JP7189657B2 - coil parts - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coil component including a coil and a core, which is used for reactors and the like.

A coil component of this type is disclosed, for example, in US Pat.

As shown in FIGS. 10 and 11, the coil component 900 of Patent Document 1 includes a coil 910, a core 930, a bobbin 950, and a case 960. Coil 910 has a rectangular wire 912 . The rectangular wire 912 is edgewise wound around the winding axis (X direction). The surface of the coil 910 is covered with a resin mold 914 made of insulating resin. Core 930 includes an inner core 932 , an outer core 934 and a pair of end cores 936 . An inner core 932 is housed within the coil 910 . The outer core 934 is arranged above and below the coil 910 in the vertical direction (Z direction). Each end core 936 has an abutment 937 and a base 938 . The adjoining portion 937 of the +X side end core 936 adjoins the +X side end face of the inner core 932 . The adjacent portion 937 of the −X side end core 936 is adjacent to the −X side end surface of the inner core 932 . The base 938 of the +X side end core 936 faces the +X side end face of the coil 910 . The base 938 of the −X side end core 936 faces the −X side end face of the coil 910 . Base 938 of end core 936 is coupled to outer core 934 . The magnetic permeability μ _e of end core 936 is higher than the magnetic permeability μ _i and μ ₀ of inner core 932 and outer core 934 . The bobbin 950 is arranged between the inner peripheral surface of the coil 910 and the outer surface of the inner core 932 . Case 960 houses coil 910 , core 930 and bobbin 950 .

JP 2013-179264 A

When a coil component is used as a reactor, it is required to reduce not only the iron loss of the core but also the AC resistance of the coil as much as possible in order to increase the efficiency of the reactor.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a coil component having a coil and a core and capable of reducing the AC resistance of the coil.

As a result of extensive studies, the applicant of the present application has found that when a core composed of a low-permeability core and a high-permeability core having a predetermined shape is used in a coil component, the magnetic permeability of the high-permeability core and the low-permeability core and the magnetic permeability is within a predetermined range, the AC resistance of the coil can be reduced, and the present invention has been completed.

That is, the present invention provides, as a first coil component,
A coil component comprising a coil and a core,
the coil is at least partially embedded in the core and has at least one coil cross-section in a plane containing the winding axis of the coil;
The winding shaft extends along the vertical direction,
The coil cross section has an outer peripheral portion, an inner peripheral portion, an upper end portion, a lower end portion, two first corners, and two second corners,
The outer peripheral portion is positioned outside the inner peripheral portion in a direction orthogonal to the winding shaft,
The upper end portion is positioned above the lower end portion in the vertical direction,
The two first corners are located at both ends of the upper end portion or at both ends of the outer peripheral portion,
When the two first corners are located at both ends of the upper end, the two second corners are located at both ends of the lower end,
When the two first corners are positioned at both ends of the outer peripheral part, the two second corners are positioned at both ends of the inner peripheral part,
The core comprises a high magnetic permeability core and a low magnetic permeability core,
The high permeability core covers the two first corners or the two second corners,
the high-permeability core has a _first magnetic permeability μ1 and the low-permeability core has a _second magnetic permeability μ2,
A coil component is provided wherein 1<μ ₁ /μ ₂ ≦15.

Further, the present invention provides a first coil component as the second coil component,
2≦μ ₁ /μ ₂ ≦8
Provide coil parts.

Further, according to the present invention, the third coil component is the first or second coil component,
The high magnetic permeability core is a dust core,
The low permeability core provides a coil component that is a cast core.

Further, according to the present invention, the fourth coil component is any one of the first to third coil components,
The low permeability core provides a coil component with a non-magnetic gap.

Further, according to the present invention, a fifth coil component is any one of the first to fourth coil components,
The coil has a rectangular wire,
The flat wire is edgewise wound around the winding shaft,
The two first corners are located on both sides of the upper end,
The two second corners provide coil components located on opposite sides of the lower end.

Further, the present invention provides a fifth coil component as a sixth coil component,
The low-permeability core includes a first low-permeability core and a second low-permeability core,
The first low-permeability core is in contact with at least part of the high-permeability core,
The first low-permeability core is in contact with at least part of the outer peripheral portion of the coil cross section,
The second low-permeability core is in contact with at least part of the high-permeability core,
The second low-permeability core provides a coil component in contact with at least a portion of the inner periphery of the coil cross-section.

Further, according to the present invention, a seventh coil component is any one of the first to fourth coil components,
The coil has a rectangular wire,
The flat wire is flatwise wound around the winding shaft,
The two first corners are located on both sides of the outer peripheral portion,
The two second corners provide coil components located on opposite sides of the inner periphery.

Further, the present invention provides a seventh coil component as an eighth coil component,
The low-permeability core includes a first low-permeability core and a second low-permeability core,
The first low-permeability core is in contact with at least part of the high-permeability core,
The first low-permeability core is in contact with at least part of the upper end of the coil cross section,
The second low-permeability core is in contact with at least part of the high-permeability core,
The second low permeability core provides a coil component in contact with at least a portion of the lower end of the coil cross-section.

Further, according to the present invention, a ninth coil component is any one of the first to eighth coil components,
The high permeability core provides a coil component having a U-shaped or U-shaped portion covering the two first corners or the two second corners.

Further, according to the present invention, a tenth coil component is any one of the first to eighth coil components,
The high permeability core covers the two first corners,
The high permeability additional core covers the two second corners,
the high permeability additional core has a _third permeability μ3,
A coil component with 1<μ ₃ /μ ₂ ≦15 is provided.

Further, the present invention provides a tenth coil component as an eleventh coil component,
Provide a coil component where μ ₃ =μ ₁ .

Further, the present invention provides the 10th or 11th coil component as the 12th coil component,
The high magnetic permeability core has a U-shaped or U-shaped portion that covers the two first corners,
The high permeability additional core provides a coil component having a U-shaped or U-shaped portion covering the two second corners.

In the coil component of the present invention, the high-permeability core covers the two first corners or the two second corners of the coil cross-section. ratio is within a predetermined range. Accordingly, in the coil component of the present invention, the AC resistance of the coil is reduced. Therefore, the efficiency of the reactor using the coil component of the present invention is improved.

1 is a perspective view showing a coil component according to a first embodiment of the invention; FIG. FIG. 2 is a perspective cross-sectional view showing the coil component of FIG. 1 along line VII-VII; In the figure, a part of the low permeability core is shown enlarged. FIG. 2 is a perspective view showing a coil included in the coil component of FIG. 1; FIG. 2 is a cross-sectional view showing the coil component of FIG. 1 along line VII-VII; In the figure, part of the coil is shown in an enlarged manner. FIG. 2 is a sectional view showing part of the coil component of FIG. 1; The figure schematically shows the magnetic flux generated in the coil and the high-permeability core. 2 is a diagram showing the correlation between the _AC resistance RAC and μ ₁ /μ ₂ of the coil component of FIG. 1; FIG. 2 is a diagram showing the correlation between the _AC resistance RAC and μ ₁ /μ ₂ of the coil component of FIG. 1; FIG. It is a sectional view showing a coil component by a modification of a 1st embodiment. FIG. 5 is a cross-sectional view showing a coil component according to a second embodiment of the invention; In the figure, part of the coil is shown in an enlarged manner. FIG. 11 is a cross-sectional view showing a coil component according to a modification of the second embodiment; FIG. 4 is a cross-sectional view showing a coil component of Patent Document 1; 11 is an exploded perspective view showing a coil, core and bobbin included in the coil component of FIG. 10; FIG.

(First embodiment)
As shown in FIGS. 1 to 4, coil component 10 according to the first embodiment of the present invention includes case 600, coil 100, and core 400. As shown in FIG. Coil component 10 can be used, for example, as an in-vehicle reactor. However, the present invention is not limited to this, and can be applied to various coil components.

As shown in FIGS. 1 to 4, the case 600 of this embodiment is made of a non-magnetic material such as aluminum, and has a bottom surface 610 and four side surfaces 620. As shown in FIG. The bottom surface 610 has a substantially rectangular shape with two sides perpendicular to the X direction and two sides perpendicular to the Y direction. The side surfaces 620 extend upward in the vertical direction from each side of the bottom surface 610 . In this embodiment, the vertical direction is the Z direction, and the upward direction is the +Z direction. That is, the case 600 of this embodiment has an opening 630 on the upper side.

As shown in FIGS. 1 to 4, the coil 100 of this embodiment has a rectangular wire 120. As shown in FIG. The rectangular wire 120 of the coil 100 is edgewise wound around the winding axis WA. Here, the winding axis WA of the coil 100 extends along the vertical direction. Coil 100 according to the present embodiment has a rectangular shape on a horizontal plane (XY plane) orthogonal to winding axis WA. However, the present invention is not limited to this, and the coil 100 may have a shape other than a rectangular shape (for example, a circular shape) on the XY plane. The flat wire 120 of this embodiment has a wound coil body 121 and two terminals 122 that are free ends. The terminal 122 is positioned above the coil body 121 . Each of the terminals 122 is connected to an external electronic circuit (not shown) or the like when the coil component 10 is used. In this embodiment, each of terminals 122 is an end of flat wire 120 forming coil 100 . However, the present invention is not limited to this. For example, each of terminals 122 may be formed separately from coil 100 and then welded to coil 100 . Also, each of the coil 100 and terminals 122 can be formed from a variety of materials. For example, the coil 100 may be copper wire or aluminum wire. In addition, the coil body 121 of the coil 100 may further have an insulator surrounding it. Also, the rectangular wire 120 may be a sheet conductor.

As shown in FIGS. 1 to 4, in the present embodiment, coil body 121 of flat wire 120 of coil 100 is entirely embedded in core 400, and terminal 122 of flat wire 120 of coil 100 is located in the core. 400 protruding above. However, the present invention is not limited to this, and the coil may be at least partially embedded in the core.

Referring to FIG. 4, when the coil component 10 is used, a magnetic flux FX is generated around the coil body 121 of the coil 100 along the magnetic path FP. In the present embodiment, the magnetic path FP circulates inside the core 400 so as to surround the coil 100 in any plane including the winding axis WA of the coil 100 . That is, the coil 100 of the present embodiment has at least one coil cross-section within a plane (hereinafter referred to as a "predetermined plane") including the winding axis WA of the coil 100 and the magnetic path FP that circulates inside the core 400. has 200. In the present embodiment, the predetermined plane is any plane including the winding axis WA of the coil 100, such as the YZ plane. The coil 100 has two coil cross sections 200 having the same structure on the YZ plane, which is a predetermined plane.

As shown in FIG. 4 , the coil cross-section 200 includes an outer circumference 210 , an inner circumference 220 , an upper end 230 , a lower end 250 , two first corners 232 and two second corners 252 . and The outer peripheral portion 210 is located outside the inner peripheral portion 220 in the direction perpendicular to the winding axis WA. The upper end portion 230 is positioned above the lower end portion 250 in the vertical direction. The two first corners 232 are located at both ends of the upper end 230 . Two second corners 252 are located at both ends of the lower end 250 . More specifically, the two first corners 232 are positioned at both ends of the upper end 230 in a direction orthogonal to the vertical direction (hereinafter referred to as "perpendicular direction"), and the two second corners 252 are They are positioned at both ends of the lower end portion 250 in the orthogonal direction. One of the two first corners 232 of the upper end portion 230 is connected to the upper end 212 of the outer peripheral portion 210 . The remaining one of the two first corners 232 of the upper end portion 230 is connected to the upper end 222 of the inner peripheral portion 220 . One of the two second corners 252 of the lower end portion 250 is connected to the lower end 214 of the outer peripheral portion 210 . The remaining one of the two second corners 252 of the lower end portion 250 is connected to the lower end 224 of the inner peripheral portion 220 .

More specifically, as shown in FIG. 4, the coil cross-section 200 is composed of a plurality of winding cross-sections 300 arranged in the vertical direction. Each winding cross-section 300 is a cross-section of the rectangular wire 120 of the coil 100 . Winding sections 300 that are adjacent in the vertical direction are in contact with each other. However, the present invention is not limited to this. Some gaps may be formed between the winding sections 300 that are adjacent in the vertical direction.

Referring to FIG. 4, the structure of the coil cross section 200 is not limited to the structure in this embodiment, and can be variously modified. For example, the coil cross-section 200 according to the present embodiment has only one cross-section row 300X in the orthogonal direction, which is composed of a plurality of winding cross-sections 300 that are arranged in the vertical direction. Assuming a general coil, the number of cross-sectional rows 300X may be two or more. However, from the viewpoint of reducing AC copper loss, the winding cross section 300 preferably has only one or two cross section rows 300X in the orthogonal direction. The reason is as follows.

When the coil component 10 is used, some eddy currents are generated at both ends of each winding cross-section 300 in the orthogonal direction. Further, when the number of cross-section rows 300X is two, eddy currents are generated not only at both ends of the cross-section rows 300X in the orthogonal direction but also between the two cross-section rows 300X. However, the eddy current is greater as it approaches both ends of the winding cross section 300 in the orthogonal direction, and the eddy current in the intermediate portion of the winding cross section 300 in the orthogonal direction (that is, between the two cross-section rows 300X) is is infinitesimally smaller than both ends in the orthogonal direction. Therefore, when the number of cross-section rows 300X is two, the magnetic flux FX hardly enters between the two cross-section rows 300X. On the other hand, when the number of cross-section rows 300X is three or more, part of the magnetic flux FX generates an eddy current between two cross-section rows 300X adjacent in the orthogonal direction and enters the winding cross-section 300 in the vertical direction. . As a result, the influence of eddy currents increases, which may increase AC copper loss. Therefore, from the viewpoint of reducing the AC copper loss, the number of cross-sectional rows 300X is preferably as small as possible, particularly preferably 2 or less.

As shown in FIGS. 1 to 4, core 400 of the present embodiment includes high permeability core 410 , high permeability additional core 420 , and low permeability core 450 .

As shown in FIGS. 2 and 4, the high permeability core 410 of this embodiment includes two outer protrusions (protrusions) 412, two inner protrusions (protrusions) 414, and a base 416. have. In other words, the high-permeability core 410 includes two pairs of bases 416 and two protrusions (the outer protrusion 412 and the inner protrusion 414). The outer protrusion 412 is positioned outside the inner protrusion 414 in the orthogonal direction. Each of the outer protruding portions 412 protrudes downward from the base portion 416 in the vertical direction. Each of the inner protrusions 414 protrudes downward from the base 416 in the vertical direction. In this embodiment, downward is the -Z direction. Each of the protrusions (the outer protrusion 412 and the inner protrusion 414) protrudes from the base 416 toward the high permeability additional core 420 by _a distance D1. However, the present invention is not limited to this. The coil component may comprise multiple high permeability cores of various shapes.

1 to 4, high magnetic permeability core 410 of the present embodiment is a dust core and has a _first magnetic permeability μ1. The high magnetic permeability core 410 of the present embodiment is obtained by compression-molding an insulated soft magnetic alloy powder and a binder. However, the high magnetic permeability core is not limited to this and can be manufactured by any manufacturing method.

As shown in FIGS. 2 and 4, the high-permeability additional core 420 of the present embodiment is separate from the high-permeability core 410 and is positioned below the high-permeability core 410 in the vertical direction. ing. The high-permeability additional core 420 has a shape in which the high-permeability core 410 is inverted upside down. 424 and an additional base 426 . In other words, the high-permeability additional core 420 includes two pairs of additional bases 426 and two additional protrusions (the outer additional protrusion 422 and the inner additional protrusion 424). The outer additional protrusion 422 is positioned outside the inner additional protrusion 424 in the orthogonal direction. Each of the outer additional protrusions 422 protrudes upward in the vertical direction from the additional base 426 . Each of the inner additional protrusions 424 protrudes upward in the vertical direction from the additional base 426 . Each of the additional protrusions (the outer additional protrusion 422 and the inner additional protrusion 424) protrudes from the additional base 426 toward the high permeability core 410 by _a distance D1. The protrusion of the high permeability core 410 (the outer protrusion 412 or the inner protrusion 414) and the additional protrusion of the high permeability additional core 420 (the outer additional protrusion 422 or the inner additional protrusion 424) _are separated by a distance D2. ing. However, the present invention is not limited to this. The coil component may comprise multiple high permeability additional cores of various shapes.

1 to 4, high magnetic permeability additional core 420 of the present embodiment is a dust core and has a _third magnetic permeability μ3. The high-permeability additional core 420 of the present embodiment is, like the high-permeability core 410, compression-molded from an insulated soft magnetic alloy powder and a binder. However, the high permeability additional core is not limited to this and can be manufactured by any manufacturing method.

As shown in FIGS. 2 and 4, the high permeability core 410 of this embodiment covers the two first corners 232 . That is, the high magnetic permeability core 410 of the present embodiment has L-shaped portions covering the two first corners 232 respectively. More specifically, high permeability core 410 of the present embodiment has a U-shaped or U-shaped portion that covers two first corners 232 of coil cross section 200 . Also, the base 416 and the two protrusions (the outer protrusion 412 and the inner protrusion 414) define a U-shaped or U-shaped portion of the high magnetic permeability core 410. As shown in FIG. When the structure composed of the high permeability core 410 and the coil 100 is viewed from the orthogonal direction, the two first corners 232 of the coil cross section 200 of the coil 100 are invisible. Similarly, the high permeability additional core 420 covers the two second corners 252 . That is, the high permeability additional core 420 has L-shaped portions covering the two second corners 252 respectively. More specifically, the high permeability additional core 420 has a U-shaped or U-shaped portion that covers the two second corners 252 of the coil cross section 200 . Further, the additional base 426 and the two additional protrusions (the outer additional protrusion 422 and the inner additional protrusion 424 ) define the U-shaped or U-shaped portion of the high permeability additional core 420 . When the structure composed of the high permeability additional core 420 and the coil 100 is viewed from the orthogonal direction, the two second corners 252 of the coil cross section 200 of the coil 100 are invisible. As a result, the magnetic flux FX passing from the inner side of the inner peripheral portion 220 of the coil cross section 200 of the coil 100 to the outer side of the outer peripheral portion 210 through the upper side of the upper end portion 230 circulates around the first corner portion 232 without being dispersed. Similarly, the magnetic flux FX passing from the outer side of the outer peripheral portion 210 of the coil cross section 200 of the coil 100 to the inner side of the inner peripheral portion 220 through the lower side of the lower end portion 250 does not disperse near the second corner portion 252. It will go around. Note that the present invention is not limited to this, and the high magnetic permeability core only needs to cover the two first corners or the two second corners. Also, the high permeability core may have an L-shaped portion that covers the two first corners or the two second corners, respectively, and the two first corners or the two second corners It may have a U-shaped or U-shaped portion covering the . In addition, when the high permeability core covers the two first corners, the high permeability additional core only needs to cover the two second corners. Furthermore, it may not have a high permeability additional core. Additionally, the high permeability core may be composed of a plurality of members. Specifically, even if the high-permeability core is composed of three members: a member having one outer protrusion, a member having two inner protrusions, and a member having one outer protrusion. good. Further, the high magnetic permeability core has four members, a member having one outer protrusion, a member having one inner protrusion, a member having one inner protrusion, and a member having one outer protrusion. You may be comprised by the member. Here, when the high-permeability core is composed of a plurality of members, the members do not need to be connected, and the low-permeability core may exist between the members. Similarly, the high permeability additional core may be composed of multiple members. Specifically, the high permeability additional core is composed of three members: a member having one outer additional protrusion, a member having two inner additional protrusions, and a member having one outer additional protrusion. may have been Further, the high permeability additional core has a member having one outer additional protrusion, a member having one inner additional protrusion, a member having one inner additional protrusion, and one outer additional protrusion. It may be composed of four members. Here, when the high-permeability additional core is composed of a plurality of members, the members do not need to be connected, and a low-permeability core may exist between the members.

More specifically, as shown in FIGS. 2 and 4, the lower end 413 of the outer projecting portion 412 of the high magnetic permeability core 410 of the present embodiment is located vertically above the upper end 212 of the outer peripheral portion 210 of the coil cross section 200. is also located below. Further, the lower end 415 of the inner protruding portion 414 of the high magnetic permeability core 410 of the present embodiment is positioned below the upper end 222 of the inner peripheral portion 220 of the coil cross section 200 in the vertical direction. The lower end 413 of the outer protruding portion 412 and the lower end 415 of the inner protruding portion 414 of the high permeability core 410 are in contact with the low permeability core 450 on the magnetic path FP that circulates inside the core 400 . A lower end 413 of the outer protruding portion 412 and a lower end 415 of the inner protruding portion 414 of the high magnetic permeability core 410 are located below the first corner portion 232 .

As shown in FIGS. 2 and 4, the upper end 423 of the outer additional projecting portion 422 of the high permeability additional core 420 of the present embodiment is located above the lower end 214 of the outer peripheral portion 210 of the coil cross section 200 in the vertical direction. located in Further, the upper end 425 of the inner additional projecting portion 424 of the high permeability additional core 420 of the present embodiment is positioned above the lower end 224 of the inner peripheral portion 220 of the coil cross section 200 in the vertical direction. The upper end 423 of the outer additional protrusion 422 and the upper end 425 of the inner additional protrusion 424 of the high permeability additional core 420 are in contact with the low permeability core 450 on the magnetic path FP that circulates inside the core 400 . An upper end 423 of the outer additional protrusion 422 and an upper end 425 of the inner additional protrusion 424 of the high permeability additional core 420 are located above the second corner 252 .

As shown in FIGS. 2 and 4, the low-permeability core 450 of this embodiment includes a low-permeability inner core 451 and a low-permeability outer core 452 . The low magnetic permeability inner core 451 is positioned inside the coil main body 121 of the coil 100 in a plane perpendicular to the vertical direction. In addition, the outer surface of the low magnetic permeability inner core 451 is in contact with the inner peripheral portion 220 of the coil cross section 200 of the coil 100 on a plane orthogonal to the vertical direction. The low magnetic permeability outer core 452 is positioned outside the coil body 121 of the coil 100 in a plane perpendicular to the vertical direction. In addition, the inner surface of the low magnetic permeability outer core 452 is in contact with the outer peripheral portion 210 of the coil cross section 200 of the coil 100 on a plane perpendicular to the vertical direction. On the magnetic path FP that circulates inside the core 400, the lower end 413 of the outer protrusion 412 of the high permeability core 410 is in contact with the low permeability outer core 452, and the inner protrusion 414 of the high permeability core 410 is in contact with the outer protrusion 414 of the high permeability core 410. The lower end 415 of is in contact with the low permeability inner core 451 . Similarly, on the magnetic path FP that circulates inside the core 400, the upper end 423 of the outer additional protrusion 422 of the high permeability additional core 420 is in contact with the low permeability outer core 452, and the high permeability additional core The upper end 425 of the inner additional protrusion 424 of 420 is in contact with the low permeability inner core 451 . The present invention is not limited to this, and the low-permeability core includes a first low-permeability core in contact with at least a portion of the high-permeability core and a second low-permeability core in contact with at least a portion of the high-permeability core. 2 low permeability cores. Here, when the flat wire is edgewise wound, the first low permeability core may be in contact with at least a part of the outer peripheral portion of the coil cross section, and the second low permeability core may be in contact with the coil cross section. contact with at least part of the inner circumference of the Further, when the rectangular wire is wound flatwise, the first low-permeability core should be in contact with at least a part of the upper end of the coil cross-section, and the second low-permeability core should be in contact with the coil cross-section. It is sufficient if it is in contact with at least part of the lower end.

Referring to FIG. 2, low permeability core 450 of the present embodiment is a cast core. More specifically, the low-permeability core 450 of the present embodiment is a composite magnetic body in which soft magnetic alloy powder 454 made of an iron-based alloy, ferrite, or the like is dispersed in hardened binder 455 . That is, the low magnetic permeability core 450 of the present embodiment is obtained by hardening slurry containing soft magnetic alloy powder 454, binder 455, and the like. However, the low magnetic permeability core is not limited to this, and can be manufactured by any manufacturing method. Also, the low magnetic permeability core 450 of the present embodiment has a _second magnetic permeability μ2.

In coil component 10 of the present embodiment, first magnetic permeability μ ₁ of high-permeability core 410 and second magnetic permeability μ ₂ of low-permeability core 450 satisfy 1<μ ₁ /μ ₂ ≦15. The _third magnetic permeability μ3 of the high-permeability additional core 420 and the _second magnetic permeability μ2 of the low-permeability core 450 satisfy ₁ < _μ3 /μ2≦15. More specifically, μ ₃ =μ ₁ .

In the coil 100 of the coil component 10 of the present invention, the principle of reducing the AC copper loss will be described in detail below in comparison with the conventional example. In a conventional coil component having an air gap in a portion of a high-permeability core surrounding a coil, a large amount of magnetic flux enters the coil around the air gap. For this reason, by adopting a configuration in which the air gap is replaced with a low-permeability cast core or the like, the entry of magnetic flux into the coil at the replaced location has been alleviated. The magnetic flux that short-circuits the surrounding high permeability core has increased, and the AC copper loss has not been improved in the coil parts as a whole. On the other hand, in the coil component 10 of the present invention, the high magnetic permeability core 410 having high magnetic permeability is arranged so as to cover the two first corners 232 or the two second corners 252 of the coil cross section 200 of the coil 100. is doing. As a result, as can be understood from FIG. 5, magnetic flux 800 is generated in the high permeability core 410 in the opposite direction to the direction of the magnetic flux 700 generated in the coil 100 itself. This cancels out the AC copper loss of the coil component 10 and reduces it. Further, the coil component 10 of the present invention is adjusted so as to satisfy 1<μ ₁ /μ ₂ ≦15, so that the effect of reducing the AC copper loss can be maximized. As described above, even when the low-permeability core includes the first low-permeability core and the second low-permeability core, the first low-permeability core is the high-permeability core and the coil. and the second low-permeability core is in contact with the high-permeability core and the coil, the flow of magnetic flux 800 shown in FIG. is reduced.

FIG. 6 shows the correlation between the AC resistance R _AC of the coil 100 and the magnetic permeability ratio μ ₁ /μ ₂ when D ₁ =7.5 mm and D ₂ =15 mm. From this figure, it can be understood that the _AC resistance RAC of the coil 100 is low when the permeability ratio μ ₁ /μ ₂ is within a predetermined range. That is, as understood from FIG. 6, by satisfying μ ₁ /μ ₂ ≦15, the AC resistance RAC of the coil 100 is made equal to or less than the _AC resistance _RAC when μ ₁ /μ ₂ =1. Therefore, eddy current loss in the coil body 121 of the coil 100 can be suppressed. In addition, by satisfying 1<μ ₁ /μ ₂ , the vortex at the first corner 232 or the second corner 252 in the coil cross-section 200 of the coil 100 and covered by the high permeability core 410 Current loss can be suppressed. That is, the coil component 10 of the present embodiment is designed to reduce the _AC resistance RAC of the coil 100 of the coil component 10 by satisfying 1<μ ₁ /μ ₂ ≦15. Furthermore, as understood from FIG. 6, from the viewpoint of further reducing the _AC resistance RAC of the coil 100 of the coil component 10, 2≦μ ₁ /μ ₂ ≦8 is preferable.

Similarly, as understood from FIG. 6, by satisfying μ ₃ /μ ₂ ≦15, the AC resistance RAC of the coil 100 is equal to or less than the _AC resistance _RAC when μ ₃ /μ ₂ =1. Therefore, eddy current loss in the coil body 121 of the coil 100 can be suppressed. In addition, by satisfying 1<μ ₃ /μ ₂ , eddy current loss at the second corner 252 in the coil cross section 200 of the coil 100 can be suppressed. That is, the coil component 10 of the present embodiment is designed to reduce the _AC resistance RAC of the coil 100 of the coil component 10 by satisfying 1<μ ₃ /μ ₂ ≦15. Furthermore, as understood from FIG. 6, from the viewpoint of further reducing the _AC resistance RAC of the coil 100 of the coil component 10, 2≦μ ₃ /μ ₂ ≦8 is preferable.

Coil component 10 of the present embodiment satisfies the following formula (1). As a result, the _AC resistance RAC of the coil 100 can be further reduced, and the eddy current loss in the coil body 121 of the coil 100 can be further suppressed.

1 to 4, in coil component 10 of the present embodiment, coil 100, low magnetic permeability core 450, high magnetic permeability core 410, and high magnetic permeability additional core 420 are housed inside case 600. It is Here, the low permeability core 450 of the present embodiment fills the space inside the case 600 except for the coil main body 121 , the high permeability core 410 and the high permeability additional core 420 of the coil 100 .

The configuration of the coil component 10 is not limited to that described above, and for example, the following modifications are possible.

Referring to FIGS. 1, 4 and 7, coil component 10A according to the modification of the present embodiment includes case 600, coil 100, and core 400A. Among them, the case 600 and the coil 100 have the same structures as those of the coil component 10 of the first embodiment described above. Therefore, detailed description of these will be omitted.

1, 4 and 7, core 400A of the present embodiment includes high permeability core 410, high permeability additional core 420, and low permeability core 450A. Here, core 400A of the present embodiment has the same configuration as core 400 of the first embodiment described above, except for low magnetic permeability core 450A. Therefore, among the constituent elements shown in FIG. 7, the constituent elements that are the same as those in the first embodiment are denoted by the same reference numerals.

As shown in FIG. 7, the low-permeability core 450A of this embodiment has a low-permeability inner core 451A, a low-permeability outer core 452, and a non-magnetic gap 480. As shown in FIG. The nonmagnetic gap 480 of the present embodiment is positioned near the center of the low magnetic permeability inner core 451A in the vertical direction, and is positioned inside the inner peripheral portion 220 of the coil cross section 200 of the coil 100 in the orthogonal direction. . As a result, the magnetic saturation of the coil component 10A of the present embodiment is relaxed, and the coil component 10A has better DC superimposition characteristics.

(Second embodiment)
As shown in FIG. 8, coil component 10B according to the second embodiment of the present invention includes case 600, coil 100B, and core 400B. Of these, the case 600 has the same structure as the case 600 of the coil component 10 of the first embodiment, so detailed description thereof will be omitted.

Referring to FIG. 8, the coil 100B of this embodiment has a rectangular wire 120B. The flat wire 120B of the coil 100B is wound flatwise around the winding axis WA. Here, the winding axis WA of the coil 100B extends along the vertical direction. Coil 100B according to the present embodiment has a rectangular shape on a horizontal plane (XY plane) orthogonal to winding axis WA. However, the present invention is not limited to this, and the coil 100B may have a shape other than a rectangular shape (for example, a circular shape) on the XY plane. The rectangular wire 120B of the present embodiment has a wound coil body 121B and two terminals (not shown) that are free ends. Each of the two terminals (not shown), which are free ends, is connected to an external electronic circuit (not shown) or the like when the coil component 10B is used. In this embodiment, each of the terminals (not shown) is the end of the rectangular wire 120B forming the coil 100B. However, the present invention is not limited to this. For example, each of the terminals (not shown) may be formed separately from coil 100B and then welded to coil 100B. Also, each of the coil 100B and terminals (not shown) can be formed from a variety of materials. For example, the coil 100B may be copper wire or aluminum wire. In addition, the coil body 121B of the coil 100B may further have an insulator surrounding it.

As shown in FIG. 8, in this embodiment, the entire coil body 121B of the rectangular wire 120B of the coil 100B is embedded in the core 400B. However, the present invention is not limited to this, and the coil may be at least partially embedded in the core.

Referring to FIG. 8, when the coil component 10B is used, a magnetic flux FX along the magnetic path FP is generated around the coil body 121B of the coil 100B. In the present embodiment, the magnetic path FP circulates inside the core 400B so as to surround the coil 100B in any plane including the winding axis WA of the coil 100B. That is, the coil 100B of the present embodiment has at least one coil cross section within a plane (hereinafter referred to as a "predetermined plane") including the winding axis WA of the coil 100B and the magnetic path FP that circulates inside the core 400B. 200B. In the present embodiment, the predetermined plane is any plane including the winding axis WA of the coil 100B, such as the YZ plane. The coil 100B has two coil cross sections 200B having the same structure on the YZ plane.

As shown in FIG. 8, the coil cross section 200B includes an outer peripheral portion 210B, an inner peripheral portion 220B, an upper end portion 230B, a lower end portion 250B, two first corners 215, and two second corners 225. and The outer peripheral portion 210B is located outside the inner peripheral portion 220B in the direction orthogonal to the winding axis WA. The upper end portion 230B is positioned above the lower end portion 250B in the vertical direction. The two first corners 215 are located at both ends of the outer peripheral portion 210B. The two second corners 225 are positioned at both ends of the inner peripheral portion 220B. More specifically, the two first corners 215 are positioned at both ends of the outer peripheral part 210B in the vertical direction, and the two second corners 225 are positioned at both ends of the inner peripheral part 220B in the vertical direction. . One of the two first corners 215 of the outer peripheral portion 210B is connected to the outer end 235 of the upper end portion 230B. The remaining one of the two first corners 215 of the outer peripheral portion 210B is connected to the outer end 255 of the lower end portion 250B. One of the two second corners 225 of the inner peripheral portion 220B is connected to the inner end 236 of the upper end portion 230B. The remaining one of the two second corners 225 of the inner peripheral portion 220B is connected to the inner end 256 of the lower end portion 250B.

More specifically, as shown in FIG. 8, the coil cross-section 200B is composed of a plurality of winding cross-sections 300B arranged in a direction orthogonal to the vertical direction (hereinafter referred to as "perpendicular direction"). Each winding cross-section 300B is a cross-section of the rectangular wire 120B of the coil 100B. The winding sections 300B adjacent in the orthogonal direction are in contact with each other. However, the present invention is not limited to this. Some gaps may be formed between winding sections 300B adjacent in the orthogonal direction.

As shown in FIG. 8, the core 400B of this embodiment includes two high permeability cores 410B, two high permeability additional cores 420B, and a low permeability core 450B.

As shown in FIG. 8 , high permeability core 410B of the present embodiment has upper protrusion (protrusion) 431 , lower protrusion (protrusion) 433 , and base 435 . In other words, the high permeability core 410B includes a base 435 and two projections (an upper projection 431 and a lower projection 433). The upper projecting portion 431 is positioned above the lower projecting portion 433 in the vertical direction. The upper protrusion 431 protrudes inward from the base 435 in the orthogonal direction. The lower protruding portion 433 protrudes inward from the base portion 435 in the orthogonal direction. Each of the protrusions (the upper protrusion 431 and the lower protrusion 433) protrudes from the base 435 toward the high permeability additional core 420B by _a distance D1. However, the present invention is not limited to this. The coil component may comprise multiple high permeability cores of various shapes.

Referring to FIG. 8, each of high magnetic permeability cores 410B of the present embodiment is a dust core and has a _first magnetic permeability μ1. The high magnetic permeability core 410B of the present embodiment is obtained by compression-molding an insulated soft magnetic alloy powder and a binder. However, the high magnetic permeability core is not limited to this and can be manufactured by any manufacturing method.

As shown in FIG. 8, high-permeability additional core 420B of the present embodiment is separate from high-permeability core 410B and positioned inside high-permeability core 410B in the orthogonal direction. The high permeability additional core 420B has a shape obtained by horizontally reversing the high permeability core 410B. and an additional base 445 . In other words, the high permeability additional core 420B includes an additional base 445 and two additional protrusions (an upper additional protrusion 441 and a lower additional protrusion 443). The upper additional projecting portion 441 is positioned above the lower additional projecting portion 443 in the vertical direction. The upper additional protrusion 441 protrudes outward from the additional base 445 in the orthogonal direction. The lower additional protrusion 443 protrudes outward from the additional base 445 in the orthogonal direction. Each of the additional protrusions (the upper additional protrusion 441 and the lower additional protrusion 443) protrudes from the additional base 445 toward the high permeability core 410B by _a distance D1. However, the present invention is not limited to this. The coil component may comprise multiple high permeability additional cores of various shapes.

Referring to FIG. 8, high magnetic permeability additional core 420B of the present embodiment is a dust core and has a _third magnetic permeability of μ3. The additional high-permeability core 420B of the present embodiment is formed by compression-molding an insulated soft magnetic alloy powder and a binder, similarly to the high-permeability core 410B. However, the high permeability additional core is not limited to this and can be manufactured by any manufacturing method.

As shown in FIG. 8, high permeability core 410B of the present embodiment covers two first corners 215. As shown in FIG. That is, the high magnetic permeability core 410B of the present embodiment has L-shaped portions covering the two first corners 215 respectively. More specifically, high permeability core 410B of the present embodiment has a U-shaped or U-shaped portion covering two first corners 215 of coil cross section 200B. Also, the base 435 and the two protrusions (the upper protrusion 431 and the lower protrusion 433) define the U-shaped or U-shaped portion of the high magnetic permeability core 410B. The two first corners 215 of the coil cross section 200B of the coil 100B are invisible when the structure composed of the high permeability core 410B and the coil 100B is viewed from above. Similarly, the high permeability additional core 420B covers the two second corners 225 . That is, the high permeability additional core 420B has L-shaped portions covering the two second corners 225 respectively. More specifically, the high permeability additional core 420B has a U-shaped or U-shaped portion that covers the two second corners 225 of the coil cross section 200B. Further, the additional base 445 and the two additional protrusions (the upper additional protrusion 441 and the lower additional protrusion 443) define the U-shaped or U-shaped portion of the high permeability additional core 420B. When the structure composed of the high permeability additional core 420B and the coil 100B is viewed from above, the two second corners 225 of the coil cross section 200B of the coil 100B are invisible. As a result, the magnetic flux FX passing from the upper side of the upper end portion 230B of the coil cross section 200B of the coil 100B to the lower side of the lower end portion 250B through the outside of the outer peripheral portion 210B circulates around the first corner portion 215 without being dispersed. Similarly, the magnetic flux FX passing from the lower side of the lower end portion 250B of the coil cross section 200B of the coil 100B to the upper side of the upper end portion 230B through the inner peripheral portion 220B does not disperse near the second corner portion 225. It will go around. Note that the present invention is not limited to this, and the high magnetic permeability core only needs to cover the two first corners or the two second corners. Also, the high permeability core may have an L-shaped portion that covers the two first corners or the two second corners, respectively, and the two first corners or the two second corners It may have a U-shaped or U-shaped portion covering the . In addition, when the high permeability core covers the two first corners, the high permeability additional core only needs to cover the two second corners. Furthermore, it may not have a high permeability additional core. Additionally, the high permeability core may be composed of a plurality of members. Specifically, the high magnetic permeability core may be composed of two members, a member having one upper protrusion and a member having one lower protrusion. Here, when the high-permeability core is composed of a plurality of members, the members do not need to be connected, and the low-permeability core may exist between the members. Similarly, the high permeability additional core may be composed of multiple members. Specifically, the high permeability additional core may be composed of two members, a member having one upper additional protrusion and a member having one lower additional protrusion. Here, when the high-permeability additional core is composed of a plurality of members, the members do not need to be connected, and a low-permeability core may exist between the members.

More specifically, as shown in FIG. 8, the inner end 432 of the upper protruding portion 431 of the high magnetic permeability core 410B of the present embodiment is positioned further than the outer end 235 of the upper end portion 230B of the coil cross section 200B in the orthogonal direction. located inside. In addition, the inner end 434 of the lower projecting portion 433 of the high magnetic permeability core 410B of the present embodiment is located inside the outer end 255 of the lower end portion 250B of the coil cross section 200B in the orthogonal direction. The inner end 432 of the upper protruding portion 431 and the inner end 434 of the lower protruding portion 433 of the high magnetic permeability core 410B are in contact with the low magnetic permeability core 450B on the magnetic path FP that circulates inside the core 400B. An inner end 432 of the upper protruding portion 431 and an inner end 434 of the lower protruding portion 433 of the high magnetic permeability core 410B are located inside the first corner portion 215 .

As shown in FIG. 8, the outer end 442 of the upper additional projecting portion 441 of the high permeability additional core 420B of the present embodiment extends outside the inner end 236 of the upper end portion 230B of the coil cross section 200B in the orthogonal direction. positioned. Further, the outer end 444 of the lower additional projecting portion 443 of the high permeability additional core 420B of the present embodiment is located outside the inner end 256 of the lower end portion 250B of the coil cross section 200B in the orthogonal direction. On the magnetic path FP that circulates inside the core 400B, the outer end 442 of the upper additional protrusion 441 and the outer end 444 of the lower additional protrusion 443 of the high permeability additional core 420B are in contact with the low permeability core 450B. ing. An outer end 442 of the upper additional protrusion 441 and an outer end 444 of the lower additional protrusion 443 of the high permeability additional core 420B are positioned outside the second corner 225 .

Referring to FIG. 8, low magnetic permeability core 450B of the present embodiment is a cast core. More specifically, the low magnetic permeability core 450B of the present embodiment is a composite magnetic body in which soft magnetic alloy powder made of an iron-based alloy, ferrite, or the like is dispersed inside a hardened binder. That is, the low magnetic permeability core 450B of the present embodiment is obtained by hardening a slurry containing soft magnetic alloy powder, a binder, and the like. However, the low magnetic permeability core is not limited to this, and can be manufactured by any manufacturing method. Also, the low magnetic permeability core 450B of the present embodiment has a _second magnetic permeability μ2.

As in coil component 10 of the first embodiment, also in coil component 10B of the present embodiment, high permeability core 410B has _first magnetic permeability μ1 and low permeability core 450B has _second magnetic permeability μ2. satisfies 1<μ ₁ /μ ₂ ≦15, and the third magnetic permeability μ ₃ of the high-permeability additional core 420B and the second magnetic permeability μ ₂ of the low-permeability core 450B are 1<μ ₃ /μ ₂ ≦15 is satisfied. More specifically, μ ₃ =μ ₁ .

Also in the coil component 10B of the second embodiment, by satisfying μ ₁ /μ ₂ ≦15, the AC resistance RAC of the coil 100B is equal to or less than the _AC resistance _RAC when μ ₁ /μ ₂ =1. Therefore, eddy current loss in the coil body 121B of the coil 100B can be suppressed. In addition, by satisfying 1<μ ₁ /μ ₂ , the vortex at the first corner 215 or the second corner 225 in the coil cross-section 200B of the coil 100B and covered by the high permeability core 410B Current loss can be suppressed. That is, the _AC resistance RAC of the coil 100B of the coil component 10B is reduced by satisfying 1<μ ₁ /μ ₂ ≦15 in the coil component 10B of the present embodiment. Furthermore, similarly to the coil component 10 of the first embodiment, from the viewpoint of further reducing the _AC resistance RAC of the coil 100B of the coil component 10B, 2≦μ ₁ /μ ₂ ≦8 is preferable.

Similarly, in the coil component 10B of the second embodiment, by satisfying μ ₃ /μ ₂ ≦15, the _AC resistance RAC of the coil 100B is changed from the _AC resistance RAC when μ ₃ /μ ₂ =1. , the eddy current loss in the coil body 121B of the coil 100B can be suppressed. In addition, by satisfying 1<μ ₃ /μ ₂ , eddy current loss at the second corner 225 in the coil cross section 200B of the coil 100B can be suppressed. That is, the _AC resistance RAC of the coil 100B of the coil component 10B is reduced by satisfying 1<μ ₃ /μ ₂ ≦15 in the coil component 10B of the present embodiment. Furthermore, similarly to the coil component 10 of the first embodiment, from the viewpoint of further reducing the _AC resistance RAC of the coil 100B of the coil component 10B, 2≦μ ₃ /μ ₂ ≦8 is preferable.

Coil component 10B of the present embodiment satisfies the above formula (1). As a result, the _AC resistance RAC of the coil 100B can be further reduced, and the eddy current loss in the coil body 121B of the coil 100B can be further suppressed.

As shown in FIG. 8, in coil component 10B of the present embodiment, coil 100B, low-permeability core 450B, high-permeability core 410B, and high-permeability additional core 420B are housed inside case 600 . Here, the low permeability core 450B of the present embodiment fills the space inside the case 600 other than the coil main body 121B, the high permeability core 410B, and the high permeability additional core 420B of the coil 100B.

The configuration of the coil component 10B is not limited to the one described above, and for example, the following modifications are possible.

8 and 9, a coil component 10C according to the modification of the present embodiment includes a case 600, a coil 100B and a core 400C. Among them, the case 600 and the coil 100B have the same structure as the coil component 10B of the second embodiment described above. Therefore, detailed description of these will be omitted.

8 and 9, core 400C of the present embodiment includes high permeability core 410B, high permeability additional core 420B, and low permeability core 450C. Here, core 400C of the present embodiment has the same configuration as core 400B of the above-described second embodiment except for low magnetic permeability core 450C. Therefore, among the constituent elements shown in FIG. 9, the constituent elements that are the same as those in the second embodiment are denoted by the same reference numerals.

As shown in FIG. 9, the low permeability core 450C of this embodiment has a non-magnetic gap 480C. The non-magnetic gap 480C of the present embodiment is located between the inner end 432 of the upper protrusion 431 of the high permeability core 410B and the outer end 442 of the additional upper protrusion 441 of the additional high permeability core 420B. . As a result, the magnetic saturation of the coil component 10C of the present embodiment is relaxed, and the coil component 10C has better DC superimposition characteristics. The present invention is not limited to this, and the non-magnetic gap is positioned between the inner end of the lower protrusion of the high permeability core and the outer end of the additional lower protrusion of the high permeability additional core. may

The embodiments and modifications described above can be combined in various ways. In addition to the above-described embodiments and modifications, the present invention can be applied in various ways as described below.

4 and 8, the high permeability core and the high permeability additional core are not dust cores as long as 1<μ ₁ /μ ₂ ≦15 and 1<μ ₃ /μ ₂ ≦15 are satisfied. good too. For example, the high permeability core may be a ferrite core. Moreover, when a plurality of high magnetic permeability cores are provided, the high magnetic permeability cores may be made of different materials. For example, one of the high-permeability cores may be a dust core, and the other one of the high-permeability cores may be a ferrite core. Similarly, when a plurality of high permeability additional cores are provided, the high permeability additional cores may be made of different materials. For example, one of the high permeability additional cores may be a dust core, and another one of the high permeability additional cores may be a ferrite core.

The coil used in the coil component of the present invention may have various shapes on the XY plane, not limited to rectangular and circular shapes. Also, the high permeability core used in the coil component of the present invention may have various shapes corresponding to the shape of the coil. Similarly, the high permeability additional core used in the coil component of the present invention may have various shapes corresponding to the shape of the coil.

The case used for the coil component of the present invention is not limited to a rectangular parallelepiped shape, and may have various shapes. Also, the case may not be provided.

10, 10A, 10B, 10C Coil component 100, 100B Coil 120, 120B Rectangular wire 121, 121B Coil main body 122 Terminal 200, 200B Coil cross section 210, 210B Outer periphery 212 Upper end 214 Lower end 215 First corner 220, 220B Inner periphery 222 upper end 224 lower end 225 second corner 230, 230B upper end 232 first corner 235 outer end 236 inner end 250, 250B lower end 252 second corner 255 outer end 256 inner end 300, 300B winding cross section 300X cross section row 400, 400A, 400B, 400C core 410, 410B high magnetic permeability core 412 outer protruding part (protruding part)
413 lower end 414 inner protrusion (protrusion)
415 lower end 416 base 420, 420B high permeability additional core 422 outer additional protrusion (additional protrusion)
423 upper end 424 inner additional protrusion (additional protrusion)
425 Upper end 426 Additional base 431 Upper protrusion (protrusion)
432 inner end 433 lower protrusion (protrusion)
434 inner end 435 base 441 upper additional protrusion (additional protrusion)
442 outer end 443 lower additional protrusion (additional protrusion)
444 Outer end 445 Additional base 450, 450A, 450B, 450C Low magnetic permeability core 451, 451A Low magnetic permeability inner core 452 Low magnetic permeability outer core 454 Soft magnetic alloy powder 455 Binder 480, 480C Nonmagnetic gap 600 Case 610 Bottom surface 620 Side 630 Opening 700 Magnetic flux 800 Magnetic flux WA Winding _shaft FP Magnetic path FX Magnetic flux _D1 distance D2 distance

Claims (5)

A coil component comprising a coil and a core,
the coil is at least partially embedded in the core and has at least one coil cross-section in a plane containing the winding axis of the coil;
The winding shaft extends along the vertical direction,
The coil cross section has an outer peripheral portion, an inner peripheral portion, an upper end portion, a lower end portion, two first corners, and two second corners,
The outer peripheral portion is positioned outside the inner peripheral portion in a direction orthogonal to the winding shaft,
The upper end portion is positioned above the lower end portion in the vertical direction ,
The core comprises a high magnetic permeability core and a low magnetic permeability core ,
The high permeability core has a _first magnetic permeability μ1,
the low-permeability core has a _second magnetic permeability μ2;
1<μ ₁ /μ ₂ ≦15,
The high permeability core has a base,
The base is located on the winding shaft,
The coil has a rectangular wire,
The flat wire is edgewise wound around the winding shaft,
The two first corners are located on both sides of the upper end,
The two second corners are located on both sides of the lower end,
In the plane, the high permeability core further has two outer protrusions and two inner protrusions,
the two outer protrusions correspond to the two inner protrusions, respectively;
The outer protruding portion is positioned outside the corresponding inner protruding portion in the direction orthogonal to the winding shaft ,
Each of the outer protrusions protrudes downward in the vertical direction from the base,
each of the inner protruding portions protrudes downward in the vertical direction from the base;
In the direction perpendicular to the winding shaft , the outer end of the base is located outside the outer end of the outer protrusion ,
A U-shaped or U-shaped portion defined by the base, the outer protrusion and the corresponding inner protrusion covers the two first corners.
coil parts. The coil component according to claim 1,
2≦μ ₁ /μ ₂ ≦8
coil parts. The coil component according to claim 1 or claim 2,
The high magnetic permeability core is a dust core,
The coil component, wherein the low-permeability core is a cast core. The coil component according to any one of claims 1 to 3,
A coil component in which the low magnetic permeability core has a non-magnetic gap. The coil component according to any one of claims 1 to 4,
The low-permeability core includes a first low-permeability core and a second low-permeability core,
The first low-permeability core is in contact with at least part of the high-permeability core,
The first low-permeability core is in contact with at least part of the outer peripheral portion of the coil cross section,
The second low-permeability core is in contact with at least part of the high-permeability core,
The second low-permeability core is a coil component that is in contact with at least a portion of the inner peripheral portion of the coil cross section.

Images