JP4092978B2

JP4092978B2 - Water repellent treatment agent, water repellent treatment method, and electronic component mounting body manufacturing method

Info

Publication number: JP4092978B2
Application number: JP2002229833A
Authority: JP
Inventors: 禎一稲田; 圭二住谷
Original assignee: Hitachi Chemical Co Ltd; Showa Denko Materials Co Ltd; Resonac Corp
Current assignee: Resonac Corp
Priority date: 2001-08-07
Filing date: 2002-08-07
Publication date: 2008-05-28
Anticipated expiration: 2022-08-07
Also published as: JP2003119457A

Description

【０００１】
【発明の属する技術分野】
本発明は、撥水処理剤、撥水処理方法及び電子部品実装体の製造方法に関する。
【０００２】
【従来の技術】
固体表面の水に対する濡れ性の尺度として水との接触角があり、接触角が大きいものは撥水性が大きいと言われる。特に、接触角が１５０°以上になるものを超撥水性と呼ばれ、高い撥水性や滑水性を持つため、防汚性等の機能を有する。
撥水処理としては、従来、フッ素樹脂等の非極性の樹脂を被覆することや、メッキ処理、表面エッチング等の方法によって表面の凹凸を形成することが知られている。しかし、非極性樹脂を被覆したものは、表面の汚染等により効果が低下する等の問題があり、また、表面形状を凹凸に加工したものは、その凹部に汚染物質が入り込む等により、表面の汚染が除去しにくい等の問題があった。さらに、撥水処理した面から撥水処理剤を除去することは難しく、必要な工程においてのみ撥水処理を施すのは困難であった。
【０００３】
【発明が解決しようとする課題】
電子部品を実装基板に搭載して実装体を得る方法として、液状またはペースト状の導電性接着剤を実装基板に塗布してその上に電子部品を実装することが行われてきた。電子部品実装体が小型化されるに伴って、該接着剤を塗布するパターンも細密化され、実装時における電子部品と実装基板との位置合わせの精度の向上が要求されている。
本発明者らは、接着剤が所定の部位に選択的にかつ容易に塗布されるように、予め実装基板の表面に選択的に撥水処理を施すことに着目し、さらに撥水処理剤および撥水処理方法について鋭意検討を重ねて本発明を完成させた。
【０００４】
すなわち、本発明は、上記問題点に鑑み、撥水性に優れ、除去が容易であり、複数回の撥水処理が可能な撥水処理剤を提供するものである。
また、本発明は、上記撥水処理剤により、耐久性に優れ、また、目的に応じて任意の部位のみ選択性良く容易に撥水性を付与する撥水処理方法を提供するものである。
【０００５】
さらに、本発明は、上記撥水処理剤を使用した撥水処理方法により、実装の位置合わせにおいて容易にセルフアライメントできる電子部品実装体の製造方法を提供するものである。
【０００６】
【課題を解決するための手段】
本発明は、平均粒径が１〜１００ｎｍの粒子を含有してなる撥水処理剤に関し、特に前記撥水処理剤が半導体素子等の電子部品用の実装基板の表面撥水化に用いられるのが好ましい。
また本発明は、上記撥水処理剤を該被処理面の全体または一部に付着させる撥水処理方法に関するものである。
【０００７】
さらに本発明は、実装基板の表面を処理する撥水処理工程と、該処理をした面に電子部品と実装基板との親水性接着剤を塗布する工程とを含む電子部品実装体の製造方法に関し、特に撥水処理工程は上記撥水処理方法によるのが好ましい。
電子部品として、例えば半導体素子、コンデンサ、抵抗等が挙げられ、実装基板として、例えば回路基板、多層基板やハイブリッドＩＣ等が挙げられる。
【０００８】
【発明の実施の形態】
本発明の撥水処理剤に使用する粒子の平均粒径は１ｎｍ以上１００ｎｍ以下である必要がある。平均粒径が１ｎｍ未満の場合、２次凝集が著しく、撥水効果が低下する。また１００ｎｍ超の場合、撥水の効果が減少するため好ましくない。
なお、平均粒径の表し方には数種類あるが、本発明においては、粒子をＳＥＭ（走査型電子顕微鏡）を用いて観察し、任意の１００個の粒子についてその最も長い径を測定し、その平均値を平均粒径とする。
【０００９】
本発明の撥水処理剤は、平均粒径が１〜１００ｎｍの粒子の単体であっても、上記粒子を樹脂組成物、溶剤、水等に分散させたものでも良い。粒子を樹脂組成物、溶剤、水等に分散させたものは、撥水処理剤塗布時に粒子の飛散による汚染がなく、撥水処理が容易に行える点で好ましい。
【００１０】
前記の溶剤としては、特に制限は無いが、メチルエチルケトン、アセトン、メチルイソブチルケトン、２−エトキシエタノール、トルエン、キシレン、ブチルセルソルブ、メタノール、エタノール、２−メトキシエタノール等比較的低沸点（およそ２００℃以下）の溶媒を使用するのが好ましい。また、ジメチルアセトアミド、ジメチルホルムアミド、Ｎ−メチルピロリドン、シクロヘキサノン等比較的高沸点の溶媒を加えることもできる。
【００１１】
粒子を分散させる前記樹脂組成物としてはエポキシ樹脂、シアネート樹脂、フェノール樹脂及びその硬化剤、アクリルゴム、アクリロニトリルブタジエンゴム、シリコーンゴム、ポリウレタン、ポリイミド、ポリアミドイミド等の高分子化合物、及びそれらの共重合物または混合物等が挙げられる。
特に、樹脂組成物が熱硬化性であると、撥水処理剤を被処理面へ塗布して加熱乾燥後に、溶剤等が付着した場合でも樹脂が溶解せず、塗膜表面の微細な凹凸形状を維持出来る点で好ましい。
【００１２】
撥水処理剤は平均粒径１〜１００ｎｍの粒子と樹脂組成物と溶剤とを含むのが好ましく、さらに前記粒子７６〜９５重量部、樹脂組成物５〜３４重量部及び溶剤を含んだものが好ましい。このような系では、被処理面へ塗布した後、溶剤の乾燥により塗膜表面に生じる凹凸の強度が高いため、良好な撥水性を付与できる。特に、平均粒径１〜１００ｎｍの粒子７６〜８５重量部、樹脂組成物１５〜３４重量部の場合、接着性や塗膜の可とう性を維持したまま、撥水性を付与できる点でより好ましい。溶剤の量は、撥水処理剤の取り扱いやすさ、溶剤の揮発性等を考慮して適宜選択できるが、粒子７６〜９５重量部、樹脂組成物５〜３４重量部の場合には、一般に５００〜４０００重量部が好ましい。
【００１３】
上記溶剤、樹脂組成物中に粒子を分散させた撥水処理剤の製造方法としては、粒子の分散性を考慮して、例えば、らいかい機、３本ロール、ボールミルまたはビーズミル等を使用して、撹拌、混練する方法等が挙げられる。これらの装置は単独で、または二種類以上を組み合わせて使用することができる。粒子を混合した後、真空脱気等によって、溶剤、ワニス中の気泡を除去することが好ましい。
【００１４】
粒子としては平均粒径が１〜１００ｎｍであれば有機粒子、無機粒子共に、特に制限が無く用いることができ、例えば、フィラーとして通常使用されるものを用いることができる。
【００１５】
無機粒子としては、例えば、水酸化アルミニウム、水酸化マグネシウム、炭酸カルシウム、炭酸マグネシウム、ケイ酸カルシウム、ケイ酸マグネシウム、酸化カルシウム、酸化マグネシウム、酸化アルミニウム（アルミナ）、酸化チタン、酸化インジウム、酸化ジルコニウム、酸化銅、酸化ホルミウム、酸化ネオジウム、窒化アルミニウム、窒化ほう素等の金属塩粒子、金、銀、銅、アルミニウム等の金属粒子、結晶質シリカ、非晶質シリカ等のシリカ粒子等が挙げられ、中でも、各種シリカ粒子、アルミナ、酸化チタンが入手が容易である点で好ましい。これらは単独でまたは二種類以上を組み合わせて使用することができる。
【００１６】
有機粒子としては、例えば、各種ゴム粒子等が挙げられ、具体的には、アクリロニトリルブタジエンゴム粒子、シリコーンゴム粒子等が挙げられる。
【００１７】
また、上記粒子の形状としては、平均粒径が１〜１００ｎｍであれば特に制限はなく、球状（真球状でないものも含む。）、フレーク状、針状等種々公知のものを広く利用することができる。
【００１８】
上記無機粒子としては、例えば、シリカはシーアイ化成株式会社からナノテックＳｉＯ₂（接触角：４３度、平均粒径：１２ｎｍ）という商品名で、或いは日本アエロジル株式会社からアエロジルＲ９７２（平均粒径：１６ｎｍ）という商品名で市販されている。アルミナは、シーアイ化成株式会社からナノテックＡｌ₂Ｏ₃（接触角：５５度、平均粒径：３３ｎｍ）という商品名で市販されている。三酸化二アンチモンは日本精鉱株式会社からＰＡＴＯＸ−Ｕ（接触角：４３度、平均粒径：２０ｍｍ）という商品名で市販されている。
【００１９】
本発明において使用する粒子は、水との接触角が１００°以上であることが好ましい。水との接触角が１００度未満の場合、撥水効果が減少する傾向がある。なお、本明細書において、接触角とは粒子の水との接触角を指し、例えば、以下の方法で測定することができる。
【００２０】
粒子をハンドプレス（理研精機株式会社製、モデルＮｏ：Ｐ−１６Ｂ−０２８）を用いて、成形圧力：４００ｋｇｆ／ｃｍ²で３分間圧縮して成形し、大きさ：１３ｍｍφ、厚さ１〜５ｍｍ平板を作製する。その上に水滴（０．００５〜０．０３ｇ）を滴下し、その水滴が平板と接触する角度を接触角計で測定する。接触角の値は、この測定を１０回行い、その平均値を採用する。
【００２１】
水との接触角が１００°以上である粒子としては、例えば、表面に有機物を被覆したシリカ粒子等が挙げられる。表面に有機物を被覆したシリカ粒子は、例えば、シリカ表面にジメチルジクロロシランをコートし、４００℃の反応器中で加水分解させ、メチル基等からなる有機物の表面処理を行う等して得ることができ、具体的には、日本アエロジル株式会社製のＲ９７２（接触角１５０°、平均粒径：１６ｎｍ）、Ｒ２０２（接触角１３０°、平均粒径：１４ｎｍ）、Ｒ８１２（接触角１５０°、平均粒径：７ｎｍ）、Ｒ９７４（接触角１４０°、平均粒径：１２ｎｍ）、ＲＹ２００（接触角１３０°平均粒径：７ｎｍ）等が挙げられる。粒子表面を被覆する有機物としては、上記のようなシラン化合物の他に、フッ素化合物を使用することができる。
【００２２】
本発明の撥水処理剤は、以下の撥水処理方法により、被処理面の全体に付着させることも、また、被処理面の一部に付着させて位置選択的に撥水処理を施すことも可能である。本発明の撥水処理剤の使用には、特に制限はなく、平均粒径が１〜１００ｎｍの粒子をそのまま撥水処理剤として使用する場合は、例えば、刷毛、へら、布等を用いて被処理面に直接塗布する方法等が挙げられる。また、粒子を溶剤、ワニス等に分散させて使用する場合は、被処理面に撥水処理剤を塗布したのち溶剤を乾燥させる方法等が挙げられる。
【００２３】
具体的な塗布方法としては、例えば、刷毛、へら、布を用いて塗布する方法、塗工、印刷、スプレー、浸せき等の手段により均一に塗布する方法等が挙げられる。上記の塗工の方式としては、例えば、ナイフコータ、コンマロールコータ、リバースロールコータ、キスコータ、カレンダーコータ、グラビアロールコータ、ロッドコータ等の通常使用される全面に均一に塗布する塗工方式等が挙げられる。また、上記の印刷の方式としては、例えば、凸版、平版、グラビア、スクリーン印刷等が挙げられる。
また、上記方法以外にも、撥水処理剤をあらかじめ他のフィルムや布等に塗布または含浸させたものを被処理面に接触させることもできる。これらの使用方法は、撥水処理剤の使用量、被処理面の面積、特性等に応じて自由に選択することができる。
【００２４】
本発明の撥水処理剤は、使用する粒子によっては、被処理面に過剰に付着すると、表面の透明性や平滑性が失われることがあるため、これらの特性を維持したい場合には、過剰に塗布された撥水処理剤を除去することが好ましい。
【００２５】
上記除去方法としては、例えば、刷毛、ヘラ、布等を用いて余分な粒子を除去する方法等が挙げられる。さらに、本発明の撥水処理剤は除去が容易であるため、上記以外の方法でも、例えば、水、溶剤等を吹き付ける方法、空気、窒素ガス等で吹き飛ばす方法等の、被撥水処理面にキズ、変形等の衝撃を与えない方法で除去することができる。
【００２６】
被処理面における粒子の付着量は１ｍｍ四方あたり１０個以上であることが好ましい。１０個未満の場合、撥水性が劣る傾向がある。なお、粒子の付着量は、例えば以下の（１）〜（３）の方法等を用いて算出することができる。
（１）：走査型電子顕微鏡（ＳＥＭ）で用いた粒子の平均粒径の１００倍の長さを１辺とする正方形の面積Ａ（ｍｍ²）を有する場所を設定する。
（２）：その正方形中にある粒子の数Ｂを測定する。
（３）：Ｂ／Ａを算出する。
（４）：（１）〜（３）を５回繰り返し、得られたＢ／Ａの平均値を粒子の付着量とする。
【００２７】
本発明の撥水処理剤を使用する被処理面は、固体状のものとしては、例えば、金属、セラミックス、ガラス、プラスチックスが挙げられる。上記プラスチックスとしては、例えば、ポリテトラフルオロエチレンフィルム、ポリエチレンテレフタレートフィルム、ポリエチレンフィルム、ポリプロピレンフィルム、ポリメチルペンテンフィルム、ポリイミドフィルム等のプラスチックフィルムを使用することができ、これらプラスチックフィルムは表面を予め離型処理して使用することもできる。
【００２８】
また、上記被処理面は凹凸を有するものであってもよい。このような被処理面としては、例えば、半導体等の電子部品を搭載する実装基板等の表面の他、印刷原板の表面、塗料を塗布した表面が挙げられる。また、上記被処理面はゲル状物、粘性の高い液体等であってもよい。他に、被処理面として、紙、繊維、布、不織布、ゴム、皮、皮膚等にも使用できる。
【００２９】
実装基板としては、具体的には、アルミナ基板、窒化アルミ基板等のセラミック基板、ガラスクロスにエポキシ樹脂組成物を含浸させたＦＲ−４基板、ビスマレイミド−トリアジン樹脂組成物を含漬させたＢＴ基板、ポリイミドフィルムを基材として用いたポリイミドフィルム基板等の有機基板等が例示される。
【００３０】
本発明の撥水処理剤は、一旦被処理面に施した後、撥水処理が不要な部分の撥水処理剤を除去するのが容易である。これにより、例えば、凹凸を有する被処理面の凹部にのみ撥水処理を施したい場合に特に好適に使用することができる。このような場合として、例えば、配線基板の凹部にのみ撥水処理剤を付着させる撥水処理方法等が挙げられる。上記配線基板上は、通常、配線が凸部で、基板が凹部になっている。このような凹凸を有する被処理面の凹部にのみ撥水処理を行う場合には、例えば、全面に撥水処理剤を塗布した後、凸部の配線上の撥水処理剤のみを平板等で掻き取って除去することで、凹部のみ撥水処理が施される。次いで、親水性材料を該被処理面の全面に塗布すれば、撥水処理剤が除去された凸部の配線上のみに、選択的に親水性材料が付着する。
【００３１】
撥水処理剤を掻き取る用具は平板の他、平板状のスキージに濾紙を巻き付けたものが挙げられる。また、被処理面が平面であっても、塗布の際に例えばスクリーン状のパターンを介したり、塗布後に掻き取って剥離させたりすることにより、所望の位置のみに微細かつ精度良く撥水処理を施すことができる。
【００３２】
以下、図面に沿って、本発明の撥水処理方法の実施態様の一例を説明する。図１（Ｉ）〜（IV）は、実装基板上の所望の部位に銀接着剤を塗布する工程を順に示す断面模式図である。図１（Ｉ）に示すように、回路用銅パターン１を設けた基材フィルム（ポリイミド製フレキシブル基板）２を用意し、図１（II）に示すように、該基材フィルム２上に本発明の撥水処理剤３を塗布する。６０℃１０分程度で乾燥した後、平板を銅パターン１上に密着させ数回往復させると、図１（III）に示すように銅パターン１上の撥水処理剤３は除去され、銅パターン間の凹部のみ撥水処理剤３の粒子が残存する。
次いで、親水性材料として、銀接着剤４を全面に塗布し、６０℃１０分間乾燥すると、図１（IV）に示すように撥水処理剤が除去された銅パターン上にのみ銀接着剤４が付着することとなる。
一方、上記と同種の基材フィルム２上に上記撥水処理剤３を塗布せず、銀接着剤４を全面に塗布し、乾燥すると、銀接着剤４は基材フィルム上全面に分散する。図３に全面に分散した状態の断面模式図を示す。
【００３３】
次に、本発明の電子部品実装体の製造方法について説明する。本発明の電子部品実装体の製造方法は、実装基板の表面を処理する撥水処理工程と、該撥水処理をした面に電子部品と実装基板との親水性接着剤を塗布する塗布工程とを含むものである。該撥水処理工程の後、例えば、図１（IV）の回路上に銀接着剤４を塗布し、次いで乾燥、回路上に電子部品を設置、銀接着剤を１７０℃で１時間熱硬化することにより固定して電子部品実装体を製造することができる。ここで、撥水処理される被処理面は実装基板の表面、すなわち図１でいうフレキシブル基板の表面であり、電子部品と実装基板との接着剤は親水性であって、図１でいう銀接着剤に相当する。
【００３４】
本発明の電子部品実装体の製造方法においては、特に上記本発明の撥水処理方法により実装基板表面を処理した撥水処理工程の後に、実装基板上に塗布された、電子部品と実装基板との接着剤は、撥水処理されていないか、もしくは撥水処理剤を剥離した、実装基板上の所望の特定の部分のみに精密に局在させることができる。よって、電子部品を接着剤に接触させると、銀接着剤の表面張力により電子部品を容易にセルフアライメントすることができ、電子部品を実装基板に対して精度良く位置合わせ配置できる。さらに、撥水処理された実装基板表面は防汚性が付与されるため、実装体の製造工程中の汚染による不良品発生が低減される。
【００３５】
親水性接着剤としては、例えば、半導体素子とリードフレームマウント部との接着に使用される銀接着剤４が挙げられ、具体的には、ポリビニルアルコール１０重量部に、銀フレーク（徳力化学株式会社製、製品名ＴＣ−２０Ｅ）４０重量部を撹拌混合して得られた銀接着剤が例示される。
【００３６】
【実施例】
以下において本発明を実施例に基き更に詳しく説明するが、本発明はこれらに限定されるものではない。
（実施例１〜８）
下記の被処理面１〜３を作製した。
（被処理面１）ガラス板に両面紙粘着テープ（コクヨ株式会社製、商品名Ｔ−２２５）を貼り、離型紙を取り除き、粘着面が表面に露出するようにした。
（被処理面２）銅箔（古河電工株式会社製ＧＴＳ−３５）の粗化面。
（被処理面３）印刷紙（株式会社ＮＢＳリコー製中性紙マイペーパー９０−１３１１）を用いた。
上記で得た被処理面１〜３に、下記の撥水処理剤試料および撥水処理方法１〜４を、表１に示すように組み合わせて処理サンプル１〜８をそれぞれ作製し、水との接触角を測定した（実施例１〜８）。水との接触角の値を表１に併記する。
【００３７】
（撥水処理剤試料および撥水処理方法１）メチル基等からなる有機物の表面処理を行った粒子として、日本アエロジル株式会社製の製品名Ｒ９７２（シラン化合物被覆シリカ、接触角１５０°、平均粒径：１６ｎｍ）１ｇをＭＥＫ１００ｇ中に添加し、１０分間、攪拌モータで攪拌し、真空脱泡して撥水処理剤試料（１）を作製した。被処理面に撥水処理剤試料（１）を刷毛で塗布後、６０℃で１０分間乾燥した。
（撥水処理剤試料および撥水処理方法２）日本アエロジル株式会社製の製品名Ｒ９７２（接触角１５０°、平均粒径：１６ｎｍ）をそのまま撥水処理剤試料（２）として、被処理面に刷毛で塗布後、風速２０ｍ／分のファンで過剰な粒子を除去した。
（撥水処理剤試料および撥水処理方法３）日本アエロジル株式会社製の製品名Ｒ２０２（シラン化合物被覆シリカ、接触角１３０°、平均粒径：１４ｎｍ）１ｇをＭＥＫ１００ｇ、アクリルゴム０．２ｇ中に添加し、１０分間、攪拌モータで攪拌し、真空脱泡して撥水処理剤試料（３）を作製した。撥水処理剤試料（３）を被処理面に刷毛で塗布後、６０℃で１０分間乾燥した。
（撥水処理剤試料および撥水処理方法４）
日本アエロジル株式会社製の製品名Ｒ９７２（接触角１５０°、平均粒径：１６ｎｍ）１５ｇをＭＥＫ３００ｇ、エポキシ樹脂組成物（硬化剤、硬化促進剤を含む）２ｇに添加し、ビーズミルで１０分間攪拌した後、ビーズを除去及び真空脱泡して撥水処理剤試料（４）を作製した。被処理面２に撥水処理剤試料（４）をコータで塗布後、１７０℃で３０分間乾燥した。
ここで、上記エポキシ樹脂組成物は、
ビスフェノールＡ型エポキシ樹脂（ジャパンエポキシレジン株式会社製の製品名エピコート８２８）４０重量部、
硬化剤（大日本インキ化学工業株式会社製の製品名ＬＦ２８８２）２３重量部、硬化促進剤（１−シアノエチル−２−フェニルイミダゾール、四国化成工業株式会社製の製品名２ＰＺ−ＣＮ）０．４重量部とした。
【００３８】
（比較例１〜３）被処理面１〜３に撥水処理剤試料を塗布しなかった以外は実施例１、２および５と同様にして処理サンプル９〜１１を作製し、水との接触角を実施例と同様に測定した。水との接触角を表１に併記する。
【００３９】
【表１】

【００４０】
処理サンプル１〜８はいずれも水との接触角が大きく、被処理面を水平から３０度傾けると、水は落下し、被処理面に残らなかった。
【００４１】
（実施例９、１０：撥水処理剤除去後の接触角）
処理サンプル２、３の撥水処理面をＭＥＫ中で１０分間超音波洗浄した。超音波洗浄前後の、水との接触角の変化を表２に示す。
表２から、洗浄により、容易に撥水処理剤を除去することができ、以上から、接着、表面処理等を必要に応じて選択して容易に実施できることがわかった。
【００４２】
【表２】

【００４３】
（実施例１１）
図１（Ｉ）に示すように、実装基板として、４００μｍ間隔で２００μｍ幅、厚さ３５μｍの銅パターン（銅箔回路）１を設けた基材フィルム（ポリイミド製フレキシブル基板）２を用意した。図１（II）に示すように、該基材フィルム２上に撥水処理剤３として上記で調製した撥水処理剤試料（１）を塗布した。６０℃１０分乾燥した後、平板上のスキージに濾紙を巻き付けたものを回路上に密着させ３回往復させたところ、図１（III）に示すように回路上の撥水処理剤３は除去され、銅パターン１間の凹部のみ撥水処理剤３の粒子が残存していた。次いで、水に水溶性ポリマと銀フレークを分散させた銀接着剤４（ポリビニルアルコール１０重量部に、銀フレーク（徳力化学株式会社製、製品名ＴＣ−２０Ｅ）４０重量部を撹拌混合して得られた銀接着剤）を全面に塗布し、６０℃１０分間乾燥したところ、図１（IV）に示すように銅パターン１上にのみ銀接着剤４が付着していた。
【００４４】
（比較例４）
実施例１１で用いたのと同じ基材フィルム２上に上記撥水処理剤３を塗布せずに銀接着剤４を全面に塗布し、６０℃１０分間乾燥した。
【００４５】
図３に示すように、比較例４では銀接着剤４は全面に分散していたのに対して、実施例１１では、図１（IV）に示すように銅パターン１上にのみ分布していた。
【００４６】
（実施例１２）
図２（Ｉ）〜（Ｖ）に、本実施例により、銀接着剤で半導体素子と基材フィルムとを接着する工程の断面模式図を順に示した。図２（I）に示すように、実装基板として、４００μｍ間隔で直径２００μｍ、厚さ３５μｍの銅箔のパッド６を設けた基材フィルム（ポリイミド製フレキシブル基板）５を用意した。該基板上に撥水処理剤３として上記で調製した撥水処理剤試料（１）を塗布し、６０℃１０分乾燥した後に、実施例１１と同様にして、図２（II）に示すように銅パターン上の撥水処理剤３を除去した。その後、実施例１１で用いたものと同じ銀接着剤７を全面に塗布したところ、図２（III）に示すように、銀接着剤７はパッド６上にのみ分布していた。
【００４７】
この基材フィルム５のパッド６上に、図２（IV）に示すように、半導体素子８のパッド９とを位置合わせした。位置合わせ時にはパッド６、９同士の中心間に５０μｍのずれがあった。そのまま、半導体素子８を下方に移動させ、図２（Ｖ）に示すように、銀接着剤７が両方のパッド６、９に接するようにした。半導体素子８を図示しない位置合わせ装置から離して基材フィルム５上に載せたところ、パッドの中心間のずれは３μｍであった。この半導体素子を載せた基材フィルムを６０℃１０分間乾燥したところ、パッドの中心間のずれは３μｍのままであった。
【００４８】
【発明の効果】
本発明の撥水処理剤は、水との接触角が大きく、被処理面を傾けると、水は落下し、被処理面に残らないため、汚染が少ない等の利点を有する。洗浄により、容易に撥水性を除去することが可能であり、必要に応じて接着、表面処理等を容易に行うことができる。
また、本発明の撥水処理方法によれば、全面に親水性材料を塗布するだけで、所定の位置に親水性材料が印刷される。
さらに、本発明の電子部品実装体の製造方法によれば、通常の接着剤のスクリーン印刷で使用される、スクリーン作製及び位置あわせの必要がなく、位置ずれもないため、実装基板の製造工程上、有益である。さらに、半導体チップ等の電子部品が実装時にセルフアライメントされ、位置ずれを精度良く修正できるので、実装体の製造工程が簡略化され、有益である。
【図面の簡単な説明】
【図１】（Ｉ）〜（IV）は、本発明により、実装基板上の所望の部位に銀接着剤を塗布する工程を順に示す断面模式図である。
【図２】（Ｉ）〜（Ｖ）は、本発明により、銀接着剤で半導体素子と基材フィルムとを接着する工程を順に示す断面模式図である。
【図３】本発明の撥水処理を施さない実装基板上に銀接着剤を塗布し、乾燥した状態の一例を示す断面模式図である。
【符号の説明】
１銅パターン２、５基材フィルム（実装基板）
３撥水処理剤４、７銀接着剤
６、９パッド８半導体素子[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water repellent treatment agent, a water repellent treatment method, and a method for manufacturing an electronic component mounting body.
[0002]
[Prior art]
There is a contact angle with water as a measure of wettability with respect to water on a solid surface, and a material with a large contact angle is said to have high water repellency. In particular, those having a contact angle of 150 ° or more are called super water repellency, and have high water repellency and water slidability, and thus have functions such as antifouling properties.
Conventionally, as the water repellent treatment, it is known to coat a nonpolar resin such as a fluororesin, or to form surface irregularities by a method such as plating or surface etching. However, those coated with a non-polar resin have problems such as reduced effectiveness due to surface contamination, etc., and those whose surface shape has been processed into irregularities have surface contamination caused by contaminants entering the recesses. There were problems such as contamination being difficult to remove. Furthermore, it is difficult to remove the water repellent agent from the surface subjected to the water repellent treatment, and it is difficult to perform the water repellent treatment only in a necessary process.
[0003]
[Problems to be solved by the invention]
As a method for obtaining a mounting body by mounting an electronic component on a mounting substrate, a liquid or paste conductive adhesive is applied to the mounting substrate and the electronic component is mounted thereon. As the electronic component mounting body is miniaturized, the pattern to which the adhesive is applied becomes finer, and it is required to improve the alignment accuracy between the electronic component and the mounting substrate during mounting.
The inventors of the present invention focused on preliminarily performing a water-repellent treatment on the surface of the mounting substrate in advance so that the adhesive is selectively and easily applied to a predetermined site. The present invention was completed through extensive studies on the water repellent treatment method.
[0004]
That is, in view of the above problems, the present invention provides a water-repellent treatment agent that is excellent in water repellency, can be easily removed, and can be subjected to water-repellent treatment multiple times.
In addition, the present invention provides a water repellent treatment method that is excellent in durability and easily imparts water repellency only to an arbitrary site with good selectivity according to the purpose by the water repellent treatment agent.
[0005]
Furthermore, the present invention provides a method for manufacturing an electronic component mounting body that can be easily self-aligned in mounting alignment by the water repellent treatment method using the water repellent treatment agent.
[0006]
[Means for Solving the Problems]
The present invention relates to a water repellent treatment agent comprising particles having an average particle diameter of 1 to 100 nm, and in particular, the water repellent treatment agent is used for surface water repellency of a mounting substrate for an electronic component such as a semiconductor element. Is preferred.
The present invention also relates to a water repellent treatment method in which the water repellent treatment agent is attached to the whole or a part of the surface to be treated.
[0007]
Furthermore, the present invention relates to a method for producing an electronic component mounting body, which includes a water repellent treatment step for treating the surface of a mounting substrate, and a step of applying a hydrophilic adhesive between the electronic component and the mounting substrate to the treated surface. In particular, the water repellent treatment step is preferably performed by the above water repellent treatment method.
Examples of the electronic component include a semiconductor element, a capacitor, and a resistor. Examples of the mounting substrate include a circuit board, a multilayer board, and a hybrid IC.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The average particle size of the particles used in the water repellent treatment agent of the present invention needs to be 1 nm or more and 100 nm or less. When the average particle diameter is less than 1 nm, secondary aggregation is remarkable and the water repellent effect is lowered. On the other hand, if it exceeds 100 nm, the water repellent effect is reduced, which is not preferable.
Although there are several ways of expressing the average particle diameter, in the present invention, the particles are observed using an SEM (scanning electron microscope), and the longest diameter of any 100 particles is measured. Let the average value be the average particle size.
[0009]
The water repellent treatment agent of the present invention may be a single particle having an average particle diameter of 1 to 100 nm or may be a dispersion of the particle in a resin composition, a solvent, water or the like. Those in which the particles are dispersed in a resin composition, a solvent, water, or the like are preferable in that they are free from contamination due to scattering of particles when the water repellent treatment agent is applied, and the water repellent treatment can be easily performed.
[0010]
The solvent is not particularly limited, but has a relatively low boiling point (approximately 200 ° C.) such as methyl ethyl ketone, acetone, methyl isobutyl ketone, 2-ethoxyethanol, toluene, xylene, butyl cellosolve, methanol, ethanol, 2-methoxyethanol. The following solvents are preferably used. Further, a solvent having a relatively high boiling point such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, cyclohexanone can be added.
[0011]
Examples of the resin composition for dispersing particles include epoxy resins, cyanate resins, phenol resins and their curing agents, polymer compounds such as acrylic rubber, acrylonitrile butadiene rubber, silicone rubber, polyurethane, polyimide, polyamideimide, and copolymers thereof. Product or a mixture.
In particular, if the resin composition is thermosetting, the resin does not dissolve even when a solvent or the like adheres after applying a water-repellent treatment agent to the surface to be treated and drying by heating. Is preferable in that it can be maintained.
[0012]
The water repellent treatment agent preferably contains particles having an average particle diameter of 1 to 100 nm, a resin composition and a solvent, and further contains 76 to 95 parts by weight of the particles, 5 to 34 parts by weight of the resin composition and a solvent. preferable. In such a system, since the unevenness generated on the surface of the coating film by drying of the solvent after application to the surface to be processed is high, good water repellency can be imparted. In particular, in the case of 76 to 85 parts by weight of particles having an average particle diameter of 1 to 100 nm and 15 to 34 parts by weight of the resin composition, it is more preferable in terms of imparting water repellency while maintaining the adhesiveness and flexibility of the coating film. . The amount of the solvent can be appropriately selected in consideration of the ease of handling of the water repellent treatment agent, the volatility of the solvent, etc., but in the case of 76 to 95 parts by weight of the particles and 5 to 34 parts by weight of the resin composition, it is generally 500. -4000 parts by weight are preferred.
[0013]
As a method for producing a water-repellent treatment agent in which particles are dispersed in the solvent and the resin composition, in consideration of the dispersibility of the particles, for example, a rough machine, a three-roll, a ball mill or a bead mill is used. And a method of stirring and kneading. These apparatuses can be used alone or in combination of two or more. After mixing the particles, it is preferable to remove bubbles in the solvent and varnish by vacuum degassing or the like.
[0014]
As the particles, if the average particle diameter is 1 to 100 nm, both organic particles and inorganic particles can be used without any particular limitation. For example, those usually used as fillers can be used.
[0015]
Examples of the inorganic particles include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide (alumina), titanium oxide, indium oxide, zirconium oxide, Metal salt particles such as copper oxide, holmium oxide, neodymium oxide, aluminum nitride and boron nitride, metal particles such as gold, silver, copper and aluminum, silica particles such as crystalline silica and amorphous silica, etc. Among these, various silica particles, alumina, and titanium oxide are preferable because they are easily available. These can be used alone or in combination of two or more.
[0016]
Examples of the organic particles include various rubber particles, and specific examples include acrylonitrile butadiene rubber particles and silicone rubber particles.
[0017]
The shape of the particles is not particularly limited as long as the average particle size is 1 to 100 nm, and various known materials such as spherical (including non-spherical), flakes, and needles are widely used. Can do.
[0018]
As the inorganic particles, for example, silica is a product name of Nanotech SiO ₂ (contact angle: 43 degrees, average particle size: 12 nm) from C-I Kasei Co., Ltd., or Aerosil R972 (average particle size: 16 nm) from Nippon Aerosil Co., Ltd. ). Alumina is commercially available from CI Kasei Co., Ltd. under the trade name Nanotech Al ₂ O ₃ (contact angle: 55 degrees, average particle size: 33 nm). Antimony trioxide is commercially available from Nippon Seiko Co., Ltd. under the trade name PATOX-U (contact angle: 43 degrees, average particle size: 20 mm).
[0019]
The particles used in the present invention preferably have a contact angle with water of 100 ° or more. When the contact angle with water is less than 100 degrees, the water repellent effect tends to decrease. In addition, in this specification, a contact angle refers to the contact angle with water of particle | grains, for example, can be measured with the following method.
[0020]
Using a hand press (Model No .: P-16B-028, manufactured by Riken Seiki Co., Ltd.), the particles are molded by compression at a molding pressure of 400 kgf / cm ² for 3 minutes, size: 13 mmφ, thickness 1-5 mm A flat plate is produced. A water droplet (0.005 to 0.03 g) is dropped on it, and the angle at which the water droplet contacts the flat plate is measured with a contact angle meter. For the value of the contact angle, this measurement is performed 10 times, and the average value is adopted.
[0021]
Examples of the particles having a contact angle with water of 100 ° or more include silica particles having a surface coated with an organic substance. Silica particles coated with an organic substance on the surface can be obtained, for example, by coating dimethyldichlorosilane on the silica surface, hydrolyzing it in a reactor at 400 ° C., and performing a surface treatment of an organic substance consisting of a methyl group or the like. Specifically, R972 (contact angle 150 °, average particle size: 16 nm), R202 (contact angle 130 °, average particle size: 14 nm), R812 (contact angle 150 °, average particle) manufactured by Nippon Aerosil Co., Ltd. Diameter: 7 nm), R974 (contact angle 140 °, average particle size: 12 nm), RY200 (contact angle 130 ° average particle size: 7 nm), and the like. As the organic substance covering the particle surface, a fluorine compound can be used in addition to the silane compound as described above.
[0022]
The water repellent treatment agent of the present invention can be attached to the whole surface to be treated by the following water repellent treatment method, or can be attached to a part of the surface to be treated and subjected to position selective water repellent treatment. Is also possible. The use of the water-repellent treatment agent of the present invention is not particularly limited, and when particles having an average particle diameter of 1 to 100 nm are used as they are as the water-repellent treatment agent, for example, they are covered with a brush, a spatula, a cloth or the like. The method etc. which apply | coat directly to a process surface are mentioned. In the case of using the particles dispersed in a solvent, varnish or the like, there may be mentioned a method of drying the solvent after applying a water repellent treatment agent to the surface to be treated.
[0023]
Specific examples of the application method include a method of applying using a brush, a spatula, and a cloth, a method of applying uniformly by means of coating, printing, spraying, dipping, and the like. Examples of the coating method include, for example, a coating method that uniformly applies to the generally used surface of a knife coater, comma roll coater, reverse roll coater, kiss coater, calendar coater, gravure roll coater, rod coater, etc. It is done. Examples of the printing method include letterpress, planographic, gravure, and screen printing.
In addition to the above method, the surface to be treated can be brought into contact with a water repellent treatment agent previously applied or impregnated on another film or cloth. These usage methods can be freely selected according to the amount of the water repellent treatment agent used, the area of the surface to be treated, characteristics, and the like.
[0024]
Depending on the particles used, the water repellent treatment agent of the present invention may lose surface transparency and smoothness if it is excessively adhered to the surface to be treated. It is preferable to remove the water-repellent agent applied to the surface.
[0025]
Examples of the removal method include a method of removing excess particles using a brush, a spatula, a cloth, or the like. Furthermore, since the water-repellent treatment agent of the present invention is easy to remove, it can be applied to a water-repellent treated surface such as a method of spraying water, a solvent or the like, a method of blowing off with air, nitrogen gas, or the like. It can be removed by a method that does not give impacts such as scratches and deformation.
[0026]
The adhesion amount of particles on the surface to be treated is preferably 10 or more per 1 mm square. If it is less than 10, the water repellency tends to be inferior. In addition, the adhesion amount of particles can be calculated using, for example, the following methods (1) to (3).
(1): A place having a square area A (mm ² ) having a length of 100 times the average particle diameter of the particles used in the scanning electron microscope (SEM) as one side is set.
(2): The number B of particles in the square is measured.
(3): B / A is calculated.
(4): (1) to (3) are repeated 5 times, and the average value of the obtained B / A is defined as the amount of adhered particles.
[0027]
Examples of the surface to be treated using the water repellent treatment agent of the present invention include metals, ceramics, glass, and plastics. As the plastic, for example, a plastic film such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, or a polyimide film can be used. It can also be used after mold processing.
[0028]
Further, the surface to be processed may have unevenness. Examples of such a surface to be treated include the surface of a printing original plate and the surface to which a paint is applied, in addition to the surface of a mounting substrate or the like on which an electronic component such as a semiconductor is mounted. The surface to be treated may be a gel-like material, a highly viscous liquid, or the like. In addition, the surface to be treated can be used for paper, fiber, cloth, nonwoven fabric, rubber, leather, skin, and the like.
[0029]
Specifically, the mounting substrate is a ceramic substrate such as an alumina substrate or an aluminum nitride substrate, an FR-4 substrate in which a glass cloth is impregnated with an epoxy resin composition, or a BT in which a bismaleimide-triazine resin composition is impregnated. Examples of the substrate include organic substrates such as a polyimide film substrate using a polyimide film as a base material.
[0030]
The water-repellent treatment agent of the present invention is easy to remove the water-repellent treatment agent in a portion where the water-repellent treatment is unnecessary after once applied to the surface to be treated. Thereby, for example, it can be particularly preferably used when it is desired to perform water repellent treatment only on the concave portion of the surface to be processed having irregularities. Examples of such a case include a water repellent treatment method in which a water repellent treatment agent is attached only to the concave portion of the wiring board. On the wiring substrate, the wiring is usually a convex portion and the substrate is a concave portion. In the case where the water repellent treatment is performed only on the concave portion of the surface to be processed having such irregularities, for example, after applying the water repellent treatment agent to the entire surface, only the water repellent treatment agent on the wiring of the convex portion is applied with a flat plate or the like. By scraping and removing, only the recesses are subjected to water repellent treatment. Next, when a hydrophilic material is applied to the entire surface to be treated, the hydrophilic material selectively adheres only on the wiring of the convex portion from which the water repellent treatment agent has been removed.
[0031]
Examples of the tool for scraping off the water-repellent agent include a flat plate or a flat squeegee wound with filter paper. In addition, even if the surface to be treated is flat, water repellent treatment can be performed only at a desired position with fine and high accuracy by applying, for example, a screen-like pattern at the time of application or by scraping and peeling after application. Can be applied.
[0032]
Hereinafter, an example of an embodiment of the water repellent treatment method of the present invention will be described with reference to the drawings. 1 (I) to 1 (IV) are schematic cross-sectional views sequentially showing steps of applying a silver adhesive to a desired portion on a mounting substrate. As shown in FIG. 1 (I), a base film (polyimide flexible substrate) 2 provided with a circuit copper pattern 1 is prepared. As shown in FIG. The water repellent agent 3 of the invention is applied. After drying at 60 ° C. for about 10 minutes, when the flat plate is brought into close contact with the copper pattern 1 and reciprocated several times, the water repellent 3 on the copper pattern 1 is removed as shown in FIG. The particles of the water repellent agent 3 remain only in the recesses between them.
Next, when a silver adhesive 4 is applied to the entire surface as a hydrophilic material and dried at 60 ° C. for 10 minutes, the silver adhesive 4 only on the copper pattern from which the water repellent treatment agent has been removed as shown in FIG. 1 (IV). Will adhere.
On the other hand, when the water-repellent treatment agent 3 is not applied on the same type of base film 2 as described above, the silver adhesive 4 is applied to the entire surface and dried, whereby the silver adhesive 4 is dispersed on the entire surface of the base film. FIG. 3 shows a schematic cross-sectional view in a state of being dispersed over the entire surface.
[0033]
Next, the manufacturing method of the electronic component mounting body of this invention is demonstrated. The method for producing an electronic component mounting body according to the present invention includes a water repellent treatment step for treating the surface of the mounting substrate, and a coating step for applying a hydrophilic adhesive between the electronic component and the mounting substrate on the surface subjected to the water repellent treatment. Is included. After the water repellent treatment step, for example, the silver adhesive 4 is applied on the circuit of FIG. 1 (IV), then dried, the electronic component is placed on the circuit, and the silver adhesive is thermally cured at 170 ° C. for 1 hour. Thus, the electronic component mounting body can be manufactured by fixing. Here, the surface to be treated to be water repellent is the surface of the mounting substrate, that is, the surface of the flexible substrate as shown in FIG. 1, and the adhesive between the electronic component and the mounting substrate is hydrophilic, and the silver as shown in FIG. Corresponds to adhesive.
[0034]
In the manufacturing method of the electronic component mounting body of the present invention, the electronic component and the mounting substrate coated on the mounting substrate, particularly after the water repellent treatment step of treating the surface of the mounting substrate by the water repellent treatment method of the present invention. This adhesive can be precisely localized only at a desired specific portion on the mounting substrate that has not been subjected to the water repellent treatment or has been peeled off. Therefore, when the electronic component is brought into contact with the adhesive, the electronic component can be easily self-aligned by the surface tension of the silver adhesive, and the electronic component can be accurately aligned and arranged with respect to the mounting substrate. Furthermore, since the surface of the mounting substrate subjected to the water repellent treatment is imparted with antifouling properties, the occurrence of defective products due to contamination during the manufacturing process of the mounting body is reduced.
[0035]
Examples of the hydrophilic adhesive include a silver adhesive 4 used for bonding a semiconductor element and a lead frame mount, and specifically, 10 parts by weight of polyvinyl alcohol with silver flakes (Tokuriku Chemical Co., Ltd.). A silver adhesive obtained by stirring and mixing 40 parts by weight of manufactured product name TC-20E) is exemplified.
[0036]
【Example】
Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.
(Examples 1-8)
The following to-be-processed surfaces 1-3 were produced.
(Processed surface 1) A double-sided paper adhesive tape (trade name T-225, manufactured by KOKUYO Co., Ltd.) was attached to a glass plate, the release paper was removed, and the adhesive surface was exposed on the surface.
(Surface 2) A roughened surface of copper foil (GTS-35 manufactured by Furukawa Electric Co., Ltd.).
(Surface 3) Printing paper (NBS Ricoh Co., Ltd., neutral paper My Paper 90-1311) was used.
The treated surfaces 1 to 3 obtained above were combined with the following water-repellent treatment agent samples and water-repellent treatment methods 1 to 4 as shown in Table 1 to produce treated samples 1 to 8, respectively. The contact angle was measured (Examples 1-8). The values of the contact angle with water are also shown in Table 1.
[0037]
(Water-repellent treatment sample and water-repellent treatment method 1) As a particle subjected to surface treatment of an organic substance composed of a methyl group or the like, product name R972 (silica compound-coated silica, contact angle 150 °, average particle, manufactured by Nippon Aerosil Co., Ltd.) 1 g (diameter: 16 nm) was added to 100 g of MEK, stirred with a stirring motor for 10 minutes, and vacuum degassed to produce a water repellent sample (1). The water repellent sample (1) was applied to the surface to be treated with a brush, and then dried at 60 ° C. for 10 minutes.
(Water-repellent treatment sample and water-repellent treatment method 2) The product name R972 (contact angle 150 °, average particle size: 16 nm) manufactured by Nippon Aerosil Co., Ltd. was directly used as the water-repellent treatment sample (2) on the surface to be treated. After applying with a brush, excess particles were removed with a fan with a wind speed of 20 m / min.
(Water repellent treatment agent sample and water repellent treatment method 3) 1 g of product name R202 (silane compound-coated silica, contact angle 130 °, average particle size: 14 nm) manufactured by Nippon Aerosil Co., Ltd. in 100 g of MEK and 0.2 g of acrylic rubber The mixture was stirred for 10 minutes with a stirring motor and vacuum degassed to prepare a water repellent sample (3). The water repellent sample (3) was applied to the surface to be treated with a brush and then dried at 60 ° C. for 10 minutes.
(Water repellent treatment agent sample and water repellent treatment method 4)
15 g of product name R972 (contact angle 150 °, average particle size: 16 nm) manufactured by Nippon Aerosil Co., Ltd. is added to 300 g of MEK and 2 g of an epoxy resin composition (including a curing agent and a curing accelerator) and stirred for 10 minutes in a bead mill. Then, the beads were removed and vacuum defoamed to prepare a water repellent treatment sample (4). The water repellent treatment sample (4) was applied to the surface 2 to be treated with a coater and then dried at 170 ° C. for 30 minutes.
Here, the epoxy resin composition is
40 parts by weight of bisphenol A type epoxy resin (product name Epicoat 828 manufactured by Japan Epoxy Resin Co., Ltd.)
23 parts by weight of curing agent (product name LF2882 manufactured by Dainippon Ink & Chemicals, Inc.), curing accelerator (1-cyanoethyl-2-phenylimidazole, product name 2PZ-CN manufactured by Shikoku Kasei Kogyo Co., Ltd.) 0.4 weight The part.
[0038]
(Comparative Examples 1 to 3) Treated samples 9 to 11 were produced in the same manner as in Examples 1, 2 and 5 except that the water repellent treatment agent sample was not applied to the treated surfaces 1 to 3, and contacted with water. The corners were measured as in the examples. The contact angle with water is also shown in Table 1.
[0039]
[Table 1]

[0040]
All of the treated samples 1 to 8 had a large contact angle with water, and when the treated surface was tilted 30 degrees from the horizontal, the water fell and did not remain on the treated surface.
[0041]
(Examples 9 and 10: Contact angle after removing the water repellent agent)
The water repellent treated surfaces of the treated

samples

2 and 3 were ultrasonically cleaned in MEK for 10 minutes. Table 2 shows changes in contact angle with water before and after ultrasonic cleaning.
From Table 2, it was found that the water-repellent agent can be easily removed by washing, and from the above, it was found that adhesion, surface treatment, etc. can be easily selected and implemented as necessary.
[0042]
[Table 2]

[0043]
(Example 11)
As shown in FIG. 1I, a base film (polyimide flexible substrate) 2 provided with a copper pattern (copper foil circuit) 1 having a width of 200 μm and a thickness of 35 μm at 400 μm intervals was prepared as a mounting substrate. As shown in FIG. 1 (II), the water repellent treatment agent sample (1) prepared above was applied as the water repellent treatment agent 3 on the base film 2. After drying at 60 ° C. for 10 minutes, a filter paper wrapped around a squeegee on a flat plate was brought into close contact with the circuit and reciprocated three times. As a result, the water repellent 3 on the circuit was removed as shown in FIG. The particles of the water repellent agent 3 remained only in the recesses between the copper patterns 1. Next, a silver adhesive 4 in which water-soluble polymer and silver flakes are dispersed in water (40 parts by weight of polyvinyl alcohol and 40 parts by weight of silver flakes (product name TC-20E), obtained by stirring and mixing) The obtained silver adhesive) was applied to the entire surface and dried at 60 ° C. for 10 minutes. As a result, the silver adhesive 4 was adhered only on the copper pattern 1 as shown in FIG.
[0044]
(Comparative Example 4)
The silver adhesive 4 was applied on the entire surface of the same base film 2 as used in Example 11 without applying the water repellent 3 and dried at 60 ° C. for 10 minutes.
[0045]
As shown in FIG. 3, in Comparative Example 4, the silver adhesive 4 was dispersed on the entire surface, whereas in Example 11, it was distributed only on the copper pattern 1 as shown in FIG. 1 (IV). It was.
[0046]
(Example 12)
In FIGS. 2 (I) to 2 (V), cross-sectional schematic diagrams of steps of bonding a semiconductor element and a base film with a silver adhesive are sequentially shown according to this example. As shown in FIG. 2 (I), a base film (polyimide flexible substrate) 5 provided with copper foil pads 6 having a diameter of 200 μm and a thickness of 35 μm at 400 μm intervals was prepared as a mounting substrate. As shown in FIG. 2 (II), the water repellent treatment agent sample (1) prepared above was applied as the water repellent treatment agent 3 on the substrate and dried at 60 ° C. for 10 minutes. The water repellent agent 3 on the copper pattern was removed. Thereafter, when the same silver adhesive 7 as used in Example 11 was applied to the entire surface, the silver adhesive 7 was distributed only on the pad 6 as shown in FIG.
[0047]
As shown in FIG. 2 (IV), the pad 9 of the semiconductor element 8 was aligned on the pad 6 of the base film 5. At the time of alignment, there was a shift of 50 μm between the centers of the pads 6 and 9. The semiconductor element 8 was moved downward as it was, and the silver adhesive 7 was in contact with both pads 6 and 9 as shown in FIG. When the semiconductor element 8 was placed on the base film 5 away from the alignment device (not shown), the deviation between the centers of the pads was 3 μm. When the base film on which this semiconductor element was placed was dried at 60 ° C. for 10 minutes, the deviation between the centers of the pads remained at 3 μm.
[0048]
【The invention's effect】
The water repellent treatment agent of the present invention has an advantage that the contact angle with water is large, and when the surface to be treated is tilted, the water falls and does not remain on the surface to be treated. The water repellency can be easily removed by washing, and adhesion, surface treatment, and the like can be easily performed as necessary.
Further, according to the water repellent treatment method of the present invention, the hydrophilic material is printed at a predetermined position simply by applying the hydrophilic material to the entire surface.
Furthermore, according to the method for manufacturing an electronic component mounting body of the present invention, there is no need for screen preparation and alignment, which is used in ordinary adhesive screen printing, and there is no displacement. Be beneficial. Furthermore, since electronic components such as semiconductor chips are self-aligned during mounting and the positional deviation can be corrected with high accuracy, the manufacturing process of the mounting body is simplified, which is beneficial.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 (I) to (IV) are schematic cross-sectional views sequentially showing steps of applying a silver adhesive to a desired site on a mounting substrate according to the present invention.
2 (I) to (V) are schematic cross-sectional views sequentially showing steps of bonding a semiconductor element and a base film with a silver adhesive according to the present invention.
FIG. 3 is a schematic cross-sectional view showing an example of a dried state in which a silver adhesive is applied on a mounting substrate not subjected to the water repellent treatment of the present invention.
[Explanation of symbols]
1 Copper pattern 2, 5 Base film (mounting substrate)
3 Water

repellent treatment agent

4, 7 Silver adhesive agent 6, 9 Pad 8 Semiconductor element

Claims

A water repellent treatment method in which a water repellent treatment agent containing particles having an average particle diameter of 1 to 100 nm is attached only to a concave portion of a surface to be processed having irregularities, and a hydrophilic material is further adhered to the convex portion .

After having been subjected to water-repellent treatment agent to the treatment surface having irregularities, water repellent processing method according to claim 1, wherein the water-repellent treatment to remove only the water repellent agent of the convex portion is an unnecessary portion.

The water-repellent treatment method according to claim 1 or 2, wherein the adhesion amount of particles on the surface to be treated is 10 particles / mm ² or more.

The water repellent treatment method according to claim 1, which is used for water repellency on a surface of a mounting substrate for electronic components.

The water repellent treatment method according to any one of claims 1 to 4, wherein the water repellent treatment agent has a contact angle between the particles and water of 100 ° or more.

The water repellent treatment method according to any one of claims 1 to 5 , wherein the water repellent treatment agent contains one or more kinds selected from the group consisting of silica, alumina, and titanium oxide.

The water repellent treatment method according to any one of claims 1 to 6, wherein the surface of the particle is coated with an organic substance.

The water repellent treatment method according to claim 7 , wherein the organic substance is a silane compound or a fluorine compound.

Water repellent, the particles from 76 to 95 parts by weight of the average particle diameter of 1 to 100 nm, comprising a resin composition 5-34 parts by weight and a solvent, drying the solvent, any one of claims 1-8 which irregularities on the surface occurs Or a water-repellent treatment method as described above.

The water repellent treatment method according to claim 9 , wherein the resin composition is thermosetting.

A method for producing an electronic component mounting body, comprising: a water repellent treatment step for subjecting a part of a surface of a mounting substrate to a water repellent treatment; and a step of applying a hydrophilic adhesive between the electronic component and the mounting substrate to the treated surface.

Applying a water-repellent treatment step of water repellent treatment of the surface of the mounting substrate by any of claims 1 to 10 water-repellent processing method according, the hydrophilic adhesive between the electronic component and the mounting substrate to the surface which is the process The manufacturing method of the electronic component mounting body including a process.