JP4032439B2

JP4032439B2 - Connection member, electrode connection structure and connection method using the connection member

Info

Publication number: JP4032439B2
Application number: JP12798196A
Authority: JP
Inventors: 功塚越; 幸寿廣澤; 宏治小林; 共久太田; 寛松岡; 伊津夫渡辺; 賢三竹村; 直行塩沢; 治渡辺; 和良小島
Original assignee: Hitachi Chemical Co Ltd; Showa Denko Materials Co Ltd
Current assignee: Showa Denko Materials Co Ltd
Priority date: 1996-05-23
Filing date: 1996-05-23
Publication date: 2008-01-16
Anticipated expiration: 2016-05-23
Also published as: JPH09312176A

Description

【０００１】
【発明の属する技術分野】
本発明は、半導体チップ等の電子部品と回路板を接着固定すると共に、両者の電極同士を電気的に接続する接続部材、およびこれを用いた電極の接続構造並びに接続方法に関する。
【０００２】
【従来の技術】
近年、電子部品の小型薄型化に伴い、これらに用いる回路は高密度、高精細化している。このような電子部品と微細電極の接続は、従来のはんだやゴムコネクタ等では対応が困難であることから、最近では分解能に優れた異方導電性の接着剤や膜状物（以下接続部材）が多用されている。
この接続部材は、導電粒子等の導電材料を所定量含有した接着剤からなるもので、この接続部材を電子部品と電極や回路との間に設け、加圧または加熱加圧手段を構じることによって、両者の電極同士が電気的に接続されると共に、電極に隣接して形成されている電極同士には絶縁性を付与して、電子部品と回路とが接着固定されるものである。
上記接続部材を高分解能化するための基本的な考えは、導電粒子の粒径を隣接電極間の絶縁部分よりも小さくすることで隣接電極間における絶縁性を確保し、併せて導電粒子の含有量をこの粒子同士が接触しない程度とし、かつ電極上に確実に存在させることにより、接続部分における導電性を得ることである。
【０００３】
【発明が解決しようとする課題】
上記従来の方法は、導電粒子の粒径を小さくすると、粒子表面積の著しい増加により粒子が２次凝集を起こして連結し、隣接電極間の絶縁性が保持できなくなる。また、導電粒子の含有量を減少すると接続すべき電極上の導電粒子の数も減少することから、接触点数が不足し接続電極間での導通が得られなくなるため、長期接続信頼性を保ちながら接続部材を高分解能化することは極めて困難であった。すなわち、近年の著しい高分解能化すなわち電極面積や隣接電極間（スペース）の微細化により、電極上の導電粒子が接続時の加圧または加熱加圧により、接着剤と共に隣接電極間に流出し、接続部材の高分解能化の妨げとなっていた。
このとき、接着剤の流出を抑制するために、接着剤を高粘度とすると電極と導電粒子の接触が不十分となり、相対峙する電極の接続が不可能となる。一方、接着剤を低粘度とすると、導電粒子の流出に加えてスペース部に気泡を含みやすく接続信頼性、特に耐湿性が低下してしまう欠点がある。
【０００４】
このようなことから、導電粒子含有層と絶縁性接着層を分離した多層構成の接続部材とし、導電粒子含有層の接続時における粘度を絶縁性接着層よりも相対的に高粘度もしくは高凝集力することで、導電粒子を流動し難くして電極上に導電粒子を保持する試みも、例えば特開昭６１−１９５１７９号公報、特開平４−３６６６３０号公報等にみられる。しかしながらこれらは接続時に導電粒子含有層が絶縁性接着層に比べ高粘度であるため、電極と導電粒子の接触が不十分となるために、接続抵抗値が高いことから接続信頼性が不満足である。また、接続抵抗値を低下するために導電粒子含有層から導電粒子をあらかじめ露出させ、電極との接触を得やすい構成とした場合、導電粒子の粒子径を大きくする必要があり高分解能化に対応できない。
なお、このような微細電極や回路の接続を可能とし、かつ接続信頼性に優れた接続部材として、両方向の必要部に導電粒子の密集領域を有する接続部材の提案もある。これによれば、半導体チップのようなドット状の微細電極の接続が可能となるものの、導電粒子の密集領域とドット状電極との正確な位置合わせが必要で、作業性に劣る欠点がある。
【０００５】
本発明は、上記欠点に鑑みなされたもので、導電粒子が接続時に電極上から流出し難いので電極上に保持可能であり、かつ電極と導電粒子の接触が得やすく、また接続部に気泡を含み難いことから、長時間接続信頼性に優れ、導電粒子と電極との正確な位置合わせが不要なことから作業性に優れた、半導体チップ類の接続に有用な高分解能の接続部材に関する。
すなわち、我々の検討（後述実施例の項に詳述）によれば、接続後の電極上の導電粒子の保持性について、多層の接続部材の構成と、電極接続面の長径と短径の比（Ｌ／Ｄ）とに極めて特徴的な事実の存在することが分かり本発明に至った。
【０００６】
【課題を解決するための手段】
本発明の第１は、導電材料とバインダとよりなる加圧方向に導電性を有する接着層の少なくとも片面に絶縁性の接着層が形成されてなる多層接続部材であって、バインダ成分の接続時の溶融粘度が５００ポイズ以下であってかつ絶縁性接着層に比べ０．１ポイズから１０００ポイズ低く、半導体チップの接続用電極面の長径と短径の比（Ｌ／Ｄ）が２０以下であることを特徴とする半導体チップ類の接続部材に関する。また本発明の第２は相対峙する電極列間の少なくとも一方が突出した電極列間の接続構造であって、前記導電材料が相対峙する電極間に存在し、かつ絶縁性接着層が突出電極の少なくとも基板側の周囲を覆ってなることを特徴とする電極の構造に関する。また本発明の第３は、少なくとも一方が突出した電極を有する相対峙する電極列間に、前記接続部材の絶縁性接着層が突出した電極側となるように配置し、バインダ成分と絶縁性の接着層との接続時の溶融粘度が絶縁性の接着層に比べて、相対的にバインダ成分が低い条件で加熱加圧することを特徴とする電極の接続方法に関する。さらに本発明の第４は、絶縁性接着層が突出した電極側となるように配置し加熱加圧してなる接続方法において、加熱加圧工程を２段階以上に分割し、その間に接続電極の通電検査工程および／またはリペア工程とを必要に応じて行うことを特徴とする電極の接続方法に関する。
【０００７】
【発明の実施の形態】
本発明を図面を参照しながら説明する。図１は、本発明の一実施例を説明する接続部材の断面模式図である。本発明の接続部材は、導電粒子とバインダとよりなる加圧方向に導電性を有する導電性接着層１の少なくとも片面に絶縁性接着層２が形成されてなる多層接続部材である。図２のように絶縁性接着層２は、導電性接着層１の両面に形成しても良い。図１〜２において、図示していないが絶縁性接着層２を、さらに多層構成として接着性等の機能を付加しても良い。これらの表面には不要な粘着性やごみ等の付着防止のために、図１のように剥離可能なセパレータ５が必要に応じて存在出来る。セパレータ５は、図示していないが表裏にも形成可能である。図１の場合、セパレータ５が絶縁性接着層２に接してなるので、例えば片側の基板が平面電極の場合の仮貼り付けに際して、凹凸の少ない平面電極側にセパレータ５の存在しない導電性接着層１を形成出来るので、接続が行いやすので作業性が良く好都合である。これらの場合、連続テープ状であると接続作業工程の連続自動化が図れるので好ましい。
【０００８】
図３は、加圧方向に導電性を有する導電性接着層１を説明する断面模式図である。導電性接着層１は、導電粒子３を含有したバインダ４よりなる。ここに導電粒子３としては、図３（ａ）〜（ｇ）のようなものが適用可能である。これらのうち導電粒子３は、図３（ｃ）〜（ｅ）のようにバインダ４の厚み方向に単層で存在できる粒径、すなわちバインダ４の厚みとほぼ同等の粒径とすることが、接続時に導電粒子３が流動しにくいために電極上に導電粒子３が保持しやすく好ましい。導電粒子３がバインダ４の厚みとほぼ同等の場合、簡単な接触により電極と導電可能となり導電性が得やすい。バインダ４に対する導電粒子３の割合は、０．１〜２０体積％程度、より好ましくは１〜１５体積％が、異方導電性が得やすく好ましい。また厚み方向の導電性を得やすくして高分解能とするために、バインダ４の厚さは膜形成の可能な範囲で薄い方が好ましく、２０μｍ以下より好ましくは１０μｍ以下である。導電粒子３としては、例えば図３の（ａ）〜（ｅ）の例示のように導電粒子で形成することが、製造が比較的容易に入手しやすいことから好ましい。また、導電粒子３は、図３（ｆ）のようにバインダ４に貫通口を設けてめっき等で導電体を形成したり、図３（ｇ）のようにワイヤ等の導電繊維状としても良い。
【０００９】
導電粒子としては、Ａｕ、Ａｇ、Ｐｔ、Ｎｉ、Ｃｕ、Ｗ、Ｓｂ、Ｓｎ、はんだ等の金属粒子やカーボン等があり、またこれら導電粒子を核材とするか、あるいは非導電性のガラス、セラミックス、プラスチック等の高分子等からなる核材に前記したような材質からなる導電層を被覆形成したもので良い。さらに導電粒子３を絶縁層で被覆してなる絶縁被覆粒子や、導電粒子とガラス、セラミックス、プラスチック等の絶縁粒子の併用等も分解能が向上するので適用可能である。微小な電極上に１個以上好ましくはなるべく多くの粒子数を確保するには、１５μｍ以下の小粒径粒子が好適であり、より好ましくは７μｍ以下１μｍ以上である。１μｍ以下では絶縁性接着層を突き破って電極と接触し難い。また、導電粒子３は、均一粒子径であると電極間からの流出が少ないので好ましい。これら導電粒子の中では、プラスチック等の高分子核材に導電層を形成したものや、はんだ等の熱溶融金属が、加熱加圧もしくは加圧により変形性を有し、接続時に回路との接触面積が増加し、信頼性が向上するので好ましい。特に高分子類を核とした場合、はんだのように融点を示さないので軟化の状態を接続温度で広く制御でき、電極の厚みや平坦性のばらつきに対応し易いので特に好ましい。また、例えばＮｉやＷ等の硬質金属粒子や、表面に多数の突起を有する粒子の場合、導電粒子が電極や配線パターンに突き刺さるので、酸化膜や汚染層の存在する場合にも低い接続抵抗が得られ、信頼性が向上するので好ましい。
【００１０】
バインダ４と絶縁性接着層２は、熱可塑性材料や、熱や光により硬化性を示す材料が広く適用できる。これらは接着性の大きいことが好ましい。
これらのなかでは、接続後の耐熱性や耐湿性に優れることから、硬化性材料の適用が好ましい。なかでもエポキシ系接着剤は、短時間硬化が可能で接続作業性が良く、分子構造上接着性に優れるので特に好ましい。
エポキシ系接着剤は、例えば高分子量のエポキシ、固形エポキシと液状エポキシ、ウレタンやポリエステル、アクリルゴム、ＮＢＲ、シリコーン、ナイロン等で変性したエポキシを主成分とし、硬化剤や触媒、カップリング剤、充填剤等を添加してなるものが一般的である。
本発明のバインダ成分４と絶縁性接着層２とは、各成分中に共通材料を１％以上好ましくは５％以上含有すると、両層の界面接着力が向上するので好適である。共通材料としては、主材料や硬化剤等がより効果的である。
【００１１】
本発明においては、バインダ成分の接続時の溶融粘度が、絶縁性接着層に比べ同等以下であることを特徴とする。この点について、図４〜５を用いて説明する。
図４は、バインダ成分４と絶縁性接着層２との加熱時の溶融粘度を示す模式説明図である。本願は、接続時の温度下でバインダ成分４（Ａ）が絶縁性接着層２（Ｂ）に比べ相対的に同等以下であり、好ましくはこの時の（Ａ）と（Ｂ）の粘度の差を０．１〜１０００ポイズ程度とし、より好ましくは１〜２００ポイズとすることが特徴である。粘度の差が大き過ぎると電極と粒子との接触が不十分になりやすい。後述する図５でも説明するが、接続時の接触と流動過程のバランスから電極上に粒子を保持し、かつ電極と粒子との接触を有効に得るために好ましい粘度範囲が存在する。同様な理由により、接続時の溶融粘度は、バインダ成分が５００ポイズ以下で行うことが好ましく、この時、絶縁性接着層が１０００ポイズ以下であることがより好ましい。
【００１２】
図５（ａ）に示す接触過程で、まず導電粒子３が相対的に溶融粘度が、同等以上の絶縁性接着層２に埋め込まれあるいは一部が捕捉された状態で、導電粒子３の位置が保持される。次いで図５（ｂ）の流動過程において、絶縁性の接着層の軟化により導電粒子３が突出電極１２と接触し、平面電極１４との間で導電可能となる。バインダ成分の接続時の溶融粘度が絶縁性接着層に比べ、低粘度である好ましい実施態様の場合、絶縁性接着層２は、導電粒子３の保持が可能で隣接する突出電極間のスペースを気泡の無い状態で接続できる。この場合、絶縁性接着層２の軟化促進のために、接続部材の絶縁性接着層が突出した電極側となるように配置し、絶縁性接着層側に熱源を配し加熱加圧することがさらに好ましい。この時、加熱加圧工程を２段階以上に分割し、必要に応じて通電検査工程および／またはリペア工程とを含む電極の接続方法とすることも可能である。加熱加圧工程を２段階以上に分解することで、接着剤の硬化反応に伴う流動過程の粘度制御が可能になるので、気泡の無い良好な接続が可能となる。加えて硬化型接着剤の問題点であるリペア性の付与が可能となる。
【００１３】
通電検査工程は、接続電極の保持が可能な程度に、接続部材の凝集力を増加せしめ、あるいは電極接続部を加圧しながら行うことができる。通電検査は、例えば両電極からリード線を取り出し接続抵抗の測定や動作試験により可能である。この時、導電粒子３と電極との接触状態の外観検査も、併用もしくは独立して行うことも出来る。リペア性とは、不要部の接着剤を除去して溶剤等で清浄化し再接続することである。一般的に硬化型接着剤は、硬化終了後に網状構造が発達し、熱や溶剤等に不溶不融性となり、清浄化が極めて困難なため従来から問題視されていた。加熱加圧工程の第一段階で、例えば導電粒子３が突出電極１２と接触し、平面電極１４との間で導通可能な状態で両電極の通電検査を行う。この時、不良電極の接続部があれば、この状態でリペアし再接続を行う。接着剤は、未硬化あるいは硬化反応の不十分な状態なので、剥離し易く溶剤にも浸され易くリペア作業が容易である。
【００１４】
溶融粘度の測定法としては、バインダ成分４と絶縁性接着層２とを相対的に比較できれば良く特に規定しないが、同一の方法とすることが好ましく、例えば高温下の測定が可能な一般的な回転式粘度計を使用できる。この時、測定時に反応が進行し粘度の変化が生じる例えば熱硬化系配合の場合は、硬化剤を除去したモデル配合での測定値を採用出来る。バインダ成分４と絶縁性接着層２との接続時の溶融粘度に差を設ける方法としては、材料の分子量や分子の絡み合いよる固有粘度の組み合わせや、増粘材としての充填剤の選択、および硬化系における反応速度の相違制御等が一般的である。本発明の接続部材の製法としては、例えば導電性接着層１と、絶縁性接着層２をラミネートしたり、積層して順次塗工する等の方法が採用できる。
【００１５】
本発明の接続部材を用いた電極の接続構造とその製法について、図６〜８により説明する。図６は、チップ基板１１に形成された突出電極１２と、基板１３の平面電極１４とが、本発明の接続部材を介して接続された構造である。すなわち、相対峙する電極列間の少なくとも一方が突出した電極列間の接続構造であって相対峙する電極間１２−１４間に導電粒子３が存在し、かつ突出電極１２の周囲１５よりも導電粒子の密度が高い状態で存在し、相対峙する電極列間が接続される。また、絶縁性接着層２が突出電極１２の少なくとも突出する電極の周囲１５を覆っている。ここに平面電極１４は、基板１３面からの凹凸がないか、あっても数μｍ以下とわずかな場合をいう。これらを例示すると、アディティブ法や薄膜法で得られた電極類が代表的である。
【００１６】
図７は、基板に形成された電極が突出電極１２と１２’同士の場合である。すなわち、図２で示した両面に絶縁性接着層２および２’を有する接続部材を介して接続した構造である。絶縁性接着層２および２’は、それぞれ突出電極１２と１２’の突出する電極の周囲を覆っており、また、チップ基板面１１および基板面１３と接している。
図８は、基板に形成された電極が突出電極１２と凹状電極１６の場合である。この場合も凹状電極１６を図６に示した平面電極１４に置き換えた形で可能である。ここに凹状電極１６の例として、例えば半導体チップ類の突出電極（バンプ）形成前のＡｌパッド等があり、不要部は絶縁層１８で被覆される。絶縁層１８はシリカ、窒化ケイ素、ポリイミド等が使用され、厚みは数μｍが一般的である。図８の場合、チップ類に突出電極が形成不要であり、低コスト化が可能である。
【００１７】
図６〜８においては、導電性接着層１と絶縁性接着層２が境界を形成している場合を図示したが両層は混合されても良く、また図９のように突出した電極１２の頂部１７から基板１１側にかけて、導電粒子３の密度が傾斜的に薄くなる構成でも良い。図６〜８において、チップ基板１１としては、シリコン、ガリウム−ヒ素、ガリウム−リン、水晶、サファイア、ガ−ネット、フェライト等の半導体類がある。基板１３としては、ポリイミドやポリエステル等のプラスチックフィルム、ガラス繊維／エポキシ等の複合体、シリコン等の半導体、ガラスやセラミックス等の無機質等を例示できる。突出電極１２は、バンプ類の他に各種回路類や端子類も含むことができる。なお、図６〜８で示した各種電極類は、それぞれ任意に組み合わせて適用できる。ここにチップ基板１１の突出電極１２は、半導体チップの接続用電極面の長径と短径の比（Ｌ／Ｄ）が２０以下であることが好ましく、１〜１０であることがより好ましい。この理由は、本発明の接続部材を用いた接続後の電極上の導電粒子の保持性が、Ｌ／Ｄの上記範囲内で良好なことによる。
【００１８】
接続後の電極上の導電粒子の保持性について、多層の接続部材の構成と、電極接続面の長径と短径の比（Ｌ／Ｄ）とに極めて特徴的な事実の存在する理由については十分に明らかとなっていないが、接着剤の流動する際の方向性と熱伝達性の影響と考えられる。
本発明の接続部材を用いた電極の接続方法は、接続部材の絶縁性接着層２が突出した電極１２側となるように配置し、バインダ成分と絶縁性の接着層との接続時の溶融粘度が絶縁性の接着層に比べて、相対的にバインダ成分の方が低い条件下で加熱加圧する。
【００１９】
【作用】
本発明によれば、バインダ成分の接続時の溶融粘度が５００ポイズ以下であって、絶縁性接着層に比べ、同等以下であるので、電極の接続時に、導電性接着層１の導電粒子３が相対的に溶融粘度が同等以上の絶縁性接着層２に埋め込まれ、あるいは一部が捕捉された状態で接触し、突出電極１２上に導電粒子３の位置が保持される。次いで、絶縁性の接着層の軟化流動により、導電粒子３が突出電極１２と接触し導通可能となる。この時絶縁性接着層２は、バインダ成分４に比べ粘度が高く、導電粒子３の保持が可能であり、隣接する突出電極間のスペース部分を気泡の無い状態で接続できる。本発明によれば、半導体チップ等の接続用電極面の長径と短径の比（Ｌ／Ｄ）が２０以下で小さな場合、微小な突出電極１２上に多くの導電粒子３が確実に保持されるので接続信頼性が高く、また高価な導電粒子を効率良く適用できるので省資源的である。
【００２０】
本発明によれば、突出電極１２上に導電粒子３が確実に保持され導通可能となるので、導通検査の信頼性が向上する。接着剤は、未硬化あるいは硬化反応の不十分な状態で導通検査可能なのでリペア作業が容易である。絶縁性接着層２は、突出した電極１２側となるように配置するので、隣接電極間の絶縁性と分解能が向上する。加えて、絶縁性接着層２の溶融粘度が高い構成の場合に、接続圧力が加わらないので隣接電極間に導電粒子３が一層流入しにくい。導電性接着層１の導電粒子３は、全面に均一に分散されてなるので、導電粒子と電極との正確な位置合わせが不要なことから作業性に優れる。接着層は、その目的に応じ、例えば電極基板の材質に適合した接着性を示す組み合わせが可能なことから材料の選択肢が拡大し、接続部の気泡減少等により、やはり接続信頼性が向上する。また一方を溶剤に可溶性もしくは膨潤性としたり、あるいは耐熱性に差を持たせることで、一方の基板面から優先的に剥離可能とし、再接続するいわゆるリペア性を付与することも可能となる。あるいは電極基板の材質に適合した任意の組み合わせとすることも可能であり、電極と導電粒子の接触が得やすく、製法も簡単である。また、接着層を接続部の外にはみ出させ封止材的作用により、補強や防湿効果を得ることもできる。
【００２１】
【実施例】
以下実施例でさらに詳細に説明するが、本発明はこれに限定されない。
実施例１
（１）導電性接着層の作製
フェノキシ樹脂（高分子量エポキシ樹脂）とマイクロカプセル型潜在性硬化剤を含有する液状エポキシ樹脂（エポキシ当量１８５）の比率を３０／７０とし、酢酸エチルの３０％溶液を得た。この溶液に、粒径４±０．２μｍのポリスチレン系粒子にＮｉ／Ａｕの厚さ０．２／０．０２μｍの金属被覆を形成した導電粒子を８体積％添加し、混合分散した。この分散液をセパレータ（シリコーン処理ポリエチレンテレフタレートフィルム、厚み４０μｍ）にロールコータで塗布し、１１０℃で２０分乾燥し、厚み５μｍの導電性接着層を得た。この接着層の硬化剤を除去したモデル配合の粘度を、デジタル粘度計ＨＶ−８（株式会社レスカ製）により測定した。１５０℃における粘度は８０ポイズであった。
【００２２】
（２）絶縁性接着層の形成と接続部材の作製
（１）の配合比を４０／６０とし導電性接着層から導電粒子を除去し、厚み１５μｍのシートを前記（１）と同様に作製した。まず（１）の導電性接着層面と（２）の接着層面とをゴムロール間で圧延しながらラミネートした。以上で図１の２層構成の厚みが２０μｍの多層接続部材を得た。前記と同様に測定した絶縁性接着層の１５０℃における粘度は２８０ポイズであった。したがって１５０℃における導電性接着層と絶縁性接着層との粘度の差は、２００ポイズである。
【００２３】
（３）接続
評価用ＩＣチップ（シリコン基板、２×１２ｍｍ、高さ０．５ｍｍ、長辺側２辺にバンプと呼ばれる５０μｍφ、高さ２０μｍの金電極が３００個形成）と、ガラス１．１ｍｍ上に酸化インジウム厚み０．２μｍ（ＩＴＯ、表面抵抗２０Ω／□）の薄膜回路を有する平面電極とを接続した。ガラス側のＩＴＯ電極を前記ＩＣチップのバンプ電極サイズに対応させ周辺に測定用のリ−ドを引き出した。接続部材をＩＣチップの大きさよりも若干大きい２．５×１４ｍｍに切断し、平面電極側に導電性接着層がくるようにして仮接続した。基板が平滑であることに加え接続部材の有する粘着性により、貼り付けが容易でこの後のセパレータ剥離も簡単であった。次にＩＣチップのバンプと、平面電極とを位置合わせし、１５０℃、３０ｋｇｆ／ｍｍ^２、１５秒で加熱加圧し接続体を得た。この時接続装置の熱源は絶縁性の接着層側に配置し、平面電極側に導電性接着層を配置した。
【００２４】
（４）評価
この接続体の断面を研磨し顕微鏡で観察したところ、図６相当の接続構造であった。隣接電極間のスペースは気泡混入がなく粒子が球状であったが、電極上は粒子が圧縮変形され上下電極と接触保持されていた。相対峙する電極間を接続抵抗、隣接する電極間を絶縁抵抗として評価したところ、接続抵抗は１Ω以下、絶縁抵抗は１０^１０Ω以上であり、これらは８５℃、８５％ＲＨ１０００時間処理後も変化が殆どなく良好な長期信頼性を示した。本実施例における電極上（５０μｍφ＝１９６２．５μｍ^２）の接続に寄与している有効平均粒子数は、２０個（最大２３個、最小１８個、以下同様に表示）であった。接続に寄与している有効粒子とは、接続面をガラス側から顕微鏡（×１００）で観察し、電極との接触により光沢を有しているものとした。またＬ／Ｄは５０μｍφ（直径）のなので１．０である。本実施例では、バンプ上の粒子は圧縮変形され上下電極と接触保持されていた。隣接バンプ間に気泡混入がなく、良好な長期信頼性を示した。導電粒子は、相対峙する電極間距離のばらつきに応じて粒子の変形度が異なり、部分的にバンプに食い込むものも見られ、全電極において良好な接続を得た。
【００２５】
比較例１
実施例１と同様であるが、厚みが２０μｍの従来構成の単層の導電性接着層を得た。実施例１と同様に評価したところ、電極上（５０μｍφ）の粒子数は最大１３個、最小０個であり、電極上に有効粒子の無いものが見られ、また実施例１に比べ最大と最小のばらつきが大きかった。また、接続体の絶縁抵抗を測定したところショート不良が発生した。接続時に導電粒子が電極上から流出し、隣接電極間（スペース部）での絶縁性が保持できなくなったと見られる。
【００２６】
実施例２
実施例１の導電性接着層の他の面に、さらに同様に絶縁性接着層を形成し、図２の３層構成の多層接続部材を得た。また、実施例１のガラス平面電極に代えて、ポリイミドフィルム上に、高さ１８μｍの銅の回路を有する２層ＦＰＣ回路板とした。実施例１と同様に接続し、図７相当の接続体を得た。
実施例１と同様に評価したところ良好な接続特性を示した。電極上の有効粒子数は、突出電極同士の接続なので粒子が流出しやすい構成にもかかわらず、全電極において１０個以上の確保が可能であった。
【００２６】
実施例３〜５および比較例２〜３
実施例１と同様であるが、絶縁性接着層のフェノキシ樹脂と液状エポキシ樹脂の配合比を変えることで、両層の１５０℃における粘度の差を変化させた。結果を前述実施例１と共に表１に示す。各実施例では、電極上の有効粒子数が多くばらつきも比較的少なく、実施例１と同様に良好な接続特性を示した。
比較例２では、粘度の差が大きすぎるため絶縁性接着層から導電粒子が露出できずに電極上に有効粒子が見られず、接続が不可能であった。
比較例３は、接続部材の構成を実施例１と逆にした従来から知られている２層構成であるが、有効粒子数が少なく電極上に有効粒子の無いものが見られ、また実施例１に比べ最大と最小のばらつきが大きかった。
【００２７】
【表１】

【００２８】
比較例４〜５
平行電極の接続として実施例２のＦＰＣ回路板同士を接続（電極幅Ｄ＝５０μｍ、接続幅Ｌ＝１５００μｍ、Ｌ／Ｄ＝３０）した。
比較例４は、実施例１の接続部材による接続であるが、５０μｍφに換算した電極上の有効粒子数は９個（０〜１６）と実施例１に比べ１／２以下であった。
比較例５は、比較例３の接続部材による接続であるが、有効粒子数は１８個（１４〜２４）と比較例３に比べて向上した。
これらの結果から，Ｌ／Ｄの大きな回路板のような平行電極の接続の場合と、半導体チップ電極のようなＬ／Ｄの小さなドット状電極の場合とでは、接続部材の最適構成が異なることが分かった。この理由については不明であるが、接続時の熱伝達性や接着剤の流動がＬ／Ｄの影響で変化するためと考えられる。
【００２９】
実施例６〜８
実施例１と同様であるが、ＩＣチップ接続面のバンプ形状を変化させた。
バンプは長径をＩＣチップの中央に向けた。結果を表２に示す。
Ｌ／Ｄ＝１〜１０の各実施例では、電極上の有効粒子数が多く、ばらつきが
比較的少なく、実施例１と同様に良好な接続特性を示した。
【００３０】
【表２】
――――――――――――――――――――――――――――――――――――――――
バンプ形状長径と短径の比電極上の有効粒子数
（μｍ）（Ｌ／Ｄ）（個／５０μｍφ）
――――――――――――――――――――――――――――――――――――――――
実施例６５０×５０１．０２４（２２〜２７）
実施例７２０×１００５．０１６２（１４１〜１８２）
実施例８２０×２００１０．０２４５（２２８〜２５３）
――――――――――――――――――――――――――――――――――――――――
【００３１】
実施例９
実施例１と同様であるが、ＩＣチップ接続面のバンプを形成しなかった。すなわち、Ａｌ配線の必要部にパッドが形成され、パッド以外は厚み１μｍの絶縁層（この場合ＳｉＯ₂ ）で覆われた凹状電極の半導体チップであり、図８の構成である。この場合、半導体チップに導電性接着層側を仮接続した。本実施例では実施例１と同様に良好な接続特性を示し、チップ類への突出電極が形成不要であり、極めて経済的であった。
【００３２】
実施例１０
実施例２の接続部材と同様であるが、導電粒子の粒子径を７μｍとし導電性接着層厚みを７μｍとした。また絶縁性接着層の厚みを片側２５μｍ、他の面を５０μｍに形成した。電極は、ＱＦＰ形ＩＣのリード（厚み１００μｍ、ピッチ３００μｍ、電極幅３５０μｍ、接続幅３０００μｍ、Ｌ／Ｄ＝８．６）であり、ガラスエポキシ基板上の銅の厚み３５μｍの端子と接続した。本構成は図７類似であるが、ＩＣのリード側（片側）に基板のない構成である。本実施例は、高さの大きな電極同士の接続であるが、電極ずれがなく良好な接続特性を示した。導電性シート中の導電粒子は図示していないが、粒子は圧縮変形され上下電極と接触保持されていた。隣接電極間に気泡混入がなく、良好な長期信頼性を示した。本実施例では、基板のない部分もリード高さに沿って接着層が形成され、リードを固定できた。電極上の有効粒子数は、全電極において１０個以上の確保が可能であった。
【００３３】
実施例１１〜１２
実施例１と同様であるが、ガラス基板上に５個のＩＣチップを搭載できる基板に変更し、加熱加圧工程を２段階とした。まず、１５０℃、２０ｋｇｆ／ｍｍ^２で、２秒後に加圧しながら各接続点の接続抵抗をマルチメータで測定検査した（実施例１１）。同様であるが他の一方は、１５０℃、２０ｋｇｆ／ｍｍ^２、３秒後に接続装置から除去した。加熱加圧により接着剤の凝集力が向上したので、各ＩＣチップは、ガラス側に仮固定が可能で無加圧で同様に検査（実施例１２）した。両実施例ともに１個のＩＣチップが異常であった。そこで異常チップを剥離して新規チップで前記同様の接続を行ったところ、いずれも良好であった。両実施例ともに接着剤は硬化反応の不十分な状態なので、チップの剥離や、その後のアセトンを用いた清浄化も極めて簡単であり、リペア作業が容易であった。以上の通電検査工程およびリペア工程の後で、１５０℃、２０ｋｇｆ／ｍｍ^２、１５秒で接続したところ、両実施例ともに良好な接続特性を示した。バンプ上の有効粒子数は、全電極において１９個以上の確保が可能であった。本実施例では実施例１に比べバンプ上の有効粒子数が増加し、電極上からの流出が少ない。加熱加圧工程を２段階としたので、粒子の保持性がさらに向上したと見られる。
【００３４】
実施例１３
実施例１の接続部材と同様であるが、導電粒子を表面に凹凸有するカルボニルニッケル（平均粒径３μｍ）とし、添加量４体積％、導電性接着層の厚みを５μｍに変更した。また絶縁性接着層をカルボキシル変性ＳＥＢＳ（スチレン−エチレン−ブチレン−スチレンブロック共重合体）とマイクロカプセル型潜在性硬化剤を含有する液状エポキシ樹脂（エポキシ当量１８５）の比率を２０／８０とし、厚み１５μｍのシートを前記と同様に作製し、前記導電性接着層面とラミネートした。同様に測定した１５０℃における粘度は１００ポイズであった。したがって導電性接着層と絶縁性接着層との粘度の差は２０ポイズである。
実施例１と同様に評価したところ、電極に導電粒子の先端が食い込んでおり、電極上の有効粒子数は、１００個以上が確保できた。接続抵抗、絶縁抵抗、長期信頼性ともに良好あった。本実施例では、導電性接着層と絶縁性接着層とで、高分子成分を変えたので接着後に、絶縁性接着層側の面から綺麗に剥離可能であった。このことは、リペア作業の容易さを意味する。導電性接着層と絶縁性接着層とのＴＭＡ（熱機械分析）による引っ張り法で求めたＴｇ（ガラス転移点）は、前者が１２５℃、後者が１００℃であった。これはリペア作業において剥離温度を高温とした場合、接着層の耐熱性の差を利用して剥離可能であり、凝集力の差を設け易いことから剥離作業に有効である。
【００３５】
実施例１４〜１６
実施例１の接続部材と同様であるが、絶縁粒子として実施例１の導電性粒子の核体であるポリスチレン系粒子を１体積％、導電性接着層（実施例１４）、絶縁性接着層（実施例１５）、および両層（実施例１６）にそれぞれ混合分散した。実施例１と同様に評価したところ、接続抵抗、絶縁抵抗、長期信頼性ともに良好であった。絶縁粒子の添加量が少ないので、各実施例で流動性に対する影響は見られなかった。実施例１４では、導電粒子の間に絶縁粒子が分散され導電性接着層のみの異方導電性の分解能向上に有効であった。実施例１５は、絶縁性接着層の絶縁性保持に有効で、実施例１６は、実施例１４〜１５の両者の特徴を有していた。実施例１４と１６の絶縁粒子は、電極間で導電粒子と同様に変形保持された。
【００３６】
実施例１７
実施例１の接続部材と同様であるが、導電粒子の表面を絶縁被覆処理を行った。すなわち、平均粒径４μｍの導電粒子の表面を、ガラス転移点１２７℃のナイロン樹脂で厚み約０．２μｍ被覆し、添加量を１５体積％に増加した。実施例１と同様に評価したが、良好な接続特性を示した。本実施例では、電極上の粒子数が著しく増加した。電極接続部は、接続時の熱圧による絶縁層およびバインダの軟化により導通可能であるが、隣接電極列のスペース部は熱圧が少なく導電粒子の表面が絶縁層で被覆されたままなので、絶縁性も良好であった。バンプ上の有効粒子数は、全電極で３０個以上の確保が可能であった。本構成では、導電粒子のバインダに対する濃度を高密度に構成できた。
【００３７】
【発明の効果】
以上詳述したように本発明によれば、バインダ成分の接続時の溶融粘度が相対的に絶縁性の接着層に比べて同等以下であることから、電極上からの流出が少ない。したがって、高分解能かつ接続信頼性に優れた接続部材およびこれを用いた電極の接続構造並びに接続方法が提供できる。
【図面の簡単な説明】
【図１】本発明の接続部材を示す断面模式図。
【図２】本発明の他の接続部材を示す断面模式図。
【図３】本発明における導電性接着層を示す断面模式図。
【図４】本発明における接着剤層の溶融粘度を示す線図。
【図５】本発明における接続過程を示す説明図（ａ）（ｂ）。
【図６】本発明の接続部材を用いた電極の接続構造例を示す断面模式図。
【図７】本発明の接続部材を用いた電極の接続構造例を示す断面模式図。
【図８】本発明の接続部材を用いた電極の接続構造例を示す断面模式図。
【図９】本発明の接続部材を用いた電極の接続構造例を示す断面模式図。
【符号の説明】
１導電性接着層
２絶縁性接着層
３導電粒子
４バインダ
５セパレータ
１１チップ基板
１２突出電極
１３基板
１４平面電極
１５周囲
１６凹状電極
１７頂部
１８絶縁層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection member that bonds and fixes an electronic component such as a semiconductor chip and a circuit board and electrically connects both electrodes, and an electrode connection structure and a connection method using the connection member.
[0002]
[Prior art]
In recent years, with the miniaturization and thinning of electronic components, circuits used for these have become denser and higher definition. Since it is difficult to connect such electronic components and fine electrodes with conventional solders or rubber connectors, anisotropically conductive adhesives and membranes with excellent resolution (hereinafter referred to as connecting members) Is frequently used.
This connecting member is made of an adhesive containing a predetermined amount of a conductive material such as conductive particles, and this connecting member is provided between the electronic component and the electrode or circuit to form a pressurizing or heating / pressing means. As a result, the electrodes are electrically connected to each other, and the electrodes formed adjacent to the electrodes are provided with insulating properties so that the electronic component and the circuit are bonded and fixed.
The basic idea for increasing the resolution of the connecting member is to ensure the insulation between the adjacent electrodes by making the particle size of the conductive particles smaller than the insulating portion between the adjacent electrodes. The amount is set so that the particles do not come into contact with each other and is surely present on the electrode to obtain conductivity at the connection portion.
[0003]
[Problems to be solved by the invention]
In the conventional method, when the particle size of the conductive particles is reduced, the particles are secondarily agglomerated due to a significant increase in the particle surface area, and the insulation between the adjacent electrodes cannot be maintained. In addition, if the content of the conductive particles is reduced, the number of conductive particles on the electrodes to be connected also decreases, so the number of contact points is insufficient and conduction between the connection electrodes cannot be obtained. It has been extremely difficult to increase the resolution of the connecting member. In other words, due to the recent significant increase in resolution, that is, the electrode area and the miniaturization between adjacent electrodes (spaces), the conductive particles on the electrodes flow out between the adjacent electrodes together with the adhesive by the pressurization or heating and pressurization at the time of connection, This hinders high resolution of the connecting member.
At this time, in order to suppress the outflow of the adhesive, if the adhesive has a high viscosity, the contact between the electrode and the conductive particles becomes insufficient, and it becomes impossible to connect the opposing electrodes. On the other hand, if the adhesive has a low viscosity, in addition to the outflow of the conductive particles, there is a drawback in that bubbles are likely to be included in the space portion and connection reliability, particularly moisture resistance is lowered.
[0004]
Therefore, a connection member having a multilayer structure in which the conductive particle-containing layer and the insulating adhesive layer are separated from each other, and the viscosity at the time of connecting the conductive particle-containing layer is relatively higher than that of the insulating adhesive layer or higher cohesive force. Thus, attempts to hold the conductive particles on the electrode by making the conductive particles difficult to flow can be seen in, for example, Japanese Patent Application Laid-Open Nos. 61-195179 and 4-366630. However, since the conductive particle-containing layer has a higher viscosity than the insulating adhesive layer at the time of connection, the contact between the electrode and the conductive particles becomes insufficient, and the connection resistance value is high, so the connection reliability is unsatisfactory. . In addition, in order to reduce the connection resistance value, if conductive particles are exposed in advance from the conductive particle-containing layer to facilitate contact with the electrode, it is necessary to increase the particle size of the conductive particles, which corresponds to higher resolution. Can not.
In addition, there is also a proposal of a connection member having a conductive particle dense region in a necessary part in both directions as a connection member capable of connecting such fine electrodes and circuits and having excellent connection reliability. According to this, although a dot-shaped fine electrode such as a semiconductor chip can be connected, there is a disadvantage that the precise alignment between the conductive particle dense region and the dot-shaped electrode is necessary and the workability is inferior.
[0005]
The present invention has been made in view of the above-described drawbacks, and since the conductive particles are difficult to flow out from the electrode when connected, it can be held on the electrode, and contact between the electrode and the conductive particle can be easily obtained. The present invention relates to a high-resolution connection member useful for connecting semiconductor chips, which is excellent in connection reliability for a long time because it is difficult to include, and does not require accurate alignment between conductive particles and electrodes.
That is, according to our study (detailed in the Examples section below), regarding the retention of the conductive particles on the electrode after connection, the configuration of the multilayer connection member and the ratio of the major axis to the minor axis of the electrode connection surface It was found that there was a very characteristic fact in (L / D), and the present invention was reached.
[0006]
[Means for Solving the Problems]
A first aspect of the present invention is a multilayer connection member in which an insulating adhesive layer is formed on at least one surface of an adhesive layer having conductivity in a pressurizing direction composed of a conductive material and a binder. the melt viscosity of 1000 poises low 0.1 poise compared with a by and insulating adhesive layer 500 poises, major and the ratio of the minor axis of the connecting electrode surface of the semiconductor chip (L / D) is 20 or less The present invention relates to a connection member for semiconductor chips. According to a second aspect of the present invention, there is provided a connection structure between electrode rows in which at least one of the opposed electrode rows protrudes, wherein the conductive material exists between the opposed electrodes, and the insulating adhesive layer is a protruding electrode. In particular, the present invention relates to an electrode structure that covers at least the periphery of the substrate. According to a third aspect of the present invention, at least one of the electrodes has a protruding electrode, and the connecting member is disposed so that the insulating adhesive layer of the connecting member is on the protruding electrode side. The present invention relates to a method for connecting electrodes, characterized in that heat-pressing is performed under a condition in which a melt viscosity at the time of connection with an adhesive layer is relatively lower than that of an insulating adhesive layer. Further, according to a fourth aspect of the present invention, in the connection method in which the insulating adhesive layer is disposed on the protruding electrode side and heated and pressed, the heating and pressing step is divided into two or more stages, and the connection electrode is energized between them. The present invention relates to a method for connecting electrodes, wherein an inspection step and / or a repair step are performed as necessary.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a connecting member for explaining an embodiment of the present invention. The connection member of the present invention is a multilayer connection member in which an insulating adhesive layer 2 is formed on at least one surface of a conductive adhesive layer 1 having conductivity in a pressurizing direction composed of conductive particles and a binder. As shown in FIG. 2, the insulating adhesive layer 2 may be formed on both surfaces of the conductive adhesive layer 1. Although not shown in FIGS. 1-2, you may add functions, such as adhesiveness, to the insulating contact bonding layer 2 as a multilayer structure further. In order to prevent unnecessary adhesion such as stickiness and dust on these surfaces, a peelable separator 5 as shown in FIG. 1 can be present as required. Although not shown, the separator 5 can be formed on both sides. In the case of FIG. 1, since the separator 5 is in contact with the insulating adhesive layer 2, for example, when temporary bonding is performed when the substrate on one side is a flat electrode, the conductive adhesive layer in which the separator 5 does not exist on the flat electrode side with less unevenness. Since 1 can be formed, the connection is easy and the workability is good and convenient. In these cases, the continuous tape shape is preferable because continuous automation of the connection work process can be achieved.
[0008]
FIG. 3 is a schematic cross-sectional view illustrating the conductive adhesive layer 1 having conductivity in the pressing direction. The conductive adhesive layer 1 is composed of a binder 4 containing

conductive particles

3. Here, the conductive particles 3 shown in FIGS. 3A to 3G are applicable. Among these, the

conductive particles

3 may have a particle size that can exist in a single layer in the thickness direction of the binder 4 as shown in FIGS. 3C to 3E, that is, a particle size substantially equal to the thickness of the binder 4 .

conductive particles

3 on the electrode is preferably easily held to the conductive particles 3 hardly flow at the time of connection. When the conductive particles 3 are substantially equal to the thickness of the binder 4, the

conductive particles

3 can be electrically connected to the electrode by simple contact, and the conductivity is easily obtained. The ratio of the

conductive particles

3 to the binder 4 is preferably about 0.1 to 20% by volume, more preferably 1 to 15% by volume, because anisotropic conductivity is easily obtained. In order to easily obtain conductivity in the thickness direction and achieve high resolution, the thickness of the binder 4 is preferably as thin as possible within the range in which a film can be formed, and is preferably 20 μm or less, more preferably 10 μm or less. For example, the

conductive particles

3 are preferably formed of conductive particles as illustrated in FIGS. 3A to 3E because the production is relatively easy. Further, the

conductive particles

3 may be provided with a through-hole in the binder 4 as shown in FIG. 3 (f) to form a conductor by plating or the like, or may be in the form of conductive fibers such as wires as shown in FIG. 3 (g). .
[0009]
Examples of the conductive particles include metal particles such as Au, Ag, Pt, Ni, Cu, W, Sb, Sn, and solder, carbon, and the like. These conductive particles are used as a core material, or non-conductive glass, A core material made of a polymer such as ceramics or plastic may be coated with a conductive layer made of the above-described material. Furthermore, insulating coated particles obtained by coating the conductive particles 3 with an insulating layer, or the combined use of conductive particles and insulating particles such as glass, ceramics, and plastics can be applied because the resolution is improved. In order to secure one or more particles, preferably as many particles as possible, on a minute electrode, a small particle size of 15 μm or less is suitable, and more preferably 7 μm or less and 1 μm or more. If it is 1 μm or less, it is difficult to break through the insulating adhesive layer and contact the electrode. Further, it is preferable that the conductive particles 3 have a uniform particle diameter because there is little outflow from between the electrodes. Among these conductive particles, those in which a conductive layer is formed on a polymer core material such as plastic, and hot-melt metal such as solder are deformable by heating or pressurization, and contact with the circuit at the time of connection This is preferable because the area is increased and the reliability is improved. In particular, when a polymer is used as a nucleus, it does not show a melting point like solder, so that the softening state can be widely controlled by the connection temperature, and it is easy to cope with variations in electrode thickness and flatness, which is particularly preferable. Also, for example, in the case of hard metal particles such as Ni and W, or particles having a large number of protrusions on the surface, the conductive particles pierce the electrode and the wiring pattern, so that even when an oxide film or a contaminated layer exists, a low connection resistance is obtained. It is preferable because it is obtained and reliability is improved.
[0010]
For the binder 4 and the insulating adhesive layer 2, a thermoplastic material or a material that exhibits curability by heat or light can be widely applied. These are preferably highly adhesive.
Among these, application of a curable material is preferable because of excellent heat resistance and moisture resistance after connection. Among these, an epoxy adhesive is particularly preferable because it can be cured for a short time, has good connection workability, and has excellent molecular adhesion.
Epoxy adhesives are mainly composed of epoxy modified with high molecular weight epoxy, solid epoxy and liquid epoxy, urethane, polyester, acrylic rubber, NBR, silicone, nylon, etc., curing agent, catalyst, coupling agent, filling A material obtained by adding an agent or the like is generally used.
When the binder component 4 and the insulating adhesive layer 2 of the present invention contain 1% or more, preferably 5% or more of a common material in each component, the interfacial adhesive force between the two layers is improved, which is suitable. As the common material, a main material, a curing agent, and the like are more effective.
[0011]
In the present invention, the melt viscosity at the time of connecting the binder component is equal to or less than that of the insulating adhesive layer. This point will be described with reference to FIGS.
FIG. 4 is a schematic explanatory diagram showing the melt viscosity during heating of the binder component 4 and the insulating adhesive layer 2. In the present application, the binder component 4 (A) is relatively equal to or less than that of the insulating adhesive layer 2 (B) at the temperature at the time of connection, and preferably the difference in viscosity between (A) and (B) at this time Is about 0.1 to 1000 poise, more preferably 1 to 200 poise. If the difference in viscosity is too large, the contact between the electrode and the particles tends to be insufficient. As will be described later with reference to FIG. 5, there is a preferable viscosity range in order to hold the particles on the electrode and to effectively obtain the contact between the electrode and the particle from the balance between the contact at the time of connection and the flow process. For the same reason, the melt viscosity at the time of connection is preferably such that the binder component is 500 poise or less, and at this time, the insulating adhesive layer is more preferably 1000 poise or less.
[0012]
In the contact process shown in FIG. 5 (a), first, the

conductive particles

3 are embedded in the insulating adhesive layer 2 having a relatively high melt viscosity or are partially captured, and the

conductive particles

3 are positioned. Retained. Next, in the flow process of FIG. 5B, the

conductive particles

3 come into contact with the protruding electrodes 12 by the softening of the insulating adhesive layer, and can conduct electricity with the planar electrodes 14 . In a preferred embodiment in which the melt viscosity at the time of binder component connection is lower than that of the insulating adhesive layer, the insulating adhesive layer 2 is capable of holding the

conductive particles

3 and bubbles between adjacent protruding electrodes. It can be connected in the state without. In this case, in order to promote softening of the insulating adhesive layer 2, the insulating adhesive layer of the connecting member is disposed on the protruding electrode side, a heat source is disposed on the insulating adhesive layer side, and heating and pressing are further performed. preferable. At this time, it is also possible to divide the heating and pressurizing process into two or more stages and to make an electrode connection method including an energization inspection process and / or a repair process as necessary. By decomposing the heating and pressurizing step into two or more steps, it is possible to control the viscosity of the flow process associated with the curing reaction of the adhesive, and therefore, a good connection without bubbles is possible. In addition, it is possible to impart repairability, which is a problem with curable adhesives.
[0013]
The energization inspection step can be performed while increasing the cohesive force of the connection member to the extent that the connection electrode can be held, or while pressurizing the electrode connection portion. Passing Denken査is, for example, be by measurement or operation test of the connection resistance extraction leads from the electrodes. At this time, the appearance inspection of the contact state between the

conductive particles

3 and the electrodes can also be performed together or independently. Repairability is to remove unnecessary part of the adhesive, clean it with a solvent, and reconnect. In general, a curable adhesive has been regarded as a problem because a network structure develops after curing, becomes insoluble and infusible with heat, solvent, and the like, and is extremely difficult to clean. In the first stage of the heating and pressurizing process, for example, the

conductive particles

3 are in contact with the protruding electrodes 12, and an energization inspection of both electrodes is performed in a state where the

conductive particles

3 can conduct with the planar electrode 14 . At this time, if there is a connection portion of a defective electrode, repair and reconnection are performed in this state. Since the adhesive is uncured or has an insufficient curing reaction, it is easy to peel off and soak in a solvent, and repair work is easy.
[0014]
The method for measuring the melt viscosity is not particularly limited as long as the binder component 4 and the insulating adhesive layer 2 can be relatively compared with each other. However, it is preferable to use the same method, for example, a general method capable of measuring at high temperatures. A rotary viscometer can be used. At this time, in the case of, for example, thermosetting blending in which the reaction proceeds at the time of measurement and the viscosity changes, the measured value in the model blending with the curing agent removed can be adopted. As a method of providing a difference in melt viscosity at the time of connection between the binder component 4 and the insulating adhesive layer 2, a combination of the intrinsic viscosity depending on the molecular weight of the material and the entanglement of the molecules, selection of a filler as a thickener, and curing Control of the difference in reaction rate in the system is common. As production method of the connection member of the present invention includes, for example, a conductive adhesive layer 1, or laminating the insulating adhesive layer 2, can methods employed, such as sequentially coating laminated.
[0015]
An electrode connection structure using the connection member of the present invention and a manufacturing method thereof will be described with reference to FIGS. FIG. 6 shows a structure in which the protruding electrode 12 formed on the chip substrate 11 and the planar electrode 14 of the substrate 13 are connected via the connecting member of the present invention. That is, it is a connection structure between electrode rows in which at least one of the oppositely facing electrode rows protrudes, and the

conductive particles

3 exist between the oppositely facing electrodes 12-14 and are more conductive than the periphery 15 of the protruding electrode 12. There is a high density of particles , and the electrode rows facing each other are connected. The insulating adhesive layer 2 covers at least the periphery 15 of the protruding electrode 12 protruding. Here, the planar electrode 14 refers to a case where there is no unevenness from the surface of the substrate 13 or even a few μm or less. When these are illustrated, the electrodes obtained by the additive method and the thin film method are typical.
[0016]
FIG. 7 shows a case where the electrodes formed on the substrate are the protruding

electrodes

12 and 12 ′. That is, it is a structure in which both surfaces shown in FIG. 2 are connected via a connecting member having insulating

adhesive layers

2 and 2 ′. The insulating

adhesive layers

2 and 2 ′ cover the periphery of the protruding

electrodes

12 and 12 ′, respectively, and are in contact with the chip substrate surface 11 and the substrate surface 13.
FIG. 8 shows the case where the electrodes formed on the substrate are the protruding electrode 12 and the concave electrode 16. In this case as well, the concave electrode 16 can be replaced with the planar electrode 14 shown in FIG. Here, as an example of the concave electrode 16, there is, for example, an Al pad before the protruding electrode (bump) of the semiconductor chip is formed, and an unnecessary portion is covered with the insulating layer 18. The insulating layer 18 is made of silica, silicon nitride, polyimide or the like, and generally has a thickness of several μm. In the case of FIG. 8, it is not necessary to form protruding electrodes on the chips, and the cost can be reduced.
[0017]
6 to 8 show the case where the conductive adhesive layer 1 and the insulating adhesive layer 2 form a boundary, the two layers may be mixed, and the protruding electrode 12 as shown in FIG. A configuration in which the density of the

conductive particles

3 is gradually decreased from the top portion 17 to the substrate 11 side may be employed. 6 to 8, the chip substrate 11 includes semiconductors such as silicon, gallium arsenide, gallium phosphorus, crystal, sapphire, garnet, and ferrite. Examples of the substrate 13 include plastic films such as polyimide and polyester, composites such as glass fiber / epoxy, semiconductors such as silicon, inorganic materials such as glass and ceramics, and the like. The protruding electrode 12 can include various circuits and terminals in addition to the bumps. The various electrodes shown in FIGS. 6 to 8 can be applied in any combination. Here, the protruding electrode 12 of the chip substrate 11 has a ratio of the major axis to the minor axis (L / D) of the connecting electrode surface of the semiconductor chip of 20 or less, and more preferably 1 to 10. This is because the retention property of the conductive particles on the electrode after connection using the connection member of the present invention is good within the above range of L / D.
[0018]
Regarding the retention of conductive particles on the electrode after connection, the reason for the existence of extremely characteristic facts in the structure of the multilayer connection member and the ratio of the major axis to minor axis (L / D) of the electrode connection surface is sufficient. Although not clarified, it is considered to be an influence of the directionality and heat transfer when the adhesive flows.
The electrode connecting method using the connecting member of the present invention is arranged so that the insulating adhesive layer 2 of the connecting member is on the protruding electrode 12 side, and the melt viscosity at the time of connecting the binder component and the insulating adhesive layer. However, it is heated and pressurized under a condition in which the binder component is relatively lower than the insulating adhesive layer.
[0019]
[Action]
According to the present invention, since the melt viscosity at the time of connecting the binder component is 500 poises or less, which is equal to or less than that of the insulating adhesive layer, the

conductive particles

3 of the conductive adhesive layer 1 are connected when the electrodes are connected. The

conductive particles

3 are held on the protruding electrodes 12 by being embedded in the insulating adhesive layer 2 having a relatively equal or higher melt viscosity or in contact with a part of the insulating layer 2 being captured. Next, the

conductive particles

3 come into contact with the protruding electrodes 12 and become conductive by the softening flow of the insulating adhesive layer. At this time, the insulating adhesive layer 2 has a higher viscosity than the binder component 4, can hold the

conductive particles

3, and can connect the space portion between adjacent protruding electrodes without bubbles. According to the present invention, when the ratio of the major axis to the minor axis (L / D) of the connecting electrode surface of the semiconductor chip or the like is 20 or less, many

conductive particles

3 are reliably held on the minute protruding electrode 12. Therefore, the connection reliability is high, and expensive conductive particles can be efficiently applied, which saves resources.
[0020]
According to the present invention, since the

conductive particles

3 are reliably held on the protruding electrodes 12 and can be conducted, the reliability of the conduction test is improved. Since the adhesive can be inspected for continuity in an uncured state or in an insufficient curing reaction, the repair work is easy. Since the insulating adhesive layer 2 is disposed so as to be on the protruding electrode 12 side, the insulation and resolution between adjacent electrodes are improved. In addition, when the insulating adhesive layer 2 has a high melt viscosity, no connection pressure is applied, so that the

conductive particles

3 are less likely to flow between adjacent electrodes. Since the conductive particles 3 of the conductive adhesive layer 1 are uniformly dispersed on the entire surface, it is excellent in workability because accurate alignment between the conductive particles and the electrodes is unnecessary. Depending on the purpose of the adhesive layer, for example, a combination that exhibits adhesion suitable for the material of the electrode substrate is possible, so that the choice of materials is expanded, and the connection reliability is also improved due to the reduction of bubbles in the connection portion. Further, by making one of them soluble or swellable in a solvent or having a difference in heat resistance, it is possible to preferentially peel off from one substrate surface and to impart so-called repair property for reconnection. Alternatively it is also possible to any combination of conforms to the material of the electrode substrate, the contact is likely to give the electrodes and the conductive particles, method is simple. Further, it is possible to obtain a reinforcing or moisture-proof effect by causing the adhesive layer to protrude outside the connecting portion and acting as a sealing material.
[0021]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.
Example 1
(1) Preparation of conductive adhesive layer 30/70 solution of ethyl acetate with a ratio of liquid epoxy resin (epoxy equivalent 185) containing phenoxy resin (high molecular weight epoxy resin) and microcapsule type latent curing agent as 30/70 Got. To this solution, the particle size 4 thickness 0.2 / 0.02 [mu] m conductive particles children forming a metal coating of Ni / Au on the polystyrene particles ± 0.2 [mu] m was added 8% by volume, were mixed and dispersed. This dispersion was applied to a separator (silicone-treated polyethylene terephthalate film, thickness 40 μm) with a roll coater and dried at 110 ° C. for 20 minutes to obtain a conductive adhesive layer having a thickness of 5 μm. The viscosity of the model blend from which the curing agent of the adhesive layer was removed was measured with a digital viscometer HV-8 (manufactured by Reska Co., Ltd.). The viscosity at 150 ° C. was 80 poise.
[0022]
(2) the blending ratio of Preparation (1) of the connecting member and forming the insulating adhesive layer to remove the conductive particles children from the conductive adhesive layer and 40/60, in the same manner as said thickness 15μm sheet (1) Produced. First, the conductive adhesive layer surface (1) and the adhesive layer surface (2) were laminated while being rolled between rubber rolls. Thus, a multilayer connection member having a thickness of 20 μm in the two-layer configuration of FIG. 1 was obtained. The viscosity at 150 ° C. of the insulating adhesive layer measured in the same manner as described above was 280 poise. Therefore, the difference in viscosity between the conductive adhesive layer and the insulating adhesive layer at 150 ° C. is 200 poise.
[0023]
(3) Connection Evaluation IC chip (silicon substrate, 2 × 12 mm, height 0.5 mm, 300 gold electrodes of 50 μmφ called 20 μm height called bumps are formed on the two long sides) and glass 1.1 mm A flat electrode having a thin film circuit with an indium oxide thickness of 0.2 μm (ITO, surface resistance 20Ω / □) was connected to the upper surface. The ITO electrode on the glass side was made to correspond to the bump electrode size of the IC chip, and a measurement lead was drawn around. The connecting member was cut into 2.5 × 14 mm slightly larger than the size of the IC chip, and temporarily connected such that the conductive adhesive layer was on the flat electrode side. In addition to the smoothness of the substrate, it was easy to attach due to the adhesiveness of the connecting member, and the subsequent peeling of the separator was also easy. Next, the bump of the IC chip and the planar electrode were aligned, and heated and pressed at 150 ° C., 30 kgf / mm ² for 15 seconds to obtain a connection body. At this time, the heat source of the connecting device was disposed on the insulating adhesive layer side, and the conductive adhesive layer was disposed on the planar electrode side.
[0024]
(4) Evaluation When the cross section of this connection body was polished and observed with a microscope, it was a connection structure corresponding to FIG. The space between adjacent electrodes was free of bubbles and the particles were spherical, but the particles were compressed and deformed on the electrodes and held in contact with the upper and lower electrodes. As a result of evaluating the connection resistance between the electrodes facing each other as the insulation resistance between the adjacent electrodes, the connection resistance was 1Ω or less and the insulation resistance was 10 ¹⁰ Ω or more, which changed even after treatment at 85 ° C. and 85% RH for 1000 hours. No long-term reliability was observed. The number of effective average particles contributing to the connection on the electrode (50 μmφ = 1962.5 μm ² ) in this example was 20 (maximum 23 particles, minimum 18 particles, and so on). The effective particles contributing to the connection were observed by observing the connection surface from the glass side with a microscope (× 100) and having gloss due to contact with the electrode. Since L / D is 50 μmφ (diameter), it is 1.0. In this example, the particles on the bumps were compressed and deformed and held in contact with the upper and lower electrodes. Air bubbles were not mixed between adjacent bumps, and good long-term reliability was demonstrated. The conductive particles had different degrees of deformation of the particles depending on the variation in the distance between the electrodes facing each other, and some of the conductive particles bite into the bumps, and good connection was obtained for all the electrodes.
[0025]
Comparative Example 1
Although it was the same as that of Example 1, a single-layer conductive adhesive layer having a conventional structure with a thickness of 20 μm was obtained. When evaluated in the same manner as in Example 1, the number of particles on the electrode (50 μmφ) was 13 at the maximum and 0 at the minimum, and there were no effective particles on the electrode, and the maximum and the minimum as compared with Example 1. The variation of was large. Further, when the insulation resistance of the connection body was measured, a short circuit defect occurred. It seems that the conductive particles flowed out from the electrodes at the time of connection, and the insulation between adjacent electrodes (space portions) cannot be maintained.
[0026]
Example 2
Similarly, an insulating adhesive layer was formed on the other surface of the conductive adhesive layer of Example 1 to obtain a multi-layer connecting member having a three-layer structure shown in FIG. Moreover, it replaced with the glass plane electrode of Example 1, and was set as the 2 layer FPC circuit board which has a 18 micrometers high copper circuit on a polyimide film. Connections were made in the same manner as in Example 1 to obtain a connection body corresponding to FIG.
When evaluated in the same manner as in Example 1, good connection characteristics were shown. The number of effective particles on the electrodes can be secured to 10 or more in all the electrodes regardless of the configuration in which the particles easily flow out because of the connection between the protruding electrodes.
[0026]
Examples 3-5 and Comparative Examples 2-3
Although it is the same as that of Example 1, the difference in the viscosity at 150 ° C. of both layers was changed by changing the blending ratio of the phenoxy resin and the liquid epoxy resin of the insulating adhesive layer. The results are shown in Table 1 together with Example 1 described above. In each example, the number of effective particles on the electrode was large and the variation was relatively small, and good connection characteristics were exhibited as in Example 1.
In Comparative Example 2, since the difference in viscosity was too large, the conductive particles could not be exposed from the insulating adhesive layer, and no effective particles were seen on the electrode, and connection was impossible.
Comparative Example 3 is a conventionally known two-layer structure in which the structure of the connecting member is reversed from that of Example 1. However, the number of effective particles is small and there is no effective particle on the electrode. Compared to 1, the maximum and minimum variations were large.
[0027]
[Table 1]

[0028]
Comparative Examples 4-5
The FPC circuit boards of Example 2 were connected as parallel electrode connections (electrode width D = 50 μm, connection width L = 1500 μm, L / D = 30).
Comparative Example 4 is a connection using the connection member of Example 1, but the number of effective particles on the electrode converted to 50 μmφ was 9 (0 to 16), which was 1/2 or less compared to Example 1.
Comparative Example 5 is a connection using the connection member of Comparative Example 3, but the number of effective particles was 18 (14 to 24), which was improved as compared with Comparative Example 3.
From these results, the optimum configuration of the connecting member differs between the connection of parallel electrodes such as a circuit board having a large L / D and the case of dot-shaped electrodes having a small L / D such as a semiconductor chip electrode. I understood. Although the reason for this is unknown, it is considered that the heat transfer property at the time of connection and the flow of the adhesive change due to the influence of L / D.
[0029]
Examples 6-8
Although it is the same as that of Example 1, the bump shape of the IC chip connection surface was changed.
The long diameter of the bump was directed to the center of the IC chip. The results are shown in Table 2.
In each example of L / D = 1 to 10, the number of effective particles on the electrode was large and the variation was relatively small, and good connection characteristics were shown as in Example 1.
[0030]
[Table 2]
――――――――――――――――――――――――――――――――――――――――
Bump shape Ratio of major axis to minor axis Number of effective particles on electrode
(Μm) (L / D) (pieces / 50μmφ)
――――――――――――――――――――――――――――――――――――――――
Example 6 50x50 1.0 24 (22-27)
Example 7 20 × 100 5.0 162 (141-182)
Example 8 20x200 10.0 245 (228-253)
――――――――――――――――――――――――――――――――――――――――
[0031]
Example 9
Similar to Example 1, but no bumps on the IC chip connection surface were formed. In other words, the semiconductor chip is a concave electrode in which a pad is formed in a necessary portion of the Al wiring, and other than the pad is covered with an insulating layer having a thickness of 1 μm (in this case, SiO ₂ ), and has the configuration of FIG. In this case, the conductive adhesive layer side was temporarily connected to the semiconductor chip. In this example, good connection characteristics were exhibited as in Example 1, and it was not necessary to form protruding electrodes on the chips, which was extremely economical.
[0032]
Example 10
It is similar to the connecting member of Example 2, but the particle diameter of the conductive particles child and 7 [mu] m conductive adhesive layer thickness was set to 7 [mu] m. The thickness of the insulating adhesive layer was 25 μm on one side and 50 μm on the other side. The electrodes were QFP type IC leads (thickness: 100 μm, pitch: 300 μm, electrode width: 350 μm, connection width: 3000 μm, L / D = 8.6), and were connected to a copper terminal having a thickness of 35 μm on the glass epoxy substrate. This configuration is similar to that shown in FIG. 7, but has no substrate on the lead side (one side) of the IC. In this example, the electrodes were connected to each other with a large height, but there was no electrode displacement and good connection characteristics were shown. Although the conductive particles in the conductive sheet are not shown, the particles were compressed and deformed and held in contact with the upper and lower electrodes. Air bubbles were not mixed between adjacent electrodes, and good long-term reliability was demonstrated. In this example, the adhesive layer was formed along the lead height even in the portion without the substrate, and the lead could be fixed. The number of effective particles on the electrode could be 10 or more for all electrodes.
[0033]
Examples 11-12
Although it is the same as that of Example 1, it changed into the board | substrate which can mount five IC chips on a glass substrate, and made the heating-pressing process into two steps. First, the connection resistance at each connection point was measured and inspected with a multimeter while applying pressure after 2 seconds at 150 ° C. and 20 kgf / mm ² (Example 11). Similar but the other was removed from the connecting device after 150 seconds at 20 ° C. and 20 kgf / mm ² . Since the cohesive force of the adhesive was improved by heating and pressing, each IC chip could be temporarily fixed on the glass side and similarly tested without pressure (Example 12). In both examples, one IC chip was abnormal. Therefore, when the abnormal chip was peeled off and the same connection as described above was performed with a new chip, both were good. In both examples, since the adhesive was in a state where the curing reaction was insufficient, peeling of the chip and subsequent cleaning with acetone were extremely simple, and repair work was easy. After the above energization inspection process and repair process, when connected at 150 ° C., 20 kgf / mm ² for 15 seconds, both examples showed good connection characteristics. The number of effective particles on the bumps could be 19 or more for all the electrodes. In the present embodiment, the number of effective particles on the bumps is increased and the outflow from the electrodes is less than that in the first embodiment. Since the heating and pressurizing process is in two stages, it is considered that the retention of particles is further improved.
[0034]
Example 13
Although it is the same as that of the connection member of Example 1, carbonyl nickel (average particle diameter of 3 μm) having conductive particles on the surface was used, the addition amount was 4% by volume, and the thickness of the conductive adhesive layer was changed to 5 μm. The insulating adhesive layer has a thickness of 20/80 as the ratio of carboxyl-modified SEBS (styrene-ethylene-butylene-styrene block copolymer) and a liquid epoxy resin (epoxy equivalent 185) containing a microcapsule type latent curing agent. A 15 μm sheet was prepared in the same manner as described above, and laminated with the conductive adhesive layer surface. Similarly, the viscosity at 150 ° C. was 100 poise. Therefore, the difference in viscosity between the conductive adhesive layer and the insulating adhesive layer is 20 poise.
As a result of evaluation in the same manner as in Example 1, the tip of the conductive particles bite into the electrode, and the number of effective particles on the electrode was 100 or more. Good connection resistance, insulation resistance, and long-term reliability. In this example, since the polymer component was changed between the conductive adhesive layer and the insulating adhesive layer, it could be cleanly peeled off from the surface on the insulating adhesive layer side after bonding. This means the ease of repair work. The Tg (glass transition point) determined by the TMA (thermomechanical analysis) tensile method between the conductive adhesive layer and the insulating adhesive layer was 125 ° C. for the former and 100 ° C. for the latter. This is effective for the peeling work because it can be peeled off using the difference in heat resistance of the adhesive layer when the peeling temperature is set high in the repair work, and it is easy to provide a difference in cohesive force.
[0035]
Examples 14-16
Although it is the same as the connection member of Example 1, 1 volume% of the polystyrene-type particle | grains which are the cores of the electroconductive particle of Example 1 as an insulating particle, a conductive adhesive layer (Example 14), an insulating adhesive layer ( Example 15) and both layers (Example 16) were mixed and dispersed. When evaluated in the same manner as in Example 1, the connection resistance, insulation resistance, and long-term reliability were all good. Since the addition amount of the insulating particles was small, no influence on the fluidity was observed in each example. In Example 14, insulating particles between the conductive particles child was enabled resolution enhancement of the anisotropic conductive only dispersed conductive adhesive layer. Example 15 was effective in maintaining the insulating property of the insulating adhesive layer, and Example 16 had the characteristics of both Examples 14-15. The insulating particles of Examples 14 and 16 were deformed and held between the electrodes in the same manner as the conductive particles.
[0036]
Example 17
Although it is the same as that of the connection member of Example 1, the surface of the conductive particles was subjected to an insulation coating treatment. That is, the surface of conductive particles having an average particle diameter of 4 μm was covered with a nylon resin having a glass transition point of 127 ° C. to a thickness of about 0.2 μm, and the amount added was increased to 15% by volume. Evaluation was performed in the same manner as in Example 1, but good connection characteristics were exhibited. In this example, the number of particles on the electrode increased significantly. The electrode connection part can be conducted by softening the insulating layer and binder due to the thermal pressure at the time of connection, but the space part of the adjacent electrode row has little heat pressure and the surface of the conductive particles remains covered with the insulating layer. The property was also good. The number of effective particles on the bump could be 30 or more for all electrodes. In this structure, the density | concentration with respect to the binder of an electrically-conductive particle was able to be comprised with high density.
[0037]
【The invention's effect】
As described above in detail, according to the present invention, since the melt viscosity at the time of connecting the binder component is relatively equal to or less than that of the insulating adhesive layer, there is little outflow from the electrode. Therefore, it is possible to provide a connection member with high resolution and excellent connection reliability, an electrode connection structure and a connection method using the connection member.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a connecting member of the present invention.
FIG. 2 is a schematic cross-sectional view showing another connection member of the present invention.
FIG. 3 is a schematic cross-sectional view showing a conductive adhesive layer in the present invention.
FIG. 4 is a diagram showing the melt viscosity of the adhesive layer in the present invention.
FIGS. 5A and 5B are explanatory diagrams showing a connection process in the present invention.
FIG. 6 is a schematic cross-sectional view showing an example of an electrode connection structure using the connection member of the present invention.
FIG. 7 is a schematic cross-sectional view showing an example of an electrode connection structure using the connection member of the present invention.
FIG. 8 is a schematic cross-sectional view showing an example of an electrode connection structure using the connection member of the present invention.
FIG. 9 is a schematic cross-sectional view showing an example of an electrode connection structure using the connection member of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Conductive adhesive layer 2 Insulating adhesive layer 3

Conductive particle

4 Binder 5 Separator 11 Chip substrate 12 Projecting electrode 13 Substrate 14 Planar electrode 15 Perimeter 16 Concave electrode 17 Top 18 Insulating layer

Claims

A multilayer connection member in which an insulating adhesive layer is formed on at least one side of an adhesive layer having conductivity in the pressurizing direction composed of a conductive material and a binder, and has a melt viscosity of 500 poise or less when connecting the binder component a and and 1000 poises lower from 0.1 poise compared with the insulating adhesive layer in the semiconductor chip major and the ratio of the minor axis of the connecting electrode surface of the semiconductor chip (L / D) is equal to or greater than 20 Connecting member.

The connecting member according to claim 1, wherein the binder component and the insulating adhesive layer contain a common material.

The connecting member according to claim 1, wherein the binder component and the insulating adhesive layer have a difference in adhesiveness.

The connecting member according to claim 1, wherein the binder component and / or the insulating adhesive layer contains insulating particles.

The connecting member according to claim 1, wherein the conductive material is formed by forming an insulating coating on the surface of the conductive particles or the conductive particles.

The connecting member according to claim 1, wherein the separator is in contact with the insulating adhesive layer.

A connection structure between electrode rows in which at least one of the opposing electrode rows protrudes, wherein the conductive material according to claim 1 exists between the opposing electrodes, and an insulating adhesive layer is at least the substrate of the protruding electrode An electrode connection structure characterized by covering the periphery of the side.

8. The electrode connection structure according to claim 7, wherein the density of the conductive material is gradually reduced from the top of the protruding electrode to the substrate side.

Connection structure according to claim 7 or claim 8, wherein the effective electrode number of particles on the electrode is 10 or more / diameter 50μm in all the electrodes.

The insulating member of the connecting member according to claim 1 is arranged between the opposing electrode rows having at least one protruding electrode so that the insulating adhesive layer is on the protruding electrode side, and the binder component and the insulating adhesive layer A method for connecting electrodes, characterized by heating and pressurizing under conditions where the binder component is relatively low compared to the insulating adhesive layer having a melt viscosity at the time of connection.

The electrode connection method according to claim 10 , wherein a heat source is disposed on the insulating adhesive layer side and heated and pressurized.

In the connection method in which the insulating adhesive layer of the connection member according to claim 1 is disposed so as to be on the protruding electrode side between the opposing electrode rows having at least one protruding electrode, An electrode connection method, wherein the pressure process is divided into two or more stages, and a connection electrode energization inspection process and / or a repair process are performed as needed.

The electrode connection method according to claim 12 , wherein an energization test is performed by increasing the cohesive force of the connection member to such an extent that the connection electrode can be held.

The electrode connection method according to claim 13 , wherein an energization inspection is performed while pressing the electrode connection portion.