Magnetic sheet and wireless charging device including the same

Abstract

The present invention discloses a magnetic sheet and a wireless charging device including the magnetic sheet, wherein the magnetic sheet includes a first region and a second region disposed adjacent to each other on the same surface, wherein the first region includes a first crack line formed along a first direction, and the second region includes a second crack line formed along a second direction.

Description

[0001] This application claims the benefit of priority from Korean Patent Application No. 10-2017-0043150 filed on April 3, 2017, 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 and a wireless charging device including the magnetic sheet. Background Art

[0003] Recently, wireless transmission technologies such as wireless charging (WPC), near field communication (NFC), and magnetic secure transmission (MST) have been adopted in portable electronic devices.

[0004] In such wireless transmission technology, the magnetic sheet performs the function of shielding and collecting electromagnetic waves.

[0005] For example, a magnetic sheet is disposed on one side of a transmitting coil and a receiving coil in a wireless charging device for wireless power charging (WPC), and the magnetic sheet shields and collects the electromagnetic field generated by the transmitting coil and the receiving coil to significantly reduce the impact of the magnetic field on the electronic device and effectively transmit the electromagnetic field radiated from the wireless power transmitter to the wireless power receiver.

[0006] Since portable electronic devices using such magnetic sheets are multifunctional and high-functional, there is a need to improve the performance of the magnetic sheets. Summary of the invention

[0007] 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.

[0008] In one general aspect, a magnetic sheet includes: a first region and a second region disposed adjacent to each other on the same surface, wherein the first region includes a first crack line formed along a first direction, and the second region includes a second crack line formed along a second direction.

[0009] The first areas and the second areas may be alternately disposed relative to a center point of the surface.

[0010] The first direction may be a direction of an easy magnetization axis of the first region, and the second direction may be a direction of an easy magnetization axis of the second region.

[0011] The first direction and the second direction may be perpendicular to each other.

[0012] The first crack line and the second crack line may form a pattern including concentric polygons including a center located at the center point.

[0013] The first crack line and the second crack line may form a cross pattern.

[0014] Mutually adjacent boundaries of the first region and the second region may intersect at the center point.

[0015] The first crack line and the second crack line may be linearly compressed by a roller including a protrusion.

[0016] In another general aspect, a wireless charging device includes: a wireless charging coil; and a shielding sheet, including stacked magnetic sheets arranged at one side of the wireless charging coil, wherein the magnetic sheets each include a first region and a second region, the first region includes a first crack line formed along a first direction, the second region includes a second crack line formed along a second direction, and wherein the first region and the second region are alternately arranged relative to the center point of the corresponding magnetic sheet.

[0017] The first direction may be a direction of an easy magnetization axis of the first region, and the second direction may be a direction of an easy magnetization axis of the second region.

[0018] The first direction and the second direction may be perpendicular to each other.

[0019] The first crack line and the second crack line may form a pattern including concentric polygons including a center located at the center point.

[0020] The first crack line and the second crack line may form a cross pattern.

[0021] Mutually adjacent boundaries of the first region and the second region may intersect at the center point.

[0022] The first crack line and the second crack line may be linearly compressed by a roller including a protrusion.

[0023] The wireless charging coil may include a winding center disposed at a central portion of the magnetic sheet.

[0024] In another general aspect, a magnetic sheet includes: a first linear depression formed on a surface of the magnetic sheet, located in a first region of the magnetic sheet, and extending along an easy magnetization axis direction of the first region; and a second linear depression formed on the surface, located in a second region of the magnetic sheet, and extending along an easy magnetization axis direction of the second region, wherein the easy magnetization axis direction of the first region is different from the easy magnetization axis direction of the second region.

[0025] The easy magnetization axis direction of the first region may be perpendicular to the easy magnetization axis direction of the second region.

[0026] Each of the first regions may be disposed adjacent to each of the second regions.

[0027] The first linear recesses may intersect corresponding ones of the second linear recesses to form any one of a pattern including a cross shape and a pattern including concentric polygons.

[0028] Other features and aspects will be apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a perspective view of an appearance of a conventional wireless charging system according to an embodiment.

[0030] Figure 2 It is shown Figure 1 An exploded cross-sectional view of the internal components of a wireless charging system.

[0031] Figure 3 is a cross-sectional view schematically showing a shielding sheet according to the embodiment.

[0032] Figures 4 to 7 is a perspective view showing a magnetic sheet according to other embodiments.

[0033] Figure 8 is a process diagram illustrating a method for manufacturing a magnetic sheet according to an embodiment.

[0034] Fig. 9 is a schematic diagram showing a Figure 4 The magnetic sheet and coil are arranged on Figure 1 A wireless charging device in the form of a perspective view.

[0035] Fig.10 is a schematic diagram showing a Figure 5 The magnetic sheet and coil are arranged on Figure 1 A perspective view of a wireless charging device in the form of a wireless charging device.

[0036] Fig.11 is a schematic diagram showing a Figure 4 The magnetic sheet and two coils are arranged in Figure 1 A perspective view of a wireless charging device in the form of a wireless charging device.

[0037] Throughout the drawings and detailed description, like reference numerals refer to like elements. The drawings may not be drawn to scale, and the relative sizes, proportions, and depictions of elements in the drawings may be exaggerated for clarity, illustration, and convenience. DETAILED DESCRIPTION

[0038] The following specific embodiments are provided to help the reader gain 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 after understanding the disclosure of the present application. For example, the order of operations described herein is merely an example and is not limited to the examples set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, descriptions of features known in the art may be omitted for increased clarity and brevity.

[0039] 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 various possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0040] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, “directly bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0041] As used herein, the term "and / or" includes any one and any combination of any two or more of the associated listed items.

[0042] 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. Rather, 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.

[0043] For ease of description, spatially relative terms such as "above", "above", "below", and "below" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientations depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "above" 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.

[0044] The terms used herein are only for describing various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "comprise", "include" and "have" list the existence of the stated features, quantities, operations, components, elements and / or their combinations, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0045] 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.

[0046] The features of the examples described herein can 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 feasible.

[0047] Hereinafter, example embodiments will be described in detail with reference to the accompanying drawings.

[0048] Figure 1 4 is a perspective view of the appearance of the wireless charging system 1 . Figure 2is an exploded cross-sectional view showing internal components of the wireless charging system 1 .

[0049] Reference Figure 1 and Figure 2 , the wireless charging system includes a wireless power transmitter 10 and a wireless power receiver 20. The wireless power receiver 20 is included in, for example, an electronic device 30. The electronic device 30 is, for example, a cellular phone, a notebook, or a tablet PC. However, the electronic device 30 is not limited to the above examples.

[0050] Reference Figure 2 The transmitting coil 11 is formed on a substrate 12 located in the interior of the wireless power transmitter 10. When an alternating current (AC) voltage is applied to the wireless power transmitter 10, a magnetic field is formed around the transmitting coil 11. Therefore, the receiving coil 21 buried in the wireless power receiver 20 charges the battery 22 by the electromotive force induced by the transmitting coil 11.

[0051] The battery 22 may be a rechargeable nickel-metal hydride battery or a lithium-ion battery, but is not limited to such examples. In addition, the battery 22 may be formed to be physically separated from the wireless power receiver 20 and removable from the wireless power receiver 20, or the battery 22 and the wireless power receiver 20 may be integrally formed.

[0052] The transmitting coil 11 and the receiving coil 21 may be electromagnetically coupled to each other and have a shape in which a conductive wire in the form of a metal wire is wound or a conductive pattern formed on a substrate is wound. In this case, the winding shape of the transmitting coil 11 and the receiving coil 21 may be a circular shape, an elliptical shape, a quadrilateral shape, or a diamond shape, and the size of the transmitting coil 11 and the receiving coil 21 and the number of windings may be appropriately set according to the desired properties.

[0053] The shielding sheet 100 is disposed at the receiving side between the receiving coil 21 and the battery 22. Another shielding sheet 100 is disposed at the transmitting side between the transmitting coil 11 and the substrate 12. The shielding sheet 100 disposed at the transmitting side shields the magnetic flux formed at the central portion of the transmitting coil 11. The shielding sheet 100 disposed at the receiving side collects the magnetic flux so that the magnetic flux is effectively received by the receiving coil 21. Together with the above functions, the shielding sheet 100 at the receiving side blocks at least a portion of the magnetic flux from reaching the battery 22. Hereinafter, in the absence of a need for special distinction, both the wireless power transmitter 10 and the wireless power receiver 20 are referred to as wireless charging devices, and both the transmitting coil 11 and the receiving coil 21 are referred to as coils.

[0054] In this way, the shielding sheet 100 is applied to the coil of the wireless charging device. In addition, in addition to using the coil in the wireless charging device, the coil can also be used as a wireless antenna in magnetic secure transmission (MST), near field communication (NFC) or other wireless transmissions, and the shielding sheet 100 can be applied to the wireless transmission antenna.

[0055] Figure 3 is a cross-sectional view schematically showing a shielding sheet 100 according to an embodiment.

[0056] Reference Figure 3 , the shielding sheet 100 includes a magnetic sheet 110, a bonding sheet 120, and a coating layer 130 stacked along a thickness direction of the shielding sheet 100. Here, the number of stacked magnetic sheets 110 may be appropriately adjusted according to desired shielding and collecting functions.

[0057] The magnetic sheet 110 is formed by pressing and molding a powder magnetic material or sintering the powder magnetic material after pressing the powder magnetic material. The magnetic sheet 110 may be a soft magnetic material, and a thin sheet metal strip having an amorphous structure or a nanocrystalline structure may be used as the magnetic sheet 110. Alternatively, the magnetic sheet 110 may be formed of permalloy (a material having a high magnetic permeability).

[0058] The thin sheet metal strip having an amorphous structure may be formed of an Fe-based or Co-based magnetic alloy. The Fe-based magnetic alloy is, for example, an Fe-Si-B alloy. When the metallic Fe content is high, the saturation magnetic flux density increases, but when the Fe content is too large, it is difficult to form an amorphous structure. Therefore, the Fe content may be 70 at% to 90 at%, and in view of the amorphous forming ability, the total content of Si and B may preferably be in the range of 10 at% to 30 at%. In order to prevent corrosion of such a basic component, corrosion-resistant elements such as Cr or Co may be added in an amount of up to 20 at%, and a small amount of other metal elements may be included as needed to provide other properties.

[0059] The metal strip with nanocrystalline structure can be formed by Fe-based nanocrystalline magnetic alloy. In addition, Fe-Si-B-Cu-Nb alloy can be used as Fe-based nanocrystalline alloy. In addition, amorphous metal strip can be heat treated at a suitable temperature to form nanocrystalline alloy.

[0060] Adjacent magnetic sheets 110 are adhered to each other by bonding sheets 120. The bonding sheet 120 may be a bonding tape, and the bonding sheet 120 may also be formed by applying a bonding agent or a resin having bonding properties to surfaces of the corresponding magnetic sheets 110.

[0061] The coating layer 130 is provided to effectively radiate heat generated by the magnetic sheet 110, and is formed to cover the top surface of the magnetic sheet 110. Figure 3 As shown in Figure 3Showing a case where the magnetic sheets 110 are stacked, the coating layer 130 is formed to cover the top surface of the magnetic sheet 110 disposed in the uppermost portion among the plurality of magnetic sheets 110. For example, the coating layer 130 includes graphene powder as a material having excellent thermal conductivity.

[0062] The magnetic sheet 110 includes a crack line (e.g., a linearly recessed or scored line) to reduce eddy currents and enhance the magnetic field. Specifically, the magnetic sheet 110 includes at least one first region and at least one second region disposed adjacent to each other on the same surface. In addition, the first region includes a first crack line formed along a first direction, and the second region adjacent to the first region includes a second crack line formed along a second direction.

[0063] In the following, reference will be made to Figures 4 to 7 Various embodiments of the magnetic sheet are described in more detail.

[0064] Although Figures 4 to 7 For the sake of convenience, the magnetic sheets 111, 112, 113 and 114 having a quadrilateral shape, two first regions and two second regions are shown, but the shape of the magnetic sheet can be circular, elliptical or other shapes, and the number of the first region and the second region can be adjusted. Figures 4 to 7 In the example embodiment, when some of the two first regions and the two second regions are omitted, the magnetic sheet may include one first region and one second region. In addition, when the first region and the second region are subdivided, the magnetic sheet may include three or more first regions or three or more second regions.

[0065] Reference Figure 4 , the magnetic sheet 111 includes two first regions A1 and two second regions B1. The two first regions A1 and the two second regions B1 are alternately arranged relative to the center point O. Through such an arrangement, the two first regions A1 may be symmetrical to each other relative to the center point O, and the two second regions B1 may be symmetrical to each other relative to the center point O.

[0066] In addition, the first area A1 and the second area B1 are adjacent to each other. That is, the first area A1 and the second area B1 contact each other at the center point O, and the side of the first area A1 and the side of the second area B1 contact each other to form a boundary between the first area A1 and the second area B1. Figure 4 As shown in FIG, the boundaries of the first area A1 and the second area B1 adjacent to each other intersect at a center point O.

[0067] In addition, the first region A1 includes: a first crack line C11 formed along a first direction; and a second region B1 adjacent to the first region A1, including a second crack line C12 formed along a second direction. The first direction is the direction of the easy magnetization axis of the first region A1, and the second direction is the direction of the easy magnetization axis of the second region B1. The first direction and the second direction may be perpendicular to each other. However, the first direction and the second direction may form other angles such that the first direction and the second direction are not perpendicular to each other.

[0068] Therefore, if Figure 4 As shown in FIG. 1 , the first crack line C11 and the second crack line C12 form a pattern in which polygons having a center point O as a concentric are arranged. That is, the first crack line C11 and the second crack line C12 form a pattern including concentric polygons having a center located at the center point O. Figure 4 A pattern in which the first crack line C11 and the second crack line C12 are connected at the boundary between the first area A1 and the second area B1 is shown, but such an example pattern is for ease of explanation. The first crack line C11 and the second crack line C12 may form a pattern in which the first crack line C11 and the second crack line C12 are staggered at the boundary between the first area A1 and the second area B1.

[0069] Reference Figure 5 , the magnetic sheet 112 includes two first regions A2 and two second regions B2. The first region A2 includes a first crack line C21 formed along a first direction, and the second region B2 adjacent to the first region A2 includes a second crack line C22 formed along a second direction. However, Figure 5 The first direction and the second direction of the magnetic sheet 112 are Figure 4 The first direction and the second direction of the magnetic sheet 111 are different.

[0070] That is, the first crack line C21 and the second crack line C22 extend from the boundary between the first area A2 and the second area B2 to the outer edges of the first area A2 and the second area B2, respectively. Figure 5 As shown in , a pattern formed by the first crack line C21 and the second crack line C22 may be defined as a cross pattern.

[0071] refer to Figure 6 The magnetic sheet 113 includes two first regions A3 and two second regions B3. The first region A3 includes a first crack line C31 formed along a first direction, and the second region B3 adjacent to the first region A3 includes a second crack line C32 formed along a second direction. Figure 6 The magnetic sheet 113 and Figure 4The magnetic sheet 111 is similar in that the first crack line C31 and the second crack line C32 form a pattern in which a plurality of polygons having the center point O as a concentric circle are arranged, but the first area A3 and the second area B3 have the same Figure 4 The shapes of the first area A1 and the second area B1 of the magnetic sheet 111 are different in shape.

[0072] refer to Figure 7 The magnetic sheet 114 includes two first regions A4 and two second regions B4. The first region A4 includes a first crack line C41 formed along a first direction, and the second region B4 adjacent to the first region A4 includes a second crack line C42 formed along a second direction. Figure 7 The magnetic sheet 114 and Figure 5 The magnetic sheet 112 is similar in that the first crack line C41 and the second crack line C42 form a cross pattern, but the first area A4 and the second area B4 have the same Figure 5 The shapes of the first area A2 and the second area B2 of the magnetic sheet 112 are different in shape.

[0073] Figure 8 is a process diagram showing a method of manufacturing a magnetic sheet 111 according to an embodiment. It will be understood that the following reference Figure 8 The described method can also be modified to produce magnetic sheets 112 , 113 , and 114 .

[0074] refer to Figure 8 , the crack line C1 is formed by applying the roller 200 having the protrusion 211 to the magnetic sheet 111. That is, the magnetic sheet 111 is pressed or engraved into a form corresponding to the protrusion 211. Therefore, the magnetic sheet 111 is formed by the crack line C1 (including Figure 4 The crack line C1 is formed along the direction of the easy magnetization axis (MA) of the magnetic sheet 111.

[0075] Specifically, the roller 200 rotates (R) on the surface of the magnetic sheet 111, and the magnetic sheet 111 moves (S) together with such rotation (R) of the roller 200. For example, the direction in which the magnetic sheet 111 moves (S) and the crack line C1 are perpendicular to each other. That is, the protrusion 211 of the roller 200 is formed perpendicular to the direction in which the roller 200 rotates and moves. However, according to another embodiment, the protrusion 211 of the roller 200 may be formed parallel to the direction in which the roller 200 rotates and moves.

[0076] In addition, the crack lines C1 have a uniform pitch P1, that is, there is a uniform interval between adjacent lines C1. The magnetic permeability of the magnetic sheet 111 is determined by the pitch P1.

[0077] According to an example, the magnetic sheet 111 is reassembled to form the first area A1 and the second area B1 after being processed (eg, cut) along the dotted line B by a pressing operation. In addition, according to another embodiment, the protrusion 211 of the roller is formed to correspond to a pattern formed by the crack line C1.

[0078] Fig. 9 is a schematic diagram showing a Figure 4 A perspective view of a form in which a magnetic sheet 111 and a wireless charging coil 21 are provided in a wireless charging device. Fig.10 is a schematic diagram showing a Figure 5 A perspective view of a form in which a magnetic sheet 112 and a wireless charging coil 21 are provided in a wireless charging device.

[0079] Reference Fig. 9 and Fig.10 , the wireless charging device includes: a wireless charging coil 21; and a shielding sheet, in which magnetic sheets 111 and 112 are respectively stacked and arranged on one side of the coil 21. In addition, the coil 21 has a winding center arranged at the central portion of the magnetic sheets 111 / 112. That is, the coil 21 is arranged so that the center point O of the magnetic sheet 111 is located inside the inner winding 21-1 of the coil.

[0080] Although as reference Figure 3 Describes forming a shielding sheet by stacking magnetic sheets, but Fig. 9 and Fig.10 Only one magnetic sheet 111 / 112 is shown.

[0081] For example, the formation Fig. 9 The direction of the crack lines C1 on the magnetic sheet 111 is approximately perpendicular to the direction of the magnetic field MF formed around the coil 21. In this case, the magnetic sheet 111 has magnetic properties such as magnetic permeability adjusted by the intervals between the crack lines C1. That is, the crack lines C1 determine the properties of the magnetic sheet 111 suitable for the amount of electricity, the transmission frequency, and the coil characteristics.

[0082] In addition, the formation Fig.10 The plurality of crack lines C2 (including Figure 5 The directions of the first crack line C21 and the second crack line C22 in the magnetic sheet 112 are approximately parallel to the direction of the magnetic field MF. In this case, the magnetic sheet 112 collects the magnetic field more effectively.

[0083] That is, the crack lines C1 and C2 formed on the magnetic sheets 111 and 112 , respectively, adjust magnetic properties such as magnetic permeability of the magnetic sheets according to the magnetic field MF.

[0084] Furthermore, the crack lines C1 and C2 formed on the magnetic sheets 111 and 112 , respectively, reduce the eddy current EC formed in the magnetic sheets 111 and 112 due to the magnetic field MF.

[0085] Fig.11 2 is a perspective view schematically showing a form in which a magnetic sheet 111 a and two coils 21 a and 21 b are provided in a wireless charging device according to an embodiment.

[0086] Reference Fig.11 The wireless charging device includes a first coil 21a, a second coil 21b, and a magnetic sheet 111a on which crack lines C1a and C1b are formed.

[0087] Similar to Fig. 9 The crack lines C1, C1a and C1b in the magnetic sheet 111 form a pattern including a polygon having a concentric center point O, but the spacing of the crack lines C1b formed on the area of ​​the magnetic sheet 111a corresponding to the second coil 21b is different from the spacing of the crack lines C1a formed on the area of ​​the magnetic sheet 111a corresponding to the first coil 21a.

[0088] For example, the first coil 21a and the second coil 21b are wireless charging coils having different power, transmission frequency and coil characteristics, and the area of ​​the magnetic sheet 111a corresponding to the first coil 21a and the area of ​​the magnetic sheet 111a corresponding to the second coil 21b provide different magnetic permeabilities.

[0089] That is, in a multi-coil structure employing two or more coils, the crack lines C1a and C1b reduce eddy current in the magnetic sheet and determine the permeability of the magnetic sheet 111a suitable for the amount of electricity, transmission frequency, and coil characteristics of each coil.

[0090] As described above, according to example embodiments disclosed herein, a magnetic sheet and a wireless charging device including the same reduce eddy currents generated by an electromagnetic field and improve shielding performance of the electromagnetic field and transmission efficiency and reception efficiency.

[0091] Furthermore, since the magnetic sheet has magnetic permeability that can be adjusted according to the frequency of the wireless transmission signal, the magnetic sheet can be applied to various frequency bands.

[0092] Furthermore, a wireless charging device including such a magnetic sheet can be advantageously miniaturized and thinned.

[0093] Various advantages and effects disclosed herein are not limited to the above description and can be more easily understood in the description of the exemplary embodiments.

[0094] Although the present disclosure includes specific examples, it will be apparent that, after understanding the disclosure of the present application, various changes in form and detail can 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 as descriptive meanings only, not for the purpose of limitation. 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 different orders, and / or if the components in the described system, architecture, device or circuit are combined in different ways and / or replaced or supplemented with other components or their equivalents, the components in the described system, architecture, device or circuit can be obtained. Appropriate results can be obtained. 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: The first region and the second region are disposed adjacent to each other on the same surface, The first region includes a first crack line formed along a first direction, and the second region includes a second crack line formed along a second direction. The first crack line and the second crack line extend from boundaries of the first region and the second region to outer edges of the first region and the second region, respectively. The first crack line is perpendicular to the edge of the first region, and the second crack line is perpendicular to the edge of the second region. The first crack line and the second crack line form a cross pattern.

2. The magnetic sheet according to claim 1, wherein The first areas and the second areas are alternately arranged relative to a center point of the surface.

3. The magnetic sheet according to claim 1, wherein The first direction is the direction of the easy magnetization axis of the first region, and the second direction is the direction of the easy magnetization axis of the second region.

4. The magnetic sheet according to claim 1, wherein The first direction and the second direction are perpendicular to each other.

5. The magnetic sheet according to claim 1, wherein Mutually adjacent boundaries of the first region and the second region intersect at a center point of the surface.

6. The magnetic sheet according to claim 1, wherein The first crack line and the second crack line are linearly pressed by a roller including protrusions.

7. A wireless charging device, comprising: Wireless charging coil; as well as a shielding sheet including stacked magnetic sheets disposed at one side of the wireless charging coil, The magnetic sheet includes a first region and a second region, the first region includes a first crack line formed along a first direction, the second region includes a second crack line formed along a second direction, and wherein the first region and the second region are alternately arranged relative to the center point of the corresponding magnetic sheet, The first crack line and the second crack line extend from boundaries of the first region and the second region to outer edges of the first region and the second region, respectively. The first crack line is perpendicular to the edge of the first region, and the second crack line is perpendicular to the edge of the second region. The first crack line and the second crack line form a cross pattern.

8. The wireless charging device according to claim 7, wherein: The first direction is the direction of the easy magnetization axis of the first region, and the second direction is the direction of the easy magnetization axis of the second region.

9. The wireless charging device according to claim 7, wherein: The first direction and the second direction are perpendicular to each other.

10. The wireless charging device according to claim 7, wherein: Mutually adjacent boundaries of the first region and the second region intersect at the center point.

11. The wireless charging device according to claim 7, wherein: The first crack line and the second crack line are linearly pressed by a roller including protrusions.

12. The wireless charging device according to claim 7, wherein: The wireless charging coil includes a winding center disposed at a central portion of the magnetic sheet.

13. A magnetic sheet comprising: a first linear depression formed on the surface of the magnetic sheet, located in the first region of the magnetic sheet, and extending along the easy magnetization axis direction of the first region; as well as a second linear depression formed on the surface, located in the second region of the magnetic sheet, and extending along the easy magnetization axis direction of the second region, The direction of the easy magnetization axis of the first region is different from the direction of the easy magnetization axis of the second region. The first linear depression and the second linear depression extend from boundaries of the first region and the second region to outer edges of the first region and the second region, respectively. The first linear depression is perpendicular to the edge of the first region, and the second linear depression is perpendicular to the edge of the second region. The first linear depressions intersect with the second linear depressions to form a cross-shaped pattern.

14. The magnetic sheet according to claim 13, wherein The easy magnetization axis direction of the first region is perpendicular to the easy magnetization axis direction of the second region.

15. The magnetic sheet according to claim 13, wherein Each of the first regions is disposed adjacent to each of the second regions.

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