Coil components, power transmission equipment, power receiving equipment, and power transmission systems

Abstract

To provide a coil section that can effectively suppress losses. [Solution] The coil component 10 according to one embodiment has a conductor 11E that forms a spiral shape with a plurality of turn portions 12n, the plurality of turn portions 12n being a planar coil 11 which is connected so as to move radially outward from the central axis C of the spiral shape and gradually away from the central axis C, a support plate portion 21 which is in contact with the planar coil 11 on one surface along the central axis C, and a base portion 22 which is raised from the one surface and located in the gap between adjacent turn portions 12n, and the support member 20 which is magnetic as a whole, and a magnetic shielding member 30 which is provided on the other surface of the support plate portion 21 opposite to the one surface, and is magnetic.

Description

Technical Field

[0001] The present disclosure relates to a coil component, a power transmission device, a power reception device, and a power transmission system.

Background Art

[0002] In recent years, wireless power transmission systems that transmit power without contact have been becoming popular. In the future, the demand for wireless power transmission systems capable of transmitting large power is particularly expected to increase.

[0003] When transmitting large power wirelessly, a high-frequency large current flows through a resonant circuit including a coil. At this time, the amount of heat generated by the coil increases. The amount of heat generated by the coil increases, for example, due to the skin effect.

[0004] The skin effect increases the AC resistance and causes an increase in power consumption due to heat generation, which also causes a decrease in transmission efficiency.

[0005] When using Litz wire as the coil, the skin effect is suppressed. However, since Litz wire is formed by twisting a large number of enameled wires, the manufacturing cost is high and the manufacturing is time-consuming. On the other hand, a technique of adopting a spiral and plate-shaped planar coil is also known (see Patent Document 1). According to such a planar coil, the manufacturing efficiency can be improved regardless of the size of the coil. Therefore, the planar coil is suitable for a high-power system in which the size of the coil can be large.

[0006] The coil unit disclosed in Patent Document 1 has a gap between adjacent turn portions in the coil that is narrower on the central side. Thereby, an attempt is made to suppress losses due to the skin effect and the proximity effect. In addition, a magnetic body is provided in the gap between the turn portions. This magnetic body forms a magnetic path, thereby further suppressing losses.

[0007] Furthermore, the coil unit in Patent Document 1 includes a magnetic shield positioned away from the coil so as not to directly contact the coil. This magnetic shield suppresses leakage flux. Patent Document 1 also discloses a configuration in which a plate-shaped magnetic material portion that contacts the coil is formed between the coil and the magnetic shield. In this configuration, the magnetic material that passes through the gap between the turn portions rises up from the plate-shaped magnetic material portion. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2020-47614 [Overview of the project] [Problems that the invention aims to solve]

[0009] In the coil unit of Patent Document 1, magnetism may flow to the magnetic shield side through the magnetic material provided in the gap between the turn sections. However, because the coil and the magnetic shield are separated, not all of the magnetism flowing through the magnetic material is guided to the magnetic shield; some of it may be induced in the coil, causing eddy current losses.

[0010] On the other hand, in a configuration where a plate-shaped magnetic material portion is formed in contact with the coil, the flow of magnetism through the plate-shaped magnetic material portion can suppress the situation in which magnetism is guided to the coil. However, the plate-shaped magnetic material portion is very thin, specifically about 0.5 mm thick. Therefore, depending on the amount of magnetism, the magnetism may saturate and be easily guided to the coil.

[0011] Therefore, Patent Document 1 has room for improvement in further reducing losses.

[0012] Furthermore, Patent Document 1 attempts to suppress losses due to the skin effect and proximity effect by narrowing the gap between the turns in the coil towards the center. However, when the gap between the turns is narrowed, the influence of the proximity effect becomes larger, and desirable coil performance may not be obtained. Also, if the gap is widened, the total amount of coil decreases, which may lower the Q value. Moreover, the desirable setting of the gap can vary depending on the size of the coil. Patent Document 1 does not adequately consider the trade-off between performance degradation due to the proximity effect and securing the Q value, and the relationship between this trade-off and the coil size. Therefore, there is a risk that losses will not be sufficiently suppressed and good coil performance may not be obtained.

[0013] This disclosure has been made in consideration of the above circumstances, and its objective is to provide coil components, power transmission equipment, power receiving equipment, and power transmission systems that can effectively suppress losses. [Means for solving the problem]

[0014] A coil component according to one embodiment has a conductor that forms a spiral shape with a plurality of turned portions, the plurality of turned portions comprising a planar coil that is connected so as to move radially outward from the central axis of the spiral shape and gradually away from the central axis, a support plate portion that contacts the planar coil on one surface along the central axis, and a base portion that rises from the one surface and is located in the gap between adjacent turned portions, and the support member as a whole is magnetic, and a magnetic member provided on the other surface of the support plate portion opposite to the one surface is magnetic.

[0015] The support member may further have a wall portion that rises from the base and extends from the planar coil.

[0016] The magnetic member may be provided on the other surface of the support member via a heat dissipation layer.

[0017] The thickness of the heat dissipation layer may be 10 mm or less.

[0018] The ratio of the radial width of the gap to the pitch defined by the sum of the radial width of the gap and the radial width of the turn portion may be 15% or more and 40% or less.

[0019] The pitch is 6 mm or more and 12 mm or less, and the ratio of the radial width of the gap to the pitch may be 25% or more and 40% or less.

[0020] The pitch is 16 mm or more and 25 mm or less, and the ratio of the radial width of the gap to the pitch may be 15% or more and 30% or less.

[0021] The pitch may be 6 mm or more and 25 mm or less.

[0022] The base portion may be positioned so as to entirely fill the gap in the radial direction.

[0023] The radial width of the wall portion may be the same as the radial width of the base portion or 90% or more and less than 100% of the radial width of the base portion.

[0024] The ratio of the radial width of the wall portion to the pitch defined by the sum of the radial width of the gap and the radial width of the turn portion may be 20% or more and 30% or less.

[0025] The connection surface between the base portion and the wall portion is at the same height as the portion opposite to the portion in contact with the support plate portion in the planar coil, the wall portion is a portion extending from the planar coil, and the height of the wall portion may be 0.5 mm or more.

[0026] The height of the wall portion may be 1.0 mm or more.

[0027] The first combined thickness obtained by adding the thickness of the support plate portion and the thickness of the base portion may be 2 times or more the thickness of the conductor.

[0028] The connection surface between the base and the wall is at the same height as the portion of the planar coil opposite to the portion in contact with the support plate, the wall is a portion extending from the planar coil, and the thickness of the support plate may be greater than or equal to the height of the wall.

[0029] The connection surface between the base and the wall is at the same height as the portion of the planar coil opposite to the portion in contact with the support plate, the wall is a portion extending from the planar coil, and the second combined thickness, which is the sum of the thickness of the support plate and the thickness of the magnetic member, may be greater than or equal to the height of the wall.

[0030] The magnetic member may include a soft magnetic material or a nanocrystalline magnetic material.

[0031] The relative permeability of the support member may be 5.0 or higher.

[0032] The planar coil is plate-shaped, and the radial cross-sectional shape of each turn portion may be rectangular.

[0033] Furthermore, the power transmission device according to one embodiment includes the aforementioned coil component. Furthermore, the power receiving device according to one embodiment includes the aforementioned coil component. Furthermore, a power transmission system according to one embodiment comprises a power transmission device and a power receiving device, wherein at least one of the power transmission device and the power receiving device comprises the coil component. [Effects of the Invention]

[0034] This disclosure provides coil components, power transmission equipment, power receiving equipment, and power transmission systems that can effectively suppress losses. [Brief explanation of the drawing]

[0035] [Figure 1] This figure schematically shows a wireless power transmission system to which a coil component according to one embodiment is applied. [Figure 2] This is a perspective view of a coil component according to one embodiment. [Figure 3] Figure 2 is a top view of the coil component shown. [Figure 4] This is a cross-sectional view of the coil component along the IV-IV line in Figure 3. [Figure 5A] Figure 2 shows an example of a manufacturing method for the coil component shown. [Figure 5B] Figure 2 shows an example of a manufacturing method for the coil component shown. [Figure 6A] Figure 2 is a cross-sectional view of the conductive material of a planar coil in the coil component shown, illustrating the relationship between the pitch of the turn portion in the conductive material, the radial width of the turn portion, and the radial width of the gap between the turn portions. [Figure 6B] This figure 6A is a graph illustrating the relationship between the gap in the turn section and the Q value of the coil component. [Figure 7A] Figure 2 is a cross-sectional view of the conductor and support member of a planar coil in the coil component shown, and shows the base and wall portion of the support member located in the gap between the turn sections. [Figure 7B] Figure 2 shows a graph illustrating the relationship between the radial width of the support member wall in the coil component and the Q value of the coil component. [Figure 7C] Figure 2 shows a graph illustrating the relationship between the radial width of the support member wall in the coil component and the Q value of the coil component. [Figure 8] Figure 2 shows a graph illustrating the relationship between the height of the support member wall in the coil component and the Q value of the coil component. [Figure 9] This figure shows a graph illustrating the rate of increase in the Q value of a coil component when a support member has a wall, compared to when the support member does not have a wall, in relation to the height of the wall. [Figure 10] Figure 2 shows a cross-sectional view of the conductor and support member of a planar coil in the coil component, illustrating that the radial width of the wall portion of the support member differs from that of the base portion. [Figure 11] Figure 2 shows a graph illustrating the relationship between the radial width of the support member wall in the coil component and the Q value of the coil component. [Figure 12] Figure 2 shows a graph illustrating the relationship between the radial width of the support member wall in the coil component and the Joule loss of the coil component. [Figure 13] Figure 2 shows a graph illustrating the relationship between the radial width of the wall portion of the support member in the coil component and the coupling coefficient of the coil component. [Figure 14] Figure 2 shows a graph illustrating the relationship between the thickness of the support member from the support plate to the base of the coil component and the Q value of the coil component. [Figure 15] This is a diagram showing a modified example of a coil component. [Modes for carrying out the invention]

[0036] An embodiment will be described below with reference to the drawings.

[0037] In this specification, terms such as "sheet," "film," and "plate" are not distinguished from each other solely based on differences in name. Therefore, for example, "sheet" is a concept that includes components that could also be called films or plates.

[0038] Furthermore, in this specification, "sheet surface (plate surface, film surface)" refers to the surface that coincides with the planar direction (surface direction) of the sheet-like member in question when viewed as a whole and in a broad sense. In addition, in this specification, the normal direction of a sheet-like member refers to the direction normal to the sheet surface of the sheet-like member in question. Moreover, the dimension of the member in the direction normal to the sheet surface may be referred to as thickness.

[0039] Figure 1 schematically shows a wireless power transmission system S to which a coil component 10 according to one embodiment is applied. First, the wireless power transmission system S (hereinafter abbreviated as power transmission system S) will be described with reference to Figure 1.

[0040] <Wireless Power Transmission System> The power transmission system S comprises 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. The high-frequency current supply unit 1A supplies high-frequency current to the coil component 10 as a power transmission coil.

[0041] The power receiving device 2 includes a coil component 10 and a conversion unit 2A. The coil component 10 in the power receiving device 2 functions as a power receiving coil. The conversion unit 2A shapes the high-frequency current generated in the coil component 10. The conversion unit 2A has a rectifier circuit and the like that converts the high-frequency current into a DC current.

[0042] In this embodiment, both the power transmission device 1 and the power receiving device 2 include a coil component 10. However, the coil component 10 may be used in only one of the power transmission device 1 or the power receiving device 2, while a different type of coil component may be used in the other.

[0043] When transmitting power wirelessly (contactlessly) from the power transmission device 1 to the power receiving device 2, the power transmission device 1 supplies a high-frequency current of a predetermined frequency to the coil component 10, which acts as a power transmission coil, from the high-frequency current supply unit 1A. At this time, a magnetic field is generated in the coil component 10 due to electromagnetic induction. Due to the influence of this magnetic field, a high-frequency current is generated in the coil component 10, which acts as a power receiving coil, in the power receiving device 2. The conversion unit 2A converts this high-frequency current into a DC current and supplies the converted DC current to, for example, a battery (not shown).

[0044] The power transmission system S shown in Figure 1 employs a magnetic resonance method as the power transmission method. However, the coil component 10 in this embodiment may also be used in an electromagnetic induction power transmission system. Furthermore, the power transmission system S is configured as a system for wirelessly transmitting power to an electric vehicle. In this case, the power transmission device 1 is installed on a road, parking lot, etc. The power receiving device 2 is installed in the electric vehicle.

[0045] However, the applications of the power transmission system S are not limited to power transmission to electric vehicles. For example, the power transmission system S may be used to transmit power to flying objects such as drones and robots. Furthermore, the power transmission system S may be used to transmit power to submersibles and exploration robots underwater. Also, the applications of the coil component 10 are not limited to wireless power transmission systems. For example, the coil component 10 may be used in transformers, DC-DC converters, antennas, etc.

[0046] <Coil components> The coil component 10 will be described below. Figure 2 is a perspective view of the coil component 10. Figure 3 is a top view of the coil component 10. Figure 4 is a cross-sectional view of the coil component 10 along the line IV-IV in Figure 3.

[0047] As shown in Figures 2 to 4, the coil component 10 includes a planar coil 11, a support member 20, a magnetic shielding member 30, a spacer plate 40, a case 50, a first connection terminal 61, and a second connection terminal 62. The case 50 has a bottom wall portion 51 and a side wall portion 52 rising from the bottom wall portion 51. The spacer plate 40, magnetic shielding member 30, support member 20, and planar coil 11 are arranged in this order on the bottom wall portion 51. The planar coil 11, support member 20, magnetic shielding member 30, and spacer plate 40 are surrounded by the side wall portion 52.

[0048] Note that in Figure 2, for the sake of explanation, a portion of the side wall 52 of the case 50 has been removed. Also, dots have been added to the planar coil 11 shown in Figures 2 to 4 for the sake of explanation.

[0049] (Planar coil) The planar coil 11 is spiral-shaped and made of a conductive material. In this embodiment, the planar coil 11 is made of copper, but the planar coil 11 can be made of any conductive material, such as aluminum. The planar coil 11 is also plate-shaped. As shown in Figure 4, the cross-sectional shape of the planar coil 11 in the direction perpendicular to the winding direction of the spiral shape is rectangular.

[0050] The symbol C shown in Figures 2 and 3 indicates the central axis of the planar coil 11, passing through the center of the spiral shape of the planar coil 11. Hereafter, when referring to the axial direction of the planar coil 11, it means the direction extending along the central axis C or the direction parallel to the central axis C. The direction perpendicular to the central axis C is called the radial direction.

[0051] The planar coil 11 has a conductor 11E that forms a spiral shape with a plurality of turned sections 12n. The plurality of turned sections 12n are connected so as to gradually move away from the central axis C radially outward from the central axis C of the spiral shape, thereby forming the spiral shape. The linear conductive portion of the turned section 12n does not form a ring but rotates 360 degrees around the central axis C. In the case of a so-called planar coil 11, both ends of the turned section 12n are offset radially. In the plurality of turned sections 12n, the radially inward end of one turned section 12n is connected to the radially outward end of another turned section 12n, and the other turned sections 12n extend away from the central axis C.

[0052] In the following, the turn section 12n closest to the central axis C may be referred to as turn section 121. Furthermore, the turn section connected to turn section 121 may be referred to as turn section 122, and the turn section connected to turn section 122 may be referred to as turn section 123. In the examples in Figures 2 and 3, the multiple turn sections 12n are composed of 12 turn sections 121 to 1212. Turn section 1212 is the 12th turn section counting from the innermost turn section 121, and corresponds to the turn section located on the outermost circumference. In the following, when explaining matters common to each of the multiple turn sections 12n, they will generally be referred to as turn section 12n.

[0053] In this embodiment, the turn portion 12n circulates in a rectangular shape. However, the turn portion 12n may also circulate in a circular shape. In this specification and disclosure, the spiral shape refers to the shape of a spirally wound planar curve. The planar curve referred to here also includes planar patterns that are bent and connected in a broken line shape as shown in the figure. In other words, the spiral shape is a shape that circulates around the central axis C of the planar coil 11 so that it is gradually positioned outward.

[0054] In this embodiment, the planar coil 11 is formed, for example, by punching a spiral shape out of a copper plate. Alternatively, the planar coil 11 can also be formed by etching a spiral shape out of copper foil. In this case, the planar coil 11 can be formed with a complex spiral pattern. However, etching is time-consuming in ensuring the thickness of the planar coil 11 that is capable of transmitting high power. Therefore, from the viewpoint of manufacturing efficiency, punching is preferable.

[0055] The thickness of the conductor 11E in the planar coil 11, in other words, the thickness of the turn portion 12n, may be, for example, 0.2 mm or more and 1.0 mm or less. Also, the radius of the planar coil 11 (the distance from the central axis C to the part furthest in the radial direction) may be 200 mm or more. When transmitting power to an electric vehicle using a magnetic resonance method, it is desirable to be able to transmit power of 1 kW or more, preferably 5 kW or more, in the high-frequency current frequency range of 10 kHz to 200 kHz, particularly 79 kHz to 90 kHz. In this case, the thickness of the copper planar coil 11 is preferably 0.4 mm or more. However, if the thickness of the planar coil 11 is too large, the weight increases, which is undesirable, for example, for vehicle installation. Therefore, the thickness of the planar coil 11 may be, for example, 2.0 mm or less, 1.5 mm or less, or 1.0 mm or less.

[0056] The wire width of the conductor 11E in the planar coil 11, that is, the radial width (width in the radial direction) of each turn portion 12n, is not particularly limited. However, considering that it is possible to transmit power of 1 kW or more, preferably 5 kW or more, in the frequency range of high-frequency currents from 79 kHz to 90 kHz, the radial width of the turn portion 12n may be 2 mm to 20 mm, 2 mm to 16 mm, 2 mm to 12 mm, or 2 mm to 8 mm.

[0057] Referring to Figure 4, in this embodiment, the pitch P of the turn portion 12n is determined by the sum of the radial width Ws of the gap Sp between adjacent turn portions 12n and the radial width Wc of the turn portion 12n. When the gap Sp between the turn portions 12n is narrowed, the proximity effect may become more pronounced. Also, when the gap Sp is widened, the total amount of the planar coil 11 decreases, which may lower the Q value.

[0058] Through diligent research into the relationship between the proximity effect and the Q value as described above, the inventors of this invention have found that the ratio of the radial width Ws of the gap Sp to the pitch P is preferably 15% to 40%. This range is effective, for example, when the thickness of the planar coil 11 is 2.0 mm or less, the radial width of the turn portion 12n is 2 mm to 20 mm, and the planar coil 11 is combined with a magnetic support member 20 and a magnetic shielding member 30 as described later, and is also effective when the support member 20 and magnetic shielding member 30 are absent.

[0059] However, if prioritizing Q-value maintenance, the radial width Ws of the gap Sp may be 15% to 28% of the pitch P, or if prioritizing the suppression of proximity effect, it may be 32% to 40%. Furthermore, when a support member 20 and a magnetic shielding member 30 are provided, the ratio of the radial width Ws of the gap Sp to the pitch P, in relation to the wall portion 23 of the support member 20, allows for a more limited range than the aforementioned 15% to 40% range that effectively improves coil performance. This will be discussed later.

[0060] In this embodiment, the pitch P is constant between the innermost turn portion 121 and the outermost turn portion 12121. However, the pitch P does not have to be constant. If the pitch is not constant, it is preferable that one of the adjacent gaps Sp be between 0.5 and 2 times, or between 0.8 and 1.5 times, of the other (excluding 1 time). Considering practicality, for example, the ability to transmit power of 1 kW or more, preferably 5 kW or more, in the high-frequency current range of 79 kHz to 90 kHz, the pitch P may be between 6 mm and 25 mm, or between 8 mm and 20 mm. The aspect ratio of the turn portion 12n, which has a rectangular cross-sectional shape, is determined by dividing the radial width Wc of the turn portion 12n by the thickness of the turn portion 12n. The aspect ratio of the turn portion 12n may be between 2 and 12, or between 3 and 10.

[0061] (Support member) As shown in Figure 4, the support member 20 has a support plate portion 21 that contacts the planar coil 11 with its upper surface 21A as one surface along the central axis C, a base portion 22 that rises from the upper surface 21A and is located in the gap Sp between adjacent turn portions 12n, and a wall portion 23 that rises from the base portion 22 and extends from the planar coil 11.

[0062] The support plate portion 21 has an upper surface 21A and a lower surface 21B opposite to the upper surface 21A, and is formed to encompass the entire planar coil 11 when viewed from above. In Figure 4, the connection surface 22f between the base portion 22 and the wall portion 23 is shown by a dashed line. The connection surface 22f is at the same height as the upper surface 11A, which is the part of the planar coil 11 opposite to the lower surface 11B, which is the part that contacts the support plate portion. In other words, the wall portion 23 refers to the part that extends from the planar coil 11, or more precisely, from its upper surface 11A. Although the support plate portion 21 is rectangular when viewed from above, its shape is not particularly limited as long as it is large enough to encompass the entire planar coil 11; for example, it may be circular.

[0063] The base portion 22 and the wall portion 23 are formed in a spiral shape that extends along the spiral-shaped conductor 11E. The base portion 22 is positioned to completely fill the gap Sp between the turn portions 12n in the radial direction. That is, the radial width of the base portion 22 is the same as the radial width of the gap Sp. The radial width of the base portion 22 may be smaller than the radial width of the gap Sp, but in this case, there is a risk that the position of the planar coil 11 will shift, so it is desirable to fill the space between the planar coil 11 and the base portion 22 with another material.

[0064] The support member 20 having the base portion 22 and wall portion 23 as described above is magnetic as a whole, that is, the support plate portion 21, base portion 22, and wall portion 23 are each magnetic. The support member 20 aims to improve coil performance by suppressing eddy current losses and leakage flux through magnetism and by increasing the coupling coefficient. The relative permeability of the support member 20 is preferably 2.0 or higher, and may be between 2.0 and 10.0. The relative permeability of the support member 20 is more preferably 5.0 or higher, and may be between 5.0 and 10.0. The relative permeability of the support member is not particularly limited, but if it is too high, the flexibility and strength of the support member 20 may be undesirably impaired. Therefore, the relative permeability of the support member 20 may be 200 or less. Furthermore, the inventor's diligent research has revealed that when a magnetic support member 20 is used, the Q value of the coil component 10 tends to increase sharply when the relative permeability of the support member 20 reaches approximately 10, compared to the case without the support member 20. On the other hand, while the Q value increases as the relative permeability of the support member 20 increases, it has been found that the rate of increase in the Q value tends to slow down when the relative permeability of the support member 20 exceeds 20. Therefore, the relative permeability of the support member 20 may be 20 or less. In this embodiment, the support member 20 is formed, for example, of a plurality or countless granules made of a magnetic material and a holding material containing a resin containing the granules.

[0065] The granular material composed of magnetic material may be one or more of the following: ferrite, particularly soft magnetic material ferrite, nanocrystalline magnetic material, silicon steel, electromagnetic soft iron, and amorphous metal. The holding material may be glass fiber reinforced polyamide. That is, the holding material may be formed from a material containing polyamide as a thermoplastic resin (thermoplastic material) and glass fibers.

[0066] In this embodiment, the planar coil 11 and the support member 20 are integrated by hot pressing, as will be described later. In this case, the planar coil 11 is pressed into the forming material of the support member 20 (the support member forming sheet 20S described later). When the forming material of the support member 20 is glass fiber reinforced polyamide, the polyamide softens and flows along the side surface of the planar coil 11. At this time, the glass fibers suppress the excessive flow of the polyamide. This makes it easier to form the desired shape.

[0067] For the reasons stated above, the support member 20 and its forming material (the support member forming sheet 20S described later) are preferably made of glass fiber reinforced polyamide. However, the support member 20 and its forming material are not particularly limited. For example, they do not need to contain glass fibers. Carbon fibers or the like may be used instead of glass fibers. Thermoplastic resins other than polyamide may also be used. On the other hand, the support member 20 may be formed entirely of ferrite, silicon steel, electromagnetic soft iron, or amorphous metal.

[0068] In this embodiment, the flat coil 11 and the support member 20 are integrated by heat pressing, thereby welding the support member 20 to the flat coil 11. In other words, the flat coil 11 and the support member 20 are joined by an anchoring effect. When the flat coil 11 and the support member 20 are integrated by heat pressing, a part of the support member 20 enters into a recess on the surface of the flat coil 11, and then hardens. As a result, the flat coil 11 and the support member 20 are welded together, and the support member 20 supports the flat coil 11. Note that the support member 20 does not necessarily have to be welded to the flat coil 11. However, when the coil component 10 is installed in a vehicle, it is subjected to strong vibrations. Therefore, when it is installed in a vehicle, it is better for the flat coil 11 and the support member 20 to be welded together.

[0069] As described above, when the planar coil 11 and the support member 20 are integrated by heat pressing, the greater the thickness of the support plate portion 21, the more stable the integration with the planar coil 11 becomes. Furthermore, the greater the thickness of the support plate portion 21, the more the effect of suppressing eddy current loss and leakage flux tends to improve. From this viewpoint, for example, it is preferable that the first combined thickness, which is the sum of the thickness of the support plate portion 21 and the thickness of the base portion 22, is at least twice the thickness of the conductor 11E. Also, it is preferable that the thickness of the support plate portion 21 is greater than or equal to the height of the wall portion 23.

[0070] Furthermore, in this embodiment, the radial width of the wall portion 23 is the same as the radial width of the base portion 22. However, the radial width of the wall portion 23 may be smaller than the radial width of the base portion 22. However, from the viewpoint of ensuring good coil performance and reducing the effort required during manufacturing, it is preferable that the radial width of the wall portion 23 is the same as the radial width of the base portion 22. Through the inventor's diligent research, it has been confirmed that coil performance is good when the radial width of the wall portion 23 is the same as the radial width of the base portion 22. However, due to the manufacturing process, the radial width of the wall portion 23 may be smaller than the radial width of the base portion 22. In this case, it is preferable that the radial width of the wall portion 23 be 90% or more and less than 100% of the radial width of the base portion 22.

[0071] Furthermore, as described above, the ratio of the radial width Ws of the gap Sp to the pitch P is preferably 15% to 40%. Therefore, the radial width of the wall portion 23 is preferably 15% to 40% of the pitch P. On the other hand, the wall portion 23 functions to reduce losses due to the proximity effect. As a result, the wall portion 23 enables performance improvement by increasing the radial width of the turn portion 12n while suppressing the gap Sp to be small. As a result of diligent research from this perspective, the inventors have found that coil performance can be effectively improved when the ratio of the radial width of the wall portion 23 to the pitch P is 20% to 30%, particularly 20% to 28%, and more preferably 20% to 25%.

[0072] Furthermore, the height of the wall portion 23 is not particularly limited, but it may be 2 / 3 times or more the thickness of the conductor 11E. The height of the wall portion 23 may be 0.5 mm or more, or 1.0 mm or more. Also, the height of the wall portion 23 may be 2 times or more the thickness of the conductor 11E. As described above, the support member 20 aims to improve coil performance by suppressing eddy current loss and leakage flux through magnetism, and by increasing the coupling coefficient. The higher the height of the wall portion 23, the greater the effect of suppressing eddy current loss and the higher the coupling coefficient tends to be. On the other hand, the higher the wall portion 23 is, the more prone it is to break starting from the base. For this reason, when the thickness of the conductor 11E is relatively small, it is preferable that the height of the wall portion 23 be 2 times or more the thickness of the conductor 11E. And, when the thickness of the conductor 11E is relatively small, it is preferable that the height of the wall portion 23 be 2 times or more but 5 times or 2 times or more but 3 times or less the thickness of the conductor 11E.

[0073] (Magnetic shielding member) The magnetic shielding member 30 is provided to suppress magnetic transmission and / or leakage magnetic fields. The magnetic shielding member corresponds to the magnetic member. The magnetic shielding member 30 is sheet-shaped and is formed to be large enough to encompass the planar coil 11 in a planar view. The magnetic shielding member 30 is positioned so as to overlap the planar coil 11 and the support member 20 when viewed in the axial direction of the planar coil 11. In this embodiment, it is provided on the lower surface 21B of the support plate portion 21 and is in direct contact with the lower surface 21B. Here, the planar coil 11, the support member 20, and the magnetic shielding member 30 are in a state where they are parallel to each other and overlapping in the axial direction.

[0074] In this embodiment, the magnetic shielding member 30 is magnetic and contains or is made of a magnetic material. The magnetic field generated by the coil component 10 is generated to spread in all directions with respect to the central axis C of the planar coil 11. In this case, because the magnetic shielding member 30 is magnetic, it can orient the spreading magnetic flux lines toward the central axis C. Furthermore, the coil component 10 can be installed in a vehicle, but in this case, if the magnetic field generated by the coil component 10 flows toward other vehicle parts, it may adversely affect the vehicle parts. In such cases, the magnetic shielding member 30 can suppress leakage magnetic fields that do not contribute to the generation of current.

[0075] In this embodiment, as described above, the support member 20 is magnetic, and therefore the support plate portion 21 of the support member 20 functions in the same way as the magnetic shielding member 30. However, since the support member 20 includes a holding member containing resin, it may not be possible to achieve a high relative permeability. Also, it may be desirable for the thickness of the support plate portion 21 of the support member 20 to be small, or it may not be possible to manufacture it in a large size. Here, the magnetic shielding member 30 works in cooperation with the support member 20 to effectively function in forming a magnetic path. The relative permeability of the magnetic shielding member 30 is preferably 1000 or more, but may be between 500 and 1000. In this embodiment, since the magnetic shielding member 30 works in cooperation with the support member 20, it may not be necessary to ensure a high relative permeability depending on the required specifications. In this case, the thickness of the magnetic shielding member 30 can be reduced and costs can be reduced. Furthermore, the inventors have found that the second combined thickness, which is the sum of the thickness of the support plate portion 21 and the thickness of the magnetic shielding member 30 as a magnetic member, is preferably greater than or equal to the height of the wall portion 23.

[0076] The magnetic shielding member 30 preferably contains a soft magnetic material or a nanocrystalline magnetic material. More specifically, the magnetic shielding member 30 contains ferrite, preferably soft ferrite. The magnetic shielding member 30 may also be provided on the lower surface 21B of the support plate portion 21 via a heat dissipation layer as an intermediate layer, and may be indirectly in contact with the lower surface 21B. The thickness of the heat dissipation layer may be, for example, 10 mm or less, 8 mm or less, 5 mm or less, or 3 mm or less. A smaller distance between the magnetic shielding member 30 and the support plate portion 21 allows the magnetic path formed by the magnetic shielding member 30 cooperating with the support member 20 to function more effectively. The heat dissipation layer may be a heat transfer sheet or may be formed of a heat conductive gel. The heat dissipation layer is preferably non-magnetic, preferably insulating, and preferably both non-magnetic and insulating. For example, the heat transfer sheet may be a sheet material made of a resin containing an inorganic material that has relatively high thermal conductivity and is non-magnetic, such as ceramics.

[0077] (Spacer plate and case) The case 50 supports the planar coil 11 and the magnetic shielding member 30 on its bottom wall portion 51 via a spacer plate 40. The spacer plate 40 is insulating and non-magnetic and may be made of, for example, resin. As described above, the case 50 has a bottom wall portion 51 and side wall portions 52 rising from the bottom wall portion 51. The bottom wall portion 51 is rectangular in top view, but its shape is not particularly limited as long as it is large enough to encompass the entire planar coil 11, magnetic shielding member 30 and spacer plate 40; for example, it may be circular.

[0078] The side wall portion 52 is located on the outer circumference of the planar coil 11 and, in this example, surrounds the entire circumference of the planar coil 11. The side wall portion 52 is open at the end opposite to the bottom wall portion 51. That is, the case 50 has an open shape at one end. The case 50 is made of a metallic material and is conductive. Specifically, the bottom wall portion 51 in this embodiment is made of aluminum. In this case, leakage of magnetism from the planar coil 11 through the case 50 is suppressed. When the case 50 is used to suppress magnetic leakage, the case 50 may be made of copper, stainless steel, or the like.

[0079] (Connection terminals) As shown in Figure 2, the first connection terminal 61 is connected to the radially inner end of the turn portion 121, which is closest to the central axis C among the multiple turn portions 12n. The second connection terminal 62 is connected to the radially outer end of the turn portion 1212, which is located on the outermost periphery among the multiple turn portions 12n. The first connection terminal 61 and the second connection terminal 62 can be used, for example, when connecting to a high-frequency current supply unit 1A or a conversion unit 2A. The connection between the first connection terminal 61 and the turn portion 121, and the connection between the second connection terminal 62 and the turn portion 1212 are performed by ultrasonic bonding. However, the connection method is not limited, and for example, a connection using a conductive adhesive may be employed.

[0080] <Applications of coil components> The coil component 10 according to this embodiment can be used as a power transmission coil in the power transmission device 1 of the wireless power transmission system S described above, and can also be used as a power receiving coil in the power receiving device 2.

[0081] When the coil component 10 is used as a power transmission coil, the first connection terminal 61 and the second connection terminal 62 are connected to the high-frequency current supply unit 1A or AC power supply as shown in Figure 1. When a high-frequency current is supplied to the coil component 10, the current can be passed from the first connection terminal 61 to the planar coil 11, and then from the second connection terminal 62 to the high-frequency current supply unit 1A or AC power supply. Alternatively, the current can be passed from the second connection terminal 62 to the planar coil 11, and then from the first connection terminal 61 to the high-frequency current supply unit 1A or AC power supply. This makes it possible to generate a magnetic field including magnetic field lines along the central axis of the planar coil 11.

[0082] On the other hand, when the coil component 10 is used as the power receiving coil, a high-frequency current can be generated in the planar coil 11 by receiving a magnetic field that includes magnetic field lines along the central axis of the planar coil 11. This high-frequency current can then be supplied to an external device from the first connection terminal 61 or the second connection terminal 62.

[0083] Furthermore, the coil component 10 can also be used in transformers, antennas, and the like. For example, when the coil component 10 functions as the primary coil in a transformer, the first connection terminal 61 and the second connection terminal 62 are connected to an AC power source. By supplying a high-frequency current, magnetic flux can be supplied to the iron core from the central side of the planar coil 11.

[0084] <Manufacturing method for coil components> Next, an example of a method for manufacturing the coil component 10 will be described with reference to Figures 5A and 5B. Figures 5A and 5B are diagrams illustrating the method for manufacturing the coil component 10, and each shows a different process.

[0085] In this example, first, as shown in Figure 5A, a planar coil 11, a support member forming sheet 20S, and a mold 100 are prepared, and each member is positioned. The support member forming sheet 20S is the material for forming the support member 20, and includes a plurality or countless granules made of magnetic material and a holding material containing a resin containing the granules. The resin contained in the holding material is a thermoplastic resin and may selectively contain glass fibers.

[0086] The mold 100 has recesses 101 formed for creating the base portion 22 and wall portion 23 of the support member 20. The recesses 101 are formed in a spiral shape. During positioning, the planar coil 11 is positioned on the mold 100 so that it overlaps with radially adjacent portions of the recesses 101. Then, the support member forming sheet 20S is placed on top of the planar coil 11, creating a state in which the planar coil 11 is sandwiched between the support member forming sheet 20S and the mold 100.

[0087] Subsequently, the flat coil 11 and the support member forming sheet 20S are sandwiched between mold 100 and a pair of molds (not shown) that are paired with mold 100, and the flat coil 11 and the support member forming sheet 20S are heated and pressurized (hot press). This integrates the flat coil 11 and the support member 20. At this time, a portion of the molten support member forming sheet 20S enters between the turn portions 12n and the recess 101, forming the base portion 22 and the wall portion 23 of the support member 20. After that, the integrated flat coil 11 and support member 20 are released from the mold and housed in the case 50 together with the magnetic shielding member 30, etc. Note that the manufacturing method described above is just one example, and the coil component 10 can be manufactured by other procedures as well.

[0088] <Various conditions> In the coil component 10 described above, the support member 20 improves coil performance by suppressing eddy current losses and leakage flux through magnetism and by increasing the coupling coefficient. Furthermore, the coil performance is further improved when the support member 20 is in contact with or close to the magnetic shield member 30. In such a coil component 10, there are conditions that effectively improve coil performance. The following describes these conditions for performance improvement.

[0089] (Conditions for the gap between turning sections and the width of the base and walls) Figure 6A shows the relationship between the pitch P of the turn portion 12n, the radial width Wc of the turn portion 12n, and the radial width Ws of the gap Sp between the turn portions 12n in the conductor 11E. Figure 6B shows a graph illustrating the relationship between the gap Ws between the turn portions 12n and the Q value of the coil component 10.

[0090] The Q-value in Figure 6B was calculated through simulation. The simulation was performed using Femtet®, a registered trademark of Murata Software Corporation. Several simulations described below were also performed using Femtet®. In the simulation for Figure 6B, the Q-value was calculated by changing the radial width Wc of the turn section 12n and the radial width Ws of the gap S between the turn sections 12n. The simulation conditions were set as follows.

[0091] The pitch P is 8 mm. The gap Sp between the turn sections 12n was set to four patterns: 2.5 mm, 3.0 mm, 3.5 mm, and 4.5 mm. In other words, the radial width Wc of the turn section 12n was set to four patterns: 5.5 mm, 5.0 mm, 4.5 mm, and 3.5 mm. The thickness of the conductor 11E (each turn portion 12n) is 0.5 mm. The supplied high-frequency current is 40A, and the frequency is 85KHz. The material of the planar coil 11 is copper, and its electrical conductivity is 6.45 × 10⁻⁶. 7 It is [S / m]. The simulation was performed assuming that the support member 20, magnetic shielding member 30, and case 50 do not exist. The simulation was performed by dividing the coil and air layer into 300,000 to 500,000 meshes. The Q-value was then derived from the analysis of the simulated magnetic field.

[0092] The simulation shown in Figure 6B indicates that the Q value tends to reach its maximum when the gap Sp is between 2.5 mm and 3.5 mm. From the results in Figure 6B, it can be inferred that, when the support member 20 is not considered, the Q value tends to reach its maximum when the ratio of the radial width Ws of the gap Sp to the pitch P is between 31.25% and 43.75%.

[0093] On the other hand, Figure 7A shows the base 22 and wall portion 23 of the support member 20 located in the gap Sp between the turn portions 12n. Figures 7B and 7C are graphs illustrating the relationship between the radial width Ww of the wall portion 23 of the support member 20 and the Q value of the coil component 10. The Q values ​​in Figures 7B and 7C were calculated by simulation. In the simulation, the radial width Ww of the wall portion 23 (i.e., the gap Ws between the turn portions 12n) and the radial width Wc of the turn portion 12n were changed and the Q values ​​were calculated. The simulation conditions were set as follows.

[0094] In the simulation shown in Figure 7B, the pitch P is 8 mm. The radial width Ww of the wall portion 23 was set to one of five patterns: 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, and 4.0 mm. The relative permeability of the support member 20 is 10. The thickness of the support member 20 from the support plate portion 21 to the base portion 22 is 1.5 mm, and the height of the wall portion 23 is 1.5 mm. The magnetic shielding member 30 is a ferrite plate, and its electrical conductivity is 1.67 × 10⁻⁶. -1 The ratio is [S / m], and the relative permeability is 3000. The thickness of the magnetic shielding member 30 is 3.0 mm. Case 50 was simulated as if it did not exist. Other conditions were the same as in Figure 6B, and the Q value was derived from the analysis of the simulated magnetic field.

[0095] On the other hand, in Figure 7C, the pitch P is 20 mm. The radial width Ww of the wall portion 23 was set to one of six patterns: 2.0 mm, 3.0 mm, 4.0 mm, 6.0 mm, 8.0 mm, and 10.0 mm. All other conditions were the same as in Figure 7B, and the Q value was derived from the analysis of the simulated magnetic field.

[0096] The simulation shown in Figure 7B indicates that the Q value tends to reach its maximum when the radial width Ww of the wall portion 23 is between 2.0 mm and 3.0 mm. From the results in Figure 7B, it can be inferred that, when the support member 20 is considered, the Q value tends to reach its maximum when the ratio of the radial width Ww of the wall portion 23 (radial width Ws of the gap Sp) to the pitch P is between 20% and 37.5%.

[0097] The simulation shown in Figure 7C indicates that the Q value tends to reach its maximum when the radial width Ww of the wall portion 23 is between 3.0 mm and 6.0 mm. From the results in Figure 7C, it can be inferred that, when the support member 20 is considered, the Q value tends to reach its maximum when the radial width Ww of the wall portion 23 (the radial width Ws of the gap Sp) is between 15% and 30% of the pitch P.

[0098] Examining the results in Figures 7B and 7C, it can be seen that when the support member 20 is provided, a higher Q value is obtained when the gap Ws between the turn sections 12n is smaller than when the support member 20 is not considered. From this result, it can be inferred that the loss reduction function due to the proximity effect provided by the wall section 23 is at work. Furthermore, it can be inferred that a high Q value is obtained in combination with the fact that a large radial width Wc of the turn section 12n can be secured.

[0099] Considering the size of the coil component 10 for practical high-power transmission, the pitch P is between 6 mm and 25 mm, or between 8 mm and 20 mm. Within this range of pitch P, the range in which the radial width Ww of the wall portion 23 is between 20% and 37.5% of the pitch P, based on the results in Figure 7B, and the range in which the radial width Ww of the wall portion 23 (radial width Ws of the gap Sp) is between 15% and 30% of the pitch P, based on the results in Figure 7C, are effective.

[0100] Furthermore, the range in which the radial width Ww of the wall portion 23 is 20% to 30% of the pitch P, which is the overlapping range between 20% to 37.5% and 15% to 30%, can be said to be a range in which coil performance can be stably improved. Therefore, it is particularly preferable that the radial width Ww of the wall portion 23 is 20% to 30% of the pitch P.

[0101] (Conditions for wall height) Figure 8 is a graph illustrating the relationship between the height of the wall portion 23 of the support member 20 and the Q value of the coil component 10. Figure 9 is a graph illustrating the rate of increase in the Q value of the coil component 10 when the support member 20 has a wall portion 23, compared to when the support member 20 does not have a wall portion 23, in relation to the height of the wall portion 23.

[0102] The Q-value in Figure 8 was calculated through simulation. In the simulation shown in Figure 8, the Q-value was calculated by changing the height of the wall section 23 in several patterns for each of the following conditions (1) to (3). ·Condition (1): The thickness of the conductor 11E is 1.5 mm and the pitch P is 8 mm. The radial width Wc of the turn section 12n (the radial width Ws of the gap Sp) is 5.5 mm. The radial width Ww of the wall portion 23 (the radial width Ws of the gap Sp) is 2.5 mm. Then, the height of the wall section 23 was varied to 0 mm, 1.0 mm, 1.5 mm, 3.0 mm, and 4.5 mm. The other conditions are the same as in the case of Figure 7B. ·Condition(2) The thickness of the conductor 11E is 0.5 mm and the pitch P is 8 mm. Then, the height of the wall section 23 was varied to 0 mm, 0.5 mm, 1.0 mm, 1.5 mm, 3.0 mm, and 4.5 mm. The other conditions are the same as in condition (1). ·Conditions (3) The thickness of the conductor 11E is 0.5 mm and the pitch P is 20 mm. The radial width Wc of the turn section 12n (the radial width Ws of the gap Sp) is 16 mm. The radial width Ww of the wall portion 23 (the radial width Ws of the gap Sp) is 4 mm. Then, the height of the wall section 23 was varied to 0 mm, 1.0 mm, 1.5 mm, 2.0 mm, and 3.0 mm. The other conditions are the same as in condition (1).

[0103] The simulation results in Figures 8 and 9 show that the Q value increases as the height of the wall 23 increases under each of the conditions (1) to (3). The results corresponding to conditions (1) to (3) are shown by the broken lines (1) to (3). As mentioned above, the higher the height of the wall 23, the greater the effect of suppressing eddy current loss and the higher the coupling coefficient tends to be. As a result, it is inferred that the Q value improves. This trend can be confirmed from the results in Figure 8.

[0104] On the other hand, as shown in Figure 9, in the range where the height of the wall portion 23 is greater than 2 mm, the rate of increase in the Q value slows down regardless of the thickness of the conductor 11E. Considering this trend, it is considered undesirable to make the wall portion 23 excessively large. Also, as mentioned above, the higher the wall portion 23 is, the more prone it is to break starting from the base. Considering this point, it is considered preferable that the height of the wall portion 23 be 2 mm or less under conditions (1) to (3) and conditions close to these.

[0105] Therefore, considering the size of the coil component 10 for practical high-power transmission, it is preferable that the height of the wall portion 23 be 2 mm or less.

[0106] (Conditions for the width of the wall section) Figure 10 is a cross-sectional view of the conductor 11E and support member 20 of the planar coil 11, showing that the radial width Ww of the wall portion 23 of the support member 20 is different from that of the base portion 22. Figures 11 to 13 show the results of simulation verification of the Q value, Joule loss, and coupling coefficient when the radial width Ww of the wall portion 23 of the support member 20 is different from that of the base portion 22, by changing the radial width Ww of the wall portion 23.

[0107] Figure 11 shows a graph illustrating the relationship between the radial width Ww of the wall 23 and the Q value of the coil component 10. Figure 12 shows a graph illustrating the relationship between the radial width Ww of the wall 23 and the Joule loss of the coil component 10. Figure 13 shows a graph illustrating the relationship between the radial width Ww of the wall 23 and the coupling coefficient of the coil component 10. The coupling coefficient is calculated assuming that coil components of the same shape are facing each other. The simulation conditions are as follows.

[0108] The thickness of the conductor 11E is 0.5 mm and the pitch P is 8 mm. The radial width Wc of the turn section 12n (the radial width Ws of the gap Sp) is 5 mm, and the radial width of the gap Sp between the turn sections 12n is 3 mm. The height of the wall section 23 is 1.5 mm. Then, the radial width Ww of the wall portion 23 was changed to 0 mm, 1.0 mm, 2.0 mm, 3.0 mm, and 5.0 mm. The other conditions are the same as in the case of Figure 7B.

[0109] In Figures 11 and 12, the Q value is maximized and Joule heating is minimized when the radial width Ww of the wall portion 23 is 3.0 mm, that is, when it is the same as the radial width of the base portion 22 and the gap Sp. On the other hand, in Figure 13, the smaller the radial width Ww of the wall portion 23 (excluding 0 mm), the larger the coupling coefficient. However, when the radial width Ww of the wall portion 23 is the same as the radial width of the base portion 22 and the gap Sp, a high coupling coefficient is maintained. From these results, it can be said that it is preferable for the radial width Ww of the wall portion 23 to be the same as the radial width of the base portion 22 and the gap Sp.

[0110] On the other hand, when the radial width Ww of the wall portion 23 is 5.0 mm, that is, when it is larger than the radial width of the base portion 22 and the gap Sp, the Q value is about the same as the maximum value, but the Joule heating is large. Also, when the radial width Ww of the wall portion 23 is 5.0 mm, the coupling coefficient is relatively lower compared to when the radial width Ww of the wall portion 23 is the same as the radial width of the base portion 22 and the gap Sp. Furthermore, when the radial width Ww of the wall portion 23 is 1.0 mm and 2.0 mm, that is, when it is smaller than the radial width of the base portion 22 and the gap Sp, the Q value decreases relatively significantly from the maximum value, and the Joule heating is also large. In addition, the coupling coefficient when the radial width Ww of the wall portion 23 is 1.0 mm and 2.0 mm is relatively significantly higher than when the radial width Ww of the wall portion 23 is the same as the radial width of the base portion 22 and the gap Sp.

[0111] Considering the results shown in Figures 11 to 13 above, it is preferable that the radial width Ww of the wall portion 23 is the same as the radial width of the base portion 22 and the gap Sp.

[0112] (Conditions for the thickness of the support plate) Figure 14 is a graph illustrating the relationship between the thickness of the support member 20 from the support plate portion 21 to the base portion 22 in the coil component 10 and the Q value of the coil component.

[0113] The Q-value in Figure 14 was calculated through simulation. In the simulation, the Q-value was calculated by changing the thickness from the support plate portion 21 to the base portion 22. The following simulation conditions were set.

[0114] The pitch P is 8 mm. The thickness of the conductor 11E is 0.5 mm. The radial width Ww of the wall portion 23 is 5.5 mm. The height of the wall section 23 is 2.5 mm. Then, the Q value was calculated by changing the thickness of the support member 20 from the support plate portion 21 to the base portion 22 to 0.5 mm, 1.0 mm, 3.0 mm, 4.0 mm, and 6.0 mm. The other conditions are the same as in the case of Figure 7B.

[0115] The simulation results in Figure 14 show that the Q value increases as the thickness from the support plate portion 21 to the base portion 22 increases. On the other hand, if the thickness of the support member 20 becomes too large, manufacturing efficiency may decrease from the standpoint of material procurement, etc. Therefore, it is undesirable for the thickness of the support member 20 to be too large. Accordingly, considering the size of the coil component 10 for practical high-power transmission, the thickness of the support member 20 from the support plate portion 21 to the base portion 22 is preferably 3 mm or less, taking into account coil performance and manufacturing efficiency.

[0116] <Effects and Actions> The coil component 10 according to this embodiment described above comprises a planar coil 11, a support member 20, and a magnetic shielding member 30. The planar coil 11 has a conductor 11E that forms a spiral shape with a plurality of turned portions 12n, and the plurality of turned portions 12n are connected so as to gradually move away from the central axis C in the radial direction outward from the central axis C of the spiral shape. The support member 20 as a whole is magnetic. The support member 20 has a support plate portion 21 that contacts the planar coil 11 at its upper surface 21A along the central axis C, and a base portion 22 that rises from the upper surface 21A and is located in the gap Sp between adjacent turned portions 12n. The magnetic shielding member 30 is provided on the lower surface 21B of the support plate portion 21 and is magnetic.

[0117] In this coil component 10, the support plate portion 21 of the magnetic support member 20 forms a magnetic path extending radially on one axial side of the planar coil 11, and the base portion 22 forms a magnetic path extending radially on the other axial side of the planar coil 11. In this embodiment, a wall portion 23 is formed rising from the base portion 22, and the wall portion 23 facilitates the flow of magnetism radially on the other axial side of the planar coil 11. Furthermore, the base portion 22 and the wall portion 23 suppress the guidance of magnetism to the planar coil 11 and guide the magnetism to the support plate portion 21. This suppresses the guidance of magnetism to the planar coil 11, which would cause eddy current losses. The support plate portion 21 is in contact with or close to the magnetic shielding member 30. In this embodiment, the support plate portion 21 is in contact with the magnetic shielding member 30. As a result, the support plate portion 21, together with the magnetic shielding member 30, forms a magnetic path extending radially on one axial side of the planar coil 11. In this case, the cross-sectional area of ​​the path can be increased, which further suppresses eddy current losses caused by the magnetic field being guided into the planar coil 11. This effectively reduces losses and improves coil performance.

[0118] Furthermore, in this embodiment, the pitch P is determined by the radial width Ws of the gap Sp between the turned sections 12n and the radial width Wc of the turned section 12n located radially inward relative to the gap Sp. The ratio of the radial width Ws of the gap Sp to the pitch P is 15% to 40%. This allows for improved coil performance by increasing the Q value, while suppressing the effects of the proximity effect and ensuring a large total amount of the planar coil 11.

[0119] In particular, in this embodiment, the base portion 22 is positioned to completely fill the gap Sp in the radial direction. Furthermore, the radial width of the wall portion 23 is the same as the radial width of the base portion 22, or 90% or more but less than 100% of the radial width of the base portion 22. Preferably, the radial width of the wall portion 23 is 20% or more but 30% or less of the pitch P. In this case, coil performance can be effectively improved by ensuring a Q value.

[0120] Furthermore, the height of the wall portion 23 may be 2 / 3 or more the thickness of the conductor 11E. Specifically, the height of the wall portion 23 may be 0.5 mm or more, or 1.0 mm or more. It is also preferable that the height of the wall portion 23 be 2 times or more the thickness of the conductor 11E. The higher the height of the wall portion 23, the greater the effect of suppressing eddy current loss and the higher the coupling coefficient tends to be. On the other hand, the higher the wall portion 23 is, the more prone it is to break starting from the base. From this viewpoint, it is preferable that the height of the wall portion 23 be 3 mm or less.

[0121] Furthermore, it is preferable that the first combined thickness, which is the sum of the thickness of the support plate portion 21 and the thickness of the base portion 22, is at least twice the thickness of the conductor 11E. Also, it is preferable that the thickness of the support plate portion 21 is greater than or equal to the height of the wall portion 23. Furthermore, it is preferable that the second combined thickness, which is the sum of the thickness of the support plate portion 21 and the thickness of the magnetic shielding member 30, is greater than or equal to the height of the wall portion 23. In these cases, it becomes easier to secure a larger path for the magnet, which further suppresses the generation of eddy current losses caused by the magnet being guided to the planar coil 11.

[0122] Although embodiments of the present disclosure have been described above, various modifications may be made to the above-described embodiments. Such modifications may also fall within the technical scope of the present disclosure. For example, in the modified example shown in Figure 15, in the coil component, the magnetic shielding member 30 is provided on the lower surface 21B of the support plate portion 21 via the heat dissipation layer 200. The thickness of the heat dissipation layer 200 may be, for example, 10 mm or less, 8 mm or less, 5 mm or less, or 3 mm or less. The heat dissipation layer 200 may be a heat transfer sheet or may be formed of a heat conductive gel. It is desirable that the heat dissipation layer 200 be non-magnetic, insulating, and both non-magnetic and insulating. [Explanation of symbols]

[0123] S...Power transmission system 1... Power transmission equipment 1A…High-frequency current supply unit 2…Power receiving device 2A...Conversion section 10…Coil components 11… Planar coil 11E... Conductor 12n... Turn section 20…Support member 20S…Sheet for forming support members 21...Support plate part 21A…Top surface 21B…Bottom surface 22...Base 22f...Connection surface 23...Wall part 30…Magnetic shielding material 40... Spacer plate 50...cases 51...Bottom wall 52... Side wall section 61...First connection terminal 62...Second connection terminal 100…Mold 200...heat dissipation layer C…Central axis line Sp...Gap between turn parts Wc...Radial width of the coil Ws...Radial width of the gap between the turn sections P...Pitch

Claims

[Claim 1] The conductive material has a spiral shape formed by multiple turned sections, and the multiple turned sections are planar coils arranged so as to gradually move away from the central axis of the spiral shape radially outward from the central axis, A support member comprising a support plate portion that contacts the planar coil on one side along the central axis, and a base portion that rises from the one side and is located in the gap between adjacent turn portions, and having overall magnetic properties, A coil component comprising a magnetic member having magnetism, provided on the other surface of the support plate portion opposite to the one surface.

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