JP2004140081A - Multilayer wiring board - Google Patents

Abstract

A main object of the present invention is to provide a multilayer wiring board which can form a high-definition pattern, can be formed by a simple process, and has no problem such as waste liquid treatment. is there.
In order to achieve the above object, a wiring board comprising a characteristic change layer whose characteristics change by the action of a photocatalyst and a conductive pattern formed along a pattern whose characteristics of the characteristic change layer have changed is provided. And a multilayer wiring board comprising at least two layers laminated.
[Selection diagram] Fig. 1

Description

【００６５】
ただし、ｎは２以上の整数であり、Ｒ^１，Ｒ^２はそれぞれ炭素数１〜１０の置換もしくは非置換のアルキル、アルケニル、アリールあるいはシアノアルキル基であり、モル比で全体の４０％以下がビニル、フェニル、ハロゲン化フェニルである。また、Ｒ^１、Ｒ^２がメチル基のものが表面エネルギーが最も小さくなるので好ましく、モル比でメチル基が６０％以上であることが好ましい。また、鎖末端もしくは側鎖には、分子鎖中に少なくとも１個以上の水酸基等の反応性基を有する。
【００６６】
また、上記のオルガノポリシロキサンとともに、ジメチルポリシロキサンのような架橋反応をしない安定なオルガノシリコーン化合物を混合してもよい。
【００６７】
本発明においては、このようにオルガノポリシロキサン等の種々の材料を濡れ性変化層に用いることができるのであるが、上述したように、濡れ性変化層にフッ素を含有させることが、濡れ性のパターン形成に効果的である。したがって、光触媒の作用により劣化・分解しにくい材料にフッ素を含有させる、具体的にはオルガノポリシロキサン材料にフッ素を含有させて濡れ性変化層とすることが好ましいといえる。
【００６８】
本発明における濡れ性変化層には、さらに界面活性剤を含有させることができる。具体的には、日光ケミカルズ（株）製ＮＩＫＫＯＬ　ＢＬ、ＢＣ、ＢＯ、ＢＢの各シリーズ等の炭化水素系、デュポン社製ＺＯＮＹＬ　ＦＳＮ、ＦＳＯ、旭硝子（株）製サーフロンＳ−１４１、１４５、大日本インキ化学工業（株）製メガファックＦ−１４１、１４４、ネオス（株）製フタージェントＦ−２００、Ｆ２５１、ダイキン工業（株）製ユニダインＤＳ−４０１、４０２、スリーエム（株）製フロラードＦＣ−１７０、１７６等のフッ素系あるいはシリコーン系の非イオン界面活性剤を挙げることかでき、また、カチオン系界面活性剤、アニオン系界面活性剤、両性界面活性剤を用いることもできる。
【００６９】
また、濡れ性変化層には上記の界面活性剤の他にも、ポリビニルアルコール、不飽和ポリエステル、アクリル樹脂、ポリエチレン、ジアリルフタレート、エチレンプロピレンジエンモノマー、エポキシ樹脂、フェノール樹脂、ポリウレタン、メラミン樹脂、ポリカーボネート、ポリ塩化ビニル、ポリアミド、ポリイミド、スチレンブタジエンゴム、クロロプレンゴム、ポリプロピレン、ポリブチレン、ポリスチレン、ポリ酢酸ビニル、ポリエステル、ポリブタジエン、ポリベンズイミダゾール、ポリアクリルニトリル、エピクロルヒドリン、ポリサルファイド、ポリイソプレン等のオリゴマー、ポリマー等を含有させることができる。
【００７０】
このような濡れ性変化層は、上述した成分を必要に応じて他の添加剤とともに溶剤中に分散して塗布液を調製し、この塗布液を基材上に塗布することにより形成することができる。使用する溶剤としては、エタノール、イソプロパノール等のアルコール系の有機溶剤が好ましい。塗布はスピンコート、スプレーコート、ディップコート、ロールコート、ビードコート等の公知の塗布方法により行うことができる。また、紫外線硬化型の成分を含有している場合、紫外線を照射して硬化処理を行うことにより濡れ性変化層を形成することができる。
【００７１】
また、本発明に用いられる濡れ性変化層は、表面の濡れ性が光触媒の作用により変化し得る材料で形成されたものであれば、自己支持性を有する材料であってもよく、また自己支持性を有さない材料であってもよい。なお、本発明でいう自己支持性を有するとは、他の支持材無しで有形な状態で存在し得ることをいうこととする。
【００７２】
濡れ性変化層が自己支持性を有する材料である場合には、例えば濡れ性変化層となり得る材料からなる市販の樹脂製フィルムを用いることが可能であり、コスト面で有利であるといえる。このような材料としては、上述した材料を製膜したものが自己支持性を有するのであれば、これを用いることも可能であるが、例えば、ポリエチレン、ポリカーボネート、ポリプロピレン、ポリスチレン、ポリエステル、ポリビニルフロライド、アセタール樹脂、ナイロン、ＡＢＳ、ＰＴＦＥ、メタクリル樹脂、フェノール樹脂、ポリ弗化ビニリデン、ポリオキシメチレン、ポリビニルアルコール、ポリ塩化ビニル、ポリエチレンテレフタレート、シリコーン等を挙げることができる。
【００７３】
本発明においては、自己支持性のない濡れ性変化層であることが好ましい。上述した特性が大幅に変化する材料で形成される濡れ性変化層は、通常自己支持性のある材料が少なく、また、下から２層目以上の配線基板に用いられる濡れ性変化層に関しては、上記自己支持性のない材料を塗布法により塗布することにより、下層の配線基板の導電性パターン部を保護することが可能となるからである。これにより、酸素や水蒸気による影響を防止することが可能となるのである。
【００７４】
本発明において上述した成分の濡れ性変化層を用いることにより、光触媒含有層中の光触媒の作用により、上記成分の一部である有機基の酸化、分解等の作用を用いて、エネルギー照射部の濡れ性を変化させて親液性とし、エネルギー未照射部との濡れ性に大きな差を生じさせることができる。よって、後述する導電性パターン組成物を塗布した場合においても、比較的容易にエネルギー照射部である親液性領域内のみに導電性パターン組成物を付着させることが可能であり、高精細な多層配線基板を低コストで製造することが可能となる。
【００７５】
なお、本発明に用いられる濡れ性変化層は、上述したように光触媒の作用により濡れ性の変化する層であれば特に限定されるものではないが、特に、光触媒を含まない層であることが好ましい。このように濡れ性変化層内に光触媒が含まれなければ、その後多層配線基板として用いた場合に、経時的に影響を受ける心配をする必要がなく、長期間に渡り問題なく使用することが可能だからである。
【００７６】
（２）密着性変化層
次に、本発明に用いられる密着性変化層について説明する。本発明に用いられる密着性変化層は、光触媒の作用により密着性が変化する層であれば、特に限定されるものではないが、一般にはエネルギーの照射に伴う光触媒の作用により、その密着性変化層表面における物との密着性が向上するように密着性が変化する層であることが好ましい。
【００７７】
このように、エネルギー照射により物との密着性が向上するように密着性が変化する密着性変化層とすることにより、エネルギーが照射された部分を密着性良好領域、エネルギーが照射されていない部分を密着阻害領域とすることが可能となるのである。この密着性の差を利用して、例えば、全面に導電性パターンを形成する導電性パターン組成物を蒸着した場合に、密着性良好領域のみに導電性パターン組成物が密着し、密着阻害領域には導電性パターン組成物が密着しないことから、密着阻害領域における導電性パターン組成物を容易に除去することが可能となり、後述する導電性パターンを容易に形成することが可能となるのである。
【００７８】
ここで、密着性良好領域とは、物との密着性が良好な領域であり、後述する導電性パターンを形成する導電性パターン組成物に対する密着性の良好な領域をいうこととする。また、密着阻害領域とは、物との密着性が悪い領域であり、導電性パターン組成物に対する密着性が悪い領域をいうこととする。
【００７９】
本発明における密着性変化層は、密着性阻害物質を含有し、エネルギー照射により密着性阻害物質が除去される層である場合（第一の態様）と、エネルギー照射により密着性変化層上に凹凸が形成され、物理的に密着性が向上する場合（第二の態様）とがある。
【００８０】
まず、第一の態様について説明する。本態様の密着性変化層は、密着性を阻害する物質が含有されており、この密着性阻害物質により、エネルギー照射されていない密着阻害領域においては、例えば蒸着法等により塗布された導電性パターン組成物が密着することを阻害することが可能となる。また、エネルギー照射に伴う光触媒の作用により、この密着性阻害物質が除去されることによって密着性が向上し、密着性良好領域を形成することが可能となるのである。
【００８１】
この密着性変化層の第一の態様として、具体的には、上記濡れ性変化層で説明したものと同様のものを用いることが可能である。
【００８２】
次に、第二の態様について説明する。本態様の密着性変化層は、エネルギー照射に伴う光触媒の作用により、表面に凹凸が形成される層であり、この表面の凹凸によるアンカー効果により導電性パターン組成物の密着性を向上させることが可能となるのである。また、エネルギー照射されていない密着阻害領域においては、凹凸が形成されていないことから、導電性パターン組成物が密着することが困難であり、この密着性の差を利用して、特性変化パターンを容易に形成することが可能となるのである。
【００８３】
この光触媒密着性変化層の第二の態様に用として具体的には、ポリエチレンテレフタレート、ポリビニルアルコール、ポリカーボネート、メチルメタクリレート単重合体または共重合体、ポリスチレン、ポリエチレン、ポリプロピレン、ポリエステル、ＰＴＦＥ等を用いることが可能である。
【００８４】
（３）分解除去層
次に、本発明に用いられる分解除去層について説明する。本発明に用いられる分解除去層とは、分解除去層用基板と、この分解除去層用基板上に形成された光触媒の作用により分解除去され、エネルギーが照射されたパターン状に分解除去される分解除去用層とを有する層である。
【００８５】
上記分解除去用層は、エネルギー照射した部分が光触媒の作用により分解除去されることから、現像工程や洗浄工程を行うことなく分解除去用層のある部分と無い部分とからなるパターン、すなわち分解除去層用基板上に凹凸を有するパターンを形成することができるのである。この凹凸を利用して、例えばインクジェット法等により、導電性パターン形成用組成物を塗布することにより、導電性パターンを高精細に形成することが可能となるのである。
【００８６】
なお、この分解除去用層は、エネルギー照射による光触媒の作用により酸化分解され、気化等されることから、現像・洗浄工程等の特別な後処理なしに除去されるものであるが、分解除去用層の材質によっては、洗浄工程等を行ってもよい。
【００８７】
以下、分解除去用層および分解除去層用基板についてわけて説明する。
【００８８】
（ｉ）分解除去用層
本発明に用いられる分解除去用層とは、エネルギー照射された部分が光触媒の作用により分解除去されてパターン状に凹凸を形成する層であれば、特に限定されるものではないが、本発明においては、凹凸を形成するのみならず、この分解除去用層が、後述する分解除去層用基板と比較して、液体との接触角が高いことが好ましい。これにより、分解除去用層が分解除去され、分解除去層用基板が露出した領域を親液性領域、上記分解除去用層が残存する領域を撥液性領域とすることが可能となり、上記凹凸のみではなく、この濡れ性の差を利用することにより、例えばインクジェット法等により、より容易に高精細な導電性パターンを形成することが可能となるのである。
【００８９】
ここで、親液性領域とは、液体との接触角が小さい領域であり、後述する導電性パターン組成物に対する濡れ性の良好な領域をいうこととする。また、撥液性領域とは、液体との接触角が大きい領域であり、導電性パターン組成物に対する濡れ性が悪い領域をいうこととする。
【００９０】
また、上記分解除去用層は、４０ｍＮ／ｍの液体との接触角が、５０°以上、中でも９０°以上であることが好ましい。これは、本発明は、残存する特性変化層が、撥液性が要求される部分であることから、液体との接触角が小さい場合は、撥液性が十分でなく、導電性パターンを形成しない撥液性領域にまで導電性パターン組成物が付着する可能性が生じるため好ましくないからである。
【００９１】
上記のような分解除去用層に用いることができる膜としては、具体的にはフッ素系や炭化水素系の撥液性を有する樹脂等による膜を挙げることができる。これらのフッ素系や炭化水素系の樹脂は、撥液性を有するものであれば、特に限定されるものではなく、これらの樹脂を溶媒に溶解させ、例としてスピンコート法等の一般的な成膜方法により形成することが可能である。
【００９２】
また、本発明においては、機能性薄膜、すなわち、自己組織化単分子膜、ラングミュア−ブロケット膜、および交互吸着膜等を用いることにより、欠陥のない膜を形成することが可能であることから、このような成膜方法を用いることがより好ましいといえる。
【００９３】
ここで、本発明に用いられる自己組織化単分子膜、ラングミュア−ブロケット膜、および交互吸着膜について具体的に説明する。
【００９４】
▲１▼自己組織化単分子膜
自己組織化単分子膜（Ｓｅｌｆ−Ａｓｓｅｍｂｌｅｄ　Ｍｏｎｏｌａｙｅｒ）の公式な定義の存在を発明者らは知らないが、一般的に自己組織化膜として認識されているものの解説文としては、例えばＡｂｒａｈａｍ　Ｕｌｍａｎによる総説“Ｆｏｒｍａｔｉｏｎ　ａｎｄ　Ｓｔｒｕｃｔｕｒｅ　ｏｆ　Ｓｅｌｆ−Ａｓｓｅｍｂｌｅｄ　Ｍｏｎｏｌａｙｅｒｓ”，　Ｃｈｅｍｉｃａｌ　Ｒｅｖｉｅｗ，　９６，　１５３３−１５５４　（１９９６）が優れている。本総説を参考にすれば、自己組織化単分子膜とは、適当な分子が適当な基板表面に吸着・結合（自己組織化）した結果生じた単分子層のことと言える。自己組織化膜形成能のある材料としては、例えば、脂肪酸などの界面活性剤分子、アルキルトリクロロシラン類やアルキルアルコキシド類などの有機ケイ素分子、アルカンチオール類などの有機イオウ分子、アルキルフォスフェート類などの有機リン酸分子などが挙げられる。分子構造の一般的な共通性は、比較的長いアルキル鎖を有し、片方の分子末端に基板表面と相互作用する官能基が存在することである。アルキル鎖の部分は分子同士が２次元的にパッキングする際の分子間力の源である。もっとも、ここに示した例は最も単純な構造であり、分子のもう一方の末端にアミノ基やカルボキシル基などの官能基を有するもの、アルキレン鎖の部分がオキシエチレン鎖のもの、フルオロカーボン鎖のもの、これらが複合したタイプの鎖のものなど様々な分子から成る自己組織化単分子膜が報告されている。また、複数の分子種から成る複合タイプの自己組織化単分子膜もある。また、最近では、デンドリマーに代表されるような粒子状で複数の官能基（官能基が一つの場合もある）を有する高分子や直鎖状（分岐構造のある場合もある）の高分子が一層基板表面に形成されたもの（後者はポリマーブラシと総称される）も自己組織化単分子膜と考えられる場合もあるようである。本発明は、これらも自己組織化単分子膜に含める。
【００９５】
▲２▼ラングミュア−ブロジェット膜
本発明に用いられるラングミュア−ブロジェット膜（Ｌａｎｇｍｕｉｒ−Ｂｌｏｄｇｅｔｔ　Ｆｉｌｍ）は、基板上に形成されてしまえば形態上は上述した自己組織化単分子膜との大きな相違はない。ラングミュア−ブロジェット膜の特徴はその形成方法とそれに起因する高度な２次元分子パッキング性（高配向性、高秩序性）にあると言える。すなわち、一般にラングミュア−ブロジェット膜形成分子は気液界面上に先ず展開され、その展開膜がトラフによって凝縮されて高度にパッキングした凝縮膜に変化する。実際は、これを適当な基板に移しとって用いる。ここに概略を示した手法により単分子膜から任意の分子層の多層膜まで形成することが可能である。また、低分子のみならず、高分子、コロイド粒子なども膜材料とすることができる。様々な材料を適用した最近の事例に関しては宮下徳治らの総説“ソフト系ナノデバイス創製のナノテクノロジーへの展望”　高分子　５０巻　９月号　６４４−６４７
（２００１）に詳しく述べられている。
【００９６】
▲３▼交互吸着膜
交互吸着膜（Ｌａｙｅｒ−ｂｙ−Ｌａｙｅｒ　Ｓｅｌｆ−Ａｓｓｅｍｂｌｅｄ　Ｆｉｌｍ）は、一般的には、最低２個の正または負の電荷を有する官能基を有する材料を逐次的に基板上に吸着・結合させて積層することにより形成される膜である。多数の官能基を有する材料の方が膜の強度や耐久性が増すなど利点が多いので、最近ではイオン性高分子（高分子電解質）を材料として用いることが多い。また、タンパク質や金属や酸化物などの表面電荷を有する粒子、いわゆる“コロイド粒子”も膜形成物質として多用される。さらに最近では、水素結合、配位結合、疎水性相互作用などのイオン結合よりも弱い相互作用を積極的に利用した膜も報告されている。比較的最近の交互吸着膜の事例については、静電的相互作用を駆動力にした材料系に少々偏っているがＰａｕｌａ　Ｔ．　Ｈａｍｍｏｎｄによる総説“Ｒｅｃｅｎｔ　Ｅｘｐｌｏｒａｔｉｏｎｓ　ｉｎ　Ｅｌｅｃｔｒｏｓｔａｔｉｃ　Ｍｕｌｔｉｌａｙｅｒ　Ｔｈｉｎ　Ｆｉｌｍ　Ａｓｓｅｍｂｌｙ”Ｃｕｒｒｅｎｔ　Ｏｐｉｎｉｏｎ　ｉｎ　Ｃｏｌｌｏｉｄ　＆　Ｉｎｔｅｒｆａｃｅ　Ｓｃｉｅｎｃｅ，　４，　４３０−４４２　（２０００）に詳しい。交互吸着膜は、最も単純なプロセスを例として説明すれば、正（負）電荷を有する材料の吸着−洗浄−負（正）電荷を有する材料の吸着−洗浄のサイクルを所定の回数繰り返すことにより形成される膜である。ラングミュア−ブロジェット膜のように展開−凝縮−移し取りの操作は全く必要ない。また、これら製法の違いより明らかなように、交互吸着膜はラングミュア−ブロジェット膜のような２次元的な高配向性・高秩序性は一般に有さない。しかし、交互吸着膜及びその作製法は、欠陥のない緻密な膜を容易に形成できること、微細な凹凸面やチューブ内面や球面などにも均一に成膜できることなど、従来の成膜法にない利点を数多く有している。
【００９７】
また、分解除去用層の膜厚としては、後述する特性変化パターン形成工程において照射されるエネルギーにより分解除去される程度の膜厚であれば特に限定されるものではない。具体的な膜厚としては、照射されるエネルギーの種類や分解除去用層の材料等により大きく異なるものではあるが、一般的には、０．００１μｍ〜１μｍの範囲内、特に０．０１μｍ〜０．１μｍの範囲内とすることが好ましい。
【００９８】
（ｉｉ）分解除去層用基板
次に、本発明に用いられる分解除去層用基板について説明する。本発明に用いられる分解除去層用基板は、上述した分解除去用層をその表面に形成できる基板であれば、特に限定されるものではないが、本発明においては、上記分解除去用層と比較して、液体との接触角が低いことが好ましい。これにより、分解除去用層が分解除去され、分解除去層用基板が露出した領域を親液性領域、上記分解除去用層が残存する領域を撥液性領域とすることが可能となり、種々のパターンを形成することが可能となるからである。
【００９９】
本発明における分解除去層用基板は、４０ｍＮ／ｍの液体との接触角が、エネルギーが照射されていない部分において４９°以下、中でも１０°以下であることが好ましい。本発明においては分解除去層用基板が、親液性が要求される部分であることから、後述する導電性パターン組成物の塗布に際して、親液性領域においても導電性パターン組成物をはじいてしまう可能性があり、親液性領域上に導電性パターン組成物をパターニングすることが難しくなる可能性があるからである。ここで、液体との接触角は、上述した方法により測定した値である。
【０１００】
この場合、分解除去層用基板は表面を親液性となるように、表面処理したものであってもよい。材料の表面を親液性となるように表面処理した例としては、アルゴンや水などを利用したプラズマ処理による親液性表面処理が挙げられ、分解除去層用基板上に形成する親液性の層としては、例えばテトラエトキシシランのゾルゲル法によるシリカ膜等を挙げることができる。
【０１０１】
（基材）
次に、本発明に用いられる基材について説明する。本発明においては、例えば多層配線基板の最下層部に形成される特性変化層に自己支持性のない場合や、多層配線基板に強度が必要とされる場合に基材が用いられ、例として図２に示すように、基材４上に多層配線基板における最下層部の配線基板の特性変化層１が設けられる。
【０１０２】
このような基材としては、最終的に得られる多層配線基板の用途等に応じて適宜選択されるものであり、例えば通常のプリント配線板等の場合においては、一般的に用いられている材料、具体的には紙基材の樹脂積層板、ガラス布・ガラス不織布基材の樹脂積層板、セラミック、金属等を用いることができる。また、フレキシブル配線板においては、可撓性を有する樹脂製フィルムを基材として用いることも可能である。
【０１０３】
（導電性パターン）
次に、本発明に用いられる導電性パターンについて説明する。本発明に用いられる導電性パターンは、上述した特性変化層の特性が変化したパターンに沿って形成された導電性を有するパターンであれば、そのパターンの形状や材料等は特に限定されるものではない。本実施態様における導電性パターンに用いられる材料として、具体的には、銅、金、銀、ニッケル、アルミニウム、パラジウム、鉛、スズおよびこれらのなかの金属を一種以上含む粉末状の金属または合金と、バインダ樹脂、分散材、有機溶剤からなる金属インキを挙げることができ、中でも銅および銀を用いた金属インキであることが好ましい。
【０１０４】
また、本発明の導電性パターンの形成方法は、上述した特性変化層の特性の変化により適宜選択されるものであるが、具体的には、蒸着法、無電界めっき、ディップコート、ロールコート、ブレードコート、スピンコート等の塗布手段、インクジェット、電解ジェット等を含むノズル吐出手段等の手段等が挙げられる。
【０１０５】
（配線基板）
次に、本発明における配線基板について説明する。本発明における配線基板とは、上記特性変化層と、上記特性変化層の特性が変化したパターンに沿って上記導電性パターンが形成されたものであり、その配線パターン等は特に限定されるものではない。
【０１０６】
（導電性コネクタ）
次に、本発明における導電性コネクタについて説明する。本発明における導電性コネクタとは、隣接する配線基板の導電性パターン同士を電気的に接続するために設けられる、導電性の材料により形成された部位であり、例えば図３に示すように、配線基板３における導電性部２と、隣接する配線基板３′における導電性部２′間に導電性の材料により形成されたものである。本発明においては、この導電性コネクタは、電気的に接続可能なものであれば、その形成方法等は特に限定されるものではないが、本発明においては、上述した特性変化層に形成されたスルーホールに導電性材料が充填されることにより、形成されたものであることが好ましい。
【０１０７】
ここで、本発明におけるスルーホールとは、導電性パターンと、この導電性パターンと特性変化層をはさんだ直下に存在する導電性パターンとを、電気的に接続する導電性コネクタを形成するために、特性変化層に設けられた孔部のことをいう。
【０１０８】
本発明の導電性コネクタに用いられる材料および形成方法は、上述した導電性パターンと同様のものを用いることが可能であるので、ここでの説明は省略する。
【０１０９】
（多層配線基板）
次に、本発明の多層配線基板について説明する。本発明の多層配線基板は、上記配線基板が少なくとも２層以上積層されたものであり、中でも３層から５層積層されたものであることが好ましい。
【０１１０】
本発明においては、隣接する配線基板の導電性パターン間に、上述したような導電性コネクタを有していてもよく、また最下層部の特性変化層に自己支持性がない場合や、多層配線基板に強度が必要とされる場合等には、多層配線基板が上記基材上に形成されたものであってもよい。
【０１１１】
Ｂ．多層配線基板の製造方法
次に、本発明の多層配線基板の製造方法について説明する。本発明の多層配線基板の製造方法は、
エネルギー照射に伴う光触媒の作用により特性が変化する特性変化層を調製する特性変化層調製工程と、
基体および光触媒を含有する光触媒含有層を有する光触媒含有層側基板と、上記特性変化層とを、上記光触媒含有層および上記特性変化層が２００μｍ以下となるように間隙をおいて配置した後、所定の方向からエネルギーを照射することにより、上記特性変化層表面に特性の変化した特性変化パターンを形成する特性変化パターン形成工程と、
上記特性変化パターンに沿って、導電性パターンを形成する導電性パターン形成工程と、
を有する配線基板形成工程を少なくとも２回以上行うことを特徴とする方法である。
【０１１２】
本発明の多層配線基板の製造方法は、配線基板工程を少なくとも２回以上、好ましくは３回から５回行うことを特徴とするものである。この配線基板形成工程を、図４を例として用いて説明する。
【０１１３】
まず、特性変化層１を調製する特性変化層調整工程を行う（図４（ａ））。次に、基体５および光触媒含有層６を有する光触媒含有層側基板７を、上記特性変化層１と光触媒含有層６とが所定の間隙となるように配置した後、例えばフォトマスク８等を用いて、所定の方向からエネルギー９をパターン状に照射する特性変化パターン形成工程を行う（図４（ｂ））。これにより、上記特性変化層１上に特性の変化した特性変化パターン１０が形成される。次に、この特性変化パターン１０に沿って、例えばインクジェット法等により、導電性パターン２を形成する導電性パターン形成工程を行い、配線基板３を形成する（図４（ｄ））。
【０１１４】
本発明の多層配線基板形成の製造方法は、上記特性変化パターンに沿って、導電性パターンを形成することから、高精細な導電性パターンを形成することができるのである。また、この配線基板形成工程を少なくとも２回以上行うことにより、多層配線基板とすることから、得られる多層配線基板を高精細な導電性パターンを有するものとすることが可能となるのである。
【０１１５】
また、本発明においては、図５に示すように、上記特性変化層調整工程後（図５（ａ））、上記配線基板形成工程で用いたものと同様の光触媒含有層側基板７と、上記特性変化層１とを、上記光触媒含有層５および上記特性変化層１が２００μｍ以下となるように間隙をおいて配置した後、例えばフォトマスク８等を用いて、所定の方向からエネルギー９を照射することにより（図５（ｂ））、上記特性変化層１表面に特性の変化したスルーホール特性変化パターン１３を形成する（図５（ｃ））スルーホール特性変化パターン形成工程を行い、そのスルーホール特性変化パターン１３に沿って、液体を塗布することにより、スルーホール１４を形成するスルーホール形成工程（図５（ｄ））を行ってもよい。これにより、上記導電性パターン形成工程において、導電性パターンを形成するのと同時に、スルーホールにも導電性材料を充填することが可能となり、導電性パターン間を電気的に接続する導電性コネクタを容易に形成することが可能となるのである。以下、本発明の多層配線基板の製造方法について各工程ごとに説明する。
【０１１６】
（１）特性変化層調製工程
まず、本発明の特性変化層調製工程について説明する。本発明における特性変化層調製工程は、エネルギー照射に伴う光触媒の作用により特性が変化する特性変化層を調製する工程であれば、その方法等は特に限定されるものではないが、少なくとも２回目以降の配線基板形成工程においては、塗布法により行なわれることが好ましい。上記特性変化層調製工程が塗布法であることにより、直前の配線基板形成工程により形成された導電性パターンの周囲にも特性変化層を形成することが可能となり、これにより導電性パターンを酸素や水蒸気から保護することが可能となるのである。また、製造効率やコストの面からも好ましい。
【０１１７】
また、本発明に用いられる多層配線基板の最下層部に位置する配線基板の特性変化層が自己支持性を有しない場合は、その最下層部の特性変化層は、基材上に形成されることが必要である。
【０１１８】
なお、本発明に用いられる特性変化層、特性変化層の形成方法および基材等については、上述した「Ａ．多層配線基板」で説明したものと同様であるので、ここでの説明は省略する。
【０１１９】
（２）特性変化パターン形成工程
次に、本発明における特性変化パターン形成工程について説明する。本発明における特性変化パターン形成工程は、基体および光触媒を含有する光触媒含有層を有する光触媒含有層側基板と、上記特性変化層とを、上記光触媒含有層および上記特性変化層が２００μｍ以下となるように間隙をおいて配置した後、所定の方向からエネルギーを照射することにより、上記特性変化層表面に特性の変化した特性変化パターンを形成する工程である。
【０１２０】
本発明の特性変化パターン形成工程は、後述するスルーホール特性変化パターン形成工程およびスルーホール形成工程を行った配線基板について行ってもよく、またスルーホール特性変化パターン形成工程およびスルーホール形成工程を行っていない配線基板について行ってもよい。
【０１２１】
本工程は、後述する導電性パターン形成工程において形成される導電性パターンのパターン状にエネルギーを照射し、後述する導電性パターン形成工程において形成する導電性パターンのパターン状に、上記特性変化層の特性を変化させる工程である。これにより、後述する導電性パターン形成工程において、容易に導電性パターンを形成することが可能となるのである。以下、この工程の各構成についてそれぞれ説明する。
【０１２２】
（光触媒含有層側基板）
まず、本発明に用いられる光触媒含有層側基板について説明する。本発明に用いられる光触媒含有層側基板は、少なくとも光触媒含有層と基体とを有するものであり、通常は基体上に所定の方法で形成された薄膜状の光触媒含有層が形成されてなるものである。また、この光触媒含有層側基板には、パターン状に形成された光触媒含有層側遮光部やプライマー層が形成されたものも用いることができる。以下、この光触媒含有層側基板の各構成について説明する。
【０１２３】
ａ．光触媒含有層
本発明に用いられる光触媒含有層は、光触媒含有層中の光触媒が、特性変化層の特性を変化させるような構成であれば、特に限定されるものではなく、光触媒とバインダとから構成されているものであってもよいし、光触媒単体で製膜されたものであってもよい。また、その表面の特性は、特に親液性であっても撥液性であってもよい。
【０１２４】
本発明において用いられる光触媒含有層は、例えば上記図４（ｂ）等に示すように、基体６上に全面に形成されたものであってもよいが、例えば図６に示すように、基体６上に光触媒含有層５がパターン状に形成されたものであってもよい。
【０１２５】
このように光触媒含有層をパターン状に形成することにより、後述する特性変化パターンの形成の項において説明するように、光触媒含有層を特性変化層にエネルギーを照射する際に、フォトマスク等を用いるパターン照射をする必要がなく、全面に照射することにより、特性変化層上に特性変化領域と特性未変化領域とからなる特性変化パターンを形成することができる。
【０１２６】
この光触媒処理層のパターニング方法は、特に限定されるものではないが、例えばフォトリソグラフィー法等により行うことが可能である。
【０１２７】
また、光触媒含有層と特性変化層とを例えば密着させてエネルギー照射を行う場合には、実際に光触媒含有層の形成された部分のみの特性が変化するものであるので、エネルギーの照射方向は上記光触媒含有層と特性変化層とが対向する部分にエネルギーが照射されるものであれば、いかなる方向から照射されてもよく、さらには、照射されるエネルギーも特に平行光等の平行なものに限定されないという利点を有するものとなる。
【０１２８】
このような光触媒含有層における、後述するような二酸化チタンに代表される光触媒の作用機構は、必ずしも明確なものではないが、光の照射によって生成したキャリアが、近傍の化合物との直接反応、あるいは、酸素、水の存在下で生じた活性酸素種によって、有機物の化学構造に変化を及ぼすものと考えられている。本発明においては、このキャリアが光触媒含有層上で特性変化層中の化合物に作用を及ぼすものであると思われる。
【０１２９】
本発明で使用する光触媒としては、光半導体として知られる例えば二酸化チタン（ＴｉＯ_２）、酸化亜鉛（ＺｎＯ）、酸化スズ（ＳｎＯ_２）、チタン酸ストロンチウム（ＳｒＴｉＯ_３）、酸化タングステン（ＷＯ_３）、酸化ビスマス（Ｂｉ_２Ｏ_３）、および酸化鉄（Ｆｅ_２Ｏ_３）を挙げることができ、これらから選択して１種または２種以上を混合して用いることができる。
【０１３０】
本発明においては、特に二酸化チタンが、バンドギャップエネルギーが高く、化学的に安定で毒性もなく、入手も容易であることから好適に使用される。二酸化チタンには、アナターゼ型とルチル型があり本発明ではいずれも使用することができるが、アナターゼ型の二酸化チタンが好ましい。アナターゼ型二酸化チタンは励起波長が３８０ｎｍ以下にある。
【０１３１】
このようなアナターゼ型二酸化チタンとしては、例えば、塩酸解膠型のアナターゼ型チタニアゾル（石原産業（株）製ＳＴＳ−０２（平均粒径７ｎｍ）、石原産業（株）製ＳＴ−Ｋ０１）、硝酸解膠型のアナターゼ型チタニアゾル（日産化学（株）製ＴＡ−１５（平均粒径１２ｎｍ））等を挙げることができる。
【０１３２】
光触媒の粒径は小さいほど光触媒反応が効果的に起こるので好ましく、平均粒径が５０ｎｍ以下が好ましく、２０ｎｍ以下の光触媒を使用するのが特に好ましい。
【０１３３】
本発明における光触媒含有層は、上述したように光触媒単独で形成されたものであってもよく、またバインダと混合して形成されたものであってもよい。光触媒のみからなる光触媒含有層の場合は、特性変化層上の特性の変化に対する効率が向上し、処理時間の短縮化等のコスト面で有利である。一方、光触媒とバインダとからなる光触媒含有層の場合は、光触媒含有層の形成が容易であるという利点を有する。
【０１３４】
光触媒のみからなる光触媒含有層の形成方法としては、例えば、スパッタリング法、ＣＶＤ法、真空蒸着法等の真空製膜法を用いる方法を挙げることができる。真空製膜法により光触媒含有層を形成することにより、均一な膜でかつ光触媒のみを含有する光触媒含有層とすることが可能であり、これにより特性変化層上の特性を均一に変化させることが可能であり、かつ光触媒のみからなることから、バインダを用いる場合と比較して効率的に特性変化層上の特性を変化させることが可能となる。
【０１３５】
また、光触媒のみからなる光触媒含有層の他の形成方法としては、例えば光触媒が二酸化チタンの場合は、基体上に無定形チタニアを形成し、次いで焼成により結晶性チタニアに相変化させる方法等が挙げられる。ここで用いられる無定形チタニアとしては、例えば四塩化チタン、硫酸チタン等のチタンの無機塩の加水分解、脱水縮合、テトラエトキシチタン、テトライソプロポキシチタン、テトラ−ｎ−プロポキシチタン、テトラブトキシチタン、テトラメトキシチタン等の有機チタン化合物を酸存在下において加水分解、脱水縮合によって得ることができる。次いで、４００℃〜５００℃における焼成によってアナターゼ型チタニアに変性し、６００℃〜７００℃の焼成によってルチル型チタニアに変性することができる。
【０１３６】
また、バインダを用いる場合は、バインダの主骨格が上記の光触媒の光励起により分解されないような高い結合エネルギーを有するものが好ましく、例えば後述する特性変化層の中の濡れ性変化層の説明の欄で詳しく説明するオルガノポリシロキサン等を挙げることができる。
【０１３７】
このようにオルガノポリシロキサンをバインダとして用いた場合は、上記光触媒含有層は、光触媒とバインダであるオルガノポリシロキサンとを必要に応じて他の添加剤とともに溶剤中に分散して塗布液を調製し、この塗布液を基体上に塗布することにより形成することができる。使用する溶剤としては、エタノール、イソプロパノール等のアルコール系の有機溶剤が好ましい。塗布はスピンコート、スプレーコート、ディッブコート、ロールコート、ビードコート等の公知の塗布方法により行うことができる。バインダとして紫外線硬化型の成分を含有している場合、紫外線を照射して硬化処理を行うことにより光触媒含有層を形成することかできる。
【０１３８】
また、バインダとして無定形シリカ前駆体を用いることができる。この無定形シリカ前駆体は、一般式ＳｉＸ_４で表され、Ｘはハロゲン、メトキシ基、エトキシ基、またはアセチル基等であるケイ素化合物、それらの加水分解物であるシラノール、または平均分子量３０００以下のポリシロキサンが好ましい。
【０１３９】
具体的には、テトラエトキシシラン、テトライソプロポキシシラン、テトラ−ｎ−プロポキシシラン、テトラブトキシシラン、テトラメトキシシラン等が挙げられる。また、この場合には、無定形シリカの前駆体と光触媒の粒子とを非水性溶媒中に均一に分散させ、基体上に空気中の水分により加水分解させてシラノールを形成させた後、常温で脱水縮重合することにより光触媒含有層を形成できる。シラノールの脱水縮重合を１００℃以上で行えば、シラノールの重合度が増し、膜表面の強度を向上できる。また、これらの結着剤は、単独あるいは２種以上を混合して用いることができる。
【０１４０】
バインダを用いた場合の光触媒含有層中の光触媒の含有量は、５〜６０重量％、好ましくは２０〜４０重量％の範囲で設定することができる。また、光触媒含有層の厚みは、０．０５〜１０μｍの範囲内が好ましい。
【０１４１】
また、光触媒含有層には上記の光触媒、バインダの他に、界面活性剤を含有させることができる。具体的には、日光ケミカルズ（株）製ＮＩＫＫＯＬ　ＢＬ、ＢＣ、ＢＯ、ＢＢの各シリーズ等の炭化水素系、デュポン社製ＺＯＮＹＬ　ＦＳＮ、ＦＳＯ、旭硝子（株）製サーフロンＳ−１４１、１４５、大日本インキ化学工業（株）製メガファックＦ−１４１、１４４、ネオス（株）製フタージェントＦ−２００、Ｆ２５１、ダイキン工業（株）製ユニダインＤＳ−４０１、４０２、スリーエム（株）製フロラードＦＣ−１７０、１７６等のフッ素系あるいはシリコーン系の非イオン界面活性剤を挙げることができ、また、カチオン系界面活性剤、アニオン系界面活性剤、両性界面活性剤を用いることもできる。
【０１４２】
さらに、光触媒含有層には上記の界面活性剤の他にも、ポリビニルアルコール、不飽和ポリエステル、アクリル樹脂、ポリエチレン、ジアリルフタレート、エチレンプロピレンジエンモノマー、エポキシ樹脂、フェノール樹脂、ポリウレタン、メラミン樹脂、ポリカーボネート、ポリ塩化ビニル、ポリアミド、ポリイミド、スチレンブタジエンゴム、クロロプレンゴム、ポリプロピレン、ポリブチレン、ポリスチレン、ポリ酢酸ビニル、ポリエステル、ポリブタジエン、ポリベンズイミダゾール、ポリアクリルニトリル、エピクロルヒドリン、ポリサルファイド、ポリイソプレン等のオリゴマー、ポリマー等を含有させることができる。
【０１４３】
ｂ．基体
本発明においては、例えば図４（ｂ）に示すように、光触媒含有層側基板７は、少なくとも基体６とこの基体６上に形成された光触媒含有層５とを有するものである。
【０１４４】
この際、用いられる基体を構成する材料は、後述する特性変化パターンの形成の項で説明するエネルギーの照射方向や、得られる多層配線基板が透明性を必要とするか等により適宜選択される。
【０１４５】
すなわち、例えば多層配線基板が紙基体フェノール樹脂積層板といった不透明なものを基体として用いる場合においては、エネルギー照射方向は必然的に光触媒含有層側基板側からとなり、図４（ｂ）に示すように、フォトマスク８を光触媒含有層側基板７側に配置して、エネルギー９を照射する必要がある。また、後述するように光触媒含有層側基板に光触媒含有層側遮光部を予め所定のパターンで形成しておき、この光触媒含有層側遮光部を用いて特性変化パターンを形成する場合においても、光触媒含有層側基板側からエネルギーを照射する必要がある。このような場合、基体は透明性を有するものであることが必要となる。
【０１４６】
一方、多層配線基板の基材が例えば透明樹脂フィルムである場合等であれば、多層配線基板の種類によっては、多層配線基板側にフォトマスクを配置してエネルギーを照射することも可能である。
【０１４７】
また本発明に用いられる基体は、可撓性を有するもの、例えば樹脂製フィルム等であってもよいし、可撓性を有さないもの、例えばガラス基板等であってもよい。これは、後述する特性変化パターン形成工程におけるエネルギー照射方法により適宜選択されるものである。
【０１４８】
このように、本発明における光触媒含有層側基板に用いられる基体は特にその材料を限定されるものではないが、本発明においては、この光触媒含有層側基板は、繰り返し用いられるものであることから、所定の強度を有し、かつその表面が光触媒含有層との密着性が良好である材料が好適に用いられる。
【０１４９】
具体的には、ガラス、セラミック、金属、プラスチック等を挙げることができる。
【０１５０】
なお、基体表面と光触媒含有層との密着性を向上させるために、基体上にアンカー層を形成するようにしてもよい。このようなアンカー層としては、例えば、シラン系、チタン系のカップリング剤等を挙げることができる。
【０１５１】
ｃ．光触媒含有層側遮光部
本発明に用いられる光触媒含有層側基板には、パターン状に形成された光触媒含有層側遮光部が形成されたものを用いても良い。このように光触媒含有層側遮光部を有する光触媒含有層側基板を用いることにより、エネルギー照射に際して、フォトマスクを用いたり、レーザ光による描画照射を行う必要がない。したがって、光触媒含有層側基板とフォトマスクとの位置合わせが不要であることから、簡便な工程とすることが可能であり、また描画照射に必要な高価な装置も不必要であることから、コスト的に有利となるという利点を有する。
【０１５２】
このような光触媒含有層側遮光部を有する光触媒含有層側基板は、光触媒含有層側遮光部の形成位置により、下記の二つの実施態様とすることができる。
【０１５３】
一つが、例えば図７に示すように、基体６上に光触媒含有層側遮光部１１を形成し、この光触媒含有層側遮光部１１上に光触媒含有層５を形成して、光触媒含有層側基板７とする実施態様である。もう一つは、例えば図８に示すように、基体６上に光触媒含有層５を形成し、その上に光触媒含有層側遮光部１１を形成して光触媒含有層側基板７とする実施態様である。
【０１５４】
いずれの実施態様においても、フォトマスクを用いる場合と比較すると、光触媒含有層側遮光部が、上記光触媒含有層と特性変化層との配置部分の近傍に配置されることになるので、基体内等におけるエネルギーの散乱の影響を少なくすることができることから、エネルギーのパターン照射を極めて正確に行うことが可能となる。
【０１５５】
さらに、上記光触媒含有層上に光触媒含有層側遮光部を形成する実施態様においては、光触媒含有層と特性変化層とを所定の位置に配置する際に、この光触媒含有層側遮光部の膜厚をこの間隙の幅と一致させておくことにより、上記光触媒含有層側遮光部を上記間隙を一定のものとするためのスペーサとしても用いることができるという利点を有する。
【０１５６】
すなわち、所定の間隙をおいて上記光触媒含有層と特性変化層とを対向させた状態で配置する際に、上記光触媒含有層側遮光部と特性変化層とを密着させた状態で配置することにより、上記所定の間隙を正確とすることが可能となり、そしてこの状態で光触媒含有層側基板からエネルギーを照射することにより、特性変化層上に特性変化パターンを精度良く形成することが可能となるのである。
【０１５７】
このよう光触媒含有層側遮光部の形成方法は、特に限定されるものではなく、光触媒含有層側遮光部の形成面の特性や、必要とするエネルギーに対する遮蔽性等に応じて適宜選択されて用いられる。
【０１５８】
例えば、スパッタリング法、真空蒸着法等により厚み１０００〜２０００Å程度のクロム等の金属薄膜を形成し、この薄膜をパターニングすることにより形成されてもよい。このパターニングの方法としては、スパッタ等の通常のパターニング方法を用いることができる。
【０１５９】
また、樹脂バインダ中にカーボン微粒子、金属酸化物、無機顔料、有機顔料等の遮光性粒子を含有させた層をパターン状に形成する方法であってもよい。用いられる樹脂バインダとしては、ポリイミド樹脂、アクリル樹脂、エポキシ樹脂、ポリアクリルアミド、ポリビニルアルコール、ゼラチン、カゼイン、セルロース等の樹脂を１種または２種以上混合したものや、感光性樹脂、さらにはＯ／Ｗエマルジョン型の樹脂組成物、例えば、反応性シリコーンをエマルジョン化したもの等を用いることができる。このような樹脂製遮光部の厚みとしては、０．５〜１０μｍの範囲内で設定することができる。このよう樹脂製遮光部のパターニングの方法は、フォトリソ法、印刷法等一般的に用いられている方法を用いることができる。
【０１６０】
なお、上記説明においては、光触媒含有層側遮光部の形成位置として、基体と光触媒含有層との間、および光触媒含有層表面の二つの場合について説明したが、その他、基体の光触媒含有層が形成されていない側の表面に光触媒含有層側遮光部を形成する態様も採ることが可能である。この態様においては、例えばフォトマスクをこの表面に着脱可能な程度に密着させる場合等が考えられ、特性変化パターンを小ロットで変更するような場合に好適に用いることができる。
【０１６１】
ｄ．プライマー層
次に、本発明の光触媒含有層側基板に用いられるプライマー層について説明する。本発明において、上述したように基体上に光触媒含有層側遮光部をパターン状に形成して、その上に光触媒含有層を形成して光触媒含有層側基板とする場合においては、上記光触媒含有層側遮光部と光触媒含有層との間にプライマー層を形成してもよい。
【０１６２】
このプライマー層の作用・機能は必ずしも明確なものではないが、光触媒含有層側遮光部と光触媒含有層との間にプライマー層を形成することにより、プライマー層は光触媒の作用による特性変化層の特性変化を阻害する要因となる光触媒含有層側遮光部および光触媒含有層側遮光部間に存在する開口部からの不純物、特に、光触媒含有層側遮光部をパターニングする際に生じる残渣や、金属、金属イオン等の不純物の拡散を防止する機能を示すものと考えられる。したがって、プライマー層を形成することにより、高感度で特性変化の処理が進行し、その結果、高解像度のパターンを得ることが可能となるのである。
【０１６３】
なお、本発明においてプライマー層は、光触媒含有層側遮光部のみならず光触媒含有層側遮光部間に形成された開口部に存在する不純物が光触媒の作用に影響することを防止するものであるので、プライマー層は開口部を含めた光触媒含有層側遮光部全面にわたって形成されていることが好ましい。
【０１６４】
図９はこのようなプライマー層を形成した光触媒含有層側基板の一例を示すものである。光触媒含有層側基板７の光触媒含有層側遮光部１１が形成された基体６の光触媒含有層側遮光部１１が形成されている側の表面にプライマー層１２が形成されており、このプライマー層１２の表面に光触媒含有層５が形成されている。
【０１６５】
本発明におけるプライマー層は、光触媒含有層側基板の光触媒含有層側遮光部と光触媒含有層とが接触しないようにプライマー層が形成された構造であれば特に限定されるものではない。
【０１６６】
このプライマー層を構成する材料としては、特に限定されるものではないが、光触媒の作用により分解されにくい無機材料が好ましい。具体的には無定形シリカを挙げることができる。このような無定形シリカを用いる場合には、この無定形シリカの前駆体は、一般式ＳｉＸ_４で示され、Ｘはハロゲン、メトキシ基、エトキシ基、またはアセチル基等であるケイ素化合物であり、それらの加水分解物であるシラノール、または平均分子量３０００以下のポリシロキサンが好ましい。
【０１６７】
また、プライマー層の膜厚は、０．００１μｍから１μｍの範囲内であることが好ましく、特に０．００１μｍから０．１μｍの範囲内であることが好ましい。
【０１６８】
（特性変化パターンの形成）
次に、特性変化パターンの形成について説明する。本発明の特性変化パターン形成工程においては、上記光触媒含有層および上記特性変化層を所定の位置に配置した後、所定の方向からエネルギーを照射することにより、上記特性変化層表面にパターンを形成する工程が行われる。以下、この特性変化パターンの形成について説明する。
【０１６９】
ａ．光触媒含有層および特性変化層の配置
本発明の特性変化パターン形成工程においては、まずエネルギー照射時に光触媒含有層と特性変化層とを光触媒の作用が及ぶように所定の間隔をおいて配置する必要があり、本発明においては、上述した光触媒含有層および特性変化層を２００μｍ以下の間隙をおいて配置した後、所定の方向からエネルギーを照射する。この際、光触媒含有層および特性変化層を密着させてもよい。
【０１７０】
本発明において上記間隙は、パターン精度が極めて良好であり、光触媒の感度も高く、したがって特性変化層の特性変化の効率が良好である点を考慮すると特に０．２μｍ〜１０μｍの範囲内、好ましくは１μｍ〜５μｍの範囲内とすることが好ましい。このような間隙の範囲は、特に間隙を高い精度で制御することが可能である小面積の特性変化層に対して特に有効である。
【０１７１】
一方、例えば３００ｍｍ×３００ｍｍといった大面積の特性変化層に対して処理を行う場合は、接触することなく、かつ上述したような微細な間隙を光触媒含有層側基板と特性変化層との間に形成することは極めて困難である。したがって、特性変化層が比較的大面積である場合は、上記間隙は、１０〜１００μｍの範囲内、特に５０〜７５μｍの範囲内とすることが好ましい。間隙をこのような範囲内とすることにより、パターンがぼやける等のパターン精度の低下の問題や、光触媒の感度が悪化して特性変化の効率が悪化する等の問題が生じることなく、さらに特性変化層上の特性変化にムラが発生しないといった効果を有するからである。
【０１７２】
このように比較的大面積の特性変化層をエネルギー照射する際には、エネルギー照射装置内の光触媒含有層側基板と特性変化層との位置決め装置における間隙の設定を、１０μｍ〜２００μｍの範囲内、特に２５μｍ〜７５μｍの範囲内に設定することが好ましい。設定値をこのような範囲内とすることにより、パターン精度の大幅な低下や光触媒の感度の大幅な悪化を招くことなく、かつ光触媒含有層側基板と特性変化層とが接触することなく配置することが可能となるからである。
【０１７３】
このように光触媒含有層と特性変化層表面とを所定の間隔で離して配置することにより、酸素と水および光触媒作用により生じた活性酸素種が脱着しやすくなる。すなわち、上記範囲より光触媒含有層と特性変化層との間隔を狭くした場合は、上記活性酸素種の脱着がしにくくなり、結果的に特性変化速度を遅くしてしまう可能性があることから好ましくない。また、上記範囲より間隔を離して配置した場合は、生じた活性酸素種が特性変化層に届き難くなり、この場合も特性変化の速度を遅くしてしまう可能性があることから好ましくない。
【０１７４】
本発明においては、このような配置状態は、少なくともエネルギー照射の間だけ維持されればよい。
【０１７５】
このような極めて狭い間隙を均一に形成して光触媒含有層と特性変化層とを配置する方法としては、例えばスペーサを用いる方法を挙げることができる。そして、このようにスペーサを用いることにより、均一な間隙を形成することができると共に、このスペーサが接触する部分は、光触媒の作用が特性変化層表面に及ばないことから、このスペーサを上述した特性変化パターンと同様のパターンを有するものとすることにより、特性変化層上に所定の特性変化パターンを形成することが可能となる。
【０１７６】
本発明においては、このようなスペーサを一つの部材として形成してもよいが、工程の簡略化等のため、上記光触媒含有層側基板の欄で説明したように、光触媒含有層側基板の光触媒含有層表面に形成することが好ましい。なお、上記光触媒含有層側基板における説明においては、光触媒含有層側遮光部として説明したが、本発明においては、このようなスペーサは特性変化層表面に光触媒の作用が及ばないように表面を保護する作用を有すればよいものであることから、特に照射されるエネルギーを遮蔽する機能を有さない材料で形成されたものであってもよい。
【０１７７】
ｂ．エネルギー照射
次に、上述したような配置を維持した状態で、対向する部分へのエネルギー照射が行われる。なお、本発明でいうエネルギー照射（露光）とは、光触媒含有層による特性変化層表面の特性を変化させることが可能ないかなるエネルギー線の照射をも含む概念であり、可視光の照射に限定されるものではない。
【０１７８】
通常このようなエネルギー照射に用いる光の波長は、４００ｎｍ以下の範囲、好ましくは３８０ｎｍ以下の範囲から設定される。これは、上述したように光触媒含有層に用いられる好ましい光触媒が二酸化チタンであり、この二酸化チタンにより光触媒作用を活性化させるエネルギーとして、上述した波長の光が好ましいからである。
【０１７９】
このようなエネルギー照射に用いることができる光源としては、水銀ランプ、メタルハライドランプ、キセノンランプ、エキシマランプ、その他種々の光源を挙げることができる。
【０１８０】
上述したような光源を用い、フォトマスクを介したパターン照射により行う方法の他、エキシマ、ＹＡＧ等のレーザを用いてパターン状に描画照射する方法を用いることも可能である。
【０１８１】
また、エネルギー照射に際してのエネルギーの照射量は、特性変化層表面が光触媒含有層中の光触媒の作用により特性変化層表面の特性の変化が行われるのに必要な照射量とする。
【０１８２】
この際、光触媒含有層を加熱しながらエネルギー照射することにより、感度を上昇させることが可能となり、効率的な特性の変化を行うことができる点で好ましい。具体的には３０℃〜８０℃の範囲内で加熱することが好ましい。
【０１８３】
本発明におけるエネルギー照射方向は、多層配線基板が透明である多層配線基板のパターンによっては、多層配線基板側から行ってもよいが、通常、光触媒含有層側基板側からエネルギー照射が行われる。
【０１８４】
すなわち、光触媒含有層側遮光部が形成されている場合は、光触媒含有層側基板側からエネルギー照射が行なわれる必要があり、かつこの場合は光触媒含有層側基板が照射されるエネルギーに対して透明である必要がある。なお、この場合、光触媒含有層上に光触媒含有層側遮光部が形成され、かつこの光触媒含有層側遮光部を上述したようなスペーサとしての機能を有するように用いた場合においては、多層配線基板の種類によっては、エネルギー照射方向は光触媒含有層側基板側からでも多層配線基板側からであってもよい。
【０１８５】
また、光触媒含有層がパターン状に形成されている場合におけるエネルギー照射方向は、上述したように、光触媒含有層と特性変化層とが対向する部分にエネルギーが照射されるのであれば、多層配線基板の種類によっては、いかなる方向から照射されてもよい。
【０１８６】
同様に、上述したスペーサを用いる場合も、対向する部分にエネルギーが照射されるのであれば、多層配線基板の種類によっては、いかなる方向から照射されてもよい。
【０１８７】
フォトマスクを用いる場合は、フォトマスクが配置された側からエネルギーが照射される。この場合は、フォトマスクが配置された側の基板、すなわち光触媒含有層側基板もしくは多層配線基板のいずれかが透明である必要がある。
【０１８８】
ｃ．光触媒含有層側基板の取り外し
上述したようなエネルギー照射が終了すると、光触媒含有層側基板が特性変化層との配置位置から離され、これにより図４（ｃ）に示すように特性変化パターン１０が特性変化層１上に形成される。
【０１８９】
（３）導電性パターン形成工程
次に、本発明の導電性パターン形成工程について説明する。本発明の導電性パターン形成工程は、上記特性変化パターン形成工程で形成された特性変化パターンに沿って、導電性パターンを形成する工程であり、後述するスルーホール特性変化パターン形成工程およびスルーホール形成工程が行われた配線基板については、導電性パターンを形成することと同時にスルーホールを充填して、導電性コネクタを形成してもよい。
【０１９０】
本発明の導電性パターン形成工程は、上記特性変化パターン上に導電性パターンを形成することが可能な方法であれば、特に限定されるものではなく、上記特性変化層の特性により適宜選択されるものであるが、例えば上記特性変化層が濡れ性変化層である場合には、ディップコート、ロールコート、ブレードコート、スピンコート等の塗布手段、インクジェット、電解ジェット等を含むノズル吐出手段等の手段を用いることが可能である。本発明においては中でも、ノズル吐出手段を用いることが好ましい。上記ノズル吐出手段においては、目的とするパターン状に導電性パターンを形成する導電性パターン組成物を塗布することが可能となり、より高精細に導電性パターンを形成することが可能となるからである。
【０１９１】
また、上記特性変化層が密着変化層である場合には、上記方法の他に、蒸着法、無電界めっき等も用いることが可能であり、導電性パターン組成物を成膜後、密着阻害領域に付着した導電性パターン組成物を除去することにより、密着性良好領域にのみ導電性パターン組成物を密着させることができ、導電性パターンを形成することが可能となるのである。
【０１９２】
ここで、上記スルーホールを充填し、導電性コネクタを形成する場合にも、同様の方法を用いることができることから、この導電性コネクタは、上記導電性パターンの形成と同時に行うことが可能である。
【０１９３】
（４）スルーホール特性変化パターン形成工程
次に、本発明のスルーホール特性変化パターン形成工程について説明する。本発明におけるスルーホール特性変化パターン形成工程とは、上記特性変化層調整工程後、光触媒を含有する光触媒含有層および基体を有する光触媒含有層側基板と上記特性変化層とを、上記光触媒含有層および上記特性変化層が２００μｍ以下となるように間隙をおいて配置した後、所定の方向からエネルギーを照射することにより、上記特性変化層表面に特性の変化したスルーホール特性変化パターンを形成する工程である。
【０１９４】
本発明において、隣接する配線基板の導電性パターン間に導電性コネクタを形成する場合には、この導電性コネクタを形成するためのスルーホールを、特性変化層に形成するスルーホール特性変化層形成工程およびスルーホール形成工程を有していてもよい。上記スルーホール特性変化パターン形成工程により、上記特性変化層上に、特性の変化したスルーホール特性変化パターンを形成することにより、後述するスルーホール形成工程において、このスルーホール特性パターンの特性の差を利用して、例えば液体を滴下すること等により、容易にスルーホールを形成することが可能となるからである。
【０１９５】
このスルーホール形成工程における光触媒含有層側基板やエネルギーの照射等は、上述した特性変化パターン形成工程と同様であるので、ここでの説明は省略する。
【０１９６】
（５）スルーホール形成工程
次に、スルーホール形成工程について説明する。本発明におけるスルーホール形成工程は、上記スルーホール特性変化パターンに沿って、液体を塗布することにより、スルーホールを形成する工程である。
【０１９７】
上記液体の塗布は、スルーホールを形成することが可能な方法であれば、特に方法等は限定されるものではないが、本発明においては、他の部材と接触させることなくスルーホール特性変化領域のみに選択的に液体を塗布できる点から、ノズル吐出による方法を用いることが好ましい。このようなノズル吐出法としては、例えばマイクロシリンジ、ディスペンサー、インクジェット等を用いた方法、または針先より電解等の外部刺激により吐出する方法、針先に付着させた液体を特性変化領域に付着させる方法等を用いることができる。本発明においては、中でもディスペンサーまたはインクジェットを用いた方法であることが好ましい。
【０１９８】
また、本発明のスルーホール形成工程に用いられる液体は、アルカリ溶液であることが好ましく、具体的には有機アルカリと無機アルカリの水溶液を上げることができる。好ましいアルカリ溶液としては、水酸化ナトリウム水溶液および水酸化カリウム水溶液を挙げることができ、ｐＨとしては、ｐＨ７〜１４、中でもｐＨ１０〜１４、特にｐＨ１２〜１４であることが好ましい。
【０１９９】
本発明に用いられる導電性パターンおよび導電性コネクタの材料は、上記「Ａ．多層配線基板」で説明したものと同様であるので、ここでの説明は省略する。
【０２００】
なお、本発明は上記実施形態に限定されるものではない。上記実施形態は、例示であり、本実施態様の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本実施態様の技術的範囲に包含される。
【０２０１】
【実施例】
以下、本実施態様について、実施例を通じてさらに詳述する。
【０２０２】
（光触媒含有層側基板の形成・一層目形成用）
フォトマスク表面に、テイカ（株）製の光触媒用酸化チタンコーティング剤ＴＫＣ３０１をコーティングし、３５０℃で３時間乾燥させ、光触媒含有層側基板を調整した。フォトマスクは、カーボンブラックと樹脂の分散体にて形成された膜厚１μｍのブラックマトリックスが、２０μｍの幅のラインにて形成されたものを使用した。ラインは、マスクの開口部が配線基板の回路パターンとなるように設計した。
【０２０３】
（特性変化層の形成・一層目）
次にフルオロアルキルシランが主成分であるＭＦ−１６０Ｅ（商品名、トーケムプロダクツ（株）製）０．４ｇに０．１Ｎ塩酸水３ｇを添加し、１時間室温にて攪拌した溶液を、膜厚０．７ｍｍのガラス基板上にスピンコーティングし、１５０℃で１０分間乾燥させた。これにより、基板上に撥液性を有する膜厚１μｍの特性変化層が形成された。このとき特性変化層の電気抵抗は１×１０^１２Ω・ｃｍであった。
【０２０４】
（特性変化パターン形成・一層目）
特性変化層を形成した基板上に、光触媒含有層側基板を５０μｍのギャップをあけて配置し、光触媒含有層側基板側から超高圧水銀ランプにて露光した。これにより、特性変化層表面の露光された部分のみ親液性領域となった。露光量は３６５ｎｍにて１０００ｍＪであった。
【０２０５】
（導電性材料の付与・一層目）
次に、銀微粒子分散体インキ（真空冶金製　Ａｇ００１Ｔ）を用い、インクジェットヘッドより特性変化層上の親液性領域のみに着弾するように吐出した。このインキの特性変化層に対する接触角は撥液性部分で５０°、親液性部分で１５°であった。着弾したインキは撥液性部分に付着することなく、親液性領域のみに濡れ広がった。
【０２０６】
１００℃、３分間の乾燥後、２５０℃、１５分間の焼成を行うことにより、上記フォトマスクの開口部と同様のパターン形状を有する、幅２０μｍ、膜厚０．６μｍの導電性パターンが形成された。導電性パターンの電気抵抗は６×１０^−６Ω・ｃｍであった。
【０２０７】
（光触媒含有層側基板の形成・スルーホール形成用）
次に、配線基板の一層目形成用の光触媒含有層側基板の形成時に用いたものと同様の材料、塗布手法により、スルーホール形成用の光触媒含有層側基板を形成した。このとき、フォトマスクは、露光時に直径１５μｍの、円形状の複数の開口部が、上記金属パターン部分に重なるように配置されたものを使用した。
【０２０８】
（特性変化層の形成・二層目）
次に、特性変化層の一層目の形成時に用いたものと同様の材料、塗布手法により、上記の導電性パターンが形成された配線基板上に二層目の特性変化層を形成した。
【０２０９】
（スルーホール特性変化パターンの形成）
二層目の特性変化層を形成した基板上に、スルーホール形成用の光触媒含有層側基板を５０μｍのギャップをあけて配置し、光触媒含有層側基板側から超高圧水銀ランプにて露光した。これにより、特性変化層表面の露光された部分（直径１５μｍの円形状のパターン）のみ親液性領域であるスルーホール特性変化パターンが形成された。この際、露光量は３６５ｎｍにて１５００ｍＪであった。
【０２１０】
（スルーホールの形成）
次に、上記複数の直径１５μｍのスルーホール特性変化パターンに、耐アルカリ処理を施したインクジェットヘッドから水酸化カリウム水溶液を塗布した。上記水酸化カリウム水溶液は撥液性部分に付着することなく、親液性領域のみに濡れ広がった。この際、水酸化カリウム水溶液はｐＨ１３であり、撥液性部分に対する接触角は５５°、親液性部分に対する接触角は５°であった。
【０２１１】
これを１分間室温にて放置し、純水にてリンス後、乾燥することにより、親液性部分のみ特性変化層が分解除去され、金属配線部分が露出したスルーホールが形成された。
【０２１２】
（特性変化パターン形成・二層目）
上記スルーホールを形成した基板上に、一層目の回路パターン形成にて使用した光触媒含有層側基板により、一層目と同様の手法にて露光し、二層目の特性変化層表面の露光された部分のみを親液性領域とした。このとき、スルーホールの位置は光触媒含有層側基板の開口部の位置と重なるため、スルーホール周辺およびスルーホール側面は親液性となった。
【０２１３】
（導電性材料の付与・二層目）
一層目の導電性材料の付与と同様の材料および手法にて、導電性材料を付与した。着弾したインキは、撥液性部分に付着することなく、親液性部分のみに濡れ広がり、またスルーホールにも充填された。
【０２１４】
１００℃、３分間の乾燥後、２５０℃、１５分間の焼成を行うことにより、幅２０μｍ、膜厚０．６μｍの二層目の導電性パターンおよび導電性コネクタが形成された。
【０２１５】
（三層目以降）
二層目までの手法と同様の手法にて、配線基板が四層積層された多層配線基板を作成した。各配線パターンの電気的導通および、導電性コネクタによる各層回路パターン間の電気的導通が良好に取れる多層配線基板を形成することができた。
【０２１６】
【発明の効果】本発明の多層配線基板は、上記特性変化層を有することにより、上記導電性パターンをその特性の変化したパターンに沿って容易に高精細に形成することが可能となり、その配線基板を積層することにより、高品質な多層配線基板とすることが可能となるのである。
【図面の簡単な説明】
【図１】本発明の多層配線基板の一例を示す概略断面図である。
【図２】本発明の多層配線基板の他の例を示す概略断面図である。
【図３】本発明の多層配線基板の他の例を示す概略断面図である。
【図４】本発明の多層配線基板の製造方法の一例を示す工程図である。
【図５】本発明の多層配線基板の製造方法のスルーホール形成工程を示す工程図である。
【図６】本発明に用いられる光触媒含有層側基板の一例を示す概略断面図である。
【図７】本発明に用いられる光触媒含有層側基板の他の例を示す概略断面図である。
【図８】本発明に用いられる光触媒含有層側基板の他の例を示す概略断面図である。
【図９】本発明に用いられる光触媒含有層側基板の他の例を示す概略断面図である。
【符号の説明】
１　…　特性変化層
２　…　導電性パターン
３　…　配線基板
４　…　基材
５　…　光触媒含有層
６　…　基体
７　…　光触媒含有層側基板
８　…　フォトマスク
９　…　エネルギー
１０…　特性変化パターン
１１…　光触媒含有層側遮光部
１２…　プライマー層
１３…　スルーホール特性変化パターン
１４…　スルーホール
１６…　導電性コネクタ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a multilayer wiring board which can be used for various high-definition electric circuits such as a printed circuit board.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a method of manufacturing a multilayer wiring board has been performed by forming an insulating film and a metal wiring on a substrate. At this time, an insulating material such as a polyimide resin is used as the insulating film. However, since it is difficult to directly pattern these insulating films, a metal is entirely plated on the insulating film, and a photoresist such as a dry film is further laminated. Then, pattern exposure is performed using a photomask or the like. And a number of steps such as development. Further, the waste liquid generated at the time of development is harmful, and there is an environmental problem such that it is necessary to perform a treatment in order to discharge the waste liquid to the environment.
[0003]
In the case of forming a through hole in an insulating film, generally, an insulating material such as a polyimide resin is applied on a metal wiring, a through hole pattern is formed with a photoresist, and then etching is performed. Exposure and development using a photosensitive insulating material, a method of opening a through-hole, a pattern of the shape of a through-hole in a photoresist by over-exposure, in a region where the through-hole is opened, polyimide-based There is a method of opening the through hole by coating with a resin, etching the resist pattern with oxygen plasma or the like until the resist pattern is exposed, and then removing the exposed resist (for example, see Patent Document 1).
[0004]
However, even in these cases, since the patterning of the insulating film is difficult, the step of removing the resist after the formation of the through-hole is necessary, so that the manufacturing process is complicated, and there is a problem in terms of manufacturing efficiency and cost. was there.
[0005]
[Patent Document 1]
JP-A-5-198687
[0006]
[Problems to be solved by the invention]
In view of the above, it is desired to provide a multilayer wiring board that can form a pattern with high definition in a simple process and that has no problem such as waste liquid treatment.
[0007]
[Means for Solving the Problems]
According to the present invention, as described in claim 1, there is provided a wiring board including a characteristic change layer whose characteristics change by the action of a photocatalyst, and a conductive pattern formed along a pattern whose characteristics of the characteristic change layer change. And a multilayer wiring board comprising at least two layers laminated.
[0008]
Since the multilayer wiring board of the present invention has the above-mentioned characteristic change layer, it becomes possible to easily form the above-mentioned conductive pattern with high definition along the pattern whose characteristics have changed, and to stack the wiring boards. Thus, a high-quality multilayer wiring board can be obtained.
[0009]
In the first aspect of the present invention, as described in the second aspect, a conductive connector may be provided between conductive patterns of adjacent wiring boards. This is because by having the conductive connector, a more complicated multilayer wiring board can be obtained and can be used for various applications.
[0010]
According to the first or second aspect of the present invention, as described in the third aspect, the conductive connector is one in which a conductive material is filled in a through hole formed in a characteristic change layer. Preferably, there is. Thereby, the conductive connector can be easily formed, which is preferable in terms of cost and manufacturing efficiency.
[0011]
In the invention described in any one of claims 1 to 3, as described in claim 4, it may be formed on a base material. In the case where the characteristic change layer of the lowermost wiring board in the multilayer wiring board of the present invention has no self-supporting property, or when the multilayer wiring board requires strength, it is formed on the base material. Because it may be.
[0012]
In the invention according to any one of the first to fourth aspects, as described in the fifth aspect, the electric resistance of the characteristic change layer is 1 × 10⁸Ω · cm to 1 × 10¹⁸It is preferably within the range of Ω · cm. The characteristic change layer is formed around the conductive pattern, and when the electric resistance of the characteristic change layer is within the above range, an excellent multilayer wiring board can be obtained. is there.
[0013]
In the invention according to any one of the first to fifth aspects, at least one of the characteristic change layers is formed by the action of a photocatalyst accompanying energy irradiation as described in the sixth aspect. It may be a wettability changing layer in which the wettability changes so as to lower the contact angle with the layer. Since the property change layer is the wettability change layer, a portion irradiated with energy can be a lyophilic region and a portion not irradiated with energy can be a lyophobic region. This is because the conductive pattern can be easily formed by using, for example, an inkjet method or the like.
[0014]
In the sixth aspect of the invention, as described in the seventh aspect, the contact angle between the wettability changing layer and a liquid of 40 mN / m on the wettability changing layer is irradiated with energy. It is preferable that the angle is 50 ° or more in the non-existing portion and 49 ° or less in the irradiated portion. When the wettability in the wettability changing layer is within the above-described range, the conductive pattern can be easily formed with high definition.
[0015]
In the invention described in claim 6 or claim 7, as described in claim 8, the wettability changing layer is preferably a layer containing an organopolysiloxane. In the present invention, the property required for the wettability changing layer is that it is lyophobic when energy is not irradiated, and is lyophilic by the action of the photocatalyst in the opposing photocatalyst containing layer when energy is irradiated. It is a characteristic that it becomes sexual. This is because organopolysiloxane is preferably used as a material that imparts such properties to the wettability changing layer.
[0016]
In the invention described in claim 8, as described in claim 9, the organopolysiloxane is preferably a polysiloxane containing a fluoroalkyl group. This is because, if the material contains a fluoroalkyl group, the difference in wettability between the energy irradiated portion and the non-irradiated portion can be increased.
[0017]
In the invention described in claim 8 or claim 9, as described in claim 10, the organopolysiloxane is Y_nSix_(4-n)(Here, Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group, X represents an alkoxyl group or a halogen, and n is an integer of 0 to 3.) It is preferably an organopolysiloxane which is one or more hydrolytic condensates or cohydrolytic condensates of the silicon compound to be produced. By using such an organopolysiloxane, it is possible to exhibit the property against the change in wettability as described above.
[0018]
In the invention according to any one of claims 1 to 5, as described in claim 11, at least one of the characteristic change layers adheres due to the action of a photocatalyst accompanying energy irradiation. It may be an adhesion changing layer in which the property changes.
[0019]
This is because the conductive property pattern can be easily formed by, for example, a vapor deposition method when the property change layer is the adhesion change layer.
[0020]
In the invention described in any one of the first to eleventh aspects, as described in the twelfth aspect, the characteristic change layer is preferably a layer that is etched by a liquid. This is because, for example, a through-hole or the like can be formed by applying a liquid to the characteristic change layer.
[0021]
In the twelfth aspect, as described in the thirteenth aspect, the liquid is preferably an alkaline solution. When the liquid is an alkaline solution, for example, a through hole or the like can be efficiently formed in the characteristic change layer, which is preferable in terms of manufacturing efficiency and the like.
[0022]
Further, the present invention provides, as described in claim 14,
A property change layer preparation step of preparing a property change layer whose properties change by the action of a photocatalyst accompanying energy irradiation,
After arranging the photocatalyst-containing layer-side substrate having the photocatalyst-containing layer containing the substrate and the photocatalyst, and the property-changing layer with a gap such that the photocatalyst-containing layer and the property-change layer are 200 μm or less, a predetermined A characteristic change pattern forming step of forming a characteristic change pattern having changed characteristics on the surface of the characteristic change layer by irradiating energy from the direction of
Along with the characteristic change pattern, a conductive pattern forming step of forming a conductive pattern,
Providing a method for manufacturing a multilayer wiring board, wherein the wiring board forming step having the above is performed at least twice.
[0023]
According to the present invention, since the characteristic change pattern in which the characteristic is changed is formed by the characteristic change pattern forming step, the conductive pattern is easily formed along the characteristic change pattern by, for example, an inkjet method. This makes it possible to form a high-definition wiring board. Further, by performing the wiring board forming step at least twice or more, a multilayer wiring board can be obtained, and a high-definition multilayer wiring board can be manufactured.
[0024]
In the fourteenth aspect of the present invention, as described in the fifteenth aspect, it is preferable that the characteristic change layer preparing step in the second and subsequent wiring board forming steps is performed by a coating method. This makes it possible to form the characteristic change layer also around the conductive pattern formed by the immediately preceding wiring board forming step, and to prevent the influence of oxygen or water vapor on high quality. This is because it is possible to obtain a multi-layer wiring board, and it is preferable from the viewpoint of manufacturing efficiency.
[0025]
In the invention according to claim 14 or 15, after the characteristic change layer adjusting step, the photocatalyst-containing layer-side substrate and the characteristic change layer are replaced with the photocatalyst-containing layer. And arranging a gap so that the characteristic change layer becomes 200 μm or less, and then irradiating energy from a predetermined direction to form a through-hole characteristic change pattern having a changed characteristic on the surface of the characteristic change layer. The method may include a hole characteristic changing pattern forming step and a through hole forming step of forming a through hole by applying a liquid along the through hole characteristic changing pattern.
[0026]
After the property change layer preparation step, by having the through hole property change pattern forming step, it is possible to easily change the property of the property change layer in a pattern shape for forming a through hole. By using the changed pattern, it is possible to easily form a through hole. This makes it possible to form high-definition through-holes in a small number of steps, and to manufacture a low-cost, high-quality multilayer wiring board.
[0027]
In the sixteenth aspect, as described in the seventeenth aspect, it is preferable that the through-hole forming step is performed by applying an alkaline solution. This makes it possible to efficiently perform the through-hole forming step, which is preferable in terms of manufacturing efficiency and cost.
[0028]
In the invention according to any one of claims 14 to 17, as described in claim 18, the photocatalyst-containing layer may be a layer made of a photocatalyst. This is because if the photocatalyst-containing layer is a layer composed of only a photocatalyst, it is possible to improve the efficiency of changing the characteristics of the characteristic change layer, and it is possible to efficiently manufacture a characteristic change pattern.
[0029]
In the invention according to claim 18, as described in claim 19, the photocatalyst-containing layer is preferably a layer formed by forming a photocatalyst on a substrate by a vacuum film-forming method. By forming the photocatalyst-containing layer by the vacuum film forming method as described above, it is possible to form a uniform photocatalyst-containing layer having a uniform thickness with a small amount of surface irregularities, and forming a characteristic change pattern on the surface of the characteristic change layer Can be performed uniformly and with high efficiency.
[0030]
In the invention described in any one of claims 14 to 17, as described in claim 20, the photocatalyst-containing layer may be a layer having a photocatalyst and a binder. By using the binder in this manner, the photocatalyst-containing layer can be formed relatively easily, and as a result, a multilayer wiring board can be manufactured at low cost.
[0031]
In the invention according to any one of claims 14 to 20, as described in claim 21, the photocatalyst is made of titanium oxide (TiO 2).₂), Zinc oxide (ZnO), tin oxide (SnO)₂), Strontium titanate (SrTiO)₃), Tungsten oxide (WO₃), Bismuth oxide (Bi₂O₃), And iron oxide (Fe₂O₃) Is preferably one or two or more substances selected from the group consisting of titanium oxide (TiO 2) and titanium oxide (TiO 2).₂) Is preferable. This is because titanium dioxide has a high bandgap energy, is effective as a photocatalyst, is chemically stable, has no toxicity, and is easily available.
[0032]
In the invention according to any one of claims 14 to 22, the multilayer wiring board may be formed on a base material, as described in claim 23. When the characteristic change layer of the lowermost wiring board in the multilayer wiring board does not have self-supporting property, or when the multilayer wiring board requires strength, it may be formed on the base material. Because it is good.
[0033]
In the invention according to any one of claims 14 to 23, as described in claim 24, the characteristic change layer is irradiated with energy by the action of a photocatalyst in the photocatalyst containing layer. It is preferable that the wettability changing layer changes the wettability so that the contact angle with the liquid decreases when the coating is performed. This makes it possible to easily form the conductive pattern by utilizing the difference in wettability between the energy irradiated portion and the energy non-irradiated portion.
[0034]
In the invention according to claim 24, as described in claim 25, the contact angle with the liquid of 40 mN / m on the wettability changing layer is 50 ° or more in a portion where energy is not irradiated. And it is preferable that the angle be 49 ° or less at the irradiated portion. This makes it possible to make the energy non-irradiated area a lyophobic area and the irradiated area a lyophilic area. Since the wettability is within the above-described range, the conductive pattern can be easily raised. This is because it is possible to form the wiring finely and to form a high-definition multilayer wiring board.
[0035]
In the invention according to any one of the fourteenth to twenty-third aspects, as described in the twenty-sixth aspect, the characteristic change layer is irradiated with energy by the action of a photocatalyst in the photocatalyst containing layer. It may be an adhesiveness change layer whose adhesiveness changes when being performed. This makes it possible to easily form the conductive pattern by, for example, a vapor deposition method by utilizing a difference in adhesion between the energy irradiation section and the energy non-irradiation section, thereby forming a high-definition multilayer wiring board. This is because it becomes possible.
[0036]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention relates to a multilayer wiring board and a method for manufacturing a multilayer wiring board. Hereinafter, each of them will be described in detail.
[0037]
A. Multilayer wiring board
First, the multilayer wiring board of the present invention will be described. The multilayer wiring board according to the present invention is obtained by laminating at least two or more wiring boards each including a characteristic change layer whose characteristics change by the action of a photocatalyst and a conductive pattern formed in a pattern on the characteristic change layer. It is characterized by becoming.
[0038]
As shown in FIG. 1, for example, the multilayer wiring board of the present invention has at least two or more wiring boards 3 each having a characteristic change layer 1 and a conductive pattern 2 formed on the characteristic change layer 1. As shown in FIG. 2, a multi-layer wiring board may be formed on a base material 4, as shown in FIG. A wiring board 3 ′ similar to the wiring board 3 is laminated on a wiring board 3 composed of the conductive pattern 2 formed on the characteristic change layer 1 and the conductive pattern 2 on the wiring board 3. The conductive connector 16 may be provided between the conductive pattern 2 'and the adjacent wiring board 3'.
[0039]
According to the present invention, since the wiring substrate has the characteristic change layer, the conductive pattern can be easily formed with high definition along the pattern whose characteristics have been changed. By laminating, a high-quality multilayer wiring board can be obtained.
[0040]
Hereinafter, each configuration of the multilayer wiring board as described above will be described.
[0041]
(Characteristic change layer)
First, the characteristic change layer used in the present invention will be described. The property change layer used in the present invention is a layer whose properties change by the action of a photocatalyst.
[0042]
In the present invention, the electric resistance of the characteristic change layer is 1 × 10⁸Ω · cm to 1 × 10¹⁸Ω · cm, especially 1 × 10^FifteenΩ · cm to 1 × 10¹⁸It is preferably within the range of Ω · cm. If the electric resistance of the characteristic change layer is lower than the above range, it is difficult to use a conductive pattern described later as electric wiring when forming a multilayer wiring board.
[0043]
Further, in the present invention, the characteristic change layer is preferably a layer that is etched with a liquid, and particularly preferably a layer that is etched with an alkaline solution. Accordingly, for example, when forming a through hole for forming a conductive connector described later in the characteristic change layer, etching can be easily performed using a liquid, and the liquid is an alkaline solution. Thereby, etching can be performed more efficiently.
[0044]
Further, the property change layer used in the present invention is not particularly limited as long as the property change layer used in the present invention has the above-described properties. In the case of a wettability changing layer in which a pattern is formed by changing the wettability in the direction in which the contact angle with the liquid decreases due to the action of the photocatalyst, the adhesiveness changes due to the action of the photocatalyst and the difference in the adhesiveness The three cases of the adhesion change layer on which the pattern is formed, or the decomposition removal layer on which the pattern is formed by the unevenness which is decomposed and removed by the action of the photocatalyst, are more preferable in the present invention from the relation of the obtained characteristic change pattern. It is preferable because it brings out the effectiveness. Hereinafter, these wettability change layer, adhesion change layer, and decomposition removal layer will be described.
[0045]
(1) wettability changing layer
First, the wettability changing layer used in the present invention will be described. The wettability changing layer used in the present invention is not particularly limited as long as it is a layer whose surface wettability changes by the action of a photocatalyst. The layer is preferably a layer whose wettability changes so that the contact angle with the liquid on the surface of the variable layer decreases.
[0046]
As described above, by making the wettability changing layer such that the wettability changes so that the contact angle with the liquid is reduced by the energy irradiation, the part irradiated with the energy is made a lyophilic region, and the energy is not irradiated. The portion can be a liquid-repellent region, and a conductive pattern described later can be easily formed by utilizing the difference in wettability.
[0047]
Here, the lyophilic region is a region having a small contact angle with a liquid, and refers to a region having good wettability with a conductive pattern composition forming a conductive pattern described later. Further, the lyophobic region is a region having a large contact angle with a liquid and a region having poor wettability to the conductive pattern composition.
[0048]
In the portion of the wettability changing layer that has not been irradiated with energy, that is, in the liquid-repellent region, the contact angle with a liquid of 40 mN / m is preferably 50 ° or more, particularly preferably 90 ° or more. This is because the portion that is not irradiated with energy is a portion that requires liquid repellency in the present invention. Therefore, when the contact angle with the liquid is small, the liquid repellency is not sufficient, and the conductive pattern is not formed. This is because the possibility that the conductive pattern composition adheres to the region where the conductive pattern composition is not formed is not preferable.
[0049]
In the wettability changing layer, a contact angle with a liquid of 40 mN / m is preferably 49 ° or less, and more preferably 10 ° or less in a portion irradiated with energy, that is, a lyophilic region. When the contact angle with the liquid in the energy-irradiated portion, that is, the lyophilic region is high, the conductive pattern composition may be repelled even in the lyophilic region when the conductive pattern composition described later is applied. This is because it may be difficult to pattern the conductive pattern on the lyophilic region.
[0050]
In addition, the contact angle with the liquid referred to here is a contact angle with a liquid having various surface tensions measured using a contact angle measuring device (CA-Z type manufactured by Kyowa Interface Science Co., Ltd.) (from the micro syringe to the liquid). 30 seconds after dropping) and obtained from the results or as a graph. In this measurement, wetting index standard solutions manufactured by Junsei Chemical Co., Ltd. were used as liquids having various surface tensions.
[0051]
Further, when the wettability changing layer as described above is used in the present invention, fluorine is contained in the wettability changing layer, and the fluorine content on the surface of the wettability changing layer increases the energy relative to the wettability changing layer. The wettability changing layer may be formed so as to be lower than that before the energy irradiation by the action of the photocatalyst when irradiated.
[0052]
With a wettability changing layer having such characteristics, a pattern composed of a portion having a low fluorine content can be easily formed by pattern irradiation with energy. Here, fluorine has an extremely low surface energy, so that the surface of a substance containing a large amount of fluorine has a smaller critical surface tension. Therefore, the critical surface tension of the portion having a small content of fluorine is higher than the critical surface tension of the surface of the portion having a large content of fluorine. This means that a portion having a low fluorine content is a lyophilic region as compared with a portion having a high fluorine content. Therefore, forming a pattern composed of a portion having a lower fluorine content than the surrounding surface means forming a pattern of a lyophilic region in a lyophobic region.
[0053]
Therefore, when such a wettability changing layer is used, the pattern of the lyophilic region can be easily formed in the lyophobic region by irradiating the pattern with energy. It is possible to easily form a conductive pattern by adhering the conductive pattern composition only to the conductive pattern composition, and a low-cost, high-definition multilayer wiring substrate can be formed.
[0054]
As described above, as the content of fluorine contained in the fluorine-containing wettability changing layer, the content of fluorine in a lyophilic region having a low fluorine content formed by irradiation with energy is determined by energy irradiation. When the fluorine content of the non-existing portion is 100, it is preferably 10 or less, more preferably 5 or less, and particularly preferably 1 or less.
[0055]
By setting it in such a range, a large difference can be caused in the wettability between the energy-irradiated portion and the non-irradiated portion. Therefore, by forming a conductive pattern on such a wettability changing layer, it becomes possible to accurately form a conductive pattern only in a lyophilic region having a reduced fluorine content, and to obtain a wiring board with high accuracy. Because you can do it. In addition, this reduction rate is based on weight.
[0056]
For the measurement of the fluorine content in such a wettability changing layer, various methods generally used can be used, and for example, X-ray photoelectron spectroscopy (X-ray \ Photoelectron \ Spectroscopy, ESCA (Electron) The method is not particularly limited as long as it is a method capable of quantitatively measuring the amount of fluorine on the surface, such as spectroscopy for chemical analysis), fluorescent X-ray analysis, or mass spectrometry.
[0057]
The material used for such a wettability changing layer is a material whose wettability is changed by the photocatalyst in the photocatalyst containing layer facing by the irradiation of energy, that is, the material having the property of the wettability changing layer described above, and is deteriorated by the action of the photocatalyst. There is no particular limitation as long as it has a main chain that is difficult to decompose, and specific examples include organopolysiloxane. In the present invention, the organopolysiloxane is preferably an organopolysiloxane containing a fluoroalkyl group.
[0058]
Examples of such an organopolysiloxane include (1) an organopolysiloxane that hydrolyzes and polycondensates chloro or alkoxysilane by a sol-gel reaction or the like to exhibit large strength, and (2) has water repellency or oil repellency. An organopolysiloxane such as an organopolysiloxane obtained by crosslinking an excellent reactive silicone can be used.
[0059]
In the case of the above (1), the general formula:
Y_nSix_(4-n)
(Here, Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group, or an epoxy group, X represents an alkoxyl group, an acetyl group, or a halogen. N is an integer of 0 to 3. )
Is preferably an organopolysiloxane which is one or more hydrolytic condensates or cohydrolytic condensates of the silicon compound represented by Here, the carbon number of the group represented by Y is preferably in the range of 1 to 20, and the alkoxy group represented by X is preferably a methoxy group, an ethoxy group, a propoxy group, or a butoxy group. preferable.
[0060]
Further, in particular, an organopolysiloxane containing a fluoroalkyl group can be preferably used, and specific examples thereof include one or more hydrolytic condensates and co-hydrolytic condensates of the following fluoroalkylsilanes. What is generally known as a fluorine-based silane coupling agent can be used.
[0061]
CF₃(CF₂)₃CH₂CH₂Si (OCH₃)₃;
CF₃(CF₂)₅CH₂CH₂Si (OCH₃)₃;
CF₃(CF₂)₇CH₂CH₂Si (OCH₃)₃;
CF₃(CF₂)₉CH₂CH₂Si (OCH₃)₃;
(CF₃)₂CF (CF₂)₄CH₂CH₂Si (OCH₃)₃;
(CF₃)₂CF (CF₂)₆CH₂CH₂Si (OCH₃)₃;
(CF₃)₂CF (CF₂)₈CH₂CH₂Si (OCH₃)₃;
CF₃(C₆H₄) C₂H₄Si (OCH₃)₃;
CF₃(CF₂)₃(C₆H₄) C₂H₄Si (OCH₃)₃;
CF₃(CF₂)₅(C₆H₄) C₂H₄Si (OCH₃)₃;
CF₃(CF₂)₇(C₆H₄) C₂H₄Si (OCH₃)₃;
CF₃(CF₂)₃CH₂CH₂SiCH₃(OCH₃)₂;
CF₃(CF₂)₅CH₂CH₂SiCH₃(OCH₃)₂;
CF₃(CF₂)₇CH₂CH₂SiCH₃(OCH₃)₂;
CF₃(CF₂)₉CH₂CH₂SiCH₃(OCH₃)₂;
(CF₃)₂CF (CF₂)₄CH₂CH₂SiCH₃(OCH₃)₂;
(CF₃)₂CF (CF₂)₆CH₂CH₂Si CH₃(OCH₃)₂;
(CF₃)₂CF (CF₂)₈CH₂CH₂Si CH₃(OCH₃)₂;
CF₃(C₆H₄) C₂H₄SiCH₃(OCH₃)₂;
CF₃(CF₂)₃(C₆H₄) C₂H₄SiCH₃(OCH₃)₂;
CF₃(CF₂)₅(C₆H₄) C₂H₄SiCH₃(OCH₃)₂;
CF₃(CF₂)₇(C₆H₄) C₂H₄SiCH₃(OCH₃)₂;
CF₃(CF₂)₃CH₂CH₂Si (OCH₂CH₃)₃;
CF₃(CF₂)₅CH₂CH₂Si (OCH₂CH₃)₃;
CF₃(CF₂)₇CH₂CH₂Si (OCH₂CH₃)₃;
CF₃(CF₂)₉CH₂CH₂Si (OCH₂CH₃)₃;and
CF₃(CF₂)₇SO₂N (C₂H₅) C₂H₄CH₂Si (OCH₃)₃.
[0062]
By using a polysiloxane containing a fluoroalkyl group as described above as a binder, the liquid repellency of the energy non-irradiated portion of the wettability changing layer is greatly improved, and when the conductive pattern composition is entirely applied, It is possible to prevent adhesion of the conductive pattern composition, and it is possible to adhere the conductive pattern composition only to the lyophilic region that is the energy irradiation section.
[0063]
Examples of the reactive silicone of the above (2) include compounds having a skeleton represented by the following general formula.
[0064]
Embedded image

[0065]
Here, n is an integer of 2 or more, and R¹, R²Is a substituted or unsubstituted alkyl, alkenyl, aryl or cyanoalkyl group having 1 to 10 carbon atoms, and the vinyl, phenyl or halogenated phenyl accounts for 40% or less of the whole in a molar ratio. Also, R¹, R²Is preferably a group having a methyl group since the surface energy is minimized, and the molar ratio of the methyl group is preferably 60% or more. Further, the chain terminal or the side chain has at least one or more reactive group such as a hydroxyl group in the molecular chain.
[0066]
Further, a stable organosilicone compound which does not undergo a cross-linking reaction, such as dimethylpolysiloxane, may be mixed with the above-mentioned organopolysiloxane.
[0067]
In the present invention, various materials such as an organopolysiloxane can be used for the wettability changing layer as described above. It is effective for pattern formation. Therefore, it can be said that it is preferable that the material which is hardly deteriorated or decomposed by the action of the photocatalyst contain fluorine, specifically, the organopolysiloxane material contains fluorine to form the wettability changing layer.
[0068]
The wettability changing layer in the present invention may further contain a surfactant. Specifically, hydrocarbons such as NIKKOL @ BL, BC, BO, and BB series manufactured by Nikko Chemicals Co., Ltd., ZONYL @ FSN, FSO manufactured by DuPont, Surflon S-141, 145 manufactured by Asahi Glass Co., Ltd., and Dainippon Japan Megafac F-141 and 144 manufactured by Ink Chemical Industry Co., Ltd., Futagent F-200 and F251 manufactured by Neos Co., Ltd., Unidyne DS-401 and 402 manufactured by Daikin Industries, Ltd., and Florad FC-170 manufactured by 3M Corporation. 176 and the like, and a fluorine-based or silicone-based nonionic surfactant can be mentioned, and a cationic surfactant, an anionic surfactant, and an amphoteric surfactant can also be used.
[0069]
Further, in addition to the above surfactant, the wettability changing layer, polyvinyl alcohol, unsaturated polyester, acrylic resin, polyethylene, diallyl phthalate, ethylene propylene diene monomer, epoxy resin, phenol resin, polyurethane, melamine resin, polycarbonate , Polyvinyl chloride, polyamide, polyimide, styrene butadiene rubber, chloroprene rubber, polypropylene, polybutylene, polystyrene, polyvinyl acetate, polyester, polybutadiene, polybenzimidazole, polyacrylonitrile, oligomers such as epichlorohydrin, polysulfide, polyisoprene, polymers, etc. Can be contained.
[0070]
Such a wettability changing layer can be formed by dispersing the above-described components in a solvent together with other additives as necessary to prepare a coating solution, and applying the coating solution onto a substrate. it can. As the solvent to be used, alcohol-based organic solvents such as ethanol and isopropanol are preferable. The coating can be performed by a known coating method such as spin coating, spray coating, dip coating, roll coating, and bead coating. When the composition contains an ultraviolet curable component, the wettability changing layer can be formed by performing a curing treatment by irradiating ultraviolet rays.
[0071]
In addition, the wettability changing layer used in the present invention may be a self-supporting material as long as it is formed of a material whose surface wettability can be changed by the action of a photocatalyst. A material having no property may be used. In the present invention, having the self-supporting property means that it can exist in a tangible state without any other supporting material.
[0072]
When the wettability changing layer is a material having self-supporting properties, it is possible to use, for example, a commercially available resin film made of a material that can be a wettability changing layer, which is advantageous in terms of cost. As such a material, it is also possible to use a material obtained by forming a film of the above-described material as long as the material has self-supporting properties. Examples thereof include polyethylene, polycarbonate, polypropylene, polystyrene, polyester, and polyvinyl fluoride. , Acetal resin, nylon, ABS, PTFE, methacrylic resin, phenol resin, polyvinylidene fluoride, polyoxymethylene, polyvinyl alcohol, polyvinyl chloride, polyethylene terephthalate, silicone and the like.
[0073]
In the present invention, a wettability changing layer having no self-supporting property is preferable. The wettability changing layer formed of a material whose characteristics are significantly changed as described above generally has a low self-supporting material, and the wettability changing layer used for the second or higher wiring board from the bottom, This is because, by applying the material having no self-supporting property by an application method, the conductive pattern portion of the lower wiring board can be protected. This makes it possible to prevent the effects of oxygen and water vapor.
[0074]
In the present invention, by using the wettability changing layer of the component described above, by the action of the photocatalyst in the photocatalyst containing layer, by using the action of oxidation, decomposition and the like of the organic group which is a part of the component, the energy irradiation section The wettability can be changed to make it lyophilic, and a large difference can be produced in the wettability with the energy non-irradiated portion. Therefore, even when the conductive pattern composition described later is applied, the conductive pattern composition can be relatively easily adhered only to the lyophilic region that is the energy irradiation part, and a high-definition multilayer is formed. The wiring board can be manufactured at low cost.
[0075]
The wettability changing layer used in the present invention is not particularly limited as long as it is a layer whose wettability changes due to the action of the photocatalyst as described above. preferable. If the photocatalyst is not contained in the wettability changing layer in this way, there is no need to worry about being affected over time when subsequently used as a multilayer wiring board, and it can be used without problems for a long time That's why.
[0076]
(2) Adhesion change layer
Next, the adhesiveness change layer used in the present invention will be described. The adhesiveness change layer used in the present invention is not particularly limited as long as the adhesiveness changes by the action of a photocatalyst, but generally, the adhesiveness change is caused by the action of the photocatalyst due to energy irradiation. It is preferable that the layer is a layer whose adhesiveness changes so that the adhesiveness to an object on the layer surface is improved.
[0077]
As described above, by forming the adhesiveness changing layer in which the adhesiveness is changed so that the adhesiveness with the object is improved by the energy irradiation, the portion irradiated with the energy can be a region having a good adhesiveness, and the portion not irradiated with the energy. Can be used as the adhesion inhibition region. Utilizing this difference in adhesion, for example, when a conductive pattern composition for forming a conductive pattern is vapor-deposited on the entire surface, the conductive pattern composition adheres only to the good adhesion region, and adheres to the adhesion inhibition region. Since the conductive pattern composition does not adhere, the conductive pattern composition in the adhesion inhibition region can be easily removed, and a conductive pattern described later can be easily formed.
[0078]
Here, the region having good adhesion is a region having good adhesion to an object, and means a region having good adhesion to a conductive pattern composition for forming a conductive pattern described later. Further, the adhesion inhibition region is a region having poor adhesion to an object, and is a region having poor adhesion to the conductive pattern composition.
[0079]
The adhesion change layer according to the present invention contains an adhesion inhibitor and is a layer from which the adhesion inhibitor is removed by energy irradiation (the first embodiment), and unevenness on the adhesion change layer by energy irradiation. Is formed and the adhesion is physically improved (second embodiment).
[0080]
First, the first embodiment will be described. The adhesion change layer of the present embodiment contains a substance that inhibits adhesion, and in the adhesion inhibition area that is not irradiated with energy due to the adhesion inhibition substance, for example, a conductive pattern applied by a vapor deposition method or the like. It becomes possible to inhibit the composition from sticking. In addition, by the action of the photocatalyst accompanying the energy irradiation, the adhesion-inhibiting substance is removed, whereby the adhesion is improved, and a region having good adhesion can be formed.
[0081]
Specifically, as the first embodiment of the adhesion change layer, the same one as described in the above wettability change layer can be used.
[0082]
Next, the second embodiment will be described. The adhesiveness change layer of this embodiment is a layer in which unevenness is formed on the surface by the action of a photocatalyst accompanying energy irradiation, and can improve the adhesiveness of the conductive pattern composition by an anchor effect due to the unevenness on the surface. It is possible. Further, in the adhesion inhibition region not irradiated with energy, since the unevenness is not formed, it is difficult for the conductive pattern composition to adhere to the region. It can be easily formed.
[0083]
Specifically, for the second embodiment of the photocatalytic adhesion change layer, use of polyethylene terephthalate, polyvinyl alcohol, polycarbonate, methyl methacrylate homopolymer or copolymer, polystyrene, polyethylene, polypropylene, polyester, PTFE, etc. Is possible.
[0084]
(3) Decomposition removal layer
Next, the decomposition removal layer used in the present invention will be described. The decomposition and removal layer used in the present invention is a decomposition and removal layer that is decomposed and removed by the action of a photocatalyst formed on the substrate for the decomposition and removal layer and the photocatalyst formed on the substrate for the decomposition and removal layer, and is decomposed and removed in an energy-irradiated pattern. It is a layer having a layer for removal.
[0085]
The decomposition / removal layer has a pattern composed of a portion with and without a decomposition / removal layer without performing a developing step or a cleaning step, that is, a pattern that is decomposed and removed without performing a developing step or a washing step, since a portion irradiated with energy is decomposed and removed by the action of a photocatalyst. Thus, a pattern having irregularities can be formed on the layer substrate. Utilizing the irregularities, a conductive pattern can be formed with high definition by applying the composition for forming a conductive pattern by, for example, an inkjet method.
[0086]
The layer for decomposition and removal is oxidized and decomposed by the action of a photocatalyst by energy irradiation and is vaporized. Therefore, the layer for removal and removal is removed without a special post-treatment such as a developing and washing step. Depending on the material of the layer, a washing step or the like may be performed.
[0087]
Hereinafter, the decomposition removal layer and the decomposition removal layer substrate will be separately described.
[0088]
(I) Layer for decomposition removal
The decomposition removal layer used in the present invention is not particularly limited as long as the layer irradiated with energy is decomposed and removed by the action of a photocatalyst to form a pattern-like unevenness. It is preferable that not only the unevenness is formed but also that the decomposition removal layer has a higher contact angle with the liquid than the decomposition removal layer substrate described later. As a result, the decomposition removal layer is decomposed and removed, and the region where the decomposition removal layer substrate is exposed can be made a lyophilic region, and the region where the decomposition removal layer remains can be made a lyophobic region. In addition, by utilizing this difference in wettability, a high-definition conductive pattern can be more easily formed by, for example, an ink-jet method.
[0089]
Here, the lyophilic region is a region having a small contact angle with a liquid, and refers to a region having good wettability to a conductive pattern composition described later. Further, the lyophobic region is a region having a large contact angle with a liquid and a region having poor wettability to the conductive pattern composition.
[0090]
Further, the decomposition and removal layer preferably has a contact angle with a liquid of 40 mN / m of 50 ° or more, particularly preferably 90 ° or more. This is because, in the present invention, since the remaining property change layer is a portion where liquid repellency is required, when the contact angle with the liquid is small, the liquid repellency is not sufficient and a conductive pattern is formed. This is because there is a possibility that the conductive pattern composition may adhere to the liquid-repellent region where the liquid-repellent region does not exist.
[0091]
Specific examples of the film that can be used for the decomposition removal layer as described above include a film made of a fluorine-based or hydrocarbon-based liquid-repellent resin or the like. These fluorine-based and hydrocarbon-based resins are not particularly limited as long as they have liquid repellency, and these resins are dissolved in a solvent and, for example, a common resin such as spin coating is used. It can be formed by a film method.
[0092]
Further, in the present invention, a functional thin film, that is, a self-assembled monomolecular film, a Langmuir-Brocket film, and by using an alternate adsorption film and the like, it is possible to form a film without defects, It can be said that such a film formation method is more preferably used.
[0093]
Here, the self-assembled monolayer, the Langmuir-Brocket film, and the alternating adsorption film used in the present invention will be specifically described.
[0094]
(1) Self-assembled monolayer
Although the inventors do not know the existence of an official definition of a self-assembled monolayer (Self-Assembled @ Monolayer), a commentary on what is generally recognized as a self-assembled monolayer is, for example, a review by Abraham @ Ulman. “Formation and Structure of the Self-Assembled Monolayers”, Chemical Review, 96, 1533-1554 (1996) are excellent. With reference to this review, a self-assembled monolayer can be said to be a monolayer formed as a result of adsorption and binding (self-assembly) of appropriate molecules to an appropriate substrate surface. Materials capable of forming a self-assembled film include, for example, surfactant molecules such as fatty acids, organic silicon molecules such as alkyltrichlorosilanes and alkylalkoxides, organic sulfur molecules such as alkanethiols, and alkyl phosphates. Organic phosphoric acid molecule. The general commonality of molecular structures is that they have a relatively long alkyl chain and that at one molecular end there is a functional group that interacts with the substrate surface. The portion of the alkyl chain is a source of intermolecular force when the molecules are packed two-dimensionally. However, the example shown here is the simplest structure, having a functional group such as an amino group or a carboxyl group at the other end of the molecule, an alkylene chain having an oxyethylene chain, or a fluorocarbon chain. A self-assembled monolayer composed of various molecules, such as a complex-type chain, has been reported. There is also a composite self-assembled monolayer composed of a plurality of molecular species. Recently, a polymer having a plurality of functional groups (in some cases, one functional group) or a linear (in some cases having a branched structure) polymer in the form of particles, such as a dendrimer, has been developed. It seems that the one formed on the substrate surface (the latter is collectively referred to as a polymer brush) may be considered as a self-assembled monolayer. The present invention also includes these in self-assembled monolayers.
[0095]
(2) Langmuir-Blodgett membrane
The Langmuir-Blodgett (Film) film used in the present invention is not significantly different from the above-described self-assembled monomolecular film in form when formed on a substrate. The characteristics of the Langmuir-Blodgett film can be said to be its formation method and the resulting high two-dimensional molecular packing properties (high orientation and high ordering). That is, in general, Langmuir-Blodgett film-forming molecules are first developed on the gas-liquid interface, and the developed film is condensed by the trough and changes into a highly packed condensed film. In practice, this is transferred to an appropriate substrate and used. It is possible to form from a monomolecular film to a multilayer film of an arbitrary molecular layer by the method outlined here. In addition, not only low molecules but also polymers, colloid particles, etc. can be used as the film material. For a review of recent applications of various materials, see Tokuharu Miyashita et al., "Prospects for Nanotechnology for Creating Soft Nanodevices", Polymer, Volume 50, September, 644-647.
(2001).
[0096]
(3) Alternate adsorption film
In general, an alternating adsorption film (Layer-by-Layer @ Self-Assembled @ Film) is formed by sequentially adsorbing and bonding at least two materials having a functional group having a positive or negative charge onto a substrate. This is a film formed by performing Since a material having a larger number of functional groups has more advantages such as an increase in the strength and durability of the membrane, an ionic polymer (polymer electrolyte) is often used recently as a material. Particles having a surface charge such as proteins, metals and oxides, so-called "colloidal particles" are also frequently used as film-forming substances. More recently, membranes have been reported that actively utilize weaker interactions than ionic bonds, such as hydrogen bonds, coordinate bonds, and hydrophobic interactions. In the case of a relatively recent alternately adsorbed film, the bias is slightly biased toward a material system using electrostatic interaction as a driving force, but Paula @ T. Review by Hammond, "Recent \ Explorations \ in \ Electrostatic \ Multilayer \ Thin \ Film \ Assembly" Current Current Opinion in Colloid & Interface Science, 4, 430-4. In the alternate adsorption film, taking the simplest process as an example, the cycle of adsorption-washing of a material having a positive (negative) charge-adsorption-washing of a material having a negative (positive) charge is repeated a predetermined number of times. It is a film to be formed. No development-condensation-transfer operations are required at all as with Langmuir-Blodgett membranes. Further, as is apparent from the difference between these production methods, the alternating adsorption film generally does not have a two-dimensional high orientation and high order unlike the Langmuir-Blodgett film. However, the alternate adsorption film and its manufacturing method have advantages over conventional film forming methods, such as being able to easily form a dense film without defects and being able to uniformly form a film on a fine uneven surface, a tube inner surface, a spherical surface, and the like. Have many.
[0097]
The thickness of the decomposition removal layer is not particularly limited as long as it is a thickness that can be decomposed and removed by the energy applied in the later-described characteristic change pattern forming step. The specific film thickness varies greatly depending on the type of energy to be irradiated, the material of the decomposition removal layer, and the like, but is generally in the range of 0.001 μm to 1 μm, particularly 0.01 μm to 0 μm. It is preferably within a range of 1 μm.
[0098]
(Ii) Substrate for decomposition removal layer
Next, the substrate for a decomposition removal layer used in the present invention will be described. The substrate for the decomposition removal layer used in the present invention is not particularly limited as long as the substrate can form the above-described decomposition removal layer on the surface thereof. Then, it is preferable that the contact angle with the liquid is low. Thereby, the decomposition removal layer is decomposed and removed, the region where the decomposition removal layer substrate is exposed can be made a lyophilic region, and the region where the decomposition removal layer remains can be made a lyophobic region. This is because a pattern can be formed.
[0099]
In the substrate for a decomposition removal layer in the present invention, the contact angle with a liquid of 40 mN / m is preferably 49 ° or less, particularly preferably 10 ° or less in a portion where energy is not irradiated. In the present invention, since the substrate for the decomposition removal layer is a portion where lyophilicity is required, the conductive pattern composition is repelled even in the lyophilic region when applying the conductive pattern composition described below. This is because there is a possibility that it may be difficult to pattern the conductive pattern composition on the lyophilic region. Here, the contact angle with the liquid is a value measured by the method described above.
[0100]
In this case, the substrate for the decomposition removal layer may be surface-treated so that the surface becomes lyophilic. Examples of surface treatment of the material to be lyophilic include lyophilic surface treatment by plasma treatment using argon, water, etc., and the lyophilic surface formed on the substrate for the decomposition removal layer. Examples of the layer include a silica film formed by a sol-gel method of tetraethoxysilane.
[0101]
(Base material)
Next, the base material used in the present invention will be described. In the present invention, for example, a substrate is used when the property change layer formed on the lowermost layer portion of the multilayer wiring board has no self-supporting property or when the multilayer wiring board requires strength. As shown in FIG. 2, a characteristic change layer 1 of the wiring board at the lowermost layer portion of the multilayer wiring board is provided on the base material 4.
[0102]
Such a base material is appropriately selected depending on the use of the finally obtained multilayer wiring board and the like. For example, in the case of a normal printed wiring board or the like, generally used materials are used. Specifically, a resin laminate of a paper base, a resin laminate of a glass cloth / glass nonwoven fabric base, ceramic, metal, or the like can be used. In the flexible wiring board, a resin film having flexibility can be used as a base material.
[0103]
(Conductive pattern)
Next, the conductive pattern used in the present invention will be described. As long as the conductive pattern used in the present invention is a pattern having conductivity formed along the pattern in which the characteristics of the above-described characteristic change layer have changed, the shape and material of the pattern are not particularly limited. Absent. As the material used for the conductive pattern in the present embodiment, specifically, copper, gold, silver, nickel, aluminum, palladium, lead, tin and a powdery metal or alloy containing one or more of these metals and , A binder resin, a dispersant, and an organic solvent. Among them, a metal ink using copper and silver is preferable.
[0104]
Further, the method for forming a conductive pattern of the present invention is appropriately selected depending on the change in the characteristics of the above-described characteristic change layer. Specifically, the vapor deposition method, electroless plating, dip coating, roll coating, Examples include coating means such as blade coating and spin coating, and means such as nozzle discharging means including ink jet and electrolytic jet.
[0105]
(Wiring board)
Next, the wiring board according to the present invention will be described. The wiring board according to the present invention is a wiring board in which the above-described characteristic change layer and the conductive pattern are formed along a pattern in which the characteristics of the above-mentioned characteristic change layer are changed, and the wiring pattern and the like are not particularly limited. Absent.
[0106]
(Conductive connector)
Next, the conductive connector according to the present invention will be described. The conductive connector according to the present invention is a portion formed of a conductive material and provided for electrically connecting conductive patterns on adjacent wiring boards. For example, as shown in FIG. It is formed of a conductive material between the conductive portion 2 of the substrate 3 and the conductive portion 2 'of the adjacent wiring board 3'. In the present invention, the method of forming the conductive connector is not particularly limited as long as it is electrically connectable, but in the present invention, the conductive connector is formed on the above-described characteristic change layer. It is preferable that the through hole is formed by filling a conductive material.
[0107]
Here, the through hole in the present invention is used to form a conductive pattern and a conductive connector that electrically connects the conductive pattern and the conductive pattern present immediately below the characteristic change layer. , A hole provided in the characteristic change layer.
[0108]
The material and the forming method used for the conductive connector of the present invention can be the same as those of the above-described conductive pattern, and thus description thereof will be omitted.
[0109]
(Multilayer wiring board)
Next, the multilayer wiring board of the present invention will be described. The multilayer wiring board of the present invention has at least two or more layers of the above wiring boards, and preferably has three to five layers.
[0110]
In the present invention, the conductive connector as described above may be provided between the conductive patterns of the adjacent wiring boards. When the board requires strength, a multilayer wiring board may be formed on the base material.
[0111]
B. Method for manufacturing multilayer wiring board
Next, a method for manufacturing a multilayer wiring board of the present invention will be described. The method for manufacturing a multilayer wiring board of the present invention includes:
A property change layer preparation step of preparing a property change layer whose properties change by the action of a photocatalyst accompanying energy irradiation,
After arranging the photocatalyst-containing layer-side substrate having the photocatalyst-containing layer containing the substrate and the photocatalyst, and the property-changing layer with a gap such that the photocatalyst-containing layer and the property-change layer are 200 μm or less, a predetermined A characteristic change pattern forming step of forming a characteristic change pattern having changed characteristics on the surface of the characteristic change layer by irradiating energy from the direction of
Along with the characteristic change pattern, a conductive pattern forming step of forming a conductive pattern,
The step of forming a wiring board having at least two times.
[0112]
The method for manufacturing a multilayer wiring board according to the present invention is characterized in that the wiring board step is performed at least twice, preferably three to five times. This wiring board forming step will be described using FIG. 4 as an example.
[0113]
First, a property changing layer adjusting step for preparing the property changing layer 1 is performed (FIG. 4A). Next, the photocatalyst-containing layer-side substrate 7 having the base 5 and the photocatalyst-containing layer 6 is disposed such that the characteristic change layer 1 and the photocatalyst-containing layer 6 have a predetermined gap. Then, a characteristic change pattern forming step of irradiating the energy 9 in a pattern from a predetermined direction is performed (FIG. 4B). As a result, a characteristic change pattern 10 having changed characteristics is formed on the characteristic change layer 1. Next, a conductive pattern forming step of forming the conductive pattern 2 is performed along the characteristic change pattern 10 by, for example, an ink-jet method or the like, thereby forming the wiring board 3 (FIG. 4D).
[0114]
According to the manufacturing method for forming a multilayer wiring board of the present invention, a conductive pattern is formed along the above-mentioned characteristic change pattern, so that a high-definition conductive pattern can be formed. In addition, by performing this wiring board forming step at least twice or more, a multilayer wiring board is obtained, so that the obtained multilayer wiring board can have a high-definition conductive pattern.
[0115]
Further, in the present invention, as shown in FIG. 5, after the above-mentioned property changing layer adjusting step (FIG. 5 (a)), the same photocatalyst containing layer side substrate 7 as used in the above-mentioned wiring board forming step, After arranging the property changing layer 1 with a gap such that the photocatalyst containing layer 5 and the property changing layer 1 are 200 μm or less, energy 9 is irradiated from a predetermined direction using, for example, a photomask 8 or the like. (FIG. 5B), a through-hole characteristic changing pattern 13 having changed characteristics is formed on the surface of the characteristic changing layer 1 (FIG. 5C). A through-hole forming step (FIG. 5D) of forming a through-hole 14 by applying a liquid along the hole characteristic changing pattern 13 may be performed. Thereby, in the conductive pattern forming step, at the same time as forming the conductive pattern, the through hole can be filled with a conductive material, and a conductive connector for electrically connecting the conductive patterns can be provided. It can be easily formed. Hereinafter, the method for manufacturing a multilayer wiring board of the present invention will be described for each step.
[0116]
(1) Property change layer preparation step
First, the step of preparing the characteristic change layer of the present invention will be described. The method of preparing a property-change layer in the present invention is not particularly limited as long as it is a step of preparing a property-change layer whose properties change by the action of a photocatalyst accompanying energy irradiation. In the wiring substrate forming step, it is preferable to perform the coating method. Since the property changing layer preparing step is a coating method, it is possible to form a property changing layer also around the conductive pattern formed in the immediately preceding wiring board forming step, thereby forming the conductive pattern with oxygen or It is possible to protect from water vapor. It is also preferable in terms of manufacturing efficiency and cost.
[0117]
Further, when the characteristic change layer of the wiring board located at the lowermost layer part of the multilayer wiring board used in the present invention does not have self-supporting property, the characteristic change layer of the lowermost layer part is formed on the base material. It is necessary.
[0118]
Note that the property change layer, the method of forming the property change layer, the base material, and the like used in the present invention are the same as those described in the above “A. Multilayer Wiring Board”, and thus description thereof will be omitted. .
[0119]
(2) Characteristic change pattern forming step
Next, the characteristic change pattern forming step in the present invention will be described. The property change pattern forming step in the present invention is such that the photocatalyst containing layer side substrate having a substrate and a photocatalyst containing layer containing a photocatalyst, and the above property change layer, the photocatalyst containing layer and the above property change layer are 200 μm or less. And forming a characteristic change pattern having changed characteristics on the surface of the characteristic change layer by irradiating energy from a predetermined direction after disposing a gap.
[0120]
The characteristic change pattern forming step of the present invention may be performed on a wiring board on which a through-hole characteristic change pattern forming step and a through-hole forming step described below have been performed, or the through-hole characteristic changing pattern forming step and the through-hole forming step may be performed. It may be performed for a wiring board that is not used.
[0121]
This step irradiates energy to the pattern shape of the conductive pattern formed in the conductive pattern forming step described later, and forms the conductive pattern formed in the conductive pattern forming step described later, This is a step of changing characteristics. This makes it possible to easily form a conductive pattern in a conductive pattern forming step described later. Hereinafter, each configuration of this step will be described.
[0122]
(Photocatalyst containing layer side substrate)
First, the photocatalyst-containing layer-side substrate used in the present invention will be described. The photocatalyst-containing layer-side substrate used in the present invention has at least a photocatalyst-containing layer and a substrate, and usually has a thin-film-like photocatalyst-containing layer formed by a predetermined method on the substrate. is there. The photocatalyst-containing layer-side substrate may also be a substrate on which a photocatalyst-containing layer-side light-shielding portion or a primer layer formed in a pattern is formed. Hereinafter, each configuration of the photocatalyst containing layer side substrate will be described.
[0123]
a. Photocatalyst containing layer
The photocatalyst containing layer used in the present invention is not particularly limited as long as the photocatalyst in the photocatalyst containing layer changes the properties of the property changing layer, and is made up of a photocatalyst and a binder. The photocatalyst may be used, or the photocatalyst alone may be used. In addition, the characteristics of the surface may be particularly lyophilic or lyophobic.
[0124]
The photocatalyst-containing layer used in the present invention may be formed on the entire surface of the substrate 6 as shown in FIG. 4B, for example. The photocatalyst containing layer 5 may be formed thereon in a pattern.
[0125]
By forming the photocatalyst-containing layer in a pattern as described above, a photomask or the like is used when irradiating the photocatalyst-containing layer with energy to the characteristic-change layer, as described in the section of forming a characteristic-change pattern described later. There is no need to perform pattern irradiation, and by irradiating the entire surface, a characteristic change pattern including a characteristic change region and a characteristic non-change region can be formed on the characteristic change layer.
[0126]
The method of patterning the photocatalyst treatment layer is not particularly limited, but can be performed by, for example, a photolithography method.
[0127]
Further, when the energy irradiation is performed by, for example, bringing the photocatalyst-containing layer and the property changing layer into close contact with each other, the property of only the portion where the photocatalyst-containing layer is actually changed is changed. Irradiation may be performed from any direction as long as the energy is applied to the portion where the photocatalyst-containing layer and the property change layer are opposed to each other, and the energy to be applied is also limited to parallel light such as parallel light. This has the advantage of not being performed.
[0128]
In such a photocatalyst-containing layer, the action mechanism of a photocatalyst represented by titanium dioxide as described below is not necessarily clear, but the carrier generated by light irradiation is a direct reaction with a nearby compound, or It is considered that the reactive oxygen species generated in the presence of oxygen, water and water change the chemical structure of organic matter. In the present invention, it is considered that this carrier acts on the compound in the property change layer on the photocatalyst containing layer.
[0129]
The photocatalyst used in the present invention includes, for example, titanium dioxide (TiO 2) which is known as an optical semiconductor.₂), Zinc oxide (ZnO), tin oxide (SnO)₂), Strontium titanate (SrTiO)₃), Tungsten oxide (WO₃), Bismuth oxide (Bi₂O₃), And iron oxide (Fe₂O₃), And one or more of them may be used in combination.
[0130]
In the present invention, titanium dioxide is particularly preferably used because it has a high band gap energy, is chemically stable, has no toxicity, and is easily available. Titanium dioxide includes anatase type and rutile type, and any of them can be used in the present invention, but anatase type titanium dioxide is preferable. Anatase type titanium dioxide has an excitation wavelength of 380 nm or less.
[0131]
Examples of such anatase-type titanium dioxide include, for example, anatase-type titania sol of peptized hydrochloric acid (STS-02 (average particle size: 7 nm) manufactured by Ishihara Sangyo Co., Ltd .; ST-K01 manufactured by Ishihara Sangyo Co., Ltd.); Glue-type anatase titania sol (TA-15 (average particle diameter: 12 nm) manufactured by Nissan Chemical Industries, Ltd.) and the like can be mentioned.
[0132]
The smaller the particle size of the photocatalyst is, the more effective the photocatalytic reaction takes place. It is preferable that the average particle size is 50 nm or less, and it is particularly preferable to use a photocatalyst having a mean size of 20 nm or less.
[0133]
The photocatalyst containing layer in the present invention may be formed by using only the photocatalyst as described above, or may be formed by mixing with a binder. In the case of the photocatalyst-containing layer composed of only the photocatalyst, the efficiency with respect to the change of the property on the property change layer is improved, which is advantageous in terms of cost such as shortening of the processing time. On the other hand, a photocatalyst-containing layer composed of a photocatalyst and a binder has an advantage that the photocatalyst-containing layer can be easily formed.
[0134]
Examples of a method for forming the photocatalyst-containing layer composed of only a photocatalyst include a method using a vacuum film forming method such as a sputtering method, a CVD method, and a vacuum evaporation method. By forming the photocatalyst-containing layer by a vacuum film forming method, it is possible to form a uniform film and a photocatalyst-containing layer containing only the photocatalyst, thereby uniformly changing the characteristics on the characteristic change layer. Since it is possible and consists only of a photocatalyst, it becomes possible to change the characteristics on the characteristic change layer more efficiently than when using a binder.
[0135]
Further, as another method for forming the photocatalyst-containing layer composed of only the photocatalyst, for example, when the photocatalyst is titanium dioxide, a method in which amorphous titania is formed on a substrate, and then the phase is changed to crystalline titania by calcination. Can be As the amorphous titania used here, for example, titanium tetrachloride, hydrolysis and dehydration condensation of inorganic salts of titanium such as titanium sulfate, tetraethoxytitanium, tetraisopropoxytitanium, tetra-n-propoxytitanium, tetrabutoxytitanium, An organic titanium compound such as tetramethoxytitanium can be obtained by hydrolysis and dehydration condensation in the presence of an acid. Next, it can be denatured to anatase type titania by baking at 400 ° C. to 500 ° C., and can be denatured to rutile type titania by baking at 600 ° C. to 700 ° C.
[0136]
When using a binder, it is preferable that the main skeleton of the binder has a high binding energy such that the binder is not decomposed by the photoexcitation of the photocatalyst.For example, in the description of the wettability changing layer in the property changing layer described later, An organopolysiloxane described in detail can be mentioned.
[0137]
When the organopolysiloxane is used as a binder in this manner, the photocatalyst-containing layer is prepared by dispersing a photocatalyst and an organopolysiloxane as a binder in a solvent together with other additives as necessary to prepare a coating solution. It can be formed by applying this coating solution on a substrate. As the solvent to be used, alcohol-based organic solvents such as ethanol and isopropanol are preferable. The coating can be performed by a known coating method such as spin coating, spray coating, dip coating, roll coating, and bead coating. When an ultraviolet-curable component is contained as a binder, the photocatalyst-containing layer can be formed by performing a curing treatment by irradiating ultraviolet rays.
[0138]
Further, an amorphous silica precursor can be used as a binder. This amorphous silica precursor has the general formula SiX₄X is preferably a silicon compound such as a halogen, a methoxy group, an ethoxy group, or an acetyl group, a hydrolyzate of the compound, silanol, or a polysiloxane having an average molecular weight of 3000 or less.
[0139]
Specific examples include tetraethoxysilane, tetraisopropoxysilane, tetra-n-propoxysilane, tetrabutoxysilane, tetramethoxysilane and the like. In this case, the precursor of the amorphous silica and the particles of the photocatalyst are uniformly dispersed in a non-aqueous solvent, and hydrolyzed by moisture in the air on the substrate to form silanol, and then the mixture is heated at room temperature. A photocatalyst-containing layer can be formed by dehydration-condensation polymerization. If the dehydration-condensation polymerization of silanol is performed at 100 ° C. or higher, the degree of polymerization of silanol increases and the strength of the film surface can be improved. These binders can be used alone or in combination of two or more.
[0140]
When the binder is used, the content of the photocatalyst in the photocatalyst containing layer can be set in the range of 5 to 60% by weight, preferably 20 to 40% by weight. Further, the thickness of the photocatalyst containing layer is preferably in the range of 0.05 to 10 μm.
[0141]
The photocatalyst-containing layer may contain a surfactant in addition to the photocatalyst and the binder. Specifically, hydrocarbons such as NIKKOL @ BL, BC, BO, and BB series manufactured by Nikko Chemicals Co., Ltd., ZONYL @ FSN, FSO manufactured by DuPont, Surflon S-141, 145 manufactured by Asahi Glass Co., Ltd., and Dainippon Japan Megafac F-141 and 144 manufactured by Ink Chemical Industry Co., Ltd., Futagent F-200 and F251 manufactured by Neos Co., Ltd., Unidyne DS-401 and 402 manufactured by Daikin Industries, Ltd., and Florad FC-170 manufactured by 3M Corporation. 176 and the like, and a fluorine-based or silicone-based nonionic surfactant, and a cationic surfactant, an anionic surfactant, and an amphoteric surfactant can also be used.
[0142]
Further, in addition to the above surfactant, the photocatalyst-containing layer, polyvinyl alcohol, unsaturated polyester, acrylic resin, polyethylene, diallyl phthalate, ethylene propylene diene monomer, epoxy resin, phenol resin, polyurethane, melamine resin, polycarbonate, Oligomers, polymers such as polyvinyl chloride, polyamide, polyimide, styrene butadiene rubber, chloroprene rubber, polypropylene, polybutylene, polystyrene, polyvinyl acetate, polyester, polybutadiene, polybenzimidazole, polyacrylonitrile, epichlorohydrin, polysulfide, polyisoprene, etc. It can be contained.
[0143]
b. Base
In the present invention, for example, as shown in FIG. 4B, the photocatalyst-containing layer-side substrate 7 has at least a substrate 6 and a photocatalyst-containing layer 5 formed on the substrate 6.
[0144]
At this time, the material constituting the base to be used is appropriately selected depending on the irradiation direction of energy described in the section of forming a characteristic change pattern described later, whether the obtained multilayer wiring board requires transparency, and the like.
[0145]
That is, for example, when an opaque substrate such as a paper-based phenolic resin laminate is used as the substrate, the energy irradiation direction is necessarily from the photocatalyst-containing layer side substrate side, as shown in FIG. 4B. It is necessary to dispose the photomask 8 on the photocatalyst-containing layer-side substrate 7 side and radiate the energy 9. Further, as described later, a photocatalyst-containing layer-side light-shielding portion is formed in a predetermined pattern on a photocatalyst-containing layer-side substrate in advance, and a photocatalyst-containing layer-side light-shielding portion is used to form a characteristic change pattern. It is necessary to irradiate energy from the substrate side on the containing layer side. In such a case, the substrate needs to have transparency.
[0146]
On the other hand, when the base material of the multilayer wiring board is, for example, a transparent resin film, depending on the type of the multilayer wiring board, a photomask may be arranged on the multilayer wiring board side to radiate energy.
[0147]
The substrate used in the present invention may be a substrate having flexibility, for example, a resin film, or a substrate having no flexibility, for example, a glass substrate. This is appropriately selected depending on an energy irradiation method in a later-described characteristic change pattern forming step.
[0148]
As described above, the substrate used for the photocatalyst-containing layer-side substrate in the present invention is not particularly limited in its material, but in the present invention, the photocatalyst-containing layer-side substrate is used repeatedly. A material having a predetermined strength and a surface having good adhesion to the photocatalyst-containing layer is preferably used.
[0149]
Specific examples include glass, ceramic, metal, plastic, and the like.
[0150]
Note that an anchor layer may be formed on the substrate in order to improve the adhesion between the substrate surface and the photocatalyst-containing layer. Examples of such an anchor layer include silane-based and titanium-based coupling agents.
[0151]
c. Photocatalyst containing layer side light shielding part
The photocatalyst-containing layer-side substrate used in the present invention may have a photocatalyst-containing layer-side light-shielding portion formed in a pattern. By using the photocatalyst-containing layer-side substrate having the photocatalyst-containing layer-side light-shielding portion as described above, it is not necessary to use a photomask or perform drawing irradiation with a laser beam when irradiating energy. Therefore, since there is no need to align the photocatalyst-containing layer-side substrate with the photomask, it is possible to simplify the process, and it is not necessary to use an expensive apparatus required for drawing irradiation, thereby reducing cost. This is advantageous in that it is advantageous.
[0152]
The photocatalyst-containing layer-side substrate having such a photocatalyst-containing layer-side light-shielding portion can be in the following two embodiments depending on the formation position of the photocatalyst-containing layer-side light-shielding portion.
[0153]
One is, for example, as shown in FIG. 7, a photocatalyst-containing layer-side light-shielding portion 11 is formed on a substrate 6, and a photocatalyst-containing layer 5 is formed on the photocatalyst-containing layer-side light-shielding portion 11. 7 is an embodiment. The other is an embodiment in which a photocatalyst containing layer 5 is formed on a substrate 6 and a photocatalyst containing layer side light shielding portion 11 is formed thereon to form a photocatalyst containing layer side substrate 7 as shown in FIG. 8, for example. is there.
[0154]
In any of the embodiments, the photocatalyst-containing layer-side light-shielding portion is disposed near the portion where the photocatalyst-containing layer and the property-changing layer are disposed, as compared with the case where a photomask is used. Can reduce the influence of the energy scattering in the above, so that the energy pattern irradiation can be performed very accurately.
[0155]
Further, in the embodiment in which the photocatalyst-containing layer-side light-shielding portion is formed on the photocatalyst-containing layer, when the photocatalyst-containing layer and the property changing layer are arranged at predetermined positions, the thickness of the photocatalyst-containing layer-side light-shielding portion is reduced. Has the advantage that the light-shielding portion on the photocatalyst-containing layer side can be used also as a spacer for making the gap constant.
[0156]
That is, when the photocatalyst-containing layer and the property change layer are arranged facing each other with a predetermined gap therebetween, the photocatalyst-containing layer-side light-shielding portion and the property change layer are arranged in close contact with each other. The above-mentioned predetermined gap can be made accurate, and in this state, by irradiating energy from the photocatalyst-containing layer side substrate, it becomes possible to accurately form a characteristic change pattern on the characteristic change layer. is there.
[0157]
The method of forming the photocatalyst-containing layer-side light-shielding portion is not particularly limited, and may be appropriately selected and used depending on the characteristics of the surface on which the photocatalyst-containing layer-side light-shielding portion is formed, the shielding property against required energy, and the like. Can be
[0158]
For example, it may be formed by forming a metal thin film of chromium or the like having a thickness of about 1000 to 2000 ° by a sputtering method, a vacuum evaporation method, or the like, and patterning the thin film. As the patterning method, a normal patterning method such as sputtering can be used.
[0159]
Alternatively, a method in which a layer containing light-shielding particles such as carbon fine particles, metal oxides, inorganic pigments, and organic pigments in a resin binder may be formed in a pattern. As the resin binder to be used, one or a mixture of two or more resins such as polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, and cellulose, photosensitive resin, and O / O A W emulsion type resin composition, for example, an emulsion of reactive silicone can be used. The thickness of such a resin light-shielding portion can be set within a range of 0.5 to 10 μm. A commonly used method such as a photolithography method and a printing method can be used as a method for patterning the resin light-shielding portion.
[0160]
In the above description, the photocatalyst-containing layer side light-shielding portion is formed at two positions, that is, between the substrate and the photocatalyst-containing layer and on the surface of the photocatalyst-containing layer. It is also possible to adopt a mode in which a photocatalyst-containing layer-side light-shielding portion is formed on the surface on the side that is not provided. In this embodiment, for example, a case where the photomask is brought into close contact with the surface to the extent that it can be detached or the like can be considered, and it can be suitably used when the characteristic change pattern is changed in a small lot.
[0161]
d. Primer layer
Next, the primer layer used in the photocatalyst-containing layer-side substrate of the present invention will be described. In the present invention, when the photocatalyst-containing layer-side substrate is formed by forming the photocatalyst-containing layer-side light-shielding portion on the substrate in a pattern as described above, and forming the photocatalyst-containing layer thereon, A primer layer may be formed between the side light shielding portion and the photocatalyst containing layer.
[0162]
The function and function of this primer layer are not necessarily clear, but by forming the primer layer between the light-shielding part on the photocatalyst containing layer side and the photocatalyst containing layer, the primer layer becomes a characteristic change layer due to the action of the photocatalyst. Impurities from the openings existing between the photocatalyst-containing layer-side light-shielding portion and the photocatalyst-containing layer-side light-shielding portion, which are factors that hinder the change, in particular, residues, metals, and metals generated when patterning the photocatalyst-containing layer-side light-shielding portion This is considered to indicate a function of preventing diffusion of impurities such as ions. Therefore, by forming the primer layer, the process of changing the characteristics proceeds with high sensitivity, and as a result, a high-resolution pattern can be obtained.
[0163]
In the present invention, the primer layer prevents not only the photocatalyst-containing layer-side light-shielding portion but also impurities present in the opening formed between the photocatalyst-containing layer-side light-shielding portions from affecting the action of the photocatalyst. The primer layer is preferably formed over the entire light-shielding portion on the photocatalyst-containing layer side including the opening.
[0164]
FIG. 9 shows an example of a photocatalyst-containing layer-side substrate having such a primer layer formed thereon. A primer layer 12 is formed on the surface of the substrate 6 on which the photocatalyst-containing layer-side light-shielding portions 11 of the photocatalyst-containing layer-side substrate 7 are formed. Has a photocatalyst containing layer 5 formed on the surface thereof.
[0165]
The primer layer in the present invention is not particularly limited as long as the primer layer is formed so that the photocatalyst-containing layer-side light-shielding portion of the photocatalyst-containing layer-side substrate does not contact the photocatalyst-containing layer.
[0166]
The material constituting the primer layer is not particularly limited, but an inorganic material that is not easily decomposed by the action of a photocatalyst is preferable. Specific examples include amorphous silica. When such an amorphous silica is used, the precursor of the amorphous silica has a general formula of SiX₄Wherein X is a silicon compound such as a halogen, a methoxy group, an ethoxy group, or an acetyl group. Silanol, which is a hydrolyzate thereof, or a polysiloxane having an average molecular weight of 3000 or less is preferable.
[0167]
Further, the thickness of the primer layer is preferably in the range of 0.001 μm to 1 μm, and particularly preferably in the range of 0.001 μm to 0.1 μm.
[0168]
(Formation of characteristic change pattern)
Next, formation of the characteristic change pattern will be described. In the characteristic change pattern forming step of the present invention, after arranging the photocatalyst containing layer and the characteristic change layer at predetermined positions, by irradiating energy from a predetermined direction, a pattern is formed on the surface of the characteristic change layer. A process is performed. Hereinafter, formation of this characteristic change pattern will be described.
[0169]
a. Arrangement of photocatalyst containing layer and property change layer
In the property change pattern forming step of the present invention, first, it is necessary to arrange the photocatalyst containing layer and the property change layer at a predetermined interval so that the action of the photocatalyst is exerted during energy irradiation. After arranging the photocatalyst containing layer and the property change layer with a gap of 200 μm or less, energy is irradiated from a predetermined direction. At this time, the photocatalyst containing layer and the property change layer may be brought into close contact with each other.
[0170]
In the present invention, in consideration of the fact that the gap has extremely good pattern accuracy and high sensitivity of the photocatalyst, and thus has a good property change efficiency of the property change layer, it is particularly in the range of 0.2 μm to 10 μm, preferably It is preferable that the thickness be in the range of 1 μm to 5 μm. Such a range of the gap is particularly effective for a small-area characteristic change layer in which the gap can be controlled with high accuracy.
[0171]
On the other hand, when processing is performed on a large-area characteristic change layer of, for example, 300 mm × 300 mm, a fine gap as described above is formed between the photocatalyst-containing layer-side substrate and the characteristic change layer without contact. It is extremely difficult to do. Therefore, when the characteristic change layer has a relatively large area, the gap is preferably in the range of 10 to 100 μm, particularly preferably in the range of 50 to 75 μm. By setting the gap to be in such a range, a problem such as a decrease in pattern accuracy such as blurring of the pattern and a problem such as a decrease in sensitivity of the photocatalyst and a decrease in efficiency of the characteristic change do not occur. This is because there is an effect that unevenness does not occur in the characteristic change on the layer.
[0172]
When the relatively large area of the property change layer is irradiated with energy, the gap in the positioning device between the photocatalyst-containing layer-side substrate and the property change layer in the energy irradiation device is set within a range of 10 μm to 200 μm. In particular, it is preferable to set within the range of 25 μm to 75 μm. By setting the set value within such a range, the photocatalyst-containing layer-side substrate and the property change layer are arranged without contacting without significantly lowering the pattern accuracy or significantly lowering the sensitivity of the photocatalyst. This is because it becomes possible.
[0173]
By arranging the photocatalyst-containing layer and the surface of the property change layer at a predetermined distance in this manner, oxygen and water and active oxygen species generated by the photocatalysis can be easily desorbed. That is, when the distance between the photocatalyst-containing layer and the property change layer is narrower than the above range, the desorption of the active oxygen species becomes difficult, and as a result, there is a possibility that the property change rate may be reduced. Absent. Further, when the active oxygen species are arranged at an interval larger than the above range, it becomes difficult for the generated active oxygen species to reach the characteristic change layer, and also in this case, the speed of the characteristic change may be reduced, which is not preferable.
[0174]
In the present invention, such an arrangement state need only be maintained at least during energy irradiation.
[0175]
As a method of forming such an extremely narrow gap uniformly and arranging the photocatalyst containing layer and the property changing layer, for example, a method using a spacer can be mentioned. By using the spacer in this manner, a uniform gap can be formed, and at the portion where the spacer contacts, the action of the photocatalyst does not reach the surface of the characteristic change layer. By having the same pattern as the change pattern, it is possible to form a predetermined characteristic change pattern on the characteristic change layer.
[0176]
In the present invention, such a spacer may be formed as one member, but as described in the section of the photocatalyst containing layer side substrate, for the sake of simplification of the process, the photocatalyst containing layer side substrate It is preferably formed on the surface of the containing layer. In the above description of the photocatalyst containing layer side substrate, the photocatalyst containing layer side light shielding portion has been described. However, in the present invention, such a spacer protects the surface so that the action of the photocatalyst does not reach the surface of the characteristic change layer. It may be formed of a material that does not have a function of shielding the irradiated energy, as long as it has the function of performing the above operation.
[0177]
b. Energy irradiation
Next, energy irradiation is performed on the opposing portion while maintaining the above arrangement. The term “energy irradiation (exposure)” in the present invention is a concept including irradiation of any energy ray capable of changing the properties of the surface of the property change layer by the photocatalyst-containing layer, and is limited to visible light irradiation. Not something.
[0178]
Usually, the wavelength of light used for such energy irradiation is set in a range of 400 nm or less, preferably in a range of 380 nm or less. This is because the preferable photocatalyst used for the photocatalyst-containing layer is titanium dioxide as described above, and light having the above-mentioned wavelength is preferable as the energy for activating the photocatalysis by the titanium dioxide.
[0179]
Examples of the light source that can be used for such energy irradiation include a mercury lamp, a metal halide lamp, a xenon lamp, an excimer lamp, and various other light sources.
[0180]
In addition to the above-described method using a light source and irradiating a pattern through a photomask, a method of drawing and irradiating a pattern using a laser such as excimer or YAG can also be used.
[0181]
Further, the energy irradiation amount at the time of energy irradiation is an irradiation amount necessary for changing the characteristics of the surface of the characteristic change layer by the action of the photocatalyst in the photocatalyst containing layer.
[0182]
In this case, by irradiating energy while heating the photocatalyst-containing layer, the sensitivity can be increased, which is preferable in that the characteristics can be changed efficiently. Specifically, it is preferable to heat in the range of 30 ° C to 80 ° C.
[0183]
The energy irradiation direction in the present invention may be performed from the multilayer wiring board side depending on the pattern of the multilayer wiring board in which the multilayer wiring board is transparent, but the energy irradiation is usually performed from the photocatalyst containing layer side substrate side.
[0184]
That is, when the photocatalyst-containing layer-side light-shielding portion is formed, it is necessary to perform energy irradiation from the photocatalyst-containing layer-side substrate side, and in this case, the energy is irradiated to the photocatalyst-containing layer-side substrate. Need to be In this case, when the photocatalyst-containing layer-side light-shielding portion is formed on the photocatalyst-containing layer and the photocatalyst-containing layer-side light-shielding portion is used so as to have a function as a spacer as described above, the multilayer wiring substrate Depending on the type, the energy irradiation direction may be from the photocatalyst containing layer side substrate side or from the multilayer wiring substrate side.
[0185]
The energy irradiation direction in the case where the photocatalyst containing layer is formed in a pattern is, as described above, if the energy is applied to the portion where the photocatalyst containing layer and the property change layer are opposed to each other, as described above. Depending on the type, irradiation may be performed from any direction.
[0186]
Similarly, even when the above-described spacer is used, the irradiation may be performed from any direction depending on the type of the multilayer wiring board, as long as the energy is applied to the opposing portion.
[0187]
When a photomask is used, energy is applied from the side where the photomask is arranged. In this case, the substrate on which the photomask is disposed, that is, either the photocatalyst-containing layer-side substrate or the multilayer wiring substrate needs to be transparent.
[0188]
c. Removal of photocatalyst containing layer side substrate
When the above-described energy irradiation is completed, the photocatalyst-containing layer-side substrate is separated from the position where the photocatalyst-containing layer and the characteristic change layer are arranged, whereby a characteristic change pattern 10 is formed on the characteristic change layer 1 as shown in FIG. Is done.
[0189]
(3) Conductive pattern forming step
Next, the conductive pattern forming step of the present invention will be described. The conductive pattern forming step of the present invention is a step of forming a conductive pattern along the characteristic change pattern formed in the characteristic change pattern forming step, and includes a through hole characteristic change pattern forming step and a through hole formation described later. With respect to the wiring board on which the process has been performed, the conductive connector may be formed by filling the through hole at the same time as forming the conductive pattern.
[0190]
The conductive pattern forming step of the present invention is not particularly limited as long as it is a method capable of forming a conductive pattern on the characteristic change pattern, and is appropriately selected according to the characteristics of the characteristic change layer. Although, for example, when the property change layer is a wettability change layer, means such as dip coating, roll coating, blade coating, application means such as spin coating, ink jet, nozzle discharging means including electrolytic jet, etc. Can be used. In the present invention, it is particularly preferable to use a nozzle discharging means. This is because, in the nozzle discharging means, it is possible to apply a conductive pattern composition that forms a conductive pattern in a target pattern, and it is possible to form a conductive pattern with higher definition. .
[0191]
In addition, when the property change layer is an adhesion change layer, in addition to the above-described method, an evaporation method, electroless plating, or the like can also be used. By removing the conductive pattern composition adhered to the substrate, the conductive pattern composition can be brought into close contact only with the region having good adhesion, and a conductive pattern can be formed.
[0192]
Here, the same method can be used to fill the through hole and form a conductive connector, and thus the conductive connector can be formed simultaneously with the formation of the conductive pattern. .
[0193]
(4) Through hole characteristic change pattern forming step
Next, the through hole characteristic change pattern forming step of the present invention will be described. The through-hole characteristic change pattern forming step in the present invention, after the characteristic change layer adjusting step, the photocatalyst containing layer containing a photocatalyst and the photocatalyst containing layer side substrate having a substrate and the characteristic change layer, the photocatalyst containing layer and A step of forming a through-hole characteristic change pattern having a changed characteristic on the surface of the characteristic change layer by irradiating energy from a predetermined direction after arranging the characteristic change layer with a gap so as to be 200 μm or less. is there.
[0194]
In the present invention, when a conductive connector is formed between conductive patterns of adjacent wiring boards, a through hole for forming the conductive connector is formed in the characteristic change layer. And a through-hole forming step. By forming a through-hole characteristic changing pattern having changed characteristics on the characteristic changing layer by the through-hole characteristic changing pattern forming step, a difference in characteristics of the through-hole characteristic pattern is reduced in a through-hole forming step described later. This is because it is possible to easily form a through-hole by, for example, dropping a liquid.
[0195]
Since the photocatalyst-containing layer-side substrate and the irradiation of energy in the through-hole forming step are the same as those in the above-described characteristic change pattern forming step, description thereof will be omitted.
[0196]
(5) Through-hole forming step
Next, a through hole forming step will be described. The through-hole forming step in the present invention is a step of forming a through-hole by applying a liquid along the through-hole characteristic change pattern.
[0197]
The method of applying the liquid is not particularly limited as long as it is a method capable of forming a through-hole. In the present invention, the through-hole characteristic change area is not applied without contact with other members. From the viewpoint that the liquid can be selectively applied only to the nozzle, it is preferable to use a method using nozzle discharge. As such a nozzle discharge method, for example, a method using a micro syringe, a dispenser, an ink jet, or the like, a method of discharging from a needle tip by an external stimulus such as electrolysis, or a method of attaching a liquid attached to a needle tip to a characteristic change region A method or the like can be used. In the present invention, a method using a dispenser or an ink jet is particularly preferable.
[0198]
Further, the liquid used in the through hole forming step of the present invention is preferably an alkaline solution, and specifically, an aqueous solution of an organic alkali and an inorganic alkali can be used. Preferred examples of the alkaline solution include an aqueous solution of sodium hydroxide and an aqueous solution of potassium hydroxide, and the pH is preferably pH 7 to 14, more preferably pH 10 to 14, particularly preferably pH 12 to 14.
[0199]
The materials of the conductive pattern and the conductive connector used in the present invention are the same as those described in the above-mentioned "A. Multilayer Wiring Board", and thus description thereof will be omitted.
[0200]
Note that the present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the claims of the present embodiment, and any device having the same function and effect can be provided. The technical scope of the present embodiment is included.
[0201]
【Example】
Hereinafter, the present embodiment will be described in more detail through examples.
[0202]
(For formation of the photocatalyst containing layer side substrate / first layer formation)
The photomask surface was coated with a titanium oxide coating agent for photocatalyst TKC301 manufactured by Teica Co., Ltd., and dried at 350 ° C. for 3 hours to prepare a photocatalyst-containing layer-side substrate. The photomask used was a black matrix having a thickness of 1 μm formed of a dispersion of carbon black and a resin and formed with lines having a width of 20 μm. The lines were designed such that the openings in the mask corresponded to the circuit patterns of the wiring board.
[0203]
(Formation and first layer of characteristic change layer)
Next, 3 g of 0.1N hydrochloric acid water was added to 0.4 g of MF-160E (trade name, manufactured by Tochem Products Co., Ltd.) containing fluoroalkylsilane as a main component, and a solution stirred at room temperature for 1 hour was added to a membrane. It was spin-coated on a glass substrate having a thickness of 0.7 mm and dried at 150 ° C. for 10 minutes. As a result, a 1 μm-thick film having a liquid-repellent property was formed on the substrate. At this time, the electric resistance of the characteristic change layer is 1 × 10¹²Ω · cm.
[0204]
(Characteristic change pattern formation, first layer)
The photocatalyst-containing layer-side substrate was arranged on the substrate on which the characteristic change layer was formed with a gap of 50 μm, and exposed from the photocatalyst-containing layer-side substrate side with an ultra-high pressure mercury lamp. As a result, only the exposed portions on the surface of the property change layer became lyophilic regions. The exposure was 1000 mJ at 365 nm.
[0205]
(Applying conductive material / first layer)
Next, using a silver fine particle dispersion ink (Ag001T manufactured by Vacuum Metallurgy), the ink was ejected from an ink jet head so as to land only on the lyophilic region on the characteristic change layer. The contact angle of the ink with respect to the property changing layer was 50 ° in the lyophobic portion and 15 ° in the lyophilic portion. The landed ink did not adhere to the lyophobic portion but spread only to the lyophilic region.
[0206]
After drying at 100 ° C. for 3 minutes and baking at 250 ° C. for 15 minutes, a conductive pattern having a pattern shape similar to that of the opening of the photomask and having a width of 20 μm and a thickness of 0.6 μm is formed. Was. The electrical resistance of the conductive pattern is 6 × 10^-6Ω · cm.
[0207]
(For formation of photocatalyst containing layer side substrate and through hole formation)
Next, a photocatalyst-containing layer-side substrate for forming a through-hole was formed using the same material and the same coating method as those used for forming the photocatalyst-containing layer-side substrate for forming the first layer of the wiring substrate. At this time, a photomask in which a plurality of circular openings each having a diameter of 15 μm at the time of exposure were arranged so as to overlap the metal pattern portion was used.
[0208]
(Formation of property change layer, second layer)
Next, a second property change layer was formed on the wiring substrate on which the conductive pattern was formed by using the same material and the same coating method as those used in forming the first property change layer.
[0209]
(Formation of through-hole characteristic change pattern)
A photocatalyst-containing layer-side substrate for forming a through-hole was placed on the substrate on which the second layer of the property change layer was formed, with a gap of 50 μm, and exposed from the photocatalyst-containing layer-side substrate with an ultrahigh-pressure mercury lamp. As a result, a through-hole characteristic change pattern, which is a lyophilic region, was formed only on the exposed portion (circular pattern having a diameter of 15 μm) on the surface of the characteristic change layer. At this time, the exposure amount was 1500 mJ at 365 nm.
[0210]
(Formation of through hole)
Next, an aqueous potassium hydroxide solution was applied to the plurality of 15 μm diameter through-hole characteristic change patterns from an alkali-resistant inkjet head. The aqueous solution of potassium hydroxide did not adhere to the liquid-repellent portion and spread only on the lyophilic region. At this time, the pH of the aqueous potassium hydroxide solution was 13, the contact angle with the liquid-repellent portion was 55 °, and the contact angle with the lyophilic portion was 5 °.
[0211]
This was left at room temperature for 1 minute, rinsed with pure water, and then dried, whereby the characteristic change layer was decomposed and removed only in the lyophilic portion, and a through-hole in which the metal wiring portion was exposed was formed.
[0212]
(Characteristic change pattern formation, second layer)
On the substrate on which the through hole was formed, the photocatalyst-containing layer-side substrate used in the formation of the first-layer circuit pattern was exposed in the same manner as in the first layer, and the surface of the second-layer property change layer was exposed. Only the part was made lyophilic. At this time, since the position of the through hole overlapped with the position of the opening of the photocatalyst-containing layer side substrate, the periphery of the through hole and the side surface of the through hole became lyophilic.
[0213]
(Conduction of conductive material, second layer)
The conductive material was applied using the same material and method as the application of the first conductive material. The landed ink did not adhere to the lyophobic portion, but spread only on the lyophilic portion, and also filled the through hole.
[0214]
After drying at 100 ° C. for 3 minutes and baking at 250 ° C. for 15 minutes, a second-layer conductive pattern and a conductive connector having a width of 20 μm and a film thickness of 0.6 μm were formed.
[0215]
(From the third layer)
By the same method as the method up to the second layer, a multilayer wiring board in which four wiring boards were stacked was prepared. It was possible to form a multilayer wiring board in which the electrical continuity of each wiring pattern and the electrical continuity between the circuit patterns of each layer by the conductive connector could be satisfactorily obtained.
[0216]
According to the multilayer wiring board of the present invention, having the above-mentioned characteristic change layer, the above-mentioned conductive pattern can be easily formed with high definition along the pattern whose characteristic has changed. By laminating the substrates, a high-quality multilayer wiring substrate can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an example of a multilayer wiring board of the present invention.
FIG. 2 is a schematic sectional view showing another example of the multilayer wiring board of the present invention.
FIG. 3 is a schematic sectional view showing another example of the multilayer wiring board of the present invention.
FIG. 4 is a process chart showing an example of a method for manufacturing a multilayer wiring board of the present invention.
FIG. 5 is a process diagram showing a through-hole forming step of the method for manufacturing a multilayer wiring board of the present invention.
FIG. 6 is a schematic sectional view showing an example of a photocatalyst-containing layer-side substrate used in the present invention.
FIG. 7 is a schematic sectional view showing another example of the photocatalyst-containing layer side substrate used in the present invention.
FIG. 8 is a schematic sectional view showing another example of the photocatalyst-containing layer side substrate used in the present invention.
FIG. 9 is a schematic cross-sectional view showing another example of the photocatalyst-containing layer-side substrate used in the present invention.
[Explanation of symbols]
1 ... Characteristic change layer
2… Conductive pattern
3… Wiring board
4… Base material
5 ... Photocatalyst containing layer
6 ... Base
7 ... Photocatalyst containing layer side substrate
8 Photo mask
9… Energy
10 ... Characteristic change pattern
11 ... Photocatalyst-containing layer-side light-shielding portion
12 ... Primer layer
13 ... Through hole characteristic change pattern
14 ... Through hole
16 ... conductive connector

Claims (26)

It is characterized by laminating at least two or more wiring boards each including a characteristic change layer whose characteristic is changed by the action of a photocatalyst and a conductive pattern formed along a pattern whose characteristic of the characteristic change layer is changed. Multilayer wiring board. The multilayer wiring board according to claim 1, further comprising a conductive connector between conductive patterns on adjacent wiring boards. 3. The multilayer wiring board according to claim 1, wherein the conductive connector is formed by filling a conductive material into a through hole formed in a characteristic change layer. 4. The multilayer wiring board according to claim 1, wherein the multilayer wiring board is formed on a base material. The electric resistance of the characteristic change layer is in a range of 1 × 10 ⁸ Ω · cm to 1 × 10 ¹⁸ Ω · cm, 5. Multilayer wiring board. At least one of the property change layers is a wettability change layer whose wettability changes so that a contact angle with a liquid is reduced by the action of a photocatalyst accompanying energy irradiation. The multilayer wiring board according to claim 5. The contact angle of the wettability changing layer with a liquid of 40 mN / m on the wettability changing layer is 50 ° or more in a portion where energy is not irradiated and 49 ° or less in a portion where energy is irradiated. The multilayer wiring board according to claim 6, wherein: The multilayer wiring board according to claim 6, wherein the wettability changing layer is a layer containing an organopolysiloxane. 9. The multilayer wiring board according to claim 8, wherein the organopolysiloxane is a polysiloxane containing a fluoroalkyl group. The _{organopolysiloxane, Y n SiX (4-n} ) ( wherein, Y represents an alkyl group, fluoroalkyl group, vinyl group, amino group, phenyl group or epoxy group, X represents an alkoxyl group or a halogen. n is an integer from 0 to 3.) An organopolysiloxane which is one or more hydrolytic condensates or co-hydrolytic condensates of a silicon compound represented by the formula: Alternatively, the multilayer wiring board according to claim 9. The method according to any one of claims 1 to 5, wherein at least one of the characteristic change layers is an adhesion change layer whose adhesion changes due to the action of a photocatalyst accompanying energy irradiation. Multilayer wiring board. The multilayer wiring board according to claim 1, wherein the characteristic change layer is a layer etched by a liquid. 13. The multilayer wiring board according to claim 12, wherein the liquid is an alkaline solution. A property change layer preparation step of preparing a property change layer whose properties change by the action of a photocatalyst accompanying energy irradiation,
After arranging a photocatalyst-containing layer-side substrate having a photocatalyst-containing layer containing a substrate and a photocatalyst, and the property changing layer with a gap such that the photocatalyst-containing layer and the property changing layer become 200 μm or less, By irradiating energy from the direction of, a characteristic change pattern forming step of forming a characteristic change pattern having changed characteristics on the surface of the characteristic change layer,
Along with the characteristic change pattern, a conductive pattern forming step of forming a conductive pattern,
Performing a wiring board forming step having at least two times. 15. The method for manufacturing a multilayer wiring board according to claim 14, wherein the step of preparing the characteristic change layer in the step of forming the wiring board performed after the first time is performed by a coating method. After the property change layer adjusting step, after arranging the photocatalyst containing layer side substrate and the property change layer with a gap such that the photocatalyst containing layer and the property change layer are 200 μm or less, from a predetermined direction By irradiating energy, a through-hole characteristic change pattern forming step of forming a through-hole characteristic change pattern having changed characteristics on the characteristic change layer surface, and applying a liquid along the through-hole characteristic change pattern, 16. The method for manufacturing a multilayer wiring board according to claim 14, further comprising a through hole forming step of forming a through hole. 17. The method according to claim 16, wherein the through hole forming step is performed by applying an alkaline solution. 18. The method for manufacturing a multilayer wiring board according to claim 14, wherein the photocatalyst-containing layer is a layer made of a photocatalyst. 19. The method for manufacturing a multilayer wiring board according to claim 18, wherein the photocatalyst-containing layer is a layer formed by forming a photocatalyst on a substrate by a vacuum film forming method. The method according to any one of claims 14 to 17, wherein the photocatalyst-containing layer is a layer having a photocatalyst and a binder. The photocatalyst includes titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), strontium titanate (SrTiO ₃ ), tungsten oxide (WO ₃ ), bismuth oxide (Bi ₂ O ₃ ), and oxidized method for manufacturing a multilayer wiring board according to any one of claims of claims 14 to 20, characterized in that one or more substances selected from iron (Fe 2 _{O 3).} Method for manufacturing a multilayer wiring board according to claim 21, wherein the photocatalyst is titanium oxide (TiO _2). The method for manufacturing a multilayer wiring board according to any one of claims 14 to 22, wherein the multilayer wiring board is formed on a base material. The characteristic change layer is a wettability change layer in which, when irradiated with energy by the action of a photocatalyst in the photocatalyst-containing layer, the wettability changes so that the contact angle with a liquid decreases. A method for manufacturing a multilayer wiring board according to any one of claims 14 to 23. 25. A contact angle with a liquid of 40 mN / m on the wettability changing layer is 50 ° or more in a portion where energy is not irradiated and 49 ° or less in a portion where energy is irradiated. 3. The method for manufacturing a multilayer wiring board according to item 1. The method according to any one of claims 14 to 23, wherein the property change layer is an adhesion change layer whose adhesion changes when irradiated with energy by the action of a photocatalyst in the photocatalyst containing layer. A method for manufacturing a multilayer wiring board according to any one of the preceding claims.

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