JP2004184479A

JP2004184479A - Method of manufacturing master disk for manufacturing aperture conversion type high polymer optical waveguide and method of manufacturing the waveguide using the method

Info

Publication number: JP2004184479A
Application number: JP2002347947A
Authority: JP
Inventors: Takashi Shimizu; 敬司清水; Shigemi Otsu; 茂実大津; Kazutoshi Tanida; 和敏谷田; Hidekazu Akutsu; 英一圷
Original assignee: Fuji Xerox Co Ltd
Current assignee: Fujifilm Business Innovation Corp
Priority date: 2002-11-29
Filing date: 2002-11-29
Publication date: 2004-07-02
Anticipated expiration: 2022-11-29
Also published as: JP4161697B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a low-cost and highly accurate master disk for a aperture conversion type optical waveguide by a simple method and to provide a method to easily manufacture an optical waveguide using the above method. <P>SOLUTION: (A) the method of manufacturing the master disk is provided in which (1) on an electrodeposition substrate having power feeding terminals on the tip part of an electrically conductive thin film, an electrodeposition/photosensitive film forming material is electrodeposited to deposit an electrodeposition layer, a photosensitive resin layer is formed on the above layer and the layer is exposure developed in a core shape, or (2) an optical semiconductor film of an optical electrodeposited substrate is irradiated with light while adjusting exposure strength etc., to deposit a film (a projecting part) having different cross sectional areas in a longitudinal direction, or (3) a film is deposited on an optical electrodeposited substrate having grooves so that the film thicknesses are varied along the longitudinal direction similar to (2) and the groove shape is made correspond to the core shape and then, electroforming is applied to the groove etc., and the electroformed section is peeled off. (B) the method of manufacturing an aperture converting type high polymer optical waveguide is provide in which a hardening layer of casting forming hardening resin is formed on the above master disk and the layer is peeled off, is adhered to a clad member, core hardeng resin is filled into a gap section and is peeled off the hardened resin. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、口径変換型高分子光導波路作製用原盤の製造方法及び該方法を用いる口径変換型高分子光導波路の製造方法に関する。
【０００２】
【従来の技術】
高分子導波路の製造方法としては、（１）フイルムにモノマーを含浸させてコア部を選択的に露光して屈折率を変化させフイルムを張り合わせる方法（選択重合法）、（２）コア層及びクラッド層を塗布後、反応性イオンエチングを用いてクラッド部を形成する方法（ＲＩＥ法）、（３）高分子材料中に感光性の材料を添加した紫外線硬化樹脂を用いて、露光・現像するフォトリソグラフィー法を用いる方法（直接露光法）、（４）射出成形を利用する方法、（５）コア層及びクラッド層を塗布後、コア部を露光してコア部の屈折率を変化させる方法（フォトブリーチング法）等が提案されている。
しかし、（１）の選択重合法はフイルムの張り合わせに問題があり、（２）や（３）の方法は、フォトリソグラフィー法を使うためコスト高になり、（４）の方法は、得られるコア径の精度に課題がある。また、（５）の方法はコア層とクラッド層との十分な屈折率差がとれないと言う問題がある。
現在、性能的に優れた実用的な方法は、（２）や（３）の方法だけであるが前記のごときコストの問題がある。したがって、大面積な基材、特に大面積でフレキシブルな基材に高分子導波路を形成するのに適した製造方法はないのが現状である。
【０００３】
また、高分子光導波路を製造する方法として、キャピラリーとなる溝のパターンが形成されたパターン基板（クラッド）にコア用のポリマー前駆体材料を充填し、その後硬化させてコア層を作り、その上に平面基板（クラッド）を貼り合わせる方法が知られているが、この方法ではキャピラリー溝にだけでなく、パターン基板と平面基板の間にも全面的にポリマー前駆体材料が薄く充填され硬化されてコア層と同じ組成の薄い層が形成される結果、この薄い層を通って光が漏洩してしまうという問題があった。
この問題を解決する方法の１つとして、デビット・ハートはキャピラリーとなる溝のパターンが形成されたパターン基板と平面基板とをクランプ用治具で固着し、さらにパターン基板と平面基板との接触部分を樹脂でシールなどした後減圧して、モノマー（ジアリルイソフタレート）溶液をキャピラリーに充填して、高分子光導波路を製造する方法を提案した（以下の特許文献１を参照）。この方法はコア形成用樹脂材料としてポリマー前駆体材料を用いる代わりにモノマーを用いて充填材料を低粘度化し、キャピラリー内に毛細管現象を利用して充填させ、キャピラリー以外にはモノマーが充填されないようにする方法である。
しかし、この方法はコア形成用材料としてモノマーを用いているため、モノマーが重合してポリマーになる際の体積収縮率が大きく、高分子光導波路の透過損失が大きくなるいう問題や、キャピラリー内で高分子化したコア樹脂が平面基板に部分的に接着して、剥離するときコア形状が崩れるという問題もある。
また、この方法は、パターン基板と平面基板とをクランプで固着する、あるいはこれに加えさらに接触部を樹脂でシールするなど煩雑な方法であり、量産にはむかず、その結果コスト低下を期待することはできない。また、クラッドとして厚さがｍｍオーダーあるいは１ｍｍ以下のフィルムを用いる高分子光導波路の製造に適用することは不可能である。
【０００４】
また、最近、ハーバード大学のＧｅｏｒｇｅＭ．Ｗｈｉｔｅｓｉｄｅｓらは、ナノ構造を作る新技術として、ソフトリソグラフィーの一つとして毛細管マイクロモールドという方法を提唱している。これは、フォトリソグラフィーを利用してマスター基板を作り、ポリジメチルシロキサン（ＰＤＭＳ）の密着性と容易な剥離性を利用してマスター基板のナノ構造をＰＤＭＳの鋳型に写し取り、この鋳型に毛細管現象を利用して液体ポリマーを流し込んで固化させる方法である。以下の非特許文献１に詳しい解説記事が記載されている。
【０００５】
また、バード大学のＧｅｏｒｇｅＭ．ＷｈｉｔｅｓｉｄｅｓのグループのＫｉｍＥｎｏｃｈらによって毛細管マイクロモールド法に関する特許が出願されている（以下の特許文献２参照）。
しかし、この特許に記載の製造方法を高分子光導波路の製造方法は、光導波路のコア部のような断面積が小さい場合には、時間がかかり量産に適さないし、モノマー溶液が高分子に反応して固化するときに体積変化を起こしコアの形状が変化するという欠点を持つ。
【０００６】
これに対して本発明者等は、フィルム基材に光導波路を設けたフレキシブル高分子光導波路を作製する方法を提案した（特願２００２−１８７４７３号）。この方法は、製造工程が極めて単純化されたもので、容易に高分子光導波路を作製することができ、従来の高分子光導波路の製造方法に比較し、非常に低コストで高分子光導波路を作製することができる。
このような高分子光導波路には、各種の光学部品、例えば光ファイバーや発光素子、受光素を接続する機能が求められ、その際、各種光学部品の大きさに合わせて、作製する高分子光導波路の入出力部の断面積や断面形状（口径）を変更することにより結合損失を低下できる。しかし原盤を作製する際、従来のフォトリソグラフィを利用した直接露光法に代表される方法では、原盤に形成する高分子光導波路コアに対応する凸部の膜厚を連続的に変化させること（口径変換）が困難なため、この方法では、結合損失を低下させるように、自由に原盤凸部の膜厚を制御することができなかった。また、原盤を、ＦＩＢなどでシリコン基板を微細加工するような方法により作製する方法はあるものの、マルチモード導波路のような口径が大きく、しかも大面積にわたるものを作製するための原盤の場合では、非常に工数がかかり不可能に近いという問題があった。
【０００７】
上記問題点を解決する試みとして、下記の特許文献３には、高分子光導波路と光ファイバー等の光学部品との接続を行なう高分子光導波路（ただしフレキシブルではない）の製造方法が記載されている。この方法では、高分子光導波路と光ファイバーの接続には、基板に浅い液貯めプールと該プールの両側に溝を形成して、該溝に光ファイバーを置く方法が採用されているので、基板に液貯めプールの他に溝を加工する必要もあり工数が増えたり、作製する高分子光導波路ごとに、溝とフォトマスクの位置を正確に合わせる必要があるため、依然としてコスト高の問題がある。また、光導波路の断面積を長手方向に三次元的に変化させるには、浅い液貯めプールの深さを精密に制御する必要があること、液貯めプールを厳密に水平に保つ必要があるが振動に対し弱いことなどが原因になり、歩留まりが低くなり、大量生産の方法として実用的でない。さらに導波路に要求される表面粗さや形状精度をもち、なおかつ厚みと幅を長手方向位置により変化させた溝を作製する具体的な方法は記載されていない。
【０００８】
また、以下の特許文献４には、光源に合わせて口径、屈折率を制御して、ファイバーとの結合効率を向上させる光結合装置が記載されているが、高分子導波路に適用できるような具体的な製造方法は記載されていない。
【０００９】
【特許文献１】
特許第３１５１３６４号明細書
【特許文献２】
米国特許６３５５１９８号明細書
【特許文献３】
特開平１０−２５３８４５号公報
【特許文献４】
特公昭５５−００６２０１号公報
【非特許文献１】
ＳＣＩＥＮＴＩＦＩＣＡＭＥＲＩＣＡＮＳＥＰＴＥＭＢＥＲ２００１（日経サイエンス２００１年１２月号）
【００１０】
【発明が解決しようとする課題】
本発明は、前記のごとき問題点に鑑みてなされたものであり、その目的は、簡便な方法により低コストで、精度の高い、口径変換型高分子光導波路作製用原盤を製造する方法を提供することにあり、さらに、この原盤の製造方法を用いて、作業工程が少なく低コストで、導波損失が小さくかつ結合損失の少ない高分子光導波路を製造する方法を提供することにある。
【００１１】
【課題を解決するための手段】
前記課題は、以下の（１）ないし（４）の口径変換型高分子光導波路作製用原盤の製造方法、及び該方法を用いる口径変換型高分子光導波路の製造方法（５）〜（２４）を提供することにより解決される。
（１）絶縁性基板上に導電性薄膜を有しかつ導電性薄膜の端部に給電端子が設けられた電着基板に、電着性及び感光性をもつ膜形成材料を電着して電着層を形成する工程、及び該層を高分子光導波路コアパターン形状に露光現像する工程を有する、高分子光導波路コアに対応する凸部を有する口径変換型高分子光導波路作製用原盤を製造する方法。
（２）絶縁性基板上に導電性薄膜を有しかつ導電性薄膜の端部に給電端子が設けられた電着基板に、電着性及び感光性をもつ膜形成材料を電着して電着層を形成する工程、該層上に感光性樹脂材料の層を形成する工程、及び前記２つの工程で形成した層を高分子光導波路コアパターン形状に露光現像する工程を有する、高分子光導波路コアに対応する凸部を有する口径変換型高分子光導波路作製用原盤を製造する方法。
【００１２】
（３）絶縁性基板上に導電性薄膜及び光半導体薄膜をこの順に積層した光電着基板を、ｐＨが変化することにより水性液体に対する溶解性ないし分散性が低下する膜形成材料を含む水系の電着液に、前記光電着基板の少なくとも光半導体薄膜が電着液に接触するように配置する工程、及び、露光時間及び／又は露光強度を調節しつつ、光半導体薄膜の選択領域に光を照射して起電力を発生させ、長手方向においてその断面形状及び／又は断面積が異なる高分子光導波路コアに対応する薄膜を形成する工程を有する、高分子光導波路コアに対応する凸部を有する口径変換型高分子光導波路作製用原盤を製造する方法。
【００１３】
（４）▲１▼絶縁性基板上に、導電性薄膜、光半導体薄膜、及び光半導体薄膜が露出するようにかつ両端部の断面形状及び／又は断面積が異なる溝が設けられた層をこの順に積層した光電着基板を、ｐＨが変化することにより水性液体に対する溶解性ないし分散性が低下する膜形成材料を含む水系の電着液に、前記光電着基板の少なくとも溝底部の光半導体薄膜が電着液に接触するように配置する工程、▲２▼露光時間及び／又は露光強度を調節しつつ、溝底部の光半導体薄膜の選択領域に光を照射して起電力を発生させ、電着後の長手方向における溝の形状が高分子高分子光導波路コアに対応する形状となるように溝底部の光半導体薄膜上に薄膜を形成する工程、▲３▼前記▲２▼の工程により溝底部に薄膜が形成された光電着基板に電鋳を施す工程、▲４▼光電着基板と電鋳部を剥離する工程を有する、高分子光導波路コアに対応する凸部を有する口径変換型高分子光導波路作製用原盤を製造する方法。
【００１４】
また、前記（１）ないし（４）の方法において、電着液に導電性微粒子を含ませることができ、また、前記（３）及び（４）の方法において、膜形成材料を、疎水性基と親水性基を有し、疎水基の数が、親水基と疎水基の総数の３０％から８０％の範囲にある高分子材料とすることができる。
【００１５】
（５）前記（１）ないし（４）に記載のいずれか１に記載の方法により原盤を作製した後、以下の＜１＞ないし＜４＞の工程を行うことにより口径変換型高分子光導波路を製造する方法。
＜１＞前記原盤に鋳型形成用硬化性樹脂の硬化層を形成した後剥離して前記凸部に対応する凹部が形成された鋳型を作製する工程
＜２＞前記鋳型の凹部形成面にクラッド用基材を密着させる工程
＜３＞前記鋳型凹部とクラッド用基材の間に形成された溝にコア形成用硬化性樹脂を充填する工程
＜４＞前記コア形成用硬化性樹脂を硬化し、その後鋳型を剥離する工程
【００１６】
（６）前記クラッド用基材がフィルム基材であり、かつ前記＜２＞の工程においてフィルム基材が平坦な剛体によって支えられることを特徴とする前記（５）に記載の口径変換型高分子光導波路の製造方法。
（７）前記フィルム基材が脂環式オレフィン樹脂フイルムであることを特徴とする前記（５）又は（６）に記載の口径変換型高分子光導波路の製造方法。
（８）前記脂環式オレフィン樹脂フイルムが主鎖にノルボルネン構造を有しかつ側鎖に極性基をもつ樹脂フィルムであることを特徴とする前記（５）ないし（７）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
【００１７】
（９）前記クラッド層の形成が、紫外線硬化性樹脂又は熱硬化性樹脂を塗布した後硬化させることによる前記（５）ないし（８）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（１０）前記クラッド層の形成が、クラッド用のフィルムを該フィルムと近い屈折率をもつ接着剤により貼り合わせることによる前記（５）ないし（９）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
【００１８】
（１１）前記鋳型形成用硬化性樹脂が硬化性シリコーンゴムオリゴマーまたはモノマーであることを特徴とする前記（５）ないし（１０）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（１２）前記鋳型の表面エネルギーが１０ｄｙｎ／ｃｍ〜３０ｄｙｎ／ｃｍであることを特徴とする前記（５）ないし（１１）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（１３）前記鋳型のシェア（Ｓｈａｒｅ）ゴム硬度が１５〜８０であることを特徴とする前記（５）ないし（１２）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（１４）前記鋳型の表面粗さが０．５μｍ以下であることを特徴とする前記（５）ないし（１３）のいずれか１に記載の口径変換型高分子光導波路の製造方法。（１５）前記鋳型の厚さが０．１ｍｍ〜５０ｍｍであることを特徴とする前記（５）ないし（１４）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
【００１９】
（１６）前記フィルム基材の屈折率が１．５５以下であることを特徴とする前記（５）ないし（１５）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（１７）前記コア形成用硬化性樹脂の粘度が１０ｍＰａ・ｓ〜２０００ｍＰａ・ｓであることを特徴とする前記（５）ないし（１６）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（１８）前記コア形成用硬化性樹脂が硬化したときの体積変化が１０％以下であることを特徴とする前記（５）ないし（１７）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（１９）前記コア形成用硬化性樹脂の硬化物の屈折率が１．５５以上であることを特徴とする前記（５）ないし（１８）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
【００２０】
（２０）前記＜４＞の工程の後、クラッド用基材のコア形成面にクラッド層を形成する工程を有する前記（５）ないし（１９）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（２１）前記クラッド層の屈折率がクラッド用基材と同じであることを特徴とする前記（５）ないし（２０）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（２２）前記クラッド層が脂環式オレフィン樹脂フイルムであることを特徴とする前記（５）ないし（２１）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（２３）前記脂環式オレフィン樹脂フイルムが主鎖にノルボルネン構造を有しかつ側鎖に極性基をもつ樹脂フィルムであることを特徴とする前記（５）ないし（２２）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
（２４）前記クラッド用基材及びクラッド層とコアとの屈折率差が０．０２以上あることを特徴とする前記（５）ないし（２３）のいずれか１に記載の口径変換型高分子光導波路の製造方法。
【００２１】
【発明の実施の形態】
最初に、口径変換型高分子光導波路作製用原盤の製造方法について説明する。原盤に形成される口径変換型高分子光導波路コアに対応する凸部は、長手方向に断面形状及び／又は断面積が異なる。
（第１の原盤の製造方法）
本発明における第１の原盤の製造方法は、絶縁性基板上に導電性薄膜を有し、かつ導電性薄膜の端部に給電端子が設けられた電着基板に、電着性及び感光性をもつ膜形成材料を電着して電着層を形成した後、該層を高分子光導波路コアパターン形状に露光現像する方法である。ここで、高分子光導波路コアパターン形状とは、光導波路コアを上部からみた平面形状をさす。
この第１の方法は、バルク金属に比べて抵抗の大きくなる薄膜電極を利用する方法である。すなわち、電着基板として絶縁性基板上に導電性薄膜（薄膜電極）を設け、該導電性薄膜の端部に給電端子を設けたものを用い、給電端子からの距離（抵抗）及び基板を流れる電流量によって発生する電圧降下を利用して、電着を行う方法である。この方法により、電着基板の場所により電流量を制御することが可能となり、給電端子近傍では層厚が厚くなり、離れるほど薄くなる電着層を得ることができる（長手方向に層厚が異なる）。スピンコート法のごとき塗布法では、場所により層の厚みを制御することは困難であるが、前記のごとき電着法は、電着基板の場所による電流量を制御でき、容易に場所により異なる厚みの電着層を得ることができる。
電着材料としては、電着性及び感光性をもつ膜形成材料を含むものを用いる。例えば、電着レジスト（関西ペイント（株）製、ゾンネＰ−５００など）として市販されているものが用いられる。
その後、フォトマスクを用いて光導波路コアパターン形状に露光現像する。露光現像の前にプリベークを行ってもよい。
図１は、第１の原盤の製造工程を説明する概念図である。図１（Ａ）は電着基板の長手方向断面図である。１０は電着基板、１２は絶縁性基板、１４は導電性薄膜、１６は給電端子をそれぞれ示す。図１（Ｂ）は前記電着基板の上に電着材料が電着された状態を示す断面図で、電着材料の層１８は、給電端子１６に近い側の層厚が厚く、離れるにしたがい層厚が薄く形成される。図１（Ｃ）は、導電性薄膜の全面に形成された電着材料の層１８を、光導波路コアパターン形状に露光現像して作製した原盤２０を示し、２２は高分子光導波路コアに対応する凸部を示す。給電端子に近い凸部では幅を大きく、離れるにしたがい凸部の幅を小さくしている。
【００２２】
前記電着基板の絶縁性基板としては、絶縁性を有し寸法安定性や機械的強度を備えていれば特に制限はなく、たとえがガラス板、セラミック板等が用いられる。また、導電性薄膜としてはＩＴＯ薄膜等が好ましく用いられ、給電端子としては、電着液との絶縁を保ったものが用いられる。
【００２３】
（第２の原盤の製造方法）
前記第１の方法は簡便な方法であるが、電着で形成される層は絶縁膜のため、層厚を３０μｍ程度までしか厚くすることができない。しかし、高分子光導波路はその口径が５０μｍ以上のものが要請される場合があり、大口径の高分子光導波路は第１の方法では作製が困難である。
第２の原盤の製造方法は、より大口径の高分子光導波路を作製することが可能な方法で、第１の方法で用いた電着基板を用い、同様にして電着性及び感光性をもつ膜形成材料を電着して電着層を形成し、給電端子近傍ではより厚く、離れるほど薄くなる電着層を形成した後、電着層の上に感光性樹脂材料の層を形成し、次いで前記電着層と感光性樹脂材料の層を光導波路コアパターン形状に露光現像する方法である。感光性樹脂材料の層は、必要な原盤凸部高さになるように、スピンコート法等の塗布により形成される。感光性樹脂材料の層を形成する前に、電着層をプリベークしてもよい。
この方法により、長手方向に断面形状及び／又は断面積が異なり、大口径の凸部を有する原盤を作製することができる。なおこの場合、電着に用いる感光性材料と電着膜の上に設ける感光性樹脂材料とは、ポジ型・ネガ型を一致させる必要がある。さらに露光現像条件が極力一致している感光性材料であることが望ましい。
【００２４】
図２は、第２の原盤の製造方法における工程を示す概念図である。図２（Ａ）は第１の方法において用いる電着基板と同様な電着基板の長手方向断面図を示す。図２（Ｂ）は、電着基板の上に、給電端子に近い側の膜厚が厚く、離れるにしたがい層厚が薄く電着形成された層１８を示す断面図である。図２（Ｃ）は電着層の上に必要な層厚で感光性樹脂材料の層１９を形成した断面図を示す。また、図２（Ｄ）は、電着材料の層１８及び感光性樹脂材料の層１９を、光導波路コアパターン形状に露光現像して作製した原盤２０を示し、２２は高分子光導波路コアに対応する凸部を示す。給電端子に近い凸部では幅を大きく、離れるにしたがい凸部の幅を小さくしている。この方法により、第１の方法よりも大口径の凸部を作製することができる。
【００２５】
（第３の原盤の製造方法）
次に、本発明の第３の原盤の製造方法について説明する。この方法は、光電着法を利用するもので、光電着法は、基板の場所により電流量を制御できる方法として、本発明者らが既に提案している方法である（特許３１５２１９２号等）。この光電着法は、光電着基板として、絶縁性基板上に導電性薄膜及び光半導体薄膜をこの順に積層したものを用い、前記光半導体薄膜の所定の場所に所定の光起電力を所定の時間発生させることにより、発生した光起電力及び時間に対応する膜厚の電着膜を形成することができる。第３の原盤の製造方法は、前記のごとき光電着基板の光半導体薄膜が電着液に接触した状態で、光半導体薄膜の所定の場所に露光時間及び／又は露光強度を調節しながら光照射して、これらに対応する膜厚を形成させる方法であり、膜厚（口径）を大きくしたい場所では露光強度及び／又は露光時間を増加させればよい。この方法により、口径変換型高分子光導波路コアの原盤を容易に作製することができる。光半導体薄膜の所定の場所に露光時間及び／又は露光強度を調節しながら光照射する手段としてはレーザー光照射が好ましい。
図３に第３の原盤の製造方法の工程の概念図を示す。図３（Ａ）は光電着装置に納めた電着液に、光電着基板の光半導体薄膜が少なくとも接触する状態に配置して、光半導体薄膜の所定の場所に露光時間及び／又は露光強度を調節しながら、Ｈｅ−Ｃｄレーザー等のレーザー光を走査照射して、長手方向に断面積（口径）が変化する薄膜を形成する方法の途中の段階を示している。図３（Ａ）中、３０は光電着基板、３２は絶縁性基板、３４は導電性薄膜、３６は光半導体薄膜を示し、４０は光電着装置、４５は電着液、５０はレーザー光照射装置、６０はポテンショスタット、６２は参照電極、６４は対向電極をそれぞれ示す。また、２２ａは、電着により形成された薄膜を示す。
また、図３（Ｂ）は、光電着基板３０の光半導体薄膜の上に、長手方向に断面積（口径）が変化する薄膜（凸部）２２が形成された原盤２０を示す。
【００２６】
（第４の原盤の製造方法）
また、本発明の第４の原盤の製造方法は、第３の方法と同様、光電着法を利用する方法である。第４の方法における光電着法で用いる光電着基板は、絶縁性基板上に、導電性薄膜、光半導体薄膜、及び光半導体薄膜が露出するようにかつ両端部の断面形状及び／又は断面積が異なる溝が設けられた層をこの順に積層したものである。溝が設けられた層は、フォトレジスト法（例えばＪＳＲ（株）製、ＴＨＢ−６１１Ｐ等の厚膜レジスト）により形成することができる。
この光電着基板を用い、光半導体薄膜が露出した溝底部に光電着を行う。光電着は、長手方向において形成される膜厚を異ならせ、電着終了後の溝の形状が高分子光導波路コアに対応する形状となるように、露光時間及び／又は露光強度を調節して光照射する。この光照射もレーザー光によることが好ましい。
次に、溝底部に電着膜が形成された光電着基板に電鋳（ニッケル電鋳など）を施して、溝部分及び溝が設けられた層の上に金属膜を形成し、その後、光電着基板と電鋳部を剥離すると、高分子光導波路コアに対応する凸部が形成された原盤が完成する。
【００２７】
この方法によると、凸部断面のエッジ部分の角度が４５°以上の原盤を作製することができる。単に光電着法を利用すると（第３の原盤の製造方法）エッジ部分の角度が４５°以上（例えば断面が矩形）の凸部を作製することは難しく、結合する相手デバイスの形状や大きさによっては必ずしも結合損失を有効に減らすことができない。しかし、前記の第４の方法によると、光電着は、溝を構成する左右の層に挟まれる場所に行われる形になり、かつ電着時の水素イオンの拡散が限定されるので溝型の矩形が実現できる。ただ、この方法では、高分子光導波路コアに対応する形状は、形成される薄膜ではなく、電着後の溝の形状であり反転しているので、さらに、電鋳により高分子光導波路コアに対応する凸部を形成する必要がある。
【００２８】
図４に、第４の原盤の製造方法の工程を概念図で示す。図４（Ａ）は用いる光電着基板の長手方向断面を示し、１００は光電着基板、１０２は絶縁性基板、１０４は導電性薄膜、１０６は光半導体薄膜、１０８は図示しない溝が設けられた層をそれぞれ示す。図４（Ｂ）は前記光電着基板の上面を示し、１１０は溝であり、溝の両端部の断面形状及び／又は断面積が異なるように形成され、溝底部では光半導体薄膜が露出している。
また、図４（Ｃ）は、前記光電着基板の溝底部に、長手方向に膜厚が異なる電着膜１１４が形成された状態を示し、図４（Ｄ）は、図４（Ｃ）で示されるものに電鋳を施し、溝部分及び層１０８の上に電鋳金属膜１１６を形成した状態を示す。図４（Ｅ）は図４（Ｄ）で示されるものから電鋳部分１１６を剥離した原盤２００を示し、原盤には、長手方向に断面積が異なる凸部２２０が形成されている。なお、溝底部への光電着は、図３（Ａ）で示したのと同様の装置が用いられる。
【００２９】
前記第３の原盤の製造方法に用いる光電着基板は、絶縁性基板上に導電性薄膜及び光半導体薄膜をこの順に積層したものが用いられる。前記絶縁性基板としては、ガラス板、石英板、プラスチックフィルム、エポキシ基板等が、導電性薄膜としてはＩＴＯ、酸化インジウム、ニッケル、アルミニウム等が、また、光半導体薄膜としては、酸化チタン薄膜等が用いられる。なお、絶縁性基板を通して光半導体薄膜に光照射する場合には、絶縁性基板及び導電性薄膜は光透過性であることが必要である。ただし、電着液を通して光照射する場合はこの限りでない。
また、第４の原盤の製造方法に用いる光電着基板は、第３の方法で用いる光電着基板に、前記のごとき溝が形成された層が設けられ、該層は、感光性樹脂の露光現像等により形成される。
前記第３及び第４の原盤の製造方法において、光照射は、絶縁性基板を通して行うことが、解像度および露光強度の点からみて好ましい。
【００３０】
また、前記第３及び第４の原盤の製造方法に用いる、ｐＨが変化することにより水性液体に対する溶解性ないし分散性が低下する膜形成材料は、カルボキシル基やアミノ基などのように、液のｐＨが変わることにより、そのイオン解離性が変化する基（イオン性基）を分子中に有している物質を含むことが好ましい。
【００３１】
また、ｐＨの変化により水性液体に対する溶解性ないし分散性が低下する機能をもたせるために、分子中に親水基と疎水基を有していることが好ましく、親水基として、カルボキシル基（アニオン性基）、アミノ基（カチオン性基）等のイオン化可能性基（以下、単に「イオン化基」という）が導入されていることが好ましい。
前記高分子材料における疎水基の存在により、前記のようなｐＨの変化によってイオン解離している基がイオン性を失うこととあいまって、瞬時に膜を析出させるという機能を高分子材料に付与している。
【００３２】
疎水基と親水基を有する重合体中の疎水基の数が、親水基と疎水基の総数の３０％から８０％の範囲にあるものが好ましい。疎水基の数が親水基と疎水基の総数の３０％未満のものは、形成された膜が再溶解し易く、膜の耐水性や膜強度が不足する場合があり、また疎水基数が親水基と疎水基の総数の８０％より大きい場合は、水系液体への重合体の溶解性が不十分となるため、電着液が濁ったり、材料の沈殿物が生じたり、電着液の粘度が上昇しやすくなるので、前記の範囲にあることが望ましい。親水基と疎水基の総数に対する疎水基数は、より好ましくは５５％から７０％の範囲である。この範囲のものは、特に膜の析出効率が高く、電着液の液性も安定している。また、光起電力程度の低い電着電位で膜形成ができる。
【００３３】
前記高分子材料としては、例えば、親水基を有する重合性モノマー、疎水基を有する重合性モノマーを共重合させたものが挙げられる。
親水基を含む重合性モノマーとしては、メタクリル酸、アクリル酸、無水マレイン酸、フマル酸、プロピオル酸、イタコン酸などのα，β−エチレン性不飽和カルボン酸の他、メタクリル酸ヒドロキシエチル等のα，β−エチレン性不飽和カルボン酸のヒドロキシアルキルエステル、アクリルアミド等のα，β−エチレン性不飽和カルボン酸アミド、及びこれらの誘導体が用いられるが、これらに限定されるものではない。中でも特に、メタクリル酸、アクリル酸はｐＨ変化による着膜効率が高く、有用な親水基含有モノマーである。
また、疎水基を含む重合性モノマー材料は、アルケン、スチレン、α−メチルスチレン及びα−エチルスチレン等のスチレン誘導体、酢酸ビニル等のビニルエステル、アクリロニトリル、メタクリル酸メチル、メタクリル酸ブチル、アクリル酸エチル、アクリル酸ブチル、メタクリル酸ラウリルなどの（メタ）アクリル酸エステル及びこれらの誘導体が用いられるが、これらに限定されるものではない。特に、スチレン、α−メチルスチレン、α−エチルスチレンは疎水性が強いために、再溶解に対するヒステリシス特性を得やすく有用な疎水性モノマーである。本発明において用いる高分子材料としては、親水基含有モノマーとしてアクリル酸又はメタクリル酸を、疎水基含有モノマーとしてスチレン又はα−メチルスチレンを用いる共重合体が好ましく用いられる。
【００３４】
また、第１ないし第４の方法において用いる電着液には、カーボンなどの導電性微粒子を混入することにより、絶縁膜ではせいぜい５０μｍ程度の電着膜厚をさらに増やすことが可能になる。
【００３５】
前記光電着法は特許第３１５２１９２号明細書に詳細に説明されている。例えば、光半導体を含む光電着基板は段落００２３〜００３２に、電着材料を含む電着液は段落００２２、００３２〜００３９に、光電着装置は段落００４２〜００４６に記載され、これらの技術事項はすべて本発明の光電着に利用することができる。
【００３６】
本発明の前記第１ないし第４の鋳型の製造方法は、前記のごとく、電着又は光電着、感光性材料の露光・現像、及び電鋳という、それぞれが安価な方法を組み合わせたものであるにもかかわらず、高精度でかつ簡便に、口径変換型高分子光導波路コアに対応する凸部が形成された原盤を作製することができる。
【００３７】
次に、前記の第１ないし第４の原盤製造方法を用いて、口径変換型高分子光導波路を作製する方法について説明する。
第１ないし第４の原盤製造方法により原盤を作製した後、以下の工程を行うことにより口径変換型高分子光導波路を作製する。
（１）原盤に鋳型形成用硬化性樹脂の硬化層を形成した後剥離して前記凸部に対応する凹部が形成された鋳型を作製する工程
（２）前記鋳型の凹部形成面にクラッド用基材を密着させる工程
（３）前記鋳型凹部とクラッド用基材の間に形成された溝にコア形成用硬化性樹脂を充填する工程
（４）前記コア形成用硬化性樹脂を硬化し、その後鋳型を剥離する工程
また導波路の機械的な強度を安定にし、導波特定も向上させるため、前記（４）の工程の後に、クラッド用基材のコア形成面にクラッド層を形成する工程を行うことが望ましい。
【００３８】
まず、図５を用いて本発明の高分子光導波路の製造方法の概略を説明する。
図５（Ａ）は光導波路コアに対応する凸部３０２（長手方向に断面形状及び／又は断面積が異なる）が形成された原盤３００を示す。最初に図５（Ｂ）で示すように、原盤３００の凸部３０２が形成された面に、鋳型形成用硬化性樹脂の硬化層３２０を形成する。次に、硬化層３２０を原盤３００から剥離する。前記凸部３０２に対応する凹部３２２の末端が端部に露出していない場合には、凹部３２２が露出するように両端を切断して鋳型３２４を作製する（図５（Ｃ）参照）。
このようにして作製した鋳型３２４に、クラッド用基材３３０を密着させる（図５（Ｄ）参照）。次に、鋳型の一端をコアとなる硬化性樹脂３４０ａに接触させ、毛細管現象を利用して鋳型の凹部３２２に進入させる。図５（Ｅ）は鋳型の凹部３２２に硬化性樹脂３４０ａが充填された状態を示す。その後、凹部内の硬化性樹脂を硬化させ、鋳型３２４を剥離する（図示せず）。図５（Ｆ）が示すように、クラッド用フィルム基材の上に光導波路用凸部（コア）３４０が形成される。
さらに、クラッド用基材のコア形成面にクラッド層３５０を形成することにより、本発明の高分子光導波路３６０（図５（Ｇ）参照）が作製される。
【００３９】
以下に、各工程を詳細に説明する。
（１）原盤に鋳型形成用硬化性樹脂の硬化層を形成した後剥離して原盤凸部に対応する凹部が形成された鋳型を作製する工程
鋳型は、前記のようにして作製した原盤の凸部形成面に、鋳型形成用硬化性樹脂の硬化層を形成した後剥離して作製される。
鋳型形成用硬化性樹脂としては、その硬化物が原盤から容易に剥離することができること、鋳型（繰り返し用いる）として一定以上の機械的強度・寸法安定性を有することが好ましい。鋳型形成用硬化性樹脂には、必要に応じて各種添加剤を加えてもよい。
鋳型形成用硬化性樹脂は、原盤に形成された個々の光導波路を正確に写し取らなければならないので、ある限度以下の粘度、例えば、５００〜７０００ｍＰａ・ｓ、さらには、２０００〜５０００ｍＰａ・ｓ程度を有することが好ましい。また、粘度調節のために溶剤を、溶剤の悪影響がない程度に加えることができる。（なお本発明において用いる鋳型形成用硬化性樹脂としては、硬化性シリコーンゴムオリゴマー又はモノマーのように、硬化後、弾性を有するゴム状体となるものも含まれる。）
【００４０】
前記鋳型形成用硬化性樹脂としては、硬化後、シリコーンゴム又はシリコーン樹脂となる硬化性シリコーンゴムオリゴマー又はモノマー、硬化性シリコーン樹脂オリゴマー又はモノマー（熱硬化型、室温硬化型、）が、剥離性、機械強度・寸法安定性の観点から、また、クラッド用基材との密着性の良さから好ましく用いられる。特にシリコーンゴムはクラッド用基材との密着性と剥離性という相反した特性に優れ、ナノ構造を写し取る能力を持ち、シリコーンゴムとクラッド用基材とを密着させると液体の進入させ防ぐことができる。このようなシリコーンゴムを用いた鋳型は高精度に原盤を写し取り、クラッド用基材に良く密着するため、鋳型とクラッド用基材の間の凹部のみに効率よくコア形成用樹脂を充填することが可能となり、さらにクラッド用基材と鋳型の剥離も容易である。したがって、この鋳型からは高精度に形状を維持した高分子光導波路を、極めて簡便に作製することができる。
硬化性シリコーンゴムオリゴマー又はモノマー及び硬化性シリコーン樹脂オリゴマー又はモノマーとしては、メチルシロキサン基、エチルシロキサン基、フェニルシロキサン基を含むものが好ましく、特に硬化性ジメチルシロキサンゴムオリゴマー（ＰＤＭＳ）が密着性及び剥離性の点から好ましい。ＰＤＭＳの硬化物は、一般に屈折率が１．４３程度と低いために、ＰＤＭＳから作った鋳型は、クラッド用基材から剥離せずに、そのままクラッド層として利用することができる。この場合には、ＰＤＭＳ鋳型と、充填したコア形成用樹脂及びクラッド用基材とが剥がれないような工夫が必要になる。
【００４１】
前記原盤にはあらかじめ離型剤塗布などの離型処理を行なって鋳型との剥離を促進させることが望ましい。その後、原盤の凸部形成面に、鋳型形成用硬化性樹脂を塗布したり注型するなどの方法により鋳型形成用硬化性樹脂の層を形成し、その後硬化させる。
硬化層の厚さは鋳型としての取り扱い性を考慮して適宜決められるが、一般的に０．１〜５０ｍｍ程度が適切である。
その後、硬化層と原盤を剥離し、鋳型とする。鋳型端面に凹部が露出していない場合には、鋳型の両端を切断し凹部断面を露出させる。
鋳型の表面エネルギーは、１０ｄｙｎ／ｃｍ〜３０ｄｙｎ／ｃｍ、好ましくは１５ｄｙｎ／ｃｍ〜２４ｄｙｎ／ｃｍの範囲にあることが、基材フィルムとの密着性の点からみて好ましい。
鋳型のシェア（Ｓｈａｒｅ）ゴム硬度は、１５〜８０、好ましくは２０〜６０であることが、型取り性能や剥離性の点からみて好ましい。
鋳型の表面粗さ（二乗平均粗さ（ＲＭＳ））は、０．５μｍ以下、好ましくは０．１μｍ以下にすることが、型取り性能の点からみて好ましい。
【００４２】
（２）鋳型の凹部形成面にクラッド用基材を密着させる工程
本発明において用いるクラッド用基材としては、ガラス基材、セラミック基材、プラスチック基材等のものが制限なく用いられる。また屈折率制御のために前記基材に樹脂コートしたものも用いられる。クラッド用基材の屈折率は、１．５５より小さく、１．５０より小さいものがより好ましい。特に、コア材の屈折率より０．０２以上、さらには０．０５以上小さいことが好ましい。また、クラッド基材としては、鋳型との密着性に優れ、両者を密着させた場合、鋳型凹部以外に空隙が生じないものが好ましい。
プラスチック基材の中でも、フレキシブルなフィルム基材を用いた高分子光導波路は、カプラー、ボード間の光配線や光分波器等としても使用でき、その用途に応じて、フィルム基材の屈折率、光透過性等の光学的特性、機械的強度、耐熱性、鋳型との密着性、フレキシビリティー（可撓性）等を考慮して選択される。前記フィルムとしては脂環式アクリルフイルム、脂環式オレフィンフイルム、三酢酸セルロースフイルム、含フッ素樹脂フイルム等が挙げられる。フィルム基材の屈折率は、コアとの屈折率差を確保するため、１．５５より小さく、好ましくは１．５３より小さくすることが望ましい。
【００４３】
前記脂環式アクリルフイルムとしてはトリシクロデカン等の脂肪族環状炭化水素をエステル置換基に導入した、ＯＺ−１０００、ＯＺ−１１００等が用いられる。
また、脂環式オレフィンフイルムとしては主鎖にノルボルネン構造を有するもの、及び主鎖にノルボルネン構造を有しかつ側鎖にアルキルオキシカルボニル基（アルキル基としては炭素数１から６のものやシクロアルキル基）等の極性基をもつものが挙げられる。中でも前記のごとき主鎖にノルボルネン構造を有しかつ側鎖にアルキルオキシカルボニル基等の極性基をもつ脂環式オレフィン樹脂は、低屈折率（屈折率が１．５０近辺であり、コア・クラッドの屈折率の差を確保できる）及び高い光透過性等の優れた光学的特性を有し、鋳型との密着性に優れ、さらに耐熱性に優れているので特に本発明の高分子光導波路の作製に適している。アートンフイルム（ＪＳＲ（株）製）やゼオネアフイルム（日本ゼオン（株）製）は、屈折率１．５０近辺であり利用しやすい。
また、前記フィルム基材の厚さはフレキシビリティーと剛性や取り扱いの容易さ等を考慮して適切に選ばれ、一般的には０．１ｍｍ〜０．５ｍｍ程度が好ましい。
また、クラッド用基材としてフィルム基材を用いる場合は、フィルム基材を表面が平坦な剛体の上に置いた状態で鋳型と密着させることが好ましい。
【００４４】
（３）鋳型凹部とクラッド用基材の間に形成された溝にコア形成用硬化性樹脂を充填する工程
この工程においては、コア形成用硬化性樹脂、例えば紫外線硬化性樹脂又は熱硬化性樹脂を、毛細管現象により鋳型とクラッド用基材との間に形成された空隙（鋳型の凹部）に充填させる。鋳型に、クラッド用基材を密着させると、両者を特別な手段を用いて固着させなくても（前記特許第３１５１３６４号明細書に記載のごとき固着手段）、鋳型に形成された凹部構造以外には、鋳型とクラッド用基材の間に空隙が生ずることなく、紫外線硬化性樹脂又は熱硬化性樹脂を前記凹部のみに進入させることができる。
一方、鋳型凹部の径が小さければ小さいほど充填速度が遅くなり、実用的な速度での充填が不可能になるので、毛細管現象の充填速度を上げることが実際に使うときに課題となる。充填速度を上げる方法としては、コア形成用硬化性樹脂の粘度を下げることと、凹部排出側の圧力を下げる（例えば吸引）のが効果的である。
【００４５】
前記観点から、前記硬化性樹脂の粘度は、１０ｍＰａ・ｓ〜２０００ｍＰａ・ｓ、望ましくは２０ｍＰａ・ｓ〜１０００ｍＰａ・ｓ、更に好ましくは３０ｍＰａ・ｓ〜５００ｍＰａ・ｓにするのが好ましい。
このほかに、原盤に形成された光導波路用凸部が有する元の形状を高精度に再現するため、前記コア形成用硬化性樹脂の硬化前後の体積変化が小さいことが必要である。例えば、体積が減少すると所定の形状と異なる形になり導波損失の原因になる。したがって、前記硬化性樹脂は、溶剤フリーで体積変化ができるだけ小さいものが望ましく、１０％以下、好ましくは５％以下であるのが望ましい。
また、前記紫外線硬化性樹脂としてエポキシ系、ポリイミド系、アクリル系紫外線硬化性樹脂が好ましく用いられる。
【００４６】
コア形成用硬化性樹脂の硬化物の屈折率は、クラッドを構成する高分子材料よりも高い（クラッドとの差が０．０２以上、好ましくは０．０５以上）ことが必要である。例えば、クラッド用基材としてフィルム基材を用いると、鋳型との密着性の良いフィルム基材は、屈折率１．５０近辺のものが多いため、屈折率差を０．０５以上とる場合には、コア形成用硬化性樹脂の硬化物の屈折率は１．５５以上が好ましい。
【００４７】
（４）コア形成用硬化性樹脂を硬化し、その後鋳型を剥離する工程
充填したコア形成用硬化性樹脂を硬化させる。紫外線硬化性樹脂を硬化させるには、紫外線ランプ、紫外線ＬＥＤ、ＵＶ照射装置等が用いられる。また、熱硬化性樹脂を硬化させるには、オーブン中での加熱等が用いられる。
また、前記鋳型をそのままクラッド層に用いることも可能で、この場合は、鋳型を剥離する必要はなくそのままクラッド層として利用する。
【００４８】
（５）クラッド用基材のコア形成面にクラッド層を形成する工程
コアが形成されたフィルム基材の上にクラッド層を形成するが、クラッド層としては前記クラッド用基材が同様に用いられる他、硬化性樹脂（紫外線硬化性樹脂、熱硬化性樹脂）を塗布して硬化させた層、高分子材料の溶剤溶液を塗布して乾燥して得られる高分子膜等が挙げられる。クラッド層としてフィルムを用いる場合は、接着剤を用いて貼り合わされるが、その際、接着剤の屈折率がフィルムの屈折率と近いことが望ましい。
クラッド層の屈折率は、コアとの屈折率差を確保するため、１．５５より小さく、好ましくは１．５３より小さくすることが望ましい。また、クラッド層の屈折率を前記クラッド用基材の屈折率と同じにすることが、光の閉じ込めの点からみて好ましい。
【００４９】
本発明の高分子光導波路の製造方法において、特に、鋳型形成用硬化性樹脂として熱硬化性のシリコーンゴムオリゴマー又はモノマー、中でも熱硬化性のジメチルシロキサンゴムオリゴマー又はモノマーを用い、フィルム基材として主鎖にノルボルネン構造を有しかつ側鎖にアルキルオキシカルボニル基等の極性基をもつ脂環式オレフィン樹脂を用いる組み合わせは、両者の密着性が特に高く、また、凹部構造の断面積が極めて小さくても（例えば１０×１０μｍの矩形）毛細管現象により素早く凹部に硬化性樹脂を充填することができる。
【００５０】
さらに、前記の鋳型をクラッド層として用いることもできるが、その場合には、鋳型の屈折率が１．５以下で、鋳型とコア材料の接着性を向上させるために鋳型をオゾン処理することが好ましく、また、鋳型の３５０ｎｍ〜７００ｎｍ領域における光透過率が８０％以上であることが望ましい。
【００５１】
本発明の口径変換型高分子光導波路の製造方法においては、前記のごとく原盤が安価にかつ高精度に作製され、また、この原盤を用いるその後の高分子光導波路の製造工程も簡易な工程の組み合わせであるため、従来の口径変換型高分子光導波路の製造方法に比較し、極めて低コストで高分子光導波路を作製することができる。また、本発明の高分子光導波路の製造方法により、損失ロスが少なく高精度であり、かつ各種機器への自由な装填を可能とするフレキシブルな高分子光導波路を製造することができる。さらに高分子光導波路の形状等を自由に設定することができる。
【００５２】
【実施例】
以下に実施例を示し本発明をさらに具体的に説明するが、本発明はこれらの実施例により限定されるものではない。
実施例１
＜原盤の作製＞
厚み１．１ｍｍで７０ｍｍ角のガラス基板上に、ＩＴＯ薄膜を厚み１５０ｎｍ積層し、かつ基板の一辺に前記ＩＴＯ薄膜と電気的に接続する給電端子を幅１ｍｍで設けた電着基板を用意し、別途、白金めっきしたチタン板（対向電極）、及び参照電極（飽和カロメル電極）を用意した。
電着装置として３極式のものを用い、液槽に電着レジスト材（関西ペイント（株）製、ゾンネＥＤＵＶＰ−５００）を含む電着液を満たし、対向電極と参照電極を液槽中にセットし、さらに前記電着基板を、ＩＴＯ薄膜が電着液に接触するように電着装置に配置した。給電端子をポテンショスタットに接続し、給電端子の電圧が参照電極の基準に対して３０Ｖになるように電圧印加し、２分電着した。
その結果、ＩＴＯ薄膜上に電着レジストが着膜したが、その膜厚は、給電端子に最も近い地点で１７μｍ、最も遠い地点で５μｍとなった。
電着レジストをプリベーク後、導波路コアパターンをもつフォトマスクを用いて、５００ｍｊ／ｃｍ^２の露光強度で露光した。フォトマスクの開口部は、給電端子に近い側の幅が１７μｍ、遠い側が５μｍの幅になるようにした。その後ＴＭＡＨ現像液で現像、ポストベークしたところ、両端が５μｍと１７μｍの矩形で連続的に断面積が変化する光導波路コアに相当する凸型が形成された原盤が得られた。
【００５３】
＜口径変換型高分子光導波路の作製＞
次に、この原盤に離型剤を塗布した後、ポリジメチルシロキサンゴム（ＰＤＭＳ）オリゴマー（ダウコウニングアジア社製：ＳＹＬＧＡＲＤ１８４）を流し込んで１２０℃で３０分間加熱することで硬化させた後、剥離して前記凸部に対応する凹部を持った厚み１ｍｍの型を作製し、次に、型の両端を切断して下記紫外線硬化性樹脂の入出力部を作り鋳型とした。
この鋳型と、鋳型より一回り大きく、平板ガラス上に真空チャックされたフィルム基材（アートンフイルム、膜厚１８８μｍ、ＪＳＲ（株）製、屈折率１．５１）を接触させたところ、両者は密着した。
次に、鋳型の一端にある入力部に、粘度が２００ｍＰａ・ｓのエポキシ系紫外線硬化性樹脂（ＮＴＴ−ＡＴ社製）を数滴落とし、２０ｋＰａの吸引力で出力部から吸引したところ、約３分で毛細管現象により前記凹部の全領域に紫外線硬化性樹脂が充填された。
上記状態において鋳型を透して５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させ、鋳型を剥離してアートンフイルム基材上に、屈折率１．５４のコアを作製した。さらに、コア形成面上に、屈折率がアートンフイルムと同じ１．５１の紫外線硬化樹脂（ＪＳＲ（株）製）を塗布し、さらにこの上に前記基材フィルムと同じアートンフィルムを重ねて、５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させた。さらに両端をダイシングソーで切断することにより口径変換型高分子光導波路を完成させた。
【００５４】
実施例２
＜原盤の作製＞
実施例１と同様にして、電着基板に電着レジストを電着してプリベークした工程に続いて、スピンコート法により厚膜レジスト（ＪＳＲ（株）製、ＴＨＢＰ６１１）を重ねて塗布した。これにより膜厚は最も薄いところで５０μｍ、最も厚いところで６３μｍとなった。
さらにプリベークを行った後、開口部が、給電端子に近い側の幅が６３μｍ、遠い側が５０μｍの幅である導波路コアパターンフォトマスクを用いて５００ｍＷ／ｃｍ^２の露光強度で露光した。その後ＴＭＡＨ現像液で現像し、ポストベークしたところ、両端が５０μｍと６３μｍの矩形で連続的に断面積が変化する導波路コアに相当する凸型が形成された原盤が得られた。
＜口径変換型高分子光導波路の作製＞
次に、この原盤に離型剤を塗布した後、ポリジメチルシロキサンゴム（ＰＤＭＳ）オリゴマー（ダウコウニングアジア社製：ＳＹＬＧＡＲＤ１８４）を流し込んで１２０℃で３０分間加熱することで硬化させた後、剥離して前記凸部に対応する凹部を持った厚み１ｍｍの型を作製し、次に、型の両端を切断して下記紫外線硬化性樹脂の入出力部を作り鋳型とした。
この鋳型と、鋳型より一回り大きく、平板ガラス上に真空チャックされたフィルム基材（アートンフイルム、膜厚１８８μｍ、ＪＳＲ（株）製、屈折率１．５１）を接触させたところ、両者は密着した。
次に、鋳型の一端にある入力部に、粘度が２００ｍＰａ・ｓのエポキシ系紫外線硬化性樹脂（ＮＴＴ−ＡＴ社製）を数滴落としたところ、約１０分で毛細管現象により前記凹部の全領域に紫外線硬化性樹脂が充填された。
上記状態において鋳型を透して５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させ、鋳型を剥離してアートンフイルム基材上に、屈折率１．５２のコアを作製した。さらに、コア形成面上に、屈折率がアートンフイルムと同じ１．５１の紫外線硬化樹脂（ＪＳＲ（株）製）を塗布し、さらにこの上に前記基材フィルムと同じアートンフィルムを重ねて、５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させた。さらに両端をダイシングソーで切断することにより、両端が各々６２．５μｍ及び５０μｍ角の口径変換型高分子光導波路が得られた。
【００５５】
実施例３
＜原盤の作製＞
厚み１．１ｍｍで７０ｍｍ角のガラス基板上に、ＩＴＯ薄膜を厚み１５０ｎｍ、さらに酸化チタンを厚み１５０ｎｍ積層した光電着基板と、白金めっきしたチタン板（対向電極）、及び参照電極（飽和カロメル電極）を用意した。
電着液として、純水１００ｇに対してスチレン−アクリル酸共重合体（分子量１３，０００、スチレンとアクリル酸の共重合モル比６５：３５、酸価１５０）を１０ｇ溶解させ、更にテトラメチルアンモニウムハイドロオキサイド及び塩化アンモニウムを用いてｐＨ７．８、導電率１２ｍＳ／ｃｍになるように調整したものを用意した。
図３（Ａ）で示すような電気化学で一般的な三極式の電着装置に前記電着液を入れ、対向電極及び参照電極を電着液中にセットし、さらに、前記基板の酸化チタン薄膜が電着液に接するように電着装置に基板を配置した。飽和カロメル電極に対しＴｉＯ_２電極を作用電極として利用した。
形成すべき光導波路コア形状にしたがって、Ｈｅ−Ｃｄレーザーの強度を変化させながらスキャン照射し、酸化チタン薄膜上に、膜厚が５μｍから２０μｍ、幅が１０〜４０μｍまで連続的に変化する凸型が形成された原盤を得た。
【００５６】
＜口径変換型高分子光導波路の作製＞
次に、この原盤に離型剤を塗布した後、ポリジメチルシロキサンゴム（ＰＤＭＳ）オリゴマー（ダウコウニングアジア社製：ＳＹＬＧＡＲＤ１８４）を流し込んで１００℃で１時間加熱することで硬化させた後、剥離して前記凸部に対応する凹部を持った厚み１ｍｍの型を作製し、次に、型の両端を切断して下記紫外線硬化性樹脂の入出力部を作り鋳型とした。
この鋳型と、鋳型より一回り大きく、平板ガラス上に真空チャックされたフィルム基材（アートンフイルム、膜厚１８８μｍ、ＪＳＲ（株）製、屈折率１．５１）を接触させたところ、両者は密着した。
次に、鋳型の一端にある入出力部に、粘度が２００ｍＰａ・ｓのエポキシ系紫外線硬化性樹脂（ＮＴＴ−ＡＴ社製）を数滴落としたところ、約３０分で毛細管現象により前記凹部の全領域に紫外線硬化性樹脂が充填された。
上記状態において鋳型を透して５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させ、鋳型を剥離してアートンフイルム基材上に、屈折率１．５４のコアを作製した。さらに、コア形成面上に、屈折率がアートンフイルムと同じ１．５１の紫外線硬化樹脂（ＪＳＲ（株）製）を塗布し、さらにこの上に前記基材フィルムと同じアートンフィルムを重ねて、５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させた。さらに両端をダイシングソーで切断することにより、口径変換型導波路を完成させた。
【００５７】
実施例４
＜原盤の作製＞
厚み１．１ｍｍで７０ｍｍ角のガラス基板上に、ＩＴＯ薄膜を厚み１５０ｎｍ、さらに酸化チタンを厚み１５０ｎｍ積層した。酸化チタン層の上に厚膜フォトレジスト（膜厚６３μｍ）を形成し、その後露光現像して溝（酸化チタン薄膜が露出）を形成し、光電着基板とした。厚膜レジストにおける溝の深さは６３μｍであり、また溝の幅は、基板の端から端へ５０〜６３μｍとなるように変化させた。別途、白金めっきしたチタン板（対向電極）、及び参照電極（飽和カロメル電極）を用意した。
電着液として、純水１００ｇに対してスチレン−アクリル酸共重合体（分子量１３，０００、スチレンとアクリル酸の共重合モル比６５：３５、酸価１５０）を１０ｇ溶解させ、更にテトラメチルアンモニウムハイドロオキサイド及び塩化アンモニウムを用いてｐＨ７．８、導電率１２ｍＳ／ｃｍになるように調整したものを用意した。
図３（Ａ）で示すような電気化学で一般的な三極式の電着装置に前記電着液を入れ、対向電極及び参照電極を電着液中にセットし、さらに、前記光電着基板溝底部の、露出した酸化チタン薄膜が電着液に接するように光電着基板を配置した。飽和カロメル電極に対し酸化チタン電極を作用電極として利用した。
前記厚膜レジストに設けた溝に沿って、Ｈｅ−Ｃｄレーザーの強度を変えながらスキャンし、厚膜レジストにおける溝幅が最も狭いところから最も広いところまでの膜厚がほぼ１３μｍ〜０μｍとなるように、光電着により溝部の酸化チタン膜の上に薄膜形成を行い、最終的に、溝の断面形状が、溝の幅が最も狭いところから最も広いところへ向かって、５０μｍ角から６３μｍ角まで連続的に変化する凹型母型を作製した。
この凹型母型に対してニッケル電鋳を行い、厚さ２ｍｍで、表面に断面形状が５０μｍ角から６３μｍ角の凸部が形成された原盤を作製した。
【００５８】
＜口径変換型高分子光導波路の作製＞
次に、この原盤に離型剤を塗布した後、ポリジメチルシロキサンゴム（ＰＤＭＳ）オリゴマー（ダウコウニングアジア社製：ＳＹＬＧＡＲＤ１８４）を流し込んで１００℃で１時間加熱することで硬化させた後、剥離して前記凸部に対応する凹部を持った厚み１ｍｍの型を作製し、次に、型の両端を切断して下記紫外線硬化性樹脂の入出力部を作り鋳型とした。
この鋳型と、鋳型より一回り大きく、平板ガラス上に真空チャックされたフィルム基材（アートンフイルム、膜厚１８８μｍ、ＪＳＲ（株）製、屈折率１．５１）を接触させたところ、両者は密着した。
次に、鋳型の一端にある入出力部に、粘度が２００ｍＰａ・ｓのエポキシ系紫外線硬化性樹脂（ＮＴＴ−ＡＴ社製）を数滴落としたところ、約１０分で毛細管現象により前記凹部の全領域に紫外線硬化性樹脂が充填された。
上記状態において鋳型を透して５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させ、鋳型を剥離してアートンフイルム基材上に、屈折率１．５４のコアを作製した。さらに、コア形成面上に、屈折率がアートンフイルムと同じ１．５１の紫外線硬化樹脂（ＪＳＲ（株）製）を塗布し、さらにこの上に前記基材フィルムと同じアートンフィルムを重ねて、５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させた。さらに両端をダイシングソーで切断することにより、両端部の断面形状がそれぞれ６２．５μｍと５０μｍ角のマルチモード光ファイバーに対応した口径変換型導波路を完成させた。このときの結合損失は０．１〜０．３ｄＢ程度であった。
【００５９】
実施例５
＜原盤の作製＞
厚み１．１ｍｍで７０ｍｍ角のガラス基板上に、ＩＴＯ薄膜を厚み１５０ｎｍ、さらに酸化チタンを厚み１５０ｎｍ積層した。酸化チタン層の上に厚膜フォトレジスト（膜厚５０μｍ）を形成し、その後露光現像して溝（酸化チタン薄膜が露出）を形成し、光電着基板とした。厚膜レジストにおける溝の深さは５０μｍであり、また溝の幅は、基板の端から端へ５０〜１０μｍとなるように変化している。別途、白金めっきしたチタン板（対向電極）、及び参照電極（飽和カロメル電極）を用意した。
電着液として、純水１００ｇに対してスチレン−アクリル酸共重合体（分子量１３，０００親水基／（親水基＋疎水基）のモル比６５％酸価１５０）を１０ｇ溶解させ、これに平均粒子径が６０ｎｍの導電性カーボンを１０ｇ分散させ、更にテトラメチルアンモニウムハイドロオキサイド及び塩化アンモニウムを用いてｐＨ７．８、導電率１２ｍＳ／ｃｍになるように調整したものを用意した。
電気化学で一般的な三極式の電着装置に前記電着液を入れ、対向電極及び参照電極を電着液中にセットし、さらに、前記基板の露出した酸化チタン薄膜が電着液に接するように基板を配置した。飽和カロメル電極に対しＴｉＯ_２電極を作用電極として利用した。
前記厚膜レジストに設けた溝に沿って、Ｈｅ−Ｃｄレーザーの強度を変えながらスキャンし、厚膜レジストにおける溝幅が最も狭いところから最も広いところまでの膜厚が４０μｍ〜０μｍとなるように、光電着により溝部のＴｉＯ_２膜の上に薄膜形成を行い、最終的に、溝の断面形状が、溝の幅が最も狭いところから最も広いところへ向かって、１０μｍ角から５０μｍ角まで連続的に変化する凹型母型を作製した。
この凹型母型に対してニッケル電鋳を行い、厚さ２ｍｍで、表面に断面形状が１０μｍ角から５０μｍ角の凸部をもつ凸型母型（原盤）を作製した。
【００６０】
＜口径変換型高分子光導波路の作製＞
次に、この原盤に離型剤を塗布した後、ポリジメチルシロキサン（ＰＤＭＳ）オリゴマー（ダウコウニングアジア社製：ＳＹＬＧＡＲＤ１８４）を流し込んで１００℃で１時間加熱することで硬化させた後、剥離して前記凸部に対応する凹部を持った厚み１ｍｍの型を作製し、次に、型の両端を切断して下記紫外線硬化性樹脂の入出力部を作り鋳型とした。
この鋳型と、鋳型より一回り大きく、平板ガラス上に真空チャックされたフィルム基材（アートンフイルム、膜厚１８８μｍ、ＪＳＲ（株）製、屈折率１．５１）を接触させたところ、両者は密着した。
次に、鋳型の一端にある入力部に、粘度が２００ｍＰａ・ｓのエポキシ系紫外線硬化性樹脂（ＮＴＴ−ＡＴ社製）を数滴落とし、２０ｋＰａの吸引力で出力部から吸引したところ、約３分で毛細管現象により前記凹部の全領域に紫外線硬化性樹脂が充填された。
上記状態において鋳型を透して５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させ、鋳型を剥離してアートンフイルム基材上に、屈折率１．５４のコアを作製した。さらに、コア形成面上に、屈折率がアートンフイルムと同じ１．５１の紫外線硬化樹脂（ＪＳＲ（株）製）を塗布し、さらにこの上に前記基材フィルムと同じアートンフィルムを重ねて、５０ｍＷ／ｃｍ^２のＵＶ光を１０分間照射して硬化させた。さらに両端をダイシングソーで切断することにより、発光面積１０μｍのＶＣＳＥＬを直結して５０μｍのマルチモード光ファイバーに接続する口径変換型導波路を完成させた。このときの結合損失は０．１〜０．３ｄＢ程度であった。
【００６１】
【発明の効果】
本発明の前記第１ないし第４の鋳型の製造方法は、前記のごとく、電着又は光電着、感光性材料の露光・現像、及び電鋳という、それぞれが安価な方法を組み合わせたものであるにもかかわらず、高精度でかつ簡便に、口径変換型高分子光導波路コアに対応する凸部が形成された原盤を作製することができる。
本発明の高分子光導波路の製造方法は、製造工程が極めて単純化され容易に高分子光導波路を作製することができ、従来の高分子光導波路の製造方法に比較し、極めて低コストで高分子光導波路を作製することができ、量産性にも優れている。また、本発明の高分子光導波路の製造方法により、損失ロス及び結合ロスが少なく高精度であり、かつ各種機器への自由な装填を可能とするフレキシブルな高分子光導波路を簡便に量産性よく製造することができる。さらに高分子光導波路の形状等を自由に設定することができる。
【図面の簡単な説明】
【図１】本発明の第１の原盤の製造工程を示す概念図である。
【図２】本発明の第２の原盤の製造工程を示す概念図である。
【図３】本発明の第３の原盤の製造工程を示す概念図である。
【図４】本発明の第４の原盤の製造工程を示す概念図である。
【図５】本発明の口径変換型高分子光導波路の製造工程を示す概念図である。
【符号の説明】
１０電着基板
１８電着層
１９感光性樹脂材料の層
２０、２００、３００原盤
２２、２２０、３０２高分子光導波路コアに対応する凸部
１００光電着基板
１１０溝
１１４薄膜（電着膜）
１１６電鋳金属膜
３２４鋳型
３３０クラッド用基材
３４０高分子光導波路コア
３５０クラッド層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a master for producing a diameter-converting polymer optical waveguide and a method for manufacturing a diameter-converting polymer optical waveguide using the method.
[0002]
[Prior art]
As a method for producing a polymer waveguide, (1) a method of impregnating a film with a monomer, selectively exposing a core portion to change a refractive index, and bonding a film (selective polymerization method), and (2) a core layer And a method of forming a clad portion by using reactive ion etching after coating the clad layer (RIE method). (3) Exposure and development using an ultraviolet curable resin obtained by adding a photosensitive material to a polymer material A method using a photolithography method (direct exposure method), (4) a method using injection molding, (5) a method in which after applying a core layer and a cladding layer, exposing the core portion to change the refractive index of the core portion ( Photo bleaching method) has been proposed.
However, the selective polymerization method (1) has a problem in laminating the films, and the methods (2) and (3) use photolithography to increase the cost, and the method (4) requires the core obtained. There is a problem with the accuracy of the diameter. Further, the method (5) has a problem that a sufficient refractive index difference between the core layer and the clad layer cannot be obtained.
At present, the only practical methods excellent in performance are the methods (2) and (3), but there is a problem of cost as described above. Therefore, at present, there is no manufacturing method suitable for forming a polymer waveguide on a large-area substrate, particularly a large-area flexible substrate.
[0003]
As a method of manufacturing a polymer optical waveguide, a pattern substrate (cladding) on which a pattern of grooves serving as capillaries is formed is filled with a polymer precursor material for a core, and then cured to form a core layer. It is known that a planar substrate (cladding) is bonded to the substrate. In this method, a polymer precursor material is thinly filled and cured not only in the capillary groove but also between the pattern substrate and the planar substrate. As a result of forming a thin layer having the same composition as the core layer, there is a problem that light leaks through the thin layer.
As one of the methods to solve this problem, David Hart fixes a pattern substrate on which a pattern of grooves serving as capillaries is formed to a flat substrate with a jig for clamping, and furthermore, a contact portion between the pattern substrate and the flat substrate. Was sealed with a resin, etc., and then decompressed, and a monomer (diallyl isophthalate) solution was filled in a capillary to produce a polymer optical waveguide (see Patent Document 1 below). In this method, instead of using a polymer precursor material as a core forming resin material, the filling material is reduced in viscosity using a monomer instead of using a polymer, and the capillary is filled using a capillary phenomenon so that the monomer is not filled except for the capillary. How to
However, since this method uses a monomer as a material for forming the core, the volume shrinkage when the monomer is polymerized into a polymer is large, and the transmission loss of the polymer optical waveguide is increased. There is also a problem in that the polymerized core resin partially adheres to the flat substrate and the core shape is broken when peeled off.
In addition, this method is a complicated method such as fixing the pattern substrate and the flat substrate with a clamp, or additionally sealing the contact portion with a resin, and is not suitable for mass production, and as a result, is expected to reduce cost. Can not. Further, it cannot be applied to the production of a polymer optical waveguide using a film having a thickness on the order of mm or 1 mm or less as a clad.
[0004]
Recently, George M. of Harvard University. Whitesides et al. Have proposed a method called capillary micromolding as one of soft lithography as a new technology for producing nanostructures. In this method, a master substrate is made using photolithography, and the nanostructure of the master substrate is transferred to a PDMS mold using the adhesiveness of polydimethylsiloxane (PDMS) and the easy peeling property. This is a method in which a liquid polymer is poured and solidified using the above method. A detailed commentary article is described in Non-Patent Document 1 below.
[0005]
Also, George M. of Bird University. A patent on capillary micromolding has been filed by Kim Enoch et al. Of the Whitesides group (see Patent Document 2 below).
However, the manufacturing method of the polymer optical waveguide described in this patent is time-consuming and not suitable for mass production when the cross-sectional area such as the core of the optical waveguide is small, and the monomer solution reacts with the polymer. There is a disadvantage that when solidified, the volume changes and the shape of the core changes.
[0006]
On the other hand, the present inventors have proposed a method of manufacturing a flexible polymer optical waveguide in which an optical waveguide is provided on a film substrate (Japanese Patent Application No. 2002-187473). In this method, the manufacturing process is extremely simplified, a polymer optical waveguide can be easily manufactured, and the polymer optical waveguide is manufactured at a very low cost as compared with the conventional polymer optical waveguide manufacturing method. Can be produced.
Such a polymer optical waveguide is required to have a function of connecting various optical components, for example, an optical fiber, a light emitting element, and a light receiving element. In this case, the polymer optical waveguide to be manufactured is adjusted according to the size of the various optical components. The coupling loss can be reduced by changing the cross-sectional area or cross-sectional shape (diameter) of the input / output unit. However, when fabricating a master, a method typified by a conventional direct exposure method using photolithography involves continuously changing the film thickness of a convex portion corresponding to a polymer optical waveguide core formed on the master (aperture). Conversion) is difficult, so that this method could not freely control the film thickness of the convex portions of the master so as to reduce the coupling loss. In addition, although there is a method of manufacturing a master by a method such as microfabrication of a silicon substrate by FIB or the like, in the case of a master for manufacturing a large-diameter and large-area such as a multi-mode waveguide, However, there was a problem that it was very time-consuming and almost impossible.
[0007]
As an attempt to solve the above problem, Patent Document 3 below describes a method for manufacturing a polymer optical waveguide (but not flexible) for connecting a polymer optical waveguide to an optical component such as an optical fiber. . In this method, a method of connecting a polymer optical waveguide and an optical fiber by forming a shallow liquid storage pool on a substrate and forming grooves on both sides of the pool and placing optical fibers in the grooves is adopted. Grooves need to be processed in addition to the storage pool, which increases the man-hours, and it is necessary to precisely match the positions of the grooves and the photomask for each polymer optical waveguide to be manufactured. In addition, in order to change the cross-sectional area of the optical waveguide three-dimensionally in the longitudinal direction, it is necessary to precisely control the depth of the shallow liquid pool, and it is necessary to keep the liquid pool strictly horizontal. Due to weakness against vibration, the yield is low, and it is not practical as a mass production method. Further, there is no description of a specific method for producing a groove having a surface roughness and a shape accuracy required for a waveguide and having a thickness and a width changed according to a position in a longitudinal direction.
[0008]
Patent Document 4 below describes an optical coupling device that controls the aperture and the refractive index in accordance with the light source to improve the coupling efficiency with a fiber, but is applicable to a polymer waveguide. No specific manufacturing method is described.
[0009]
[Patent Document 1]
Patent No. 3151364
[Patent Document 2]
US Pat. No. 6,355,198
[Patent Document 3]
JP-A-10-253845
[Patent Document 4]
Japanese Patent Publication No. 55-006201
[Non-patent document 1]
SCIENTIFIC AMERICA SEPTEMBER 2001 (Nikkei Science December 2001)
[0010]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a master for producing a diameter-converting type polymer optical waveguide at a low cost, with high accuracy, by a simple method. Another object of the present invention is to provide a method for producing a polymer optical waveguide having a small number of working steps, a low cost, a small waveguide loss and a small coupling loss by using the method for producing a master.
[0011]
[Means for Solving the Problems]
The object is to provide the following method (1) to (4) for producing a master for producing a diameter-converting polymer optical waveguide, and to produce a diameter-converting polymer optical waveguide using the method (5) to (24). Is solved by providing.
(1) An electrodeposited and photosensitive film forming material is electrodeposited on an electrodeposited substrate having a conductive thin film on an insulating substrate and a power supply terminal provided at an end of the conductive thin film. Producing a master for producing a diameter-converting type polymer optical waveguide having a convex portion corresponding to the polymer optical waveguide core, comprising a step of forming a deposition layer and a step of exposing and developing the layer into a polymer optical waveguide core pattern shape. how to.
(2) An electrodeposited and photosensitive film forming material is electrodeposited on an electrodeposited substrate having a conductive thin film on an insulating substrate and a power supply terminal provided at an end of the conductive thin film. A polymer photoconductive layer comprising a step of forming a deposition layer, a step of forming a layer of a photosensitive resin material on the layer, and a step of exposing and developing the layer formed in the above two steps into a polymer optical waveguide core pattern shape. A method for producing a master for producing a diameter-converting polymer optical waveguide having a convex portion corresponding to a waveguide core.
[0012]
(3) An electro-deposited substrate in which a conductive thin film and an optical semiconductor thin film are laminated in this order on an insulative substrate is used as an aqueous electrode containing a film-forming material whose solubility or dispersibility in an aqueous liquid decreases due to a change in pH. A step of arranging at least the optical semiconductor thin film of the photo-deposited substrate in contact with the electrodeposition liquid, and irradiating a selected area of the optical semiconductor thin film with light while adjusting the exposure time and / or the exposure intensity; Generating a thin film corresponding to the polymer optical waveguide core having a different cross-sectional shape and / or cross-sectional area in the longitudinal direction, and having a convex portion corresponding to the polymer optical waveguide core. A method for producing a master for producing a conversion type polymer optical waveguide.
[0013]
(4) {circle around (1)} A conductive thin film, an optical semiconductor thin film, and a layer provided with grooves having different cross-sectional shapes and / or cross-sectional areas at both ends so as to expose the optical semiconductor thin film are formed on the insulating substrate. The photo-deposited substrate laminated in order, an aqueous electro-deposition liquid containing a film-forming material whose solubility or dispersibility decreases with respect to an aqueous liquid due to a change in pH, an optical semiconductor thin film at least at the bottom of the groove of the photo-deposited substrate. (2) irradiating a selected area of the optical semiconductor thin film at the bottom of the groove with light while adjusting the exposure time and / or the exposure intensity to generate an electromotive force; Forming a thin film on the optical semiconductor thin film at the bottom of the groove so that the shape of the groove in the longitudinal direction later corresponds to the shape of the polymer / polymer optical waveguide core; Electroforming on a photo-deposited substrate with a thin film formed on it Subjecting step, ▲ 4 ▼ comprising the step of separating the light electrodeposited substrate and electroformed part, a method of manufacturing a diameter conversion type polymer optical waveguide fabrication master having convex portions corresponding to the polymer optical waveguide core.
[0014]
In the methods (1) to (4), the electrodeposition liquid may contain conductive fine particles. In the methods (3) and (4), the film-forming material may be a hydrophobic group. And a hydrophilic group, and the number of hydrophobic groups is in the range of 30% to 80% of the total number of hydrophilic groups and hydrophobic groups.
[0015]
(5) After producing a master by the method described in any one of (1) to (4) above, the following <1> to <4> steps are performed to obtain a diameter-converting polymer optical waveguide. How to manufacture.
<1> Step of forming a cured layer of a curable resin for forming a mold on the master and then peeling to form a mold having a concave portion corresponding to the convex portion
<2> Step of bringing a clad substrate into close contact with the concave portion forming surface of the mold
<3> Step of filling core-forming curable resin into a groove formed between the mold concave portion and the cladding base material
<4> Step of curing the curable resin for forming the core and then peeling off the mold
[0016]
(6) The caliber-converting polymer according to (5), wherein the clad base is a film base, and the film base is supported by a flat rigid body in the step <2>. Manufacturing method of optical waveguide.
(7) The method for producing a diameter-converting polymer optical waveguide according to (5) or (6), wherein the film base is an alicyclic olefin resin film.
(8) The alicyclic olefin resin film is a resin film having a norbornene structure in a main chain and a polar group in a side chain, according to any one of the above (5) to (7). A method for manufacturing a diameter-converting polymer optical waveguide.
[0017]
(9) The diameter conversion type polymer optical waveguide according to any one of the above (5) to (8), wherein the cladding layer is formed by applying an ultraviolet curable resin or a thermosetting resin and then curing the applied resin. Production method.
(10) The caliber-converting polymer according to any one of (5) to (9), wherein the cladding layer is formed by bonding a film for cladding with an adhesive having a refractive index close to that of the film. Manufacturing method of optical waveguide.
[0018]
(11) The method for producing a diameter-converting polymer optical waveguide according to any one of (5) to (10), wherein the curable resin for forming a mold is a curable silicone rubber oligomer or monomer. .
(12) The method for manufacturing a diameter-converting polymer optical waveguide according to any one of (5) to (11), wherein the template has a surface energy of 10 dyn / cm to 30 dyn / cm.
(13) The method of manufacturing a diameter-converting polymer optical waveguide according to any one of (5) to (12), wherein the mold has a Share rubber hardness of 15 to 80.
(14) The method for producing a diameter-converting polymer optical waveguide according to any one of (5) to (13), wherein the surface roughness of the mold is 0.5 μm or less. (15) The method for producing a diameter-converting polymer optical waveguide according to any one of (5) to (14), wherein the thickness of the mold is 0.1 mm to 50 mm.
[0019]
(16) The method for producing a diameter-converting polymer optical waveguide according to any one of (5) to (15), wherein the film substrate has a refractive index of 1.55 or less.
(17) The diameter-converting polymer optical waveguide according to any one of (5) to (16), wherein the curable resin for forming a core has a viscosity of 10 mPa · s to 2000 mPa · s. Production method.
(18) The diameter-converting polymer optical waveguide according to any one of (5) to (17), wherein a volume change when the curable resin for core formation is cured is 10% or less. Manufacturing method.
(19) The aperture-converting polymer optical waveguide according to any one of (5) to (18), wherein the cured product of the core-forming curable resin has a refractive index of 1.55 or more. Manufacturing method.
[0020]
(20) The aperture-converting polymer photoconductor according to any one of (5) to (19), further comprising a step of forming a clad layer on the core forming surface of the clad substrate after the step <4>. Waveguide manufacturing method.
(21) The method for manufacturing a diameter-converting polymer optical waveguide according to any one of the above (5) to (20), wherein the refractive index of the cladding layer is the same as that of the cladding base material.
(22) The method for manufacturing a diameter-converting polymer optical waveguide according to any one of (5) to (21), wherein the clad layer is an alicyclic olefin resin film.
(23) The alicyclic olefin resin film is a resin film having a norbornene structure in a main chain and a polar group in a side chain, according to any one of the above (5) to (22). A method for manufacturing a diameter-converting polymer optical waveguide.
(24) The aperture-converting polymer photoconductor according to any one of (5) to (23), wherein the refractive index difference between the cladding substrate and the cladding layer and the core is 0.02 or more. Waveguide manufacturing method.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
First, a method of manufacturing a master for producing a diameter-converting polymer optical waveguide will be described. The convex portions corresponding to the aperture-converting polymer optical waveguide core formed on the master have different cross-sectional shapes and / or cross-sectional areas in the longitudinal direction.
(Method of manufacturing the first master)
The first method of manufacturing a master according to the present invention provides an electrodeposited substrate having a conductive thin film on an insulating substrate, and a power supply terminal provided at an end of the conductive thin film. This is a method in which an electrodeposition layer is formed by electrodepositing a film-forming material having the layer, and the layer is exposed and developed to a polymer optical waveguide core pattern shape. Here, the polymer optical waveguide core pattern shape refers to a planar shape of the optical waveguide core viewed from above.
The first method is to use a thin film electrode whose resistance is larger than that of a bulk metal. That is, a conductive thin film (thin film electrode) provided on an insulating substrate as an electrodeposition substrate and a power supply terminal provided at an end of the conductive thin film is used, and a distance (resistance) from the power supply terminal and a current flowing through the substrate are used. This is a method of performing electrodeposition using a voltage drop generated by the amount of current. According to this method, it is possible to control the amount of current depending on the location of the electrodeposited substrate, and it is possible to obtain an electrodeposited layer that is thicker near the power supply terminal and becomes thinner as the distance increases. ). In a coating method such as a spin coating method, it is difficult to control the thickness of a layer depending on a place. However, in the electrodeposition method such as the above, the amount of current depending on the position of an electrodeposited substrate can be controlled, and the thickness varies depending on the place. Can be obtained.
As the electrodeposition material, a material containing a film forming material having electrodeposition properties and photosensitivity is used. For example, a commercially available electrodeposition resist (Sone P-500, manufactured by Kansai Paint Co., Ltd.) is used.
After that, exposure and development are performed using a photomask to form an optical waveguide core pattern. Prebaking may be performed before exposure and development.
FIG. 1 is a conceptual diagram illustrating a manufacturing process of a first master. FIG. 1A is a longitudinal sectional view of the electrodeposited substrate. Reference numeral 10 denotes an electrodeposited substrate, 12 denotes an insulating substrate, 14 denotes a conductive thin film, and 16 denotes a power supply terminal. FIG. 1B is a cross-sectional view showing a state in which an electrodeposition material is electrodeposited on the electrodeposited substrate. Accordingly, the layer thickness is reduced. FIG. 1 (C) shows a master 20 produced by exposing and developing an electrodeposition material layer 18 formed on the entire surface of a conductive thin film into an optical waveguide core pattern shape, and 22 corresponds to a polymer optical waveguide core. FIG. The width of the convex portion near the power supply terminal is large, and the width of the convex portion is reduced as the distance from the terminal increases.
[0022]
The insulating substrate of the electrodeposited substrate is not particularly limited as long as it has insulating properties and has dimensional stability and mechanical strength, and examples thereof include a glass plate and a ceramic plate. In addition, as the conductive thin film, an ITO thin film or the like is preferably used, and as the power supply terminal, one that maintains insulation from the electrodeposition liquid is used.
[0023]
(Method of manufacturing the second master)
The first method is a simple method. However, since the layer formed by electrodeposition is an insulating film, the layer thickness can be increased only to about 30 μm. However, a polymer optical waveguide having a diameter of 50 μm or more may be required, and it is difficult to produce a large-diameter polymer optical waveguide by the first method.
The method for producing the second master is a method capable of producing a polymer optical waveguide having a larger diameter, and using the electrodeposition substrate used in the first method, the electrodeposition property and photosensitivity are similarly determined. An electrodeposition layer is formed by electrodepositing a film-forming material having an electrodeposition layer.The electrodeposition layer is formed thicker near the power supply terminal and thinner as the distance increases, and then a layer of a photosensitive resin material is formed on the electrodeposition layer. And a method of exposing and developing the electrodeposited layer and the layer of the photosensitive resin material into an optical waveguide core pattern shape. The layer of the photosensitive resin material is formed by application such as spin coating so as to have a necessary height of the convex portion of the master. Before forming the layer of the photosensitive resin material, the electrodeposition layer may be pre-baked.
According to this method, it is possible to produce a master having a large-diameter convex portion having a different cross-sectional shape and / or cross-sectional area in the longitudinal direction. In this case, the photosensitive material used for the electrodeposition and the photosensitive resin material provided on the electrodeposition film need to match the positive type and the negative type. Further, it is preferable that the photosensitive material has the same exposure and development conditions as possible.
[0024]
FIG. 2 is a conceptual diagram showing the steps in the second master manufacturing method. FIG. 2A is a longitudinal sectional view of an electrodeposited substrate similar to the electrodeposited substrate used in the first method. FIG. 2B is a cross-sectional view showing a layer 18 formed on the electrodeposited substrate by electrodeposition with a thicker film near the power supply terminal and a smaller thickness as the distance increases. FIG. 2C is a cross-sectional view in which a photosensitive resin material layer 19 is formed on the electrodeposition layer with a required thickness. FIG. 2 (D) shows a master 20 produced by exposing and developing an electrodeposition material layer 18 and a photosensitive resin material layer 19 into an optical waveguide core pattern shape. Reference numeral 22 denotes a polymer optical waveguide core. The corresponding projection is shown. The width of the convex portion near the power supply terminal is large, and the width of the convex portion is reduced as the distance from the terminal increases. According to this method, a projection having a larger diameter than the first method can be manufactured.
[0025]
(Third master production method)
Next, a method of manufacturing a third master of the present invention will be described. This method uses a photoelectrodeposition method, and the photoelectrodeposition method has already been proposed by the present inventors as a method capable of controlling the amount of current depending on the location of a substrate (Japanese Patent No. 3152192). This photoelectric deposition method uses, as a photoelectric deposition substrate, a conductive thin film and an optical semiconductor thin film laminated in this order on an insulating substrate, and applies a predetermined photovoltaic force to a predetermined location of the optical semiconductor thin film for a predetermined time. By the generation, an electrodeposition film having a film thickness corresponding to the generated photovoltaic power and time can be formed. The third method for producing a master includes irradiating a light on a predetermined place of the optical semiconductor thin film while adjusting the exposure time and / or the exposure intensity in a state where the optical semiconductor thin film of the photoelectrically deposited substrate is in contact with the electrodeposition liquid. This is a method of forming a film thickness corresponding to these, and in a place where the film thickness (diameter) is to be increased, the exposure intensity and / or exposure time may be increased. According to this method, the master of the aperture-converting polymer optical waveguide core can be easily manufactured. As a means for irradiating a predetermined place of the optical semiconductor thin film with light while adjusting the exposure time and / or the exposure intensity, laser light irradiation is preferable.
FIG. 3 shows a conceptual diagram of the steps of the third master disc manufacturing method. FIG. 3 (A) shows that the photo-semiconductor thin film of the photo-electrode substrate is placed at least in contact with the electrodeposition liquid contained in the photo-electrodeposition device, and the exposure time and / or the intensity of the photo-semiconductor thin film are determined at a predetermined location. The drawing shows a stage in the middle of a method of forming a thin film whose cross-sectional area (diameter) changes in the longitudinal direction by scanning and irradiating a laser beam such as a He-Cd laser while adjusting. In FIG. 3A, reference numeral 30 denotes a photoelectric deposition substrate, 32 denotes an insulating substrate, 34 denotes a conductive thin film, 36 denotes an optical semiconductor thin film, 40 denotes a photoelectric deposition device, 45 denotes an electrodeposition liquid, and 50 denotes laser light irradiation. The apparatus, 60 indicates a potentiostat, 62 indicates a reference electrode, and 64 indicates a counter electrode. Reference numeral 22a denotes a thin film formed by electrodeposition.
FIG. 3B shows the master 20 in which a thin film (convex portion) 22 having a cross-sectional area (diameter) that changes in the longitudinal direction is formed on the optical semiconductor thin film of the photoelectric deposition substrate 30.
[0026]
(Fourth master production method)
Further, the fourth method for producing a master according to the present invention is a method utilizing a photoelectrodeposition method, as in the third method. The photo-deposition substrate used in the photo-deposition method in the fourth method has a cross-sectional shape and / or cross-sectional area at both ends such that the conductive thin film, the optical semiconductor thin film, and the optical semiconductor thin film are exposed on the insulating substrate. The layers provided with different grooves are stacked in this order. The layer provided with the grooves can be formed by a photoresist method (for example, a thick-film resist such as THB-611P manufactured by JSR Corporation).
Using this photo-deposition substrate, photo-deposition is performed on the groove bottom where the optical semiconductor thin film is exposed. The photoelectric deposition is performed by changing the film thickness formed in the longitudinal direction and adjusting the exposure time and / or the exposure intensity so that the shape of the groove after the electrodeposition becomes a shape corresponding to the polymer optical waveguide core. Irradiate with light. This light irradiation is also preferably performed by laser light.
Next, electroforming (such as nickel electroforming) is performed on the photo-deposited substrate having the electrodeposited film formed on the bottom of the groove, and a metal film is formed on the groove portion and the layer provided with the groove. When the mounting substrate and the electroformed portion are peeled off, a master on which convex portions corresponding to the polymer optical waveguide core are formed is completed.
[0027]
According to this method, it is possible to produce a master having an angle of 45 ° or more at the edge of the cross section of the convex portion. Simply using the photoelectrodeposition method (the method of manufacturing the third master), it is difficult to produce a convex portion having an edge portion angle of 45 ° or more (for example, a rectangular cross section), and it depends on the shape and size of the mating device to be coupled. Cannot necessarily reduce the coupling loss effectively. However, according to the fourth method, the photo-electrodeposition is performed in a place sandwiched between the left and right layers constituting the groove, and diffusion of hydrogen ions during electrodeposition is limited, so that the groove-type electrodeposition is performed. A rectangle can be realized. However, in this method, the shape corresponding to the polymer optical waveguide core is not the thin film to be formed, but the shape of the groove after electrodeposition and is inverted. It is necessary to form corresponding projections.
[0028]
FIG. 4 is a conceptual diagram showing steps of a fourth master manufacturing method. FIG. 4A shows a cross section in the longitudinal direction of the photoelectric deposition substrate to be used. 100 is a photoelectric deposition substrate, 102 is an insulating substrate, 104 is a conductive thin film, 106 is an optical semiconductor thin film, and 108 is a groove (not shown). Each layer is shown. FIG. 4B shows an upper surface of the photoelectric deposition substrate. Reference numeral 110 denotes a groove, which is formed so that the cross-sectional shape and / or cross-sectional area of both ends of the groove are different, and the optical semiconductor thin film is exposed at the groove bottom. I have.
FIG. 4C shows a state in which an electrodeposited film 114 having a different thickness in the longitudinal direction is formed at the bottom of the groove of the photo-deposited substrate, and FIG. The figure shows a state in which electroforming has been performed and an electroformed metal film 116 has been formed on the groove portion and the layer 108. FIG. 4E shows a master 200 in which the electroformed portion 116 has been peeled off from the one shown in FIG. 4D, and the master has a projection 220 having a different cross-sectional area in the longitudinal direction. The same device as shown in FIG. 3A is used for the photoelectric deposition on the bottom of the groove.
[0029]
As the photo-deposited substrate used in the third master manufacturing method, a conductive thin film and an optical semiconductor thin film laminated on an insulating substrate in this order are used. Examples of the insulating substrate include a glass plate, a quartz plate, a plastic film, and an epoxy substrate. Examples of the conductive thin film include ITO, indium oxide, nickel, and aluminum, and examples of the optical semiconductor thin film include a titanium oxide thin film. Used. When light is applied to the optical semiconductor thin film through the insulating substrate, the insulating substrate and the conductive thin film need to be light-transmissive. However, this does not apply when light is irradiated through the electrodeposition liquid.
The photoelectrically-coated substrate used in the fourth master manufacturing method is provided with the above-described grooved layer on the photoelectrically-coated substrate used in the third method, and the layer is formed by exposure and development of a photosensitive resin. And the like.
In the third and fourth methods for producing a master, light irradiation is preferably performed through an insulating substrate from the viewpoint of resolution and exposure intensity.
[0030]
Further, the film-forming material used in the third and fourth methods for producing a master, which has reduced solubility or dispersibility in an aqueous liquid due to a change in pH, may be formed of a liquid such as a carboxyl group or an amino group. It is preferable to include a substance having in its molecule a group (ionic group) whose ionic dissociation property changes when the pH changes.
[0031]
Further, in order to provide a function of lowering the solubility or dispersibility in an aqueous liquid due to a change in pH, the molecule preferably has a hydrophilic group and a hydrophobic group in the molecule, and the hydrophilic group includes a carboxyl group (anionic group). ), An ionizable group such as an amino group (cationic group) (hereinafter, simply referred to as an “ionized group”) is preferably introduced.
Due to the presence of the hydrophobic group in the polymer material, the function of instantaneously depositing a film is imparted to the polymer material, in combination with the loss of ionicity due to the ion dissociation due to the change in pH as described above. ing.
[0032]
Preferably, the number of hydrophobic groups in the polymer having a hydrophobic group and a hydrophilic group is in the range of 30% to 80% of the total number of hydrophilic groups and hydrophobic groups. When the number of hydrophobic groups is less than 30% of the total number of hydrophilic groups and hydrophobic groups, the formed film is easily redissolved, and the water resistance and strength of the film may be insufficient. If it is larger than 80% of the total number of hydrophobic groups, the solubility of the polymer in the aqueous liquid becomes insufficient, so that the electrodeposition solution becomes turbid, the material precipitates, or the viscosity of the electrodeposition solution becomes low. Since it is easy to ascend, it is desirable to be within the above range. The number of hydrophobic groups based on the total number of hydrophilic groups and hydrophobic groups is more preferably in the range of 55% to 70%. In this range, the deposition efficiency of the film is particularly high, and the liquid property of the electrodeposition liquid is stable. Further, a film can be formed at a low electrodeposition potential such as a photoelectromotive force.
[0033]
Examples of the polymer material include those obtained by copolymerizing a polymerizable monomer having a hydrophilic group and a polymerizable monomer having a hydrophobic group.
Examples of the polymerizable monomer containing a hydrophilic group include α, β-ethylenically unsaturated carboxylic acids such as methacrylic acid, acrylic acid, maleic anhydride, fumaric acid, propiolic acid, and itaconic acid, and α such as hydroxyethyl methacrylate. Α, β-ethylenically unsaturated carboxylic acid amides, such as hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids, acrylamide, and derivatives thereof, but are not limited thereto. Among them, methacrylic acid and acrylic acid are particularly useful hydrophilic group-containing monomers because of their high deposition efficiency due to pH change.
Polymerizable monomer materials containing a hydrophobic group include alkene, styrene, styrene derivatives such as α-methylstyrene and α-ethylstyrene, vinyl esters such as vinyl acetate, acrylonitrile, methyl methacrylate, butyl methacrylate, and ethyl acrylate. (Meth) acrylates such as butyl acrylate and lauryl methacrylate, and derivatives thereof, but are not limited thereto. In particular, styrene, α-methylstyrene, and α-ethylstyrene are useful hydrophobic monomers that have a strong hydrophobicity and thus easily obtain hysteresis characteristics with respect to re-dissolution. As the polymer material used in the present invention, a copolymer using acrylic acid or methacrylic acid as a hydrophilic group-containing monomer and styrene or α-methylstyrene as a hydrophobic group-containing monomer is preferably used.
[0034]
Also, by mixing conductive fine particles such as carbon into the electrodeposition liquid used in the first to fourth methods, it is possible to further increase the electrodeposition film thickness of the insulating film to about 50 μm at most.
[0035]
The photoelectrodeposition method is described in detail in Japanese Patent No. 3152192. For example, a photoelectric deposition substrate containing an optical semiconductor is described in paragraphs 0023 to 0032, an electrodeposition liquid containing an electrodeposition material is described in paragraphs 0022 and 0032 to 0039, and a photoelectric deposition apparatus is described in paragraphs 0042 to 0046. All can be used for the photoelectric deposition of the present invention.
[0036]
As described above, the first to fourth mold manufacturing methods of the present invention combine inexpensive methods of electrodeposition or photoelectric deposition, exposure and development of a photosensitive material, and electroforming. Nevertheless, a master having projections corresponding to the aperture-converting polymer optical waveguide core can be manufactured with high accuracy and ease.
[0037]
Next, a method of manufacturing a diameter-converting polymer optical waveguide by using the first to fourth master manufacturing methods will be described.
After the master is manufactured by the first to fourth master manufacturing methods, the following steps are performed to manufacture the aperture-converting polymer optical waveguide.
(1) A step of forming a cured layer of a curable resin for forming a mold on a master and then peeling the cured layer to form a mold having a concave portion corresponding to the convex portion.
(2) a step of bringing a clad substrate into close contact with the concave portion forming surface of the mold;
(3) A step of filling a groove formed between the mold concave portion and the cladding base material with a core-forming curable resin.
(4) a step of curing the curable resin for forming a core and then peeling off the mold;
Further, in order to stabilize the mechanical strength of the waveguide and improve the waveguiding property, it is preferable to perform a step of forming a clad layer on the core forming surface of the clad base material after the step (4).
[0038]
First, the outline of the method for producing a polymer optical waveguide of the present invention will be described with reference to FIG.
FIG. 5A shows an original master 300 on which a convex portion 302 (having a different cross-sectional shape and / or cross-sectional area in the longitudinal direction) corresponding to the optical waveguide core is formed. First, as shown in FIG. 5B, a cured layer 320 of a mold-forming curable resin is formed on the surface of the master 300 on which the convex portions 302 are formed. Next, the cured layer 320 is separated from the master 300. If the end of the concave portion 322 corresponding to the convex portion 302 is not exposed at the end, the mold 324 is manufactured by cutting both ends so that the concave portion 322 is exposed (see FIG. 5C).
The clad substrate 330 is brought into close contact with the mold 324 thus manufactured (see FIG. 5D). Next, one end of the mold is brought into contact with the curable resin 340a serving as a core, and is caused to enter the concave portion 322 of the mold by utilizing a capillary phenomenon. FIG. 5E shows a state in which the concave portion 322 of the mold is filled with the curable resin 340a. Thereafter, the curable resin in the concave portion is cured, and the mold 324 is peeled off (not shown). As shown in FIG. 5F, a convex portion (core) 340 for an optical waveguide is formed on the film base material for a clad.
Further, by forming the cladding layer 350 on the core forming surface of the cladding base material, the polymer optical waveguide 360 of the present invention (see FIG. 5G) is manufactured.
[0039]
Hereinafter, each step will be described in detail.
(1) A step of forming a cured layer of a curable resin for forming a mold on a master and then peeling the same to form a mold having a concave portion corresponding to a convex portion of the master.
The mold is manufactured by forming a cured layer of a curable resin for mold formation on the surface of the master formed as described above on which the convex portions are formed, and then peeling the mold.
The curable resin for forming a mold preferably has a cured product that can be easily peeled off from the master and has a certain or more mechanical strength and dimensional stability as a mold (repeated use). Various additives may be added to the curable resin for forming a mold, if necessary.
Since the mold-forming curable resin must accurately copy the individual optical waveguides formed on the master, the viscosity is less than a certain limit, for example, 500 to 7000 mPa · s, and further about 2000 to 5000 mPa · s. It is preferable to have Further, a solvent can be added to adjust the viscosity to such an extent that the solvent is not adversely affected. (Note that the curable resin for forming a mold used in the present invention includes a resin that becomes an elastic rubber-like body after curing, such as a curable silicone rubber oligomer or monomer.)
[0040]
As the mold-forming curable resin, a curable silicone rubber oligomer or monomer which becomes a silicone rubber or a silicone resin after curing, a curable silicone resin oligomer or monomer (thermosetting type, room temperature curing type), It is preferably used from the viewpoints of mechanical strength and dimensional stability and good adhesion to a cladding substrate. In particular, silicone rubber is excellent in contradictory properties of adhesion to the cladding substrate and releasability, has the ability to copy the nanostructure, and can prevent liquid from entering when the silicone rubber and the cladding substrate are brought into close contact. . Such a mold using silicone rubber transfers the master with high precision and adheres well to the base material for cladding, so it is necessary to efficiently fill only the recess between the mold and the base material for cladding with the core forming resin. And the separation between the cladding substrate and the mold is easy. Therefore, a polymer optical waveguide whose shape is maintained with high precision can be extremely easily manufactured from this mold.
As the curable silicone rubber oligomer or monomer and the curable silicone resin oligomer or monomer, those containing a methylsiloxane group, an ethylsiloxane group, and a phenylsiloxane group are preferable. In particular, a curable dimethylsiloxane rubber oligomer (PDMS) is used for adhesion and peeling. It is preferable from the viewpoint of properties. Since a cured product of PDMS generally has a low refractive index of about 1.43, a mold made of PDMS can be used as it is as a cladding layer without peeling from a cladding substrate. In this case, it is necessary to take measures to prevent the PDMS mold from being peeled off from the filled core forming resin and clad base material.
[0041]
It is preferable that the master is subjected to a release treatment such as application of a release agent in advance to promote separation from the mold. Thereafter, a layer of the mold-forming curable resin is formed on the convex-formation surface of the master by applying or casting a mold-forming curable resin, and then cured.
The thickness of the hardened layer is appropriately determined in consideration of the handleability as a mold, but generally about 0.1 to 50 mm is appropriate.
After that, the cured layer and the master are peeled off to obtain a mold. If the concave portion is not exposed on the end face of the mold, both ends of the mold are cut to expose the cross section of the concave portion.
The surface energy of the mold is preferably in the range of 10 dyn / cm to 30 dyn / cm, and more preferably in the range of 15 dyn / cm to 24 dyn / cm from the viewpoint of adhesion to the substrate film.
The shear rubber hardness of the mold is preferably from 15 to 80, and more preferably from 20 to 60, from the viewpoint of mold-making performance and releasability.
The surface roughness (root mean square roughness (RMS)) of the mold is preferably 0.5 μm or less, and more preferably 0.1 μm or less, from the viewpoint of molding performance.
[0042]
(2) A step of bringing the clad base material into close contact with the concave portion forming surface of the mold
As the cladding substrate used in the present invention, a glass substrate, a ceramic substrate, a plastic substrate and the like can be used without any limitation. In addition, a resin coated on the base material for controlling the refractive index is also used. The refractive index of the cladding substrate is smaller than 1.55, and more preferably smaller than 1.50. In particular, it is preferable that the refractive index is smaller than the refractive index of the core material by 0.02 or more, more preferably 0.05 or more. Further, as the clad base material, a material that has excellent adhesion to the mold and does not form a void other than the concave portion of the mold when both are adhered is preferable.
Among plastic substrates, polymer optical waveguides using flexible film substrates can be used as couplers, optical wiring between boards, optical demultiplexers, etc., and depending on the application, the refractive index of the film substrate , Optical properties such as light transmittance, mechanical strength, heat resistance, adhesion to a mold, flexibility (flexibility), and the like. Examples of the film include an alicyclic acrylic film, an alicyclic olefin film, a cellulose triacetate film, and a fluorine-containing resin film. It is desirable that the refractive index of the film substrate is smaller than 1.55, preferably smaller than 1.53, in order to secure a refractive index difference from the core.
[0043]
Examples of the alicyclic acrylic film include OZ-1000 and OZ-1100 in which an aliphatic cyclic hydrocarbon such as tricyclodecane is introduced into an ester substituent.
Examples of the alicyclic olefin film include those having a norbornene structure in the main chain, and those having a norbornene structure in the main chain and having an alkyloxycarbonyl group (an alkyl group having 1 to 6 carbon atoms or cycloalkyl) as a side chain. And a polar group having a polar group such as Above all, an alicyclic olefin resin having a norbornene structure in the main chain and a polar group such as an alkyloxycarbonyl group in the side chain as described above has a low refractive index (the refractive index is around 1.50, and the core / clad Of the polymer optical waveguide of the present invention because it has excellent optical properties such as high refractive index and excellent light transmittance, excellent adhesion to a mold, and excellent heat resistance. Suitable for fabrication. Arton film (manufactured by JSR Corporation) and ZEONEA film (manufactured by Zeon Corporation) have a refractive index around 1.50 and are easy to use.
The thickness of the film substrate is appropriately selected in consideration of flexibility, rigidity, ease of handling, and the like, and is generally preferably about 0.1 mm to 0.5 mm.
When a film substrate is used as the cladding substrate, it is preferable that the film substrate be adhered to a mold while being placed on a rigid body having a flat surface.
[0044]
(3) A step of filling the core formed curable resin into the groove formed between the concave portion of the mold and the base material for the clad.
In this step, a curable resin for forming a core, for example, an ultraviolet curable resin or a thermosetting resin, is filled into the voids (concave portions of the mold) formed between the mold and the cladding base material by a capillary phenomenon. When the base material for cladding is brought into close contact with the mold, it is not necessary to fix both using a special means (the fixing means as described in the specification of Japanese Patent No. 3151364). According to the method, the ultraviolet curable resin or the thermosetting resin can enter only the concave portion without generating a gap between the mold and the base material for the clad.
On the other hand, the smaller the diameter of the concave portion of the mold, the slower the filling speed becomes, and the filling at a practical speed becomes impossible. Therefore, increasing the filling speed of the capillary phenomenon becomes a problem when actually using the device. As a method of increasing the filling speed, it is effective to lower the viscosity of the core-forming curable resin and to lower (for example, suction) the pressure on the concave portion discharge side.
[0045]
From the above viewpoint, the viscosity of the curable resin is preferably from 10 mPa · s to 2000 mPa · s, more preferably from 20 mPa · s to 1000 mPa · s, and still more preferably from 30 mPa · s to 500 mPa · s.
In addition, in order to accurately reproduce the original shape of the optical waveguide convex portion formed on the master, it is necessary that the volume change of the core-forming curable resin before and after curing is small. For example, when the volume decreases, the shape becomes different from a predetermined shape, which causes a waveguide loss. Therefore, the curable resin is desirably a solvent-free resin whose volume change is as small as possible, desirably 10% or less, preferably 5% or less.
In addition, an epoxy-based, polyimide-based, or acrylic-based UV-curable resin is preferably used as the UV-curable resin.
[0046]
The cured product of the core-forming curable resin needs to have a higher refractive index than the polymer material constituting the clad (the difference from the clad is 0.02 or more, preferably 0.05 or more). For example, when a film substrate is used as a cladding substrate, a film substrate having good adhesion to a mold often has a refractive index of around 1.50. The refractive index of the cured product of the core-forming curable resin is preferably 1.55 or more.
[0047]
(4) Step of curing the core-forming curable resin and then peeling off the mold
The filled core-forming curable resin is cured. In order to cure the ultraviolet curable resin, an ultraviolet lamp, an ultraviolet LED, a UV irradiation device, or the like is used. Heating in an oven or the like is used to cure the thermosetting resin.
In addition, the mold can be used as it is for the clad layer. In this case, the mold need not be peeled off and is used as it is as the clad layer.
[0048]
(5) Step of forming a cladding layer on the core forming surface of the cladding base material
A clad layer is formed on the film substrate on which the core is formed. As the clad layer, the above-mentioned clad substrate is used in the same manner, and a curable resin (ultraviolet curable resin, thermosetting resin) is applied. And a polymer film obtained by applying and drying a solvent solution of a polymer material, and the like. When a film is used as the cladding layer, they are bonded together using an adhesive, and in this case, it is desirable that the refractive index of the adhesive be close to the refractive index of the film.
It is desirable that the refractive index of the cladding layer is smaller than 1.55, preferably smaller than 1.53 in order to secure a difference in refractive index from the core. In addition, it is preferable that the refractive index of the cladding layer is the same as the refractive index of the cladding substrate from the viewpoint of confining light.
[0049]
In the method for producing a polymer optical waveguide of the present invention, in particular, a thermosetting silicone rubber oligomer or monomer, particularly a thermosetting dimethylsiloxane rubber oligomer or monomer, is used as a curable resin for forming a mold, The combination using an alicyclic olefin resin having a norbornene structure in the chain and having a polar group such as an alkyloxycarbonyl group in the side chain has a particularly high adhesion between the two, and the cross-sectional area of the concave structure is extremely small. The concave portion can be quickly filled with the curable resin by capillary action (for example, a rectangle of 10 × 10 μm).
[0050]
Further, the above-mentioned mold can be used as a clad layer.In that case, the mold has an index of refraction of 1.5 or less, and the mold may be subjected to ozone treatment to improve the adhesion between the mold and the core material. Preferably, the light transmittance of the template in the region of 350 nm to 700 nm is desirably 80% or more.
[0051]
In the method of manufacturing the aperture-converting polymer optical waveguide of the present invention, as described above, the master is manufactured inexpensively and with high accuracy, and the subsequent manufacturing process of the polymer optical waveguide using the master is also a simple process. Because of the combination, a polymer optical waveguide can be manufactured at extremely low cost as compared with a conventional method of manufacturing a diameter-converting polymer optical waveguide. Further, according to the method for manufacturing a polymer optical waveguide of the present invention, a flexible polymer optical waveguide which has a small loss loss and high accuracy and can be freely loaded into various devices can be manufactured. Further, the shape and the like of the polymer optical waveguide can be freely set.
[0052]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.
Example 1
<Preparation of master>
On a 70 mm square glass substrate having a thickness of 1.1 mm, an ITO thin film is laminated to a thickness of 150 nm, and an electrodeposition substrate having a width of 1 mm provided with a power supply terminal electrically connected to the ITO thin film on one side of the substrate is prepared. Separately, a platinum-plated titanium plate (counter electrode) and a reference electrode (saturated calomel electrode) were prepared.
A three-electrode type electrodeposition apparatus is used, and the liquid tank is filled with an electrodeposition liquid containing an electrodeposition resist material (manufactured by Kansai Paint Co., Ltd., Sonne EDUV P-500), and the counter electrode and the reference electrode are placed in the liquid tank. And the electrodeposited substrate was placed in an electrodeposition apparatus such that the ITO thin film was in contact with the electrodeposition liquid. The power supply terminal was connected to a potentiostat, a voltage was applied so that the voltage of the power supply terminal became 30 V with respect to the reference electrode reference, and electrodeposition was performed for two minutes.
As a result, an electrodeposition resist was deposited on the ITO thin film, and the film thickness was 17 μm at a point closest to the power supply terminal and 5 μm at a point farthest.
After pre-baking the electrodeposited resist, using a photomask having a waveguide core pattern, 500 mj / cm ² Exposure at an exposure intensity of The opening of the photomask had a width of 17 μm near the power supply terminal and a width of 5 μm far from the power supply terminal. Thereafter, development with a TMAH developer and post-baking yielded a master having a rectangular shape having both ends of 5 μm and 17 μm and having a convex shape corresponding to an optical waveguide core having a continuously changing cross-sectional area.
[0053]
<Preparation of aperture-converting polymer optical waveguide>
Next, after applying a release agent to the master, a polydimethylsiloxane rubber (PDMS) oligomer (manufactured by Dow Corning Asia Ltd .: SYLGARD184) is poured into the master, heated at 120 ° C. for 30 minutes, cured, and then separated. Then, a mold having a thickness of 1 mm having a concave portion corresponding to the convex portion was produced, and then both ends of the mold were cut to form an input / output portion of the following ultraviolet-curable resin, which was used as a mold.
When this mold was brought into contact with a film base material (arton film, film thickness: 188 μm, manufactured by JSR Corporation, refractive index: 1.51), which was slightly larger than the mold and was vacuum chucked on a flat glass, did.
Next, a few drops of an epoxy ultraviolet curable resin (manufactured by NTT-AT) having a viscosity of 200 mPa · s were dropped into an input portion at one end of the mold, and the solution was sucked from the output portion with a suction force of 20 kPa. As a result, the entire area of the concave portion was filled with the ultraviolet curable resin by capillary action.
50 mW / cm through the mold in the above condition ² UV light was applied for 10 minutes to cure, and the mold was peeled off to form a core having a refractive index of 1.54 on the ARTON film substrate. Further, an ultraviolet curable resin (manufactured by JSR Corporation) having the same refractive index as that of Arton Film (1.51) was applied on the core forming surface, and the same Arton film as that of the base film was overlaid thereon. / Cm ² For 10 minutes to cure. Further, both ends were cut with a dicing saw to complete a diameter-converting polymer optical waveguide.
[0054]
Example 2
<Preparation of master>
In the same manner as in Example 1, following the step of electrodepositing an electrodeposited resist on an electrodeposited substrate and prebaking, a thick film resist (THB P611, manufactured by JSR Corporation) was applied by spin coating. As a result, the film thickness was 50 μm at the thinnest point and 63 μm at the thickest point.
After further pre-baking, the opening was 500 mW / cm using a waveguide core pattern photomask having a width of 63 μm on the side near the power supply terminal and 50 μm on the far side. ² Exposure at an exposure intensity of Thereafter, the resultant was developed with a TMAH developer and post-baked. As a result, a master having a rectangular shape having both ends of 50 μm and 63 μm and corresponding to a waveguide core having a continuously changing cross-sectional area was obtained.
<Preparation of aperture-converting polymer optical waveguide>
Next, after applying a release agent to the master, a polydimethylsiloxane rubber (PDMS) oligomer (manufactured by Dow Corning Asia Ltd .: SYLGARD184) is poured into the master, heated at 120 ° C. for 30 minutes, cured, and then separated. Then, a mold having a thickness of 1 mm having a concave portion corresponding to the convex portion was produced, and then both ends of the mold were cut to form an input / output portion of the following ultraviolet-curable resin, which was used as a mold.
When this mold was brought into contact with a film substrate (arton film, film thickness: 188 μm, manufactured by JSR Corporation, refractive index: 1.51), which was slightly larger than the mold and vacuum chucked on a flat glass, did.
Next, when a few drops of an epoxy-based ultraviolet curable resin (manufactured by NTT-AT) having a viscosity of 200 mPa · s were dropped into the input portion at one end of the mold, the entire area of the concave portion was caused by capillary action in about 10 minutes. Was filled with an ultraviolet curable resin.
50 mW / cm through the mold in the above condition ² Was irradiated for 10 minutes to cure, the mold was peeled off, and a core having a refractive index of 1.52 was formed on the ARTON film substrate. Further, an ultraviolet curable resin (manufactured by JSR Corporation) having the same refractive index as that of Arton Film (1.51) was applied on the core forming surface, and the same Arton film as that of the base film was overlaid thereon. / Cm ² For 10 minutes to cure. Further, both ends were cut with a dicing saw to obtain aperture-converted polymer optical waveguides having both ends of 62.5 μm and 50 μm square.
[0055]
Example 3
<Preparation of master>
A 1.1 mm thick, 70 mm square glass substrate, an ITO thin film having a thickness of 150 nm and a titanium oxide layer having a thickness of 150 nm laminated on a 70 mm square glass substrate, a platinum-plated titanium plate (counter electrode), and a reference electrode (saturated calomel electrode) Was prepared.
As an electrodeposition solution, 10 g of a styrene-acrylic acid copolymer (molecular weight 13,000, copolymerization molar ratio of styrene and acrylic acid 65:35, acid value 150) was dissolved in 100 g of pure water, and tetramethylammonium was further dissolved. A material prepared using a hydroxide and ammonium chloride so as to have a pH of 7.8 and a conductivity of 12 mS / cm was prepared.
The electrodeposition liquid is put into a general three-electrode electrodeposition apparatus in electrochemical as shown in FIG. 3A, the counter electrode and the reference electrode are set in the electrodeposition liquid, and the oxidation of the substrate is further performed. The substrate was placed on the electrodeposition apparatus so that the titanium thin film was in contact with the electrodeposition liquid. TiO to saturated calomel electrode ₂ The electrodes were used as working electrodes.
According to the shape of the core of the optical waveguide to be formed, scan irradiation is performed while changing the intensity of the He-Cd laser, and a convex type having a thickness continuously changing from 5 μm to 20 μm and a width from 10 to 40 μm on the titanium oxide thin film. Was obtained.
[0056]
<Preparation of aperture-converting polymer optical waveguide>
Next, after a release agent is applied to the master, a polydimethylsiloxane rubber (PDMS) oligomer (manufactured by Dow Corning Asia Ltd .: SYLGARD184) is poured into the master, heated at 100 ° C. for 1 hour, cured, and then separated. Then, a mold having a thickness of 1 mm having a concave portion corresponding to the convex portion was produced, and then both ends of the mold were cut to form an input / output portion of the following ultraviolet-curable resin, which was used as a mold.
When this mold was brought into contact with a film substrate (arton film, film thickness: 188 μm, manufactured by JSR Corporation, refractive index: 1.51), which was slightly larger than the mold and vacuum chucked on a flat glass, did.
Next, when a few drops of an epoxy-based ultraviolet-curable resin (manufactured by NTT-AT) having a viscosity of 200 mPa · s were dropped into the input / output unit at one end of the mold, the entirety of the recess was caused by capillary action in about 30 minutes. The region was filled with UV curable resin.
50 mW / cm through the mold in the above condition ² UV light was applied for 10 minutes to cure, and the mold was peeled off to form a core having a refractive index of 1.54 on the ARTON film substrate. Further, an ultraviolet curable resin (manufactured by JSR Corporation) having the same refractive index as that of Arton Film (1.51) was applied on the core forming surface, and the same Arton film as that of the base film was overlaid thereon. / Cm ² For 10 minutes to cure. Further, the both ends were cut with a dicing saw to complete a diameter conversion type waveguide.
[0057]
Example 4
<Preparation of master>
An ITO thin film having a thickness of 150 nm and titanium oxide having a thickness of 150 nm were laminated on a glass substrate having a thickness of 1.1 mm and a square of 70 mm. A thick photoresist (thickness 63 μm) was formed on the titanium oxide layer, and then exposed and developed to form a groove (a titanium oxide thin film was exposed), thereby forming a photo-deposited substrate. The depth of the groove in the thick-film resist was 63 μm, and the width of the groove was changed from 50 to 63 μm from one end of the substrate to the other. Separately, a platinum-plated titanium plate (counter electrode) and a reference electrode (saturated calomel electrode) were prepared.
As an electrodeposition solution, 10 g of a styrene-acrylic acid copolymer (molecular weight 13,000, copolymerization molar ratio of styrene and acrylic acid 65:35, acid value 150) was dissolved in 100 g of pure water, and tetramethylammonium was further dissolved. A material prepared using a hydroxide and ammonium chloride so as to have a pH of 7.8 and a conductivity of 12 mS / cm was prepared.
The electrodeposition liquid is put into a general three-electrode electrodeposition apparatus in electrochemical as shown in FIG. 3 (A), the counter electrode and the reference electrode are set in the electrodeposition liquid, and The photo-deposited substrate was arranged such that the exposed titanium oxide thin film at the bottom of the groove was in contact with the electrodeposition liquid. A titanium oxide electrode was used as a working electrode for the saturated calomel electrode.
Scanning is performed along the grooves provided in the thick-film resist while changing the intensity of the He-Cd laser so that the film thickness from the narrowest to the widest groove width in the thick-film resist is approximately 13 μm to 0 μm. Then, a thin film is formed on the titanium oxide film in the groove by photoelectric deposition, and finally, the cross-sectional shape of the groove is continuous from 50 μm square to 63 μm square from the narrowest width to the widest width. A concave matrix that changes in nature was produced.
Nickel electroforming was performed on the concave mold to produce a master having a thickness of 2 mm and a convex portion having a cross section of 50 μm square to 63 μm square formed on the surface.
[0058]
<Preparation of aperture-converting polymer optical waveguide>
Next, after a release agent is applied to the master, a polydimethylsiloxane rubber (PDMS) oligomer (manufactured by Dow Corning Asia Ltd .: SYLGARD184) is poured into the master, heated at 100 ° C. for 1 hour, cured, and then separated. Then, a mold having a thickness of 1 mm having a concave portion corresponding to the convex portion was produced, and then both ends of the mold were cut to form an input / output portion of the following ultraviolet-curable resin, which was used as a mold.
When this mold was brought into contact with a film substrate (arton film, film thickness: 188 μm, manufactured by JSR Corporation, refractive index: 1.51), which was slightly larger than the mold and vacuum chucked on a flat glass, did.
Next, when a few drops of an epoxy-based ultraviolet-curable resin (manufactured by NTT-AT) having a viscosity of 200 mPa · s were dropped into the input / output section at one end of the mold, the entirety of the recess was reduced by capillary action in about 10 minutes. The region was filled with UV curable resin.
50 mW / cm through the mold in the above condition ² UV light was applied for 10 minutes to cure, and the mold was peeled off to form a core having a refractive index of 1.54 on the ARTON film substrate. Further, an ultraviolet curable resin (manufactured by JSR Corporation) having the same refractive index as that of Arton Film (1.51) was applied on the core forming surface, and the same Arton film as that of the base film was overlaid thereon. / Cm ² For 10 minutes to cure. Further, both ends were cut with a dicing saw to complete a diameter conversion type waveguide corresponding to a multimode optical fiber having a cross-sectional shape of 62.5 μm and a 50 μm square at both ends. The coupling loss at this time was about 0.1 to 0.3 dB.
[0059]
Example 5
<Preparation of master>
An ITO thin film having a thickness of 150 nm and titanium oxide having a thickness of 150 nm were laminated on a glass substrate having a thickness of 1.1 mm and a square of 70 mm. A thick photoresist (thickness: 50 μm) was formed on the titanium oxide layer, and then exposed and developed to form a groove (a titanium oxide thin film was exposed), thereby forming a photo-deposited substrate. The depth of the groove in the thick-film resist is 50 μm, and the width of the groove changes from 50 to 10 μm from one end of the substrate to the other. Separately, a platinum-plated titanium plate (counter electrode) and a reference electrode (saturated calomel electrode) were prepared.
As an electrodeposition solution, 10 g of a styrene-acrylic acid copolymer (having a molecular weight of 13,000 and a molar ratio of hydrophilic group / (hydrophilic group + hydrophobic group) of 65% acid value 150) was dissolved in 100 g of pure water. A dispersion prepared by dispersing 10 g of conductive carbon having a particle diameter of 60 nm and further adjusting the pH to 7.8 and the conductivity to 12 mS / cm using tetramethylammonium hydroxide and ammonium chloride was prepared.
The electrodeposition liquid is put into a triode electrodeposition apparatus generally used in electrochemistry, the counter electrode and the reference electrode are set in the electrodeposition liquid, and the exposed titanium oxide thin film on the substrate is added to the electrodeposition liquid. The substrates were arranged so as to be in contact with each other. TiO to saturated calomel electrode ₂ The electrodes were used as working electrodes.
Along the grooves provided in the thick-film resist, scanning is performed while changing the intensity of the He-Cd laser so that the thickness of the thick-film resist from the narrowest to the widest becomes 40 μm to 0 μm. And TiO in the groove by photoelectric deposition ₂ A thin film is formed on the film, and finally, a concave mold in which the cross-sectional shape of the groove continuously changes from 10 μm square to 50 μm square from the narrowest width to the widest width. did.
Nickel electroforming was performed on the concave mold to produce a convex mold (master) having a thickness of 2 mm and a convex portion having a cross section of 10 μm square to 50 μm square on the surface.
[0060]
<Preparation of aperture-converting polymer optical waveguide>
Next, after a release agent is applied to the master, a polydimethylsiloxane (PDMS) oligomer (manufactured by Dow Corning Asia Ltd .: SYLGARD184) is poured into the master, heated at 100 ° C. for 1 hour, cured, and then separated. Then, a mold having a thickness of 1 mm having a concave portion corresponding to the convex portion was produced, and then both ends of the mold were cut to form an input / output portion of the following ultraviolet-curable resin, which was used as a mold.
When this mold was brought into contact with a film substrate (arton film, film thickness: 188 μm, manufactured by JSR Corporation, refractive index: 1.51), which was slightly larger than the mold and vacuum chucked on a flat glass, did.
Next, a few drops of an epoxy ultraviolet curable resin (manufactured by NTT-AT) having a viscosity of 200 mPa · s were dropped into an input portion at one end of the mold, and the solution was sucked from the output portion with a suction force of 20 kPa. As a result, the entire area of the concave portion was filled with the ultraviolet curable resin by capillary action.
50 mW / cm through the mold in the above condition ² UV light was applied for 10 minutes to cure, and the mold was peeled off to form a core having a refractive index of 1.54 on the ARTON film substrate. Further, an ultraviolet curable resin (manufactured by JSR Corporation) having the same refractive index as that of Arton Film (1.51) was applied on the core forming surface, and the same Arton film as that of the base film was overlaid thereon. / Cm ² For 10 minutes to cure. Further, both ends were cut with a dicing saw to complete a diameter conversion type waveguide which was directly connected to a VCSEL having a light emitting area of 10 μm and connected to a 50 μm multimode optical fiber. The coupling loss at this time was about 0.1 to 0.3 dB.
[0061]
【The invention's effect】
As described above, the first to fourth mold manufacturing methods of the present invention combine inexpensive methods of electrodeposition or photoelectric deposition, exposure and development of a photosensitive material, and electroforming. Nevertheless, a master having projections corresponding to the aperture-converting polymer optical waveguide core can be manufactured with high accuracy and ease.
The manufacturing method of the polymer optical waveguide of the present invention is extremely simplified in the manufacturing process, can easily produce the polymer optical waveguide, and is extremely low cost and high in cost as compared with the conventional method of manufacturing the polymer optical waveguide. A molecular optical waveguide can be manufactured, and mass productivity is excellent. In addition, the method for producing a polymer optical waveguide of the present invention provides a high-precision flexible polymer optical waveguide that has low loss loss and coupling loss and that can be freely loaded into various devices with good mass productivity. Can be manufactured. Further, the shape and the like of the polymer optical waveguide can be freely set.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a manufacturing process of a first master of the present invention.
FIG. 2 is a conceptual diagram illustrating a manufacturing process of a second master according to the present invention.
FIG. 3 is a conceptual diagram showing a manufacturing process of a third master of the present invention.
FIG. 4 is a conceptual diagram showing a manufacturing process of a fourth master according to the present invention.
FIG. 5 is a conceptual diagram showing a manufacturing process of the aperture-converting polymer optical waveguide of the present invention.
[Explanation of symbols]
10 Electroplated substrate
18 electrodeposition layer
19 Photosensitive resin material layer
20, 200, 300 master
22, 220, 302 Projection corresponding to polymer optical waveguide core
100 photoelectric deposition substrate
110 grooves
114 Thin film (electrodeposited film)
116 Electroformed metal film
324 mold
330 Base material for cladding
340 Polymer Optical Waveguide Core
350 cladding layer

Claims

An electrodeposited substrate having an electroconductive thin film on an insulating substrate and a power supply terminal provided at an end of the conductive thin film is electrodeposited with an electrodepositable and photosensitive film forming material to form an electrodeposited layer. Producing a master for producing a diameter-converting type polymer optical waveguide having a convex portion corresponding to the polymer optical waveguide core, comprising a step of forming and a step of exposing and developing the electrodeposited layer into a pattern of a polymer optical waveguide core. Method.

An electrodeposited substrate having an electroconductive thin film on an insulating substrate and a power supply terminal provided at an end of the conductive thin film is electrodeposited with an electrodepositable and photosensitive film forming material to form an electrodeposited layer. Forming, a step of forming a layer of a photosensitive resin material on the electrodeposition layer, and a step of exposing and developing the layer formed in the above two steps into a polymer optical waveguide core pattern shape, A method for producing a master for producing a diameter-converting polymer optical waveguide having a convex portion corresponding to a core.

A photoelectrodeposited substrate in which a conductive thin film and an optical semiconductor thin film are laminated in this order on an insulative substrate is applied to an aqueous electrodeposition liquid containing a film-forming material whose solubility or dispersibility in an aqueous liquid decreases due to a change in pH. Arranging at least the optical semiconductor thin film of the photo-deposited substrate so as to come into contact with the electrodeposition liquid; A step of generating electric power and forming a thin film corresponding to a polymer optical waveguide core having a different cross-sectional shape and / or cross-sectional area in the longitudinal direction, the diameter-converting height having a convex portion corresponding to the polymer optical waveguide core; A method for producing a master for producing a molecular optical waveguide.

{Circle around (1)} A conductive thin film, an optical semiconductor thin film, and a layer provided with grooves having different cross-sectional shapes and / or cross-sectional areas at both ends so as to expose the optical semiconductor thin film are laminated in this order on an insulating substrate. The photo-deposited substrate is coated with an aqueous electro-deposition solution containing a film-forming material whose solubility or dispersibility in an aqueous liquid is reduced due to a change in pH. (2) While adjusting the exposure time and / or exposure intensity, irradiate a selected area of the optical semiconductor thin film at the bottom of the groove with light to generate an electromotive force, and the length after the electrodeposition is adjusted. Forming a thin film on the optical semiconductor thin film at the bottom of the groove so that the shape of the groove in the direction corresponds to the polymer optical waveguide core; (3) forming the thin film at the bottom of the groove by the process of (2). Electroforming the photo-deposited substrate, 4 ▼ a step of peeling the optical electrodeposition substrate and electroformed part, a method of manufacturing a diameter conversion type polymer optical waveguide fabrication master having convex portions corresponding to the polymer optical waveguide core.

The master for producing a diameter-converting polymer optical waveguide having a convex portion corresponding to the polymer optical waveguide core according to claim 3 or 4, wherein the electrodeposition liquid contains conductive fine particles. how to.

The film-forming material is a polymer material having a hydrophobic group and a hydrophilic group, wherein the number of hydrophobic groups is in the range of 30% to 80% of the total number of hydrophilic groups and hydrophobic groups. A method for producing a master for producing a diameter-converting polymer optical waveguide having a convex portion corresponding to the polymer optical waveguide core according to claim 3.

1) Electrodeposition by electrodepositing a film-forming material having electrodeposition and photosensitivity on an electrodeposition substrate having a conductive thin film on an insulating substrate and a power supply terminal provided at an end of the conductive thin film. After forming the layer, the layer is exposed and developed into a polymer optical waveguide core pattern shape, to produce a master having a convex portion corresponding to the polymer optical waveguide core,
2) a step of forming a cured layer of a curable resin for forming a mold on the master and then peeling the cured layer to form a mold having a concave portion corresponding to the convex portion;
3) a step of bringing a clad substrate into close contact with the concave portion forming surface of the mold;
4) filling a groove formed between the concave portion of the mold and the base material for cladding with a curable resin for forming a core; 5) curing the curable resin for forming a core, and thereafter removing the mold;
A method for producing a diameter-converting polymer optical waveguide having at least:

1) An electrodeposited substrate having a conductive thin film on an insulating substrate and a power supply terminal provided at an end of the conductive thin film is electrodeposited with an electrodepositable and photosensitive film forming material. After forming the adhesion layer, a layer of a photosensitive resin material is formed on the layer, and then the layer formed in the above two steps is exposed and developed into a polymer optical waveguide core pattern shape, and the polymer optical waveguide core is formed. Producing a master having projections corresponding to
2) a step of forming a cured layer of a curable resin for forming a mold on the master and then peeling the cured layer to form a mold having a concave portion corresponding to the convex portion;
3) a step of bringing a clad substrate into close contact with the concave portion forming surface of the mold;
4) filling a groove formed between the concave portion of the mold and the base material for cladding with a curable resin for forming a core; 5) curing the curable resin for forming a core, and thereafter removing the mold;
A method for producing a diameter-converting polymer optical waveguide having at least:

1) A water-based electrodeposition of a photo-deposited substrate in which a conductive thin film and an optical semiconductor thin film are laminated on an insulating substrate in this order, including a film-forming material whose solubility or dispersibility in an aqueous liquid is reduced due to a change in pH. In the liquid, in a state where at least the optical semiconductor thin film of the photo-deposited substrate is arranged so as to be in contact with the electrodeposition liquid, light is irradiated to a selected region of the optical semiconductor thin film while adjusting the exposure time and / or the exposure intensity. To generate a thin film corresponding to a polymer optical waveguide core having a different cross-sectional shape and / or cross-sectional area in the longitudinal direction, thereby producing a master having a convex portion corresponding to the polymer optical waveguide core. Process,
2) a step of forming a cured layer of a curable resin for forming a mold on the master and then peeling the cured layer to form a mold having a concave portion corresponding to the convex portion;
3) a step of bringing a clad substrate into close contact with the concave portion forming surface of the mold;
4) filling a groove formed between the concave portion of the mold and the base material for cladding with a curable resin for forming a core; 5) curing the curable resin for forming a core, and thereafter removing the mold;
A method for producing a diameter-converting polymer optical waveguide having at least:

1) (1) A conductive thin film, an optical semiconductor thin film, and a layer provided with grooves having different cross-sectional shapes and / or cross-sectional areas at both ends so as to expose the optical semiconductor thin film are arranged in this order on an insulating substrate. An optical semiconductor thin film at least at the bottom of the groove of the photo-deposited substrate is placed on an aqueous electrodeposition solution containing a film-forming material whose solubility or dispersibility in an aqueous liquid is reduced due to a change in pH. (2) irradiating a selected area of the optical semiconductor thin film at the bottom of the groove with light to generate an electromotive force while adjusting the exposure time and / or the exposure intensity; Forming a thin film on the optical semiconductor thin film at the bottom of the groove so that the shape of the groove in the longitudinal direction of the groove corresponds to the polymer / polymer optical waveguide core; Electroforming the photo-deposited substrate with the thin film formed To process, ▲ 4 ▼ comprising the step of separating the light electrodeposited substrate and electroformed portion, the step of producing a master having a convex portion corresponding to the polymer optical waveguide core,
2) a step of forming a cured layer of a curable resin for forming a mold on the master and then peeling the cured layer to form a mold having a concave portion corresponding to the convex portion;
3) a step of bringing a clad substrate into close contact with the concave portion forming surface of the mold;
4) filling a groove formed between the concave portion of the mold and the base material for cladding with a curable resin for forming a core; 5) curing the curable resin for forming a core, and thereafter removing the mold;
A method for producing a diameter-converting polymer optical waveguide having at least:

The method for producing a diameter-converting polymer optical waveguide according to any one of claims 7 to 10, further comprising, after the step (5), a step of forming a clad layer on the core forming surface of the clad substrate. .