JP2021057394A

JP2021057394A - Inductor

Info

Publication number: JP2021057394A
Application number: JP2019177147A
Authority: JP
Inventors: 直剛羽田; Naotake Haneda
Original assignee: Murata Manufacturing Co Ltd
Current assignee: Murata Manufacturing Co Ltd
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-04-08

Abstract

To provide an inductor with high dielectric strength characteristics and sufficient dielectric strength.SOLUTION: An inductor 2 includes a coil having a winding portion 24 in which a winding 22 having a conductor 22A and a coating layer 22B made of a first resin is wound around a winding shaft 10 and a pair of drawing portions 26 drawn from the winding portion 24, a magnetic portion 30 that is composed of magnetic powder and resin and seals at least a part of the winding portion 24 and the drawing portion 26, and a pair of external electrodes provided on the surface of the magnetic portion 30 and electrically connected to the drawing portion 26. A distance D2 between the conductor 22A of a winding 22q on the outer peripheral side of the winding portion 24 and the magnetic portion 30 is longer than a distance D1 between the conductor 22A of the winding 22p on the inner peripheral side of the winding portion 24 and the winding shaft 10.SELECTED DRAWING: Figure 3

Description

本発明は、コイルおよびコイルを封止する磁性部を有するインダクタに関する。 The present invention relates to a coil and an inductor having a magnetic portion that seals the coil.

コイルおよびコイルを封止する磁性部を有するインダクタが、広く用いられている。その中には、コイルの内部に周辺部より透磁率の大きい巻軸を備えたインダクタが開示されている（例えば、特許文献１参照）。このようなインダクタでは、透磁率の大きい巻軸により、高インダクタ特性を得ることができる。 Inductors having a coil and a magnetic part that seals the coil are widely used. Among them, an inductor having a winding shaft having a magnetic permeability higher than that of the peripheral portion inside the coil is disclosed (see, for example, Patent Document 1). In such an inductor, high inductor characteristics can be obtained by a winding shaft having a large magnetic permeability.

特開２０１５−２２８４１２号公報Japanese Unexamined Patent Publication No. 2015-228412

しかしながら、特許文献１に記載されたインダクタでは、磁性粉および樹脂の混合物をコイルの周囲に配置して圧縮して磁性部を形成する。このとき、磁性粉の粒子が、コイルを構成する巻線の被覆層に侵入して中の導体と接触して、コイルの絶縁性が低下する虞がある。これにより、インダクタの絶縁耐圧性能が低下する。 However, in the inductor described in Patent Document 1, a mixture of magnetic powder and resin is arranged around the coil and compressed to form a magnetic portion. At this time, the particles of the magnetic powder may invade the coating layer of the winding forming the coil and come into contact with the conductor inside, so that the insulating property of the coil may be deteriorated. As a result, the dielectric strength performance of the inductor deteriorates.

よって、本発明は、高いインダクタ特性を有するとともに、十分な絶縁耐圧性能を有するインダクタを提供することを目的とする。 Therefore, an object of the present invention is to provide an inductor having high inductor characteristics and sufficient dielectric strength.

本発明の１つの態様に係るインダクタは、
巻軸と、
導体および第１の樹脂からなる被覆層を有する巻線が前記巻軸の周囲に巻回されてなる巻回部、並びに前記巻回部から引き出される１対の引き出し部を有するコイルと、
磁性粉および樹脂からなり、前記巻回部、および前記引き出し部の少なくとも一部を封止する磁性部と、
前記磁性部の表面に設けられ、前記引き出し部と電気的に接続された１対の外部電極と、
を備え、
前記巻回部の外周側の前記巻線の前記導体および前記磁性部の間の距離が、前記巻回部の内周側の前記巻線の前記導体および前記巻軸の間の距離より長くなっている。 The inductor according to one aspect of the present invention is
Axle and
A winding portion in which a winding having a coating layer made of a conductor and a first resin is wound around the winding shaft, and a coil having a pair of drawing portions drawn out from the winding portion.
A magnetic part made of magnetic powder and resin, which seals at least a part of the winding part and the drawing part,
A pair of external electrodes provided on the surface of the magnetic portion and electrically connected to the drawer portion,
With
The distance between the conductor and the magnetic portion of the winding on the outer peripheral side of the winding portion is longer than the distance between the conductor and the winding shaft of the winding on the inner peripheral side of the winding portion. ing.

上記の態様によれば、高いインダクタ特性を有するとともに、十分な絶縁耐圧性能を有するインダクタを提供することができる。 According to the above aspect, it is possible to provide an inductor having high inductor characteristics and sufficient dielectric strength.

本発明に係るインダクタの一例を模式的に示す斜視図である。It is a perspective view which shows an example of the inductor which concerns on this invention typically. 図１のＡ−Ａ断面を示す側面断面図であって、本発明の第１の実施形態に係るインダクタを模式的に示す図である。It is a side sectional view which shows the AA cross section of FIG. 1, and is the figure which shows typically the inductor which concerns on 1st Embodiment of this invention. 図２のＢで示す枠内を拡大して示す側面断面図である。It is a side sectional view which shows the inside of the frame shown by B of FIG. 2 in an enlarged manner. 図１のＡ−Ａ断面を示す側面断面図であって、本発明の第２の実施形態に係るインダクタを模式的に示す図である。It is a side sectional view which shows the AA cross section of FIG. 1, and is the figure which shows typically the inductor which concerns on 2nd Embodiment of this invention. 図１のＡ−Ａ断面を示す側面断面図であって、本発明の第３の実施形態に係るインダクタを模式的に示す図である。It is a side sectional view which shows the AA cross section of FIG. 1, and is the figure which shows typically the inductor which concerns on 3rd Embodiment of this invention.

以下、図面を参照しながら、本発明を実施するための実施形態を説明する。なお、以下に説明するインダクタは、本発明の技術思想を具体化するためのものであって、特定的な記載がない限り、本発明を以下のものに限定しない。
各図面中、同一の機能を有する部材には、同一符号を付している場合がある。要点の説明または理解の容易性を考慮して、便宜上実施形態や実施例に分けて示す場合があるが、異なる実施形態で示した構成の部分的な置換または組み合わせは可能である。後述の実施形態では、前述と共通の事柄についての記述を省略し、異なる点についてのみ説明する。特に、同様の構成による同様の作用効果については、実施形態や実施例ごとには逐次言及しないものとする。各図面が示す部材の大きさや位置関係等は、説明を明確にするため、誇張して示している場合もある。 Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The inductor described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following unless otherwise specified.
In each drawing, members having the same function may be designated by the same reference numerals. In consideration of the explanation of the main points or the ease of understanding, the configurations may be divided into embodiments and examples for convenience, but the configurations shown in different embodiments can be partially replaced or combined. In the embodiment described later, the description of the matters common to the above will be omitted, and only the differences will be described. In particular, similar actions and effects with the same configuration will not be mentioned sequentially for each embodiment or embodiment. The size and positional relationship of the members shown in each drawing may be exaggerated for the sake of clarity.

（第１の実施形態）
はじめに、図１、図２および図３を参照しながら、本発明の第１の実施形態に係るインダクタの説明を行う。図１は、本発明に係るインダクタの一例を模式的に示す斜視図である。図２は、図１のＡ−Ａ断面を示す側面断面図であって、本発明の第１の実施形態に係るインダクタを模式的に示す図である。図３は、図２のＢで示す枠内を拡大して示す側面断面図である。なお、図３では、図２（後述する図４、５も同様）で模式的に示す巻線２２を断面で示し、巻線２２が導体２２Ａおよび被覆層２２Ｂで構成されていることを示している。 (First Embodiment)
First, the inductor according to the first embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. 1 is a perspective view schematically showing an example of an inductor according to the present invention. FIG. 2 is a side sectional view showing a cross section taken along the line AA of FIG. 1, which schematically shows an inductor according to the first embodiment of the present invention. FIG. 3 is a side sectional view showing an enlarged view of the inside of the frame shown by B in FIG. In addition, in FIG. 3, the winding 22 schematically shown in FIG. 2 (the same applies to FIGS. 4 and 5 described later) is shown in cross section, and it is shown that the winding 22 is composed of the conductor 22A and the coating layer 22B. There is.

本実施形態に係るインダクタ２は、巻軸１０およびコイル２０を備える。コイル２０は、導体２２Ａおよび第１の樹脂からなる被覆層２２Ｂを有する巻線２２が、巻軸１０の周囲に巻回されてなる巻回部２４、並びに巻回部２４から引き出される１対の引き出し部２６、２６を有する。巻線２２の少なくとも一部は、巻軸１０の外周に接している。 The inductor 2 according to the present embodiment includes a winding shaft 10 and a coil 20. The coil 20 includes a winding portion 24 in which a winding 22 having a coating layer 22B made of a conductor 22A and a first resin is wound around a winding shaft 10, and a pair of winding portions drawn from the winding portion 24. It has drawers 26 and 26. At least a part of the winding 22 is in contact with the outer circumference of the winding shaft 10.

巻軸１０は、例えば、断面形状が円形または楕円形の筒状に形成されている。巻軸１０として、磁性粉および樹脂を成形してなるものを用いることができる。その場合には、予め大きな圧力で磁性粉を圧縮して巻軸を形成することにより高い直流重畳特性が得られるとともに、高い強度および硬度が得られるので、巻軸が崩れて巻線２２に磁性粉が食い込むことを防ぐことができる。
また、巻軸１０として、Ｎｉ−Ｚｎ系、Ｍｎ−Ｚｎ系をはじめとするフェライトからなるものを用いることもできる。フェライトからなる巻軸１０は、予め焼結により高い強度および硬度が得られるので、巻軸が崩れて巻線２２に磁性粉が食い込むことを防ぐことができる。 The winding shaft 10 is formed, for example, in a tubular shape having a circular or elliptical cross-sectional shape. As the winding shaft 10, one formed by molding magnetic powder and resin can be used. In that case, by compressing the magnetic powder with a large pressure in advance to form a winding shaft, high DC superimposition characteristics can be obtained, and high strength and hardness can be obtained. It is possible to prevent the powder from biting into it.
Further, as the winding shaft 10, one made of ferrite such as Ni-Zn type and Mn-Zn type can also be used. Since the winding shaft 10 made of ferrite can obtain high strength and hardness by sintering in advance, it is possible to prevent the winding shaft from collapsing and the magnetic powder from biting into the winding 22.

本実形態に係る巻線２２は、略円形の断面形状を有する丸線を用いているが、これに限られるものではなく、例えば、略矩形の断面形状を有する平角線を用いることもできる。巻線２２の導体２２Ａの材料として、銅、アルミ、銅クラッドアルミ、銅合金等の導電性材料を例示することができる。被覆層２２Ｂを形成する第１の樹脂として、ポリウレタン、ポリエステル、ポリエステルイミド、ポリアミドイミド、ポリイミド等を例示することができる。被覆層２２Ｂの厚みは、３μｍ〜５０μｍを例示することができる。 The winding 22 according to the present embodiment uses a round wire having a substantially circular cross-sectional shape, but is not limited to this, and for example, a flat wire having a substantially rectangular cross-sectional shape can also be used. As the material of the conductor 22A of the winding 22, a conductive material such as copper, aluminum, copper clad aluminum, or a copper alloy can be exemplified. Examples of the first resin forming the coating layer 22B include polyurethane, polyester, polyesterimide, polyamideimide, and polyimide. The thickness of the coating layer 22B can be exemplified by 3 μm to 50 μm.

更に、本実施形態に係るインダクタ２は、磁性粉および樹脂からなり、コイル２０の巻回部２４および引き出し部２６を封止する磁性部３０を備える。本実施形態では、引き出し部２６が全て磁性部３０に覆われているが、これに限られているものではなく、引き出し部２６の一部が磁性部３０の外側に露出している場合もあり得る。その場合も含めると、引き出し部２６の少なくとも一部が、磁性部３０で封止されているということができる。 Further, the inductor 2 according to the present embodiment is made of magnetic powder and resin, and includes a magnetic portion 30 that seals the winding portion 24 and the drawing portion 26 of the coil 20. In the present embodiment, the drawer portion 26 is entirely covered with the magnetic portion 30, but the present invention is not limited to this, and a part of the drawer portion 26 may be exposed to the outside of the magnetic portion 30. obtain. Including this case, it can be said that at least a part of the drawer portion 26 is sealed with the magnetic portion 30.

本実施形態では、磁性部３０が、略直方体の形状を有する。略直方体形状の磁性部３０の大きさとして、長手方向の長さが、１．０ｍｍ以上２５ｍｍ以下、短手方向の長さが０．８ｍｍ以上２５ｍｍ以下、高さが０．５ｍｍ以上２５ｍｍ以下である場合を例示できるが、これに限られるものではない。長手方向と短手方向の長さが同じあってよい。 In this embodiment, the magnetic portion 30 has a substantially rectangular parallelepiped shape. The size of the magnetic portion 30 having a substantially rectangular parallelepiped shape is such that the length in the longitudinal direction is 1.0 mm or more and 25 mm or less, the length in the lateral direction is 0.8 mm or more and 25 mm or less, and the height is 0.5 mm or more and 25 mm or less. Examples can be given, but the present invention is not limited to this. The length in the longitudinal direction and the length in the lateral direction may be the same.

磁性部３０は、磁性粉および樹脂の混合物からなる。この混合物における磁性粉充填率は、例えば、６０重量％以上であり、好ましくは８０重量％以上である。磁性粉としては、Ｆｅ、Ｆｅ−Ｓｉ−Ｃｒ、Ｆｅ−Ｎｉ−Ａｌ、Ｆｅ−Ｃｒ−Ａｌ、Ｆｅ−Ｓｉ、Ｆｅ−Ｓｉ−Ａｌ、Ｆｅ−Ｎｉ、Ｆｅ−Ｎｉ−Ｍｏ等の鉄系の金属磁性粉、他の組成系の金属磁性粉、アモルファス等の金属磁性粉、表面がガラス等の絶縁体で被覆された金属磁性粉、表面を改質した金属磁性粉、ナノレベルの微小な金属磁性粉が用いられる。樹脂としては、エポキシ樹脂、ポリイミド樹脂、フェノール樹脂等の熱硬化性樹脂、ポリエチレン樹脂、ポリアミド樹脂等の熱可塑性樹脂が用いられる。磁性粉の平均粒径は、２μｍ〜５０μｍを例示することができる。 The magnetic portion 30 is made of a mixture of magnetic powder and resin. The magnetic powder filling factor in this mixture is, for example, 60% by weight or more, preferably 80% by weight or more. The magnetic powder includes iron-based metals such as Fe, Fe-Si-Cr, Fe-Ni-Al, Fe-Cr-Al, Fe-Si, Fe-Si-Al, Fe-Ni, and Fe-Ni-Mo. Magnetic powder, metal magnetic powder of other composition system, metal magnetic powder such as amorphous, metal magnetic powder whose surface is coated with an insulator such as glass, metal magnetic powder with modified surface, nano-level minute metal magnetism Powder is used. As the resin, a thermosetting resin such as an epoxy resin, a polyimide resin and a phenol resin, and a thermoplastic resin such as a polyethylene resin and a polyamide resin are used. The average particle size of the magnetic powder can be exemplified by 2 μm to 50 μm.

更に、インダクタ２は、磁性部３０の表面に設けられ、引き出し部２６と電気的に接続された１対の外部電極４０、４０とを備える。外部電極４０は、金属板からなり、磁性部３０から露出する露出部４２と、磁性部３０に埋設される埋設部４４とを備える。外部電極４０の材料として、巻線２２と同様に、銅、アルミ、銅クラッドアルミ、銅合金等の導電性材料を例示できる。更に、表面に、ニッケル、スズ等のメッキを施すことができる。 Further, the inductor 2 includes a pair of external electrodes 40, 40 provided on the surface of the magnetic portion 30 and electrically connected to the extraction portion 26. The external electrode 40 is made of a metal plate and includes an exposed portion 42 exposed from the magnetic portion 30 and an embedded portion 44 embedded in the magnetic portion 30. As the material of the external electrode 40, a conductive material such as copper, aluminum, copper clad aluminum, or a copper alloy can be exemplified as the winding 22. Further, the surface can be plated with nickel, tin or the like.

外部電極４０、４０は、それぞれ対向する面３０Ａ、３０Ｂおよび対向する面３０Ａ、３０Ｂを接続する面３０Ｃの一部に亘って設けられている。この面３０Ｃが、インダクタ２の実装面となる。なお、全図において、実装面が下側に位置するように示されている。対向する面３０Ａ、３０Ｂが、略直方体の長手方向に離間した両端面の場合、１対の外部電極４０、４０の間の距離を長くとることができるので、絶縁耐圧性能を向上できる。なお、対向する面３０Ａ、３０Ｂが略直方体の短手方向に離間した両側面の場合や、磁性部３０が立方体形状の場合もあり得る。 The external electrodes 40 and 40 are provided over a part of the surfaces 30A and 30B facing each other and the surfaces 30C connecting the facing surfaces 30A and 30B, respectively. This surface 30C serves as a mounting surface for the inductor 2. In all the drawings, the mounting surface is shown to be located on the lower side. When the facing surfaces 30A and 30B are both end surfaces separated in the longitudinal direction of a substantially rectangular parallelepiped, the distance between the pair of external electrodes 40 and 40 can be increased, so that the dielectric strength performance can be improved. The facing surfaces 30A and 30B may be both side surfaces separated from each other in the lateral direction of a substantially rectangular parallelepiped, or the magnetic portion 30 may have a cubic shape.

このように、磁性部３０が略直方体の形状を有し、外部電極４０が、対向する面３０Ａ、３０Ｂおよび対向する面を接続する面３０Ｃの一部に亘って設けられているので、実装面およびそれに繋がる端面または側面の２面を用いて基板との半田付けが可能であり、実装時における信頼性を高めることができる。 As described above, since the magnetic portion 30 has a substantially rectangular parallelepiped shape and the external electrodes 40 are provided over a part of the facing surfaces 30A and 30B and the surface 30C connecting the facing surfaces, the mounting surface is mounted. It is possible to solder to the substrate by using the two end faces or side surfaces connected to it, and it is possible to improve the reliability at the time of mounting.

＜第２の樹脂＞
本実施形態に係るインダクタ２では、コイル２０および磁性部３０の間に、第２の樹脂５０が存在する。具体的には、コイル２０の巻回部２４および引き出し部２６、並びに引き出し部２６に接続された外部電極４０の埋設部４４が、第２の樹脂５０で覆われている。更に、巻軸１０の軸方向における両端部も、第２の樹脂５０で覆われている。
第２の樹脂５０の材質として、ビニルベンジル樹脂、ポリビニルベンジルエーテル化合物樹脂、ビスマレイミドトリアジン樹脂、ポリフェニレエーテル樹脂、シアネートエステル樹脂、エポキシ＋活性エステル硬化樹脂、ポリフェニレンエーテル樹脂、ポリオレフィン樹脂、ベンゾシクロブテン樹脂、ポリイミド樹脂、芳香族ポリエステル樹脂、芳香族液晶ポリエステル樹脂、ポリフェニレンサルファイド樹脂、ポリエーテルイミド樹脂、ポリアクリレート樹脂、ポリエーテルエーテルケトン樹脂、フッ素樹脂、エポキシ樹脂、フェノール樹脂、ベンゾオキサジン樹脂等を例示することができる。 <Second resin>
In the inductor 2 according to the present embodiment, the second resin 50 is present between the coil 20 and the magnetic portion 30. Specifically, the winding portion 24 and the pull-out portion 26 of the coil 20, and the embedded portion 44 of the external electrode 40 connected to the pull-out portion 26 are covered with the second resin 50. Further, both ends of the winding shaft 10 in the axial direction are also covered with the second resin 50.
As the material of the second resin 50, vinylbenzyl resin, polyvinylbenzyl ether compound resin, bismaleimide triazine resin, polyphenyle ether resin, cyanate ester resin, epoxy + active ester cured resin, polyphenylene ether resin, polyolefin resin, benzocyclobutene. Examples of resins, polyimide resins, aromatic polyester resins, aromatic liquid crystal polyester resins, polyphenylene sulfide resins, polyetherimide resins, polyacrylate resins, polyether ether ketone resins, fluororesins, epoxy resins, phenol resins, benzoxazine resins, etc. can do.

図３に示すように、第２の樹脂５０は、コイル２０の巻回部２４の外周側に位置する巻線２２（例えば、２２ｑ）および磁性部３０の間に配置されている。更に、第２の樹脂５０は、巻回部２４の軸方向における図面下側の端部側に位置する巻線２２（例えば、２２ｒ）および磁性部３０の間に配置されている。同様に、第２の樹脂５０は、巻回部２４の軸方向における図面上側の端部側に位置する巻線２２（例えば、２２ｓ）および磁性部３０の間に配置されている。つまり、コイル２０の巻回部２４は、巻軸１０に面する内周側を除き、第２の樹脂５０で覆われている。 As shown in FIG. 3, the second resin 50 is arranged between the winding 22 (for example, 22q) and the magnetic portion 30 located on the outer peripheral side of the winding portion 24 of the coil 20. Further, the second resin 50 is arranged between the winding 22 (for example, 22r) and the magnetic portion 30 located on the lower end side of the drawing in the axial direction of the winding portion 24. Similarly, the second resin 50 is arranged between the winding 22 (for example, 22s) and the magnetic portion 30 located on the upper end side of the drawing in the axial direction of the winding portion 24. That is, the winding portion 24 of the coil 20 is covered with the second resin 50 except for the inner peripheral side facing the winding shaft 10.

更に、図２に示すように、第２の樹脂５０は、コイル２０の引き出し部２６および磁性部３０の間にも配置されている。更に、第２の樹脂５０は、引き出し部２６と接続された外部電極４０の埋設部４４および磁性部３０の間に配置されている。また、第２の樹脂５０は、巻軸１０の軸方向における両端部および磁性部３０の間に配置されている。 Further, as shown in FIG. 2, the second resin 50 is also arranged between the lead-out portion 26 and the magnetic portion 30 of the coil 20. Further, the second resin 50 is arranged between the embedded portion 44 and the magnetic portion 30 of the external electrode 40 connected to the drawer portion 26. Further, the second resin 50 is arranged between both ends of the winding shaft 10 in the axial direction and the magnetic portion 30.

巻回部２４の内周側の巻線２２（例えば、２２ｐ）は、原則として、巻軸１０の外周に接している。よって、巻回部２４の内周側の巻線２２ｐの導体２２Ａおよび巻軸１０の間の距離Ｄ１は、原則として、巻線２２ｐの被覆層２２Ｂの厚みに一致する。
一方、巻回部２４の外周側の巻線２２ｑの導体２２Ａおよび磁性部３０の間の距離Ｄ２は、巻線２２ｑの被覆層２２Ｂの厚みに第２の樹脂５０の厚みが加わる。よって、巻回部２４の外周側の巻線２２ｑの導体２２Ａおよび磁性部３０の間の距離Ｄ２は、巻回部２４の内周側の巻線２２ｐの導体２２Ａおよび巻軸１０の間の距離Ｄ１より長くなる。 As a general rule, the winding 22 (for example, 22p) on the inner peripheral side of the winding portion 24 is in contact with the outer circumference of the winding shaft 10. Therefore, in principle, the distance D1 between the conductor 22A of the winding 22p on the inner peripheral side of the winding portion 24 and the winding shaft 10 matches the thickness of the coating layer 22B of the winding 22p.
On the other hand, the distance D2 between the conductor 22A of the winding 22q on the outer peripheral side of the winding portion 24 and the magnetic portion 30 adds the thickness of the second resin 50 to the thickness of the coating layer 22B of the winding 22q. Therefore, the distance D2 between the conductor 22A of the winding 22q on the outer peripheral side of the winding portion 24 and the magnetic portion 30 is the distance between the conductor 22A of the winding 22p on the inner peripheral side of the winding portion 24 and the winding shaft 10. It will be longer than D1.

同様に、巻回部２４の軸方向における端部側に位置する巻線２２ｒ、２２ｓの導体２２Ａおよび磁性部３０の間の距離Ｄ３、Ｄ４は、巻線２２ｒ、２２ｓの被覆層２２Ｂの厚みに第２の樹脂５０の厚みが加わる。よって、巻回部２４の軸方向における端部側に位置する巻線２２ｒ、２２ｓの導体２２Ａおよび磁性部の間の距離Ｄ３、Ｄ４は、巻回部２４の内周側の巻線２２ｐの導体２２Ａおよび巻軸１０の間の距離Ｄ１より長くなる。 Similarly, the distances D3 and D4 between the conductors 22A and the magnetic portion 30 of the windings 22r and 22s located on the end side in the axial direction of the winding portion 24 are set to the thickness of the coating layer 22B of the windings 22r and 22s. The thickness of the second resin 50 is added. Therefore, the distances D3 and D4 between the conductors 22A of the windings 22r and 22s located on the end side of the winding portion 24 in the axial direction and the magnetic portion are the conductors of the winding 22p on the inner peripheral side of the winding portion 24. It is longer than the distance D1 between 22A and the winding shaft 10.

（インダクタの製造方法）
次に、第１の実施形態に係るインダクタ２を例にとって、インダクタの製造方法を説明する。
（１）コイル形成工程
巻軸１０と、導体２２Ａ及びその周囲を覆う被覆層２２Ｂを有する巻線２２とを準備し、巻線２２を巻軸１０に直接巻回して、巻回部２４を形成する。そして、巻回部２４の両端の巻線２２をそれぞれ反対側に引き出して、１対の引き出し部２６、２６を形成する。これにより、巻軸１０の周囲に巻回されてなるコイル２０が形成される。
なお、はじめに巻線２２のみを巻回して空芯コイルを形成し、この空芯コイルの孔に巻軸１０挿入して、巻軸１０の周囲に配置された巻回部２４を形成することもできる。 (Inductor manufacturing method)
Next, a method of manufacturing the inductor will be described by taking the inductor 2 according to the first embodiment as an example.
(1) Coil forming step A winding shaft 10 and a winding 22 having a conductor 22A and a coating layer 22B covering the circumference thereof are prepared, and the winding 22 is directly wound around the winding shaft 10 to form a winding portion 24. To do. Then, the windings 22 at both ends of the winding portion 24 are pulled out to the opposite sides to form a pair of drawing portions 26, 26. As a result, the coil 20 wound around the winding shaft 10 is formed.
It is also possible to first wind only the winding 22 to form an air-core coil, and then insert the winding shaft 10 into the hole of the air-core coil to form a winding portion 24 arranged around the winding shaft 10. it can.

（２）外部電極接続工程
次に、金属薄板からなる１対の外部電極４０、４０を準備し、１対の引き出し部２６、２６と接続する。具体的には、外部電極４０の一方の端部と、引き出し部２６の先端部を付き合わせて、半田や溶接等を用いて接合する。このとき、金型に入れる後工程を考慮して、外部電極４０を概ね直線状に伸ばしておくこともできるし、予め最終形状に近い形に一部を折り曲げておくこともできる。 (2) External electrode connection step Next, a pair of external electrodes 40, 40 made of a thin metal plate are prepared and connected to a pair of drawer portions 26, 26. Specifically, one end of the external electrode 40 and the tip of the lead-out portion 26 are brought together and joined by soldering, welding, or the like. At this time, the external electrode 40 can be extended in a substantially linear shape in consideration of the post-process of putting into the mold, or a part of the external electrode 40 can be bent in advance to a shape close to the final shape.

（３）第２の樹脂被覆工程
このようにして形成された巻軸１０、コイル２０および外部電極４０の組立体の外面に、含浸や塗布等により、第２の樹脂５０を被覆する。これにより、巻軸１０の軸方向における両端部、巻回部２４の軸方向の両端部、巻回部２４の外周部、引き出し部２６および引き出し部２６に接続された外部電極４０の埋設部４４が、第２の樹脂５０で覆われる。 (3) Second Resin Coating Step The outer surface of the assembly of the winding shaft 10, the coil 20, and the external electrode 40 thus formed is coated with the second resin 50 by impregnation, coating, or the like. As a result, both ends in the axial direction of the winding shaft 10, both ends in the axial direction of the winding portion 24, the outer peripheral portion of the winding portion 24, the drawer portion 26, and the embedded portion 44 of the external electrode 40 connected to the drawer portion 26. Is covered with the second resin 50.

（４）磁性部形成工程
次に、第２の樹脂５０で覆われた巻軸１０、コイル２０および外部電極４０の組立体を金型内にセットする。このとき、第２の樹脂５０で覆われた埋設部４４が金型の内部に配置され、露出部４２が金型に設けられた切り欠きを通して金型の外部に配置される。
そして、組立体がセットされた金型内に、磁性粉と樹脂の混合物を充填する。金型内で、磁性粉と樹脂の混合物を１ｔ／ｃｍ^２〜１０ｔ／ｃｍ^２程度の圧力で数秒〜数分加圧する。磁性粉と樹脂の混合物を、樹脂の軟化温度以上の温度（例えば、６０℃〜１５０℃）に加温した状況で加圧して成形しても良い。次いで、樹脂の硬化温度以上の温度(例えば、１００℃〜２２０℃)を加えて硬化させて、磁性部３０を形成する。 (4) Magnetic portion forming step Next, the assembly of the winding shaft 10, the coil 20, and the external electrode 40 covered with the second resin 50 is set in the mold. At this time, the embedded portion 44 covered with the second resin 50 is arranged inside the mold, and the exposed portion 42 is arranged outside the mold through the notch provided in the mold.
Then, the mold in which the assembly is set is filled with the mixture of the magnetic powder and the resin. In a mold, a mixture of magnetic powder and resin ^1t / cm ² ^~10t / cm 2 of about pressure of seconds several minutes pressing-in pressure. A mixture of the magnetic powder and the resin may be formed by pressurizing the mixture at a temperature equal to or higher than the softening temperature of the resin (for example, 60 ° C. to 150 ° C.). Next, a temperature equal to or higher than the curing temperature of the resin (for example, 100 ° C. to 220 ° C.) is applied to cure the resin to form the magnetic portion 30.

なお、予め磁性粉と樹脂からなる予備成形体を形成し、第２の樹脂５０で覆われた巻軸１０、コイル２０および外部電極４０の組立体を、この予備成形体内に組み込んで、金型内で圧力をかけて成形することもできる。
この場合、樹脂の軟化温度以上の温度(例えば、６０℃〜１５０℃)に加温した状態で、１００ｋｇ／ｃｍ^２〜５００ｋｇ／ｃｍ^２程度で加圧し、樹脂の硬化温度以上の温度(例えば、１００℃〜２２０℃)に加温して成形・硬化する。これにより、予備成形体と、第２の樹脂５０で覆われた巻軸１０、コイル２０および外部電極４０の組立体とが一体化され、磁性部３０を形成することができる。 A premolded body made of magnetic powder and resin is formed in advance, and the assembly of the winding shaft 10, the coil 20, and the external electrode 40 covered with the second resin 50 is incorporated into the premolded body to form a mold. It can also be molded by applying pressure inside.
In this case, the resin softening temperature or higher (e.g., 60 ° C. to 150 DEG ° C.) and heated ^{at, 100kg / cm 2 ~500kg / cm} 2 approximately pressurized, the resin curing temperature or higher (e.g., It is molded and cured by heating to 100 ° C to 220 ° C). As a result, the preformed body and the assembly of the winding shaft 10, the coil 20, and the external electrode 40 covered with the second resin 50 can be integrated to form the magnetic portion 30.

＜第２の樹脂による効果＞
磁性部形成工程において、従来のインダクタでは、成形時の圧力により、金型内で磁性粉がコイル２０の巻線２２に食い込んで、コイル２０の絶縁耐圧が低下し、延いてはインダクタの絶縁耐圧性能が低下する可能性がある。つまり、磁性粉の粒子が、コイル２０の巻線２２の被覆層２２Ｂに侵入して中の導体２２Ａと接触して、コイル２０の絶縁性が低下する可能性がある。 <Effect of the second resin>
In the process of forming the magnetic portion, in the conventional inductor, the magnetic powder bites into the winding 22 of the coil 20 in the mold due to the pressure at the time of molding, and the insulation withstand voltage of the coil 20 decreases, which in turn reduces the insulation withstand voltage of the inductor. Performance may be reduced. That is, there is a possibility that the particles of the magnetic powder invade the coating layer 22B of the winding 22 of the coil 20 and come into contact with the conductor 22A inside, so that the insulating property of the coil 20 is lowered.

しかし、本実施形態では、コイル２０の巻回部２４および引き出し部２６と、磁性部３０を構成する磁性粉との間に、第２の樹脂５０が存在するので、磁性粉がコイル２０の巻線２２に食い込むことを防ぐことができる。同様に、外部電極４０の埋設部４４と磁性部３０を構成する磁性粉との間に、第２の樹脂５０が存在するので、磁性粉および埋設部４４の間の絶縁性を確保することができる。これにより、コイル２０の絶縁性の低下、延いては、インダクタ２の絶縁耐圧性能の低下を抑制することができる。 However, in the present embodiment, since the second resin 50 exists between the winding portion 24 and the drawing portion 26 of the coil 20 and the magnetic powder constituting the magnetic portion 30, the magnetic powder winds the coil 20. It is possible to prevent the wire 22 from being cut into the wire 22. Similarly, since the second resin 50 exists between the embedded portion 44 of the external electrode 40 and the magnetic powder constituting the magnetic portion 30, it is possible to secure the insulating property between the magnetic powder and the embedded portion 44. it can. As a result, it is possible to suppress a decrease in the insulating property of the coil 20, and thus a decrease in the withstand voltage performance of the inductor 2.

この観点で言えば、第２の樹脂５０と被覆層２２Ｂの合計の厚みは、磁性粉の平均粒径より大きい値の厚み有することが好ましく、安全代を考慮すれば、磁性粉の平均粒径よりも２倍以上大きな値の厚みを有することが更に好ましい。具体的な厚みとしては、４μｍ〜１００μｍを例示することができる。 From this point of view, the total thickness of the second resin 50 and the coating layer 22B preferably has a thickness larger than the average particle size of the magnetic powder, and considering the safety allowance, the average particle size of the magnetic powder. It is more preferable to have a thickness having a value twice or more larger than that of the above. As a specific thickness, 4 μm to 100 μm can be exemplified.

（５）外部電極折り曲げ工程
金型から取り出したインダクタ２において、磁性部３０から外側に延びた外部電極４０を、外面に沿ってコの字形に折り曲げる。これにより、対向する面３０Ａ、３０Ｂおよび対向する面３０Ａ、３０Ｂを接続する面３０Ｃの一部に亘って設けられる１対の外部電極４０、４０を得ることができる。以上のような製造工程を経て、インダクタ２を製造することができる。 (5) External Electrode Bending Step In the inductor 2 taken out from the mold, the external electrode 40 extending outward from the magnetic portion 30 is bent into a U shape along the outer surface. As a result, it is possible to obtain a pair of external electrodes 40, 40 provided over a part of the surfaces 30A and 30B facing each other and the surfaces 30C connecting the facing surfaces 30A and 30B. The inductor 2 can be manufactured through the above manufacturing steps.

（第２の実施形態）
次に、図４を参照しながら、本発明の第２の実施形態に係るインダクタの説明を行う。図４は、図１のＡ−Ａ断面を示す側面断面図であって、本発明の第２の実施形態に係るインダクタを模式的に示す図である。
本実施形態では、巻軸１０の軸方向における図面下側の実装面側の端部に第１の鍔部１２を有する点で、上記の第１の実施形態と異なる。つまり、筒状の巻軸１０の側面の実装面側の端部領域の周囲に、鍔部１２が成形されている。 (Second embodiment)
Next, the inductor according to the second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a side sectional view showing a cross section taken along the line AA of FIG. 1, which schematically shows an inductor according to a second embodiment of the present invention.
The present embodiment is different from the first embodiment in that the first flange portion 12 is provided at the end portion of the winding shaft 10 on the mounting surface side on the lower side of the drawing in the axial direction. That is, the flange portion 12 is formed around the end region on the mounting surface side of the side surface of the tubular winding shaft 10.

図４に示すように、第１の鍔部１２の周囲にも第２の樹脂５０が配置されている。第１の鍔部１２の存在により、コイル２０の巻回部２４の軸方向における図面下側の実装面側の端部に位置する巻線２２は、第１の鍔部１２の鍔面に面しており、第２の樹脂５０とは接していない。つまり、巻線２２および第２の樹脂５０の間に、第１の鍔部１２が配置されている。なお、コイル２０の巻回部２４の外周側に位置する巻線２２、および巻回部２４の軸方向における図面上側の端部に位置する巻線２２は、上記の第１の実施形態と同様に、第２の樹脂５０と接している。
本実施形態においても、コイル２０と磁性部３０を構成する磁性粉との間に第２の樹脂５０が存在するので、磁性部形成工程において、成形時の圧力により、磁性粉がコイルの巻線２２に食い込むことを防ぐことができる。 As shown in FIG. 4, the second resin 50 is also arranged around the first flange portion 12. Due to the presence of the first flange portion 12, the winding 22 located at the end of the winding portion 24 of the coil 20 on the lower side of the drawing in the axial direction on the mounting surface side faces the flange surface of the first flange portion 12. It is not in contact with the second resin 50. That is, the first flange portion 12 is arranged between the winding 22 and the second resin 50. The winding 22 located on the outer peripheral side of the winding portion 24 of the coil 20 and the winding 22 located at the upper end of the drawing in the axial direction of the winding portion 24 are the same as those in the first embodiment described above. Is in contact with the second resin 50.
Also in this embodiment, since the second resin 50 exists between the coil 20 and the magnetic powder constituting the magnetic portion 30, in the magnetic portion forming step, the magnetic powder winds the coil due to the pressure during molding. It is possible to prevent it from biting into 22.

（第３の実施形態）
次に、図５を参照しながら、本発明の第３の実施形態に係るインダクタの説明を行う。図５は、図１のＡ−Ａ断面を示す側面断面図であって、本発明の第３の実施形態に係るインダクタを模式的に示す図である。
本実施形態では、巻軸１０の軸方向における両側の端部に第１の鍔部１２および第２の鍔部１４を有する点で、上記の第１の実施形態や第２の実施形態と異なる。つまり、筒状の巻軸１０の側面の両側の端部領域の周囲に、それぞれ鍔部１２、１４が成形されている。 (Third Embodiment)
Next, the inductor according to the third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a side sectional view showing a cross section taken along the line AA of FIG. 1, which schematically shows an inductor according to a third embodiment of the present invention.
The present embodiment is different from the first and second embodiments described above in that the winding shaft 10 has a first flange portion 12 and a second flange portion 14 at both ends in the axial direction. .. That is, the collar portions 12 and 14, respectively, are formed around the end regions on both sides of the side surface of the tubular winding shaft 10.

図５に示すように、第１、第２の鍔部１２、１４の周囲にも第２の樹脂５０が配置されている。第１、第２の鍔部１２、１４により、巻回部２４の軸方向における両端部に位置する巻線２２は、鍔部１２、１４の鍔面に面しており、第２の樹脂５０とは接していない。つまり、巻線２２および第２の樹脂５０の間に、第１、第２の鍔部１２、１４が配置されている。なお、コイル２０の巻回部２４の外周側に位置する巻線２２は、上記の第１の実施形態と同様に、第２の樹脂５０と接している。
本実施形態においても、コイル２０と磁性部３０を構成する磁性粉との間に第２の樹脂５０が存在するので、磁性部形成工程において、成形時の圧力により磁性粉がコイルの巻線２２に食い込むのを防ぐことができる。 As shown in FIG. 5, the second resin 50 is also arranged around the first and second flange portions 12 and 14. The windings 22 located at both ends of the winding portion 24 in the axial direction by the first and second flange portions 12 and 14 face the flange surfaces of the flange portions 12 and 14, and the second resin 50 Not in contact with. That is, the first and second flange portions 12 and 14 are arranged between the winding 22 and the second resin 50. The winding 22 located on the outer peripheral side of the winding portion 24 of the coil 20 is in contact with the second resin 50, as in the first embodiment described above.
Also in this embodiment, since the second resin 50 exists between the coil 20 and the magnetic powder constituting the magnetic portion 30, in the magnetic portion forming step, the magnetic powder is wound on the coil winding 22 due to the pressure during molding. It can be prevented from biting into.

第２の実施形態また第３の実施形態のように、巻軸１０の軸方向の少なくとも一方の端部に鍔部１２（１４）を有することで、巻回部の巻き崩れを防ぐとともに、より大きなインダクタンスを得ることができる。 As in the second embodiment and the third embodiment, by having the flange portion 12 (14) at at least one end in the axial direction of the winding shaft 10, the winding portion can be prevented from collapsing and more. A large inductance can be obtained.

（その他の実施形態）
上記の第１から第３の実施形態においては、コイル２０と磁性部３０を構成する磁性粉との間に、第２の樹脂５０が存在するが、これに限られるものではない。例えば、磁性部形成工程において、予備成形体を用いて成形する場合、コイル２０および予備成形体の間に一定の隙間が生じるように、絶縁物質からなるスペーサを配置して、加圧成形することが考えられる。この場合、成形時の圧力により、磁性粉がコイル２０の巻線２２に食い込むことがないように、スペーサの厚みを定める必要がある。 (Other embodiments)
In the first to third embodiments described above, the second resin 50 is present between the coil 20 and the magnetic powder constituting the magnetic portion 30, but the present invention is not limited to this. For example, in the process of forming a magnetic portion, when molding using a preformed body, a spacer made of an insulating material is arranged so as to generate a certain gap between the coil 20 and the preformed body, and pressure molding is performed. Can be considered. In this case, it is necessary to determine the thickness of the spacer so that the magnetic powder does not bite into the winding 22 of the coil 20 due to the pressure during molding.

また、磁性部形成工程において、金型内にコイル２０と磁性粉および樹脂の混合物との間に緩衝部材を配置して成形し、成形後にこの緩衝部材を除去または消失させることも考えられる。
このようにして製造されたインダクタ２でも、コイル２０および磁性部３０の間に空隙を有する構造が形成される。この構造でも、巻回部２４の外周側の巻線２２や軸方向における端部側に位置する巻線２２の導体２２Ａおよび磁性部３０の間の距離が、巻回部２４の内周側の巻線２２の導体２２Ａおよび巻軸１０の間の距離より長くなる。 Further, in the process of forming the magnetic portion, it is also conceivable to arrange a cushioning member between the coil 20 and the mixture of the magnetic powder and the resin in the mold for molding, and remove or eliminate the cushioning member after molding.
Even in the inductor 2 manufactured in this manner, a structure having a gap is formed between the coil 20 and the magnetic portion 30. Even in this structure, the distance between the winding 22 on the outer peripheral side of the winding portion 24, the conductor 22A of the winding 22 located on the end side in the axial direction, and the magnetic portion 30 is on the inner peripheral side of the winding portion 24. It is longer than the distance between the conductor 22A of the winding 22 and the winding shaft 10.

以上のように、上記の実施形態に係るインダクタ２は、何れも、巻軸１０と、導体２２Ａおよび第１の樹脂からなる被覆層２２Ｂを有する巻線２２が巻軸１０の周囲に巻回されてなる巻回部２４、並びに巻回部２４から引き出される１対の引き出し部２６、２６を有するコイル２０と、磁性粉および樹脂からなり、巻回部２４、および引き出し部２６の少なくとも一部を封止する磁性部３０と、磁性部３０の表面に設けられ、引き出し部２６と電気的に接続された１対の外部電極４０、４０とを備える。このようなインダクタ２は、巻軸１０を有するので、高いインダクタ特性を有することができる。 As described above, in each of the inductors 2 according to the above embodiment, the winding shaft 10 and the winding 22 having the coating layer 22B made of the conductor 22A and the first resin are wound around the winding shaft 10. A coil 20 having a winding portion 24 and a pair of drawing portions 26, 26 drawn from the winding portion 24, and at least a part of the winding portion 24 and the drawing portion 26 made of magnetic powder and resin. It includes a magnetic portion 30 for sealing and a pair of external electrodes 40, 40 provided on the surface of the magnetic portion 30 and electrically connected to the lead-out portion 26. Since such an inductor 2 has a winding shaft 10, it can have high inductor characteristics.

特に、図３に示すように、コイル２０の巻回部２４の外周側の巻線２２の導体２２Ａおよび磁性部３０の間の距離Ｄ２が、巻回部２４の内周側の巻線２２の導体２２Ａおよび巻軸１０の間の距離Ｄ１より長くなっている。距離Ｄ１は、概ね巻線２２の被覆層２２Ｂの厚みに相当すると考えられるので、距離Ｄ２は、巻線２２の被覆層２２Ｂの厚みより大きな値になっている。 In particular, as shown in FIG. 3, the distance D2 between the conductor 22A of the winding 22 on the outer peripheral side of the winding portion 24 of the coil 20 and the magnetic portion 30 is the winding 22 on the inner peripheral side of the winding portion 24. It is longer than the distance D1 between the conductor 22A and the winding shaft 10. Since the distance D1 is considered to roughly correspond to the thickness of the coating layer 22B of the winding 22, the distance D2 is a value larger than the thickness of the coating layer 22B of the winding 22.

巻回部２４の外周側の巻線２２の導体２２Ａおよび磁性部３０の間に、巻線２２の被覆層２２Ｂの厚みより大きな距離Ｄ２を確保できるので、磁性部成形工程において、成形時に圧力をかけたとしても、金型内で磁性粉が巻回部２４の外周側の巻線２２に食い込むことを防ぐことができる。これにより、十分な絶縁耐圧性能を有するコイル２０を得ることができる。よって、上記の実施形態に係るインダクタ２は、高いインダクタ特性を有するとともに、十分な絶縁耐圧性能を有することができる。更に、成形時の圧力を高めることができるので、磁性部３０における磁性粉の充填率を高めて、高いインダクタの特性を有することもできる。なお、単に巻線の被覆層を厚くした場合は、巻回部２４の外周側の巻線２２の導体２２Ａおよび磁性部３０の間に第２の樹脂層を配置したほうが、占積率（インダクタの断面積に対し、電線が占める割合）の低下を少なくできるので、インダクタ特性の劣化を最小限にすることができる。 Since a distance D2 larger than the thickness of the coating layer 22B of the winding 22 can be secured between the conductor 22A of the winding 22 and the magnetic portion 30 on the outer peripheral side of the winding portion 24, a pressure is applied during molding in the magnetic portion molding step. Even if it is applied, it is possible to prevent the magnetic powder from biting into the winding 22 on the outer peripheral side of the winding portion 24 in the mold. As a result, the coil 20 having sufficient dielectric strength can be obtained. Therefore, the inductor 2 according to the above embodiment can have high inductor characteristics and sufficient dielectric strength. Further, since the pressure at the time of molding can be increased, the filling rate of the magnetic powder in the magnetic portion 30 can be increased to have high inductor characteristics. When the coating layer of the winding is simply thickened, it is better to arrange the second resin layer between the conductor 22A of the winding 22 on the outer peripheral side of the winding portion 24 and the magnetic portion 30. Since the decrease in the ratio of the electric wire to the cross-sectional area of the above can be reduced, the deterioration of the inductor characteristics can be minimized.

同様に、図３に示すように、コイル２０の巻回部２４の軸方向における端部側に位置する巻線２２の導体２２Ａおよび磁性部３０の間の距離Ｄ３、Ｄ４が、巻回部２４の内周側の巻線２２の導体２２Ａおよび巻軸１０の間の距離Ｄ１より長くなっている。
コイル２０の巻回部２４の軸方向における端部側に位置する巻線２２の導体２２Ａおよび磁性部３０の間に、巻線２２の被覆層２２Ｂの厚みより大きな距離Ｄ３、Ｄ４を確保できるので、磁性部成形工程において、成形時に圧力をかけたとしても、金型内で磁性粉が巻回部２４の軸方向における端部側に位置する巻線２２に食い込むことを防ぐことができる。これにより、十分な絶縁耐圧性能を有するコイル２０有するインダクタ２を得ることができる。 Similarly, as shown in FIG. 3, the distances D3 and D4 between the conductor 22A and the magnetic portion 30 of the winding 22 located on the axial end side of the winding portion 24 of the coil 20 are the winding portion 24. It is longer than the distance D1 between the conductor 22A of the winding 22 on the inner peripheral side of the winding shaft 10 and the winding shaft 10.
Since distances D3 and D4 larger than the thickness of the coating layer 22B of the winding 22 can be secured between the conductor 22A and the magnetic portion 30 of the winding 22 located on the end side of the winding portion 24 of the coil 20 in the axial direction. In the magnetic portion molding step, even if pressure is applied during molding, it is possible to prevent the magnetic powder from biting into the winding 22 located on the end side in the axial direction of the winding portion 24 in the mold. Thereby, the inductor 2 having the coil 20 having sufficient dielectric strength can be obtained.

特に、上記の第１から第３の実施形態のように、コイル２０巻回部２４の外周側に位置する巻線２２および磁性部３０の間、並びに巻回部２４の軸方向における端部側に位置する巻線２２および磁性部３０の間に、第２の樹脂５０が配置されている場合、距離Ｄ２,Ｄ３、Ｄ４を確保するとともに、非磁性の第２の樹脂５０が磁気ギャップとして機能する。これにより、直流重畳特性を向上させることができる。 In particular, as in the first to third embodiments described above, between the winding 22 and the magnetic portion 30 located on the outer peripheral side of the coil 20 winding portion 24, and on the end side of the winding portion 24 in the axial direction. When the second resin 50 is arranged between the winding 22 and the magnetic portion 30 located at, the distances D2, D3, and D4 are secured, and the non-magnetic second resin 50 functions as a magnetic gap. To do. Thereby, the DC superimposition characteristic can be improved.

更に、外部電極４０が金属板からなり、磁性部３０から露出する露出部４２と、磁性部３０に埋設される埋設部４４とを備え、埋設部４４でコイル２０の引き出し部２６と接続されるとともに、埋設部４４は第２の樹脂５０で被覆されている。外部電極４０は、埋設部４４が第２の樹脂５０で被覆されているので、埋設部と磁性粉との間およびその接続部の絶縁性も確保することができる。 Further, the external electrode 40 is made of a metal plate, includes an exposed portion 42 exposed from the magnetic portion 30, and a buried portion 44 embedded in the magnetic portion 30, and is connected to the drawing portion 26 of the coil 20 by the embedded portion 44. At the same time, the buried portion 44 is covered with the second resin 50. Since the embedded portion 44 of the external electrode 40 is coated with the second resin 50, the insulating property between the embedded portion and the magnetic powder and the connection portion thereof can be ensured.

上記の実施形態に係るインダクタ２では、巻線２２を巻軸１０に直接巻回して、巻回部２４を形成するので、基本的に、巻線２２が巻軸１０に接していると考えられるが、巻線２２と巻軸１０の間の隙間に第２の樹脂が存在することがあり得る。よって、巻回部２４の内周側の巻線２２の少なくとも一部が、巻軸１０と接しているということができる。インダクタ２は、巻回部２４の内周側の巻線２２の少なくとも一部が巻軸１０と接しているので、巻線２２と巻軸１０の間に磁性粉が侵入して巻回部の内周側に磁性粉が食い込むのを抑制することができる。 In the inductor 2 according to the above embodiment, since the winding 22 is directly wound around the winding shaft 10 to form the winding portion 24, it is considered that the winding 22 is basically in contact with the winding shaft 10. However, there may be a second resin in the gap between the winding 22 and the winding shaft 10. Therefore, it can be said that at least a part of the winding 22 on the inner peripheral side of the winding portion 24 is in contact with the winding shaft 10. In the inductor 2, at least a part of the winding 22 on the inner peripheral side of the winding portion 24 is in contact with the winding shaft 10, so that magnetic powder penetrates between the winding 22 and the winding shaft 10 to form the winding portion. It is possible to prevent the magnetic powder from biting into the inner peripheral side.

本発明の実施の形態、実施の態様を説明したが、開示内容は構成の細部において変化してもよく、実施の形態、実施の態様における要素の組合せや順序の変化等は請求された本発明の範囲および思想を逸脱することなく実現し得るものである。 Although the embodiments and embodiments of the present invention have been described, the disclosed contents may be changed in the details of the configuration, and the invention in which the embodiments and the combinations and orders of the elements in the embodiments are changed are requested. It can be realized without departing from the scope and ideas of.

２インダクタ
１０巻軸
１２第１の鍔
１４第２の鍔
２０コイル
２２巻線
２２Ａ導体
２２Ｂ被覆層（第１の樹脂）
２４巻回部
２６引き出し部
３０磁性部
３０Ａ、Ｂ対向する面
３０Ｃ対向する面を接続する面
４０外部電極
４２露出部
４４埋設部
５０第２の樹脂 2 Inductor 10 Winding shaft 12 First collar 14 Second collar 20 Coil 22 Winding 22A Conductor 22B Coating layer (first resin)
24 Winding part 26 Drawer part 30 Magnetic part 30 A, B Facing surface 30C Surface connecting facing surfaces 40 External electrode 42 Exposed part 44 Embedded part 50 Second resin

Claims

Axle and
A winding portion in which a winding having a coating layer made of a conductor and a first resin is wound around the winding shaft, and a coil having a pair of drawing portions drawn out from the winding portion.
A magnetic part made of magnetic powder and resin, which seals at least a part of the winding part and the drawing part,
A pair of external electrodes provided on the surface of the magnetic portion and electrically connected to the drawer portion,
With
The distance between the conductor and the magnetic portion of the winding on the outer peripheral side of the winding portion is longer than the distance between the conductor and the winding shaft of the winding on the inner peripheral side of the winding portion. An inductor characterized by.

The distance between the conductor and the magnetic portion of the winding located on the end side in the axial direction of the winding portion is the distance between the conductor and the winding shaft of the winding on the inner peripheral side of the winding portion. The inductor according to claim 1, wherein the inductor is longer than the distance between them.

A second resin is provided between the winding and the magnetic portion located on the outer peripheral side of the winding portion, and between the winding and the magnetic portion located on the end side in the axial direction of the winding portion. The inductor according to claim 1 or 2, wherein the inductor is arranged.

The inductor according to claim 3, wherein at least a part of the winding on the inner peripheral side of the winding portion is in contact with the winding shaft.

The external electrode is made of a metal plate and includes an exposed portion exposed from the magnetic portion and a buried portion embedded in the magnetic portion.
The inductor according to claim 3 or 4, wherein the buried portion is connected to the drawer portion, and the embedded portion is coated with the second resin.

The inductor according to any one of claims 1 to 5, wherein the winding shaft is formed by molding a magnetic powder and a resin.

The inductor according to any one of claims 1 to 5, wherein the winding shaft is made of ferrite.

The inductor according to any one of claims 1 to 7, wherein the inductor has a collar at at least one end in the axial direction of the winding shaft.

Any of claims 1 to 8, wherein the magnetic portion has a substantially rectangular parallelepiped shape, and the external electrode is provided over a part of a facing surface and a surface connecting the facing surfaces. The inductor according to item 1.