Coil component, power transmission device, power reception device, and power transmission system

Abstract

To provide a coil component capable of suppressing insulation breakdown or short-circuiting, which may occur in the coil component, while suppressing enlargement or while attaining downsizing.SOLUTION: A coil component 100 comprises: a plane coil 110 including a plurality of turn parts 1101-1108; and a first lead wire part 161A connected to a radially inner end of the first turn part 1101, which is positioned radially innermost in the plane coil 110, and extending radially outward so as to successively cross the plurality of turn parts 1101-1108. A distance CL8 in an axial direction between the eighth turn part 1108, which is positioned radially outermost and the first lead wire part 161A is larger than a distance CL1 in the axial direction between a connection portion 161C with the first lead wire part 161A in the first turn part 1101, which is positioned radially innermost, and the first lead wire part 161A.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

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

[0003] For example, a system is known that transmits power in a non-contact manner by passing a high-frequency current through a resonant circuit including a coil.

[0004] When a high-frequency current is passed through a coil, a skin effect can occur. The skin effect increases AC resistance, which causes a decrease in transmission efficiency during power transmission. If the coil is made of Litz wire in consideration of this, the skin effect can be suppressed, and therefore the decrease in transmission efficiency can be suppressed. However, since Litz wire is formed by twisting together many enameled wires, the manufacturing costs are high and it takes a lot of effort to manufacture, and the larger the coil, the greater the manufacturing effort.

[0005] On the other hand, a technique is also known that employs a planar coil that is spirally shaped and plate-like, and has a rectangular conductor cross section (see Patent Document 1). Such a planar coil can be formed, for example, by punching out the coil from a plate material. Therefore, such a planar coil can improve manufacturing efficiency regardless of the size of the coil. It is also advantageous in terms of making the device into which the coil is incorporated thinner and lighter. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-47614 A Summary of the Invention [Problem to be solved by the invention]

[0007] When connecting the planar coil to, for example, a power source, connection terminals connected to the radially inner end and the radially outer end of the planar coil may be connected to the power source via wiring. In this case, for example, the connection terminal connected to the radially inner end may have a conductor portion extending from the radially inner to the radially outer side so as to intersect with the multiple turns of the planar coil in sequence, and a terminal portion provided at the radially outer end of the conductor portion.

[0008] However, when the conductor portion extends as described above, if the distance between the mutually intersecting conductor portion and the turn portion becomes small, dielectric breakdown or short circuiting becomes likely to occur between them. On the other hand, in some cases, a ferrite sheet that functions as a magnetic shield and an aluminum plate are layered in this order in a planar coil, and in this case, it is also necessary to consider how to avoid dielectric breakdown or short circuiting between the conductor portion and the aluminum plate.

[0009] When the ferrite sheet and the aluminum plate are superimposed on the planar coil as described above, a notch or gap may be formed in a part of the ferrite sheet, and the conductor may be passed through the notch or gap located between the aluminum plate and the planar coil. In such a configuration, if a large distance is sought between the conductor and the turn, dielectric breakdown or short circuit may easily occur between the conductor and the aluminum plate. If a large distance is sought between the aluminum plate and the planar coil to avoid this, the overall thickness increases, and the advantages of the planar coil are lost. Therefore, a measure to simply increase the distance between the conductor and other conductive parts is not necessarily good. In addition, since the ferrite sheet is relatively heavy, it is expected that it will be required to be lightweight, and the weight can be reduced by making it thinner. However, if the ferrite sheet is made thinner, there is a risk that the risk of dielectric breakdown or short circuit between the planar coil and the aluminum plate may increase, and this is also a concern.

[0010] The objective of the present disclosure is to provide a coil component, a power transmission device, a power receiving device, and a power transfer system that can properly ensure insulation between a conductor portion connected to the end of a planar coil and other conductive portions such as the turn portion of the planar coil while preventing the component from becoming too large or while achieving miniaturization; in other words, that can suppress insulation breakdown or short circuits that may occur in the coil component while preventing the component from becoming too large or while achieving miniaturization. [Means for solving the problem]

[0011] The embodiments of the present disclosure relate to the following [1] to

[18] .

[0012] [1] A planar coil including a plurality of turns arranged in a radial direction; a conductor portion connected to an inner end of a turn portion located at an innermost position in the radial direction of the planar coil, the conductor portion extending radially outward so as to intersect the plurality of turn portions in sequence, a distance in the axial direction of the planar coil between a turn portion located radially outermost among the plurality of turn portions and the conductor portion is greater than a distance in the axial direction between a connection portion of the turn portion located radially innermost with the conductor portion and the conductor portion.

[0013] [2] The coil component according to [1], wherein the distance between the plurality of turn portions and the conductor portion increases radially outward.

[0014] [3] The plurality of turn portions are positioned so as to be arranged in the same plane, The coil component according to [1] or [2], wherein the conductor portion extends at an angle with respect to the plane.

[0015] [4] A first shield member is provided that is overlapped with the planar coil and has magnetic and insulating properties; The coil component according to any one of [1] to [3], wherein the conductor portion extends such that the distance in the axial direction from the first shield member increases as the conductor portion extends radially outward.

[0016] [5] A coil component described in any one of [1] to [4], wherein at least the turn portion located outermost in the radial direction among the plurality of turn portions is bent so as to move away from the conductor portion at a position where it intersects with the conductor portion.

[0017] [6] A coil component described in any one of [1] to [5], wherein all of the turn portions among the plurality of turn portions that intersect with the conductor portion are bent so as to move away from the conductor portion at the positions where they intersect with the conductor portion.

[0018] [7] A first shield member is provided that is overlapped with the planar coil and has magnetic and insulating properties; The coil component according to [5] or [6], wherein the turn portion is bent so as to be away from the conductor portion at a position where it intersects with the conductor portion, and is bent so as to be away from the first shielding member.

[0019] [8] The turn portion located most inward in the radial direction and the conductor portion are connected via a conductive connecting portion, The coil component according to any one of [1] to [7], wherein the distance in the axial direction between the turn portion located outermost in the radial direction and the conductor portion is greater than a thickness of the conductive connection portion.

[0020] [9] A coil component according to any one of [1] to [8], comprising a first shielding member overlapping the planar coil and having magnetic and insulating properties.

[0021]

[10] The coil component described in [9], wherein the conductor portion is arranged on a side opposite the first shielding member with respect to the planar coil.

[0022]

[11] The coil component according to

[10] , wherein the conductor portion is disposed between the planar coil and the first shielding member.

[0023]

[12] The coil component described in

[11] , wherein the conductor portion contacts a surface of the first shielding member that faces the planar coil.

[0024]

[13] The coil component according to any one of [9] to

[12] , wherein the first shielding member contains ferrite.

[0025]

[14] A coil component described in any of [9] to

[13] , further comprising a second shielding member which is non-magnetic and conductive and overlaps the first shielding member so as to face a surface of the first shielding member opposite to the surface facing the planar coil.

[0026]

[15] The coil component according to

[14] , wherein the second shield member contains aluminum or an aluminum alloy.

[0027]

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

[15] .

[0028]

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

[15] .

[0029]

[18] A power transmitting device and a power receiving device, A power transfer system, wherein at least one of the power transmitting device and the power receiving device is equipped with a coil component described in any one of [1] to

[15] . Effect of the Invention

[0030] According to the present disclosure, it is possible to suppress dielectric breakdown or short circuit that may occur in a coil component while preventing an increase in size or while achieving miniaturization. [Brief description of the drawings]

[0031] [Figure 1] 1 is a diagram illustrating a schematic view of a wireless power transmission system to which a coil component according to a first embodiment is applied. [Diagram 2] FIG. 1 is a perspective view of a coil component according to a first embodiment. [Diagram 3] FIG. 3 is an exploded perspective view of the coil component shown in FIG. 2. [Figure 4] FIG. 3 is a plan view of the coil device shown in FIG. 2. [Diagram 5] 5 is a cross-sectional view of the coil device shown in FIG. 2 taken along line VV in FIG. 4. [Figure 6] FIG. 13 is a perspective view of a coil component according to a second embodiment. [Figure 7] 7 is an enlarged perspective view of a portion of the coil component shown in FIG. 6. [Figure 8] FIG. 7 is a plan view of the coil device shown in FIG. [Figure 9] 9 is a cross-sectional view of the coil component taken along line IX-IX in FIG. 8. [Figure 10] 9 is a cross-sectional view of the coil component taken along line XX in FIG. 8. [Figure 11] FIG. 4 is a graph showing a simulation result of an electric field intensity when a current is supplied to the coil component in the first embodiment. [Figure 12] FIG. 11 is a graph showing a simulation result of an electric field intensity when a current is supplied to the coil component according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Each embodiment will be described below with reference to the drawings.

[0033] In this specification, the terms "sheet," "film," "plate," and the like are not distinguished from one another solely on the basis of differences in name. Thus, for example, "sheet" is a concept that includes members that may also be called films or plates.

[0034] <<First embodiment>> Fig. 1 shows a schematic diagram of a wireless power transmission system S to which a coil component 100 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 according to an embodiment different from the first embodiment can be applied to the power transmission system S.

[0035] <Wireless power transmission system> The power transfer system S includes a power transmitting device 1 and a power receiving device 2. The power transmitting device 1 includes a coil component 100 and a high-frequency current supplying unit 1A. The coil component 100 in the power transmitting device 1 functions as a power transmitting coil. The high-frequency current supplying unit 1A supplies a high-frequency current to the coil component 100 serving as a power transmitting coil.

[0036] The power receiving device 2 includes a coil component 100 and a conversion unit 2A. The coil component 100 in the power receiving device 2 functions as a power receiving coil. The conversion unit 2A shapes a high-frequency current generated in the coil component 100. The conversion unit 2A includes a rectifier circuit that converts the high-frequency current into a direct current, and the like. The conversion unit 2A may be configured to include, for example, a full-wave rectifier circuit including a plurality of diodes and a smoothing capacitor.

[0037] In this embodiment, each of the power transmitting device 1 and the power receiving device 2 includes the coil component 100. However, the coil component 100 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.

[0038] 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 100 serving as a power transmitting coil. At this time, a magnetic field is generated in the coil component 100 by electromagnetic induction. Then, due to the influence of this magnetic field, a high-frequency current is generated in the coil component 100 serving as a power receiving coil in the power receiving device 2. That is, the power receiving device 2 receives a magnetic field from the power transmitting device 1 or is influenced by the magnetic field in the power transmitting device 1, and causes a 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.

[0039] The power transmission system S shown in Fig. 1 employs a magnetic resonance method as a power transmission method. However, the coil component 100 according to the present embodiment may be used in a power transmission system that employs an electromagnetic induction method. The power transmission system S is configured as a system that wirelessly transmits power to an electric vehicle. In this case, the power transmitting device 1 is installed on a road, a parking lot, or the like. The power receiving device 2 is installed in the electric vehicle.

[0040] However, the use of the power transmission system S is not limited to power transmission to an electric vehicle. For example, the power transmission system S may be used to transmit power to an aircraft such as a drone or a robot. The power transmission system S may also be used to transmit power to a submarine or an exploration robot in the sea. The use of the coil component 100 is not limited to a wireless power transmission system. For example, the coil component 100 may be used in a transformer, a DC-DC converter, an antenna, or the like.

[0041] <Coil parts> Fig. 2 is a perspective view of coil component 100 according to the present embodiment. Fig. 3 is an exploded perspective view of coil component 100. Fig. 4 is a plan view of coil component 100. Fig. 5 is a cross-sectional view of coil component 100 taken along line VV in Fig. 2. In Fig. 4, a spacer member 120, which will be described later, is omitted from illustration.

[0042] As shown in FIGS. 2 to 5, the coil device 100 includes a planar coil 110, a spacer member 120, a first shield member 130, a second shield member 150, a first connection terminal 161, and a second connection terminal 162.

[0043] 5, the planar coil 110 has a first main surface 110a and a second main surface 110b. The second main surface 110b is the surface opposite to the first main surface 110a. The planar coil 110 and the spacer member 120 are integrated. The second shield member 150, the first shield member 130, the planar coil 110, and the spacer member 120 are arranged in this order in a direction from the second main surface 110b toward the first main surface 110a.

[0044] (Planar coil) As shown in Figs. 2 to 4, the planar coil 110 is formed in a spiral shape. More specifically, the planar coil 110 includes a conductor 110E formed in a spiral shape around an arbitrary central axis C. The spiral shape refers to the shape of a plane curve that moves away from the center as it turns (or approaches the center as it turns). The plane curve referred to here also includes a plane pattern that is bent like a broken line. In the illustrated embodiment, the spiral shape is located on a virtual plane perpendicular to the central axis C.

[0045] Hereinafter, the axial direction means a direction extending on the central axis C or a direction parallel to the central axis C. Additionally, the radial direction means the radial direction of a circle drawn on a plane centered on an arbitrary point on the central axis C and perpendicular to the central axis C. Additionally, the circumferential direction means a direction along a circle centered on the central axis C (the circumferential direction of the circle).

[0046] The conductor 110E is formed from a conductive material. In this embodiment, the conductor 110E is formed from copper, but is not limited to this. The conductor 110E may be formed from a copper alloy, aluminum, an aluminum alloy, or the like. In this embodiment, the planar coil 110 is composed only of the conductor 110E. Therefore, the planar coil 110 is formed from copper, but may be formed from a copper alloy, aluminum, an aluminum alloy, or the like.

[0047] Planar coil 110 (conductor 110E) is plate-shaped. More specifically, planar coil 110 is a non-litz wire planar coil. As shown in Fig. 5, the cross-sectional shape of the conductor in a direction perpendicular to the winding direction of the spiral shape of planar coil 110 (conductor 110E) is rectangular.

[0048] The planar coil 110 includes a plurality of turn portions 110n arranged in a direction perpendicular to the central axis C of the spiral shape. The conductor 110E is composed of the plurality of turn portions 110n. The plurality of turn portions 110n are connected so as to gradually move away from the central axis C in a radially outward direction from the central axis C. As a result, the plurality of turn portions 110n form a spiral shape as a whole.

[0049] Specifically, the turn portion 110n is basically a shape in which a linear conductor portion does not form a ring but turns 360 degrees around the central axis C. In the case of a so-called planar coil, both ends of the turn portion 110n are shifted in the radial direction. In the case of multiple turn portions 110n, a radially outer end of a certain turn portion 110n is connected to a radially inner end of another turn portion 110n. As a result, the multiple turn portions 110n as a whole extend so as to move away from the central axis C. The radially inward direction means a direction approaching the central axis C in the radial direction. Moreover, the radially outward direction means a direction moving away from the central axis C in the radial direction.

[0050] In this embodiment, the turn portion 110n winds around to form a polygon. In this specification and disclosure, the spiral shape refers to a planar curved shape wound in a spiral shape. The planar curved shape here includes a planar pattern that winds around repeatedly while bending like a broken line as shown in the figure. In other words, the spiral shape refers to a planar curved shape that moves away from the center as it turns (or approaches the center as it turns).

[0051] In the illustrated example, the planar coil 110 (conductor 110E) includes first to eighth turn portions 1101 to 1108. The first to eighth turn portions 1101 to 1108 are arranged in this order from the innermost position in the radial direction toward the outermost position. In other words, the first turn portion 1101 is located at the innermost position in the radial direction, and the eighth turn portion 1108 is located at the outermost position in the radial direction. In further other words, the first turn portion 1101 forms the innermost portion of the planar coil 110 (conductor 110E). The eighth turn portion 1108 forms the outermost portion of the planar coil 110 (conductor 110E). In the following, when describing matters common to each of the multiple turn portions 110n, they are referred to as the turn portion 110n or the turn portions 1101 to 1108.

[0052] Each of the turn portions 1101 to 1108 extends on the imaginary plane. The first to eighth turn portions 1101 to 1108 are connected in this order, and the planar coil 110 (the conductor 110E) forms a spiral shape. In the illustrated example, the conductor 110E is octagonal in shape as a whole. The conductor 110E is wound so that each of the turn portions 1101 to 1108 forms a roughly octagonal shape. However, the shape of the conductor 110E is not limited thereto. The conductor 110E may be a polygonal shape other than an octagonal shape as a whole (for example, a square, a hexagon, or a dodecagon). In this case, each of the turn portions 1101 to 1108 may be wound so as to roughly form a polygonal shape other than an octagon (for example, a square, a hexagon, or a dodecagon). The conductor 110E may also be circular in shape as a whole. In this case, each of the turn portions 1101 to 1108 may be wound so as to form a roughly circular shape.

[0053] One end of each of the turn portions 1101 to 1108 is located radially inward from the other end of the turn portion 1101 to 1108. In other words, the other end of each of the turn portions 1101 to 1108 is located radially outward from the one end of the turn portion 1101 to 1108.

[0054] As shown in FIG. 4, each of the turn portions 1101-1108 includes a plurality of straight portions 111-119 arranged around the central axis C. The straight portions 111-119 adjacent to each other in the circumferential direction of the circle centered on the central axis C are connected to each other. In the illustrated example, the first to seventh turn portions 1101-1107 include the first to ninth straight portions 111-119. In contrast, the eighth turn portion 1108 includes the first to eighth straight portions 111-118 but does not include the ninth straight portion 119. In the first to seventh turn portions 1101-1107, the first to ninth straight portions 111-119 are arranged in this order along the circumferential direction. In the eighth turn portion 1108, the first to eighth straight portions 111-118 are arranged in this order along the circumferential direction.

[0055] The end of the first straight portion 111 on the side not connected to the second straight portion 112 forms the radially inner end of each of the turn portions 1101-1108. In the first to seventh turn portions 1101-1107, the end of the ninth straight portion 119 on the side not connected to the eighth straight portion 118 forms the radially outer end of the first to seventh turn portions 1101-1107. The ninth straight portion 119 extends parallel to the first straight portion 111 on the radially outer side of the first straight portion 111. In the eighth turn portion 1108, the end of the eighth straight portion 118 on the side not connected to the seventh straight portion 117 forms the radially outer end. The radially inner starting points (ends of the first straight portion 111) of each of the turn portions 1101-1108 are aligned on a straight line ST (a two-dot chain line) parallel to a straight line extending parallel to the radial direction. The first to seventh turn portions 1101 to 1107 have their respective radially outer ends connected to the radially inner ends of the second to eighth turn portions 1108 that are adjacent to them on the radially outer side.

[0056] The planar coil 110 (conductor 110E) described above is formed, for example, by punching a metal plate such as a copper plate or an aluminum plate into a spiral shape. Alternatively, the planar coil 110 can also be formed by etching a metal foil such as a copper foil or an aluminum foil into a spiral shape.

[0057] The radius of the planar coil 110 (the distance from the central axis C to the part furthest from the center axis C in the radial direction) may be 80 mm or more and may be 450 mm or less. When the coil component 100 is used as a power transmitting coil component or a power receiving coil component of a power transmission system S that transmits power to an electric vehicle by a magnetic field resonance method, the radius of the planar coil 110 may be 200 mm or more and 350 mm or less.

[0058] The thickness of the planar coil 110 (the conductor 110E) is measured along the axial direction of the planar coil 110. The thickness of the planar coil 110 (the thickness of the conductor 110E) may be, for example, 0.1 mm or more and 2.0 mm or less, 0.2 mm or more and 1.0 mm or less, or 0.3 mm or more and 0.7 mm or less. The thickness of the planar coil 110 (the conductor 110E) may be, for example, 0.15 mm or more and 0.35 mm or less. When transmitting power to an electric vehicle using the magnetic resonance method, it is desirable to be able to transmit power of 1 kW or more, preferably 5 kW or more, in a high-frequency current frequency range of 10 kHz to 200 kHz, particularly 79 kHz to 90 kHz. In this case, the thickness of the planar coil 110 made of copper is preferably 0.4 mm or more.

[0059] The line width of the planar coil 110 (conductor 110E) is not particularly limited. However, in consideration of being able to transmit power of 1 kW or more, preferably 5 kW or more, in a high-frequency current frequency range of, for example, 79 kHz to 90 kHz, the line width of each turn portion 1101 to 1108 may be 2 mm to 20 mm, 2 mm to 16 mm, 2 mm to 12 mm, or 2 mm to 8 mm. The line width means the distance between the inner peripheral surface and the outer peripheral surface of the linear portion of the planar coil 110 (conductor 110E) in a cross section perpendicular to the direction in which the planar coil 110 (conductor 110E) turns.

[0060] The aspect ratio of the planar coil 110 (conductor 110E) having a rectangular cross-sectional shape is determined by dividing the line width (the radial width of each turn portion 110n) of the planar coil 110 (conductor 110E) by the thickness of the planar coil 110 (conductor 110E). The aspect ratio of the planar coil 110 (conductor 110E) may be 2 or more and 12 or less, or 3 or more and 10 or less.

[0061] The thickness and line width of the planar coil 110 (conductor 110E) may be measured by cutting the coil component 100 in the axial direction to expose the planar coil 110 (conductor 110E) at a cross section, and measuring each part of the planar coil 110 (conductor 110E) with a ruler or the like, or by analyzing a cross-sectional image.

[0062] In this embodiment, the central axis C is determined as follows. First, linear imaginary turn portions similar in shape to the innermost turn portion 1101 are drawn in sequence from the radially inner end of the innermost turn portion 1101 to form a spiral shape radially inward. Drawing is continued until a virtual turn portion that fits within a diameter of 1 cm is drawn. A line that passes through the radially inner region of the imaginary turn portion that fits within a diameter of 1 cm in a direction perpendicular to the circumferential and radial directions of the spiral shape is determined as the central axis C.

[0063] (Spacer material) The spacer member 120 is a member that fills the gap between the planar coil 110 and the first shield member 130. The spacer member 120 overlaps the planar coil 110 in the axial direction of the planar coil 110. By being integrated with the spacer member 120, the planar coil 110 is held at a position separated from the first shield member 130.

[0064] The spacer member 120 is in direct contact with the second main surface 110b of the planar coil 110. In other words, the spacer member 120 is in direct contact with the conductor 110E. In the illustrated example, the spacer member 120 is in close contact with the second main surface 110b of the planar coil 110. In other words, the spacer member 120 is in close contact with the conductor 110E. In the illustrated example, the spacer member 120 is formed such that its outer edge is located outside the planar coil 110 when viewed in the axial direction.

[0065] Moreover, the spacer member 120 has a magnetic property and has a function of suppressing magnetic transmission and / or leakage magnetic field. More specifically, the spacer member 120 has a magnetic property and an insulating property. The magnetic field generated by the coil component 100 is generated so as to spread in all directions with respect to the central axis C of the planar coil 110. At this time, the spacer member 120 has a magnetic property, and can orient the spreading magnetic flux lines toward the central axis C side. Furthermore, if the magnetic field generated by the coil component 100 reaches the peripheral components located around the coil component 100, the peripheral components may be adversely affected. Therefore, the spacer member 120 is provided to suppress the magnetic field lines from reaching the peripheral components. As a result, the spacer member 120 can suppress the leakage magnetic field that does not contribute to the generation of current.

[0066] The spacer member 120 includes, for example, a holding material containing a resin and a plurality or an infinite number of magnetic particles made of a magnetic material. The magnetic particles are held by the holding material. The holding material is insulating, more specifically, non-magnetic and insulating. Note that the insulating property is a property that the volume resistivity is 10 10 This means that the resistance is Ω·m or more.

[0067] As the resin for forming the holding material of the spacer member 120, for example, a thermosetting resin such as epoxy resin or polyimide can be adopted. In this case, when the planar coil 110 and the spacer member 120 are integrated by heat pressing as described later, the resin of the spacer member 120 can be easily deformed according to the shape of the planar coil 110 during the heat curing process. In addition, a thermoplastic resin such as nylon, polyethylene, polypropylene, etc. can also be adopted as the resin for forming the spacer member 120. In this case, too, it is easy to deform the resin of the spacer member 120 according to the shape of the planar coil 110. In addition, the holding material may include, for example, fiber reinforced plastic or be formed from fiber reinforced plastic. For example, the holding material may include, or be formed from glass fiber reinforced polyamide.

[0068] The magnetic particles of the spacer member 120 may be made of one or more of ferrite, particularly soft magnetic material ferrite, nanocrystalline magnetic material, silicon steel, soft magnetic iron, and amorphous metal.

[0069] As shown in FIG. 5, the spacer member 120 has a spiral-shaped recess 122 corresponding to the spiral shape of the planar coil 110. The recess 122 is a portion of the spacer member 120 recessed in the axial direction of the planar coil 110, in other words, in the thickness direction of the spacer member 120. The recess 122 has a spiral shape when viewed in the axial direction of the planar coil 110. At least a part of the planar coil 110 is accommodated in the recess 122 with its spiral shape aligned with the spiral shape of the recess 122. More specifically, the recess 122 accommodates the entire conductor 110E. For this reason, as shown in FIG. 5, the spacer member 120 is in direct contact with three surfaces of the planar coil 110 other than the first main surface 110a.

[0070] The relative magnetic permeability of the spacer member 120 is preferably 2.0 or more, and may be 2.0 or more and 20.0 or less. The relative magnetic permeability of the spacer member 120 is more preferably 5.0 or more, and may be 5.0 or more and 20.0 or less. The relative magnetic permeability of the spacer member 120 is not particularly limited, but if it is too large, the flexibility and strength of the spacer member 120 may be undesirably impaired. Therefore, the relative magnetic permeability of the spacer member 120 may be 30 or less.

[0071] In the present embodiment, the spacer member 120 has magnetic properties, but the spacer member 120 may be non-magnetic and insulating, and may be made of only resin. The spacer member 120 does not have to be provided, and an air layer may be formed between the planar coil 110 and the first shield member 130.

[0072] (First shielding member) The first shield member 130 is provided to suppress magnetic transmission and / or leakage magnetic field. The first shield member 130 is provided between the second shield member 150 and the planar coil 110 and the spacer member 120. The first shield member 130 is formed in a plate shape and spreads along a plane perpendicular to the axial direction of the planar coil 110. The first shield member 130 has a size such that its outer periphery is located outside the spacer member 120 and the planar coil 110 when viewed in the axial direction. In the illustrated example, the first shield member 130 is rectangular when viewed in the axial direction.

[0073] The first shield member 130 includes a magnetic material. As described above, the magnetic field generated by the coil component 100 spreads in all directions relative to the central axis C of the planar coil 110. At this time, the first shield member 130 has magnetism, and thus can orient the spreading magnetic flux lines toward the central axis C. In addition, the first shield member 130 prevents the magnetism from reaching surrounding components. This allows the first shield member 130 to suppress leakage magnetic fields that do not contribute to the generation of current.

[0074] The first shielding member 130 preferably includes a soft magnetic material. More specifically, the first shielding member 130 includes a ferrite, preferably a soft ferrite. The first shielding member 130 may also include a nanocrystalline magnetic material.

[0075] The relative magnetic permeability of the first shield member 130 is not particularly limited, but is preferably 100 or more, and may be 100 or more and 10,000 or less. The relative magnetic permeability of the first shield member 130 may be 1,000 or more, 2,000 or more, or 3,000 or more. The relative magnetic permeability of the first shield member 130 may be 8,000 or less, 6,000 or less, or 4,000 or less.

[0076] In the example shown in FIG. 5, the first shield member 130 is in contact with the spacer member 120, but this is not limited thereto. The first shield member 130 may be spaced apart from the spacer member 120. When the first shield member 130 is disposed so as to be spaced apart from the spacer member 120, the distance between the first shield member 130 and the spacer member 120 is not particularly limited, but is, for example, 3 mm or less. Note that, as the distance between the first shield member 130 and the spacer member 120 becomes longer, it becomes more difficult for heat from the coil component 100 to be dissipated, and there is a risk that the coil component 100 will become hot. For this reason, it is preferable that the distance between the first shield member 130 and the spacer member 120 is 1 mm or less. In addition, reducing the distance between the first shield member 130 and the spacer member 120 is advantageous in terms of reducing the dimensions of the coil component 100 (particularly, the dimensions along the axial direction).

[0077] The thickness of the first shield member 130 is not particularly limited, and may be 3 mm or less, 2 mm or less, or 1.5 mm or less. Reducing the thickness of the first shield member 130 is advantageous from the standpoint of reducing the dimensions of the coil device 100 (particularly the dimensions along the axial direction) and from the standpoint of miniaturization.

[0078] 3 and 4, the first shield member 130 in this embodiment is divided into a plurality of shield pieces 13P. In other words, the first shield member 130 includes a plurality of shield pieces 13P arranged in the same plane. By forming the first shield member 130 from a plurality of shield pieces 13P, it is possible to easily manufacture the first shield member 130 having a size such that the outer edge is located outside the planar coil 110 when viewed in the axial direction.

[0079] In the illustrated example, the first shield member 130 includes eight shield pieces 13P each having a right-angled triangular shape and having approximately the same size. The eight shield pieces 13P may be referred to as first to eighth shield pieces 131 to 138 hereinafter. In the illustrated example, each shield piece 13P includes soft ferrite. More specifically, each shield piece 13P is formed of a ferrite plate including soft ferrite.

[0080] In the illustrated example, each shield piece 13P is arranged adjacent to two other shield pieces 13P different from itself. In detail, each shield piece 13P forms a quadrangle by aligning its hypotenuse with the hypotenuse of the other shield pieces 13P, and forms a triangle by aligning one of two adjacent sides with one of two adjacent sides of the other shield pieces 13P. Specifically, for example, the first shield piece 131 and the second shield piece 132 are adjacent to each other with their hypotenuses facing each other, and the first shield piece 131 and the eighth shield piece 138 are adjacent to each other with their adjacent sides facing each other. As a result, the first shield member 130 is formed into a quadrangle.

[0081] In the illustrated example, each of the shield pieces 131-138 is arranged adjacent to two different shield pieces, and a gap is formed between the adjacent shield pieces 131, 132; 132, 133; 133, 134; 134, 135; 135, 136; 136, 137; 137, 138; 138, 131. In order to suppress the transmission of magnetic lines through the gap, it is preferable that the width of the gap is 6 mm or less. In the illustrated example, the multiple shield pieces 13P are arranged so that the gap extends radially from the central axis C, and the gap extends perpendicular to the straight portions 111-119 in the turn portions 1101-1108. When the gaps and the straight portions 111 to 119 intersect at right angles, the magnetic field lines formed around the straight portions 111 to 119 are prevented from leaking out through the gaps, and a decrease in loss can be suppressed.

[0082] The shape and arrangement of the shield pieces 13P are not particularly limited and may be different from the illustrated example. However, the above-mentioned dimensions of the gaps between adjacent shield pieces 13P and the state of intersection with the turn portions are also useful for embodiments in which the shape and arrangement of the shield pieces 13P are different from the illustrated example.

[0083] (Second shielding member) The second shield member 150 is overlapped on the planar coil 110 via the first shield member 130. In other words, the second shield member 150 is overlapped on the first shield member 130 so as to face the surface of the first shield member 130 opposite to the surface facing the planar coil 110. The second shield member 150 is formed in a plate shape and spreads along a surface perpendicular to the axial direction of the planar coil 110. The second shield member 150 has a size such that its outer periphery is located outside the spacer member 120 and the planar coil 110, and outside the first shield member 130, when viewed in the axial direction. In the illustrated example, the first shield member 130 is rectangular when viewed in the axial direction.

[0084] The second shield member 150 is non-magnetic and conductive. This allows the second shield member 150 to suppress magnetic transmission and / or leakage magnetic field. This makes it possible to prevent the magnetic field or electromagnetic waves generated in the coil component 100 from affecting other electronic components, the human body, etc. The second shield member 150 can be made of a metal such as aluminum or an aluminum alloy.

[0085] As shown in Fig. 5, the second shield member 150 is disposed away from the first shield member 130. In the illustrated example, a spacer block 155 is disposed between the second shield member 150 and the first shield member 130 as a gap material. This allows the distance between the second shield member 150 and the first shield member 130 to be maintained at a predetermined distance. The spacer block 155 is preferably an insulating and heat-conducting material. This allows the spacer block 155 to promote heat dissipation from the coil component 100.

[0086] For example, when the coil component 100 is mounted on an automobile, the space available for installation is limited. For example, when the coil component 100 is used for such an application, it is preferable that the coil component 100 is thin and small. Therefore, for example, when the coil component 100 is a power receiving coil component installed in an automobile, the distance between the second shield member 150 and the first shield member 130 may be 10 mm or less, 5 mm or less, 3 mm or less, 2 mm or less, or 1 mm or less. On the other hand, when the coil component 100 is a power transmitting coil component installed on a road or a parking lot, the distance between the second shield member 150 and the first shield member 130 may be 10 mm or more, 15 mm or more, or 20 mm or more. However, the longer the distance between the second shield member 150 and the first shield member 130, the more difficult it is for heat to be dissipated from the coil component 100, and the coil component 100 may become hot. In addition, even when the coil component 100 is used as a power transmitting coil component installed on a road or a parking lot, it is desirable to suppress the overhang. Therefore, even when the coil component 100 is used as a power transmission coil component installed on a road or a parking lot, the distance between the second shield member 150 and the first shield member 130 may be 10 mm or less, 5 mm or less, 3 mm or less, 2 mm or less, or 1 mm or less.

[0087] On the other hand, when the second shield member 150 is disposed close to the first shield member 130, it is considered that the magnetic field lines generated in the planar coil 110 are more likely to reach the second shield member 150, which makes it easier for eddy currents to be generated in the second shield member 150. In contrast, in the present embodiment, the first shield member 130 suppresses the transmission of the magnetic field lines, which makes it possible to suppress the magnetic field lines from the planar coil 110 from reaching the second shield member 150, and also suppresses dielectric breakdown or short circuit between the planar coil 110 and the second shield member 150. This makes it easier to bring the second shield member 150 close to the first shield member 130, which makes it easier to make the shield member smaller and thinner.

[0088] (Connection terminal) 2 and 3, the first connection terminal 161 is connected to a radially inner end of the first turn portion 1101 located on the innermost periphery side of the planar coil 110. The second connection terminal 162 is connected to a radially outer end of the eighth turn portion 1108 located on the outermost periphery side of the planar coil 110. The first connection terminal 161 and the second connection terminal 162 can be used, for example, when connecting to the high-frequency current supply unit 1A or the conversion unit 2A.

[0089] When the coil component 100 is used as a power transmission coil, the first connection terminal 161 and the second connection terminal 162 are connected to the high-frequency current supply unit 1A or the AC power supply as shown in Fig. 1. When a high-frequency current is supplied to the coil component 100, the current can be passed from the first connection terminal 161 to the planar coil 110, and then from the second connection terminal 162 to the high-frequency current supply unit 1A or the AC power supply. Also, the current can be passed from the second connection terminal 162 to the planar coil 110, and then from the first connection terminal 161 to the high-frequency current supply unit 1A or the AC power supply. This makes it possible to generate a magnetic field including magnetic lines of force along the central axis of the planar coil 110.

[0090] On the other hand, when the coil device 100 is used as a power receiving coil, a high-frequency current can be generated in the planar coil 110 by receiving a magnetic field including magnetic field lines along the central axis of the planar coil 110. Then, this high-frequency current can be supplied to an external device from the first connection terminal 161 or the second connection terminal 162.

[0091] The first connection terminal 161 includes a first conductor portion 161A having one end connected to a radially inner end of the first turn portion 1101, and a first terminal portion 161B provided at the other end of the first conductor portion 161A. The first conductor portion 161A extends radially outward from a radially inner end of the first turn portion 1101 (an end of the first straight portion 111) so as to intersect with the plurality of turn portions 1101 to 1108 in sequence. The first conductor portion 161A extends outward beyond the outer edge of the spacer member 120, and the first terminal portion 161B is provided at a portion of the first conductor portion 161A located outward beyond the outer edge of the spacer member 120.

[0092] The second connection terminal 162 includes a second conductor portion 162A having one end connected to an outer radial end of the eighth turn portion 1108, and a second terminal portion 162B provided at the other end of the second conductor portion 162A. The second conductor portion 162A extends outward from the outer radial end of the eighth turn portion 1108 (the end of the eighth straight portion 118) beyond the outer edge of the spacer member 120. The second terminal portion 162B is provided at a portion of the second conductor portion 162A located outward from the outer edge of the spacer member 120.

[0093] Needless to say, the first connection terminal 161 and the second connection terminal 162 are made of a conductive material. In this embodiment, the first connection terminal 161 and the second connection terminal 162 are made of copper, which is the same material as the conductor 110E of the planar coil 110, but this is not limited thereto. The first connection terminal 161 and the second connection terminal 162 may be made of a copper alloy, aluminum, an aluminum alloy, or the like. The first connection terminal 161 and the planar coil 110 are connected by ultrasonic bonding. However, the connection method is not limited thereto, and for example, a connection using a conductive adhesive may be adopted.

[0094] (Positional relationship between the first connection terminal and the turn portion) The positional relationship between the first connection terminal 161 and the turn portions 1101-1108 will be described in detail below. As shown in Fig. 2 to Fig. 5, in this embodiment, the first conductor portion 161A of the first connection terminal 161 extends radially outwardly so as to intersect with the plurality of turn portions 1101-1108 in sequence on the side opposite to the side on which the first shielding member 130 and the second shielding member 150 are positioned with respect to the planar coil 110 in the axial direction of the planar coil 110. The first conductor portion 161A is connected to a surface of the first turn portion 1101 at an inner end in the radial direction, the surface opposite to the surface facing the first shielding member 130.

[0095] 5, the distance CL8 in the axial direction between the eighth turn portion 1108, which is located radially outward among the plurality of turn portions 1101-1108, and the first conductor portion 161A is greater than the distance CL1 in the axial direction between the connection portion 161C of the first turn portion 1101, which is located radially inward, with the first conductor portion 161A, and the first conductor portion 161A. In the illustrated example, the end of the first turn portion 1101 opposite to the end connected to the second turn portion 1102 is connected to the first conductor portion 161A via the conductive connection portion 170. In this embodiment, the thickness of the conductive connection portion 170 corresponds to the dimension of the distance CL1. Therefore, the distance CL8 is greater than the thickness of the conductive connection portion 170. More specifically, the distance CL8 is determined by the dimension between the radial center position of the portion of the eighth turn portion 1108 that intersects with the first conductor portion 161A and the position of the first conductor portion 161A that faces this position in the axial direction.

[0096] 5, the plurality of turn portions 1101-1108 are positioned so as to be arranged on the same plane, while the first conductor portion 161A extends at an angle to the plane, more specifically, extends at an angle so as to move away from the planar coil 110 as it moves radially outward. More specifically, the first conductor portion 161A extends such that the axial distance from the planar coil 110, the first shield member 130, and the second shield member 150 increases as it moves radially outward. As a result, the distance between the plurality of turn portions 1101-1108 and the first conductor portion 161A increases as it moves radially outward.

[0097] When a current is supplied to the planar coil 110, a potential difference between the radially inner end and the radially outer end increases. Therefore, a potential difference increases between the first conductor portion 161A connected to the first turn portion 1101 located radially innermost of the planar coil 110, and the eighth turn portion 1108 located radially outermost. In this case, if the distance between the first conductor portion 161A and the eighth turn portion 1108 is short, the electric field intensity becomes excessively large, and there is a risk that insulation breakdown or a short circuit may easily occur between the first conductor portion 161A and the eighth turn portion 1108.

[0098] Therefore, in this embodiment, the distance CL8 in the axial direction between the eighth turn portion 1108 and the first conductor portion 161A is set to be greater than the distance CL1 between the first conductor portion 161A and the connection portion 161C of the first turn portion 1101 with the first conductor portion 161A. This reduces the electric field strength between the eighth turn portion 1108 and the first conductor portion 161A, thereby making it possible to suppress the occurrence of dielectric breakdown or short circuit. In other words, the volume resistance value between the eighth turn portion 1108 and the first conductor portion 161A increases, making it possible to suppress the occurrence of dielectric breakdown or short circuit between the eighth turn portion 1108 and the first conductor portion 161A.

[0099] The size of the distance CL8 is not particularly limited, but making it excessively large is undesirable from the viewpoint of miniaturization, since the first connection terminal 161 will protrude in the axial direction even though the range occupied by the first connection terminal 161 is partial. Therefore, the size of the distance CL8 may be, for example, 10 mm or less, 5 mm or less, or 3 m or less.

[0100] In this embodiment, as described above, first conductor portion 161A is inclined, but for example, first conductor portion 161A may be formed in a stepped shape in which the distance from planar coil 110 increases stepwise as it goes radially outward. Also, first conductor portion 161A may extend parallel to the radial direction from the innermost turn portion in the radial direction (first turn portion 1101) to a position between the innermost turn portion and the outermost turn portion (eighth turn portion 1108), and then incline or bend so that the distance from planar coil 110 increases.

[0101] In the present embodiment, a void is formed between the first conductor portion 161A and the plurality of turn portions 1101-1108, but an inserting material may be provided to maintain the distance. Such an inserting material is preferably nonmagnetic and insulating. In the present embodiment, the first turn portion 1101 is connected to the first conductor portion 161A via the conductive connecting portion 170, but the conductive connecting portion 170 may not be provided and the first turn portion 1101 may be directly connected to the first conductor portion 161A. In this case, the distance CL8 is preferably larger than the axial distance between the first conductor portion 161A and a turn portion (which may be the first turn portion or the second turn portion) that the first conductor portion 161A connected to the first turn portion 1101 first crosses when extending radially outward from the connection position with the first turn portion 1101.

[0102] The coil component 100 according to the present embodiment described above includes a planar coil 110 including a plurality of turn portions 1101-1108, and a first conductor portion 161A connected to a radially inner end of a first turn portion 1101 located radially innermost in the planar coil 110 and extending radially outward so as to sequentially intersect with the plurality of turn portions 1101-1108. An axial distance CL8 between an eighth turn portion 1108 located radially outermost and the first conductor portion 161A is greater than an axial distance CL1 between a connection portion 161C of the first turn portion 1101 located radially innermost with the first conductor portion 161A and the first conductor portion 161A.

[0103] As a result, according to the present embodiment, it is possible to suppress dielectric breakdown or short circuit that may occur in the coil component 100 while suppressing an increase in size or achieving miniaturization. That is, when a current is supplied to the planar coil 110, a potential difference between the first conductor portion 161A connected to the first turn portion 1101 located radially inward of the planar coil 110 and the eighth turn portion 1108 located radially outward increases. At this time, if the distance between the first conductor portion 161A and the eighth turn portion 1108 is short, dielectric breakdown or short circuit may easily occur. In contrast, in the present embodiment, the distance CL8 in the axial direction between the eighth turn portion 1108 and the first conductor portion 161A is made larger than the distance CL1 between the first conductor portion 161A and the connection portion 161C of the first turn portion 1101 with the first conductor portion 161A. This reduces the electric field intensity between the eighth turn portion 1108 and the first conductor portion 161A. As a result, the occurrence of dielectric breakdown or short circuit between the eighth turn portion 1108 and the first conductor portion 161A can be suppressed.

[0104] In the present embodiment, the distance between the first conductor portion 161A and the planar coil 110 is partially increased at least between the eighth turn portion 1108, so that the coil component 100 can be prevented from becoming large due to the addition of a configuration for suppressing dielectric breakdown or short circuit. In addition, the first conductor portion 161A is not passed through a notch or gap formed in the first shield member 130, but extends so as to move away from the second shield member 150. Therefore, even if the thickness of the first shield member 130 is reduced, dielectric breakdown or short circuit between the first conductor portion 161A and the second shield member 150 is suppressed, which is advantageous for miniaturization. Therefore, dielectric breakdown or short circuit that may occur in the coil component 100 can be suppressed while suppressing the size or while achieving miniaturization.

[0105] In this embodiment, the distance between the multiple turn portions 1101 and the first conductor portion 161A increases radially outward. In this case, the reliability of avoiding dielectric breakdown or short circuit can be improved. Furthermore, the multiple turn portions 1101-1108 are positioned so as to be arranged on the same plane, and the first conductor portion 161A extends so as to be inclined with respect to the plane. In this case, the reliability of avoiding dielectric breakdown or short circuit can be improved without complicating the shape of the first conductor portion 161A.

[0106] Moreover, in this embodiment, the first conductor portion 161A is disposed on the side opposite to the first shield member 130 with respect to the planar coil 110. Therefore, the first conductor portion 161A is not passed through a notch or gap formed in the first shield member 130, and further, the constraints imposed by the position of the first conductor portion 161A on the thickness and position of the first shield member 130 are alleviated. Therefore, for example, by reducing the thickness of the first shield member 130 and placing the second shield member 150 closer to the first shield member 130, it is advantageous for miniaturization and thinning.

[0107] <<Second embodiment>> Next, a coil component 102 according to a second embodiment will be described with reference to Figs. 6 to 10. Among the components in the embodiments described below, those that are the same as or correspond to those in the first embodiment will be given the same reference numerals. When the configuration is the same, detailed description thereof will be omitted. Fig. 6 is a perspective view of the coil component 102. Fig. 7 is an enlarged perspective view of a portion of the coil component 102. Fig. 8 is a plan view of the coil component 102. Fig. 9 is a cross-sectional view of the coil component 102 taken along line IX-IX in Fig. 8. Fig. 10 is a cross-sectional view of the coil component 102 taken along line XX in Fig. 8. In Fig. 10, the spacer member 120 is omitted from illustration.

[0108] In the second embodiment, the configuration of the first conductor portion 161A is different from that of the first embodiment. Specifically, the first conductor portion 161A in the first connection terminal 161 is disposed on the side of the planar coil 110 where the first shield member 130 and the second shield member 150 are located in the axial direction of the planar coil 110.

[0109] The first conductor portion 161A extends radially outward from the first turn portion 1101 so as to intersect with the plurality of turn portions 1101 to 1108 in sequence. The first conductor portion 161A is connected to a surface of the first turn portion 1101 at a radially inner end thereof facing the first shield member 130. As shown in FIG. 9 and FIG. 10, the first conductor portion 161A and the radially inner end of the first turn portion 1101 are connected via a conductive connection portion 170. However, the conductive connection portion 170 may not be provided and the first turn portion 1101 may be directly connected to the first conductor portion 161A. The spacer member 120 has a through hole at the installation position of the conductive connection portion 170, and the conductor line connection portion 170 is provided in the through hole.

[0110] In this embodiment, the first conductor portion 161A extends parallel to the radial direction. In contrast, at least the eighth turn portion 1108, which is located at the outermost position in the radial direction among the plurality of turn portions 1101-1108, is bent away from the first conductor portion 161A at a position where it intersects with the first conductor portion 161A. As a result, a distance CL8 in the axial direction of the planar coil 110 between the eighth turn portion 1108, which is located at the outermost position in the radial direction among the plurality of turn portions 1101-1108, and the first conductor portion 161A is greater than a distance CL1 in the axial direction between the first conductor portion 161A and a connection portion 161C' of the first turn portion 1101, which is located at the innermost position in the radial direction, and the first conductor portion 161A.

[0111] 9, the first conductor portion 161A intersects with the second turn portion 1102 to the eighth turn portion 1108. The second turn portion 1102 to the eighth turn portion 1108 that intersect with the first conductor portion 161A are all bent away from the first conductor portion 161A at the positions where they intersect with the first conductor portion 161A. In particular, in the present embodiment, the second turn portion 1102 to the eighth turn portion 1108 are bent away from the first conductor portion 161A, the first shielding member 130, and the second shielding member 150 at the positions where they intersect with the first conductor portion 161A.

[0112] In the illustrated example, the distances between the second turn portion 1102 to the seventh turn portion 1107 and the first conductor portion 161A are the same (substantially the same) as the distance CL8 between the eighth turn portion 1108 and the first conductor portion 161A. However, the distances between the second turn portion 1102 to the eighth turn portion 1108 and the first conductor portion 161A do not have to be the same. For example, the second turn portion 1102 to the eighth turn portion 1108 may be bent so that the distances between the second turn portion 1102 to the eighth turn portion 1108 and the first conductor portion 161A increase radially outward.

[0113] In the illustrated example, the first conductor portion 161A crosses an area including the connection positions of adjacent turn portions (1101, 1102; 1102, 1103; 1103, 1104; 1104, 1105; 1105, 1106; 1106, 1107; 1107, 1108) or in the vicinity of the connection positions. Therefore, a portion including the radially outer end of the radially inner turn portion of the adjacent turn portions is bent away from the first conductor portion 161A, and a portion including the radially inner end of the radially outer turn portion of the adjacent turn portions is bent away from the first conductor portion 161A.

[0114] As shown in FIG. 10, the first conductor portion 161A is disposed between the planar coil 110 and the first shield member 130. More specifically, the first conductor portion 161A is disposed between the surface of the planar coil 110 facing the first shield member 130 and the surface of the first shield member 130 facing the planar coil 110, and is in contact with the surface of the first shield member 130 facing the planar coil 110. In the illustrated example, a groove 124 (see FIG. 9) is formed on the surface of the spacer member 120 facing the first shield member 130, and the first conductor portion 161A is passed through the groove 124. This prevents the first conductor portion 161A from protruding. The first conductor portion 161A is positioned so as to cover the gap between the first shield piece 131 and the eighth shield piece 138 constituting the first shield member 130.

[0115] In the present embodiment, the spacer member 120 has magnetic properties, but the spacer member 120 may be non-magnetic and insulating, and may be made of only resin. The spacer member 120 may not be provided, and an air layer may be formed between the planar coil 110 and the first shield member 130.

[0116] In the second embodiment described above, the distance between the first conductor portion 161A and the planar coil 110 is partially increased at least at the portion of the eighth turn portion 1108 that intersects with the first conductor portion 161A, and other portions of the eighth turn portion 1108 do not protrude. This makes it possible to prevent the coil component 102 from becoming larger due to the addition of a configuration for preventing dielectric breakdown or short circuiting. This makes it possible to prevent dielectric breakdown or short circuiting that may occur in the coil component 100 while preventing an increase in size or while achieving a reduction in size.

[0117] In addition, in this embodiment, the first conductor portion 161A is disposed between the planar coil 110 and the first shield member 130. This allows the first conductor portion 161A to be laid out compactly. The first conductor portion 161A contacts the surface of the first shield member 130 facing the planar coil 110. In this case, a large distance can be secured between the first conductor portion 161A and the second shield member 150. This makes it possible to suppress insulation breakdown or short circuit between the first conductor portion 161A and the second shield member 150 while achieving miniaturization and thinning by, for example, reducing the thickness of the first shield member 130 and bringing the second shield member 150 closer to the first shield member 130. On the other hand, when the first conductor portion 161A contacts the surface of the first shield member 130 facing the planar coil 110, the first conductor portion 161A may come closer to the planar coil 110. In response to this, the distance between the first conductor portion 161A and the planar coil 110 is partially increased at least at the portion where the eighth turn portion 1108 intersects with the first conductor portion 161A, thereby effectively suppressing problems of insulation breakdown or short circuit between the first conductor portion 161A and the planar coil 110.

[0118] <<Simulation for performance evaluation>> Fig. 11 shows a simulation result of the electric field intensity when a current is supplied to the coil device 100 in the first embodiment. Fig. 12 shows a simulation result of the electric field intensity when a current is supplied to the coil device 102 in the second embodiment.

[0119] 11 and 12, the horizontal axis of the graphs indicates the distance from the center of first conductor portion 161A to the center of planar coil 110, and the vertical axis indicates the electric field strength (V / m) between first conductor portion 161A and planar coil 110.

[0120] 11, the dashed line indicated by the symbol E1 indicates the electric field strength between the first conductor portion 161A and the planar coil 110 when an AC current of 85 KHz is supplied to the coil component 100 according to the first embodiment. The solid line indicated by the symbol E2 indicates the electric field strength between the first conductor portion 161A and the planar coil 110 when an AC current of 85 KHz is supplied to a modified example of the coil component 100 according to the first embodiment. In this modified example, the spacer member 120 is not provided, and an air layer is formed between the planar coil 110 and the first shield member 130.

[0121] 11, the symbol Co indicates the electric field strength (V / m) between the portion corresponding to the first conductor portion 161A and the portion corresponding to the planar coil 110 when an AC current of 85 KHz is supplied to the coil component according to the comparative example. In the comparative example, the distance between the portion corresponding to the first conductor portion 161A and the portion corresponding to the planar coil 110 is constant, and the dimension of this distance corresponds to the dimension of the distance CL1 shown in FIG. 5. Lines E1, E2, and Co indicate that the electric field strength increases at the position where the conductor portion intersects with the turn portion, and increases stepwise toward the outside in the radial direction. Note that lines E1 and E2 partially indicate the portion including the peak of the electric field strength.

[0122] The value and frequency of the AC current set in the simulations are the same. As is clear from a comparison of lines E1, E2, and Co, in coil device 100 according to the first embodiment, the distance between first conductor portion 161A and turn portions 1102-1108 intersecting therewith is made larger than in the comparative example, thereby suppressing the electric field intensity between first conductor portion 161A and planar coil 110 to a greater extent than in the comparative example. From these results, the effect of the first embodiment can be confirmed.

[0123] 12, the dashed line indicated by the symbol E1' indicates the electric field strength between the first conductor portion 161A and the planar coil 110 when an AC current of 85 KHz is supplied to the coil component 102 according to the second embodiment. The solid line indicated by the symbol E2' indicates the electric field strength between the first conductor portion 161A and the planar coil 110 when an AC current of 85 KHz is supplied to a modified example of the coil component 100 according to the second embodiment. In this modified example, the spacer member 120 is not provided, and an air layer is formed between the planar coil 110 and the first shield member 130.

[0124] 11, the symbol Co in Fig. 12 indicates the electric field strength (V / m) between the portion corresponding to the first conductor portion 161A and the portion corresponding to the planar coil 110 when an AC current of 85 KHz is supplied to the coil device according to the comparative example. Note that lines E1' and E2' partially indicate the portions including the peaks of the electric field strength.

[0125] The value and frequency of the AC current set in the simulations are the same. As is clear from a comparison of lines E1, E2, and Co, in coil device 102 according to the second embodiment, the distance between first conductor portion 161A and turn portions 1102-1108 intersecting therewith is made larger than in the comparative example, so that the electric field intensity between first conductor portion 161A and planar coil 110 is suppressed more significantly than in the comparative example. From these results, the effect of the second embodiment can be confirmed.

[0126] Although the embodiments of the present disclosure have been described above, various modifications may be made to the above-described embodiments, and such modifications are also within the technical scope of the present disclosure. [Explanation of symbols]

[0127] S…Power transmission system 1...Power transmission device 1A…High frequency current supply 2...Power receiving device 2A…Conversion section 100, 102... Coil parts 110a...first principal surface 110b…Second main surface 110... Planar coil 110E…Conductor 110n…Turn section 1101…First turn 1102…Turn 2 1103…Third turn 1104…Turn 4 1105…5th turn 1106…Turn 6 1107…Turn 7 1108…Turn 8 111~119…Straight section 111...First straight section 112…Second straight section 113…Third straight section 114…4th straight line part 115...5th straight section 116…6th straight line section 117…7th straight section 118...8th straight section 119...9th straight line section 120...Spacer member 122…Recess 124...Groove 130...First shield member 13P…Shield piece 131…First shield piece 132…Second shield piece 133…Third shield piece 134…Fourth shield piece 135…51st shield piece 136…6th shield piece 137…7th shield piece 138…8th Shield Piece 150…Second shield member 155…Spacer block 161…First connection terminal 161A…1st conductor part 161B…1st terminal section 161C, 161C'...Connection part 162…Second connection terminal 162A…Second conductor part 162B…Second terminal part 170...Conductive connection part C…Central axis line CL1…Distance CL8…distance

Claims

1. a planar coil including a plurality of turns arranged in a radial direction; a conductor portion connected to an inner end of a turn portion located at an innermost position in the radial direction of the planar coil, the conductor portion extending radially outward so as to intersect the plurality of turn portions in sequence, a distance in the axial direction of the planar coil between a turn portion located radially outermost among the plurality of turn portions and the conductor portion is greater than a distance in the axial direction between a connection portion of the turn portion located radially innermost with the conductor portion and the conductor portion.

2. The coil component according to claim 1 , wherein a distance between the plurality of turn portions and the conductor portion increases outward in the radial direction.

3. The turn portions are arranged in the same plane, The coil component according to claim 1 , wherein the conductor portion extends at an angle with respect to the plane.

4. a first shield member overlapping the planar coil and having magnetic and insulating properties; The coil component according to claim 1 , wherein the conductor portions extend such that a distance in the axial direction from the first shield member increases toward an outer side in the radial direction.

5. The coil component according to claim 1 , wherein at least the turn portion located outermost in the radial direction among the plurality of turn portions is bent so as to move away from the conductor portion at a position where the turn portion intersects with the conductor portion.

6. The coil component according to claim 5 , wherein all of the turn portions that intersect with the conductor portion are bent so as to move away from the conductor portion at positions where the turn portions intersect with the conductor portion.

7. a first shield member overlapping the planar coil and having magnetic and insulating properties; The coil component according to claim 5 , wherein the turn portion bent so as to be away from the conductor portion at a position where the turn portion intersects with the conductor portion is bent so as to be away from the first shield member.

8. the turn portion located most inward in the radial direction and the conductor portion are connected via a conductive connecting portion, The coil component according to claim 1 , wherein the distance in the axial direction between the turn portion located outermost in the radial direction and the conductor portion is greater than a thickness of the conductive connection portion.

9. The coil component according to claim 1 , further comprising a first shield member overlapping the planar coil and having magnetic and insulating properties.

10. The coil component according to claim 9 , wherein the conductor portion is disposed on a side of the planar coil opposite to a side of the first shield member.

11. The coil component according to claim 10 , wherein the conductor portion is disposed between the planar coil and the first shield member.

12. The coil component according to claim 11 , wherein the conductor portion is in contact with a surface of the first shield member that faces the planar coil.

13. The coil component according to claim 9 , wherein the first shield member includes ferrite.

14. 10. The coil component according to claim 9, further comprising a second shielding member which is non-magnetic and conductive and is overlapped on the first shielding member so as to face a surface of the first shielding member opposite to a surface facing the planar coil.

15. The coil component according to claim 14 , wherein the second shield member includes aluminum or an aluminum alloy.

16. A power transmitting device comprising the coil component according to claim 1.

17. A power receiving device comprising the coil component according to claim 1.

18. The power transmission device and the power receiving device are provided. A power transfer system, wherein at least one of the power transmitting device and the power receiving device comprises the coil component according to claim 1 .

Images