Coil array

Abstract

To provide a coil array which can improve the property of a coil and can achieve a low-profile design.SOLUTION: Two coil components 10 are connected in parallel in a coil array 1. This enables flowing approximately twice as much as current, compared to when a coil component is used alone, and the DC resistance can be reduced to half. In other words, improvement of the coil property is realized. In addition, since two coil components 10 are lined along a first direction D1 in parallel to a mounting substrate 100 while sharing a coil axis X of a coil 13, a low-profile design is achieved.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] The following Cited Document 1 discloses a coil component provided within an element body having a mounting surface facing a mounting board, the coil having a coil axis extending in a direction perpendicular to the mounting surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-106523 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is difficult to use the coil components according to the above-mentioned conventional techniques in a circuit through which a relatively large current flows, and it is also difficult to reduce the direct current resistance.

[0005] As a result of extensive research, the inventors have discovered a new technology that can improve coil characteristics such as larger current and lower resistance while also achieving a smaller height.

[0006] An object of one aspect of the present disclosure is to provide a coil array that can improve coil characteristics and reduce the height. [Means for solving the problem]

[0007] A coil array according to one aspect of the present disclosure comprises a plurality of coil components including a base body having a mounting surface facing a mounting board, a coil provided within the base body and having a coil axis along a first direction extending parallel to the mounting surface, and a pair of external terminals provided on a surface of the base body and electrically connected to the coil, the plurality of coil components being aligned along the first direction with a common coil axis and connected in parallel.

[0008] In the coil array, multiple coil components are connected in parallel to improve coil characteristics such as high current and low resistance. In this case, since the multiple coil components are arranged in a first direction extending parallel to the mounting surface of the element body, the height can be suppressed (i.e., the height can be reduced) compared to a configuration in which multiple coil components are stacked on a mounting board. Effect of the Invention

[0009] According to various aspects of the present disclosure, a coil array capable of improving coil characteristics and reducing the height is provided. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic perspective view showing a coil array according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the coil array shown in FIG. [Diagram 3] FIG. 3 is a diagram showing the internal structure of the coil component of FIGS. [Figure 4] FIG. 4 is a cross-sectional view of the coil device shown in FIG. 3 taken along line IV-IV. [Diagram 5] FIG. 5 is a cross-sectional view of the coil device shown in FIG. 3 taken along line VV. [Figure 6] FIG. 6 is a side view of the coil device shown in FIGS. [Figure 7] FIG. 7 is an end view of the coil array shown in FIG. [Figure 8] FIG. 8 is a schematic perspective view showing a coil array according to a different embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Various embodiments and examples will be described below with reference to the drawings. Note that the same or corresponding parts in each drawing are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0012] A coil array 1 according to one embodiment has the configuration shown in Figs. 1 and 2. The coil array 1 is mounted (for example, solder mounted) on a mounting board 100 described later. The coil array 1 is applied, for example, to an in-vehicle device that requires a large current. The coil array 1 is configured to include a plurality of coil components 10, and in this embodiment, is configured to include 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.

[0013] Each coil component 10 has a substantially rectangular parallelepiped outer shape and is substantially rectangular when viewed in the height direction. As an example, each coil component 10 may 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 convenience of explanation, the short side direction of the coil component 10 is also referred to as the first direction, the short side direction of the coil component 10 is also referred to as the first direction D1, the long side direction is also referred to as the second direction D2, and the height direction is also referred to as the third direction D3. The first direction D1, the second direction D2, and the third direction D3 are mutually perpendicular.

[0014] Each coil component 10 is configured to include an element body 11, a pair of external terminals 12A, 12B provided on the surface of the element body 11, and a coil 13 provided within the element body 11.

[0015] The element body 11 is made of a magnetic material. In this embodiment, the element body 11 is made of a resin containing a metal magnetic powder, which is a type of magnetic material. The resin containing a metal magnetic powder is a binding powder in which a metal magnetic powder is bound by a binder resin. The metal magnetic powder may be made of, for example, an iron-nickel alloy (permalloy alloy), carbonyl iron, an amorphous, non-crystalline or crystalline FeSiCr-based alloy, sendust, or the like. The binder resin is, for example, a thermosetting epoxy resin. In this embodiment, the content of the metal magnetic powder in the binding powder is 80 to 92 vol% in volume percent and 95 to 99 wt% in mass percent. From the viewpoint of magnetic properties, the content of the metal magnetic powder in the binding powder may be 85 to 92 vol% in volume percent and 97 to 99 wt% in mass percent.

[0016] The element body 11 has a substantially rectangular parallelepiped outer shape and has six faces 11a to 11f. Of the faces 11a to 11f of the element body 11, the upper face 11a and the lower face 11b face each other in the third direction D3, the end face 11c and the end face 11d face each other in the second direction D2, and the side face 11e and the side face 11f face each other in the first direction D1. The upper face 11a and the lower face 11b are parallel to each other, the end face 11c and the end face 11d are parallel to each other, and the side face 11e and the side face 11f are parallel to each other. The lower face 11b of the element body 11 is a face facing a mounting board 100 on which the coil array 1 is mounted.

[0017] 3 to 5 is provided within element body 11. Coil 13 according to this embodiment includes an insulating substrate 14, a first coil portion 17A, and a second coil portion 17B.

[0018] The insulating substrate 14 is a plate-like member made of a non-magnetic insulating material, and extends perpendicular to the first direction D1. The insulating substrate 14 has a substantially elliptical annular shape when viewed from the first direction D1. An elliptical through hole 14c is provided in the center of the insulating substrate 14. The insulating substrate 14 may be a substrate made of glass cloth impregnated with epoxy resin and having a thickness of 10 μm to 60 μm. In addition to epoxy resin, BT resin, polyimide, aramid, etc. may also be used. The insulating substrate 14 may be made of ceramic or glass. The insulating substrate 14 is preferably made of a mass-produced printed circuit board material, and is most preferably made of a resin material used for a BT printed circuit board, an FR4 printed circuit board, or an FR5 printed circuit board.

[0019] The first coil portion 17A is configured to include a planar coil pattern 15 provided on one surface 14a (surface on the side of the side surface 11f) of the insulating substrate 14, and resin walls 16 located between the lines of the planar coil pattern 15, and on the inner and outer periphery. The planar coil pattern 15 is formed by plating with a conductive material such as Cu. The planar coil pattern 15 is formed so as to be wound 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 element 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 resin walls 16 are configured of an insulating resin material. The resin walls 16 can be provided on the insulating substrate 14 before the planar coil pattern 15 is formed, and in this case, the planar coil pattern 15 is plated and grown between the walls defined by the resin walls 16. That is, the resin walls 16 provided on the insulating substrate 14 define the formation area of ​​the planar coil pattern 15. The resin wall 16 can be provided on the insulating substrate 14 after the planar coil pattern 15 is formed. In this case, the resin wall 16 is provided on the planar coil pattern 15 by filling or coating.

[0020] The second coil portion 17B is configured to include a planar coil pattern 15 provided on the other surface 14b (surface on the side of the side 11e) of the insulating substrate 14, and resin walls 16 located between the lines of the planar coil pattern 15, and on the inner and outer periphery. The planar coil pattern 15 of the second coil portion 17B is also formed by plating with a conductive material such as Cu, similar to the planar coil pattern 15 of the first coil portion 17A. The planar coil pattern 15 of the second coil portion 17B is also formed to be wound around the through hole 14c of the insulating substrate 14, similar to the planar coil pattern 15 of the first coil portion 17A. The outer peripheral end 15a of the planar coil pattern 15 of the second coil portion 17B reaches the end surface 11d of the element 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 the inner peripheral end 15b of the planar coil pattern 15 of the first coil portion 17A in the first direction D1). Like the resin wall 16 of the first coil portion 17A, the resin wall 16 of the second coil portion 17B is also made of an insulating resin material.

[0021] In the first coil portion 17A and the second coil portion 17B, the resin walls 16 located on the inner and outer periphery 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.

[0022] 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 over the entire upper surface of the planar coil pattern 15 between adjacent resin walls 16. The insulating layer 18 is made of a resin such as an epoxy resin or a polyimide resin. In this embodiment, the insulating layer 18 is an electrodeposited layer formed by an electrodeposition method and has a uniform thickness.

[0023] An inner peripheral end 15b of the planar coil pattern 15 of the first coil portion 17A and an inner peripheral end 15b of the planar coil pattern 15 of the second coil portion 17B are connected via a through-hole conductor 19 that penetrates the edge of a through-hole 14c of the insulating substrate 14. The through-hole conductor 19 may be composed of a hole provided in the insulating substrate 14 and a conductive material (e.g., a metal material such as Cu) filled in the hole.

[0024] 4 and 5, the magnetic material constituting element body 11 integrally covers coil 13. More specifically, the magnetic material constituting element body 11 covers coil 13 from above and below, and also covers the outer periphery of coil 13. In addition, the magnetic material constituting element body 11 fills the inner region of coil 13.

[0025] Of the pair of external terminals 12A and 12B, the external terminal 12A is provided on the end surface 11c side of the element body 11, and the external terminal 12B is provided on the end surface 11d side of the element body 11. The external terminal 12A integrally covers the end surface 11c and the upper surface 11a, lower surface 11b, side surface 11e, and side surface 11f near the end surface 11c, and is connected to the outer peripheral end 15a of the planar coil pattern 15 of the first coil part 17A exposed from the end surface 11c. The external terminal 12A integrally covers the end surface 11d and the upper surface 11a, lower surface 11b, side surface 11e, and side surface 11f near the end surface 11d, and is connected to the outer peripheral end 15a of the planar coil pattern 15 of the second coil part 17B exposed from the end surface 11d.

[0026] 1, in the coil array 1, the two coil components 10 are arranged along the first direction D1 with the side surfaces 11e, 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 components 10 have a common coil axis X extending in the first direction D1.

[0027] In this embodiment, as shown in Fig. 6, the upper surface 11a and the lower surface 11b of each coil component 10 have a convex portion S1 and a concave portion S2 when viewed from the first direction D1. Each convex portion S1 on the upper surface 11a and the lower surface 11b is located approximately at the center of the element body 11 in the second direction D2, and the concave portions S2 are located on both sides of the convex portion S1. Each convex portion S1 is approximately flat, and the concave portions S2 are slightly recessed from the convex portion S1 and are slightly curved. Each convex portion S1 corresponds to a portion of the insulating substrate 14 described above exposed from the element body 11, and a portion of the insulating substrate 14 is exposed from the upper surface 11a and the lower surface 11b of the element body 11 at each convex portion S1.

[0028] The side surfaces 11e, 11f of the body 11 of each coil component 10 may be flat surfaces, or at least one of them may be curved (expanded) so as to be outwardly convex.

[0029] In the coil array 1 according to this embodiment, a magnetic sheet 30 is interposed between two coil components 10. The magnetic sheet 30 has approximately the same dimensions as the side surface 11f of the element body 11 of the first coil component 10A, and covers the entire surface of the side surface 11f of the element body 11 of the first coil component 10A and covers the entire surface of the side surface 11e of the element body 11 of the second coil component 10B. The magnetic sheet 30 is configured to include a magnetic material such as an iron-nickel alloy (permalloy alloy), carbonyl iron, an amorphous, non-crystalline or crystalline FeSiCr-based alloy, sendust, or the like, and to include a thermosetting epoxy resin as a binder resin.

[0030] The coil array 1 has two coil components 10 connected in parallel. In this 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 a first metal plate 20A and a second metal plate 20B. As an example, each metal plate 20 can be made of pure copper (more specifically, tough pitch copper), and the surface may be Ni / Sn plated.

[0031] The first metal plate 20A is located on the end face 11c side of the element body 11 of each coil component 10, and covers the external terminal 12A that covers the end face 11c. The first metal plate 20A has a size that is approximately twice the end face 11c, and 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 element body 11 of each coil component 10, and covers the external terminal 12B that covers the end face 11d. The second metal plate 20B, like the first metal plate 20A, has a size that is approximately twice the end face 11d, and 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 may be attached to the external terminals 12A and 12B using a conductive adhesive.

[0032] In this embodiment, as shown in Fig. 7, each metal plate 20 is designed to be recessed from the outer edges of the external terminals 12A, 12B by a predetermined distance. That is, when viewed from the second direction D2, each metal plate 20 does not protrude outward from the outer edges of the external terminals 12A, 12B. In particular, on the lower side of the coil component 10 (the lower surface 11b side of the element body 11), the lower edge of each metal plate 20 is recessed from the lower edges of the external terminals 12A, 12B by a distance G. As a result, each metal plate 20 is separated from the mounting substrate 100 on which the coil array 1 is mounted.

[0033] As described above, in the coil array 1, two coil components 10 are connected in parallel, which allows approximately twice as much current to flow as in the case of using a single coil component, and the direct current resistance can be reduced by approximately half. That is, the coil characteristics are improved. In addition, the two coil components 10 are arranged along the first direction D1 parallel to the mounting board 100 while sharing the coil axis X of the coil 13, thereby achieving a low profile. That is, in a configuration in which a plurality of coil components 10 are stacked on the mounting board 100, the height increases as the number of coil components 10 increases, but in a configuration in which a plurality of coil components 10 are arranged along the first direction D1 as in the coil array 1 of this embodiment, the height (dimension in the third direction D3) does not change even if the number of coil components 10 increases, and the increase in height is suppressed. In addition, in the coil array 1, the coil components 10 are arranged vertically (rather than horizontally) on the mounting board 100, thereby effectively reducing the mounting space.

[0034] In addition, in the coil array 1, the two coil components 10 are arranged in the same position, so that the magnetic flux generated in each coil 13 has the same direction when a voltage is applied between the pair of metal plates 20. In this case, magnetic flux coupling may occur between the two coil components 10.

[0035] Furthermore, in the coil array 1, since the lower surface 11b of the body 11 of each coil component 10 has the convex portion S1 and the concave portion S2, the creepage distance between the pair of external terminals 12A, 12B is extended compared to when the surface is flat, thereby effectively preventing an electrical short circuit from occurring between the pair of external terminals 12A, 12B.

[0036] Furthermore, in the coil array 1, since a magnetic sheet 30 is interposed between the two coil components 10, the strength is increased compared to when there is a gap between the two coil components 10, and particularly high strength against vibration is achieved.

[0037] The number of coil components 10 in the coil array 1 is not limited to two and can be increased as appropriate. FIG. 8 shows a coil array 1A including four coil components 10A to 10D. The dimensions of the metal plate 20 can be extended as appropriate according to the number of coil components 10. The magnetic sheets 30 can be interposed between each of the coil components 10 adjacent to each other in the first direction D1. In the coil array 1A, it is possible to pass approximately four times as much current as in the case where a single coil component 10 is used, and the DC resistance can be reduced to approximately one-quarter.

[0038] In the coil array 1A, like the coil array 1, all four coil components 10A to 10D can be arranged in the same orientation. In this case, the direction of magnetic flux generated in each coil 13 when a voltage is applied between a pair of metal plates 20 is the same. In the coil array 1A, the orientation of some of the coil components 10 (for example, only the coil component 10B) may be reversed so that the direction of magnetic flux generated in the coil 13 is opposite to the other coil components. In this case, interference of coil magnetic flux may occur between adjacent coil components 10A and 10B.

[0039] The present invention is not limited to the above-described embodiment, and can be modified in various ways. For example, the coil may include an insulating substrate, or may not include an insulating substrate. The coil is not limited to an elliptical ring shape, and may be, for example, a circular ring shape or a rectangular ring shape. Furthermore, the number of turns of the coil can be increased or decreased as appropriate.

[0040] As can be understood from the above description, the present specification discloses the following. [Appendix 1] a coil component including a body having a mounting surface facing a mounting substrate, a coil provided in the body and having a coil axis along a first direction extending parallel to the mounting surface, and a pair of external terminals provided on a surface of the body and electrically connected to the coil; A coil array in which the multiple coil components are aligned along the first direction while sharing the coil axis and are connected in parallel. [Appendix 2] 2. The coil array of claim 1, wherein the magnetic flux direction of the coils in all of the multiple coil components is the same. [Appendix 3] 2. The coil array of claim 1, wherein the magnetic flux directions of coils in adjacent coil components in the first direction are opposite. [Appendix 4] 4. The coil array according to claim 1, wherein the 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. [Appendix 5] the coil component includes a substrate extending in a direction perpendicular to the mounting surface, 5. The coil array according to claim 1, wherein the mounting surface has a convex portion and a concave portion, and a part of the substrate is exposed from the mounting surface at the convex portion. [Appendix 6] 6. The coil array according to claim 1, further comprising a magnetic sheet interposed between the coil components adjacent to each other in the first direction. [Appendix 7] 7. The coil array according to claim 1, further comprising a metal plate integrally covering external terminals of the plurality of coil components. [Appendix 8] 8. The coil array of claim 7, wherein an end of the metal plate is recessed from an edge of the external terminal on the mounting surface side of the body. [Explanation of symbols]

[0041] 1...coil array, 10, 10A to 10D...coil components, 11...element body, 11a...upper surface, 11b...lower surface, 11c, 11d...end surfaces, 11e, 11f...side surfaces, 12A, 12B...external terminals, 13...coil, 14...insulating substrate, 20, 20A, 20B...metal plate, 30...magnetic sheet, D1...first direction, D2...second direction, D3...third direction.

Claims

1. a coil component including a body having a mounting surface facing a mounting substrate, a coil provided in the body and having a coil axis along a first direction extending parallel to the mounting surface, and a pair of external terminals provided on a surface of the body and electrically connected to the coil; A coil array in which the multiple coil components are aligned along the first direction while sharing the coil axis and are connected in parallel.

2. The coil array according to claim 1 , wherein the magnetic flux directions 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 flux of coils in the coil parts adjacent to each other in the first direction are opposite to each other.

4. The coil array according to claim 1 , wherein the 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 component includes a substrate extending in a direction perpendicular to the mounting surface, The coil array according to claim 1 , wherein the mounting surface has a protrusion and a recess, and a part of the substrate is exposed from the mounting surface at the protrusion.

6. The coil array according to claim 1 , further comprising a magnetic sheet interposed between adjacent ones of the coil components in the first direction.

7. The coil array according to claim 1 , further comprising a metal plate integrally covering external terminals of the plurality of coil components.

8. The coil array according to claim 7 , wherein an end of said metal plate is recessed from an edge of said external terminal on a mounting surface side of said element body.

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