JP7255754B2 - coil parts - Google Patents

Description

The present disclosure relates to coil components.

As a coil component in which a coil conductor is embedded in a magnetic body portion, a coil component using a composite magnetic body in which magnetic powder and resin are mixed as a magnetic body portion is used. In such a coil component, it has been proposed to use flat or acicular soft magnetic metal powder as the magnetic powder contained in the composite magnetic body in order to increase the magnetic permeability of the magnetic body portion and increase the inductance. (Patent Document 1).

JP-A-2009-9985

With the recent development of high-frequency technology, there is a demand for coil components with excellent frequency characteristics. A coil component using flat or needle-like soft magnetic metal powder as described in Patent Document 1 generally has better frequency characteristics than the case using spherical magnetic powder, but it is not sufficient. More specifically, the ends of the soft magnetic metal powder do not have excellent magnetic properties, and when a magnetic field generated by a coil is strongly applied to the ends of the soft magnetic metal powder, sufficient frequency characteristics cannot be obtained. .

As a result of intensive studies to solve the above problem, the present inventors have found that in a coil component using a composite magnetic body containing an insulating material and a magnetic filler as described above, the long axis of the magnetic filler is in the magnetic field direction. and the ratio of the length of the long axis of the magnetic filler to the thickness of the wire in the direction of the magnetic field is greater than 1, so that the magnetic domains grow and disappear at the ends of the magnetic filler. was suppressed, and as a result, excellent frequency characteristics were obtained, leading to the present invention.

The present disclosure includes the following aspects.
[1] A coil component having a composite magnetic body part containing an insulating material and a magnetic filler and a coil, wherein the coil is wound around the composite magnetic body part,
The magnetic filler is non-spherical and has a core made of a non-magnetic material and a soft magnetic layer provided on the surface of the core,
The magnetic filler is arranged so that its long axis is oriented in the direction of the magnetic field generated by the coil,
A coil component, wherein a ratio of the length of the major axis of the magnetic filler to the thickness of the wire constituting the coil in the direction of the magnetic field is greater than 1.
[2] A coil component having a composite magnetic body part containing an insulating material and a magnetic filler and a coil, wherein the coil is wound around the composite magnetic body part,
The magnetic filler is non-spherical and has a core made of a non-magnetic material and a soft magnetic layer provided on the surface of the core,
The magnetic filler is arranged on the side of the lamination surface of the coil so that its long axis is oriented in the lamination direction of the coil,
A coil component, wherein a ratio of the length of the major axis of the magnetic filler to the thickness of the wire constituting the coil in the stacking direction is greater than 1.
[3] A coil component having a composite magnetic body part containing an insulating material and a magnetic filler and a coil, wherein the coil is wound around the composite magnetic body part,
The coil is an air core coil,
The magnetic filler is non-spherical and has a core made of a non-magnetic material and a soft magnetic layer provided on the surface of the core,
The magnetic filler is arranged in the air-core portion of the air-core coil such that its long axis is oriented in the axial direction of the air-core coil,
A coil component, wherein a ratio of the length of the long axis of the magnetic filler to the thickness of the wire constituting the coil in the axial direction is greater than 1.
[4] The coil component according to any one of [1] to [3] above, wherein the soft magnetic layer in the magnetic filler has striped domain walls.
[5] The coil component according to any one of [1] to [4] above, wherein the major axis lengths of the magnetic filler particles are substantially the same.
[6] The coil component according to any one of [1] to [5] above, wherein at least one end of the core is exposed in at least a portion of the magnetic filler.
[7] The coil component according to any one of [1] to [6] above, wherein the ratio of the length of the long axis of the magnetic filler to the thickness of the laminated coil is 1 or more.
[8] The coil component according to any one of [1] to [7] above, wherein one end of the magnetic filler is on the same plane.
[9] The coil component according to any one of [1] to [8] above, wherein the core of the magnetic filler is a carbon nanotube.
[10] The coil component according to any one of [1] to [9] above, wherein at least one end of the magnetic filler is positioned outside the lateral region of the laminated surface of the coil.
[11] The coil component according to any one of [1] to [10] above, wherein the magnetic filler particles are connected to each other with the same material as the magnetic filler particles or the core portion of the magnetic filler particles.

According to the present invention, in a coil component using a composite magnetic body containing an insulating material and a magnetic filler, the magnetic filler is arranged such that its long axis is oriented in the direction of the magnetic field, and the long axis of the magnetic filler is By setting the ratio of the length of to the thickness of the wire in the magnetic field direction to be greater than 1, a coil component having excellent frequency characteristics can be obtained.

FIG. 1 is a cross-sectional view schematically showing a cross section of a coil component 1a according to one embodiment of the present disclosure. FIG. 2 is a cross-sectional view schematically showing the magnetic filler 8. As shown in FIG. FIG. 3 is a perspective view schematically showing the magnetic domain structure of the soft magnetic layer 12 of the magnetic filler 8. As shown in FIG. FIG. 4 is a diagram for explaining the thickness of the wire rod and the lamination thickness of the coil. FIG. 5 is a cross-sectional view schematically showing magnetic filler 8 in one embodiment. FIG. 6 is a cross-sectional view schematically showing a cross section of a coil component 1b according to another embodiment of the present disclosure. FIG. 7 is a cross-sectional view schematically showing a cross section of a coil component 1c according to another embodiment of the present disclosure. FIG. 8 is a cross-sectional view schematically showing a cross section of a coil component 1d according to another embodiment of the present disclosure. FIG. 9 is a plan view (a) and a cross-sectional view (b) schematically showing a coil component 1e according to another embodiment of the present disclosure. FIG. 10 is a diagram showing a state in which two magnetic fillers are entangled.

Hereinafter, the coil component of the present disclosure will be described in detail with reference to the drawings. However, the shape, arrangement, etc. of the coil component and each component of the present embodiment are not limited to the illustrated example.

(Embodiment 1)
FIG. 1 shows a cross section of a coil component 1a that is one embodiment of the present disclosure. As shown in FIG. 1, the coil component 1a of the present embodiment includes a composite magnetic body portion 2, a coil 3, external electrodes 4 and 5 connected to both ends of the coil 3, and protective layers for protecting the coil 3. 6, a so-called drum core type coil component. The coil 3 is wound around the composite magnetic body portion 2 . The magnetic filler 8 is dispersed in the insulating material 7 in the composite magnetic body portion 2 . As shown in FIG. 2, the magnetic filler 8 has a non-spherical core 11 made of a non-magnetic material and a soft magnetic layer 12 provided on the surface of the core 11 . The magnetic filler 8 is arranged such that its long axis is oriented in the direction of the magnetic field generated by the coil 3 . Also, the ratio of the length of the long axis of the magnetic filler 8 to the thickness of the wire rod in the stacking direction is greater than one.

As described above, the coil component of the present disclosure has a composite magnetic body portion containing an insulating material and a magnetic filler. In this embodiment, the magnetic filler 8 in the composite magnetic body portion 2 is positioned in the air core portion 9 of the coil 3 .

The insulating material 7 is not particularly limited as long as it is an insulating material, and may be resin, ceramic, or the like, for example. When a resin is used as the insulating material, the dispersibility and filling properties of the magnetic filler can be enhanced. On the other hand, when ceramic is used as the insulating material, the heat dissipation of the composite magnetic body portion can be enhanced. Resin and ceramic may be used in combination.

Examples of the resin include, but are not limited to, epoxy resin, phenol resin, polyester resin, polyimide resin, and polyolefin resin. The resin may be used alone or in combination of two or more.

Examples of the ceramic include, but are not limited to, inorganic oxides such as aluminum oxide (typically Al ₂ O ₃ ) and silicon oxide (typically SiO ₂ ); non-magnetic ferrite materials such as Zn, Cu, Composite oxides containing two or more metals selected from Mn and Fe, and the like. The ceramic may be of one type or two or more types.

In one aspect, the composite magnetic body portion 2 may have a gap portion, in other words, an air layer. By including an air layer in the composite magnetic body portion, the leak current between the magnetic fillers is reduced, and excellent frequency characteristics can be obtained.

As shown in FIG. 2, the magnetic filler 8 is non-spherical and has a core 11 made of a non-magnetic material and a soft magnetic layer 12 provided on the surface of the core.

The term "non-spherical" refers to a shape having an aspect ratio of 2 or more. Here, the aspect ratio refers to the ratio of the length of the major axis to the length of the minor axis (length of major axis/length of minor axis). The major axis is the axis (straight line) that can take the longest length in the object, and the minor axis is the axis that has the longest length when the length is taken in a straight line perpendicular to the major axis. (straight line).

The shape of the core 11 has an aspect ratio of 2 or more, preferably 10 or more, more preferably 50 or more. shape, rectangular shape, scaly shape, irregular shape, etc., preferably needle-like or fibrous shape having a high aspect ratio.

The core portion 11 may have a form in which a plurality of core members are assembled. For example, needle-like core members may be assembled to form one core.

Examples of the nonmagnetic material forming the core 11 include carbon, silicon, silicon oxide, and zinc oxide.

Examples of the core portion include, but are not limited to, nanotubes, nanowires, nanofibers, and the like.

Examples of the nanotube include, but are not particularly limited to, metallic nanotube, organic nanotube, inorganic nanotube, and the like. Typically, the nanotubes can be carbon nanotubes, or titania carbon nanotubes.

Examples of the nanowires include, but are not limited to, silicon nanowires, silver nanowires, and the like.

Examples of the nanofibers include, but are not limited to, carbon nanofibers, cellulose nanofibers, and the like.

In a preferred embodiment, the core is a carbon nanotube. By using a carbon nanotube as the core portion, the mechanical strength of the magnetic filler can be enhanced, and the orientation of the magnetic filler can be enhanced. In addition, since the carbon nanotubes grown vertically on the substrate can be used as they are, the coil component can be easily manufactured.

The chirality of the carbon nanotubes is not particularly limited, and may be either semiconductor type or metal type, or a mixture of these may be used. From the viewpoint of reducing the resistance value, it is preferable that the ratio of the metal type is high.

In a preferred embodiment, the core, especially carbon nanotubes, is passivated. Conduction of eddy currents generated in the soft magnetic layer can be prevented by rendering the core nonconductive.

The number of layers of the carbon nanotube is not particularly limited, and may be either single-layer SWCNT (single wall carbon nanotube) or two or more layers MWCNT (multiwall carbon nanotube).

The diameter and length of the nanotubes or nanofibers are not particularly limited. Nanotubes or nanofibers can be, for example, a few microns or longer, 20 microns or longer, 50 microns or longer, 100 microns or longer, 500 microns or longer, 750 microns or longer, 1000 microns or longer, or 2000 microns or longer. A longer length of the carbon nanotube is preferable because the capacity density per area can be increased.

The diameter of the nanotubes or nanofibers is preferably 1000 nm or less, more preferably 800 nm or less, and even more preferably 600 nm or less.

As the material constituting the soft magnetic layer, a soft magnetic material containing iron is preferable. alloys, Fe--Si--Cr alloys, ferritic materials such as MFe ₂ O ₄ (wherein M is Mg, Mn, Fe, Ni, Co, Cu, Zn or Cd), and the like.

A high saturation magnetization can be obtained by using a soft magnetic material containing iron. Also, excellent soft magnetic properties can be obtained by using a multicomponent soft magnetic material. Furthermore, excellent high frequency characteristics can be obtained by using a soft magnetic material containing oxygen. In addition, by using a soft magnetic material containing iron, when the core has a high conductivity, the filmability is enhanced. On the other hand, by using a multicomponent or oxygen-based soft magnetic material, when the core is insulative, the filmability is enhanced.

The soft magnetic layer is formed on the surface of the core.

In a preferred embodiment, as shown in FIG. 3, the soft magnetic layer 12 has a magnetic domain structure with striped domain walls 13 along the width direction of the core 11 . In other words, the domain wall 13 is annularly formed around the core 11 . That is, the magnetic domains of the soft magnetic layer 12 are formed in an annular shape around the core portion 11 . The distance between the striped domain walls 13 may be constant or random, but is usually random. By having the soft magnetic layer having striped domain walls, excellent superimposition characteristics and frequency characteristics can be obtained. The magnetic domain structure can be observed by X-ray magnetic circular dichroism (XMCD) measurement or transmission electron microscope (TEM).

The thickness of the soft magnetic layer is not particularly limited, but may be, for example, 10 nm or more and 1000 nm or less, preferably 10 nm or more and 200 nm or less. By setting the thickness of the soft magnetic layer within this range, it is possible to achieve excellent superimposition characteristics due to the anisotropic shape and excellent frequency characteristics due to the thinness of the magnetic material.

Although the soft magnetic layer is not particularly limited, it can be formed using CVD, atomic layer deposition (ALD), sputtering, or the like. When the soft magnetic layer is formed by CVD, it becomes easier to form a thicker layer. When the soft magnetic layer is formed by sputtering, the magnetic lattice becomes disordered and excellent magnetic properties can be obtained. When the soft magnetic layer is formed by ALD, excellent coating properties can be obtained.

The magnetic filler has a shape with an aspect ratio of 2 or more, preferably 5 or more, more preferably 10 or more. It may be rectangular, scaly, irregular, etc., preferably acicular or fibrous.

In one aspect, the magnetic filler is arranged such that its long axis is oriented in the direction of the magnetic field generated by the coil.

Here, "orientate" means that the orientation parameter P is 0.7 or more.

The orientation parameter P will be described below.
First, a circular plane with a diameter of 10 μm, which is perpendicular to the reference direction and centered at an arbitrary point in the region where the magnetic filler exists in the magnetic field generated by the coil, is defined as the reference plane.
Let θ be the angle formed by the magnetic filler material intersecting the reference plane and the reference plane. If there are N magnetic fillers intersecting the reference plane, the angle formed by each magnetic filler is θi (1≦i≦N). At this time, the orientation parameter P is defined as follows.
The above measurements can be made by cutting out the composite magnetic material portion and observing it with an electron microscope.

P=<Σi(sin θi) ² >/N
(In the formula, <> means average and i takes 1 to N.)

In the above aspect, ^P1 is the orientation parameter P between the magnetic filler and the direction of the magnetic field. The reference direction is the direction of the magnetic field generated by the coil. The orientation parameter ^P1 is preferably 0.8 or higher, more preferably 0.9 or higher, particularly preferably 0.95 or higher. By increasing the orientation parameter ^P1 , the frequency characteristics are further improved.

In one aspect, the magnetic filler is arranged on the side of the lamination surface of the coil so that its major axis is oriented in the lamination direction of the coil. Here, the lamination surface of the coil refers to a surface formed by laminating wire rods forming the coil. For example, in FIG. 1, a plane (10 in FIG. 1) defined by a plurality of wire rods laminated in the innermost part of the air-core coil is a lamination plane of the coil. Moreover, the side of the lamination plane refers to a region perpendicular to the lamination plane. For example, in FIG. 1 , the air core portion is located in a region perpendicular to the stacking surface 10 , that is, located on the side of the stacking surface 10 .

In this aspect, the orientation parameter P between the magnetic filler and the stacking direction of the coil is defined as ^P2 . The reference direction is the stacking direction of the coils. The orientation parameter ^P2 is preferably 0.8 or more, more preferably 0.9 or more, and particularly preferably 0.95 or more. Increasing the orientation parameter ^P2 further improves the frequency characteristics.

In one aspect, the coil is an air-core coil, and the magnetic filler is arranged in the air-core portion of the air-core coil such that its major axis is oriented in the axial direction of the air-core coil. Here, the air core portion refers to a portion surrounded by wires (so-called windings) forming a coil. The axis of the air-core coil refers to the axis that is the center of the wire winding in the coil.

In this aspect, the orientation parameter P between the magnetic filler and the axial direction of the air-core coil, which is the symmetrical direction, is set to ^P3 . The reference direction is the axial direction of the air-core coil. The orientation parameter ^P3 is preferably 0.8 or more, more preferably 0.9 or more, and particularly preferably 0.95 or more. Increasing the orientation parameter ^P3 further improves the frequency characteristics.

The length of the long axis of the magnetic filler is greater than the thickness of the wire rod in the lamination direction. That is, the ratio of the length of the major axis of the magnetic filler to the thickness of the wire in the lamination direction (the length of the major axis of the magnetic filler/the thickness of the wire in the lamination direction) is greater than one. Here, the thickness of the wire rod in the stacking direction is the thickness t of one wire rod along the coil stacking direction (vertical direction in the drawing), as shown in FIG. By making the above ratio larger than 1, the ends of the magnetic filler, which may adversely affect the frequency characteristics, are less likely to be arranged in the region where the magnetic field generated by the coil is strong, thereby improving the frequency characteristics of the coil component.

In a preferred embodiment, the above ratio can be preferably 1.1 or higher, more preferably 2 or higher, even more preferably 5 or higher. Increasing the ratio further improves the frequency characteristics of the coil component.

The upper limit of the length of the long axis of the magnetic filler is not particularly limited. could be.

In a preferred embodiment, the major axis lengths of the magnetic filler particles are substantially the same. By making the major axis lengths of the magnetic filler particles the same, the magnetic properties of the coil component can be made more stable. Here, "substantially the same" means that the difference in the length of the long axis of each magnetic filler is within 10 μm.

In one aspect, the length of the long axis of the magnetic filler has variation. The mechanical strength can be improved by varying the length of the long axis of the magnetic filler.

In a preferred embodiment, a portion of the magnetic filler extends to the outside of the lateral region of the laminated surface of the coil. In FIG. 1 , part of the magnetic filler 8 extends outside the lateral region of the coil stacking surface, that is, extends above the upper end of the coil 3 in the drawing and below the lower end of the coil 3 in the drawing. are doing. By extending a portion of the magnetic filler to the outside of the lateral region of the laminated surface of the coil, the frequency characteristics of the coil component are further improved.

The number of magnetic fillers is not particularly limited. Even if there is only one magnetic filler, the effect of improving the coil characteristics is exhibited, but the larger the number, the better the effect, which is preferable.

The location where the magnetic filler is dispersed is not particularly limited. In one aspect, the location where the magnetic filler is dispersed may be the central position of the air core portion of the coil. By dispersing the magnetic filler material in the center of the air core of the coil, a uniform magnetic field is applied to the magnetic filler material, which reduces manufacturing variations and prevents contact between the coil and the magnetic filler material. be able to. In another aspect, the magnetic filler may be dispersed in the vicinity of the coil. By dispersing the magnetic fillers near the coil, conductive contact between the magnetic fillers can be prevented, and the frequency characteristics are improved. In still another aspect, the magnetic filler may be dispersed both in the center position of the air core portion of the coil and in the vicinity of the coil.

In one aspect, the magnetic filler particles are entangled with each other. In particular, when the magnetic fillers are nanotubes or nanofibers, they are preferably entangled with each other. From the viewpoint of mechanical properties, it is preferable to increase the number of locations where the magnetic filler particles are entangled (in other words, the locations where they are in contact with each other). Moreover, from the viewpoint of stability of magnetic properties, it is preferable to reduce the number of entangled portions as much as possible. In particular, by making the entangled portions the ends, the generated eddy current cannot escape uniformly, and the frequency characteristics are improved. Here, the entanglement means the state shown in FIG. 10, that is, a plurality of magnetic fillers (the magnetic fillers 21 and 22 in FIG. 10) are in contact with each other not at points but in a certain area. , a state in which the axes of the two magnetic fillers are directed in different directions in the contact region 23, typically a state in which at least one of the magnetic fillers is wrapped around the surface of the other magnetic filler. say.

In a preferred embodiment, at least one, preferably both ends of the core are exposed in at least a portion of the magnetic filler (FIG. 5). Here, the term "end" refers to a region from the end in the longitudinal direction to a certain distance, for example, a region within 100 μm, a region within 10 μm, a region within 5 μm, or a region within 1 μm from the end. obtain. By exposing the end of the core, it is possible to suppress the generation of eddy currents, and as a result, it is possible to reduce the loss.

In a preferred embodiment, if the soft magnetic layer were formed on the exposed portion, the portion where the soft magnetic layer would curve is exposed. Loss can be further reduced by exposing the portion of the core.

In a preferred embodiment, the exposed amount of the edge of the core may be 1 nm or more and 10 μm or less, preferably 1 nm or more and 5 μm or less, more preferably 1 nm or more and 1 μm or less, from the edge of the core. Loss can be further reduced by setting the amount of exposure at the end of the core within the above range.

When a resin material is used as an insulating material, the composite magnetic body part is formed by mixing a solvent, a resin material, and a magnetic filler, and stretching the sheet into a sheet and pressing it at room temperature, or making a thin film by screen printing and pressing it at room temperature. a method of repeating spray coating, a method of mixing while heating at a temperature equal to or higher than the melting temperature of the resin material, and then a method of cooling and hardening. On the other hand, when ceramic is used as the insulating material, the composite magnetic body portion can be formed by a method of mixing ceramic raw material and magnetic filler and baking the mixture.

The material and shape of the wire that constitutes the coil 3 are not particularly limited. For example, in the present embodiment, a wire having a circular cross section is used, but the wire is not limited to this, and a wire having an elliptical cross section may be used. Alternatively, a flat wire used for a laminated coil component 1b as shown in FIG. 6 may be used. When a wire having a flat or elliptical cross section is used, the non-uniformity of the magnetic field increases, so the advantage of making the length of the major axis of the magnetic filler larger than the thickness of the wire increases.

It should be noted that the number of turns and the number of turns of the coil are not limited to those shown in the drawings. The number of turns of the coil may be a plurality of turns, one turn, or less than one turn, as long as it can function as a coil. The number of coils may be two or more.

The protective layer 6 is not particularly limited as long as it can protect the coil 3 . The material constituting the protective layer is not particularly limited as long as it is an insulating material, and examples thereof include resin materials with high electrical insulation such as acrylic resin, epoxy resin, phenol resin, and polyimide. These materials may be used alone or in combination of two or more. Note that the protective layer is not an essential element and may be absent.

The external electrodes 4 and 5 are not particularly limited, and may be external electrodes used for general coils. The external electrodes are composed of a conductive material, preferably one or more metallic materials selected from Au, Ag, Pd, Ni, Sn and Cu.

The external electrodes may be formed by, for example, plating, applying a paste containing a conductive material, and curing or baking the paste, or by combining these methods.

The external electrode may be a single layer or multiple layers.

(Embodiment 2)
A cross-section of a coil component 1c that is another embodiment of the present disclosure is shown in FIG. As shown in FIG. 7, the coil component 1c of the present embodiment has the coil component 1a except that the length of the long axis of the magnetic filler 8 is longer than that of the magnetic filler in the coil component 1a of the above embodiment. has the same configuration as A description of the same configuration as that of the coil component 1a is omitted.

In the present embodiment, the length of the long axis of the magnetic filler 8 is equal to or greater than the thickness of the laminated coil. That is, the ratio of the length of the major axis of the magnetic filler to the thickness of the laminated coil (the length of the major axis of the magnetic filler/the thickness of the laminated coil) is 1 or more. Here, the lamination thickness of the coil is, as shown in FIG. 4, the distance T between the upper and lower ends of the laminated wires in the lamination direction (vertical direction in the drawing). By setting the ratio to 1 or more, the end portion of the magnetic filler, which may adversely affect the frequency characteristics, is less likely to be arranged in a region where the magnetic field generated by the coil is strong, thereby further improving the frequency characteristics of the coil component.

In preferred embodiments, the ratio may preferably be greater than 1, more preferably 1.1 or greater. By increasing the ratio, the magnetic flux passing through the ends of the magnetic filler, which may adversely affect the frequency characteristics, can be further reduced, further improving the frequency characteristics of the coil component.

In a preferred embodiment, one end of the magnetic filler may be on the same plane. In other words, the ends of the plurality of magnetic fillers have the same height position in the composite magnetic body portion and form one plane. By aligning the ends of the magnetic filler on the same plane, the magnetic characteristics are made uniform and the frequency characteristics are improved.

In another aspect, one end of the magnetic filler may be on one curved surface. By aligning the ends of the magnetic filler on one curved surface, the frequency characteristics are improved.

In the embodiment in which the ends are aligned on the same plane or on one curved surface, it is preferable that all the ends of the magnetic filler particles are aligned, but part of them may not be present on such a surface. For example, 95% or more, preferably 98% or more, more preferably 99% or more of all the magnetic fillers may have ends aligned on the surface.

In a preferred embodiment, at least one end of the magnetic filler is positioned outside the lateral region of the laminated surface of the coil. That is, the magnetic filler extends from inside the side area to outside the side area. Here, the lateral region of the coil stacking surface refers to a region perpendicular to the stacking surface. For example, in FIG. 7, the side region of the coil stacking surface is the region surrounded by the inner wall of the coil, the plane including the upper end of the coil and the plane including the lower end of the coil, the so-called air core portion, and the lower end of the magnetic filler is , is positioned below the lower end of the coil, and the upper end of the magnetic filler is positioned above the upper end of the coil. By arranging at least one end of the magnetic filler outside the side region of the laminated surface of the coil, the frequency characteristics of the coil component are further improved.

In the above aspect, one end of the magnetic filler is preferably located entirely outside the lateral region of the coil lamination surface, but part of it may be located within the lateral region. For example, 95% or more, preferably 98% or more, and more preferably 99% or more of all the magnetic filler ends may be positioned outside the lateral region.

(Embodiment 3)
FIG. 8 shows a cross section of a coil component 1d that is another embodiment of the present disclosure. As shown in FIG. 8, in the coil component 1d of the present embodiment, the magnetic fillers 8 are connected to each other by a bridging portion 15 made of the same material as the magnetic filler or the core portion of the magnetic filler. It has the same configuration as the coil component 1c except that the coil component 1c is provided. A description of the same configuration as that of the coil component 1c is omitted.

By connecting the magnetic fillers with the same material as the magnetic filler or the core of the magnetic filler, the mechanical strength of the magnetic filler is improved.

In FIG. 8, the connection is made by the bridging portion 15, but the connection may be made by bringing the magnetic fillers into contact with each other, preferably by entangling them. By bringing the magnetic filler particles into contact with each other, the mechanical strength of the magnetic filler particles is further improved.

(Embodiment 4)
A plan view of a coil component 1e, which is an embodiment of the present disclosure, is shown in FIG. 9(a), and a cross-sectional view taken along the line XX is shown in FIG. 9(b). As shown in FIG. 9, the coil component 1e of the present embodiment includes a composite magnetic body portion 2, a coil 3a embedded in the composite magnetic body portion 2 and having a wire wound on the same plane, and a It is a coil component having an electrically connected external electrode 4 and an external electrode 5 electrically connected to a coil 3a through an extraction electrode 3b.

In this aspect, the coils 3a are stacked in a direction perpendicular to the axis of the coils 3a (horizontal direction in FIG. 9(b)). Therefore, in this embodiment, the stacking direction of the coil is the horizontal direction in FIG. 9B, the thickness of the wire in the stacking direction is the width t of the wire in the horizontal direction in FIG. is the distance T from the innermost end to the outermost end of the coil.

In one aspect, the magnetic fillers 8 are arranged above and below the coil 3 so that their long axes are oriented in the direction of the magnetic field generated by the coil.

In one aspect, the magnetic fillers 8 are arranged above and below the coil 3 such that the long axis thereof is oriented outward from the winding center of the coil, that is, in the radial direction.

In the coil component 1e of this embodiment, the configuration of the composite magnetic body portion 2, the configuration of the magnetic filler 8, and the configuration of the external electrodes 4 and 5 are the same as those of the coil components 1a, 1c and 1d described above.

The type of coil component of the present disclosure is not particularly limited, and may be a drum core type coil component, a wire wound type coil component, a laminated type coil component, or the like.

The coil component of the present disclosure can be used for inductors, choke coils, transformers, and the like.

Since the coil component of the present disclosure has excellent frequency characteristics, it can be suitably used as a coil component for high frequency applications.

DESCRIPTION OF SYMBOLS 1a, 1b, 1c, 1d, 1e... Coil component 2... Composite magnetic body part 3... Coil 3a... Coil 3b... Extraction electrode 4... External electrode 5... External electrode 6... Protective layer 7... Insulating material 8... Magnetic filler DESCRIPTION OF SYMBOLS 9... Air core part 10... Laminated surface 11... Core part 12... Soft magnetic layer 13... Domain wall 15... Bridge part 21... Magnetic filler 22... Magnetic filler 23... Contact area

Claims (11)

A coil component having a composite magnetic body part containing an insulating material and a magnetic filler and a coil, wherein the coil is wound around the composite magnetic body part,
The magnetic filler is non-spherical and has a core made of a non-magnetic material and a soft magnetic layer provided on the surface of the core,
The magnetic filler is arranged so that its long axis is oriented in the direction of the magnetic field generated by the coil,
A coil component, wherein a ratio of the length of the major axis of the magnetic filler to the thickness of the wire constituting the coil in the direction of the magnetic field is greater than 1. A coil component having a composite magnetic body part containing an insulating material and a magnetic filler and a coil, wherein the coil is wound around the composite magnetic body part,
The magnetic filler is non-spherical and has a core made of a non-magnetic material and a soft magnetic layer provided on the surface of the core,
The magnetic filler is arranged on the side of the lamination surface of the coil so that its long axis is oriented in the lamination direction of the coil,
A coil component, wherein a ratio of the length of the major axis of the magnetic filler to the thickness of the wire constituting the coil in the stacking direction is greater than 1. A coil component having a composite magnetic body part containing an insulating material and a magnetic filler and a coil, wherein the coil is wound around the composite magnetic body part,
The coil is an air core coil,
The magnetic filler is non-spherical and has a core made of a non-magnetic material and a soft magnetic layer provided on the surface of the core,
The magnetic filler is arranged in the air-core portion of the air-core coil such that its long axis is oriented in the axial direction of the air-core coil,
A coil component, wherein a ratio of the length of the long axis of the magnetic filler to the thickness of the wire constituting the coil in the axial direction is greater than 1. 4. The coil component according to claim 1, wherein the soft magnetic layer in said magnetic filler has striped domain walls. The coil component according to any one of claims 1 to 4, wherein said magnetic filler has substantially the same major axis length. The coil component according to any one of claims 1 to 5, wherein at least one end of the core is exposed in at least a portion of the magnetic filler. The coil component according to any one of claims 1 to 6, wherein a ratio of the length of the long axis of said magnetic filler to the thickness of said coil lamination is 1 or more. The coil component according to any one of claims 1 to 7, wherein one end of said magnetic filler is on the same plane. The coil component according to any one of claims 1 to 8, wherein the core portion of said magnetic filler is a carbon nanotube. The coil component according to any one of claims 1 to 9, wherein at least one end of said magnetic filler is positioned outside a lateral region of a laminated surface of the coil. The coil component according to any one of claims 1 to 10, wherein the magnetic filler particles are connected to each other with the same material as the magnetic filler particles or the core portion of the magnetic filler particles.

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