KR102018174B1

KR102018174B1 - Magnetic sheet and apparatus for receiving a wireless power using the same

Info

Publication number: KR102018174B1
Application number: KR1020130015422A
Authority: KR
Inventors: 배석; 최돈철; 이상원; 문원하; 현순영; 염재훈; 노진미; 이희정; 김소연; 송지연
Original assignee: 엘지이노텍 주식회사
Priority date: 2013-02-13
Filing date: 2013-02-13
Publication date: 2019-09-04
Also published as: KR20140102033A

Abstract

A magnetic sheet and a wireless power receiver including the same are disclosed. The magnetic sheet includes a heat dissipation layer and a plurality of magnetic blocks coupled to the heat dissipation layer and separated by gaps formed periodically along the longitudinal direction and the transverse direction.

Description

Magnetic sheet and wireless power receiver including the same {MAGNETIC SHEET AND APPARATUS FOR RECEIVING A WIRELESS POWER USING THE SAME}

The present invention relates to a magnetic sheet and a wireless power receiver including the same , and more particularly , to a magnetic sheet used in the field of wireless charging or NFC integrated receiving device that transmits and receives power in a non-contact manner using electromagnetic induction and includes the same. It relates to a wireless power receiver.

The wireless power transmission technology used in cellular phones and small home appliances is to transmit power from the transmitting side to the receiving side by causing electromagnetic induction between the wireless power transmitting apparatus and the wireless power receiving apparatus.

In such a wireless power transmission technology, a ferrite substrate is used for the transmitting side and a magnetic sheet is used for the receiving side in order to minimize leakage magnetic flux generated between the transmitting side and the receiving side to improve transmission efficiency.

The transmitting ferrite substrate is not limited in thickness or size, but the receiving magnetic sheet, which is mainly used in a small device such as a mobile terminal, is thin and requires a small size.

In addition, since the magnetic sheet must satisfy these thinning and miniaturization conditions and minimize leakage magnetic flux, high magnetic permeability and low magnetic flux loss must be satisfied, and reliability under environmental conditions such as high temperature, high humidity, and brine must be guaranteed.

However, the conventional magnetic sheet has a problem in that the magnetic field generated at the transmitting side collides and cancels each other during the movement, and the wireless power transmission efficiency is greatly reduced by the eddy current occurring in the high frequency band.

In addition, there was a problem in terms of reliability because the rate of change of thickness was about 10% under high temperature, high humidity environment or brine spraying conditions.

Korean Patent Laid-Open No. 2012-0086669 discloses a magnetic sheet including a flat part and a hollow area installed in a coil part in a receiving device, but problems such as magnetic field offset, eddy current phenomenon, and thickness change as mentioned above are disclosed. exist.

The technical problem to be achieved by the present invention is to provide a magnetic sheet and a wireless power receiver including the same to reduce the canceling effect of the magnetic field generated in the wireless power transmission apparatus and the eddy current effect generated in the high frequency to improve the wireless transmission efficiency. have.

In addition, the present invention provides a magnetic sheet capable of improving reliability by minimizing a rate of change of thickness according to environmental conditions such as temperature, humidity, and salinity, and a wireless power receiver including the same.

According to one aspect of the invention provides a magnetic sheet comprising a magnetic layer consisting of a plurality of magnetic blocks separated.

The magnetic block may be formed by being separated by a gap that is periodically formed in the longitudinal and transverse directions.

One side may be configured to further include a heat dissipation layer coupled to the magnetic layer.

Further comprising an adhesive layer applied to one surface of the heat dissipation layer, the heat dissipation layer may be coupled to the magnetic layer through the adhesive layer.

The gap may be 1 to 3000 μm.

The gap may be formed at intervals of 3 to 5 mm.

The heat dissipation layer may include at least one of graphite, alumina, aluminum nitride, boron nitride, and silicon carbide.

The gap may be formed through a slitting process using a blade.

According to another aspect of the present invention, there is provided a wireless power receiver including a magnetic layer including a plurality of separated magnetic blocks and a coil part mounted on the magnetic layer.

One side may further include a heat dissipation layer coupled to the magnetic layer and a battery coupled to the other side of the heat dissipation layer.

The battery may be coupled through a first adhesive layer applied to the other surface of the heat dissipation layer,

The heat dissipation layer may further include a second adhesive layer applied to one surface of the heat dissipation layer, and the heat dissipation layer may be coupled to the magnetic layer through the second adhesive layer.

The gap may be 1 to 3000 μm.

The gap may be formed at intervals of 3 to 5 mm.

The gap may be formed through a slitting process using a blade.

The coil unit may have a planar shape.

The magnetic sheet of the present invention and the wireless power receiver including the same can improve the wireless transmission efficiency by reducing the canceling effect of the magnetic field generated in the wireless power transmission device and the eddy current effect generated in the high frequency phase.

In addition, reliability can be improved by minimizing the rate of change of thickness according to environmental conditions such as temperature, humidity, and salinity.

1 is a cross-sectional view of a magnetic sheet according to an embodiment of the present invention;
2 is a perspective view of a magnetic sheet according to an embodiment of the present invention;
3 is an exploded perspective view of a wireless power charging device according to an embodiment of the present invention;
4 is a cross-sectional view of a wireless power charging device according to an embodiment of the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers, such as second and first, may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

1 is a cross-sectional view of a magnetic sheet according to an embodiment of the present invention, Figure 2 is a perspective view of a magnetic sheet according to an embodiment of the present invention.

Referring to FIG. 1, a magnetic sheet according to an embodiment of the present invention may be provided on a heat dissipation layer 30 through a heat dissipation layer 30, an adhesive layer 20 and an adhesive layer 20 applied to one surface of the heat dissipation layer 30. It can be configured to include a magnetic layer (10) comprising a plurality of magnetic blocks (11) coupled and separated by gaps formed periodically along the longitudinal and transverse directions.

First, the heat dissipation layer 30 may include, for example, at least one of graphite, alumina, aluminum nitride, boro nitride, and silicon carbide, and fixes the plurality of magnetic blocks 11 through the adhesive layer 20. .

The heat dissipation layer 30 may be composed of a composite film based on a polymer resin using at least one of graphite, alumina, aluminum nitride, boron nitride, and silicon carbide as a filler.

Graphite, alumina, aluminum nitride, boron nitride, silicon carbide, or the like constituting the heat dissipation layer 30 may have a thermal conductivity of 1 W / mK or more, for example.

For example, the heat dissipation layer 30 may be formed to have a thickness of 100 to 200 μm, and the entire area may be formed to be the same as or slightly larger than that of the magnetic layer 10.

The adhesive layer 20 may be formed by, for example, applying or coating acrylic, silicon, or the like on the entire surface of the heat dissipation layer 30.

The adhesive layer 20 may be formed to have a thickness of, for example, 30 to 40 μm.

In one embodiment of the present invention has been described as an example that the heat dissipation layer 30 and the adhesive layer 20 is formed in a separate configuration, alternatively, the heat dissipation layer 30 and the adhesive layer 20 may be integrally formed. Yes it will be said that naturally included in the technical scope of the present invention.

The magnetic layer 10 may be made of, for example, an alloy powder containing at least one of iron (Fe), cobalt (Co), and nickel (Ni).

The magnetic layer 10 may be composed of a plurality of magnetic blocks 11 separated by gaps periodically formed along the longitudinal direction and the transverse direction.

The gap G of the gap between the magnetic layers 10 may be, for example, 1 to 3000 μm, and may be formed at intervals of 3 to 5 mm. In one embodiment of the present invention, the period in which the gap is formed may be based on, for example, an imaginary center line of the gap or based on one end of the gap.

As a method of manufacturing the magnetic layer 10, for example, the alloy powder is used as a material to form a flake shape using a powder milling equipment, and then mixed with a predetermined amount of resin after the anti-corrosion coating process to make a magnetic ink. Thereafter, a bare film manufactured by drying the magnetic ink is laminated, and when a hot pressing process is applied thereto, a sheet having a flat shape is completed. When a slitting process using a blade is applied to the flat sheet thus completed, gaps are periodically formed along the longitudinal and transverse directions.

Various methods may be used as a method of manufacturing the magnetic layer 10, and forming the magnetic layer 10 using such a method will naturally be included in the technical scope of the present invention.

In addition, it will be obvious that the shape of the magnetic block 11 may be formed in various shapes such as a circle, an ellipse, and a polygon.

3 is an exploded perspective view of a wireless power charging apparatus according to an embodiment of the present invention and Figure 4 is a cross-sectional view of a wireless power charging apparatus according to an embodiment of the present invention.

3 and 4, the wireless power charging apparatus according to an embodiment of the present invention may include a wireless power transmission apparatus 200 and a wireless power receiving apparatus 100.

First, the wireless power transmitter 200 includes a ferrite substrate 210, a permanent magnet 230 fixed on the ferrite substrate 210, and a transmission coil in which the hollow part is inserted into the permanent magnet 230 and fixed on the ferrite substrate 210. And 220.

The apparatus 200 for transmitting power wirelessly receives power from an external power source, from which the permanent magnet 230 and the transmitting coil 220 form a magnetic field.

The wireless power receiver 100 may include a battery 110, a first adhesive layer 120 applied to one surface of the battery 110, a heat dissipation layer 130 coupled to the battery 110 through the first adhesive layer 120, Coupled to the heat dissipation layer 130 through the second adhesive layer 140, the second adhesive layer 140 is applied to one surface of the heat dissipation layer 130 and separated by a gap formed periodically in the longitudinal and transverse directions It may be configured to include a magnetic layer 150 including two magnetic blocks and a coil portion 160 having a planar shape mounted on the magnetic layer 150.

The wireless power receiver 100 receives a magnetic field generated from the permanent magnet 230 and the transmission coil 220 of the wireless power transmitter 200, converts it into a predetermined current through an electromagnetic induction action, and converts it into a battery 110. Will print).

At this time, the magnetic field generated in the permanent magnet 230 and the transmission coil 220 of the wireless power transmitter 200 is independently generated to pass through the magnetic layer 150 of the wireless power receiver 100, the magnetic layer There is a section within 150 that mutually cancels the strength of the magnetic field.

In the wireless power receiver 100 according to the exemplary embodiment of the present invention, the gap separating the magnetic layer 150 is periodically formed, thereby effectively attenuating the magnetic field canceling effect.

In addition, each magnetic block is electrically insulated by the gap formed in the magnetic layer 150, and the eddy current in the high frequency band can be effectively reduced.

Table 1 is a table for explaining the wireless power transmission efficiency according to the period in which the gap is formed.

No gap One mm 3 mm 5 mm Wireless power transmission efficiency (%) 65.0 62.73 65.17 65.45 Specific Permeability @ 150 kHz 42.6 32.9 35.2 36.0 Magnetic loss tan δ (%)
@ 150 kHz 1.1 1.1 0.8 0.7 Specific Permeability @ 13.56 MHz 43.9 33.6 35.4 36.7 Magnetic loss tan δ (%)
@ 13.56 MHz 4.3 3.4 3.2 3.0

Referring to Table 1, it can be seen that the wireless power transmission efficiency is improved when the gap is formed in a period of 3mm and 5mm compared to the case without the gap. However, when the gap is formed at a period of 1 mm, the ratio of the gap to the total area of the magnetic layer 150 is too large, and thus the overall wireless power transmission efficiency is rather reduced.

As the period of formation of the gap increases, the decrease in specific permeability decreases, and the magnetic losses are effectively reduced. In particular, in the case of 5mm it was confirmed that a good loss characteristic of about 3.0% can be obtained at 13.56MHz, the NFC frequency band.

In addition, since the residual stress in the plane direction of the magnetic layer 150 is alleviated by the gap formed in the magnetic layer 150, the expansion of the thickness of the magnetic layer 150 may be prevented in a high temperature / high humidity and salt spray environment to improve reliability.

Table 2 is a table for explaining the rate of change of the thickness of the magnetic layer 150, the gap formed in the high temperature / high humidity environment and the salt spray environment.

No gap 5 mm High temperature / humidity test
(85 degrees / 85%, 96 hours) 12.5% 2.7% Salt spray test
( KSC0223 : 1990, 48 hours) 9.5% 3.5%

Referring to Table 2, the thickness change rate of the magnetic layer 150 is 12.5% to 2.7% when the gap is formed at a period of 5 mm compared to the case where there is no gap in a high temperature / high humidity environment (85 degrees / 85%, 96 hours). It can be seen that the percentage decrease.

In addition, in the salt spray test (KSC0223: 1990, 48 hours) it can be seen that the thickness change rate was reduced by 6% from 9.5% to 3.5%.

The change in the thickness of the magnetic layer 150 eventually causes a change in the permeability, and due to impedance mismatch, NFC performance may be degraded. Therefore, in general, the thickness change rate is to be limited to 5 to 10%, and as in the embodiment of the present invention, the magnetic layer 150 having a gap of 5 mm intervals can satisfy this requirement.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

10, 150: magnetic layer
11: Magnetic Block
20: adhesive layer
30, 130: heat dissipation layer
100: wireless power receiver
110: battery
120: first adhesive layer
140: second adhesive layer
160: coil unit
200: wireless power transmitter
210: ferrite substrate
220: transmitting coil
230: permanent magnet

Claims

A magnetic layer comprising a plurality of magnetic blocks separated by gaps periodically formed along the longitudinal and transverse directions,
The gap is formed in a period of 3 to 5mm,
The magnetic layer has a magnetic permeability of 35.2 to 36.0 and a magnetic loss of 0.7% to 0.8% at 150 kHz, a magnetic permeability of 35.4 to 36.7 and a magnetic loss of 3.0% to 3.2% at 13.56 MHz.

The method of claim 1,
The magnetic layer is a magnetic sheet having a wireless power transmission efficiency of 65.17% to 65.45%.

The method of claim 1,
Magnetic sheet further comprises a heat dissipation layer having one surface coupled to the magnetic layer.

The method of claim 3,
Further comprising an adhesive layer applied to one surface of the heat dissipation layer,
The heat dissipation layer is a magnetic sheet coupled to the magnetic layer through the adhesive layer.

The method of claim 1,
The gap between the magnetic sheet is 1 to 3000㎛.

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The method of claim 3,
The heat dissipation layer is a magnetic sheet comprising at least one of graphite, alumina, aluminum nitride, boron nitride and silicon carbide.

A magnetic layer comprising a plurality of magnetic blocks separated by gaps periodically formed along the longitudinal and transverse directions;
It includes a coil unit mounted on the magnetic layer,
The gap is formed in a period of 3 to 5mm,
The magnetic layer has a specific permeability of 35.2 to 36.0 and a magnetic loss of 0.7% to 0.8% at 150 kHz, and has a specific permeability of 35.4 to 36.7 and a magnetic loss of 3.0% to 3.2% at 13.56 MHz.

The method of claim 8,
The magnetic layer has a wireless power transmission efficiency of 65.17% to 65.45% wireless power.

The method of claim 8,
A heat dissipation layer having one surface bonded to the magnetic layer;
Wireless power receiver further comprises a battery coupled to the other surface of the heat dissipation layer.

The method of claim 10,
Further comprising a second adhesive layer applied to one surface of the heat dissipation layer,
The heat dissipation layer is a wireless power receiving device coupled to the magnetic layer through the second adhesive layer.

The method of claim 8,
The interval of the gap is 1 to 3000㎛ wireless power receiver.

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The method of claim 10,
The heat dissipation layer is a wireless power receiver including at least one of graphite, alumina, aluminum nitride, boron nitride and silicon carbide.

The method of claim 8,
The coil unit has a planar wireless power receiver.