WO2023176682A1 - Inductor component - Google Patents

Abstract

This inductor component comprises an annular core and a coil wound around the core, wherein: the core has a first portion including MnZn-based ferrite and a second portion including NiZn-based ferrite; the coil has a conductor member, and a covering member that covers a portion of the conductor member; and at least a portion of the second portion faces an uncovered region of the coil, the uncovered region being not covered by the covering member.

Description

inductor parts

The present disclosure relates to inductor components.

Conventionally, as an inductor component, there is one described in Japanese Patent Application Laid-Open No. 2021-150314 (Patent Document 1). This inductor component has an annular core, a resin cap that partially covers the core, and a coil wound around the core and the cap. The coil has a plurality of pin members, and the ends of adjacent pin members have welds welded together. A cap exists between the weld and the core. By providing the cap in this manner, the welded portion and the core can be insulated.

JP 2021-150314 Publication

However, since the conventional inductor component is provided with a cap, there is a problem in that the cross-sectional area of the core is reduced by the thickness of the cap, and the obtainable inductance is reduced. Alternatively, if the core size is increased in order to obtain the target inductance, there is a problem in that the product size increases.

Therefore, an object of the present disclosure is to provide an inductor component that can suppress the increase in product size and ensure high inductance.

In order to solve the above problems, an inductor component that is one aspect of the present disclosure includes:
a circular core;
and a coil wound around the core,
The core has a first part containing MnZn-based ferrite and a second part containing NiZn-based ferrite,
The coil includes a conductor member and a covering member that covers a part of the conductor member,
At least a portion of the second portion faces an uncovered region of the coil that is not covered by the covering member.

Here, the expression "the second part is opposite to the non-covered area" means that another member such as a resin member may be present between the second part and the non-covered area, and the second part and the non-covered area It refers to the relative relationship between

According to the aspect, the electrical conductivity of the NiZn-based ferrite in the second portion is lower than the electrical conductivity of the MnZn-based ferrite in the first portion, and the surface resistance of the second portion is higher than the surface resistance of the first portion. Since the second portion of the core faces the uncovered area of the coil, insulation between the core and the coil can be ensured. Therefore, a conventional resin cap covering the core is not required, and the cross-sectional area of the core can be secured by the thickness of the cap. This ensures high inductance. Therefore, it is possible to suppress the increase in product size and ensure high inductance.

In addition, when a toroidal coil is created using the MnZn ferrite of the first part, there is an impedance peak around 1 MHz, and when a toroidal coil is created using the NiZn ferrite of the second part, the impedance peak is around 1 MHz. Impedance peaks exist in high frequency ranges. Since MnZn-based ferrite and NiZn-based ferrite are combined, the frequency characteristics of the core are the sum of their respective frequency characteristics, and high impedance can be obtained over a wide band.

Preferably, in one embodiment of the inductor component:
a bottom plate portion on which the core and the coil are placed;
further comprising a resin member disposed on the bottom plate portion,
The resin member contacts the second portion and the bottom plate to fix the core to the bottom plate.

According to the embodiment, when stress occurs due to curing and shrinkage of the resin member or stress due to thermal expansion of the resin member at high temperatures, the stress in the resin member is reduced to the second portion because the resin member is in contact with the second portion. It is transmitted to the part. The NiZn-based ferrite of the second portion has a lower magnetic permeability and is less affected by magnetostriction than the MnZn-based ferrite of the first portion, so that deterioration in the characteristics of the core due to magnetostriction can be reduced.

Preferably, in one embodiment of the inductor component:
The coil has a plurality of pin members, the ends of adjacent pin members have welded parts welded to each other, and the welded parts are included in the conductor member and are located in the uncovered area. ,
At least a portion of the second portion faces the weld.

According to the embodiment, insulation between the core and the welded portion of the coil can be ensured.

Preferably, in one embodiment of the inductor component:
The plurality of pin members include a first pin member and a second pin member,
The first pin member and the second pin member constitute one turn,
The welded portion includes, in adjacent turns, a first welded portion where a first pin member of one turn and a second pin member of the one turn are welded to each other, and a first welded portion where a first pin member of the one turn is welded to each other; the pin member and the second pin member of the other turn have a second welded portion welded to each other;
The core has a first surface, a second surface that intersects the first surface, and a third surface that faces the second surface and intersects the first surface,
The first welded portion is located above at least one of the first surface and the second surface,
The second welded portion is located above at least one of the first surface and the third surface,
The second portion is provided over the first surface, a portion of the second surface, and a portion of the third surface.

According to the embodiment, the insulation between the core and the coil can be improved.

Note that intersecting the first surface and the second surface may mean that the first surface and the second surface intersect directly; for example, the first surface and the second surface may be connected via a curved portion. In this case, the extended surface of the first surface and the extended surface of the second surface may intersect.

"Located above the first surface" means to be located above the surface of the first surface in a direction orthogonal to the first surface. Note that the first welded portion being located above the first surface means that the first welded portion is present without directly contacting the first surface. The same applies to the second surface, the third surface, the fourth surface, and the second welded portion.

Preferably, in one embodiment of the inductor component:
The core has a fourth surface opposite to the first surface,
At least a portion of the first portion is provided on the fourth surface that does not face the welded portion.

According to the embodiment, by providing the first portion on the fourth surface, it is possible to improve the insulation between the core and the coil.

Preferably, in one embodiment of the inductor component:
The core further includes a connecting member connecting the first part and the second part,
The elastic modulus of the connecting member is 1.0 MPa or more and 50 MPa or less.

According to the embodiment, since the elastic modulus of the connecting member is low, for example, when the resin member is in contact with the second portion, even if the stress of the resin member is transmitted to the second portion, the stress of the second portion is It is relieved by the connecting member. Thereby, stress transmitted from the second portion to the first portion can be reduced, and reduction in inductance due to magnetostriction can be reduced.

Preferably, in one embodiment of the inductor component:
In a cross section including the central axis of the core,
The first portion is L-shaped and includes a first wall portion extending in a direction parallel to the central axis, and a first base portion extending in a direction perpendicular to the central axis,
The second portion is L-shaped and includes a second wall portion extending in a direction parallel to the central axis, and a second base portion extending in a direction perpendicular to the central axis,
The first wall portion and the second wall portion are arranged in a direction perpendicular to the central axis such that the inner surface of the first wall portion and the inner surface of the second wall portion are in contact with each other,
The first base part and the second base part are arranged on opposite sides of the first wall part and the second wall part in a direction parallel to the central axis.

According to the embodiment, since the first wall portion and the second wall portion are arranged in a direction perpendicular to the central axis, it is possible to suppress misalignment of the first portion and the second portion in the direction perpendicular to the central axis. . Further, the first wall portion and the second wall portion are arranged in a direction perpendicular to the central axis, and the first base portion and the second base portion are arranged on opposite sides in a direction parallel to the central axis. The cross-sectional shape of the core, which is a combination of the first part and the second part, can be rectangular.

Preferably, in one embodiment of the inductor component, the first wall portion is located closer to the central axis than the second wall portion.

According to the embodiment, since the first wall portion is located closer to the center axis than the second wall portion, it is possible to increase the volume of the first portion in the region on the inner peripheral side of the core where the magnetic path length is short. can. As a result, the characteristics of MnZn-based ferrite appear strongly, and the impedance near 1 MHz can be increased.

Furthermore, since the first wall portion is located closer to the central axis than the second wall portion, the volume of the second portion can be increased in the region on the outer peripheral side of the core. As a result, when applying a resin member to the outer peripheral side of the core, even if the resin member wets the outer peripheral surface of the core, the resin member adheres to the second part of the NiZn-based ferrite, which is less affected by magnetostriction. It becomes difficult for the resin member to adhere to the first portion of the MnZn-based ferrite, which has a large influence. Therefore, even if stress is generated in the resin member, the stress in the resin member is transmitted to the second portion instead of the first portion. The NiZn-based ferrite of the second portion has a lower magnetic permeability and is less affected by magnetostriction than the MnZn-based ferrite of the first portion, so that deterioration in the characteristics of the core due to magnetostriction can be reduced.

Preferably, in one embodiment of the inductor component, in terms of the ratio of the first portion to the second portion, the area on the inner circumferential side of the core is larger than the area on the outer circumferential side of the core.

According to the embodiment, in terms of the ratio of the first part to the second part, the area on the inner circumferential side of the core is larger than the area on the outer circumferential side of the core, so the magnetic path length on the inner circumferential side of the core is short. The volume of the first portion can be increased in the region. As a result, the characteristics of MnZn-based ferrite appear strongly, and the impedance near 1 MHz can be increased.

In addition, regarding the ratio of the first part to the second part, since the area on the inner circumferential side of the core is larger than the area on the outer circumferential side of the core, it is possible to increase the volume of the second part in the area on the outer circumferential side of the core. can. As a result, when applying a resin member to the outer peripheral side of the core, even if the resin member wets the outer peripheral surface of the core, the resin member adheres to the second part of the NiZn-based ferrite, which is less affected by magnetostriction. It becomes difficult for the resin member to adhere to the first portion of the MnZn-based ferrite, which has a large influence. Therefore, even if stress is generated in the resin member, the stress in the resin member is transmitted to the second portion instead of the first portion. The NiZn-based ferrite of the second portion has a lower magnetic permeability and is less affected by magnetostriction than the MnZn-based ferrite of the first portion, so that deterioration in the characteristics of the core due to magnetostriction can be reduced.

Preferably, in one embodiment of the inductor component, the volume ratio of the first portion to the second portion is 6:4 to 8:2.

According to the embodiment, when the magnetic permeability of MnZn-based ferrite is about 7,000 to 10,000 and the magnetic permeability of NiZn-based ferrite is about 500-800, the volume ratio of MnZn-based ferrite and NiZn-based ferrite is 6:4. When the ratio is ~8:2, a constant high impedance can be obtained over a wide band.

In order to solve the above problem, in one embodiment of the present disclosure,
a circular core;
a coil wound around the core;
a bottom plate portion on which the core and the coil are placed;
and a resin member disposed on the bottom plate portion,
The core has a first part containing MnZn-based ferrite and a second part containing NiZn-based ferrite,
The resin member contacts the second portion and the bottom plate to fix the core to the bottom plate.

According to the embodiment, when a toroidal coil is created using the MnZn-based ferrite of the first part, an impedance peak exists near 1 MHz, and a toroidal coil is created using the NiZn-based ferrite of the second part. In this case, the impedance peak exists in a frequency range higher than 1 MHz. Since MnZn-based ferrite and NiZn-based ferrite are combined, the frequency characteristics of the core are the sum of their respective frequency characteristics, and high impedance can be obtained over a wide band.

Furthermore, when stress occurs during curing and shrinkage of the resin member or stress due to thermal expansion of the resin member at high temperatures, the stress in the resin member is transmitted to the second portion because the resin member is in contact with the second portion. The NiZn-based ferrite of the second portion has a lower magnetic permeability and is less affected by magnetostriction than the MnZn-based ferrite of the first portion, so that deterioration in the characteristics of the core due to magnetostriction can be reduced.

On the other hand, in the conventional inductor component described in JP-A-2021-150314, ferrite is used for the core. Another conventional problem is that when MnZn-based ferrite is used for the core, there is an impedance peak around 1 MHz, so high impedance cannot be obtained in higher frequency ranges.

Therefore, another object of the present disclosure is to provide an inductor component that can obtain high impedance over a wide band.

According to the inductor component that is one aspect of the present disclosure, it is possible to suppress increase in product size and ensure high inductance.

FIG. 1 is a top perspective view showing an inductor component according to a first embodiment of the present invention. FIG. 3 is a bottom perspective view of the inductor component. FIG. 3 is a downward perspective view showing the inside of the inductor component. FIG. 3 is an exploded perspective view of an inductor component. FIG. 3 is a cross-sectional view of an inductor component. FIG. 3 is a cross-sectional view of an inductor component. It is a graph showing the relationship between frequency and impedance when changing the volume ratio of MnZn-based ferrite and NiZn-based ferrite. FIG. 7 is a cross-sectional view of an inductor component according to a second embodiment. It is a graph showing the relationship between frequency and impedance when the shapes of the first portion and the second portion of the core are L-shaped or rectangular. FIG. 7 is a cross-sectional view of an inductor component according to a third embodiment. It is a sectional view of an inductor component of a 4th embodiment. It is a sectional view of an inductor component of a 5th embodiment. It is a sectional view of an inductor component of a 6th embodiment. It is a sectional view of an inductor component of a 7th embodiment.

Hereinafter, an inductor component that is one aspect of the present disclosure will be described in detail with reference to illustrated embodiments. Note that some of the drawings are schematic and may not reflect actual dimensions and proportions.

<First embodiment>
(Configuration of inductor parts)
FIG. 1 is a top perspective view showing an inductor component according to an embodiment of the present invention. FIG. 2 is a bottom perspective view of the inductor component. FIG. 3 is a bottom perspective view showing the inside of the inductor component. FIG. 4 is an exploded perspective view of the inductor component.

As shown in FIGS. 1 to 4, the inductor component 1 includes a case 2, an inductor element L housed in the case 2, and first to fourth external parts attached to the case 2 and connected to the inductor element L. It has electrodes 51 to 54 and a resin member 90 placed inside the case 2. The inductor component 1 is, for example, a common mode choke coil. The inductor element L has an annular core 3 and a first coil 41 and a second coil 42 wound around the core 3.

The case 2 has a bottom plate part 21 and a box part 22 that covers the bottom plate part 21. The case 2 is made of a material that has strength and heat resistance, and is preferably made of a material that is flame retardant. The case 2 is made of a resin such as PPS (polyphenylene sulfide), LCP (liquid crystal polymer), or PPA (polyphthalamide), or ceramics.

The bottom plate part 21 includes a bottom part 210 including a first main surface 210a and a second main surface 210b facing each other, and a side wall part 211 provided along the outer periphery of the bottom part 210 on the first main surface 210a of the bottom part 210. have The bottom plate part 21 has a recess 215, and the recess 215 is surrounded by the bottom part 210 and the side wall part 211. The side wall portion 211 is provided continuously in the circumferential direction, but may be provided intermittently in the circumferential direction. The bottom portion 210 has a plurality of openings 216 passing through the first main surface 210a and the second main surface 210b. The plurality of openings 216 are provided at positions corresponding to the first to fourth external electrodes 51 to 54. In this embodiment, there are three openings 216, but the number can be increased or decreased as desired.

An inductor element L is arranged on the bottom plate part 21. That is, the core 3 is arranged in the bottom plate part 21 so that the central axis C of the core 3 is orthogonal to the first main surface 210a of the bottom part 210. The central axis C of the core 3 refers to the central axis of the inner diameter hole of the core 3. The shape of the case 2 (the bottom plate part 21 and the box part 22) is rectangular when viewed from the direction of the central axis C of the core 3. In this embodiment, the shape of case 2 is rectangular.

Here, the lateral direction of the case 2 viewed from the direction of the central axis C of the core 3 is defined as the X direction, the longitudinal direction of the case 2 viewed from the direction of the central axis C of the core 3 is defined as the Y direction, and the lateral direction and the longitudinal direction are defined as the Y direction. The height direction of case 2, which is a direction perpendicular to both, is defined as the Z direction. The bottom plate part 21 and the box part 22 of the case 2 are arranged facing each other in the Z direction, the bottom plate part 21 is on the lower side and the box part 22 is on the upper side, the upper side is in the forward direction of the Z direction, and the lower side is in the Z direction. The direction is the opposite direction. That is, in the height direction perpendicular to the first main surface 210a, the direction from the first main surface 210a toward the core 3 is defined as the upward direction. Note that when the bottom plate portion 21 of the case 2 has a square shape, the length of the case 2 in the X direction and the length of the case 2 in the Y direction are the same.

The box part 22 is attached to the bottom plate part 21 so as to cover the inductor element L. That is, the core 3 and the coils 41 and 42 are surrounded by the box part 22 and are not exposed to the outside. Therefore, the inductor element L can be protected from the outside.

The first to fourth external electrodes 51 to 54 are attached to the bottom plate portion 21. The first external electrode 51 and the second external electrode 52 are located at two corners of the bottom plate 21 facing each other in the Y direction, and the third external electrode 53 and the fourth external electrode 54 are located opposite in the Y direction of the bottom plate 21. It is located in two corners. The first external electrode 51 and the third external electrode 53 face each other in the X direction, and the second external electrode 52 and the fourth external electrode 54 face each other in the X direction.

The core 3 is a toroidal core, and the shape of the core 3 is oval (track shape) when viewed from the direction of the central axis C. When viewed from the direction of the central axis C, the core 3 includes a pair of longitudinal parts 31 extending along the long axis and facing each other in the short axis direction, and a pair of short sides 31 extending along the short axis and facing each other in the long axis direction. portion 32. Note that the shape of the core 3 may be rectangular, elliptical, or circular when viewed from the central axis C direction.

The core 3 has a first end surface 301 and a second end surface 302 that face each other in the direction of the central axis C, and an inner circumferential surface 303 and an outer circumferential surface 304. Inner peripheral surface 303 intersects first end surface 301 . The outer circumferential surface 304 faces the inner circumferential surface 303 and intersects with the first end surface 301. The second end surface 302 faces the first end surface 301. The first end surface 301 is the lower end surface of the core 3 and faces the first main surface 210a of the bottom plate portion 21. The second end surface 302 is the upper end surface of the core 3 and faces the inner surface of the box portion 22. The core 3 is housed in the case 2 so that the long axis direction of the core 3 coincides with the Y direction.

In this embodiment, the first end surface 301 is the first surface described in the claims, the second end surface 302 is the fourth surface described in the claims, and the inner peripheral surface 303 is the fourth surface described in the claims. The second surface described in the claims and the outer peripheral surface 304 respectively correspond to the third surface described in the claims.

The shape of the cross section perpendicular to the circumferential direction when viewed from the direction of the central axis C of the core 3 is rectangular. The first end surface 301 and the second end surface 302 are arranged perpendicularly to the direction of the central axis C of the core 3. The inner circumferential surface 303 and the outer circumferential surface 304 are arranged parallel to the direction of the central axis C of the core 3. In this specification, "vertical (orthogonal)" includes not only a completely vertical state but also a substantially vertical (orthogonal) state. Moreover, "parallel" is not limited to a completely parallel state, but also includes a substantially parallel state.

The resin member 90 is disposed within the recess 215 of the bottom plate portion 21 and contacts the bottom plate portion 21 and the inductor element L. As a material for the resin member 90, for example, thermosetting epoxy resin can be used.

The first coil 41 is wound around the core 3 between the first external electrode 51 and the second external electrode 52. One end of the first coil 41 is connected to the first external electrode 51. The other end of the first coil 41 is connected to the second external electrode 52.

The second coil 42 is wound around the core 3 between the third external electrode 53 and the fourth external electrode 54. One end of the second coil 42 is connected to the third external electrode 53. The other end of the second coil 42 is connected to the fourth external electrode 54.

The first coil 41 and the second coil 42 are wound helically around the core 3 along the circumferential direction of the core 3 as viewed from the direction of the central axis C of the core 3. Specifically, the first coil 41 is wound around one longitudinal part 31 of the core 3 along the longitudinal direction of the core 3, and the second coil 42 is wound around the other longitudinal part 31 of the core 3. 3 along the long axis direction. The winding axis of the first coil 41 and the winding axis of the second coil 42 run in parallel. The first coil 41 and the second coil 42 are symmetrical with respect to the long axis of the core 3.

The number of turns of the first coil 41 and the number of turns of the second coil 42 are the same. The winding direction of the first coil 41 around the core 3 and the winding direction of the second coil 42 around the core 3 are opposite directions. In other words, the winding direction of the first coil 41 from the first external electrode 51 to the second external electrode 52 is opposite to the winding direction of the second coil 42 from the third external electrode 53 to the fourth external electrode 54. direction.

Then, a common mode current flows from the first external electrode 51 to the second external electrode 52 in the first coil 41, and from the third external electrode 53 to the fourth external electrode 54 in the second coil 42, That is, the first to fourth external electrodes 51 to 54 are connected so that the current flows in the same direction. When a common mode current flows through the first coil 41, a first magnetic flux is generated by the first coil 41 in the core 3. When a common mode current flows through the second coil 42, a second magnetic flux is generated in the core 3 in a direction in which the first magnetic flux and the core 3 strengthen each other. Therefore, the first coil 41 and core 3 and the second coil 42 and core 3 act as inductance components, and noise is removed from the common mode current.

The first coil 41 is formed by connecting a plurality of pin members by, for example, welding such as laser welding or spot welding. Note that FIG. 3 does not show a state in which a plurality of pin members are actually welded, but a state in which a plurality of pin members are assembled.

The plurality of pin members are not printed wiring or conductive wires, but are rod-shaped members. The pin member has rigidity. Specifically, in a cross section perpendicular to the circumferential direction of the core 3, the pin member extends around the outer circumference of the core passing through the first end surface 301, second end surface 302, inner circumferential surface 303, and outer circumferential surface 304 of the core 3. Because it is shorter than the length of a 100-minute length and has high rigidity, it is difficult to bend.

The plurality of pin members include a bent pin member 410 that is bent into a substantially U-shape, and straight pin members 411 and 412 that extend substantially linearly. Note that the straight pin members 411 and 412 are also referred to as a first pin member, and the bent pin member 410 is also referred to as a second pin member.

The first coil 41 includes, in order from one end to the other end, a first straight pin member 411 on one end side (one side), a plurality of sets of bent pin members 410 and a second straight pin member 412, and a second straight pin member 412 on the other end side (on the other side). and a first straight pin member 411. The lengths of the first linear pin member 411 and the second linear pin member 412 are different. Regarding the spring index of the bending pin member 410, as shown in FIG. The radius of curvature R1 of the bending pin member 410 located at the corner of the outer peripheral surface 304 of the core 3, and the radius of curvature R2 of the bending pin member 410 located at the corner of the inner peripheral surface 303 of the core 3, the bending pin The spring index Ks of member 410 is smaller than 3.6. The spring index Ks can be expressed by the radius of curvature R1, R2 of the bending pin member/the wire diameter r of the bending pin member. In this way, the bending pin member 410 has high rigidity and is difficult to bend.

The bent pin members 410 and the second straight pin members 412 are alternately connected by welding, such as laser welding or spot welding, for example. One end of a second straight pin member 412 is connected to one end of the bending pin member 410, and the other end of the second straight pin member 412 is connected to one end of another bending pin member 410. By repeating this, the plurality of bent pin members 410 and the second straight pin members 412 are connected, and the connected plurality of bent pin members 410 and the second straight pin members 412 are connected to the core 3 in a spiral shape. Placed. In other words, one set of bending pin member 410 and second straight pin member 412 constitutes one turn.

The bending pin member 410 is arranged in parallel along each of the second end surface 302, inner peripheral surface 303, and outer peripheral surface 304 of the core 3. The second straight pin member 412 is arranged parallel to the first end surface 301 of the core 3 . The first linear pin member 411 is arranged parallel to the first end surface 301 of the core 3 .

The bending pin members 410 of adjacent turns are fixed to each other by an adhesive member 70. Thereby, the state in which the plurality of bending pin members 410 are attached to the core 3 can be made stable. Similarly, the adjacent first straight pin member 411 and second straight pin member 412 are fixed by the adhesive member 70, and the adjacent second straight pin member 412 is fixed by the adhesive member 70. Thereby, the attachment state of the plurality of first straight pin members 411 and second straight pin members 412 to the core 3 can be made stable.

The first external electrode 51 is connected to one first straight pin member 411, and the first straight pin member 411 is connected to one end of the bent pin member 410 of the turn next to the first straight pin member 411. Connected. One first straight pin member 411 has a mounting piece 411c. The first external electrode 51 has a mounting portion 51 a that fits into the case 2 . The attachment piece 411c of the first straight pin member 411 is connected to the attachment portion 51a of the first external electrode 51. Specifically, the attachment portion 51a passes through the first opening 216 and is connected to the attachment piece 411c. In short, the first coil 41 and the first external electrode 51 are electrically connected via the first opening 216.

The second external electrode 52 is connected to the other first straight pin member 411, and the other first straight pin member 411 is connected to one end of the second straight pin member 412 of the turn next to the other first straight pin member 411. connected to. The attachment piece 411c of the other first linear pin member 411 is connected to the attachment portion 52a of the second external electrode 52. Specifically, the attachment portion 52a passes through the second opening 216 and is connected to the attachment piece 411c. In short, the first coil 41 and the second external electrode 52 are electrically connected via the second opening 216.

The second coil 42, like the first coil 41, is composed of a plurality of pin members. That is, the second coil 42 includes, in order from one end to the other, a first straight pin member 421 on one end (one side), a plurality of sets of bent pin members 420 and a second straight pin member 422, and a second straight pin member 422 on the other end (one side). the other) first straight pin member 421. Bent pin members 420 and second straight pin members 422 are alternately connected and wound around the core 3 . That is, the plurality of bent pin members 420 and the second straight pin members 422 are connected, and the connected plurality of bent pin members 420 and the second straight pin members 422 are spirally wound around the core 3. .

The third external electrode 53 is connected to one first straight pin member 421, and one first straight pin member 421 is connected to one end of the bent pin member 420 of the turn next to the one first straight pin member 421. Connected. The attachment piece 421c of the first straight pin member 421 is connected to the attachment portion 53a of the third external electrode 53. Specifically, the attachment portion 53a passes through the first opening 216 and is connected to the attachment piece 421c. In short, the second coil 42 and the third external electrode 53 are electrically connected via the first opening 216.

The fourth external electrode 54 is connected to the other first straight pin member 421, and the other first straight pin member 421 is connected to one end of the second straight pin member 412 of the turn next to the other first straight pin member 421. connected to. The attachment piece 421c of the other first linear pin member 421 is connected to the attachment portion 54a of the fourth external electrode 54. Specifically, the attachment portion 54a passes through the third opening 216 and is connected to the attachment piece 421c. In short, the second coil 42 and the fourth external electrode 54 are electrically connected via the third opening 216.

As shown in FIG. 3, the first coil 41 and the second coil 42 (pin members 410 to 412, 420 to 422) each include a conductor portion and a coating covering a portion of the conductor portion. The conductor portion is, for example, a copper wire, and the coating is, for example, a polyamide-imide resin. The thickness of the coating is, for example, 0.02 to 0.04 mm.

The first linear pin members 411, 421 are composed of conductor portions 411a, 421a without a coating. The second straight pin members 412, 422 are composed of conductor portions 412a, 422a without a coating. The bending pin members 410, 420 are composed of conductor portions 410a, 420a and coatings 410b, 420b.

At one end and the other end of the bending pin members 410, 420, the conductor portions 410a, 420a are exposed from the coatings 410b, 420b. That is, the first straight pin members 411, 421, the second straight pin members 412, 422, and the bent pin members 410, 420 are welded to each other at the exposed conductor parts 411a, 421a, 412a, 422a, 410a, 420a. has been done.

In this way, the first coil 41 and the second coil 42 have a conductor member and a covering member that covers a part of the conductor member. The conductor member includes conductor portions 411a, 421a, 412a, 422a, 410a, and 420a, and a welding portion for welding the conductor portions. The covering member includes coatings 410b and 420b. The conductor member that is not covered by the covering member, that is, the conductor portion and welded portion exposed from the film (without a film) corresponds to an uncoated region of the coil that is not covered by the covering member.

FIG. 6 is a cross-sectional view of the inductor component 1 including the central axis C of the core 3, and more specifically, an XZ cross-sectional view passing through the center of the inductor component 1 in the Y direction. In FIG. 6, the box portion 22 is omitted.

As shown in FIG. 6, in the first coil 41, the ends of adjacent pin members have welded parts welded to each other. A welded part refers to a part that melts during welding and then hardens. Specifically, the first coil 41 has a first welded portion w11 and a second welded portion w12. More specifically, in adjacent turns in the first coil 41, the second straight pin member 412 and the bent pin member 410 of one turn are connected to one conductor portion 412a of the second straight pin member 412. The conductor portions 410a of the pin members 410 are welded to each other to form a first welded portion w11, and the second straight pin member 412 and the bent pin member 410 of the other turn are connected to the other turn of the second straight pin member 412. The conductor portion 412a and the conductor portion 410a of the bending pin member are welded together to form a second welded portion w12.

The first welded portion w11 is located above the first end surface 301 of the core 3. Being located above the first end surface 301 means being above the surface of the first end surface 301, and does not mean above or below in the drawing. Note that the first welded portion w11 may be located above the inner peripheral surface 303 of the core 3, or may be located above the first end surface 301 and the inner peripheral surface 303 of the core 3.

The second welding portion w12 is located above the first end surface 301 of the core 3. Note that the second welded portion w12 may be located above the outer peripheral surface 304 of the core 3, or may be located above the first end surface 301 and the outer peripheral surface 304 of the core 3.

Note that, although FIG. 6 shows a turn made up of the second straight pin member 412 and the bending pin member 410 of the first coil 41, a turn made of the first straight pin member 411 and the bending pin member 410 The same applies to constructed turns. Specifically, the first straight pin member 411 is welded at the conductor portion 410a of the bent pin member 410 connected to the conductor portion 411a to form a first welded portion w11 or a second welded portion w12.

The second coil 42 has a first weld part w21 and a second weld part w22. In the second coil 42, similarly to the first coil 41, in adjacent turns, the second straight pin member 422 and the bent pin member 420 of one turn are connected to one conductor portion of the second straight pin member 422. 422a and the conductor portion 420a of the bending pin member 420 to form a first welded portion w21, and the second straight pin member 422 and the bending pin member 420 of the other turn are welded to each other at the conductor portion 420a of the bending pin member 420. The other conductor portion 422a of the bent pin member is welded to the conductor portion 420a of the bending pin member to form a second weld portion w22. Further, the first straight pin member 421 is welded at the conductor portion 420a of the bent pin member 420 connected to the conductor portion 421a, forming a first welded portion w21 or a second welded portion w22. The first welded portion w21 and the second welded portion w22 of the second coil 42 have the same configuration as the first welded portion w11 and the second welded portion w12 of the first coil 41, and the description thereof will be omitted.

The core 3 has a first portion 310 containing MnZn-based ferrite and a second portion 320 containing NiZn-based ferrite. The composition of the MnZn-based ferrite is, for example, 51% Fe, 4% O, 12% Mn, and 12% Zn. The composition of the NiZn-based ferrite is, for example, 45% Fe, 3% O, 8% Ni, and 18% Zn.

At least a portion of the second portion 320 faces an uncoated region of the first coil 41 and the second coil 42 that is not covered with the covering member. Specifically, at least a portion of the second portion 320 faces the first linear pin member 411, the second linear pin member 422, the first welds w11, w21, and the second welds w12, w22. .

The first portion 310 and the second portion 320 are each rectangular in cross section including the central axis C. The first portion 310 and the second portion 320 are arranged above and below in the Z direction. The second portion 320 is located on the lower side in the Z direction, that is, on the uncovered region side of the first coil 41 and the second coil 42.

According to the above configuration, the electrical conductivity of the NiZn-based ferrite of the second portion 320 is lower than the electrical conductivity of the MnZn-based ferrite of the first portion 310, and the surface resistance of the second portion 320 is the surface resistance of the first portion 310. higher than For example, the electrical conductivity of MnZn-based ferrite is 3.33 (S/m), and the electrical conductivity of NiZn-based ferrite is 1×10 ⁻⁶ (S/m).

Since the second portion 320 of the core 3 is opposed to the uncovered areas of the coils 41 and 42, insulation between the core 3 and the coils 41 and 42 can be ensured. Therefore, a conventional resin cap covering the core 3 is not required, and the cross-sectional area of the core 3 can be secured by the thickness of the cap. This ensures high inductance. Therefore, it is possible to suppress the increase in product size and ensure high inductance.
Preferably, all of the uncovered regions face the second portion 320, so that insulation between the core 3 and the coils 41, 42 can be further ensured. Note that at least a portion of the non-covered region may face the second portion 320.
Preferably, all of the welded portions face the second portion 320, so that insulation between the core 3 and the coils 41, 42 can be further ensured. Note that at least a portion of may be opposed to the second portion 320.

Furthermore, when a toroidal coil is created using the MnZn ferrite of the first portion 310, there is an impedance peak around 1 MHz, and when a toroidal coil is created using the NiZn ferrite of the second portion 320, An impedance peak exists in a frequency range higher than 1 MHz. Since MnZn-based ferrite and NiZn-based ferrite are combined, the frequency characteristics of the core 3 are the sum of their respective frequency characteristics, and high impedance can be obtained over a wide band.

As shown in FIG. 6, the second portion 320 is provided over the first end surface 301, a portion of the inner circumferential surface 303, and a portion of the outer circumferential surface 304. Thereby, the insulation between the core 3 and the coils 41 and 42 can be improved. On the other hand, at least a portion of the first portion 310 is provided on the second end surface 302 where the welded portion is not opposed. Thereby, by providing the first portion 310 on the second end surface 302, the insulation between the core 3 and the coils 41 and 42 can be improved.

As shown in FIG. 6, the resin member 90 contacts the second portion 320 and the bottom plate portion 21 to fix the core 3 to the bottom plate portion 21. According to this, when stress occurs during curing and shrinkage of the resin member 90 or stress due to thermal expansion of the resin member 90 at high temperatures, the resin member 90 is in contact with the second portion 320, so that stress on the resin member 90 is generated. is transmitted to the second portion 320. The NiZn-based ferrite of the second portion 320 has a lower magnetic permeability than the MnZn-based ferrite of the first portion 310 and is less affected by magnetostriction, so deterioration of the characteristics of the core 3 due to magnetostriction can be reduced. Specifically, for example, the initial magnetic permeability of MnZn-based ferrite is 8,500, and the initial magnetic permeability of NiZn-based ferrite is 800. In this case, NiZn-based ferrite can reduce the rate of decrease in inductance and impedance due to magnetostriction compared to MnZn-based ferrite.

The resin member 90 is fixed in the recess 215, fixes the inductor element L to the bottom plate part 21, and covers at least part of the uncovered areas of the coils 41 and 42. Preferably, resin member 90 covers all uncovered areas of coils 41 and 42.

Since the resin member 90 is made of, for example, a thermosetting resin, it is fixed to the inductor element L and the bottom plate portion 21 by curing. Further, in the manufacturing process of the inductor component 1, when filling the recess 215 with the liquid resin member 90, the liquid resin member 90 can be retained in the recess 215, and the resin member 90 can hold the inductor element L into the bottom plate portion 21. can be securely fixed.

Preferably, the core 3 further includes a connecting member 80 that connects the first portion 310 and the second portion 320. The elastic modulus (specifically, bending elastic modulus) of the connecting member 80 is 1.0 MPa or more and 50 MPa or less. The connection member 80 is made of, for example, urethane resin or silicone resin. According to this, since the elastic modulus of the connecting member 80 is low, for example, when the resin member 90 is in contact with the second portion 320, even if the stress of the resin member 90 is transmitted to the second portion 320, the second portion The stress at 320 is relieved by the connecting member 80. Thereby, stress transmitted from the second portion 320 to the first portion 310 can be reduced, and reduction in inductance due to magnetostriction can be reduced. Note that the first portion 310 and the second portion 320 may be directly connected without providing the connecting member 80.

Preferably, the volume ratio of the first portion 310 and the second portion 320 is 6:4 to 8:2. According to this, when the magnetic permeability of MnZn ferrite is about 7,000 to 10,000 and the magnetic permeability of NiZn ferrite is about 500 to 800, the volume ratio of MnZn ferrite and NiZn ferrite is 6:4 to 8. :2, a constant high impedance can be obtained over a wide band. To measure the volume ratio, the cross-sectional area is measured from a cross-section including the central axis C, the circumference of the oval shape of the core 3 is multiplied by this cross-sectional area to determine the volume, and the volume ratio is determined from each volume.

Here, FIG. 7 shows the relationship between frequency and impedance. FIG. 7 shows the relationship when the volume ratio of MnZn-based ferrite and NiZn-based ferrite is changed.

Graph L1 is shown by a solid line and shows the relationship when the volume ratio of MnZn-based ferrite and NiZn-based ferrite is 7:3. Graph L2 is indicated by a dashed line and shows the relationship when the volume ratio of MnZn-based ferrite and NiZn-based ferrite is 8:2.

Graph L3 is indicated by a two-dot chain line, and shows the relationship when the volume ratio of MnZn-based ferrite and NiZn-based ferrite is 6:4. Graph L4 is indicated by a dotted line and shows the relationship when the volume ratio of MnZn-based ferrite and NiZn-based ferrite is 5:5.

Graph L5 is indicated by a three-dot chain line and shows a comparative example when the core is made of MnZn-based ferrite. Graph L6 is indicated by a three-dot chain line and shows a comparative example in which the core is made of NiZn-based ferrite.

As can be seen from FIG. 7, the graph L5 has an impedance peak around 1 MHz, and the graph L6 has an impedance peak around 20 MHz. On the other hand, in graphs L1, L2, L3, and L4, impedance peaks exist near 1 MHz and 20 MHz, respectively.

Compared with graphs L2, L3, and L4, graph L1 can make the peak around 1 MHz equal to the peak around 20 MHz, and can obtain a constant high impedance in a wide frequency band. In graph L2, compared to graph L1, the peak around 1 MHz is higher, while the peak around 20 MHz is lower. In graph L3, compared to graph L1, the peak around 1 MHz is lower, while the peak around 20 MHz is higher. In graph L4, compared to graph L1, the peak around 1 MHz is lower, while the peak around 20 MHz is higher. In graph L4, compared to graph L3, the peak around 1 MHz is lower, while the peak around 20 MHz is higher.
From the above, preferably, in the case of graph L1, graph L2, and graph L3, that is, when the volume ratio of MnZn ferrite to NiZn ferrite is 6:4 to 8:2, a constant high impedance is achieved in a wide band. You can see what you can get. More preferably, in the case of graph L1, that is, when the volume ratio of MnZn-based ferrite to NiZn-based ferrite is 7:3, it can be seen that a constant high impedance can be obtained more significantly over a wide band.

(Method of manufacturing inductor parts)
Next, a method for manufacturing the inductor component 1 will be explained.

As shown in FIG. 3, the first coil 41 and the second coil 42 are wound around the core 3 so that their winding axes run parallel to each other, and the exposed conductor parts 411a, 412a, 410a of the first coil 41 are At least a portion of the exposed conductor portions 421a, 422a, and 420a of the second coil 42 are arranged on the first end surface 301 side of the core 3.

Thereafter, each pin member of the first coil 41 is welded, and each pin member of the second coil 42 is welded, with the first end surface 301 of the core 3 facing upward.

Thereafter, as shown in FIG. 6, the core 3 and the coils 41, 42 are placed in the recess 215 of the bottom plate part 21 so that the conductor parts exposed from the coating in the coils 41, 42 are located on the first main surface 210a side. Place it inside. Then, the liquid resin member 90 is filled into the recess 215 by, for example, a potting method. At this time, the liquid resin member 90 remains in the recess 215 and spreads over the conductor portions and parts of the core 30 exposed from the coatings of the coils 41 and 42. Note that in order to prevent the liquid resin member 90 from leaking from the opening 216, a tape is attached to the second main surface 210b of the bottom portion 210 so as to close the opening 216.

Thereafter, heat is applied to harden the liquid resin member 90. Thereby, the core 3 and the coils 41 and 42 can be fixed to the bottom plate part 21 by the resin member 90, and the conductor parts of the coils 41 and 42 exposed from the coating can be covered by the resin member 90. Further, the opening 216 can be filled with the resin member 90. A thermosetting epoxy resin is used as the material for the resin member 90, and has an elastic modulus of 7 GPa, and is cured by heating at 120° C. for 30 minutes as a curing condition.

Thereafter, the inductor component 1 is manufactured by covering the box part 22 and storing it in the case 2. By using such a manufacturing method, the number of steps for manufacturing the inductor component 1 can be reduced, and the inductor component 1 can be manufactured more easily.

<Second embodiment>
FIG. 8A is a cross-sectional view of the inductor component of the second embodiment. FIG. 8A shows an XZ cross section of the core of the inductor component. The second embodiment differs from the first embodiment in the configuration of the core. This difference will be explained below. The other configurations are the same as those in the first embodiment, and their explanation will be omitted.

As shown in FIG. 8A, in the inductor component 1A of the second embodiment, the first portion 310 and the second portion 320 of the core 3A are each L-shaped in a cross section including the central axis C of the core 3A.

The first portion 310 includes a first wall portion 311 extending in a direction parallel to the central axis C, and a first base portion 312 extending in a direction perpendicular to the central axis C (hereinafter also referred to as the radial direction). have The first base portion 312 is a portion extending in the radial direction from the inner peripheral surface 303 to the outer peripheral surface 304 of the core 3A, and the first wall portion 311 extends from the upper surface of the first base portion 312 along the central axis C. It is an extended part. The first wall portion 311 and the first base portion 312 are formed in an annular shape centered on the central axis C. The boundary between the first wall portion 311 and the first base portion 312 is indicated by a two-dot chain line.

The second portion 320 has a second wall portion 321 extending in a direction parallel to the central axis C, and a second base portion 322 extending in a direction perpendicular to the central axis C. The second base portion 322 is a portion extending in the radial direction from the inner peripheral surface 303 to the outer peripheral surface 304 of the core 3A, and the second wall portion 321 extends from the upper surface of the second base portion 322 along the central axis C. It is an extended part. The second wall portion 321 and the second base portion 322 are formed in an annular shape centered on the central axis C. The boundary between the second wall portion 321 and the second base portion 322 is indicated by a two-dot chain line.

The first wall portion 311 and the second wall portion 321 are arranged in a direction perpendicular to the central axis C such that the inner surface 311a of the first wall portion 311 and the inner surface 321a of the second wall portion 321 are in contact with each other. The inner side surface 311a of the first wall section 311 refers to the inner side (notch side ). The inner side surface 321a of the second wall portion 321 refers to the inner side (notch side ). The first base portion 312 and the second base portion 322 are arranged on opposite sides of the first wall portion 311 and the second wall portion 321 in a direction parallel to the central axis C.

According to the above configuration, the first wall portion 311 and the second wall portion 321 are arranged in a direction perpendicular to the central axis C, so that Positional shift can be suppressed. Further, the first wall portion 311 and the second wall portion 321 are arranged in a direction perpendicular to the central axis C, and the first base portion 312 and the second base portion 322 are arranged on opposite sides in a direction parallel to the central axis C. Since the first portion 310 and the second portion 320 are arranged, the cross-sectional shape of the core 3A, which is a combination of the first portion 310 and the second portion 320, can be made rectangular.

As shown in FIG. 8A, the first wall portion 311 is located closer to the central axis C than the second wall portion 321. The first wall portion 311 is provided on the inner peripheral surface 303 side of the core 3A, and the second wall portion 321 is provided on the outer peripheral surface 304 side of the core 3A.

In other words, regarding the ratio of the first portion 310 to the second portion 320, the area on the inner circumferential side of the core 3A is larger than the area on the outer circumferential side of the core 3A. The inner peripheral side region of the core 3A refers to the region on the inner peripheral surface 303 side of the center line M in the width direction (direction perpendicular to the central axis C) of the core 3A in a cross section including the central axis C of the core 3A. The region on the outer peripheral side of the core 3A refers to the region closer to the outer peripheral surface 304 than the center line M in the width direction of the core 3A in a cross section including the central axis C of the core 3A.

According to the above configuration, the first wall portion 311 is located closer to the central axis C than the second wall portion 321, so that the volume of the first portion 310 is reduced in the region where the magnetic path length is short on the inner peripheral side of the core 3A. Can be many. As a result, the characteristics of MnZn-based ferrite appear strongly, and the impedance near 1 MHz can be increased.

Here, FIG. 8B shows the relationship between frequency and impedance. Graph L1 is indicated by a solid line and shows the relationship when the first portion 310 and second portion 320 of the core 3A have an L-shape, as shown in the second embodiment of FIG. 8A. Graph L2 is indicated by a dotted line and shows the relationship when the shapes of the first portion 310 and the second portion 320 of the core 3 are rectangular, as shown in the first embodiment of FIG. Graph L1 and graph L2 both show the relationship when the volume ratio of MnZn-based ferrite and NiZn-based ferrite is 5:5. As can be seen from FIG. 8B, the graph L1 can improve the impedance around 1 MHz compared to the graph L2. That is, in the graph L1, the volume of the first portion 310 is larger in the region on the inner peripheral side of the core 3A than in the graph L2, so the characteristics of MnZn-based ferrite appear more strongly.

Further, as shown in FIG. 8A, since the first wall portion 311 is located closer to the central axis C than the second wall portion 321, it is possible to increase the volume of the second portion 320 in the area on the outer peripheral side of the core 3A. can. As a result, when applying the liquid resin member 90 to the outer peripheral side of the core 3A, even if the resin member 90 wets the outer peripheral surface 304 of the core 3A, the resin is applied to the second portion 320 of NiZn-based ferrite, which is less affected by magnetostriction. While the member 90 adheres, it becomes difficult for the resin member 90 to adhere to the first portion 310 of MnZn-based ferrite, which is largely affected by magnetostriction. That is, since the liquid resin member 90 is applied to the outer circumferential side of the core 3A, the amount of the resin member 90 on the outer circumferential side of the core 3A increases, and the resin member 90 wets the outer circumferential surface 304 of the core 3A. It is difficult for the resin member 90 to enter the inner peripheral side of the core 3A, and the amount of the resin member 90 is reduced, making it difficult for the resin member 90 to wet the inner peripheral surface 303 of the core 3A.

Therefore, even if stress occurs in the resin member 90, the stress in the resin member 90 is transmitted to the second portion 320 instead of the first portion 310. The NiZn-based ferrite of the second portion 320 has a lower magnetic permeability than the MnZn-based ferrite of the first portion 310 and is less affected by magnetostriction, so that deterioration of the characteristics of the core 3A due to magnetostriction can be reduced.

<Third embodiment>
FIG. 9 is a cross-sectional view of an inductor component according to the third embodiment. FIG. 9 shows an XZ cross section of the core of the inductor component. The third embodiment differs from the second embodiment in the configuration of the core. This difference will be explained below. The other configurations are the same as those in the second embodiment, and their explanation will be omitted.

As shown in FIG. 9, in the inductor component 1B of the third embodiment, the first portion 310 and the second portion 320 of the core 3B are each L-shaped in a cross section including the central axis C of the core 3B. The first portion 310 has a first wall portion 311 and a first base portion 312 . The second portion 320 has a second wall portion 321 and a second base portion 322.

In the inductor component 1B of the third embodiment, the second wall portion 321 is located closer to the central axis C than the first wall portion 311, unlike the inductor component 1A of the second embodiment (see FIG. 8A). In other words, regarding the ratio of the first portion 310 to the second portion 320, the area on the outer circumferential side of the core 3B is larger than the area on the inner circumferential side of the core 3B.

According to the above configuration, since the second wall portion 321 is located closer to the central axis C than the first wall portion 311, the volume of the second portion 320 is can be increased. As a result, the characteristics of NiZn-based ferrite appear strongly, and the impedance near 20 MHz can be increased.

<Fourth embodiment>
FIG. 10 is a cross-sectional view of an inductor component according to the fourth embodiment. FIG. 10 shows an XZ cross section of the core of the inductor component. The fourth embodiment differs from the second embodiment in the configuration of the core. This difference will be explained below. The other configurations are the same as those in the second embodiment, and their explanation will be omitted.

As shown in FIG. 10, in the inductor component 1C of the fourth embodiment, in a cross section including the central axis C of the core 3C, the first portion 310 of the core 3C has a T-shape, and the second portion 320 of the core 3C has a T-shape. is U-shaped.

The first portion 310 has a first base portion 313 and a convex portion 314 provided on the lower surface of the first base portion 313. The first base portion 313 is provided on the second end surface 302, the inner peripheral surface 303, and the outer peripheral surface 304. The convex portion 314 extends downward from the lower surface of the first base portion 313 and is located on the center line M. The outer surface shape of the cross section of the convex portion 314 is rectangular, but may be polygonal or curved. The first base portion 313 and the convex portion 314 are formed in an annular shape centered on the central axis C.

The second portion 320 has a second base portion 323. The second base portion 323 is provided on the first end surface 301, the inner peripheral surface 303, and the outer peripheral surface 304. A recess 324 is provided on the upper surface of the second base portion 323 . The recess 324 extends downward from the upper surface of the second base portion 323 and is located on the center line M. The inner surface shape of the cross section of the recess 324 is rectangular, but may be polygonal or curved. The height dimension of the second base part 323 in the Z direction is larger than the height dimension of the first base part 313 in the Z direction. The second base portion 323 and the recessed portion 324 are formed in an annular shape centered on the central axis C.

With the convex portion 314 of the first portion 310 fitted into the recess 324 of the second portion 320, the first portion 310 and the second portion 320 are combined, and the cross-sectional shape of the core 3C becomes rectangular. Thereby, positional deviation in the direction orthogonal to the central axis C between the first portion 310 and the second portion 320 can be suppressed.

As shown in FIG. 10, in the cross section including the central axis C, the area of the second portion 320 is larger than the area of the first portion 310 in the inner circumference side region of the core 3C and the outer circumference side region of the core 3C. It's also big. According to this, in the region on the inner circumferential side of the core 3C, the area of the second portion 320 is larger than the area of the first portion 310, so that in the region on the inner circumferential side of the core 3C where the magnetic path length is short, The volume of portion 320 can be increased. As a result, the characteristics of NiZn-based ferrite appear strongly, and the impedance near 20 MHz can be increased.

Furthermore, since the area of the second portion 320 is larger than the area of the first portion 310 in the inner and outer peripheral regions of the core 3C, the second portion 320 has a larger area than the first portion 310 in the inner and outer peripheral regions of the core 3C. The volume can be increased. As a result, when applying the liquid resin member 90, even if the resin member 90 wets the inner circumferential surface 303 and the outer circumferential surface 304 of the core 3C, the resin member is applied to the second portion 320 of NiZn-based ferrite, which is less affected by magnetostriction. On the other hand, it becomes difficult for the resin member 90 to adhere to the first portion 310 of MnZn-based ferrite, which is largely affected by magnetostriction. Therefore, even if stress is generated in the resin member 90, the stress in the resin member 90 is transmitted to the second portion 320 instead of the first portion 310. The NiZn-based ferrite of the second portion 320 has a lower magnetic permeability than the MnZn-based ferrite of the first portion 310 and is less affected by magnetostriction, so that deterioration of the characteristics of the core 3C due to magnetostriction can be reduced.

<Fifth embodiment>
FIG. 11 is a cross-sectional view of an inductor component according to the fifth embodiment. FIG. 11 shows an XZ cross section of the core of the inductor component. The fifth embodiment differs from the fourth embodiment in the core configuration. This difference will be explained below. The other configurations are the same as those of the fourth embodiment, and the explanation thereof will be omitted.

As shown in FIG. 11, in the inductor component 1D of the fifth embodiment, in a cross section including the central axis C of the core 3D, the first portion 310 of the core 3D is U-shaped, and the second portion 320 of the core 3D is U-shaped. is T-shaped.

The first portion 310 has a first base portion 313. The first base portion 313 is provided on the second end surface 302, the inner peripheral surface 303, and the outer peripheral surface 304. A recess 315 is provided on the lower surface of the first base portion 313 . The recessed portion 315 extends upward from the lower surface of the first base portion 313 .

The second portion 320 includes a second base portion 323 and a convex portion 325 provided on the lower surface of the second base portion 323. The second base portion 323 is provided on the first end surface 301, the inner peripheral surface 303, and the outer peripheral surface 304. The convex portion 325 extends upward from the upper surface of the second base portion 323. The height dimension of the second base part 323 in the Z direction is smaller than the height dimension of the first base part 313 in the Z direction.

With the convex portion 325 of the second portion 320 fitted into the recess 315 of the first portion 310, the first portion 310 and the second portion 320 are combined, and the cross-sectional shape of the core 3D becomes rectangular. Thereby, positional deviation in the direction orthogonal to the central axis C between the first portion 310 and the second portion 320 can be suppressed.

As shown in FIG. 11, in the cross section including the central axis C, the area of the first portion 310 is larger than the area of the second portion 320 in the inner peripheral side region of the core 3D and the outer peripheral side region of the core 3D. It's also big. According to this, in the region on the inner circumferential side of the core 3D, the area of the first portion 310 is larger than the area of the second portion 320, so in the region on the inner circumferential side of the core 3D where the magnetic path length is short, the first portion 310 The volume of portion 310 can be increased. As a result, the characteristics of MnZn-based ferrite appear strongly, and the impedance near 1 MHz can be increased.

<Sixth embodiment>
FIG. 12 is a cross-sectional view of an inductor component according to the sixth embodiment. FIG. 12 shows an XZ cross section of the core of the inductor component. The sixth embodiment differs from the second embodiment in the configuration of the core. This difference will be explained below. The other configurations are the same as those in the second embodiment, and their explanation will be omitted.

As shown in FIG. 12, in the inductor component 1E of the sixth embodiment, the first portion 310 and the second portion 320 of the core 3E are each rectangular in a cross section including the central axis C of the core 3E.

The first portion 310 has a first wall portion 316. The second portion 320 has a second wall 326 . The first wall portion 316 and the second wall portion 326 are formed in an annular shape centered on the central axis C. The first wall portion 316 is arranged closer to the central axis C than the second wall portion 326 is. The second wall portion 326 is provided on the outer peripheral side of the first wall portion 316. That is, the first wall portion 316 is located in an area on the inner peripheral side of the core 3E, and the second wall portion 326 is located in an area on the outer peripheral side of the core 3E. Thereby, positional deviation in the direction orthogonal to the central axis C between the first portion 310 and the second portion 320 can be suppressed.

Here, a plurality of wire members constituting one turn bent into an annular shape may be used in the coil, and in this case, the welding part connecting two wire members of adjacent turns is arranged on the outer peripheral side of the core 3E. . Thereby, since the second portion 320 faces the welded portion, insulation between the core 3E and the coil can be ensured.

As shown in FIG. 12, regarding the ratio of the first portion 310 to the second portion 320, the area on the inner circumferential side of the core 3E is larger than the area on the outer circumferential side of the core 3E. According to this, the volume of the first portion 310 can be increased in the region on the inner peripheral side of the core 3E where the magnetic path length is short. As a result, the characteristics of MnZn-based ferrite appear strongly, and the impedance near 1 MHz can be increased.

Furthermore, the volume of the second portion 320 can be increased in the region on the outer peripheral side of the core 3E. As a result, when applying the liquid resin member 90 to the outer peripheral side of the core 3E, even if the resin member 90 wets the outer peripheral surface 304 of the core 3E, the resin is applied to the second portion 320 of NiZn-based ferrite, which is less affected by magnetostriction. While the member 90 adheres, it becomes difficult for the resin member 90 to adhere to the first portion 310 of MnZn-based ferrite, which is largely affected by magnetostriction. Therefore, even if stress is generated in the resin member 90, the stress in the resin member 90 is transmitted to the second portion 320 instead of the first portion 310. The NiZn-based ferrite of the second portion 320 has a lower magnetic permeability than the MnZn-based ferrite of the first portion 310 and is less affected by magnetostriction, so that deterioration of the characteristics of the core 3E due to magnetostriction can be reduced.

<Seventh embodiment>
FIG. 13 is a cross-sectional view of an inductor component according to the seventh embodiment. FIG. 13 shows an XZ cross section of the core of the inductor component. The seventh embodiment differs from the sixth embodiment in the configuration of the core. This difference will be explained below. The other configurations are the same as those in the sixth embodiment, and their explanation will be omitted.

As shown in FIG. 13, in the inductor component 1F of the seventh embodiment, the first portion 310 and the second portion 320 of the core 3F are each rectangular in a cross section including the central axis C of the core 3F. The first portion 310 has a first wall 316 . The second portion 320 has a second wall 326 .

In the inductor component 1F of the seventh embodiment, unlike the inductor component 1E of the sixth embodiment (see FIG. 12), the second wall portion 326 is arranged closer to the central axis C than the first wall portion 316. The first wall portion 316 is provided on the outer peripheral side of the second wall portion 326. That is, the second wall portion 326 is located in an area on the inner peripheral side of the core 3F, and the first wall portion 316 is located in an area on the outer peripheral side of the core 3F. Thereby, positional deviation in the direction orthogonal to the central axis C between the first portion 310 and the second portion 320 can be suppressed.

Here, a plurality of wire members constituting one turn bent into an annular shape may be used in the coil, and in this case, the welding part connecting two wire members of adjacent turns is arranged on the inner circumferential side of the core 3F. do. Thereby, since the second portion 320 faces the welded portion, insulation between the core 3F and the coil can be ensured.

As shown in FIG. 13, regarding the ratio of the second portion 320 to the first portion 310, the area on the inner circumferential side of the core 3F is larger than the area on the outer circumferential side of the core 3F. According to this, the volume of the second portion 320 can be increased in the region where the magnetic path length is short on the inner peripheral side of the core 3F. As a result, the characteristics of NiZn-based ferrite appear strongly, and the impedance near 20 MHz can be increased.

<Eighth embodiment>
Next, referring to FIG. 6, an inductor component according to an eighth embodiment will be described. Referring to FIG. 6, the inductor component of the eighth embodiment includes an annular core 3, coils 41 and 42 wound around the core 3, and a bottom plate portion 21 on which the core 3 and the coils 41 and 42 are placed. , and a resin member 90 disposed on the bottom plate portion 21. The core 3 has a first portion 310 containing MnZn-based ferrite and a second portion 320 containing NiZn-based ferrite. The resin member 90 contacts the second portion 320 and the bottom plate portion 21 to fix the core 3 to the bottom plate portion 21 .
In this embodiment, the coil does not necessarily have a conductor member and a covering member that covers a part of the conductor member. Furthermore, it is not essential that at least a portion of the second portion faces an uncoated region of the coil that is not covered by the covering member.
Note that the configuration of each member is the same as that of the inductor component of the first embodiment, so a description thereof will be omitted.

According to the above configuration, when a toroidal coil is created using the MnZn-based ferrite of the first portion 310, an impedance peak exists near 1 MHz, and when a toroidal coil is created using the NiZn-based ferrite of the second portion 320. In this case, an impedance peak exists in a frequency range higher than 1 MHz. Since MnZn-based ferrite and NiZn-based ferrite are combined, the frequency characteristics of the core 3 are the sum of their respective frequency characteristics, and high impedance can be obtained over a wide band.

Further, when stress occurs due to curing and shrinkage of the resin member 90 or stress due to thermal expansion of the resin member 90 at high temperatures, since the resin member 90 is in contact with the second portion 320, the stress in the resin member 90 is reduced to the second portion 320. This is transmitted to portion 320. The NiZn-based ferrite of the second portion 320 has a lower magnetic permeability than the MnZn-based ferrite of the first portion 310 and is less affected by magnetostriction, so deterioration of the characteristics of the core 3 due to magnetostriction can be reduced.

On the other hand, in the conventional inductor component described in JP-A-2021-150314, ferrite is used for the core. Another conventional problem is that when MnZn-based ferrite is used for the core, there is an impedance peak around 1 MHz, so high impedance cannot be obtained in higher frequency ranges.

Therefore, another object of the present disclosure is to provide an inductor component that can obtain high impedance over a wide band.

Note that the present disclosure is not limited to the above-described embodiments, and design changes can be made without departing from the gist of the present disclosure. For example, the features of the first to eighth embodiments may be combined in various ways. The shape of the case and the shape of the core are not limited to this embodiment, and can be changed in design. Further, the number of coils is not limited to this embodiment, and the design can be changed. Further, it is not necessary to provide a box portion of the case.

In the embodiment described above, the coil is made up of a plurality of bent pin members and a straight pin member, and one turn is made up of the bent pin members and the straight pin member, but the coil is made up of a plurality of wire members. Alternatively, the wire member may be bent into an annular shape to form one turn.

This application claims priority based on Japanese Patent Application No. 2022-041606 filed in Japan on March 16, 2022, and the entire content thereof is incorporated herein by reference.

1, 1A to 1F Inductor parts 2 Case 21 Bottom plate part 22 Box part 3, 3A to 3F Core 301 First end surface (bottom surface)
302 Second end surface (top surface)
303 Inner circumferential surface 304 Outer circumferential surface 310 First portion 311 First wall portion 311a Inner surface 312 First base portion 313 First base portion 314 Convex portion 315 Recessed portion 316 First wall portion 320 Second portion 321 Second wall portion 321a Inside Side surface 322 Second base part 323 Second base part 324 Recessed part 325 Convex part 326 Second wall part 41 First coil 410 Bent pin member 410a Conductor part 410b Coating 411, 412 First and second straight pin members 411a, 412a Conductor Part 411c Mounting piece 42 Second coil 420 Bent pin member 420a Conductor part 420b Coating 421, 422 First and second straight pin members 421a, 422a Conductor part 421c Mounting piece 51 to 54 First to fourth external electrodes 51a to 54a Mounting part 80 Connection member 90 Resin member C Center axis M Center line L Inductor element

Claims (10)

1. a circular core;
   and a coil wound around the core,
   The core has a first part containing MnZn-based ferrite and a second part containing NiZn-based ferrite,
   The coil includes a conductor member and a covering member that covers a part of the conductor member,
   An inductor component, wherein at least a portion of the second portion faces an uncovered region of the coil that is not covered by the covering member.
2. a bottom plate portion on which the core and the coil are placed;
   further comprising a resin member disposed on the bottom plate portion,
   The inductor component according to claim 1, wherein the resin member contacts the second portion and the bottom plate portion to fix the core to the bottom plate portion.
3. The coil has a plurality of pin members, the ends of adjacent pin members have welded parts welded to each other, and the welded parts are included in the conductor member and are located in the uncovered area. ,
   The inductor component according to claim 1 or 2, wherein at least a portion of the second portion faces the welded portion.
4. The plurality of pin members include a first pin member and a second pin member,
   The first pin member and the second pin member constitute one turn,
   The welded portion includes, in adjacent turns, a first welded portion where a first pin member of one turn and a second pin member of the one turn are welded to each other, and a first welded portion where a first pin member of the one turn is welded to each other; the pin member and the second pin member of the other turn have a second welded portion welded to each other;
   The core has a first surface, a second surface that intersects the first surface, and a third surface that faces the second surface and intersects the first surface,
   The first welded portion is located above at least one of the first surface and the second surface,
   The second welded portion is located above at least one of the first surface and the third surface,
   The inductor component according to claim 3, wherein the second portion is provided over the first surface, a portion of the second surface, and a portion of the third surface.
5. The core has a fourth surface opposite to the first surface,
   The inductor component according to claim 4, wherein at least a portion of the first portion is provided on the fourth surface that is not opposed to the welded portion.
6. The core further includes a connecting member connecting the first part and the second part,
   The inductor component according to any one of claims 1 to 5, wherein the connecting member has an elastic modulus of 1.0 MPa or more and 50 MPa or less.
7. In a cross section including the central axis of the core,
   The first portion is L-shaped and includes a first wall portion extending in a direction parallel to the central axis, and a first base portion extending in a direction perpendicular to the central axis,
   The second portion is L-shaped and includes a second wall portion extending in a direction parallel to the central axis, and a second base portion extending in a direction perpendicular to the central axis,
   The first wall portion and the second wall portion are arranged in a direction perpendicular to the central axis such that the inner surface of the first wall portion and the inner surface of the second wall portion are in contact with each other,
   Any one of claims 1 to 6, wherein the first base part and the second base part are arranged on opposite sides of the first wall part and the second wall part in a direction parallel to the central axis. Inductor parts listed in one of the above.
8. The inductor component according to claim 7, wherein the first wall portion is located closer to the central axis than the second wall portion.
9. The inductor component according to any one of claims 1 to 8, wherein in terms of the ratio of the first portion to the second portion, the area on the inner circumferential side of the core is larger than the area on the outer circumferential side of the core.
10. The inductor component according to any one of claims 1 to 9, wherein the volume ratio of the first part and the second part is 6:4 to 8:2.

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