Coil Device

Abstract

To reduce eddy current loss in a coil device including a plurality of sub coil parts.SOLUTION: A coil device C10a comprises a first sub coil part C1a and a second sub coil part C2a that are laminated in a thickness direction with an insulating layer K1a therebetween and have coil wires electrically connected with each other. The first sub coil part and the second sub coil part include winding parts 11a, 12a, terminal parts 41a, 42a in the coil wires to perform electrical connection to an external device, and wiring takeout parts 21a, 22a connecting the winding parts and the terminal parts to each other, and provided extending in a direction intersecting a winding direction of the winding parts. The wiring takeout part of the first sub coil part and the wiring takeout part of the second sub coil part are arranged to at least partially overlap each other when seen in a thickness direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a coil device. [Background technology]

[0002] Conventionally, coil devices having a structure in which multiple sub-coil sections made of wound coil wire are stacked have been proposed as coil devices constituting the power transmitting coil and power receiving coil in a contactless power transfer system. In Patent Document 1, a coil device having a structure in which multiple sub-coil sections (coil wires) are stacked with insulating layers interposed therebetween is used as a power transmitting coil device and a power receiving coil device. Each sub-coil section is provided with a terminal for electrical connection to an external device such as a power transfer device. Such terminals include an end portion of each sub-coil section and a portion of the coil wire leading to the end portion (hereinafter referred to as a "wiring outlet portion"). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-27813 Summary of the Invention [Problem to be solved by the invention]

[0004] In the cited document 1, the terminals provided on each sub-coil portion are arranged adjacent to each other when viewed in the stacking direction of each layer, and therefore, the interlinkage magnetic flux generated by the current flowing through each sub-coil (coil wire) penetrates the wiring lead-out portion at each terminal, causing a problem that eddy currents are generated at each wiring lead-out portion, resulting in power loss (eddy current loss).

[0005] This problem is not limited to power transmitting coils and power receiving coils in contactless power transfer systems, but is common to coil devices for any purpose that have a structure in which multiple sub-coil sections are stacked. For this reason, a technology that can reduce eddy current loss in coil devices that have multiple sub-coil sections is desired. [Means for solving the problem]

[0006] One aspect of the present disclosure provides a coil device (C10a), comprising a first subcoil portion (C1a) and a second subcoil portion (C2a) stacked in a thickness direction of an insulating layer (K1a) with the insulating layer interposed therebetween, the first subcoil portion and the second subcoil portion each comprising a winding portion (11a, 12a) in which a coil wire is wound along a planar direction of the insulating layer, connecting portions (b1, b2) provided in the thickness direction to electrically connect the winding portions, end portions (41a, 42a) of the coil wire for electrical connection with an external device, and wiring outlet portions (21a, 22a) connecting the winding portion and the end portions, the wiring outlet portions extending in a direction intersecting the winding direction of the winding portions, the wiring outlet portions of the first subcoil portion and the second subcoil portion being arranged to at least partially overlap each other when viewed in the thickness direction. In both the first subcoil section and the second subcoil section, the end portion is disposed inside the winding portion in the planar direction.

[0007] According to this form of coil device, the wiring take-out portion of the first subcoil portion and the wiring take-out portion of the second subcoil portion are arranged so that they at least partially overlap each other when viewed in the thickness direction, so that one wiring take-out portion receives a weakened interlinkage magnetic flux (with reduced magnetic flux density) by passing through the other wiring take-out portion, thereby suppressing the generation of eddy currents in one of the wiring take-out portions and reducing eddy current loss. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram showing a coil device according to a first embodiment. [Figure 2] FIG. 10 is an explanatory diagram showing a coil device according to a second embodiment. [Figure 3] FIG. 10 is a plan view showing a coil assembly to which a coil device according to a third embodiment is applied. [Figure 4] FIG. 10 is a cross-sectional view showing a coil assembly to which a coil device according to a third embodiment is applied. [Figure 5] FIG. 10 is an explanatory diagram showing a coil device according to a third embodiment. [Figure 6] FIG. 10 is a plan view showing an array of coil assemblies in the third embodiment. [Figure 7] FIG. 10 is an explanatory diagram showing an equivalent circuit of a coil device according to a fourth embodiment. [Figure 8] FIG. 10 is an explanatory diagram showing a coil device according to a fourth embodiment. [Figure 9] FIG. 10 is an explanatory diagram showing a coil device according to a fourth embodiment. [Figure 10] FIG. 10 is an explanatory diagram showing a coil device according to a fifth embodiment. [Figure 11] FIG. 10 is an explanatory diagram showing a coil device according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. First embodiment: The coil device C10a shown in FIG. 1 has a structure in which a first subcoil portion C1a and a second subcoil portion C2a are stacked with an insulating layer K1a interposed therebetween. The coil device C10a is used, for example, in a resonant circuit in a power transmitting device and a power receiving device that constitute a contactless power supply system. Note that the use of the coil device C10a is not limited to the resonant circuit and may be any type of use. The two subcoil portions C1a and C2a are made of coil wire formed from copper foil. In addition to the insulating layer K1a located between the two subcoil portions C1a and C2a, FIG. 1 also shows an insulating layer K2a located on the back surface of the second subcoil portion C2a. Note that the front surface of the first subcoil portion C1a (the surface opposite to the surface in contact with the insulating layer K1a) may be covered with, for example, solder resist. Furthermore, the back surface of the second subcoil portion C2a may be covered with solder resist instead of the insulating layer K2a. It can be said that the coil device C10a is formed of a multilayer substrate having a structure in which insulating layers and coil wires are alternately stacked.

[0010] To facilitate understanding, FIG. 1 shows the coil device C10a on the far right, the first subcoil portion C1a and the insulating layer K1a on the far left, and the second subcoil portion C2a and the insulating layer K2a in the center. FIG. 1 also illustrates a plan view of the coil device C10a, the two subcoil portions C1a and C2a, and the two insulating layers K1a and K2a as viewed in the +Z direction. In the rightmost view of the coil device C10a, the second subcoil portion C2a, which is not actually visible, is indicated by a dashed line. In FIG. 1, the Z-axis direction corresponds to the thickness direction of the insulating layers K1a and K2a and the stacking direction of the two subcoil portions C1a and C2a. In addition to the Z-axis, FIG. 1 also shows the X-axis and Y-axis, which are perpendicular to each other. In this embodiment, the "Z-axis direction" collectively refers to the +Z direction and the -Z direction. Similarly, the "X-axis direction" is a general term for the +X direction and the -X direction, and the "Y-axis direction" is a general term for the +Y direction and the -Y direction.

[0011] 1, the first sub-coil portion C1a includes a winding portion 11a formed of a coil wire formed on an insulating layer K1a, a terminal portion 41a, a wiring outlet portion 21a, a terminal portion 31a, a connecting portion b1, and a connecting portion b2. The insulating layers K1a and K2a have a substantially rectangular external shape when viewed in the thickness direction (Z-axis direction).

[0012] The winding portion 11a is made of a coil wire wound along the planar direction of the insulating layer K1a. The "planar direction" refers to the direction along the surface of the insulating layer K1a, and can be any direction along the XY plane. In this embodiment, the winding portion 11a is made of a coil wire wound clockwise for approximately one and a half turns.

[0013] The terminal portion 41a corresponds to the start of winding of the first subcoil portion C1a. In this embodiment, the terminal portion 41a is disposed outside the winding portion 11a in the planar direction. "Outside the winding portion 11a in the planar direction" means the side of the winding portion 11a that is in the planar direction from the center of the insulating layer K1a toward the outer edge of the insulating layer K1a when viewed in the thickness direction (Z-axis direction). The terminal portion 41a is located near the outer edge of the insulating layer K1a. The terminal portion 41a is a functional portion for electrical connection with an external device, and is connected to, for example, wiring extending from a power supply device.

[0014] The wiring outlet 21a connects the winding portion 11a and the terminal end 41a. Specifically, the wiring outlet 21a connects the end of the winding portion 11a that is located more outward in the planar direction to the terminal end 41a. The wiring outlet 21a extends in a direction from the outer edge of the insulating layer K1a toward the center of the insulating layer K1a. In this embodiment, the wiring outlet 21a intersects the winding direction of the winding portion 11a at approximately 90°. The "winding direction of the winding portion 11a" refers to the direction in which the winding portion 11a is wound, which is a clockwise direction.

[0015] The terminal portion 31a, together with the end portion 41a, is electrically connected to an external device. As shown in the leftmost drawing in Fig. 1, the terminal portion 31a is disposed near the outer edge of the insulating layer K1a and near the end portion 41a. The terminal portion 31a and the end portion 41a are electrically insulated from each other.

[0016] The connecting portion b1 connects the winding portion 11a of the first subcoil portion C1a and the winding portion of the second subcoil portion C2a (winding portion 12a, which will be described later). The connecting portion b1 is provided at one of both ends of the winding portion 11a that is located more inward in the planar direction, in other words, at an end different from the end connected to the wiring outlet portion 21a. In this embodiment, the connecting portion b1 is formed as part of a through-hole via that penetrates the coil device C10a in the thickness direction. For this reason, in FIG. 1, the connecting portion b1 of the second subcoil portion C2a, which forms a different part of the same through-hole via, is assigned the same reference numeral as the connecting portion b1 of the first subcoil portion C1a.

[0017] The connecting portion b2 connects the terminal portion 31a of the first subcoil portion C1a and the end portion (end portion 42a described below) of the second subcoil portion C2a. In this embodiment, the connecting portion b2 is formed as a part of a through-hole via that penetrates the coil device C10a in the thickness direction. For this reason, in FIG. 1, the connecting portion b2 of the second subcoil portion C2a that forms a different part of the same through-hole via is also assigned the same reference numeral as the connecting portion b2 of the first subcoil portion C1a. The connecting portion b2 of the first subcoil portion C1a is disposed at the terminal portion 31a.

[0018] 1, the second subcoil portion C2a has a configuration similar to that of the first subcoil portion C1a described above, and includes a winding portion 12a, a terminal portion 42a, a wiring outlet portion 22a, a connecting portion b1, and a connecting portion b2.

[0019] The winding portion 12a differs from the winding portion 11a of the first subcoil portion C1a in that the winding start point is the end located more inward in the planar direction, but the other configurations are similar. The terminal portion 42a differs from the terminal portion 31a of the first subcoil portion C1a in that it includes a part of the region corresponding to the terminal portion 41a in the first subcoil portion C1a, but the other configurations are similar. The wiring outlet portion 22a, like the wiring outlet portion 21a in the first subcoil portion C1a described above, connects the end located more outward in the planar direction of the winding portion 12a to the terminal portion 42a. The terminal portion 42a extends from the outer edge of the insulating layer K2a toward the center of the insulating layer K2a. In this embodiment, it intersects the winding direction of the winding portion 12a at approximately 90°.

[0020] The winding end (more inward end) of the winding portion 11a of the first subcoil portion C1a and the winding start (more inward end) of the winding portion 12a of the second subcoil portion C2a are connected to each other by the connecting portion b1, so that the winding portion of the coil device C10a as a whole has a total of approximately three turns. In the coil device C10a, a terminal portion 31a and an end portion 41a are formed on the -Z direction surface of the insulating layer K1a located furthest in the -Z direction. The coil device C10a is used by connecting an external device, such as a power supply device or a capacitor, to these terminal portion 31a and end portion 41a. Note that the capacitor may be located in the inner region of the insulating layer K1a (the empty region surrounded by the winding portion 11a). In this configuration, the coil device C10a and the capacitor are integrated into one unit.

[0021] As shown in the rightmost diagram in FIG. 1, when the first subcoil portion C1a and the second subcoil portion C2a are stacked in the thickness direction, the wiring outlet portion 21a of the first subcoil portion C1a and the wiring outlet portion 22a of the second subcoil portion C2a are arranged to overlap each other in the thickness direction. With this configuration, when the interlinkage magnetic flux formed by the current flowing through the winding portion 11a and the winding portion 12a passes through the wiring outlet portion 21a and the wiring outlet portion 22a, for example, it passes through the wiring outlet portion 21a and then the wiring outlet portion 22a. In this case, the magnetic flux passing through the wiring outlet portion 22a is weakened (the magnetic flux density is reduced) because it has passed through the wiring outlet portion 21a. This suppresses the generation of eddy currents in the wiring outlet portion 22a, thereby suppressing power loss (eddy current loss) due to such eddy currents.

[0022] Note that the above phrase "arranged so as to overlap each other when viewed in the thickness direction" does not only mean "arranged in a state where the overlap can be seen when the coil device C10a is actually viewed in the +Z direction," but also refers to a broader concept including the meaning that "in a configuration where the second sub-coil portion C2a on the back side cannot be seen when viewed in the +Z direction, the projection area in the +Z direction of the wiring outlet portion 21a of the first sub-coil portion C1a on the front side and the wiring outlet portion 22a of the second sub-coil portion C2a are arranged so as to overlap."

[0023] According to the coil device C10a of the first embodiment described above, the wiring outlet 21a of the first subcoil section C1a and the wiring outlet 22a of the second subcoil section C2a are arranged so as to completely overlap when viewed in the thickness direction, so that one wiring outlet receives weakened interlinkage magnetic flux through the other wiring outlet, thereby suppressing the generation of eddy currents in one of the wiring outlets and reducing eddy current loss.

[0024] B. Second embodiment: The coil device C10b of the second embodiment shown in FIG. 2 has a structure in which two subcoil portions (a first subcoil portion C1b and a second subcoil portion C2b) are stacked with an insulating layer K1b interposed therebetween, similar to the coil device C10a of the first embodiment. Similar to FIG. 1, FIG. 2 also shows the insulating layer K1b located between the two subcoil portions C1b and C2b, as well as the insulating layer K2b located on the back surface of the second subcoil portion C2b. The front surface of the first subcoil portion C1b (the surface opposite to the surface in contact with the insulating layer K1b) may be covered with, for example, a solder resist. Furthermore, the back surface of the second subcoil portion C2b may be covered with a solder resist instead of the insulating layer K2b. Similarly to the coil device C10a of the first embodiment, the coil device C10b can also be said to be formed of a multilayer substrate having a structure in which insulating layers and coil wires are alternately stacked.

[0025] The first subcoil portion C1b includes a winding portion 11b, an end portion 41b, a wiring outlet portion 21b, a terminal portion 31b, and connecting portions b3, b4, b5, and b6. Similar to Fig. 1, Fig. 2 shows an insulating layer K1b disposed between the two subcoil portions C1b and C2b, and an insulating layer K2b disposed on the back surface of the second subcoil portion C2b. These two insulating layers K1b and K2b have an octagonal external shape with the four corners of a substantially rectangular shape cut out when viewed in the thickness direction.

[0026] The winding portion 11b is composed of three sub-winding portions (sub-winding portion 111b, sub-winding portion 112b, and sub-winding portion 113b). The three sub-winding portions 111b to 113b are wound parallel to each other and insulated from each other. Therefore, as shown in FIG. 2, the width of each of the sub-winding portions 111b to 113b is smaller than the width of each of the winding portions 11a and 12a in the first embodiment. However, in the second embodiment, the sum of the widths of each of the sub-winding portions 111b to 113b is approximately equal to the width of each of the winding portions 11a and 12a in the first embodiment. The winding direction of the winding portion 11b is counterclockwise.

[0027] The terminal end 41b and the wiring outlet 21b are disposed inside the winding portion 11b in the planar direction. "Inside the winding portion 11b in the planar direction" refers to the side of the winding portion 11b that is located along the planar direction from the outer edge of the insulating layer K1b toward the center P1 of the insulating layer K1b when viewed in the thickness direction (Z-axis direction). In the second embodiment, the terminal end 41b is disposed at the center of the winding portion 11b. "The center of the winding portion 11b" refers to a region (empty region) inside the winding portion 11b where the winding portion 11b is not present, within a predetermined distance from the center P1. The center P1 can be determined as the intersection of two intersecting line segments connecting the midpoints of four relatively long sides that constitute the outer edge (outer shape) of the winding portion 11b. In the second embodiment, the "predetermined distance" refers to a distance equivalent to 40% of the length of each of the sides. This is not limited to 40% and may be any arbitrary ratio. The terminal end 41b corresponds to the start of winding of the winding portion 11b.

[0028] Wiring outlet 21b connects winding portion 11b and terminal end 41b. Therefore, wiring outlet 21b is composed of three straight coil wires (wiring patterns) that connect to the inner ends of three sub-winding portions 111b to 113b, respectively. As described above, terminal end 41b is located at the center of winding portion 11b, and therefore the distance (distance in the planar direction) from winding portion 11b to terminal end 41b is greater than in a configuration in which terminal end 41b is located at a position other than the center.

[0029] The three connecting portions b3 to b5 connect the three sub-winding portions 111b to 113b of the first sub-coil portion C1b to three sub-winding portions, described later, of the second sub-coil portion C2b. These three connecting portions b3 to b5 are formed as part of a through-hole that passes through the coil device C10b in the thickness direction. The connecting portion b6 connects the terminal portion 31b of the first sub-coil portion C1b to an end portion (end portion 42b, described later) of the second sub-coil portion C2b. The connecting portion b6 is formed as part of a through-hole via that passes through the coil device C10b in the thickness direction.

[0030] As shown in the center of Fig. 2, the second subcoil portion C2b has a configuration similar to that of the first subcoil portion C1b described above. The second subcoil portion C2b includes a winding portion 12b, an end portion 42b, a wiring outlet portion 22b, and connecting portions b3 to b6. The winding portion 12b is made up of three sub-winding portions (sub-winding portion 121b, sub-winding portion 122b, and sub-winding portion 123b).

[0031] As shown in the rightmost diagram in Figure 2, when the first subcoil portion C1b and the second subcoil portion C2b are stacked in the thickness direction, the wiring outlet portion 21b of the first subcoil portion C1b and the wiring outlet portion 22b of the second subcoil portion C2b are arranged so as to completely overlap each other when viewed in the thickness direction.

[0032] The subwinding portion 121b is connected to the subwinding portion 111b of the first subcoil portion C1b by the connecting portion b3. Similarly, the subwinding portion 122b is connected to the subwinding portion 112b of the first subcoil portion C1b by the connecting portion b4. Furthermore, the subwinding portion 123b is connected to the subwinding portion 113b of the first subcoil portion C1b by the connecting portion b5. Here, in the first subcoil portion C1b, the subwinding portion 111b is located on the outermost side in the winding direction among the three subwinding portions 111b to 113b. Next, the subwinding portion 112b is located on the outermost side, and the subwinding portion 113b is located on the innermost side. In contrast, in the second subcoil portion C2b, the subwinding portion 121b is located on the innermost side in the winding direction among the three subwinding portions 121b to 123b. Subsequently, sub-winding portion 122b is located on the inside, and sub-winding portion 123b is located on the outside. In the second embodiment, by adopting such a configuration, the difference in total length of the winding between each sub-winding portion is reduced, thereby reducing the difference in impedance between each sub-winding portion.

[0033] The coil device C10b of the second embodiment described above has the same effects as the coil device C10a of the first embodiment.

[0034] In addition, in both the first subcoil section C1b and the second subcoil section C2b, the end portions 41b, 42b and the terminal portion 31b are arranged inside the winding portions 11b, 12b in the planar direction, so that the overall size of the coil device C10b can be made smaller in the stacking direction compared to a configuration in which they are arranged outside the winding portions 11b, 12b.

[0035] Furthermore, because end portions 41b, 42b are disposed at the center of winding portions 11b, 12b in the planar direction, a larger portion of wiring outlet portions 21b, 22b can be disposed away from winding portions 11b, 12b compared to a configuration in which end portions 41b, 42b are disposed at a position inside winding portions 11b, 12b that is shifted from the center. This reduces the amount of magnetic flux linkage that passes through wiring outlet portions 21b, 22b, thereby suppressing the generation of eddy currents.

[0036] Furthermore, of the three sub-winding portions 111b to 113b constituting the winding portion 11b of the first sub-coil portion C1b, the sub-winding portion located more inward in the winding direction is connected to the sub-winding portion located more outward in the winding direction of the multiple sub-winding portions 121b to 123b constituting the winding portion 12b of the second sub-coil portion C2b at connecting portions b3 to b5, compared to the sub-winding portions located more outward.This reduces the difference in the total length of the windings between each sub-winding portion, and thereby reduces the difference in impedance between each sub-winding portion.

[0037] C. Third embodiment: The coil device C10c shown in Figures 3 and 4 is used as part of the coil assembly E1. In addition to the coil device C10c, the coil assembly E1 includes a magnetic plate member B1, a shield member D1, a cover portion B11, and a pair of magnetic body connecting portions B12. Figure 3 shows a plan view of the coil assembly E1 as seen in the thickness direction of the insulating layer of the coil device C10c. Figure 4 shows a cross section taken along line IV-IV in Figure 3.

[0038] The magnetic plate member B1 is a plate-shaped member made of a magnetic material, and in this embodiment, is made of ferrite. The magnetic flux generated by the coil device C10c passes through the magnetic plate member B1 more easily than through other portions. This prevents the magnetic flux generated by the coil device C10c from penetrating a device disposed near the coil device C10c, such as a device (not shown) disposed on the opposite side (+Z direction) from the side where the coil device C10c is disposed. The device (not shown) may be, for example, a circuit board on which wiring for supplying power to the coil device C10c and elements such as capacitors are disposed. As shown in FIG. 4 , an opening OP1 is provided in the magnetic plate member B1 and the shield member D1 in a portion corresponding to the cover portion B11 in the thickness direction. The device (not shown) is connected to the end portion and terminal portion of the coil device C10c (described later) through the opening OP1.

[0039] The shielding member D1 prevents electromagnetic waves from being transmitted to the above-mentioned device (not shown). In this embodiment, the shielding member D1 is made of aluminum. However, the shielding member D1 may be made of any material other than aluminum as long as it can prevent electromagnetic waves from being transmitted.

[0040] The cover portion B11 is a plate-shaped member made of a magnetic material and covers a portion of the coil device C10c in the thickness direction. In this embodiment, the cover portion B11 is made of ferrite. In the coil device C10c, the cover portion B11 covers the inside of the winding portions 11b and 12b. The cover portion B11 guides the magnetic flux generated in the coil device C10c and prevents the magnetic flux from being directed toward a device (not shown) located near the coil assembly E1.

[0041] The pair of magnetic body connectors B12 are disposed in a pair of through holes h1 (described later) provided in the coil device C10c. The pair of magnetic body connectors B12 are plate-shaped members made of a magnetic material and connect the cover portion B11 and the magnetic plate member B1. The magnetic flux guided to the cover portion B11 is guided to the magnetic plate member B1 via the pair of magnetic body connectors B12. As shown in FIG. 3, both ends of the cover portion B11 in the Y-axis direction overlap with the pair of through holes h1 when viewed in the thickness direction (when viewed in the Z-axis direction). Then, as shown in FIG. 4, both ends of the cover portion B11 in the Y-axis direction are connected to the magnetic plate member B1 by the pair of magnetic body connectors B12.

[0042] The coil device C10c of the third embodiment shown in Fig. 5 has a structure in which two subcoil portions (a first subcoil portion C1c and a second subcoil portion C2c) are stacked with an insulating layer K1b interposed therebetween, similar to the coil device C10b of the second embodiment shown in Fig. 2. The coil device C10c of the third embodiment differs from the coil device C10b of the second embodiment shown in Fig. 2 in the arrangement positions of the terminal portion 31b, the end portion 41b, and the coupling portion b6, in that it has a pair of through holes h1, in that it has a wiring outlet portion 21c instead of the wiring outlet portion 21b, and in that it has a wiring outlet portion 22c instead of the wiring outlet portion 22b. The other configurations are the same as those of the coil device C10b of the second embodiment, and therefore the same configurations are denoted by the same reference numerals and detailed description thereof will be omitted.

[0043] The pair of through holes h1 are formed by connecting a pair of through holes h11 provided in the first sub-coil portion C1c and a pair of through holes h12 provided in the second sub-coil portion C2c in the thickness direction.

[0044] A pair of through holes h11 is formed in the first subcoil portion C1c. A pair of through holes h12 is formed in the second subcoil portion C2c. The pair of through holes h11 are arranged inside the winding portion 11b, spaced a predetermined distance from each other in the Y-axis direction. The terminal portion 31b, the end portion 41b, and the connecting portion b6 are arranged in an area sandwiched between the pair of through holes h11. In this embodiment, the terminal portion 31b, the end portion 41b, and the connecting portion b6 are arranged at positions shifted in the -X direction from the center of the winding portion 11b.

[0045] The wiring extracting portion 21c differs from the wiring extracting portion 21b of the second embodiment in that the length in the X-axis direction is shorter. As described above, since the end portion 41b is disposed at a position shifted in the −X direction, the length in the X-axis direction of the wiring extracting portion 21c is configured to be shorter than the length in the X-axis direction of the wiring extracting portion 21b of the second embodiment.

[0046] The pair of through holes h12 of the second subcoil portion C2c are arranged inside the winding portion 12b, spaced a predetermined distance from each other in the Y-axis direction. The terminal portion 42b and the connecting portion b6 are arranged in an area sandwiched between the pair of through holes h12. In this embodiment, the terminal portion 42b and the connecting portion b6 are arranged at positions shifted in the -X direction from the center of the winding portion 12b.

[0047] The wiring extracting portion 22c differs from the wiring extracting portion 22b of the second embodiment in that the length in the X-axis direction is shorter. As described above, since the end portion 42b is disposed at a position shifted in the −X direction, the length in the X-axis direction of the wiring extracting portion 22c is configured to be shorter than the length in the X-axis direction of the wiring extracting portion 22b of the second embodiment.

[0048] As in the second embodiment, the wiring outlet 21c of the first subcoil portion C1c and the wiring outlet 22c of the second subcoil portion C2c are arranged to overlap each other in the thickness direction and are covered in the thickness direction by the cover portion B11. This configuration further suppresses the generation of eddy currents in the wiring outlet 21c and the wiring outlet 22c, thereby further reducing eddy current loss.

[0049] As shown in FIG. 6 , the coil assembly E1 of the third embodiment can be arranged in an array (vertical × horizontal grid). In this case, the distance between adjacent coil assemblies E1 can be configured very narrow. This is because the terminal portion 31b and the end portions 41b, 42b are located inside the winding portions 11b, 12b and are configured to be connectable to these terminal portion 31b and end portions 41b, 42b in the +Z direction. This improves the packaging density of the array-shaped coil assembly E1, enabling the device to be more compact. For example, when power transmission coils of a wireless power transfer system are arranged in an array, excessively wide spacing between the coils can result in power receiving coil positions (locations) where power cannot be supplied or the amount of power supplied is excessively small. However, when the above-described coil assembly E1 is applied to a wireless power transfer system and arranged in an array, the spacing between the coils can be made small, preventing the occurrence of positions (locations) where power cannot be supplied or the amount of power supplied is excessively small.

[0050] The coil device C10b of the third embodiment described above has the same effects as the coil device C10b of the second embodiment. In addition, the coil device C10b further includes a cover portion B11 made of a magnetic material that covers the inner surfaces of the winding portions 11b and 12b in the planar direction in the thickness direction. This prevents magnetic flux linkages generated by current flowing through the winding portions 11b and 12b from penetrating a device disposed near the coil device C10c, such as a substrate (not shown) disposed on the opposite side (+Z direction) from the side where the coil device C10c is disposed. Furthermore, the cover portion B11 covers the end portions 41b and 42b in the thickness direction, thereby preventing magnetic flux linkages from passing through the end portions 41b and 42b. Furthermore, the wiring outlet 21c of the first subcoil portion C1c and the wiring outlet 22c of the second subcoil portion C2c are arranged so as to completely overlap each other when viewed in the thickness direction, and are covered in the thickness direction by the cover portion B11, thereby further suppressing the generation of eddy currents in the wiring outlet 21c and the wiring outlet 22c, thereby further reducing eddy current loss.

[0051] D. Fourth embodiment: 7, the coil device C10d of the fourth embodiment has a configuration in which three sets of two subcoil sections connected in series are connected in parallel. Specifically, the first subcoil section C1d and the fourth subcoil section C4d are connected in series, the second subcoil section C2d and the fifth subcoil section C5d are connected in series, and the third subcoil section C3d and the sixth subcoil section C6d are connected in series. The three subcoil sections C1d to C3d are connected in parallel, and the three subcoil sections C4d to C6d are connected in parallel.

[0052] FIG. 8 shows the detailed configuration of three subcoil portions C1d to C3d, and FIG. 9 shows the detailed configuration of the other three subcoil portions C4d to C6d. The configurations of the six subcoil portions C1d to C6d are similar to those of the subcoil portions C1c and C2c of the third embodiment. Note that FIG. 8 also shows an insulating layer K1d disposed between two subcoil portions C1d and C2d, an insulating layer K2d disposed between two subcoil portions C2d and C3d, and an insulating layer K3d disposed between two subcoil portions C3d and C4d, along with the three subcoil portions C1d to C3d. Similarly, FIG. 9 also shows an insulating layer K4d disposed between two subcoil portions C4d and C5d, an insulating layer K5d disposed between two subcoil portions C5d and C6d, and an insulating layer K6d disposed on the back surface of the sixth subcoil portion C6d, along with the three subcoil portions C4d to C6d. The surface of the first subcoil portion C1d (the surface opposite to the surface in contact with the insulating layer K1d) may be covered with, for example, solder resist. Also, the back surface of the sixth subcoil portion C6d may be covered with solder resist instead of the insulating layer K6d. Similar to the coil device C10a of the first embodiment, the coil device C10d can also be said to be formed of a multilayer substrate having a structure in which insulating layers and coil wires are alternately stacked.

[0053] As shown on the leftmost side of FIG. 8, the first subcoil portion C1d includes a winding portion 11d, an end portion 41d, a wiring outlet portion 21d, connecting portions b11, b12, b21, b22, b23, b31, b32, b33, b41, b42, and b43, and a terminal portion 31d. A pair of through holes h21 is formed in the insulating layer K1d. The winding portion 11d includes three sub-winding portions 111d, 112d, and 113d. The three sub-winding portions 111d to 113d are wound in parallel and insulated from one another. The connecting portion b11 is provided on the terminal portion 31d. When viewing the first subcoil portion C1d in the +Z direction, the three connecting portions b21 to b23 are aligned at corners of the insulating layer K1d in the +Y and +X directions. The three connecting portions b31 to b33 are arranged side by side in the approximate center in the Y-axis direction near the edge of the insulating layer K1d in the +X direction. The three connecting portions b41 to b43 are arranged side by side at the corners of the insulating layer K1d in the -Y and +X directions.

[0054] Similarly, the second sub-coil portion C2d includes a winding portion 12d, an end portion 42d, a wiring outlet portion 22d, and connecting portions b11, b12, b21, b22, b23, b31, b32, b33, b41, b42, and b43. A pair of through holes h22 is formed in the insulating layer K1d. The winding portion 12d includes three sub-winding portions 121d, 122d, and 123d.

[0055] Similarly, the third sub-coil portion C3d includes a winding portion 13d, an end portion 43d, a wiring outlet portion 23d, and connecting portions b11, b12, b21, b22, b23, b31, b32, b33, b41, b42, and b43. A pair of through holes h23 is formed in the insulating layer K3d. The winding portion 13d includes three sub-winding portions 131d, 132d, and 133d.

[0056] 9, the fourth sub-coil portion C4d includes a winding portion 14d, an end portion 44d, a wiring outlet portion 24d, and connecting portions b11, b12, b21, b22, b23, b31, b32, b33, b41, b42, and b43. A pair of through holes h24 is formed in the insulating layer K4d. The winding portion 14d includes three sub-winding portions 141d, 142d, and 143d.

[0057] Similarly, the fifth subcoil portion C5d includes a winding portion 15d, an end portion 45d, a wiring outlet portion 25d, and connecting portions b11, b12, b21, b22, b23, b31, b32, b33, b41, b42, and b43. A pair of through holes h25 is formed in the insulating layer K5d. The winding portion 15d includes three sub-winding portions 151d, 152d, and 153d.

[0058] Similarly, the sixth sub-coil portion C6d includes a winding portion 16d, an end portion 46d, a wiring outlet portion 26d, and connecting portions b11, b12, b21, b22, b23, b31, b32, b33, b41, b42, and b43. A pair of through holes h26 is formed in the insulating layer K6d. The winding portion 16d includes three sub-winding portions 161d, 162d, and 163d.

[0059] As can be seen from Figures 8 and 9, in the fourth embodiment, as in the second and third embodiments, the subwinding portions of two subcoil sections that are connected to each other correspond to any of the following combinations: a combination of the outermost subwinding portion and the innermost subwinding portion, a combination of the innermost subwinding portion and the outermost subwinding portion, or a combination of two middle subwinding portions. Specifically, for example, the innermost subwinding portion 111d of the winding portion 11d of the first subcoil section C1d is connected to the outermost subwinding portion 141d of the winding portion 14d of the fourth subcoil section C4d at the connecting portion b41. The middle subwinding portion 112d is connected to the middle subwinding portion 142d at the connecting portion b32, and the outermost subwinding portion 113d is connected to the innermost subwinding portion 143d at the connecting portion b21. The same applies to the other subwinding portions of the other subcoil sections.

[0060] As shown in FIG. 8 , the sub-winding portion 123d has a detour portion 125d at a corner of the second subcoil portion C2d facing the +Y and +X directions. The detour portion 125d has a shape that detours outward to avoid the connecting portion b21 so that the sub-winding portion 123d extending from the connecting portion b22 does not come into contact with the connecting portion b21 located near the connecting portion b22. Similarly, the sub-winding portion 133d has a detour portion 135d at a corner of the third subcoil portion C3d facing the +Y and +X directions. The detour portion 135d has a shape that detours outward to avoid the two connecting portions b21 and b22 located near the connecting portion b23 so that the sub-winding portion 133d extending from the connecting portion b23 does not come into contact with these connecting portions b21 and b22. 9, the sub-winding portion 141d has a detour portion 145d at a corner of the fourth sub-coil portion C4d facing the -Y direction and the +X direction. The detour portion 145d has a shape that detours outward to avoid the two connecting portions b42 and b43 located near the connecting portion b41 so that the sub-winding portion 141d extending from the connecting portion b41 does not come into contact with these connecting portions b42 and b43. Similarly, the sub-winding portion 151d has a detour portion 155d at a corner of the fifth sub-coil portion C5d facing the -Y direction and the +X direction.

[0061] The pair of through holes h21 to h26 of each of the sub-coil portions C1d to C6d described above are connected to each other in the thickness direction to form a pair of through holes that penetrate the coil device C10d in the thickness direction.The pair of magnetic material connecting portions B12 described above are then arranged in the pair of through holes.

[0062] The coil device C10d of the fourth embodiment described above has the same effects as the coil device C10c of the third embodiment. Furthermore, since the detour portions 125d, 135d, 145d, and 155d are arranged at the corners of the insulating layers, an increase in the dimensions of the insulating layers (the vertical or horizontal dimensions in plan view) required to ensure a path for the coil wire that bulges due to the detour can be suppressed compared to a configuration in which such detour portions are provided in straight portions (portions along each side in plan view of each insulating layer).

[0063] E. Fifth embodiment: The coil device C10e of the fifth embodiment shown in FIG. 10 differs from the coil device C10c of the third embodiment in that the winding portions 11e and 12e are each formed of a single coil wire. Note that FIG. 10 only shows the coil device C10e of the coil assembly E1. Also, in addition to the two sub-coil portions C1e and C2e described below, FIG. 10 also shows two insulating layers K1e and K2e. Note that the surface of the first sub-coil portion C1e (the surface opposite to the surface in contact with the insulating layer K1e) may be covered with, for example, solder resist. Furthermore, the back surface of the second sub-coil portion C2e may be covered with solder resist instead of the insulating layer K2e. Similar to the coil device C10a of the first embodiment, the coil device C10e can also be said to be formed of a multilayer substrate having a structure in which insulating layers and coil wires are alternately stacked.

[0064] The coil device C10e includes a first subcoil portion C1e and a second subcoil portion C2e. The first subcoil portion C1e includes a winding portion 11e, a terminal portion 41e, and a wiring outlet portion 21e. A pair of through holes h31 are formed in the insulating layer K1e. The terminal portion 41e is located in a region sandwiched between the pair of through holes h31.

[0065] The second sub-coil portion C2e includes a winding portion 12e, a terminal portion 42e, and a wiring extraction portion 22e. A pair of through holes h32 are formed in the insulating layer K2e. The terminal portion 42e is located in the region sandwiched between the pair of through holes h32.

[0066] The two winding portions 11e and 12e are connected to each other by a connecting portion b51. The two wiring extracting portions 21e and 22e completely overlap each other in the thickness direction. This suppresses the generation of eddy currents in one of the wiring extracting portions, thereby reducing eddy current loss.

[0067] The coil device C10e of the fifth embodiment described above has the same effects as the coil device C10c of the third embodiment.

[0068] F. Sixth embodiment: The coil device C10f of the sixth embodiment shown in FIG. 11 differs from the coil device C10b of the second embodiment shown in FIG. 2 in the detailed configuration of the wiring outlet portion. Note that, for convenience of illustration, terminal portions and end portions are omitted in FIG. 11. Also, in addition to two subcoil portions C1f and C2f described below, two insulating layers K1f and K2f are shown in FIG. 11. Note that the surface of the first subcoil portion C1f (the surface opposite to the surface in contact with the insulating layer K1f) may be covered with, for example, solder resist. Also, the back surface of the second subcoil portion C2f may be covered with solder resist instead of the insulating layer K2f. Similar to the coil device C10a of the first embodiment, the coil device C10f can be said to be formed of a multilayer substrate having a structure in which insulating layers and coil wires are alternately stacked.

[0069] The coil device C10f includes a first subcoil portion C1f and a second subcoil portion C2f. The first subcoil portion C1f includes a winding portion 11f, a terminal portion 41f, a wiring outlet portion 21f, and a connecting portion b61, a connecting portion b62, and a connecting portion b63. ​​The winding portion 11f includes three subwinding portions 111f, 112f, and 113f that are insulated from each other and arranged in parallel. The terminal portion 41f is arranged inside the winding portion 11f. The three connecting portions b61 to b63 are arranged near the edge of the insulating layer K1f in the -X direction. The wiring outlet portion 21f extends from the end of the winding portion 11f in the +Y direction and the -X direction in a direction that intersects at approximately 45°, then bends 90° and extends linearly toward the terminal portion 41f.

[0070] The second subcoil portion C2f includes a winding portion 12f, a terminal portion 42f, a wiring extraction portion 22f, a connecting portion b61, a connecting portion b62, and a connecting portion b63. ​​The winding portion 12f includes three sub-winding portions 121f, 122f, and 123f that are insulated from each other and arranged in parallel. The terminal portion 42f is arranged inside the winding portion 12f. The wiring extraction portion 22f has a shape that extends from the end of the winding portion 12f in the -Y direction and the -X direction in a direction that intersects at approximately 45°, then bends 90° and extends linearly toward the terminal portion 42f.

[0071] The sub-winding portion 111f located on the outer side of the winding portion 11f of the first subcoil portion C1f is connected via a connecting portion b61 to the sub-winding portion 121f located on the inner side of the winding portion 12f of the second subcoil portion C2f. The sub-winding portion 112f located in the middle of the winding portion 11f of the first subcoil portion C1f is connected via a connecting portion b62 to the sub-winding portion 122f located in the middle of the winding portion 12f of the second subcoil portion C2f. The sub-winding portion 113f located on the inner side of the winding portion 11f of the first subcoil portion C1f is connected via a connecting portion b63 to the sub-winding portion 123f located on the outer side of the winding portion 12f of the second subcoil portion C2f.

[0072] As shown in the rightmost drawing in Fig. 11, wiring outlet portions 21f and 22f do not overlap in part when viewed in the thickness direction. Specifically, the portions extending from winding portions 11f and 12f in a direction intersecting at 45° do not overlap. On the other hand, the portions bending 90° from these portions and extending linearly toward end portions 41f and 42f do overlap.

[0073] The coil device C10f of the sixth embodiment described above has the same effects as the coil device C10b of the second embodiment. In the coil device C10f of the sixth embodiment, the wiring outlet portion 21f and the wiring outlet portion 22f also partially overlap, so that eddy current loss can be suppressed compared to a configuration in which the wiring outlet portions do not completely overlap each other.

[0074] G. Other Embodiments: (G1) In the second, third, fourth and sixth embodiments, among the multiple sub-winding portions constituting the winding portions 11b, 11c, 11d and 11f of the first sub-coil portions C1b, C1c, C1d and C1f, the sub-winding portions located more inward in the winding direction were connected to the sub-winding portions located more outward in the winding direction among the multiple sub-winding portions constituting the winding portions 12b, 12c, 12d and 12f of the second sub-coil portions C2b, C2c, C2d and C2f, compared to the sub-winding portions located more outward. However, the present disclosure is not limited to this. Of the multiple sub-winding portions constituting the winding portions 11b, 11c, 11d, 11f of the first sub-coil portions C1b, C1c, C1d, C1f, the sub-winding portion located more inward in the winding direction may be connected to the sub-winding portion of the multiple sub-winding portions constituting the winding portions 12b, 12c, 12d, 12f of the second sub-coil portions C2b, C2c, C2d, C2f that is located more inward in the winding direction compared to the sub-winding portion located more outward.

[0075] (G2) In each embodiment, the wiring outlet portions of all subcoil sections constituting the coil device are arranged so as to at least partially overlap each other when viewed in the thickness direction, but the present disclosure is not limited to this. The wiring outlet portions of only some of the subcoils constituting the coil device may be arranged so as to at least partially overlap each other when viewed in the thickness direction. For example, of the six subcoil sections C1d to C6d constituting the coil device C10d of the fourth embodiment, the wiring outlet portions of only some of the subcoil sections may be changed from being arranged along the X-axis direction to being arranged along the Y-axis direction. Even in such a configuration, the presence of two or more wiring outlet portions arranged so as to at least partially overlap each other when viewed in the thickness direction can achieve the same effects as each of the embodiments.

[0076] (G3) The coil devices C10a to C10f of each embodiment are merely examples and may be modified in various ways. For example, in the third to fifth embodiments, the cover portion B11 covers the end portion in the thickness direction, but the end portion may not be covered. The number of subcoil portions in each embodiment is not limited to two or six, and may be any number more than one. The cover portion B11 is integrated with the magnetic plate member B1, but may be configured as a separate member. The array of coil assemblies E1 in the third embodiment is composed of a total of nine coil assemblies E1 in a 3 x 3 arrangement, but may be composed of any number of coil assemblies E1. In the second to fourth embodiments, the insulating layer has an octagonal shape with four notched corners in a planar view. However, instead, it may have a rounded rectangular shape with rounded corners in a planar view. In such a configuration, connecting portions (through-hole vias) and detour portions may be provided at the rounded corners. Furthermore, the insulating layer may have any shape in a planar view, such as a circular shape or an elliptical shape. In the fourth embodiment, all six sub-coil portions C1d to C6d may be connected in series. Furthermore, in each embodiment, the angle at which the wiring extracting portion intersects with the winding direction of the winding portion is not limited to 90° or 45°, and may be any angle.

[0077] The present disclosure is not limited to the above-described embodiments and can be realized in various configurations without departing from the spirit thereof. For example, the technical features in each embodiment corresponding to the technical features in the form described in the Summary of the Invention section can be appropriately replaced or combined to solve some or all of the above-described problems or achieve some or all of the above-described effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. The features of the present disclosure are as follows: [Form 1] A coil device (C10a), a first sub-coil portion (C1a) and a second sub-coil portion (C2a) stacked in the thickness direction of an insulating layer (K1a) with an insulating layer (K1a) interposed therebetween; The first sub-coil section and the second sub-coil section each include: a winding portion (11a, 12a) in which a coil wire is wound along the planar direction of the insulating layer; end portions (41a, 42a) of the coil wire for electrical connection with an external device; a wiring take-out portion (21a, 22a) connecting the winding portion and the end portion, the wiring take-out portion extending in a direction intersecting the winding direction of the winding portion; Equipped with the wiring lead-out portion of the first subcoil portion and the wiring lead-out portion of the second subcoil portion are arranged so as to at least partially overlap each other when viewed in the thickness direction. Coil device. [Form 2] In the coil device according to aspect 1, A coil device in which the winding portion of the first sub-coil portion and the winding portion of the second sub-coil portion are both composed of multiple sub-winding portions (111b to 113b, 121b to 123b) wound in parallel and insulated from each other. [Form 3] In the coil device according to aspect 1 or 2, A coil device in which, among the multiple sub-winding portions constituting the winding portion of the first sub-coil portion, a sub-winding portion located more inward in the winding direction is connected to a sub-winding portion, among the multiple sub-winding portions constituting the winding portion of the second sub-coil portion, located more outward in the winding direction than a sub-winding portion located more outward. [Form 4] In the coil device according to any one of the first to third aspects, A coil device, wherein in both the first subcoil section and the second subcoil section, the end portion is arranged inside the winding portion in the planar direction. [Form 5] In the coil device according to aspect 4, A coil device, wherein the end portion is disposed at the center of the winding portion in the planar direction. [Form 6] In the coil device according to aspect 4 or aspect 5, The coil device further comprises a cover portion (B11) formed of a magnetic material and covering the inside of the winding portion in the planar direction in the thickness direction. [Form 7] In the coil device according to aspect 6, The cover portion covers the end portion in the thickness direction. [Explanation of symbols]

[0078] C10a...coil device, K1a...insulating layer, K2a...insulating layer, C1a...first sub-coil portion, C2a...second sub-coil portion, 11a...winding portion, 12a...winding portion, b1...connecting portion, b2...connecting portion, 41a...terminal portion, 42a...terminal portion, 21a...wiring outlet portion, 22a...wiring outlet portion

Claims

1. A coil device (C10a), a first sub-coil portion (C1a) and a second sub-coil portion (C2a) stacked with an insulating layer (K1a) interposed therebetween in the thickness direction of the insulating layer; The first sub-coil section and the second sub-coil section each include: a winding portion (11a, 12a) in which a coil wire is wound along the planar direction of the insulating layer; End portions (41 a, 42 a) of the coil wire for electrical connection with an external device; a wiring take-out portion (21a, 22a) connecting the winding portion and the end portion, the wiring take-out portion extending in a direction intersecting the winding direction of the winding portion; Equipped with the wiring lead-out portion of the first subcoil portion and the wiring lead-out portion of the second subcoil portion are arranged so as to at least partially overlap each other when viewed in the thickness direction, In both the first subcoil section and the second subcoil section, the end portion is disposed inside the winding portion in the planar direction. Coil device.

2. The coil device according to claim 1, A coil device in which the winding portion of the first sub-coil portion and the winding portion of the second sub-coil portion are both composed of multiple sub-winding portions (111b to 113b, 121b to 123b) wound in parallel and insulated from each other.

3. In the coil device described in claim 2, A coil device in which, among the multiple sub-winding portions constituting the winding portion of the first sub-coil portion, a sub-winding portion located more inward in the winding direction is connected to a sub-winding portion, among the multiple sub-winding portions constituting the winding portion of the second sub-coil portion, located more outward in the winding direction than a sub-winding portion located more outward.

4. The coil device according to claim 1, A coil device, wherein the end portion is disposed at the center of the winding portion in the planar direction.

5. The coil device according to claim 1, The coil device further includes a cover portion (B11) formed of a magnetic material and covering the inside of the winding portion in the planar direction in the thickness direction.

6. The coil device according to claim 5, The cover portion covers the end portion in the thickness direction.

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