Coil component, coil intermediate material, power transmission device, power reception device, and power transmission system

Abstract

A coil component (10) comprises: planar coils (11, 12) that have a spiral shape, each include a first surface (11A, 12A) and a second surface (11B, 12B) that are opposite each other in the axial direction extending on a central axis (C1, C2) of the spiral shape, and each include a plurality of turn portions (11n, 12n) arranged in the radial direction of the spiral shape; partition walls portion (32, 36) provided between adjacent turn portions (11n, 12n) of the plurality of turn portions (11n, 12n); a first holding member (20) provided so as to face the first surface (11A, 12A) of the planar coils (11, 12); a first magnetic shield member (40) that, together with the first holding member (20), sandwiches the planar coils (11, 12); and a second magnetic shield member (50) that, together with the first holding member (20) sandwiches first magnetic shield member (40).

Description

Coil components, coil intermediate materials, power transmission devices, power receiving devices, and power transmission systems

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

[0002] Wireless power transmission systems that transmit power in a contactless manner are becoming increasingly popular.

[0003] When transmitting power contactlessly, a high-frequency current flows through a resonant circuit including a coil. For example, as disclosed in Patent Document 1, the coil may be formed in a spiral shape with electric wires running parallel to each other. Generally, the coil is used while being housed in a hollow case.

[0004] Japanese Patent Application Laid-Open No. 2021-27112

[0005] When high-frequency current flows in the same direction through parallel electric wires, the magnetic field from the adjacent wires hinders the flow of electricity. This results in increased resistance. This is called the proximity effect. To address this issue, the influence of the magnetic field can be reduced by providing a magnetic barrier between the parallel electric wires. This reduces high-frequency resistance. A magnetic-resin composite, in which magnetic powder is dispersed in a resin material, can be used as such a magnetic material.

[0006] When using a magnetic material-resin composite, increasing the content of magnetic material powder and increasing the magnetic impermeability is more effective in reducing the effects of magnetic fields. On the other hand, if the content of magnetic material powder is increased, the fluidity of the material used to mold the magnetic material-resin composite decreases, which can make it difficult to mold the magnetic material-resin composite. In this case, it may be difficult to provide a magnetic material barrier between the electric wires, making it difficult to reduce the effects of magnetic fields.

[0007] The present embodiment aims to provide a coil component, a coil intermediate material, a power transmitting device, a power receiving device, and a power transfer system that are capable of reducing the influence of a magnetic field.

[0008] Furthermore, there is a demand for improved performance in such coils.

[0009] The present embodiment aims to provide a coil component, a coil intermediate material, a power transmitting device, a power receiving device, and a power transfer system that can improve performance.

[0010] An embodiment of the present disclosure relates to the following [1] to

[21] .

[0011] [1] A coil component comprising: a planar coil having a spiral shape, including a first surface and a second surface that are opposite to each other in an axial direction extending on a central axis of the spiral shape, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; a first holding member provided so as to face the first surface side of the planar coil; a first magnetic shield member that sandwiches the planar coil with the first holding member; and a second magnetic shield member that sandwiches the first magnetic shield member with the first holding member.

[0012] [2] The coil component according to [1], wherein the partition includes a first partition surface facing the first holding member and a second partition surface opposite the first partition surface in the axial direction, and a distance in the axial direction between a midpoint between the first surface and the second surface of the planar coil and the first partition surface of the partition is 35% to 65% of a height of the partition.

[0013] [3] The coil component according to [1] or [2], wherein the partition wall is divided into a plurality of divided bodies.

[0014] [4] The coil component according to [3], wherein the partition wall is divided in at least one of a radial direction and a circumferential direction of the spiral shape.

[0015] [5] The coil component according to any one of [1] to [4], further comprising a second holding member provided on a second surface side of the planar coil, wherein the second holding member has a base portion positioned between the planar coil and the first magnetic shield member and supporting the partition portion, and the partition portion.

[0016] [6] The coil component according to [5], wherein the second holding member has an inner region located radially inward, an outer region located radially outward, and an intermediate region located between the inner region and the outer region, wherein the second holding member is located between the planar coil and the first magnetic shield member only in the intermediate region and has a base portion that supports the partition portion, and wherein the relative permeability of the partition portion and the relative permeability of the base are equal to each other.

[0017] [7] The coil component according to [5] or [6], wherein an opening is formed in the base portion.

[0018] [8] The coil component according to any one of [1] to [7], further comprising a resin portion filled between the partition portion and the planar coil.

[0019] [9] The coil component according to [8], wherein the resin portion has magnetic properties.

[0020]

[10] The coil component according to [8] or [9], wherein the relative permeability of the partition portion is greater than the relative permeability of the resin portion.

[0021]

[11] The coil component according to any one of [1] to

[10] , wherein the planar coil is formed in a plate shape.

[0022]

[12] The coil component according to any one of [1] to

[11] , wherein the relative permeability of the partition wall is greater than 10.

[0023]

[13] The coil component according to any one of [1] to

[12] , wherein the partition wall portions are located between the turn portions and on the outer side of the radial center.

[0024]

[14] The coil component according to

[13] , wherein the partition wall portion is provided with a protruding piece that protrudes radially inward.

[0025]

[15] A first planar coil having a spiral shape, including a first surface and a second surface that are opposite to each other in an axial direction extending on a central axis of the spiral shape, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a second planar coil having a spiral shape, including a third surface facing the second surface and a fourth surface that is opposite to the third surface in the axial direction, and including a plurality of turn portions arranged in the radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; a first holding member provided to face the first surface side of the first planar coil; a first magnetic shield member that sandwiches the first planar coil and the second planar coil with the first holding member; and a second magnetic shield member that sandwiches the first magnetic shield member with the first holding member, wherein the partition portion includes a first partition surface that faces the first holding member and a second partition surface that is opposite to the first partition surface in the axial direction, a distance between the first surface of the first planar coil and the first partition surface of the partition portion in the axial direction is 35% or more and 65% or less of a difference between a height of the partition portion and a distance between the first surface and the fourth surface.

[0026]

[16] A coil intermediate material comprising: a planar coil having a spiral shape, including a first surface and a second surface that are opposite to each other in an axial direction extending on a central axis of the spiral shape, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; and a first holding member provided to face the first surface side of the planar coil, wherein the partition portion includes a first partition surface that faces the first holding member and a second partition surface that is opposite to the first partition surface in the axial direction, and a distance in the axial direction between a midpoint between the first surface and the second surface of the planar coil and the first partition surface of the partition portion is 35% to 65% of a height of the partition portion.

[0027]

[17] A coil intermediate material comprising: a planar coil having a spiral shape, including a first surface and a second surface that are opposite to each other in an axial direction extending on a central axis of the spiral shape, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; and a first holding member provided so as to face the first surface side of the planar coil, wherein the partition portion is divided into a plurality of divisions.

[0028]

[18] A first planar coil having a spiral shape, including a first surface and a second surface that are opposite to each other in an axial direction extending on a central axis of the spiral shape, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a second planar coil having a spiral shape, including a third surface facing the second surface and a fourth surface that is opposite to the third surface in the axial direction, and including a plurality of turn portions arranged in the radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; and a first holding member provided to face the first surface side of the first planar coil, wherein the partition portion includes a first partition surface that faces the first holding member and a second partition surface that is opposite to the first partition surface in the axial direction, a distance in the axial direction between the first surface of the first planar coil and the first partition surface of the partition portion that is 35% or more and 65% or less of a difference between a height of the partition portion and a distance between the first surface and the fourth surface.

[0029]

[19] A power transmitting device including the coil component according to any one of [1] to

[15] .

[0030]

[20] A power receiving device comprising the coil component according to any one of [1] to

[15] .

[0031]

[21] A power transfer system including a power transmitting device and a power receiving device, wherein at least one of the power transmitting device and the power receiving device includes the coil component according to any one of [1] to

[15] .

[0032] According to the present disclosure, the influence of a magnetic field can be reduced in a coil component.

[0033] Furthermore, according to the present disclosure, the performance of the coil component can be improved.

[0034] FIG. 1 is a diagram schematically illustrating a wireless power transmission system to which a coil component according to a first embodiment can be applied. FIG. 2 is an exploded perspective view illustrating the coil component according to the first embodiment. FIG. 3 is a perspective view illustrating a first planar coil, a second planar coil, a second holding member, a first magnetic shield member, and a second magnetic shield member of the coil component according to the first embodiment, where the coil component is viewed from a second surface of the first planar coil. FIG. 4 is a perspective view illustrating the first planar coil, the second planar coil, and the second holding member of the coil intermediate member according to the first embodiment, where the first planar coil, the second planar coil, and the second holding member are viewed from a second surface of the first planar coil. FIG. 5 is a cross-sectional view (cross-sectional view taken along line VV in FIG. 4 ) illustrating the coil component according to the first embodiment. FIG. 6 is an enlarged cross-sectional view (cross-sectional view of portion VI in FIG. 5 ) illustrating the coil component according to the first embodiment. FIG. 7 is a perspective view showing a second planar coil and a second holding member of the coil intermediate material according to the first embodiment, where the second planar coil and the second holding member are viewed from the second surface side of the second planar coil. FIG. 8 is a perspective view showing the second holding member of the coil intermediate material according to the first embodiment, where the second holding member is viewed from the second surface side of the second planar coil. FIG. 9 is a cross-sectional view (cross-sectional view along line IX-IX in FIG. 4 ) showing the coil component according to the first embodiment. FIG. 10 is an enlarged cross-sectional view (cross-sectional view of part X in FIG. 9 ) showing the coil component according to the first embodiment. FIG. 11 is a cross-sectional view for explaining an example of a manufacturing method for the coil component according to the first embodiment. FIG. 12 is a cross-sectional view for explaining an example of a manufacturing method for the coil component according to the first embodiment. FIG. 13 is a cross-sectional view for explaining an example of a manufacturing method for the coil component according to the first embodiment. FIG. 14 is a cross-sectional view for explaining an example of a manufacturing method for the coil component according to the first embodiment. FIG. 15 is a cross-sectional view for explaining an example of a manufacturing method for the coil component according to the first embodiment. Fig. 16 is a cross-sectional view for explaining an example of a manufacturing method of the coil component according to the first embodiment. Fig. 17 is an exploded perspective view showing a modified example of the coil component according to the first embodiment. Fig. 18 is a bottom view showing a planar coil, a second holding member, a first magnetic shield member, and a second magnetic shield member of the modified example of the coil component according to the first embodiment.FIG. 19 is a cross-sectional view (cross-sectional view taken along line XIX-XIX in FIG. 18 ) showing a modified example of the coil component according to the first embodiment. FIG. 20 is an enlarged cross-sectional view (cross-sectional view taken along line XX in FIG. 19 ) showing a modified example of the coil component according to the first embodiment. FIG. 21 is a cross-sectional view (cross-sectional view corresponding to FIG. 5 ) showing a modified example of the coil component according to the first embodiment. FIG. 22 is an enlarged cross-sectional view (cross-sectional view taken along line XXII in FIG. 21 ) showing a modified example of the coil component according to the first embodiment. FIG. 23 is a perspective view showing a divided body of the second holding member of the modified example of the coil component according to the first embodiment. FIG. 24 is an enlarged perspective view showing a divided body of the second holding member of the modified example of the coil component according to the first embodiment. FIG. 25 is a cross-sectional view showing a divided body of the second holding member and a first holding member of the modified example of the coil component according to the first embodiment. FIG. 26 is a cross-sectional view (cross-sectional view corresponding to FIG. 19 ) showing a modified example of the coil component according to the first embodiment. FIG. 27 is an enlarged cross-sectional view (cross-sectional view of part XXVII in FIG. 26 ) showing a modified example of the coil component according to the first embodiment. FIG. 28 is a plan view showing a second holding member of the modified example of the coil component according to the first embodiment. FIG. 29 is a cross-sectional view (cross-sectional view corresponding to FIG. 19 ) showing a modified example of the coil component according to the first embodiment. FIG. 30 is an enlarged cross-sectional view (cross-sectional view of part XXX in FIG. 29 ) showing a modified example of the coil component according to the first embodiment. FIG. 31 is a perspective view showing a second holding member of the coil component according to the second embodiment. FIG. 32 is a cross-sectional view (cross-sectional view corresponding to FIG. 19 ) showing the coil component according to the second embodiment. FIG. 33 is an enlarged cross-sectional view (cross-sectional view of part XXXIII in FIG. 32 ) showing the coil component according to the second embodiment. FIG. 34 is a plan view showing a second holding member of the modified example of the coil component according to the second embodiment. FIG. 35 is a diagram showing a simulation result in performance evaluation of the coil component. FIG. 36 is a diagram showing a simulation result in performance evaluation of the coil component. Fig. 37 is a graph showing simulation results in performance evaluation of the coil component. Fig. 38 is a perspective view showing a second holding member of the coil component according to the third embodiment. Fig. 39 is a cross-sectional view (cross-sectional view corresponding to Fig. 19 ) showing the coil component according to the third embodiment.FIG. 40 is an enlarged cross-sectional view (cross-sectional view of line XL in FIG. 39 ) showing a coil component according to the third embodiment. FIG. 41 is an enlarged cross-sectional view (cross-sectional view of line XLI in FIG. 39 ) showing a coil component according to the third embodiment. FIG. 42 is an enlarged cross-sectional view (cross-sectional view of line XLII in FIG. 39 ) showing a coil component according to the third embodiment. FIG. 43 is an exploded perspective view showing a coil component according to the fourth embodiment. FIG. 44 is a bottom view showing a first planar coil, a second planar coil, a second holding member, a first magnetic shield member, and a second magnetic shield member of a coil component according to the fourth embodiment. FIG. 45 is a cross-sectional view (cross-sectional view along line XLV-XLV in FIG. 44 ) showing a first planar coil, a second planar coil, and a second holding member of a coil component according to the fourth embodiment. FIG. 46 is an enlarged cross-sectional view (cross-sectional view of line XLVI in FIG. 45 ) showing a coil component according to the fourth embodiment. FIG. 47 is an exploded perspective view showing a modified example of the coil component according to the fourth embodiment. FIG. 48 is a bottom view showing a planar coil, a second holding member, a first magnetic shield member, and a second magnetic shield member of a modified coil component according to the fourth embodiment. FIG. 49 is a cross-sectional view (cross-sectional view taken along line XLIX-XLIX in FIG. 48 ) showing a modified coil component according to the fourth embodiment. FIG. 50 is an enlarged cross-sectional view (cross-sectional view of portion L in FIG. 49 ) showing a planar coil and a second holding member of a modified coil component according to the fourth embodiment. FIG. 51 is a graph showing the results of a simulation in performance evaluation of the coil component, illustrating the relationship between the distance from the midpoint between the first surface of the first planar coil and the second surface of the second planar coil to the center of the partition wall and the Q value. FIG. 52 is a graph showing the results of a simulation in performance evaluation of the coil component, illustrating the relationship between the distance from the midpoint between the first surface of the first planar coil and the second surface of the second planar coil to the center of the partition wall and the Q value. FIG. 53 is a graph showing the results of a simulation in performance evaluation of the coil component, illustrating the relationship between each turn portion and loss density.

[0035] Each embodiment will be described below with reference to the drawings. Note that in the drawings attached to this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of ease of illustration and understanding.

[0036] Furthermore, in this specification, terms such as "sheet," "film," and "plate" are not distinguished from one another solely based on differences in name. Therefore, for example, "sheet" is a concept that also includes members that can be called films or plates.

[0037] (First embodiment) Fig. 1 schematically shows a wireless power transmission system S to which a coil component 10 according to a first embodiment is applied. First, the wireless power transmission system S (hereinafter abbreviated as power transmission system S) will be described with reference to Fig. 1. It goes without saying that a coil component different from the coil component 10 according to the present embodiment can be applied to the power transmission system S.

[0038] <Wireless Power Transmission System> The power transmission system S includes a power transmission device 1 and a power receiving device 2. The power transmission device 1 includes a coil component 10 and a high-frequency current supply unit 1A. The coil component 10 in the power transmission device 1 functions as a power transmission coil component. The high-frequency current supply unit 1A supplies a high-frequency current to the coil component 10 serving as a power transmission coil component.

[0039] 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 component. The conversion unit 2A shapes the high-frequency current generated in the coil component 10. The conversion unit 2A includes a rectifier circuit that converts the high-frequency current into a direct current. The conversion unit 2A may include, for example, a full-wave rectifier circuit including a plurality of diodes and a smoothing capacitor.

[0040] In the present 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.

[0041] 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 component. 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 component in the power receiving device 2. That is, the power receiving device 2 receives the magnetic field from the power transmitting device 1 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).

[0042] 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 also 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.

[0043] However, the use of the power transmission system S is not limited to power transmission to electric vehicles. For example, the power transmission system S may be used to transmit power to drones and other flying objects, or robots. Furthermore, the power transmission system S may be used to transmit power to underwater submersibles and exploration robots. In this way, the power transmission system S can be used to transmit power to various moving objects, such as electric vehicles, flying objects, robots, and submersibles. Furthermore, the use of the coil component 10 is not limited to wireless power transmission systems. For example, the coil component 10 may be used in transformers, DC-DC converters, antennas, etc.

[0044] <Coil Component> The coil component 10 will be described below.

[0045] As shown in FIG. 2 , the coil component 10 includes a coil intermediate material 10M, a first magnetic shield member 40 , a second magnetic shield member 50 , a first connection terminal 61 , and a second connection terminal 62 .

[0046] As shown in Fig. 2, in coil component 10, a first magnetic shield member 40 and a second magnetic shield member 50 are stacked in this order on coil intermediate material 10M. Also, as shown in Fig. 2, coil intermediate material 10M includes first holding member 20, first planar coil (planar coil) 11, second planar coil (planar coil) 12, and partition wall portion 36 (second holding member 30). Coil intermediate material 10M may also include, as second holding member 30, partition wall portion 36 and a resin portion 30b filled between first planar coil 11 and second planar coil 12. Each portion of coil component 10 and coil intermediate material 10M will be described in detail below.

[0047] 2 to 4 , first planar coil 11 has a spiral shape and is made of a conductive material. In the present embodiment, first planar coil 11 contains copper. Specifically, first planar coil 11 is made of a copper thin film. However, first planar coil 11 may also be made of a copper alloy, aluminum, an aluminum alloy, or the like.

[0048] 2 to 4, first planar coil 11 has a plate shape. As shown in Fig. 5 and Fig. 6, the cross-sectional shape of first planar coil 11 in the direction in which first planar coil 11 winds in a spiral shape, in other words, in the direction perpendicular to the direction in which the spiral shape extends, is rectangular.

[0049] 2 to 5 indicates a first central axis (center 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. Furthermore, the radial direction of a circle drawn on a plane centered at an arbitrary point on first central axis C1 and perpendicular to first central axis C1 is referred to as the radial direction of first planar coil 11. First planar coil 11 includes first surface 11A and second surface 11B that are opposite each other in the axial direction. First surface 11A of first planar coil 11 faces first holding member 20, and second planar coil 12 and the like are stacked on second surface 11B.

[0050] 2 to 4 , first planar coil 11 has conductor portion 11E having a spiral shape formed by a plurality of turn portions 11n. The plurality of turn portions 11n of first planar coil 11 are arranged in a direction perpendicular to a first central axis C1 of the spiral shape. In other words, first planar coil 11 includes a plurality of turn portions 11n arranged in the radial direction of the spiral shape. More specifically, the plurality of turn portions 11n are connected so as to gradually move away from first central axis C1 of the spiral shape toward the radially outward direction of first planar coil 11. This forms the spiral shape.

[0051] The turn portions 11n are basically linear conductor portions that do not form a loop but wrap around the first central axis C1 360 degrees. In the case of a so-called planar coil, both ends of the turn portions 11n are offset in the radial direction of the first planar coil 11. In the case of the multiple turn portions 11n, the radially outer end of one turn portion 11n is connected to the radially inner end of another turn portion 11n, and the other turn portions 11n extend away from the first central axis C1.

[0052] Hereinafter, the turn portion 11n that is closest to the first central axis C1 may be referred to as the turn portion 111. Furthermore, 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 include six turn portions 111 to 116. Hereinafter, when describing matters common to each of the turn portions 11n, they will basically be referred to as the turn portion 11n.

[0053] In this embodiment, the turn section 11n goes around to form an octagon (regular octagon). However, the turn section 11n may go around to form a polygon other than an octagon or a circle. For example, the turn section 11n may go around to form a dodecagon or a regular dodecagon. Note that the term "spiral shape" as used in this specification and this disclosure refers to a planar curved shape wound in a spiral shape. The planar curved shape here also includes a planar pattern that goes around repeatedly while bending like a broken line, as shown in the figure. In other words, the spiral shape refers to a planar curved shape that moves away from the center as it goes around (or moves closer to the center as it goes around).

[0054] The radially inner end (the end closest 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. On the other hand, the radially outer end (the end farthest from the first central axis C1) of the turn portion 116 of the multiple turn portions 11 n that is farthest from the first central axis C1 is connected to the first connection terminal 61.

[0055] Here, the radial inward direction of first planar coil 11 (turn portions 11n) refers to a direction approaching first central axis C1 in the radial direction. The radial outward direction of first planar coil 11 (turn portions 11n) refers to a direction moving away from first central axis C1 in the radial direction. In this embodiment, first central axis C1 is determined as follows: First, starting from the radially inner end of turn portion 112 adjacent to innermost turn portion 111, linear virtual turn portions similar in shape to turn portion 112 are sequentially drawn radially inward to form a spiral shape. Drawing is continued until virtual turn portions that fit within a 1 cm diameter are drawn. A line that passes through the radially inner region of the virtual turn portions that fit within a 1 cm diameter in a direction perpendicular to the circumferential and radial directions of the spiral shape is determined as first central axis C1.

[0056] In the present embodiment, first planar coil 11 is formed by punching a metal plate such as a copper plate or an aluminum plate into a spiral shape, for example. However, first planar coil 11 can also be formed by etching a metal foil such as a copper foil or an aluminum foil into a spiral shape.

[0057] The thickness of first planar coil 11 (thickness of conductor portion 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 farthest point 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 portion 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 portion 11E) by the thickness of first planar coil 11 (conductor portion 11E). The aspect ratio of first planar coil 11 (conductor portion 11E) may be 2 or more and 12 or less, or 3 or more and 10 or less.

[0058] When transmitting power to an electric vehicle using magnetic resonance, it is desirable to be able to transmit 1 kW or more, preferably 5 kW or more, of power in a high-frequency current frequency band of 10 kHz to 200 kHz, particularly 75 kHz to 100 kHz, and even more preferably 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. From this perspective, the lower limit of the thickness of first planar coil 11 may be set to 0.2 mm. Furthermore, when transmitting power to an electric vehicle, excessively large size is not desirable, and size may be limited. From this perspective, first planar coil 11 and second planar coil 12 (described below), specifically, conductor portion 11E of first planar coil 11 and conductor portion 12E of second planar coil 12, are preferably formed to a size that fits within a square with sides of 800 mm.

[0059] Furthermore, the wire width of first planar coil 11 (wire width of conductor portion 11E), i.e., the radial width of each turn portion 11n (width in the radial direction), is not particularly limited. However, considering that a power of 1 kW or more, preferably 5 kW or more, can be transmitted 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 to 20 mm, 2 mm to 16 mm, 2 mm to 12 mm, or 2 mm to 8 mm. Furthermore, the number of turns in first planar coil 11 may be 4 to 12, but is not particularly limited.

[0060] 2 to 4 and 7, second planar coil 12 also has a spiral shape, and in this embodiment, second planar coil 12 also contains copper. Specifically, second planar coil 12 is formed using a copper thin film. The material of second planar coil 12 is not particularly limited, and may be a copper alloy, aluminum, an aluminum alloy, or the like. Second planar coil 12 also has a plate shape. As shown in FIGS. 5 and 6, the cross section 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.

[0061] 2 to 5 and 7 indicates a second central axis (center 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. The radial direction of a circle drawn on a plane centered at an arbitrary point on second central axis C2 and perpendicular to second central axis C2 is referred to as the radial direction of second planar coil 12. Second planar coil 12 includes a first surface (third surface) 12A and a second surface (fourth surface) 12B that are opposite each other in the axial direction. The first surface 12A of second planar coil 12 faces first planar coil 11 (second surface 11B), and a second holding member 30, a first magnetic shield member 40, and a second magnetic shield member 50 are superimposed on second surface 12B.

[0062] In the present embodiment, second planar coil 12 is arranged coaxially 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.

[0063] 2 to 4 and 7, second planar coil 12 also has a conductor portion 12E having a spiral shape formed by a plurality of turn portions 12n. The plurality of turn portions 12n of second planar coil 12 are arranged in a direction perpendicular to second central axis C2 of the spiral shape. In other words, second planar coil 12 includes a plurality of turn portions 12n arranged in the radial direction of the spiral shape.

[0064] The connection pattern of the plurality of turn portions 12n and the names (such as turn portion 121) according to their positions are the same as those of turn portion 11n of first planar coil 11. In this embodiment, the number of turns of first planar coil 11 and second planar coil 12 are the same, and the plurality of turn portions 12n includes six turn portions 121 to 126. Similarly to turn portion 11n, turn portion 12n winds around to form an octagon (regular octagon). Turn portion 12n may wind around to form a polygon other than an octagon or a circle. For example, turn portion 12n may wind around to form a dodecagon or a regular dodecagon. The number of turns of first planar coil 11 and second planar coil 12 may differ. For example, turn portion 12n may be octagonal and turn portion 11n may be circular.

[0065] 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 the radially inner end of turn portion 121 in second planar coil 12. Here, when first planar coil 11 and second planar coil 12 are connected, the direction in which first planar coil 11 winds becomes the same as the direction in which second planar coil 12 winds.

[0066] Note that the above-described "direction in which first planar coil 11 winds" refers to the direction in which first planar coil 11 winds from the end of first planar coil 11 that is not connected to second planar coil 12 to the end that is connected to second planar coil 12. The end of first planar coil 11 that is not connected to second planar coil 12 refers to the radially outer end of first planar coil 11. The end of first planar coil 11 that is connected to second planar coil 12 refers to the radially inner end of first planar coil 11. In the present embodiment, as shown in FIG. 2 , first planar coil 11 winds in a clockwise direction in a planar view from the end that is not connected to second planar coil 12 to the end that is connected to second planar coil 12.

[0067] Furthermore, the above-described "direction in which second planar coil 12 winds" refers to the direction in which second planar coil 12 winds from the end of second planar coil 12 that is connected to first planar coil 11 to the end that is not connected to first planar coil 11. The end of second planar coil 12 that is connected to first planar coil 11 refers to the radially inner end of second planar coil 12. The end of second planar coil 12 that is not connected to first planar coil 11 refers to the radially outer end of second planar coil 12. In this embodiment, as shown in FIG. 2 , second planar coil 12 winds in a clockwise direction in a planar view from the end that is connected to first planar coil 11 to the end that is not connected to first planar coil 11. In this case, as shown in FIG. 4 , in some regions, spaces G between turn portions 12 n of second planar coil 12 are covered by first planar coil 11.

[0068] As shown in FIG. 2 , the radially outer end of the turn portion 126 farthest from the second central axis C2 among the plurality of turn portions 12n is connected to the second connection terminal 62. The radially inner and outer directions of the second planar coil 12 (turn portions 12n) are defined in the same manner as the radially inner and outer directions of the first planar coil 11 described above. The position of the second central axis C2 is also determined in the same manner as the first central axis C1. In addition, the second planar coil 12 in this embodiment is also formed by punching a metal plate, such as a copper plate or an aluminum plate, into a spiral shape, for example. However, the second planar coil 12 can also be formed by etching a metal foil, such as a copper foil or an aluminum foil, into a spiral shape.

[0069] In the present embodiment, the thickness of second planar coil 12 (the thickness of conductor portions 12E) may be, for example, 0.1 mm to 1.0 mm. Similarly to first planar coil 11, the radius of second planar coil 12 (the distance from second center axis C2 to the farthest point in the radial direction) may be 80 mm or more, or 80 mm to 450 mm. Similarly to first planar coil 11, the aspect ratio of second planar coil 12 (conductor portions 12E) having a rectangular cross section may be 2 to 12, or 3 to 10. Similarly to first planar coil 11, the line width of second planar coil 12 (the line width of conductor portions 12E), i.e., the radial width of each turn portion 12n (the width in the radial direction), may be 2 mm to 20 mm, 2 mm to 16 mm, 2 mm to 12 mm, or 2 mm to 8 mm. The number of turns of second planar coil 12 may be 4 or more and 12 or less, but is not particularly limited thereto.

[0070] 5 and 6 , first planar coil 11 and second planar coil 12 overlap with a gap in the axial direction. 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 generated in first planar coil 11 and second planar coil 12 when current is supplied tends to increase. Furthermore, if the gap is too large, the thinning of coil component 10 is impaired. The gap between first planar coil 11 and second planar coil 12 is maintained by the presence of second holding member 30 between planar coils 11 and 12, as described below.

[0071] 2 and 6 , first holding member 20 is disposed to face first surface 11A of first planar coil 11. Specifically, first holding member 20 overlaps first planar coil 11 so as to face first surface 11A of first planar coil 11, and holds first planar coil 11. In the present embodiment, first holding member 20 has a rectangular shape corresponding to the shape of turn portion 11n in a planar view. In coil device 10, for example, when transmitting power, the magnetic fields generated in first planar coil 11 and second planar coil 12 pass through first holding member 20. Therefore, first holding member 20 is preferably non-conductive (insulating) and non-magnetic so as not to interfere with the magnetic field and to prevent eddy currents from being generated.

[0072] Considering that non-conductive (insulating) and non-magnetic properties are preferable, the material of the first holding member 20 is, for example, resin, and may also be fiber-reinforced plastic. More specifically, the material of the first holding member 20 may be glass fiber-reinforced polyamide. However, the material of the first holding member 20 is not particularly limited. For example, it may not contain glass fiber. Furthermore, thermoplastic resins or thermosetting resins other than polyamide may also be used. Note that insulating properties are defined as those having a volume resistivity of 10 １０ It means that the resistance is Ω·m or more. Non-magnetic means that it does not exhibit magnetism.

[0073] First holding member 20 is integrated with first planar coil 11 to hold first planar coil 11. In the present embodiment, first planar coil 11 is placed in first holding member forming dies 201 and 202 (see FIG. 11 , etc.), and then a material for forming first holding member is pressed into dies 201 and 202 by hot pressing to form the material, which is then cooled and solidified, thereby integrating first planar coil 11 and first holding member 20. In this specification, first holding member 20 and second holding member 30 integrated with first planar coil 11 are also referred to as coil intermediate material 10M.

[0074] In the present embodiment, first holding member 20 sandwiches first planar coil 11 and second planar coil 12 with second holding member 30. As shown in Figures 5 and 6, first holding member 20 has contact surface 20S1 that contacts first surface 11A of first planar coil 11. Contact surface 20S1 forms the inner surface of first holding member 20. First holding member 20 also has outer surface 20S2, which is the surface opposite contact surface 20S1.

[0075] As shown in Figures 5 and 6, the contact surface 20S1 is formed with a groove 24 that receives a partition portion (protrusion) 32 of the divided body 30a of the second holding member 30, which will be described later, and a part of the resin portion 30b, which will be described later.

[0076] Grooves 24 are formed between adjacent turn portions 11n of first planar coil 11 as viewed in the axial direction of first planar coil 11. In the illustrated example, grooves 24 are also formed radially outward of outermost turn portion 116. In addition, in the illustrated example, grooves 24 are also formed radially inward of innermost turn portion 111. Grooves 24 are formed along the spiral shape of first planar coil 11. Therefore, grooves 24 are formed in a spiral shape corresponding to the spiral shape of first planar coil 11.

[0077] (Second Holding Member) At least a portion of second holding member 30 is provided on the second surface (11B, 12B) side of planar coils 11, 12. As shown in FIGS. 2 , 5 , and 6 , second holding member 30 in this embodiment is integrated with first planar coil 11, second planar coil 12, and first holding member 20 so as to sandwich first planar coil 11 and second planar coil 12 between first holding member 20 and second holding member 20. In this embodiment, second holding member 30 has an octagonal shape in a planar view that corresponds to the shape of turn portion 11n. As described above, second holding member 30 has a portion interposed between second planar coil 12 and first magnetic shield member 40, and another portion interposed between first planar coil 11 and second planar coil 12.

[0078] 4 to 10, second holding member 30 has a plurality of segments 30a divided in the radial and circumferential directions. Also, as shown in FIGS. 5, 6, 9, and 10, second holding member 30 may further have resin portions 30b filled between segments 30a and first and second planar coils 11, 12.

[0079] In the illustrated example, eight segments 30 a are arranged in the circumferential direction, and two rows of eight segments 30 a are arranged in the radial direction. Note that the number of segments 30 a is arbitrary and can be changed as appropriate depending on the size of the coil device 10, etc.

[0080] Each divided body 30a is manufactured by injection molding. In this case, the divided bodies 30a can be molded at high temperatures. This makes it easy to obtain divided bodies 30a with high relative magnetic permeability. Furthermore, since the second holding member 30 has multiple divided bodies 30a, it is easy to arrange the pre-molded divided bodies 30a without gaps between the turn portions 11n, 12n. This effectively reduces the influence of magnetic fields and high-frequency resistance.

[0081] As shown in Figures 5, 6, 8, 9, and 10, segment 30a (second holding member 30) has a base 31 and a partition wall 32 that protrudes from base 31 and fits between turn portions 11n, 12n. More specifically, as shown in Figures 5, 6, 9, and 10, segment 30a has base 31 located between second planar coil 12 and first magnetic shield member 40, and partition wall 32 that protrudes from base 31 toward first holding member 20. Of these, base 31 is formed in a plate shape and supports partition wall 32. Base 31 and first holding member 20 sandwich first planar coil 11 and second planar coil 12 therebetween.

[0082] Partition wall portion 32 is provided between adjacent turn portions 11n, 12n of the plurality of turn portions 11n, 12n. Partition wall portion 32 extends between adjacent turn portions 11n of first planar coil 11 along the axial direction of first planar coil 11. Partition wall portion 32 also extends between adjacent turn portions 12n of second planar coil 12 along the axial direction of second planar coil 12. Therefore, partition wall portion 32 is formed along spiral-shaped first planar coil 11 and spiral-shaped second planar coil 12. In the illustrated example, partition wall portion 32 is formed in a spiral shape corresponding to the spiral shapes of first planar coil 11 and second planar coil 12. As described above, partition wall portion 32 is received in groove 24 of first holding member 20. In other words, partition wall portion 32 fills groove 24 of first holding member 20.

[0083] In this embodiment, partition wall portion 32 is located at the radial center between turn portions 11n and 12n. In this case, within groove 24, partition wall portion 32 is covered from both radial sides by resin portion 30b (described later). As described above, in some regions, spaces G between turn portions 12n of second planar coil 12 are covered by first planar coil 11 (see FIGS. 4 and 10 ). In this case, partition wall portion 32 does not extend between turn portions 11n in the above-mentioned regions. Therefore, the height of partition wall portion 32 in the above-mentioned regions is lower than the height of partition wall portion 32 in other regions.

[0084] In the illustrated example, resin portion 30b is disposed between first planar coil 11 and second planar coil 12, and serves to maintain the spacing between first planar coil 11 and second planar coil 12. Resin portion 30b is filled between first holding member 20 and first magnetic shield member 40.

[0085] The second holding member 30 has magnetic properties that suppress eddy current loss and leakage flux and increase the coupling coefficient, thereby improving coil performance. Therefore, the divided body 30a and the resin portion 30b of the second holding member 30 are magnetic as a whole. That is, the base portion 31 and the partition portion 32 of the divided body 30a, and the resin portion 30b are each magnetic.

[0086] In this embodiment, the relative permeability of the divided body 30a is preferably greater than the relative permeability of the resin portion 30b, which makes it possible to more effectively reduce the influence of the magnetic field between the turn portions 11n (12n), and thus to more effectively reduce the high-frequency resistance.

[0087] In this case, the relative permeability of the divided body 30a may be greater than 10. This more effectively reduces the influence of the magnetic field between the turn portions 11n (12n), and more effectively reduces high-frequency resistance. The relative permeability of the divided body 30a may also be 40 or less. This allows the divided body 30a to maintain good flexibility and strength.

[0088] The relative magnetic permeability of the resin portion 30b is preferably 2.0 or more, and may be 2.0 or more and 10 or less. The relative magnetic permeability of the resin portion 30b is more preferably 5.0 or more, and may be 5.0 or more and 10 or less. The relative magnetic permeability of the resin portion 30b is not particularly limited, but if it is too high, the flexibility and strength of the second holding member 30 may be undesirably impaired. Therefore, the relative magnetic permeability of the resin portion 30b may be 10 or less.

[0089] Furthermore, by including partition wall 32 in second holding member 30, coil performance can be effectively improved. The height of partition wall 32 (the distance between the top of partition wall 32 and second surface 12B of second planar coil 12 along the axial direction of first planar coil 11) is not particularly limited, but may be, for example, 0.5 mm or more, or 1.0 mm or more. The higher the partition wall 32, the greater the effect of suppressing eddy current loss and the higher the coupling coefficient. On the other hand, the higher the partition wall 32, the more susceptible it is to breakage, starting from its base. Therefore, the height of partition wall 32 may be, for example, 10 mm or less.

[0090] The second holding member 30 in the present embodiment includes, for example, a resin and a plurality or a large number of magnetic particles made of a magnetic material. The magnetic particles are held by the resin as a holding material.

[0091] The magnetic particles may be made of one or more of ferrite, particularly soft magnetic ferrite, nanocrystalline magnetic material, silicon steel, soft electromagnetic iron, and amorphous metal. The resin used 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 molding material of the second holding member 30 is not particularly limited.

[0092] (First Magnetic Shield Member) First magnetic shield member 40 is provided to suppress magnetic transmission and / or leakage magnetic fields. First magnetic shield member 40 sandwiches first planar coil 11, second planar coil 12, and second holding member 30 between first holding member 20 and first magnetic shield member 40. This first magnetic shield member 40 is a sheet-like member separate from first planar coil 11, second planar coil 12, first holding member 20, and second holding member 30. Being separate from first planar coil 11, second planar coil 12, first holding member 20, and second holding member 30 means that first magnetic shield member 40 is not integrated with first planar coil 11, second planar coil 12, first holding member 20, and second holding member 30. However, first magnetic shield member 40 and second holding member 30 may be joined via an adhesive layer or the like. First magnetic shield member 40 is formed to a size sufficient to encompass first planar coil 11, second planar coil 12, and second holding member 30 in a planar view. First magnetic shield member 40 overlaps first planar coil 11, second planar coil 12, and second holding member 30, and is in direct contact with second holding member 30.

[0093] In this embodiment, first magnetic shield member 40 is magnetic and includes or is made of a magnetic material. In coil component 10, a magnetic field is generated when current is supplied to first planar coil 11 and second planar coil 12. The magnetic field generated by coil component 10 spreads in all directions relative to central axes C1 and C2 of first planar coil 11 and second planar coil 12. Since first magnetic shield member 40 is magnetic, it can direct the spreading magnetic flux lines toward central axes C1 and C2. Coil component 10 may be installed in a vehicle. If the magnetic field generated by coil component 10 flows toward other vehicle components, adverse effects may be caused to the vehicle components. In such cases, first magnetic shield member 40 can suppress leakage magnetic fields that do not contribute to the generation of current.

[0094] The first magnetic shield member 40 preferably includes a soft magnetic material or a nanocrystalline magnetic material. More specifically, the first magnetic shield member 40 includes a ferrite, preferably a soft ferrite.

[0095] The relative permeability of the first magnetic shield member 40 may be equal to or greater than 500, or may be equal to or greater than 1000. The relative permeability of the first magnetic shield member 40 may be equal to or greater than 500 and equal to or less than 3000, or may be equal to or greater than 1000 and equal to or less than 10000. Note that the relative permeability in this specification is a value measured at a frequency of 85 kHz and an ambient temperature of 23 degrees.

[0096] (Second Magnetic Shield Member) The second magnetic shield member 50 is provided to cover the first magnetic shield member 40. The second magnetic shield member 50 is a member that sandwiches the first magnetic shield member 40 with the first holding member 20. In the present embodiment, the second magnetic shield member 50 contacts the first magnetic shield member 40. Alternatively, the second magnetic shield member 50 may contact the first magnetic shield member 40 via a spacer. The second magnetic shield member 50 is formed of a metallic material and is conductive. Specifically, in the present embodiment, the second magnetic shield member 50 is formed of aluminum. In this case, magnetic leakage from the first planar coil 11 and the second planar coil 12 through the second magnetic shield member 50 is suppressed. The second magnetic shield member 50 may also be formed of an aluminum alloy, copper, stainless steel, or the like.

[0097] 2 , the first connection terminal 61 is connected to a radially outer end of the turn portion 116 of the first planar coil 11. The second connection terminal 62 is connected to a radially outer end of the turn portion 126 of the second planar coil 12. The first connection terminal 61 and the second connection terminal 62 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 61 and the turn portion 116 and the connection between the second connection terminal 62 and the turn portion 126 may be performed by ultrasonic bonding. However, the connection method is not limited thereto, and for example, a conductive adhesive may be used for connection.

[0098] <Method for Manufacturing Coil Component 10> Next, an example of a method for manufacturing the coil component 10 will be described.

[0099] First, molds 201 and 202 shown in Fig. 11 are prepared. Of these, mold 202 has a main body portion 203 and a protruding portion 204 extending from main body portion 203. Protruding portion 204 has a spiral shape corresponding to the spiral shape of groove 24. Therefore, protruding portion 204 corresponds to the shape of the gap extending between adjacent turn portions 11n of first planar coil 11.

[0100] 12 , first planar coil 11 is placed on main body portion 203 of mold 202. At this time, first planar coil 11 is placed on main body portion 203 so that convex portions 204 of mold 202 extend out from between adjacent turn portions 11 n of first planar coil 11.

[0101] Next, material 220 for fabricating first holding member 11 is prepared. In the illustrated example, material 220 is a molding material formed into a plate shape. Next, material 220 is heated, and as shown in FIG. 12 , material 220 is placed on mold 202 and first planar coil 11.

[0102] Next, as shown in FIG. 13 , first planar coil 11 and material 220 are heat-pressed between mold 202 and another mold 201. Material 220 softens and melts between molds 201 and 202. As a result, grooves 24 corresponding to protrusions 204 of mold 202 are formed on one surface of material 220. In this manner, first holding member 20 having grooves 24 is formed. As viewed in the coil axis direction, grooves 24 are formed between adjacent turn portions 11n of first planar coil 11. Furthermore, first holding member 20 is cooled and solidified, thereby integrating first holding member 20 and first planar coil 11.

[0103] Also, a material 230 is prepared that constitutes the resin portion 30b of the second holding member 30. At this time, the relative permeability of the material 230 that constitutes the resin portion 30b may be 10 or less. This increases the fluidity of the material 230, allowing the material 230 to be filled into the groove 24 without gaps.

[0104] Next, as shown in FIG. 14 , first holding member 20 and first planar coil 11 are removed from molds 201 and 202, and then material 230 constituting resin portion 30b of second holding member 30 is placed on second surface 11B of first planar coil 11 (see FIG. 5 , etc.).

[0105] Next, as shown in FIG. 15, second planar coil 12 is placed on material 230 .

[0106] Next, the divided bodies 30a of the second holding member 30 are prepared. The divided bodies 30a are manufactured by injection molding. By manufacturing the divided bodies 30a by injection molding in this manner, divided bodies 30a with high relative magnetic permeability can be easily obtained. Furthermore, by preparing the divided bodies 30a molded in advance, it becomes easier to arrange the divided bodies 30a with high relative magnetic permeability without gaps between the turn portions 11n, 12n.

[0107] 16 , divided body 30a is placed on second planar coil 12 and material 230 and fixed in a predetermined position. Divided body 30a can be positioned by forming positioning pins or the like on first holding member 20 and fitting divided body 30a onto the pins, or by providing a structure that allows positioning in groove 24 of first holding member 20. This integrates first holding member 20, first planar coil 11, material 230 (resin portion 30b), second planar coil 12, and divided body 30a. In this manner, coil intermediate material 10M is produced.

[0108] Note that when dividing body 30a is placed on material 230, the position of second planar coil 12 may be shifted. Therefore, to prevent the position of second planar coil 12 from being shifted, a spacer (not shown) may be placed between first planar coil 11 and second planar coil 12. In this case, for example, before placing material 230 on first planar coil 11, a spacer (not shown) is placed between first planar coil 11 and second planar coil 12. Then, after the positional relationship between first planar coil 11 and second planar coil 12 is fixed, dividing body 30a is placed in a predetermined position. Thereafter, material 230 is poured between first planar coil 11, second planar coil 12, and dividing body 30a. The spacer may be a member obtained by solidifying material 230 or a member obtained by solidifying an insulating material different from material 230.

[0109] Thereafter, the first magnetic shield member 40 and the second magnetic shield member 50 are placed on the second holding member 30. In this manner, the coil component 10 is manufactured.

[0110] <Use of Coil Component> The coil component 10 according to the present 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.

[0111] When coil component 10 is used as a power transmission coil, first connection terminal 61 and second connection terminal 62 are connected to high-frequency current supply unit 1A or an AC power supply as shown in FIG. 1 . When high-frequency current is supplied to coil component 10, the current can flow from first connection terminal 61 to first planar coil 11 and second planar coil 12, and then from second connection terminal 62 to high-frequency current supply unit 1A or the AC power supply. Alternatively, the current can flow from second connection terminal 62 to second planar coil 12 and first planar coil 11, and then from first connection terminal 61 to high-frequency current supply unit 1A or the AC power supply. This allows a magnetic field including magnetic field lines along the central axis of the planar coil to be generated.

[0112] On the other hand, when coil component 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 or generating a magnetic field including magnetic field lines that pass through the inside of first planar coil 11 and second planar coil 12. This high-frequency current can then be supplied to an external device from first connection terminal 61 or second connection terminal 62.

[0113] 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 of a transformer, the first connection terminal 61 and the second connection terminal 62 are connected to an AC power source. When a high-frequency current is supplied, magnetic flux can be supplied from the center of the planar coil to the iron core.

[0114] <Modifications> Various modifications can be made to the above-described embodiment. For example, the coil component 10 includes two planar coils 11 and 12, but this is not limiting. The number of planar coils included in the coil component 10 may be one, or may be three or more.

[0115] 17, for example, in this modification, the coil device 10 includes one planar coil 11. In this case, the plurality of turn portions 11n of the planar coil 11 may include nine turn portions 111 to 119. In the following description, when matters common to each of the plurality of turn portions 11n are described, they will basically be referred to as the turn portion 11n.

[0116] 17 and 18 , in this modification, the radially inner end (the end closest to the first central axis C1) of the turn portion 111 closest to the first central axis C1 is electrically connected to the second connection terminal 62. On the other hand, the radially outer end (the end farthest from the first central axis C1) of the turn portion 119 of the multiple turn portions 11 n that is farthest from the first central axis C1 is connected to the first connection terminal 61.

[0117] 19 and 20 , in this modification, the second holding member 30 also has multiple segments 30a divided radially and circumferentially. Each segment 30a has a base 31 and a partition 32 that protrudes from the base 31 and fits between the turn portions 11n. This makes it easier to arrange the pre-formed segments 30a without gaps between the turn portions 11n, 12n. This effectively reduces the influence of magnetic fields and high-frequency resistance.

[0118] Furthermore, the coil component 10 includes, but is not limited to, the planar coils 11 and 12, each of which has a rectangular cross section in the direction in which the planar coils 11 and 12 are wound in a spiral shape. The planar coils 11 and 12 do not have to be planar. The coil component 10 may also include a planar coil formed of a Litz wire. The Litz wire is formed by twisting together multiple conductor wires. In this case, the cross section of the planar coil in the direction in which the planar coil is wound in a spiral shape may be circular.

[0119] Furthermore, although the partition wall 32 is located at the radial center between the turn portions 11n and 12n, this is not limiting. For example, as shown in FIGS. 21 and 22 , the partition wall 32 may be located outside the radial center between the turn portions 11n and 12n. In this case, as shown in FIGS. 23 and 24 , the partition wall 32 of the divided body 30a may be provided with a protruding piece 33 that protrudes radially inward. This protruding piece 33 serves to position the partition wall 32. That is, as shown in FIG. 25 , when the partition wall 32 of the divided body 30a is inserted into the groove 24 of the first holding member 20, the partition wall 32 abuts against the wall surface of the groove 24, so that the partition wall 32 is located outside the radial center between the turn portions 11n and 12n. This protruding piece 33 extends along the height direction (Z direction) of the partition wall 32. 24 and 25, a notch 34 may be formed in the end of the protruding piece 33 on the side opposite the base 31. This makes it easier to insert the partition wall 32 of the divided body 30a into the groove 24 of the first holding member 20, as shown in FIG.

[0120] In this modification, the partition wall 32 is located between the turn portions 11n, 12n, outside the radial center. When high-frequency current flows in the same direction through the parallel turn portions 11n, 12n, the current flowing toward the radial outside increases due to the proximity effect. Therefore, by locating the partition wall 32 outside the radial center, the influence of the magnetic field can be effectively reduced. This effectively reduces high-frequency resistance.

[0121] 21 and 22, the coil device 10 includes two planar coils 11 and 12. However, the present invention is not limited to this, and the coil device 10 may include only one planar coil 11, as shown in FIGS.

[0122] In the embodiment described above, the base 31 is formed in a plate shape. In this case, as shown in FIG. 28 , an opening 35 may be formed in the base 31. Increasing the magnetic permeability of a magnetic material decreases its resistance. Therefore, loss increases due to leakage current leaking from portions of the magnetic material with high magnetic permeability. Specifically, increasing the relative permeability of the base 31 and the partitions 32 increases loss due to leakage current leaking from the base 31 and the partitions 32. Furthermore, in the divided body 30a, the electric field strength is higher in the base 31 than in the partitions 32. Therefore, the impact of loss is greater in the base 31 than in the partitions 32. Therefore, by forming the opening 35 in the base 31, loss due to leakage current can be reduced even when the relative permeability of the base 31 and the partitions 32 is increased. Note that the electric field strength varies depending on the radial position. In this case, the electric field strength is higher at the radially outer and radially inner sides than at the radial center. Therefore, by forming openings 35 in the base 31 on the radially outer and inner sides, loss due to leakage current can be more effectively reduced. In this modification, multiple openings 35 are formed in the base 31 of each divided body 30a. This makes it possible to reduce loss due to leakage current while maintaining good strength of the divided body 30a.

[0123] The coil component 10 according to the embodiment described above includes a spiral-shaped planar coil 11 including a first surface 11A and a second surface 11B that are opposite each other in an axial direction extending on a central axis C1 of the spiral shape, a first holding member 20 that overlaps the planar coil 11 so as to face the first surface 11A and holds the planar coil 11, a second holding member 30 that sandwiches the planar coil 11 between the first holding member 20, a first magnetic shield member 40 that sandwiches the second holding member 30 between the first holding member 20, and a second magnetic shield member 50 that sandwiches the first magnetic shield member 40 between the first holding member 20. The planar coil 11 includes a plurality of turn portions 11n arranged in the radial direction of the planar coil 11. The second holding member 30 has a plurality of segments 30a that are divided in the radial and circumferential directions. Each divided body 30a has a base 31 and a partition wall 32 that protrudes from the base 31 and fits between the turn portions 11n. In this case, the divided body 30a can be molded at high temperatures. This makes it easy to obtain divided bodies 30a with high relative magnetic permeability. Furthermore, since the second holding member 30 has multiple divided bodies 30a, it is easy to arrange the pre-molded divided bodies 30a without gaps between the turn portions 11n, 12n. This effectively reduces the influence of magnetic fields and high-frequency resistance.

[0124] In the embodiment described above, the second holding member 30 further includes a resin portion 30b filled between the divided body 30a and the planar coil 11. This allows the resin portion 30b to fill the gap between the divided body 30a and the planar coil 11. This makes it possible to more effectively reduce the influence of the magnetic field and more effectively reduce high-frequency resistance.

[0125] In the embodiment described above, the resin portion 30b has magnetic properties.

[0126] In the embodiment described above, the relative permeability of the divided body 30a is greater than the relative permeability of the resin portion 30b, which makes it possible to more effectively reduce the influence of the magnetic field between the turn portions 11n (12n), and thus makes it possible to more effectively reduce the high-frequency resistance.

[0127] In the embodiment described above, the planar coil 11 is formed in a plate shape.

[0128] In the embodiment described above, the planar coil 11 is formed using a copper thin film.

[0129] In the embodiment described above, the relative permeability of the divided body 30a is greater than 10.

[0130] In the embodiment described above, the partition wall portions 32 are located between the turn portions 11 n and on the outer side of the radial center, which effectively reduces the influence of the magnetic field and the high-frequency resistance.

[0131] In the embodiment described above, the opening 35 is formed in the base 31. This makes it possible to reduce loss due to leakage current.

[0132] In the embodiment described above, the coil intermediate material 10M includes a spiral-shaped planar coil 11 including a first surface 11A and a second surface 11B that are opposite each other in an axial direction extending along a central axis C1 of the spiral shape; a first holding member 20 that overlaps the planar coil 11 and holds the planar coil 11 so as to face the first surface 11A; and a second holding member 30 that sandwiches the planar coil 11 between the first holding member 20. The planar coil 11 includes a plurality of turn portions 11n arranged in the radial direction of the planar coil 11. The second holding member 30 has a plurality of divisions 30a divided in the radial and circumferential directions. Each division 30a has a base 31 and a partition wall 32 that protrudes from the base 31 and fits between the turn portions 11n. In this case, the divisions 30a can be molded at high temperatures. This makes it easy to obtain divisions 30a with high relative magnetic permeability. Furthermore, since the second holding member 30 has multiple segments 30a, the pre-formed segments 30a can be easily arranged without gaps between the turn portions 11n, 12n, which effectively reduces the influence of the magnetic field and the high-frequency resistance.

[0133] The power transmitting device 1 and / or the power receiving device 2 according to the embodiment described above includes the coil component 10 described above.

[0134] The power transmission system S according to the embodiment described above includes the power transmitting device 1 and the power receiving device 2. At least one of the power transmitting device 1 and the power receiving device 2 includes the coil component 10 described above.

[0135] <Performance Evaluation of Coil Component> Next, the results of the performance evaluation of the coil component 10 according to this embodiment will be described.

[0136] (Evaluation 1) In the performance evaluation described below, the relative permeability of the divided body 30a and the resin portion 30b was set, and the Q value, inductance, and resistance were calculated. Specifically, the Q value, inductance, and resistance were calculated from a simulation. The simulation was performed using Femtet (registered trademark) manufactured by Murata Software Co., Ltd.

[0137] In the simulations described below, the conditions for the thickness and material of first planar coil 11 and second planar coil 12 are as follows: 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 0.025 mm (Al0.5 / Cu0.025).

[0138] The common conditions in the simulations are as follows: The supplied high-frequency current is 40 A, and the frequency is 85 kHz. The electrical conductivity of first planar coil 11, which is made of aluminum, is 3.77×107 [S / m]. The electrical conductivity of second planar coil 12, which is made of copper, is 5.98×107 [S / m]. The relative permeability of first magnetic shield member 40 is 3000. Second magnetic shield member 50 is made of aluminum. The diameter of first planar coil 11 and second planar coil 12 shown in FIG. 2 is 400 mm.

[0139] The results are shown in Table 1.

[0140]

[0141] With reference to the columns for Comparative Example A1 and Example A1 in Table 1, it is found that the Q value can be improved by using the divided body 30a with a high relative magnetic permeability. Therefore, in the present embodiment, it is found that the influence of the magnetic field can be reduced in the coil device 10, and the performance of the coil device 10 can be improved.

[0142] Furthermore, referring to the columns for Comparative Examples A1 and A2 in Table 1, when the relative permeability of the resin portion 30b was reduced from 10 to 5 to improve fluidity, the Q value decreased by about 30%. In contrast, referring to the columns for Example A2 and Comparative Example A1 in Table 1, it was found that the performance of the coil device 10 could be improved even when a resin portion 30b with high fluidity and a relative permeability of 5 was used as the resin portion 30b (Example A2). That is, in Example A2, the decrease in the Q value could be suppressed to about 10% compared to when a resin portion 30b with a relative permeability of 10 was used overall (Comparative Example 1).

[0143] (Evaluation 2) In the performance evaluation described below, the relative permeability of the divided body 30a and the resin portion 30b was set, and the Q value, inductance, and resistance were calculated. Specifically, the Q value, inductance, and resistance were calculated from a simulation. The simulation was performed using Femtet (registered trademark) manufactured by Murata Software Co., Ltd.

[0144] In the simulations described below, the conditions for the thickness and material of first planar coil 11 are as follows: First planar coil 11 is made of aluminum and has a thickness of 0.5 mm.

[0145] The common conditions in the simulations are as follows: - The supplied high-frequency current is 40 A, and the frequency is 85 kHz. - The electrical conductivity of first planar coil 11, which is made of aluminum, is 3.77 × 107 [S / m]. - In Examples B1 to B4, the width of partition 32 along the radial direction is 2 mm, and the height of partition 32 (Z-direction distance) is 5.5 mm. - The relative permeability of first magnetic shield member 40 is 3000. - Second magnetic shield member 50 is made of aluminum. - The diameter of first planar coil 11 shown in FIG. 17 is 400 mm.

[0146] The results are shown in Table 2.

[0147]

[0148] With reference to the columns for Comparative Example B1 and Example B1, Comparative Example B2 and Example B2, and Comparative Example B3 and Examples B3 to B4 in Table 2, it was found that the Q value can be improved by using divided bodies 30a with high relative permeability. Therefore, in the present embodiment, it was found that the influence of the magnetic field can be reduced in coil device 10, and the performance of coil device 10 can be improved.

[0149] (Evaluation 3) In the performance evaluation described below, the relative permeability of the divided body 30a and the resin portion 30b was set, and the Q value, inductance, and resistance were calculated. Specifically, the Q value, inductance, and resistance were calculated from a simulation. The simulation was performed using Femtet (registered trademark) manufactured by Murata Software Co., Ltd.

[0150] In the simulations described below, the conditions for the thickness and material of first planar coil 11 are as follows: First planar coil 11 is made of aluminum and has a thickness of 0.5 mm.

[0151] The common conditions in the simulations are as follows: - The supplied high-frequency current is 40 A, and the frequency is 85 kHz. - The electrical conductivity of first planar coil 11, which is made of aluminum, is 3.77 × 107 [S / m]. - In Examples C1 to C4, the relative permeability of divided body 30a is 20, and the relative permeability of resin portion 30b is 3. - In Examples C1 to C4, the height (Z-direction distance) of partition portion 32 is 5.5 mm. - The relative permeability of first magnetic shield member 40 is 3000. - Second magnetic shield member 50 is made of aluminum. - The diameter of first planar coil 11 shown in FIG. 17 is 400 mm.

[0152] The results are shown in Table 3.

[0153]

[0154] In the "Position of Partition Wall" column of Table 3, "center" means that the partition wall 32 is located at the radial center between the turn portions 11n, as shown in Figures 19 and 20. In the "Position of Partition Wall" column of Table 3, "outside" means that the partition wall 32 is located outside the radial center between the turn portions 11n, as shown in Figures 26 and 27. In the "Position of Partition Wall" column of Table 3, "inside" means that the partition wall 32 is located inside the radial center between the turn portions 11n, as shown in Figures 29 and 30.

[0155] Referring to the columns for Examples C2 to C4 in Table 3, it was found that the Q value could be improved by positioning the partition wall 32 outside the radial center between the turn portions 11n. Furthermore, referring to the columns for Examples C1 and C2 in Table 3, it was found that even when the width of the partition wall 32 was set to 1 mm, performance similar to that when the width of the partition wall 32 was set to 2 mm could be obtained.

[0156] Second Embodiment Next, a second embodiment will be described with reference to Figures 31 to 33. The second embodiment shown in Figures 31 to 33 differs from the first embodiment mainly in the configuration of the second holding member. In Figures 31 to 33, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0157] 31 to 33 , in this embodiment, the second holding member 30 has a spiral shape and includes a partition portion 36 that fits between the turn portions 11 n. The second holding member 30 may further include a resin portion 30 b that is filled between the partition portion 36 and the planar coil 11. In this embodiment, the second holding member 30 does not include a base portion 31, and the planar coil 11 is sandwiched between the resin portion 30 b and the first holding member 20.

[0158] The partition wall portion 36 is manufactured by injection molding. In this case, the partition wall portion 36 may be manufactured by bending a linearly formed member into a spiral shape. By manufacturing the partition wall portion 36 by injection molding in this manner, the partition wall portion 36 can be molded at high temperatures. This makes it easy to obtain a partition wall portion 36 with high relative magnetic permeability. Furthermore, since the second holding member 30 has the partition wall portion 36 with a spiral shape, it is easy to arrange the pre-molded partition wall portion 36 between the turn portions 11n. This effectively reduces the influence of the magnetic field and effectively reduces high-frequency resistance.

[0159] The partition wall portion 36 extends between adjacent turn portions 11n of the planar coil 11 along the axial direction of the planar coil 11. Therefore, the partition wall portion 36 is formed along the spiral-shaped planar coil 11. In the illustrated example, the partition wall portion 36 is formed in a spiral shape corresponding to the spiral shape of the planar coil 11. As shown in FIG. 33 , the partition wall portion 36 is received in the groove 24 of the first holding member 20. In other words, the partition wall portion 36 fills the groove 24 of the first holding member 20, similar to the above-described partition wall portion 32.

[0160] In this embodiment, the partition wall 36 is located between the turn portions 11n and outside the radial center, thereby effectively reducing the influence of the magnetic field and the high-frequency resistance.

[0161] In the illustrated example, the resin portion 30 b is filled between the first holding member 20 and the planar coil 11 and the first magnetic shield member 40 .

[0162] In this embodiment, the second holding member 30 also uses magnetism to suppress eddy current loss and leakage flux and to increase the coupling coefficient, thereby improving coil performance. For this reason, the partition wall 36 and the resin portion 30b of the second holding member 30 each have magnetism.

[0163] In the present embodiment, the relative magnetic permeability of the partition portion 36 is preferably greater than the relative magnetic permeability of the resin portion 30b, which makes it possible to more effectively reduce the influence of the magnetic field between the turn portions 11n and to more effectively reduce the high-frequency resistance.

[0164] In this case, the relative magnetic permeability of the partition wall portion 36 may be greater than 10. This makes it possible to more effectively reduce the influence of the magnetic field between the turn portions 11n and to more effectively reduce high-frequency resistance. The relative magnetic permeability of the partition wall portion 36 may also be 40 or less. This makes it possible to maintain good flexibility and strength of the partition wall portion 36.

[0165] Furthermore, the second holding member 30 includes a partition wall 36, which can effectively improve coil performance. The height of the partition wall 36 (the distance along the axial direction of the planar coil 11) is not particularly limited, but may be, for example, 0.5 mm or more, or 1.0 mm or more. The higher the partition wall 36, the greater the effect of suppressing eddy current loss and the higher the coupling coefficient. On the other hand, the higher the partition wall 36, the more susceptible it is to breakage. Therefore, the height of the partition wall 36 may be, for example, 10 mm or less.

[0166] In the present embodiment, the partition wall 36 includes, for example, a resin and a plurality or a large number of magnetic particles made of a magnetic material. The magnetic particles are held by the resin as a holding material. The material of the partition wall 36 may be the same as the material of the divided body 30a described above.

[0167] <Modifications> Note that various modifications can be made to the above-described embodiment. For example, the coil component 10 includes one planar coil 11, but this is not limiting. The number of planar coils included in the coil component 10 may be two or more.

[0168] In this embodiment, the partition wall 36 has a spiral shape. In this case, the partition wall 36 may be divided into a plurality of divided bodies 30c as shown in FIG.

[0169] 34, the partition 36 has a plurality of segments 30c divided in the radial and circumferential directions of the spiral shape. In the illustrated example, the partition 36 is divided to correspond to each side of an octagon that corresponds to the shape of the turn portion 11n. The number of segments 30c is optional and can be changed as appropriate depending on the size of the coil component 10, etc. Although not illustrated, the partition 36 may be divided in at least one of the radial and circumferential directions of the spiral shape.

[0170] The coil component 10 according to the embodiment described above includes a spiral-shaped planar coil 11 including a first surface 11A and a second surface 11B that are opposite each other in an axial direction extending along a central axis C1 of the spiral shape, a first holding member 20 that overlaps the planar coil 11 so as to face the first surface 11A and holds the planar coil 11, a second holding member 30 that sandwiches the planar coil 11 with the first holding member 20, a first magnetic shield member 40 that sandwiches the second holding member 30 with the first holding member 20, and a second magnetic shield member 50 that sandwiches the first magnetic shield member 40 with the first holding member 20. The planar coil 11 includes a plurality of turn portions 11n arranged in the radial direction of the planar coil 11. The second holding member 30 has a spiral shape and includes partition portions 36 that are inserted between the turn portions 11n. In this case, as with the divided body 30a described above, the partition portions 36 can be molded at high temperatures. This makes it easy to obtain partitions 36 with high relative magnetic permeability. Furthermore, it is easy to arrange pre-formed partitions 36 between the turn portions 11n. This effectively reduces the influence of the magnetic field, and thus the high-frequency resistance. Furthermore, in this embodiment, the second holding member 30 does not have a base portion 31. Therefore, as will be described later, loss due to leakage current can be reduced, and the performance of the coil device 10 can be improved.

[0171] In the embodiment described above, the second holding member 30 further includes a resin portion 30b filled between the partition portion 36 and the planar coil 11. This allows the resin portion 30b to fill the gap between the partition portion 36 and the planar coil 11. This makes it possible to more effectively reduce the influence of the magnetic field and more effectively reduce high-frequency resistance.

[0172] In the embodiment described above, the relative magnetic permeability of the partition portion 36 is greater than the relative magnetic permeability of the resin portion 30b, which makes it possible to more effectively reduce the influence of the magnetic field between the turn portions 11n and to more effectively reduce the high-frequency resistance.

[0173] In the embodiment described above, the relative permeability of the partition wall 36 is greater than 10.

[0174] In the embodiment described above, the partition wall 36 is divided into multiple segments 30c. This makes it easier to arrange the pre-formed segments 30a without gaps between the turn portions 11n. This effectively reduces the influence of magnetic fields and high-frequency resistance.

[0175] In the embodiment described above, the coil intermediate material 10M includes a spiral-shaped planar coil 11 including a first surface 11A and a second surface 11B that are opposite each other in an axial direction extending along a central axis C1 of the spiral shape, a first holding member 20 that overlaps the planar coil 11 so as to face the first surface 11A and hold the planar coil 11, and a second holding member 30 that sandwiches the planar coil 11 between the first holding member 20. The planar coil 11 includes a plurality of turn portions 11n arranged in the radial direction of the planar coil 11. The second holding member 30 has a spiral shape and includes partition portions 36 that are inserted between the turn portions 11n. In this case, as with the divided body 30a described above, the partition portions 36 can be molded at high temperatures. This facilitates the formation of partition portions 36 with high relative magnetic permeability. Furthermore, it is easy to arrange pre-formed partition portions 36 between the turn portions 11n. Therefore, the influence of the magnetic field can be effectively reduced, and the high-frequency resistance can be effectively reduced. Furthermore, in this embodiment, the second holding member 30 does not have a base portion 31. Therefore, as will be described later, loss due to leakage current can be reduced, and the performance of the coil device 10 can be improved.

[0176] <Performance Evaluation of Coil Component> Next, the results of the performance evaluation of the coil component 10 according to this embodiment will be described.

[0177] (Evaluation 4) In the performance evaluation described below, the relative permeabilities of the partition wall portion 36 and the resin portion 30b shown in Fig. 31 and the like, and the relative permeabilities of the divided body 30a and the resin portion 30b shown in Fig. 3 and the like were set, and the Q value was calculated. Specifically, the Q value was calculated from a simulation. The simulation was performed using Femtet (registered trademark) manufactured by Murata Software Co., Ltd.

[0178] In the simulations described below, the conditions for the thickness and material of first planar coil 11 are as follows: First planar coil 11 is made of aluminum and has a thickness of 0.5 mm (Al0.5).

[0179] The common conditions in the simulations are as follows: - The supplied high-frequency current is 40 A, and the frequency is 85 kHz. - The electrical conductivity of first planar coil 11, which is made of aluminum, is 3.77 × 107 [S / m]. - The relative permeability of first magnetic shield member 40 is 3000. - Second magnetic shield member 50 is made of aluminum. - The diameter of planar coil 11 is 400 mm.

[0180] The above results are shown in Figures 35 to 37. Note that Figure 35 shows the simulation results for the partition wall portion 36 and resin portion 30b shown in Figure 31 and other figures. That is, Figure 35 shows the simulation results for the case where the second holding member 30 does not have the base portion 31. On the other hand, Figure 36 shows the simulation results for the divided body 30a and resin portion 30b shown in Figure 3 and other figures. That is, Figure 36 shows the simulation results for the case where the second holding member 30 has the base portion 31.

[0181] 35 to 37 , it was found that the Q value can be improved when the second holding member 30 does not have the base 31. That is, because the resistance of the base 31 is small, if the second holding member 30 has the base 31, loss may increase due to leakage current at the base 31. Furthermore, in the divided body 30a, the electric field strength is higher at the base 31 than at the partition wall 32. Therefore, the impact of loss is greater at the base 31 than at the partition wall 32. Therefore, it was found that by not having the base 31 in the second holding member 30, loss due to leakage current can be reduced and the performance of the coil device 10 can be improved.

[0182] (Third Embodiment) Next, a third embodiment will be described with reference to Figures 38 to 42. The second embodiment shown in Figures 38 to 42 differs from the first or second embodiment mainly in the configuration of the second holding member. In Figures 38 to 42, the same parts as those in the first or second embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0183] As shown in Figures 38 to 42, in this embodiment, the second retaining member 30 has an inner region R1 located radially inward, an outer region R3 located radially outward, and an intermediate region R2 located between the inner region R1 and the outer region R3.

[0184] Among these, the inner region R1 and the outer region R3 may be regions as follows. First, as shown in FIG. 38 , the minimum radius of the second holding member 30 (the distance from the first center axis C1 to the radially closest portion) is defined as RC, and the maximum radius of the second holding member 30 (the distance from the first center axis C1 to the radially furthest portion) is defined as RO. Then, R is the value obtained by subtracting the minimum radius from the maximum radius. In this case, the inner region R1 may be an annular region that varies from 10% to 30% of R from the radially closest portion from the first center axis C1 (i.e., the portion with the smallest radius) toward the radially outward direction. The outer region R3 may be an annular region that varies from 10% to 20% of R from the radially furthest portion from the first center axis C1 (i.e., the portion with the largest radius) toward the radially inward direction.

[0185] In this embodiment, only in the intermediate region R2, the second holding member 30 further includes a base 31 that supports the partition wall 36. This base 31 is positioned between the planar coil 11 and the first magnetic shield member 40 (see FIG. 41 ). The partition wall 36 and the base 31 are integrally molded by injection molding. Therefore, the relative permeability of the partition wall 36 and the relative permeability of the base 31 are equal to each other.

[0186] On the other hand, as shown in FIGS. 40 and 42, the second holding member 30 does not have a base portion 31 in the inner region R1 and the outer region R3.

[0187] The coil component 10 according to the embodiment described above includes a spiral-shaped planar coil 11 including a first surface 11A and a second surface 11B that are opposite each other in an axial direction extending on a central axis C1 of the spiral shape, a first holding member 20 that overlaps the planar coil 11 so as to face the first surface 11A and holds the planar coil 11, a second holding member 30 that sandwiches the planar coil 11 between the first holding member 20, a first magnetic shield member 40 that sandwiches the second holding member 30 between the first holding member 20, and a second magnetic shield member 50 that sandwiches the first magnetic shield member 40 between the first holding member 20. The planar coil 11 includes a plurality of turn portions 11n arranged in the radial direction of the planar coil 11. The second holding member 30 has a spiral shape and includes partition portions 36 that are inserted between the turn portions 11n. The second holding member 30 has an inner region R1 located radially inward, an outer region R3 located radially outward, and an intermediate region R2 located between the inner region R1 and the outer region R3. In addition, only in the intermediate region R2, the second holding member 30 further includes a base 31 located between the planar coil 11 and the first magnetic shield member 40 and supporting the partition wall 36. Furthermore, the relative permeability of the partition wall 36 and the relative permeability of the base 31 are equal to each other. As described above, the electric field strength varies depending on the radial position. In this case, the electric field strength is higher at the radial outer and inner sides than at the radial center. Therefore, by configuring the second holding member 30 to further include the base 31 supporting the partition wall 36 only in the intermediate region R2, loss due to leakage current can be effectively reduced. In other words, since the second holding member 30 does not include the base 31 in the inner region R1 and the outer region R3, loss due to leakage current can be effectively reduced.

[0188] In the embodiment described above, the coil intermediate material 10M includes a spiral-shaped planar coil 11 including a first surface 11A and a second surface 11B that are opposite each other in an axial direction extending along a central axis C1 of the spiral shape, a first holding member 20 that overlaps the planar coil 11 so as to face the first surface 11A and hold the planar coil 11, and a second holding member 30 that sandwiches the planar coil 11 between the first holding member 20. The planar coil 11 includes a plurality of turn portions 11n arranged in the radial direction of the planar coil 11. The second holding member 30 has a spiral shape and includes partition portions 36 that intersect between the turn portions 11n. The second holding member 30 includes an inner region R1 located radially inward, an outer region R3 located radially outward, and an intermediate region R2 located between the inner region R1 and the outer region R3. Moreover, only in the intermediate region R2, the second holding member 30 further includes a base 31 that supports the partition wall 36. Furthermore, the relative permeability of the partition wall 36 and the relative permeability of the base 31 are equal to each other. This effectively reduces loss due to leakage current.

[0189] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Figures 43 to 46. The fourth embodiment shown in Figures 43 to 46 differs from the first, second, or third embodiment mainly in the configuration of the second holding member. In Figures 43 to 46, the same parts as those in the first, second, or third embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0190] 43 to 46, in the present embodiment, second holding member 30 also has a spiral shape and includes partition portions 36 that are inserted between turn portions 11n (111 to 115), 12n (121 to 125). Second holding member 30 is placed on first holding member 20 and holds first planar coil 11 and second planar coil 12.

[0191] As shown in FIG. 46, the partition wall portion 36 includes a first partition wall surface 36a facing the first holding member 20 and a second partition wall surface 36b opposite the first partition wall surface 36a in the axial direction.

[0192] In this embodiment, in a cross section along the axial direction (Z direction), the first surface 11A and the second surface 11B of the first planar coil 11 are located between the first partition surface 36a of the partition portion 36 and the center CP of the partition portion 36 in the axial direction.

[0193] In the axial direction, distance D1 between first surface 11A of first planar coil 11 and first partition surface 36a of partition portion 36 may be 35% to 65% of the difference between height H of partition portion 36 and distance Dz between first surface 11A and second surface (fourth surface) 12B of second planar coil 12. That is, distance D1, height H, and distance Dz may satisfy the following inequality: 35(%)≦distance D1×100 / (height H−distance Dz)≦65(%)

[0194] Here, the partition wall 36 also serves to control the magnetic field generated by the planar coils 11 and 12. In this case, if the distance from the location where the magnetic field is generated to the first partition wall surface 36a is significantly different from the distance from the location where the magnetic field is generated to the second partition wall surface 36b, the magnetic field balance may be disrupted. If the magnetic field balance is disrupted, the magnetic field shielding effect of the partition wall 36 may be weakened. In response to this, by setting the distance D1 between the first surface 11A of the first planar coil 11 and the first partition wall surface 36a of the partition wall 36 to 35% to 65% of the difference between the height H of the partition wall 36 and the distance Dz between the first surface 11A and the second surface (fourth surface) 12B of the second planar coil 12, the difference between the distance D1 and the distance D2 (described later) can be reduced, thereby maintaining a good magnetic field balance. This effectively increases the Q value.

[0195] In addition, in this embodiment, in a cross section along the axial direction, the first surface (third surface) 12A and the second surface (fourth surface) 12B of the second planar coil 12 are located between the second partition surface 36b of the partition portion 36 and the center CP of the partition portion 36 in the axial direction.

[0196] In the axial direction, distance D2 between second surface (fourth surface) 12B of second planar coil 12 and second partition surface 36b of partition 36 may be 35% to 65% of the difference between height H of partition 36 and distance Dz. That is, distance D2, height H, and distance Dz may satisfy the following inequality: 35%≦distance D2×100 / (height H−distance Dz)≦65%. This reduces the difference between distance D1 and distance D2, thereby maintaining a good balance of the magnetic field. This effectively increases the Q value.

[0197] Here, the midpoint between first surface 11A of first planar coil 11 and second surface 12B of second planar coil 12 is defined as MP1. In this case, the distance in the axial direction from midpoint MP1 to center CP of partition 36 (Z-direction distance) may be 0% or more and 20% or less of height H of partition 36. In the example shown in FIG. 46 , the distance from midpoint MP1 to center CP of partition 36 (Z-direction distance) is 0% (i.e., 0 mm) of height H of partition 36. By setting the distance from midpoint MP1 to center CP of partition 36 to 20% or less of height H of partition 36, the Q value can be effectively increased.

[0198] The distance between first planar coil 11 and second planar coil 12 (hereinafter simply referred to as the "distance between the coils") may be determined appropriately, taking insulation properties into consideration. For example, generally, when a large current (high power) flows through planar coils 11 and 12, the distance between the coils may be longer than when a small current flows through planar coils 11 and 12. Furthermore, the distance between the coils in each turn portion 11n and 12n may be uniform or may vary. For example, in turn portions 11n and 12n, the electric field strength may increase from the radially inner turn portion 11n and 12n toward the radially outer turn portion 11n and 12n. Therefore, the distance between the coils in each turn portion 11n and 12n may vary in accordance with the increase in electric field strength. In this case, the distance between the coils in a given turn portion 11n, 12n may be longer than the distance between the coils in the turn portion 11n, 12n adjacent to the given turn portion 11n, 12n in the radial direction.

[0199] <Modifications> Various modifications can be made to the above-described embodiment. For example, the coil component 10 includes two planar coils 11 and 12, but this is not limiting. The number of planar coils included in the coil component 10 may be one, or may be three or more.

[0200] In this case, for example, as shown in FIGS. 47 to 50, in this modification, the coil device 10 includes one planar coil 11.

[0201] 47 to 50, in this embodiment as well, the second holding member 30 has a spiral shape and includes partitions 36 that fit between the turn portions 11n (1101 to 1114). The second holding member 30 is placed on the first holding member 20 and holds the planar coil 11.

[0202] In this modified example, as shown in Figure 50, in a cross section along the axial direction, the first surface 11A of the planar coil 11 is located between the first partition surface 36a of the partition portion 36 and the center CP of the partition portion 36 in the axial direction.

[0203] In the axial direction, a distance D3 between a midpoint MP2 between the first surface 11A and the second surface 11B of the planar coil 11 and the first partition surface 36a of the partition portion 36 may be 35% to 65% of the height H of the partition portion 36. This reduces the difference between the distance D3 and a distance D4 (described later), thereby maintaining a good balance of the magnetic field. This effectively increases the Q value.

[0204] In addition, in this embodiment, in a cross section along the axial direction, the second surface 11B of the planar coil 11 is located between the second partition surface 36b of the partition portion 36 and the center CP of the partition portion 36 in the axial direction.

[0205] In the axial direction, a distance D4 between a midpoint MP2 between the first surface 11A and the second surface 11B of the planar coil 11 and the second partition surface 36b of the partition portion 36 may be 35% to 65% of the height H of the partition portion 36. This reduces the difference between the distance D3 and the distance D4, thereby maintaining a good balance of the magnetic field. This effectively increases the Q value.

[0206] Here, the midpoint between the first surface 11A and the second surface 11B of the planar coil 11 is defined as MP2. In this case, the distance from the midpoint MP2 to the center CP of the partition wall 36 in the axial direction (Z-direction distance) may be 0% or more and 20% or less of the height H of the partition wall 36. In the example shown in Fig. 50, the distance from the midpoint MP2 to the center CP of the partition wall 36 (Z-direction distance) is 0% (i.e., 0 mm) of the height H of the partition wall 36. By setting the distance from the midpoint MP2 to the center CP of the partition wall 36 to 20% or less of the height H of the partition wall 36, the Q value can be effectively increased.

[0207] As shown in FIG. 47, the first magnetic shield member 40 may be formed with slits 41 that divide the first magnetic shield member 40 into a plurality of members.

[0208] Coil device 10 according to the embodiment described above includes first planar coil 11 having a spiral shape and including first surface 11A and second surface 11B that are opposite to each other in an axial direction extending on central axis C1 of the spiral shape; second planar coil 12 having a spiral shape and including first surface (third surface) 12A facing second surface 11B of first planar coil 11 and second surface (fourth surface) 12B that is opposite to first surface (third surface) 12A in the axial direction; The coil assembly includes a first holding member 20 that overlaps first planar coil 11 and faces first surface 11A of planar coil 11 to hold first planar coil 11, a second holding member 30 that overlaps first holding member 20 and holds first planar coil 11 and second planar coil 12, a first magnetic shield member 40 that sandwiches second holding member 30 with first holding member 20, and a second magnetic shield member 50 that sandwiches first magnetic shield member 40 with first holding member 20. First planar coil 11 and second planar coil 12 each include a plurality of turn portions 11n, 12n arranged in the radial direction. Second holding member 30 has a spiral shape and includes a partition portion 36 that fits between turn portions 11n, 12n. Partition portion 36 includes a first partition surface 36a that faces first holding member 20 and a second partition surface 36b that is axially opposite first partition surface 36a. In the axial direction, distance D1 between first surface 11A of first planar coil 11 and first partition surface 36a of partition portion 36 is 35% to 65% of the difference between height H of partition portion 36 and distance Dz between first surface 11A and second surface (fourth surface) 12B of second planar coil 12. This reduces the difference between distance D1 and distance D2, thereby maintaining a good balance of the magnetic field. This effectively increases the Q value, as described below, and improves the performance of coil device 10.

[0209] In the embodiment described above, the coil component 10 includes a spiral-shaped planar coil 11 including a first surface 11A and a second surface 11B that are opposite each other in an axial direction extending on a central axis C1 of the spiral shape, a first holding member 20 that overlaps the planar coil 11 so as to face the first surface 11A and holds the planar coil 11, a second holding member 30 that overlaps the first holding member 20 and holds the planar coil 11, a first magnetic shield member 40 that sandwiches the second holding member 30 with the first holding member 20, and a second magnetic shield member 50 that sandwiches the first magnetic shield member 40 with the first holding member 20. The planar coil 11 includes a plurality of turn portions 11n arranged in the radial direction of the planar coil 11. The second holding member 30 has a spiral shape and includes a partition portion 36 that fits between the turn portions 11n. The partition wall portion 36 includes a first partition wall surface 36a facing the first holding member 20 and a second partition wall surface 36b opposite the first partition wall surface 36a in the axial direction. In a cross section along the axial direction, the first surface 11A of the planar coil 11 is located between the first partition wall surface 36a of the partition wall portion 36 and a center CP of the partition wall portion 36 in the axial direction. In the axial direction, a distance D3 between a midpoint MP2 between the first surface 11A and the second surface 11B of the planar coil 11 and the first partition wall surface 36a of the partition wall portion 36 is 35% to 65% of the height H of the partition wall portion 36. This reduces the difference between the distance D3 and the distance D4, thereby maintaining a good magnetic field balance. This effectively increases the Q value and improves the performance of the coil device 10, as described below.

[0210] Furthermore, in the embodiment described above, coil intermediate material 10M includes: first planar coil 11 having a spiral shape and including first surface 11A and second surface 11B that are opposite to each other in an axial direction extending on central axis C1 of the spiral shape; second planar coil 12 having a spiral shape and including first surface (third surface) 12A facing second surface 11B of first planar coil 11 and second surface (fourth surface) 12B that is opposite first surface (third surface) 12A in the axial direction; first holding member 20 that overlaps first planar coil 11 so as to face first surface 11A of first planar coil 11 and holds first planar coil 11; and second holding member 30 that overlaps first holding member 20 and holds first planar coil 11 and second planar coil 12. First planar coil 11 and second planar coil 12 each include a plurality of turn portions 11n, 12n arranged in the radial direction. The second holding member 30 has a spiral shape and a partition wall portion 36 that fits between the turn portions 11n and 12n. The partition wall portion 36 includes a first partition wall surface 36a facing the first holding member 20 and a second partition wall surface 36b that is opposite the first partition wall surface 36a in the axial direction. In the axial direction, the distance D1 between the first surface 11A of the first planar coil 11 and the first partition wall surface 36a of the partition wall portion 36 is 35% to 65% of the difference between the height H of the partition wall portion 36 and the distance Dz between the first surface 11A and the second surface (fourth surface) 12B of the second planar coil 12. This reduces the difference between the distance D1 and the distance D2, thereby maintaining a good balance of the magnetic field. This effectively increases the Q value, as described below, and improves the performance of the coil device 10.

[0211] In the embodiment described above, the coil intermediate material 10M includes a spiral-shaped planar coil 11 including a first surface 11A and a second surface 11B that are opposite each other in an axial direction extending on a central axis C1 of the spiral shape, a first holding member 20 that overlaps the planar coil 11 so as to face the first surface 11A and holds the planar coil 11, and a second holding member 30 that overlaps the first holding member 20 and holds the planar coil 11. The planar coil 11 includes a plurality of turn portions 11n arranged in the radial direction of the planar coil 11. The second holding member 30 has a spiral shape and includes a partition portion 36 that fits between the turn portions 11n. The partition portion 36 includes a first partition surface 36a that faces the first holding member 20 and a second partition surface 36b that is opposite the first partition surface 36a in the axial direction. In a cross section along the axial direction, the first surface 11A of the planar coil 11 is located between the first partition surface 36a of the partition portion 36 and the center CP of the partition portion 36 in the axial direction. In the axial direction, a distance D3 between a midpoint MP2 between the first surface 11A and the second surface 11B of the planar coil 11 and the first partition surface 36a of the partition portion 36 is 35% to 65% of the height H of the partition portion 36. This reduces the difference between the distance D3 and the distance D4, thereby maintaining a good balance of the magnetic field. This effectively increases the Q value, as described below, and improves the performance of the coil device 10.

[0212] <Performance Evaluation of Coil Component> Next, the results of the performance evaluation of the coil component 10 according to this embodiment will be described.

[0213] (Evaluation 5) In the performance evaluation described below, the positions of the planar coils 11 and 12 relative to the partition wall 36 shown in FIG. 43 and other figures were set, and the Q value, inductance, and resistance were calculated. Specifically, the Q value, inductance, and resistance were calculated from a simulation. The simulation was performed using Femtet (registered trademark) manufactured by Murata Software Co., Ltd.

[0214] In the simulations described below, the conditions for the thickness and material of first planar coil 11 and second planar coil 12 are as follows: First planar coil 11 is made of aluminum and has a thickness of 0.25 mm. Second planar coil 12 is made of copper and has a thickness of 0.5 mm (Al0.25 / Cu0.5).

[0215] The common conditions in the simulations are as follows: - The supplied high-frequency current is 40 A, and the frequency is 85 kHz. - The electrical conductivity of first planar coil 11, which is made of aluminum, is 3.77×107 [S / m]. - The electrical conductivity of second planar coil 12, which is made of copper, is 5.98×107 [S / m]. - The height H of partition portion 36 of second holding member 30 is 11 mm. - The relative permeability of first magnetic shield member 40 is 3000. - Second magnetic shield member 50 is made of aluminum. - The diameter of first planar coil 11 and second planar coil 12 shown in FIG. 43 is 300 mm.

[0216] The above results are shown in FIG. 51 and Tables 4, 5, and 6. Note that the "distance" in FIG. 51 and Table 4 refers to the distance from midpoint MP1 to the center CP of partition portion 36. When the distance from midpoint MP1 to the center CP of partition portion 36 is a positive value, this means that the center CP of partition portion 36 is located closer to first planar coil 11 than midpoint MP1. On the other hand, when the distance from midpoint MP1 to the center CP of partition portion 36 is a negative value, this means that the center CP of partition portion 36 is located closer to second planar coil 12 than midpoint MP1.

[0217]

[0218]

[0219]

[0220] 51 and the columns for Example D1 to Comparative Example D4 in Tables 4 and 5, it is found that the Q value can be improved by setting distance D1 between first surface 11A of first planar coil 11 and first partition surface 36a of partition portion 36 to be 35% to 65% (37.9% to 62.1%) of the difference between height H of partition portion 36 and distance Dz between first surface 11A and second surface (fourth surface) 12B of second planar coil 12. Therefore, it is found that the performance of coil device 10 can be improved in this embodiment.

[0221] Furthermore, referring to the columns for Example D1 to Comparative Example D4 in Tables 4 and 6, it was found that copper loss could be reduced by setting distance D1 between first surface 11A of first planar coil 11 and first partition surface 36a of partition portion 36 to be 35% to 65% (37.9% to 62.1%) of the difference between height H of partition portion 36 and distance Dz between first surface 11A and second surface (fourth surface) 12B of second planar coil 12.

[0222] (Evaluation 6) In the performance evaluation described below, the position of the planar coil 11 relative to the partition wall 36 shown in Fig. 47 etc. was set, and the Q value, inductance, and resistance were calculated. Specifically, the Q value, inductance, and resistance were calculated from a simulation. The simulation was performed using Femtet (registered trademark) manufactured by Murata Software Co., Ltd.

[0223] In the simulations described below, the conditions for the thickness and material of the planar coil 11 are as follows: The planar coil 11 is made of aluminum and has a thickness of 1.0 mm.

[0224] The common conditions in the simulations are as follows: - The supplied high-frequency current is 40 A, and the frequency is 85 kHz. - The electrical conductivity of the planar coil 11 made of aluminum is 3.77 x 107 [S / m]. - The height H of the partition wall portion 36 of the second holding member 30 is 7 mm to 11 mm. - The relative permeability of the first magnetic shield member 40 is 3000. - The second magnetic shield member 50 is made of aluminum. - The diameter of the planar coil 11 shown in FIG. 47 is 300 mm.

[0225] The above results are shown in Figures 52, 53, Tables 7, 8, and 9. Note that the "distance" in Figure 52 and Table 7 refers to the distance from the midpoint MP2 to the center CP of the partition portion 36. When the distance from the midpoint MP2 to the center CP of the partition portion 36 is a positive value, this means that the center CP of the partition portion 36 is located closer to the first surface 11A of the planar coil 11 than the midpoint MP2. On the other hand, when the distance from the midpoint MP2 to the center CP of the partition portion 36 is a negative value, this means that the center CP of the partition portion 36 is located closer to the second surface 11B of the planar coil 11 than the midpoint MP2.

[0226]

[0227]

[0228]

[0229] 52 and the columns for Examples E1 to E6 in Tables 7 and 8, it was found that the Q value could be improved by setting the distance D3 between the midpoint MP2 between the first surface 11A and the second surface 11B of the planar coil 11 and the first partition surface 36a of the partition portion 36 to 35% to 65% (38.9% to 61.1%) of the height H of the partition portion 36. Furthermore, as shown in FIG. 53 , the coil component 10 according to Examples E1 to E3 had lower loss density even near the turn portions 1101 and 1102 compared to the coil component according to Comparative Example E2. Therefore, it was found that the performance of the coil component 10 could be improved in this embodiment.

[0230] Furthermore, referring to the columns for Example E1 to Comparative Example E6 in Tables 7 and 9, it was found that copper loss and iron loss can be reduced by setting the distance D3 between the midpoint MP2 between the first surface 11A and the second surface 11B of the planar coil 11 and the first partition surface 36a of the partition portion 36 to be 35% or more and 65% or less (38.9% or more and 61.1% or less) of the height H of the partition portion 36.

[0231] Although several modifications to the above-described embodiment have been described, it is of course possible to combine a plurality of modifications as appropriate.

[0232] DESCRIPTION OF SYMBOLS 1 Power transmitting device 1A High frequency current supply unit 2 Power receiving device 2A Conversion unit 10 Coil component 10M Coil intermediate material 11 First planar coil 11A First surface 11B Second surface 11E Conductor portion 11n Turn portion 12 Second planar coil 12A First surface 12B Second surface 12E Conductor portion 12n Turn portion 20 First holding member 20S1 Contact surface 20S2 Outer surface 24 Groove 30 Second holding member 30a Divided body 30b Resin portion 30c Divided body 31 Base portion 32 Partition wall portion 33 Projecting piece 34 Notch portion 35 Opening portion 36 Partition wall portion 40 First magnetic shielding member 50 Second magnetic shielding member 61 First connection terminal 62 Second connection terminal 201 Mold 202 Mold 203 Main body 204 Convex portion 220 Material 230 Material C1 First central axis C2 Second central axis R1 Inner region R2 Middle region R3 Outer region S Power transmission system

Claims

1. A coil component comprising: a planar coil having a spiral shape, including a first surface and a second surface that are opposite each other in an axial direction extending on a central axis of the spiral shape, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; a first holding member provided so as to face the first surface side of the planar coil; a first magnetic shield member that sandwiches the planar coil with the first holding member; and a second magnetic shield member that sandwiches the first magnetic shield member with the first holding member.

2. The coil component according to claim 1, wherein the partition portion includes a first partition surface facing the first holding member and a second partition surface opposite the first partition surface in the axial direction, and the distance in the axial direction between the midpoint between the first surface and the second surface of the planar coil and the first partition surface of the partition portion is 35% to 65% of the height of the partition portion.

3. The coil component according to claim 1, wherein the partition wall is divided into a plurality of divided bodies.

4. The coil component according to claim 3, wherein the partition wall is divided in at least one of the radial and circumferential directions of the spiral shape.

5. The coil component according to claim 1, further comprising a second holding member provided on a second surface side of the planar coil, the second holding member having a base portion positioned between the planar coil and the first magnetic shield member and supporting the partition portion, and the partition portion.

6. A coil component as described in claim 5, wherein the second holding member has an inner region located radially inward, an outer region located radially outward, and an intermediate region located between the inner region and the outer region, wherein the second holding member is located between the planar coil and the first magnetic shield member only in the intermediate region and has a base portion that supports the partition portion, and the relative permeability of the partition portion and the relative permeability of the base portion are equal to each other.

7. The coil component according to claim 5, wherein an opening is formed in the base.

8. The coil component according to claim 1, further comprising a resin portion filled between the partition wall and the planar coil.

9. The coil component according to claim 8, wherein the resin portion is magnetic.

10. The coil component according to claim 8, wherein the relative magnetic permeability of the partition wall portion is greater than the relative magnetic permeability of the resin portion.

11. The coil component according to claim 1, wherein the planar coil is formed in a plate shape.

12. The coil component according to claim 1, wherein the relative permeability of the partition wall is greater than 10.

13. The coil component according to claim 1, wherein the partition wall is located between the turn portions and outside the radial center.

14. The coil component according to claim 13, wherein the partition wall is provided with a protruding piece that protrudes radially inward.

15. A first planar coil having a spiral shape, including a first surface and a second surface that are opposite to each other in an axial direction extending on a central axis of the spiral shape, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a second planar coil having a spiral shape, including a third surface facing the second surface and a fourth surface that is opposite to the third surface in the axial direction, and including a plurality of turn portions arranged in the radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; a first holding member provided so as to face the first surface side of the first planar coil; a first magnetic shield member that sandwiches the first planar coil and the second planar coil with the first holding member; and a second magnetic shield member that sandwiches the first magnetic shield member with the first holding member, wherein the partition portion includes a first partition surface that faces the first holding member and a second partition surface that is opposite to the first partition surface in the axial direction, a distance between the first surface of the first planar coil and the first partition surface of the partition portion in the axial direction is 35% or more and 65% or less of a difference between a height of the partition portion and a distance between the first surface and the fourth surface.

16. A coil intermediate material comprising: a planar coil having a spiral shape, including a first surface and a second surface that are opposite to each other in an axial direction extending on a central axis of the spiral shape, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; and a first holding member provided so as to face the first surface side of the planar coil, wherein the partition portion includes a first partition surface that faces the first holding member and a second partition surface that is opposite to the first partition surface in the axial direction, and the distance in the axial direction between the midpoint between the first surface and the second surface of the planar coil and the first partition surface of the partition portion is 35% to 65% of the height of the partition portion.

17. A coil intermediate material comprising: a planar coil having a spiral shape, including a first surface and a second surface that are opposite each other in an axial direction extending on the central axis of the spiral shape, and including a plurality of turn portions arranged in the radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; and a first holding member provided so as to face the first surface side of the planar coil, wherein the partition portion is divided into a plurality of segments.

18. A coil comprising: a first planar coil having a spiral shape, including a first surface and a second surface that are opposite to each other in an axial direction extending on a central axis of the spiral shape, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a second planar coil having a spiral shape, including a third surface facing the second surface and a fourth surface that is opposite to the third surface in the axial direction, and including a plurality of turn portions arranged in a radial direction of the spiral shape; a partition portion provided between adjacent turn portions of the plurality of turn portions; and a first holding member provided so as to face the first surface side of the first planar coil, wherein the partition portion includes a first partition surface that faces the first holding member and a second partition surface that is opposite to the first partition surface in the axial direction; a distance in the axial direction between the first surface of the first planar coil and the first partition surface of the partition portion that is 35% or more and 65% or less of a difference between a height of the partition portion and a distance between the first surface and the fourth surface.

19. A power transmission device comprising a coil component according to any one of claims 1 to 15.

20. A power receiving device comprising a coil component according to any one of claims 1 to 15.

21. A power transmission system comprising a power transmitting device and a power receiving device, wherein at least one of the power transmitting device and the power receiving device comprises a coil component according to any one of claims 1 to 15.

Images