitudinal and lateral directions. By this process, the magnetic material present in the protective layer is finely divided, and the magnetic sheet becomes flexible.

By applying such a break treatment to the peripheral portion 10, the permeability of that portion tends to decrease, but the saturation magnetic flux density becomes high. When the saturation magnetic flux density is high in the peripheral portion 10, there is an advantage that, in particular, the detection operation of PMA is stabilized.

The magnetic sheet 1 may have a protective layer (not shown) on the front side and the back side, respectively. As the protective layer, an ultraviolet curable resin, a visible light curable resin, a thermoplastic resin, a thermosetting resin, a heat resistant resin, a synthetic rubber, a double-sided tape, an adhesive layer, a film or the like can be used. The protective layer may not be provided.

Next, the diamagnetic part 7 provided in the coil module of the present embodiment will be described. In the present embodiment, the “diamagnetic part” means a region having a higher diamagnetism than a peripheral region (outside the diamagnetic portion in a plan view). Specifically, it refers to a region which can be expressed as a numerical value of the diamagnetic susceptibility and in which the diamagnetic susceptibility shows a value higher than -1.6 × 10 ^-5 .

The diamagnetic part 7 is disposed adjacent to the air holes 8 of the magnetic sheet 1. Further, in plan view, the diamagnetic portion 7 is preferably the same size as the area of the air holes 8 or smaller in size.

As a material that can be used as the diamagnetic part 7, as described above, any material having high diamagnetic properties (diamagnetic susceptibility) is considered to be usable without particular limitation, but specifically, for example, pyrolytic carbon Or silver foil can be used. Pyrolytic carbon is a heat diffusion material with high thermal conductivity. A commercial item can also be used as such thermal decomposition carbon, For example, "PGS (Pyrolytic Graphite Sheet: thermal decomposition graphite sheet)" made from Panasonic etc. is mentioned.

The periphery of the diamagnetic part 7 may be formed of a support or the like, but preferably, in the coil module of this embodiment, the heat dissipation layer 5 is disposed adjacent to (laminated with) the magnetic sheet 1. The diamagnetic portion 7 may occupy the central region of the heat dissipation layer 5.

In particular, in the case of PMA wireless charging, a Hall element sensor and a magnet are used for the wireless charger (Tx) to transmit power in order to detect the coil position on the side of the mobile phone terminal (Rx) to receive power. As in the present embodiment, the presence of the diamagnetic region at the central portion of the heat dissipation layer is considered to cause the magnetic flux from the magnet to be bent and the magnetic flux to be directed to the magnetic sheet (magnetic body). By changing the magnetic flux in this manner, a PMA detection operation is obtained and charging is started.

On the other hand, PMA detection does not occur in a coil module using a thin magnetic sheet only by providing a general carbon sheet used until now as a heat dissipation layer. On the other hand, when a sheet having diamagnetism in the entire region is used as the heat dissipation layer, the saturation magnetic flux density of the magnetic sheet decreases, and the PMA detection operation becomes unstable.

Further, in the coil module of the present embodiment, the battery pack (described later) disposed near the heat dissipation layer does not reach the magnetic flux due to the diamagnetism of the diamagnetic portion 7 in the heat dissipation layer 5. No eddy current is generated on the surface of Therefore, according to the present embodiment, there is also an advantage that the heat generation of the battery pack is suppressed at the time of charging.

In the present embodiment, in the heat dissipation layer 5, the diamagnetic portion 7 is made of pyrolytic carbon or silver foil, and the peripheral region outside the diamagnetic portion 7 is made of a material having a lower diamagnetic susceptibility than the diamagnetic portion 7. Is preferred. More preferably, the peripheral region is made of a graphite sheet.

The diamagnetic portion 7 is present in the central region of the heat dissipation layer 5, but in the present embodiment, the central region of the heat dissipation layer is the innermost portion of the planar coil 2 and is the conductor circuit of the innermost diameter. The area of the insulating layer portion of the substrate 3 which is not in contact is referred to.

Thus, the presence of the diamagnetic portion 7 in the central region can more reliably obtain the above-described effect.

The thickness of the heat dissipation layer 5 in the present embodiment is preferably 10 to 100 μm. If the thickness of the heat dissipation layer 5 is within the above range, there is an advantage that a relatively thin heat dissipation effect with high efficiency can be obtained. A more preferable thickness range for thinning is 10 to 30 μm.

Furthermore, the coil module of the present embodiment may further include a metal plate disposed adjacent to the diamagnetic portion 7 (or the heat dissipation layer 5) and used as a battery pack.

The metal plate that can be used as the battery pack in the present embodiment is not particularly limited as long as it is a metal plate used for non-contact charging, and examples thereof include an aluminum alloy and the like.

Second Embodiment
When the thickness of the magnetic sheet included in the coil module is less than 130 μm, as shown in FIG. 3, the holes 8 in FIG. 2 have the second magnetic body 9 different from the first magnetic body constituting the magnetic sheet 1 Is preferred. As the second magnetic body 9, it is preferable to use a material having a saturation magnetic flux density higher than that of the first magnetic body.

The “material having high saturation magnetic flux density” is a material having a saturation magnetic flux density of 1 (unit T: Tesla) or more, and specifically, for example, a silicon steel plate (saturation magnetic flux density: 1.7 to 2. 1), electromagnetic soft iron (saturation magnetic flux density: 2.1 to 2.3), Fe-based amorphous (saturation magnetic flux density: 0.8 to 1.8), and the like.

That is, the coil module according to the second embodiment of the present invention includes the planar coil 2 and the magnetic sheet 1 having the second magnetic body 9 at the center and having a thickness of less than 130 μm, and the second magnetic body 9. At least the adjacent diamagnetic portion 7 (or the heat dissipation layer 5 having the diamagnetic portion 7 in the central region) is provided. Here, the planar coil 2 and the diamagnetic portion 7 (or the heat dissipation layer 5) have the same configuration as the coil module of the first embodiment described above. Furthermore, you may provide the metal plate for battery packs which was mentioned above.

In the coil module of the present embodiment, the second magnetic body 9 receives the magnetic field from the permanent magnet incorporated in the wireless charger (Tx) due to its high saturation magnetic flux density, and the coil module in the mobile phone terminal (Rx) It plays a role of greatly changing the saturation flux density in the periphery.

Therefore, by providing the second magnetic body 9 having a high saturation magnetic flux density, the saturation magnetic flux density is largely changed, and the Hall element sensor immediately below the permanent magnet detects the change, which is advantageous in that PMA wireless charging can be easily activated. There is.

The size of the second magnetic body 9 is not particularly limited as long as it is present at the central portion of the magnetic sheet 1, but the second magnetic body 9 preferably has the same shape as the holes 8 of the magnetic sheet 1. It is preferable that it be inserted inside. Thereby, there is an advantage that the thickness reduction of the coil module can be further achieved.

The thickness of the second magnetic body 9 is preferably equal to or greater than the thickness of the magnetic sheet 1.

Third Embodiment
If the thickness of the magnetic sheet 1 is 200 μm or more, the inside of the air hole 8 of the magnetic sheet 1 may be a void (that is, the second magnetic body 9 or the like need not be provided in the air hole 8) ).

(Antenna module)
The present invention further includes an antenna module including a planar coil used for non-contact charge power transmission, a magnetic sheet made of a ferrite sheet, and a heat dissipation layer. The antenna module according to the present embodiment is characterized in that the magnetic sheet and the planar coil are directly stacked, and the antenna module is fixed to the antenna substrate by the adhesive surface of the heat dissipation layer.

In the conventional antenna module, Fe-based amorphous metal or the like is used as the magnetic material in the magnetic sheet. Since such a magnetic body is a conductor, it is necessary to put some sort of insulator between the magnetic sheet and the coil. Therefore, in the conventional antenna module, as shown in FIG. 5, the double-sided tape 11 and the protective layer 12 which also play a role as an insulator were provided on the front and back of the magnetic sheet 1.

In the antenna module of this embodiment, since ferrite, which is an insulating material, is used as the magnetic body, no problem occurs even if it is in direct contact with the coil. Therefore, the double-sided tape, which was conventionally required, can omit the protective layer, and can realize further thinning and cost reduction of the antenna module.

More specifically, as shown in FIG. 6, in the antenna module of the present embodiment, the FPC 6 having an antenna coil, the magnetic sheet 1, and the heat dissipation layer 5 are stacked in this order. The FPC 6 and the magnetic sheet 1 can be directly stacked without being bonded.

The magnetic sheet 1 and the heat dissipation layer 5 may be joined using the double-sided tape 11. In addition, the central portion of the magnetic sheet 1 may be provided with a magnetic sheet 4 made of a magnetic material different from the magnetic sheet 1.

As the FPC 6 including the planar coil used in the antenna module of the present embodiment, the same FPC as that used in the above-described coil module can be used.

Further, in the antenna module of the present embodiment, the magnetic body constituting the magnetic sheet 1 is a ferrite sintered body, and more specifically, Mn—Zn ferrite, Ni—Zn ferrite, Mn— depending on the application. Magnetic materials such as Ni-based ferrite and Mg-Zn-based ferrite can be used.

It is preferable that the thermal radiation layer 5 of this embodiment is a graphite sheet.

As a magnetic body which comprises the magnetic sheet 4 which consists of a magnetic body different from the magnetic sheet 1, it is preferable that they are materials with high saturation magnetic flux density, such as a silicon steel plate, electromagnetic soft iron, an amorphous sheet, for example.

The antenna module of the present embodiment is fixed to the antenna substrate by the adhesive surface of the heat dissipation layer 5. Here, the adhesive surface refers to on the polyimide film or on a conductor other than the planar coil at the margin portion outside the conductor circuit of the outermost diameter of the planar coil in the FPC 6.

First, the materials used will be described.
Magnetic sheet: Ferrite sheet having a thickness of 100, 120 or 200 μm (“MC1900”, manufactured by Panasonic Excel Products Co., Ltd.)
Magnetic material different from the above magnetic sheet: Silicon steel sheet ("GT-100", manufactured by Nichigan Denka Kogyo Co., Ltd.)
・ Antimagnetic part: Pyrolytic carbon sheet (graphite carbon, "PGS" made by Panasonic Corporation)
Heat dissipation sheet: General graphite sheet (sheet with a diamagnetic susceptibility lower than -1.6 × 10 ^-5 , "TGS series" manufactured by Tanyuan Co.)

(Manufacture of antenna module)
A hole for a copper plating through hole was arbitrarily created in a polyimide flexible copper clad laminate having a copper foil of 50 μm thickness on both sides, and 10 μm thick copper plating was applied on both sides. A design circuit functioning as a wireless charging antenna coil was formed by etching to obtain a planar coil.

Then, as shown in Table 1 below, the antennas of Examples 1 to 3 and Comparative Example 1 using the above-mentioned magnetic sheet, the heat dissipation sheet with high diamagnetic susceptibility (diamagnetic part), the heat dissipation sheet, and the magnetic material. I created a module.

(PMA detection and charging)
Whether the PMA detection was performed by removing the existing antenna module built in to the actual smartphone using the battery pack ("Battery pack for GALAXY NOTE FE manufactured by Samsung Electronics Co., Ltd.") and attaching the antenna module of this creation, Then I checked if it was charged.

The results are shown in Table 1.

From the results of Table 1, it was confirmed that the use of the coil module of the present invention enables PMA detection and charging while being very thin.

This application is based on Japanese Patent Application No. 2017-234117 filed on Dec. 6, 2017, the contents of which are included in the present application.

Although the present invention has been described appropriately and sufficiently through the embodiments with reference to specific examples, drawings, etc. in order to express the present invention, those skilled in the art may change and / or improve the above embodiments. It should be recognized that is an easy thing to do. Therefore, unless a change or improvement performed by a person skilled in the art is at a level that deviates from the scope of the claims of the claims, the change or the improvement is the scope of the claims of the claim It is interpreted as being included in

The coil module of the present invention is a so-called combo-type coil module that is very thin and enables power transfer in both PMA and WPC non-contact charging. Therefore, the present invention is extremely useful for various electronic devices such as an antenna device provided with a non-contact charging coil, a portable terminal, particularly a smartphone, a portable audio, a personal computer, a digital camera, a video camera and the like.

Claims

A planar coil used for non-contact charge power transmission;
A magnetic sheet made of a first magnetic material forming a magnetic path of the planar coil, having a thickness of 10 to 300 μm, and having a hole at the center portion;
And a diamagnetic part disposed adjacent to the air hole.
The coil module according to claim 1, wherein the diamagnetic part exhibits a diamagnetic susceptibility higher than −1.6 × 10 −5 .
The coil module according to claim 1, wherein the diamagnetic part is made of pyrolytic carbon or silver foil.
The coil module according to any one of claims 1 to 3, further comprising a heat dissipation layer adjacent to the magnetic sheet, wherein the diamagnetic portion occupies a central region of the heat dissipation layer.
The coil module according to claim 4, wherein in the heat dissipation layer, a peripheral region outside the diamagnetic portion is made of a material having a diamagnetic susceptibility lower than that of the diamagnetic portion.
The coil module according to claim 5, wherein in the heat dissipation layer, the peripheral region is formed of a graphite sheet.
The coil module according to any one of claims 4 to 6, wherein the thickness of the heat dissipation layer is 10 to 100 μm.
The thickness of the said magnetic sheet is less than 130 micrometers, and it is equipped with the 2nd magnetic body which has a saturation magnetic flux density higher than the said 1st magnetic body in the void | hole of the said magnetic sheet. Coil module.
The coil module according to claim 8, wherein the second magnetic body is at least one selected from silicon steel, electromagnetic soft iron, and amorphous.
The coil module according to any one of claims 1 to 9, wherein the diamagnetic part has a size equal to or smaller than the area of the void in a plan view.
The coil module according to claim 1, wherein the thickness of the magnetic sheet is 200 μm or more, and the inside of the pores of the magnetic sheet is a void.
The coil module according to any one of claims 1 to 11, further comprising a metal plate disposed adjacent to the diamagnetic part and used as a battery pack.
The coil module according to any one of claims 1 to 12, wherein the first magnetic body is ferrite.
The coil module according to any one of claims 1 to 13, wherein the magnetic sheet has a higher saturation magnetic density at the periphery of the void than in a region outside the periphery.
A planar coil used for non-contact charge power transmission, a magnetic sheet made of a ferrite sheet, and a heat dissipation layer,
An antenna module characterized in that the magnetic sheet and the planar coil are directly stacked, and the antenna sheet is fixed to the antenna substrate by an adhesive surface of the heat dissipation layer.