JP2004281777A

JP2004281777A - Choke coil

Info

Publication number: JP2004281777A
Application number: JP2003072154A
Authority: JP
Inventors: Masayoshi Ishii; 政義石井; Haruki Hoshi; 晴輝保志
Original assignee: Tokyo Coil Engineering Co Ltd
Current assignee: Tokyo Coil Engineering Co Ltd
Priority date: 2003-03-17
Filing date: 2003-03-17
Publication date: 2004-10-07

Abstract

<P>PROBLEM TO BE SOLVED: To provide a choke coil whoes resistance can be decreased when dc current is superposed while reducing the cost. <P>SOLUTION: The choke coil comprises a core 12 having a core 15, and a coil 18 wound around the core 15. The coil 18 is formed in a U-shape when a copper plate 19 is viewed perpendicularly to the plate surface thereof. The coil 18 comprises a winding part 20 having an intermediate part applied with insulation coating, and terminal parts 21 and 22 at the opposite end parts. One terminal part 21 side serves as the winding core side and the winding part 20 is wound into a spiral winding body 25. The terminal parts 21 and 22 at the opposite end parts are let out from the outer circumference of the spiral winding body 25. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
この発明は、例えば、プリント基板に対して表面実装できるチョークコイルに関する。
【０００２】
【従来の技術】
近年、各種電子機器は、高集積化及び高周波化により大幅に多機能化、さらに小型軽量化が進んでいる。高集積化の電子機器としてノートパソコンをみると、多機能、高品位の流れとして、ＣＰＵの高速化（処理能力向上）に伴い、記録装置やＣＰＵ等の電力を供給する各ラインごとに大電流化が進んでいる。
【０００３】
比較的大きな電流に対応したチョークコイルにおいて、上下２分割したコアの一方に磁芯部を設け、この磁芯部に帯状導体からなる渦巻状のコイルを嵌合し、上下２分割されたコアによってコイルを包容し、このコイルの両端の端子部をコアから導出したものが知られている（例えば、特許文献１参照。）。
【０００４】
また、薄型化とプリント基板への実装の自動化を図るために、上下２分割したコアの一方に磁芯部を設け、平角導線を渦巻状に巻いた主コイルを樹脂によって一体成形し、この主コイルを前記磁芯部に嵌合し、上下２分割されたコアによってコイルを包容し、このコイルの両端に帯状導体からなる端子を接続し、この端子をコアから導出したものが知られている（例えば、特許文献２参照。）。
【０００５】
【特許文献１】
特開平１１−２５１１６４号公報
【０００６】
【特許文献２】
特開平２０００−２２３３３２号公報
コイルは、前述した平角タイプや丸線タイプが主流であり、主として空芯コイルを作成し、コアの磁芯部に嵌合した後、コイルと端子部とを半田もしくは溶接等によって接続し、端子部をコアから外部に導出している。
【０００７】
一方、市場からは低直流重畳抵抗（Ｒｄｃ）化が望まれ、銅線の占有率を高くする平角線化の方向へ進んでいる。
【０００８】
【発明が解決しようとする課題】
しかし、コイルとして使用する平角線はコストが丸線の約５倍程度であること、巻線方法もエッジワイズ巻き、α巻きなどあり、平角巻線ではエッジ部の絶縁・耐圧不良が発生することが問題となっている。また、チョークコイルは表面実装タイプが主流であり、コイルと端子部とを半田もしくは溶接等によって接続しなくてはならず、組立て工数がかかり、コストアップの原因となっている。
【０００９】
この発明は、前記事情に着目してなされたもので、その目的とするところは、低直流重畳抵抗化とコストダウンを図ることができるチョークコイルを提供することにある。
【００１０】
【課題を解決するための手段】
この発明は、前記目的を解決するために、請求項１は、少なくとも磁芯部を有するコアと、前記磁芯部に巻回されるコイルとからなるチョークコイルにおいて、前記コイルは、銅板をその板面に対して垂直に見たときにコ字状になるように形成し、中間部を絶縁被覆した巻線部、両端部を端子部とし、一方の端子部側を巻き芯側として前記巻線部を渦巻状巻線体に巻線し、前記両端部の端子部を渦巻状巻線体の外周から導出したことを特徴とする。
【００１１】
請求項２は、請求項１の前記コアは、磁芯部及び底面部を有するリベットコアと、このリベットコアに嵌合されるポットコアとからなり、前記コイルを包容したことを特徴とする。
【００１２】
請求項３は、請求項１または２の前記端子部は、少なくとも片面に導電部を有し、前記リベットコアの底面部の外周部に沿って折り返し折曲し、前記導電部をリベットコアの底面部の下面に露出させたことを特徴とする。
【００１３】
前記構成によれば、渦巻状巻線体を、両端子部がコアの底面部側に位置するように磁芯部に嵌合すると、両端子部はコアの底面部から外方へ延出した状態となる。そこで、両端子部をコアの底面部の外周部に沿って折り返し折曲すると、導電部はコアの底面部の下面に露出した状態となる。
【００１４】
【発明の実施の形態】
以下、この発明の実施の形態を図面に基づいて説明する。
【００１５】
図１〜図３は第１の実施形態を示し、図１はチョークコイルの縦断側面図、図２はコイルの平面図及び断面図、図３は渦巻状巻線体の平面図である。
【００１６】
図１に示すように、例えば、Ｍｎ−Ｚｎ系フェライトからなるコア１１は、リベットコア１２とポットコア１３とから構成されている。リベットコア１２は円板状の底面部１４を有し、この底面部１４の上面中央部には上方へ突出する円柱状の磁芯部１５が一体に設けられている。ポットコア１３は円板状の天板部１６を有し、この天板部１６の外周縁には下方へ突出する円筒状の周壁部１７が一体に設けられている。そして、リベットコア１２の磁芯部１５には渦巻状巻線体からなるコイル１８が嵌合され、このコイル１８はコア１１によって包容されている。
【００１７】
次に、コイル１８について説明すると、図２及び図３に示すように構成されている。すなわち、１９は巻線用銅板を打ち抜き加工等によってその板面に対して垂直に見たときにコ字状になるように形成した薄肉帯状銅板であり、中間部は巻線部２０に形成されている。巻線部２０の端部には第１の端子部２１と第２の端子部２２が一体に設けられ、第１の端子部２１は第２の端子部２２より若干長く形成されている。
【００１８】
巻線部２０及び第１及び第２の端子部２１，２２の表面には絶縁フィルム、絶縁コーティング、絶縁被膜等によって絶縁被覆層２３が形成されている。また、第１及び第２の端子部２１，２２の先端部における片面は錫メッキ層からなる導電部２４が設けられている。
【００１９】
コ字形の薄肉帯状銅板１９は、第１の端子部２１側を巻き芯側として巻線部２０は渦巻状に巻線され、渦巻状巻線体２５が形成されている。従って、渦巻状巻線体２５の巻き芯側に第１の端子部２１が位置し、その根元部を折曲することにより、第１の端子部２１は渦巻状巻線体２５の下端面に沿ってその外周から外部に導出されている。また、第２の端子部２２は渦巻状巻線体２５の外周側に位置し、その根元部を折曲することにより、外部に導出されている。従って、第１及び第２の端子部２１，２２の導電部２４は上向きになっている。
【００２０】
前述のように構成された渦巻状巻線体２５を、第１及び第２の端子部２１，２２が前記リベットコア１２の底面部１４側に位置するように磁芯部１５に嵌合すると、第１及び第２の端子部２１，２２はリベットコア１２の底面部１４から外方へ延出した状態となる。そこで、第１及び第２の端子部２１，２２をリベットコア１２の底面部１４の外周部に沿って折り返し折曲すると、導電部２４はリベットコア１２の底面部１４の下面１４ａに露出した状態となる。次に、リベットコア１２にポットコア１３を嵌合し、周壁部１７の下端面をリベットコア１２の底面部１４に接着することにより完成する。
【００２１】
このように構成されたチョークコイルは、その下面、具体的にはリベットコア１２の底面部１４の下面に導電部２４が露出しているために、プリント基板２６のプリント配線にリフロー半田付けによって表面実装することができる。
【００２２】
また、ポットコア１２の磁芯部１５の高さはポットコア１３の周壁部１７より低く形成されており、ポットコア１３の天板部１６の内面とリベットコア１２の磁芯部１５の端面との間に磁路のギャップ２８を形成している。このギャップ２８を調整してコイルのインダクタンスを設定することができる。
【００２３】
また、渦巻状巻線体２５を構成する薄肉帯状銅板１９の幅を狭くすれば、チョークコイルの高さ寸法が低くなり、薄型化が可能であり、また大電流用のチョークコイルとする場合には、渦巻状巻線体２５を構成する薄肉帯状銅板１９の肉厚を厚くすれば良く、ユーザーのニーズに対応できる。
【００２４】
さらに、コイル１８として高価な平角線を用いず、安価な銅板を使用しているため、大幅なコストダウンが図れるとともに、渦巻状に巻線しているため、平角線エッジワイズ巻きと同等の銅線の占有率が得られるため、低直流重畳抵抗化が可能となる。また、コイル１８は渦巻状巻線体２５と第１と第２の端子部２１，２２が一体であるため、半田や溶接等の接続が不要となり、接続工程数が省け、工程の簡素化と低コスト化が図れる。
【００２５】
また、コア１１がＭｎ−Ｚｎ系フェライト等によって形成されているため、直流重畳特性及び高周波でのコアロスを改善でき、インダクタンスのばらつきを減少できる。しかも、高集積化によって実装基板にランドパターンが存在しても、実装基板とコア１１との間を完全に電気的に絶縁でき、信頼性の向上を図ることができる。
【００２６】
なお、前記第１の実施形態においては、第１及び第２の端子部２１，２２をリベットコア１２の底面部１４の外周に沿って折り返し折曲したが、図４の変形例に示すように、底面部１４の外周へ水平に突出せ、第１及び第２の端子部２１，２２の突出部２１ａ，２２ａにリード線を絡げて半田付けする接続方法でも良い。
【００２７】
図５及び図６は第２の実施形態を示し、図５はコイルの平面図、図６は渦巻状巻線体の斜視図であり、第１の実施形態と同一構成部分は同一符号を付して説明を省略する。
【００２８】
３０は巻線用銅板を打ち抜き加工等によってその板面に対して垂直に見たときにコ字状になるように形成した薄肉帯状銅板であり、中間部は広幅の巻線部３１に形成されている。巻線部３１の端部には狭幅の第１の端子部２１と第２の端子部２２が一体に設けられ、第１の端子部２１は第２の端子部２２より若干長く形成されている。
【００２９】
前記薄肉帯状銅板３０は、第１の端子部２１側を巻き芯側として巻線部３１は渦巻状に巻線され、渦巻状巻線体３２が形成されている。従って、渦巻状巻線体３２の高さは、巻線部３１の幅によって決定されるため、図６に示すように、高さ寸法Ｈが高い渦巻状巻線体３２を形成することができる。
【００３０】
図７はコアの変形例を示し、（ａ）は磁芯部３３を有する円板状の第１のコア３４と、円板状の第２のコア３５と、コイル３６を囲むように設けられた円筒状の第３のコア３７とから構成されている。（ｂ）は磁芯部３８の両端部に一体に鍔部３９ａ，３９ｂを有するコアであり、磁芯部３８にはコイル４０が巻回されている。
【００３１】
なお、前記実施形態においては円筒状のコアについて説明したが、矩形状のコアでもよく、コアの形状に限定されるものではない。
【００３２】
【発明の効果】
以上説明したように、この発明によれば、コイルとして高価な平角線を用いず、安価な銅板を使用しているため、大幅なコストダウンが図れるとともに、渦巻状に巻線しているため、平角線エッジワイズ巻きと同等の銅線の占有率が得られるため、低直流重畳抵抗化が可能となる。
【００３３】
また、コイルは渦巻状巻線体と両端子部が一体であるため、半田や溶接等の接続が不要となり、接続工程数が省け、工程の簡素化と低コスト化が図れる。
【図面の簡単な説明】
【図１】この発明の第１の実施形態を示し、チョークコイルの縦断側面図。
【図２】同実施形態を示し、（ａ）は薄肉帯状銅板の平面図、（ｂ）はＡ−Ａ線に沿う断面図、（ｃ）はＢ−Ｂ線に沿う断面図、（ｄ）はＣ−Ｃ線に沿う断面図。
【図３】同実施形態を示し、渦巻状巻線体の平面図。
【図４】同実施形態の変形例を示すチョークコイルの縦断側面図。
【図５】この発明の第２の実施形態を示し、薄肉帯状銅板の平面図。
【図６】同実施形態を示し、渦巻状巻線体の斜視図。
【図７】この発明のコアの変形例を示し、（ａ）（ｂ）は縦断側面図。
【符号の説明】
１１…コア、１２…リベットコア、１３…ポットコア、１４…底面部、１５…磁芯部、１８…コイル、１９…銅板、２０…巻線部、２１，２２…端子部、２５…渦巻状巻線体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to, for example, a choke coil that can be surface-mounted on a printed circuit board.
[0002]
[Prior art]
2. Description of the Related Art In recent years, various electronic devices have been significantly multifunctional due to higher integration and higher frequency, and furthermore, have been reduced in size and weight. Looking at notebook PCs as highly integrated electronic equipment, multi-function, high-quality flows have resulted in large currents for each line that supplies power to recording devices and CPUs as CPU speeds up (improves processing capacity). Is progressing.
[0003]
In a choke coil corresponding to a relatively large current, a magnetic core portion is provided on one of upper and lower divided cores, and a spiral coil made of a band-shaped conductor is fitted to this magnetic core portion, and the upper and lower divided cores are used. A coil is known, in which terminals at both ends of the coil are led out of a core (for example, see Patent Document 1).
[0004]
In order to reduce the thickness and automate mounting on a printed circuit board, a magnetic core is provided on one of the upper and lower divided cores, and a main coil in which a flat rectangular wire is spirally formed is integrally molded with resin. It is known that a coil is fitted to the magnetic core portion, a coil is enclosed by a core divided into upper and lower parts, terminals formed of a strip-shaped conductor are connected to both ends of the coil, and the terminals are led out of the core. (For example, see Patent Document 2).
[0005]
[Patent Document 1]
Japanese Patent Application Laid-Open No. H11-251164
[Patent Document 2]
Japanese Patent Application Laid-Open No. 2000-223332 discloses a coil in which the above-mentioned flat type or round type coil is mainly used. An air-core coil is mainly formed, and after fitting to the magnetic core of the core, the coil and the terminal are soldered or soldered. Connection is made by welding or the like, and the terminal portion is led out of the core.
[0007]
On the other hand, the market demands a low DC superimposed resistance (Rdc), and the trend is toward a rectangular wire that increases the occupancy of copper wires.
[0008]
[Problems to be solved by the invention]
However, the cost of a flat wire used as a coil is about five times that of a round wire, and the winding method is edgewise winding or α winding. Is a problem. The choke coil is mainly of a surface mount type, and the coil and the terminal must be connected to each other by soldering, welding, or the like, which requires assembling man-hours and causes an increase in cost.
[0009]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a choke coil capable of achieving low DC superimposed resistance and cost reduction.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned object, the present invention provides a choke coil comprising at least a core having a magnetic core portion and a coil wound around the magnetic core portion, wherein the coil is a copper plate. The winding portion is formed so as to have a U-shape when viewed perpendicularly to the plate surface, the winding portion insulated at the middle portion, the both end portions as the terminal portions, and one terminal portion side as the winding core side. The wire portion is wound around a spiral wound body, and the terminal portions at both ends are led out from the outer periphery of the spiral wound body.
[0011]
A second aspect of the present invention is characterized in that the core according to the first aspect includes a rivet core having a magnetic core portion and a bottom portion, and a pot core fitted to the rivet core, and encloses the coil.
[0012]
According to a third aspect of the present invention, the terminal portion according to the first or second aspect has a conductive portion on at least one side, and is bent back along an outer peripheral portion of a bottom portion of the rivet core, and the conductive portion is connected to the bottom surface of the rivet core. It is characterized by being exposed to the lower surface of the part.
[0013]
According to the configuration, when the spirally wound coil body is fitted to the magnetic core so that both terminal portions are located on the bottom surface side of the core, both terminal portions extend outward from the bottom surface of the core. State. Then, when both terminal portions are folded back along the outer peripheral portion of the bottom surface of the core, the conductive portion is exposed on the lower surface of the bottom surface of the core.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
1 to 3 show a first embodiment, FIG. 1 is a vertical sectional side view of a choke coil, FIG. 2 is a plan view and a sectional view of the coil, and FIG. 3 is a plan view of a spirally wound body.
[0016]
As shown in FIG. 1, for example, a core 11 made of Mn—Zn-based ferrite includes a rivet core 12 and a pot core 13. The rivet core 12 has a disk-shaped bottom surface portion 14, and a columnar magnetic core portion 15 projecting upward is integrally provided at the center of the upper surface of the bottom surface portion 14. The pot core 13 has a disc-shaped top plate portion 16, and a cylindrical peripheral wall portion 17 protruding downward is integrally provided on an outer peripheral edge of the top plate portion 16. A coil 18 composed of a spiral winding is fitted into the magnetic core 15 of the rivet core 12, and the coil 18 is enclosed by the core 11.
[0017]
Next, the coil 18 will be described. The coil 18 is configured as shown in FIGS. That is, reference numeral 19 denotes a thin strip-shaped copper plate formed by punching a copper plate for winding so as to have a U-shape when viewed perpendicularly to the plate surface. ing. A first terminal portion 21 and a second terminal portion 22 are integrally provided at an end of the winding portion 20, and the first terminal portion 21 is formed to be slightly longer than the second terminal portion 22.
[0018]
An insulating coating layer 23 is formed on the surfaces of the winding portion 20 and the first and second terminal portions 21 and 22 using an insulating film, an insulating coating, an insulating coating, or the like. In addition, a conductive portion 24 made of a tin plating layer is provided on one surface at the tip of the first and second terminal portions 21 and 22.
[0019]
In the U-shaped thin strip copper plate 19, the winding part 20 is spirally wound with the first terminal part 21 side as the winding core side, and a spiral winding body 25 is formed. Therefore, the first terminal portion 21 is located on the winding core side of the spiral winding body 25, and the first terminal portion 21 is attached to the lower end surface of the spiral winding body 25 by bending the root portion thereof. Along its outer periphery. The second terminal portion 22 is located on the outer peripheral side of the spirally wound coil body 25, and is led out to the outside by bending the root portion. Accordingly, the conductive portions 24 of the first and second terminal portions 21 and 22 face upward.
[0020]
When the spiral wound body 25 configured as described above is fitted to the magnetic core portion 15 such that the first and second terminal portions 21 and 22 are located on the bottom surface portion 14 side of the rivet core 12, The first and second terminal portions 21 and 22 are in a state of extending outward from the bottom portion 14 of the rivet core 12. Then, when the first and second terminal portions 21 and 22 are folded back along the outer peripheral portion of the bottom portion 14 of the rivet core 12, the conductive portion 24 is exposed on the lower surface 14a of the bottom portion 14 of the rivet core 12. It becomes. Next, the pot core 13 is fitted to the rivet core 12 and the lower end surface of the peripheral wall portion 17 is adhered to the bottom surface portion 14 of the rivet core 12 to complete the process.
[0021]
Since the conductive portion 24 is exposed on the lower surface of the choke coil thus configured, specifically, on the lower surface of the bottom portion 14 of the rivet core 12, the surface of the choke coil is reflow soldered to the printed wiring of the printed circuit board 26. Can be implemented.
[0022]
The height of the magnetic core portion 15 of the pot core 12 is formed lower than the peripheral wall portion 17 of the pot core 13, and is between the inner surface of the top plate portion 16 of the pot core 13 and the end surface of the magnetic core portion 15 of the rivet core 12. The gap 28 of the magnetic path is formed. The gap 28 can be adjusted to set the inductance of the coil.
[0023]
In addition, if the width of the thin strip copper plate 19 constituting the spiral winding body 25 is reduced, the height of the choke coil is reduced, and the choke coil can be reduced in thickness. The thickness of the thin strip-shaped copper plate 19 constituting the spirally wound coil body 25 may be increased, which can meet the needs of the user.
[0024]
In addition, since an inexpensive copper plate is used instead of an expensive rectangular wire as the coil 18, the cost can be greatly reduced. In addition, since the coil 18 is wound in a spiral shape, a copper equivalent to a rectangular wire edgewise winding is used. Since the line occupancy can be obtained, low DC superimposed resistance can be achieved. Further, since the coil 18 has the spiral winding body 25 and the first and second terminal portions 21 and 22 integrated with each other, connection such as soldering or welding is not required, so that the number of connection steps can be reduced, and the process can be simplified. Cost reduction can be achieved.
[0025]
Further, since the core 11 is formed of Mn-Zn-based ferrite or the like, the DC superposition characteristics and the core loss at high frequencies can be improved, and the variation in inductance can be reduced. Moreover, even if a land pattern exists on the mounting board due to the high integration, the mounting board and the core 11 can be completely electrically insulated, and the reliability can be improved.
[0026]
In the first embodiment, the first and second terminal portions 21 and 22 are folded back along the outer periphery of the bottom portion 14 of the rivet core 12, but as shown in a modification of FIG. Alternatively, a connection method may be used in which the projection is horizontally protruded to the outer periphery of the bottom portion 14 and a lead wire is tied to the projections 21a and 22a of the first and second terminal portions 21 and 22 and soldered.
[0027]
5 and 6 show a second embodiment, FIG. 5 is a plan view of a coil, FIG. 6 is a perspective view of a spirally wound body, and the same components as those in the first embodiment are denoted by the same reference numerals. And the description is omitted.
[0028]
Reference numeral 30 denotes a thin strip-shaped copper plate formed by punching a copper plate for winding so as to have a U-shape when viewed perpendicularly to the plate surface. The middle part is formed by a wide winding part 31. ing. A first terminal portion 21 and a second terminal portion 22 having a narrow width are integrally provided at an end of the winding portion 31, and the first terminal portion 21 is formed to be slightly longer than the second terminal portion 22. I have.
[0029]
The thin strip-shaped copper plate 30 has a winding part 31 wound spirally with the first terminal part 21 side as a winding core side, and a spiral wound body 32 is formed. Accordingly, since the height of the spirally wound coil body 32 is determined by the width of the winding portion 31, the spirally wound coil body 32 having a high height H can be formed as shown in FIG. .
[0030]
FIG. 7 shows a modification of the core. FIG. 7A is provided so as to surround a disk-shaped first core 34 having a magnetic core 33, a disk-shaped second core 35, and a coil 36. And a cylindrical third core 37. (B) is a core having flanges 39a and 39b integrally provided at both ends of the magnetic core 38, and a coil 40 is wound around the magnetic core 38.
[0031]
In the above embodiment, a cylindrical core is described, but a rectangular core may be used, and the shape of the core is not limited.
[0032]
【The invention's effect】
As described above, according to the present invention, an inexpensive rectangular wire is not used as the coil, and an inexpensive copper plate is used. Since the occupation ratio of the copper wire equivalent to that of the rectangular wire edgewise winding can be obtained, a low DC superimposed resistance can be achieved.
[0033]
Further, since the coil has a spiral wound body and both terminal portions integrated with each other, connection such as soldering or welding is not required, the number of connection steps can be reduced, and the steps can be simplified and cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional side view of a choke coil according to a first embodiment of the present invention.
FIGS. 2A and 2B show the same embodiment, wherein FIG. 2A is a plan view of a thin strip copper plate, FIG. 2B is a cross-sectional view along line AA, FIG. 2C is a cross-sectional view along line BB, and FIG. Is a cross-sectional view along the line CC.
FIG. 3 is a plan view of the spirally wound body, showing the embodiment.
FIG. 4 is a vertical sectional side view of a choke coil showing a modification of the embodiment.
FIG. 5 shows a second embodiment of the present invention and is a plan view of a thin strip copper plate.
FIG. 6 is a perspective view of the spirally wound body, showing the embodiment.
FIGS. 7A and 7B show a modified example of the core of the present invention, wherein FIGS.
[Explanation of symbols]
11 core, 12 rivet core, 13 pot core, 14 bottom surface, 15 magnetic core, 18 coil, 19 copper plate, 20 winding, 21, 22 terminal, 25 spiral winding Linear body

Claims

In a choke coil including at least a core having a magnetic core and a coil wound around the magnetic core,
The coil is formed such that a copper plate is formed into a U-shape when viewed perpendicularly to the plate surface, a winding portion insulated at an intermediate portion, terminal portions at both ends, and one terminal portion side Wherein the winding portion is wound around a spirally wound body with a winding core side, and the terminal portions at both ends are led out from the outer periphery of the spirally wound body.

The choke coil according to claim 1, wherein the core includes a rivet core having a magnetic core portion and a bottom portion, and a pot core fitted to the rivet core, and encloses the coil.

The terminal portion has a conductive portion on at least one side, and is folded back along the outer peripheral portion of the bottom portion of the rivet core to expose the conductive portion to the lower surface of the bottom portion of the rivet core. The choke coil according to claim 1 or 2, wherein: