Wireless power transmission device for vehicle

A wireless power transmission device for a vehicle is provided. A wireless power transmission device for a vehicle comprises: a magnetic field shielding sheet having a plate shape and a predetermined area, at least one wireless power transmission antenna disposed on a first surface of the magnetic field shielding sheet, and a wireless communication antenna formed in an antenna pattern on at least one surface of a circuit board, wherein the circuit board is disposed on a second surface of the magnetic field shielding sheet which is a surface opposite to the first surface.

TECHNICAL FIELD

The present invention relates to a wireless power transmission technology, and more particularly, to a wireless power transmission device for vehicles which may be installed in a vehicle to charge batteries of an electronic device.

BACKGROUND ART

Recently, usage of electric devices with a battery which is charged by external power, for example, usage of a portable electronic device, such as a mobile phone, a smartphone, a tablet personal computer (PC), a notebook computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), or a navigation system, has been increased.

In the portable electronic device, the battery of the electronic device is often charged through a charger while moving in a dynamic space such as a vehicle.

To this end, a method capable of easily charging batteries of electronic devices in a vehicle by transmitting power supplied from the vehicle in a wireless manner has been proposed.

Meanwhile, near field communication (NFC) is a technology capable of transmitting data between terminals at a close distance within 10 cm in a contactless communication method. Recently, electronic devices include functions such as data transmission through NFC in addition to wireless charging.

Accordingly, a user having an electronic device to which an NFC technology is applied may conveniently check various information of a vehicle by receiving the information of the vehicle through the electronic device.

However, when the electronic device does not smoothly perform wireless charging and data transmission at the same position, there is an inconvenience that the user has to move the electronic device to a position in which the wireless charging is smoothly performed or move the electronic device to a position in which the data transmission is smoothly performed.

Accordingly, there is a need for a solution in which both data transmission and wireless charging may be smoothly performed even without changing the position of an electronic device in a vehicle.

DISCLOSURE

Technical Problem

The present invention is directed to providing a wireless power transmission device for vehicles capable of smoothly performing both data communication and wireless charging without changing the position of an electronic device.

The present invention is also directed to providing a wireless power transmission device for vehicles capable of improving the problem of heat generated during wireless charging.

Technical Solution

One aspect of the present invention provides a wireless power transmission device including at least one wireless power transmission antenna for power transmission, a wireless communication antenna formed in an antenna pattern on at least one surface of a circuit board, and a magnetic field shielding sheet having a plate shape and disposed on one surface of the wireless power transmission antenna, wherein the circuit board on which the wireless communication antenna is formed is disposed to be located above the wireless power transmission antenna.

The wireless power transmission antenna may be formed of a planar coil having a hollow portion, and the wireless communication antenna may include a first patterned portion disposed on a region corresponding to the wireless power transmission antenna and a second patterned portion disposed on a region which does not correspond to the wireless power transmission antenna.

The first patterned portion may be formed such that a portion thereof which is located directly above a coil body of the planar coil has a relatively longer length or wider area than a portion thereof which is located directly above the hollow portion or has a relatively shorter length or narrower area than the portion thereof which is located directly above the hollow portion.

Another aspect of the present invention provides a wireless power transmission device including a magnetic field shielding sheet having a plate shape and a predetermined area, at least one wireless power transmission antenna disposed on a first surface of the magnetic field shielding sheet, and a wireless communication antenna formed in an antenna pattern on at least one surface of a circuit board, wherein the circuit board is disposed on a second surface of the magnetic field shielding sheet which is a surface opposite to the first surface.

The circuit board may include a protruding region which protrudes outward from an edge of the magnetic field shielding sheet, and the wireless communication antenna may be patterned in the protruding region.

The wireless power transmission device may include a planar heat-dissipating member to increase a heat-dissipating property.

The wireless power transmission device may include a supporting plate to increase both alignment workability and a heat-dissipating property in a case in which the wireless power transmission antenna is configured with a plurality of antennas.

The wireless power transmission device may include a housing including at least one circuit board built therein for an overall operation and configured to release heat generated by a heat source, and a heat-dissipating coating layer applied to an outer surface of the housing to improve a heat-dissipating property.

Advantageous Effects

According to the present invention, even when an electronic device is located at the same position without changing its position, both data communication and wireless charging can be smoothly performed by optimizing the arrangement position of the near field communication (NFC) antenna, thereby improving usability.

In addition, according to the present invention, since a plurality of planar coils can be conveniently disposed according to the certification standard using a supporting plate, assembling productivity can be increased, heat-dissipating performance can be improved by a heat-dissipating member, and assembling property and fastening property with other components can be increased.

Furthermore, according to the present invention, the surface temperature of a cover during wireless charging can be lowered by increasing the heat-dissipating performance of a housing using a heat-dissipating coating layer.

MODES OF THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art to which the present invention pertains may readily implement the embodiments. The present invention may be embodied in many different forms and is not limited to the embodiments set forth herein. In the drawings, a part which is not related to the description is omitted to clearly describe the present invention, and the same reference numerals throughout the specification are used for the same or similar components or elements.

A vehicle wireless power transmission device100or200according to one embodiment of the present invention may be equipped or installed in a vehicle, and may charge a battery included in an electronic device with power by transmitting wireless power toward a wireless power reception module built in a portable electronic device when the portable electronic device such as a smartphone is disposed on an upper side of the vehicle wireless power transmission device100or200. In addition, in the vehicle wireless power transmission device100or200according to one embodiment of the present invention, near field communication (NFC) may be smoothly performed at the same position as a position in which the battery is charged.

In the present invention, the electronic device may be one of portable electronic devices such as a mobile phone, a personal digital assistant (PDA), a portable multimedia player (PMP), a tablet, and a multimedia device.

To this end, the vehicle wireless power transmission device100or200according to one embodiment of the present invention includes an antenna unit and a magnetic field shielding sheet120as shown inFIGS. 1 to 6.

The antenna unit performs various functions such as data communication and wireless power transmission using a predetermined frequency band. To this end, the antenna unit may include a plurality of antennas, and the plurality of antennas may perform different functions.

For example, the antenna unit may include one or more wireless power transmission antennas111,112, and113for transmitting wireless power toward the wireless power reception module, and a wireless communication antenna114or214for data communication.

In the present invention, the antennas111,112,113,114, and214may be configured by a circular, elliptical, or rectangular planar coil formed by winding a conductive member having a predetermined length multiple times in a clockwise or counterclockwise direction or may be an antenna pattern formed by patterning a conductor such as a copper foil on one surface of a circuit board115or215in a loop shape or formed of a loop-shaped metal pattern using conductive ink. Here, the circuit board115or215may be formed of a flexible circuit board made of a material such as polyimide (PI) and polyethylene terephthalate (PET), or a rigid circuit board made of a material such as FR4.

Further, the wireless power transmission antennas111,112, and113may transmit power by an inductive coupling method or a magnetic resonance method based on an electromagnetic induction phenomenon, and the wireless communication antenna114or214may be formed of an NFC type antenna. In addition, the wireless power transmission antennas111,112, and113may be a Qi standard or Power Matters Alliance (PMA) standard antenna which operates in a frequency band of 100 to 350 kHz by a magnetic induction method or an Alliance for Wireless Power (A4WP) standard antenna which operates at 6.78 MHz by a magnetic resonance method, or may have a form in which at least two of the Qi standard, the PMA standard, and the A4WP standard are combined. In addition, the wireless communication antenna114or214may transmit and receive data using the frequency of 13.56 MHz.

Here, the wireless power transmission antennas111,112, and113may be provided as a plurality of antennas as shown inFIGS. 1 and 4, and at least some of the wireless power transmission antennas111,112, and113may be stacked over the other to overlap each other. Specifically, the wireless power transmission antennas111,112, and113may be provided as three planar coils, and one planar coil111of the three planar coils may be disposed above the remaining two planar coils112and113so as to partially overlap the remaining two planar coils112and113.

Hereinafter, for convenience of description, the two planar coils which are disposed on the same plane are referred to as a second coil112and a third coil113, and the planar coil which is stacked on one surface of each of the second coil112and the third coil113is referred to as a first coil111.

However, the number and the arrangement relationship of the wireless power transmission antennas applied to the present invention are not limited thereto, and the total number of the planar coils and the vertical arrangement relationship of the first coil111, the second coil112, and the third coil113may be changed in various manners.

Meanwhile, the wireless communication antenna114or214may transmit and receive data to/from the portable electronic device. Through this, various information of the vehicle may be transmitted to the portable electronic device or a function such as a startup/shutoff of the vehicle or a lock/unlock of a door may be controlled by a signal transmitted from the portable electronic device.

The wireless communication antenna114or214may be an antenna pattern formed by patterning a conductor in a loop shape on at least one surface of the circuit board115or215.

Here, the wireless power transmission device100or200according to one embodiment of the present invention may smoothly perform both data communication and wireless power transmission at the same position without changing the position of the portable electronic device.

That is, in the wireless power transmission device100or200according to one embodiment of the present invention, the wireless communication antenna114or214may be disposed at an appropriate position with respect to the wireless power transmission antennas111,112, and113so that both the data communication and the wireless power transmission may be smoothly performed at the same position.

For example, in a case in which the portable electronic device is disposed at a position corresponding to the wireless power transmission antennas111,112, and113, both the wireless charging using the wireless power transmission antennas111,112, and113and the data communication using the wireless communication antenna114or214may be performed smoothly.

To this end, as shown inFIGS. 1 to 3, the wireless power transmission device100according to one embodiment of the present invention may be disposed such that the circuit board115on which the wireless communication antenna114is patterned is positioned on an upper side of the first coil111.

In this case, the circuit board115may be stacked on the upper side of the first coil111, and as shown inFIGS. 2 and 3, at least a part of the pattern among the antenna pattern constituting the wireless communication antenna114may be disposed directly above a region corresponding to the wireless power transmission antennas111,112, and113.

In the present embodiment, the circuit board115may be attached to one surface of the first coil111through an adhesive member and may include at least one fastening hole115aformed on a corner side thereof, thereby being coupled with other components through a fastening member such as a bolt member. In addition, the circuit board115may be in contact with the first coil111, but may be disposed to be spaced apart from the upper side of the first coil111at a predetermined interval.

Here, the wireless communication antenna114may include a first patterned portion114adisposed in the region corresponding to the wireless power transmission antennas111,112, and113and a second patterned portion114bdisposed in the region that does not correspond to the wireless power transmission antennas111,112, and113. In addition, a pair of terminals114cmay be formed on one surface of the circuit board115to be electrically connected to other components.

In the present invention, the region corresponding to the wireless power transmission antennas111,112, and113may be defined as a region including a coil body and a hollow portion constituting the planar coil, and the region that does not correspond to the wireless power transmission antennas111,112, and113may be defined as the remaining region excluding the coil body and the hollow portion constituting the planar coil.

In this case, the second patterned portion114bmay be formed to be located on an edge side along the edge of the circuit board115, and the first patterned portion114amay be formed to be located on an inner side of the circuit board115and an inner side of the second patterned portion114b. Accordingly, in the wireless power transmission device100according to the present embodiment, in a case in which the circuit board115is disposed on the upper side of the first coil111, the first patterned portion114amay be located above the region corresponding to the wireless power transmission antennas111,112, and113.

Therefore, in a case in which the portable electronic device is disposed above the region corresponding to the wireless power transmission antennas111,112, and113, both the wireless charging using the wireless power transmission antennas111,112, and113and the data communication using the wireless communication antenna114may be performed at the same position even when the position of the portable electronic device is not changed.

Here, the first patterned portion114aformed at the position corresponding to the wireless power transmission antennas111,112, and113may be patterned in various ways depending on design conditions. For example, as shown inFIG. 2, the first patterned portion114amay be patterned such that a portion thereof which is located directly above the planar coil body constituting the wireless power transmission antennas111,112, and113has a relatively longer length or a wider area than a portion thereof which is located directly above the hollow portion of the planar coil.

Alternatively, as shown inFIG. 3, the first patterned portion114amay be patterned such that the portion thereof which is located directly above the planar coil body constituting the wireless power transmission antennas111,112, and113has a relatively shorter length or a narrower area than the portion thereof which is located directly above the hollow portion of the planar coil. That is, the first patterned portion114amay be patterned to be concentrically disposed on the hollow portion side of the planar coil.

However, the patterning method of the first patterned portion114ais not limited thereto and may be changed in various ways depending on design conditions, and a line width of the antenna pattern constituting the wireless communication antenna114, a separation distance between the patterns, and the like may all be appropriately changed. In addition, it is noted that the wireless communication antenna114may be formed of only the first patterned portion114adisposed on the region corresponding to the wireless power transmission antennas111,112, and113.

As another example, as shown inFIGS. 4 to 6, the wireless power transmission device200according to one embodiment of the present invention may be disposed such that the circuit board215on which the wireless communication antenna214is patterned is positioned on a lower side of the magnetic field shielding sheet120.

In this case, the wireless power transmission antennas111,112, and113may be disposed on a first surface of the magnetic field shielding sheet120, and the circuit board215on which the wireless communication antenna214is patterned may be disposed on a second surface of the magnetic field shielding sheet120, which is a surface opposite to the first surface.

Here, the circuit board215may be provided to have a relatively wider area than the magnetic field shielding sheet120, and the magnetic field shielding sheet120may be disposed to be located on an inner side of the circuit board215.

Accordingly, as shown inFIGS. 4 and 5, in a case in which the circuit board215is disposed on the second surface of the magnetic field shielding sheet120, the circuit board215may include a protruding region215awhich protrudes outward from an edge of the magnetic field shielding sheet120, and the protruding region215amay be disposed to surround the edge of the magnetic field shielding sheet120.

Here, the wireless communication antenna214may be patterned in the protruding region215a.

Accordingly, the wireless communication antenna214may be disposed outside the wireless power transmission antennas111,112, and113, and since the patterned portion of the wireless communication antenna214is not covered by the magnetic field shielding sheet120, the patterned portion of the wireless communication antenna214may smoothly operate.

Therefore, in a case in which the portable electronic device is disposed above the region corresponding to the wireless power transmission antennas111,112, and113, both the wireless charging using the wireless power transmission antennas111,112, and113and the data communication using the wireless communication antenna214may be performed at the same position even when the position of the portable electronic device is not changed.

The magnetic field shielding sheet120may be formed of a plate-shaped member having a predetermined area and may be disposed on one surface of the wireless power transmission antennas111,112, and113. The magnetic field shielding sheet120may shield magnetic fields generated by the wireless power transmission antennas111,112, and113and may increase the focusability of the magnetic fields in a required direction, thereby increasing the performance of the antenna operating in a predetermined frequency band.

To this end, the magnetic field shielding sheet120may be made of a magnetic material.

For example, an amorphous ribbon sheet, a ferrite sheet, a polymer sheet, or the like may be used as the magnetic field shielding sheet120. The amorphous ribbon sheet may be a ribbon sheet including at least one of an amorphous alloy and a nanocrystalline alloy, the amorphous alloy may include a Fe-based or Co-based magnetic alloy, and the ferrite sheet may be a sintered ferrite sheet such as Mn—Zn ferrite or Ni—Zn ferrite.

Further, the magnetic field shielding sheet120may be divided into a plurality of minute pieces through a flake process for increasing the entire resistance to suppress generation of eddy current or increase flexibility, and the plurality of minute pieces may be formed to be atypical.

In addition, the magnetic field shielding sheet120may have a form in which a plurality of magnetic sheets are stacked in multiple layers through an adhesive layer, each of the plurality of magnetic sheets may have a form in which is divided into a plurality of minute pieces through a flake process, and the adjacent minute pieces may be entirely or partially insulated from each other.

Since the magnetic field shielding sheet120has a known configuration, detailed description thereof will be omitted, and it is noted that as the materials for the shielding sheet, all known materials which are generally used may be used.

Meanwhile, as shown inFIGS. 7 to 12, the wireless power transmission device100or200according to one embodiment of the present invention may further include a supporting plate130configured to fix the positions of a plurality of planar coils111,112, and113in a case in which the wireless power transmission antennas111,112, and113are provided as the plurality of planar coils, and at least one planar coil is stacked on one surfaces of the other planar coils

That is, in the wireless power transmission device according to the present embodiment, in a case in which the plurality of planar coils111,112, and113are stacked in multiple layers, and parts of the plurality of planar coils111,112, and113are disposed to overlap each other, overlapping regions A1, A2, A3, and A4may be formed between the planar coils in desired positions with desired areas by the supporting plate130.

To this end, as shown inFIG. 7, the supporting plate130may be formed of a plate-shaped member which includes a first surface130aand a second surface130bwhich are surfaces opposite to each other and has a predetermined area. Further, as shown inFIGS. 8 and 9, the supporting plate130may include a plurality of seating grooves131and132formed to be sunk by a predetermined depth in at least one of the first surface130aand the second surface130b.

Here, the plurality of seating grooves131and132may include a first seating groove131for receiving the first coil111disposed on an upper portion among the plurality of coils and two second seating grooves132for receiving the second coil112and the third coil113which are disposed on the same plane.

At this point, the first seating groove131and the second seating groove132may be formed on surfaces opposite to each other, respectively. That is, the first seating groove131may be formed on the first surface130aof the supporting plate130, and the second seating groove132may be formed on the second surface130bof the supporting plate130. Further, as shown inFIG. 11, the first seating groove131and the second seating groove132may be formed on the first surface130aand the second surface130b, respectively, to form overlapping regions S1and S2in which at least some areas overlap each other.

Accordingly, when a worker inserts the first coil111into the first seating groove131and inserts the second coil112and the third coil113into the second seating grooves132, the first coil111may overlap the second coil112and the third coil113at positions corresponding to partial regions S11and S12of the overlapping regions S1and S2.

Here, the partial regions of the overlapping regions S1and S2may be formed to pass through the supporting plate130so that a part of the first coil111which is disposed in the first seating groove131may be in direct contact with parts of the second coil112and the third coil113which are disposed in the second seating grooves132.

Therefore, when the overlapping regions, which overlap each other, are formed to have positions and areas according to a required standard in the process of forming the first seating groove131and the second seating groove132, the alignment between the coils may be simply completed without performing additional alignment work.

Further, protrusions133and134, which protrude from the corresponding seating grooves131and132, may be provided at central portions of the first seating groove131and the second seating groove132at positions corresponding to central empty spaces of the coils111,112, and113.

For example, the protrusions may include a first protrusion133which protrudes at the central portion of the first seating groove131from a bottom surface of the first seating groove131with a predetermined height and a second protrusion134which protrudes at the central portion of the second seating groove132from a bottom surface of the second seating groove132with a predetermined height. Here, the first protrusion133and the second protrusion134may be formed to have the height which is the same as the depth of the corresponding seating grooves131and132.

The protrusions133and134may be located in the central empty spaces of the coils111,112, and113and may be in contact with inner sides of the coils111,112, and113when the coils are inserted. Thus, the inner sides of the coils which are inserted into the corresponding seating grooves131and132may be supported by the protrusions133and134, respectively, and outer sides thereof may be supported by inner walls of the seating grooves131and132, respectively.

Therefore, even when a shake of the wireless power transmission device100or200, for example, a shake while the vehicle is being driven, is generated, the position of each of the first coil111, the second coil112, and the third coil113may be fixed by the seating grooves131and132, thereby preventing the movement of each of the coils111,112, and113.

Here, the protrusions133and134may be provided to have areas corresponding to the central empty spaces of the coils. Accordingly, some areas of the protrusions133and134may be disposed in the overlapping regions S1and S2in which the first seating groove131and the second seating groove132overlap each other, and the remaining areas may be disposed in a region in which the first seating groove131and the second seating groove132do not overlap each other.

Therefore, some areas of the first protrusion131formed in the first seating groove123, which are disposed in the overlapping regions S1and S2, may be in direct contact with a part of the coils112and113disposed in the second seating grooves132to support the part of the coils112and113disposed in the second seating grooves132, and some areas of the second protrusion134formed in the second seating groove132, which are disposed in the overlapping regions S1and S2, may be in direct contact with a part of the coil111disposed in the first seating groove131to support the part of the coil111disposed in the first seating groove131.

In addition, all the remaining portions of one surface of each of the coils except the overlapping regions A1, A2, A3, and A4may be in contact with the supporting plate130. With this configuration, in a case in which a heat-dissipating function is added to the supporting plate130, the contact area of the coils with the supporting plate130may be secured at maximum so that heat generated by the coils may be quickly dispersed by the supporting plate130. Here, the heat-dissipating function of the supporting plate130will be described below.

Meanwhile, the first seating groove131and the second seating grooves132may be formed to have a depth which is the same as the thickness of the coils111,112, and113, and the thickness of the supporting plate130may be the same as the sum of thicknesses of two coils111and112or111and113which overlap each other. For example, the maximum thickness of the supporting plate130may be the same as the sum of the thickness of the first coil111and the thickness of the second coil112.

Accordingly, even though the wireless power transmission device100or200according to one embodiment of the present invention uses the supporting plate130for aligning the positions of the coils, the plurality of coils111,112, and113may be conveniently aligned without increasing the thickness of the wireless power transmission device100or200.

In addition, since one surface of the supporting plate130including one surface of the coil forms a horizontal plane after the coils111,112, and113are received in the seating grooves131and132formed in the supporting plate130, the contact area of the supporting plate130with the magnetic field shielding sheet120may be increased. Accordingly, even though the magnetic field shielding sheet120is manufactured in a form of a sheet which has flexibility or is made of a material having strong brittleness, one surface of the magnetic field shielding sheet120is supported by the supporting plate130so that the magnetic field shielding sheet120may be prevented from being damaged due to an external shock and disposed in a horizontal state.

Meanwhile, guide grooves135each configured to receive a connection terminal drawn out from each of the coil bodies may be formed on at least one surface of the supporting plate130. The guide groove135may be formed to communicate with at least one seating groove of the first seating groove131and the second seating groove132so that the connection terminals of the coils which are received in the corresponding seating grooves may be appropriately disposed. For example, all the guide grooves135may be formed on the second surface130bof the supporting plate130, as shown inFIG. 9.

The guide groove135may be provided to have a height which is approximately the same as a wire diameter of a conductive member constituting the planar coils111,112, and113so that one surface of each of the first coil111and the second coil112may be completely in surface contact with one surface of the magnetic field shielding sheet120in a case in which the magnetic field shielding sheet120is disposed on one surface of the supporting plate130.

Meanwhile, the supporting plate130applied to the present invention may further have a heat-dissipating function to quickly disperse the heat generated by the coils to solve a thermal issue in addition to the function of easily disposing the coils and fixing the position of the coils.

To this end, a coating layer136having a heat-dissipating property may be formed on an outer surface of the supporting plate130, as shown inFIG. 10, the supporting plate130may be formed of a plastic material having a heat-dissipating property, or the coating layer136having a heat-dissipating property may be formed on the outer surface of the supporting plate130which is formed of a plastic material having a heat-dissipating property.

For example, the coating layer136may include a heat-conductive filler, such as a carbon-based filler, and graphene, carbon nanotube, borne nitride, or the like may be used as the heat-conductive filler.

In addition, as the plastic having a heat-dissipating property, composite plastic including planar graphite may be used. However, it should be noted that the material for the coating layer136and/or the heat-dissipating plastic for heat dissipation is not limited thereto, and all known coating materials and heat-dissipating plastic which are used for heat dissipation may be used.

Meanwhile, at least one fastening hole137may be formed to pass through the supporting plate130so as to be coupled to other members. A fastening member such as a bolt member may be coupled to or pass through the fastening hole137.

Here, in a case in which the supporting plate130is made of a plastic material, a metal member (not shown) may be partially embedded in the supporting plate130to prevent the supporting plate130from being damaged when the supporting plate130is coupled to other components by the fastening member.

Accordingly, the fastening hole137is formed in the supporting plate130at a position corresponding to the metal member, thereby increasing fastening force and durability. Here, the metal member may be integrated with the supporting plate130through insert-molding.

Meanwhile, the wireless power transmission device100or200according to one embodiment of the present invention may further include a heat-dissipating member140to increase heat-dissipating performance.

That is, as shown inFIGS. 13 and 14, the heat-dissipating member140may be disposed on one surface of the magnetic field shielding sheet120or on one surface of the circuit board215to disperse the heat transmitted from a heat source or release the heat to the outside.

To this end, the heat-dissipating member140may be made of a material having excellent thermal conductivity. For example, the heat-dissipating member140may be formed of any one of copper, aluminum, and graphite, or a mixture of two or more thereof. In addition, the material of the heat-dissipating member140is not limited to those listed above and the heat-dissipating member140may be formed of a material having a thermal conductivity which is equal to or higher than 200 W/m·K.

Here, the heat-dissipating member140may be formed of a plate-shaped member having a predetermined area to quickly disperse heat generated by a heat source by increasing the contact area with the heat source.

The heat-dissipating member140may be a plate-shaped metal sheet which is made of a metal material such as a copper or aluminum material and has a predetermined thickness so as to serve as a support which supports the magnetic field shielding sheet120simultaneously in addition to the heat-dissipating function for dispersing or releasing heat generated by a heat source such as the wireless power transmission antennas111,112, and113.

That is, even though the magnetic field shielding sheet120is formed of a weak sheet or a flexible sheet such as a ferrite sheet or a polymer sheet, the magnetic field shielding sheet120may be supported by the heat-dissipating member140which is formed of a metal material having a predetermined strength, and thus, when the wireless power transmission device according to one embodiment of the present invention is assembled with other components such as a case or a housing, an assembling property and a fastening property may be improved.

The heat-dissipating member140may be attached to one surface of the magnetic field shielding sheet120or one surface of the circuit board215through an adhesive layer (not shown) including a heat-conductive component and at least one assembling hole147through which a fastening member passes may be formed to pass through the heat-dissipating member140. Here, a separate assembling hole126may be formed to pass through the magnetic field shielding sheet120in a position corresponding to the assembling hole147.

Thus, the heat generated by the planar coils111,112, and113may be transmitted to the heat-dissipating member140through the magnetic field shielding sheet120or the circuit board215and then dispersed so that a temperature of air over the planar coils111,112, and113may be lowered.

As another example, as shown inFIG. 14, in a case in which the circuit board215on which the wireless communication antenna214is formed is disposed on the second surface of the magnetic field shielding sheet120, and the heat-dissipating member140is disposed on a side opposite to the magnetic field shielding sheet120with the circuit board215as a boundary, the heat-dissipating member140may be a thin metal sheet having a very thin thickness. In this case, the thin metal sheet may be attached to one surface of the circuit board215through an adhesive layer or may be integrally formed on one surface of the circuit board215.

Meanwhile, one or more through holes124,142, and215bmay be formed to pass through the magnetic field shielding sheet120, the heat-dissipating member140, and/or the circuit board215, respectively, in regions corresponding to each other.

That is, at least one first through hole124may be formed to pass through the magnetic field shielding sheet120, and a second through hole142may be formed in a position corresponding to the first through hole124to pass through the heat-dissipating member140. Further, in a case in which the circuit board215is disposed on the second surface of the magnetic field shielding sheet120, a third through hole215bmay be formed in a position corresponding to the first through hole124and the second through hole142to pass through the circuit board215.

When a circuit board191is disposed on a bottom surface of the heat-dissipating member140, the through holes124,142, and215bserve as passages through which air around the planar coils111,112, and113may move toward the circuit board191.

Here, a temperature sensor194such as a thermistor may be disposed on the circuit board191in a region corresponding to the second through hole142, and in a case in which the temperature sensor194protrudes from the circuit board at a predetermined height, the second through hole142may simultaneously perform the role of an arrangement hole configured to receive the temperature sensor. In this case, the second through hole142may be provided to have a relatively wider area than that of the temperature sensor so that the temperature sensor may be not in contact with the heat-dissipating member140.

Thus, air heat-exchanged with the heat generated by the planar coils111,112, and113when the wireless power transmission device operates may flow into the temperature sensor so that the temperature sensors detect the temperature of the heat generated by the planar coils111,112, and113and thus when it is detected that the temperature of the planar coils111,112, and113is equal to or higher than a predetermined value, an entire operation may be stopped, thereby preventing several problems such as damage of the electronic components due to overheating in advance.

At this point, the first through hole124may be formed in a region corresponding to the hollow portion of the planar coil constituting the wireless power transmission antennas111,112, and113. The reason is that the first through hole124does not overlap the patterned portions of the planar coils so that the air around the planar coils smoothly flows toward the first through hole124.

Meanwhile, the vehicle wireless power transmission device100or200according to the embodiment described above may further include a housing150or250and a cover160detachably coupled to the housing150or250.

For example, as shown inFIGS. 15 to 19, the wireless power transmission device may have a form in which both the supporting plate130and the heat-dissipating member140, which are described above, are applied and may be embedded in the vehicle such that one surface of the cover160is exposed to the outside.

Specifically, the housing150or250may be provided in a box shape having an accommodation space with an open upper portion, and one or more circuit boards191and192which are electrically connected to the wireless power transmission antennas111,112, and113and the wireless communication antenna114or214to control the overall operation may be accommodated in the accommodation space.

Further, the wireless power transmission antennas111,112, and113and the wireless communication antenna114or214may be arranged to be located on upper sides of the circuit boards191and192which are built-in the accommodation space by being fastened to the open upper side of the housing150or250by a fastening member158.

Here, various circuit elements for controlling the overall operation of the wireless power transmission device may be mounted on the circuit boards191and192, and driving chips for driving the wireless communication antenna114or214and the wireless power transmission antennas111,112, and113may be mounted on the circuit boards191and192. In addition, the circuit elements may be provided as a plurality of elements, or integrated into one. In addition, a connector193for connection with an external power source may be mounted on at least one of the circuit boards191and192, and the connector193may be exposed to the outside through an opening152formed on one side of the housing150or250.

Even though the housing150or250may be formed of a conventional plastic material, the housing150or250may be formed of a material having an excellent thermal conductivity to release heat generated by a heat source to the outside when driving.

For example, the housing150or250may be formed of a metal material such as copper or aluminum, and a plastic material using a heat-dissipating member forming composition C including a graphite composite A or A′ illustrated inFIG. 20. Alternatively, as shown inFIG. 22, the housing150or250may have a form in which a metal plate D and heat-dissipating plastic are integrated by insert-molding the heat-dissipating member forming composition C including the graphite composite A or A′, and the planar metal plate D such as copper or aluminum.

Here, the heat-dissipating member140may be disposed such that at least a part of the heat-dissipating member140is in direct contact with the housing150or250when the heat-dissipating member140is coupled to the housing150or250. For example, the heat-dissipating member140may be provided to have a relatively wider area than an upper edge of the housing150or250so that an edge of the heat-dissipating member140may be disposed to be in contact with the upper edge of the housing150or250. With this configuration, the heat generated by the planar coils111,112, and113may be dispersed in the heat-dissipating member140and then directly transmitted to the housing150or250. Accordingly, the heat transmitted to the housing150or250may be released to the outside, thereby further reducing the amount of heat transferred toward the cover160.

In addition, an insulation member (not shown) having a plate shape may be disposed on one surface of the heat-dissipating member140to electrically isolate the heat-dissipating member140from the circuit board191. For example, the insulation member may be formed of a fluororesin-based film such as PET.

Meanwhile, the housing150or250applied to the present invention may include a heat-dissipating coating layer170formed on a surface thereof so as to realize a more excellent heat-dissipating property as shown inFIG. 22.

With this configuration, the heat generated by the heat source may be released through the housing150or250, thereby further lowering a surface temperature of the cover160on which an electronic device to be charged is placed.

That is, the surface temperature of the cover160may be further lowered by applying the heat-dissipating coating layer170to outer surfaces of the housing150or250with a predetermined thickness to further enhance the overall heat-dissipating property. Thus, the vehicle wireless power transmission device100or200according to one embodiment of the present invention may minimize the increase in the surface temperature of the cover160due to the heat generated by the heat source during operation. Accordingly, since in the vehicle wireless power transmission device100or200according to one embodiment of the present invention, the surface temperature of the cover160may be lowered, a user may feel less uncomfortable due to a high temperature even if a user's body is in contact with the cover160.

To this end, even though the heat-dissipating coating layer170may be formed of any coating layer having a known heat-dissipating property, the heat-dissipating coating layer170may include a coating layer forming component, a carbon-based filler, and a physical property enhancing component for enhancing a heat-dissipating property and an adhesive property. Here, the carbon-based filler may be contained in an amount of 8 to 72 parts by weight based on 100 parts by weight of a main resin.

The coating layer forming component may include the main resin and may further include a curing agent when the main resin is a curable resin, and the coating layer forming component may further include other curing accelerators and curing catalysts.

Although any component known in the art which can form the coating layer may be used as the main resin without limitation, the main resin may include one or more epoxy resins selected from the group consisting of a glycidyl ether type epoxy resin, a glycidyl amine type epoxy resin, a glycidyl ester type epoxy resin, a linear aliphatic type epoxy resin, a rubber modified epoxy resin, and derivatives thereof.

This is to simultaneously achieve an enhancement in adhesion with the housing150or250, an enhancement in heat resistance which is not weakened by heat, an enhancement in mechanical strength, and an enhancement in heat-dissipating performance due to improvement in compatibility with a carbon-based filler.

Specifically, the glycidyl ether type epoxy resin may include a glycidyl ether of a phenol and a glycidyl ether of an alcohol, and the glycidyl ether of a phenol may include one kind or more selected from a bisphenol-based epoxy such as bisphenol A type, bisphenol B type, bisphenol AD type, bisphenol S type, bisphenol F type, and resorcinol, a phenol-based novolak such as phenol novolak epoxy, aralkyl phenol novolac, and terpene phenol novolak, and a cresol novolak-based epoxy resin such as o-cresol novolac epoxy.

Here, the main resin may be a glycidyl ether type epoxy resin including a bisphenol A type epoxy resin, which is excellent in compatibility with carbon-based fillers, especially carbon black among them, to enhance heat-dissipating properties, durability, and surface quality.

Here, the bisphenol A type epoxy resin may have an epoxy equivalent of 350 to 600 g/eq. This is because when the epoxy equivalent is less than 350 g/eq, the hardness of the heat-dissipating coating layer170may increase so that the heat-dissipating coating layer170may be easily broken or cracked or peeling may easily occur in a curved surface to be coated, and when the epoxy equivalent exceeds 600 g/eq, chemical resistance, adhesion, and durability may be deteriorated due to occurrence of uncured portions.

Further, the bisphenol A type epoxy resin may have a viscosity of 10 to 200 cps. This is because when the viscosity of the bisphenol A type epoxy resin is less than 10 cps, the heat-dissipating coating layer170may be difficult to form, and the adhesion between the heat-dissipating coating layer170and the surfaces of the housing150or250may be lowered even after the formation of the heat-dissipating coating layer170. On the other hand, when the viscosity of the bisphenol A type epoxy resin exceeds 200 cps, it is difficult to form the heat-dissipating coating layer170to have a thin thickness, and the coating process may not be easy, and the coating process may be more difficult especially in the case of spray-based coating. In addition, the dispersibility of carbon black in the heat-dissipating coating layer170may be deteriorated.

Meanwhile, the type of the curing agent contained in the coating layer forming component together with the epoxy resin which is the main resin may be varied depending on the specific type of the epoxy resin selected, and specific examples of the type of the curing agent may include those known in the art, and preferably, one or more components among an acid anhydride-based component, an amine-based component, an imidazole-based component, a polyamide-based component, and a polymercaptan-based component.

Further, when the main resin includes a bisphenol A type epoxy resin, the coating layer forming component may further include a polyimide-based component as a curing agent. This is because it is very advantageous for enhancing the compatibility with carbon-based fillers, to be described later, particularly carbon black among them, and it is advantageous in all physical properties such as adhesive property, durability, and surface quality of the heat-dissipating coating layer170. In addition, this is for preventing cracks or peeling from occurring in the heat-dissipating coating layer170formed in curved or stepped portions of the housing150or250when the outer surfaces of the housing150or250to which the heat-dissipating coating layer170is applied are curved or stepped rather than a flat plane.

Here, in order to exhibit further enhanced physical properties, the polyamide-based component may have an amine value of 180 to 300 mgKOH/g, and preferably, a viscosity of 50,000 to 70,000 cps at 40° C. This is because when the amine value of the polyamide-based curing agent is less than 180 mgKOH/g, curing quality is deteriorated so that all surface quality, durability, and adhesive property may be deteriorated, and heat-dissipating performance may also be deteriorated simultaneously. In addition, when the amine value exceeds 300 mgKOH/g, curing may proceed rapidly so that an agglomeration phenomenon may occur during coating. Further, when the viscosity of the polyamide-based curing agent is less than 50,000 cps, the coating may flow down after coating, and when the viscosity of the polyamide-based curing agent exceeds 70,000 cps, the application may not be performed uniformly during spray coating, or the nozzle may be clogged and aggregated.

Further, in a case in which the main resin contained in the coating layer forming component is a bisphenol A type epoxy resin, the polyamide-based curing agent may be contained in an amount of 45 to 75 parts by weight based on 100 parts by weight of the bisphenol A type epoxy resin. This is because when the amount of the polyamide-based curing agent is contained less than 45 parts by weight, problems such as non-curing and durability deterioration may occur, and when the amount of the polyamide-based curing agent is contained greater than 75 parts by weight, a breakage phenomenon or the like due to excessive curing may occur.

Any carbon-based material may be used as the carbon-based filler without limitation as long as it includes carbon, and carbon-based materials known in the art may be used. In addition, the carbon-based filler is not limited in shape and size and may have a porous structure or non-porous structure, which may be selected depending on the purpose and is not particularly limited in the present invention. For example, the carbon-based filler may include one kind or more selected from the group consisting of carbon nanotubes such as a single-walled carbon nanotube, a double-walled carbon nanotube, and a multi-walled carbon nanotube, graphene, graphene oxide, graphite, carbon black, and a carbon-metal complex. However, preferably, the carbon-based filler may include at least one of graphite and carbon black in terms of achieving desired physical properties such as excellent heat-dissipating performance, ease of formation of the coating layer, and improved surface quality of the coating layer and may include carbon black in terms of improving the surface quality of the coating layer.

As the carbon black, at least one kind of known carbon black such as furnace black, lamp black, and channel black may be selected and used without limitation. However, the carbon black may preferably have an average particle diameter of 250 nm or less, and more preferably, 50 to 250 nm. This is because when the average particle diameter of the carbon black exceeds 250 nm, the uniformity of the surface may be deteriorated, and when the average particle diameter is less than 50 nm, the product unit price may be increased. In addition, when the average particle diameter of the carbon black exceeds 250 nm, the amount of carbon black peeled off from the surface increases to deteriorate the heat-dissipating performance after the coating layer is implemented.

In addition, in order to improve the surface quality of the heat-dissipating coating layer170, the carbon black may have a D90 of 260 nm or less in volume cumulative particle size distribution. This is because when the D90 exceeds 260 nm in the volume cumulative particle size distribution of the carbon black, the surface quality of the heat-dissipating coating layer170may be particularly deteriorated, for example, the surface roughness of the coating layer of the heat-dissipating coating layer170is increased.

Here, the D90 refers to a particle diameter of the carbon black particles when an accumulation degree in the volume cumulative particle size distribution is 120%. Specifically, in a graph (particle diameter distribution based on volume) that takes the volume cumulative frequency from the side having the smallest particle diameter on the vertical axis relative to the particle diameter on horizontal axis, for the volume cumulative value (100%) of the whole particles, a particle diameter of a particle corresponding to the cumulative value having 90% of the cumulative volume % from the smallest particle diameter corresponds to D90. The volume cumulative particle size distribution of the carbon black may be measured using a laser diffraction scattering particle size distribution measuring apparatus.

Further, as the carbon-based filler, a carbon-based filler obtained by modifying the surface with a functional group such as a silane group, an amino group, an amine group, a hydroxyl group, or a carboxyl group may be used, and at this point, the functional group may be directly bonded to the surface of the carbon-based filler or may be indirectly bonded to a carbon-based filler through a substituted or unsubstituted aliphatic hydrocarbon having 1 to 20 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon having 6 to 14 carbon atoms as mediation.

In addition, it may be a core-shell type filler that the carbon-based material is used as a core or a shell, and the heterogeneous material constitutes the shell or the core.

In order to exhibit further enhanced physical properties, the carbon-based filler may be contained in an amount of 8 to 72 parts by weight based on above-described 100 parts by weight of the main resin, and preferably, 17 to 42 parts by weight.

This is because when the carbon-based filler is contained in an amount of less than 8 parts by weight based on 100 parts by weight of the main resin, the desired level of heat-dissipating performance may not be exhibited. In addition, when the carbon-based filler exceeds 72 parts by weight based on 100 parts by weight of the main resin, the adhesion of the heat-dissipating coating layer170is weakened and peeling easily occurs, and the hardness of the coating layer becomes large so that it may be easily broken or crushed by a physical impact, and as the number of carbon-based fillers protruding on the surface of the heat-dissipating coating layer170increases, the surface roughness may increase, and the surface quality of the heat-dissipating coating layer170may be deteriorated.

Meanwhile, preferably, the carbon-based filler may be contained in an amount of 42 parts by weight or less based on 100 parts by weight of the main resin. This is because when the carbon-based filler is used in an amount of greater than 42 parts by weight based on 100 parts by weight of the main resin, in the process of applying the heat-dissipating coating layer to the housing150or250in order to realize the heat-dissipating coating layer170with a thin thickness, it is difficult for a composition to be uniformly applied to the housing150or250when coating by some coating methods, for example, spraying, and since there is a possibility that the dispersibility of the carbon-based filler dispersed in the composition is deteriorated, even though the composition is applied to the housing150or250, the carbon-based filler may be non-uniformly dispersed, and therefore, it may be difficult to exhibit a uniform heat-dissipating performance over the entire surface of the heat-dissipating coating layer170.

The physical property enhancing component causes a more enhanced heat-dissipating property to be exhibited when a heat-dissipating coating composition according to the present invention is coated on the housing150or250and simultaneously causes an excellent adhesive property to be exhibited, thereby improving durability.

To this end, the physical property enhancing component may be a silane-based compound, and the known silane-based compounds employed in the art may be used without limitation. However, when used together with carbon black among the carbon-based filler and the main resin of the above-described coating layer forming component, in order to exhibit a remarkable durability and heat-dissipating property by causing a synergistic action of desired physical properties, the silane-based compound may include one or more selected from the group consisting of 3-(N-anil-N-glycidyl)aminopropyltrimethoxysilane, 3-glycidoxypropylmethylethoxysilane, γ-glycidoxytrimethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethylmethoxysilane, and 3-glycidoxypropylmethyldimethoxysilane.

In addition, the physical property enhancing component may be contained in an amount of 2 to 5 parts by weight based on 100 parts by weight of the main resin. This is because when the physical property enhancing component is contained in an amount of less than 2 parts by weight based on 100 parts by weight of the main resin, desired physical properties such as heat-dissipating property improvement and adhesive property improvement through the physical property enhancing component may not be achieved to the desired level, and when the physical property enhancing component is contained in an amount of greater than 5 parts by weight based on 100 parts by weight of the main resin, the adhesion with the surfaces of the housing150or250may be weakened.

Meanwhile, the heat-dissipating coating layer170may further include a dispersant and a solvent for improving the dispersibility of the carbon-based filler. As the dispersant, a known component employed in the art as a dispersant for a carbon-based filler may be used.

In addition, the heat-dissipating coating layer170may contain one kind or two kinds or more of various additives such as a leveling agent, a pH adjusting agent, an ion trapping agent, a viscosity modifier, a thixotropic agent, an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, a coloring agent, a dehydrating agent, a flame retardant, an antistatic agent, an antifungal agent, a preservative, and the like. The various additives described above may be those well known in the art and are not particularly limited in the present invention.

The above-described heat-dissipating coating layer170may have a viscosity of 50 to 250 cps at 25° C. This is because when the viscosity of the heat-dissipating coating layer170is less than 50 cps, the formation of the heat-dissipating coating layer170may be difficult due to flowing down of the composition from the surface to be coated during the coating process, and the adhesion to the surface to be coated may be weakened even after the formation, and when the viscosity of the heat-dissipating coating layer170exceeds 250 cps, it is difficult to manufacture a thin coating layer, the surface may not be uniform even when it is manufactured, the coating process may not be easy, and in particular, the coating process may be more difficult in the case of spray coating. In addition, when the viscosity of the heat-dissipating coating layer170exceeds 250 cps, the dispersibility of carbon black in the heat-dissipating coating layer may be deteriorated.

In addition, the heat-dissipating coating layer170may include 5 to 30% by weight of a carbon-based filler based on the total weight of the heat-dissipating coating layer. This is because when the carbon-based filler is contained in an amount of less than 5% by weight in the heat-dissipating coating layer170, the desired level of heat-dissipating performance may not be exhibited. In addition, when the carbon-based filler is contained in an amount of greater than 30% by weight in the heat-dissipating coating layer170, the adhesion of the heat-dissipating coating layer170is weakened and peeling easily occurs, and the hardness of the coating layer increases and the coating layer may easily be broken or crushed by a physical impact. In addition, when the carbon-based filler is contained in an amount of greater than 30% by weight in the heat-dissipating coating layer170, as the number of carbon-based fillers protruded on the surface of the heat-dissipating coating layer170increases, the surface roughness may increase, and the surface quality of the heat-dissipating coating layer may be deteriorated.

Meanwhile, in a case in which the housing150or250applicable to the present invention is made of a plastic material using the heat-dissipating member forming composition C, the heat-dissipating member forming composition C may include the graphite composite A or A′ and a polymer resin B as shown inFIG. 20and may be realized in the form of the housing150or250through insert injection molding and then curing.

That is, the housing150or250may have significantly improved thermal conductivity by including the heat-dissipating member forming composition containing the graphite having high thermal conductivity, thereby realizing excellent heat-dissipating performance.

Here, as shown inFIGS. 21A and 21B, the graphite composite A or A′ may be formed of a composite in which nano metal particles A2are bonded to a surface of graphite A1having a plate shape, and the nano metal particles A2may be formed of a conductive metal so as to exhibit an electromagnetic wave shielding effect. For example, the nano metal particles A2may include one kind or more selected from the group consisting of Ni, Si, Ti, Cr, Mn, Fe, Co, Cu, Sn, In, Pt, Au, and Mg.

Here, since the nano metal particles A2contained in the graphite composite A or A′ must be present at a high density on the surface of the graphite A1having a plate shape, the nano metal particles A2may be contained in an amount of 20 to 50 wt. % based on the total weight of the graphite A1and may be bonded to the surface of the graphite A1in the form of crystals having an average particle diameter of 10 to 200 nm. In addition, the nano metal particles A2may have a surface area range of 30 to 70 area % with respect to the cross section of the graphite composite A or A′.

Here, in the heat-dissipating member forming composition, as shown inFIG. 20, the graphite composite A or A′ may form a dispersed phase in the polymer resin B. Here, the polymer resin B may include at least one of a thermosetting resin and a thermoplastic resin.

To this end, the graphite composite A or A′ may include a catecholamine layer A3on the nano metal particle A2as shown inFIGS. 21A and 21B. This is because it is possible to enhance the strong interfacial bonding with the polymer resin using the strong adhesive property of catecholamine without deteriorating the inherent physical properties of planar graphite itself by coating the planar graphite A1in which the nano metal particles A2are crystallized on the surface thereof with catecholamine such as polydodamine to modify the surface of the planar graphite A1.

In addition, in a case in which the catecholamine layer A3is coated on the nano metal particles A2, dispersibility is improved in an organic solvent, and thus, when the heat-dissipating member forming composition C contains an organic solvent, the graphite composite A or A′ may be uniformly dispersed in the polymer resin B.

Accordingly, a composite material in which the dispersibility in the desired polymer resin is remarkably improved may be produced by preferentially producing the graphite composite A or A′ including graphite-nano metal particles-catecholamines.

The term “catecholamine” as used herein means a single molecule having a hydroxyl group (—OH) as an ortho group of a benzene ring and various alkylamines as a para group, and various derivatives of these structures such as dopamine, dopamine-quinone, alpha-methyldopamine, norepinephrine, epinephrine, alphamethyldopa, droxidopa, indolamine, serotonin, and 5-hydroxydopamine may be included in the catecholamines. Most preferably, the dopamine may be used.

Generally, the catecholamine layer is hard to coat on a surface of pure planar graphite, but, the crystallized nano metal particles A2are bonded at high density to the surface of the graphite composite A or A′ applied to the present invention, and thus, the catecholamine layer A3may be stably formed by bonding a catecholamine compound such as polydodamine to the crystallized nano metal particles A2.

In a case in which the catecholamine layer is composed of dopamine, the catecholamine layer may be formed by dipping the graphite composite A or A′ in a dopamine aqueous solution. At this point, when a basic dopamine aqueous solution is used as the dopamine aqueous solution, dopamine reacts spontaneously under oxidizing conditions to be polymerized on the nano metal particles A2of the graphite composite A or A′, thereby forming a polydopamine layer. Therefore, a separate sintering process is not required, and the addition of an oxidizing agent is not particularly limited, but oxygen gas in the air may be used as the oxidizing agent without adding the oxidizing agent.

As described above, since the graphite composite A or A′ applied to the present invention is in a state in which the nano metal particles A2are bonded to the surface of the graphite, the catecholamine layer may be formed by the nano metal particles A2.

Accordingly, the interfacial characteristics between the polymer resin B and the graphite composite A or A′ are enhanced through the catecholamine layer, thereby improving the orientation and dispersibility of the graphite composite A or A′. Therefore, since the content of the graphite composite included in the heat-dissipating member forming composition may be increased, it is possible to produce the composition in the form of a sheet even if a small amount of the polymer resin is included in the heat-dissipating member forming composition.

Meanwhile, the graphite composite A′ may include a polymer A4bonded on the catecholamine layer A3(seeFIG. 21B). For example, the graphite composite A in which the nano metal particles A2are coated with the catecholamine may be added to the polymer resin solution to bind the polymer A4on the catecholamine layer.

Here, the polymer A4may be formed so as to completely cover the catecholamine layer A3or may be bonded to the catecholamine layer A3in the form of particles or may be formed so as to completely cover the graphite composite A.

In addition, the polymer A4is not particularly limited in its kind, but may be selected from the group consisting of a thermosetting resin, a thermoplastic resin, and rubber. Here, although the kind of the polymer A4is not particularly limited as long as it has reactivity and compatibility with the polymer resin B constituting the heat-dissipating member forming composition, preferably, a polymer of the same kind as that of the polymer resin B may be used as the polymer A4.

Thus, when the graphite composite A′ including the graphite A1, the nano metal particles A2, the catecholamine layer A3, and the polymer A4is first prepared and then dispersed in the desired polymer resin B, the graphite composite A′ may be dispersed in the polymer resin B very uniformly and evenly.

That is, since the graphite composite A′ includes the polymer A4on the surface thereof, not only low dispersibility and an aggregation phenomenon of the graphite itself but also an aggregation phenomenon due to the high adhesion of the catecholamine layer itself does not occur. Accordingly, the graphite composite A′ may be uniformly dispersed in the polymer resin. As a result, since the total content of the graphite composite A′ may be increased in constituting the heat-dissipating member forming composition, excellent heat-dissipating performance may be obtained.

Meanwhile, in addition to the organic solvent, the above-described heat-dissipating member forming composition may contain one kind or two kinds or more of various additives such as a leveling agent, a pH adjusting agent, an ion trapping agent, a viscosity modifier, a thixotropic agent, antioxidant, a heat stabilizer, a light stabilizer, a ultraviolet absorber, a coloring agent, a dehydrating agent, a flame retardant, an antistatic agent, an antifungal agent, a preservative, and the like. The various additives described above may be those well known in the art and are not particularly limited in the present invention. Further, the catecholamine layer A3may further include a solvent, and a suitable solvent may be selected according to the selected adhesive component, and therefore, the present invention is not particularly limited thereto, and any solvent capable of appropriately dissolving each component may be used as the solvent.

When the housing150or250applied to the present invention is realized as the heat-dissipating member forming composition obtained by mixing the graphite composite A or A′ and the polymer resin B, the housing150or250may be realized using only the heat-dissipating member forming composition through injection molding, and alternatively, the housing150or250may be realized by integrating the heat-dissipating member forming composition with the metal plate D by covering the metal plate D through insert injection. Thus, the heat-dissipating performance may be enhanced even when the housing150or250having the same size are realized as compared with the case in which the housing150or250is realized by the metal material only. In addition, by enhancing the heat-dissipating performance as described above, the thickness of the housing may be reduced, thereby reducing the weight thereof.

Meanwhile, the vehicle wireless power transmission device100or200according to the present invention may include a heat transfer member180disposed on a bottom surface of the housing150or250as shown inFIGS. 16, 19, and 22.

Since the heat transfer member180is disposed to be in contact with the bottom surface of the housing150or250and one surface of the circuit board192disposed inside the housing150or250, heat generated by the circuit board192may be transferred to the housing150or250.

For example, the heat transfer member180may be disposed in a region corresponding to heat generating devices such as an integrated circuit (IC) chip mounted on the circuit board192, thereby transferring heat generated by the heat generating devices to the housing150or250.

At this point, the heat transfer member180may have a thermal conductivity of 0.8 W/m·K or more. This is because when the thermal conductivity of the heat transfer member180is less than 0.8 W/m·K, a heat-dissipating effect is insignificant, resulting in deterioration of the wireless charging efficiency.

The heat transfer member180may be formed in a pad shape in which a heat-dissipating forming composition including at least one of a heat-conductive filler and a phase change material is solidified or may be formed by directly applying a heat-dissipating forming composition including at least one of a phase change material and a heat-conductive filler to the bottom surface of the housing150or250to a predetermined thickness and solidifying the same.

Here, when the heat transfer member180is formed of a heat-dissipating forming composition including a heat-conductive filler, the heat-conductive filler may include one kind or more of a metal filler, a ceramic filler, and a carbon-based filler.

At this point, the metal filler may include one kind or more of known metal fillers such as A1, Ag, Cu, NI, an In—Bi—Sn alloy, a Sn—In—Zn alloy, a Sn—In—Ag alloy, a Sn—Ag—Bi alloy a Sn—Bi—Cu—Ag alloy, a Sn—Ag—Cu—Sb alloy, a Sn—Ag—Cu alloy, a Sn—Ag alloy, and a Sn—Ag—Cu—Zn alloy, the ceramic filler may include one kind or more of known ceramic fillers such as AN, Al2O3, BN, SiC, and BeO, and the carbon-based filler may include one kind or more of known carbon-based fillers such as graphite, carbon nanotube, carbon fiber, diamond, and graphene.

Further, when the heat transfer member180is formed of the heat-dissipating forming composition including a heat-conductive filler, the heat transfer member180may further include a coating layer forming component and a curable component which are conventionally and generally used.

Meanwhile, when the heat-dissipating forming composition constituting the heat transfer member180includes a phase change material, the heat transfer member180may utilize a change in phase in which the phase changes from a solid phase to a semi-solid phase or a liquid phase due to the heat generated by the heat generating devices.

In other words, the heat absorbing or releasing when a certain material undergoes a phase change, for example, when changing from solid to liquid (or liquid to solid) or from liquid to gas (or gas to liquid), is called latent heat, and the latent heat is much larger than the heat absorbed (or released) according to the temperature change in the state in which the phase change does not occur, and thus it may be advantageous to achieve a remarkable heat-dissipating effect when the latent heat is utilized.

Here, the above-described phase change material may be a known phase change material. For example, the phase change material may include one kind or more selected from the group consisting of a linear aliphatic hydrocarbon, a hydrated inorganic salt, a polyhydric alcohol, a higher fatty acid, an alcohol fatty acid ester, and a polyether.

As described above, in the vehicle wireless power transmission device100or200according to the present invention, the surface temperature of an exposed surface of the cover160may be further reduced by forming the heat-dissipating coating layer170on the outer surfaces of the housing150or250and disposing the heat-dissipating member140made of a metal material on one surface of the magnetic field shielding sheet120.

This may be confirmed in Table 1 below.

Table 1 shows measurement results of a heating temperature at the exposed surface of the cover160according to the material of the housing150or250and whether the heat-dissipating coating layer170is applied to the outer surfaces of the housing150or250in the state in which the heat-dissipating member140made of aluminum is disposed on one surface of the magnetic field shielding sheet120.

As can be seen in Table 1 above, it may be confirmed that when the heat-dissipating coating layer170is formed on the outer surfaces of the housing150or250, the surface temperature of the cover160is reduced in all cases regardless of the material of the housing, and it may be confirmed that when the housing150or250is realized with the above-described heat-dissipating member forming composition, the weight is reduced and the surface temperature of the cover160is reduced in all cases compared to the housing150or250made of aluminum alone.

Here, as described above, the heat-dissipating member forming composition means a plastic material including the graphite composite A or A′, and the heat-dissipating member forming composition+the aluminum plate means a form in which the aluminum plate is integrated with the heat-dissipating member forming composition C including the graphite composite A or A′ through insert injection.

Meanwhile, it is noted that when the wireless power transmission device according to the present invention includes the housing150or250and the cover160, it is illustrated in the drawings that both the supporting plate130and the heat-dissipating member140are applied, but the present invention is not limited thereto, and the supporting plate130and the heat-dissipating member140may be selectively applied, or both may not be applied.

The embodiments of the present invention have been described above. However, it should be noted that the spirit of the present invention is not limited to the embodiments in the specification and those skilled in the art and understanding the present invention may easily suggest other embodiments by addition, modification, and removal of the components within the same spirit, but these are construed as being included in the spirit of the present invention.