JP2004087259A

JP2004087259A - Connector for electric circuit connection

Info

Publication number: JP2004087259A
Application number: JP2002245519A
Authority: JP
Inventors: Yoshizumi Ooi; 大井　義積; Shinji Mizuno; 水野　伸二; Takeya Hirayama; 平山　雄也
Original assignee: Teikoku Tsushin Kogyo Co Ltd
Current assignee: Teikoku Tsushin Kogyo Co Ltd
Priority date: 2002-08-26
Filing date: 2002-08-26
Publication date: 2004-03-18
Anticipated expiration: 2022-08-26
Also published as: JP3953390B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connector for electric circuit connection without causing electro-migration even when a pitch interval between contact patters is narrow. <P>SOLUTION: The connector is provided with a first connector 10 provided with the contact pattern 30 on an insulating substrate 20 and an anisotropic conductive film 31 on the contact pattern 30, and a second connector 50 provided with a resilient contact 61 having resiliency. The connector connects the resilient contact 61 and the contact pattern 30 of the first connector 10 through the anisotropic conductive film 31 by the resilient force of the resilient contact 61 of the second connector 50 by engaging both the connectors 10 and 50. The anisotropic conductive film 31 has the distribution of conductive powder 313 and insulating powder 315 in a binder resin 311. The conductive powder 313 contains conductive powder of a larger particle diameter larger than film thickness of the anisotropic conductive film 31. The insulating powder 315 has hardness collapsed by the resilient contact force of the resilient contact 61. The average particle diameter of the insulating powder 315 is equal to or larger than that of the conductive powder 313. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、二つの電気回路間を接続するのに用いて好適な電気回路接続用コネクタに関するものである。
【０００２】
【従来の技術】
従来、各種電気機器の電気回路間を接続するためにコネクタが用いられている。図９はこの種のコネクタ接続構造の一例を示す斜視図である。同図に示すようにこのコネクタ接続構造は、可撓性を有する合成樹脂製の絶縁基板３１０の端部に並列に銀ペーストを印刷乾燥してなる接点パターン３１３を設けるとともにその裏面側に補強板３１５を貼り付けてなる第一コネクタ（オス型コネクタ）３００と、可撓性を有する合成樹脂製の絶縁基板３３０上に設置される第二コネクタ（メス型コネクタ）３７０とを具備して構成されている。絶縁基板３３０は基台３５０上に設置されている。また第二コネクタ３７０には収納部３７１が設けられ、収納部３７１内には図示はしないが前記第一コネクタ３００の各接点パターン３１３に対応する数の弾性金属製の弾発接点が収納され、各弾発接点には第二コネクタ３７０の下方から突出する端子接続部３７３が設けられている。そして各端子接続部３７３には絶縁基板３３０上の端子接続パターン３３３が接続されている。
【０００３】
そして第二コネクタ３７０の収納部３７１内に第一コネクタ３００を挿入・収納すれば、第二コネクタ３７０内に設置した前記図示しない弾発接点が前記各接点パターン３１３に弾接し、これによって各接点パターン３１３と各端子接続パターン３３３間が電気的に導通する。
【０００４】
ところで第一コネクタ３００の接点パターン３１３は、回路パターン３１７の端部に絶縁層３１９を設けない部分を設けることで外部に露出するように形成されている。
【０００５】
そして近年、第一コネクタ３００の露出した接点パターン３１３間のピッチ間隔は、機器の小型化のため、ますます狭くなっており、このためこの部分に水分が付着すると隣接する接点パターン３１３間でエレクトロマイグレーションを生じてショートしてしまう危険性が増大してきた。
【０００６】
【発明が解決しようとする課題】
本発明は上述の点に鑑みてなされたものでありその目的は、たとえ接点パターンのピッチ間隔が狭くなっても、エレクトロマイグレーションを生じることのない電気回路接続用コネクタを提供することにある。
【０００７】
【課題を解決するための手段】
上記問題点を解決するため本発明は、絶縁基板上に接点パターンを設け、さらに該接点パターンの上に異方性導電膜を設けてなる電気回路接続用の第一コネクタと、弾性を有する弾発接点を設けてなる電気回路接続用の第二コネクタとを具備し、前記両コネクタが係合することにより、前記第二コネクタの前記弾発接点の弾接力にて該弾発接点と前記第一コネクタの前記接点パターンとが前記異方性導電膜を介して接続することを特徴とする。
【０００８】
また本発明は、前記異方性導電膜が、バインダー樹脂中に導電粉を分散して構成され、且つこの導電粉は、異方性導電膜の膜厚よりも大きい粒径の導電粉を含むことを特徴とする。
【０００９】
また本発明は、前記異方性導電膜中に、絶縁粉が分散されていることを特徴とする。
【００１０】
また本発明は、前記絶縁粉が、前記第二コネクタの弾発接点の弾接力によって崩壊する硬度の絶縁粉であることを特徴とする。
【００１１】
また本発明は、前記絶縁粉の平均粒径が、前記導電粉の平均粒径に比べて同等若しくは大きいことを特徴とする。
【００１２】
【発明の実施の形態】
以下、本発明の実施の形態を図面を参照して詳細に説明する。
図１は本発明の一実施形態にかかる電気回路接続用の第一コネクタ（オス型コネクタ）１０とこの第一コネクタ１０を接続する第二コネクタ（メス型コネクタ）５０とを示す斜視図である。同図において第一コネクタ１０は、絶縁基板２０上に並列（平行）に複数（５本）の回路パターン２１を銀ペーストをスクリーン印刷することによって形成し、回路パターン２１の端部を除く部分に絶縁層２３を印刷することでこれを覆い、これによって絶縁層２３で覆われない回路パターン２１の先端部分を接点パターン３０とし、この接点パターン３０の上面全体に異方性導電膜３１を印刷・焼成して構成されている。
【００１３】
ここで絶縁基板２０は可撓性を有する合成樹脂フイルム製の基板（フレキシブル基板）であり、その先端の接点パターン３０を設けた部分の裏面側には、接点パターン３０の部分を補強する硬質（例えば合成樹脂板）の補強板２５が貼り付けられている。
【００１４】
図２は図１のＡ−Ａ線部分の概略断面図である。なお説明の都合上、各部材の厚みや大きさは、分かり易い寸法に変更して示している。同図に示すように異方性導電膜３１は、導電粉３１３と絶縁粉３１５とをバインダー樹脂３１１中に混練してなる異方性導電ペーストを、接点パターン３０の上面全体に印刷・焼成することによって構成されている。バインダー樹脂３１１は、この実施形態では熱硬化性のフェノール樹脂を用いているが、もちろん他の各種絶縁性の樹脂を用いても良い。熱硬化性樹脂を用いたのは、熱可塑性樹脂よりも硬くて機械的強度が強く、従って下記する挟持部６５，６５による強い挟持・弾接・摺接力によっても異方性導電膜３１が基板２０から剥がれる等の問題が生じないからである。
【００１５】
導電粉３１３は、一般的なカーボンビーズ等の球状の粒子（導電体でも絶縁体でも良い）であって、平均粒径が１０μｍのものの表面全体に、ニッケル下地の金メッキを施して構成されている。メッキの材質は種々の変更が可能であることは言うまでもなく、例えばニッケル下地のパラジウムメッキや、ニッケル下地のロジウムメッキ等でもよい。要は水分が付着してもエレクトロマイグレーションを生じにくい材質であればどのような材質のものを用いても良い。
【００１６】
絶縁粉３１５は、タルクやクレー等、外力によって容易に崩壊する硬度の材質のものを用いている。ここでタルクは滑石ともいい、化学組成は、（４ＳｉＯ_２３ＭｇＯ　Ｈ_２Ｏ）即ち含水硅酸マグネシウムで成り立っており、硬さ１〜１．５とはなはだ軟らかくて崩壊性に富んでおり、滑らかな感触を持つ絶縁物である。クレーは高品質の吸着能のある粘土であって含水硅酸アルミナを主成分としており、はなはだ軟らかくて崩壊性に富んでいる絶縁物である。もちろん絶縁粉３１５はこれら物質に限定されず、要は下記する弾発接点６１（挟持部６５）の弾接力によって崩壊する硬度の絶縁粉３１５であればどのような材質のものであっても良い。また絶縁粉３１５の平均粒径は、♯３００のふるいで分球して平均粒径１５μｍとした。つまりこの実施形態では、〔導電粉３１３の平均粒径〕≦〔絶縁粉３１５の平均粒径〕となるようにしている。導電粉３１３，絶縁粉３１５の粒径の測定には、粒度分布測定装置を用いて粒径の分布を求め、粒径の小さい粒子側からの粒子の累積％が５０％となる粒径（粒径の大きい粒子側からの粒子の累積％が５０％でも同じ粒径となる）を平均粒径とした。
【００１７】
そしてバインダー樹脂３１１と導電粉３１３と絶縁粉３１５の重量比を、
〔バインダー樹脂３１１〕：〔導電粉３１３〕：〔絶縁粉３１５〕
＝〔６５〜８１．７〕：〔８．３〜１８〕：〔１０〜１７〕
とし、塗布した異方性導電膜３１の厚み（バインダー樹脂３１１の厚み）を、８μｍとした。つまりこの実施形態では導電粉３１３の平均粒径を異方性導電膜３１の膜厚よりも大きくした。但し、導電粉３１３の平均粒径が異方性導電膜３１の膜厚より小さくても、導電粉３１３中に異方性導電膜３１の膜厚よりも大きい粒径の導電粉を含むものであれば良い。つまり導電粉３１３の少なくとも一部に、異方性導電膜３１の上面から突出する粒径のものがあれば良い。
【００１８】
図１に戻って第二コネクタ５０は、合成樹脂製のケース５１の一側面に設けた挿入部５３の内部に、複数（５個）の弾性を有する略矩形の金属板からなる弾発接点６１を並列に設置して構成されている。各弾発接点６１は前記金属板の長手方向の一端側を基部６３とし、その他端側から弾性を有する二本のアーム部６４，６４を突出し、さらに基部６３の外側から端子部６７を突出して構成されている。両アーム部６４，６４の両先端には挟持部６５，６５が設けられている。端子部６７はこの第二コネクタ５０を載置する別の基板の端子パターンに低融点金属等で接続する部分である。
【００１９】
そして第二コネクタ５０の挿入部５３に第一コネクタ１０を挿入し、係合すると、第一コネクタ１０の先端が二本のアーム部６４，６４間を押し広げて挿入され、第一コネクタ１０の上下面間、即ち異方性導電膜３１の上面と補強板２５の下面間が、両アーム部６４，６４先端の挟持部６５，６５によって挟持され、これによって異方性導電膜３１の上面に各挟持部６５が強く弾接する。
【００２０】
図３は第一コネクタ１０と第二コネクタ５０の回路接続状態を示す概略断面図であり、図２に示すと同一の断面部分を示している。同図に示すように第一コネクタ１０の上下面間が第二コネクタ５０の弾発接点６１の挟持部６５，６５によって挟持されると、異方性導電膜３１の上面に上側の挟持部６５が強く弾接し、その弾接力によって異方性導電膜３１の上面から突出している絶縁粉３１５が崩壊され、これによって各挟持部６５が異方性導電膜３１の上面から突出している導電粉３１３に当接し、この導電粉３１３を介して各挟持部６５と接点パターン３０間が導通する。なお導電粉３１３の表面には薄くバインダー樹脂３１１が覆っているが、薄いので前記挟持部６５の弾接力によって容易に剥がれ、挟持部６５と接点パターン３０間は導通する。このように面方向（隣接する各接点パターン３０を直交して横切る方向。以下同じ）の絶縁性を向上するために絶縁粉３１５の粒径を大きくしておいても、絶縁粉３１５を崩壊性の材料で構成したので挟持部６５の弾接力によって崩壊し、挟持部６５と接点パターン３０間の導通は確実に行えるのである。
【００２１】
以上のように構成された電気回路接続用コネクタは、第一コネクタ１０中の上面に異方性導電膜３１を設けた接点パターン３０と第二コネクタ中の弾性を有する弾発接点６１が異方性導電膜３１を介して接続している為、第一コネクタ１０の接点パターン３０としてエレクトロマイグレーションの生じ易い銀ペースト材等を用いても、接点パターンは面方向に絶縁性を有する異方性導電膜で直接覆われているため湿気にさらされず、更には異方性導電膜３１中の導電粉３１３をエレクトロマイグレーションを起こしづらい金属で構成しているため、隣接する接点パターン３０間でエレクトロマイグレーションを生じることはなくなる。またバインダー樹脂３１１中に導電粉３１３だけでなく、絶縁粉３１５をも混合したので、この絶縁粉３１５が導電粉３１３同士の間に入り込み、面方向の絶縁性をより向上する。また導電粉３１３の少なくとも一部に異方性導電膜３１の上面に突出する粒径のものを含ませたので、この導電粉３１３の上に絶縁粉３１５やバインダー樹脂３１１が覆うことはなく（但し導電粉３１３の上面にはバインダー樹脂３１１の薄膜が覆っている）、この導電粉３１３によって確実に接点パターン３０と第二コネクタ５０の弾発接点６１の挟持部６５間の電気的接触を図ることができる。さらにこの実施形態においては、絶縁粉３１５の平均粒径を、導電粉３１３の平均粒径に比べて同等若しくは大きくしているので、導電粉３１３同士の間に入り込んだ大きな絶縁粉３１５が面方向の絶縁性をより向上する。また絶縁粉３１５を小さくすると、絶縁粉３１５が導電粉３１３と接点パターン３０の間に入り込み易くなり、異方性導電膜３１の厚み方向の導電性を阻害する可能性が増大するので、これを防止する効果もある。つまり絶縁粉３１５の粒径を大きくすると、面方向の絶縁性と厚み方向の導電性を同時に向上することができる。
【００２２】
図４は異方性導電膜３１Ａの性能試験方法を示す図であり、図５は絶縁粉３１５の平均粒径を大きく（１５μｍ）した場合の異方性導電膜３１Ａの性能試験結果を示す図、図６は絶縁粉３１５の平均粒径を小さく（３μｍ）した場合の異方性導電膜３１Ａの性能試験結果を示す図である。即ちこの試験では、図４に示すように、前記第一コネクタ１０と同様に、補強板２５Ａ上に２本の接点パターン３０Ａ，３０Ａを印刷形成した基板（フレキシブル基板）２０Ａを設置し、その上に前記実施形態と同様のバインダー樹脂３１１Ａに導電粉３１３Ａと絶縁粉３１５Ａを分散した異方性導電膜３１Ａを印刷形成し、さらにその上に金属板製の導電板９０を軽く載置する。絶縁粉３１５Ａの平均粒径を変化する以外は導電粉３１３Ａの粒径や、各部材の材質として前記実施形態と同じものを使用している。
【００２３】
そして予め導電板９０を載置しないときの両接点パターン３０Ａ，３０Ａ間の抵抗値を測定しておき、次に図４に示すように導電板９０を載せた状態及びこの導電板９０を少しずつ接点パターン３０Ａ，３０Ａ方向に押圧していったときの両接点パターン３０Ａ，３０Ａ間の抵抗値を順次測定していく。そしてこの測定をバインダー樹脂３１１Ａと導電粉３１３Ａと絶縁粉３１５Ａの配合割合（重量割合）を変化した異方性導電膜３１Ａについてそれぞれ行ない、それぞれ異方性導電膜３１Ａとして適当か否かを検査する。なお図５，図６の性能試験結果において、横軸は「樹脂」対「導電粉」の重量比であり、縦軸は「樹脂＋導電粉」対「絶縁粉」の重量比である。
【００２４】
各異方性導電膜３１Ａが適当か否かの判断方法は、導電板９０を載置しない状態のときに両接点パターン３０Ａ，３０Ａ間が導通すれば、両接点パターン３０Ａ，３０Ａ間が面方向に導通していることを意味するので、異方性導電膜３１Ａとして機能しておらず、不適当であると判断する（図５，図６の正方形の点）。次に厚み方向の導通性を調べるため導電板９０を低荷重で押圧した際に導電板９０と各接点パターン３０Ａ，３０Ａとの間で抵抗値にバラツキが大きく、強い荷重で押圧した際に抵抗値が低くなる場合も、異方性導電膜３１Ａとして機能が安定せず、適当でないと判断する（図５，図６の正三角形の点）。そして強い荷重で押圧しても導電板９０と各接点パターン３０Ａ，３０Ａとの間で導通しない場合はもちろん異方性導電膜３１Ａとして機能しておらず不適当と判断する（図５，図６のひし形の点）。一方導電板９０を載置しない場合と導電板９０を載置しただけの場合でも両接点パターン３０Ａ，３０Ａ間が導通せず、さらに導電板９０を弱い荷重で押圧しても、強い荷重で押圧しても導電板９０と各接点パターン３０Ａ，３０Ａとの間で略安定した低い抵抗値を示す場合は、異方性導電膜３１Ａとして適当と判断する（図５，図６の円形の点）。図５は絶縁粉３１５Ａの粒径を１５μｍとし、図６は絶縁粉３１５Ａの粒径を３μｍとしたときの試験結果を示しており、両図を比較すると分かるように、絶縁粉３１５Ａの平均粒径を導電粉３１３Ａの平均粒径よりも小さくした場合は、異方性導電膜３１Ａとして適当と判断される領域（円形の点）の範囲が狭まることが分かる。特に図６に示すＦの部分が、図５においては最適な状態であったものが不適な状態に変わっているが、これはバインダー樹脂３１１Ａと絶縁粉３１５Ａに対して導電粉３１３Ａの量が同じ割合であっても、絶縁粉３１５Ａの粒径が大きい方が面方向の絶縁性が増すことを意味している。
【００２５】
図７は本発明を適用する他の構造の電気回路接続用コネクタを示す断面図である。この実施形態においては、第一コネクタ（オス型コネクタ）１０−２と第二コネクタ（メス型コネクタ）５０−２とを具備している。同図において第一コネクタ１０−２は、合成樹脂製の補強部材２５−２の一端を基部２５−２Ａとし、該基部２５−２Ａから突出する突出部２５−２Ｂの下面に、可撓性を有する合成樹脂フイルム製の絶縁基板２０−２を固定して構成されている。絶縁基板２０−２の突出部２５−２Ｂに固定された部分の下面には、並列に複数の接点パターン３０−２が形成されている。一方第二コネクタ５０−２は成形樹脂製の基板収納部材５１−２Ａに設けた溝状の収納部５３−２の上に金属板製の覆い部材５１−２Ｂを被せて取り付け、また収納部５３−２内に設けた凹状の弾発部材収納部５５内に略「コ」字状に折り曲げた弾発部材６１−２Ａを収納し、弾発部材収納部５５上を覆うように可撓性を有する絶縁基板６１−２Ｃを設置してその先端を基板収納部材５１−２Ａに設けた貫通孔５７を通して折り返してその裏面側で固定して構成されている。絶縁基板６１−２Ｃの収納部５３−２内に位置する部分の上面には、並列に複数の接点パターン６１−２Ｂが形成され、該接点パターン６１−２Ｂを弾発部材６１−２Ａが収納部５３−２側に押し上げることにより弾発接点６１−２が構成される。
【００２６】
そして第二コネクタ５０−２の収納部５３−２内に第一コネクタ１０−２の挿入部２５−２Ｂを挿入、係合すれば、図８に示すように、両絶縁基板２０−２，６１−２Ｃ間は弾発部材６１−２Ａの弾発部６１−３Ａによって圧接され、両絶縁基板２０−２，６１−２Ｃに設けた各接点パターン３０−２，６１−２Ｂ間が接続される。
【００２７】
そして本実施形態の場合、絶縁基板２０−２に設けた接点パターン３０−２及び／又は絶縁基板６１−２Ｃに設けた接点パターン６１−２Ｂの上に、前記実施形態と同様に異方性導電膜を形成しておけば、例え接点パターン間のピッチ間隔を狭くしてもエレクトロマイグレーションは生じない。この実施形態の場合、弾発部材６１−２Ａの弾発部６１−３Ａが直接接点パターン３０−２に当接するのではなく、二枚の絶縁基板２０−２，６１−２Ｃに設けた接点パターン３０−２，６１−２Ｂ間をその外側から押圧する構造となるが、この場合でも異方性導電膜中に分散した導電粉の粒径に、異方性導電膜の膜厚よりも大きい粒径のものを含むようにし、また異方性導電膜中に分散した絶縁粉を弾発接点６１−２（弾発部６１−３Ａ）の弾接力によって崩壊する硬度・性状の絶縁粉とし、さらに絶縁粉の平均粒径を導電粉の平均粒径よりも同等以上に大きくすれば、前記実施形態と同様の効果が生じる。
【００２８】
以上本発明の実施形態を説明したが、本発明は上記実施形態に限定されるものではなく、特許請求の範囲、及び明細書と図面に記載された技術的思想の範囲内において種々の変形が可能である。なお直接明細書及び図面に記載がない何れの形状や構造や材質であっても、本願発明の作用・効果を奏する以上、本願発明の技術的思想の範囲内である。例えばコネクタの構造は上記各実施形態に限定されるものではなく、種々の変形が可能であり、要は接点パターンの上に異方性導電膜を設けてなる電気回路接続用の第一コネクタと、弾性を有する弾発接点を設けてなる電気回路接続用の第二コネクタとを具備する電気回路接続用コネクタであれば、どのような構造のコネクタにも適用できる。
【００２９】
【発明の効果】
以上詳細に説明したように本発明によれば、たとえ接点パターンのピッチ間隔が狭くなっても、エレクトロマイグレーションを生じる恐れがないという優れた効果を有する。
【図面の簡単な説明】
【図１】
本発明の一実施形態にかかる電気回路接続用の第一コネクタ１０とこの第一コネクタ１０を接続する第二コネクタ５０とを示す斜視図である。
【図２】
図１のＡ−Ａ線部分の概略断面図である。
【図３】
第一コネクタ１０と第二コネクタ５０の回路接続状態を示す図である。
【図４】
異方性導電膜３１Ａの性能試験方法を示す図である。
【図５】
絶縁粉３１５Ａの平均粒径を大きく（１５μｍ）した場合の異方性導電膜３１Ａの性能試験結果を示す図である。
【図６】
絶縁粉３１５Ａの平均粒径を小さく（３μｍ）した場合の異方性導電膜３１Ａの性能試験結果を示す図である。
【図７】
本発明を適用する他の構造の電気回路接続用コネクタを示す断面図である。
【図８】
第一コネクタ１０−２と第二コネクタ５０−２とを接続した状態を示す図である。
【図９】
コネクタ接続構造の一例を示す斜視図である。
【符号の説明】
１０　第一コネクタ
２０　絶縁基板
２１　回路パターン
２３　絶縁層
２５　補強板
３０　接点パターン
３１　異方性導電膜
３１１　バインダー樹脂
３１３　導電粉
３１５　絶縁粉
５０　第二コネクタ
５１　ケース
５３　挿入部
６１　弾発接点
６３　基部
６４　アーム部
６５　挟持部
６７　端子部
９０　導電板
１０−２　第一コネクタ
２０−２　絶縁基板
２５−２　補強部材
２５−２Ａ　基部
２５−２Ｂ　突出部
５０−２　第二コネクタ
５１−２Ａ　基板収納部材
５３−２　収納部
５５　弾発部材収納部
５１−２Ｂ　覆い部材
６１−２　弾発接点
６１−２Ａ　弾発部材
６１−３Ａ　弾発部
６１−２Ｃ　絶縁基板[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to an electric circuit connector suitable for connecting two electric circuits.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, connectors have been used to connect electrical circuits of various electrical devices. FIG. 9 is a perspective view showing an example of this type of connector connection structure. As shown in the figure, this connector connection structure has a contact pattern 313 formed by printing and drying a silver paste in parallel on an end portion of an insulating substrate 310 made of a synthetic resin having flexibility, and a reinforcing plate on the back side thereof. A first connector (male connector) 300 to which the 315 is attached and a second connector (female connector) 370 provided on an insulating substrate 330 made of a synthetic resin having flexibility. ing. The insulating substrate 330 is set on the base 350. The second connector 370 is provided with a storage portion 371, and a number of elastic metal resilient contacts corresponding to the respective contact patterns 313 of the first connector 300 are stored in the storage portion 371 (not shown). Each resilient contact is provided with a terminal connection portion 373 projecting from below the second connector 370. The terminal connection pattern 333 on the insulating substrate 330 is connected to each terminal connection portion 373.
[0003]
Then, when the first connector 300 is inserted and stored in the storage portion 371 of the second connector 370, the resilient contacts (not shown) provided in the second connector 370 resiliently contact the respective contact patterns 313. The pattern 313 and each terminal connection pattern 333 are electrically connected.
[0004]
The contact pattern 313 of the first connector 300 is formed so as to be exposed to the outside by providing a portion where the insulating layer 319 is not provided at an end of the circuit pattern 317.
[0005]
In recent years, the pitch interval between the exposed contact patterns 313 of the first connector 300 has become smaller and smaller due to the miniaturization of the device. The risk of migration and shorting has increased.
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide an electrical circuit connector which does not cause electromigration even when a pitch interval between contact patterns is reduced.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a first connector for connecting an electric circuit, comprising a contact pattern provided on an insulating substrate, and further providing an anisotropic conductive film on the contact pattern; A second connector for connecting an electric circuit provided with a starting contact, wherein the two connectors are engaged with each other so that the resilient contact of the second contact with the resilient contact force of the resilient contact and the second connector The contact pattern of one connector is connected via the anisotropic conductive film.
[0008]
Further, according to the present invention, the anisotropic conductive film is formed by dispersing a conductive powder in a binder resin, and the conductive powder includes a conductive powder having a particle diameter larger than the thickness of the anisotropic conductive film. It is characterized by the following.
[0009]
Further, the present invention is characterized in that an insulating powder is dispersed in the anisotropic conductive film.
[0010]
Further, the present invention is characterized in that the insulating powder is an insulating powder having a hardness that is collapsed by an elastic contact force of a resilient contact of the second connector.
[0011]
Further, the present invention is characterized in that the average particle size of the insulating powder is equal to or larger than the average particle size of the conductive powder.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing a first connector (male connector) 10 for connecting an electric circuit and a second connector (female connector) 50 for connecting the first connector 10 according to one embodiment of the present invention. . In FIG. 1, a first connector 10 is formed by printing a plurality of (five) circuit patterns 21 in parallel (parallel) on an insulating substrate 20 by screen printing silver paste, and excluding the end portions of the circuit patterns 21. The tip of the circuit pattern 21 that is not covered by the insulating layer 23 is covered with the insulating layer 23 by printing, and the anisotropic conductive film 31 is printed on the entire upper surface of the contact pattern 30. It is configured by firing.
[0013]
Here, the insulating substrate 20 is a substrate made of a synthetic resin film having flexibility (flexible substrate), and on the back side of the portion where the contact pattern 30 is provided at the tip thereof, a hard ( A reinforcing plate 25 (for example, a synthetic resin plate) is attached.
[0014]
FIG. 2 is a schematic sectional view taken along the line AA of FIG. In addition, for convenience of explanation, the thickness and size of each member have been changed to dimensions that are easy to understand. As shown in the drawing, the anisotropic conductive film 31 is formed by printing and baking an anisotropic conductive paste obtained by kneading a conductive powder 313 and an insulating powder 315 in a binder resin 311 over the entire upper surface of the contact pattern 30. It is constituted by that. In this embodiment, a thermosetting phenol resin is used as the binder resin 311, but other various insulating resins may be used. The use of the thermosetting resin is harder than the thermoplastic resin and has higher mechanical strength. Therefore, the anisotropic conductive film 31 can be formed on the substrate even by the strong clamping, elastic contact, and sliding contact force by the clamping portions 65 described below. This is because there is no problem such as peeling off from the substrate 20.
[0015]
The conductive powder 313 is a spherical particle (either a conductor or an insulator) such as general carbon beads and has an average particle size of 10 μm, and is formed by plating the entire surface of the surface with gold under nickel. . It goes without saying that the material of the plating can be variously changed, and for example, palladium plating under nickel or rhodium plating under nickel may be used. In short, any material may be used as long as it does not easily cause electromigration even when moisture adheres.
[0016]
The insulating powder 315 is made of a material having a hardness such as talc or clay that is easily collapsed by an external force. Here, talc is also referred to as talc and has a chemical composition of (4SiO ₂ 3MgOH ₂ O), that is, hydrous magnesium silicate. It is an insulator with a feel. Clay is a high-quality clay having adsorptive power, which is composed mainly of hydrated alumina silicate, and is a soft, highly disintegratable insulator. Needless to say, the insulating powder 315 is not limited to these substances. In short, any material may be used as long as the insulating powder 315 has a hardness that is collapsed by the elastic contact force of the below-described resilient contacts 61 (holding portions 65). . The average particle size of the insulating powder 315 was determined by sieving with a sieve of # 300 to obtain an average particle size of 15 μm. In other words, in this embodiment, [average particle size of conductive powder 313] ≦ [average particle size of insulating powder 315]. In measuring the particle size of the conductive powder 313 and the insulating powder 315, the particle size distribution is determined using a particle size distribution measuring device, and the particle size (particle size) at which the cumulative% of the particles from the small particle side becomes 50%. The same particle size is obtained even when the cumulative% of the particles from the larger particle side is 50%.
[0017]
Then, the weight ratio of the binder resin 311, the conductive powder 313, and the insulating powder 315 is
[Binder resin 311]: [conductive powder 313]: [insulating powder 315]
= [65-81.7]: [8.3-18]: [10-17]
The thickness of the applied anisotropic conductive film 31 (the thickness of the binder resin 311) was set to 8 μm. That is, in this embodiment, the average particle size of the conductive powder 313 is larger than the film thickness of the anisotropic conductive film 31. However, even if the average particle size of the conductive powder 313 is smaller than the film thickness of the anisotropic conductive film 31, the conductive powder 313 contains conductive powder having a particle size larger than the film thickness of the anisotropic conductive film 31. I just want it. That is, it is sufficient that at least a part of the conductive powder 313 has a particle diameter protruding from the upper surface of the anisotropic conductive film 31.
[0018]
Returning to FIG. 1, the second connector 50 includes a resilient contact 61 made of a plurality of (five) substantially rectangular metal plates having elasticity inside an insertion portion 53 provided on one side surface of a synthetic resin case 51. Are installed in parallel. Each of the resilient contacts 61 has a base 63 at one end in the longitudinal direction of the metal plate, protrudes two elastic arms 64, 64 from the other end, and further protrudes a terminal 67 from outside the base 63. It is configured. Holders 65, 65 are provided at both ends of both arms 64, 64, respectively. The terminal portion 67 is a portion that is connected to a terminal pattern of another substrate on which the second connector 50 is mounted by using a low melting point metal or the like.
[0019]
Then, when the first connector 10 is inserted into the insertion portion 53 of the second connector 50 and engaged, the distal end of the first connector 10 is inserted by pushing between the two arm portions 64, 64 and inserted. The upper and lower surfaces, that is, between the upper surface of the anisotropic conductive film 31 and the lower surface of the reinforcing plate 25 are sandwiched by the clamping portions 65, 65 at the ends of both arms 64, 64, so that the upper surface of the anisotropic conductive film 31 Each of the holding portions 65 is elastically contacted.
[0020]
FIG. 3 is a schematic cross-sectional view showing a circuit connection state between the first connector 10 and the second connector 50, and shows the same cross-section as that shown in FIG. As shown in the drawing, when the upper and lower surfaces of the first connector 10 are clamped by the clamping portions 65 of the resilient contacts 61 of the second connector 50, the upper clamping portion 65 on the upper surface of the anisotropic conductive film 31. Are elastically contacted with each other, and the insulating powder 315 protruding from the upper surface of the anisotropic conductive film 31 is broken by the elastic contact force, so that each holding portion 65 is electrically conductive powder 313 protruding from the upper surface of the anisotropic conductive film 31. , And the conduction between each of the holding portions 65 and the contact pattern 30 is conducted through the conductive powder 313. Although the surface of the conductive powder 313 is thinly covered with the binder resin 311, the binder resin 311 is so thin that the binder resin 311 is easily peeled off by the elastic contact force of the holding portion 65, and the holding portion 65 and the contact pattern 30 are electrically connected. As described above, even if the particle size of the insulating powder 315 is increased in order to improve the insulating property in the surface direction (the direction crossing the adjacent contact patterns 30 at right angles; the same applies to the following), the insulating powder 315 is not easily disintegrated. Since it is made of the above material, it collapses due to the elastic contact force of the holding portion 65, and conduction between the holding portion 65 and the contact pattern 30 can be reliably performed.
[0021]
In the electrical circuit connecting connector configured as described above, the contact pattern 30 in which the anisotropic conductive film 31 is provided on the upper surface in the first connector 10 and the elastic resilient contacts 61 in the second connector are anisotropic. Since the connection is made through the conductive film 31, even if a silver paste material or the like that easily causes electromigration is used as the contact pattern 30 of the first connector 10, the contact pattern has an anisotropic conductive property having an insulating property in the surface direction. The conductive powder 313 in the anisotropic conductive film 31 is made of a metal that is unlikely to cause electromigration because it is directly covered with the film and is not exposed to moisture. Will not occur. In addition, since the insulating powder 315 as well as the conductive powder 313 is mixed in the binder resin 311, the insulating powder 315 enters between the conductive powders 313 to further improve the insulating property in the surface direction. In addition, since at least a part of the conductive powder 313 has a particle diameter protruding from the upper surface of the anisotropic conductive film 31, the insulating powder 315 and the binder resin 311 do not cover the conductive powder 313 ( However, the upper surface of the conductive powder 313 is covered with a thin film of the binder resin 311), and the conductive powder 313 ensures electrical contact between the contact pattern 30 and the holding portion 65 of the resilient contact 61 of the second connector 50. be able to. Further, in this embodiment, the average particle size of the insulating powder 315 is equal to or larger than the average particle size of the conductive powder 313, so that the large insulating powder 315 that has entered between the conductive powders 313 is in the plane direction. To further improve the insulation properties of In addition, when the insulating powder 315 is small, the insulating powder 315 easily enters between the conductive powder 313 and the contact pattern 30, and the possibility of inhibiting the conductivity of the anisotropic conductive film 31 in the thickness direction increases. It also has the effect of preventing. That is, when the particle size of the insulating powder 315 is increased, the insulating property in the surface direction and the conductivity in the thickness direction can be simultaneously improved.
[0022]
FIG. 4 is a diagram showing a performance test method of the anisotropic conductive film 31A, and FIG. 5 is a diagram showing a performance test result of the anisotropic conductive film 31A when the average particle size of the insulating powder 315 is large (15 μm). FIG. 6 is a diagram showing the performance test results of the anisotropic conductive film 31A when the average particle size of the insulating powder 315 is small (3 μm). That is, in this test, as shown in FIG. 4, a board (flexible board) 20A on which two contact patterns 30A and 30A are formed by printing is placed on a reinforcing plate 25A, as in the case of the first connector 10 described above. The anisotropic conductive film 31A in which the conductive powder 313A and the insulating powder 315A are dispersed is formed by printing on the same binder resin 311A as in the above embodiment, and the conductive plate 90 made of a metal plate is lightly placed thereon. Except for changing the average particle size of the insulating powder 315A, the same particle size as that of the above-described embodiment is used as the particle size of the conductive powder 313A and the material of each member.
[0023]
Then, the resistance between the two contact patterns 30A and 30A when the conductive plate 90 is not mounted is measured in advance, and then the state where the conductive plate 90 is mounted as shown in FIG. The resistance value between the contact patterns 30A, 30A when the contact patterns 30A, 30A are pressed in the direction is measured sequentially. Then, this measurement is performed for each of the anisotropic conductive films 31A in which the mixing ratio (weight ratio) of the binder resin 311A, the conductive powder 313A, and the insulating powder 315A is changed, and whether or not each is appropriate as the anisotropic conductive film 31A is inspected. . In the performance test results shown in FIGS. 5 and 6, the horizontal axis represents the weight ratio of “resin” to “conductive powder”, and the vertical axis represents the weight ratio of “resin + conductive powder” to “insulating powder”.
[0024]
The method of determining whether or not each anisotropic conductive film 31A is appropriate is as follows. If the conductive pattern 90 is not placed and the conductive pattern between the two contact patterns 30A and 30A is conductive, the conductive pattern between the two contact patterns 30A and 30A is in the plane direction. , It does not function as the anisotropic conductive film 31A and is determined to be inappropriate (square points in FIGS. 5 and 6). Next, in order to check the conductivity in the thickness direction, when the conductive plate 90 is pressed with a low load, the resistance varies greatly between the conductive plate 90 and each of the contact patterns 30A, 30A. Even when the value is low, the function is not stable as the anisotropic conductive film 31A, and it is determined that the anisotropic conductive film 31A is not appropriate (the point of the equilateral triangle in FIGS. 5 and 6). If there is no conduction between the conductive plate 90 and each of the contact patterns 30A, 30A even when pressed with a strong load, it is judged that the conductive plate 90 does not function as the anisotropic conductive film 31A and is inappropriate (FIGS. 5, 6). Diamond point). On the other hand, even when the conductive plate 90 is not mounted and when the conductive plate 90 is simply mounted, the conduction between the two contact patterns 30A, 30A is not conducted, and even when the conductive plate 90 is pressed with a weak load, it is pressed with a strong load. Even when the conductive plate 90 and the contact patterns 30A, 30A show a substantially stable low resistance value, it is determined that the anisotropic conductive film 31A is appropriate (circular points in FIGS. 5 and 6). . FIG. 5 shows the test results when the particle size of the insulating powder 315A was 15 μm, and FIG. 6 shows the test results when the particle size of the insulating powder 315A was 3 μm. When the diameter is smaller than the average particle diameter of the conductive powder 313A, it can be seen that the range of a region (circular point) determined to be appropriate as the anisotropic conductive film 31A is narrowed. In particular, the portion F shown in FIG. 6 is changed from an optimal state in FIG. 5 to an inappropriate state. This is because the amount of the conductive powder 313A is the same as that of the binder resin 311A and the insulating powder 315A. Even if the ratio is large, it means that the larger the particle size of the insulating powder 315A is, the higher the insulating property in the plane direction is.
[0025]
FIG. 7 is a sectional view showing an electric circuit connecting connector having another structure to which the present invention is applied. In this embodiment, a first connector (male connector) 10-2 and a second connector (female connector) 50-2 are provided. In the figure, a first connector 10-2 has a base 25-2A at one end of a reinforcing member 25-2 made of a synthetic resin, and the lower surface of a protruding portion 25-2B protruding from the base 25-2A has flexibility. The insulating substrate 20-2 made of synthetic resin film is fixed. A plurality of contact patterns 30-2 are formed in parallel on the lower surface of the portion fixed to the protrusion 25-2B of the insulating substrate 20-2. On the other hand, the second connector 50-2 is mounted on the groove-shaped storage portion 53-2 provided on the substrate storage member 51-2A made of a molded resin with a cover member 51-2B made of a metal plate put thereon. -2, a resilient member 61-2A bent in a substantially "U" shape is stored in a concave resilient member storage portion 55 provided in the concave portion, and flexibility is provided so as to cover the resilient member storage portion 55. The insulating substrate 61-2C is provided, and its front end is folded back through a through hole 57 provided in the substrate housing member 51-2A, and is fixed on the back side. A plurality of contact patterns 61-2B are formed in parallel on an upper surface of a portion of the insulating substrate 61-2C located in the storage section 53-2, and the contact pattern 61-2B is formed by a resilient member 61-2A. By pushing up to the 53-2 side, a resilient contact 61-2 is formed.
[0026]
Then, when the insertion portion 25-2B of the first connector 10-2 is inserted into and engaged with the storage portion 53-2 of the second connector 50-2, as shown in FIG. -2C is pressed by the resilient portion 61-3A of the resilient member 61-2A, and the contact patterns 30-2 and 61-2B provided on the insulating substrates 20-2 and 61-2C are connected.
[0027]
In the case of the present embodiment, the anisotropic conductive material is provided on the contact pattern 30-2 provided on the insulating substrate 20-2 and / or the contact pattern 61-2B provided on the insulating substrate 61-2C, similarly to the above embodiment. If a film is formed, electromigration does not occur even if the pitch between contact patterns is reduced. In the case of this embodiment, the resilient portion 61-3A of the resilient member 61-2A does not directly contact the contact pattern 30-2, but the contact patterns provided on the two insulating substrates 20-2 and 61-2C. 30-2 and 61-2B are pressed from the outside, but even in this case, the particle size of the conductive powder dispersed in the anisotropic conductive film is smaller than the film thickness of the anisotropic conductive film. Insulation powder dispersed in the anisotropic conductive film is made into a hardness / properties insulation powder which is collapsed by the elastic contact force of the resilient contact 61-2 (elastic portion 61-3A). If the average particle size of the insulating powder is made equal to or larger than the average particle size of the conductive powder, the same effect as in the above-described embodiment is obtained.
[0028]
Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications may be made within the scope of the claims and the technical idea described in the specification and the drawings. It is possible. Note that any shape, structure, or material not directly described in the specification and drawings is within the scope of the technical idea of the present invention as long as the effects and effects of the present invention are exhibited. For example, the structure of the connector is not limited to the above embodiments, and various modifications are possible. In short, the first connector for connecting an electric circuit is provided by providing an anisotropic conductive film on a contact pattern. The present invention can be applied to a connector having any structure as long as the connector has an electrical circuit connection provided with a second connector for electrical circuit connection provided with elastic resilient contacts.
[0029]
【The invention's effect】
As described in detail above, according to the present invention, there is an excellent effect that there is no possibility that electromigration occurs even if the pitch interval between the contact patterns becomes narrow.
[Brief description of the drawings]
FIG.
FIG. 1 is a perspective view showing a first connector 10 for connecting an electric circuit and a second connector 50 connecting the first connector 10 according to an embodiment of the present invention.
FIG. 2
FIG. 2 is a schematic sectional view taken along line AA of FIG. 1.
FIG. 3
FIG. 3 is a diagram illustrating a circuit connection state between a first connector 10 and a second connector 50.
FIG. 4
It is a figure showing the performance test method of 31 A of anisotropic conductive films.
FIG. 5
It is a figure showing the performance test result of 31 A of anisotropic conductive films when average particle diameter of insulating powder 315A is enlarged (15 micrometers).
FIG. 6
It is a figure showing the performance test result of 31 A of anisotropic conductive films when the average particle size of insulating powder 315A is made small (3 micrometers).
FIG. 7
It is sectional drawing which shows the connector for electric circuit connection of another structure which applies this invention.
FIG. 8
It is a figure showing the state where the 1st connector 10-2 and the 2nd connector 50-2 were connected.
FIG. 9
It is a perspective view which shows an example of a connector connection structure.
[Explanation of symbols]
Reference Signs List 10 first connector 20 insulating substrate 21 circuit pattern 23 insulating layer 25 reinforcing plate 30 contact pattern 31 anisotropic conductive film 311 binder resin 313 conductive powder 315 insulating powder 50 second connector 51 case 53 insertion portion 61 resilient contact 63 base 64 Arm part 65 Holding part 67 Terminal part 90 Conductive plate 10-2 First connector 20-2 Insulating board 25-2 Reinforcing member 25-2A Base 25-2B Projecting part 50-2 Second connector 51-2A Board storage member 53- 2 Storage part 55 Resilient member storage part 51-2B Covering member 61-2 Resilient contact 61-2A Resilient member 61-3A Resilient part 61-2C Insulating substrate

Claims

A contact pattern is provided on an insulating substrate, and a first connector for electric circuit connection further provided with an anisotropic conductive film on the contact pattern, and an electric circuit connection for providing an elastic resilient contact. And a second connector,
By the engagement of the two connectors, the resilient contact and the contact pattern of the first connector are connected via the anisotropic conductive film by the resilient contact force of the resilient contact of the second connector. A connector for connecting an electric circuit, comprising:

The anisotropic conductive film is formed by dispersing a conductive powder in a binder resin, and the conductive powder includes a conductive powder having a particle diameter larger than the thickness of the anisotropic conductive film. The electrical circuit connecting connector according to claim 1.

The electrical circuit connector according to claim 2, wherein insulating powder is dispersed in the anisotropic conductive film.

The electrical circuit connecting connector according to claim 3, wherein the insulating powder is an insulating powder having a hardness that is collapsed by an elastic contact force of a resilient contact of the second connector.

The electrical circuit connection connector according to claim 4, wherein the average particle size of the insulating powder is equal to or larger than the average particle size of the conductive powder.