JP3909834B2

JP3909834B2 - Coil component connection structure and method

Info

Publication number: JP3909834B2
Application number: JP2002163976A
Authority: JP
Inventors: 一三小林; 昂三梶原; 敏浩黒嶋; 孝輝佐藤
Original assignee: TDK Corp
Current assignee: TDK Corp
Priority date: 2002-06-05
Filing date: 2002-06-05
Publication date: 2007-04-25
Anticipated expiration: 2022-06-05
Also published as: JP2004014671A

Description

【０００１】
【発明の属する技術分野】
本発明は、磁気コアやボビンに巻線を施したＥＭＣフィルタ等のコイル部品に係り、特に使用環境の厳しい自動車等に好適で、磁気コアやボビンに端部電極となる端子金具を装着したものに巻線を行い、継線を溶接で行う場合に、巻線端末と端部電極との継線構造部分の信頼性向上が図れるコイル部品の継線構造及び方法に関する。
【０００２】
【従来の技術】
従来のこの種のコイル部品としては、図６に示されるように、角ドラムタイプの磁気コア（フェライトコア等）１に銀ペーストを焼き付けた後、Ｓｎめっき処理して端部電極２とし、前記磁気コア１に巻線３を設け、前記巻線３の端末を熱圧着により端部電極２に接続して表面実装型のコイル部品を構成したものがある。
【０００３】
また、他の表面実装型のコイル部品としては、図７（Ａ）,（Ｂ）に示されるように、角ドラムタイプの磁気コア１にＬ字状の端子金具５を接着、貼り付けして端部電極とし、前記磁気コア１に巻線３を設け、前記巻線３の端末を端子金具５の絡げ部５ａに絡げてレーザやアーク溶接にて接続したものがある。
【０００４】
さらに、図８（Ａ）のように端部電極としての端子金具６に、その本体の一部６ａと当該本体の一部６ａに対して庇状に折り返された折り返し部６ｂとで略Ｕ形状を成した継線部７を設け、巻線端末３ａのワイヤを略Ｕ形状の継線部７に通し、折り返し部６ｂをかしめた後、同図（Ｂ）のように溶接接続する構成がある。
【０００５】
また、本発明者が従来考慮した構造として、図９（Ａ）のように端部電極としての端子金具６に、その本体の一部６ａと当該本体の一部６ａに対して庇状に折り返された折り返し部６ｂとで略Ｕ形状を成した継線部７を設け、さらに折り返し部６ｂを基部にまで達するスリット８で仮止め部７ａと溶接部７ｂとに分離したものがある。この場合、巻線端末３ａのワイヤを略Ｕ形状の継線部７に通し、仮止め部７ａをかしめた後、図９（Ｂ）のように溶接部７ｂと巻線端末３ａとを溶接接続する。
【０００６】
なお、図１０は小型製品の端子金具であって、端子金具６のワイヤ引出方向の長さＬを大きくとれない場合に本発明者が従来考慮した構造であり、溶接部７ｂの基部（根本）の幅よりも上面部分の幅を大きくしたものである（図９と同一又は相当部分に同一符号を付した）。巻線端末の溶接接続は図９の場合と同様に行う。
【０００７】
【発明が解決しようとする課題】
図６の表面実装型コイル部品は、熱圧着により巻線端末を端部電極に接続しているが、熱圧着は基本的に端部電極のＳｎ部と巻線ワイヤの銅部との溶融接続となっており、とくに相手側基板に対する鉛フリーの比較的高温のリフロー実装時にＳｎ部が溶融してしまうため、接続信頼性に問題があった。
【０００８】
また、図７（Ａ）,（Ｂ）の端子金具５の絡げ部５ａに巻線端末を絡げてレーザやアーク溶接にて接続する場合、巻線端末のワイヤ被覆の熱劣化や線細り（溶接時の熱が巻線端末に伝導するため）、テンション（テンションがワイヤにかかっていると断線の問題がある）等の品質の問題と製品高さが大きくなる問題があった。
【０００９】
図８の巻線端末３ａのワイヤを継線部７のかしめによって係止し溶接で固定する構造は、製品高さは低くできるが、巻線端末のワイヤ被覆の熱劣化や線細りの問題があった。
【００１０】
図９の継線部７の折り返し部６ｂを仮止め部７ａと溶接部７ｂとに分割する構造は、巻線端末３ａを挟持する仮止め部７ａでワイヤが固定されるとともに溶接時の熱が放熱されるため、ワイヤ被覆の熱劣化は軽減できるが、端子金具６のワイヤ引出方向の長さを十分確保する必要があり、ワイヤ引出方向の小型化に対応できない。
【００１１】
また、図１０のように端子金具６のワイヤ引出方向の長さＬを小さくしたときは、溶接部７ｂの基部の幅が極めて狭くなり継線部７の端子強度に問題があった。例えば、前記長さＬが０.５mm程度の場合、折り返し部６ｂの基部は０.３５mm程度しか確保できず、スリット８の幅を０.１mmとすると、仮止め部７ａと溶接部７ｂの基部の幅は各々０.１２５mmとなり、細くて弱く、最悪の場合に折損してしまう恐れがある。
【００１２】
本発明は、上記の問題に鑑みなされたものであって、特に自動車等の使用環境の厳しい場合でも、巻線端末のワイヤ被覆の熱劣化や線細り等の品質の問題がなく、継線部の高さも低く、ワイヤ引出方向の寸法も小さくでき、しかも継線部の端子強度も問題が無く、溶接状態のバラツキが少なく安定した作業ができるため、歩留まりが良く安価に作製可能なコイル部品の継線構造及び方法を提供することを目的とする。
【００１３】
本発明のその他の目的や新規な特徴は後述の実施の形態において明らかにする。
【００１４】
【課題を解決するための手段】
上記目的を達成するために、本願請求項１の発明は、端子金具の端部電極に巻線端末を継線するコイル部品の継線構造において、
前記端部電極は、本体の一部である上面部と当該上面部に対して庇状に折り返された折り返し部とで略Ｕ形状を成した継線部を有し、前記折り返し部の上面部分のみにスリットを形成して仮止め部と溶接部となる圧着部とに分け、かつ前記圧着部の前記仮止め部に対して反対側の縁部が、前記本体の一部である上面部からはみ出しており、
前記略Ｕ形状の継線部に通された前記巻線端末を、前記圧着部の手前側に位置する前記仮止め部で挟持し、巻線先端部と前記圧着部の前記縁部側とをレーザやアーク等の溶接で溶融接続したことを特徴としている。
本願請求項２の発明に係るコイル部品の継線構造は、請求項１において、前記圧着部は前記仮止め部より大きいことを特徴としている。
本願請求項３の発明に係るコイル部品の継線構造は、請求項１又は２において、前記圧着部は前記折り返し部の基部に比べて幅広であることを特徴としている。
本願請求項４の発明に係るコイル部品の継線構造は、請求項１，２又は３において、前記仮止め部は放熱機能を有していることを特徴としている。
【００１５】
本願請求項５の発明は、端子金具の端部電極に巻線端末を継線するコイル部品の継線方法において、
前記端部電極は、本体の一部である上面部と当該上面部に対して庇状に折り返された折り返し部とで略Ｕ形状を成した継線部を有し、前記折り返し部の上面部分のみにスリットを形成して仮止め部と溶接部となる圧着部とに分け、かつ前記圧着部の前記仮止め部に対して反対側の縁部が、前記本体の一部である上面部からはみ出しており、
前記略Ｕ形状の継線部に前記巻線端末を挿通し、前記折り返し部をかしめて挟持した後、巻線先端部と前記圧着部の前記縁部側とをレーザやアーク等の溶接で溶融接続することを特徴としている。
本願請求項６の発明に係るコイル部品の継線方法は、請求項５において、前記仮止め部は放熱機能を有していることを特徴としている。
【００１６】
本願請求項７の発明に係るコイル部品の継線方法は、請求項５又は６において、レーザビームの照射パターンの端部電極幅方向の中心を、前記巻線先端部と前記圧着部との境界部にあわせて照射し、前記レーザビームが少なくとも前記巻線先端部と前記圧着部の両方にかかるようにしてレーザ溶接を行うことを特徴としている。
【００１７】
本願請求項８の発明に係るコイル部品の継線方法は、請求項７において、前記レーザビームの照射パターンが前記巻線端末の引出方向と交差する方向に長径を有する略楕円乃至長円形状であることを特徴としている。
【００１８】
【発明の実施の形態】
以下、本発明に係るコイル部品の継線構造及び方法の実施の形態を図面に従って説明する。
【００１９】
図１で本発明の第１の実施の形態を説明する。図１（Ａ）は端子金具２０を装着した磁気コア１１に巻線３０を施して巻線端末３０ａを端子金具２０の継線部２２にて圧着固定した状態の斜視図、同図（Ｂ）は前記端子金具２０における継線部２２の拡大斜視図であって、スリット２４により仮止め部２５と溶接部２６とに分けられており、同図（Ｃ）は継線部２０における溶接部２６と巻線端末とを溶接した状態をそれぞれ示す。また、図２は第１の実施の形態で用いる端子金具２０（但し、かしめる前の状態）を示す。
【００２０】
ここで使用する磁気コア１１は角ドラムタイプのフェライトコア（フェライト・ドラムコア）であり、図１（Ａ）のように、巻芯部の両側に方形鍔１２を形成したものである。なお、磁気コア１１の形状寸法は、例えば長さが４.５mm、方形鍔横幅が３.２mm、その高さが２mm程度である。
【００２１】
端子電極となる端子金具２０は、燐青銅、真鍮等の銅合金であって、図２（Ａ）,（Ｂ）,（Ｃ）のように、略コ字形状に折り曲げ成形されており、側面部２０ａ、上面部２０ｂ及び底面部２０ｃ及び上下の折り返し部２０ｄからなる本体を有している。また、側面部２０ａの内面には磁気コア１１側抜け止め部（図示せず）に係合する金具側抜け止め部としてのポッチ部（内面側に突出した凸部）２１が形成されている。
【００２２】
さらに、図１（Ｂ）、図２（Ａ）,（Ｂ）,（Ｃ）のように、本体の上面部２０ｂに形成される継線部２２は、本体の一部（つまり上面部２０ｂ）と当該本体の一部に対して庇状に折り返された折り返し部２３とで略Ｕ形状を成しており、折り返し部２３の上面部分のみにスリット２４を形成して仮止め部２５と溶接部２６とに分けている。溶接部２６は折り返し部２３の基部２３ａに比べて幅広に形成されている。前記端子金具２０の板厚は０.０８〜０.１mmであり、図２（Ｃ）に示す端子金具２０のワイヤ引出方向の長さＬが０.５mm程度の場合、折り返し部２３の基部２３ａの幅が０.３５mm程度となるが、スリット２４（幅０.１mm程度）は折り返し部２３の基部２３ａに達していないため、その基部２３ａの強度が損なわれることは無い。
【００２３】
このような端子金具２０は、磁気コア１１の端面部、つまり方形鍔１２に、その側方より挿入され、嵌合装着される。そして、磁気コア１１の巻芯部の周囲に、ウレタン線等の絶縁被覆線を用いて巻線３０が巻回され、各巻線３０の巻線端末３０ａのワイヤは、方形鍔１２に嵌合装着された端子金具２０の継線部２２の略Ｕ形状部分に通され、継線部２２の折り返し部２３（仮止め部２５及び溶接部２６）をかしめることで圧着固定される。この場合、ワイヤ先端は溶接部２６を通過して溶接部２６よりも僅かに突出する配置が好ましく、仮止め部２５は、溶接部２６で押さえられるワイヤ先端部より手前側を押さえる。
【００２４】
その後、前記ワイヤ端末と端子金具２０の継線部２２との接続をレーザ溶接又はアーク溶接で行い、図１（Ｃ）のように、継線部２２の溶接部２６とワイヤ先端部とを溶融させて溶融接続部Ｋとして、継線部２２とワイヤの導体部分（銅線部分）とを機械的及び電気的に接続する。このとき、仮止め部２５は溶接されないで巻線端末３０ａのワイヤ押さえを継続するため、溶接部２６が溶融してもワイヤの押さえが不安定になることはなく（ワイヤの位置ずれが発生せず）、また溶接部２６からワイヤに伝わる熱を放熱する作用も果たすため、巻線３０の本体部分のワイヤ被覆の熱劣化、線細りの問題も解消できる。
【００２５】
それらにより、巻線３０を磁気コア１１に設け、端部電極としての端子金具２０に巻線端末３０ａを溶接、接続した表面実装型コイル部品が得られる。
【００２６】
この第１の実施の形態によれば、次の通りの効果を得ることができる。
【００２７】
(1) 磁気コア１１に装着された端部電極としての端子金具２０は、本体（上面部２０ｂ）の一部と当該本体の一部に対して庇状に折り返された折り返し部２３とで略Ｕ形状を成した継線部２２を有し、折り返し部２３の上面部分のみにスリット２４を形成して仮止め部２５と溶接部２６とに分け、前記略Ｕ形状の継線部２２に通された巻線端末３０ａを、仮止め部２５（溶接部２６の手前側に位置する）及び溶接部２６で挟持して圧着固定し、巻線端末３０ａと溶接部２６とをレーザやアーク等の溶接で溶融接続しており、環境に配慮して融点の高い鉛レスはんだを用いて表面実装型コイル部品を配線基板に装着する場合であっても、はんだ付け時に表面実装型コイル部品の巻線端末３０ａと端子金具２０間の接合部分が溶融することはない。
【００２８】
(2) 溶接部２６は巻線端末３０ａのワイヤと溶接で接続されるが、仮止め部２５は溶接されないで巻線端末３０ａのワイヤ押さえを継続するため、溶接部２６が溶融してもワイヤの押さえが不安定になることはなく（ワイヤの位置ずれが発生せず）、また仮止め部２５は溶接部２６からワイヤに伝わる熱を放熱する作用も果たすため、巻線３０の本体部分のワイヤ被覆の熱劣化、線細りの問題も解消できる。
【００２９】
(3) 図９や図１０の従来例においては、継線部の折り返し部を仮止め部と溶接部とに分けるスリットが略Ｕ形状の継線部の下面部にまで達しているため、端子金具のワイヤ引出方向の長さを小さくし、折り返し部の基部の幅が０.３５mm程度しか確保できない場合、端子金具２０の板厚０.０８mm、スリット幅０.１mmで、仮止め部と溶接部の根本の幅がそれぞれ０.１２５mmとなり（ワイヤ径０.０６〜０.０８mm）、強度的に弱くなってしまい、信頼性に問題があった。また、溶融接続時の熱を、仮止め部で放熱させてワイヤ被覆やワイヤ自体の劣化を防止する訳であるが、前記仮止め部が小さく不十分となってしまう。本実施の形態においては、図１（Ｂ）や図２のように、継線部２２の折り返し部２３の上面部分のみにスリット２４を形成しており、折れ易い根本部の幅は広くとれるため、強度確保が十分にとれるばかりでなく、放熱容量も大きくなり、ワイヤ被覆やワイヤ自体の劣化を防止できる。また、これらにより、製品の歩留も向上し、安価で高品質のコイル部品が供給できるようになる。
【００３０】
図３は本発明の第２の実施の形態を示す。この場合、絶縁樹脂製のボビン４１に端部電極である端子金具５０をインサート成形で設け、さらに巻線６０をボビン４１の外周に巻回して、巻線端末６０ａのワイヤを端子金具５０に溶接で接続している。端子金具５０は第１の実施の形態の端子金具２０と同様であり、本体（上面部）５０ａの一部と当該本体の一部に対して庇状に折り返された折り返し部５３とで略Ｕ形状を成した継線部５２を有し、折り返し部５３の上面部分のみにスリット５４を形成して仮止め部５５と溶接部５６とに分け、前記略Ｕ形状の継線部５２に通された巻線端末６０ａを、溶接部５６の手前側に位置する仮止め部５５と溶接部５６とで挟持し、巻線端末６０ａと溶接部５６とをレーザやアーク等の溶接で溶融接続している。
【００３１】
この第２の実施の形態の場合も、前述の第１の実施の形態と同様の効果、つまりワイヤ被覆やワイヤ自体の劣化を防止でき、ひいては製品の歩留向上、安価で高品質のコイル部品の提供が可能である。
【００３２】
図４は、第１及び第２の実施の形態において、巻線端末３０ａ，６０ａと端子金具２０，５０の継線部２２，５２とをレーザ溶接する場合のレーザビーム照射位置を示す。図４（Ａ）のレーザビーム照射位置Ｐのように円形のレーザビーム照射パターンが少なくとも巻線端末３０ａ，６０ａのワイヤと継線部２２，６２に形成された溶接部２６，５６にかかるように設定するか、レーザビーム照射位置Ｑのように円形のレーザビーム照射パターンがワイヤ上の溶接部２６，５６にかかるように設定することで溶接部２６，５６とワイヤとの溶融結合を良好に行うことができる。図４（Ｂ）のようにレーザビーム照射位置Ｐに対してワイヤずれが発生したとき、あるいは同図（Ｃ）のようにレーザビーム照射位置がＰ’にずれたときは溶融結合が良好な結果とならない場合が多い。
【００３３】
図５は第１及び第２の実施の形態において、巻線端末３０ａ，６０ａと端子金具２０，５０の継線部２２，５２とをレーザ溶接する場合の好ましいレーザビーム照射位置及び照射パターンを示す。ここで、レーザビーム照射位置はレーザビーム照射パターンＳが少なくとも巻線端末３０ａ，６０ａのワイヤと継線部２２，６２に形成された溶接部２６，５６にかかるように設定され、かつ照射パターンＳは巻線端末ワイヤの引出方向と交差する方向に長径を有する略楕円乃至長円形状である。このような照射パターンＳとすることで、図５中に点線で示すようにワイヤずれが発生しても端子金具側溶接部２６，５６とワイヤとの溶融結合を広範囲にわたり良好に行うことができる。
【００３４】
例えば、ＹＡＧレーザビーム処理で溶融接続する場合、図４の円形のレーザビーム照射パターンではビーム径０.３mmで１ジュール程度で良好な継線接続が得られるが、ビーム径を０.４mmにした場合には１.３ジュール程度必要となり、溶融過大やワイヤの熱影響が懸念された。一方、図５のようにビーム形状を短径０.２mm×長径０.４mmの略楕円乃至長円形状とした場合、１ジュール程度のエネルギーで、円形ビーム径０.３mmではワイヤ１本分のずれが許容範囲であったものが、ワイヤ２本分のずれ程度をカバーすることができた。このように、略楕円乃至長円形状とすることで、少ないレーザビームパワーで広範囲にわたる溶融をカバーできる。
【００３５】
以上本発明の実施の形態について説明してきたが、本発明はこれに限定されることなく請求項の記載の範囲内において各種の変形、変更が可能なことは当業者には自明であろう。
【００３６】
【発明の効果】
以上説明したように、本発明によれば、端子金具の端部電極に巻線端末を継線する場合において、前記端部電極は、本体の一部と当該本体の一部に対して庇状に折り返された折り返し部とで略Ｕ形状を成した継線部を有し、前記折り返し部の上面部分のみにスリットを形成して仮止め部と溶接部とに分け、前記略Ｕ形状の継線部に通された前記巻線端末を、前記溶接部の手前側に位置する前記仮止め部で挟持し、前記巻線端末と前記溶接部とをレーザやアーク等の溶接で溶融接することで、巻線端末のワイヤ被覆の熱劣化や線細り等の品質の問題がなく、継線部の高さも低く、ワイヤ引出方向の寸法も小さくでき、しかも継線部の端子強度も問題が無く、溶接状態のバラツキが少なく安定した作業が可能なコイル部品を実現できる。
【００３７】
とくに、本発明はコイル部品が小型化された場合に有効であり、図９や図１０の従来例においては、継線部スリットが下面部までとなっているため、継線部に形成した折り返し部の基部幅を０.３５mm程度と小さくする場合、板厚０.０８mm、スリット幅０.１mm、スリットで区分された仮止め部と溶接部の基部の幅は各々０.１２５mmとなり（ワイヤ径０.０６〜０.０８mm）、強度的に弱くなってしまい、信頼性に問題があった。また、溶接部を溶融させて接続する際の熱を、仮止め部で放熱させてワイヤ被覆やワイヤ自体の劣化を防止する訳であるが、前記仮止め部が小さく不十分となってしまう。本発明においては、例えば図１（Ｂ）に示すように折り返し部の上面部分のみにスリットがあるため、折れ易い根本部は幅広にすることができ、強度確保が十分にとれるばかりでなく、放熱容量も大きくなるため、ワイヤ被覆やワイヤ自体の劣化を効果的に防止できる。また、これらにより、製品の歩留も向上し、安価で高品質のコイル部品が提供できるようになる。
【００３８】
さらに、継線部と巻線端末とをレーザ溶接する場合、レーザビームの照射パターンを前記巻線端末引出方向と交差する方向に長径を有する略楕円乃至長円形状とすれば、前記巻線端末ワイヤの位置ずれに対する許容度が増し、いっそうの歩留向上を図ることが可能になる。
【図面の簡単な説明】
【図１】本発明に係るコイル部品の継線構造及び方法の第１の実施の形態であって、（Ａ）は表面実装型コイル部品の磁気コアに端子金具を装着し巻線した状態を示す斜視図、（Ｂ）は端部電極としての端子金具の継線部であって巻線端末を係止した溶接前の拡大斜視図、（Ｃ）は継線部を溶接した状態を示す拡大斜視図である。
【図２】第１の実施の形態で用いる端子金具であり、（Ａ）は平面図、（Ｂ）は正面図、（Ｃ）は側面図である。
【図３】本発明の第２の実施の形態を示す斜視図である。
【図４】第１及び第２の実施の形態において、巻線端末と端子金具の継線部とをレーザ溶接する場合のレーザビーム照射位置を示し、（Ａ）は好ましい照射位置、（Ｂ）はワイヤずれが発生した場合、（Ｃ）はビームずれが発生した場合を示す説明図である。
【図５】第１及び第２の実施の形態において、巻線端末と端子金具の継線部とをレーザ溶接する場合のレーザビーム照射パターンの好ましい例を示す説明図である。
【図６】従来の表面実装型コイル部品の１例を示す斜視図である。
【図７】従来の表面実装型コイル部品の他の例を示し、（Ａ）は巻線端末を絡げた状態の斜視図、（Ｂ）は巻線端末をレーザやアーク溶接で接続した状態の部分斜視図である。
【図８】従来のコイル部品の継線構造であって、（Ａ）は溶接前、（Ｂ）は溶接後を示す拡大斜視図である。
【図９】本発明者が先に考慮していたコイル部品の継線構造の例であって、（Ａ）は溶接前、（Ｂ）は溶接後を示す拡大斜視図である。
【図１０】本発明者が先に考慮していたコイル部品の継線構造の他の例を示す拡大斜視図である。
【符号の説明】
１，１１磁気コア
２端部電極
３，３０，６０巻線
３ａ，３０ａ，６０ａ巻線端末
５，６，２０，５０端子金具
６ａ本体の一部
６ｂ，２３，５３折り返し部
７，２２，５２継線部
７ａ，２５，５５仮止め部
７ｂ，２６，５６溶接部
８，２４，５４スリット
１２方形鍔
４１ボビン
Ｋ溶融接続部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coil component such as an EMC filter in which a winding is provided on a magnetic core and a bobbin, and is particularly suitable for automobiles and the like having a severe use environment, and is equipped with a terminal fitting serving as an end electrode on the magnetic core or bobbin. The present invention relates to a coil component connection structure and method that can improve the reliability of a connection structure portion between a winding terminal and an end electrode when winding is performed on the wire and welding is performed by welding.
[0002]
[Prior art]
As a conventional coil component of this type, as shown in FIG. 6, a silver paste is baked on a square drum type magnetic core (ferrite core or the like) 1 and then Sn plating is performed to form an end electrode 2. There is one in which a winding 3 is provided on a magnetic core 1 and a terminal of the winding 3 is connected to an end electrode 2 by thermocompression bonding to constitute a surface mount type coil component.
[0003]
As another surface mount type coil component, as shown in FIGS. 7A and 7B, an L-shaped terminal fitting 5 is bonded and pasted to a square drum type magnetic core 1. There is an end electrode in which a winding 3 is provided on the magnetic core 1 and an end of the winding 3 is connected to a binding portion 5a of a terminal fitting 5 and connected by laser or arc welding.
[0004]
Further, as shown in FIG. 8A, the terminal fitting 6 as the end electrode is substantially U-shaped with a part 6a of the main body and a folded part 6b folded back in a hook shape with respect to the part 6a of the main body. The connecting portion 7 is provided, the wire of the winding terminal 3a is passed through the substantially U-shaped connecting portion 7, the folded portion 6b is crimped, and then welded and connected as shown in FIG. .
[0005]
Further, as a structure that the inventor has conventionally considered, as shown in FIG. 9A, a terminal metal fitting 6 as an end electrode is folded in a hook shape with respect to a part 6a of the main body and a part 6a of the main body. There is a connecting portion 7 having a substantially U shape with the folded portion 6b, and the folded portion 6b is separated into a temporary fixing portion 7a and a welded portion 7b by a slit 8 reaching the base portion. In this case, after passing the wire of the winding terminal 3a through the substantially U-shaped connecting portion 7 and caulking the temporary fixing portion 7a, the welding portion 7b and the winding terminal 3a are welded and connected as shown in FIG. 9B. To do.
[0006]
FIG. 10 shows a terminal fitting of a small product, which is a structure that the present inventor has conventionally considered when the length L of the terminal fitting 6 in the wire drawing direction cannot be increased, and is the base (root) of the welded portion 7b. The width of the upper surface portion is made larger than the width of (the same reference numerals are given to the same or corresponding portions as in FIG. 9). The welding connection of the winding end is performed in the same manner as in FIG.
[0007]
[Problems to be solved by the invention]
In the surface mount type coil component of FIG. 6, the winding terminal is connected to the end electrode by thermocompression bonding, but the thermocompression bonding is basically a fusion connection between the Sn portion of the end electrode and the copper portion of the winding wire. In particular, there is a problem in connection reliability because the Sn portion melts during reflow mounting of lead-free relatively high temperature on the counterpart substrate.
[0008]
7A and 7B, when the winding end is entangled with the binding portion 5a of the terminal fitting 5 and connected by laser or arc welding, the wire coating of the winding end is thermally deteriorated or thinned. There are problems of quality such as tension (because heat at the time of welding is conducted to the winding end), tension (there is a problem of disconnection when the tension is applied to the wire), and a problem that the product height becomes large.
[0009]
The structure in which the wire of the winding terminal 3a in FIG. 8 is locked by caulking of the connecting portion 7 and fixed by welding can reduce the product height, but there is a problem of thermal deterioration and wire thinning of the wire coating of the winding terminal. there were.
[0010]
In the structure in which the folded portion 6b of the connecting portion 7 in FIG. 9 is divided into the temporary fixing portion 7a and the welding portion 7b, the wire is fixed by the temporary fixing portion 7a sandwiching the winding terminal 3a and the heat during welding is reduced. Since the heat is radiated, the thermal deterioration of the wire coating can be reduced, but it is necessary to ensure a sufficient length of the terminal fitting 6 in the wire drawing direction, and it is not possible to cope with downsizing in the wire drawing direction.
[0011]
Further, when the length L of the terminal fitting 6 in the wire drawing direction is reduced as shown in FIG. 10, the width of the base portion of the welded portion 7 b becomes extremely narrow and there is a problem in the terminal strength of the connecting portion 7. For example, when the length L is about 0.5 mm, the base portion of the folded portion 6b can be secured only about 0.35 mm, and when the width of the slit 8 is 0.1 mm, the base portion of the temporary fixing portion 7a and the welded portion 7b. Each width is 0.125 mm, is thin and weak, and may be broken in the worst case.
[0012]
The present invention has been made in view of the above problems, and there is no problem in quality such as thermal deterioration or wire thinning of the wire covering of the winding terminal even in a severe use environment such as an automobile, and the connecting portion. The coil part can be manufactured at low cost because the height of the wire is small, the dimensions in the wire drawing direction can be reduced, and there is no problem with the terminal strength of the connection part, and there is little variation in the welded state and stable operation is possible. It is an object to provide a connecting structure and method.
[0013]
Other objects and novel features of the present invention will be clarified in embodiments described later.
[0014]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention of claim 1 of the present application is a connection structure of a coil component for connecting a winding terminal to an end electrode of a terminal fitting.
The end electrode has a connecting portion having a substantially U shape with an upper surface portion that is a part of the main body and a folded portion that is folded in a hook shape with respect to the upper surface portion, and an upper surface portion of the folded portion A slit is formed only in the crimping part to be a temporary fastening part and a welding part , and an edge of the crimping part opposite to the temporary fastening part is from an upper surface part which is a part of the main body. It is sticking out
The winding terminal passed through the substantially U-shaped connecting portion is clamped by the temporary fixing portion located on the front side of the crimping portion , and the winding tip and the edge side of the crimping portion are It is characterized by being fusion-bonded by laser or arc welding.
The connecting structure for coil parts according to the invention of claim 2 is characterized in that, in claim 1, the crimping portion is larger than the temporary fixing portion .
The connection structure of the coil component according to the invention of claim 3 is characterized in that, in claim 1 or 2, the crimping part is wider than the base part of the folded part.
The coil component connecting structure according to the invention of claim 4 is characterized in that, in claim 1, 2 or 3, the temporary fixing portion has a heat radiation function.
[0015]
The invention of claim 5 of the present application is a method of connecting a coil component for connecting a winding terminal to an end electrode of a terminal fitting.
The end electrode has a connecting portion having a substantially U shape with an upper surface portion that is a part of the main body and a folded portion that is folded in a hook shape with respect to the upper surface portion, and an upper surface portion of the folded portion A slit is formed only in the crimping part to be a temporary fastening part and a welding part , and an edge of the crimping part opposite to the temporary fastening part is from an upper surface part which is a part of the main body. It is sticking out
The winding end is inserted into the substantially U-shaped connecting portion, and the folded portion is crimped and sandwiched, and then the winding tip and the edge side of the crimping portion are melted by welding with a laser or an arc. It is characterized by connecting.
According to a sixth aspect of the present invention, there is provided a coil component connecting method according to the fifth aspect, wherein the temporary fixing portion has a heat dissipation function.
[0016]
The method for connecting coil parts according to the invention of claim 7 is the method of claim 5 or 6 , wherein the center of the irradiation pattern of the laser beam in the end electrode width direction is the boundary between the winding tip and the crimping part. The laser welding is performed so that the laser beam is applied to at least both of the winding tip portion and the crimping portion .
[0017]
The method for connecting coil parts according to the invention of claim 8 is the method according to claim 7 , wherein the laser beam irradiation pattern has a substantially elliptical or oval shape having a major axis in a direction intersecting with a drawing direction of the winding terminal. It is characterized by being.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Embodiments of a coil component connection structure and method according to the present invention will be described below with reference to the drawings.
[0019]
A first embodiment of the present invention will be described with reference to FIG. FIG. 1A is a perspective view of a state in which a winding 30 is applied to a magnetic core 11 to which a terminal fitting 20 is attached, and a winding terminal 30a is crimped and fixed at a connecting portion 22 of the terminal fitting 20, FIG. Is an enlarged perspective view of the connecting portion 22 in the terminal fitting 20, and is divided into a temporary fixing portion 25 and a welded portion 26 by a slit 24, and FIG. And the state where the winding ends are welded. FIG. 2 shows the terminal fitting 20 (in the state before caulking) used in the first embodiment.
[0020]
The magnetic core 11 used here is a square drum type ferrite core (ferrite drum core), as shown in FIG. 1A, in which square rods 12 are formed on both sides of the core. The magnetic core 11 has a shape dimension of, for example, a length of 4.5 mm, a rectangular basket width of 3.2 mm, and a height of about 2 mm.
[0021]
The terminal metal fitting 20 serving as a terminal electrode is a copper alloy such as phosphor bronze or brass, and is bent into a substantially U shape as shown in FIGS. 2 (A), (B), (C), It has a main body including a portion 20a, an upper surface portion 20b, a bottom surface portion 20c, and upper and lower folded portions 20d. Further, on the inner surface of the side surface portion 20a, a potch portion (a protruding portion protruding toward the inner surface side) 21 is formed as a metal fitting side retaining portion that engages with the retaining portion (not shown) on the magnetic core 11 side.
[0022]
Further, as shown in FIGS. 1B, 2A, 2B, and 2C, the connecting portion 22 formed on the upper surface portion 20b of the main body is a part of the main body (that is, the upper surface portion 20b). And a folded portion 23 folded in a hook shape with respect to a part of the main body, has a substantially U shape, and a slit 24 is formed only in the upper surface portion of the folded portion 23 to temporarily fix the portion 25 and the welded portion. 26. The welded portion 26 is formed wider than the base portion 23 a of the folded portion 23. When the thickness of the terminal fitting 20 is 0.08 to 0.1 mm and the length L in the wire drawing direction of the terminal fitting 20 shown in FIG. 2C is about 0.5 mm, the base 23a of the folded portion 23 is provided. However, since the slit 24 (width of about 0.1 mm) does not reach the base portion 23a of the folded portion 23, the strength of the base portion 23a is not impaired.
[0023]
Such a terminal fitting 20 is inserted into the end face portion of the magnetic core 11, that is, the rectangular basket 12 from the side, and is fitted and mounted. Then, the winding 30 is wound around the core portion of the magnetic core 11 by using an insulation covering wire such as urethane wire, and the wire of the winding terminal 30a of each winding 30 is fitted and attached to the square rod 12. The terminal fitting 20 is passed through a substantially U-shaped portion of the connecting portion 22 and is crimped and fixed by caulking the folded portion 23 (temporary fastening portion 25 and welded portion 26) of the connecting portion 22. In this case, the wire tip is preferably disposed so as to pass through the welded portion 26 and slightly protrude from the welded portion 26, and the temporary fixing portion 25 presses the front side of the wire tip portion pressed by the welded portion 26.
[0024]
Thereafter, the connection between the wire terminal and the connecting portion 22 of the terminal fitting 20 is performed by laser welding or arc welding, and the welded portion 26 and the wire tip portion of the connecting portion 22 are melted as shown in FIG. Then, the connecting portion 22 and the conductor portion (copper wire portion) of the wire are mechanically and electrically connected as the fusion connection portion K. At this time, since the temporary fixing portion 25 is not welded and continues the wire pressing of the winding terminal 30a, even if the welding portion 26 melts, the pressing of the wire does not become unstable (the position of the wire does not shift). In addition, since the heat transmitted from the welded portion 26 to the wire is also dissipated, it is possible to solve the problems of heat deterioration and wire thinning of the wire covering of the main body portion of the winding 30.
[0025]
As a result, the surface mount type coil component in which the winding 30 is provided on the magnetic core 11 and the winding terminal 30a is welded and connected to the terminal fitting 20 as the end electrode is obtained.
[0026]
According to the first embodiment, the following effects can be obtained.
[0027]
(1) The terminal fitting 20 as an end electrode attached to the magnetic core 11 is substantially composed of a part of the main body (upper surface part 20b) and a folded part 23 folded back in a hook shape with respect to a part of the main body. It has a U-shaped connecting portion 22, and a slit 24 is formed only on the upper surface portion of the folded-back portion 23 to divide it into a temporary fixing portion 25 and a welded portion 26, and pass through the substantially U-shaped connecting portion 22. The wound terminal 30a is clamped and fixed between the temporary fixing part 25 (located on the front side of the welded part 26) and the welded part 26, and the coiled terminal 30a and the welded part 26 are connected to each other by a laser or an arc. Even if the surface mount coil components are mounted on the wiring board using leadless solder with a high melting point in consideration of the environment, the winding of the surface mount coil components is performed during soldering. The joint portion between the terminal 30a and the terminal fitting 20 is not melted.
[0028]
(2) The welding portion 26 is connected to the wire of the winding terminal 30a by welding, but the temporary fixing portion 25 is not welded and continues to hold the wire of the winding terminal 30a. Since the holding of the wire 30 does not become unstable (the position of the wire does not shift), and the temporary fixing portion 25 also serves to dissipate heat transmitted from the welding portion 26 to the wire, The problem of heat deterioration and wire thinning of the wire coating can also be solved.
[0029]
(3) In the conventional examples of FIG. 9 and FIG. 10, since the slit that divides the folded portion of the connecting portion into the temporary fixing portion and the welded portion reaches the lower surface portion of the substantially U-shaped connecting portion, the terminal When the length of the metal pull-out direction of the metal fitting is reduced and the width of the base portion of the folded portion can be secured only about 0.35 mm, the thickness of the terminal metal fitting 20 is 0.08 mm, the slit width is 0.1 mm, and the temporary fixing portion and the weld The root width of each part was 0.125 mm (wire diameter 0.06 to 0.08 mm), and the strength was weak, resulting in a problem in reliability. Moreover, although the heat | fever at the time of a fusion | melting connection is radiated in a temporary fix | stop part and the deterioration of wire covering or the wire itself is prevented, the said temporary fix | stop part will become small and insufficient. In the present embodiment, as shown in FIG. 1B and FIG. 2, the slit 24 is formed only in the upper surface portion of the folded portion 23 of the connecting portion 22, and the width of the root portion that can be easily broken can be widened. Not only can the strength be ensured sufficiently, but also the heat dissipation capacity can be increased, and the wire coating and the wire itself can be prevented from deteriorating. These also improve the yield of the product, and can supply inexpensive and high-quality coil components.
[0030]
FIG. 3 shows a second embodiment of the present invention. In this case, the terminal metal fitting 50 as an end electrode is provided by insert molding on the bobbin 41 made of insulating resin, and the winding 60 is wound around the outer periphery of the bobbin 41, and the wire of the winding terminal 60 a is welded to the terminal metal fitting 50. Connected with. The terminal fitting 50 is the same as the terminal fitting 20 of the first embodiment. The terminal fitting 50 includes a part of the main body (upper surface part) 50a and a folded part 53 that is folded back in a hook shape with respect to a part of the main body. The connecting portion 52 having a shape is formed, and a slit 54 is formed only on the upper surface portion of the folded portion 53 to divide it into a temporary fixing portion 55 and a welded portion 56, and is passed through the substantially U-shaped connecting portion 52. The winding terminal 60a is sandwiched between the temporary fixing part 55 and the welding part 56 located on the front side of the welded part 56, and the winding terminal 60a and the welded part 56 are melt-connected by welding such as laser or arc. Yes.
[0031]
In the case of the second embodiment, the same effect as that of the first embodiment described above, that is, the deterioration of the wire coating and the wire itself can be prevented. Can be provided.
[0032]
FIG. 4 shows a laser beam irradiation position when the winding terminals 30a, 60a and the connecting portions 22, 52 of the terminal fittings 20, 50 are laser welded in the first and second embodiments. As shown in the laser beam irradiation position P in FIG. 4A, a circular laser beam irradiation pattern is applied to at least the welding portions 26 and 56 formed on the wires 22 and 62 of the winding terminals 30a and 60a. By setting or setting so that a circular laser beam irradiation pattern is applied to the welded portions 26 and 56 on the wire as in the laser beam irradiation position Q, the welded portions 26 and 56 and the wire are fused well. be able to. As shown in FIG. 4B, when the wire shift occurs with respect to the laser beam irradiation position P, or when the laser beam irradiation position shifts to P ′ as shown in FIG. Often not.
[0033]
FIG. 5 shows a preferable laser beam irradiation position and irradiation pattern when laser welding the winding terminals 30a and 60a and the connecting portions 22 and 52 of the terminal fittings 20 and 50 in the first and second embodiments. . Here, the laser beam irradiation position is set so that the laser beam irradiation pattern S covers at least the wires of the winding terminals 30a and 60a and the welded portions 26 and 56 formed on the connecting portions 22 and 62, and the irradiation pattern S. Is a substantially oval or oval shape having a major axis in a direction intersecting with the direction in which the winding terminal wire is drawn. By adopting such an irradiation pattern S, even if a wire shift occurs as shown by a dotted line in FIG. 5, fusion bonding between the terminal fitting side welded portions 26 and 56 and the wire can be performed well over a wide range. .
[0034]
For example, in the case of fusion connection by YAG laser beam processing, the circular laser beam irradiation pattern in FIG. 4 can provide good connection at about 1 joule with a beam diameter of 0.3 mm, but the beam diameter is set to 0.4 mm. In some cases, about 1.3 joules were required, and there were concerns about overmelting and the thermal effects of the wires. On the other hand, as shown in FIG. 5, when the beam shape is approximately ellipse or ellipse with a minor axis of 0.2 mm and a major axis of 0.4 mm, an energy of about 1 Joule and a circular beam diameter of 0.3 mm are equivalent to one wire. Although the deviation was within the allowable range, the deviation of two wires could be covered. In this way, by forming a substantially elliptical or oval shape, it is possible to cover a wide range of melting with a small laser beam power.
[0035]
Although the embodiments of the present invention have been described above, it will be obvious to those skilled in the art that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims.
[0036]
【The invention's effect】
As described above, according to the present invention, when connecting the winding terminal to the end electrode of the terminal fitting, the end electrode has a hook shape with respect to a part of the main body and a part of the main body. And having a substantially U-shaped joint portion with the folded portion that is folded back, and forming a slit only in the upper surface portion of the folded portion to divide it into a temporary fixing portion and a welded portion. The winding terminal passed through the wire part is sandwiched by the temporary fixing part located on the front side of the welded part, and the winding terminal and the welded part are melt-welded by welding such as laser or arc. There is no quality problem such as thermal deterioration or wire thinning of the wire coating of the winding terminal, the height of the connecting part is low, the dimension in the wire drawing direction can be reduced, and the terminal strength of the connecting part is also no problem, It is possible to realize a coil component capable of stable work with little variation in welding state.
[0037]
In particular, the present invention is effective when the coil component is miniaturized. In the conventional examples of FIGS. 9 and 10, since the connecting portion slit extends to the lower surface portion, the folded portion formed in the connecting portion. When the base width of the part is reduced to about 0.35 mm, the plate thickness is 0.08 mm, the slit width is 0.1 mm, and the width of the base part of the temporary fixing part and the welded part divided by the slit is 0.125 mm (wire diameter 0.06 to 0.08 mm), which is weak in strength and has a problem in reliability. Moreover, although the heat at the time of melting and connecting the welded portion is radiated by the temporary fixing portion to prevent the wire covering or the wire itself from being deteriorated, the temporary fixing portion becomes small and insufficient. In the present invention, for example, as shown in FIG. 1B, since there is a slit only in the upper surface portion of the folded portion, the root portion that is easy to break can be widened, and not only sufficient strength can be secured, but also heat dissipation. Since the capacity increases, it is possible to effectively prevent the wire coating and the wire itself from being deteriorated. These also improve the product yield, and provide inexpensive and high-quality coil components.
[0038]
Further, when laser welding the connecting portion and the winding terminal, if the laser beam irradiation pattern is a substantially elliptical or oval shape having a major axis in a direction intersecting the winding terminal drawing direction, the winding terminal The tolerance for the positional deviation of the wire is increased, and the yield can be further improved.
[Brief description of the drawings]
FIG. 1 is a first embodiment of a coil component connection structure and method according to the present invention, in which (A) shows a state in which a terminal fitting is mounted on a magnetic core of a surface mount type coil component and wound. The perspective view to show, (B) is the connection part of the terminal metal fitting as an end electrode, and is an expansion perspective view before welding which locked the winding terminal, (C) is an expansion showing the state where the connection part was welded It is a perspective view.
FIG. 2 is a terminal fitting used in the first embodiment, (A) is a plan view, (B) is a front view, and (C) is a side view.
FIG. 3 is a perspective view showing a second embodiment of the present invention.
FIG. 4 shows a laser beam irradiation position when laser welding a winding terminal and a connecting portion of a terminal fitting in the first and second embodiments, (A) is a preferable irradiation position, and (B). (C) is an explanatory view showing a case where a beam shift occurs.
FIG. 5 is an explanatory diagram showing a preferable example of a laser beam irradiation pattern in the case where laser welding is performed between a winding terminal and a connecting portion of a terminal fitting in the first and second embodiments.
FIG. 6 is a perspective view showing an example of a conventional surface mount type coil component.
7A and 7B show another example of a conventional surface mount type coil component, where FIG. 7A is a perspective view of a state in which a winding terminal is entangled, and FIG. 7B is a state in which the winding terminal is connected by laser or arc welding. It is a fragmentary perspective view.
8A and 8B are enlarged perspective views showing a conventional coil component connecting structure, in which FIG. 8A shows before welding and FIG. 8B shows after welding.
FIGS. 9A and 9B are examples of a coil component connecting structure considered by the present inventor, and FIG. 9A is an enlarged perspective view showing before welding and FIG. 9B after welding.
FIG. 10 is an enlarged perspective view showing another example of the coil component connection structure considered by the inventor in advance.
[Explanation of symbols]
1, 11 Magnetic core 2 End electrodes 3, 30, 60 Windings 3a, 30a, 60a Winding terminals 5, 6, 20, 50 Terminal fitting 6a Part 6b, 23, 53 of main body Folded portions 7, 22, 52 Connecting portion 7a, 25, 55 Temporary fixing portion 7b, 26, 56 Welded portion 8, 24, 54 Slit 12 Rectangular rod 41 Bobbin K Melt connecting portion

Claims

In the connection structure of the coil component that connects the winding terminal to the end electrode of the terminal fitting,
The end electrode has a connecting portion having a substantially U shape with an upper surface portion that is a part of the main body and a folded portion that is folded in a hook shape with respect to the upper surface portion, and an upper surface portion of the folded portion A slit is formed only in the crimping part to be a temporary fastening part and a welding part , and an edge of the crimping part opposite to the temporary fastening part is from an upper surface part which is a part of the main body. It is sticking out
The winding terminal passed through the substantially U-shaped connecting portion is clamped by the temporary fixing portion located on the front side of the crimping portion , and the winding tip and the edge side of the crimping portion are Coil parts connection structure characterized by fusion-bonding by welding such as laser or arc.

The coil part connecting structure according to claim 1, wherein the crimping part is larger than the temporary fixing part.

The coil part joint structure according to claim 1, wherein the crimping part is wider than a base part of the folded part.

The coil part connection structure according to claim 1, wherein the temporary fixing portion has a heat dissipation function.

In the method of connecting coil parts that connect the winding terminal to the end electrode of the terminal fitting,
The end electrode has a connecting portion having a substantially U shape with an upper surface portion that is a part of the main body and a folded portion that is folded in a hook shape with respect to the upper surface portion, and an upper surface portion of the folded portion A slit is formed only in the crimping part to be a temporary fastening part and a welding part , and an edge of the crimping part opposite to the temporary fastening part is from an upper surface part which is a part of the main body. It is sticking out
The winding terminal is inserted into the substantially U-shaped connecting portion, and the folded portion is crimped and sandwiched, and then the winding tip and the edge side of the crimping portion are melted by welding such as laser or arc. A method of connecting coil parts, characterized by being connected.

6. The method of connecting coil parts according to claim 5, wherein the temporary fixing portion has a heat dissipation function.

The center of the laser beam irradiation pattern in the end electrode width direction is irradiated in accordance with the boundary between the winding tip and the crimping portion, and the laser beam is at least both of the winding tip and the crimping portion . 7. The method for connecting coil parts according to claim 5, wherein the laser welding is performed as described above.

8. The method of connecting coil parts according to claim 7, wherein the laser beam irradiation pattern has a substantially elliptical or elliptical shape having a major axis in a direction intersecting with a drawing direction of the winding terminal.