Coil device

Abstract

To provide a coil device capable of sufficiently securing mounting strength to a mounting substrate.SOLUTION: A coil device 10 includes a pair of first core 20a and second core 20b, a third core 20c disposed adjacent to the first core 20a or the second core 20b, and a pair of a first coil 30 and a second coil 40 each disposed between any two cores of the first core 20a, the second core 20b, and the third core 20c adjacent to each other. Each surface of the first coil 30 and the second coil 40 are opposed to each other. A part of each of the first coil 30 and the second coil 40 is exposed in a lateral direction of the first core 20a, the second core 20b, or the third core 20c.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to a coil device used as an inductor or the like. [Background technology]

[0002] As a coil device used as an inductor or the like, for example, the coil device described in Patent Document 1 is known. The coil device described in Patent Document 1 has a pair of a first core and a second core, and a third core arranged between the first core and the second core with a gap therebetween. A first coil is arranged between the first core and the third core, and a second coil is arranged between the second core and the third core. By forming a gap between the first core and the third core and between the second core and the third core, it is possible to reduce magnetic coupling between the first coil and the second coil.

[0003] However, in the coil device described in Patent Document 1, it is difficult to mount the respective mounting portions of the first coil and the second coil on the mounting board with sufficient mounting strength. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2017 / 0178794 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coil device capable of ensuring sufficient mounting strength to a mounting board. [Means for solving the problem]

[0006] In order to achieve the above object, a coil device according to the present invention comprises: A pair of a first core and a second core; a third core disposed adjacent to the first core or the second core; a pair of a first coil and a second coil respectively disposed between any two of the first core, the second core, and the third core adjacent to each other; The plate surfaces of the first coil and the second coil face each other, A portion of each of the first coil and the second coil is exposed to a side of the first core, the second core, or the third core.

[0007] In the coil device according to the present invention, a portion of each of the first coil and the second coil is exposed to the side of the first core, the second core, or the third core. Therefore, when mounting the coil device, it is possible to form a solder fillet on the portion of the first coil exposed to the side of any of the cores and the portion of the second coil exposed to the side of any of the cores, and the mounting strength to the mounting board can be reinforced via this solder fillet. Therefore, according to the coil device according to the present invention, it is possible to realize a coil device that can sufficiently ensure mounting strength to the mounting board.

[0008] In the coil device according to the present invention, the plate surfaces of the first coil and the second coil face each other. Therefore, the first coil is disposed between adjacent cores with its plate surface facing in a direction perpendicular to the mounting board, and the second coil is disposed between adjacent cores with its plate surface facing in a direction perpendicular to the mounting board. This makes it possible to reduce the thickness of the coil device along the arrangement direction of the first core, the second core, and the third core, and thus to miniaturize the coil device.

[0009] Preferably, the first coil has a pair of plate-shaped first side parts and a plate-shaped first connection part connecting each of the pair of first side parts, and the second coil has a pair of plate-shaped second side parts and a plate-shaped second connection part connecting each of the pair of second side parts. With this configuration, the first coil and the second coil can be easily arranged between adjacent cores, and the coil device can be easily manufactured. Furthermore, by configuring the first coil and the second coil in a plate shape, the thickness of the coil device along the arrangement direction of the first core, the second core, and the third core can be reduced, and the coil device can be effectively miniaturized. Furthermore, a large current can be passed through the first coil and the second coil compared to when the first coil and the second coil are configured with wire.

[0010] Preferably, each of the first connection portion and the second connection portion is disposed between any two of the adjacent first core, second core, and third core. With this configuration, the plate surfaces of the first connection portion and the second connection portion are disposed opposite each other. Therefore, it is possible to reduce the thickness of the coil device along the arrangement direction of the first core, second core, and third core, and the coil device can be effectively miniaturized.

[0011] Preferably, the first side portion and the second side portion face a side surface of any one of the first core, the second core, and the third core, respectively. With this configuration, the first side portion and the second side portion can be exposed over a wide range to the side of any one of the first core, the second core, and the third core, respectively. Therefore, it is possible to sufficiently form solder fillets on the first side portion and the second side portion, and the mounting strength to the mounting board can be effectively reinforced via the solder fillets.

[0012] Preferably, the first side portion and the second side portion face side surfaces of any two of the first core, the second core, and the third core, respectively. With this configuration, when the coils and cores are combined during the manufacture of the coil device, the first side portion can fix the sides of any two of the cores, and the second side portion can fix the sides of any two of the cores. Therefore, the first side portion and the second side portion can prevent the cores from being misaligned.

[0013] Preferably, the first side portion and the second side portion each extend from a side surface to a bottom surface of any one of the first core, the second core, and the third core. With this configuration, a part of the first side portion extending to the bottom surface of any one of the cores can be connected to a mounting board as a mounting surface, and a part of the second side portion extending to the bottom surface of any one of the cores can be connected to a mounting board as a mounting surface.

[0014] Preferably, the first side portion and the second side portion extend from a side surface to an upper surface of any one of the first core, the second core, and the third core. With this configuration, it is possible to form a mounting surface not only on the bottom surface side but also on the top surface side of the coil device. Therefore, when mounting the coil device, even if the coil device is upside down (top surface side and bottom surface side), it can be mounted on a mounting board, making it easy to mount the coil device.

[0015] Preferably, the first side portion and the second side portion extend from a side surface to an end surface of any one of the first core, the second core, and the third core. With this configuration, it is possible to form a solder fillet on a part of the first side portion located on the end surface side of any one of the cores, and to form a solder fillet on a part of the second side portion located on the end surface side of any one of the cores, and the mounting strength to the mounting board can be reinforced via this solder fillet.

[0016] Preferably, the first core, the second core, and the third core are formed so as to be elongated in a direction perpendicular to the surface of the mounting board. With this configuration, it is possible to reduce the width of the coil device relative to its height, and thus it is possible to mount a plurality of coil devices on the mounting board at high density.

[0017] Preferably, the first core is formed with a first recess through which the first coil passes, and the second core is formed with a second recess through which the second coil passes, and the first recess or the second recess is formed offset from the bottom surface side or the top surface side of the first core or the second core. With this configuration, it is possible to change the magnetic path of the first coil or the second coil, and to adjust the magnetic characteristics of the coil device.

[0018] Preferably, there are n more cores corresponding to the first core or the second core. By adding n more first cores or second cores and correspondingly adding n more coils corresponding to the first coil or the second coil, it is possible to realize a coil device having, for example, a high inductance value. In addition, by arranging these coils so as to be sandwiched between these cores, it is possible to make the coil device more compact (space-saving) even if the number of cores and coils is increased.

[0019] Preferably, any one of the first core, the second core, and the third core is a split core. With this configuration, when the split cores are combined, a gap can be formed between the split cores, and the magnetic coupling between the first coil and the second coil can be adjusted.

[0020] Preferably, the first core and the second core are each made of a magnetic material, and the third core is made of a non-magnetic material. By making only the third core out of a non-magnetic material in this manner, for example, it becomes possible to adjust the inductance value of the coil device to a desired value.

[0021] Preferably, the third core is disposed between the first core and the second core, the first coil is disposed between the first core and the third core, the second coil is disposed between the second core and the third core, the plate surfaces of the first coil and the second coil face each other across the third core, a part of the first coil is exposed on a side of the first core, and a part of the second coil is exposed on a side of the second core. With such a configuration, a coil device having symmetry with respect to the third core can be obtained, and a coil device having good magnetic properties can be realized. [Brief description of the drawings]

[0022] [Figure 1A] FIG. 1A is a perspective view of a coil device according to a first embodiment of the present invention. [Figure 1B] FIG. 1B is a bottom view of the coil device shown in FIG. 1A. [Figure 1C] FIG. 1C is a perspective view showing a modification of the coil device shown in FIG. 1A. [Diagram 2] FIG. 2 is an exploded perspective view of the coil device shown in FIG. 1A. [Figure 3A] FIG. 3A is a perspective view of a coil device according to a second embodiment of the present invention. [Figure 3B] FIG. 3B is a perspective view showing a modification of the coil device shown in FIG. 3A. [Figure 4] FIG. 4 is an exploded perspective view of the coil device shown in FIG. 3A. [Figure 5A] FIG. 5A is a perspective view of a coil device according to a third embodiment of the present invention. [Figure 5B] FIG. 5B is a perspective view showing a modification of the coil device shown in FIG. 5A. [Figure 6] FIG. 6 is an exploded perspective view of the coil device shown in FIG. 5A. [Figure 7] FIG. 7 is a perspective view of a coil device according to a fourth embodiment of the present invention. [Figure 8]FIG. 8 is an exploded perspective view of the coil device shown in FIG. [Figure 9] FIG. 9 is a perspective view of a coil device according to a fifth embodiment of the present invention. [Figure 10] FIG. 10 is an exploded perspective view of the coil of the coil device shown in FIG. [Figure 11] FIG. 11 is a perspective view of a coil device according to the sixth embodiment of the present invention. [Figure 12] FIG. 12 is a perspective view of a coil device according to the seventh embodiment of the present invention. [Figure 13] FIG. 13 is a perspective view of a coil device according to an eighth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, the present invention will be described based on the embodiments shown in the drawings.

[0024] First embodiment As shown in Fig. 1A, the coil device 10 has a core 20 having an overall substantially rectangular parallelepiped outer shape, and a pair of a first coil 30 and a second coil 40, at least a portion of which is disposed inside the core 20. The coil device 10 is, for example, an inductor, and has an array structure in which the coils 30, 40 are disposed along the X-axis direction together with cores 20a, 20b, 20c described below. The size of the coil device 10 is not particularly limited, but the length along each of the X-axis, Y-axis, and Z-axis directions can be appropriately determined within a range of 3 to 20 mm, for example.

[0025] The core 20 is composed of a pair of first cores 20a and second cores 20b, and a third core 20c arranged adjacent to the first cores 20a and second cores 20b in the X-axis direction. The core 20 is made of a magnetic material, for example, a magnetic powder composed of a magnetic material with a relatively high magnetic permeability, such as Ni-Zn ferrite, Mn-Zn ferrite, or a metal magnetic material, which is produced by molding and sintering. Note that the core 20c may be made of a non-magnetic material, or may be a compacted powder molding containing magnetic powder in resin. Also, the magnetic permeabilities of the cores 20a, 20b, and 20c may be different from each other.

[0026] The first core 20a and the second core 20b have mutually corresponding (symmetrical) shapes. In the illustrated example, the shape of the first core 20a and the shape of the second core 20b are the same. As shown in FIG. 2, the cores 20a and 20b have a substantially rectangular parallelepiped shape that is long in the Z-axis direction (the height direction of the coil device 10 or the direction perpendicular to the substrate surface of the mounting substrate), and are composed of C-shaped or U-shaped cores. The cores 20a and 20b have a first outer leg portion 21, a second outer leg portion 22, and a recess 23.

[0027] The first outer leg portion 21 is formed at the upper end portion of the cores 20a and 20b in the Z-axis direction, and the second outer leg portion 22 is formed at the lower end portion of the cores 20a and 20b in the Z-axis direction. The length Z1 of the first outer leg portion 21 in the Z-axis direction and the length Z2 of the second outer leg portion 22 in the Z-axis direction are equal, but Z2>Z1 may also be possible. In this case, the recess 23 can be formed with a displacement on the upper surface side of the cores 20a and 20b, and magnetic saturation of the coil device 10 can be effectively prevented. Also, Z2<Z1 may be possible. In this case, since the recess 23 can be formed with a displacement on the bottom surface side of the cores 20a and 20b, the length of the coil 30 (particularly, the length along the Z-axis direction of the first side portions 31a and 31b described later) becomes shorter, and the DC resistance of the coil 30 can be reduced accordingly. The outer leg portions 21 and 22 of the first core 20a protrude to one side in the X-axis direction, respectively, and the outer leg portions 21 and 22 of the second core 20b protrude to the other side in the X-axis direction, respectively.

[0028] The recess 23 is formed between the first outer leg 21 and the second outer leg 22. The width of the recess 23 in the Z-axis direction is approximately equal to or larger than the width of the connection parts 34, 44 of the coils 30, 40 described later. The depth of the recess 23 in the X-axis direction is approximately equal to or larger than the thickness (plate thickness) of the coils 30, 40 described later. As shown in FIG. 1A and FIG. 2, the ratio W2 / W1 of the width W2 in the X-axis direction of the third core 20c to the width W1 in the X-axis direction of the first core 20a at the position of the recess 23 is preferably 0.5 to 1, and more preferably 1. The cross-sectional area of ​​the first core 20a when cut in a plane perpendicular to the Z-axis at the position of the recess 23 is smaller than the cross-sectional area of ​​the first core 20a when cut in a plane perpendicular to the Z-axis at the other positions.

[0029] The first core 20a and the third core 20c are combined by joining at least one of the outer legs 21, 22 of the first core 20a to the other end face (surface) of the third core 20c in the X-axis direction with a bonding material such as an adhesive. The second core 20b and the third core 20c are combined by joining at least one of the outer legs 21, 22 of the second core 20b to one end face of the third core 420c in the X-axis direction with a bonding material such as an adhesive.

[0030] For example, by using Micropearl (Sekisui Chemical Co., Ltd.) or a resin containing resin beads as an adhesive, a first gap portion 51 (see FIG. 1A) described later can be easily formed between the first core 20a and the third core 20c, and a second gap portion 52 (see FIG. 1A) described later can be easily formed between the second core 20b and the third core 20c.

[0031] In a state where the cores 20a, 20b, and 20c are combined, a first gap 51 is formed along the Z-axis direction between the outer legs 21 and 22 of the first core 20a and an end face of the third core 20c, and a second gap 52 is formed along the Z-axis direction between the outer legs 21 and 22 of the second core 20b and an end face of the third core 20c. The width G1 in the X-axis direction of the first gap 51 and the width G2 in the X-axis direction of the second gap 52 are preferably 0.03 to 0.3 mm. The values ​​of the widths G1 and G2 may be different from each other.

[0032] A first gap portion 51 is formed between the first core 20a and the third core 20c, and a second gap portion 52 is formed between the second core 20b and the third core 20c, thereby making it possible to effectively prevent magnetic coupling between the first coil 30 and the second coil 40.

[0033] 2, the recess 23 is formed at approximately the center in the Z-axis direction of the cores 20a and 20b. The connection portion 34 of the first coil 30 can be inserted (passed) through the recess 23 of the first core 20a, and the connection portion 44 of the second coil 40 can be inserted (passed) through the recess 23 of the second core 20b.

[0034] The third core 20c has a rectangular parallelepiped shape that is long in the Z-axis direction, and is composed of an I-shaped (flat) core. The third core 20c is disposed so as to be sandwiched between the first core 20a and the second core 20b along the X-axis direction. With the third core 20c in between, the second coil 40 is disposed on one side in the X-axis direction, the second core 20b is disposed further outside thereof, and the first coil 30 is disposed on the other side in the X-axis direction, and the first core 20a is disposed further outside thereof.

[0035] The first coil 30 and the second coil 40 have corresponding (symmetrical) shapes, and in the illustrated example, the first coil 30 and the second coil 40 have the same shape. The second coil 40 is disposed in a direction rotated 180 degrees from the first coil 30 with the Z axis as the central axis.

[0036] The material of the coils 30, 40 may be, for example, a good conductor such as copper, copper alloy, silver, or nickel, but is not limited to any particular conductor material. The coils 30, 40 are formed, for example, by machining a metal plate (conductor plate). However, the method of forming the coils 30, 40 is not limited to this. In the illustrated example, the coils 30, 40 have a generally U-shape, and the width of the coils 30, 40 in the Y-axis direction is greater than the length of the coils 30, 40 in the X-axis direction and is smaller than the height of the coils 30, 40 in the Z-axis direction. That is, the coils 30, 40 have a shape that is long in the Z-axis direction.

[0037] At least a portion of the first coil 30 is disposed between the adjacent first core 20a and third core 20c, and at least a portion of the second coil 40 is disposed between the adjacent second core 20b and third core 20c. The first coil 30 has a pair of first side portions 31a, 31b, a pair of first recesses 33a, 33b, and a first connection portion 34.

[0038] The first side portions 31a and 31b are formed in a plate shape (flat plate shape) parallel to the XZ plane and have a long shape in the Z-axis direction. The first side portions 31a and 31b extend downward in the Z-axis direction from the position of the first connection portion 34. The first side portions 31a and 31b face each other at a predetermined interval in the Y-axis direction. The interval between the first side portions 31a and 31b is approximately equal to or larger than the width of the core 20 in the Y-axis direction. A gap may be formed between the first side portions 31a and 31b and the side surface of the core 20 (side surface in the Y-axis direction), or the side surface of the core 20 may be sandwiched between the first side portions 31a and 31b.

[0039] The first side parts 31a, 31b have first mounting parts 32a, 32b and first lateral protrusions 35a, 35b. The first lateral protrusions 35a, 35b are formed in a plate shape (flat plate shape) parallel to the XZ plane, and extend along the Z axis direction from approximately the center to the lower end of the first side parts 31a, 31b in the Z axis direction. The first lateral protrusions 35a, 35b protrude farther (to one side in the X axis direction) than the first connection part 34 along the X axis direction. The first lateral protrusions 35a, 35b correspond to a portion protruding to one side in the X axis direction from the bottom (bottom surface) of the first recesses 33a, 33b described later. The portion of the first side parts 31a, 31b excluding the first lateral protrusions 35a, 35b becomes the main body part of the first side parts 31a, 31b.

[0040] 1A, the first lateral protrusions 35a, 35b (however, the first lateral protrusion 35a is omitted from the drawing) are disposed at the lower end portions of the first core 20a and the third core 20c in the Z axis direction so as to straddle the respective side surfaces of the cores 20a, 20c in the X axis direction. That is, at least a portion of the lower end portions of the respective side surfaces of the cores 20a, 20c is covered by the first lateral protrusions 35a, 35b.

[0041] A gap is formed between the end portions of the first side portions 31a, 31b on the other side (positive side) in the X-axis direction and the end face of the first core 20a on the other side in the X-axis direction. That is, the first side portions 31a, 31b do not extend to the end face of the first core 20a on the other side in the X-axis direction, but only extend to a position inside the end face.

[0042] In this embodiment, a part of the first coil 30 (first side parts 31a, 31b) is exposed (arranged) on the side (outside) of the first core 20a and the third core 20c in the Y-axis direction. In addition, the first side parts 31a, 31b (including the first side protrusions 35a, 35b) face the side surfaces of the first core 20a and the third core 20c. As a result, the first core 20a and the third core 20c are arranged to be sandwiched in the Y-axis direction by the first side parts 31a, 31b (including the first side protrusions 35a, 35b) exposed on the side in the Y-axis direction.

[0043] As shown in FIG. 2, the first mounting parts 32a and 32b are formed in a plate shape (flat shape) parallel to the XY plane and have a shape elongated in the X-axis direction (length direction of the coil device 10). The first mounting parts 32a and 32b are formed, for example, by bending the first side parts 31a and 31b at a substantially right angle from the Z-axis direction toward the Y-axis direction. As shown in FIG. 1A, a gap is formed in the Z-axis direction between the first mounting parts 32a and 32b and the core 20. In this embodiment, the first side parts 31a and 31b extend from the side surfaces to the bottom surfaces of the first core 20a and the third core 20c via the first mounting parts 32a and 32b.

[0044] 1B, the first mounting portions 32a and 32b extend toward each other in the Y-axis direction on the bottom surface side of the core 20. The first mounting portions 32a and 32b are disposed so as to straddle the bottom surfaces of the cores 20a and 20c in the X-axis direction.

[0045] A gap is formed between the end portions of the first mounting portions 32a and 32b on the positive side in the X-axis direction and the end face of the first core 20a on the positive side in the X-axis direction. That is, the first mounting portions 32a and 32b do not extend to the end face of the first core 20a on the positive side in the X-axis direction, but only extend to a position inside the end face.

[0046] The first mounting portions 32a, 32b are connected to a land pattern of a mounting board by a bonding material such as solder or a conductive adhesive, and the coil device 10 can be connected to the mounting board via the first mounting portions 32a, 32b. At this time, solder fillets can be formed on the outer surfaces of the first side portions 31a, 31b in the Y-axis direction.

[0047] As shown in FIG. 2, the first connection portion 34 is formed of a plate (flat plate shape) parallel to the YZ plane and has a shape elongated in the Y-axis direction (width direction of the coil device 10). The first connection portion 34 is arranged in a direction facing each of the surfaces (flat plate surfaces) of the first core 20a and the third core 20c. The first connection portion 34 connects each of the pair of first side portions 31a, 31b near the upper end located on one side in the X-axis direction of each of the first side portions 31a, 31b. The first connection portion 34 and the pair of first side portions 31a, 31b intersect at approximately a right angle. The first connection portion 34 is arranged between each of the adjacent first cores 20a and third cores 20c.

[0048] The first recesses 33a, 33b are formed at approximately the center in the Z-axis direction on one end side of the first side portions 31a, 31b in the X-axis direction. The first recesses 33a, 33b have a shape recessed toward the other side in the X-axis direction, and the first recesses 33a, 33b locally reduce the width of the first side portions 31a, 31b in the X-axis direction. As shown in FIG. 1A, at the position where the first recesses 33a, 33b (however, the first recess 33a is not shown) are formed, the side surface in the Y-axis direction of the first core 20a is locally exposed.

[0049] 2, the second coil 40 has a pair of plate-shaped second side portions 41a, 41b, a pair of second recesses 43a, 43b, and a plate-shaped second connection portion 44 connecting the pair of second side portions 41a, 41b. The second side portions 41a, 41b have second lateral protrusions 45a, 45b and second mounting portions 42a, 42b. The configurations of the above-mentioned parts of the second coil 40 are similar to the configurations of the above-mentioned parts of the first coil 30 described above, and therefore detailed descriptions of overlapping parts will be omitted.

[0050] 1A, the second lateral protrusions 45a, 45b (however, the second lateral protrusion 45b is omitted from the drawing) are disposed at the lower end portions in the Z-axis direction of the second core 20b and the third core 20c so as to straddle the side surfaces of the cores 20b, 20c in the X-axis direction. That is, at least a portion of the side surfaces of the cores 20b, 20c is covered at the lower end portions by the second lateral protrusions 45a, 45b.

[0051] Although detailed illustration is omitted, a gap is formed between the end of one side (negative side) in the X-axis direction of the second side portions 41a, 41b and the end face of one side in the X-axis direction of the second core 20b. That is, the second side portions 41a, 41b do not extend to the end face of one side in the X-axis direction of the second core 20b, but only extend to a position inside the end face.

[0052] In this embodiment, a part of the second coil 40 (second side parts 41a, 41b) is exposed (arranged) on the side (outside) of the second core 20b and the third core 20c in the Y-axis direction. In addition, the second side parts 41a, 41b (including the second side protrusions 45a, 45b) face the side surfaces of the second core 20b and the third core 20c. As a result, the second core 20b and the third core 20c are arranged to be sandwiched in the Y-axis direction by the second side parts 41a, 41b (including the second side protrusions 45a, 45b) exposed on the side in the Y-axis direction.

[0053] 1B, the second mounting parts 42a, 42b are disposed so as to straddle the bottom surfaces of the cores 20b, 20c in the X-axis direction. A gap is formed between the end portions of the second mounting parts 42a, 42b on the negative side in the X-axis direction and the end face of the second core 20b on the negative side in the X-axis direction. That is, the second mounting parts 42a, 42b do not extend to the end face of the second core 20b on the negative side in the X-axis direction, but only extend to a position inside the end face.

[0054] 1A, in this embodiment, the second lateral portions 41a, 41b extend from the side surfaces to the bottom surfaces of the second core 20b and the third core 20c via the second mounting portions 42a, 42b. The second connection portion 44 is disposed between the adjacent second core 20b and the third core 20c, and is oriented to face the surfaces (flat surfaces) of the second core 20b and the third core 20c.

[0055] The plate surfaces of the first core 30 and the second coil 40 face each other in the X-axis direction. More specifically, as shown in FIG. 2, the first connection portion 34 of the first coil 30 faces the second connection portion 44 of the second coil 40 in the X-axis direction, with the third core 20c sandwiched therebetween. The first connection portion 34 is disposed between the first core 20a and the third core 20c that are adjacent to each other, and the second connection portion 44 is disposed between the second core 20b and the third core 20c that are adjacent to each other. As shown in FIG. 1A and FIG. 2, the distance between the first connection portion 34 and the second connection portion 44 along the X-axis direction is approximately equal to or greater than the length of the third core 20c in the X-axis direction.

[0056] 1A, the first lateral protrusion 35b (35a) and the second lateral protrusion 45a (45b) are disposed with a gap therebetween in the X-axis direction. The ratio W3 / W2 of the distance W3 in the X-axis direction between the first lateral protrusion 35b (35a) and the second lateral protrusion 45a (45b) to the width W2 in the X-axis direction of the third core 20c is preferably 0.1 to 0.8, and more preferably 0.3 to 0.5.

[0057] In manufacturing the coil device 10, the cores 20a, 20b, and 20c, the first coil 30, and the second coil 40 shown in FIG. 1A are prepared. Next, the cores 20a, 20b, and 20c are assembled while the coils 30 and 40 are disposed inside. At this time, as shown in FIG. 2, the first coil 30 is sandwiched between the first core 20a and the third core 20c so that the first connection portion 34 is inserted into the inside of the recess 23 of the first core 20a. Also, the second coil 40 is sandwiched between the second core 20b and the third core 20c so that the second connection portion 44 is inserted into the inside of the recess 23 of the second core 20b. Also, the coils 30 and 40 may be fixed to the cores 20a, 20b, and 20c with an adhesive or the like.

[0058] Next, the first outer leg 21 and / or the second outer leg 22 of the first core 20a are joined to the flat surface on the other side in the X-axis direction of the third core 20c with an adhesive or the like, and the first outer leg 21 and / or the second outer leg 22 of the second core 20b are joined to the flat surface on one side in the X-axis direction of the third core 20c with an adhesive or the like, thereby obtaining the coil device 10 shown in FIG. 1A.

[0059] In the coil device 10 of this embodiment, a part (first side parts 31a, 31b) of the first coil 30 is exposed to the side of the cores 20a, 20c, and a part (second side parts 41a, 41b) of the second coil 40 is exposed to the side of the cores 20b, 20c. Therefore, when mounting the coil device 10, it is possible to form a solder fillet on the first side parts 31a, 31b exposed to the side of the cores 20a, 20c and the second side parts 41a, 41b exposed to the side of the cores 20b, 20c, and the mounting strength to the mounting board can be reinforced through this solder fillet. Therefore, according to the coil device 10 of this embodiment, it is possible to realize a coil device 10 that can sufficiently ensure the mounting strength to the mounting board.

[0060] In the coil device 10 of this embodiment, the plate surfaces of the first coil 30 (first connection portion 34) and the second coil 40 (second connection portion 44) face each other. Therefore, the first coil 30 is disposed between the adjacent cores 20a and 20c with its plate surface facing in a direction perpendicular to the mounting board, and the second coil 40 is disposed between the adjacent cores 20b and 20c with its plate surface facing in a direction perpendicular to the mounting board. This makes it possible to reduce the thickness of the coil device 10 along the arrangement direction of the first core 20a, the second core 20b, and the third core 20c, and thus makes it possible to miniaturize the coil device 10.

[0061] In this embodiment, the first coil 30 has a pair of first side parts 31a, 31b and a first connection part 34, and the second coil 40 has a pair of second side parts 41a, 41b and a second connection part 44. Therefore, the first coil 30 can be easily arranged between the adjacent cores 20a, 20c, and the second coil 40 can be easily arranged between the adjacent cores 20b, 20c, making it easier to manufacture the coil device 10. Furthermore, by configuring the first coil 30 and the second coil 40 in a plate shape, it is possible to reduce the thickness of the coil device 10 along the arrangement direction of the first core 20a, the second core 20b, and the third core 20c, and the coil device 10 can be effectively miniaturized. Furthermore, a large current can be passed through the first coil 30 and the second coil 40 compared to when the first coil 30 and the second coil 40 are configured with wires.

[0062] In this embodiment, the first connection portion 34 is disposed between the adjacent first core 20a and the adjacent third core 20c, and the second connection portion 44 is disposed between the adjacent second core 20b and the adjacent third core 20c. Therefore, the plate surfaces of the first connection portion 34 and the second connection portion 44 are disposed opposite each other. As a result, it is possible to reduce the thickness of the coil device 10 along the arrangement direction of the first core 20a, the second core 20b, and the third core 20c, and the coil device 10 can be effectively miniaturized.

[0063] In this embodiment, the first side portions 31a, 31b face the side surfaces of the first core 20a and the third core 20c, and the second side portions 41a, 41b face the side surfaces of the second core 20b and the third core 20c. Therefore, the first side portions 31a, 31b can be exposed over a wide range to the sides of the first core 20a and the third core 20c, and the second side portions 41a, 41b can be exposed over a wide range to the sides of the second core 20b and the third core 20c. Therefore, it is possible to sufficiently form solder fillets on the first side portions 31a, 31b and the second side portions 41a, 41b, and the mounting strength to the mounting board can be effectively reinforced via the solder fillets.

[0064] Furthermore, when the coils 30, 40 and the cores 20a, 20b, 20c are combined during the manufacture of the coil device 10, the first side portions 31a, 31b can fix the sides of the cores 20a, 20c, and the second side portions 41a, 41b can fix the sides of the cores 20b, 20c. Therefore, the first side portions 31a, 31b and the second side portions 41a, 41b can prevent the cores 20a, 20b, 20c from shifting in position.

[0065] In this embodiment, the first side portions 31a, 31b extend from the side surfaces of the first core 20a and the third core 20c to the bottom surfaces, and the second side portions 41a, 41b extend from the side surfaces of the second core 20b and the third core 20c to the bottom surfaces. Therefore, a part of the first side portions 31a, 31b extending on the bottom surfaces of the cores 20a, 20b (mounting portions 32a, 32b) can be connected to a mounting board as a mounting surface, and a part of the second side portions 41a, 41b extending on the bottom surfaces of the cores 20b, 20c (mounting portions 42a, 42b) can be connected to a mounting board as a mounting surface.

[0066] In this embodiment, the first core 20a, the second core 20b, and the third core 20c are formed to be elongated in a direction perpendicular to the surface of the mounting board, which makes it possible to reduce the width of the coil device 10 relative to its height, and thus allows multiple coil devices 10 to be mounted on the mounting board at high density.

[0067] In this embodiment, the third core 20c is disposed between the first core 20a and the second core 20b, the first coil 30 is disposed between the first core 20a and the third core 20c, and the second coil 40 is disposed between the second core 20b and the third core 20c. The first coil 30 (connection portion 34) and the second coil 40 (connection portion 44) face each other across the third core 20c. A part of the first coil 30 (first side portions 31a, 31b) is exposed to the side of the first core 20a, and a part of the second coil 40 (second side portions 41a, 41b) is exposed to the side of the second core 20b. Therefore, a coil device 10 having symmetry with respect to the third core 20c is obtained, and a coil device 10 having good magnetic properties can be realized.

[0068] Second embodiment The coil device 110 according to the second embodiment of the present invention differs only in the following respects, and the other configurations are the same as those of the first embodiment described above, and similar effects are obtained, so that a description of overlapping parts will be omitted. In addition, in the drawings, members common to the first embodiment are given the same reference numerals.

[0069] As shown in Fig. 3A, the coil device 110 has a first coil 130 and a second coil 140. As shown in Fig. 4, the first coil 130 has first side portions 131a and 131b, and the first side portions 131a and 131b have first lateral protrusions 135a and 135b and first mounting portions 132a and 132b.

[0070] As is clear from comparing Figures 4 and 2, the first lateral protrusions 135a, 135b differ from the first lateral protrusions 35a, 35b in the first embodiment in that the protrusion length to one side in the X-axis direction is smaller.

[0071] More specifically, the protruding length of the first lateral protrusions 135a, 135b from the bottom surfaces of the first recesses 33a, 33b shown in FIG. 4 is approximately half the protruding length of the first lateral protrusions 35a, 35b from the bottom surfaces of the first recesses 33a, 33b shown in FIG. 2, and the first lateral protrusions 135a, 135b protrude toward one side in the X-axis direction to approximately the same position as the connection portion 34.

[0072] 3A and 4, in this embodiment, the first lateral protrusions 135a, 135b are not disposed so as to straddle the side surfaces of the first core 20a and the third core 20c at the lower ends in the Z-axis direction of each of the cores 20a, 20c, but are disposed only on the side surface of the first core 20a. The position of the end of one side in the X-axis direction (the negative X-axis direction side) of the first lateral protrusions 135a, 135b is substantially equal to the position of the end of one side in the X-axis direction of the second outer leg 22.

[0073] The first mounting parts 132a, 132b are different from the first mounting parts 32a, 32b in the first embodiment in that the length in the X-axis direction is shorter. As described above, in this embodiment, the length in the X-axis direction of the first lateral protrusions 135a, 135b to one side in the X-axis direction is reduced, and the length in the X-axis direction of the first lateral parts 131a, 131b is reduced. Therefore, the length in the X-axis direction of the first mounting parts 132a, 132b is shorter than the length in the X-axis direction of the first mounting parts 32a, 32b in the first embodiment.

[0074] The second coil 140 has second side portions 141a, 141b, and the second side portions 141a, 141b have second lateral protrusions 145a, 145b and second mounting portions 142a, 142b. The configurations of the above-mentioned parts in the second side portions 141a, 141b are similar to the configurations of the above-mentioned parts in the first side portions 131a, 131b described above, and therefore detailed descriptions of overlapping parts will be omitted.

[0075] 3A and 4, the second lateral protrusions 145a, 145b are not disposed so as to straddle the side surfaces of the second core 20b and the third core 20c at the lower ends in the Z-axis direction of each of the cores 20b, 20c, but are disposed only on the side surface of the second core 20b. The position of the end of the second lateral protrusions 145a, 145b on the other side in the X-axis direction (the X-axis positive direction side) is substantially the same as the position of the end of the second outer leg 22 on the other side in the X-axis direction.

[0076] The present embodiment also provides the same effects as the first embodiment. In addition, in the present embodiment, the protruding length in the X-axis direction of each of the first lateral protrusions 135a, 135b and the second lateral protrusions 145a, 145b is relatively small. Therefore, the distance in the X-axis direction between the first lateral protrusion 135b (135a) and the second lateral protrusion 145a (145b) is large, and it is possible to prevent the occurrence of a short circuit failure between them.

[0077] Third embodiment The coil device 210 according to the third embodiment of the present invention differs only in the following points, and the other configurations are the same as those of the second embodiment described above, and similar effects are obtained, so that a description of the overlapping parts will be omitted. In the drawings, the same reference numerals are used to designate the same members as those of the second embodiment.

[0078] As shown in Fig. 5A, the coil device 210 has a first coil 230 and a second coil 240. As shown in Fig. 6, the first coil 230 has first side portions 231a and 231b, and the first side portions 231a and 231b have first mounting portions 232a and 232b.

[0079] As is clear from a comparison between Fig. 6 and Fig. 4, the first lateral protrusions 135a, 135b shown in Fig. 4 are omitted from the first lateral portions 231a, 231b shown in Fig. 6, and the first lateral portions 231a, 231b are not provided with a configuration corresponding to the first lateral protrusions 135a, 135b. In addition, due to the omission of the first lateral protrusions 135a, 135b, the first recesses 33a, 33b shown in Fig. 4 are omitted.

[0080] 5A and 6, in this embodiment, the first side portions 235a, 235b, at the lower end portion in the Z axis direction of the first core 20a, extend only to the inside of the position of the end portion on one side in the X axis direction (the negative X axis direction side) of the second outer leg portion 22. The position of the end portion on one side in the X axis direction of the first side portions 231a, 231b is substantially equal to the position of the bottom surface of the recess 23 of the first core 20a, or is located on the other side in the X axis direction.

[0081] 6, the first mounting parts 232a, 232b are different from the first mounting parts 132a, 132b in the second embodiment in that the length in the X-axis direction is further shortened. As described above, in this embodiment, the first lateral protrusions 135a, 135b are omitted, so that the length in the X-axis direction of the first lateral parts 231a, 231b is shortened. Therefore, the length in the X-axis direction of the first mounting parts 232a, 232b is shorter than the length in the X-axis direction of the first mounting parts 132a, 132b in the second embodiment.

[0082] The second coil 240 has second side portions 241a and 241b, and the second side portions 241a and 241b have second mounting portions 242a and 242b. The configurations of the above-mentioned parts in the second side portions 241a and 241b are similar to the configurations of the above-mentioned parts in the first side portions 231a and 231b described above, and therefore detailed descriptions of overlapping parts will be omitted.

[0083] 5A and 6, second side portions 245a, 245b, at the lower end portion in the Z axis direction of second core 20b, extend only to the inside of the position of the end portion on the other side in the X axis direction (the positive X axis direction side) of second outer leg portion 22. The position of the end portion on the other side in the X axis direction of second side portions 241a, 241b is located approximately equal to the position of the bottom surface of recess 23 of second core 20b or is located to one side in the X axis direction.

[0084] The present embodiment also provides the same effects as those of the second embodiment. In addition, in the present embodiment, the first lateral protrusions 135a, 135b and the second lateral protrusions 145a, 145b shown in Fig. 4 are omitted, so that the occurrence of short circuit defects can be more effectively prevented than in the coil device 110 of the second embodiment.

[0085] Fourth embodiment The coil device 310 according to the fourth embodiment of the present invention differs only in the following points, and the other configurations are the same as those of the third embodiment described above, and similar effects are obtained, so that a description of overlapping parts will be omitted. In addition, in the drawings, members common to the third embodiment are given the same reference numerals.

[0086] As shown in Fig. 7, coil device 310 has first coil 330 and second coil 340. As shown in Fig. 8, first coil 330 has first side portions 331a, 331b, and second coil 340 has second side portions 341a, 341b. The configurations of second side portions 341a, 341b are similar to the configurations of the above-mentioned portions in first side portions 331a, 331b, and therefore detailed description of overlapping portions will be omitted.

[0087] As is clear from comparing Figures 8 and 6, the first side portions 331a, 331b differ from the first side portions 231a, 231b in the third embodiment in that they extend not only downward in the Z-axis direction but also upward in the Z-axis direction.

[0088] Of the first side portions 331a and 331b, a portion located below the Z-axis direction and a portion located above the Z-axis direction across the connection portion 34 have the same shape. Therefore, the overall shape of the coil device 310 remains the same even if it is turned upside down from the state shown in FIG.

[0089] In addition, among the first side portions 331a, 331b, a portion located below the Z-axis direction across the connection portion 34 and a portion located above the Z-axis direction have the same function. Therefore, it is possible to form a solder fillet in the portion located above the Z-axis direction across the connection portion 34 among the first side portions 331a, 331b. In addition, the first mounting portions 232a, 232b formed in the same portions function as a connection surface with the mounting board, and it is possible to connect the coil device 310 to the mounting board via the first mounting portions 232a, 232b formed in the same portions.

[0090] The present embodiment also provides the same effects as the third embodiment. In addition, in the present embodiment, the first side parts 331a and 331b extend from the side surface to the top surface of the first core 20a, and the second side parts 341a and 341b extend from the side surface to the top surface of the second core 20b. Therefore, it is possible to form a mounting surface not only on the bottom surface side but also on the top surface side of the coil device 310. Therefore, when mounting the coil device 310, even if the coil device 310 is upside down (upper surface side and bottom surface side), it can be mounted on a mounting board, making it easy to mount the coil device 310.

[0091] Fifth embodiment The coil device 410 according to the fifth embodiment of the present invention differs only in the following points, and the other configurations are the same as those of the third embodiment described above, and similar effects are obtained, so that a description of the overlapping parts will be omitted. In the drawings, the same reference numerals are used to designate the same members as those of the third embodiment.

[0092] As shown in Fig. 9, the coil device 410 has a first coil 430 and a second coil 440. As shown in Fig. 10, the first coil 430 has first side portions 431a and 431b, and the second coil 440 has second side portions 441a and 441b. The configurations of the second side portions 441a and 441b are similar to the configurations of the above-mentioned parts in the first side portions 431a and 431b, so detailed description of overlapping parts will be omitted.

[0093] As is clear from comparing Fig. 10 with Fig. 6, the first side portions 431a, 431b are different from the first side portions 231a, 231b in the third embodiment in that they have first outer ends 36a, 36b but do not have first mounting portions 232a, 232b. The second side portions 441a, 441b are different from the second side portions 241a, 241b in the third embodiment in that they have second outer ends 46a, 46b but do not have second mounting portions 242a, 242b.

[0094] The first outer ends 36a, 36b are formed in a plate shape (flat plate shape) parallel to the YZ plane and have a shape elongated in the Z axis direction. The first outer ends 36a, 36b extend downward in the Z axis direction and are connected to the other ends of the first side portions 431a, 431b (main body portions of the first side portions 431a, 431b) in the X axis direction.

[0095] 9, the first outer ends 36a, 36b extend substantially parallel to an end face on the other side in the X-axis direction of the first core 20a, and the first outer ends 36a, 36b and the end face on the other side in the X-axis direction of the first core 20a face each other along the X-axis direction. The second outer ends 46a, 46b extend substantially parallel to an end face on one side in the X-axis direction of the second core 20c, and the second outer ends 46a, 46b and the end face on one side in the X-axis direction of the second core 20c face each other along the X-axis direction.

[0096] A gap may be formed between the first outer ends 36a, 36b and the end face on the other side in the X-axis direction of the first core 20a, or the first outer ends 36a, 36b may abut on the end face. Also, a gap may be formed between the second outer ends 46a, 46b and the end face on one side in the X-axis direction of the second core 20b, or the second outer ends 46a, 46b may abut on the end face.

[0097] In this embodiment, the same effect as in the third embodiment can be obtained. In addition, in this embodiment, the first side parts 431a, 431b extend from the side surface to the end surface of the first core 20a, and the second side parts 441a, 441b extend from the side surface to the end surface of the second core 20b. Therefore, it is possible to form a solder fillet on a part (first outer end parts 36a, 36b) of the first side parts 431a, 431b located on the end surface side of the first core 20a, and to form a solder fillet on a part (second outer end parts 46a, 46b) of the second side parts 441a, 441b located on the end surface side of the second core 20b, and the mounting strength to the mounting board can be reinforced through this solder fillet.

[0098] Sixth embodiment The coil device 510 according to the sixth embodiment of the present invention differs only in the following points, and other configurations are the same as those of the third embodiment described above, and similar effects are achieved, so that explanations of overlapping parts will be omitted. In addition, in the drawings, members common to the third embodiment are given the same reference numerals.

[0099] As shown in Fig. 11, the coil device 510 has a core 520. As is clear from comparing Fig. 11 with Fig. 5A, in the core 520, the arrangement of the cores 20a, 20b, and 20c is different from the arrangement of the cores 20a, 20b, and 20c in the third embodiment. More specifically, in this embodiment, the third core 20c, the first core 20a, and the second core 20b are arranged in this order toward the negative direction of the X-axis. That is, in this embodiment, of the three cores 20a, 20b, and 20c, the third core 20c is arranged at the end on the positive direction side of the X-axis, and the first core 20a is arranged between the third core 20c and the second core 20b.

[0100] In core 520, the orientation of first core 20a is different from that of first core 20a in the third embodiment. More specifically, first core 20a is arranged so that the protruding direction of outer legs 21, 22 is on the positive side of the X-axis, and the orientation of first core 20a in this embodiment is opposite to that of first core 20a in the third embodiment in the X-axis direction. Therefore, in this embodiment, the orientation of first core 20a and the orientation of second core 20b are the same in the X-axis direction.

[0101] In the coil device 510, the orientation of the first coil 230 is different from that of the first coil 230 in the third embodiment. More specifically, in the third embodiment, the orientation of the first coil 230 is opposite to that of the second coil 230 in the X-axis direction as shown in Fig. 5A, but in this embodiment, the orientation of the first coil 230 is the same as that of the second coil 240 in the X-axis direction as shown in Fig. 11.

[0102] As long as the coils 230 and 240 are disposed inside the core 520 (so as to be sandwiched between any of the cores 20a, 20b, and 20c), the arrangement and orientation of the cores 20a, 20b, and 20c or the orientation of the coils 30 and 40 may be appropriately changed as described above. In this case as well, the same effects as those of the third embodiment can be obtained.

[0103] Seventh embodiment The coil device 610 according to the seventh embodiment of the present invention differs only in the following points, and other configurations are the same as those of the sixth embodiment described above, and similar effects are obtained, so that explanations of overlapping parts will be omitted. In addition, in the drawings, members common to the sixth embodiment are given the same reference numerals.

[0104] As shown in Fig. 12, the coil device 610 has a core 620 and a third coil 60. The core 620 has a fourth core 20d in addition to the first core 20a, the second core 20b, and the third core 20c. The fourth core 20d has a shape corresponding to the first core 20a or the second core 20b, and in the illustrated example, the shape of the fourth core 20d is the same as the shape of the first core 20a or the second core 20b. The fourth core 20d is arranged facing the same direction as the first core 20a and the second core 20b in the X-axis direction.

[0105] The third coil 60 has a shape corresponding to the first coil 30 or the second coil 40, and in the illustrated example, the shape of the third coil 60 is the same as the shape of the first coil 30 or the second coil 40. The third coil 60 is disposed facing in the same direction as the first coil 30 and the second coil 40 in the X-axis direction.

[0106] The present embodiment also provides the same effect as the sixth embodiment. In addition, the present embodiment further includes n cores (fourth core 20d) corresponding to the first core 20a or the second core 20b (one in the illustrated example). By further adding n cores (fourth core 20d) corresponding to the first core 20a or the second core 20b and accordingly adding n coils (third coil 60) corresponding to the first coil 230 or the second coil 240 (one in the illustrated example), it is possible to realize a coil device 610 having, for example, a high inductance value. In addition, by arranging the coils 30, 40, and 60 between the cores 20a, 20b, 20c, and 20d so as to sandwich them, it is possible to make the coil device 610 compact (space-saving) even if the number of cores and coils increases.

[0107] Eighth embodiment The coil device 710 according to the eighth embodiment of the present invention differs only in the following points, and the other configurations are the same as those of the seventh embodiment described above, and similar effects are obtained, so that a description of the overlapping parts will be omitted. In addition, in the drawings, the same reference numerals are used to designate the same members as those of the seventh embodiment.

[0108] The coil device 710 has a core 720. As is clear from comparing Fig. 13 with Fig. 12, the core 720 differs from the core 720 in the seventh embodiment in that the fourth coil 20d, which was disposed adjacent to the second coil 20b, is disposed adjacent to the third core 20c. The fourth core 20d is disposed such that its outer legs 21, 22 face the other end face of the third core 20c in the X-axis direction.

[0109] The third coil 60 is disposed so as to be sandwiched between the third core 20c and the fourth core 20d disposed adjacent to each other. The third coil 60 is disposed in a state facing in the opposite direction to the first coil 30 and the second coil 40 in the X-axis direction. Note that the coil device 710 can also be obtained, for example, by disposing the fourth core 20d adjacent to the second core 20b shown in FIG. 5A, and further disposing the third coil 60 so as to be sandwiched between the second core 20b and the fourth core 20d disposed adjacent to each other.

[0110] As long as the coils 30, 40, 60 are disposed inside the core 20 (so as to be sandwiched between any of the cores 20a, 20b, 20c, 20d), the arrangement and orientation of the cores 20a, 20b, 20c, 20d or the orientation of the coils 30, 40, 60 may be changed as appropriate. In this case as well, the same effects as those of the seventh embodiment can be obtained.

[0111] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

[0112] In the first embodiment, the shapes of the first coil 30 and the second coil 40 may be different from each other. The same applies to the second to eighth embodiments.

[0113] In the first embodiment, the first mounting portions 32a, 32b and the second mounting portions 42a, 42b are not essential and may be omitted as shown in Fig. 1C. In this case, the configuration of the coils 30, 40 can be simplified.

[0114] In the second embodiment, the first mounting portions 132a, 132b and the second mounting portions 142a, 142b are not essential and may be omitted as shown in Fig. 3B. In this case, the configuration of the coils 130, 140 can be simplified.

[0115] In the third embodiment, the first mounting portions 232a, 232b and the second mounting portions 242a, 242b are not essential and may be omitted as shown in Fig. 5B. In this case, the configuration of the coils 230, 240 can be simplified.

[0116] The technique shown in the fourth embodiment may be applied to the coil device 10 in the first embodiment. That is, the first side portions 31a, 31b of the first coil 30 shown in Fig. 1A (similarly to the second side portions 41a, 41b of the second coil 40) may be configured to extend not only downward in the Z-axis direction from the connection portion 34 but also upward in the Z-axis direction. Similarly, the technique shown in the fourth embodiment may be applied to the coil devices in the second to third embodiments and the fifth to eighth embodiments.

[0117] The technique shown in the fifth embodiment may be applied to the coil device 10 in the first embodiment. That is, the first side portions 31a, 31b of the first coil 30 shown in Fig. 1A (similarly to the second side portions 41a, 41b of the second coil 40) may be provided with the first outer ends 36a, 36b shown in Fig. 10. Similarly, the technique shown in the fifth embodiment may be applied to the coil devices in the second, fourth, and sixth to eighth embodiments.

[0118] In the sixth embodiment, the coils 30, 40, etc. in the first, second, fourth, or fifth embodiment may be used. In that case, the size of the coils 30, 40, etc. may be changed as necessary. The same applies to the seventh and eighth embodiments.

[0119] In the seventh embodiment, the coil device 610 includes only one core (fourth core 20d) corresponding to the first core 20a or the second core 20b, but the number of the cores may be two or more. The same applies to the eighth embodiment.

[0120] In the first embodiment, the recess 23 of the first core 20a and / or the recess 23 of the second core 20b may be formed to be misaligned on the bottom or top side of the first core 20a or the second core 20b. With this configuration, it is possible to change the magnetic path of the first coil 30 or the second coil 40, and it is possible to adjust the magnetic characteristics of the coil device 30. The same applies to the second to eighth embodiments.

[0121] In the first embodiment, any of the first core 20a, the second core 20b, and the third core 20c may be configured as a split core. With this configuration, when the split cores are combined, a gap can be formed between the split cores, and the magnetic coupling between the first coil 30 and the second coil 40 can be adjusted. The same applies to the second to eighth embodiments.

[0122] In the first embodiment, the first core 20a and the second core 20b may each be made of a magnetic material, and the third core 20c may be made of a non-magnetic material. By making only the third core 20c of a non-magnetic material in this way, for example, it is possible to adjust the inductance value of the coil device 10 to a desired value. The same applies to the second to eighth embodiments.

[0123] In the first embodiment, the core 20 is configured by combining the first core 20a and the second core 20b each having a U-shape with the third core 20c having an I-shape, but the core 20 may be configured by combining, for example, an H-shape core with two I-shape cores. The same applies to the second to sixth embodiments. Also, the H-shape core may be used in the seventh and eighth embodiments. [Explanation of symbols]

[0124] 10,110,210,310,410,510,610,710...Coil device 20,520,620,720…Core 20a…First core 20b…Second core 20c…3rd Core 20d…4th core 21...First outer leg 22...Second outer leg 23…Recess 30, 130, 230, 330, 430...First coil 31a, 31b, 131a, 131b, 231a, 231b, 331a, 331b, 431a, 431b...first side part 32a, 32b, 132a, 132b, 232a, 232b...First mounting section 33a, 33b...First recess 34…First connection part 35a, 35b, 135a, 135b...first lateral protrusion 36a, 36b...first outer end 40,140,240,340,440…Second coil 41a, 41b, 141a, 141b, 241a, 241b, 341a, 341b, 441a, 441b...Second side part 42a, 42b, 142a, 142b, 242a, 242b...Second mounting section 43a, 43b...Second recess 44…Second connection part 45a, 45b, 145a, 145b...Second lateral protrusion 46a, 46b...Second outer end 51…First gap section 52…Second gap section

Claims

1. A pair of a first core and a second core; a third core disposed adjacent to the first core or the second core; a pair of a first coil and a second coil each disposed between any two of the first core, the second core, and the third core adjacent to each other; The plate surfaces of the first coil and the second coil face each other, The opposing plate surface of the first coil is a first connection portion, the opposing plate surface of the second coil is a second connection portion, a portion of each of the first coil and the second coil is exposed to a side of the first core, the second core, or the third core; a portion of the first coil exposed to the side is a pair of plate-shaped first side portions, and is bent from the first connection portion in a direction away from the third core, The part of the second coil exposed to the side is a pair of plate-shaped second side portions, which are bent from the second connection portion in a direction away from the third core. Coil device.

2. The coil device according to claim 1 , wherein each of the first connection portion and the second connection portion is disposed between any two of the first core, the second core, and the third core that are adjacent to each other.

3. The coil device according to claim 1 , wherein the first side portion and the second side portion face a side surface of any one of the first core, the second core, and the third core, respectively.

4. The coil device according to claim 3 , wherein the first side portion and the second side portion each face a side surface of any two of the first core, the second core, and the third core.

5. The coil device according to any one of claims 2 to 4, wherein the first side portion and the second side portion each extend from a side surface to a bottom surface of any one of the first core, the second core, and the third core.

6. The coil device according to any one of claims 2 to 5, wherein the first side portion and the second side portion each extend from a side surface to an upper surface of any one of the first core, the second core, and the third core.

7. A coil device according to any one of claims 2 to 6, wherein the first side portion and the second side portion each extend from a side surface to an end surface of any one of the first core, the second core, and the third core.

8. 8. The coil device according to claim 1, wherein the first core, the second core and the third core are formed so as to be elongated in a direction perpendicular to a surface of a mounting substrate.

9. The first core has a first recess through which the first coil passes, The second core has a second recess through which the second coil passes, The coil device according to any one of claims 1 to 8, wherein the first recess or the first concave portion is formed offset to a bottom surface side or an upper surface side of the first core or the second core.

10. 10. The coil device according to claim 1, further comprising n cores corresponding to the first core or the second core.

11. The coil device according to any one of claims 1 to 10, wherein any one of the first core, the second core and the third core is made of a split core.

12. the first core and the second core are each made of a magnetic material, The coil device according to any one of claims 1 to 11, wherein the third core is made of a non-magnetic material.

13. the third core is disposed between the first core and the second core, the first coil is disposed between the first core and the third core, the second coil is disposed between the second core and the third core, The plate surfaces of the first coil and the second coil face each other across the third core, The coil device according to any one of claims 1 to 12, wherein a portion of the first coil is exposed to a side of the first core, and a portion of the second coil is exposed to a side of the second core.

Images