Coil component, power transmission device, power receiving device, power transmission system, and power transmission method

Abstract

To provide a coil component, a power transmission device, a power receiving device, a power transmission system, and a high-efficiency power transmission method that can improve performance while suppressing the increase in size and weight.SOLUTION: In a wireless power transmission system, a coil component 10 included in a receiving device and a transmission device respectively includes a first planar coil 11, a second planar coil 12 stacked on the first planar coil 11, and a magnetic holding member 30 that has magnetic properties and includes a portion covering the opposite surface of the surface facing the second planar coil 12 in the first planar coil 11. The first planar coil 11 and the second planar coil 12 are connected in series. The thickness of the second planar coil 12 is 0.15 mm or more and 0.35 mm or less.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a coil component, a power transmitting device, a power receiving device, a power transfer system, and a power transfer method. [Background technology]

[0002] 2. Description of the Related Art Wireless power transmission systems that transmit power in a non-contact manner are becoming more and more common.

[0003] When transmitting power contactlessly, for example, a high-frequency current flows through a resonant circuit including a coil. In this case, the skin effect may occur in the coil. The skin effect increases AC resistance and leads to increased power consumption due to heat generation. Therefore, the skin effect causes a decrease in transmission efficiency.

[0004] When a litz wire is used as the coil, the skin effect is suppressed. However, since the litz wire is formed by twisting together a large number of enameled wires, the manufacturing cost is high and the manufacturing process is laborious, and the manufacturing process becomes more laborious as the size of the coil increases. On the other hand, a technology is also known that employs a spiral-shaped, plate-shaped planar coil with a rectangular conductor cross section (see JP2020-47614A). With such a planar coil, the manufacturing efficiency can be improved regardless of the size of the coil. Therefore, such a planar coil is suitable for a high-power wireless power transmission system, for example, for an electric vehicle, in which the size of the coil may be large.

[0005] In a wireless power transmission system for an electric vehicle, a power transmitting device is installed on a road surface such as a parking lot, and a power receiving device is installed on the electric vehicle. For example, when the above-mentioned planar coil is used for an electric vehicle, the height dimensions of both the power transmitting device and the power receiving device can be suppressed. Therefore, the above-mentioned planar coil is useful in, for example, the vehicle field where space constraints are severe. Summary of the Invention

[0006] In devices incorporating coils, such as power transmitting devices and power receiving devices, it is generally desirable to suppress increases in size and weight. In this case, it is even more desirable to have good transmission performance while suppressing increases in size and weight.

[0007] An object of the present disclosure is to provide a coil component, a power transmitting device, a power receiving device, a power transfer system, and a highly efficient power transfer method that can improve performance while suppressing increases in size and weight.

[0008] The embodiments of the present disclosure relate to the following [1] to

[77] .

[0009] [1] A first planar coil; a second planar coil overlapping the first planar coil; a magnetic member including a portion covering a surface of the first planar coil opposite to a surface facing the second planar coil, the magnetic member having magnetism; the first planar coil and the second planar coil are connected in series, and a thickness of the second planar coil is not less than 0.15 mm and not more than 0.35 mm.

[0010] [2] The coil component described in [1], wherein the first planar coil and the second planar coil are supplied with an alternating current of 79 KHz or more and 90 KHz or less, or are supplied with an alternating magnetic field of 79 KHz or more and 90 KHz or less.

[0011] [3] A first magnetic shield member arranged to face a surface of the covering portion of the magnetic member opposite to a surface facing the first planar coil; a second magnetic shield member disposed to face a surface of the first magnetic shield member opposite to a surface of the first magnetic shield member facing the portion of the magnetic member that is to be covered; The coil component according to [1] or [2], wherein the first magnetic shield member and the second magnetic shield member are made of different materials.

[0012] [4] The volume resistivity of the first magnetic shield member is greater than the volume resistivity of the second magnetic shield member, The coil component according to [3], wherein the relative permeability of the first magnetic shield member is greater than the relative permeability of the second magnetic shield member.

[0013] [5] The coil component according to [3] or [4], wherein the first magnetic shield member includes plate-shaped ferrite.

[0014] [6] The coil component according to any one of [3] to [5], wherein the first magnetic shield member has a relative permeability of 500 or more.

[0015] [7] The coil component according to any one of [3] to [6], wherein the second magnetic shield member contains aluminum.

[0016] [8] The coil component according to any one of [1] to [7], wherein the covering portion of the magnetic member entirely covers the opposite surface of the first planar coil.

[0017] [9] The coil component according to any one of [1] to [7], wherein the covering portion of the magnetic member partially covers the opposite surface of the first planar coil.

[0018]

[10] The coil component described in [9], wherein the magnetic member includes multiple pieces separated from each other.

[0019]

[11] The first planar coil includes a straight portion extending along a straight line and a corner portion connected to the straight portion and extending in a curved shape, The coil component according to [9] or

[10] , wherein the covering portion of the magnetic member covers the straight portion and does not cover the corner portion.

[0020]

[12] A power transmission device comprising a coil component according to any one of [1] to

[11] .

[0021]

[13] The power transmitting device according to

[12] , further comprising a high-frequency current supply unit that supplies an alternating current of 79 KHz or more and 90 KHz or less to the coil component.

[0022]

[14] A power receiving device comprising a coil component described in any one of [1] to

[11] .

[0023]

[15] The power receiving device according to

[14] , further comprising a conversion unit that converts an AC current of 79 KHz or more and 90 KHz or less generated by electromagnetic induction in the coil component into a DC current.

[0024]

[16] A power transfer system comprising a power transmitting device and a power receiving device, at least one of the power transmitting device and the power receiving device comprising a coil component described in any one of [1] to

[11] .

[0025]

[17] A step of supplying an AC current of 79 KHz or more and 90 KHz or less to a coil component in a power transmission device including the coil component according to any one of [1] to

[11] ; generating a current in a power receiving device based on a magnetic field generated in the power transmitting device,

[0026]

[18] A first planar coil; a second planar coil overlapping the first planar coil; a magnetic member having magnetism, the magnetic member including a portion covering a surface of the first planar coil opposite to a surface facing the second planar coil; Equipped with the first planar coil and the second planar coil are connected in series; the thickness of the second planar coil is equal to or greater than 0.225 mm and equal to or less than 0.275 mm; The coil component, wherein the first planar coil and the second planar coil are supplied with an alternating current of 100 KHz or more and less than 200 KHz, or are supplied with an alternating magnetic field of 100 KHz or more and less than 200 KHz.

[0027]

[19] A first planar coil; a second planar coil overlapping the first planar coil; a magnetic member having magnetism, the magnetic member including a portion covering a surface of the first planar coil opposite to a surface facing the second planar coil; Equipped with the first planar coil and the second planar coil are connected in series; The thickness of the second planar coil is equal to or greater than 0.075 mm and equal to or less than 0.175 mm; The first planar coil and the second planar coil are supplied with an AC current of 200 KHz or more and 1 MHz or less, or are supplied with an AC magnetic field of 200 KHz or more and 1 MHz or less.

[0028]

[20] A first planar coil; a second planar coil overlapping the first planar coil; a magnetic member having magnetism, the magnetic member including a portion covering a surface of the first planar coil opposite to a surface facing the second planar coil; Equipped with the first planar coil and the second planar coil are connected in series; The second planar coil has a thickness of 0.45 mm or more; The coil component, wherein the first planar coil and the second planar coil are supplied with an AC current of 1.1 MHz or more, or an AC magnetic field of 1.1 MHz or more.

[0029]

[21] A first planar coil; a second planar coil overlapping the first planar coil; a magnetic holder including a portion covering a surface of the first planar coil opposite to a surface facing the second planar coil; a magnetic shield member disposed to face a surface of the holder opposite to a surface facing the first planar coil, the first planar coil and the second planar coil are connected in series, and a thickness of the second planar coil is not less than 0.15 mm and not more than 0.35 mm.

[0030]

[22] The coil component described in

[21] , wherein the first planar coil and the second planar coil are supplied with an alternating current of 79 KHz or more and 90 KHz or less, or are supplied with an alternating magnetic field of 79 KHz or more and 90 KHz or less.

[0031]

[23] The coil component according to

[21] or

[22] , wherein a thickness of the first planar coil is not less than 0.1 mm and not more than 1.0 mm.

[0032]

[24] The coil component according to any one of

[21] to

[23] , wherein the first planar coil and the second planar coil overlap with a gap therebetween, the gap being equal to or greater than 0.5 mm and equal to or less than 1.5 mm.

[0033]

[25] The coil component described in any of

[21] to

[24] , wherein the holding body integrally holds the first planar coil and the second planar coil in a state where the first planar coil and the second planar coil overlap with a gap therebetween, and the holding body further includes a portion covering side surfaces of the first planar coil and a portion filling the gap.

[0034]

[26] The coil component according to any one of

[21] to

[25] , wherein the holding body includes a resin and magnetic particles held by the resin.

[0035]

[27] The coil component according to any one of

[21] to

[26] , wherein the relative permeability of the holder is 5.0 or more.

[0036]

[28] The coil component according to any one of

[21] to

[27] , wherein the holder includes a wall portion protruding from the second planar coil.

[0037]

[29] The coil component according to any one of

[21] to

[28] , wherein the magnetic shielding member includes plate-shaped ferrite.

[0038]

[30] The coil component according to any one of

[21] to

[29] , wherein the magnetic shielding member has a relative permeability of 500 or more.

[0039]

[31] The coil component described in any of

[21] to

[30] , wherein the first planar coil and the second planar coil each include a plurality of turn portions arranged in a direction perpendicular to a central axis of the respective coil, any of the plurality of turn portions of the first planar coil and any of the plurality of turn portions of the second planar coil partially overlap in an axial direction of the first planar coil, and a portion of the turn portion of the first planar coil and a portion of the turn portion of the second planar coil that overlap in the axial direction of the first planar coil extend parallel to each other.

[0040]

[32] The coil component according to any one of

[21] to

[31] , wherein the first planar coil and the second planar coil are made of the same material.

[0041]

[33] The coil component according to any one of

[21] to

[32] , wherein the number of turns of the first planar coil and the number of turns of the second planar coil are 4 or more and 12 or less.

[0042]

[34] The coil component according to any one of

[21] to

[33] , wherein the first planar coil and the second planar coil are sized to fit within a square with each side measuring 800 mm.

[0043]

[35] The coil component according to any one of

[21] to

[34] , further comprising an even number of other planar coils arranged between the first planar coil and the second planar coil, the first planar coil, the other planar coil, and the second planar coil being connected in series, and at least the different planar coil among the planar coil connected to the first planar coil in the other planar coil and the planar coil different from the first planar coil, has a thickness of 0.15 mm or more and 0.35 mm or less.

[0044]

[36] The coil component according to

[25] , wherein the thickness of the planar coil connected to the first planar coil among the other planar coils is also 0.15 mm or more and 0.35 mm or less.

[0045]

[37] A power transmitting device comprising the coil component according to any one of

[21] to

[36] .

[0046]

[38] The power transmitting device according to

[37] , further comprising a high-frequency current supply unit that supplies an alternating current of 79 KHz or more and 90 KHz or less to the coil component.

[0047]

[39] A power receiving device comprising the coil component according to any one of

[21] to

[36] .

[0048]

[40] The power receiving device described in

[39] , further comprising a conversion unit that converts an AC current of 79 KHz or more and 90 KHz or less generated by electromagnetic induction in the coil component into a DC current.

[0049]

[41] A power transfer system comprising a power transmitting device and a power receiving device, at least one of the power transmitting device and the power receiving device comprising a coil component according to any one of

[21] to

[36] .

[0050]

[42] A power transmission method comprising the steps of: supplying an AC current of 79 KHz or more and 90 KHz or less to a coil component in a power transmission device having the coil component described in any one of

[21] to

[36] ; and receiving a magnetic field generated by the power transmission device with a power receiving device.

[0051]

[43] A first planar coil; a second planar coil overlapping the first planar coil; a holder that includes a portion covering a surface of the first planar coil opposite to a surface facing the second planar coil, the holder having magnetism and holding at least the first planar coil; a magnetic shield member disposed to face a surface of the covering portion of the holder opposite to a surface facing the first planar coil; Equipped with the first planar coil and the second planar coil are connected in series; the first planar coil comprises aluminum; The second planar coil has a thickness of 0.15 mm or more and 0.35 mm or less.

[0052]

[44] The coil component according to

[43] , wherein a thickness of the first planar coil is greater than a thickness of the second planar coil.

[0053]

[45] The coil component described in

[43] or

[44] , wherein the specific gravity of the second planar coil is greater than the specific gravity of the first planar coil, and the electrical conductivity of the second planar coil is greater than the electrical conductivity of the first planar coil.

[0054]

[46] The coil component according to any one of

[43] to

[45] , wherein the second planar coil contains copper.

[0055]

[47] A coil component described in any of

[43] to

[46] , wherein the first planar coil and the second planar coil are supplied with an alternating current of 79 KHz or more and 90 KHz or less, or are supplied with an alternating magnetic field of 79 KHz or more and 90 KHz or less.

[0056]

[48] ​​The coil component according to any one of

[43] to

[47] , wherein a thickness of the first planar coil is not less than 0.5 mm and not more than 1.0 mm.

[0057]

[49] The sum of the weight per square meter of the first planar coil and the weight per square meter of the second planar coil is 5.0 kg / m 2 A coil component according to any one of

[43] to

[48] , which is:

[0058]

[50] The holding body integrally holds the first planar coil and the second planar coil in a state in which the first planar coil and the second planar coil overlap with a gap therebetween, The coil component according to any one of

[43] to

[49] , wherein the holder further includes a portion that covers a side surface of the first planar coil and a portion that fills the gap.

[0059]

[51] The coil component according to any one of

[43] to

[50] , wherein the holder includes a resin and magnetic particles held by the resin.

[0060]

[52] A coil component according to any one of

[43] to

[51] , wherein the relative permeability of the holder is 5.0 or more.

[0061]

[53] The coil component described in any one of

[43] to

[52] , wherein the holder includes a wall portion protruding from the second planar coil.

[0062]

[54] The coil component according to any one of

[43] to

[53] , wherein the magnetic shielding member includes plate-shaped ferrite.

[0063]

[55] A coil component according to any one of

[43] to

[54] , wherein the magnetic shielding member has a relative permeability of 500 or more.

[0064]

[56] Further comprising an even number of other planar coils disposed between the first planar coil and the second planar coil. the first planar coil, the other planar coil, and the second planar coil are connected in series; The coil component according to any one of

[43] to

[55] , wherein a thickness of at least the different planar coil among the planar coil connected to the first planar coil in the other planar coil and the planar coil different from the first planar coil is 0.15 mm or more and 0.35 mm or less.

[0065]

[57] The coil component according to

[56] , wherein the thickness of the planar coil connected to the first planar coil among the other planar coils is also 0.15 mm or more and 0.35 mm or less.

[0066]

[58] A power transmission device comprising a coil component according to any one of

[43] to

[57] .

[0067]

[59] The power transmitting device according to

[58] , further comprising a high-frequency current supply unit that supplies an alternating current of 79 KHz or more and 90 KHz or less to the coil component.

[0068]

[60] A power receiving device comprising a coil component according to any one of

[43] to

[57] .

[0069]

[61] The power receiving device according to

[60] , further comprising a conversion unit that converts an AC current of 79 KHz or more and 90 KHz or less generated by electromagnetic induction in the coil component into a DC current.

[0070]

[62] A power transmitting device and a power receiving device, A power transmission system, wherein at least one of the power transmitting device and the power receiving device is equipped with a coil component described in any one of

[43] to

[57] .

[0071]

[63] A step of supplying an AC current of 79 KHz or more and 90 KHz or less to a coil component in a power transmission device including the coil component according to any one of

[43] to

[57] ; and receiving the magnetic field generated by the power transmitting device with a power receiving device.

[0072]

[64] A first planar coil; a second planar coil overlapping the first planar coil; a magnetic member having magnetism, the magnetic member including a portion covering a surface of the first planar coil opposite to a surface facing the second planar coil; a magnetic shield member disposed to face a surface of the covering portion of the magnetic member opposite to a surface facing the first planar coil; Equipped with the first planar coil and the second planar coil are connected in series; the thickness of the second planar coil is equal to or greater than 0.225 mm and equal to or less than 0.275 mm; The coil component, wherein the first planar coil and the second planar coil are supplied with an alternating current of 100 KHz or more and less than 200 KHz, or are supplied with an alternating magnetic field of 100 KHz or more and less than 200 KHz.

[0073]

[65] A first planar coil; a second planar coil overlapping the first planar coil; a magnetic member having magnetism, the magnetic member including a portion covering a surface of the first planar coil opposite to a surface facing the second planar coil; a magnetic shield member disposed to face a surface of the covering portion of the magnetic member opposite to a surface facing the first planar coil; Equipped with the first planar coil and the second planar coil are connected in series; The thickness of the second planar coil is equal to or greater than 0.075 mm and equal to or less than 0.175 mm; The first planar coil and the second planar coil are supplied with an AC current of 200 KHz or more and 1 MHz or less, or are supplied with an AC magnetic field of 200 KHz or more and 1 MHz or less.

[0074]

[66] A first planar coil; a second planar coil overlapping the first planar coil; a magnetic member having magnetism, the magnetic member including a portion covering a surface of the first planar coil opposite to a surface facing the second planar coil; a magnetic shield member disposed to face a surface of the covering portion of the magnetic member opposite to a surface facing the first planar coil; Equipped with the first planar coil and the second planar coil are connected in series; The second planar coil has a thickness of 0.45 mm or more; The coil component, wherein the first planar coil and the second planar coil are supplied with an AC current of 1.1 MHz or more, or an AC magnetic field of 1.1 MHz or more.

[0075]

[67] The coil component of any one of

[64] to

[66] , wherein the first planar coil includes copper or aluminum, and the second planar coil includes copper.

[0076]

[68] The coil component according to any one of

[64] to

[67] , wherein the magnetic member includes a resin and magnetic particles held in the resin.

[0077]

[69] A coil component according to any one of

[64] to

[68] , wherein the magnetic member has a relative permeability of 5.0 or more.

[0078]

[70] The coil component according to any one of

[64] to

[69] , wherein the magnetic shielding member includes plate-shaped ferrite.

[0079]

[71] A coil component according to any one of

[64] to

[70] , wherein the magnetic shielding member has a relative permeability of 500 or more.

[0080]

[72] A coil component according to any one of

[64] to

[71] , a high frequency current supply unit that supplies an alternating current to the coil component.

[0081]

[73] A coil component according to any one of

[64] to

[71] , A conversion unit that converts an AC current generated by electromagnetic induction in the coil component into a DC current.

[0082]

[74] A power transmitting device and a power receiving device, A power transmission system, wherein at least one of the power transmitting device and the power receiving device is equipped with a coil component described in any one of

[64] to

[71] .

[0083]

[75] A step of supplying an AC current of 100 KHz or more and less than 200 KHz to a coil component in a power transmission device including the coil component according to

[64] ; generating a current in a power receiving device based on a magnetic field generated in the power transmitting device,

[0084]

[76] A step of supplying an AC current of 200 KHz or more and 1 MHz or less to the coil component in a power transmission device including the coil component according to

[65] ; generating a current in a power receiving device based on a magnetic field generated in the power transmitting device,

[0085]

[77] A step of supplying an AC current of 1.1 MHz or more to a coil component in a power transmission device including the coil component according to

[66] ; generating a current in a power receiving device based on a magnetic field generated in the power transmitting device,

[0086] According to the present disclosure, it is possible to improve performance while suppressing increases in size and weight. [Brief description of the drawings]

[0087] [Figure 1] 1 is a diagram illustrating a schematic diagram of a wireless power transmission system to which a coil component according to an embodiment is applied. [Diagram 2] FIG. 1 is a perspective view of a coil component according to an embodiment. [Diagram 3] FIG. 3 is an exploded perspective view of the coil component shown in FIG. 2. [Figure 4] 4 is a perspective view showing a cross section of the coil component taken along line IV-IV in FIG. 2. [Diagram 5] 4 is a cross-sectional view of the coil component taken along line IV-IV in FIG. 2. [Figure 6] FIG. 13 is a graph showing a simulation result regarding performance evaluation of the coil component. [Figure 7] FIG. 13 is a graph showing a simulation result regarding performance evaluation of the coil component. [Figure 8] FIG. 13 is a graph showing a simulation result regarding performance evaluation of the coil component. [Figure 9]FIG. 11 is a cross-sectional view of a coil component according to another embodiment. [Figure 10] FIG. 11 is a cross-sectional view of a coil component according to still another embodiment. [Figure 11] FIG. 13 is a plan view of a coil component according to still another embodiment. [Figure 12] 12 is a cross-sectional view of the coil component taken along line XI-XI shown in FIG. 11. [Figure 13] FIG. 11 is a cross-sectional view of a coil component according to still another embodiment. [Figure 14] FIG. 13 is a plan view of a coil component according to still another embodiment. [Figure 15] FIG. 15 is a bottom view of the coil device shown in FIG. [Figure 16] FIG. 15 is a cross-sectional view of the coil component shown in FIG. [Figure 17] 6 is a graph illustrating the relationship between the thickness and resistance of a planar coil in the coil component having the configuration shown in FIGS. 2 to 5. FIG. [Figure 18] 6 is a graph illustrating the relationship between the thickness of the planar coil in the coil component having the configuration shown in FIGS. 2 to 5 and the Q value. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0088] Each embodiment will be described below with reference to the drawings.

[0089] In this specification, the terms "sheet," "film," "plate," and the like are not distinguished from one another solely on the basis of differences in name. Thus, for example, "sheet" is a concept that includes members that may also be called films or plates.

[0090] Fig. 1 shows a schematic diagram of a wireless power transmission system S to which a coil device 10 according to an embodiment described later with reference to Fig. 2 to Fig. 5 is applied. First, the wireless power transmission system S (hereinafter, abbreviated as power transmission system S) will be described with reference to Fig. 1.

[0091] <Wireless power transmission system> The power transfer system S includes a power transmitting device 1 and a power receiving device 2. The power transmitting device 1 includes a coil component 10 and a high-frequency current supplying unit 1A. The coil component 10 in the power transmitting device 1 functions as a power transmitting coil. The high-frequency current supplying unit 1A supplies a high-frequency current to the coil component 10 serving as a power transmitting coil.

[0092] The power receiving device 2 includes a coil component 10 and a conversion unit 2A. The coil component 10 in the power receiving device 2 functions as a power receiving coil. The conversion unit 2A shapes a high-frequency current generated in the coil component 10. The conversion unit 2A has a rectifier circuit that converts the high-frequency current into a direct current, and the like. The conversion unit 2A may be configured to include, for example, a full-wave rectifier circuit including a plurality of diodes and a smoothing capacitor.

[0093] In this embodiment, each of the power transmitting device 1 and the power receiving device 2 includes a coil component 10. However, the coil component 10 may be used in only one of the power transmitting device 1 and the power receiving device 2, and a different type of coil component may be used in the other. Also, it goes without saying that a coil component according to another embodiment described below different from the coil component 10 may be applied to the power transmitting device 1 and / or the power receiving device 2.

[0094] When transmitting power wirelessly (contactlessly) from the power transmitting device 1 to the power receiving device 2, the power transmitting device 1 supplies a high-frequency current of a predetermined frequency from the high-frequency current supply unit 1A to the coil component 10 serving as a power transmitting coil. At this time, a magnetic field is generated in the coil component 10 by electromagnetic induction. Then, due to the influence of this magnetic field, a high-frequency current is generated in the coil component 10 serving as a power receiving coil in the power receiving device 2. That is, the power receiving device 2 receives the magnetic field or is influenced by the magnetic field, and causes the high-frequency current to flow by electromagnetic induction. The conversion unit 2A converts this high-frequency current into a direct current, and supplies the converted direct current to, for example, a battery not shown.

[0095] As an example, the coil component 10 according to the embodiment described below is manufactured so that its performance is improved when it is supplied with an AC current of 75 KHz to 100 KHz or an AC magnetic field of 75 KHz to 100 KHz. In detail, the coil component 10 is manufactured so that its performance is improved when it is supplied with an AC current of 79 KHz to 90 KHz, particularly an AC current of 85 KHz, or an AC magnetic field of 79 KHz to 90 KHz, particularly an AC magnetic field of 85 KHz. Therefore, the high-frequency current supply unit 1A may supply, for example, an AC current of 75 KHz to 100 KHz, an AC current of 79 KHz to 90 KHz, or an AC current of 85 KHz, so as to correspond to an AC current desired for the coil component 10. The converter 2A may also be configured to convert an AC current of 75KHz to 100KHz, or an AC current of 79KHz to 90KHz, or an AC current of 85KHz, generated by electromagnetic induction when an AC magnetic field is supplied, into a DC current. When the coil components incorporated in the power transmitting device 1 and the power receiving device 2 are configured to function appropriately in a frequency band other than the frequency bands exemplified above, the high-frequency current supplying device 1A and the converter 2A are configured to be suitable for the frequency band other than the frequency bands exemplified above. For example, the high-frequency current supplying device 1A may be configured to supply an AC current of 100KHz to 200KHz.

[0096] The power transmission system S shown in Fig. 1 employs a magnetic resonance method as a power transmission method. However, the coil component 10 according to the present embodiment may be used in a power transmission system that employs an electromagnetic induction method. The power transmission system S is configured as a system that wirelessly transmits power to an electric vehicle. In this case, the power transmitting device 1 is installed on a road, a parking lot, or the like. The power receiving device 2 is installed in the electric vehicle.

[0097] However, the use of the power transmission system S is not limited to power transmission to an electric vehicle. For example, the power transmission system S may be used to transmit power to an aircraft such as a drone or a robot. The power transmission system S may also be used to transmit power to a submarine or an exploration robot in the sea. The use of the coil component 10 is not limited to a wireless power transmission system. For example, the coil component 10 may be used in a transformer, a DC-DC converter, an antenna, or the like.

[0098] <Coil parts> The coil device 10 will be described below. Fig. 2 is a perspective view of the coil device 10. Fig. 3 is an exploded perspective view of the coil device 10. Fig. 4 is a perspective view of a cross section of the coil device 10 taken along line IV-IV in Fig. 2. Fig. 5 is a cross section of the coil device 10 taken along line IV-IV in Fig. 2.

[0099] 2 to 5, coil device 10 includes first planar coil 11, second planar coil 12, magnetic shield member 20, holding body 30, first connection terminal 51, and second connection terminal 52. In Fig. 3, holding body 30 is shown divided into first layer 31, second layer 32, third layer 33, and wall portion 34 for ease of explanation. However, in reality, first layer 31, second layer 32, third layer 33, and wall portion 34 are formed integrally without any seams, as shown in Fig. 5.

[0100] First planar coil 11 and second planar coil 12 are connected in series and overlap with a gap. Holding body 30 includes a portion (a part of first layer 31 shown in FIGS. 3 and 5) covering a surface of first planar coil 11 opposite to a surface facing second planar coil 12. Magnetic shield member 20 is disposed to face a surface of holding body 30 (more precisely, the covering portion of holding body 30) opposite to a surface facing first planar coil 11. Magnetic shield member 20 also includes a portion covering a surface of first planar coil 11 opposite to a surface facing second planar coil 12. More specifically, magnetic shield member 20 includes a portion covering a surface of first planar coil 11 opposite to a surface facing second planar coil 12 via first layer 31 of holding body 30. Details of first layer 31, second layer 32, third layer 33, and wall portion 34 constituting holding body 30 will be described later.

[0101] (First planar coil and second planar coil) First planar coil 11 has a spiral shape and is made of a conductive material. In the present embodiment, first planar coil 11 is made of copper, but first planar coil 11 may be made of any conductive material, such as aluminum. First planar coil 11 has a plate shape. As shown in Figs. 4 and 5, the cross-sectional shape of first planar coil 11 in a direction perpendicular to the direction in which first planar coil 11 winds around in a spiral shape is rectangular.

[0102] 2 and 3 indicates a first central axis of first planar coil 11 that passes through the center of the spiral shape of first planar coil 11. Hereinafter, the axial direction of first planar coil 11 refers to a direction extending on first central axis C1 or a direction parallel to first central axis C1. In addition, a direction perpendicular to first central axis C1 is referred to as a radial direction of first planar coil 11.

[0103] The first planar coil 11 has a conductor 11E having a spiral shape formed by a plurality of turn portions 11n. The plurality of turn portions 11n of the first planar coil 11 are arranged in a direction perpendicular to a first central axis C1 of the spiral shape. More specifically, the plurality of turn portions 11n are connected so as to gradually move away from the first central axis C1 of the spiral shape in a radially outward direction. This forms the spiral shape.

[0104] The turn portion 11n is basically a shape in which a linear conductor portion does not form a ring but goes around the first central axis C1 360 degrees. In the case of a so-called planar coil, both ends of the turn portion 11n are shifted in the radial direction. In the case of a plurality of turn portions 11n, a radially outer end of one turn portion 11n is connected to a radially inner end of another turn portion 11n, and the other turn portions 11n extend away from the first central axis C1.

[0105] Hereinafter, the turn portion 11n that is closest to the first central axis C1 may be referred to as the turn portion 111. Also, the turn portion connected to the turn portion 111 may be referred to as the turn portion 112. In this embodiment, the turn portions 11n are made up of seven turn portions 111 to 117. Hereinafter, when describing matters common to each of the turn portions 11n, they will basically be referred to as the turn portion 11n.

[0106] In this embodiment, turn portion 11n winds around to form a rectangular shape. However, turn portion 11n may also have a shape winding around to form a circle. Note that the spiral shape referred to in this specification and disclosure means a planar curved shape wound in a spiral shape. The planar curved shape referred to here also includes a planar pattern that winds around repeatedly while bending like a broken line as shown in the figure. In other words, the spiral shape is a shape that winds around first central axis C1 of first planar coil 11 so as to be gradually positioned outward.

[0107] A radially inner end (end close to the first central axis C1) of the turn portion 111 closest to the first central axis C1 is electrically connected to the second planar coil 12. The connection wiring portion 14 shown in FIGS. 2 and 3 is a conductor and electrically connects the turn portion 111 and the second planar coil 12 in series. The connection wiring portion 14 shown in the drawings is formed integrally with the second planar coil 12, as an example. The connection wiring portion 14 may be connected to the turn portion 111 by ultrasonic connection or the like. On the other hand, a radially outer end (end away from the first central axis C1) of the turn portion 117, which is the farthest from the first central axis C1 among the multiple turn portions 11n, is connected to the first connection terminal 51.

[0108] Here, the radially inward direction of first planar coil 11 (turn portion 11n) means a direction approaching first central axis C1 in the radial direction. Moreover, the radially outward direction of first planar coil 11 (turn portion 11n) means a direction moving away from first central axis C1 in the radial direction. Moreover, in this embodiment, first central axis C1 is determined as follows. First, linear virtual turn portions having a shape similar to that of innermost turn portion 111 are drawn inward in the radial direction in sequence from the radially inner end of innermost turn portion 111 so as to form a spiral shape. Then, drawing is continued until a virtual turn portion that fits within a diameter of 1 cm can be drawn. Then, a line that passes through a radially inner region of the virtual turn portion that fits within a diameter of 1 cm in a direction perpendicular to the circumferential and radial directions of the spiral shape is determined as first central axis C1.

[0109] In the present embodiment, first planar coil 11 is formed by punching a copper plate into a spiral shape, for example, although first planar coil 11 can also be formed by etching copper foil into a spiral shape.

[0110] The thickness of first planar coil 11 (thickness of conductor 11E) may be, for example, 0.1 mm or more and 1.0 mm or less. The radius of first planar coil 11 (the distance from first central axis C1 to the part farthest in the radial direction) may be 80 mm or more, or 80 mm or more and 450 mm or less. The aspect ratio of first planar coil 11 (conductor 11E) having a rectangular cross-sectional shape is determined by dividing the radial width (width in the radial direction) of first planar coil 11 (conductor 11E) by the thickness of first planar coil 11 (conductor 11E). The aspect ratio of first planar coil 11 (conductor 11E) may be 2 or more and 12 or less, or 3 or more and 10 or less.

[0111] When transmitting power to an electric vehicle using the magnetic resonance method, it is desirable to be able to transmit power of 1 Kw or more, preferably 5 Kw or more, in a high-frequency current frequency band of 10 KHz to 200 KHz, particularly 75 KHz to 100 KHz, and further 79 KHz to 90 KHz. In this case, the thickness of first planar coil 11 made of copper is preferably 0.2 mm or more. Also, if the thickness of first planar coil 11 is too large, the weight increases, which is undesirable for example for mounting on a vehicle. Therefore, the thickness of first planar coil 11 may be, for example, 2.0 mm or less, 1.5 mm or less, or 1.0 mm or less. Also, when transmitting power to an electric vehicle, excessively large size is not desirable, and the size may be limited. From this perspective, it is preferable that first planar coil 11 and second planar coil 12 described below, more specifically, conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12, be formed to a size that fits within a square with sides of 800 mm.

[0112] Moreover, the line width of first planar coil 11 (line width of conductor 11E), i.e., the radial width of each turn portion 11n (width in the radial direction) is not particularly limited. However, considering that it is possible to transmit power of 1 Kw or more, preferably 5 Kw or more, in a high-frequency current frequency band of, for example, 79 KHz to 90 KHz, the radial width of turn portion 11n may be 2 mm or more and 20 mm or less, 2 mm or more and 16 mm or less, 2 mm or more and 12 mm or less, or 2 mm or more and 8 mm or less. Moreover, the number of turns of first planar coil 11 may be 4 to 12, but is not particularly limited.

[0113] Next, second planar coil 12 also has a spiral shape, and in the present embodiment, second planar coil 12 is made of copper. The material of second planar coil 12 is not particularly limited, but is the same material as that of first planar coil 11. However, the material of first planar coil 11 and the material of second planar coil 12 may be different. Second planar coil 12 also has a plate shape, and as shown in Figures 4 and 5, the cross-sectional shape of second planar coil 12 in a direction perpendicular to the direction in which second planar coil 12 winds around in a spiral shape is rectangular.

[0114] 2 and 3 indicates a second central axis of second planar coil 12 that passes through the center of the spiral shape of second planar coil 12. Hereinafter, the axial direction of second planar coil 12 refers to a direction extending on second central axis C2 or a direction parallel to second central axis C2. In addition, a direction perpendicular to second central axis C2 is referred to as a radial direction of second planar coil 12.

[0115] In the present embodiment, second planar coil 12 is arranged to be coaxial with first planar coil 11. That is, first central axis C1 of first planar coil 11 and second central axis C2 of second planar coil 12 coincide with each other, in other words, they are located on the same straight line. However, first planar coil 11 and second planar coil 12 may overlap with each other such that first central axis C1 of first planar coil 11 and second central axis C2 of second planar coil 12 are parallel to each other. That is, first planar coil 11 and second planar coil 12 do not have to be coaxial.

[0116] Second planar coil 12 also has conductor 12E having a spiral shape with multiple turn portions 12n. Multiple turn portions 12n of second planar coil 12 are arranged in a direction perpendicular to second central axis C2 of the spiral shape.

[0117] The connection manner of the plurality of turn portions 12n and the names (such as turn portion 121) according to the positions are the same as those of turn portion 11n of first planar coil 11. In the present embodiment, the number of turns of first planar coil 11 and the number of turns of second planar coil 12 are the same, and the plurality of turn portions 12n are composed of seven turn portions 121 to 127. Similarly to turn portion 11n, turn portion 12n goes around to form a rectangular shape. Turn portion 11n may also have a shape that goes around to form a circle. The number of turns of first planar coil 11 and the number of turns of second planar coil 12 may differ. For example, turn portion 12n may be rectangular and turn portion 12n may be circular.

[0118] 4, in the present embodiment, any one of a plurality of turn portions 11n of first planar coil 11 and any one of a plurality of turn portions 12n of second planar coil 12 partially overlap in the axial direction of first planar coil 11. A part of turn portion 11n of first planar coil 11 and a part of turn portion 12n of second planar coil 12 that overlap in the axial direction of first planar coil 11 extend parallel to each other with their respective winding directions aligned. The state in which the winding directions are aligned means that the winding directions of first planar coil 11 and second planar coil 12 do not intersect at a point but overlap a certain distance on the same line.

[0119] The length of a portion of turn portions 11n of first planar coil 11 and the length of a portion of turn portions 12n of second planar coil 12, which overlap and extend parallel to each other as described above, may be ½ or more, or ¾ or more, of their respective total lengths. The present inventors have found that the greater the proportion of overlap between first planar coil 11 and second planar coil 12 extending parallel to each other, the more eddy current loss can be suppressed.

[0120] As described above, the radially inner end of turn portion 111 closest to first central axis C1 is electrically connected to second planar coil 12. More specifically, the radially inner end of turn portion 111 is connected to an inner end of turn portion 121 in second planar coil 12 via connection wiring portion 14. Here, when first planar coil 11 and second planar coil 12 are connected, the direction in which first planar coil 11 winds from an end not connected to second planar coil 12 (a radially outer end of turn portion 117) to an end connected to second planar coil 12 becomes the same as the direction in which second planar coil 12 winds from an end connected to first planar coil 11 to an end not connected to first planar coil 11 (a radially outer end of turn portion 127).

[0121] The radially outer end of turn portion 127, which is the furthest from second central axis C2, among the plurality of turn portions 12n, is connected to second connection terminal 52. The radially inner and outer directions of second planar coil 12 (turn portions 12n) are defined in the same manner as the radially inner and outer directions of first planar coil 11 described above. The position of second central axis C2 is also determined in the same manner as the first central axis C1. Second planar coil 12 in the present embodiment is also formed by punching out a copper plate into a spiral shape, as an example. However, second planar coil 12 can also be formed by etching copper foil into a spiral shape.

[0122] In the present embodiment, the thickness of second planar coil 12 (the thickness of conductor 12E) is smaller than the thickness of first planar coil 11. The thickness of second planar coil 12 is not less than 0.15 mm and not more than 0.35 mm.

[0123] The present inventors have found that when first planar coil 11 and second planar coil 12 are stacked on magnetic shield member 20 and holder 30, the performance of coil component 10 is significantly improved when used in a predetermined frequency band by setting the thickness of second planar coil 12 to 0.15 mm or more and 0.35 mm or less. For this reason, the thickness of second planar coil 12 is set to 0.15 mm or more and 0.35 mm or less. The predetermined frequency band is the frequency band of the AC current to be passed, specifically, 75 KHz or more and 100 KHz or less, and the performance of coil component 10 is significantly improved when the frequency is 79 KHz or more and 90 KHz or less. Note that the preferred thickness of second planar coil 12 changes when used in a frequency band other than 75 KHz or more and 100 KHz or less.

[0124] The radius of second planar coil 12 (the distance from second central axis C2 to the farthest part in the radial direction) may be 80 mm or more, or 80 mm or more and 450 mm or less, as in the case of first planar coil 11. The aspect ratio of second planar coil 12 (conductor 12E) having a rectangular cross-sectional shape may be 2 to 12 or less, or 3 to 10 or less, as in the case of first planar coil 11. The line width of second planar coil 12 (line width of conductor 12E), i.e., the radial width (width in the radial direction) of each turn portion 12n, may be 2 mm or more and 20 mm or less, 2 mm or more and 16 mm or less, 2 mm or more and 12 mm or less, or 2 mm or more and 8 mm or less. The number of turns of second planar coil 12 may be 4 to 12 or less, but is not particularly limited to this.

[0125] Moreover, first planar coil 11 and second planar coil 12 overlap with a gap therebetween. This gap may be 0.5 mm or more and 1.5 mm or less. The size of the gap is not particularly limited, but if the gap is too small, eddy current loss occurring in first planar coil 11 and second planar coil 12 when current is supplied tends to be large. Furthermore, if the gap is too large, the thinning of coil component 10 is hindered.

[0126] The present inventors have confirmed through experiments and simulations that the phenomenon in which the performance of coil device 10 is significantly improved when used in a predetermined frequency band by setting the thickness of second planar coil 12 to 0.15 mm or more and 0.35 mm or less occurs under conditions that assume at least the radial widths (2 mm to 20 mm) of turn portions 11n, 12n and the number of turns (4 to 12) of first planar coil 11 and second planar coil 12 exemplified above. However, the present disclosure is not limited to the conditions exemplified in the embodiment. That is, for example, the phenomenon in which the performance of coil device 10 is significantly improved when used in a predetermined frequency band by setting the thickness of second planar coil 12 to 0.15 mm or more and 0.35 mm or less can occur regardless of the dimensions, number of turns, etc.

[0127] (Magnetic shielding material) Magnetic shield member 20 is provided to suppress magnetic transmission and / or leakage magnetic field. Magnetic shield member 20 is a sheet-like member separate from first planar coil 11, second planar coil 12, and holding body 30. Magnetic shield member 20 being separate from first planar coil 11, second planar coil 12, and holding body 30 means that magnetic shield member 20 is not integrated with first planar coil 11, second planar coil 12, and holding body 30. However, magnetic shield member 20 and holding body 30 may be joined via an adhesive layer or the like. Magnetic shield member 20 is formed to a size that includes first planar coil 11 and second planar coil 12 in a planar view. Magnetic shield member 20 overlaps first planar coil 11, second planar coil 12, and holding body 30, and is in direct contact with holding body 30.

[0128] The magnetic shield member 20 in the present embodiment has magnetism and includes or is made of a magnetic material. In the coil component 10, a magnetic field is generated when a current is supplied to the first planar coil 11 and the second planar coil 12. The magnetic field generated in the coil component 10 spreads in all directions with respect to the central axes C1 and C2 of the first planar coil 11 and the second planar coil 12. In this case, the magnetic shield member 20 has magnetism, so that the spreading magnetic flux lines can be oriented toward the central axes C1 and C2. In addition, the coil component 10 may be installed in a vehicle. In this case, if the magnetic field generated by the coil component 10 flows toward other vehicle components, the vehicle components may be adversely affected. In such a case, the magnetic shield member 20 can suppress the leakage magnetic field that does not contribute to the generation of the current.

[0129] The magnetic shield member 20 preferably includes a soft magnetic material or a nanocrystalline magnetic material. More specifically, the magnetic shield member 20 includes ferrite, preferably soft ferrite. In the present embodiment, the magnetic shield member 20 includes plate-shaped ferrite. More specifically, the magnetic shield member 20 is configured by arranging a plurality of plate-shaped ferrites in a sheet shape.

[0130] The relative permeability of the magnetic shield member 20 may be equal to or greater than 500, or equal to or greater than 1000. The relative permeability of the magnetic shield member 20 may be equal to or greater than 500 and equal to or less than 3000, or equal to or greater than 1000 and equal to or less than 3000. Note that the relative permeability in this specification is a value measured at a frequency of 85 KHz and an environmental temperature of 23 degrees.

[0131] (Holding body / magnetic member) 4 and 5, holder 30 integrally holds first planar coil 11 and second planar coil 12. Holder 30 covers surface 111A of first planar coil 11 that faces second planar coil 12 and surface 111B opposite surface 111A, and fills the gap between first planar coil 11 and second planar coil 12. Holder 30 fills the gap between first planar coil 11 and second planar coil 12, thereby covering surface 121B of second planar coil 12 that faces first planar coil 11.

[0132] On the other hand, holder 30 does not cover surface 121A of second planar coil 12 opposite surface 121B that faces first planar coil 11. Holder 30 also includes wall portion 34 that protrudes from second planar coil 12 in the axial direction of second planar coil 12. Wall portion 34 has a helical (spiral) shape when viewed in the axial direction of second planar coil 12, and extends along second planar coil 12.

[0133] 3, as described above, for convenience of explanation, the holder 30 is shown divided into a first layer 31, a second layer 32, a third layer 33, and a wall portion 34. In this embodiment, the holder 30 actually includes the first layer 31, the second layer 32, the third layer 33, and the wall portion 34, which are formed integrally without any seams.

[0134] First layer 31, second layer 32, and third layer 33 are formed to a size that encompasses first planar coil 11 and second planar coil 12 as a whole when viewed in the axial direction of first planar coil 11 and second planar coil 12. First layer 31 is a portion that covers surface 111B of first planar coil 11 opposite surface 111A that faces second planar coil 12, and the side surface of first planar coil 11. First layer 31 is a portion that contacts magnetic shield member 20. Second layer 32 is a portion that is interposed between first planar coil 11 and second planar coil 12. That is, second layer 32 is a portion that fills the gap between first planar coil 11 and second planar coil 12. Third layer 33 is a portion that covers the side surface of second planar coil 12. In other words, third layer 33 is a portion that covers the entire side surface of second planar coil 12 from the inside and outside in the radial direction. The surface of third layer 33 opposite to the surface connected to second layer 32 is flush with surface 121A of second planar coil 12. Wall portion 34 protrudes from the surface of third layer 33 that is flush with surface 121A of second planar coil 12.

[0135] The holder 30 as a whole has magnetic properties, that is, the first layer 31, the second layer 32, the third layer 33, and the wall portion 34 each have magnetic properties. The holder 30 suppresses eddy current loss and leakage flux by magnetism, and increases the coupling coefficient, thereby improving coil performance. The relative permeability of the holder 30 is preferably 2.0 or more, and may be 2.0 or more and 10.0 or less. The relative permeability of the holder 30 is more preferably 5.0 or more, and may be 5.0 or more and 10.0 or less. The relative permeability of the holder 30 is not particularly limited, but if it is too large, the flexibility and strength of the holder 30 may be undesirably impaired. Therefore, the relative permeability of the holder 30 may be 200 or less.

[0136] Furthermore, the holder 30 is provided with a wall portion 34, which can effectively improve coil performance. The height of the wall portion 34 is not particularly limited, and may be, for example, 0.5 mm or more, or 1.0 mm or more. The higher the wall portion 34, the greater the effect of suppressing eddy current loss and the higher the coupling coefficient tend to be. On the other hand, the higher the wall portion 34, the more likely it is to be damaged, starting from its base. Therefore, the height of the wall portion 34 may be, for example, 10 mm or less. The wall portion 34 does not necessarily have to be provided.

[0137] The holder 30 in the present embodiment includes, as an example, a resin and a plurality or an infinite number of magnetic particles made of a magnetic material. The magnetic particles are held by the resin as a holding material. The resin included in the holder 30 has insulating properties. The insulating properties are defined as a property in which the volume resistivity is 10 10 This means that the resistance is Ω·m or more.

[0138] The magnetic particles may be made of any one or more of ferrite, particularly soft magnetic ferrite, nanocrystalline magnetic material, silicon steel, soft magnetic iron, and amorphous metal. The resin as the holding material may be glass fiber reinforced polyamide. That is, the resin may be made of a material containing polyamide as a thermoplastic resin (thermoplastic material) and glass fiber. However, the material of the holding body 30 is not particularly limited.

[0139] (Connection terminal) 2 and 3, the first connection terminal 51 is connected to a radially outer end of the turn portion 117 of the first planar coil 11. The second connection terminal 52 is connected to a radially outer end of the turn portion 127 of the second planar coil 12. The first connection terminal 51 and the second connection terminal 52 can be used, for example, when connecting to the high-frequency current supply unit 1A or the conversion unit 2A. The connection between the first connection terminal 51 and the turn portion 117 and the connection between the second connection terminal 52 and the turn portion 127 may be performed by ultrasonic bonding. However, the connection method is not limited, and for example, a connection using a conductive adhesive may be adopted.

[0140] <Simulation for evaluating the performance of coil component 10> Hereinafter, a simulation for calculating the Q value performed by setting a plurality of values ​​for the thickness of first planar coil 11 and the thickness of second planar coil 12 in coil device 10 according to the present embodiment will be described. The simulation was performed using Femtet (registered trademark) manufactured by Murata Software Co., Ltd.

[0141] The simulation conditions are as follows: (1) and (2). (1) In coil device 10 according to the above embodiment, a plurality of values ​​were set for the thickness of first planar coil 11 and the thickness of second planar coil 12, and the Q value corresponding to each was calculated. (2) In coil device 10 of the above-described embodiment, wall portion 34 in holding body 30 was not formed, and multiple values ​​were set for the thickness of first planar coil 11 and the thickness of second planar coil 12, and the corresponding Q values ​​were calculated.

[0142] The conditions common to patterns (1) and (2) are as follows: The high frequency current supplied is 40A and the frequency is 85KHz. The electrical conductivity of the first planar coil 11 and the second planar coil 12 made of copper is 6.45×10 7 [S / m]. The magnetic shield member 20 has a relative magnetic permeability of 3000, and the holder 30 has a relative magnetic permeability of 5.0. The width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction of line IV-IV shown in FIG. 2 is 200 mm, and the width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction perpendicular to line IV-IV is 200 mm.

[0143] The results of the above simulation (1) are shown in Table 1 below. The left vertical column of Table 1 shows multiple values ​​of the thickness of first planar coil 11. The upper horizontal column of Table 1 shows multiple values ​​of the thickness of second planar coil 12. The table also shows Q values ​​corresponding to combinations of the thicknesses of first planar coil 11 and second planar coil 12. Note that the portion marked with "*1" in the left vertical column indicates that the dimension of the gap between first planar coil 11 and second planar coil 12 is 1.0 mm. The portion without the "*1" mark indicates that the dimension of the gap between first planar coil 11 and second planar coil 12 is 0.5 mm.

[0144] [Table 1]

[0145] As described above, the present inventors have found that when first planar coil 11 and second planar coil 12 are overlapped on magnetic shield member 20 and holder 30, the performance of coil component 10 is significantly improved when used in a predetermined frequency band by setting the thickness of second planar coil 12 to 0.15 mm or more and 0.35 mm or less. More specifically, the inventors have found that when used in a predetermined frequency band, the Q value of coil component 10 is maximized when the thickness of second planar coil overlapping first planar coil 11 is set to any value between 0.15 mm and 0.35 mm or less. The predetermined frequency band is specifically a frequency band of 75 KHz to 100 KHz, and the performance of coil component 10 is reliably improved when the frequency is 79 KHz to 90 KHz.

[0146] In the simulation results shown in Table 1, for example, when the thickness of first planar coil 11 is fixed at 0.5 mm and the gap between first planar coil 11 and second planar coil 12 is fixed at 0.5 mm, as the thickness of second planar coil 12 decreases from 0.5 mm, the Q value tends to increase, and the Q value tends to decrease when the thickness is 0.15 mm or less. It can be seen that the maximum value of the Q value occurs under the condition where the thickness of second planar coil 12 is 0.2 to 0.275 mm. FIG. 6 is a graph showing the simulation results under the conditions. In FIG. 6, the Q value corresponding to the thickness is plotted. Referring to FIG. 6, it can be seen that there is a setting where the maximum value of the Q value occurs between 0.2 and 0.275 mm. Moreover, when the results of Table 1 are examined, a high Q value (about 170 to 210) is obtained regardless of the thickness of first planar coil 11 when the thickness of second planar coil 12 is between 0.2 and 0.3 mm. Here, when the thickness of second planar coil 12 is increased by about 20% from 0.3 mm or decreased by about 20% from 0.2 mm, it is estimated that desirable performance can be obtained in consideration of the results of the simulation. Specifically, when the thickness of second planar coil 12 is 0.15 mm, the Q value is 160.4, which is a high value. It is also observed that the Q value decreases when the thickness of second planar coil 12 becomes excessively small. Considering such a decreasing tendency and the viewpoints of manufacturing and handling, it is estimated that the thickness of second planar coil 12 is preferably 0.15 mm or more.

[0147] The above simulation results support the fact that the performance of coil component 10 when used in a predetermined frequency band is significantly improved by setting the thickness of second planar coil 12 to 0.15 mm or more and 0.35 mm or less. Note that the thickness of second planar coil 12 may be 0.20 mm or more and 0.275 mm or less, or 0.225 mm or more and 0.275 mm or less. In these cases, the coil performance can be improved more reliably.

[0148] Furthermore, the Q value is 204.8 when "first planar coil 11 has a thickness of 0.5 mm, second planar coil 12 has a thickness of 0.25 mm, and the gap between first planar coil 11 and second planar coil 12 is 1.0 mm." In contrast, the Q value is 196.1 when "first planar coil 11 has a thickness of 0.5 mm, second planar coil 12 has a thickness of 0.25 mm, and the gap between first planar coil 11 and second planar coil 12 is 0.5 mm." From this result, it is presumed that there is a tendency for performance to improve as the gap becomes larger. The phenomenon in which performance decreases as the gap becomes smaller is presumed to be caused by an increase in eddy current loss due to the influence of the proximity effect. However, if the gap becomes too large, it hinders thinning. Therefore, the desirable value of the gap may be, for example, 0.5 mm or more and 1.5 mm.

[0149] Furthermore, in the simulation shown in Table 1, when the thickness of second planar coil 12 is fixed at 0.25 mm and the thickness of first planar coil 11 is changed, the Q value tends to be larger as the thickness of first planar coil 11 is thicker. This is thought to be because the resistance decreases as the copper thickness (thickness of first planar coil 11) increases, but the resistance saturates at a thickness of about 1 mm, and no significant improvement was observed even when the thickness was increased beyond that. On the other hand, even when the thickness of first planar coil 11 was thinned to about 0.25 mm, a sufficiently large Q value was obtained compared to the case in which the first planar coil was thickened to about 0.5 mm. From this, it is inferred that a high Q value can be obtained even with a thickness of about 0.1 mm for first planar coil 11. Therefore, the thickness of first planar coil 11 may be appropriately set in consideration of the weight and economy of the coil components, but it is preferable that the thickness is 0.1 mm or more.

[0150] Next, the results of the above simulation (2) are shown in Table 2 below. Table 2 shows the relationship between thickness and Q value, similar to Table 1.

[0151] [Table 2]

[0152] In the simulation results shown in Table 2, for example, when the thickness of first planar coil 11 is fixed at 0.5 mm and the gap between first planar coil 11 and second planar coil 12 is fixed at 0.5 mm, the Q value increases as the thickness of second planar coil 12 decreases. It can be seen that the maximum value of the Q value occurs when the thickness of second planar coil 12 is between 0.2 and 0.3 mm. In addition, when the thickness of second planar coil 12 is between 0.2 and 0.3 mm, a high Q value (115 or more) is obtained regardless of the thickness of first planar coil 11. Here, it is estimated that desirable performance can be obtained when the thickness of second planar coil 12 is increased by about 20% from 0.3 mm or decreased by about 20% from 0.2 mm, taking the simulation results into consideration.

[0153] The above simulation results also support the idea that by setting the thickness of second planar coil 12 to be not less than 0.15 mm and not more than 0.35 mm, the performance of coil device 10 when used in a predetermined frequency band is significantly improved.

[0154] Moreover, the following Table 3 shows the simulation results when the frequency of the supplied current is changed from 85 KHz to 79 KHz and 90 KHz under the above simulation condition (1).

[0155] [Table 3]

[0156] The simulation results in Table 3 confirm that the performance of coil device 10 is significantly improved by setting the thickness of second planar coil 12 to be 0.15 mm or more and 0.35 mm or less, even when the frequency of the supplied current is 79 KHz and 90 KHz.

[0157] Another simulation is described below. In this simulation, a plurality of values ​​are set for the thickness of first planar coil 11 and the thickness of second planar coil 12 in coil device 10 according to the above-described embodiment, and the corresponding Q value is calculated.

[0158] In this simulation, the width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction of line IV-IV shown in FIG. 2 is 326 mm, and the width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction perpendicular to line IV-IV is 326 mm. The other conditions are the same as those in the above simulation. The thickness of first planar coil 11 was fixed at 0.5 mm, and the Q value was simulated when the thickness of second planar coil 12 was 0.5 mm, 0.35 mm, 0.25 mm, and 0.2 mm. The simulation results are shown in Table 4 below.

[0159] [Table 4]

[0160] It can also be confirmed and inferred from the simulation results shown in Table 4 that the performance of coil device 10 can be significantly improved by setting the thickness of second planar coil 12 to 0.15 mm or more and 0.35 mm or less.

[0161] Next, another simulation will be described. In this simulation, similar to the simulations whose results are shown in Tables 1 and 2, the following two patterns (1) and (2) were used. (1) In coil device 10 according to the above embodiment, a plurality of values ​​were set for the thickness of first planar coil 11 and the thickness of second planar coil 12, and the Q value corresponding to each was calculated. (2) In coil device 10 of the above-described embodiment, wall portion 34 in holding body 30 was not formed, and multiple values ​​were set for the thickness of first planar coil 11 and the thickness of second planar coil 12, and the corresponding Q values ​​were calculated. In this simulation, however, the width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction of line IV-IV shown in Fig. 2 is 470 mm, and the width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction perpendicular to line IV-IV is 570 mm. Other specific conditions are the same as those in the above simulation.

[0162] For pattern (1), the thickness of first planar coil 11 was fixed at 0.5 mm, and the Q value was simulated when the thicknesses of second planar coil 12 were 0.5 mm, 0.35 mm, 0.25 mm, and 0.15 mm. The simulation results for pattern (1) are shown in Table 5 below. For pattern (2), the thickness of first planar coil 11 was fixed at 0.5 mm, and the Q value was simulated when the thicknesses of second planar coil 12 were 0.5 mm, 0.30 mm, 0.25 mm, and 0.15 mm. The simulation results for pattern (2) are shown in Table 6 below. The simulation results for pattern (1) are shown in FIG. 7, and the simulation results for pattern (2) are shown in FIG. 8.

[0163] [Table 5]

[0164] [Table 6]

[0165] From the above simulation results, it can be confirmed and inferred that the performance of coil device 10 can be significantly improved by setting the thickness of second planar coil 12 to 0.15 mm or more and 0.35 mm or less. It is also inferred that the Q factor has a maximum value when the thickness of second planar coil 12 is 0.2 mm or more and 0.3 mm or less, as shown in Figs. 7 and 8.

[0166] <Applications of coil components> The coil component 10 according to this embodiment can be used as a power transmitting coil in the power transmitting device 1 of the wireless power transmission system S described above, and can be used as a power receiving coil in the power receiving device 2.

[0167] When coil component 10 is used as a power transmission coil, first connection terminal 51 and second connection terminal 52 are connected to high-frequency current supply unit 1A or an AC power source as shown in Fig. 1. When high-frequency current is supplied to coil component 10, the current can be passed from first connection terminal 51 to first planar coil 11 and second planar coil 12, and then passed from second connection terminal 52 to high-frequency current supply unit 1A or an AC power source. Also, the current can be passed from second connection terminal 52 to second planar coil 12 and first planar coil 11, and then passed from first connection terminal 51 to high-frequency current supply unit 1A or an AC power source. This makes it possible to generate a magnetic field including magnetic field lines along the central axis of planar coil 11.

[0168] On the other hand, when coil device 10 is used as a receiving coil, a high-frequency current can be generated in first planar coil 11 and second planar coil 12 by receiving a magnetic field including magnetic field lines passing through the inside of first planar coil 11 and second planar coil 12. Then, this high-frequency current can be supplied to an external device from first connection terminal 51 or second connection terminal 52.

[0169] The coil component 10 can also be used in a transformer, an antenna, etc. For example, when the coil component 10 functions as a primary coil in a transformer, the first connection terminal 51 and the second connection terminal 52 are connected to an AC power source. When a high-frequency current is supplied, a magnetic flux can be supplied from the center of the planar coil to the iron core.

[0170] Coil device 10 according to the present embodiment described above includes first planar coil 11, second planar coil 12 superimposed on first planar coil 11, magnetic holder 30 including a portion covering a surface of first planar coil 11 opposite to a surface facing second planar coil 12, and magnetic shield member 20 arranged to face a surface of holder 30 opposite to a surface facing first planar coil 11 in the covering portion. First planar coil 11 and second planar coil 12 are connected in series, and second planar coil 12 has a thickness of 0.15 mm or more and 0.35 mm or less.

[0171] According to the coil component 10 of the present embodiment, it is possible to improve the performance while suppressing the increase in size and weight. Generally speaking, it is assumed that the thicker the coil, the higher the inductance obtained in the coil, and the better the coil performance such as the Q value. However, the present inventor has found through intensive research that such a tendency does not necessarily occur in a configuration in which a planar coil is stacked in series on a magnetic member. The present inventor has found that, when an AC current or an AC magnetic field in a predetermined frequency band is supplied in a configuration in which first planar coil 11 and second planar coil 12 are stacked in this order on magnetic shield member 20 and holding body 30, a maximum value of the Q value occurs when the thickness of second planar coil 12 is between 0.15 mm and 0.35 mm, regardless of the thickness of first planar coil 11. Based on this finding, it has been found that the performance of coil component 10 can be improved by using second planar coil 12 having a thickness of 0.25 mm rather than using second planar coil 12 having a thickness of 0.5 mm.

[0172] That is, in coil component 10 based on such knowledge, by setting the thickness of second planar coil 12 to 0.15 mm or more and 0.35 mm or less, second planar coil 12 can be made thin. Then, the performance of coil component 10 can be improved as much as possible when used in a predetermined frequency band. This makes it possible to improve the performance of coil component 10 while suppressing the increase in the overall size and weight of coil component 10. When an AC current or AC magnetic field in a predetermined frequency band is supplied to a configuration in which first planar coil 11 and second planar coil 12 are stacked in this order on magnetic shield member 20 and holding body 30, the phenomenon that the Q value has a maximum value when second planar coil 12 has a thickness of 0.15 mm or more and 0.35 mm or less, regardless of the thickness of first planar coil 11, is a phenomenon that is difficult to predict from technical common sense. We are convinced that the above coil component invented based on such a phenomenon will have a remarkable effect that greatly contributes to improving the performance of coil components.

[0173] Specifically, the inventors of the present invention have found that when an AC current of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, or an AC magnetic field of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, is supplied to first planar coil 11 and second planar coil 12, a maximum value of the Q factor occurs when the thickness of second planar coil 12 is between 0.15 mm to 0.35 mm, regardless of the thickness of first planar coil 11. That is, a configuration in which the thickness of second planar coil 12 is set to 0.15 mm to 0.35 mm significantly improves performance when an AC current of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, or an AC magnetic field of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, is supplied as the AC current or AC magnetic field in a predetermined frequency band.

[0174] Furthermore, when the thickness of second planar coil 12 is set to 0.15 mm or more and 0.35 mm or less as described above, it is preferable that the thickness of first planar coil 11 is 0.1 mm or more and 1.0 mm or less. In this configuration, coil component 10 can be made extremely thin and lightweight while still satisfying the performance required for contactless power transmission of relatively large power, for example. Therefore, coil component 10 with excellent practicality can be provided.

[0175] Furthermore, the gap between first planar coil 11 and second planar coil 12 may be 0.5 mm or more and 1.5 mm or less. This configuration effectively improves the performance of coil device 10 without hindering a thinner design.

[0176] In the present embodiment, holding body 30 includes resin and magnetic particles held by the resin. In this case, the bonding strength between the resin and first planar coil 11 and second planar coil 12 can be improved, so that first planar coil 11 and second planar coil 12 can be integrated in a stable state.

[0177] The relative permeability of the holder 30 may be 5.0 or more. In this case, the performance of the coil component can be improved by the magnetic permeability of the holder 30. The relative permeability of the holder 30 may be 10.0 or less. In this case, the strength of the holder 30 can be appropriately ensured and the bond between the holder 30 and each of the planar coils 11 and 12 can be strengthened.

[0178] Moreover, holder 30 in the present embodiment includes a wall portion 34 protruding from second planar coil 12. This configuration can effectively improve the transmission efficiency of magnetic flux sent from coil component 10 or received from other coil components.

[0179] In the present embodiment, any one of the plurality of turn portions 11n of first planar coil 11 and any one of the plurality of turn portions 12n of second planar coil 12 partially overlap in the axial direction of first planar coil 11. A part of turn portion 11n of first planar coil 11 and a part of turn portion 12n of second planar coil 12 that overlap in the axial direction of first planar coil 11 extend parallel to each other. This configuration can effectively improve the performance of coil component 10. It is presumed that the improvement in coil performance due to this configuration occurs because eddy current loss that may occur between first planar coil 11 and second planar coil 12 is suppressed.

[0180] The inventors of the present invention found that the phenomenon in which the Q value has a maximum value when the thickness of second planar coil 12 is between 0.15 mm and 0.35 mm is related to the skin depth of the coil, and that the dimensional conditions under which the Q value has a maximum value vary depending on the skin depth of the coil. Skin depth δ can be calculated using the following formula:

[0181] δ=1 / √π f μr μ0 σ f: frequency, μr: permeability of the coil, μ0: permeability of free space, σ: conductivity of the coil

[0182] The skin depth δ varies depending on the frequency of the AC current being passed. When the frequency of the AC current is 75 KHz or more and 100 KHz or less, the skin depth δ is approximately 0.19 to 0.21 mm. The inventors of the present invention have hypothesized that when the skin depth δ is 0.19 to 0.21 mm and the thickness of second planar coil 12 is equal to or close to this value, the Q value is significantly improved.

[0183] Hereinafter, a coil device 10' according to another embodiment will be described with reference to Fig. 9. Fig. 9 is a cross-sectional view of the coil device 10'. Components similar to those in the above embodiment are given the same reference numerals, and descriptions thereof will be omitted.

[0184] (Other form 1) Coil device 10′ further includes an even number of other planar coils 201, 202 arranged between first planar coil 11 and second planar coil 12. In the present embodiment, the even number of other planar coils 201, 202 are composed of third planar coil 201 and fourth planar coil 202. However, the even number of other planar coils may be composed of four, six, etc. planar coils.

[0185] First planar coil 11, other planar coils 201 and 202, and second planar coil 12 are connected in series. Among third planar coil 201 and fourth planar coil 202 different from third planar coil 201 connected to first planar coil 11 in other planar coils 201 and 202, at least fourth planar coil 202 has a thickness of 0.15 mm or more and 0.35 mm or less. In the present embodiment, the thickness of third planar coil 201 is also 0.15 mm or more and 0.35 mm or less. Furthermore, the thickness of second planar coil 12, the thickness of third planar coil 201, and the thickness of fourth planar coil 202 are the same. The size of first planar coil 11 is in the same range as in the above-mentioned embodiment, and the thickness may be, for example, 0.2 mm or more and 1.0 mm or less. Furthermore, when the thickness of third planar coil 201 is set to a value outside the range of 0.15 mm or more and 0.35 mm or less, the thickness of third planar coil 201 may be 1.0 mm or less, or may be the same as the thickness of first planar coil 11.

[0186] Coil device 10' according to the present embodiment can also improve performance while suppressing increases in size and weight. More specifically, when an AC current of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, or an AC magnetic field of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, is supplied to first planar coil 11, other planar coils 201, 202, and second planar coil 12, the performance of coil device 10' can be significantly improved.

[0187] In coil device 10', the thickness of first planar coil 11 was 0.5 mm, the thickness of third planar coil 201 was 0.25 mm, the thickness of fourth planar coil 202 was 0.25 mm, and the thickness of second planar coil 12 was 0.25 mm. When the Q value was simulated under the same conditions as those for the simulation shown in Table 1, the Q value was 227. In addition, when the Q value was simulated with the thickness of first planar coil 11 set to 0.5 mm, the thickness of third planar coil 201 set to 0.50 mm, the thickness of fourth planar coil 202 set to 0.25 mm, and the thickness of second planar coil 12 set to 0.25 mm, the Q value was 202. For these, when the Q value was simulated with the thickness of all four planar coils set to 0.5 mm, the Q value was 101.

[0188] The above simulation results confirm that when an even number of planar coils are stacked and the current passing therethrough is 75 KHz or more and 100 KHz or less, particularly 79 KHz or more and 90 KHz or less, the coil performance can be improved by setting the thickness of at least the planar coils other than first planar coil 11 closest to magnetic bodies (20, 30) to 0.25 mm. Although the simulation results are omitted, the present inventors have confirmed that in the configuration of this embodiment, the coil performance can be improved even if the thickness of the planar coils other than first planar coil 11 is a value other than 0.25 mm and in the range of 0.15 mm or more and 0.35 mm or less.

[0189] Further, several other embodiments will be described below. In each embodiment described below, the same components as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be omitted.

[0190] (Other Form 2) Coil device 10A according to Alternative Form 2 shown in Fig. 10 further includes second magnetic shield member 60 in addition to first planar coil 11, second planar coil 12, magnetic shield member 20, and holder 30 shown in Figs. 2 to 5. Hereinafter, magnetic shield member 20 may be referred to as first magnetic shield member 20 for ease of explanation.

[0191] The second magnetic shield member 60 is disposed so as to face the surface of the first magnetic shield member 20 opposite the surface facing the first layer 31 (portion covering surface 111B of first planar coil 11) of the holder 30 (magnetic member). The second magnetic shield member 60 is plate-shaped, but the shape is not particularly limited. The second magnetic shield member 60 faces the first magnetic shield member 20 with a gap therebetween in the direction in which the first planar coil 11 and the second planar coil 12 overlap. The materials of the first magnetic shield member 20 and the second magnetic shield member 60 are different from each other.

[0192] In this embodiment, the relationship between the first magnetic shield member 20 and the second magnetic shield member 60 is as follows. The volume resistivity of the first magnetic shield member 20 is greater than the volume resistivity of the second magnetic shield member 60. The volume resistivity of the first magnetic shield member 20 is 10 times that of the second magnetic shield member 60. 2 It can be more than twice as much, or 10 3 It can be more than twice as much, or 10 4 It can be more than twice as much, or 10 5 It can be more than twice as much, or 10 6 The relative permeability of the first magnetic shield member 20 is greater than the relative permeability of the second magnetic shield member 60. The relative permeability of the first magnetic shield member 20 may be 100 times or more, 200 times or more, 500 times or more, 1000 times or more, or 2000 times or more that of the second magnetic shield member 60.

[0193] The second magnetic shield member 60 faces the first magnetic shield member 20 with a gap therebetween, but may be in direct contact with the first magnetic shield member 20. A spacer may be provided between the second magnetic shield member 60 and the first magnetic shield member 20. The second magnetic shield member 60 is made of a metal material and has electrical conductivity. Specifically, in this example, the second magnetic shield member 60 contains aluminum, and more specifically, is made of aluminum. The second magnetic shield member 60 may be made of an aluminum alloy, copper, stainless steel, or the like.

[0194] In the coil device 10A shown in FIG. 10, the thickness of the second planar coil 12 is also 0.15 mm or more and 0.35 mm or less. As a result, when an AC current of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied, or an AC magnetic field of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied, the coil device 10A is configured to significantly improve its performance. That is, when specifically used, the coil device 10A is also applied to the power transmission system S shown in FIG. 1, for example, and is configured to be supplied with an AC current of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or an AC magnetic field of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz, like the coil device 10 described above. As a result, the coil device 10A exhibits useful functions.

[0195] The thickness of first planar coil 11 (the thickness of conductor 11E) may be, for example, 0.1 mm or more and 1.0 mm or less. First planar coil 11, second planar coil 12, holder 30, and magnetic shield member 20 may be formed to have the same shape and dimensional conditions as the respective elements of coil device 10 described with reference to Figures 2 to 5, etc. Holder 30 may not have wall portion 34, for example.

[0196] Next, with reference to Table 7 below, a simulation result evaluating the performance of coil device 10A will be described. Table 7 shows the evaluation results of coil device 10A and its comparative examples 1-A and 1-B. In the simulated coil device 10A, the thickness of first planar coil 11 is set to 0.5 mm, and the thickness of second planar coil 12 is set to 0.25 mm. Comparative example 1-A is a coil device in which the thickness of first planar coil 11 and the thickness of second planar coil 12 are set to 0.5 mm, and the other configurations are the same as coil device 10A. Comparative example 1-B is a coil device in which the thickness of first planar coil 11 is set to 0.25 mm, the thickness of second planar coil 12 is set to 0.5 mm, and the other configurations are the same as coil device 10A. In coil device 10A, comparative example 1-A, and comparative example 1-B, first planar coil 11 is made of aluminum, and second planar coil 12 is made of copper. It should be noted that the comparative examples exemplified here are not necessarily excluded from this disclosure (the present invention), and may constitute this disclosure (the present invention) depending on the conditions of the frequency used.

[0197] [Table 7]

[0198] In Table 7, "This disclosure" in the left vertical column indicates coil component 10A, and in the right column, the simulated coil thickness conditions of coil component 10A (050 / 025, i.e., 0.5 mm / 0.25 mm), the Q value calculated in the simulation, the loss, and the resistance are shown in order. Similarly, in the right column of each of "Comparative Example 1-A" and "Comparative Example 1-B" in the left vertical column in Table 7, the simulated coil thickness conditions for the comparative examples, the Q value calculated in the simulation, the loss, and the resistance are shown in order. Note that the magnetic shield loss in the table refers to the loss in the second magnetic shield member 60.

[0199] As is clear from Table 7, the Q value of coil device 10A is 183, which is higher than the Q value (130) of Comparative Example 1-A and the Q value (120) of Comparative Example 1-B. Furthermore, the losses in coil device 10A (losses in magnetic shield member 60 and losses in coils 11 and 12) are lower than the losses in Comparative Example 1-A and Comparative Example 1-B. Furthermore, the simulation was performed with the frequency of the AC current supplied to the coil device set to 85 KHz, and the AC resistance of coil device 10A is also lower than that of Comparative Example 1-A and Comparative Example 1-B.

[0200] The simulation results shown in Table 7 confirm the high performance of coil device 10A. In particular, coil device 10A ensures higher performance than Comparative Example 1-A while reducing the amount of coil material used compared to Comparative Example 1-A. This point supports the usefulness of the present disclosure. Also, coil device 10A and Comparative Example 1-B use two coils with the same conditions, but there is a significant difference in performance. Another feature of the present disclosure is the ingenuity in the positioning of the coil so that the thickness is 0.15 mm or more and 0.35 mm or less.

[0201] (Other forms 3) In the above-described embodiment, first layer 31 of holding body 30 (portion covering surface 111B of first planar coil 11) entirely covers surface 111B of first planar coil 11. On the other hand, in coil component 10B according to Alternative Configuration 3 shown in FIGS. 11 and 12, first layer 31 of holding body 30 partially covers surface 111B, which is the surface of first planar coil 11 opposite the surface facing second planar coil 12. Note that in Configuration 3 described here, first layer 31 is configured only by a portion facing surface 111B, unlike the configurations described in FIGS. 2 to 5.

[0202] In this example, as shown by the dashed line in FIG. 11, each turn portion 11n of the first planar coil 11 includes a first straight portion 11ns1 extending along a straight line, a first corner portion 11nc1 connecting to the first straight portion 11ns1 and extending in a curved manner, a second straight portion 11ns2 connecting to the first corner portion 11nc1 and extending along a straight line, a second corner portion 11nc2 connecting to the second straight portion 11ns2 and extending in a curved manner, a third straight portion 11ns3 connecting to the second corner portion 11nc2 and extending along a straight line, a third corner portion 11nc3 connecting to the third straight portion 11ns3 and extending in a curved manner, and other portions, forming a circular shape. Although detailed explanation is omitted, each turn portion 12n of the second planar coil 12 similarly includes a first straight portion 12ns1, a first corner portion 12nc1, a second straight portion 12ns2, a second corner portion 12nc2, a third straight portion 12ns3, a third corner portion 12nc3, and other portions, and forms a circular shape.

[0203] Specifically, first layer 31 of holder 30 covers first straight portion 11ns1, second straight portion 11ns2, and third straight portion 11ns3. On the other hand, first layer 31 of holder 30 does not cover first corner portion 11nc1, second corner portion 11nc2, and third corner portion 11nc3. In other words, holder 30 does not overlap first corner portion 11nc1, second corner portion 11nc2, and third corner portion 11nc3 in the direction in which first planar coil 11 and second planar coil 12 overlap.

[0204] Moreover, the holder 30 in this example includes a plurality of, in this example, three, mutually separated pieces 301-303. Specifically, the holder 30 includes a first piece 301, a second piece 302, and a third piece 303. Each of the pieces 301-301 includes a first layer 31, and the first layer 31 covers the first planar coil 11. More specifically, the first layer 31 of the first piece 301 covers the first straight portion 11ns1. The first layer 31 of the second piece 302 covers the second straight portion 11ns2. The first layer 31 of the third piece 303 covers the third straight portion 11ns3.

[0205] Each of pieces 301-301 includes first layer 31 and a plurality of guide holding plate portions 35 rising from first layer 31. Guide holding plate portions 35 are made of the same material as first layer 31 and have magnetic properties. The plurality of guide holding plate portions 35 extend linearly in parallel to one another. In each of pieces 301-303, a space for accommodating linear portions (11ns1, 11ns2, 11ns3, 12ns1, 12ns2, 12ns3) is formed between adjacent guide holding plate portions 35. Holder 30 holds first planar coil 11 and second planar coil 12 with linear portions (11ns1, 11ns2, 11ns3) of first planar coil 11 and linear portions (12ns1, 12ns2, 12ns3) of second planar coil 12 overlapping in this order between adjacent guide holding plate portions 35. In this example, an air layer is formed between straight portions (11ns1, 11ns2, 11ns3) of first planar coil 11 arranged between adjacent guide holding plate portions 35 and straight portions (12ns1, 12ns2, 12ns3) of second planar coil 12. However, for example, an insulating resin may be filled between straight portions (11ns1, 11ns2, 11ns3) of first planar coil 11 and straight portions (12ns1, 12ns2, 12ns3) of second planar coil 12, or a spacer made of the same material as holding body 30 may be filled. On the other hand, a portion of first planar coil 11 that does not overlap holding body 30 overlaps with magnetic shield member 20 with a gap (air layer) provided between magnetic shield member 20 and first planar coil 11 as shown in FIG.

[0206] Also, in the coil device 10B shown in FIG. 11, the thickness of the second planar coil 12 is 0.15 mm or more and 0.35 mm or less. As a result, when an AC current of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied, or an AC magnetic field of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied, the coil device 10B is configured to significantly improve its performance. That is, when specifically used, the coil device 10B is also applied to the power transmission system S shown in FIG. 1, for example, and is configured to be supplied with an AC current of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or an AC magnetic field of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz, like the coil device 10 described above. As a result, the coil device 10B exhibits a useful function.

[0207] On the other hand, the thickness of first planar coil 11 (thickness of conductor 11E) may be, for example, 0.1 mm or more and 1.0 mm or less. First planar coil 11, second planar coil 12, holder 30, and magnetic shield member 20 may be formed with the same shape and dimensional conditions as those of the respective elements of coil component 10 described with reference to Figs. 2 to 5 and the like. Note that coil component 10 and coil component 10B have some differences in the shapes of first planar coil 11 and second planar coil 12 in the details, but are not essentially different. Specifically, in this example, the direction in which first planar coil 11 and the direction in which second planar coil 12 winds are opposite to those in coil component 10 described with reference to Figs. 2 to 5 and the like. Also, the number of turns of first planar coil 11 and the number of turns of second planar coil 12 are different from those in coil component 10 described with reference to Figs. 2 to 5 and the like. Such detailed configurations are not particularly limited.

[0208] Next, with reference to Table 8 below, a simulation result evaluating the performance of coil device 10B will be described. Table 8 shows the evaluation results of coil device 10B and comparative examples 2-A and 2-B. In the simulated coil device 10B, the thickness of first planar coil 11 is set to 0.5 mm, and the thickness of second planar coil 12 is set to 0.25 mm. Comparative example 2-A is a coil device in which the thickness of first planar coil 11 and the thickness of second planar coil 12 are set to 0.5 mm, and the other configurations are the same as coil device 10B. Comparative example 2-B is a coil device in which the thickness of first planar coil 11 is set to 0.25 mm, the thickness of second planar coil 12 is set to 0.5 mm, and the other configurations are the same as coil device 10B. In coil device 10B, comparative example 2-A, and comparative example 2-B, first planar coil 11 is made of aluminum, and second planar coil 12 is made of copper. It should be noted that the comparative examples exemplified here are not necessarily excluded from this disclosure (the present invention), and may constitute this disclosure (the present invention) depending on the conditions of the frequency used.

[0209] [Table 8]

[0210] In Table 8, "This Disclosure" in the left vertical column indicates coil device 10B, and in the columns to the right of it, the simulated coil thickness conditions of coil device 10B, the Q value, loss, and resistance calculated in the simulation are shown in that order. Similarly, in the columns to the right of "Comparative Example 2-A" and "Comparative Example 2-B" in the left vertical column of Table 8, the simulated coil thickness conditions for the comparative examples, the Q value, loss, and resistance calculated in the simulation are shown in that order.

[0211] As is clear from Table 8, the Q value of coil device 10B is 95, which is higher than the Q value (84) of Comparative Example 2-A and the Q value (78) of Comparative Example 2-B. Furthermore, the losses in coil device 10B (losses in magnetic shield member 60 and losses in coils 11 and 12) are lower than the losses in Comparative Example 2-A and Comparative Example 2-B. Furthermore, the simulation was performed with the frequency of the AC current supplied to the coil device set to 85 KHz, and the AC resistance of coil device 10B is also lower than that of Comparative Example 2-A and Comparative Example 2-B.

[0212] The simulation results shown in Table 8 confirm the high performance of the coil device 10B. In particular, the coil device 10B ensures higher performance than Comparative Example 2-A while reducing the amount of coil material used compared to Comparative Example 2-A. This point supports the usefulness of the present disclosure.

[0213] (Other forms 4) Coil device 10C according to Alternative Form 4 shown in Fig. 13 includes first planar coil 11, second planar coil 12, and holding body 30, and does not include magnetic shield member 20. This configuration is useful when applied to a power transmission device. First planar coil 11, second planar coil 12, and holding body 30 have the same configurations as those described with reference to Figs. 2 to 5, etc.

[0214] In the coil device 10C shown in FIG. 13, the thickness of the second planar coil 12 is also 0.15 mm or more and 0.35 mm or less. As a result, when an AC current of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied, or an AC magnetic field of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied, the coil device 10C is configured to significantly improve its performance. That is, when specifically used, the coil device 10C is also applied to the power transmission system S shown in FIG. 1, for example, and is configured to be supplied with an AC current of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or an AC magnetic field of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz, like the coil device 10 described above. As a result, the coil device 10C exhibits useful functions.

[0215] The thickness of first planar coil 11 (the thickness of conductor 11E) may be, for example, 0.1 mm or more and 1.0 mm or less. First planar coil 11, second planar coil 12, and holder 30 may be formed with the same shapes and dimensional conditions as the respective elements of coil component 10 described with reference to Figures 2 to 5 etc. Coil component 10 and coil component 10C may differ in the shapes of first planar coil 11 and second planar coil 12 in some details.

[0216] Next, with reference to Table 9 below, a simulation result evaluating the performance of coil device 10C will be described. Table 9 shows the evaluation results of coil device 10C and comparative examples 3-A and 3-B. In the simulated coil device 10C, the thickness of first planar coil 11 is set to 0.5 mm, and the thickness of second planar coil 12 is set to 0.25 mm. Comparative example 3-A is a coil device in which the thicknesses of first planar coil 11 and second planar coil 12 are set to 0.5 mm, and the other configurations are the same as coil device 10C. Comparative example 3-B is a coil device in which the thickness of first planar coil 11 is set to 0.25 mm, the thickness of second planar coil 12 is set to 0.5 mm, and the other configurations are the same as coil device 10C. In coil device 10C, comparative example 3-A, and comparative example 3-B, first planar coil 11 is made of aluminum, and second planar coil 12 is made of copper. It should be noted that the comparative examples exemplified here are not necessarily excluded from this disclosure (the present invention), and may constitute this disclosure (the present invention) depending on the conditions of the frequency used.

[0217] [Table 9]

[0218] In Table 9, "This Disclosure" in the left vertical column indicates coil device 10C, and in the columns to the right of it, the simulated coil thickness conditions of coil device 10C, the Q value, loss, and resistance calculated in the simulation are shown in that order. Similarly, in the columns to the right of "Comparative Example 3-A" and "Comparative Example 3-B" in the left vertical column of Table 9, the simulated coil thickness conditions for the comparative examples, the Q value, loss, and resistance calculated in the simulation are shown in that order.

[0219] As is clear from Table 9, the Q value of coil device 10C is 195, which is higher than the Q value (190) of Comparative Example 3-A and the Q value (167) of Comparative Example 3-B. Furthermore, the loss in coil device 10C (loss in coils 11 and 12) is lower than the loss in Comparative Example 3-A and the loss in Comparative Example 3-B. Furthermore, the simulation was performed with the frequency of the AC current supplied to the coil device set to 85 KHz, and the AC resistance of coil device 10C is also lower than that of Comparative Example 3-A and Comparative Example 3-B.

[0220] The simulation results shown in Table 9 confirm the high performance of the coil device 10C. In particular, the coil device 10C ensures higher performance than Comparative Example 3-A while reducing the amount of coil material used compared to Comparative Example 3-A. This point supports the usefulness of the present disclosure.

[0221] (Other forms 5) 14 to 16 includes first planar coil 11, second planar coil 12, holding body 30, and magnetic block material 70. This configuration is useful when applied to a power transmission device. First planar coil 11, second planar coil 12, and holding body 30 have the same configurations as those described with reference to FIGS. 2 to 5, etc.

[0222] Coil device 10D includes a plurality of magnetic blocks 70, four in this example. Magnetic blocks 70 are positioned to cover surface 111B, which is the surface of first layer 31 of holder 30 opposite the surface facing first planar coil 11. However, magnetic block 70 is in the shape of a long, thin plate, and covers only a portion of first planar coil 11.

[0223] The magnetic block materials 70 are arranged such that their longitudinal direction extends from a position radially outward of the center of the first planar coil 11 and the second planar coil 12 in the radial direction of the first planar coil 11 and the second planar coil 12. The four magnetic block materials 70 are arranged at 90 degree intervals in the circumferential direction and arranged to form a cross shape when viewed in the direction in which the first planar coil 11 and the second planar coil 12 overlap. In addition, three of the four magnetic block materials 70 are arranged such that they are perpendicular to one of the straight line portions (11ns1, 11ns2, 11ns3) of the first planar coil 11 and one of the straight line portions (12ns1, 12ns2, 12ns3) of the second planar coil 12 at the midpoint of each portion when viewed in the direction in which the first planar coil 11 and the second planar coil 12 overlap.

[0224] The number and positions of the magnetic blocks 70 are not particularly limited.

[0225] In the coil device 10D shown in Figs. 14 to 16, the thickness of the second planar coil 12 is also 0.15 mm or more and 0.35 mm or less. As a result, when an AC current of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied, or an AC magnetic field of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied, the coil device 10D is configured to significantly improve its performance. That is, when specifically used, the coil device 10D is applied to the power transmission system S shown in Fig. 1, for example, and is configured to be supplied with an AC current of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or an AC magnetic field of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz, like the coil device 10 described above. As a result, the coil device 10D exhibits a useful function.

[0226] The thickness of first planar coil 11 (thickness of conductor 11E) may be, for example, 0.1 mm or more and 1.0 mm or less. First planar coil 11, second planar coil 12, and holder 30 may be formed with the same shape and dimensional conditions as those of each element of coil component 10 described with reference to Figs. 2 to 5 and the like. Note that coil components 10 and 10D have some differences in the shapes of first planar coil 11 and second planar coil 12 in the details, but are not essentially different. Specifically, in this example, the direction in which first planar coil 11 and second planar coil 12 wind are opposite to those in coil component 10 described with reference to Figs. 2 to 5 and the like. Also, the number of turns of first planar coil 11 and second planar coil 12 are different from those in coil component 10 described with reference to Figs. 2 to 5 and the like. Such detailed configurations are not particularly limited.

[0227] Next, with reference to Table 10 below, a simulation result evaluating the performance of coil device 10D will be described. Table 10 shows the evaluation results of coil device 10D and comparative examples 4-A and 4-B. In the simulated coil device 10D, the thickness of first planar coil 11 is set to 0.5 mm, and the thickness of second planar coil 12 is set to 0.25 mm. Comparative example 4-A is a coil device in which the thickness of first planar coil 11 and the thickness of second planar coil 12 are set to 0.5 mm, and the other configurations are the same as coil device 10D. Comparative example 4-B is a coil device in which the thickness of first planar coil 11 is set to 0.25 mm, the thickness of second planar coil 12 is set to 0.5 mm, and the other configurations are the same as coil device 10D. In coil device 10D, comparative example 4-A, and comparative example 4-B, first planar coil 11 is made of aluminum, and second planar coil 12 is made of copper. It should be noted that the comparative examples exemplified here are not necessarily excluded from this disclosure (the present invention), and may constitute this disclosure (the present invention) depending on the conditions of the frequency used.

[0228] [Table 10]

[0229] In Table 10, "This Disclosure" in the left vertical column indicates coil device 10D, and in the columns to the right of it, the simulated coil thickness conditions of coil device 10D, the Q value, loss, and resistance calculated in the simulation are shown in that order. Similarly, in the columns to the right of "Comparative Example 4-A" and "Comparative Example 4-B" in the left vertical column of Table 10, the simulated coil thickness conditions for the comparative examples, the Q value, loss, and resistance calculated in the simulation are shown in that order.

[0230] As is clear from Table 10, the Q value of coil device 10D is 235, which is higher than the Q value (156) of Comparative Example 4-A and the Q value (142) of Comparative Example 4-B. Furthermore, the loss in coil device 10D (loss in coils 11 and 12) is lower than the loss in Comparative Example 4-A and the loss in Comparative Example 4-B. Furthermore, the simulation was performed with the frequency of the AC current supplied to the coil device set to 85 KHz, and the AC resistance of coil device 10D is also lower than that of Comparative Example 4-A and Comparative Example 4-B.

[0231] The simulation results shown in Table 10 confirm the high performance of the coil device 10D. In particular, the coil device 10D ensures higher performance than Comparative Example 4-A while reducing the amount of coil material used compared to Comparative Example 4-A. This point supports the usefulness of the present disclosure.

[0232] 2 to 5, a simulation result will be described regarding the performance of an embodiment in which first planar coil 11 is made of aluminum and second planar coil 12 is made of copper. The simulation was performed using Femtet (registered trademark) manufactured by Murata Software Co., Ltd.

[0233] In the simulation described below, a plurality of values ​​were set for the thickness of first planar coil 11 and the thickness of second planar coil 12 in coil device 10 in the above-described embodiment, and the corresponding Q value was calculated. In addition, simulations of Q values ​​of a plurality of coil devices in which "the condition in which first planar coil 11 is made of aluminum and second planar coil 12 is made of copper" or "the dimensional condition" deviate from the embodiment described using Figures 2 to 5 were also performed as comparative examples. Note that the comparative examples exemplified here are not necessarily excluded from this disclosure (the present invention), and may constitute this disclosure (the present invention) depending on the frequency conditions used.

[0234] The detailed conditions for the simulation are as follows. The high frequency current supplied is 40A and the frequency is 85KHz. The electrical conductivity of the first planar coil 11 made of aluminum is 3.77×10 7 The electrical conductivity of the second planar coil 12 made of copper is 5.98×10 7 [S / m]. The magnetic shield member 20 has a relative magnetic permeability of 3000, and the holder 30 has a relative magnetic permeability of 5.0. The width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction of line IV-IV shown in FIG. 2 is 200 mm, and the width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction perpendicular to line IV-IV is 200 mm.

[0235] The results of the simulation for the above embodiment are shown in Table 11 below. Under "Embodiment" in the top row of Table 11, several dimensional conditions of the coil device 10 according to the embodiment and the weight per square meter W (Kg / m 2), and the simulation results, Q value and Z (impedance (Ω)), are shown one above the other. Meanwhile, the simulation results for the comparative example are shown in Table 12 below. Under "Comparative Example" at the top of Table 12, multiple dimensional conditions of the coil component according to the comparative example and the weight per square meter W (Kg / m 2 ), and the simulation results, Q value and Z (impedance (Ω)), are shown one above the other. The coil component according to the comparative example has the same basic structure as coil component 10, except that the dimensional conditions and coil material conditions deviate from those of the embodiment. Also, the "weight per square meter W (Kg / m 2 "Weight per square meter W (Kg / m2)" means the sum of the weight per square meter of first planar coil 11 and the weight per square meter W of second planar coil 12. The weight per square meter of each coil is calculated by multiplying the specific gravity (weight per cubic meter) of the material of first planar coil 11 and second planar coil 12 by their thicknesses. For example, the weight per square meter W (Kg / m2) of a copper coil with a thickness of 0.25 mm is 2 ) has a specific gravity of 8960 kg / m 3 When 2 The specific gravity can be determined once the material is identified, but can also be calculated by dividing the weight of a portion of the coil by its volume.

[0236] [Table 11]

[0237] [Table 12]

[0238] As described above, the present inventors have found that when first planar coil 11 and second planar coil 12 are overlapped on magnetic shield member 20 and holder 30, the performance of coil component 10 is significantly improved when second planar coil 12 has a thickness of 0.15 mm or more and 0.35 mm or less. More specifically, the inventors have found that when the second planar coil overlapping first planar coil 11 is used in a predetermined frequency band and the thickness of the second planar coil is set to any value between 0.15 mm or more and 0.35 mm or less, the Q value of coil component 10 is extremely high. The predetermined frequency band is specifically a frequency band of 75 KHz or more and 100 KHz or less, and the performance of coil component 10 is reliably improved when the frequency is 79 KHz or more and 90 KHz or less.

[0239] As shown in Table 11, in the simulations relating to the embodiment, in Simulation 1, the thickness of first planar coil 11 made of aluminum is 0.5 mm, and the thickness of second planar coil 12 made of copper is 0.25 mm. In Simulation 2, the thickness of first planar coil 11 made of aluminum is 0.5 mm, and the thickness of second planar coil 12 made of copper is 0.35 mm. In Simulation 3, the thickness of first planar coil 11 made of aluminum is 0.5 mm, and the thickness of second planar coil 12 made of aluminum is 0.25 mm. In Simulation 4, the thickness of first planar coil 11 made of aluminum is 0.5 mm, and the thickness of second planar coil 12 made of aluminum is 0.35 mm. In Simulation 5, the thickness of first planar coil 11 made of aluminum is 1.0 mm, and the thickness of second planar coil 12 made of aluminum is 0.25 mm. In simulation 6, first planar coil 11 made of aluminum has a thickness of 0.25 mm, and second planar coil 12 made of aluminum has a thickness of 0.25 mm. The thickness of second planar coil 12 in each simulation is set to be between 0.15 mm and 0.35 mm. The Q factor in simulation 6 is the smallest, at 129.3, and the Q factors in simulations 1 to 5 are 140 or more.

[0240] In the comparative examples 1 and 3 to 8, the thickness of the coil corresponding to the second planar coil is out of the range of 0.15 mm or more and 0.35 mm or less, compared to the simulation of the embodiment described above. The Q value in the comparative examples 1 and 3 to 8 is 124.2 in the comparative example 7 at most, which is smaller than the Q value calculated in the simulation of the embodiment, and is significantly smaller than the Q value in the simulations 1 to 5 in particular. For example, in the comparative example 5, the thickness of the aluminum coil corresponding to the first planar coil is 0.5 mm, and the thickness of the copper coil corresponding to the second planar coil is 0.5 mm. In the comparative example 5, the conditions of the first planar coil are the same as those in the simulation 1 of the embodiment, and the material of the second planar coil is the same, but the Q value is smaller than that in the simulation 1 by 50 or more. In the comparative example 4, the thickness of the aluminum coil corresponding to the first planar coil is 0.5 mm, and the thickness of the aluminum coil corresponding to the second planar coil is 0.5 mm. In the comparative example 4, the conditions of the first planar coil are the same as those in the simulation 3 of the embodiment, and the material of the second planar coil is the same, but the Q value is smaller than that in the simulation 3 by about 30.

[0241] The above simulation results support that the performance of coil device 10 when used in a predetermined frequency band is significantly improved by setting the thickness of second planar coil 12 to 0.15 mm or more and 0.35 mm or less. In the above simulation, the condition of setting the thickness of second planar coil 12 to a range of 0.15 mm or more and less than 0.25 mm was not verified, but the inventors of the present invention confirmed that relatively high coil performance can be ensured even in this range. If the thickness of second planar coil 12 is set to less than 0.15 mm or more than 0.35 mm, the Q value tends to decrease. Therefore, the thickness of second planar coil 12 may be near the middle of 0.15 to 0.35 mm, may be set to 0.20 mm or more and 0.30 mm or less, may be set to 0.20 mm or more and 0.275 mm or less, or may be set to 0.225 mm or more and 0.275 mm or less.

[0242] In addition, according to the findings of the present inventors, good coil performance can be obtained when the thickness of the coil closest to magnetic shield member 20 is relatively large. From this viewpoint, the thickness of first planar coil 11 may be 0.5 mm or more and 1.0 mm or less. For example, in Simulations 1 to 5, the thickness of first planar coil 11 is in the range of 0.5 mm or more and 1.0 mm or less. On the other hand, in Simulation 6, the thickness of first planar coil 11 is 0.25 mm, and the Q value is smaller than those in Simulations 1 to 5. This result supports the effectiveness of the condition that the thickness of first planar coil 11 is 0.5 mm or more and 1.0 mm or less. In addition, when Simulation 3 is compared with Simulation 5, the thickness of first planar coil 11 in Simulation 5 is twice the thickness of first planar coil 11 in Simulation 3, but the Q values ​​of the two do not change significantly. This result suggests that the performance assurance by ensuring the thickness of first planar coil 11 tends to saturate from a thickness of 1 mm. From this perspective, in order to obtain coil component 10 rationally while taking into consideration thickness and weight reduction, it is effective to set the thickness of first planar coil 11 to 1.0 mm or less.

[0243] In the present embodiment, first planar coil 11 contains aluminum, which allows for weight reduction. In coil device 10 for which the simulations shown in Table 11 were performed, the total weight of first planar coil 11 and second planar coil 12 was kept small. Specifically, in simulations 1 to 6, the total weight per square meter of first planar coil 11 and the weight per square meter of second planar coil 12 was 5 kg / m 2 In contrast, when considering Comparative Examples 2, 9, and 10, which have Q values ​​equal to or greater than those in Simulations 1 to 6, the total weight per square meter is large, at 5 kg / m 2 (5.1 kg / m 2 , 6.7Kg / m 2 , 8.9Kg / m 2). Moreover, the amount of copper used is large, which can lead to high costs. Compared to Comparative Examples 2, 9, and 10, the coil device 10 according to the present embodiment ensures reasonable coil performance (Q value).

[0244] According to the coil component 10 according to the above simulation, it is easy to secure the desired performance while suppressing the increase in size, weight, and cost. Generally speaking, it is presumed that the thicker the coil, the higher the inductance obtained in the coil, and the tendency for the coil performance such as the Q value to improve is generated. However, the present inventor has found through intensive research that such a tendency does not necessarily occur in a configuration in which a planar coil is stacked in series on a magnetic member. The present inventor has also found that when an AC current or an AC magnetic field in a predetermined frequency band is supplied in a configuration in which the first planar coil 11 and the second planar coil 12 are stacked in this order on the magnetic shield member 20 and the holder 30, the Q value becomes extremely high when the thickness of the second planar coil 12 is between 0.15 mm and 0.35 mm, regardless of the thickness of the first planar coil 11. Based on this finding, it has been found that the performance of the coil component 10 can be improved by using the second planar coil 12 having a thickness of 0.25 mm rather than the case in which the second planar coil 12 having a thickness of 0.5 mm is used.

[0245] That is, in the coil component 10 based on such knowledge, the thickness of the second planar coil 12 is set to 0.15 mm or more and 0.35 mm or less, so that the second planar coil 12 can be made thin. Then, the performance of the coil component 10 can be improved as much as possible when used in a predetermined frequency band. This makes it possible to improve the performance of the coil component 10 while suppressing an increase in the overall size and weight of the coil component 10. When an AC current or an AC magnetic field in a predetermined frequency band is supplied to a configuration in which the first planar coil 11 and the second planar coil 12 are stacked in this order on the magnetic shield member 20 and the holder 30, the Q value becomes extremely high when the thickness of the second planar coil 12 is between 0.15 mm or more and 0.35 mm or less, regardless of the thickness of the first planar coil 11. This phenomenon is difficult to predict from technical common sense. We believe that the coil component invented based on such a phenomenon will have a remarkable effect that greatly contributes to improving the performance of the coil component. Furthermore, a material containing aluminum is used as the material of the first planar coil 11. This makes it possible to more effectively suppress weight increase and reduce costs while ensuring reasonably high coil performance. Therefore, according to the present embodiment, it is easy to ensure desired performance while suppressing size, weight increase, and costs.

[0246] Specifically, the inventors of the present invention have found that when an AC current of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, or an AC magnetic field of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, is supplied to first planar coil 11 and second planar coil 12, the Q value becomes extremely high when the thickness of second planar coil 12 is between 0.15 mm to 0.35 mm, regardless of the thickness of first planar coil 11. That is, a configuration in which the thickness of second planar coil 12 is set to 0.15 mm to 0.35 mm significantly improves performance when an AC current of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, or an AC magnetic field of 75 KHz to 100 KHz, particularly 79 KHz to 90 KHz, is supplied as an AC current or an AC magnetic field in a predetermined frequency band.

[0247] <More forms> The above-described coil component configurations significantly improve performance when an AC current of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied, or an AC magnetic field of 75 KHz to 100 KHz, 79 KHz to 90 KHz, or 85 KHz is supplied. On the other hand, when the frequency of the supplied AC current or AC magnetic field is in a range other than 75 KHz to 100 KHz, the configuration of the coil component that can significantly improve performance changes from the above-described configuration. In the following, a description will be given of configurations according to the present disclosure that can improve performance in other frequency bands other than 75 KHz to 100 KHz.

[0248] (6 other forms) First, as yet another embodiment (embodiment 6), when an AC current of 100 KHz or more and less than 200 KHz is supplied to the coil, or an AC magnetic field of 100 KHz or more and less than 200 KHz is supplied to the coil, the coil component may have the following configuration. "A first planar coil 11, a second planar coil 12 overlapping the first planar coil 11; and a holder 30 which is a magnetic member having magnetism and includes a portion covering a surface of the first planar coil 11 opposite to a surface facing the second planar coil 12 (a portion of the first layer described with reference to FIGS. 2 to 5 ). First planar coil 11 and second planar coil 12 are connected in series, The thickness of second planar coil 12 is equal to or greater than 0.225 mm and equal to or less than 0.275 mm. First planar coil 11 and second planar coil 12 are supplied with an AC current of 100 KHz or more and less than 200 KHz, or are supplied with an AC magnetic field of 100 KHz or more and less than 200 KHz. The above configuration will be referred to as embodiment 6-1 below.

[0249] The coil component according to the above-mentioned embodiment 6-1 may further include a magnetic shield member 20, similar to the configuration described with reference to Figs. 2 to 5 (embodiment 6-2).

[0250] The coil component according to the above-mentioned mode 6-1 may further include a first magnetic shield member 20 and a second magnetic shield member 60, similar to the configuration described in FIG. 10 (mode 6-3).

[0251] The coil device according to the above-mentioned embodiment 6-1 may have a configuration in which holding body 30 partially covers first planar coil 11 (embodiment 6-4), similar to the configurations described in Fig. 11 and Fig. 12. Holding body 30 may include a plurality of mutually separated pieces 301-303.

[0252] The coil component according to the above-mentioned embodiment 6-1 may include a magnetic block material 70, similar to the configuration described with reference to Figs. 14 to 16 (embodiment 6-5).

[0253] Next, referring to Table 13 below, the results of a simulation evaluating the performance of the coil devices according to the embodiments 6-1 to 6-5 are shown. Table 13 shows the evaluation results of the coil devices according to the embodiments 6-1 to 6-5 and comparative examples for each embodiment. In the simulated coil devices according to the embodiments 6-1 to 6-5, the thickness of first planar coil 11 is set to 0.5 mm, and the thickness of second planar coil 12 is set to 0.25 mm. In the comparative examples 6-A1 to 6-5, the thickness of first planar coil 11 and the thickness of second planar coil 12 are set to 0.5 mm, and the other configurations are the same as those of the coil devices according to the embodiments 6-1 to 6-5. In the coil devices according to the embodiments 6-1 to 6-5 and the comparative examples, first planar coil 11 is made of aluminum, and second planar coil 12 is made of copper. The comparative examples exemplified here are not necessarily excluded from the present disclosure (the present invention), and may constitute the present disclosure (the present invention) depending on the conditions of the frequency used.

[0254] [Table 13]

[0255] In the left vertical column of Table 13, "Disclosure 6-1 to 6-5" indicates coil components according to embodiments 6-1 to 6-5, and in the right column, the simulated coil thickness conditions of the coil components according to each embodiment, the Q value, loss, and resistance calculated in the simulation are shown in order. Similarly, in the right column of each of "Comparative Examples 6-A1 to 5" in the left vertical column of Table 13, the simulated coil thickness conditions of the comparative examples, the Q value, loss, and resistance calculated in the simulation are shown in order. In addition, the simulation was performed with the frequency of the AC current supplied to the coil components set to 100KHz, 150KHz, and 200KHz.

[0256] As is clear from Table 13, the Q value of the coil components according to each of the embodiments 6-1 to 6-5 is higher than that of the corresponding comparative example. Also, the loss in the coil components according to each of the embodiments 6-1 to 6-5 is lower than that of the comparative example. Also, the AC resistance of the coil components according to each of the embodiments 6-1 to 6-5 is lower than that of the comparative example.

[0257] From the simulation results shown in Table 13, it can be confirmed that the coil components according to Examples 6-1 to 6-5 have high performance.

[0258] The coil components according to forms 6-1 to 6-5 have different frequency bands of the supplied AC current or AC magnetic field, which are the use conditions, from coil component 10 according to the above-mentioned embodiment, but the range of thicknesses of second planar coil 12 they employ overlap. However, the range of thicknesses of second planar coil 12 employed in coil components according to forms 6-1 to 6-5 is narrower than the range of thicknesses of second planar coil 12 in coil component 10 according to the above-mentioned embodiment. In the coil components according to forms 6-1 to 6-5, particularly good performance is obtained when the thickness of second planar coil 12 is in the range of 0.225 mm or more and 0.275 mm or less, and performance may be relatively significantly degraded if the thickness is outside this range. For this reason, the thickness of second planar coil 12 is set to 0.225 mm or more and 0.275 mm or less in the coil components according to forms 6-1 to 6-5.

[0259] (Other forms 7) Next, as yet another embodiment (embodiment 7), when an AC current of 200 KHz or more and 1 MHz or less is supplied to the coil, or an AC magnetic field of 200 KHz or more and 1 MHz or less is supplied to the coil, the coil component may have the following configuration. "A first planar coil 11, a second planar coil 12 overlapping the first planar coil 11; Holder 30 is a magnetic member having magnetism, and includes a portion covering a surface of first planar coil 11 opposite to the surface facing second planar coil 12 (a portion of the first layer described with reference to FIGS. 2 to 5 ); Equipped with First planar coil 11 and second planar coil 12 are connected in series, The thickness of second planar coil 12 is equal to or greater than 0.075 mm and equal to or less than 0.175 mm. First planar coil 11 and second planar coil 12 are coil components that are supplied with an AC current of 200 KHz or more and 1 MHz or less, or that are supplied with an AC magnetic field of 200 KHz or more and 1 MHz or less. The above configuration will be referred to as embodiment 7-1 below.

[0260] The coil component according to the above-mentioned embodiment 7-1 may further include a magnetic shield member 20, similar to the configuration described with reference to Figs. 2 to 5 (embodiment 7-2).

[0261] The coil component according to the above-mentioned mode 7-1 may further include a first magnetic shield member 20 and a second magnetic shield member 60, similar to the configuration described in FIG. 10 (mode 7-3).

[0262] The coil device according to the above-mentioned embodiment 7-1 may have a configuration (embodiment 7-4) in which holding body 30 partially covers first planar coil 11, similar to the configurations described in Fig. 11 and Fig. 12. Holding body 30 may include a plurality of mutually separated pieces 301-303.

[0263] The coil component according to the above-mentioned embodiment 7-1 may include a magnetic block material 70, similar to the configuration described with reference to Figs. 14 to 16 (embodiment 5-5).

[0264] Next, referring to Tables 14 and 15 below, the results of simulations evaluating the performance of the coil components according to the embodiments 7-1 to 7-5 are shown. Tables 14 and 15 show the evaluation results of the coil components according to the embodiments 7-1 to 7-5 and comparative examples for each embodiment. In the simulated coil components according to the embodiments 7-1 to 7-5, the thickness of first planar coil 11 is set to 0.5 mm, and the thickness of second planar coil 12 is set to 0.10 mm or 0.15 mm. The simulation results when the thickness of second planar coil 12 is 0.10 mm are shown in Table 14, and the simulation results when the thickness of second planar coil 12 is 0.15 mm are shown in Table 15. Note that the comparative examples exemplified here are not necessarily excluded from this disclosure (the present invention), and may constitute this disclosure (the present invention) depending on the conditions of the frequency used.

[0265] On the other hand, in comparative examples 7-A1 to 7-5 for the coil components according to forms 7-1 to 7-5 in which the thickness of second planar coil 12 is 0.10 mm, the thickness of first planar coil 11 and the thickness of second planar coil 12 are set to 0.5 mm, and the other configurations are similar to coil component 10D according to forms 7-1 to 7-5. In addition, in comparison examples 7-A1 to 7-5, in which the thickness of second planar coil 12 is 0.15 mm, the thickness of first planar coil 11 and the thickness of second planar coil 12 are set to 0.5 mm, and the other configurations are similar to coil device 10D according to embodiments 7-1 to 7-5. In the coil components according to embodiments 7-1 to 7-5 and the comparative example, first planar coil 11 is made of aluminum, and second planar coil 12 is made of copper.

[0266] [Table 14]

[0267] [Table 15]

[0268] In the left vertical column of Tables 14 and 15, "Disclosure 7-1 to 7-5" indicates coil components according to embodiments 7-1 to 7-5, and in the right column, the coil thickness conditions in the simulation of the coil components according to each embodiment, the Q value, loss, and resistance calculated in the simulation are shown in order. In the right column of each of "Comparative Examples 7-A1 to 5" in the left vertical column of Tables 14 and 15, the coil thickness conditions in the simulation of the comparative examples, the Q value, loss, and resistance calculated in the simulation are shown in order. In addition, the simulation was performed with the frequency of the AC current supplied to the coil components set to 100KHz, 150KHz, and 200KHz.

[0269] As is clear from Tables 14 and 15, the Q values ​​of the coil components according to each of the embodiments 7-1 to 7-5 are mostly higher than the Q values ​​of the corresponding comparative examples. Moreover, the losses in the coil components according to each of the embodiments 7-1 to 7-5 are mostly lower than the losses in the comparative examples. Moreover, the AC resistance of the coil components according to each of the embodiments 7-1 to 7-5 is mostly lower than the comparative examples. In Comparative Example 7-A1 and Comparative Example 7-A5 in Table 14, there are some conditions where the Q value is higher than that of the present disclosure, but it goes without saying that the present disclosure is more advantageous than the comparative examples when considering the amount of coil material used.

[0270] From the simulation results shown in Tables 14 and 15, it can be confirmed that the coil components according to the embodiments 7-1 to 7-5 have high performance.

[0271] (Other forms 8) Next, as still another embodiment (embodiment 8), in the case where an AC current of 1.1 MHz or more is supplied to the coil, or an AC magnetic field of 1.1 MHz or more is supplied to the coil, the coil part may have the following configuration. "A first planar coil 11, a second planar coil 12 overlapping the first planar coil 11; Holder 30 is a magnetic member having magnetism, and includes a portion covering a surface of first planar coil 11 opposite to the surface facing second planar coil 12 (a portion of the first layer described with reference to FIGS. 2 to 5 ); Equipped with First planar coil 11 and second planar coil 12 are connected in series, The thickness of the second planar coil 12 is 0.45 mm or more. First planar coil 11 and second planar coil 12 are coil components that are supplied with an AC current of 1.1 MHz or more, or that are supplied with an AC magnetic field of 1.1 MHz or more." The above configuration will be referred to as embodiment 8-1 below.

[0272] The coil component according to the above-mentioned embodiment 8-1 may further include a magnetic shield member 20, similar to the configuration described with reference to Figs. 2 to 5 (embodiment 8-2).

[0273] The coil component according to the above-mentioned mode 8-1 may further include a first magnetic shield member 20 and a second magnetic shield member 60, similar to the configuration described in FIG. 10 (mode 8-3).

[0274] The coil device according to the above-mentioned embodiment 8-1 may have a configuration (embodiment 8-4) in which holding body 30 partially covers first planar coil 11, similar to the configurations described in Fig. 11 and Fig. 12. Holding body 30 may include a plurality of mutually separated pieces 301-303.

[0275] The coil component according to the above-mentioned embodiment 8-1 may include a magnetic block material 70, similar to the configuration described with reference to Figs. 14 to 16 (embodiment 8-5).

[0276] Next, referring to Table 16 below, the results of a simulation evaluating the performance of the coil devices according to the embodiments 8-1 to 8-5 are shown. Table 16 shows the evaluation results of the coil devices according to the embodiments 8-1 to 8-5 and comparative examples for each embodiment. In the simulated coil devices according to the embodiments 8-1 to 8-5, the thickness of first planar coil 11 is set to 0.5 mm, and the thickness of second planar coil 12 is set to 0.5 mm. In the comparative examples 8-A1 to 8-5, the thickness of first planar coil 11 is set to 0.50 mm, the thickness of second planar coil 12 is set to 0.25 mm, and the other configurations are the same as those of the coil devices according to the embodiments 8-1 to 8-5. In the coil devices according to the embodiments 8-1 to 8-5 and the comparative examples, first planar coil 11 is made of aluminum, and second planar coil 12 is made of copper. In addition, the comparative examples exemplified here are not necessarily excluded from the present disclosure (the present invention), and may constitute the present disclosure (the present invention) depending on the conditions of the frequency used.

[0277] [Table 16]

[0278] In the left vertical column of Table 16, "Disclosure 8-1 to 8-5" indicates coil components according to embodiments 8-1 to 8-5, and in the right column, the coil thickness conditions in the simulation of the coil components according to each embodiment, the Q value, loss, and resistance calculated in the simulation are shown in order. In the right column of each of "Comparative Examples 8-A1 to 5" in the left vertical column of Table 16, the coil thickness conditions in the simulation of the comparative examples, the Q value, loss, and resistance calculated in the simulation are shown in order. In addition, the simulation was performed with the frequency of the AC current supplied to the coil components set to 1.1 MHz, 6.78 MHz, and 13.56 MHz.

[0279] As is clear from Table 16, the Q value of the coil components according to each of the embodiments 8-1 to 8-5 is higher than that of the corresponding comparative example. Also, the loss in the coil components according to each of the embodiments 8-1 to 8-5 is lower than that of the comparative example. Also, the AC resistance of the coil components according to each of the embodiments 8-1 to 8-5 is lower than that of the comparative example.

[0280] From the simulation results shown in Table 16, it can be confirmed that the coil components according to the embodiments 8-1 to 8-5 have high performance.

[0281] Next, Fig. 17 shows a graph for explaining the relationship between the thickness of the planar coil (11, 12) in the coil component having the configuration shown in Figs. 2 to 5 and the AC resistance. Fig. 18 shows a graph for explaining the relationship between the thickness of the planar coil (11, 12) in the coil component having the configuration shown in Figs. 2 to 5 and the Q value. Figs. 17 and 18 are created based on the AC resistance and the Q value calculated by setting a plurality of values ​​for the thickness of the first planar coil 11 and the thickness of the second planar coil 12 and changing the frequency of the supply current. Specifically, the AC resistance and the Q value were calculated from a simulation. The simulation was performed using Femtet (registered trademark) manufactured by Murata Software Co., Ltd.

[0282] The individual conditions regarding the thickness and material of first planar coil 11 and second planar coil 12 are as follows. Condition 1: First planar coil 11 is made of copper and has a thickness of 0.5 mm. Second planar coil 12 is made of copper and has a thickness of 0.5 mm (Cu0.5 / Cu0.5). Condition 2: first planar coil 11 is made of aluminum and has a thickness of 0.5 mm. Second planar coil 12 is made of copper and has a thickness of 0.25 mm (Al0.5 / Cu0.25). Condition 3: first planar coil 11 is made of aluminum and has a thickness of 0.5 mm. Second planar coil 12 is made of copper and has a thickness of 0.5 mm (Al0.5 / Cu0.5). Condition 4: First planar coil 11 is made of aluminum and has a thickness of 0.5 mm. Second planar coil 12 is made of copper and has a thickness of 0.1 mm (Al0.5 / Cu0.1). Condition 5: first planar coil 11 is made of copper and has a thickness of 0.5 mm. Second planar coil 12 is made of copper and has a thickness of 0.25 mm (Cu0.5 / Cu0.25). Condition 6: First planar coil 11 is made of copper and has a thickness of 0.5 mm. Second planar coil 12 is made of copper and has a thickness of 0.1 mm (Cu0.5 / Cu0.1).

[0283] The common conditions in the simulations are as follows: The electrical conductivity of the first planar coil 11 made of aluminum is 3.77×10 7 The electrical conductivity of the second planar coil 12 made of copper is 5.98×10 7 [S / m]. The magnetic shield member 20 has a relative magnetic permeability of 3000, and the holder 30 has a relative magnetic permeability of 5.0. The width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction of line IV-IV shown in FIG. 2 is 200 mm, and the width of conductor 11E of first planar coil 11 and conductor 12E of second planar coil 12 in the direction perpendicular to line IV-IV is 200 mm.

[0284] 17 and 18, the line indicated with symbol S1 shows the results for condition 1 (Cu0.5 / Cu0.5), the line indicated with symbol S2 shows the results for condition 2 (Al0.5 / Cu0.25), the line indicated with symbol S3 shows the results for condition 3 (Al0.5 / Cu0.5), the line indicated with symbol S4 shows the results for condition 4 (Al0.5 / Cu0.1), the line indicated with symbol S5 shows the results for condition 5 (Cu0.5 / Cu0.25), and the line indicated with symbol S6 shows the results for condition 6 (Cu0.5 / Cu0.1).

[0285] 17, for example, in conditions 2 and 5 where the thickness of the second planar coil is 0.25 mm, the AC resistance is lower than other conditions when the frequency of the supply current is between 80 KHz and 200 KHz. Furthermore, in FIG. 18, the Q value is higher in conditions 2 and 5 than in other conditions.

[0286] In addition, under conditions 4 and 6, where the thickness of the second planar coil is 0.1 mm, the AC resistance is lower than the other conditions when the frequency of the supplied current is between 200 KHz and 1 MHz. Furthermore, referring to Fig. 18, under conditions 4 and 6, the Q value is higher in a wider range than the other conditions.

[0287] Moreover, under conditions 1 and 3, in which the thickness of the second planar coil is 0.5 mm, the AC resistance is lower than the other conditions when the frequency of the supply current is 1.1 MHz or higher. Specifically, under condition 1, the AC resistance is lower than the other conditions when the frequency is 1.1 MHz or higher and 13.56 MHz or lower, and under condition 3, the AC resistance is lower than the other conditions except for condition 1 when the frequency is 1 MHz or higher and 7 MHz or lower. Furthermore, referring to FIG. 18, under conditions 1 and 3, the Q value is higher over a wider range than the other conditions.

[0288] In the coil device according to the above-mentioned embodiment 6-2, as seen from Figs. 17 and 18, under conditions 2 and 5 in which the thickness of the above-mentioned second planar coil is 0.25 mm, the AC resistance is lower and the Q value is higher than under other conditions when the frequency of the supply current is between 80 KHz and 200 KHz, and similar trends have been found from a number of simulations and experiments. The range corresponding to the coil device according to the embodiment 6-2 is surrounded by the symbol E1 in Figs. 17 and 18. For example, from the result of Fig. 17, it can be said that the coil device according to the embodiment 6-2 functions to generate a magnetic field in a state in which the AC resistance is suppressed as much as possible. Therefore, in the coil device according to the embodiment 6-2, it can be said that the multi-layered planar coils (11, 12) function efficiently when an AC current of 100 KHz or more and less than 200 KHz is supplied or an AC magnetic field of 100 KHz or more and less than 200 KHz is supplied. And, from the result of Fig. 18, it can be seen that efficient transmission can be realized.

[0289] 17 is an evaluation result when an AC current is supplied to generate a magnetic field, but even when an AC current is generated by receiving an AC magnetic field, the AC resistance is similarly suppressed as much as possible. Therefore, the evaluation result of FIG. 17 supports the fact that the coil device according to embodiment 6-2 functions effectively when an AC magnetic field of 100 KHz or more and less than 200 KHz is supplied.

[0290] In addition, as seen from Figs. 17 and 18, the coil device according to the embodiment 7-2 has a tendency that the AC resistance is lower and the Q value is higher than other conditions when the frequency of the supply current is between 200 KHz and 1 MHz, as compared to other conditions, and a similar tendency has been found from a number of simulations and experiments. The range corresponding to the coil device according to the embodiment 7-2 is surrounded by the symbol E2 in Figs. 17 and 18. For example, from the result of Fig. 17, it can be said that the coil device according to the embodiment 7-2 also functions to generate a magnetic field in a state in which the AC resistance is suppressed as much as possible. Therefore, in the coil device according to the embodiment 7-2, it can be said that the multi-layered planar coils (11, 12) function efficiently when an AC current of 200 KHz or more and 1 MHz or less is supplied or an AC magnetic field of 200 KHz or more and 1 MHz or less is supplied. And, from the result of Fig. 18, it can be seen that efficient transmission can be realized.

[0291] In addition, as seen from Figs. 17 and 18, the coil device according to the embodiment 8-2 has a tendency that the AC resistance is lower and the Q value is higher than other conditions when the frequency of the supplied current is 1.1 MHz or more under conditions 1 and 3 in which the thickness of the second planar coil is 0.5 mm, and a similar tendency has been found from a number of simulations, experiments, and the like. The range corresponding to the coil device according to the embodiment 8-2 is surrounded by the symbol E3 in Figs. 17 and 18. For example, from the result of Fig. 17, it can be said that the coil device according to the embodiment 8-2 also functions to generate a magnetic field in a state in which the AC resistance is suppressed as much as possible. Therefore, in the coil device according to the embodiment 8-2, it can be said that the multi-layered planar coil (11, 12) functions efficiently when an AC current of 1.1 MHz or more is supplied or an AC magnetic field of 1.1 MHz or more is supplied. And, from the result of Fig. 18, it can be seen that efficient transmission can be realized.

[0292] Strictly speaking, in the coil component according to embodiment 8-2 related to condition 1 (Cu0.5 / Cu0.5), the multilayered planar coils (11, 12) function efficiently when an AC current or an AC magnetic field is supplied between 1.1 MHz and 13.56 MHz. Also, in the coil component according to embodiment 8-2 related to condition 3 (AL0.5 / Cu0.5), the multilayered planar coils (11, 12) function efficiently when an AC current or an AC magnetic field is supplied between 1.1 MHz and 7 MHz.

[0293] Although the embodiment of the present disclosure has been described above, various modifications may be made to the above-described embodiment, and such modifications are also within the technical scope of the present disclosure. [Explanation of symbols]

[0294] S…Power transmission system 1...Power transmission device 1A…High frequency current supply 2...Power receiving device 2A…Conversion section 10, 10', 10A... Coil parts 11…First planar coil 11n…Turn section 11ns1…1st straight line part 11nc1…First corner 11ns2…Second straight line part 11nc2: Second corner 11ns3…Third straight line part 11nc3…Third corner 11E…Conductor 12…Second planar coil 12n…Turn section 12ns1…1st straight line part 12nc1…First corner 12ns2…Second straight line part 12nc2: Second corner 12ns3…Third straight line part 12nc3…Third corner 12E…Conductor 14…Connection wiring section 20...Magnetic shielding material 30...Holding body 31…1st layer 32…Second layer 33...Third layer 34...Wall part 35...Guide holding plate 301…1st piece 302…2nd piece 303…Third piece 60...Second magnetic shield member 70...Magnetic block material C1…First central axis line C2…Second central axis line

Claims

1. The first planar coil and, The second planar coil is superimposed on the first planar coil, The first planar coil includes a magnetic member having magnetism, which covers the opposite side of the surface of the first planar coil that faces the second planar coil, The first planar coil and the second planar coil are connected in series. The first planar coil and the second planar coil are supplied with an alternating current of 75 kHz to 100 kHz, or an alternating magnetic field of 75 kHz to 100 kHz. A coil component in which the thickness of the second planar coil is 80% or more and 120% or less of the skin thickness δ.

2. A first planar coil, The second planar coil is superimposed on the first planar coil, The first planar coil includes a magnetic member having magnetism, which covers the opposite side of the surface of the first planar coil that faces the second planar coil, The first planar coil and the second planar coil are connected in series. The first planar coil and the second planar coil are supplied with an alternating current of 100 kHz or more and less than 200 kHz, or with an alternating magnetic field of 100 kHz or more and less than 200 kHz. A coil component in which the thickness of the second planar coil is 80% or more and 120% or less of the skin thickness δ.

3. A first planar coil, The second planar coil is superimposed on the first planar coil, The first planar coil includes a magnetic member having magnetism, which covers the opposite side of the surface of the first planar coil that faces the second planar coil, The first planar coil and the second planar coil are connected in series. The first planar coil and the second planar coil are supplied with an alternating current of 200 kHz to 1 MHz, or an alternating magnetic field of 200 kHz to 1 MHz. A coil component in which the thickness of the second planar coil is 80% or more and 120% or less of the skin thickness δ.

4. A first planar coil, The second planar coil is superimposed on the first planar coil, The first planar coil includes a magnetic member having magnetism, which covers the opposite side of the surface of the first planar coil that faces the second planar coil, The first planar coil and the second planar coil are connected in series. The first planar coil and the second planar coil are supplied with an alternating current of 1.1 MHz to 13.56 MHz, or an alternating magnetic field of 1.1 MHz to 13.56 MHz. A coil component in which the thickness of the second planar coil is 80% or more and 120% or less of the skin thickness δ.

5. The thickness of the first planar coil is 0.1 mm or more and 1.0 mm or less, as described in Claim 1. Coil components.

6. The first planar coil and the second planar coil overlap with a gap between them, The coil component according to claim 1, wherein the gap is 0.5 mm or more and 1.5 mm or less.

7. The magnetic member integrally holds the first planar coil and the second planar coil in a state in which they overlap with a gap between them, The coil component according to claim 1, wherein the magnetic member further includes a portion that covers the side surface of the first planar coil and a portion that fills the gap.

8. The coil component according to claim 7, wherein the magnetic member comprises a resin and magnetic particles held in the resin.

9. The coil component according to claim 7, wherein the relative permeability of the magnetic member is 5.0 or more.

10. The coil component according to claim 7, wherein the magnetic member includes a wall portion protruding from the second planar coil.

11. The magnetic shielding member is further provided to be positioned opposite to the surface of the covering portion of the magnetic member that faces the surface facing the first planar coil, The coil component according to claim 1, wherein the magnetic shielding member includes a plate-shaped ferrite.

12. The coil component according to claim 11, wherein the relative permeability of the magnetic shielding member is 500 or more.

13. The first planar coil and the second planar coil each include a plurality of turn portions arranged in a direction perpendicular to their respective central axes, The coil component according to claim 1, wherein any of the plurality of turn portions of the first planar coil and any of the plurality of turn portions of the second planar coil partially overlap in the axial direction of the first planar coil, and the overlapping portion of the turn portion of the first planar coil and the portion of the turn portion of the second planar coil in the axial direction extend parallel to each other.

14. The coil component according to claim 1, wherein the material of the first planar coil and the material of the second planar coil are the same.

15. The coil component according to claim 1, wherein the number of turns of the first planar coil and the number of turns of the second planar coil are 4 or more and 12 or less.

16. The coil component according to claim 1, wherein the first planar coil and the second planar coil are sized to fit within a square with sides of 800 mm.

17. Further comprising an even number of other planar coils disposed between the first planar coil and the second planar coil, The first planar coil, the other planar coil, and the second planar coil are connected in series. The coil component according to claim 1, wherein the thickness of at least the different planar coil among the planar coils connected to the first planar coil in the other planar coil and the planar coil different from said planar coil is 0.15 mm or more and 0.35 mm or less.

18. The coil component according to claim 17, wherein the thickness of the planar coil connected to the first planar coil among the other planar coils is 0.15 mm or more and 0.35 mm or less.

19. A power transmission device comprising the coil component described in Claim 1.

20. The power transmission device according to claim 19, further comprising a high-frequency current supply unit that supplies an alternating current of 79 kHz or more and 90 kHz or less to the coil component.

21. A power receiving device comprising the coil component described in Claim 1.

22. The power receiving device according to claim 21, further comprising a conversion unit that converts an alternating current of 79 kHz to 90 kHz generated by electromagnetic induction in the coil component into a direct current.

Images