Magnetic sheet, electronic device and electronic device

Abstract

The present invention provides a magnetic sheet, an electronic device, and an electronic device. The magnetic sheet includes: a magnetic layer; a heat radiation layer having protrusions and depressions formed in a surface facing the magnetic layer; and an adhesive layer provided between the magnetic layer and the heat radiation layer and including a heat radiation filler having shape anisotropy.

Description

[0001] This application claims the benefit of priority from Korean Patent Application No. 10-2018-0038222 filed on April 2, 2018, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety for all purposes by reference. Technical Field

[0002] The following description relates to a magnetic sheet, an electronic device, and an electronic device. Background Art

[0003] In recent years, the Wireless Power Consortium (WPC) function, the Near Field Communication (NFC) function, the Magnetic Secure Transmission (MST) function, etc. have been used in mobile portable devices. WPC technology, NFC technology and MST technology have differences in operating frequency, data rate, transmission power value, etc.

[0004] In wireless power transmitters, magnetic sheets are used to block and collect electromagnetic waves. For example, in wireless charging devices, the magnetic sheet is provided between the receiving part coil and the battery. The magnetic sheet shields and collects the magnetic field generated in the receiving part coil, and blocks the magnetic field from being transmitted to the battery, thereby allowing the electromagnetic waves generated from the wireless power transmitter to be effectively received by the wireless power receiver.

[0005] According to the multifunctionalization and improvement of the functions of portable electronic devices using such magnetic sheets, there has been a continuous demand for improving the performance of magnetic sheets. In the case of wireless charging using magnetic sheets, power of several watts to tens of watts is constantly moved, resulting in loss of materials and circuits. As a result, a large amount of heat is generated. Therefore, in the art, a method for effectively discharging heat generated from electromagnetic wave shielding sheets, coil parts, etc. is being studied. Summary of the invention

[0006] This summary is provided to introduce selected concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0007] In one general aspect, a magnetic sheet includes: a magnetic layer; a heat radiation layer including projections and depressions formed in a surface facing the magnetic layer; and an adhesive layer disposed between the magnetic layer and the heat radiation layer and including a heat radiation filler having shape anisotropy.

[0008] The thermal radiation filler may include a first thermal radiation filler having a sheet shape, a plate shape, or a rod shape, and a length of a major axis of the first thermal radiation filler may be different from a length of a minor axis of the first thermal radiation filler.

[0009] The first heat radiating filler may be oriented along a thickness direction of the magnetic layer.

[0010] The adhesive layer may fill a space formed by the protrusions and recesses.

[0011] The thickness of the protrusions and recesses may be greater than or equal to one fifth of the thickness of the adhesive layer.

[0012] The first heat radiating filler may be disposed in the space formed by the protrusions and recesses.

[0013] The protrusions and recesses may have inclined surfaces inclined with respect to the magnetic layer, and the first heat radiating filler disposed in the space may be parallel to the inclined surfaces.

[0014] A surface of the first heat radiative filler in a major axis direction may face the inclined surface.

[0015] More than half of the first heat radiative filler disposed in the space may be parallel to the inclined surface.

[0016] The length of the major axis of the first heat radiative filler may be greater than or equal to one third of the thickness of the protrusions and recesses.

[0017] The thermally radiative filler may further include a second thermally radiative filler in the form of nanowires.

[0018] The second heat radiating filler may connect two or more first heat radiating fillers to each other.

[0019] The second heat radiative filler may include a silver (Ag) component.

[0020] The second heat radiating filler may have a shape corresponding to a shape of the protrusions and recesses.

[0021] The thermal radiation filler may include nanowires having a shape corresponding to a shape of the protrusions and recesses.

[0022] The heat radiation layer may be copper foil.

[0023] In another general aspect, an electronic device includes a coil portion having a coil pattern and a magnetic sheet. The magnetic sheet includes: a magnetic layer facing the coil portion; a heat radiation layer including protrusions and depressions formed in a surface facing the magnetic layer; and an adhesive layer disposed between the magnetic layer and the heat radiation layer and including a heat radiation filler having shape anisotropy.

[0024] The heat radiation layer may include two or more protrusions and depressions, and a distance between adjacent protrusions and depressions may be shorter than a length of the heat radiation filler.

[0025] In another general aspect, an electronic device includes a coil portion having a coil pattern, a battery, and a magnetic sheet disposed between the coil pattern and the battery. The magnetic sheet includes: a magnetic layer configured to face the coil portion; a heat radiation layer including a protrusion protruding from a surface facing the magnetic layer; and an adhesive layer disposed between the magnetic layer and the heat radiation layer. The adhesive layer includes a heat radiation filler having shape anisotropy.

[0026] Other features and aspects will be apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a perspective view showing the appearance of a general wireless charging system.

[0028] Figure 2 It is shown Figure 1 Exploded cross-section view of the main internal components.

[0029] Figure 3 is a schematic plan view showing a magnetic sheet according to an example.

[0030] Figure 4 It is shown Figure 3 An enlarged view of region A in the magnetic sheet.

[0031] Figure 5A , Figure 5B and Figure 5C It shows that Figure 3 The shape of the heat radiating filler used in the magnetic sheet.

[0032] Figure 6 and Figure 7 Concerning the magnetic sheet according to the example, an enlarged view of the vicinity of the heat radiation layer and the adhesive layer is shown.

[0033] Throughout the drawings and detailed description, like reference numerals refer to like elements. The drawings may not be drawn to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience. DETAILED DESCRIPTION

[0034] The following detailed description is provided to assist the reader in obtaining a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent upon understanding the disclosure of the present application. For example, the order of operations described herein is merely exemplary and is not limited to those set forth herein, but may be altered in ways that will be apparent upon understanding the disclosure of the present application, except for operations that must occur in a particular order. Furthermore, descriptions of features known in the art may be omitted for increased clarity and brevity.

[0035] The features described herein may be implemented in different forms and shall not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0036] Here, it should be noted that the use of the term "may" with respect to an example or embodiment (e.g., with respect to what an example or embodiment may include or implement) means that there is at least one example or embodiment that includes or implements such features, and all examples and embodiments are not limited to this.

[0037] Throughout the specification, when an element such as a layer, a region or a substrate is described as being “on”, “connected to” or “coupled to” another element, the element may be directly “on”, “connected to” or “coupled to” the other element, or one or more other elements may be present between them. Conversely, when an element is described as being “directly on”, “directly connected to” or “directly coupled to” another element, other elements may not be present between them.

[0038] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more.

[0039] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Specifically, these terms are only used to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0040] For ease of description, spatially relative terms such as "above", "on", "below", and "below" may be used herein to describe the relationship of one element to another element as shown in the figure. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, an element described as being "above" or "on" relative to another element will subsequently be "below" or "below" relative to the other element. Therefore, the term "above" includes both above and below orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein will be interpreted accordingly.

[0041] The terms used herein are only used to describe various examples and are not intended to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprises", and "have" list the existence of the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0042] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0043] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations that will be apparent after understanding the disclosure of the present application are possible.

[0044] Figure 1 is a schematic perspective view showing the appearance of a general wireless charging system, Figure 2 It is shown Figure 1 Exploded cross-section view of the main internal components.

[0045] Reference Figure 1 and Figure 2 , a general wireless charging system may include a wireless power transmitter 10 and a wireless power receiver 20, and the wireless power receiver 20 may be included in an electronic device 30 such as a mobile phone, a notebook, a tablet personal computer (PC), etc.

[0046] The wireless power transmitter 10 may include a transmitting part coil 11 formed on a substrate 12. When an alternating current (AC) voltage is applied to the wireless power transmitter 10, a magnetic field may be formed around the wireless power transmitter 10. Electromotive force may be induced from the transmitting part coil 11 to the receiving part coil 21 embedded in the wireless power receiver 20, so that the battery 22 may be charged.

[0047] The battery 22 may be a rechargeable nickel-metal hydride battery or a lithium-ion battery, but is not particularly limited to these types of batteries. The battery 22 may be constructed separately from the wireless power receiver 20 and may be detachable from the wireless power receiver 20, or may be an integral form in which the battery 22 and the wireless power receiver 20 are integrally constructed.

[0048] The transmission part coil 11 and the receiving part coil 21 may be electromagnetically coupled to each other and may be formed by winding a metal wire formed using copper, etc. The winding shape of the transmission part coil 11 and the receiving part coil 21 may be circular, elliptical, quadrilateral, rhombus, etc., and the overall size, number of turns, etc. of the transmission part coil 11 and the receiving part coil 21 may be appropriately controlled and set according to the desired characteristics.

[0049] The magnetic sheet 100 may be respectively disposed between the receiving part coil 21 and the battery 22 and between the transmitting part coil 11 and the substrate 12. The magnetic sheet 100 may shield the magnetic flux formed at the central portion of the transmitting part coil 11, and when the magnetic sheet 100 is disposed on the receiving part side, the magnetic sheet 100 may be positioned between the receiving part coil 21 and the battery 22 and collect the magnetic flux to allow the magnetic flux to be effectively received by the receiving part coil 21. The magnetic sheet 100 may be used to block at least some of the magnetic flux from being transmitted to the battery 22.

[0050] The magnetic sheet 100 can be combined with the coil part and used in the receiving part of the above-mentioned wireless charging device. In addition to being used for wireless charging devices, the coil part can also be used for magnetic secure transmission (MST), near field communication (NFC), etc. When the transmitting part coil and the receiving part coil do not need to be distinguished from each other, both of them will be referred to as the coil part hereinafter. The magnetic sheet 100 will be described in more detail below.

[0051] Figure 3 is a schematic cross-sectional view showing a magnetic sheet according to an example. Figure 4 It is shown Figure 3 This is an enlarged view of region A in the magnetic sheet and corresponds to the state before heat treatment. Figures 5A to 5C It shows that Figure 3 The shape of the heat radiating filler used in the magnetic sheet.

[0052] Reference Figure 3 and Figure 4, the magnetic sheet 100 may include a magnetic layer 101, a heat radiation layer 120, and an adhesive layer 110 disposed between the magnetic layer 101 and the heat radiation layer 120. An example will be described based on a receiving-side shielding structure located inside a cover 1000 of a mobile device, but the magnetic sheet 100 may also be applied to a transmitting-side shielding structure.

[0053] The magnetic layer 101 may be used to block, collect, etc. electromagnetic waves in a wireless charging device, and the magnetic sheet 100 may have a structure in which a plurality of magnetic layers 101 are stacked. The plurality of magnetic layers 101 may be bonded to an adhesive layer 102 interposed therebetween. The magnetic layer 101 may be bonded to the coil portion 23 (the transmitting portion coil 11 or the receiving portion coil 21), and the adhesive layer 102 may be formed on one surface of the coil portion 23. The magnetic sheet 100 may be arranged so that the magnetic layer 101 points to (faces) the coil portion 23 instead of the heat radiation layer 120 relative to the arrangement direction of the magnetic sheet 100.

[0054] The magnetic layer 101 may be formed using a material having magnetic properties to be suitable for electromagnetic wave shielding, and may include, for example, alloys, ferrites, and the like. Examples of alloys that may be included in the magnetic layer 101 may include amorphous alloys or nanocrystalline alloys, and the magnetic layer 101 may be implemented as a thin metal strip formed using the above alloys. The magnetic layer 101 may use an Fe-based nanocrystalline magnetic alloy, and may use, for example, an Fe-Si-B-Cu-Nb alloy. In order to form a nanocrystalline alloy, an amorphous metal obtained in the form of a strip or the like may be heat-treated at an appropriate temperature. Examples of ferrites that may be included in the magnetic layer 101 may include Mn-Zn-based ferrites, Mn-Ni-based ferrites, Ba-based ferrites, Sr-based ferrites, and the like.

[0055] The adhesive layer 102 may be an adhesive material such as a resin composition, and may be a material that physically bonds adjacent magnetic layers 101 to each other or forms a chemical bond with the magnetic layer 101, etc. The adhesive layer 102 is not an essential component in the example, but may be omitted in some configurations.

[0056] The protective layer 130 may be disposed on the heat radiation layer 120 to protect the magnetic sheet 100, and may include a polymer material such as PET, etc. Although not shown, an additional adhesive layer may be interposed between the protective layer 130 and the heat radiation layer 120, and a black PET layer, etc. may be interposed between the protective layer 130 and the heat radiation layer 120.

[0057] Heat generated in the magnetic layer 101 and the like can be effectively discharged through the heat radiation layer 120. Figure 4As shown in , for this purpose, the heat radiation layer 120 has protrusions and depressions 121 formed on the surface. The protrusions and depressions 121 may refer to protrusions extending from the surface of the heat radiation layer 120 and protruding into the bonding layer 110 in a direction toward the magnetic layer 101. The protrusions and depressions 121 on the surface of the heat radiation layer 120 may be arranged to point to (face) the magnetic layer 101. The bonding layer 110 disposed between the heat radiation layer 120 and the magnetic layer 101 may include a heat radiation filler 111 (which may be referred to as a first heat radiation filler 111) having shape anisotropy. Here, the shape anisotropy is a shape in which the length L1 of the major (main) axis and the length L2 of the minor axis are different from each other, and may include shapes such as Figures 5A to 5C The sheet shape shown in ( Figure 5A )、plate shape( Figure 5B ) and rod-shaped ( Figure 5C ).

[0058] By forming protrusions and depressions 121 on the surface of heat radiation layer 120, the heat radiation efficiency between magnetic layer 101 and heat radiation layer 120 can be improved. This is because the thermal conductivity of adhesive layer 110 is very low. For example, when magnetic layer 101 is formed using an Fe alloy ribbon, magnetic layer 101 may have a thermal conductivity of about 12 W / (m·K), while adhesive layer 110 formed using a polymer-based material may have a thermal conductivity of about 0.5 to 0.6 W / (m·K). Therefore, when heat radiation layer 120 having protrusions and depressions 121 is used, the heat transfer efficiency from magnetic layer 101 to heat radiation layer 120 can be improved compared to the case where the heat radiation layer has a flat surface.

[0059] The heat radiation layer 120 may be formed using a material having a high thermal conductivity and on which protrusions and depressions 121 may be easily formed, and the material may include a metal component such as copper (Cu), silver (Ag), nickel (Ni), etc. The heat radiation layer 120 may be representatively formed in the form of a copper foil. The protrusions and depressions 121 may be formed on the surface of the heat radiation layer 120 in the form of a copper foil using an etching process or the like.

[0060] In order to further improve the heat transfer efficiency in the vertical direction, the first heat radiation filler 111 may be arranged in the thickness direction of the magnetic layer 101 (refer to Figure 4 The first heat radiating filler 111 is oriented in a vertical direction of the first heat radiating filler 111, and the effect of the shape and orientation will be described below. The first heat radiating filler 111 may include a metal such as copper (Cu), nickel (Ni), silver (Ag), etc., or a material with high thermal conductivity such as graphite, graphene, etc.

[0061] The adhesive layer 110 may include the same adhesive component as that of the adhesive layer 102 that bonds the magnetic layers 101 to each other, and may also include a different kind of adhesive component to contain the shape anisotropic filler 111. Figure 4 As shown in , the adhesive layer 110 can fill the space 122 formed by the protrusions and depressions 121, so the bonding force between the adhesive layer 110 and the heat radiation layer 120 can be improved. At least a portion of the first heat radiation filler 111 can be arranged in the space 122 formed by the protrusions and depressions 121. Since the first heat radiation filler 111 is arranged in the space 122 between the protrusions and depressions 121, the orientation structure of the first heat radiation filler 111 in the vertical direction can be effectively achieved. In the absence of protrusions and depressions 121, even if a heat radiation filler with shape anisotropy is used, the heat radiation filler tends to be oriented in the horizontal direction rather than in the vertical direction. The heat radiation filler oriented in the horizontal direction has low heat transfer efficiency to the heat radiation layer, and when the amount of the heat radiation filler is increased to increase the heat transfer efficiency, the bonding function of the adhesive layer is deteriorated. Since the first heat radiation filler 111 can be effectively oriented by the protrusions and depressions 121 in the example, the bonding performance of the adhesive layer 110 and the excellent heat radiation effect can be achieved.

[0062] In order to realize the vertical orientation structure of the first thermal radiation filler 111, the sizes of the first thermal radiation filler 111 and the protrusions and recesses 121 may be adjusted. The length L1 of the major axis of at least a portion of the first thermal radiation filler 111 may be greater than or equal to 1 / 3 of the thickness T1 of the protrusions and recesses 121, because when the size of the protrusions and recesses 121 is too large compared to the first thermal radiation filler 111, the degree of vertical orientation of the first thermal radiation filler 111 may be reduced. The distance P between the protrusions and recesses 121 may also affect the orientation performance of the first thermal radiation filler 111. For example, the length L1 of the major axis of at least a portion of the first thermal radiation filler 111 may be greater than the distance P between the protrusions and recesses 121. When the distance P between the protrusions and recesses 121 is too large compared to the length L1 of the first thermal radiation filler 111, the first thermal radiation filler 111 may be oriented in the horizontal direction instead of the vertical direction. Because when the thickness of the adhesive layer 110 is too large, a desired heat radiation effect cannot be obtained, the thickness T1 of the protrusions and recesses 121 may be configured to be equal to or greater than 1 / 5 times the thickness T2 of the adhesive layer 110 .

[0063] The first heat radiation filler 111 may be oriented in a vertical direction to improve heat radiation performance. However, the vertical direction does not mean that the first heat radiation filler 111 is arranged exactly perpendicular to the horizontal plane, but means that the first heat radiation filler 111 is generally oriented to be close to vertical compared to the horizontal. Figure 4, the protrusions and recesses 121 may have an inclined surface S1 inclined relative to the magnetic layer 101, and at least a portion of the first heat radiating filler 111 disposed in the space 122 formed by the protrusions and recesses 121 may be disposed parallel to the inclined surface S1 of the protrusions and recesses 121. The portion of the first heat radiating filler 111 disposed parallel to the inclined surface S1 of the protrusions and recesses 121 may be disposed so that a surface S2 of the first heat radiating filler 111 oriented along the long axis points to (faces) the inclined surface S1. Here, "disposed parallel to" does not mean that the inclined surface S1 of the protrusions and recesses 121 and the oriented surface S2 of the first heat radiating filler 111 must be disposed parallel to each other, but means that the inclined surface S1 of the protrusions and recesses 121 and the oriented surface S2 of the first heat radiating filler 111 face each other. As an example of the vertical orientation of the first heat radiative filler 111 regarding the overall orientation property of the first heat radiative filler 111 , a portion of the first heat radiative filler 111 disposed parallel to the inclined surfaces S1 of the protrusions and recesses 121 may be more than half of the entire first heat radiative filler 111 .

[0064] Figure 6 and Figure 7 In relation to the magnetic sheet according to the example, an enlarged view of the vicinity of the heat radiation layer and the adhesive layer is shown. Figure 6 In the embodiment of the present invention, the second thermal radiation filler 112 may be implemented in the form of nanowires. The second thermal radiation filler 112 may include materials such as silver (Ag), copper (Cu), nickel (Ni), etc. having high thermal conductivity, and may use, for example, silver (Ag) nanowires. As shown, at least a portion of the second thermal radiation filler 112 may follow the shape of the protrusions and depressions 121 (i.e., correspond to the shape of the protrusions and depressions 121), thereby providing an effective heat radiation path between the magnetic layer 101 and the thermal radiation layer 120.

[0065] Figure 7 The structure including the first thermal radiation filler 111 and the second thermal radiation filler 112 in the adhesive layer 110 is shown. The first thermal radiation filler 111 may be a filler having shape anisotropy, and the second thermal radiation filler 112 may be a nanowire. In this example, the second thermal radiation filler 112 may follow the shape of the protrusions and depressions 121, and the first thermal radiation fillers 111 may be further connected to each other. In the case of using two thermal radiation fillers 111 and 112 having different shapes, since the thermal radiation path between the thermal radiation fillers 111 and 112 can be further ensured, the thermal radiation performance can be further improved.

[0066] According to an example, when the magnetic sheet is used for an electronic device, since the magnetic sheet can effectively discharge heat generated during an operation such as wireless charging, reliability can be improved.

[0067] Although the present disclosure includes specific examples, it will be apparent after understanding the disclosure of the present application that various changes in form and detail may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein will be considered to be merely descriptive and not for limiting purposes. The description of the features or aspects in each example will be considered to be applicable to similar features or aspects in other examples. If the described techniques are performed in a different order, and / or if the components in the described systems, architectures, devices, or circuits are combined in different ways and / or replaced or supplemented by other components or by their equivalents, the components in the described systems, architectures, devices, or circuits can be achieved. Appropriate results can be achieved. Therefore, the scope of the present disclosure is not limited by specific embodiments, but by the claims and their equivalents, and all changes within the scope of the claims and their equivalents will be interpreted as included in the present disclosure.

Claims

1. A magnetic sheet, comprising: Magnetic layer; a heat radiation layer including projections and depressions formed in a surface facing the magnetic layer; as well as an adhesive layer disposed between the magnetic layer and the heat radiation layer and including a heat radiation filler having shape anisotropy, The heat radiation filler comprises a first heat radiation filler having a sheet shape, a plate shape or a rod shape, and the length of the major axis of the first thermal radiation filler is different from the length of the minor axis of the first thermal radiation filler, The heat radiation layer includes two or more protrusions and depressions, and a distance between adjacent protrusions and depressions is shorter than a length of the heat radiation filler.

2. The magnetic sheet according to claim 1, wherein The first heat radiating filler is oriented along a thickness direction of the magnetic layer.

3. The magnetic sheet according to claim 1, wherein The adhesive layer fills spaces formed by the protrusions and depressions.

4. The magnetic sheet according to claim 3, wherein The thickness of the protrusions and recesses is greater than or equal to one fifth of the thickness of the adhesive layer.

5. The magnetic sheet according to claim 3, wherein The first heat radiating filler is disposed in the space formed by the protrusions and the depressions.

6. The magnetic sheet according to claim 5, wherein The protrusions and recesses have inclined surfaces inclined with respect to the magnetic layer, and The first heat radiating filler disposed in the space is parallel to the inclined surface.

7. The magnetic sheet according to claim 6, wherein A surface of the first heat radiative filler in the major axis direction faces the inclined surface.

8. The magnetic sheet according to claim 6, wherein More than half of the first heat radiating filler disposed in the space is parallel to the inclined surface.

9. The magnetic sheet according to claim 1, wherein The length of the major axis of the first heat radiating filler is greater than or equal to one third of the thickness of the protrusions and recesses.

10. The magnetic sheet according to claim 1, wherein The thermally radiative filler also includes a second thermally radiative filler in the form of nanowires.

11. The magnetic sheet according to claim 10, wherein The second heat radiating filler is configured to connect two or more first heat radiating fillers to each other.

12. The magnetic sheet according to claim 10, wherein The second heat radiating filler includes a silver component.

13. The magnetic sheet according to claim 10, wherein The second heat radiating filler has a shape corresponding to a shape of the protrusions and recesses.

14. The magnetic sheet according to claim 1, wherein The thermal radiation filler includes nanowires having a shape corresponding to a shape of the protrusions and recesses.

15. The magnetic sheet according to claim 1, wherein The heat radiation layer is copper foil.

16. An electronic device comprising: a coil portion, including a coil pattern; as well as Magnetic sheet, comprising: a magnetic layer configured to face the coil portion, a heat radiation layer including projections and depressions formed in a surface facing the magnetic layer, and an adhesive layer disposed between the magnetic layer and the heat radiation layer and including a heat radiation filler having shape anisotropy, The heat radiation filler comprises a first heat radiation filler having a sheet shape, a plate shape or a rod shape, and the length of the major axis of the first thermal radiation filler is different from the length of the minor axis of the first thermal radiation filler, The heat radiation layer includes two or more protrusions and depressions, and a distance between adjacent protrusions and depressions is shorter than a length of the heat radiation filler.

17. An electronic device comprising: a coil portion, including a coil pattern; Battery; as well as a magnetic sheet disposed between the coil pattern and the battery and comprising: a magnetic layer configured to face the coil portion, a heat radiation layer including a protrusion protruding from a surface facing the magnetic layer, and an adhesive layer disposed between the magnetic layer and the heat radiation layer and including a heat radiation filler having shape anisotropy, The heat radiation filler comprises a first heat radiation filler having a sheet shape, a plate shape or a rod shape, and the length of the major axis of the first thermal radiation filler is different from the length of the minor axis of the first thermal radiation filler, The heat radiation layer includes two or more protrusions and depressions, and a distance between adjacent protrusions and depressions is shorter than a length of the heat radiation filler.

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