Coil array

Abstract

In the coil array according to the present invention, two coil components are connected in parallel, whereby it is possible to flow a current approximately twice as much as that of a single coil component, and it is possible to reduce the DC resistance approximately by half. In other words, coil characteristics can be improved. Moreover, the two coil components share the coil axis of the coil and are arranged in the first direction parallel to the mounting substrate, so that the height can be reduced.

Description

Technical Field

[0001] The present disclosure relates to a coil array. Background Art

[0002] In Japanese Unexamined Patent Application Publication No. 2019-106523, a coil component is disclosed, which includes a coil provided in a base body having a mounting surface facing a mounting substrate and having a coil axis extending in a direction orthogonal to the mounting surface. Summary of the Invention

[0003] Problems to be Solved by the Invention

[0004] In the coil component related to the above prior art, it is difficult to be used in a circuit with a large current flowing therethrough, and it is also difficult to reduce the DC resistance.

[0005] The inventors have conducted in-depth research and as a result, newly found a technique capable of improving the coil characteristics for achieving a large current and a low resistance, and also capable of achieving a low height.

[0006] According to one aspect of the present disclosure, there is provided a coil array capable of improving coil characteristics and achieving a low height.

[0007] Technical Solution for Solving the Problem

[0008] The coil array according to one aspect of the present disclosure includes a plurality of coil components, which include: a base body having a mounting surface facing a mounting substrate; a coil provided in the base body and having a coil axis extending in a first direction parallel to the mounting surface; and a pair of external terminals provided on the surface of the base body and electrically connected to the coil. The plurality of coil components share the coil axis, are arranged along the first direction, and are connected in parallel.

[0009] In the above coil array, by connecting a plurality of coil components in parallel, the characteristics of the coil for achieving a large current and a low resistance can be improved. At this time, since a plurality of coil components are arranged along the first direction extending parallel to the mounting surface of the base body, the increase in height (i.e., low height) can be suppressed compared with the method of stacking a plurality of coil components on the mounting substrate. Brief Description of the Drawings

[0010] Figure 1 It is a schematic perspective view showing the coil array according to the first embodiment.

[0011] Figure 2 It is Figure 1 an exploded perspective view of the shown coil array.

[0012] Figure 3 It is showing Figure 1 、 Figure 2A diagram of the internal structure of the coil component.

[0013] Figure 4 is Figure 3 The IV-IV line cross-sectional view of the coil component shown.

[0014] Figure 5 is Figure 3 The V-V line cross-sectional view of the coil component shown.

[0015] Figure 6 is Figure 1 、 Figure 2 The side view of the coil component shown.

[0016] Figure 7 is Figure 1 The end view of the coil array shown.

[0017] Figure 8 A schematic perspective view showing different types of coil arrays.

[0018] Figure 9 A schematic perspective view showing the coil array according to the second embodiment.

[0019] Figure 10 is Figure 9 The exploded perspective view of the coil array shown.

[0020] Figure 11 is showing Figure 9 、 Figure 10 A diagram of the internal structure of the coil component.

[0021] Figure 12 is Figure 11 The XII-XII line cross-sectional view of the coil component shown.

[0022] Figure 13 is Figure 11 The XIII-XIII line cross-sectional view of the coil component shown.

[0023] Figure 14 A diagram showing the positional relationship between the coils of two coil components.

[0024] Figure 15 A table showing the test results.

[0025] Figure 16 A chart showing the test results.

[0026] Figure 17 A schematic perspective view showing different types of coil arrays.

[0027] Figure 18 A schematic perspective view showing different types of coil arrays. Detailed Implementation Modes

[0028] Hereinafter, various implementation modes and embodiments will be described with reference to the accompanying drawings. In addition, in each of the accompanying drawings, the same or corresponding parts are given the same reference numerals, and repeated descriptions are omitted.

[0029] (First Implementation Mode)

[0030] The coil array 1 according to the first implementation mode has Figure 1 、 Figure 2 the structure shown. The coil array 1 is mounted on a mounting substrate 100 described later (for example, by soldering). The coil array 1 can be applied to in-vehicle devices that require large currents, for example. The coil array 1 is composed of a plurality of coil components 10. In the present implementation mode, it is composed of two coil components 10. Hereinafter, the two coil components 10 will be appropriately referred to as the first coil component 10A and the second coil component 10B, respectively.

[0031] Each coil component 10 has a substantially rectangular parallelepiped shape and is substantially rectangular when viewed in the height direction. As an example, each coil component 10 can be designed with dimensions of a short side of 1.0 mm, a long side of 2.5 mm, and a height of 2.0 mm. Hereinafter, for the sake of convenience of explanation, the short side direction of the coil component 10 will also be referred to as the first direction, the short side direction of the coil component 10 will be referred to as the first direction D1, the long side direction will be referred to as the second direction D2, and the height direction will be referred to as the third direction D3. The first direction D1, the second direction D2, and the third direction D3 are orthogonal to each other.

[0032] Each coil component 10 is composed of a body 11, a pair of external terminals 12A and 12B provided on the surface of the body 11, and a coil 13 provided inside the body 11.

[0033] The body 11 is made of a magnetic material. In the present implementation mode, the body 11 is made of a metal-containing magnetic powder resin, which is a kind of magnetic material. The metal-containing magnetic powder resin is an adhesive powder in which metal magnetic powder particles are bonded by an adhesive resin. The metal magnetic powder can be composed of, for example, iron-nickel alloy (Permalloy), carbonyl iron, amorphous, amorphous or crystalline FeSiCr-based alloy, iron silicon aluminum, etc. The adhesive resin is, for example, a thermosetting epoxy resin. In the present implementation mode, the volume percentage of the metal magnetic powder particles in the adhesive powder is 80 to 92 vol%, and the mass percentage is 95 to 99 wt%. From the viewpoint of magnetic properties, the volume percentage of the metal magnetic powder particles in the adhesive powder can also be 85 to 92 vol%, and the mass percentage is 97 to 99 wt%.

[0034] The blank body 11 has a substantially rectangular parallelepiped outer shape with six faces 11a to 11f. Among the faces 11a to 11f of the blank body 11, the upper surface 11a and the lower surface 11b face each other in the third direction D3, the upper end face 11c and the end face 11d face each other in the second direction D2, and the side surface 11e and the side surface 11f face each other in the first direction D1. The upper surface 11a and the lower surface 11b are parallel to each other, the upper end face 11c and the end face 11d are parallel to each other, and the side surface 11e and the side surface 11f are parallel to each other. The lower surface 11b of the blank body 11 is the face opposite to the mounting substrate 100 on which the coil array 1 is mounted.

[0035] Inside the blank body 11, there is provided Figures 3 - 5 the coil 13 shown. The coil 13 according to the present embodiment includes an insulating substrate 14, a first coil portion 17A, and a second coil portion 17B.

[0036] The insulating substrate 14 is a plate-like member made of a non-magnetic insulating material and extends in a direction orthogonal to the first direction D1. When viewed from the first direction D1, the insulating substrate 14 has a substantially elliptical ring shape. An elliptical through-hole 14c is provided in the central portion of the insulating substrate 14. As the insulating substrate 14, a substrate in which a glass cloth is impregnated with an epoxy resin can be used, and the plate thickness is 10 μm to 60 μm. In addition to the epoxy resin, BT resin, polyimide, aromatic polyamide, etc. can also be used. As the material of the insulating substrate 14, ceramics or glass can also be used. As the material of the insulating substrate 14, a printed circuit board material for mass production is preferably used, and particularly preferably a resin material for a BT printed circuit board, an FR4 printed circuit board, or an FR5 printed circuit board.

[0037] The first coil portion 17A includes a planar coil pattern 15 provided on one surface 14a (the surface on the side of the side surface 11f) of the insulating substrate 14, and resin walls 16 located between the lines, the inner periphery, and the outer periphery of the planar coil pattern 15. The planar coil pattern 15 is formed by plating a conductor material such as Cu. The planar coil pattern 15 is formed so as to wind around the through-hole 14c of the insulating substrate 14. The outer peripheral end portion 15a of the planar coil pattern 15 reaches the end face 11c of the blank body 11 and exposes from the end face 11c, and the inner peripheral end portion 15b terminates at the edge of the through-hole 14c of the insulating substrate 14. The outer resin 16 is made of an insulating resin material. The resin walls 16 can be provided on the insulating substrate 14 before forming the planar coil pattern 15. In this case, the planar coil pattern 15 grows by plating between the walls partitioned by the resin walls 16. That is, the formation region of the planar coil pattern 15 can be partitioned by the resin walls 16 provided on the insulating substrate 14. The resin walls 16 can be provided on the insulating substrate 14 after forming the planar coil pattern 15. In this case, the resin walls 16 are provided on the planar coil pattern 15 by filling or coating or the like.

[0038] The second coil part 17B includes a planar coil pattern 15 provided on the other surface 14b of the insulating substrate 14 (the surface on the side of the side surface 11e), and resin walls 16 located between the lines, inner periphery, and outer periphery of the planar coil pattern 15. The planar coil pattern 15 of the second coil part 17B is also formed by plating with a conductor material such as Cu, similar to the planar coil pattern 15 of the first coil part 17A. The planar coil pattern 15 of the second coil part 17B is also formed in a manner of winding around the through-hole 14c of the insulating substrate 14, similar to the planar coil pattern 15 of the first coil part 17A. The outer peripheral end 15a of the planar coil pattern 15 of the second coil part 17B reaches the end surface 11d of the body 11 and is exposed from the end surface 11d, and the inner peripheral end 15b terminates at the edge of the through-hole 14c of the insulating substrate 14 (more specifically, at a position overlapping with the inner peripheral end 15b of the planar coil pattern 15 of the first coil part 17A in the first direction D1). The resin walls 16 of the second coil part 17B are also made of an insulating resin material, similar to the resin walls 16 of the first coil part 17A.

[0039] In the first coil part 17A and the second coil part 17B, the resin walls 16 located at the inner and outer peripheries of the planar coil pattern 15 can be designed to be thicker than the resin walls 16 located between the lines of the planar coil pattern 15.

[0040] In the first coil part 17A and the second coil part 17B, the surface of the planar coil pattern 15 exposed from the resin walls 16 is covered by an insulating layer 18. The insulating layer 18 is provided between adjacent resin walls 16 and covers the entire upper surface of the planar coil pattern 15. The insulating layer 18 is made of a resin such as epoxy resin or polyimide resin, for example. In the present embodiment, the insulating layer 18 is an electrodeposited layer formed by an electrodeposition method and has a uniform thickness.

[0041] The inner peripheral end 15b of the planar coil pattern 15 of the first coil part 17A and the inner peripheral end 15b of the planar coil pattern 15 of the second coil part 17B are connected via a via conductor 19 passing through the edge of the through-hole 14c of the insulating substrate 14. The via conductor 19 can be composed of a hole provided in the insulating substrate 14 and a conductive material (such as a metal material such as Cu) filled in the hole.

[0042] As Figure 4 、 Figure 5 shown, the magnetic material constituting the body 11 integrally covers the coil 13. More specifically, the magnetic material constituting the body 11 covers the coil 13 from the up and down directions and covers the outer periphery of the coil 13. In addition, the magnetic material constituting the body 11 fills the inner region of the coil 13.

[0043] Among a pair of external terminals 12A and 12B, the external terminal 12A is provided on the end face 11c side of the body 11, and the external terminal 12B is provided on the end face 11d side of the body 11. The external terminal 12A integrally covers the end face 11c, the upper surface 11a, the lower surface 11b, the side surface 11e, and the side surface 11f near the end face 11c, and is connected to the outer peripheral end 15a of the planar coil pattern 15 of the first coil portion 17A exposed from the end face 11c. The external terminal 12B integrally covers the end face 11d, the upper surface 11a, the lower surface 11b, the side surface 11e, and the side surface 11f near the end face 11d, and is connected to the outer peripheral end 15a of the planar coil pattern 15 of the second coil portion 17B exposed from the end face 11d.

[0044] In the coil array 1, as Figure 1 shown, the two coil components 10 are both arranged along the first direction D1 with the side surfaces 11e and 11f of the body 11 facing each other. More specifically, the side surface 11f of the body 11 of the first coil component 10A and the side surface 11e of the body 11 of the second coil component 10B face each other in the first direction D1. Therefore, the coils 13 provided in the body 11 of the coil component 10 have a common coil axis X extending along the first direction D1.

[0045] In the present embodiment, as Figure 6 shown, when viewed from the first direction D1, the upper surface 11a and the lower surface 11b of each coil component 10 have a convex portion S1 and a concave portion S2. Each convex portion S1 of the upper surface 11a and the lower surface 11b is located approximately at the center of the body 11 in the second direction D2, and the concave portions S2 are respectively located on both sides of the convex portion S1. Each convex portion S1 is substantially flat, and the concave portion S2 is slightly recessed with respect to the convex portion S1 and is slightly curved. Each convex portion S1 corresponds to the portion where the above-mentioned insulating substrate 14 is exposed from the body 11, and in each convex portion S1, a part of the insulating substrate 14 is exposed from the upper surface 11a and the lower surface 11b of the body 11.

[0046] The side surfaces 11e and 11f of the body 11 of each coil component 10 may be flat surfaces or surfaces curved (expanded) in a manner that at least one protrudes outward.

[0047] In the coil array 1 according to the present embodiment, the magnetic sheet 30 is interposed between two coil components 10. The magnetic sheet 30 has substantially the same dimensions as the side surface 11f of the body 11 of the first coil component 10A, covers the entire side surface 11f of the body 11 of the first coil component 10A, and covers the entire side surface 11e of the body 11 of the second coil component 10B. The magnetic sheet 30 includes, for example, magnetic materials such as iron-nickel alloy (Permalloy), carbonyl iron, amorphous, amorphous or crystalline FeSiCr-based alloy, and iron silicon aluminum, and is configured to include a thermosetting epoxy resin as an adhesive resin, for example.

[0048] Two coil components 10 are connected in parallel to the coil array 1. In the present embodiment, the two coil components 10 are connected in parallel by a pair of metal plates 20. Hereinafter, the pair of metal plates 20 will be appropriately referred to as the first metal plate 20A and the second metal plate 20B, respectively. As an example, each metal plate 20 can be made of pure copper (more specifically, hard pitch copper), and Ni / Sn plating can also be applied to the surface.

[0049] The first metal plate 20A is located on the end face 11c side of the body 11 of each coil component 10 and covers the external terminal 12A covering the end face 11c. The first metal plate 20A has a size of approximately two end faces 11c, integrally covers and electrically connects the external terminal 12A of the first coil component 10A and the external terminal 12A of the second coil component 10B. Similarly, the second metal plate 20B is located on the end face 11d side of the body 11 of each coil component 10 and covers the external terminal 12B covering the end face 11d. The second metal plate 20B, like the first metal plate 20A, has a size of approximately two end faces 11d, integrally covers and electrically connects the external terminal 12B of the first coil component 10A and the external terminal 12B of the second coil component 10B. Each metal plate 20 can also be adhered to the external terminals 12A and 12B using a conductive adhesive material.

[0050] In the present embodiment, as Figure 7 shown, each metal plate 20 is designed to retreat a predetermined distance from the outer edge of the external terminals 12A and 12B. That is, when viewed from the second direction D2, each metal plate 20 does not protrude more outward than the outer edge of the external terminals 12A and 12B. In particular, below the coil component 10 (on the lower surface 11b side of the body 11), the lower edge of each metal plate 20 retreats a distance G from the lower edge of the external terminals 12A and 12B. Thereby, each metal plate 20 is separated from the mounting substrate 100 on which the coil array 1 is mounted.

[0051] As described above, in the coil array 1 according to the first embodiment, two coil components 10 are connected in parallel. As a result, compared with the case of using a single coil component, about twice the current can flow, and the DC resistance can be reduced by about half. That is, an improvement in coil characteristics can be achieved. Moreover, the two coil components 10 share the coil axis X of the coil 13 and are arranged along the first direction D1 parallel to the mounting substrate 100, so that a low-profile can be achieved. That is, in the method of stacking a plurality of coil components 10 on the mounting substrate 100, the height increases as the number of coil components 10 increases. However, in the method of arranging the plurality of coil components 10 of the coil array 1 according to the present embodiment along the first direction D1, even if the number of coil components 10 increases, the height (the dimension in the third direction D3) does not change, suppressing its increase. In addition, in the coil array 1, by arranging each coil component 10 on the mounting substrate 100 in a vertical type (not a flat type), the mounting space is effectively reduced.

[0052] In addition, in the coil array 1, the two coil components 10 are arranged in the same posture. Therefore, when a voltage is applied between a pair of metal plates 20, the directions of the magnetic fluxes generated by the respective coils 13 are the same. In this case, magnetic flux coupling can be generated between the two coil components 10.

[0053] Moreover, in the coil array 1, the lower surface 11b of the body 11 of each coil component 10 has a convex portion S1 and a concave portion S2. Therefore, compared with the case of a flat surface, the creepage distance between a pair of external terminals 12A and 12B can be extended. As a result, the occurrence of an electrical short circuit between the pair of external terminals 12A and 12B can be effectively suppressed.

[0054] In addition, in the coil array 1, a magnetic sheet 30 is interposed between the two coil components 10. Therefore, compared with the case where there is a gap between the two coil components 10, the strength is increased, and in particular, high strength against vibration is achieved.

[0055] The number of coil components 10 of the coil array 1 is not limited to two and can be appropriately increased. Figure 8 A coil array 1A including four coil components 10A to 10D is shown. According to the number of coil components 10, the size of the metal plate 20 can be appropriately extended. The magnetic sheet 30 can be interposed between the coil components 10 adjacent in the first direction D1, respectively. In the coil array 1A, compared with the case of using a single coil component 10, about four times the current can flow, and the DC resistance can be reduced to about 1 / 4.

[0056] In the coil array 1A, similar to the coil array 1, the four coil components 10A to 10D can be arranged in the same posture. In this case, when a voltage is applied between the pair of metal plates 20, the directions of the magnetic fluxes generated by the respective coils 13 are the same. In the coil array 1A, the direction of a part of the coil components 10 (for example, only the coil component 10B) can also be reversed so that the direction of the magnetic flux generated by the coil 13 is opposite to that of the others. In this case, interference of the coil magnetic fluxes may occur between the adjacent coil components 10A and 10B.

[0057] In the second embodiment, the coil may be a form including an insulating substrate or a form not including an insulating substrate. Further, the coil is not limited to an elliptical ring shape, and may be, for example, a circular ring shape or a rectangular ring shape. In addition, the number of turns of the coil can be appropriately increased or decreased.

[0058] (Second Embodiment)

[0059] The coil array 101 according to the second embodiment has Figure 9 、 Figure 10 the structure shown. The coil array 101 is mounted on a mounting substrate 100 described later (for example, by soldering). The coil array 101 can be applied to, for example, in-vehicle devices that require a large current. The coil array 101 is composed of a plurality of coil components 10. In the present embodiment, it is composed of two coil components 10. Hereinafter, the two coil components 10 will be appropriately referred to as a first coil component 10A and a second coil component 10B, respectively.

[0060] Each coil component 10 has a substantially rectangular parallelepiped outer shape and is substantially rectangular when viewed from the height direction. As an example, each coil component 10 can be designed with dimensions of a short side of 1.0 mm, a long side of 2.5 mm, and a height of 2.0 mm. Hereinafter, for the sake of convenience of explanation, the short side direction of the coil component 10 will also be referred to as the first direction, the short side direction of the coil component 10 will be referred to as the first direction D1, the long side direction will be referred to as the second direction D2, and the height direction will be referred to as the third direction D3. The first direction D1, the second direction D2, and the third direction D3 are orthogonal to each other.

[0061] Each coil component 10 includes a body 11, a pair of external terminals 12A and 12B provided on the surface of the body 11, and a coil 13 provided in the body 11.

[0062] The element body 11 is made of a magnetic material. In the present embodiment, the element body 11 is made of a metal-containing magnetic powder resin which is a kind of magnetic material. The metal-containing magnetic powder resin is an adhesive powder in which metal magnetic powder bodies are bonded by an adhesive resin. The metal magnetic powder can be composed of, for example, iron-nickel alloy (Permalloy), carbonyl iron, amorphous, FeSiCr-based alloy in amorphous or crystalline state, iron silicon aluminum, etc. The adhesive resin is, for example, a thermosetting epoxy resin. In the present embodiment, the volume percentage of the metal magnetic powder body in the adhesive powder is 80 to 92 vol%, and the mass percentage is 95 to 99 wt%. From the viewpoint of magnetic properties, the content of the metal magnetic powder body in the adhesive powder can also be a volume percentage of 85 to 92 vol% and a mass percentage of 97 to 99 wt%.

[0063] The element body 11 has a substantially rectangular parallelepiped shape and has six faces 11a to 11f. Among the faces 11a to 11f of the element body 11, the upper surface 11a and the lower surface 11b face each other in the third direction D3, the end surface 11c and the end surface 11d face each other in the second direction D2, and the side surface 11e and the side surface 11f face each other in the first direction D1. The upper surface 11a and the lower surface 11b are parallel to each other, the end surface 11c and the end surface 11d are parallel to each other, and the side surface 11e and the side surface 11f are parallel to each other. The lower surface 11b of the element body 11 is the face opposite to the mounting substrate 100 on which the coil array 101 is mounted.

[0064] Inside the element body 11, there is provided Figures 11 - 13 the coil 13 shown. The coil 13 according to the present embodiment includes an insulating substrate 14, a first coil portion 17A, and a second coil portion 17B.

[0065] The insulating substrate 14 is a plate-like member made of a non-magnetic insulating material and extends in a direction orthogonal to the first direction D1. When observed from the first direction D1, the insulating substrate 14 has a substantially elliptical ring shape. An elliptical through hole 14c is provided in the central portion of the insulating substrate 14. As the insulating substrate 14, a substrate in which a glass cloth is impregnated with an epoxy resin system can be used, and the plate thickness is 10 μm to 60 μm. In addition to the epoxy resin system, BT resin, polyimide, aromatic polyamide, etc. can also be used. As the material of the insulating substrate 14, ceramics or glass can also be used. As the material of the insulating substrate 14, a resin material for mass production of printed circuit boards is preferably used, and particularly preferably a resin material for BT printed circuit boards, FR4 printed circuit boards, or FR5 printed circuit boards.

[0066] The first coil part 17A includes a planar coil pattern 15 provided on one surface 14a of the insulating substrate 14 (the surface on the side of the side surface 11f) and resin walls 16 located between, inside, and outside the turns of the planar coil pattern 15. The planar coil pattern 15 is formed by plating a conductor material such as Cu. The planar coil pattern 15 is formed so as to wind around the through hole 14c of the insulating substrate 14. The outer peripheral end 15a of the planar coil pattern 15 reaches the end surface 11c of the body 11 and is exposed from the end surface 11c, and the inner peripheral end 15b terminates at the edge of the through hole 14c of the insulating substrate 14. The outer resin 16 is made of an insulating resin material. The resin walls 16 can be provided on the insulating substrate 14 before forming the planar coil pattern 15. In this case, the planar coil pattern 15 grows by plating between the walls partitioned by the resin walls 16. That is, the formation region of the planar coil pattern 15 can be partitioned by the resin walls 16 provided on the insulating substrate 14. The resin walls 16 can be provided on the insulating substrate 14 after forming the planar coil pattern 15. In this case, the resin walls 16 are provided on the planar coil pattern 15 by filling, coating, or the like.

[0067] The second coil part 17B includes a planar coil pattern 15 provided on the other surface 14b of the insulating substrate 14 (the surface on the side of the side surface 11e) and resin walls 16 located between, inside, and outside the turns of the planar coil pattern 15. The planar coil pattern 15 of the second coil part 17B is also formed by plating a conductor material such as Cu, similarly to the planar coil pattern 15 of the first coil part 17A. The planar coil pattern 15 of the second coil part 17B is also formed so as to wind around the through hole 14c of the insulating substrate 14, similarly to the planar coil pattern 15 of the first coil part 17A. The outer peripheral end 15a of the planar coil pattern 15 of the second coil part 17B reaches the end surface 11d of the body 11 and is exposed from the end surface 11d, and the inner peripheral end 15b terminates at the edge of the through hole 14c of the insulating substrate 14 (more specifically, at a position overlapping with the inner peripheral end 15b of the planar coil pattern 15 of the first coil part 17A in the first direction D1). The resin walls 16 of the second coil part 17B are also made of an insulating resin material, similarly to the resin walls 16 of the first coil part 17A.

[0068] In the first coil part 17A and the second coil part 17B, the resin walls 16 located inside and outside the planar coil pattern 15 can be designed to be thicker than the resin walls 16 located between the turns of the planar coil pattern 15.

[0069] In the first coil portion 17A and the second coil portion 17B, the surface of the planar coil pattern 15 exposed from the resin wall 16 is covered with an insulating layer 18. The insulating layer 18 is provided between adjacent resin walls 16 over the entire upper surface of the planar coil pattern 15. The insulating layer 18 is made of a resin such as epoxy resin or polyimide resin, for example. The insulating layer 18 may also be an electrodeposited layer formed by an electrodeposition method, and in this case, it has a uniform thickness.

[0070] The inner peripheral end portion 15b of the planar coil pattern 15 of the first coil portion 17A and the inner peripheral end portion 15b of the planar coil pattern 15 of the second coil portion 17B are connected via a through-hole conductor 19 passing through the edge of a through-hole 14c formed in the insulating substrate 14. The through-hole conductor 19 may be composed of a hole formed in the insulating substrate 14 and a conductive material (such as a metal material like Cu) filled in the hole.

[0071] As Figure 12 , Figure 13 shown, the magnetic material constituting the core 11 integrally covers the coil 13. More specifically, the magnetic material constituting the core 11 covers the coil 13 from the up and down directions and also covers the outer periphery of the coil 13. In addition, the magnetic material constituting the core 11 fills the inner region of the coil 13. The magnetic material constituting the core 11 can be formed by molding so as to cover the coil 13. By grinding the molded magnetic material, the size (thickness) of the core 11 in the first direction D1 can be easily and freely adjusted.

[0072] In Figure 11 the first coil component 10A shown, the entire coil 13 is shifted upward (toward the side surface 11f side). That is, the coil 13 of the first coil component 10A is shifted from the intermediate position Y of the core 11 in the first direction D1 toward the side surface 11f side. On the other hand, the entire coil 13 of the second coil component 10B is shifted downward (toward the side surface 11e side). That is, the coil 13 of the second coil component 10B is shifted from the intermediate position Y of the core 11 in the first direction D1 toward the side surface 11e side. As a result, as Figure 14 shown, the coils 13 of the respective coil components 10 approach each other. At this time, the insulating substrate 14 of the coil 13 of the first coil component 10A is shifted from the intermediate position Y of the core 11 in the first direction D1 toward the side surface 11f side, and the insulating substrate 14 of the coil 13 of the second coil component 10B is shifted from the intermediate position Y of the core 11 in the first direction D1 toward the side surface 11e side. In the present embodiment, the shift length L of the insulating substrate 14 of the coil 13 of the first coil component 10A is the same as the shift length L of the insulating substrate 14 of the coil 13 of the second coil component 10B. The planar coil pattern 15 of the coil 13 of the first coil component 10A and the planar coil pattern 15 of the coil 13 of the second coil component 10B are separated by a distance d in the first direction D1.

[0073] Among a pair of external terminals 12A and 12B, the external terminal 12A is provided on the side of the end face 11c of the base body 11, and the external terminal 12B is provided on the side of the end face 11d of the base body 11. The external terminal 12A integrally covers the end face 11c, the upper surface 11a, the lower surface 11b, the side surface 11e, and the side surface 11f near the end face 11c, and is connected to the outer peripheral end 15a of the planar coil pattern 15 of the first coil portion 17A exposed from the end face 11c. The external terminal 12A integrally covers the end face 11d, the upper surface 11a, the lower surface 11b, the side surface 11e, and the side surface 11f near the end face 11d, and is connected to the outer peripheral end 15a of the planar coil pattern 15 of the second coil portion 17B exposed from the end face 11d.

[0074] In the coil array 101, as Figure 9 shown, the two coil members 10 are arranged along the first direction D1 with the side surfaces 11e and 11f of the base body 11 facing each other. More specifically, the side surface 11f of the base body 11 of the first coil member 10A and the side surface 11e of the base body 11 of the second coil member 10B face each other in the first direction D1. Therefore, the coils 13 provided in the base body 11 of the coil member 10 have a common coil axis X extending along the first direction D1.

[0075] In the coil array 101 according to the present embodiment, an adhesive layer 130 is interposed between the two coil members 10. The adhesive layer 130 has substantially the same size as the side surface 11f of the base body 11 of the first coil member 10A, covers the entire side surface 11f of the base body 11 of the first coil member 10A, and covers the entire side surface 11e of the base body 11 of the second coil member 10B. As an example, the adhesive layer 130 is made of polyethylene. The adhesive layer 130 may be made of a non-magnetic material or a magnetic material.

[0076] Two coil members 10 are connected in parallel to the coil array 101. In the present embodiment, the two coil members 10 are connected in parallel by a pair of metal plates 20. Hereinafter, the pair of metal plates 20 will be appropriately referred to as the first metal plate 20A and the second metal plate 20B, respectively. As an example, each metal plate 20 can be made of pure copper (more specifically, hard pitch copper), or Ni / Sn plating can be applied to the surface.

[0077] The first metal plate 20A is located on the end face 11c side of the body 11 of each coil component 10 and covers the external terminal 12A covering the end face 11c. The first metal plate 20A has a size approximately that of two end faces 11c, integrally covers and is electrically connected to the external terminal 12A of the first coil component 10A and the external terminal 12A of the second coil component 10B. Similarly, the second metal plate 20B is located on the end face 11d side of the body 11 of each coil component 10 and covers the external terminal 12B covering the end face 11d. The second metal plate 20B, like the first metal plate 20A, has a size approximately that of two end faces 11d, integrally covers and is electrically connected to the external terminal 12B of the first coil component 10A and the external terminal 12B of the second coil component 10B. Each metal plate 20 can also be adhered to the external terminals 12A, 12B with a conductive adhesive material.

[0078] Here, a coil component in which a first coil and a second coil overlap via a substrate is disclosed in Japanese Unexamined Patent Application Publication No. 2018-137421. By disposing a substrate in the isolation space between the first coil and the second coil, an increase in the coupling coefficient is achieved. The inventors of the present invention have studied the coupling coefficient between coils and newly discovered a technique capable of adjusting the coupling coefficient.

[0079] In the coil array 101 according to the second embodiment, the two insulating substrates 14 of the coils 13 of a pair of adjacent coil components 10 are offset in a manner close to each other, whereby the distance between the planar coil patterns 15 formed on the main surfaces 14a, 14b of the insulating substrates 14 is shortened. The distance between the planar coil patterns 15 of a pair of adjacent coil components 10 can be appropriately changed in design by adjusting the thickness of the magnetic material constituting the body 11, and thus can be adjusted to a desired coupling coefficient.

[0080] In order to confirm the relationship between the offset of the insulating substrate 14 and the coupling coefficient, the inventor performed a simulation analysis using a 3D model simulating the following embodiments. In this simulation analysis, simulation software ANSYS Electronics Desktop Maxwell 2021R1 manufactured by ANSYS was used. In each of the simulation models 1 to 5, as the dimension in the first direction D1, a coil array in which a pair of coil components having a body with a thickness of 900 μm, a substrate with a thickness of 60 μm, a planar coil pattern with a height of 200 μm, and a resin wall with a height of 225 μm were adjacent was used. The same material having the same magnetic permeability was used for the magnetic material constituting the body of each of the simulation models 1 to 5. In addition, an adhesive layer with a thickness of 20 μm made of a resin material was used to bond between the coil components. In each of the simulation models 1 to simulation model 5, the offset length L of the substrates of the two coil components was made the same.

[0081] The result is as Figure 15 、Figure 16 As shown. That is, in the simulation model 1 that is not offset from the middle position Y of the element body in the first direction D1, the coupling coefficient is 0.061. In the simulation model 2 that is offset 50 μm from the middle position Y of the element body toward the side, the coupling coefficient is 0.076. In the simulation model 3 that is offset 100 μm from the middle position Y of the element body toward the side, the coupling coefficient is 0.104. In the simulation model 4 that is offset 150 μm from the middle position Y of the element body toward the side, the coupling coefficient is 0.175. In the simulation model 5 that is offset 195 μm from the middle position Y of the element body toward the side, the coupling coefficient is 0.607.

[0082] In this way, it can be confirmed that by changing the offset length L of the substrate and the distance d between the coil patterns, the coupling coefficient changes. Therefore, for example, by adjusting the thickness of the magnetic material constituting the element body, etc., to adjust the offset length L of the substrate and the distance d between the coil patterns, the coupling coefficient can be appropriately adjusted. In addition, it can be confirmed that the longer the offset length L of the substrate, the higher the coupling coefficient. For example, as in simulation models 4 and 5, when the offset length L is 150 μm or more and the distance d between the coil patterns is 160 μm or less, a relatively high coupling coefficient of 0.150 or more can be obtained.

[0083] The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the adjacent pair of coil components are not necessarily limited to the mode in which both substrates are offset, and it can also be a mode in which only one of the substrates is offset. In addition, when both substrates of the adjacent pair of coil components are offset, the offset lengths L of the two substrates can be the same or different.

[0084] In addition, it is not limited to the coil array in which a plurality of coil components are connected in parallel, and it can also be a coil array in which a plurality of coil components are connected in series. Figure 17 A coil array 101A in which two coil components 10 are connected in series is shown. The coil array 101A is of a three-terminal type and includes three metal plates 20. Among the three metal plates 20, the first metal plate 20A only covers the external terminal 12A covering the end face 11c of the first coil component 10A, the second metal plate 20B integrally covers the external terminal 12B covering the end faces 11d of the first coil component 10A and the second coil component 10B, and the third metal plate 20C only covers the external terminal 12A covering the end face 11c of the first coil component 10B. In the coil array 101A, a voltage can be applied between the first metal plate 20A and the third metal plate 20C.

[0085] And, the number of the coil components 10 of the coil array 101 is not limited to two and can be appropriately increased. Figure 18In [the figure], a coil array 101B including four coil components 10A to 10D is shown. According to the number of coil components 10, the size of the metal plate 20 can be appropriately extended. The adhesive layer 130 can be interposed between each of the coil components 10 adjacent in the first direction D1. In the coil array 101B, compared with the case of using a single coil component 10, about four times the current can flow, and the DC resistance can be reduced to about 1 / 4. In the coil array 101B, the insulating substrate 14 of a part of the coil components 10 among the four coil components 10A to 10D is displaced. Specifically, only the insulating substrate 14 of the coil 13 of the coil component 10B is displaced. Further, in the coil array 101B, when a voltage is applied between a pair of metal plates 20, the direction of the magnetic flux generated in the coils 13 of the coil components 10A to 10D can be the same, or the direction of a part of the coil components 10 (for example, only the coil component 10D) can be reversed in such a way that the direction of the magnetic flux generated in the coil 13 is opposite to that of the others. In this case, interference of the coil magnetic flux may occur between the adjacent coil components 10C and coil component 10D.

[0086] In the second embodiment, the coil is not limited to an elliptical ring shape, and for example, it may also be a circular ring shape, a rectangular ring shape, or the like. Further, the number of turns of the coil can be appropriately increased or decreased.

Claims

1. A coil array, wherein: A plurality of coil components are provided, wherein the coil components include: a body having a mounting surface opposite to a mounting substrate; a coil disposed in the element body and having a coil axis extending in a first direction parallel to the mounting surface; and a pair of external terminals disposed on a surface of the element body and electrically connected to the coil, The plurality of coil components share the coil axis and are arranged along the first direction and connected in parallel.

2. The coil array according to claim 1, wherein: The directions of the magnetic fluxes of the coils in all of the plurality of coil components are the same.

3. The coil array according to claim 1, wherein: The directions of magnetic fluxes of the coils in the coil components adjacent to each other in the first direction are opposite to each other.

4. The coil array according to any one of claims 1 to 3, wherein: The element body has a pair of side surfaces facing each other in the first direction, and at least a portion of the side surfaces is curved.

5. The coil array according to any one of claims 1 to 4, wherein: The coil component includes a substrate extending in a direction perpendicular to the mounting surface. The mounting surface has a convex portion and a concave portion, and a portion of the substrate is exposed from the mounting surface in the convex portion.

6. The coil array according to any one of claims 1 to 5, wherein: A magnetic sheet is further provided between the coil components adjacent to each other in the first direction.

7. The coil array according to any one of claims 1 to 6, wherein: A metal plate integrally covering the external terminals of the plurality of coil components is further provided.

8. The coil array according to claim 7, wherein: On the mounting surface side of the element body, the end portion of the metal plate is set back from the edge of the external terminal.

9. A coil array, wherein: A plurality of coil components are provided, wherein the coil components include: a body including metal magnetic powder; a coil including a substrate disposed in the body and orthogonal to a first direction and a planar coil pattern formed on a main surface of the substrate; and a pair of external terminals disposed on a surface of the body and electrically connected to the coil. The plurality of coil components are arranged along the first direction, and at least one substrate of a pair of coil components adjacent to each other in the first direction is offset toward the other substrate.

10. The coil array according to claim 9, wherein: The plurality of coil components are connected in parallel.

11. The coil array according to claim 9 or 10, wherein: The two substrates of a pair of coil components adjacent to each other in the first direction are offset so as to approach each other.

12. The coil array according to claim 11, wherein: The two substrates of a pair of coil components adjacent to each other in the first direction are offset by the same distance.

13. The coil array according to claim 9, wherein: The plurality of coil components are connected in series.

14. The coil array according to any one of claims 9 to 13, wherein: The element body of each coil component has a mounting surface facing the mounting substrate, and the first direction extends parallel to the mounting surface.

15. The coil array according to any one of claims 9 to 14, wherein: An adhesive layer is further provided between the coil components adjacent to each other in the first direction.

16. The coil array according to claim 15, wherein: A distance between the planar coil patterns of a pair of coil components adjacent to each other in the first direction is 160 μm or less.

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