KR102280257B1 - Wireless charging pad, wireless charging device, and electric vehicle comprising same - Google Patents

Abstract

The wireless charging pad according to an embodiment includes a heat transfer layer including a heat transfer material between the magnetic material generating heat and the shield unit, thereby effectively dissipating heat. Accordingly, the wireless charging pad and the wireless charging device employing the structure thereof may be usefully used in electric vehicles that require large-capacity power transmission between a transmitter and a receiver.

Description

Wireless charging pad, wireless charging device, and electric vehicle including the same {WIRELESS CHARGING PAD, WIRELESS CHARGING DEVICE, AND ELECTRIC VEHICLE COMPRISING SAME}

Embodiments relate to a wireless charging pad, a wireless charging device, and an electric vehicle including the same. More specifically, the embodiment relates to a wireless charging pad including a heat transfer layer including a heat transfer material between a magnetic material and a shield portion, a wireless charging device, and an electric vehicle including the same.

Today, the information and communication field is developing at a very fast pace, and various technologies that comprehensively combine electricity, electronics, communication, and semiconductor are continuously being developed. In addition, as electronic devices become more mobile, research on wireless communication and wireless power transmission technology is actively conducted in the communication field. In particular, research on a method of wirelessly transmitting power to an electronic device or the like is being actively conducted.

The wireless power transmission wirelessly transmits power through space using an electromagnetic field resonance structure such as magnetic coupling, capacitive coupling, or an antenna without physical contact between a transmitter that supplies power and a receiver that receives power. will be sent to The wireless power transmission is suitable for portable communication devices and electric vehicles that require a large-capacity battery, and since the contacts are not exposed, there is little risk of a short circuit, and a wired charging failure phenomenon can be prevented.

Meanwhile, as interest in electric vehicles has rapidly increased in recent years, interest in building charging infrastructure is increasing. Various charging methods such as electric vehicle charging using home chargers, battery replacement, fast charging devices, and wireless charging devices have already appeared, and new charging business models have also begun to appear (refer to Korean Patent Application Laid-Open No. 2011-0042403). In addition, electric vehicles and charging stations that are being tested in Europe are starting to stand out, and in Japan, car manufacturers and electric power companies are piloting electric vehicles and charging stations.

Korean Patent Publication No. 2011-0042403

A conventional wireless charging pad 600 used in an electric vehicle, etc., with reference to FIG. 6 , a magnetic material 620 is disposed adjacent to the coil 610 to improve wireless charging efficiency, and a shield unit 630 for shielding ) is disposed to be spaced apart from the magnetic material 620 by a predetermined interval.

The wireless charging pad generates heat during the wireless charging operation due to the resistance of the coil and the magnetic loss of the magnetic material. In particular, the magnetic material in the wireless charging pad generates heat in the vicinity of the coil with high electromagnetic wave energy density, and the generated heat changes the magnetic properties of the magnetic material, causing impedance mismatch between the transmitting pad and the receiving pad, and lowering the charging efficiency. There was a problem in that the heat further worsened due to this. However, since such a wireless charging pad is installed in the lower part of the electric vehicle, it is difficult to implement a heat dissipation structure because it adopts a sealed structure for dustproof, waterproof and shock absorption.

Accordingly, as a result of research conducted by the present inventors, it was found that heat can be effectively discharged by including a heat transfer layer including a heat transfer material between the magnetic material generating heat and the shield part.

Accordingly, an object of the embodiment is to provide an effective wireless charging pad for heat dissipation, a wireless charging device, and an electric vehicle including the same.

According to one embodiment, a coil comprising a conductive wire; a magnetic material disposed on one surface of the coil; a shield portion formed to be spaced apart from the magnetic material; and a heat transfer layer including a heat transfer material between the magnetic material and the shield unit, a wireless charging pad is provided.

According to another embodiment, the housing; a coil disposed within the housing and including a conductive wire; a magnetic material disposed on one surface of the coil; a shield portion formed to be spaced apart from the magnetic material; and a heat transfer layer including a heat transfer material between the magnetic material and the shield unit, a wireless charging device is provided.

According to another embodiment, there is provided an electric vehicle including a wireless charging device, wherein the wireless charging device is disposed in the housing and includes a coil including a conductive wire; a magnetic material disposed on one surface of the coil; a shield portion formed to be spaced apart from the magnetic material; and a heat transfer layer containing a heat transfer material between the magnetic material and the shield unit.

The wireless charging pad according to the embodiment includes a heat transfer layer including a heat transfer material between the magnetic material generating heat and the shield part, so that heat generated from the magnetic material can be easily transferred to the shield part to effectively dissipate heat. there is.

Accordingly, the wireless charging pad and the wireless charging device employing the structure thereof may be usefully used in electric vehicles that require large-capacity power transmission between a transmitter and a receiver.

1 shows a configuration diagram of a wireless charging pad according to an embodiment.
Figure 2a shows a cross-sectional view of a wireless charging pad according to an embodiment.
Figure 2b shows a cross-sectional view of a wireless charging pad according to another embodiment.
Figure 2c shows a cross-sectional view of a wireless charging pad according to another embodiment.
Figure 3a shows a cross-sectional view of a wireless charging pad according to another embodiment.
3B is a perspective view of a magnetic material and a heat transfer layer according to an exemplary embodiment.
4 illustrates a process of forming a magnetic material through a mold according to an exemplary embodiment.
5 is a cross-sectional view of a wireless charging device according to another embodiment.
6 shows a configuration diagram of a conventional wireless charging pad.
7 illustrates an electric vehicle having a wireless charging device according to an embodiment.

In the description of the embodiments below, one component is described as being formed above or below another component, one component is directly above or below another component, or indirectly through another component including all that are formed by

In addition, the reference for the upper / lower of each component will be described with reference to the drawings. The size of each component in the drawings may be exaggerated for explanation, and may be different from the size actually applied.

In the present specification, "including" a certain component does not exclude other components, unless otherwise stated, means that other components may be further included.

In addition, it should be understood that all numerical ranges indicating physical property values, dimensions, etc. of the components described in this specification are modified by the term "about" in all cases unless otherwise specified.

In the present specification, unless otherwise specified, the expression "a" or "a" is interpreted as meaning including the singular or the plural as interpreted in context.

[Wireless Charging Pad]

1 shows a configuration diagram of a wireless charging pad according to an embodiment.

Referring to FIG. 1 , the wireless charging pad 100 according to an embodiment includes a coil 110 including a conductive wire; a magnetic material 120 disposed on one surface of the coil 110; a shield portion 130 formed to be spaced apart from the magnetic material 120 ; and a heat transfer layer 140 including a heat transfer material between the magnetic material 120 and the shield unit 130 .

Hereinafter, each component of the wireless charging pad will be described in detail.

support plate

The wireless charging pad 100 may further include a support plate 160 for supporting the coil 110 .

The material and structure of the support plate may employ the material and structure of a conventional support plate used for a wireless charging pad.

The support plate may have a flat plate structure or a structure in which a groove is dug along a coil shape to fix the coil.

coil

The coil includes a conductive wire.

The conductive wire includes a conductive material. For example, the conductive wire may include a conductive metal. Specifically, the conductive wire may include at least one metal selected from the group consisting of copper, nickel, gold, silver, zinc, and tin.

In addition, the conductive wire may have an insulating sheath. For example, the insulating shell may include an insulating polymer resin. Specifically, the insulating shell may include a polyvinyl chloride (PVC) resin, a polyethylene (PE) resin, a Teflon resin, a silicone resin, a polyurethane resin, and the like.

The diameter of the conductive wire may be, for example, in the range of 1 mm to 10 mm, in the range of 1 mm to 5 mm, or in the range of 1 mm to 3 mm.

The conductive wire is wound in the form of a flat coil. Specifically, the planar coil may include a planar spiral coil. At this time, the shape of the planar coil may be an elliptical shape, a polygonal shape, or a polygonal shape with rounded corners, but is not particularly limited.

The outer diameter of the planar coil may be 5 cm to 100 cm, 10 cm to 50 cm, 10 cm to 30 cm, 20 cm to 80 cm, or 50 cm to 100 cm. As a specific example, the planar coil may have an outer diameter of 10 cm to 50 cm.

In addition, the inner diameter of the planar coil may be 0.5 cm to 30 cm, 1 cm to 20 cm, or 2 cm to 15 cm.

The number of windings of the flat coil may be 5 to 50 times, 10 to 30 times, 5 to 30 times, 15 to 50 times, or 20 to 50 times. As a specific example, the flat coil may be formed by winding the conductive wire 10 to 30 times.

In addition, the distance between the conductive wires in the planar coil shape may be 0.1 cm to 1 cm, 0.1 cm to 0.5 cm, or 0.5 cm to 1 cm.

When within the preferred planar coil dimensions and specifications as described above, it may be suitable for fields requiring large-capacity power transmission, such as electric vehicles.

shield part

The shield part is disposed on one surface of the coil.

The shield portion serves to increase the wireless charging efficiency through electromagnetic wave shielding.

The shield portion includes a metal plate. The material of the metal plate may be aluminum, and other metal or alloy materials having electromagnetic wave shielding ability may be used.

The thickness of the shield part may be 0.2 mm to 10 mm, 0.5 mm to 5 mm, or 1 mm to 3 mm.

In addition, the area of the shield part may be 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more.

magnetic material

The magnetic material is disposed between the coil and the shield unit.

The magnetic material may be disposed to be spaced apart from the shield part by a predetermined interval. For example, the separation distance between the magnetic material and the shield portion may be 3 mm or more, 5 mm or more, 3 mm to 10 mm, or 4 mm to 7 mm.

In addition, the magnetic material may be disposed to be spaced apart from the coil by a predetermined interval. For example, the separation distance between the magnetic material and the coil may be 0.2 mm or more, 0.5 mm or more, 0.2 mm to 3 mm, or 0.5 mm to 1.5 mm.

The magnetic material may be a polymer-type magnetic material including a binder resin and magnetic powder.

Alternatively, the magnetic material may include a metallic magnetic material, for example, a nanocrystalline magnetic material.

Alternatively, the magnetic material may be a composite material of the polymer-type magnetic material and the nanocrystalline magnetic material.

high molecular weight material

The magnetic material may include a binder resin and magnetic powder dispersed in the binder resin.

Accordingly, in the polymer-type magnetic material, magnetic powders are combined with each other by a binder resin, so that overall defects are small over a large area and damage due to impact can be small.

The magnetic powder may include oxide magnetic powder such as ferrite (Ni-Zn-based, Mg-Zn-based, Mn-Zn-based ferrite, etc.); metallic magnetic powders such as permalloy, sandust, and nanocrystalline magnetic material; Or it may be a mixed powder thereof. More specifically, the magnetic powder may be sandus particles having a Fe-Si-Al alloy composition.

As an example, the magnetic powder may have a composition of Formula 1 below.

[Formula 1]

Fe _1-abc Si _a X _b Y _c

wherein X is Al, Cr, Ni, Cu, or a combination thereof; Y is Mn, B, Co, Mo, or a combination thereof; 0.01 ≤ a ≤ 0.2, 0.01 ≤ b ≤ 0.1, and 0 ≤ c ≤ 0.05.

The average particle diameter of the magnetic powder may be in the range of about 3 nm to about 1 mm, about 1 μm to 300 μm, about 1 μm to 50 μm, or about 1 μm to 10 μm.

The polymer type magnetic material may include the magnetic powder in an amount of 50 wt% or more, 70 wt% or more, or 85 wt% or more.

For example, the polymeric magnetic material may contain 50 wt% to 99 wt%, 70 wt% to 95 wt%, 70 wt% to 90 wt%, 75 wt% to 90 wt%, 75 wt% to the magnetic powder. 95% by weight, 80% to 95% by weight, or 80% to 90% by weight.

The binder resin may be a curable resin. Specifically, the binder resin may include a photocurable resin, a thermosetting resin, and/or a high heat-resistant thermoplastic resin, preferably a thermosetting resin.

As a resin capable of exhibiting adhesiveness by being cured in this way, it includes at least one functional group or site that can be cured by heat, such as a glycidyl group, an isocyanate group, a hydroxyl group, a carboxyl group, or an amide group; or at least one functional group or moiety that can be cured by active energy such as an epoxide group, a cyclic ether group, a sulfide group, an acetal group, or a lactone group resin can be used. Such a functional group or moiety may be, for example, an isocyanate group (-NCO), a hydroxyl group (-OH), or a carboxyl group (-COOH).

Specifically, the curable resin may be exemplified by a polyurethane resin, an acrylic resin, a polyester resin, an isocyanate resin, or an epoxy resin having at least one functional group or site as described above, but is not limited thereto.

As an example, the binder resin may include a polyurethane-based resin, an isocyanate-based curing agent, and an epoxy-based resin.

The polymeric magnetic material may contain the binder resin in an amount of 5 wt% to 40 wt%, 5 wt% to 20 wt%, 5 wt% to 15 wt%, or 7 wt% to 15 wt%.

In addition, based on the weight of the polymeric magnetic material, as the binder resin, 6 wt% to 12 wt% of a polyurethane-based resin, 0.5 wt% to 2 wt% of a isocyanate-based curing agent, and 0.3 wt% to 1.5 wt% It may contain an epoxy-based resin of weight %.

The polymer-type magnetic material can be prepared by a sheet-forming process such as mixing magnetic powder and a polymer resin composition to slurry it, then molding it into a sheet shape and curing it, but a large-area polymer-type magnetic material having a constant thickness is manufactured In order to do this, the block can be manufactured by molding using a mold.

The molding may be performed by injecting a raw material of a magnetic material into a mold by injection molding. More specifically, the magnetic material is obtained by mixing a magnetic powder and a polymer resin composition to obtain a raw material composition, and then, as shown in FIG. 4 , the raw material composition 401 is injected into the mold 403 by an injection molding machine 402. can be manufactured. In this case, by designing the internal shape of the mold 403 as a three-dimensional structure, the three-dimensional structure of the magnetic material can be easily implemented. Such a process is impossible when using a conventional sintered ferrite sheet as a magnetic material.

Nanocrystalline magnetic material

The magnetic material may include a nanocrystalline magnetic material.

When the nanocrystalline magnetic material is applied, the higher the distance from the coil, the lower the resistance (Rs) even if the inductance (Ls) of the coil is lowered, so that the quality factor (Q factor: Ls/Rs) of the coil is increased and charging Efficiency can be improved and heat generation can be reduced.

For example, the nanocrystalline magnetic material may be a Fe-based nanocrystalline magnetic material, specifically, a Fe-Si-Al-based nanocrystalline magnetic material, a Fe-Si-Cr-based nanocrystalline magnetic material, or Fe-Si-B It may be a -Cu-Nb-based nanocrystalline magnetic material.

More specifically, the nanocrystalline magnetic material may be a Fe-Si-B-Cu-Nb-based nanocrystalline magnetic material, in this case, Fe is 70 element% to 85 element%, and the sum of Si and B is 10 element% to 29 element %, and the sum of Cu and Nb is preferably 1 element % to 5 element % (element % means the percentage of the number of specific elements with respect to the total number of elements constituting the magnetic material). In the above composition range, the Fe-Si-B-Cu-Nb-based alloy can be easily formed into nanophase crystalline by heat treatment.

The nanocrystalline magnetic material is manufactured by, for example, a Fe-based alloy by a rapid cooling and solidification method (RSP) by melt spinning, in a temperature range of 300 ℃ to 700 ℃ to obtain a desired magnetic permeability for 30 minutes to 2 hours without a magnetic field It can be manufactured by performing heat treatment.

If the heat treatment temperature is less than 300 ℃, nanocrystals are not sufficiently formed, so the desired permeability is not obtained, and the heat treatment time may take a long time, and if it exceeds 700 ℃, the magnetic permeability may be significantly lowered by overheating. In addition, if the heat treatment temperature is low, the treatment time is long, and conversely, if the heat treatment temperature is high, the treatment time is preferably shortened.

The nanocrystalline magnetic material is difficult to make thick in the manufacturing process, and may be formed to a thickness of, for example, 15 μm to 35 μm.

Area and thickness of magnetic material

The magnetic material may be a magnetic sheet, a magnetic sheet laminate, or a magnetic block.

The magnetic material may have a large area, specifically 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more. In addition, the magnetic material may have an area of ^{10,000 cm 2 or less.}

The large-area magnetic material may be configured by combining a plurality of unit magnetic materials, and in this case, the area of the unit magnetic material may be 60 cm ² or more, 90 cm ² , or 95 cm ² to 900 cm ² .

The thickness of the magnetic sheet may be 15 μm or more, 50 μm or more, 80 μm or more, 15 μm to 150 μm, 15 μm to 35 μm, or 85 μm to 150 μm. Such a magnetic sheet may be manufactured by a method for manufacturing a conventional film or sheet.

The magnetic sheet laminate may be one in which 20 or more magnetic sheets or 50 or more magnetic sheets are laminated. In addition, the laminate of the magnetic sheet may be a stack of 150 or less or 100 or less of the magnetic sheet.

The thickness of the magnetic block may be 1 mm or more, 2 mm or more, 3 mm or more, or 4 mm or more. In addition, the thickness of the magnetic block may be 6 mm or less.

Magnetic properties of magnetic materials

The magnetic material may have a certain level of magnetic properties in the vicinity of a standard frequency for wireless charging of an electric vehicle.

The wireless charging standard frequency of the electric vehicle may be less than 100 kHz, specifically 79 kHz to 90 kHz, specifically 81 kHz to 90 kHz, more specifically about 85 kHz, which is applied to mobile electronic devices such as cell phones It is a band that is distinct from the frequency.

For example, the magnetic permeability of the magnetic material may be 5 to 150,000, 10 to 150,000, 20 to 150,000, 5 to 300, 30 to 300, 600 to 3,500, or 10,000 to 150,000 in a frequency band of 79 kHz to 90 kHz. . Specifically, the magnetic permeability of the magnetic material may be 30 to 300, 600 to 3,500, or 10,000 to 150,000 in a frequency band of 79 kHz to 90 kHz. More specifically, the magnetic permeability of the magnetic material may be 30 to 250, or 30 to 200 in a frequency band of 79 kHz to 90 kHz.

In addition, the investment loss of the magnetic material may be 1 to 150,000, 1 to 50,000, 5 to 30,000, 10 to 3,000, 10 to 1,000, 100 to 1,000, or 5,000 to 50,000 in a frequency band of 79 kHz to 90 kHz.

Specifically, the magnetic material may have a magnetic permeability of 30 to 200 and an investment loss of 10 to 3,000 in a frequency band of 79 kHz to 90 kHz.

Properties of magnetic materials

The polymer type magnetic material may be elongated at a certain ratio. For example, the elongation of the polymer type magnetic material may be 0.5% or more. The elongation property is difficult to obtain in a ceramic-based magnetic material that does not apply a polymer, and can reduce damage even when a large-area magnetic material is distorted due to an impact. Specifically, the elongation of the polymer type magnetic material may be 0.5% or more, 1% or more, or 2.5% or more. There is no particular limitation on the upper limit of the elongation, but if the content of the polymer resin is increased to improve the elongation, physical properties such as inductance of the magnetic material may be deteriorated. Therefore, the elongation is preferably set to 10% or less.

The magnetic material has a small rate of change in physical properties before and after impact, and is significantly superior to that of a general ferrite magnetic sheet.

In the present specification, the rate of change (%) of physical properties before and after impact of certain properties may be calculated by the following formula.

Characteristic change rate (%) = | Property Values Before Impact - Property Values After Impact | / pre-impact property value x 100

For example, the magnetic material may have an inductance change rate of less than 5% or less than 3% before and after an impact applied by free-falling from a height of 1 m. More specifically, the inductance change rate may be 0% to 3%, 0.001% to 2%, or 0.01% to 1.5%. When within the above range, the inductance change rate before and after the impact is relatively small, so the stability of the magnetic material may be further improved.

In addition, the magnetic material may have a quality factor (Q factor) change rate of 0% to 5%, 0.001% to 4%, or 0.01% to 2.5% before and after the impact applied by free falling from a height of 1 m. When it is within the above range, the change in physical properties before and after impact is small, so that the stability and impact resistance of the magnetic material can be further improved.

In addition, the magnetic material may have a resistance change rate of 0% to 2.8%, 0.001% to 1.8%, or 0.1% to 1.0% before and after an impact applied by free falling from a height of 1 m. When it is within the above range, the resistance value may be well maintained below a certain level even if it is repeatedly applied in an environment to which an actual shock and vibration are applied.

In addition, the magnetic material may have a rate of change in charging efficiency before and after an impact applied by free falling from a height of 1 m to 0% to 6.8%, 0.001% to 5.8%, or 0.01% to 3.4%. When within the above range, the magnetic material of a large area may more stably maintain the physical properties even if the impact or distortion occurs repeatedly.

heat transfer layer

The wireless charging pad according to the embodiment may effectively dissipate heat by including a heat transfer layer including a heat transfer material between the magnetic material and the shield that generate heat in a portion close to the coil having high electromagnetic wave energy density.

In general, in order to prevent a problem that charging efficiency rapidly decreases due to generation of an anti-magnetic field between the magnetic material and the shield unit, an empty space or spacer unit is provided in the range of about 3 mm to 10 mm. Accordingly, it is common that the magnetic material and the shield portion are spaced apart from each other. Nevertheless, the spacer part or the empty space has a very high thermal conductivity due to the magnetic material, and when this heat is not discharged, various problems such as a sharp decrease in charging efficiency or a defect may occur.

The wireless charging pad according to an embodiment of the present invention is provided with a heat transfer layer containing a heat transfer material instead of a spacer or an empty space between the magnetic material and the shield part, so that heat due to the magnetic material or within the wireless charging pad Since the generated heat may be transferred to the shield unit through the heat transfer material, heat dissipation characteristics may be further improved, thereby improving charging efficiency.

The heat transfer layer includes a thermal interface material (TIM), and the heat transfer material functions to rapidly dissipate heat to the outside. A magnetic material generating heat through the heat transfer material and a shield unit capable of dissipating heat may be interconnected. That is, the heat transfer material may transmit heat generated from the magnetic material to the shield unit to radiate the heat to the outside.

The heat transfer layer may include the heat transfer material in an amount of 10% to 150% based on the total volume of the heat transfer layer. Specifically, the heat transfer layer may include a heat transfer material in an amount of 50% to 150%, 50% to 110%, 70% to 110%, or 70% to 100% based on the total volume of the heat transfer layer. If the content of the heat transfer material is less than the above range, the heat transfer effect may be insignificant, and if the content of the heat transfer material exceeds the above range, the weight of the wireless charging pad may increase and problems of assembly failure may occur. Accordingly, when the content of the heat transfer material satisfies the above range, heat can be effectively discharged between the magnetic material and the shield, so that heat dissipation characteristics and charging efficiency can be improved.

The heat transfer material may use various heat dissipation materials within a range that does not impair the effects of the present invention, and specifically may include one or more selected from the group consisting of ceramic materials, oxide materials, and carbon materials, for example, For example, it may include at least one selected from the group consisting of _{Al 2} O ₃ , AlN, SiO ₂ , and Si ₃ N _{4 .}

In addition, the heat transfer layer may not include a metal component in the heat transfer layer. When a metal component is included in the heat transfer layer, the flow of the magnetic field may be disturbed, and thus the effect of the present invention may be reduced.

The heat transfer layer may be inserted between the magnetic material and the shield unit in various ways. For example, the heat transfer layer may be formed by preparing a resin composition including the heat transfer material and the binder resin, and then coating the resin composition on the magnetic material. Alternatively, the sheet may be manufactured in the form of a sheet including the heat transfer material, and the sheet may be laminated on the magnetic material by attaching the sheet to a region where heat is generated using a heat conductive adhesive. The thermally conductive adhesive may include a thermally conductive material such as a metal-based, carbon-based, or ceramic-based adhesive, for example, an adhesive resin in which thermally conductive particles are dispersed.

The heat transfer material has insulation and thermal conductivity.

For example, the heat transfer material has a thermal conductivity of 3 W/mK to 20 W/mK, 4 W/mK to 20 W/mK, 5 W/mK to 20 W/mK, 3 W/mK to 10 W/mK, 10 W/mK to 20 W/mK, or 8 W/mK to 15 W/mK.

In addition, the heat transfer material has a specific resistance of 1 X 10 ² to 1 X 10 ²⁰ Ω·cm, 1 X 10 ² to 1 X 10 ¹⁵ Ω·cm, 1 X 10 ² to 1 X 10 ¹⁰ Ω·cm, or 1 X It ^{may be 10 5} to 1 X 10 ¹⁸ Ω·cm. When the heat transfer material satisfies the thermal conductivity and specific resistance in the above ranges, the heat dissipation effect desired in the present invention may be achieved.

The heat transfer layer has a volume of 50% to 150%, 60% to 120%, 50% to 100%, 100% to 150%, 70% to 110%, or 70% to 100% based on the total volume of the magnetic material. can have

In addition, the thickness ratio of the heat transfer layer and the magnetic material is 1:0.5 to 50, 1:1 to 20, 1:1 to 11, 1:0.5 to 11, 1:0.5 to 10, 1:1 to 5, 1: 5 to 11, 1:4 to 6, 1:10 to 11, 1:5 to 6, 1:1 to 3, 1:1 to 2, 1:1 to 1.5, 1:0.8 to 1.2, or 1:1 to 1.1. If the thickness ratio of the heat transfer layer and the magnetic material is less than the above range, there may be a problem in that the heat dissipation effect sharply decreases, and if it exceeds the above range, there may be a problem of an increase in the weight of the wireless charging pad.

For example, the heat transfer layer may have the same large area as the magnetic material. Specifically, the area of the heat transfer layer may be 200 cm ² or more, 400 cm ² or more, or 600 cm ² or more. In addition, the area of the heat dissipation material ^{may be 10,000 cm 2} or less. Alternatively, the heat transfer layer may have a smaller area than the magnetic material. Specifically, the heat transfer layer may have an area corresponding to the area of the coil.

In addition, the thickness of the heat transfer layer may be 0.5 mm to 5.6 mm, 0.5 mm to 3 mm, 3.5 mm to 5.6 mm, 3 mm to 5 mm, or 5 mm to 5.6 mm.

According to an embodiment of the present invention, the heat transfer layer may be in contact with the magnetic material and the shield part at least in part.

The contact area between the heat transfer layer and the magnetic material is 10% to 100%, 30% to 100%, 50% to 100%, 55% to 100%, or 60% to 100% based on the total area of the magnetic material. can be

In addition, the contact area between the heat transfer layer and the shield portion may be 10% to 100%, 30% to 100%, or 50% to 100% based on the total area of the magnetic material.

According to another embodiment of the present invention, in the wireless charging pad, the heat transfer layer may be formed of a plurality of pillars including a heat transfer material. The plurality of pillars may have a diameter of 0.5 mm to 2.0 mm, 0.5 mm to 1.5 mm, 0.6 mm to 1.0 mm, or 0.7 mm to 0.9 mm. If the plurality of pillars are less than 0.5 mm, they may be easily broken by external impact. In addition, when the plurality of pillars exceeds 2.0 mm, the formation of a magnetic field may be hindered, and thus effective heat dissipation may be hindered.

The length of the plurality of pillars may be 0.5 mm to 8 mm, 0.5 mm to 5.6 mm, 1 mm to 7 mm, 2 mm to 6 mm, 3 mm to 6 mm, or 4 mm to 5.6 mm.

In addition, a gap of 0.5 mm to 2.0 mm, 0.6 mm to 1.8 mm, 0.8 mm to 1.7 mm, or 0.8 mm to 1.5 mm may be formed between the plurality of pillars.

The number of pillars per 1 cm 2 of the plurality of pillars may be 5 to 60, 6 to 50, 8 to 50, 10 to 50, or 9 to 49.

Hereinafter, various structures of the wireless charging pad including the heat transfer layer will be described.

Various structures of wireless charging pad

2A to 2C are cross-sectional views of wireless charging pads 200a, 200b, and 200c showing various examples of the wireless charging pad including the heat transfer layer.

2A to 2C, a coil 210 including a conductive wire; a magnetic material 220 disposed on one surface of the coil 210; a shield portion 230 formed to be spaced apart from the magnetic material 220; and a heat transfer layer 240 including a heat transfer material between the magnetic material 220 and the shield 230 .

In addition, in the wireless charging pads 200a, 200b, and 200c, the heat transfer layer 240 may be in contact with the magnetic material 220 and the shield unit 230 at least in part.

As an example, as shown in FIG. 2A , the heat transfer layer 240 may be in full contact with the magnetic material 220 and the shield unit 230 . In the heat transfer layer, when a region corresponding to the coil is defined as a first region and other regions are defined as a second region, the thickness of the first region and the second region of the heat transfer layer may be the same. In this case, since the heat transfer layer is in contact with both the magnetic material and the shield portion, heat generated from the magnetic material is effectively transferred to the shield portion through the heat transfer material included in the heat transfer layer, thereby maximizing the heat dissipation effect. there is.

Also, as shown in FIG. 2B , the heat transfer layer 240 may contact only the magnetic material 220 and the shield portion 230 and a portion (a first region) corresponding to the coil. In this case, the heat transfer layer can effectively improve charging efficiency and heat dissipation characteristics even with a small area.

Also, as shown in FIG. 2C , the heat transfer layer 240 may be in contact with the magnetic material 220 , but may only be in contact with the shield portion 230 at a portion corresponding to the coil. In the heat transfer layer, when a region corresponding to the coil is defined as a first region and other regions are defined as a second region, the thickness of the first region of the heat transfer layer is thicker than the thickness of the second region. may have a thickness. In this case, the heat transfer layer can effectively improve charging efficiency and heat dissipation characteristics even with a small area.

In addition to this, as long as the effects of the present invention are not impaired, the heat transfer layer may be modified into various structures.

Meanwhile, according to one embodiment of the present invention, the heat transfer layer may be formed of a plurality of pillars including a heat transfer material.

3A and 3B are respectively a perspective view of a heat transfer layer on a magnetic material and a top view of the magnetic material and the heat transfer layer according to another embodiment of the present invention.

3A and 3B, the wireless charging pad 300 according to an embodiment of the present invention includes a coil 310 including the conductive wire; a magnetic material 320 disposed on one surface of the coil; a shield portion 330 formed to be spaced apart from the magnetic material 320; and a heat transfer layer 340 including a plurality of pillars 350 including a heat transfer material between the magnetic material 220 and the shield unit 330 , wherein the plurality of pillars 350 are formed with the magnetic It may be formed in direct contact with one surface of the material 320 . In addition, the plurality of pillars 350 are formed in direct contact with one surface of the shield unit 230 , thereby dissipating heat generated from the magnetic material 320 in the outermost layer of the wireless charging pad. can be discharged through

Meanwhile, the plurality of pillars may be disposed to correspond to an area in which the coil is present. The plurality of pillars can effectively improve charging efficiency and heat dissipation characteristics even with a small area. In addition, the plurality of pillars may be disposed in a region in which the coil is present and in a region in which the coil is not present.

The plurality of pillars 350 may be formed in direct contact with one surface of the magnetic material, and may be fixed to the magnetic material 320 by, for example, a fixing part (not shown) or an adhesive.

Specifically, the plurality of pillars may be attached to the magnetic material, or one surface of the magnetic material and the shield portion by a thermally conductive adhesive. The thermally conductive adhesive may include a thermally conductive material such as a metal-based, carbon-based, or ceramic-based adhesive, for example, an adhesive resin in which thermally conductive particles are dispersed.

In addition, as long as the fixing part does not impair the effect of the present invention and fix the plurality of pillars, the position, shape, and size thereof are not particularly limited. For example, the magnetic material may be formed into a three-dimensional structure by a mold, and may be formed to include a fixing part in a portion thereof during molding, and the plurality of pillars may be formed through the fixing part included in the magnetic material. can be fixed.

The plurality of pillars may be connected to the shield unit to effectively dissipate heat generated from the magnetic material to the outside. Specifically, the plurality of pillars may be connected to the shield part directly or by a thermal conductive medium. The thermally conductive medium may be composed of the same component as the plurality of pillars or a different component. For example, the thermally conductive medium may be made of a ceramic material or a carbon-based material. Alternatively, the thermally conductive medium may be made of the same material as the shield part, for example, may be made of aluminum.

[Wireless Charging Device]

5 is a cross-sectional view showing a wireless charging device according to an embodiment.

Referring to FIG. 5 , a wireless charging device 500 according to an embodiment includes a housing 501 ; a coil 510 disposed within the housing 501 and including a conductive wire; a magnetic material 520 disposed on one surface of the coil 510; a shield portion 530 formed to be spaced apart from the magnetic material 520; and a heat transfer layer 540 including a heat transfer material between the magnetic material 520 and the shield 530 . In addition, the wireless charging device may further include a support plate 560 for supporting the coil.

FIG. 5 shows an example in which the heat transfer layer is disposed over both a region in which the coil is present and a region in which the coil is not present, that is, over the entire magnetic material according to an embodiment of the present invention, but in which the coil is present. It can be placed only in the Alternatively, it may be disposed only in a region where the coil is present, and a part of it.

In addition, among the components of the wireless charging device, the configuration and characteristics of the heat transfer layer including the coil, the shield unit, the magnetic material and the heat transfer material are as described above.

The housing allows the coil, the shield unit, the magnetic material and the heat transfer layer including the heat transfer material to be properly disposed and assembled. The material and structure of the housing may adopt the material and structure of a typical housing used in a wireless charging device.

The wireless charging device includes a heat transfer layer including a heat transfer material between the magnetic material generating heat and the shield unit, thereby effectively discharging heat, particularly when the heat transfer layer is in contact with the magnetic material and the shield unit. , can dissipate heat more effectively.

Accordingly, the wireless charging device may be usefully used in an electric vehicle requiring large-capacity power transmission between a transmitter and a receiver.

[Electric Vehicle]

7 shows an electric vehicle to which a wireless charging device is applied.

Referring to FIG. 7 , the electric vehicle 700 according to an embodiment includes the wireless charging device according to the embodiment as a receiver 720 . The wireless charging device may serve as a receiver of wireless charging of the electric vehicle 700 and receive power from the transmitter 730 of wireless charging.

Specifically, the electric vehicle is an electric vehicle including a wireless charging device,

a coil in which the wireless charging device is disposed in the housing and includes a conductive wire; a magnetic material disposed on one surface of the coil in the housing; a shield portion formed to be spaced apart from the magnetic material; and a heat transfer layer including a heat transfer material between the magnetic material and the shield unit.

The configuration and characteristics of each component of the wireless charging device included in the electric vehicle are as described above.

The wireless charging device may be provided under the vehicle.

The electric vehicle may further include a battery receiving power from the wireless charging device. The wireless charging device may receive power wirelessly and transmit it to the battery, and the battery may supply power to a driving system of the electric vehicle. The battery may be charged by power transmitted from the wireless charging device or other additional wired charging devices.

In addition, the electric vehicle may further include a signal transmitter for transmitting information about charging to the transmitter of the wireless charging system for the electric vehicle. The information about such charging may be charging efficiency such as charging speed, charging degree, and the like.

100, 200a, 200b, 200c, 300, 500, 600: wireless charging pad
110, 210, 310, 510, 610: coil
120, 220, 320, 520, 620: magnetic material
130, 230, 330, 530, 630: shield part
140, 240, 340, 540: heat transfer layer
160, 560: support plate
350: pillar
401: raw material composition 402: injection molding machine 403: mold
501: housing
700: electric vehicle 720: receiver 730: transmitter

Claims (19)

a coil comprising a conductive wire;
a magnetic material disposed on one surface of the coil;
a shield portion formed to be spaced apart from the magnetic material; and
and a heat transfer layer disposed between the magnetic material and the shield unit and including a heat transfer material;
When defining an area corresponding to the coil in the heat transfer layer as a first area, and defining other areas as a second area, the heat transfer layer is disposed in the first area, wireless charging pad.
The method of claim 1,
The heat transfer material having a thermal conductivity of 3 W / mK to 20 W / mK, wireless charging pad.
The method of claim 1,
The heat transfer material has ^{a resistivity of 1 X 10 2} to 1 X 10 ²⁰ Ω·cm, wireless charging pad.
The method of claim 1,
The heat transfer layer is formed by coating a resin composition including the heat transfer material and the binder resin on the magnetic material, or by attaching the heat transfer material to a sheet including the heat transfer material.
The method of claim 1,
The heat transfer layer comprises 10% to 150% of the heat transfer material based on the total volume of the heat transfer layer, wireless charging pad.
The method of claim 1,
The heat transfer material comprising at least one selected from the group consisting of a carbon-based material, an oxide-based material, and a ceramic-based material, wireless charging pad.
The method of claim 1,
A wireless charging pad that does not contain a metal component in the heat transfer layer.
The method of claim 1,
The heat transfer layer is at least partially in contact with the magnetic material and the shield portion, a wireless charging pad.
The method of claim 1,
The heat transfer layer having a volume of 50% to 150% based on the total volume of the magnetic material, wireless charging pad.
The method of claim 1,
The thickness ratio of the heat transfer layer and the magnetic material is 1: 0.5 to 50, wireless charging pad.
The method of claim 1,
The contact area of the heat transfer layer and the magnetic material is 10% to 100% based on the total area of the magnetic material, the wireless charging pad.
The method of claim 1,
The contact area between the heat transfer layer and the shield portion is 10% to 100% based on the total area of the magnetic material, the wireless charging pad.
delete delete a coil comprising a conductive wire;
a magnetic material disposed on one surface of the coil;
a shield portion formed to be spaced apart from the magnetic material; and
a heat transfer layer disposed between the magnetic material and the shield unit;
The heat transfer layer is made of a plurality of pillars containing a heat transfer material, wireless charging pad.
16. The method of claim 15,
The plurality of pillars have a diameter of 0.5 mm to 2.0 mm, and a gap of 0.5 mm to 2.0 mm is formed between the plurality of pillars, a wireless charging pad.
16. The method of claim 15,
The plurality of pillars have a length of 0.5 mm to 8.0 mm, and the number of pillars per 1 cm 2 area is 5 to 60, wireless charging pad.
housing;
a coil disposed within the housing and including a conductive wire;
a magnetic material disposed on one surface of the coil;
a shield portion formed to be spaced apart from the magnetic material; and
and a heat transfer layer disposed between the magnetic material and the shield unit and including a heat transfer material;
When defining an area corresponding to the coil in the heat transfer layer as a first area, and defining other areas as a second area, the heat transfer layer is disposed in the first area, the wireless charging device.
As an electric vehicle including a wireless charging device,
The wireless charging device
housing;
a coil disposed within the housing and including a conductive wire;
a magnetic material disposed on one surface of the coil;
a shield portion formed to be spaced apart from the magnetic material; and
and a heat transfer layer disposed between the magnetic material and the shield unit and including a heat transfer material;
In the heat transfer layer, when an area corresponding to the coil is defined as a first area and other areas are defined as a second area, the heat transfer layer is disposed in the first area.

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