Coil device

Abstract

The present invention provides a coil device having a small magnetic coupling between adjacent coils. The coil device (10) comprises a core (20) and a plurality of coils (30) arranged inside the core (20). The interval between the second gap portion (26) of the core (20) located inside the coil (30) is larger than the interval between the first gap portion (25) of the core (20) located between adjacent coils (30).

Description

Technical Field

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

[0002] As a coil device used as an inductor or the like, for example, there is known a coil device described in Patent Document 1. In the coil device described in Patent Document 1, a plurality of coils are arranged inside two sets of cores combined with a gap therebetween.

[0003] However, in the coil device described in Patent Document 1, magnetic coupling between adjacent coils becomes strong, and there is a possibility that the magnetic characteristics of each coil will deteriorate.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 3-35623 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] The present invention has been made in view of such actual circumstances, and an object of the present invention is to provide a coil device in which magnetic coupling between adjacent coils is reduced.

[0009] Technical solutions to solve problems

[0010] In order to achieve the above-mentioned object, the coil device of the present invention has:

[0011] core,

[0012] A plurality of coils are arranged inside the core,

[0013] The intervals of the second gaps of the core located inside the coils are larger than the intervals of the first gaps of the core located between the adjacent coils.

[0014] In the coil device of the present invention, the spacing of the second gap portion of the core located inside the coil is larger than the spacing of the first gap portion of the core located between adjacent coils. Therefore, the magnetic resistance of the second gap portion is greater than the magnetic resistance of the first gap portion. As a result, the magnetic flux generated by a certain coil has difficulty passing through the inside of the coil adjacent to the coil (that is, the portion where the second gap portion with high magnetic resistance is formed), while on the other hand, it is easy to pass between these coils (that is, the portion where the first gap portion with low magnetic resistance is formed). Therefore, it is possible to prevent the magnetic flux generated by a certain coil from passing through the coil adjacent to the coil, and it is possible to reduce the magnetic coupling between adjacent coils.

[0015] Furthermore, by reducing the magnetic coupling between adjacent coils, even if a plurality of coils are arranged close to the core, good magnetic characteristics can be obtained, and the coil device can be effectively made compact.

[0016] Preferably, the first gap extends in a direction connecting adjacent coils, and the second gap extends in a direction connecting the inner circumferences of the coils. With this structure, the majority of the magnetic flux generated by a coil will transversely pass through the first gap formed between the coil and the coil adjacent to it, and also transversely pass through the second gap formed inside the coil, effectively achieving the aforementioned effect.

[0017] Preferably, the core has outer legs formed between adjacent coils and inner legs formed inside the coils, with the first gap formed in the outer legs and the second gap formed in the inner legs. In this case, by allowing the magnetic flux generated by a coil to pass through both the outer legs and the inner legs, sufficient inductance characteristics can be ensured. Furthermore, by allowing the magnetic flux generated by a coil to pass through both the first gap formed in the outer legs and the second gap formed in the inner legs, the aforementioned effects can be achieved.

[0018] Preferably, mounting portions for connecting to an external circuit are formed at both ends of the coil. With such a structure, the coil can be easily connected to the external circuit via the mounting portions.

[0019] A portion of the mounting portion may also be exposed from the side surface in the width direction of the core. By setting such a structure, when the coil device is mounted on an external circuit substrate, solder feet can be formed on the portion of the mounting portion exposed from the side surface of the core, thereby improving the mounting strength of the coil device relative to the external circuit.

[0020] The mounting portion may not be exposed from the side surface in the width direction of the core. In this case, because the structure of the mounting portion is simplified (for example, it is not necessary to have a protrusion protruding from the side surface of the core on the mounting portion), the coil can be easily arranged inside the core, making the manufacture of the coil device easier.

[0021] Preferably, the mounting portion extends in a manner along the arrangement direction of the plurality of coils. By setting such a structure, the balance of the coil device can be fully ensured via the mounting portion of each coil, and the coil device can be stably mounted on the external circuit even when the lateral width of the coil is narrow.

[0022] Preferably, the mounting portion of one adjacent coil and the mounting portion of another adjacent coil extend in substantially the same direction. By setting such a structure, it is possible to ensure that the spacing between the mounting portion of one adjacent coil and the mounting portion of another adjacent coil is sufficiently large, thereby preventing short circuit failures between adjacent coils.

[0023] Preferably, the core has a top plate portion covering the top of the plurality of coils. By setting it as such a structure, the upper surface of the top plate portion can be used as an adsorption surface, which can improve the handling performance of the coil device.

[0024] Preferably, the lateral width of the coil is greater than the length in a direction perpendicular to the height direction of the coil. By setting such a structure, even when multiple coils are arranged inside the core, the length of the core along the arrangement direction of the multiple coils can be shortened, which can achieve miniaturization (thinning) of the coil device.

[0025] The core may also be composed of a first core and a second core, the first core having at least one outer leg and a plurality of inner legs, the second core having at least one outer leg and a plurality of inner legs, the first gap being formed between the first and second cores at the location where the outer legs are formed, and the second gap being formed between the first and second cores at the location where the inner legs are formed. This structure facilitates the formation of the first and second gaps by combining the first and second cores, and the aforementioned effects can be easily achieved.

[0026] The core can also be composed of an E-shaped core and a flat-plate core. This configuration allows the first and second gaps to be formed at the combined positions of the E-shaped core's legs and the flat-plate core's surface. In this case, the aforementioned effects can also be effectively achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1A It is a perspective view of the coil device according to the first embodiment of the present invention.

[0028] Figure 1B Observe from another angle Figure 1A A perspective view of the coil arrangement shown.

[0029] Figure 1C yes Figure 1A Bottom view of the coil assembly shown.

[0030] Figure 2A yes Figure 1A A perspective view of the cores (first core and second core) of the coil device shown.

[0031] Figure 2B yes Figure 2A A perspective view of the core (first core) shown.

[0032] Figure 3A yes Figure 1A A perspective view of the coil of the coil arrangement is shown.

[0033] Figure 3B Yes Figure 3A A perspective view of a modified example of the coil shown.

[0034] Figure 4 Yes Figure 1A A cross-sectional view of the interior of the coil arrangement is shown.

[0035] Figure 5A It is a perspective view of a coil device according to a second embodiment of the present invention.

[0036] Figure 5B Observe from another angle Figure 5A A perspective view of the coil arrangement shown.

[0037] Figure 6 yes Figure 5A A perspective view of a core (first core) of the coil arrangement shown.

[0038] Figure 7 yes Figure 5A A perspective view of the coil of the coil arrangement is shown.

[0039] Figure 8 It is a perspective view of a coil device according to a third embodiment of the present invention.

[0040] Figure 9A yes Figure 8 A perspective view of the coil of the coil arrangement is shown.

[0041] Figure 9B yes Figure 9A A perspective view of a modified example of the coil shown.

[0042] Figure 10A It is a perspective view of a coil device according to a fourth embodiment of the present invention.

[0043] Figure 10B Observe from another angle Figure 10A A perspective view of the coil arrangement shown.

[0044] Figure 11 yes Figure 10A FIG. 1 is a top view of the cores (first core and second core) of the coil device shown. DETAILED DESCRIPTION

[0045] Hereinafter, the present invention will be described based on the embodiments shown in the drawings.

[0046] First embodiment

[0047] like Figure 1A As shown, coil device 10 includes a core 20 having a generally rectangular parallelepiped shape and multiple (six in the illustrated example) coils 30 disposed within core 20. Coil device 10 is, for example, an inductor and comprises an array structure in which multiple coils 30 are arranged along the X-axis. The size of coil device 10 is not particularly limited; for example, the length in each axial direction can be appropriately determined within a range of 3 to 20 mm.

[0048] like Figure 3A As shown, the coil 30 is composed of a conductor plate having a roughly U-shape. As the material of the coil 30, for example, copper and copper alloys, silver, nickel and other metals that are good conductors can be cited. As long as it is a conductor material, there is no particular limitation. The coil 30 can be formed, for example, by mechanically processing a metal plate. However, the method for forming the coil 30 is not limited to this. In the example shown in the figure, the lateral width of the coil 30 in the Y-axis direction is smaller than the length of the coil 30 in the X-axis direction, and smaller than the height of the coil 30 in the Z-axis direction.

[0049] The coil 30 has a first side portion 31, a second side portion 32, an upper portion 33, and a mounting portion 34. The first side portion 31 and the second side portion 32 extend along the Z-axis direction, respectively. The side of the coil 30 where the first side portion 31 is arranged functions as an input terminal (or, an output terminal), and the side where the second side portion 32 is arranged functions as an output terminal (or, an input terminal). Figure 1A In the example shown, the plurality of coils 30 are arranged such that the first side surface 31 is located on the negative side in the X-axis direction and the second side surface 32 is located on the positive side in the X-axis direction. The upper surface 33 extends along the X-axis direction and connects the first side surface 31 and the second side surface 32.

[0050] In this embodiment, if Figure 3A As shown, the lower ends of the first side portion 31 and the second side portion 32 at both ends of the coil 30 are used as mounting portions 34, and the coil 30 can be connected to an external circuit (not shown) of the mounting substrate via the mounting portions 34. Figure 1A As shown, when the coil 30 is arranged inside the core 20 (the assembly of the first core 20a and the second core 20b), as shown in FIG. Figure 4 As shown, the portion protruding outward (downward) in the Z-axis direction from the bottom surface of the first core 20a functions as a mounting portion 34. The coil 30 is connected to an external circuit (not shown) via a connecting member such as solder or a conductive adhesive.

[0051] like Figure 1AAs shown, in this embodiment, the core 20 is composed of a first core 20a and a second core 20b, which are arranged to face each other in the Y-axis direction. The first core 20b has a shape corresponding to the first core 20a (in the illustrated example, the same shape), and the cores 20a and 20b are joined using an adhesive or the like. The core 20 is made of a magnetic material, for example, by molding and sintering a magnetic powder composed of a relatively high magnetic permeability magnetic material such as Ni-Zn ferrite, Mn-Zn ferrite, or a metallic magnetic material.

[0052] like Figure 2B As shown, the first core 20a includes a first base portion 21a, a plurality of (seven in the example shown) first outer legs 22a, a plurality of (six in the example shown) first inner legs 23a, and a plurality of (six in the example shown) first grooves 24a. The first base portion 21a is formed in a substantially flat plate shape (approximately a rectangular parallelepiped shape).

[0053] The first outer leg portion 22a protrudes from the surface of the first base portion 21a on one side in the Y-axis direction to one side in the Y-axis direction by a predetermined length. The first outer leg portion 22a has a shape elongated in the Z-axis direction and extends from the upper end to the lower end of the first base portion 21a in the Z-axis direction. Figure 2B and Figure 4 As shown, the plurality of first outer leg portions 22 a are formed on one surface of the first base portion 21 a in the Y-axis direction at predetermined intervals between adjacent coils 30 along the X-axis direction.

[0054] like Figure 1C As shown, the X-axis width W1 of each of the two first outer legs 22a located at both ends of the first core 20a in the X-axis direction is smaller than the X-axis width W2 of each of the five first outer legs 22a located between the two first outer legs 22a.

[0055] exist Figures 1A to 1C In the case of adjacently arranged coils 30, Figure 3AIn the case where one side of the first side portion 31 is configured as an input terminal (output terminal), and the side where the second side portion 32 is configured as an output terminal (input terminal), the ratio (W2 / W1) of width W2 to width W1 is preferably 1.5 to 2.5, more preferably 1.8 to 2.2, and particularly preferably 2. In this case, the magnetic flux generated by one coil 30 and the magnetic flux generated by the other coil 30 disposed adjacent thereto both pass through the first outer leg 22a defined by width W2 in the same direction. Therefore, by setting the value of W2 / W1 within the above range, the magnetic flux generated by each coil 30 easily passes through the first outer leg 22a defined by width W2, effectively preventing magnetic saturation in the coil device 10.

[0056] Furthermore, when one of the adjacent coils 30 has its side with the first side portion 31 arranged as an input terminal (output terminal) and its side with the second side portion 32 arranged as an output terminal (input terminal), and when the other coil 30 has its side with the first side portion 31 arranged as an output terminal (input terminal) and its side with the second side portion 32 arranged as an input terminal (output terminal), the ratio W2 / W1 of the width W2 to the width W1 is preferably 0.5 to 1.5, more preferably 0.8 to 1.2, and particularly preferably 1. In this case, the magnetic flux generated by the adjacent coil 30 and the magnetic flux generated by the adjacent coil 30 both pass through the first outer leg 22a defined by the width W2 in different directions. Therefore, even if the above-mentioned width W2 is relatively small, the magnetic flux generated by the above-mentioned coils 30 can fully pass through the interior of the first outer leg 22a specified by the above-mentioned width W2. By setting the value of W2 / W1 within the above-mentioned range, even if the X-axis direction width of the first outer leg 22a specified by the above-mentioned width W2 is relatively small, the coil device 10 can be miniaturized.

[0057] like Figure 2B As shown, the first inner leg portion 23a protrudes from the surface on one side of the Y-axis direction of the first base portion 21a to one side of the Y-axis direction by a predetermined length. The first inner leg portion 23a has a shape that is slender in the Z-axis direction, and extends from the upper part of the first base portion 21a in the Z-axis direction (a position approximately the thickness of the coil 30 below the upper end) to the lower end. A plurality of first inner leg portions 23a are respectively formed on the surface on one side of the Y-axis direction of the first base portion 21a at predetermined intervals along the X-axis direction. In more detail, as Figure 2B and Figure 4 As shown, each first inner leg portion 23a is formed inside each coil 30. The protrusion width of the first inner leg portion 23a in the Y-axis direction is larger than the protrusion width of the first outer leg portion 22a in the Y-axis direction. Figure 2BIn the illustrated example, the width of the first inner leg portion 23 in the X-axis direction is larger than the width of the first outer leg portion 22 a in the X-axis direction, and is approximately twice as large.

[0058] The plurality of first inner leg portions 23a are sandwiched between the plurality of first outer leg portions 22a. A first groove portion 24a is formed between the first outer leg portions 22a and 22a adjacent to each other in the X-axis direction and the first inner leg portion 23a formed therebetween.

[0059] The first groove 24a has a shape corresponding to the shape of the coil 30 (approximately a U-shape) and extends along the periphery of the first inner leg 23a. The coil 30 can be arranged in the first groove 24a. The first groove 24a has a first side portion 241, a second side portion 242, and an upper portion 243.

[0060] The first side portion 241 and the second side portion 242 extend approximately linearly along the Z-axis direction, extending from the upper end of the first base portion 21a in the Z-axis direction to the lower end. The side portions 241 and 242 are respectively formed between the first outer leg portion 22a and the first inner leg portion 23a. The width of each of the first side portion 241 and the second side portion 242 in the X-axis direction is the same as or greater than the thickness (plate thickness) of the coil 30. Figure 4 As shown, the first side surface portion 31 of the coil 30 is disposed on the first side portion 241 , and the second side surface portion 32 of the coil 30 is disposed on the second side portion 242 .

[0061] like Figure 2B As shown, the upper portion 243 is formed above the first base portion 21a and extends along the X-axis direction. The upper portion 243 connects the upper end of the first side portion 241 and the upper end of the second side portion 242. The Z-axis width of the upper portion 243 is the same as or greater than the thickness (plate thickness) of the coil 30. Figure 4 As shown, the upper portion 33 of the coil 30 is arranged on the upper portion 243 .

[0062] When multiple coils 30 are arranged within each of the multiple first grooves 24a, a first inner leg 23a is positioned inside each coil 30, and a first outer leg 22a is positioned between adjacent coils 30. In other words, adjacent coils 30 are separated by the first outer leg 22a positioned therebetween. The coils 30 are hooked and secured to the first inner leg 23a within the core 20 (first core 20a and second core 20b).

[0063] like Figure 2AAs shown, the second core 20b has a second base 21b corresponding to the first base 21a, a plurality of second outer feet 22b corresponding to the plurality of first outer feet 22a respectively, a plurality of second inner feet 23b corresponding to the plurality of first inner feet 23a respectively, and a plurality of second grooves 24b corresponding to the plurality of first grooves 24a respectively.

[0064] The first outer leg 22a and the second outer leg 22b constitute the outer leg 22, and the first inner leg 23a and the second inner leg 23b constitute the inner leg 23. The first core 20a and the second core 20b constitute the core 20. The first core 20a and the second core 20b are combined along the Y-axis direction.

[0065] like Figures 1A to 1C As shown, when the first core 20a and the second core 20b are combined, the mounting portion 34 is not exposed (protrudes) from the side surface in the width direction (Y-axis direction) of the core 20 (each of the first core 20a and the second core 20b), but is housed on the inner side of the core 20 in the Y-axis direction.

[0066] like Figure 1C As shown, each mounting portion 34 of the coil 30 (the mounting portion 34 located at the lower end of the first side portion 241 and the mounting portion 34 located at the lower end of the second side portion 242) is only provided from the bottom surface of the core 20 (more specifically, Figure 2B The lower end of the first side portion 241 and the lower end of the second side portion 242 are exposed (protruded). By exposing each mounting portion 34 from the bottom surface of the core 20, the heat generated around the mounting portion 34 can be effectively dissipated to the outside of the core 20.

[0067] like Figure 1C and Figure 2A As shown, when the first core 20a and the second core 20b are combined while being placed opposite to each other in the Y-axis direction, a first gap portion 25 having a specified width in the Y-axis direction is formed between the first core 20a and the second core 20b and at the position where the outer leg portion 22 is formed, and a second gap portion 26 having a specified width in the Y-axis direction is formed at the position where the inner leg portion 23 is formed.

[0068] like Figure 1A As shown, the combination of the first core 20a and the second core 20b can be achieved by bonding the surface of the first core 20a located on the opposite side of the first base 21a in the Y-axis direction to the surface of the second core 20b located on the opposite side of the second base 21b in the Y-axis direction via an adhesive or the like (not shown). More specifically, the outer legs 22a, 22b of the cores 20a, 20b are bonded to each other and / or the inner legs 23a, 23b are bonded to each other.

[0069] like Figure 1B 、 Figure 1C and Figure 2A As shown, first gap 25 has a predetermined length in the X-axis direction and is formed between first outer leg 22a and second outer leg 22b (outer leg 22). The X-axis length of first gap 25 corresponds to (is equal to) the X-axis length of outer legs 22a and 22b. Furthermore, first gap 25 also has a predetermined length in the Z-axis direction, which corresponds to (is equal to) the Z-axis length of outer legs 22a and 22b.

[0070] The first gaps 25 are formed at predetermined intervals in the X-axis direction corresponding to the respective positions of the outer legs 22a and 22b. The intervals in the Y-axis direction of the first gaps 25 are constant along the X-axis or Z-axis direction.

[0071] Second gap 26 has a predetermined length in the X-axis direction and is formed between first inner leg 23a and second inner leg 23b (inner leg 23). The length of second gap 26 in the X-axis direction corresponds to (is equal to) the length of inner legs 23a and 23b in the X-axis direction. In the illustrated example, the length of second gap 26 in the X-axis direction is shorter than the length of first gap 25 in the X-axis direction. Furthermore, second gap 26 also has a predetermined length in the Z-axis direction, which corresponds to (is equal to) the length of first inner legs 23a and 23b in the Z-axis direction.

[0072] The second gaps 26 are formed at predetermined intervals in the X-axis direction corresponding to the respective positions of the inner legs 23a and 23b. The intervals in the Y-axis direction of the second gaps 26 are constant along the X-axis or Z-axis direction.

[0073] The first gap portions 25 and the second gap portions 26 are alternately arranged along the X-axis direction with the first side portion 241 or the second side portion 242 interposed therebetween, and are formed in a straight line along the boundary line between the first core 20 a and the second core 20 b .

[0074] The length of each first gap 25 formed at both ends of the core 20 in the X-axis direction is smaller than the length of each of the five first gaps 25 formed inside the first gaps 25 in the X-axis direction. The plurality of second gaps 26 are formed inside each coil 30 and are located (sandwiched) Figure 3A Between the first side portion 31 and the second side portion 32 shown.

[0075] In this embodiment, the spacing in the Y-axis direction of the second gaps 26 of the core 20 located inside the coils 30 is larger than the spacing in the Y-axis direction of the first gaps 25 of the core 20 located between adjacent coils 30. In other words, the first gap 25 of the gap formed between the first core 20a and the second core 20b constitutes a narrow portion, while the second gap 26 constitutes a wide portion, and the magnetic resistance of the second gap 26 is greater than that of the first gap 25.

[0076] like Figure 1C As shown, the Y-axis distance G1 of the first gap 25 is preferably 0.03 to 0.3 mm, more preferably 0.03 to 0.2 mm. The Y-axis distance G2 of the second gap 26 is preferably 0.1 to 1.0 mm, more preferably 0.1 to 0.5 mm.

[0077] When coils 30 are disposed within core 20, first gap 25 extends in a direction connecting adjacent coils 30 (in this embodiment, the X-axis direction). Furthermore, although not shown in detail, when coils 30 are disposed within core 20, second gap 26 extends in a direction connecting the inner circumferential surfaces of coils 30 (in this embodiment, the X-axis direction).

[0078] In the manufacture of the coil device 10, preparation Figure 2A The first core 20a shown and the second core 20b having a shape corresponding thereto are prepared in plurality (six in this embodiment). Figure 3A The coils 30 shown are shown. Next, each coil 30 is arranged inside the first groove portion 24a (second groove portion 24b) of the first core 20a (second core 20b).

[0079] Next, the second core 20b (first core 20a) and the first core 20a (second core 20b) are joined by an adhesive or the like so that the second groove 24b (first groove 24a) of the second core 20b (first core 20a) is overlapped with the first groove 24a (second groove 24b) of the first core 20a (second core 20b). Figures 1A to 1C The coil device 10 shown. Alternatively, after the first core 20a and the second core 20b are bonded together with an adhesive or the like to form the core 20, the plurality of coils 30 may be arranged inside the core 20 from above (the side where the upper portion 243 is formed).

[0080] In the coil device 10 of this embodiment, the spacing of the second gaps 26 of the core 20 located inside the coils 30 is larger than the spacing of the first gaps 25 of the core 20 located between adjacent coils 30. Therefore, the magnetic resistance of the second gaps 26 is greater than the magnetic resistance of the first gaps 25. As a result, the magnetic flux generated by a coil 30 has difficulty passing through the inside of the coil 30 adjacent to it (i.e., the portion where the second gaps 26 with high magnetic resistance are formed), while on the other hand, it is easy to pass between these coils 30 (i.e., the portion where the first gaps 25 with low magnetic resistance are formed). Therefore, the magnetic flux generated by a coil 30 can be prevented from passing through the coil 30 adjacent to it, and the magnetic coupling between adjacent coils 30 can be reduced.

[0081] Furthermore, by reducing the magnetic coupling between adjacent coils 30 , even if a plurality of coils 30 are closely arranged in the core 20 , good magnetic characteristics can be obtained, and the coil device 10 can be effectively made compact.

[0082] Furthermore, in this embodiment, first gaps 25 extend in a direction connecting adjacent coils 30, and second gaps 26 extend in a direction connecting the inner circumferential surfaces of coils 30. Therefore, most of the magnetic flux generated by a particular coil 30 passes transversely through first gaps 25 formed between the particular coil 30 and the adjacent coil 30, and also passes transversely through second gaps 26 formed inside the particular coil 30, effectively achieving the aforementioned effects.

[0083] Furthermore, in this embodiment, core 20 has outer legs 22 formed between adjacent coils 30 and inner legs 23 formed inside coils 30. First gaps 25 are formed in outer legs 22, and second gaps 26 are formed in inner legs 23. In this case, sufficient inductance characteristics can be ensured by allowing the magnetic flux generated by a particular coil 30 to pass through both outer legs 22 and inner legs 23. Furthermore, the aforementioned effects can be achieved by allowing the magnetic flux generated by a particular coil 30 to pass through both first gaps 25 formed in outer legs 22 and second gaps 26 formed in inner legs 23.

[0084] In addition, in this embodiment, mounting portions 34 for connection to an external circuit are formed at both ends of the coil 30. Therefore, the coil 30 can be easily connected to the external circuit via the mounting portions 34.

[0085] In this embodiment, core 20 is composed of a first core 20a and a second core 20b. First core 20a has at least one first outer leg 22a and multiple first inner legs 23a, while second core 20b has at least one second outer leg 22b and multiple second inner legs 23b. Furthermore, first gap 25 is formed between first core 20a and second core 20b at the location where outer legs 22 (first outer leg 22a and second outer leg 22b) are formed, and second gap 26 is formed between first core 20a and second core 20b at the location where inner legs 23 (first inner leg 23a and second inner leg 23b) are formed. Therefore, the combination of first core 20a and second core 20b facilitates the formation of first gap 25 and second gap 26, making it easier to achieve the aforementioned effects.

[0086] In addition, in this embodiment, the mounting portion 34 is not exposed from the side surface in the width direction (Y-axis direction) of the core 20. In this case, since the structure of the mounting portion 34 is simplified (for example, no need for Figure 7 Since the mounting portion 34 includes the protrusion 340 as in the illustrated coil 130 , the coil 30 can be easily disposed inside the core 20 (for example, inserted from above the core 20 ), making the coil device 10 easier to manufacture.

[0087] Second embodiment

[0088] The coil device of the second embodiment of the present invention differs only in the following aspects. The other structures are the same as those of the first embodiment described above, and the same functions and effects are achieved. The description of the repeated parts is omitted. In addition, in the drawings, the same symbols are marked on the components that are common to the first embodiment.

[0089] like Figure 5A As shown, the coil device 110 includes a core 120 and a plurality of (three in this embodiment) coils 130. The core 120 is composed of a first core 120a and a second core 120b, and is formed by combining the cores 120a and 120b. Figure 6 As shown, the first core 120a has a notch portion 127, which is different from the first core 20a of the first embodiment (see Figure 2B ) is different. In the following, since the shape of the second core 120b is the same as that of the first core 120a, its description is omitted.

[0090] The notch 127 is formed by Figure 2B The lower end of the first base portion 21a located between the first outer leg portion 22a and the first inner leg portion 23a is cut away in the Y-axis direction. The notch portion 127 is continuously connected to the lower end of the first side portion 241 or the second side portion 241, so that Figure 7 A portion of the mounting portion 134 of the illustrated coil 130 (a protruding portion 340 described later) is inserted into the notch portion 127 .

[0091] like Figure 7 As shown, the coil 130 includes a mounting portion 134. The mounting portion 134 is different from the mounting portion 34 of the first embodiment in that it includes a plurality of (four in the example shown) protrusions 340.

[0092] Of the two protrusions 340, 340 of the mounting portion 134 on the first side portion 31 side, one protrusion 340 is located on one side of the mounting portion 134 in the Y-axis direction and protrudes toward one side in the Y-axis direction. The other protrusion 340 is located on the other side of the mounting portion 134 in the Y-axis direction and protrudes toward the other side in the Y-axis direction.

[0093] Of the two protrusions 340, 340 of the mounting portion 134 on the second side surface portion 32 side, one protrusion 340 is located on one side of the mounting portion 134 in the Y-axis direction and protrudes toward one side in the Y-axis direction. The other protrusion 340 is located on the other side of the mounting portion 134 in the Y-axis direction and protrudes toward the other side in the Y-axis direction.

[0094] The protrusion width of the protrusion 340 in the Y-axis direction is substantially equal to the length of the cutout 127 in the Y-axis direction. The protrusion 340 is arranged inside the cutout 127 .

[0095] In this embodiment, if Figure 5A As shown, the protrusion 340 (a portion of the mounting portion 134) is exposed from the side surface in the width direction (Y-axis direction) of the core 120. In more detail, Figure 7 The protrusions 340 on one side of the mounting portion 134 shown in the figure are arranged from Figure 5A The lower end of the first base portion 21a of the first core 120a is shown exposed (protruding) outward in the Y-axis direction. The protrusions 340 of the mounting portion 134 located on the other side in the Y-axis direction are exposed (protruding) outward in the Y-axis direction from the lower end of the second base portion 21b of the second core 120b.

[0096] like Figure 5B As shown, mounting portion 134 protrudes downward in the Z-axis direction from the bottom surface of core 120. The protruding width of mounting portion 134 is approximately the same as or smaller than the Z-axis height of protruding portion 340. In mounting portion 134, the Y-axis width of coil 130 is approximately equal to the Y-axis width of core 120.

[0097] In this embodiment, a portion of mounting portion 134 (protrusion 340) is exposed from the side surface in the width direction of core 120. Therefore, when coil device 110 is mounted on an external circuit board, a solder fillet can be formed on the portion of mounting portion 134 (protrusion 340) exposed from the side surface of core 120, thereby improving the mounting strength of coil device 110 relative to the external circuit. Furthermore, the state of the solder fillet formed on protrusion 340 can be used to confirm the degree of solder adhesion to mounting portion 134.

[0098] In addition, in this embodiment, since the lateral width of the coil 130 (mounting portion 134 ) is increased by the amount of the protrusion 340 , the wiring (pad) of the external circuit can be shortened, and the direct current resistance (DCR) can be reduced.

[0099] Furthermore, by providing the mounting portion 134 with the protrusion 340 , the lateral width of the mounting portion 134 in the Y-axis direction becomes larger, which can improve the stability of the mounting posture when the coil device 110 is mounted on an external circuit, and can stably mount the coil device 110 on the external circuit.

[0100] Third embodiment

[0101] The coil device of the third embodiment of the present invention differs only in the following aspects. The other structures are the same as those of the first embodiment described above, and the same functions and effects can be achieved. The description of the repeated parts is omitted. In addition, in the drawings, the same symbols are marked on the components common to the first embodiment.

[0102] like Figure 8 As shown, the coil device 210 has a plurality of (three in this embodiment) coils 230. Figure 9A As shown, the coil 230 has a mounting portion 234 . The mounting portion 234 is different from the mounting portion 34 of the first embodiment in that it has a bent portion 341 .

[0103] The bent portion 341 of the mounting portion 234 on the first side surface portion 31 side has a shape formed by bending the lower end portion of the first side surface portion 31 substantially at a right angle from the Z-axis direction to the X-axis direction. The bent portion 341 of the mounting portion 234 on the second side surface portion 232 side has a shape formed by bending the lower end portion of the second side surface portion 32 substantially at a right angle from the Z-axis direction to the X-axis direction.

[0104] like Figure 8 As shown, when multiple (3) coils 230 are arranged inside the core 20, regardless of which coil 230, the extension direction of the curved portion 341 of the mounting portion 234 on the first side portion 231 side and the extension direction of the curved portion 341 of the mounting portion 234 on the second side portion 232 side are equal.

[0105] In this embodiment, the mounting portion 234 (bend portion 341) of each coil 230 extends along the arrangement direction (X-axis direction) of the plurality (three) coils 230. Therefore, the mounting portion 234 of each coil 230 ensures sufficient balance of the coil assembly 230, and even when the lateral width of the coil 230 in the Y-axis direction is narrow, the coil assembly 230 can be stably mounted on the external circuit.

[0106] Furthermore, in this embodiment, the mounting portion 234 (bent portion 341) of one adjacent coil 230 and the mounting portion (bent portion 341) of another adjacent coil 230 extend in substantially the same direction. Therefore, the spacing between the mounting portion 234 of one adjacent coil 230 and the mounting portion 234 of the other adjacent coil 230 can be ensured to be sufficiently large (or set to a constant spacing), thereby preventing short circuit failures between adjacent coils 230.

[0107] Fourth embodiment

[0108] The coil device of the fourth embodiment of the present invention differs only in the following aspects. The other structures are the same as those of the first embodiment described above, and the same functions and effects are achieved. The description of the repeated parts is omitted. In addition, in the drawings, the same symbols are marked on the components that are common to the first embodiment.

[0109] like Figure 10A and Figure 10B As shown, the coil device 310 includes a first core 320a and a second core 320b. In this embodiment, the first core 320a and the second core 320b do not have corresponding shapes, but are formed of different shapes.

[0110] like Figure 11 As shown, the first core 320a includes a plurality (four in the illustrated example) of first outer legs 322a and a plurality (three in the illustrated example) of first inner legs 323a. The first outer legs 322a have a longer protruding length (length along the longitudinal direction) than the first outer legs 22a of the first embodiment. The first inner legs 323a have a longer protruding length (length along the longitudinal direction) than the first inner legs 23a of the first embodiment. In this embodiment, the outer legs 322 are formed solely by the first outer legs 322a of the first core 320a, and the inner legs 322 are formed solely by the first inner legs 323a of the first core 320a.

[0111] The second core 320b has only the second base portion 221b and does not have a structure corresponding to the second outer leg portion 22b and the second inner leg portion 23b of the first embodiment, and is formed of a flat plate-shaped (I-shaped) core.

[0112] When the first core 320a and the second core 320b are combined while being opposed to each other in the Y-axis direction, a first gap portion 25 having a predetermined width in the Y-axis direction is formed between the first core 320a and the second core 320b at the position where the outer leg portion 322 is formed, and a second gap portion 26 having a predetermined width in the Y-axis direction is formed at the position where the inner leg portion 323 is formed. Therefore, even when the shapes of the first core 320a and the second core 320b are changed as in this embodiment, the same effects as those of the first embodiment can be obtained.

[0113] In addition, the present invention is not limited to the above-mentioned embodiment, and various modifications can be made within the scope of the present invention.

[0114] In each of the above embodiments, Figure 1C The Y-axis width G1 of the first gap 25 shown can also be 0. In this case, G1 < G2 can be set, and the same effects as the above-mentioned embodiments can be achieved. In this case, since the first gap 25 is omitted, the core 20 can be composed of a single core (i.e., a core formed only with the second gap 26).

[0115] In the first embodiment described above, Figure 1A As shown in FIG. 1 , six coils 30 are arranged inside the coil device 10 . However, there is no particular limitation on the number of coils 30 as long as there are a plurality of coils 30 . The same applies to the second embodiment and the third embodiment described above.

[0116] In the first embodiment described above, Figure 2A As shown, the first core 20a has multiple ( Figure 2B In the example shown, there are seven first outer legs 22a, but the number of first outer legs 22a is not limited to this. For example, the first core 20a may have only one first outer leg 22a. However, in this case, the first outer legs 22a are respectively arranged between the two first inner legs 22a, 22a. In addition, the number of first outer legs 22a may be more than two and less than six, or may be more than eight. The same applies to the second core 20b.

[0117] In addition, in each of the above embodiments, Figure 1C As shown in FIG, the first gap portion 25 extends straight along the Y-axis direction, but may also extend obliquely with respect to the Y-axis.

[0118] In the second embodiment described above, Figure 5AAs shown, core 120 is composed of a combination of symmetrical cores 120a and 120b having the same shape. However, the structure of core 120 is not limited to this and may also be composed of a combination of asymmetrical cores 120a and 120b having different shapes. For example, core 120 may be an EI-type core composed of an E-shaped core and a flat-plate (I-shaped) core. In this case, the first gap 25 and the second gap 26 can be formed at the combined position of the foot of the E-shaped core and the plate surface of the flat-plate core. In this case, the same effect as the second embodiment can be achieved. The same applies to the third embodiment.

[0119] In the above embodiments, Figure 3B As shown, the lateral width L1 of the coil 30 in the Y-axis direction may be greater than the length L2 in the direction (X-axis direction) perpendicular to the height direction (Z-axis direction) of the coil 30. With this structure, even when a plurality of coils 30 are arranged inside the core 20, the length of the core 20 along the arrangement direction (X-axis direction) of the plurality of coils 30 can be shortened, thereby achieving miniaturization (thinning) of the coil device 10.

[0120] In the above-mentioned embodiments, the core 20 may also include a top plate portion covering the top of the plurality of coils 30. In this case, the top plate portion covers the top of the plurality of coils 30. Figure 1A The top plate portion is mounted on the upper end surface of the first outer leg portion 22a of each of the first core 20a and the second core 20b shown. By setting it as this structure, the upper surface of the top plate portion can be used as an adsorption surface, which can improve the operability of the coil device 10. In addition, the top plate portion can also be formed separately from the core 20, or it can also be formed integrally with the core 20.

[0121] In the third embodiment described above, if Figure 9B As shown, the extending direction of the bent portion 341 of the mounting portion 234 on the first side portion 231 side and the extending direction of the bent portion 341 of the mounting portion 234 on the second side portion 232 side may be different. In the example shown in the figure, the bent portion 341 of the mounting portion 234 on the first side portion 231 side and the bent portion 341 of the mounting portion 234 on the second side portion 232 side face opposite sides along the X-axis direction.

[0122] Explanation of symbols

[0123] 10, 110, 210, 310... coil devices

[0124] 20, 120, 320...core

[0125] 20a, 120a, 320a…first core

[0126] 20b, 120b, 320b…second core

[0127] 21a…first base

[0128] 21b…Second base

[0129] 22, 322…outer foot

[0130] 22a, 322a…first outer leg

[0131] 22b…Second outer leg

[0132] 23, 323…Inner foot

[0133] 23a, 323a…first inner leg

[0134] 23b…Second inner leg

[0135] 24a...first groove portion

[0136] 24b...Second groove portion

[0137] 241…first lateral portion

[0138] 242…Second side

[0139] 243…upper part

[0140] 25…First gap

[0141] 26…Second gap

[0142] 127…Notch

[0143] 30, 130, 230... coils

[0144] 31…first side face

[0145] 32…Second side face

[0146] 33…upper face

[0147] 34, 134, 234…Installation

[0148] 340…protrusion

[0149] 341…bend.

Claims

1. A coil device comprising: core; and A plurality of coils are arranged inside the core, The core has an outer leg portion formed between adjacent coils and an inner leg portion formed inside the coils. A first gap is formed in the outer leg portion. A second gap is formed in the inner leg portion. The intervals of the second gaps of the core located inside the coils are larger than the intervals of the first gaps of the core located between the adjacent coils. The coil is formed of a substantially U-shaped conductor plate, the substantially U-shaped conductor plate having a pair of first and second side portions, an upper portion connecting the pair of first and second side portions, and a mounting portion formed at the lower end portions of each of the first and second side portions and connected to an external circuit, wherein the plate surfaces of the first and second side portions face each other. The plurality of coils are arranged in one direction inside the core so that inside the core, the second side surface of one adjacent coil and the first side surface of another adjacent coil face each other with the outer leg of the core having the first gap formed therein sandwiched therebetween. The upper portion of each of the coils is arranged on an upper portion formed inside the core. In each of the coils, the mounting portion formed at the lower end of the first side portion and the mounting portion formed at the lower end of the second side portion are opposed to each other with the inner leg portion having the second gap formed therein interposed therebetween. Inside the core, the mounting portion formed on the lower end of the second side surface of one adjacent coil and the mounting portion formed on the lower end of the first side surface of the other adjacent coil are arranged to face each other with the outer leg portion having the first gap formed therein interposed therebetween.

2. The coil device according to claim 1, wherein The first gap portion extends in a direction connecting the adjacent coils. The second gap portion extends in a direction connecting the inner peripheral surfaces of the coils.

3. The coil device according to claim 1 or 2, wherein: Mounting portions connected to an external circuit are formed at both ends of the coil.

4. The coil device according to claim 3, wherein A portion of the mounting portion is exposed from a side surface in a width direction of the core.

5. The coil device according to claim 3, wherein The mounting portion is not exposed from a side surface in a width direction of the core.

6. The coil device according to claim 3, wherein The mounting portion extends along an arrangement direction of the plurality of coils.

7. The coil device according to claim 3, wherein The mounting portion of one adjacent coil and the mounting portion of another adjacent coil extend in substantially the same direction.

8. The coil device according to claim 1 or 2, wherein: The core has a top plate portion that covers the upper sides of the plurality of coils.

9. The coil device according to claim 1 or 2, wherein: The lateral width of the coil is greater than the length in a direction perpendicular to the height direction of the coil.

10. The coil device according to claim 1, wherein The core is composed of a first core and a second core, The first core has at least one outer leg and a plurality of inner legs, The second core has at least one outer leg and a plurality of inner legs, The first gap is formed between the first core and the second core at a position where the outer leg is formed. The second gap is formed between the first core and the second core at a position where the inner leg is formed.

11. The coil device according to claim 1 or 2, wherein: The core is composed of an E-shaped core and a flat plate-shaped core.

Images