KR102505439B1 - Magnetic Sheet and Electronic Device - Google Patents

Abstract

One embodiment of the present invention includes one or more magnetic layers made of a metal ribbon, and at least one of the one or more magnetic layers is formed in a plate-shaped first region and a central portion of the first region and protrudes from the periphery of the second region. A magnetic sheet comprising a region is provided.

Description

Magnetic Sheet and Electronic Device {Magnetic Sheet and Electronic Device}

The present invention relates to a magnetic sheet and an electronic device.

Recently, a wireless charging (WPC) function, a near field communication (NFC) function, an electronic payment (MST) function, and the like have been adopted in mobile portable devices. Wireless charging (WPC), near field communication (NFC), and electronic payment (MST) technologies differ in operating frequency, data transmission rate, and amount of power transmitted.

In the case of such a wireless power transmission device, a magnetic sheet that performs functions such as blocking and concentrating electromagnetic waves is employed. For example, in a wireless charging device, a magnetic sheet is disposed between a receiver coil and a battery. The magnetic sheet serves to efficiently transmit electromagnetic waves generated from the wireless power transmitter to the wireless power receiver by shielding and concentrating the magnetic field generated in the receiver coil and blocking it from reaching the battery.

As portable electronic devices using such magnetic sheets become multifunctional and highly functional, improvement in performance of magnetic sheets is continuously required.

One object of the present invention is to provide a magnetic sheet having excellent electromagnetic wave shielding performance and an electronic device having the same.

As a method for solving the above problems, the present invention intends to propose a novel structure of a magnetic sheet having improved electromagnetic wave shielding performance through an embodiment, specifically, including one or more magnetic layers made of a metal ribbon, and the above one At least one of the above magnetic layers includes a plate-shaped first region and a second region formed in a central portion of the first region and protruding from the periphery.

In one embodiment, the first region and the second region may be integrally formed.

In one embodiment, the first area may have a higher density than the second area.

In one embodiment, the first region and the second region may be formed by press working.

In one embodiment, a plurality of magnetic layers may be provided and stacked.

In one embodiment, all of the plurality of magnetic layers may include the first region and the second region.

In one embodiment, the second regions included in each of the plurality of magnetic layers may be disposed to overlap each other in a thickness direction.

In one embodiment, only one of the plurality of magnetic layers may include the first region and the second region, and the rest of the plurality of magnetic layers may have a plate shape.

In one embodiment, one of the plurality of magnetic layers including the first region and the second region may be disposed on top.

On the other hand, another aspect of the present invention,

It is disposed adjacent to the coil unit and the coil unit, and includes one or more magnetic layers made of metal ribbons, and at least one of the one or more magnetic layers is formed in a plate-shaped first region and a central portion of the first region to protrude beyond the periphery. It provides an electronic device including a magnetic sheet including a second region having a shape of a shape.

In one embodiment, the coil part may be disposed on the magnetic sheet and a central portion thereof may be disposed at a position corresponding to the second region.

In one embodiment, the first region and the second region may be integrally formed.

In one embodiment, the first area may have a higher density than the second area.

In one embodiment, the first region and the second region may be formed by press working.

In the case of the magnetic sheet proposed in one embodiment of the present invention, electromagnetic wave shielding performance can be improved. In addition, it is advantageous for performance improvement or slimming of a wireless charging module or electronic device using such a magnetic sheet.

1 is an external perspective view of a general wireless charging system.
FIG. 2 is a cross-sectional view illustrating an exploded main internal configuration of FIG. 1 .
3 is a cross-sectional view schematically illustrating a magnetic sheet according to an embodiment of the present invention and shows a form in which a coil unit is applied.
FIG. 4 shows an example of a process for obtaining the magnetic sheet of FIG. 3 .
5 is a perspective view showing a magnetic sheet obtained by the process of FIG. 4 .
FIG. 6 shows some of electronic devices such as a wireless charging module to which a coil unit is applied to the magnetic sheet of FIG. 5 .
7 and 8 are cross-sectional views illustrating a magnetic sheet according to a modified example.

Hereinafter, embodiments of the present invention will be described with reference to specific embodiments and accompanying drawings. However, the embodiments of the present invention can be modified in many different forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Therefore, the shape and size of elements in the drawings may be exaggerated for clearer explanation, and elements indicated by the same reference numerals in the drawings are the same elements.

In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and the thickness is enlarged in order to clearly express various layers and regions, and components having the same function within the scope of the same idea are shown with the same reference. Explain using symbols. Furthermore, throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

1 is a schematic external perspective view of a general wireless charging system, and FIG. 2 is a cross-sectional view showing the main internal components of FIG. 1 in an exploded manner.

1 and 2, a general wireless charging system may be composed of a wireless power transmitter 10 and a wireless power receiver 20, and the wireless power receiver 20 is a mobile phone, a laptop computer, a tablet PC, etc. It can be included in the same electronic device (30).

Looking inside the wireless power transmitter 10, the transmitter coil 11 is formed on the substrate 12, so when an AC voltage is applied to the wireless power transmitter 10, a magnetic field is formed around it. Accordingly, the battery 22 may be charged in the receiver coil 21 built in the wireless power receiver 20 by the electromotive force induced from the transmitter coil 11 .

The battery 22 may be a nickel metal hydride battery or a lithium ion battery capable of charging and discharging, but is not particularly limited thereto. In addition, the battery 22 may be configured separately from the wireless power receiver 20 and implemented in a form that is detachable from the wireless power receiver 20, or the battery 22 and the wireless power receiver 20 may be It may also be implemented as an integrally configured unit.

The transmitter coil 11 and the receiver coil 21 are electromagnetically coupled and may be formed by winding a metal wire such as copper. In this case, the winding shape may be circular, elliptical, rectangular, or rhombic, and the overall size or number of windings may be appropriately controlled and set according to required characteristics.

A magnetic sheet 100 is disposed between the receiver coil 21 and the battery 22, and the magnetic sheet 100 is positioned between the receiver coil 21 and the battery 22 to focus magnetic flux to efficiently receive the receiver coil ( 21) so that it can be received on the side. In addition, the magnetic sheet 100 serves to block at least a portion of the magnetic flux from reaching the battery 22 .

The magnetic sheet 100 may be coupled to the coil unit and applied to the receiving unit of the aforementioned wireless charging device. In addition to the wireless charging device, the coil unit may also be used for magnetic secure transmission (MST), near field communication (NFC), and the like. In addition, the magnetic sheet 100 may be applied to a transmission unit other than the reception unit of the wireless charging device, and hereinafter, both the transmission unit and the reception unit coil will be referred to as a coil unit when there is no need to distinguish them. Hereinafter, the magnetic sheet 100 will be described in more detail.

3 is a cross-sectional view schematically illustrating a magnetic sheet according to an embodiment of the present invention and shows a form in which a coil unit is applied. FIG. 4 shows an example of a process for obtaining the magnetic sheet of FIG. 3 , and FIG. 5 is a perspective view illustrating the magnetic sheet obtained by the process of FIG. 4 . And, FIG. 6 shows some of electronic devices, such as a wireless charging module to which a coil unit is applied to the magnetic sheet of FIG. 5 .

Referring to FIG. 3 , the magnetic sheet 100 includes one or more magnetic layers made of metal ribbons, and since it includes only one magnetic layer in the present embodiment, the magnetic sheet is referred to as the magnetic layer 100 . In this embodiment, at least one of the one or more magnetic layers 100 includes a plate-shaped first region 101 and a second region 102 formed at the center of the first region and protruding from the periphery.

The magnetic layer 100 may be formed of a thin metal ribbon made of an amorphous alloy or a nanocrystalline alloy. In this case, an Fe-based or Co-based magnetic alloy may be used as the amorphous alloy. The Fe-based magnetic alloy may use a material containing Si, for example, an Fe-Si-B alloy. The higher the content of metals, including Fe, the higher the saturation magnetic flux density, but when the content of the Fe element is excessive Since it is difficult to form amorphous, the content of Fe may be 70-90 atomic%, and in terms of the possibility of forming amorphous, it is most suitable that the sum of Si and B is in the range of 10-30 atomic%. In order to prevent corrosion in this basic composition, corrosion resistant elements such as Cr and Co may be added within 20 atomic%, and other metal elements may be included in small amounts as necessary to impart other properties.

In addition, when the magnetic layer 100 is implemented using a nanocrystalline grain alloy, for example, an Fe-based nanocrystalline magnetic alloy may be used. The Fe-based nanocrystalline alloy may use a Fe-Si-B-Cu-Nb alloy. In this case, the amorphous metal ribbon may be heat-treated at an appropriate temperature to form a nano-crystalline alloy.

As described above, the magnetic layer 100 has a shape in which the central second region 102 protrudes more than other regions, and in the case of the coil unit 21 disposed on the magnetic sheet, the central portion of the second region 102 ) can be placed in a position corresponding to As a partial area of the magnetic layer 100, that is, the protruding second area 102 is disposed in the central portion of the coil unit 21, magnetic flux generated in the coil unit 21 can be effectively shielded and focused, so that the magnetic material Electromagnetic wave shielding performance of the sheet may be improved. In addition, an alignment error may be reduced during a process of coupling the coil unit 21 and the magnetic sheet by the second region 102 .

In the case of this embodiment, in the magnetic layer 100 made of a metal ribbon, the first region 101 and the second region 102 are integrally formed. In other words, the first region 101 and the second region 102 are not made of different materials or obtained by being separately manufactured and attached, but may be obtained by processing a metal ribbon sheet.

Specifically, as can be seen in one process example shown in FIG. 4, the first region 101 and the second region 102 are formed through press work in which a press 150 is applied to the magnetic layer 100 and compressed. can 5 shows a magnetic layer 100 obtained by press working, and FIG. 6 shows a structure in which a coil unit 21 is disposed on the magnetic layer 100 so that the central portion is located in the protruding second region 102 .

As shown in FIG. 4 , in order to process the magnetic layer 100 into an intended shape, the press 150 has a groove 151 having a shape corresponding to the second region 102 in a direction toward the magnetic layer 100 . can be provided. Since the first region 101 and the second region 102 are obtained by compressing the magnetic layer 100 made of a metal ribbon, they may have different densities. In other words, the first region 101 subjected to a large compression force by the press 150 may have a higher density than the second region 102 that is not compressed or receives a relatively small compression force.

In this way, in the present embodiment, a single metal ribbon sheet was processed to obtain the stepped magnetic layer 100 . Accordingly, the electromagnetic wave shielding performance is excellent compared to the method of bonding a plurality of sheets, and the efficiency of the manufacturing process may also be improved. In addition, the metal ribbon processing method proposed in the present embodiment has better electromagnetic wave shielding performance of the metal ribbon than a method of molding and sintering using flakes or powder. This is because the metal ribbon obtained by the press working of the present embodiment has a filling factor of 75% or more, but the magnetic material sheet by the flake or powder forming method hardly has a filling factor higher than 60%.

On the other hand, in order to have high processing convenience and a high filling rate of the metal ribbon, it is preferable that the press processing method of the metal ribbon is performed under appropriate temperature conditions. Specifically, according to the study of the present inventors, it is preferable to perform the press working of the metal ribbon at a temperature near the vitrification temperature (Tg) of the metal ribbon rather than at room temperature or excessively high temperature. By forming a single metal ribbon with an amorphous or nanocrystalline composition having high glass forming ability and processing it near Tg, the fluidity of the metal ribbon is increased, so that it can be easily processed and the processing precision can be improved. In this case, the Tg is usually 100° C. or lower than the sintering temperature, and the processing pressure of the press required to process the metal ribbon is about several MPa.

7 and 8 are cross-sectional views illustrating a magnetic sheet according to a modified example, and a plurality of magnetic layers 100 are provided and stacked. In the case of the embodiment of FIG. 7 , a plurality of magnetic layers 100 of FIG. 3 are provided and stacked, and an adhesive layer 110 may be interposed between the magnetic layers 100 . As in the present embodiment, electromagnetic wave shielding performance can be increased by using a structure in which a plurality of magnetic layers 100 are stacked, and the number of stacked magnetic layers 100 can be selected in consideration of the thickness of the magnetic sheet.

In the embodiment of FIG. 7 , all of the plurality of magnetic layers 100 include a plate-shaped first region and a protruding second region. In this case, as shown in FIG. 7 , the second regions included in each of the plurality of magnetic layers 100 may be arranged to overlap each other in the thickness direction, and thus the coil unit 21 generating strong magnetic flux. Effective shielding can be achieved in the central portion.

Meanwhile, the adhesive layer 110 may be provided for interlayer bonding of the magnetic layers 100 as well as interlayer insulation of the magnetic layers 100 . As the adhesive layer 110, any material commonly used in the art may be employed as long as it is suitable for performing the above functions, and a double-sided tape may be exemplified.

8, only one 100 of the plurality of magnetic layers 100 and 200 may have a protrusion structure described above, that is, a form including the first region and the second region, and the other ( 200) may have a plate shape. In this case, in order to secure shielding performance and alignment function in consideration of proximity to the coil unit 21, the one 100 including the first region and the second region among the plurality of magnetic layers may be disposed on top.

The present invention is not limited by the above-described embodiments and accompanying drawings, but is intended to be limited by the appended claims. Therefore, various forms of substitution, modification, and change will be possible by those skilled in the art within the scope of the technical spirit of the present invention described in the claims, which also falls within the scope of the present invention. something to do.

10: wireless power transmission device
11: transmitter coil
20: wireless power receiver
21: receiver coil (coil part)
22, 130: battery
30: electronic devices
100, 200: magnetic sheet, magnetic layer
101 First area
102 second area
110: adhesive layer
150: press
151: home

Claims (14)

one or more magnetic layers made of metal ribbon;
At least one of the one or more magnetic layers includes a plate-shaped first region and a second region formed in a central portion of the first region and protruding from the periphery,
The first region has a higher density than the second region.
According to claim 1,
The first region and the second region are integrally formed magnetic material sheet.
delete According to claim 1,
The first region and the second region are formed of a magnetic material sheet by press working.
According to claim 1,
A plurality of magnetic layers are provided and stacked.
one or more magnetic layers made of metal ribbon;
At least one of the one or more magnetic layers includes a plate-shaped first region and a second region formed in a central portion of the first region and protruding from the periphery,
The magnetic layer is provided in plurality and stacked,
All of the plurality of magnetic layers include the first region and the second region.
According to claim 6,
The second regions included in each of the plurality of magnetic layers are arranged to overlap each other in a thickness direction.
According to claim 5,
The magnetic body sheet of claim 1 , wherein only one of the plurality of magnetic layers includes the first region and the second region, and the rest of the plurality of magnetic layers have a plate shape.
According to claim 8,
Among the plurality of magnetic layers, a magnetic material sheet including the first region and the second region is disposed on an uppermost portion.
coil part; and
It is disposed adjacent to the coil unit and includes one or more magnetic layers made of a metal ribbon, and at least one of the one or more magnetic layers is formed in a plate-shaped first region and a central portion of the first region to protrude from the periphery. a magnetic sheet comprising a second region, wherein the first region has a higher density than the second region;
Electronic devices that include.
According to claim 10,
The electronic device of claim 1 , wherein the coil unit is disposed on the magnetic sheet and a central portion thereof is disposed at a position corresponding to the second region.
According to claim 10,
The electronic device wherein the first region and the second region are integrally formed.
delete According to claim 10,
The first region and the second region are formed by press working.

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