Magnetic field shielding sheet, wireless power receiving module, and portable terminal device thereof

Abstract

Provided are a magnetic field shielding sheet, a wireless power receiving module, and a portable terminal device. A magnetic field shielding sheet according to one embodiment of the present invention includes a sheet body formed of a plurality of sheets stacked in multiple layers with an adhesive layer as an interlayer, the plurality of sheets being sequentially stacked with sheet materials having relatively greater surface resistance and relatively smaller magnetic permeability. The magnetic field shielding sheet of the present invention can exhibit high magnetic permeability of 2000 or more while increasing the surface resistance of the sheet materials themselves and reducing loss caused by eddy current.

Description

Technical Field

[0001] This invention relates to magnetic field shielding sheets, wireless power receiving modules, and portable terminal devices thereof. Background Technology

[0002] Near Field Communication (NFC) and wireless charging are essentially contactless transmission methods. This contactless transmission method is achieved through an antenna that sends or receives magnetic fields, and a magnetic field shield disposed on one side of the antenna that enables the smooth transmission or reception of magnetic fields.

[0003] Generally speaking, as magnetic field shielding sheets, sheets made of magnetic materials such as amorphous ribbon sheets, ferrite materials or polymer sheets are used.

[0004] On the other hand, magnetic field shielding sheets use sheets formed from multiple fragments to greatly reduce losses caused by eddy currents or improve the flexibility of the sheet itself.

[0005] As an example, the magnetic field shielding sheet can be separated into multiple fragments through a sheet-making process. That is, the sheet-making process causes the magnetic field shielding sheet to pass repeatedly between a metal roller with multiple protrusions or spheres on its outside and a rubber roller arranged opposite to the metal roller, thereby separating the magnetic field shielding sheet into multiple fragments.

[0006] However, the more the fabrication process is repeated, the smaller the size of the separated fragments becomes. On the other hand, the total number of separated fragments increases. Therefore, the more the fabrication process is repeated, the greater the surface resistance of the shielding sheet becomes, which can reduce the influence caused by eddy currents. However, there is a problem that the magnetic permeability of the shielding sheet drops below 1500.

[0007] Therefore, in order to achieve a magnetic field shield with a high permeability of over 2000 while reducing the impact of eddy currents by increasing the surface resistance of the shield itself, there is a need to increase the overall thickness of the magnetic field shield. Summary of the Invention

[0008] Technical problems to be solved

[0009] The present invention was developed in view of the problems mentioned above, and its purpose is to provide a magnetic field shield that can reduce the loss caused by eddy currents while exhibiting a high permeability of over 2000.

[0010] Technical solution

[0011] To achieve the above objectives, the present invention provides a magnetic field shielding sheet, comprising: a sheet body, which is formed by multiple sheets of the same material stacked together with an adhesive layer as the medium; wherein the multiple sheets are sequentially stacked from sheets having relatively larger surface resistance and relatively smaller magnetic permeability.

[0012] In addition, the plurality of sheets may be strips of at least one of amorphous alloys and nanocrystalline alloys.

[0013] In addition, any one of the plurality of pieces may include a plurality of through portions formed in a linear shape with a predetermined width and length on the inner side, and a plurality of slits formed extending from the edge of the through portions.

[0014] As an example, the plurality of through-holes and the plurality of slits may be formed in the corresponding areas of the patterned portion of the antenna.

[0015] As another example, the plurality of through-holes and the plurality of slits may be formed in the corresponding region to the hollow portion of the antenna.

[0016] At this time, the plurality of through portions can be configured to be spaced apart from each other.

[0017] In addition, any one of the plurality of sheets can be a sheet material that has been separated into multiple fragments.

[0018] Additionally, the sheet body may include a protective film attached to at least one of its upper and lower surfaces using an adhesive layer medium.

[0019] In addition, the overall thickness of the magnetic field shielding sheet can be from 55 μm to 85 μm.

[0020] On the other hand, the present invention provides a wireless power receiving module, comprising: a wireless power receiving antenna, which includes a hollow portion having a predetermined area in the center and a patterned portion surrounding the hollow portion; and a magnetic field shielding sheet disposed on one side of the wireless power receiving antenna.

[0021] At this time, the magnetic field shielding sheet can be configured such that a sheet with relatively large surface resistance and low magnetic permeability is located as close as possible to the wireless power receiving antenna.

[0022] On the other hand, the present invention provides a portable terminal device including the wireless power receiving module as described above.

[0023] Invention Effects

[0024] According to the present invention, a high permeability of over 2000 can be achieved while increasing the surface resistance of the sheet itself to reduce losses caused by eddy currents. Attached Figure Description

[0025] Figure 1 This is a diagram showing a magnetic field shielding sheet according to an embodiment of the present invention.

[0026] Figure 2 It is a forced separation Figure 1Images of multiple sheets in the middle,

[0027] Figure 3 yes Figure 1 AA-direction cross section,

[0028] Figure 4 This is a diagram illustrating the forced separation of multiple sheets from a magnetic field shielding sheet according to another embodiment of the present invention.

[0029] Figure 5 yes Figure 4 Combined cross-sectional view,

[0030] Figure 6 This is a diagram illustrating the forced separation of multiple sheets from a magnetic field shielding sheet according to another embodiment of the present invention.

[0031] Figure 7 yes Figure 6 Combined cross-sectional view,

[0032] Figures 8a to 8d The diagram shows various sheet materials to which the magnetic field shielding sheet of one embodiment of the present invention can be applied, and...

[0033] Figure 9 This is a diagram showing a wireless power receiving module using a magnetic field shielding sheet according to an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures

[0035] 100, 200, 300: Magnetic field shielding sheet; 110, 210, 310: Sheet body.

[0036] 111, 211: First piece; 112, 212: Second piece

[0037] 113, 213: Third piece a: Adhesive layer

[0038] 120: Protective film; 121: Adhesive layer

[0039] 130: Through section 140: Crack

[0040] 1000: Wireless power receiving module; 400: Circuit board.

[0041] 410: Antenna, antenna for wireless power receiving Detailed Implementation

[0042] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can readily implement the invention. The present invention can be embodied in many different forms and is not limited to the embodiments described herein. For the purpose of clearly illustrating the invention in the drawings, parts unrelated to the description are omitted, and throughout the specification, the same or similar constituent elements are given the same reference numerals.

[0043] A magnetic field shielding sheet 100 according to an embodiment of the present invention is as follows: Figures 1 to 3 As shown, it includes a sheet body 110.

[0044] The plate body 110 may be made of a magnetic material so as to shield the magnetic field generated from the antenna 410.

[0045] As an example, the sheet body 110 may use at least one type of strip, including amorphous alloys and nanocrystalline alloys, ferrite sheets, polymer sheets, etc.

[0046] The antenna 410 may include a hollow portion E having a predetermined area in its central part and a patterned portion P formed around the hollow portion E by a predetermined number of turns. In this case, the patterned portion P of the antenna 410 may be an antenna pattern patterned on at least one side of the circuit board 400, or it may be a planar coil wound with a conductive member of a predetermined wire diameter wound around multiple times.

[0047] In addition, the antenna 410 can be a wireless power transmission antenna for transmitting or receiving wireless power, an MST antenna for magnetic settlement, or an NFC antenna for short-range communication.

[0048] Furthermore, the antenna 410 may also be a combination of two or more of the above-mentioned wireless power transmission antenna, MST antenna and NFC antenna.

[0049] At this time, the sheet body 110 can be composed of multiple sheets 111 and 112 stacked together with adhesive layer a as the medium. The multiple sheets 111 and 112 can be made of different materials and play different functions.

[0050] As an example, the sheet body 110 may be configured in the form of a combination of a sheet that performs the function of increasing surface resistance to reduce losses caused by eddy currents and a sheet that can ensure high permeability to exhibit a high inductance coefficient.

[0051] That is, the plurality of sheets 111 and 112 constituting the sheet body 110 can be made of the same material as each other, and can be configured such that at least one of the surface resistance and magnetic permeability has different values.

[0052] Therefore, the sheet body 110 can be a multilayer sheet material composed of multiple sheets 111 and 112 made of the same material but with different properties. In addition, the sheet bodies 110, 210, and 310 can be made of multiple sheets 111 and 112 stacked together in a manner in which at least one property increases or decreases along the stacking direction.

[0053] Specifically, the sheet body 110 can be a multilayer sheet material composed of multiple sheets 111, 112 with relatively larger surface resistance and relatively smaller magnetic permeability stacked sequentially. In this case, the surface resistance of the sheet body 110 can increase while the magnetic permeability decreases from the bottom layer to the top layer.

[0054] Therefore, in one embodiment of the present invention, the magnetic field shielding sheet 100 can reduce the loss caused by eddy currents by using the second sheet 112 among the plurality of sheets 111, 112 that has a relatively large surface resistance, and the first sheet 111 among the plurality of sheets 111, 112 that has a relatively high permeability to exhibit a high induction coefficient. In this case, the first sheet among the plurality of sheets 111, 112 with a relatively high permeability can have a permeability of 2000 or more.

[0055] Therefore, with regard to the magnetic field shielding sheet 100 of one embodiment of the present invention, even if multiple sheets 111 and 112 are made of the same material, it is possible to simultaneously ensure the function of high induction coefficient through the sheet portion with high magnetic permeability and the function of reducing losses caused by eddy currents through the sheet portion with large surface resistance.

[0056] Therefore, in the case of the magnetic field shielding sheet 100 of one embodiment of the present invention, even if multiple sheets 111 and 112 are made of the same material, it is possible to reduce eddy current loss by having a large surface resistance and exhibit a high induction coefficient by having a high permeability while maintaining a very thin thickness.

[0057] As an example, the magnetic field shield 100 of one embodiment of the present invention can reduce the loss of eddy currents by having a very thin thickness of 55 μm to 85 μm, while exhibiting a high induction coefficient by having a large surface resistance.

[0058] At this time, with regard to the magnetic field shielding sheet 100 of one embodiment of the present invention, the surface resistance and permeability of each sheet 111, 112 constituting the sheet body 110, 210, 310 can be adjusted by the presence or absence of the through portion 130 and whether it is formed separately.

[0059] That is, each piece 111, 112 constituting the piece body 110 can be as follows: Figure 8b and Figure 8c As shown, a sheet material with multiple through portions 130 formed in a linear shape with a predetermined width and length on its inner side is also shown. Figure 8d As shown, this is a sheet material formed by separating multiple fragments; it can also be like... Figure 8a As shown, the sheet is formed without the through portion 130 and without being separated into multiple fragments.

[0060] In this case, the sheet with multiple through portions 130 is as follows: Figure 8b and Figure 8c As shown, the sheet may include a plurality of slits 140 extending from the edge of the through portion 130, and the plurality of through portions 130 and the plurality of slits 140 may be partially formed in a portion of the total area of ​​the sheet. Moreover, the sheet with the plurality of through portions 130 may be formed of a material containing a metallic component so that the plurality of slits 140 can be formed together with the through portions 130.

[0061] As an example, the through portion 130 can be formed through each sheet, and the plurality of slits 140 can be formed extending from the edge of the through portion 130. Furthermore, the plurality of slits 140 formed from the edge of the through portion 130 can be connected to each other, or they can be unconnected, or some of the slits 140 can be connected while the rest are not. Moreover, the plurality of slits 140 can be induced from the edge of the through portion 130 by applying an external force to the sheet during the formation of the through portion 130.

[0062] The through portion 130 can be formed as a line with a predetermined width and length, and can be formed in more than one appropriate number. Furthermore, the through portion 130 can be formed such that its width is more than three times its length. Moreover, the total number of the plurality of slits 140 can be relatively greater than the total number of through portions 130.

[0063] Furthermore, the through portion 130 may be a linear through portion formed along a direction perpendicular to the width or length direction of each piece, or a linear through portion formed along a direction parallel to the width or length direction of each piece. Alternatively, the through portion 130 may be a linear through portion formed at a predetermined angle relative to the width or length direction of each piece, or a through portion formed in an arc shape with a predetermined curvature.

[0064] On the other hand, when the sheet constituting the sheet body 110 includes the plurality of through portions 130 and the plurality of slits 140, the plurality of through portions 130 and the plurality of slits 140 can be as follows: Figure 8b As shown, the pattern portion P of the antenna 410 is arranged in the corresponding region S, or it can be formed as follows: Figure 8c As shown, a corresponding region S is formed in the hollow portion E formed in the central part of the antenna 410.

[0065] Furthermore, multiple through-sections 130 can be formed in the corresponding region S, and these multiple through-sections 130 formed in the corresponding region S can be arranged spaced apart from each other. Moreover, the multiple through-sections 130 can be formed radially with reference to the center point of the hollow portion E of the antenna, and the multiple through-sections 130 can be formed without being connected to each other.

[0066] However, the formation of the plurality of through portions 130 is not limited to this. The plurality of through portions 130 may also be formed locally at random locations regardless of the configuration position of the antenna 410, and the plurality of through portions 130 may also be formed in a manner in which a portion is connected to each other.

[0067] In this invention, for a sheet comprising the plurality of through portions 130 and the plurality of slits 140, the greater the total number and total area of ​​the plurality of through portions 130 and the plurality of slits 140, the lower the magnetic permeability, and conversely, the greater the surface resistance.

[0068] In addition, the sheet itself, which is formed by separating multiple fragments, can have a relatively small magnetic permeability and a relatively large surface resistance compared to a sheet that includes the multiple through portions 130 and multiple slits 140.

[0069] Therefore, regarding the magnetic field shielding sheet 100 of one embodiment of the present invention, the plurality of sheets 111, 112 constituting the sheet body 110 are... Figures 8a to 8d The sheets shown are combined with each other, so that multiple sheets 111 and 112 made of the same material can be used together to reduce eddy current loss through large surface resistance and achieve a high induction coefficient through high magnetic permeability.

[0070] As a concrete example, such as Figures 1 to 3 As shown, a magnetic field shielding sheet 100 in one embodiment of the present invention may include a first sheet 111 and a second sheet 112, wherein the first sheet 111 and the second sheet 112 may be strips containing at least one of amorphous alloy and nanocrystalline alloy.

[0071] The first piece 111 may be a sheet material that does not form the aforementioned through-hole 130 and multiple slits 140 and does not separate into multiple fragments, while the second piece 112 may be a sheet material in which multiple through-holes 130 and multiple slits 140 are formed in the area corresponding to the pattern portion P of the antenna 410.

[0072] Therefore, the first sheet 111 can be a sheet with low surface resistance and high permeability, while the second sheet 112 can have a relatively small permeability than the first sheet 111, but conversely, it can have a large surface resistance.

[0073] Therefore, the magnetic field shielding sheet 100 of one embodiment of the present invention can exhibit high permeability through the first sheet 111 and reduce the loss caused by eddy currents through the second sheet 112.

[0074] However, it should be noted that the magnetic field shielding sheet 100 of this embodiment is not limited to this. As long as the magnetic permeability of the first sheet 111 and the second sheet 112 decreases and the surface resistance increases along the stacking direction, it can be used. Figures 8a to 8d Any of the sheets shown can be used as a suitable substitute.

[0075] Furthermore, the sheet bodies 210 and 310 of the magnetic field shielding sheets 200 and 300 in one embodiment of the present invention can also be made of, for example Figures 8a to 8d The diagram illustrates a multi-layered sheet material consisting of three or more layers of sheets combined together.

[0076] As an example, the magnetic field shielding sheets 200 and 300 of one embodiment of the present invention are as follows: Figure 4 As for Figure 7 As shown, the sheet body 210, 310 can be a multi-layer sheet including the first sheet 111, 211, the second sheet 112, 212 and the third sheet 113, 213.

[0077] In this case, such as Figure 4 and Figure 5 As shown, the first piece 111 may be a sheet material that does not form the aforementioned through-hole 130 and multiple slits 140 and does not separate into multiple fragments; the second piece 112 may be a sheet material that forms multiple through-holes 130 and multiple slits 140 in the area corresponding to the pattern portion P of the antenna 410; and the third piece 113 may be a sheet material that separates into multiple fragments.

[0078] As an alternative, such as Figure 6 and Figure 7 As shown, the first sheet 211 may be a sheet that does not form the aforementioned through-hole 130 and multiple slits 140 and does not separate into multiple fragments; the second sheet 212 may be a sheet in which multiple through-holes 130 and multiple slits 140 are formed in the region corresponding to the hollow portion E of the antenna 410; and the third sheet 213 may be a sheet in which multiple through-holes 130 and multiple slits 140 are formed in the region corresponding to the patterned portion P of the antenna 410.

[0079] On the other hand, in one embodiment of the present invention, the magnetic field shielding sheets 100, 200, and 300 may include a protective film 120 attached to at least one of the upper and lower surfaces of the sheet body 110, 210, and 310 with an adhesive layer 121 as the medium.

[0080] Therefore, even if each sheet constituting the sheet body 110, 210, 310 is formed by multiple fragments, or has a through portion 130 and multiple slits 140 formed on the inner side of the sheet, the sheet body 110, 210, 310 can still maintain a plate-like shape through the protective film 120.

[0081] The magnetic field shielding sheets 100, 200, and 300 of one embodiment of the present invention described above can be embodied in a wireless power receiving module 1000 for wireless power transmission.

[0082] That is, the wireless power receiving module 1000 is as follows: Figure 9 As shown, it may include: a wireless power receiving antenna 410 for receiving wireless power; and a magnetic field shielding sheet 100 disposed on one side of the wireless power receiving antenna 410 to shield the magnetic field and concentrate the magnetic field in the desired direction.

[0083] The wireless power receiving antenna 410 may be an antenna pattern formed by patterning a patterned portion P on at least one side of the circuit board 400 in such a way that a hollow portion E with a predetermined area is formed in the center, or it may be a flat coil wound with a conductive member of a predetermined wire diameter multiple times.

[0084] Furthermore, the magnetic field shield 100 constituting the wireless power receiving module 1000 can be the magnetic field shield 100 described above. In the figure, the magnetic field shield 100 is illustrated as... Figures 1 to 3 The form shown is not limited to this; other forms can also be applied. Figures 4 to 7 The magnetic field shielding sheets shown are 200 and 300.

[0085] In the case of this wireless power receiving module 1000, the antenna may consist only of the wireless power receiving antenna 410, but it may also include a variety of antennas that perform different functions.

[0086] As an example, the wireless power receiving module 1000 may include, in addition to the wireless power receiving antenna 410, at least one of an MST antenna for magnetic settlement and an NFC antenna for near-field communication.

[0087] Furthermore, in the wireless power receiving module 1000, the magnetic field shielding sheets 100, 200, and 300 can be configured such that the sheet with relatively large surface resistance and low magnetic permeability among the multiple sheets constituting the sheet bodies 110, 210, and 310 is located closest to the wireless power receiving antenna 410.

[0088] That is, such as Figure 9As shown, the magnetic field shielding sheet 100 includes a second sheet 112 stacked on top of the first sheet 111. When the wireless power receiving antenna 410 is disposed on top of the second sheet 112, the second sheet 112 may be a sheet with a relatively larger surface resistance and lower permeability than the first sheet 111.

[0089] Furthermore, the wireless power receiving module 1000 can be applied to portable terminal devices such as mobile phones and tablet computers.

[0090] The above description illustrates one embodiment of the present invention. However, the concept of the present invention is not limited to the embodiment described herein. Those skilled in the art can easily propose other embodiments within the same conceptual scope by adding, modifying, deleting, or supplementing constituent elements, which also fall within the scope of the present invention.

Claims

1. A magnetic field shielding sheet for use with an antenna including a hollow portion having a predetermined area in the center and a patterned portion surrounding the hollow portion, the magnetic field shielding sheet comprising: The sheet body is formed by stacking multiple sheets with an adhesive layer as the medium. The multiple sheets are stacked sequentially from bottom to top, with the surface resistance increasing and the magnetic permeability decreasing. At least one of the plurality of sheets is a sheet containing a metallic component; The sheet containing metallic components is a sheet formed by including multiple through portions partially formed in the total area of ​​the sheet and multiple cracks extending from the through portions, such that the sheet does not separate as a whole.

2. The magnetic field shielding sheet according to claim 1, wherein, The plurality of sheets are strips comprising at least one of amorphous alloys and nanocrystalline alloys.

3. The magnetic field shielding sheet according to claim 1, wherein, The plurality of through-sections and the plurality of slits are formed in the corresponding areas of the patterned portion of the antenna.

4. The magnetic field shielding sheet according to claim 1, wherein, The plurality of through-sections and the plurality of slits are formed in the corresponding regions that correspond to the hollow portion of the antenna.

5. The magnetic field shielding sheet according to claim 3, wherein, The plurality of through sections are arranged at intervals between each other.

6. The magnetic field shielding sheet according to claim 1, wherein, The plurality of sheets includes a sheet that is separated into a plurality of fragments.

7. The magnetic field shielding sheet according to claim 1, wherein, The sheet body includes a protective film attached to at least one of its upper and lower surfaces using an adhesive layer as a medium.

8. The magnetic field shielding sheet according to claim 1, wherein, The overall thickness of the magnetic field shielding sheet is 55 μm to 85 μm.

9. A wireless power receiving module, wherein, include: A wireless power receiving antenna includes a hollow portion having a predetermined area in the center and a patterned portion surrounding the hollow portion; and The magnetic field shielding sheet according to any one of claims 1 to 8 is disposed on one side of the wireless power receiving antenna.

10. The wireless power receiving module according to claim 9, wherein, The magnetic field shielding sheet is configured such that a sheet with relatively large surface resistance and low magnetic permeability is located as close as possible to the wireless power receiving antenna.

11. A portable terminal device comprising the wireless power receiving module as described in claim 9.

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