JP3934739B2

JP3934739B2 - Plug-in type electronic control unit and connection structure between wiring board and plug member

Info

Publication number: JP3934739B2
Application number: JP14898497A
Authority: JP
Inventors: 雅次郎井ノ上
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 1997-06-06
Filing date: 1997-06-06
Publication date: 2007-06-20
Anticipated expiration: 2017-06-06
Also published as: JPH10340992A

Description

【０００１】
【発明の属する技術分野】
本発明は、各種機械装置の制御に用いられる差込み型電子制御ユニット、および配線基板とプラグ部材との接続構造に関する。
【０００２】
【従来の技術】
従来、この種の差込み型電子制御ユニットとして、ケース内に配線基板と、それに実装された複数の電子部品を収納し、またそのケースの両側にそれぞれプラグ部材を一体に設けたものが知られている。この場合、配線基板には、その電子部品実装領域の両側にそれぞれ接続領域が設けられ、各接続領域に存する複数の接続端子と各プラグ部材の複数のピン状接触子とが、それぞワイヤボンディング法を適用して電気的に接続されている。
【０００３】
【発明が解決しようとする課題】
しかしながら前記のように構成すると、配線基板が大型になると共にその両側にそれぞれプラグ部材が配設されているので、電子制御ユニット全体が大型化する、という問題があった。
【０００４】
【課題を解決するための手段】
本発明は、配線基板における電子部品実装面と反対側の面を、プラグ部材実装面として利用し、また特定の電気的接続方式を採用することにより、小型化を実現された前記差込み型電子制御ユニットを提供することを目的とする。
【０００５】
前記目的を達成するため請求項１の発明は、配線基板と、その配線基板の一面側に、ワイヤレスボンディング法の適用下で実装された複数の電子部品と、前記配線基板の他面側にワイヤレスボンディング法の適用下で実装されたプラグ部材とより構成され、そのプラグ部材が、前記配線基板とは反対側を向いた差込み口を有する合成樹脂製箱体と、その箱体の底壁に貫通、保持されて一端部が前記差込み口内に突入すると共に他端部が該底壁の、前記配線基板との対向面より突出するピン状接触子とを有してなる差込み型電子制御ユニットであって、前記ピン状接触子の前記他端部と、前記配線基板の他面側に露出させた接続端子との間が間隔をおいて相対向すると共に、その間を電気的に接続する導電性接合材を囲繞する電気絶縁体が、前記配線基板の前記他面側と前記プラグ部材の前記底壁との間に介在、固定され、前記ピン状接触子の直径ｄと、前記電気絶縁体の厚さｅとの関係がｅ＞ｄに設定されると共に、前記ピン状接触子の前記他端部の端面と前記接続端子との対向間隔ｆがｆ＞０．０２ mm に設定されることを特徴とし、また請求項２の発明は、配線基板と、その配線基板の一面側に、ワイヤレスボンディング法の適用下で実装された複数の電子部品と、前記配線基板の他面側にワイヤレスボンディング法の適用下で実装されたプラグ部材とより構成され、そのプラグ部材が、前記配線基板とは反対側を向いた差込み口を有する合成樹脂製箱体と、その箱体の底壁に貫通、保持されて一端部が前記差込み口内に突入すると共に他端部が該底壁の、前記配線基板との対向面より突出するピン状接触子とを有してなる差込み型電子制御ユニットであって、前記ピン状接触子の前記他端部と、前記配線基板の他面側に露出させた接続端子との間が間隔をおいて相対向すると共に、その間を電気的に接続する導電性接合材を囲繞する電気絶縁体が、前記配線基板の前記他面側と前記プラグ部材の前記底壁との間に介在、固定され、硬化状態において、前記導電性接合材の硬さは、前記電気絶縁体の硬さよりも低いことを特徴とする。
【０００６】
また請求項３の発明は、一面側に電子部品を実装され、また他面側に接続端子を有する配線基板と、その配線基板の他面側に実装されたプラグ部材との間の接続構造であって、前記プラグ部材は、前記配線基板とは反対側を向いた差込み口を有する合成樹脂製箱体と、その箱体の底壁に貫通、保持されて一端部が前記差込み口内に突入すると共に他端部が該底壁の、前記配線基板との対向面より突出するピン状接触子とを有しており、そのピン状接触子の前記他端部と、前記接続端子との間が間隔をおいて相対向すると共に、その間を電気的に接続する導電性接合材を囲繞する電気絶縁体が、前記配線基板の前記他面側と前記プラグ部材の前記底壁との間に介在、固定され、前記ピン状接触子の直径ｄと、前記電気絶縁体の厚さｅとの関係がｅ＞ｄに設定されると共に、前記ピン状接触子の前記他端部の端面と前記接続端子との対向間隔ｆがｆ＞０．０２ mm に設定されることを特徴とし、また請求項４の発明は、一面側に電子部品を実装され、また他面側に接続端子を有する配線基板と、その配線基板の他面側に実装されたプラグ部材との間の接続構造であって、前記プラグ部材は、前記配線基板とは反対側を向いた差込み口を有する合成樹脂製箱体と、その箱体の底壁に貫通、保持されて一端部が前記差込み口内に突入すると共に他端部が該底壁の、前記配線基板との対向面より突出するピン状接触子とを有しており、そのピン状接触子の前記他端部と、前記接続端子との間が間隔をおいて相対向すると共に、その間を電気的に接続する導電性接合材を囲繞する電気絶縁体が、前記配線基板の前記他面側と前記プラグ部材の前記底壁との間に介在、固定され、硬化状態において、前記導電性接合材の硬さは、前記電気絶縁体の硬さよりも低いことを特徴とする。
【０００７】
前記のように、複数の電子部品、配線基板およびプラグ部材を積層構造に構成すると、前記電子制御ユニットの平面的な広がりを、従来のものに比べて大幅に抑制することができる。また各電子部品およびプラグ部材の実装のために、ワイヤレスボンディング法、つまりワイヤを使用しない接続法を採用すると、前記電子制御ユニットの積層方向への広がりを大幅に抑制することができる。このようにして、差込み型電子制御ユニットの小型化を実現することが可能である。
【０００８】
また特に請求項１，３の発明の構成によれば、ピン状接触子の直径ｄと、電気絶縁体の厚さｅとの関係がｅ＞ｄに設定されるとともに、ピン状接触子の端面と接続端子との対向間隔ｆがｆ＞０．０２ mm に設定されるので、配線基板およびプラグ部材の箱体底壁間に存する電気絶縁体の体積が大きく、また前記間隔ｆが広いことから、電子部品作動後の冷却過程で、配線基板と箱体との線膨脹率差に起因して前記接続部に作用する熱応力を十分に緩和することができる。
【０００９】
また特に請求項２，４の発明の構成によれば、硬化した状態において、導電性接合材は柔軟性を有し、その硬さは、電気絶縁体の硬さよりも低く設定されるから、前記熱応力を緩和し、また振動による各接続部の変形および破断を防止する上で有効である。
【００１０】
【発明の実施の形態】
〔実施例Ｉ〕
図１〜３において、差込み型電子制御ユニットＵは、配線基板１と、その配線基板１の一面側に、ワイヤレスボンディング法の適用下で実装された複数の電子部品２と、配線基板１の他面側にワイヤレスボンディング法の適用下で実装されたプラグ部材３とより構成される。
【００１１】
前記のように、複数の電子部品２、配線基板１およびプラグ部材３を積層構造に構成すると、差込み型電子制御ユニットＵの平面的な広がりを、従来のものに比べて大幅に抑制することができる。また各電子部品２およびプラグ部材３の実装のために、ワイヤレスボンディング法、つまりワイヤを使用しない接続法を採用すると、差込み型電子制御ユニットＵの積層方向への広がりを大幅に抑制することができる。このようにして、差込み型電子制御ユニットＵの小型化を実現することが可能である。
【００１２】
配線基板１は、電気絶縁性板状本体４と、その本体４内に保持された導電体５とよりなり、その導電体５の一部をなす複数の接続端子６，７が本体４の両面にそれぞれ露出している。
【００１３】
電子部品２には、未封止半導体を含む半導体ベアチップであるＦＣ（フリップチップ）、高密度パッケージであるＣＳＰ（チップサイズパッケージ）、ＢＧＡ（ボールグリットアレイ）等が含まれる。
【００１４】
図２に明示するように、電子部品２は配線基板１との対向面に少なくとも１つ、図示例では複数の電極８を備え、また配線基板１は各電子部品２との対向面に少なくとも１つ、図示例では電極８の数と同数の接続端子６を備えている。電子部品２および配線基板１は、加熱加圧下で硬化させた電気絶縁性の封止剤９を介して接合され、その封止剤９の各接続孔１０内において、電子部品２の各電極８と配線基板１の各接続端子６とが対向する。各電極８は、金よりなる突起部（バンプ）１１を備え、その突起部１１はワイヤボンディング技術の応用下で形成されたものであって、一定の直径ａを有する。各接続孔１０内は、加熱加圧下で硬化させた導電性接合材１２により満たされ、したがって各導電性接合材１２は封止剤９により囲繞されている。このようにして各電極８の突起部１１と各接続端子６とが導電性接合材１２を介して電気的に接続され、これら電極８、突起部１１、接続端子６および導電性接合材１２は接続部１３を構成する。
【００１５】
各電極８の突起部１１の直径ａと、電子部品２および配線基板１間における封止剤９の厚さｂとの関係はｂ＞ａに設定され、また突起部１１先端および接続端子６間の間隔ｃはｃ＞０．０２mmに設定される。
【００１６】
このように構成すると、電子部品２および配線基板１間に存する封止剤９の体積が大きく、また前記間隔ｃが広いことから電子部品２作動後の冷却過程で、電子部品２と配線基板１との線膨脹率差に起因して前記接続部１３に作用する熱応力を十分に緩和することができる。
【００１７】
これは、前記線膨脹率差に起因して電子部品２および配線基板１間の封止剤９には電子部品２および配線基板１の対向面と略平行するように横方向の剪断力が作用するが、前記のように封止剤９の体積が大きい場合にはその封止剤９における単位体積当りの剪断力を小さくすることができ、また前記間隔ｃが広いことから、前記接続部１３が前記剪断力に十分に耐えるからである。これにより、配線基板１と電子部品２との接続構造は優れた耐熱衝撃性を有する。
【００１８】
プラグ部材３は、配線基板１とは反対側を向いた差込み口１４を有する合成樹脂製箱体１５と、その箱体１５の底壁１６に、それを貫通するように保持された複数のピン状接触子１７とを有しており、そのピン状接触子１７の一端部は差込み口１４内に突入すると共に他端部が該底壁１６の、配線基板１との対向面より突出している。そして、そのピン状接触子１７の前記他端部と、配線基板１の一面に露出させた接続端子７との間が間隔をおいて相対向し、両者７，１７間は導電性接合材１８により電気的に接続されている。
【００１９】
導電性接合材１８は電気絶縁体１９により囲繞されており、その電気絶縁体１９は配線基板１およびプラグ部材３間に挟まれている。
【００２０】
図示例では、電気絶縁体１９はシート状をなし、電気絶縁性接着剤２０を介して配線基板１に接合されている。プラグ部材３は、その箱体１５と一体のフランジ部２１および電気絶縁体１９を貫通する複数のねじ２２を配線基板１にねじ込むことによってその配線基板１に固定される。
【００２１】
電気絶縁体１９は、複数の接続端子７およびピン状接触子１７に応じて複数の接続孔２３を有し、各接続孔２３内に各接続端子７、各ピン状接触子１７および導電性接合材１８が位置する。したがって、接続端子７、ピン状接触子１７および導電性接合材１８は接続部２４を構成する。
【００２２】
この場合、ピン状接触子１７の直径ｄと、電気絶縁体１９の厚さｅとの関係はｅ＞ｄに設定され、またピン状接触子１７および接続端子７間の間隔ｆはｆ＞０．０２mmに設定される。
【００２３】
このように構成すると、配線基板１およびプラグ部材３の箱体１５間に存する電気絶縁体１９の体積が大きく、また前記間隔ｆが広いことから、電子部品２作動後の冷却過程で、配線基板１と箱体１５との線膨脹率差に起因して前記接続部２４に作用する熱応力を十分に緩和することができる。
【００２４】
配線基板１としては、ＩＶＨ（Interstitial Via Hole ）４層基板が用いられ、その電気絶縁性板状本体４は、ガラス布とビスマレイミドトリアジン樹脂とよりなる複合体より構成される。
【００２５】
電子部品２と配線基板１との接続構造において、封止剤９は、シリカ系充填剤を含有するノボラック型エポキシ樹脂より構成され、皮膜の形態で用いられる。この樹脂は、常温では固体であるが、加熱すると、軟化、溶融および硬化の各過程を順次経る。この樹脂のゲル化時間は、１５０℃にて１２０秒であるが、完全に硬化させるためには１５０℃にて２０分間程度の時間を要する。
【００２６】
導電性接合材１２は、３００メッシュよりも小さな不定形銀粉末７５重量％と脂肪族炭化水素型エポキシ樹脂２５重量％とよりなる。導電性接合材１２はペーストの形態で用いられ、その導電性ペーストは、導電性接合材１２と４５．８体積％の混合溶剤とよりなり、その混合溶剤は７０重量％のキシレンと３０重量％のエタノールとを混合したものである。これを第１の導電性ペーストとする。
【００２７】
脂肪族炭化水素型エポキシ樹脂は常温では液状であるが加熱下で硬化する。この樹脂のゲル化時間は、１５０℃にて９０〜１００秒であり、前記ノボラック型エポキシ樹脂よりも短い。その際、混合溶剤は１５０℃にて６０秒間位で略完全に揮発する。
【００２８】
このように導電性接合材１２のゲル化時間を封止剤９のゲル化時間よりも短くすると、封止剤９が先にゲル化した場合に起る、導電性接合材１２への気泡の封じ込めを防止することができ、これにより各電極８の突起部１１と各接続端子６との接続不良を回避することができる。
【００２９】
また硬化後において、導電性接合材１２は柔軟性を有し、その硬さは、封止剤９の硬さよりも低い。これは、前記熱応力を緩和し、また振動による各接続部１３の変形および破断を防止する上で有効である。
【００３０】
封止剤９の構成材料としては、例えば紫外線硬化型樹脂である、多官能アクリレートモノマを含有する液状エポキシアクリレート樹脂、多官能アクリレートモノマを含有する液状ポリエステルアクリレート樹脂等を用いることもできる。また導電性接合材１２として、ハンダを用いることも可能である。
【００３１】
配線基板１とプラグ部材３との接続構造において、電気絶縁体１９は配線基板１と同様の複合体より構成され、シートの形態で用いられる。
【００３２】
導電性接合材１８は、３００メッシュよりも小さな不定形銀粉末７５重量％と一液型熱硬化性エポキシ樹脂２５重量％とよりなる。導電性接合材１８はペーストの形態で用いられ、その導電性ペーストは導電性接合材１８と２９．２体積％の溶剤とよりなる。これを第２の導電性ペーストとする。
【００３３】
また硬化した状態において、導電性接合材１８は柔軟性を有し、その硬さは、電気絶縁体１９の硬さよりも低い。これは、前記熱応力を緩和し、また振動による各接続部２４の変形および破断を防止する上で有効である。さらに導電性接合材１８として、ハンダを用いることも可能である。
【００３４】
プラグ部材３の箱体１５は、３０重量％の無機質充填材を含有するポリフェニレンスルフィド（ＰＰＳ）より構成される。
【００３５】
以下、電子制御ユニットＵの製造法について説明する。
【００３６】
（１）図４に示すように、上、下面に複数の接続端子６，７を有する配線基板１を用意した。
【００３７】
（２）図５に示すように、直径１．５mmの複数の接続孔２３を有する厚さ１．６mmのシート状電気絶縁体１９を配線基板７の下面に電気絶縁性接着剤２０を介してプレス接着し、各接続孔２３内に各接続端子７を位置させた。
【００３８】
（３）図６に示すように、前記組成の第２の導電性ペースト２５を用いて電気絶縁体１９表面にメタルマスクスクリーン印刷を施し、第２の導電性ペースト２５を各接続孔２３に充填した。
【００３９】
（４）図７に示すように、配線基板１の上面側に複数の電子部品２を実装した。この実装は図８に示す方法で行われた。
【００４０】
図８（ａ）に示すように、シリカ系充填剤を含有するノボラック型エポキシ樹脂よりなる厚さ０．２mmの皮膜状封止剤９を配線基板１上に重ね合せて仮接着し、その封止剤９の各接続孔１０を各接続端子６に合致させた。
【００４１】
図８（ｂ）に示すように、前記組成の第１の導電性ペースト２６を用いて、封止剤９表面にメタルマスクスクリーン印刷を施し、第１の導電性ペースト２６を各接続孔１０に充填した。
【００４２】
図８（ｃ）に示すように、電子部品２における各電極８の突起部１１を各接続孔１０内の第１の導電性ペースト２６に刺込んで、その電子部品２を封止剤９に重ね合せた。
【００４３】
（５）図９に示すように、プラグ部材３の各ピン状接触子１７の一端部を各接続孔２３内の第２の導電性ペースト２５に刺込んで、箱体１５の底壁１６およびフランジ部２１を電気絶縁体１９に押当て、次いで複数のねじ２２によりプラグ部材３を配線基板１に固定して、組立体２７を得た。
【００４４】
（６）各電子部品２を所定の圧力で配線基板１に押付けた状態において、組立体２７を１５０℃の加熱下に３０分間保持して、電子部品２側の封止剤９を硬化させると共に第１の導電性ペースト２６およびプラグ部材３側の第２の導電性ペースト２５をそれぞれ硬化させて２種の導電性接合材１２，１８を得、これにより図１に示す差込み型電子制御ユニットＵを得た。
〔実施例II〕
図１０に示す差込み型電子制御ユニットＵは、プラグ部材３の固定を、実施例Ｉのねじ２２に代えて、電気絶縁性接着剤２８を介して行ったものである。
【００４５】
電気絶縁性接着剤２８の電気絶縁体１９への塗布は、図６に示した第２の導電性ペースト２５の接続孔２３への充填後、その第２の導電性ペースト２５を加熱下で半硬化してからメッシュスクリーン印刷により行われた。このように第２の導電性ペースト２５を半硬化する理由は、第２の導電性ペースト２５の溶剤を予め揮発させておき、電気絶縁性接着剤２８により電気絶縁体１９とプラグ部材３とを接着する際に第２の導電性ペースト２５から発生した溶剤蒸気が接続孔２３内に封じ込められるのを防止することにあり、これにより接続端子７とピン状接触子１７との電気的接続を確実に行うことができる。
【００４６】
電気絶縁性接着剤２８の硬化は、封止剤９の硬化および第１，第２の導電性ペースト２６，２５の硬化、つまり２種の導電性接合材１２，１８の形成と同時に行われ、この場合、加熱温度は１５０℃に、また保持時間は３時間にそれぞれ設定された。
【００４７】
なお、電気絶縁性接着剤２８に代えて、電気絶縁性接着フィルムを用いることもできる。
〔実施例III 〕
図１１に示す差込み型電子制御ユニットＵは、プラグ部材３のピン状接触子１７と接続端子７との接続を導電性接合材１８としてのハンダを用いて行ったものである。この場合、接続孔２３に対するハンダの濡れ性を良好にすべく、電気絶縁体１９接着後、各接続孔２３内周面ならびに各接続端子７およびその周辺にＣｕメッキ層２９を形成した。ハンダペーストとしてはＳｎ−Ａｇ−Ｃｕ系ハンダ粉末と、合成ロジンをベースとするペースト状フラックスとよりなるものが用いられた。
【００４８】
以下、電子制御ユニットＵの製造法について説明する。
【００４９】
（１）図１２に示すように、上、下面に複数の接続端子６，７を有する配線基板１を用意した。
【００５０】
（２）図１３に示すように、直径１．５mmの複数の接続孔２３を有する厚さ１．６mmのシート状電気絶縁体１９を配線基板１の下面に電気絶縁性接着剤２０を介してプレス接着し、各接続孔２３内に各接続端子７を位置させた。
【００５１】
（３）図１４に示すように、各接続孔２３の内周面側に、無電解パネルＣｕメッキ処理、電解部分Ｃｕメッキ処理およびフラッシュエッチング処理を施して、厚さ１５〜２５μｍのＣｕメッキ層２９を形成した。
【００５２】
（４）図１５に示すように、前記組成のハンダペースト３０を用いて電気絶縁体１９表面にメタルマスクスクリーン印刷を施し、そのハンダペースト３０を各接続孔２３に充填した。
【００５３】
（５）図１６に示すように、配線基板１の上面側に複数の電子部品２を実装した。この実装は、実施例Ｉ同様に、図８に示す方法で行われた。
【００５４】
（６）図１７に示すように、プラグ部材３の各ピン状接触子１７の一端部を各接続孔２３内のハンダペースト３０に刺込んで、箱体１５の底壁１６およびフランジ部２１を電気絶縁体１９に押当て、次いで複数のねじ２２によりプラグ部材３を配線基板１に固定して、組立体２７を得た。
【００５５】
（７）各電子部品２を所定の圧力で配線基板１に押付けた状態において、組立体２７を１５０℃の加熱下に９０秒間保持し、次いで２６０℃に１分間保持してハンダペースト３０を完全に溶融し、その後組立体２７を冷却して、約１７０℃でハンダを硬化させて導電性接合材１８を得た。さらに、組立体２７を１５０℃の加熱下に３０分間保持して電子部品２側の封止剤９を硬化させると共に第１の導電性ペースト２６を硬化させて導電性接合材１２を得、これにより図１１に示す差込み型電子制御ユニットＵを得た。
〔実施例IV〕
図１８に示す差込み型電子制御ユニットＵは、プラグ部材３の固定を、実施例III のねじ２２に代えて、電気絶縁性接着剤２８を介して行ったものである。
【００５６】
電気絶縁性接着剤２８の電気絶縁体１９への塗布は、図１５に示したハンダペースト３０の接続孔２３への充填後、そのハンダペースト３０を加熱下で溶融してハンダとしてからメッシュスクリーン印刷により行われた。このようにハンダペースト３０を一旦溶融する理由は、ハンダペースト３０のフラックスによる発生ガスを抜いて、電気絶縁性接着剤２８による前記発生ガスの接続孔２３内への封じ込めを防止することにあり、これにより接続端子７とピン状接触子１７との電気的接続を確実に行うことができる。
【００５７】
またハンダペースト３０に電気絶縁性接着剤２８が混じると、ハンダペースト３０の溶融不良を起すことがあるが、前記のようにハンダペースト３０を一旦溶融させておけば、このような問題を回避することができる。
【００５８】
ハンダペースト３０の溶融条件は実施例III の場合と同じである。
【００５９】
電気絶縁性接着剤２８の硬化は、ハンダペースト３０の溶融、硬化後、つまりプラグ部材３側の導電性接合材１８の形成後、電子部品２側の封止剤９の硬化および第１の導電性ペースト２６の硬化、つまり導電性接合材１２の形成と同時に行われ、この場合、加熱温度は１５０℃に、また保持時間は３時間にそれぞれ設定された。
【００６０】
なお、電気絶縁性接着剤２８に代えて、電気絶縁性接着フィルムを用いることもできる。ハンダペーストの発生ガスが問題とならないか、またはハンダペーストに混じってもその溶融不良を起すおそれのない電気絶縁性接着剤または電気絶縁性接着フィルムを用いる場合には、その塗布前または貼付前のハンダペーストの溶融は行われない。
〔実施例Ｖ〕
図１９に示す差込み型電子制御ユニットＵは、プラグ部材３のピン状接触子１７と接続端子７との接続を実施例III と同様のハンダペースト３０を用いて行ったものである。この場合、接続孔２３に対するハンダの濡れ性を良好にすべく、電気絶縁体１９として各接続孔２３内周面にＣｕメッキ層２９を有するものを使用した。
【００６１】
以下、電子制御ユニットＵの製造法について説明する。
【００６２】
（１）図２０に示すように、上、下面に複数の接続端子６，７を有する配線基板１を用意した。
【００６３】
（２）図２１に示すように、直径１．５mmの複数の接続孔２３を有する厚さ１．６mmのシート状電気絶縁体１９を用意し、その各接続孔２３の内周面に、無電解パネルＣｕメッキ処理、電解部分Ｃｕメッキ処理およびフラッシュエッチング処理を施して、厚さ１５〜２５μｍのＣｕメッキ層２９を形成し、その後電気絶縁体１９を配線基板１の下面に電気絶縁性接着剤２０を介してプレス接着し、各接続孔２３内に各接続端子７を位置させた。
【００６４】
（３）図２２に示すように、前記組成のハンダペースト３０を用意して電気絶縁体１９表面にメタルマスクスクリーン印刷を施し、そのハンダペースト３０を各接続孔２３に充填した。
【００６５】
（４）図２３に示すように、配線基板１の上面側に複数の電子部品２を実装した。この実装は、実施例Ｉ同様に、図８に示す方法で行われた。
【００６６】
（５）図２４に示すように、プラグ部材３の各ピン状接触子１７の一端部を各接続孔２３内のハンダペースト３０に刺込んで、箱体１５の底壁１６およびフランジ部２１を電気絶縁体１９に押当て、次いで複数のねじ２２によりプラグ部材３を配線基板１に固定して、組立体２７を得た。
【００６７】
（６）各電子部品２を所定の圧力で配線基板１に押付けた状態において、組立体２７を１５０℃の加熱下に９０秒間保持し、次いで２６０℃に１分間保持してハンダペースト３０を完全に溶融し、その後組立体２７を冷却して、約１７０℃でハンダを硬化させて導電性接合材１８を得た。さらに、組立体２７を１５０℃の加熱下に３０分間保持して電子部品２側の封止剤９を硬化させると共に第１の導電性ペースト２６を硬化させて導電性接合材１２を得、これにより図１９に示す差込み型電子制御ユニットＵを得た。
〔実施例VI〕
図２５に示す差込み型電子制御ユニットＵは、プラグ部材３の固定を、実施例Ｖのねじ２２に代えて、電気絶縁性接着剤２８を介して行ったものである。
【００６８】
電気絶縁性接着剤２８の電気絶縁体１９への塗布は、図２２に示したハンダペースト３０の接続孔２３への充填後、そのハンダペースト３０を加熱下で溶融してハンダとしてからメッシュスクリーン印刷により行われた。このようにハンダペースト３０を一旦溶融する理由は、実施例IVで述べた通りである。また電気絶縁性接着剤２８の硬化条件も実施例IVで述べた通りである。
【００６９】
実施例Ｉ〜VIで述べた各電子制御ユニットＵの電子部品２側の接続部１３において、突起部１１の直径ａはａ≒０．１５mm、封止剤９の厚さｂはｂ≒０．２mm、突起部１１先端および接続端子６間の間隔ｃはｃ≒０．０５mmであり、また導電性接合材１２のショア硬さは約８０、一方、封止剤９のショア硬さは約９１であった。
【００７０】
プラグ部材３側の接続部２４において、ピン状接触子１７の直径はｄ≒０．５mm、電気絶縁体１９の厚さｅはｅ≒１．６mm、ピン状接触子１７先端および接続端子７間の間隔ｆはｆ≒０．２mmであり、また導電性接合材１８、つまり第２の導電性ペースト２５より得られたもののショア硬さは約８０およびハンダペースト３０より得られたもののショア硬さは約８３であり、一方、電気絶縁体１９のショア硬さは約９５であった。なお、前記間隔ｆは、図１１，１８の実施例III ，IVにおいてはＣｕメッキ層２９およびピン状接触子１７先端間の間隔である。
【００７１】
【発明の効果】
請求項１，２の各発明によれば、前記のように構成することによって、小型化を実現され、しかも優れた耐熱衝撃性を有する接続構造を備えた差込み型電子制御ユニットを提供することができる。
【００７２】
また請求項３，４の各発明によれば、前記のように構成することによって、優れた耐熱衝撃性を有する、配線基板とプラグ部材との接続構造を提供することができる。
【００７３】
また特に請求項１，３の各発明によれば、ピン状接触子の直径ｄと、電気絶縁体の厚さｅとの関係がｅ＞ｄに設定されるとともに、ピン状接触子の端面と接続端子との対向間隔ｆがｆ＞０．０２ mm に設定されるので、配線基板およびプラグ部材の箱体底壁間に存する電気絶縁体の体積が大きく、また前記間隔ｆが広いことから、電子部品作動後の冷却過程で、配線基板と箱体との線膨脹率差に起因して前記接続部に作用する熱応力を十分に緩和することができる。
【００７４】
また特に請求項２，４の各発明によれば、硬化した状態において、導電性接合材は柔軟性を有し、その硬さは、電気絶縁体の硬さよりも低く設定されるから、前記熱応力を緩和し、また振動による各接続部の変形および破断を防止する上で有効である。
【図面の簡単な説明】
【図１】差込み型電子制御ユニットの一部切欠き要部正面図
【図２】図１の２矢示部の拡大断面図
【図３】図１の３矢示部の拡大断面図
【図４】配線基板の一部切欠き要部正面図
【図５】配線基板に電気絶縁体を接着した状態を示す一部切欠き要部正面図
【図６】電気絶縁体の接続孔に導電性ペーストを充填した状態を示す一部切欠き要部正面図
【図７】配線基板に電子部品を実装した状態を示す一部切欠き要部正面図
【図８】電子部品の実装工程を示す説明図
【図９】組立体の一部切欠き要部正面図
【図１０】差込み型電子制御ユニットの一部切欠き要部正面図
【図１１】差込み型電子制御ユニットの一部切欠き要部正面図
【図１２】配線基板の一部切欠き要部正面図
【図１３】配線基板に電気絶縁体を接着した状態を示す一部切欠き要部正面図
【図１４】電気絶縁体の接続孔にＣｕメッキ層を形成した状態を示す一部切欠き要部正面図
【図１５】電気絶縁体の接続孔に導電性ペーストを充填した状態を示す一部切欠き要部正面図
【図１６】配線基板に電子部品を実装した状態を示す一部切欠き要部正面図
【図１７】組立体の一部切欠き要部正面図
【図１８】差込み型電子制御ユニットの一部切欠き要部正面図
【図１９】差込み型電子制御ユニットの一部切欠き要部正面図
【図２０】配線基板の一部切欠き要部正面図
【図２１】配線基板に電気絶縁体を接着した状態を示す一部切欠き要部正面図
【図２２】電気絶縁体の接続孔に導電性ペーストを充填した状態を示す一部切欠き要部正面図
【図２３】配線基板に電子部品を実装した状態を示す一部切欠き要部正面図
【図２４】組立体の一部切欠き要部正面図
【図２５】差込み型電子制御ユニットの一部切欠き要部正面図
【符号の説明】
１配線基板
２電子部品
３プラグ部材
７接続端子
１７ピン状接触子
１８導電性接合材
１９電気絶縁体[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a plug-in electronic control unit used for controlling various mechanical devices, and a connection structure between a wiring board and a plug member.
[0002]
[Prior art]
  Conventionally, as this type of plug-in electronic control unit, a wiring board and a plurality of electronic components mounted thereon are housed in a case, and plug members are integrally provided on both sides of the case. Yes. In this case, the wiring board is provided with connection regions on both sides of the electronic component mounting region, and a plurality of connection terminals existing in each connection region and a plurality of pin-like contacts of each plug member are respectively wire bonded. Electrically connected by applying the law.
[0003]
[Problems to be solved by the invention]
  However, when configured as described above, there is a problem that the entire electronic control unit is increased in size because the wiring board becomes large and plug members are provided on both sides thereof.
[0004]
[Means for Solving the Problems]
  The present invention provides the plug-in type electronic control in which the miniaturization is realized by utilizing the surface opposite to the electronic component mounting surface of the wiring board as the plug member mounting surface and adopting a specific electrical connection method. The purpose is to provide units.
[0005]
  To achieve the purposeClaim 1inventionIsA wiring board; a plurality of electronic components mounted on one side of the wiring board under application of a wireless bonding method; and a plug member mounted on the other side of the wiring board under application of a wireless bonding method. Composed ofThe plug member has a synthetic resin box having an insertion port facing the side opposite to the wiring board, and one end of the plug member is inserted into the insertion port and held in the bottom wall of the box. An insertion-type electronic control unit having an end portion having a pin-like contact protruding from a surface of the bottom wall facing the wiring board, the other end of the pin-like contact, An electrical insulator that surrounds a conductive bonding material that electrically connects between the connection terminals exposed to the other surface side of the wiring board and facing each other is provided between the other terminals of the wiring board. Between the surface side and the bottom wall of the plug member and fixed, and the relationship between the diameter d of the pin contact and the thickness e of the electrical insulator is set to e> d, The facing distance f between the end face of the other end of the pin contact and the connection terminal is f> .02 mm The invention of claim 2 is characterized in that the wiring board, a plurality of electronic components mounted on one side of the wiring board under application of the wireless bonding method, and the wiring board A plug member mounted on the surface side under the application of the wireless bonding method, and the plug member has a synthetic resin box body having an insertion port facing the side opposite to the wiring board, and the box body One end is inserted and held in the bottom wall A plug-in electronic control unit having a pin-like contact that protrudes into the mouth and has the other end protruding from the surface of the bottom wall facing the wiring board, An electrical insulator that surrounds the conductive bonding material that electrically connects between the other end and the connection terminal exposed on the other surface side of the wiring board is opposed to each other with a space therebetween. It is interposed and fixed between the other surface side of the wiring board and the bottom wall of the plug member, and in a cured state, the hardness of the conductive bonding material is lower than the hardness of the electrical insulator. Features.
[0006]
  According to a third aspect of the present invention, there is provided a connection structure between a wiring board having an electronic component mounted on one side and having a connection terminal on the other side and a plug member mounted on the other side of the wiring board. The plug member has a synthetic resin box having an insertion port facing away from the wiring board, and penetrates and is held in the bottom wall of the box, and one end portion enters the insertion port. And the other end portion of the bottom wall has a pin-like contact protruding from the surface facing the wiring board, and the other end of the pin-like contact is between the connection terminal. An electrical insulator that is opposed to each other at an interval and surrounds a conductive bonding material that is electrically connected therebetween is interposed between the other surface side of the wiring board and the bottom wall of the plug member, The relationship between the diameter d of the pin contact and the thickness e of the electrical insulator is fixed. e> d, and the facing distance f between the end surface of the other end of the pin contact and the connection terminal is f> 0.02. mm The invention of claim 4 is characterized in that an electronic component is mounted on one surface side and a wiring board having a connection terminal on the other surface side and mounted on the other surface side of the wiring substrate. The plug member has a connection structure, and the plug member penetrates and is held by a synthetic resin box having an insertion port facing the side opposite to the wiring board, and a bottom wall of the box. The other end portion of the pin-like contactor has one end portion protruding into the insertion port and the other end portion having a pin-like contact member protruding from a surface of the bottom wall facing the wiring board. And an electrical insulator that surrounds the conductive bonding material that electrically connects between the connection terminal and the connection terminal, the other surface side of the wiring board and the plug member The conductive joint is interposed and fixed between the bottom wall and in a cured state. Hardness of the is characterized by lower than the hardness of said electric insulator.
[0007]
  As described above, when the plurality of electronic components, the wiring board, and the plug member are configured in a laminated structure, the planar expansion of the electronic control unit can be significantly suppressed as compared with the conventional one. In addition, when a wireless bonding method, that is, a connection method that does not use a wire, is adopted for mounting each electronic component and plug member, the spread of the electronic control unit in the stacking direction can be significantly suppressed. In this way, it is possible to reduce the size of the plug-in electronic control unit.
[0008]
  In particular, according to the first and third aspects of the invention, the relationship between the diameter d of the pin contact and the thickness e of the electrical insulator is set to e> d, and the end face of the pin contact The distance f between the connection terminals and the connection terminal is f> 0.02. mm Since the volume of the electrical insulator existing between the wiring board and the box bottom wall of the plug member is large and the interval f is wide, the wiring board and the box are cooled in the cooling process after the electronic components are operated. The thermal stress acting on the connecting portion due to the difference in linear expansion coefficient with respect to can be sufficiently relaxed.
[0009]
  Further, particularly according to the configurations of the inventions of claims 2 and 4, in the cured state, the conductive bonding material has flexibility, and its hardness is set lower than the hardness of the electrical insulator. This is effective in relieving thermal stress and preventing deformation and breakage of each connecting portion due to vibration.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Example I
  1 to 3, the plug-in type electronic control unit U includes a wiring board 1, a plurality of electronic components 2 mounted on one surface side of the wiring board 1 under the application of the wireless bonding method, and the wiring board 1. It is comprised from the plug member 3 mounted in the surface side under application of the wireless bonding method.
[0011]
  As described above, when the plurality of electronic components 2, the wiring board 1, and the plug member 3 are configured in a laminated structure, the planar spread of the plug-in type electronic control unit U can be significantly suppressed as compared with the conventional one. it can. Further, if a wireless bonding method, that is, a connection method that does not use wires is employed for mounting each electronic component 2 and the plug member 3, the spread of the plug-in electronic control unit U in the stacking direction can be significantly suppressed. . In this way, it is possible to reduce the size of the plug-in electronic control unit U.
[0012]
  The wiring board 1 includes an electrically insulating plate-like main body 4 and a conductor 5 held in the main body 4, and a plurality of connection terminals 6 and 7 forming a part of the conductor 5 are provided on both surfaces of the main body 4. Each is exposed.
[0013]
  The electronic component 2 includes FC (flip chip) that is a semiconductor bare chip including an unsealed semiconductor, CSP (chip size package) that is a high-density package, BGA (ball grit array), and the like.
[0014]
  As clearly shown in FIG. 2, the electronic component 2 includes at least one electrode 8 on the surface facing the wiring substrate 1, in the illustrated example, a plurality of electrodes 8, and the wiring substrate 1 has at least 1 on the surface facing each electronic component 2. In the illustrated example, the same number of connection terminals 6 as the number of electrodes 8 are provided. The electronic component 2 and the wiring board 1 are bonded via an electrically insulating sealing agent 9 cured under heat and pressure, and each electrode 8 of the electronic component 2 is connected in each connection hole 10 of the sealing agent 9. And the connection terminals 6 of the wiring board 1 face each other. Each electrode 8 includes a protruding portion (bump) 11 made of gold, and the protruding portion 11 is formed under the application of wire bonding technology and has a certain diameter a. Each connection hole 10 is filled with a conductive bonding material 12 cured under heat and pressure, and thus each conductive bonding material 12 is surrounded by a sealant 9. In this way, the protrusion 11 of each electrode 8 and each connection terminal 6 are electrically connected via the conductive bonding material 12, and the electrode 8, the protrusion 11, the connection terminal 6, and the conductive bonding material 12 are The connection unit 13 is configured.
[0015]
  The relationship between the diameter a of the protrusion 11 of each electrode 8 and the thickness b of the sealant 9 between the electronic component 2 and the wiring board 1 is set to b> a, and between the tip of the protrusion 11 and the connection terminal 6 The distance c is set such that c> 0.02 mm.
[0016]
  If comprised in this way, since the volume of the sealing agent 9 which exists between the electronic component 2 and the wiring board 1 is large, and the said space | interval c is wide, in the cooling process after the electronic component 2 action | operation, the electronic component 2 and the wiring board 1 The thermal stress acting on the connecting portion 13 due to the difference in linear expansion coefficient with respect to can be sufficiently relaxed.
[0017]
  This is because a lateral shearing force acts on the sealant 9 between the electronic component 2 and the wiring board 1 so as to be substantially parallel to the facing surfaces of the electronic component 2 and the wiring board 1 due to the difference in linear expansion coefficient. However, when the volume of the sealant 9 is large as described above, the shearing force per unit volume in the sealant 9 can be reduced, and since the gap c is wide, the connecting portion 13 This is because it can sufficiently withstand the shearing force. Thereby, the connection structure of the wiring board 1 and the electronic component 2 has excellent thermal shock resistance.
[0018]
  Plug member 3Facing away from the wiring board 1It has a synthetic resin box 15 having an insertion port 14 and a plurality of pin-like contacts 17 held on the bottom wall 16 of the box 15 so as to penetrate therethrough. One end of the child 17The other end portion protrudes from the surface of the bottom wall 16 facing the wiring board 1 while entering the insertion port 14. The other end of the pin contact 17 and the connection terminal 7 exposed on one surface of the wiring board 1 are spaced apart. The phaseOppositely, both 7 and 17 are electrically connected by a conductive bonding material 18.
[0019]
  The conductive bonding material 18 is surrounded by an electrical insulator 19, and the electrical insulator 19 is sandwiched between the wiring board 1 and the plug member 3.
[0020]
  In the illustrated example, the electrical insulator 19 has a sheet shape and is joined to the wiring substrate 1 via an electrical insulating adhesive 20. The plug member 3 is fixed to the wiring board 1 by screwing a plurality of screws 22 penetrating the flange portion 21 and the electrical insulator 19 integral with the box 15 into the wiring board 1.
[0021]
  The electrical insulator 19 has a plurality of connection holes 23 corresponding to the plurality of connection terminals 7 and the pin-shaped contacts 17, and the connection terminals 7, the pin-shaped contacts 17, and the conductive joints in the connection holes 23. A material 18 is located. Therefore, the connection terminal 7, the pin-shaped contact 17 and the conductive bonding material 18 constitute a connection portion 24.
[0022]
  In this case, the relationship between the diameter d of the pin-shaped contact 17 and the thickness e of the electrical insulator 19 is set to e> d, and the interval f between the pin-shaped contact 17 and the connection terminal 7 is f> 0. .02mm is set.
[0023]
  If comprised in this way, since the volume of the electrical insulator 19 which exists between the wiring board 1 and the box 15 of the plug member 3 is large, and the said space | interval f is wide, in the cooling process after the electronic component 2 action | operation, a wiring board The thermal stress acting on the connecting portion 24 due to the difference in the linear expansion coefficient between 1 and the box 15 can be sufficiently relaxed.
[0024]
  As the wiring board 1, an IVH (Interstitial Via Hole) four-layer board is used, and the electrically insulating plate-like body 4 is composed of a composite made of glass cloth and bismaleimide triazine resin.
[0025]
  In the connection structure between the electronic component 2 and the wiring board 1, the sealant 9 is composed of a novolac type epoxy resin containing a silica-based filler, and is used in the form of a film. This resin is solid at room temperature, but when heated, it goes through the steps of softening, melting and curing in sequence. The gelation time of this resin is 120 seconds at 150 ° C., but it takes about 20 minutes at 150 ° C. for complete curing.
[0026]
  The conductive bonding material 12 is composed of 75% by weight of amorphous silver powder smaller than 300 mesh and 25% by weight of aliphatic hydrocarbon type epoxy resin. The conductive bonding material 12 is used in the form of a paste, and the conductive paste is composed of the conductive bonding material 12 and 45.8% by volume of a mixed solvent, and the mixed solvent is 70% by weight of xylene and 30% by weight. Of ethanol. This is the first conductive paste.
[0027]
  Aliphatic hydrocarbon type epoxy resins are liquid at room temperature but harden under heating. The gelation time of this resin is 90 to 100 seconds at 150 ° C., and is shorter than the novolac type epoxy resin. At that time, the mixed solvent volatilizes almost completely at 150 ° C. in about 60 seconds.
[0028]
  When the gelation time of the conductive bonding material 12 is made shorter than the gelation time of the sealing agent 9 as described above, bubbles generated in the conductive bonding material 12 when the sealing agent 9 gels first. Containment can be prevented, and thereby a connection failure between the projection 11 of each electrode 8 and each connection terminal 6 can be avoided.
[0029]
  Further, after curing, the conductive bonding material 12 has flexibility, and the hardness thereof is lower than the hardness of the sealant 9. This is effective in relieving the thermal stress and preventing deformation and breakage of each connection portion 13 due to vibration.
[0030]
  As a constituent material of the sealing agent 9, for example, a liquid epoxy acrylate resin containing a polyfunctional acrylate monomer, a liquid polyester acrylate resin containing a polyfunctional acrylate monomer, or the like, which is an ultraviolet curable resin, can be used. Also, solder can be used as the conductive bonding material 12.
[0031]
  In the connection structure between the wiring board 1 and the plug member 3, the electrical insulator 19 is composed of a composite similar to the wiring board 1, and is used in the form of a sheet.
[0032]
  The conductive bonding material 18 is composed of 75% by weight of amorphous silver powder smaller than 300 mesh and 25% by weight of a one-pack type thermosetting epoxy resin. The conductive bonding material 18 is used in the form of a paste, and the conductive paste includes the conductive bonding material 18 and 29.2% by volume of a solvent. This is a second conductive paste.
[0033]
  Further, in the cured state, the conductive bonding material 18 has flexibility, and its hardness is lower than the hardness of the electrical insulator 19. This is effective in relieving the thermal stress and preventing deformation and breakage of each connection portion 24 due to vibration. Further, solder can be used as the conductive bonding material 18.
[0034]
  The box 15 of the plug member 3 is made of polyphenylene sulfide (PPS) containing 30% by weight of an inorganic filler.
[0035]
  Hereinafter, a method for manufacturing the electronic control unit U will be described.
[0036]
  (1) As shown in FIG. 4, a wiring board 1 having a plurality of connection terminals 6 and 7 on the upper and lower surfaces was prepared.
[0037]
  (2) As shown in FIG. 5, a sheet-like electrical insulator 19 having a thickness of 1.6 mm having a plurality of connection holes 23 having a diameter of 1.5 mm is placed on the lower surface of the wiring board 7 with an electrical insulating adhesive 20 interposed therebetween. Each connection terminal 7 was positioned in each connection hole 23 by press bonding.
[0038]
  (3) As shown in FIG. 6, the surface of the electrical insulator 19 is subjected to metal mask screen printing using the second conductive paste 25 having the above composition, and each connection hole 23 is filled with the second conductive paste 25. did.
[0039]
  (4) As shown in FIG. 7, a plurality of electronic components 2 were mounted on the upper surface side of the wiring board 1. This mounting was performed by the method shown in FIG.
[0040]
  As shown in FIG. 8A, a film-like sealant 9 made of a novolac type epoxy resin containing a silica-based filler and having a thickness of 0.2 mm is superposed on the wiring substrate 1 and temporarily bonded. Each connection hole 10 of the stopper 9 was matched with each connection terminal 6.
[0041]
  As shown in FIG. 8 (b), using the first conductive paste 26 having the above composition, the surface of the sealant 9 is subjected to metal mask screen printing, and the first conductive paste 26 is applied to each connection hole 10. Filled.
[0042]
  As shown in FIG. 8 (c), the protrusion 11 of each electrode 8 in the electronic component 2 is inserted into the first conductive paste 26 in each connection hole 10, and the electronic component 2 is put into the sealant 9. Superimposed.
[0043]
  (5) As shown in FIG. 9, one end of each pin-like contact 17 of the plug member 3 is inserted into the second conductive paste 25 in each connection hole 23, and the bottom wall 16 of the box 15 and The flange portion 21 was pressed against the electrical insulator 19, and then the plug member 3 was fixed to the wiring board 1 with a plurality of screws 22 to obtain an assembly 27.
[0044]
  (6) In a state where each electronic component 2 is pressed against the wiring board 1 with a predetermined pressure, the assembly 27 is held under heating at 150 ° C. for 30 minutes to cure the sealing agent 9 on the electronic component 2 side. The first conductive paste 26 and the second conductive paste 25 on the plug member 3 side are respectively cured to obtain two types of conductive bonding materials 12 and 18, thereby the plug-in type electronic control unit U shown in FIG. Got.
Example II
  In the plug-in type electronic control unit U shown in FIG. 10, the plug member 3 is fixed via an electrically insulating adhesive 28 instead of the screw 22 of Example I.
[0045]
  Application of the electrical insulating adhesive 28 to the electrical insulator 19 is performed by filling the second conductive paste 25 shown in FIG. This was done by mesh screen printing after curing. The reason for semi-curing the second conductive paste 25 in this way is that the solvent of the second conductive paste 25 is volatilized in advance, and the electric insulator 19 and the plug member 3 are bonded by the electric insulating adhesive 28. The purpose of this is to prevent the solvent vapor generated from the second conductive paste 25 from being sealed in the connection hole 23 during bonding, thereby ensuring the electrical connection between the connection terminal 7 and the pin-like contact 17. Can be done.
[0046]
  Curing of the electrically insulating adhesive 28 is performed simultaneously with curing of the sealing agent 9 and curing of the first and second conductive pastes 26 and 25, that is, formation of the two types of conductive bonding materials 12 and 18. In this case, the heating temperature was set to 150 ° C., and the holding time was set to 3 hours.
[0047]
  In place of the electrically insulating adhesive 28, an electrically insulating adhesive film can also be used.
Example III
  The plug-in type electronic control unit U shown in FIG. 11 is obtained by connecting the pin-shaped contact 17 of the plug member 3 and the connection terminal 7 using solder as the conductive bonding material 18. In this case, in order to improve the wettability of the solder with respect to the connection hole 23, after bonding the electrical insulator 19, a Cu plating layer 29 was formed on the inner peripheral surface of each connection hole 23 and each connection terminal 7 and the periphery thereof. As the solder paste, a paste made of Sn-Ag-Cu solder powder and a paste-like flux based on synthetic rosin was used.
[0048]
  Hereinafter, a method for manufacturing the electronic control unit U will be described.
[0049]
  (1) As shown in FIG. 12, a wiring board 1 having a plurality of connection terminals 6 and 7 on the upper and lower surfaces was prepared.
[0050]
  (2) As shown in FIG. 13, a 1.6 mm-thick sheet-like electrical insulator 19 having a plurality of connection holes 23 having a diameter of 1.5 mm is placed on the lower surface of the wiring board 1 with an electrical insulating adhesive 20 interposed therebetween. Each connection terminal 7 was positioned in each connection hole 23 by press bonding.
[0051]
  (3) As shown in FIG. 14, the inner peripheral surface side of each connection hole 23 is subjected to an electroless panel Cu plating process, an electrolytic partial Cu plating process, and a flash etching process to form a Cu plating layer having a thickness of 15 to 25 μm. 29 was formed.
[0052]
  (4) As shown in FIG. 15, the surface of the electrical insulator 19 was subjected to metal mask screen printing using the solder paste 30 having the above composition, and the solder paste 30 was filled in each connection hole 23.
[0053]
  (5) As shown in FIG. 16, a plurality of electronic components 2 were mounted on the upper surface side of the wiring board 1. This mounting was performed by the method shown in FIG.
[0054]
  (6) As shown in FIG. 17, one end of each pin-shaped contact 17 of the plug member 3 is inserted into the solder paste 30 in each connection hole 23, and the bottom wall 16 and the flange portion 21 of the box 15 are attached. Then, the plug member 3 was fixed to the wiring board 1 with a plurality of screws 22, and an assembly 27 was obtained.
[0055]
  (7) In a state where each electronic component 2 is pressed against the wiring board 1 with a predetermined pressure, the assembly 27 is kept under heating at 150 ° C. for 90 seconds, and then kept at 260 ° C. for 1 minute to complete the solder paste 30 After that, the assembly 27 was cooled, and the solder was cured at about 170 ° C. to obtain the conductive bonding material 18. Further, the assembly 27 is held for 30 minutes under heating at 150 ° C. to cure the sealing agent 9 on the electronic component 2 side and the first conductive paste 26 to obtain the conductive bonding material 12. Thus, a plug-in type electronic control unit U shown in FIG. 11 was obtained.
Example IV
  In the plug-in type electronic control unit U shown in FIG. 18, the plug member 3 is fixed via an electrically insulating adhesive 28 instead of the screw 22 of Example III.
[0056]
  Application of the electrical insulating adhesive 28 to the electrical insulator 19 is performed by filling the solder paste 30 shown in FIG. 15 into the connection hole 23, melting the solder paste 30 under heating to form solder, and then mesh screen printing. Made by. The reason for once melting the solder paste 30 in this way is to remove the generated gas due to the flux of the solder paste 30 and prevent the electrically insulating adhesive 28 from confining the generated gas into the connection hole 23. Thereby, the electrical connection between the connection terminal 7 and the pin-like contact 17 can be reliably performed.
[0057]
  Further, when the electrically insulating adhesive 28 is mixed with the solder paste 30, the solder paste 30 may be poorly melted. However, if the solder paste 30 is once melted as described above, such a problem is avoided. be able to.
[0058]
  The melting conditions of the solder paste 30 are the same as in Example III.
[0059]
  The electrical insulating adhesive 28 is cured after the solder paste 30 is melted and cured, that is, after the formation of the conductive bonding material 18 on the plug member 3 side, the curing of the sealant 9 on the electronic component 2 side, and the first conductivity. The conductive paste 26 was cured, that is, simultaneously with the formation of the conductive bonding material 12. In this case, the heating temperature was set to 150 ° C. and the holding time was set to 3 hours.
[0060]
  In place of the electrically insulating adhesive 28, an electrically insulating adhesive film can also be used. When using an electrically insulating adhesive or an electrically insulating adhesive film that does not cause a problem with the gas generated by the solder paste or does not cause melting failure even when mixed with the solder paste, before applying or before applying Solder paste is not melted.
[Example V]
  In the plug-in type electronic control unit U shown in FIG. 19, the pin-shaped contact 17 of the plug member 3 and the connection terminal 7 are connected using the same solder paste 30 as in Example III. In this case, in order to improve the wettability of the solder with respect to the connection hole 23, the electrical insulator 19 having the Cu plating layer 29 on the inner peripheral surface of each connection hole 23 was used.
[0061]
  Hereinafter, a method for manufacturing the electronic control unit U will be described.
[0062]
  (1) As shown in FIG. 20, a wiring board 1 having a plurality of connection terminals 6 and 7 on the upper and lower surfaces was prepared.
[0063]
  (2) As shown in FIG. 21, a 1.6 mm-thick sheet-like electrical insulator 19 having a plurality of connection holes 23 having a diameter of 1.5 mm is prepared. An electrolytic panel Cu plating process, an electrolytic partial Cu plating process and a flash etching process are performed to form a Cu plating layer 29 having a thickness of 15 to 25 μm, and then the electrical insulator 19 is applied to the lower surface of the wiring board 1 as an electrical insulating adhesive. The connection terminals 7 were positioned in the respective connection holes 23 by press bonding.
[0064]
  (3) As shown in FIG. 22, a solder paste 30 having the above composition was prepared and subjected to metal mask screen printing on the surface of the electrical insulator 19, and the solder paste 30 was filled in each connection hole 23.
[0065]
  (4) As shown in FIG. 23, a plurality of electronic components 2 were mounted on the upper surface side of the wiring board 1. This mounting was performed by the method shown in FIG.
[0066]
  (5) As shown in FIG. 24, one end portion of each pin-like contact 17 of the plug member 3 is inserted into the solder paste 30 in each connection hole 23 so that the bottom wall 16 and the flange portion 21 of the box 15 are attached. Then, the plug member 3 was fixed to the wiring board 1 with a plurality of screws 22, and an assembly 27 was obtained.
[0067]
  (6) In a state where each electronic component 2 is pressed against the wiring board 1 with a predetermined pressure, the assembly 27 is held under heating at 150 ° C. for 90 seconds, and then held at 260 ° C. for 1 minute to complete the solder paste 30 After that, the assembly 27 was cooled, and the solder was cured at about 170 ° C. to obtain the conductive bonding material 18. Further, the assembly 27 is held for 30 minutes under heating at 150 ° C. to cure the sealing agent 9 on the electronic component 2 side and the first conductive paste 26 to obtain the conductive bonding material 12. Thus, a plug-in type electronic control unit U shown in FIG. 19 was obtained.
Example VI
  In the plug-in type electronic control unit U shown in FIG. 25, the plug member 3 is fixed via an electrically insulating adhesive 28 instead of the screw 22 of the embodiment V.
[0068]
  The electrical insulating adhesive 28 is applied to the electrical insulator 19 by filling the connection holes 23 of the solder paste 30 shown in FIG. 22, melting the solder paste 30 under heating to form solder, and then performing mesh screen printing. Made by. The reason for once melting the solder paste 30 as described above is as described in Example IV. The curing conditions for the electrical insulating adhesive 28 are also as described in Example IV.
[0069]
  In the connection part 13 on the electronic component 2 side of each electronic control unit U described in Examples I to VI, the diameter a of the protrusion 11 is a≈0.15 mm, and the thickness b of the sealant 9 is b≈0. 2 mm, the distance c between the tip of the projection 11 and the connection terminal 6 is c≈0.05 mm, and the Shore hardness of the conductive bonding material 12 is about 80, while the Shore hardness of the sealant 9 is about 91. Met.
[0070]
  In the connection part 24 on the plug member 3 side, the diameter of the pin-shaped contact 17 is d≈0.5 mm, the thickness e of the electrical insulator 19 is e≈1.6 mm, and the tip of the pin-shaped contact 17 and the connection terminal 7 are connected. The distance f of f is about 0.2 mm, and the Shore hardness of the conductive bonding material 18, that is, the one obtained from the second conductive paste 25 is about 80 and the Shore hardness of the one obtained from the solder paste 30. Was about 83, while the electrical insulator 19 had a Shore hardness of about 95. The distance f is the distance between the Cu plating layer 29 and the tip of the pin-like contact 17 in the embodiments III and IV of FIGS.
[0071]
【The invention's effect】
  Claim 1, 2 eachAccording to the invention, downsizing is realized by the configuration as described above.AndAn insertion type electronic control unit having a connection structure having excellent thermal shock resistance can be provided.
[0072]
  And claims3 and 4According to the invention, the structure as described above can provide a connection structure between the wiring board and the plug member having excellent thermal shock resistance.
[0073]
  According to the inventions of claims 1 and 3, in particular, the relationship between the diameter d of the pin contact and the thickness e of the electrical insulator is set to e> d, and the end surface of the pin contact The distance f between the connection terminals is f> 0.02. mm Since the volume of the electrical insulator existing between the wiring board and the box bottom wall of the plug member is large and the interval f is wide, the wiring board and the box are cooled in the cooling process after the electronic components are operated. The thermal stress acting on the connecting portion due to the difference in linear expansion coefficient with respect to can be sufficiently relaxed.
[0074]
  Further, particularly according to the inventions of claims 2 and 4, in the cured state, the conductive bonding material has flexibility, and its hardness is set lower than the hardness of the electrical insulator. This is effective in relieving stress and preventing deformation and breakage of each connecting portion due to vibration.
[Brief description of the drawings]
1 is a partially cutaway front view of a plug-in electronic control unit.
FIG. 2 is an enlarged sectional view of a portion indicated by an arrow 2 in FIG.
FIG. 3 is an enlarged cross-sectional view of a portion indicated by an arrow 3 in FIG.
FIG. 4 is a front view of a principal part of a wiring board with a part cut away.
FIG. 5 is a partially cutaway front view showing a state where an electrical insulator is bonded to a wiring board.
FIG. 6 is a partially cutaway front view showing a state where a conductive paste is filled in a connection hole of an electrical insulator.
FIG. 7 is a partially cutaway front view showing a state where electronic components are mounted on a wiring board.
FIG. 8 is an explanatory diagram showing a mounting process of an electronic component
FIG. 9 is a front view of an essential part of the assembly with a part cut away.
FIG. 10 is a front view of an essential part of a plug-in electronic control unit with a part cut away.
FIG. 11 is a front view of a main part of the plug-in type electronic control unit with a part cut away.
FIG. 12 is a front view of an essential part of a wiring board partially cut away.
FIG. 13 is a partially cutaway front view showing a state where an electrical insulator is bonded to a wiring board.
FIG. 14 is a partially cutaway front view showing a state in which a Cu plating layer is formed in a connection hole of an electrical insulator.
FIG. 15 is a partially cutaway front view showing a state where a conductive paste is filled in a connection hole of an electrical insulator.
FIG. 16 is a partially cutaway front view showing a state in which an electronic component is mounted on a wiring board.
FIG. 17 is a front view of an essential part of the assembly with a part cut away.
FIG. 18 is a front view of an essential part of the plug-in type electronic control unit.
FIG. 19 is a partially cutaway front view of a plug-in electronic control unit.
FIG. 20 is a front view of an essential part of a wiring board, partly cut away.
FIG. 21 is a partially cutaway front view showing a state where an electrical insulator is bonded to a wiring board.
FIG. 22 is a partially cutaway front view showing a state where a conductive paste is filled in a connection hole of an electrical insulator.
FIG. 23 is a partially cutaway front view showing a state in which an electronic component is mounted on a wiring board.
FIG. 24 is a front view of an essential part of the assembly with a part cut away.
FIG. 25 is a front view of an essential part of the plug-in type electronic control unit.
[Explanation of symbols]
1 Wiring board
2 Electronic parts
3 Plug member
7 Connection terminal
17 Pin contact
18 Conductive bonding material
19 Electrical insulator

Claims

A wiring board (1), a plurality of electronic components (2) mounted on one side of the wiring board (1) under the application of a wireless bonding method, and wireless bonding on the other side of the wiring board (1) A plug member (3) mounted under the application of the law ,
The plug member (3) has a synthetic resin box (15) having an insertion port (14) facing away from the wiring board (1), and a bottom wall (16) of the box (15). A pin-like contact (one end of which protrudes into the insertion port (14) and the other end protrudes from the surface of the bottom wall (16) facing the wiring board (1). 17) a plug-in electronic control unit comprising:
The other end of the pin-like contact (17) and the connection terminal (7) exposed on the other surface side of the wiring board (1) are opposed to each other with an interval between them. An electrical insulator (19) surrounding the electrically connecting conductive bonding material (18) is provided between the other surface side of the wiring board (1) and the bottom wall (16) of the plug member (3). Interposed, fixed and
The relationship between the diameter d of the pin contact (17) and the thickness e of the electrical insulator (19) is
e> d, and the distance f between the end face of the other end of the pin contact (17) and the connection terminal (7) is set to f> 0.02 mm. A plug-in electronic control unit.

A wiring board (1), a plurality of electronic components (2) mounted on one side of the wiring board (1) under the application of a wireless bonding method, and wireless bonding on the other side of the wiring board (1) A plug member (3) mounted under the application of the law,
The plug member (3) has a synthetic resin box (15) having an insertion port (14) facing away from the wiring board (1), and a bottom wall (16) of the box (15). A pin-like contact (one end of which protrudes into the insertion port (14) and the other end protrudes from the surface of the bottom wall (16) facing the wiring board (1). 17) a plug-in electronic control unit comprising:
The other end of the pin-like contact (17) and the connection terminal (7) exposed on the other surface side of the wiring board (1) are opposed to each other with an interval between them. An electrical insulator (19) surrounding the electrically connecting conductive bonding material (18) is provided between the other surface side of the wiring board (1) and the bottom wall (16) of the plug member (3). Interposed, fixed and
In cured state, the hardness of the conductive bonding material (18) is characterized in that the lower than the hardness of the electrical insulator (19), plug-in electronic control unit.

A wiring board (1) having an electronic component (2) mounted on one side and a connection terminal (7) on the other side, and a plug member (3) mounted on the other side of the wiring board (1 ) A connection structure between and
The plug member (3) includes a synthetic resin box (15) having an insertion port (14) facing away from the wiring board (1), and a bottom wall (16) of the box (15). A pin-like contact (one end of which protrudes into the insertion port (14) and the other end protrudes from the surface of the bottom wall (16) facing the wiring board (1). 17)
The other end of the pin-like contact (17) and the connection terminal (7) are opposed to each other with a space therebetween, and a conductive bonding material (18) that electrically connects between the other ends is enclosed. An electrical insulator (19) is interposed and fixed between the other surface side of the wiring board (1) and the bottom wall (16) of the plug member (3);
The relationship between the diameter d of the pin contact (17) and the thickness e of the electrical insulator (19) is
e> d, and the distance f between the end face of the other end of the pin contact (17) and the connection terminal (7) is set to f> 0.02 mm. A connection structure between the wiring board and the plug member.

A wiring board (1) having an electronic component (2) mounted on one side and a connection terminal (7) on the other side, and a plug member (3) mounted on the other side of the wiring board (1) a connection structure between,
The plug member (3) includes a synthetic resin box (15) having an insertion port (14) facing away from the wiring board (1), and a bottom wall (16) of the box (15). A pin-like contact (one end of which protrudes into the insertion port (14) and the other end protrudes from the surface of the bottom wall (16) facing the wiring board (1). 17)
The other end of the pin-like contact (17) and the connection terminal (7) are opposed to each other with a space therebetween, and a conductive bonding material (18) that electrically connects between the other ends is enclosed. An electrical insulator (19) is interposed and fixed between the other surface side of the wiring board (1) and the bottom wall (16) of the plug member (3);
A connection structure between a wiring board and a plug member , characterized in that, in the cured state, the hardness of the conductive bonding material (18) is lower than the hardness of the electrical insulator (19).