WO2013141653A1

WO2013141653A1 - Wireless power apparatus

Info

Publication number: WO2013141653A1
Application number: PCT/KR2013/002406
Authority: WO
Inventors: Jeong Wook An; Yang Hyun Kim; Jung Oh Lee; Sung Hyun Leem
Original assignee: Lg Innotek Co., Ltd.
Priority date: 2012-03-23
Filing date: 2013-03-22
Publication date: 2013-09-26

Abstract

Disclosed is a wireless power apparatus including a magnetic substrate and a coil directly disposed on the magnetic substrate. The coil has a spiral type structure. The thickness of the coil used in wireless power transmission is optimized, so that the power transmission efficiency is maximized.

Description

WIRELESS POWER APPARATUS

The embodiment relates to a wireless power transmission technology. In more particular, the embodiment relates to a technology of optimizing the thickness of a coil in order to improve wireless power transmission efficiency.

A wireless power transmission or a wireless energy transfer refers to a technology of wirelessly transferring electric energy to desired devices. In the 1800’s, an electric motor or a transformer employing the principle of electromagnetic induction has been extensively used and then a method of transmitting electrical energy by irradiating electromagnetic waves, such as radio waves or lasers, has been suggested. Actually, electrical toothbrushes or electrical razors, which are frequently used in daily life, are charged based on the principle of electromagnetic induction. The electromagnetic induction refers to the generation of an electric current through induction of a voltage when a magnetic field is changed around a conductor. The electromagnetic induction scheme has been successfully commercialized for electronic appliances having small sizes, but represents a problem in that the transmission distance of power is too short.

Until now, wireless energy transmission schemes include a remote telecommunication technology based on magnetic resonance and a short wave radio frequency in addition to the electromagnetic induction.

There have been made various attempts to increase the power transmission efficiency by increasing a Q value of a coil when power is wirelessly transmitted. However, difficulties exist in greatly improving the power transmission efficiency.

The embodiment provides a method capable of maximizing power transmission efficiency in a wireless power transmission technology using resonance.

The embodiment provides a method capable of improving power transmission efficiency by optimizing the thickness of a coil used in wireless power transmission.

The embodiment provides a method capable of increasing the intensity of a magnetic field formed by a coil while increasing a Q value by optimizing the thickness of the coil used in wireless power transmission.

According to the embodiment, there is provided a wireless power apparatus to transmit or receive power using an electromagnetic induction scheme. The wireless power apparatus includes a coil to wirelessly transmit or receive the power and a magnetic substrate disposed at one side of the coil, wherein the coil has a thickness in a range of 0.1 mm to 0.15 mm. According to the embodiment, the thickness of the coil used in wireless power transmission can be optimized, so that the power transmission efficiency can be maximized.

As described above, according to the embodiment, the thickness of the coil is optimized, so that the Q value is increased. The intensity of the radiated magnetic field is increased, so that the power transmission efficiency can be greatly increased.

The embodiment can provide a method capable of significantly reducing the thickness of a wireless power receiving apparatus by directly providing the coil unit on the top surface of the magnetic substrate.

The embodiment can provide a method for allowing communication with an external apparatus while maintaining the high power transmission efficiency by directly providing the coil unit and the short-range communication antenna on the top surface of the magnetic substrate.

The present invention can provide a method capable of simplifying the manufacturing process of the wireless power receiving apparatus by directly providing the coil unit on the top surface of the magnetic substrate.

Meanwhile, any other various effects will be directly and implicitly described below in the description of the embodiment.

FIG. 1 is a perspective view illustrating a wireless power apparatus 1000 according to one embodiment.

FIG. 2 is a plan view illustrating a wireless power apparatus 1000 according to one embodiment.

FIG. 3 is a sectional view taken along line A-A’ of a connecting unit 300 of the wireless power apparatus 1000 shown in FIG. 2.

FIGS. 4 to 8 are views for explaining a method of manufacturing a wireless power apparatus 1000 according to one embodiment.

FIG. 9 is a view showing the structure of a coil 230 according to one embodiment.

FIG. 10 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and a quality factor (unit: uH) of a coil 230 according to frequencies when the thickness T of the coil 230 is 0.07 mm. FIG. 11 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of a coil 230 is 0.07 mm.

FIG. 12 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and a quality factor (unit: uH) of a coil 230 according to frequencies when the thickness T of the coil 230 is 0.09 mm. FIG. 13 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of a coil 230 is 0.09 mm.

FIG. 14 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and a quality factor (unit: uH) of a coil 230 according to frequencies when the thickness T of the coil 230 is 0.1 mm. FIG. 15 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of a coil 230 is 0.1 mm.

FIG. 16 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and a quality factor (unit: uH) of a coil 230 according to frequencies when the thickness T of the coil 230 is 0.14 mm. FIG. 17 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of a coil 230 is 0.14 mm.

FIG. 18 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and a quality factor (unit: uH) of a coil 230 according to frequencies when the thickness T of the coil 230 is 0.15 mm. FIG. 19 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of a coil 230 is 0.15 mm.

FIG. 20 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and a quality factor (unit: uH) of a coil 230 according to frequencies when the thickness T of the coil 230 is 0.16 mm. FIG. 21 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of a coil 230 is 0.16 mm.

FIG. 22 is a graph showing a quality factor as a function of a frequency when the thickness T of a coil 230 is in the range of 0.07 mm to 0. 16 mm.

FIGS. 23 to 30 are graphs the relationships between the thickness of a coil 230 and a Q value according to the frequencies in order to show the maximization of the power transmission efficiency when the thickness of the coil 230 is in the range of 0.1 mm to 0.15 mm.

FIG. 31 is an exploded perspective view showing a wireless power apparatus according to another embodiment. FIG. 32 is a perspective view showing a wireless power apparatus 1000 according to another embodiment. FIG. 33 is a sectional view showing the wireless power apparatus 1000 according to another embodiment.

FIGS. 34 to 42 are views for explaining a method of manufacturing the wireless power apparatus 1000 according to one embodiment.

Hereinafter, exemplary embodiments will be described in detail with reference to accompanying drawings so that those skilled in the art can easily work with the embodiments.

Hereinafter, “conductive pattern” refers to the shape of a conductive layer and may be used to refer to a structure formed by a patterning process. In addition, “conductive layer” may be used interchangeably with “conductive pattern” and refers to a structure formed by methods including patterning, etching, deposing, selective plating, and the like.

FIG. 1 is a perspective view illustrating a wireless power apparatus 1000 according to one embodiment, FIG. 2 is a plan view illustrating the wireless power apparatus 1000 according to one embodiment, and FIG. 3 is a sectional view taken along line A-A’ of a connecting unit 300 of the wireless power apparatus 1000 shown in FIG. 2.

Referring to FIGS. 1 to 3, the wireless power apparatus 1000 may include a magnetic substrate 100, a coil unit 200 and the connecting unit 300.

The wireless power apparatus 1000 may wirelessly receive power from a transmission side. However, the embodiment is not limited thereto, and the wireless power apparatus 1000 may wirelessly receive the power from a reception side. According to one embodiment, the wireless power apparatus 1000 may wirelessly receive or transmit power using electromagnetic induction.

The magnetic substrate 100 may change the direction of the magnetic field received from the transmission side.

The magnetic substrate 100 can reduce the amount of the magnetic field to be leaked to the outside by changing the direction of the magnetic field received from the transmission side. Accordingly, an electromagnetic wave suppressing effect can be obtained.

In detail, the magnetic substrate 100 changes the direction of the magnetic field transferred from the transmission side in the lateral direction such that the magnetic field can be more concentrated onto the coil unit 200.

The magnetic substrate 100 can absorb some of the magnetic field received from the transmission side and leaked to the outside to dissipate the magnetic field as heat. If the amount of the magnetic field leaked to the outside is reduced, the undesirable influence of the magnetic field exerted on the human body can be reduced.

Referring to FIG. 3, the magnetic substrate 100 may include a magnet 110 and a support 120.

The magnet 110 may include a particle or a ceramic.

The support 120 may include thermosetting resin or thermoplastic resin.

The magnetic substrate 100 may be prepared in the form of a sheet and may have a flexible property.

Referring again to FIG. 1, the coil unit 200 may include a first connection terminal 210, a second connection terminal 220 and a coil 230. The coil 230 may have a conductive layer or a conductive pattern.

The first connection terminal 210 is located at one end of the coil 230 and the second connection terminal 220 is located at the other end of the coil 230.

The first and

second connection terminals

210 and 220 are necessary for connection with the connecting unit 300.

The coil 230 may have a conductive pattern which is obtained by winding a conductive line several times. According to one embodiment, when viewed from the top, the coil pattern may have a spiral shape. However, the embodiment is not limited thereto, and various patterns may be formed.

The coil unit 200 can be directly disposed on the top side of the magnetic substrate 100. According to one embodiment, an adhesive layer (not shown) may be interposed between the coil unit 200 and the magnetic substrate 100.

The coil unit 200 may include a conductor. The conductor may include a metal or an alloy thereof. According to one embodiment, the metal may include silver (Ag) or copper (Cu), but the embodiment is not limited thereto.

The coil unit 200 may transfer the power, which is wirelessly received from the transmission side, to the connecting unit 300. The coil unit 200 can receive the power from the transmission side using the electromagnetic induction.

The connecting unit 300 may include a first connection terminal 310, a second connection terminal 320 and a printed circuit board 330.

The first connection terminal 310 of the connecting unit 300 may be connected to the first connection terminal 210 of the coil unit 200 and the second connection terminal 320 of the connecting unit 300 may be connected to the second connection terminal 220 of the coil unit 200.

The printed circuit board 330 may include a wiring layer and a receiver circuit, which will be described later, may be disposed on the wiring layer.

The connecting unit 300 connects a wireless power receiving circuit (not shown) with the coil unit 200 to transfer the power received from the coil unit 200 to a load (not shown) through the wireless power receiving circuit. The wireless power receiving circuit may include a rectifier circuit for converting AC power into DC power and a smoothing circuit for transferring the DC power to the load after removing ripple components from the DC power.

FIGS. 2 and 3 are views for explaining the structure of the wireless power apparatus 1000 according to the first embodiment in detail when the coil unit 200 is connected with the connecting unit 300.

FIG. 2 is a plan view illustrating the wireless power apparatus 1000 according to one embodiment.

FIG. 2 shows the coil unit 200 connected with the connecting unit 300.

According to one embodiment, the connection between the coil unit 200 and the connecting unit 300 may be achieved by a solder. In detail, the first connection terminal 210 of the coil unit 200 may be connected to the first connection terminal 310 of the connecting unit 300 through a first solder 10 and the second connection terminal 220 of the coil unit 200 may be connected to the second connection terminal 320 of the connecting unit 300 through a second solder 20. In more detail, the first connection terminal 210 of the coil unit 200 may be connected to the first connection terminal 310 of the connecting unit 300 through a via hole of the first solder 10, and the second connection terminal 220 of the coil unit 200 may be connected to the second connection terminal 320 of the connecting unit 300 through a via hole of the second solder 20.

The wireless power apparatus 1000 shown in FIG. 2 may be equipped in an electronic appliance, such as a terminal.

The terminal may include a typical mobile phone, such as a cellular phone, a PCS (personal communication service) phone, a GSM phone, a CDMA-2000 phone, or a WCDMA phone, a PMP (portable multimedia player), a PDA (personal digital assistant), a smart phone, or an MBS (mobile broadcast system) phone, but the embodiment is not limited thereto. Various devices can be used as the terminal if they can wirelessly receive the power.

A section taken along dotted line A-A’ of the connecting unit 300 shown in FIG. 2 will be described with reference to FIG. 3.

FIG. 3 is a sectional view taken along dotted line A-A’ of the connecting unit 300 of the wireless power apparatus 1000 shown in FIG. 2.

Referring to FIG. 3, the first connection terminal 210, the second connection terminal 220 and the coil 230 constituting the coil unit 200 are disposed on the top side of the magnetic substrate 100.

In the wireless power apparatus 1000 according to one embodiment, the coil unit 200 is directly disposed on the top side of the magnetic substrate 100, so that the overall thickness can be remarkably reduced when comparing with the case in which the coil pattern is formed on an FPCB.

Preferably, the magnetic substrate 100 may have a thickness of 0.43 mm. The coil unit 200 may preferably have a thickness in the range of 0.1 mm to 0.15mm.

That is to say, the thickness of the wireless power apparatus 1000 can be reduced by preparing the coil unit 200 in the form of a conductor, a conductive pattern or a thin film. Since the current trend has tended toward the slimness, if the wireless power apparatus 1000 is applied to an electronic device such as the portable terminal, the overall thickness of the portable terminal can be reduced and the power can be effectively received from the transmission side.

The connecting unit 300 is directly disposed on the coil unit 200. Since the connecting unit 300 is directly disposed on the coil unit 200, the coil unit 200 can be readily connected with the connecting unit 300.

The first connection terminal 210 of the coil unit 200 is connected to the first connection terminal 310 of the connecting unit 300 through the first solder 10.

The second connection terminal 220 of the coil unit 200 is connected to the second connection terminal 320 of the connecting unit 300 through the second solder 20.

The coil 230 may be designed to have a predetermined width W and a predetermined thickness T. In addition, the coil 230 can be designed to have predetermined coil spacing.

FIGS. 4 to 8 are views for explaining a method of manufacturing the wireless power apparatus 1000 according to one embodiment.

The structure of the wireless power apparatus 1000 may be essentially identical to the structure of the wireless power apparatus 1000 described with reference to FIGS. 1 to 3.

First, referring to FIG. 4, the magnetic substrate 100 is prepared.

Then, referring to FIG. 5, a conductor 201 is directly laminated on the top side of the magnetic substrate 100. According to one embodiment, the conductor 201 may be laminated after an adhesive layer has been laminated on the top side of the magnetic substrate 100.

According to one embodiment, a laminating process can be used to form the conductor 201 on the top side of the magnetic substrate 100. According to the laminating process, the conductor 201 is heated at the predetermined temperature and then predetermined pressure is applied to the conductor 201. The laminating process refers to a process of bonding heterogeneous materials, such as a metal foil and a paper, to each other by using heat and pressure.

Then, referring to FIG. 6, a mask 500 is laminated on the top side of the conductor 201. The mask 500 may be selectively formed on only the top side of the conductor 201 corresponding to positions of the first connection terminal 210, the second connection terminal 220 and the coil 230 of the coil unit 200.

After that, referring to FIG. 7, the structure shown in FIG. 6 is immersed in an etchant so that portions of the conductor 201 where the mask 500 is not positioned may be etched. Thus, the conductor 201 may have a predetermined conductive pattern.

Then, the coil unit 200 of the wireless power apparatus 1000 is formed by removing the mask 500.

Thereafter, referring to FIG. 8, a soldering work is performed to connect the coil unit 200 with the connecting unit 300.

In other words, the first connection terminal 210 of the coil unit 200 may be connected to the first connection terminal 310 of the connecting unit 300 through the first solder 10, and the second connection terminal 220 of the coil unit 200 may be connected to the second connection terminal 320 of the connecting unit 300 through the second solder 20.

As described above, since the coil unit 200 is directly disposed on the top side of the magnetic substrate 100, the overall thickness of the wireless power apparatus 1000 can be remarkably reduced. In addition, since the wireless power apparatus 1000 can be manufactured only through the laminating and etching processes, the manufacturing process may be simplified.

Hereinafter, simulation results using the wireless power apparatus 1000 according to one embodiment will be described with reference to FIGS. 9 to 30.

The simulation results are obtained by using only the coil 230 described with reference to FIG. 1.

In other words, as shown in FIG. 9, simulation results are obtained on the condition that only the coil 230 is used. FIG. 9 shows the thickness T of the coil 230.

In the below simulation results, line to line spacing of the coil 230 may be in the range of 0.09 mm to 0.5 mm, and the frequency band used in power transceiving may be in the range of 100 KHz to 170 KHz.

In particular, the number of the turns of the coil 230 shown in FIG. 9 is 14, the diameter of the coil 230 is 38.5 mm, the coil spacing of the coil 230 is 0.09 mm, and the use frequency is in the range of 100 KHz to 170 KHz.

In addition, the coil 230 may be included in a receiving apparatus to wirelessly receive power or may be included in a transmitting apparatus to wirelessly transmit power. In this case, the coil 230 may transmit or receive power through the electromagnetic induction.

In addition, referring to FIG. 9, the coil 230 has a spiral type structure. However, the embodiment is not limited. The coil 230 shown in FIG. 1 may be substituted with the coil 230 shown in FIG. 9.

FIGS. 10 to 22 are views for explaining the relationship between the thickness of the coil 230 and a Q value, the thickness of the coil 230, and a radiation pattern of a magnetic field which are obtained by using the coil 230 according to one embodiment.

FIGS. 23 to 30 are views for explaining the relationship between the thickness of the coil 230 and the Q value according to frequencies, which is obtained by using the coil 230 according to one embodiment.

When the thickness of the coil 230 of the wireless power apparatus according to one embodiment is in the range of 0.1 mm to 0.15 mm, the Q value is increased, so that the power transmission efficiency can be greatly improved. The Q value varies depending on an operating frequency, a coil shape, a coil dimension, and a coil material. As the Q value is increased, the quantity of energy stored in the coil 230 is increased, so that the power transmission efficiency can be improved.

The relationship equation among inductance, resistance, and a Q value of the coil 230 may be expressed through Equation 1.

[Equation 1]

Q=w*L/R

In Equation 1, w denotes a frequency used in power transmission, L denotes the inductance of the coil 230, and R denotes resistance of the coil 230.

As recognized in Equation 1, as the inductance of the coil 230 is increased, the Q value is increased. If the Q value is increased, the power transmission efficiency can be improved. The resistance of the coil 230 is a value obtained by expressing the quantity of power consumed in the coil 230 as a numeric value. As the resistance of the coil 230 is decreased, the Q value is increased. As the resistance of the coil 230 is increased, the Q value is decreased.

FIG. 10 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and the quality factor (Q) of the coil 230 according to the frequencies when the thickness T of the coil 230 is 0.07 mm. FIG. 11 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of the coil 230 is 0.07 mm.

FIG. 12 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and the quality factor (Q) of the coil 230 according to the frequencies when the thickness T of the coil 230 is 0.09 mm. FIG. 13 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of the coil 230 is 0.09 mm.

FIG. 14 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and the quality factor (Q) of the coil 230 according to the frequencies when the thickness T of the coil 230 is 0.1 mm. FIG. 15 shows an H-field showing the radiation pattern of a magnetic field when the thickness T of the coil 230 is 0.1 mm.

When comparing the tables of FIGS. 12 and 14 with each other, the quality factor (Q) at each frequency is more increased when the thickness of the coil 230 is 0.1 mm as compared with when the thickness of the coil 230 is 0.09 mm. In detail, the Q value is increased by the difference of 0.69 from 9.96 to 10.65 at the frequency 100 KHz, and the Q value is increased by the difference of 0.7 from 10.48 to 11.18 at the frequency 110 KHz. The Q value is increased by the difference of 0.49 from 11.17 to 11.66 at the frequency 120 KHz, and the Q value is increased by the difference of 0.54 from 11.39 to 11.93 at the frequency 130 KHz. The Q value is increased by the difference of 0.38 from 11.79 to 12.17 at the frequency 140 KHz, and the Q value is increased by the difference of 0.34 from 11.95 to 12.29 at the frequency 150 KHz. The Q value is increased by the difference of 0.3 from 12.08 to 12.38 at the frequency 160 KHz, and the Q value is increased by the difference of 0.25 from 12.21 to 12.46 at the frequency 170 KHz. If the Q value is increased, the power transmission efficiency can be improved. Accordingly, when the thickness of the coil 230 is 0.1 mm, the power transmission efficiency is more improved as compared with when the thickness of the coil 230 is 0.09 mm.

When comparing H-Fields representing the radiation patterns of a magnetic field shown in FIGS. 13 and 15 with each other, since the deeper color represents the stronger magnetic field in the H-Field, when the thickness of the coil 230 is 0.1 mm, the magnetic field formed around the coil 230 represents stronger intensity as compared with when the thickness of the coil 230 is 0.09 mm. Since the coil 230 transceives power through the magnetic field, as the magnetic field is stronger, the power transmission efficiency is more improved. Accordingly, when the thickness of the coil 230 is 0.1 mm, the power transmission efficiency is more improved as compared with when the thickness of the coil 230 is 0.09 mm.

In other words, as the thickness of the coil 230 is decreased from 0.1 mm, the Q value is decreased, and the intensity of the magnetic field is weakened, so that the power transmission efficiency is more degraded.

FIG. 16 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and the quality factor (Q) of the coil 230 according to the frequencies when the thickness T of the coil 230 is 0.14 mm. FIG. 17 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of the coil 230 is 0.14 mm.

When the thickness of the coil 230 of the wireless power apparatus 1000 is 0.14 mm, the Q value is represented as the greatest value as comparing with other experimental results, and even the magnetic field is represented as the strongest intensity. In detail, referring to FIG. 16, the Q value is 11.11 at the frequency of 100 KHz, and is 11.60 at the frequency of 110 KHz. The Q value is 12.06 at the frequency of 120 KHz, and is 12.22 at the frequency of 130 KHz. In addition, the Q value is 12.35 at the frequency of 140 KHz, and is 12. 46 at the frequency of 150 KHz. In addition, the Q value is 12.58 at the frequency of 160 KHz, and is 12.66 at the frequency of 170 KHz. Therefore, when the thickness of the coil 230 is 0.14 mm, the Q value is represented as the greatest value.

Further, referring to FIG. 17, the intensity of the magnetic field around the coil 230 is strongest among the intensities of the magnetic fields related to other thicknesses of the coil 230.

In other words, when the thickness of the coil 230 is 0.14 mm, the Q value is represented as the greatest value, and the magnetic field is represented as the strongest intensity, so that the power transmission efficiency is most greatly improved.

FIG. 18 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and the quality factor (Q) of the coil 230 according to the frequencies when the thickness T of the coil 230 is 0.15 mm. FIG. 19 shows an H-field representing the radiation pattern of a magnetic field when the thickness T of the coil 230 is 0.15 mm.

FIG. 20 is a table showing the variation in the resistance (unit: Ω), magnetic inductance (unit: uH), and the quality factor (Q) of the coil 230 according to the frequencies when the thickness T of the coil 230 is 0.16 mm. FIG. 21 shows an H-field showing the radiation pattern of a magnetic field when the thickness T of the coil 230 is 0.16 mm.

When comparing the tables of FIGS. 18 and 20 with each other, the quality factor (Q) at each frequency is more decreased when the thickness of the coil 230 is 0.16 mm as compared with when the thickness of the coil 230 is 0.15 mm. In detail, the Q value is decreased by the difference of 0.95 from 11.03 to 10.08 at the frequency 100 KHz, and the Q value is decreased by the difference of 0.49 from 11.56 to 11.07 at the frequency 130 KHz. The Q value is decreased by the difference of 0.49 from 12.01 to 11.52 at the frequency 120 KHz, and the Q value is decreased by the difference of 0.42 from 12.17 to 11.75 at the frequency 130 KHz. The Q value is decreased by the difference of 0.35 from 12.30 to 11.95 at the frequency 140 KHz, and the Q value is decreased by the difference of 0.21 from 12.41 to 12.20 at the frequency 150 KHz. The Q value is decreased by the difference of 0.22 from 12.50 to 12.28 at the frequency 160 KHz, and the Q value is decreased by the difference of 0.21 from 12.60 to 12.39 at the frequency 170 KHz. If the Q value is decreased, the power transmission efficiency can be degraded. Accordingly, when the thickness of the coil 230 is 0.16 mm, the power transmission efficiency is more degraded as compared with when the thickness of the coil 230 is 0.15 mm.

When comparing H-Fields representing the radiation patterns of a magnetic field shown in FIGS. 19 and 21 with each other, since the deeper color represents the stronger magnetic field in the H-Field, when the thickness of the coil 230 is 0.16 mm, the magnetic field formed around the coil 230 represents weaker intensity as compared with when the thickness of the coil 230 is 0.15 mm. Since the coil 230 transceives power through the magnetic field, as the magnetic field is weakened, the power transmission efficiency is more degraded. Accordingly, when the thickness of the coil 230 is 0.16 mm, the power transmission efficiency is more degraded as compared with when the thickness of the coil 230 is 0.15 mm.

In other words, as the thickness of the coil 230 is increased from 0.15 mm, the Q value is decreased, and the intensity of the magnetic field is weakened, so that the power transmission efficiency is degraded.

As described above, if the thickness of the coil 230 is decreased from 0.1 mm, the power transmission efficiency is degraded. In addition, if the thickness of the coil 230 is increased from 0.15 mm, the power transmission efficiency is degraded. Accordingly, if the thickness of the coil 230 is in the range of 0.1 mm to 0.15 mm, the power transmission efficiency is optimized. In particular, if the thickness of the coil 230 is 0.14 mm, the power transmission efficiency is most greatly improved.

FIG. 22 is a graph showing the quality factor (Q) as a function of the frequency when the thickness of the coil 230 is in the range of 0.07 mm to 0. 16 mm. In this case, only the thickness of the coil 230 varies, and all of the number of the turns of the coil 230, the diameter of the coil 230, and the coil spacing of the coil 230 are constants. Each numeric value has been described above.

Referring to FIG. 22, when the thickness of the coil 230 is in the range of 0.1 mm to 0.15 mm, the Q value is greater than the upper limit of the range of the Q value.

FIGS. 23 to 28 are graphs showing that the power transmission efficiency is optimized when the thickness of the coil 230 is in the range of 0.1 mm to 0.15 mm. In detail, FIGS. 23 to 28 are graphs showing a Q value as a function of the thickness of the coil 230.

The graphs of FIGS. 23 to 30 are made based on data shown in tables of FIGS. 10, 12, 14, 16, 18, and 20.

FIG. 23 shows the graph when the frequency used in the wireless power transmission is 100 KHz. As shown in FIG. 23, the increase of the Q value is greatly represented from when the thickness of the coil 230 is 0.1 mm. When the thickness of the coil 230 is 0.14 mm, the Q value is maximized. The decrease of the Q value is greatly represented from when the thickness of the coil 230 is 0.15 mm.

The characteristic of the Q value of the graph shown in FIG. 23 is identically represented when the frequency used in the wireless power transmission shown in FIG. 24 is 110 KHz, when the frequency used in the wireless power transmission shown in FIG. 25 is 130 KHz, when the frequency used in the wireless power transmission shown in FIG. 26 is 130 KHz, when the frequency used in the wireless power transmission shown in FIG. 27 is 140 KHz, when the frequency used in the wireless power transmission shown in FIG. 28 is 150 KHz, when the frequency used in the wireless power transmission shown in FIG. 29 is 160 KHz, and when the frequency used in the wireless power transmission shown in FIG. 30 is 170 KHz.

In other words, when the thickness of the coil 230 is in the range of 0.1 mm to 0.15 mm, the Q value is represented as a greater value, and the power transmission efficiency is more improved as compared with when the thickness of the coil 230 is in other ranges. In particular, when the thickness of the coil 230 is 0.14 mm, the Q value is represented as the greatest value, so that the power transmission efficiency is most greatly improved.

In addition, according to the wireless power apparatus of one embodiment, a copper plate (copper conductive line) etched on a protective film is disposed through a lead frame scheme, so that the thickness of the coil 230 can be optimized in the range of 0.1 mm to 0.15 mm. When the lead frame scheme is employed, the thickness of the coil 230 can be more optimized as compared with when the coil 230 is disposed on a printed circuit board (PCB) or a flexible printed circuit board (FPCB). In other words, when the coil 230 is disposed on the PCB or the FPCB, the thickness of the protective film is thicker than that of the substrate. Accordingly, difficulties may be made when optimizing the thickness of the coil 230. Therefore, the coil 230 is disposed through the copper plate etched on the protective film, so that the thickness of the coil 230 can be optimized.

Hereinafter, a wireless power apparatus 1000 according to another embodiment will be described with reference to FIGS. 31 to 42.

In the wireless power apparatus 1000 according to another embodiment, the coil 230 may have the thickness in the range of 0.1 mm to 0.15 mm. The coil 230 used in the wireless power apparatus 1000 according to another embodiment may have the specification the same as that of the coil 230 of FIG. 9. In detail, the number of the turns of the coil 230 may be 14, the diameter of the coil 230 may be 38.5 mm, and the coil spacing of the coil 230 may be 0.09 mm.

FIG. 31 is an exploded perspective view of the wireless power apparatus 1000 according to another embodiment, FIG. 32 is a perspective view of the wireless power apparatus 1000 according to another embodiment, and FIG. 33 is a sectional view of the wireless power apparatus 1000 according to another embodiment.

Meanwhile, FIG. 32 is a perspective view showing the assembled state of the elements of the wireless power apparatus 1000 shown in FIG. 31, in which some elements are omitted.

The wireless power apparatus 1000 according to another embodiment may be disposed in an electronic device such as a portable terminal, so that the wireless power apparatus 1000 may wirelessly receive power from the transmission side.

Referring to FIGS. 31 to 33, the wireless power apparatus 1000 may include a magnetic substrate 100, a coil unit 200, a connecting unit 300, a short-range communication antenna 600, an adhesive layer 700, a first dual-side adhesive layer 710, a second dual-side adhesive layer 720, a protective film 800, and a release paper layer 730.

Referring to FIG. 31, the magnetic substrate 100 can change the direction of the magnetic field transferred from the transmission side.

The magnetic substrate 100 changes the direction of the magnetic field transferred to the coil unit 200 from the transmission side to reduce the amount of the magnetic field leaked to the outside. Thus, the magnetic substrate 100 may have the electromagnetic wave suppressing effect.

The magnetic substrate 100 can absorb some of the magnetic field transferred to the coil unit 200 from the transmission side and leaked to the outside to dissipate the magnetic field as heat. If the amount of the magnetic field leaked to the outside is reduced, the undesirable influence of the magnetic field exerted on the human body can be reduced.

Referring to FIG. 33, the magnetic substrate 100 may include a magnet 110 and a support 120.

The magnet 110 may include particles or ceramic. According to one embodiment, the magnet 110 may be one of a spinel type magnet, a hexa type magnet, a sendust type magnet and a permalloy type magnet.

The support 120 may include thermosetting resin or thermoplastic resin and support the magnetic substrate 100.

Referring again to FIG. 31, the magnetic substrate 100 may be prepared in the form of a sheet and may have a flexible property.

A receiving space 130 may be formed at a predetermined area of the magnet substrate 100. The receiving space 130 has a structure the same as that of the connecting unit 300. The connecting unit 300 is disposed in the receiving space 130 and connected to the coil unit 200.

The coil unit 200 can receive the power from the transmission side using the electromagnetic induction or resonance. Similar to the coil unit 200 illustrated in FIG. 1, the coil unit 200 may include a first connection terminal 210, a second connection terminal 220, and a coil 230. The coil 230 may have a conductive layer or a conductive pattern.

The connecting unit 300 connects a receiver circuit (not shown) with the coil unit 200 to transfer the power received from the coil unit 200 to a load (not shown) through the receiver circuit.

The connecting unit 300 may include a wiring layer and the wiring layer may include the receiving circuit. The receiving circuit may include a rectifier circuit for rectifying the power received from the coil unit 200, a smoothing circuit for removing noise signals, and a main IC chip for performing the operation to wirelessly receive the power.

In addition, the receiver circuit may transfer the signal received from a short-range communication antenna 600 to a short-range communication signal processing unit (not shown).

The connecting unit 300 is disposed in the receiving space 130 of the magnetic substrate 100 and connected to the coil unit 200. FIG. 32 shows the connecting unit 300 disposed in the receiving space 130 of the magnetic substrate 100.

The connecting unit 300 may include a first connection terminal 310, a second connection terminal 320, a third connection terminal 340, and a fourth connection terminal 350. The first connection terminal 310 of the connecting unit 300 may be connected to the first connection terminal 210 of the coil unit 200, the second connection terminal 320 of the connecting unit 300 may be connected to the second connection terminal 220 of the coil unit 200, the third connection terminal 340 of the connecting unit 300 may be connected to a first connection terminal 610 of the short-range communication antenna 600 and the fourth connection terminal 350 of the connecting unit 300 may be connected to a second connection terminal 620 of the short-range communication antenna 600.

The connecting unit 300 may have the shape corresponding to the shape of the receiving space 130 and may be disposed in the receiving space 130. Since the connecting unit 300 is disposed in the receiving space 130 of the magnetic substrate 100, the thickness of the wireless power apparatus 1000 can be remarkably reduced as much as the thickness of the connecting unit 300. Thus, the thickness of the electronic device, such as a portable terminal, equipped with the wireless power apparatus 1000 can be remarkably reduced.

According to one embodiment, the connecting unit 300 may include a flexible printed circuit board (FPCB), a tape substrate (TS) or a lead frame (LF). If the tape substrate is used as the connecting unit 300, the thickness of the connecting unit 300 can be reduced, so that the overall size of the wireless power apparatus 1000 can be reduced.

If the lead frame is used as the connecting unit 300, the wiring layer included in the connecting unit 300 can be protected from the heat, external moisture or impact and the mass production can be realized.

Referring again to FIG. 31, the short-range communication antenna 600 may make near field communication with a reader. The short-range communication antenna 600 may serve as an antenna that transceives information in cooperation with the reader.

An NFC signal processing unit (not shown) may process the signal transferred to the short-range communication antenna 600 through the connecting unit 300.

Various short-range communication protocols can be applied to the short-range communication antenna 600 and the NFC (near field communication) is preferable.

According to one embodiment, the short-range communication antenna 600 may be arranged at an outer peripheral portion of the coil unit 200. Referring to FIG. 32, when the coil unit 200 is disposed at the magnetic substrate 100, the short-range communication antenna 600 may be arranged along the outer peripheral portion of the magnetic substrate 100 to surround the coil unit 200. The short-range communication antenna 600 may have a configuration formed by winding one conductive line several times in the shape of a rectangle, but the embodiment is not limited thereto.

Referring again to FIG. 31, an adhesive layer (not shown) may be disposed under the protective film 800, or the protective film 800 may be attached to the coil unit 200 and the short-range communication antenna 600, which will be described later in detail.

The first dual-side adhesive layer 710 is interposed between the magnetic substrate 100 and the coil unit 200/short-range communication antenna 600 to adhere the coil unit 200 to the magnetic substrate 100, which will be described later in detail. Similar to the magnetic substrate 100, a receiving space having the shape the same as that of the connecting unit 300 may be formed in the first dual-side adhesive layer 710.

Referring again to FIG. 33, the second dual-side adhesive layer 720 may attach the protective film 800 to the release paper layer 730, which will be described later in detail.

The coil unit 200 may be disposed on the magnetic substrate 100 and may have a spiral structure, but the embodiment is not limited thereto.

Hereinafter, a method of manufacturing the wireless power apparatus 1000 according to another embodiment will be described with reference to FIGS. 34 to 42.

When the manufacturing process starts, as shown in FIG. 34, the conductor 201, the adhesive layer 700 and the protective film 800 are prepared.

According to one embodiment, the conductor 201 may be formed by using an alloy including copper (Cu). The copper (Cu) is in the form of roll annealed copper or electrodeposited copper. The conductor 201 may have various thicknesses depending on the specification of a product. According to one embodiment, the conductor 201 may have the thickness of 100㎛, but the embodiment is not limited thereto.

The adhesive layer 700 is used to reinforce the adhesive strength between the conductor 201 and the protective film 800. The adhesive layer 700 may include thermosetting resin, but the embodiment is not limited thereto. The adhesive layer may preferably have the thickness of 17㎛, but the embodiment is not limited thereto.

The protective film 800 protects the conductor 201 when a predetermined conductive pattern is formed in the conductor 201. In detail, the protective film 800 supports the conductor 201 in the etching process, which will be described later, to protect the conductor 201 such that the predetermined conductive pattern may be formed in the conductor 201.

According to one embodiment, the protective film 800 may include polyimide film (PI film), but the embodiment is not limited thereto.

Then, as shown in FIG. 35, the conductor 201 may be attached to the protective film 800 by the adhesive layer 700. The laminating process can be used to attach the conductor 201 to the protective film 800. The laminating process refers to the process to bond heterogeneous materials with each other by applying predetermined heat and pressure.

Then, as shown in FIG. 36, a photoresist film 900 is attached to the top side of the conductor 201. The photoresist film 900 is used for etching the conductor 201 to form a predetermined conductive pattern in the conductor 201. A UV exposure type film or an LDI exposure type film may be used as the photoresist film 900. According to another embodiment, a photoresist coating solution may be applied to the top side of the conductor 201 instead of the photoresist film 900.

After that, as shown in FIG. 37, the photoresist film 900 is subject to the exposure and development processes to form a mask pattern 910.

The mask pattern 910 may be formed on the top side of the conductor 201 corresponding to the position of the conductive pattern through the exposure and development processes.

The exposure process refers to the process for selectively irradiating light onto the photoresist film 900 corresponding to the conductive pattern. In detail, in the exposure process, the light is irradiated onto regions of the conductor 201 where the conductive pattern is not formed. The development process refers to the process for removing the regions to which the light is irradiated through the exposure process.

Due to the exposure and development processes, the mask pattern 910 may be formed in the regions corresponding to the coil unit 200 and the short-range communication antenna 600. The conductor 201 exposed through the mask pattern 910 may be etched.

Then, as shown in FIG. 38, a groove portion where the mask pattern 910 is not formed may be removed through the etching process. The etching process refers to the process of removing the predetermined portion of the conductor 201 where the mask pattern 910 is not formed through corrosion by using a chemical reacting with the predetermined portion of the conductor 201 wherein the mask pattern 910 is not formed. According to one embodiment, the conductor 201 may be patterned through the wet etching or dry etching.

After that, as shown in FIG. 39, the mask pattern 910 is removed so that the first and

second connection terminals

210 and 220 of the coil unit 200, the first and

second connection terminals

610 and 620 of the short-range communication antenna 600, the coil 230 having a predetermined conductive pattern and the short-range communication antenna 600 having a predetermined conductive pattern may be formed.

Then, as shown in FIG. 40, a soldering process is performed to connect the coil unit 200 and the short-range communication antenna 600 to the connecting unit 300. According to one embodiment, the soldering process includes the reflow process, but the embodiment is not limited thereto. The reflow process refers to the process for bonding the coil unit 230 and the short-range communication antenna 600 to the connecting unit 300 by melting solder cream using high-temperature heat to ensure the stable electrical connection between the connecting unit 300 and the coil unit 230/NFC antenna 600.

The first connection terminal 210 of the coil unit 200 may be connected to the first connection terminal 310 of the connecting unit 300 by a solder 30, the second connection terminal 220 of the coil unit 200 may be connected to the second connection terminal 320 of the connecting unit 300 by the solder 30, the first connection terminal 610 of the short-range communication antenna 600 may be connected to the third connection terminal 340 of the connecting unit 300 by the solder 30 , and the second connection terminal 620 of the short-range communication antenna 600 may be connected to the fourth connection terminal 350 of the connecting unit 300 by the solder 30.

Then, as shown in FIG. 41, the magnetic substrate 100 is laminated on a predetermined portion of the conductive pattern where the connecting unit 300 is not present. In detail, the magnetic substrate 100 may be laminated on the top sides of the coil 230 and the short-range communication antenna 600.

Prior to the above, the receiving space corresponding to the connecting unit 300 can be formed in the magnetic substrate 100. The receiving space of the magnetic substrate 100 may have the shape the same as that of the connecting unit 300.

As described above with reference to FIG. 31, since the connecting unit 300 is disposed in the receiving space 130 of the magnetic substrate 100, the thickness of the wireless power apparatus 1000 may be remarkably reduced as much as the thickness of the connecting unit 300. Thus, the thickness of the electronic device, such as a portable terminal, equipped with the wireless power apparatus 1000 may be remarkably reduced.

The coil 230/short-range communication antenna 600 and the magnetic substrate 100 may be adhered with each other by the first dual-side adhesive layer 710. According to one embodiment, the magnetic substrate 100 may have the thickness in the range of 100㎛ to 800㎛, but the embodiment is not limited thereto. According to one embodiment, the first dual-side adhesive layer 710 may have the thickness in the range of 10㎛ to 50㎛, but the embodiment is not limited thereto.

After that, as shown in FIG. 42, the release paper layer 730 may be attached to one side of the protective film 800 by interposing the second dual-size adhesive layer 720 therebetween. The release paper layer 730 is a paper layer for protecting the second dual-size adhesive layer 720 and may be removed when the release paper layer 730 is attached to a case of an electronic device such as a portable terminal.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

Claims

A wireless power apparatus to transmit or receive power using an electromagnetic induction scheme, the wireless power apparatus comprising:

a coil to wirelessly transmit or receive the power; and

a magnetic substrate disposed at one side of the coil,

wherein the coil has a thickness in a range of 0.1 mm to 0.15 mm.
The wireless power apparatus of claim 1, wherein a frequency band used when transmitting or receiving the power is in a range of 100 KHz to 170 KHz, and line to line spacing of the coil is in a range of 0.09 mm to 0.5 mm.
The wireless power apparatus of claim 1, wherein the coil includes an etched copper line, and the etched copper line is attached to the magnetic substrate through an adhesive.
The wireless power apparatus of claim 1, wherein the coil includes a conductive layer on the magnetic substrate to wirelessly receive the power.
The wireless power apparatus of claim 1, wherein the coil includes a conductive pattern on the magnetic substrate.
The wireless power apparatus of claim 1, wherein the magnetic substrate is formed in a predetermined region thereof with a receiving space having a shape a same as a shape of a connecting unit for connection with a wireless power receiving circuit.
The wireless power apparatus of claim 6, further comprising the connecting unit at the receiving space, wherein the connecting unit is connected with the coil.
The wireless power apparatus of claim 1, further comprising a short-range communication antenna provided on the magnetic substrate to surround the coil.
The wireless power apparatus of claim 8, wherein the short-range communication antenna includes a near field communication (NFC) antenna.
The wireless power apparatus of claim 8, wherein the magnetic substrate is formed in a predetermined region thereof with a receiving space having a shape a same as a shape of a connecting unit for connection with a wireless power receiving circuit.
The wireless power apparatus of claim 10, further comprising the connecting unit provided in the receiving space, wherein the connecting unit is connected with the coil and a short-range communication signal processing unit.
A terminal provided therein with the wireless power apparatus claimed according to claim 1.