JP3766288B2 - Composite member manufacturing method and electronic package - Google Patents

Description

【０１１８】
上記化学式（１）に示すように、絶縁体に形成されたナフトキノンジアジドは露光および次の工程において水を存在せしめることにより、−ＣＯＯＨ基を発生する。
【０１１９】
なお、感光性組成物層は、後工程において金属イオン含有水溶液やアルカリまたは酸性水溶液中に曝される。イオン交換反応によりイオン化した感光性組成物は水溶液に溶解しやすいため、基材としての絶縁体より剥離しやすくなる。そこで、基材からの剥離を防ぐためにイオン交換性基を生じる基がポリマーなどの高分子化合物等に担持、あるいは結合されているものが好ましく、イオン交換性基を生じる基が高分子化合物に共有結合によって化学的に結合しているのが最も好ましい。
【０１２０】
この場合、ポリマーや高分子化合物の分子量は、１０００以上であることが好ましく、２０００以上であることがより好ましい。分子量が１０００以下のポリマーでは、基材である絶縁体に対する塗布性が悪化して、均一な塗布が困難となるおそれがある。また、めっき工程などにおけるアルカリまたは酸性水溶液中への曝露により劣化を生じやすくなる。
【０１２１】
単に基材からの剥離を防止するだけなら、基材と化学結合可能な基およびイオン交換性基を併せ持つ低分子の単分子膜を基材表面に形成すればよい。例えば、特開平６−２０２３４３号には、感光してイオン交換性基となるナフトキノンジアジド基を有するシランカップリング剤の単分子膜を、ガラス基板表面に形成する方法が開示されている。
【０１２２】
しかしながら、単分子層の場合にはめっき核の吸着量が少なく、充分なめっきができないことが、本発明者らの研究により判明した。上述したようなポリマー状の感光性組成物を用いることによって、ある程度の厚みを持って基材表面を被覆することができる。したがって、充分な量のめっき核が吸着するため、良好なめっきを行なうことが可能となる。
【０１２３】
そのような観点から、本発明において２８０ｎｍ以上の波長の光照射によりイオン交換性基を生成する化合物としては、１，２−ナフトキノンジアジドスルホニル置換フェノール樹脂誘導体、１，２−ナフトキノンジアジドスルホニル置換ポリスチレン誘導体等が好適である。
【０１２４】
また、２８０ｎｍ以上の波長の光照射によりイオン交換性基を生成する化合物の他の例としては、ポリマーの構造中に含有されるカルボキシル基などのイオン交換性基に保護基を導入した化合物が挙げられる。この化合物を用いる場合には、２８０ｎｍ以上の波長の光を照射することによって酸を発生する光酸発生剤を感光性組成物に添加する。後工程の露光によって光酸発生剤から酸が発生し、その発生した酸で保護基が分解することによりイオン交換性基が生成する。なお、前述のポリマーとしては、フェノールノボラック樹脂、キシレノールノボラック樹脂、ビニルフェノール樹脂、クレゾールノボラック樹脂等のフェノール系樹脂やポリアミド酸やポリアクリル酸、ポリメタクリル酸等のカルボキシル基含有ポリマー等が挙げられる。
【０１２５】
フェノール系樹脂の保護基としては、ｔｅｒｔ−ブトキシカルボニルメチル基やｔｅｒｔ−ブトキシカルボニルエチル基などのｔｅｒｔ−ブチルエステル誘導体置換基が挙げられる。
【０１２６】
一方、ポリアミド酸やポリアクリル酸等においては、構造中のカルボキシル基の保護基としてメチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、ベンジルアルコキシ基、２−アセトキシエチル基、２−メトキシエチル基、メトキシメチル基、２−エトキシエチル基、３−メトキシ−１−プロピル基等のアルコキシ基やトリメチルシリル基、トリエチルシリル基、トリフェニルシリル基等のアルキルシリル基が挙げられる。
【０１２７】
また、光酸発生剤を用いずとも光照射だけでカルボン酸などのイオン交換性基を生成する保護基としては、ｏ−ニトロベンジルエステル基が挙げられる。
【０１２８】
こうした保護基の脱保護のために好適な光酸発生剤としては、ＣＦ₃ＳＯ₃ ^-、ｐ−ＣＨ₃ＰｈＳＯ₃ ^-、ｐ−ＮＯ₂ＰｈＳＯ₃ ^-等を対アニオンとするオニウム塩、ジアゾニウム塩、ホスホニウム塩、ヨードニウム塩等の塩、有機ハロゲン化合物、およびオルトキノン−ジアジドスルホン酸エステルなどを用いることができる。
【０１２９】
このような化学増幅によってイオン交換性基を生成する組成物を用いることで、光に対する高感度化が可能である。これらの組成物の使用は、特に、多孔質基材への三次元パターン形成のような膜厚方向への光透過性がより要求される場合において、パターンの微細化が進むにつれて有効となってくる。
【０１３０】
一方、２８０ｎｍ以上の波長の光照射によりイオン交換性基を消失する、すなわち露光前にはイオン交換能を有し、露光後に水に溶解あるいは膨潤しにくい疎水的な性質を有する官能基を発生する化合物としては、次のような化合物を用いることができる。すなわち、イオン交換性基である−ＣＯＯＸ基、−ＳＯ₃Ｘ基あるいは−ＰＯ₃Ｘ₂基等の酸性基（但し、Ｘは水素原子、アルカリ金属やアルカリ土類金属及び周期律表Ｉ、II族の属する典型金属、アンモニウム基）を、その組成物骨格中に有し、光照射によりイオン交換能が消失する化合物である。
【０１３１】
露光前にはイオン交換能を有し、露光後に水に溶解あるいは膨潤しにくい疎水的な性質を有する官能基を発生する化合物としては、塩基性物質の存在下での光照射により脱炭酸反応を起こして分解することのできるカルボキシル基含有化合物が挙げられる。この場合には、前述のカルボキシル基含有化合物に加えて、光酸発生剤と塩基性化合物とを感光性組成物中に添加する。こうした組成物においては、露光により発生した酸が、脱炭酸反応に関わる塩基性化合物を中和してしまう。このため、露光部ではカルボキシル基がそのまま残り、未露光部では脱炭酸反応が進行するというメカニズムによって、露光部のイオン交換能が消滅する。
【０１３２】
脱炭酸反応を起こして分解することのできるカルボキシル基含有化合物としては、任意の化合物を選択できるが、塩基性化合物により脱炭酸反応が進行しやすい化合物が好ましい。そのような化合物としては、カルボキシル基のα位またはβ位に電子吸引性基または不飽和結合を有するものが挙げられる。ここで、電子吸引性基は、カルボキシル基、シアノ基、ニトロ基、アリール基、カルボニル基、またはハロゲンであることが好ましい。
【０１３３】
このようなカルボキシル基含有化合物の具体例としては、α−シアノカルボン酸誘導体、α−ニトロカルボン酸誘導体、α−フェニルカルボン酸誘導体、β，γ−オレフィンカルボン酸などが挙げられる。
【０１３４】
添加する光酸発生剤としては、上述したような光酸発生剤が挙げられ、２８０ｎｍ以上の波長で酸を発生するものが特に好ましい。
【０１３５】
添加する塩基性化合物としては、光酸発生剤から放出される酸によって中和され、カルボキシル基含有化合物の脱炭酸反応の触媒として作用するものであれば任意のものを用いることができる。この塩基性化合物は有機化合物、無機化合物いずれでも構わないが、好ましいのは含窒素化合物である。具体的には、アンモニア、１級アミン類、２級アミン類、および３級アミン類等が挙げられる。これら塩基性化合物の含有量は、感光性組成物中０．１〜３０重量％、好ましくは０．５〜１５重量％である。０．１重量％未満の場合には、脱炭酸反応が充分に進まなくなり、３０重量％を越えると、未露光部に残存するカルボキシル基含有化合物の劣化を促すおそれがある。
【０１３６】
なお、後工程で感光性組成物層は金属イオン含有水溶液やアルカリまたは酸性水溶液中に曝されるため、それらに溶解することがないようイオン交換性基消失反応を生じる基がポリマーや高分子化合物等に担持、あるいは結合されているものが好ましい。すでに説明したように、イオン交換性基消失反応を生じる基は、分子量１０００以上のポリマーや高分子化合物に化学的に結合していることが最も好ましい。
【０１３７】
本発明の第３の態様においては、露光によりイオン交換性基を生成する化合物として、オニウム塩誘導体、スルフォニウムエステル誘導体、カルボン酸誘導体およびナフトキノンジアジド誘導体からなる群から選択される少なくとも１種の誘導体を使用する。
【０１３８】
オニウム塩誘導体としては、ＣＦ₃ＳＯ₃ ^-、ｐ−ＣＨ₃ＰｈＳＯ₃ ^-、ｐ−ＮＯ₂ＰｈＳＯ₃ ^-等を対アニオンとするジアゾニウム塩、ホスホニウム塩、ヨードニウム塩、スルホニウム塩等が挙げられる。より具体的には、ジフェニルヨードニウム、４，４’−ジブチルフェニルヨードニウム、トリフェニルスルホニウム、ナフチルスルホニウム等のトリフルオロ酢酸塩系誘導体、トリフルオロメタンスルホン酸塩誘導体、およびトルエンスルホン酸誘導体が挙げられる。
【０１３９】
スルフォニウムエステル誘導体としては、ベンゾイントシレート系誘導体、ｏ−ニトロベンジルトシレート系誘導体、アリールスルホン酸のｐ−ニトロベンジルエステル系誘導体、ｐ−ニトロベンジル−９，１０−ジエトキシアントラセン−２−スルホネート系誘導体等が挙げられる。
【０１４０】
また、カルボン酸誘導体としては、上述したフェノール樹脂やポリアミド酸やポリアクリル酸の水酸基、あるいはカルボキシル基が保護されたポリマー等であり、前記ポリマーとしては、フェノールノボラック樹脂誘導体、キシレノールノボラック樹脂誘導体、ビニルフェノール樹脂誘導体、クレゾールノボラック樹脂誘導体等のフェノール系樹脂誘導体やポリアミド酸誘導体やポリアクリル酸誘導体、ポリメタクリル酸誘導体等のカルボキシル基含有ポリマー誘導体等が挙げられる。
【０１４１】
フェノール系樹脂誘導体の保護基としては、ｔｅｒｔ−ブトキシカルボニルメチル基やｔｅｒｔ−ブトキシカルボニルエチル基などのｔｅｒｔ−ブチルエステル誘導体置換基が挙げられる。
【０１４２】
一方、ポリアミド酸やポリアクリル酸等においては構造中のカルボキシル基の保護基としてメチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、ｓｅｃ−ブチル基、ｔｅｒｔ−ブチル基、ベンジルアルコキシ基、２−アセトキシエチル基、２−メトキシエチル基、メトキシメチル基、２−エトキシエチル基、３−メトキシ−１−プロピル基等のアルコキシ基やトリメチルシリル基、トリエチルシリル基、トリフェニルシリル基等のアルキルシリル基が挙げられる。これらは、適当な光酸発生剤と作用することによって、カルボキシル基を生成する。
【０１４３】
ナフトキノンジアジド誘導体としては、ナフトキノンジアジド−４−スルホン酸系誘導体、ナフトキノンジアジド−５−スルホン酸系誘導体、ナフトキノンジアジドスルホニルハライド系誘導体、およびこれらのエステル化物等が挙げられる。
【０１４４】
なお、上述したような化合物を含む感光性組成物層は、後工程で金属イオン含有水溶液やアルカリまたは酸性水溶液中に曝されるため、それらに溶解することがないようイオン交換性基生成反応を生じる基がポリマーや高分子化合物等に担持、あるいは結合されているものが好ましい。すでに説明したように、イオン交換性基消失反応を生じる基は、分子量１０００以上のポリマーや高分子化合物に化学的に結合していることが最も好ましい。
【０１４５】
そのような観点から、１，２−ナフトキノンジアジドスルホニル置換フェノール樹脂誘導体、１，２−ナフトキノンジアジドスルホニル置換ポリスチレン誘導体等、または、ポリマー官能基保護基の光酸発生剤を用いた脱保護によるイオン交換性基生成が好適である。
【０１４６】
本発明の第４の態様においては、露光によりイオン交換性基を消失する、すなわち露光前にはイオン交換能を有するが、露光後に水に溶解または膨潤しにくい疎水的な性質を有する官能基を発生する化合物を含有する感光性組成物が用いられる。こうした化合物は、イオン交換性基をその骨格に有し、光照射によりイオン交換能を消滅する化合物である。イオン交換性基としては、−ＣＯＯＸ基、−ＳＯ₃Ｘ基あるいは−ＰＯ₃Ｘ₂基等の酸性基（但し、Ｘは水素原子、アルカリ金属やアルカリ土類金属及び周期律表Ｉ、II族の属する典型金属、アンモニウム基）が挙げられる。
【０１４７】
露光前にはイオン交換能を有し、露光後に水に溶解あるいは膨潤しにくい疎水的な性質を有する官能基を発生する化合物としては、脱炭酸反応を起こして分解することのできるカルボキシル基含有化合物が挙げられる。この場合には、前述のカルボキシル基含有化合物に加えて、光酸発生剤と塩基性化合物と感光性組成物中に添加する。こうした組成物においては、露光により発生した酸が、脱炭酸反応に関わる塩基性化合物を中和してしまう。このため、露光部ではカルボキシル基がそのまま残り、未露光部では脱炭酸反応が進行するというメカニズムによって、露光部のイオン交換能が消滅する。
【０１４８】
脱炭酸反応を起こして分解することのできるカルボキシル基含有化合物としては、任意の化合物を選択できるが、塩基性化合物により脱炭酸反応が進行しやすい化合物が好ましい。そのような化合物としては、カルボキシル基のα位またはβ位に電子吸引性基または不飽和結合を有するものが挙げられる。ここで、電子吸引性基が、カルボキシル基、シアノ基、ニトロ基、アリール基、カルボニル基、またはハロゲンであることが好ましい。
【０１４９】
このようなカルボキシル基含有化合物の具体例としては、α−シアノカルボン酸誘導体、α−ニトロカルボン酸誘導体、α−フェニルカルボン酸誘導体、β，γ−オレフィンカルボン酸、その他が挙げられる。
【０１５０】
添加する光酸発生剤としては、上述した光酸発生剤が挙げられ、２８０ｎｍ以上の波長で酸を発生するものが特に好ましい。
【０１５１】
添加する塩基性化合物としては、光酸発生剤から放出される酸によって中和され、カルボキシル基含有化合物の脱炭酸反応の触媒として作用するものであれば任意のものを用いることができる。この塩基性化合物は有機化合物、無機化合物いずれでも構わないが、好ましいのは含窒素化合物である。具体的には、アンモニア、１級アミン類、２級アミン類、および３級アミン類等が挙げられる。これら塩基性化合物の含有量は、感光性組成物中０．１〜３０重量％、好ましくは０．５〜１５重量％である。０．１重量％未満の場合には、脱炭酸反応が充分に進まなくなり、３０重量％を越えると、未露光部に残存するカルボキシル基含有化合物の劣化を促すおそれがある。
【０１５２】
なお、感光性組成物層は、後工程で金属イオン含有水溶液やアルカリまたは酸性水溶液中に曝されるため、それらに溶解することがないようイオン交換性基消失反応を生じる基が、ポリマーや高分子化合物等に担持、あるいは結合されているものが好ましい。すでに説明したように、イオン交換性基消失反応を生じる基は、分子量１０００以上のポリマーや高分子化合物に化学的に結合していることが最も好ましい。
【０１５３】
以上説明したように、本発明の方法によれば、まず、パターン露光を施すことによって、感光性組成物層の露光部または未露光部に、イオン交換性基が選択的に配置される。こうしたイオン交換性基のある領域は親水性であるが、イオン交換性基を含まない領域は、多くの場合、疎水性となりやすい。しかしながら、本発明においては、感光性組成物層のイオン交換性基の存在しない領域も、親水性であって水に対する濡れ性を有していることが好ましい。イオン交換性基の存在しない領域の疎水性が強すぎる場合には、後述する＜工程（５）＞のメッキ工程において、メッキ液と基板との接触が不十分となって、基板に気泡が付きやすくなる。気泡が付着するとその部分がめっきされずに残ってしまうため、良好な金属パターンが形成できない。また特に基材として多孔質体を用いた場合には、多孔質体内部へめっき液が浸透性し難くなる。このため、イオン交換性基の存在しない領域の疎水性が強すぎる場合には、多孔質体の内部にめっきをすることが難しくなる。
【０１５４】
なお、特開平６−２０２３４３号には、親水性領域と疎水性領域とからなるパターンを形成して、親水性領域に選択的にめっきを施すことにより金属パターンを形成する方法が開示されている。この際、めっきの選択性を向上させるために、疎水性領域を選択的にフッ素化して、その領域の疎水性を高めている。フッ素化することによって、親水性領域と疎水性領域の水に対する濡れ性の差が増大する。これにより、親水性領域に選択的にめっき液を接触させて、めっきの選択性を高めている。
【０１５５】
しかしながら、上述したような理由から、こうした方法では疎水性領域に気泡が付着しやすくなるので、良好なめっきを行なうことができない。さらに、多孔質体内部へめっき液が浸透し難くなるので、多孔質体内部にめっきすることも極めて困難である。
【０１５６】
これに対して、本発明の方法においては、親水性領域と疎水性領域とを形成する必要はない。むしろ、基材としての絶縁体の表面をすべて親水性とすることによって、基材とめっき液を充分に接触させることができ、良好なめっきを行なうことができる。
【０１５７】
水に対する濡れ性は、平坦な表面上に水滴を滴下した際の接触角で容易に測定できる。本発明においては、イオン交換性基の存在しない領域でも、接触角が６０°以下、さらには４０°以下であることが好ましい。
【０１５８】
本発明の製造方法に用いられる感光性組成物には、露光によりイオン交換性基を生成する化合物以外にも、目的に応じた添加剤を含有することができる。
【０１５９】
例えば、解像度や膜厚透過性などを向上させるための光増感剤を配合してもよい。光増感剤は、露光によりイオン交換性基を生成する化合物の光増感が可能なものであれば特に限定されず、使用される化合物の種類や光源などに応じて適宜選択される。
【０１６０】
光増感剤の具体例としては、芳香族炭化水素およびその誘導体、ベンゾフェノンおよびその誘導体、ｏ−ベンゾイル安息香酸エステルおよびその誘導体、アセトフェノンおよびその誘導体、ベンゾインならびにベンゾインエーテルおよびその誘導体、キサントンおよびその誘導体、チオキサントンおよびその誘導体、ジスルフィド化合物、キノン系化合物、ハロゲン化炭化水素含有化合物ならびにアミン類、エオシンＢ（Ｃ．Ｉ．Ｎｏ．４５４００）、エオシンＪ（Ｃ．Ｉ．Ｎｏ．４５３８０）、シアノシン（Ｃ．Ｉ．Ｎｏ．４５４１０）、ベンガルローズ、エリスロシン（Ｃ．Ｉ．Ｎｏ．４５４３０）、２，３，７−トリヒドロキシ−９−フェニルキサンテン−６−オン、ローダミン６Ｇなどのキサンテン色素、チオニン（Ｃ．Ｉ．Ｎｏ．５２０００）、アズレＡ（Ｃ．Ｉ．Ｎｏ．５２００５）、アズレＣ（Ｃ．Ｉ．Ｎｏ．５２００２）などのチアジン色素、ピロニンＢ（Ｃ．Ｉ．Ｎｏ．４５００５）、ピロニンＧＹ（Ｃ．Ｉ．Ｎｏ．４５００５）などのピロニン色素、３−アセチルクマリン、３−アセチル−７−ジエチルアミノクマリンなどのクマリン色素などが挙げられる。
【０１６１】
このような光増感剤の配合割合は、露光によりイオン交換性基を生成あるいは消失する化合物に対して、通常０．００１〜１０重量％、好ましくは０．０１〜５重量％である。
【０１６２】
また、露光によりイオン交換性基を生成する化合物として上述のナフトキノンジアジド誘導体を用いた場合には、カルボジイミド誘導体あるいはアミン誘導体等を架橋剤として添加することが好ましい。導電部を形成後に加熱処理を行なうことにより感光性組成物を硬化させて、得られる絶縁体に耐熱性を付与することができる。
【０１６３】
このような架橋剤の配合割合は、反応する相互の官能基等量から適宜決定される。
【０１６４】
本発明の複合部材の製造方法において用いる感光性組成物としては、ナフトキノンジアジド誘導体およびポリカルボジイミド誘導体を含有する感光性組成物が特に好ましい。こうした感光性組成物を用いた場合には、導電部形成後、加熱処理を行なうことによって、ナフトキノンジアジド誘導体から生じたイオン交換性基などとポリカルボジイミド誘導体が相互に架橋する。これにより、導電部と絶縁体との接触性を向上させる。こうして耐熱性が高いと同時に、微細なパターンを有する導電部を備えた複合部材を得ることができる。
【０１６５】
また、上述したような感光性組成物は、露光部に選択的に親水性のイオン交換性基が生じるため、感光性組成物層の露光部と未露光部とで溶解度の差異が生じる。この溶解度の差異を利用して、感光性組成物のパターンを容易に形成することもできる。
【０１６６】
なお、こうした感光性組成物は、ビルドアップ基板用の層間絶縁膜やカラー液晶表示装置、エレクトロルミネッセンスディスプレイ、カラー蛍光表示装置、プラズマディスプレイパネル、ＯＡセンサー、固体撮像素子等に使用される光学的カラーフィルターの製造に適した遮光性感光性樹脂組成物等の用途に用いることができる。この感光性組成物は、耐薬品性、耐水性、耐熱性、基板に対する高密着性などの特性を有するため、有用な感光性組成物である。
【０１６７】
上述した感光性組成物に含有されるナフトキノンジアジド誘導体としては、１，２−ナフトキノンジアジドスルホニル置換フェノール樹脂、１，２−ナフトキノンジアジドスルホニル置換ポリスチレン樹脂などが特に好ましい。これらが含有されていると、成膜性がよく、かつ薄膜を形成することができる。特に、１，２−ナフトキノンジアジドスルホニル置換フェノール樹脂は、フェノール樹脂のフェノール性水酸基がポリカルボジイミド誘導体と相互に架橋硬化するため、耐熱性に優れる、もっとも優れている。
【０１６８】
また、上述した感光性組成物に含有されるポリカルボジイミド誘導体としては、下記一般式（１）で表わされる化合物が好ましい。
【０１６９】
【化２】

（式中、Ｒ１は、メチレン基、エチレン基、プロピル基、イソプレン基、ブタジエン基等に代表される炭素数１〜２０の有機基を示す。）
【０１７０】
このように、ポリカルボジイミド誘導体が脂肪族系の骨格で構成されていると、組成物を低粘度に設定できる。そこで、スピンコート法やディップコート法等による溶剤での塗布の場合において、有機感光性組成物の薄膜化のためには、特に望ましく用いられる。
【０１７１】
また、上述したような感光性組成物においては、ナフトキノンジアジド誘導体とポリカルボジイミド誘導体はそれぞれ、反応する相互の官能基当量を考慮にいれ、カルボジイミド基１モルに対し、反応性基の割合が０．０１モル〜１モル含有されることが望ましい。反応性基の割合が０．０１モル未満であると、反応性に乏しく、望みの耐熱性を得ることが困難になる。また、反応性基の割合が１モルを越えると、室温での保存安定性が低下し、さらに本発明の工程を阻害するおそれがある。上記範囲に調整することで、反応温度を１００℃前後とすることができ、本工程終了後に反応を進めることが望ましい。
【０１７２】
本発明の複合部材の製造方法において用いられる感光性組成物は、構成成分の混合物を成形してシート状としてもよいし、構成成分の混合物を適切な溶媒に溶解して溶液状としてもよい。
【０１７３】
感光性組成物層を絶縁体に形成するには、シート状を呈した感光性組成物を、絶縁体に添着することにより絶縁体の表面に感光性組成物層を形成することができる。あるいは、溶液状とした感光性組成物を絶縁体にコーティングして絶縁体の表面に感光性組成物層を形成してもよい。導電部を形成後の複合部材の耐久性を考えると、絶縁体に溶液状の感光性組成物をコーティングして、感光性組成物層を形成するのが好適である。
【０１７４】
また、多孔質体の絶縁体を用いて３次元にわたって導電部を形成する場合には、溶液状の感光性組成物を多孔質体の絶縁体にその内表面まで含浸あるいはコーティングし、表面から内部にわたって感光性組成物層の形成を行なう。
【０１７５】
コーティング方法としては、ディッピング法、スピンコート法、スプレー法、真空蒸着法、およびラミネート法等のいずれの方法を用いても構わない。
【０１７６】
本発明の複合部材の製造方法においては、感光性組成物層が予め形成された絶縁体を用いることが、生産性の向上のために好ましい。
【０１７７】
感光性組成物層が予め形成された絶縁体としては、内部空孔表面がナフトキノンジアジド誘導体を含有する感光性組成物で被覆されている多孔質絶縁体が挙げられる。このようにナフトキノンジアジド誘導体で内部空孔表面が被覆された多孔質絶縁体を用いることによって、パターン形状の精度の高い導電部を三次元的な形状に形成することができる。
【０１７８】
＜工程（２）＞
次に、工程（１）によって絶縁体１に形成された感光性組成物層２に対して、図１（ｂ）に示すように所望の導電性パターンにパターン露光して、感光性組成物層２の露光部４にイオン交換性基を生成あるいは消失させる。
【０１７９】
図１（ｂ）においては、導電パターンが形成されたマスク３を介してパターン露光しているが、これに限定されるものではない。の導電パターンのネガ像を形成したマスクを用いて、導電パターン部以外の部分のイオン交換性基を生成あるいは消失させてもよい。
【０１８０】
露光に際しては、必ずしもマスクを用いる必要はない。例えば、レーザービームなどを用いて導電パターンどおりに描画して露光してもよい。また、光の干渉によって生じる干渉縞などの周期的な光強度パターンを用いて周期的なパターンを露光してもよい。
【０１８１】
さらには、露光パターンは二次元的なもののみならず、三次元的なパターンを露光してもよい。三次元的なパターンを露光するには、露光光をレンズで集光して、集光された光のスポットを三次元的に走査してパターンを描画するなど、高知の種々の三次元露光方法を用いることができる。
【０１８２】
本発明の第１および第２の態様においては、２８０ｎｍ以上の波長の露光光を照射する。露光による絶縁体の劣化を低く抑えるためには、露光光の波長は、３００ｎｍ以上であることが好ましく、３５０ｎｍ以上であることがより好ましい。
【０１８３】
特に多孔質体の内部の厚み方向に露光する場合など、多孔質体が芳香族化合物構造を有する場合には、長波長の露光光を用いることが肝要である。多孔質体が芳香族ポリイミドなどで構成される場合には、ポリイミドの吸収の吸収端が４５０ｎｍ以上になるものも少なくない。こうした場合には、さらに長波長の５００ｎｍ以上の波長でパターン露光を行なうことが好ましい。
【０１８４】
本発明の第３および第４の態様においては、露光光の波長は特に問わない。
【０１８５】
工程（２）で用いる露光光源としては、紫外光源、可視光源のほか、β線（電子線）、Ｘ線など光源のなかから所定の波長の露光光を生じるものを選択して使用することができる。紫外光源、あるいは可視光源は、具体的には水素放電管、希ガス放電管、タングステンランプ、ハロゲンランプのような連続スペクトル光源、各種レーザー、水銀灯のような不連続スペクトル光源などのなかから選択して用いる。
【０１８６】
工程（２）においては、感光性組成物層のイオン交換性基に対して、後工程の工程（３）で金属イオンの結合量を増量するために、イオン交換性基の中和、あるいはそのイオン交換性基を形成した部分の膨潤を行なってもよい。そのためには、絶縁体を酸またはアルカリ溶液に吹き付けや浸漬などの手法によって接触させる。特に、アルカリ溶液として水酸化リチウム、水酸化カリウム、水酸化ナトリウム等の水酸化物、炭酸リチウム、炭酸カリウム、炭酸ナトリウム等のアルカリ金属塩、ナトリウムメトキサイドやカリウムエトキサイド等の金属アルコキサイドや水素化ホウ素ナトリウム等の水溶液の少なくとも１種を用い、これらの溶液に浸漬するのがよい。こうした水溶液は、単独でも混合して用いてもよい。
【０１８７】
＜工程（３）＞
次に、形成されたイオン交換性基に、選択的に金属イオンまたは金属微粒子を結合させて、図１（ｃ）に示すように導電部を形成する。図１（ｃ）においては、露光部４が導電部となる。
【０１８８】
露光部に生じたイオン交換性基は、金属イオンとの交換反応を行なう。イオン交換性基と金属イオンとの交換反応の例を下記化学式（２）に示す。
【０１８９】
【化３】

【０１９０】
イオン交換性基と金属イオンとの交換反応を生じさせるには、例えば金属塩を含有する水溶液などに、パターン露光後の絶縁体を浸漬させるだけで容易に行なうことができる。
【０１９１】
金属イオンとして用いられる金属元素としては、銅、銀、パラジウム、ニッケル、コバルト、錫、チタン、鉛、白金、金、クロミウム、モリブデン、鉄、イリジウム、タングステン、およびロジウム等が挙げられる。
【０１９２】
これらの金属元素は、硫酸塩、酢酸塩、硝酸塩、塩化物、および炭酸塩等のような金属塩として溶液中に含有させる。特に、硫酸銅が好ましい。こうした金属塩は、溶液における金属イオンの濃度が０．００１〜１０Ｍ、好ましくは０．０１〜１Ｍとなるよう配合するのが適切である。なお、金属塩を溶解させる溶媒は、水あるいは有機溶媒系、例えばメタノールやイソプロパノール等であってもよい。
【０１９３】
ここで用いられる金属塩含有液のｐＨは、７以下であることが好ましく、６．５以下であることがより好ましい。本発明において用いられるイオン交換性基としては、水中でのイオン解離定数から求めたｐＫａ値が７．２以下であるものが好適に用いられる。この場合、金属塩を含有した水溶液のｐＨが７付近になるにしたがって、イオン交換量はほとんど変化しなくなる。
【０１９４】
また、金属塩含有溶液のｐＨが７を超えると、目的のイオン交換性基以外の極性基、例えばフェノール性水酸基、シラノール基などに対しても金属イオンが吸着してしまう。その結果、良好なパターンを得られなくなる。例えば、ガラス基板にスピンコート等により感光剤を塗布した場合では、感光剤の塗布されていない裏面には水酸基が露出している。ｐＨ７を超える金属塩含有の水溶液にこのような基板を浸漬した場合には、その水酸基に金属イオンが吸着する。このため、その後の工程において金属化が生じ、感光剤の塗布されていない裏面がめっきされてしまう。
【０１９５】
それゆえ、本発明において用いられる金属塩含有溶液は、濃度、ｐＨともに上述した範囲内であることが望まれる。
【０１９６】
本発明においては、金属微粒子が分散した溶液を用いることもできる。イオン交換性基とコロイド状態の金属微粒子とは、静電的な相互作用などによって選択的に結合を生じる。したがって、イオン交換性基と金属微粒子との結合は、金属微粒子が分散した溶液に絶縁体を浸漬させるだけで容易に生じさせることができる。
【０１９７】
例えば、塩酸酸性水溶液中に塩化パラジウムと塩化スズを混合して作製する無電解メッキの触媒として使用されるパラジウム−スズコロイド、またパラジウムのハロゲン化物、酸化物、アセチル化錯体の分散溶液中に絶縁体を浸漬させる。それにより、イオン交換性基上に位置選択的に金属微粒子が容易に結合を生じる。
【０１９８】
以上のようにして、本発明の方法により絶縁体に導電部を形成して、複合部材を得ることができる。複合部材の導電部の導電性をさらに向上させるためには、以下の工程（４）、工程（５）のいずれか、あるいはその両方を行なうことが望ましい。
【０１９９】
＜工程（４）＞
イオン交換により形成された導電部４の導電性を向上させるために、図１（ｄ）に示すように、イオン交換性基に結合した金属イオンを還元剤と接触させて金属化させる。
【０２００】
イオン交換性基と金属イオンの金属化反応の例を下記化学式（３）に示す。
【０２０１】
【化４】

【０２０２】
用いられる還元剤は特に限定されないが、ジメチルアミンボラン、トリメチルアミンボラン、ヒドラジン、ホルマリン、水素化ホウ素ナトリウムや、次亜リン酸ナトリウム等の次亜リン酸塩等が挙げられる。こうした還元剤を含有する溶液に絶縁体を浸漬することによって、導電部４を金属化させることができる。
【０２０３】
＜工程（５）＞
導電部４に対し導電性を向上させるために、図１（ｅ）に示すように無電解めっき５を施す。これにより、導電部４の空孔内を金属である程度充填することができる。
【０２０４】
金属としては、電気抵抗が少なく、比較的腐食しにくい銅が最も好ましい。具体的には、前工程で得られた導電部を触媒核として、無電解メッキ液と接触させる。
【０２０５】
無電解メッキ液としては、例えば、銅、銀、パラジウム、ニッケル、コバルト、白金、金、ロジウム等の金属イオンを含有するものが挙げられる。
【０２０６】
この無電解メッキ液には、前述の金属塩水溶液の他にホルムアルデヒド、ヒドラジン、次亜リン酸ナトリウム、水素化ホウ素ナトリウム、アスコルビン酸、グリオキシル酸等の還元剤、酢酸ナトリウム、ＥＤＴＡ、酒石酸、リンゴ酸、クエン酸、グリシン等の錯化剤や析出制御剤等が含まれており、これらの多くは市販されており簡単に入手することができる。そこで、前記部材をこれらの無電解メッキ液の所望される導電膜厚、若しくは多孔質内部への充填が完了するまで浸漬しておけばよい。
【０２０７】
なお、絶縁体として多孔質体を用いた場合には、複合体の電気絶縁性や機械的強度を向上させるために、下記の工程（６）をさらに行なうことが望ましい。
【０２０８】
＜工程（６）＞
多孔質体の空孔を、含浸樹脂または無機物質で充填する。含浸樹脂としては、エポキシ樹脂やポリイミド、ＢＴ樹脂、ベンゾシクロブテン樹脂、架橋ポリブタジエン樹脂などの硬化性樹脂からなるものが挙げられ、無機物質としては、シリカゾル、シルセスキオキサンやポリシラザンなどから生成されるシリカなどを用いることができる。
【０２０９】
絶縁体に空孔が存在していると、空孔内表面などが吸湿するなどして電気的絶縁性が損なわれるおそれがある。ただし、空孔が導電部の寸法、すなわちビアならビア径、配線なら配線幅および配線ピッチよりも十分に小さな独立気泡の場合は、絶縁性をある程度保つことが可能である。
【０２１０】
充填する材料は、上述したような含浸樹脂や前記無機物質などが挙げられ、特に限定されない。しかしながら、充填性、接着性等を考慮すると含浸樹脂が最も好ましい。
【０２１１】
含浸樹脂には、場合によってナノメートルオーダーの無機フィラーなどを混ぜるとよい。
【０２１２】
無機フィラーとしては、シリカ、アルミナなどの金属酸化物や、窒化ケイ素や窒化アルミニウムなどの金属窒化物、白金やパラジウムなどの金属超微粒子などが用いられる。無機フィラーは、予め含浸樹脂に混合して、その混合物を含浸させることができる。あるいは、無機フィラー前駆体と含浸樹脂との混合物を含浸した後、無機フィラーを空孔内で生成させてもよい。こうした無機フィラー前駆体としては、シルセスキオキサンやポリシラザンなどが良好に用いられる。
【０２１３】
なお、本発明の製造方法において、導電部を形成する目的の部位以外の感光性組成物層内にイオン交換性基含有の有機化合物が生成することは、極力避けなければならない。このため、めっきまでの操作は、短波長の光を遮断したイエロールーム内で行なうことが好ましい。
【０２１４】
また、本発明に係る複合部材の製造方法においては、熱分解性などの容易に除去可能な絶縁体を用いることもできる。この場合は、まず絶縁体の所定の領域に導電部を形成する。次いで、上述したような手法により含浸樹脂を含浸させて硬化する前に、多孔質体を加熱などの手段によって除去する。これによって、含浸樹脂の硬化物中にビアや配線が形成された配線基板を形成してもよい。この場合には、導電部の形成に用いた絶縁体とは異なる材料中に、導電部が最終的に形成されることになる。
【０２１５】
なお、含浸樹脂の硬化の際に絶縁体を加圧して圧縮すると、導電部の多孔質体が除去されて形成された空隙がつぶれて、導電性物質同士が密着する。その結果、導電性カラムの導電率を向上させることができるため好ましい。
【０２１６】
本発明の方法により製造される複合部材においては、感光性組成物に由来する有機化合物層が、絶縁体と導電部との界面に残留する。この場合、図２を参照して説明したように、絶縁体表面における単位表面積当りの有機化合物の含有量を調整することが好ましい。これによって、導電部と絶縁体との密着性を向上させ、かつ導電部の電気特性も向上させることができる。
【０２１７】
すなわち、図２に示すように多孔質の絶縁体２１の表面または内部に部分的に導電部２３が有機化合物２４を介して形成されてなる複合部材であって、絶縁体２１の表面における単位表面積当りの有機化合物２４の含有量が、次の関係を満たすことが好ましい。すなわち、絶縁体２１と導電部２３との間に存在する有機化合物２４の量は、絶縁体２１と導電部２３との間以外に存在する有機化合物２４の含有量よりも多い。
【０２１８】
複合部材の耐湿性向上、マイグレーション防止などのためには、絶縁体２１と導電部２３との間における有機化合物２４の含有量が、絶縁体２１と導電部２３との間以外に存在する有機化合物の含有量の５倍以上であることが好ましく、１０倍以上であることがより好ましい。
【０２１９】
この場合、有機化合物２４は、本発明にかかる複合部材の製造方法にて用いられる感光性組成物に由来するものであってもよいし、それ以外のものであってもよい。特に、絶縁体２１と感光性組成物が異なる構造をしたものであると、絶縁体が光照射による劣化を受けず、絶縁体の材料選択が制限を受けない点で望ましい。
【０２２０】
例えば、本発明を多層配線基板に用いる場合には、絶縁部に従来から使用されているエポキシ樹脂やフェノール樹脂、ビスマレイミド−トリアジン（ＢＴ）樹脂などの汎用性樹脂、ポリイミド、ポリアミド、ポリアリルエーテル、ポリアリレート、およびポリエーテルスルホンなどの耐熱性ポリマーを用いることができる。また、低誘電率化を望むのであれば、ポリテトラフルオロエチレン（ＰＴＦＥ）系ポリマーやベンゾシクロブテン（ＢＣＢ）樹脂等、用途に応じた材料選択が可能である。さらに、上述のように露光の際に絶縁体が光劣化などのダメージを受けにくいために、厚み等も自由に設定できる。
【０２２１】
本発明の方法により製造される複合部材を用いて、多層配線基板を作製することができる。図４を参照して、これについて説明する。
【０２２２】
図４には、多層配線基板の製造に用いられる複合部材の斜視図および断面図を示す。まず、本発明の方法にしたがって複合部材を製造する。図４に示されるように、シート状の複合部材ａ，ｂ，ｃにおいては、多孔質の絶縁体４１の表面、または内部あるいはその両方に配線パターンとなる導電部４２が形成されている。また、シート状の複合部材ｄには、多孔質の絶縁体４１の表面、または内部あるいはその両方にビアパターンとなる導電部４２が形成されている。複合部材ｂのように、ビアパターンと配線パターンとが同一のシートに形成されていてもよい。
【０２２３】
ビアパターンを形成した複合部材ｄに示されるように、ビアである導電部４２の端面は、シート表面から突出した剣山状などの鋭角の構造とすることが望ましい。それにより、ビアと配線との接続を良好にすることが可能となる。
【０２２４】
ビアの端面をはんだでコートすることも同様によいが、この場合も鋭角構造とするのがより好ましい。ただし、はんだはフラックスなどが蒸発して積層時にボイドなどの原因となりやすいので、ニッケル合金系などの比較的硬い金属により、ビアの端面に鋭角構造を形成するのが好ましい。ビア端面が偏平である場合には、含浸樹脂によって端面が被覆されて電気的接続が阻害されやすい。剣山状の構造は、例えばＣｕ／Ｎｉ共晶系の針状めっきを施すことによって形成することができる。
【０２２５】
こうして形成された配線パターンが形成された複合部材ａ、ｂ、ｃと、ビアパターンが形成された複合部材ｄとを、交互に複数積層することによって、三次元配線が形成された多層配線基板が得られる。
【０２２６】
多層配線基板は、あらかじめ配線パターンやビアパターンを形成した複数の複合部材を作製し、それを一括して積層することによって製造することができる。あるいは、配線パターンやビアパターンを形成した複合部材の上に、まだ配線パターンやビアパターンを形成していない多孔質体を重ねて、露光、めっきを施して配線パターンを形成し、これを順次繰り返すことにより多層配線基板を得ることもできる。
【０２２７】
多層配線基板における各複合部材の間は、圧着して積層することが望ましく、圧着する際には、隣接するシート間に接着層を挿入してもよい。
【０２２８】
さらに圧着後、エポキシ樹脂やポリイミド、ＢＴ樹脂、ベンゾシクロブテン樹脂などの含浸樹脂を多孔質体に充填して硬化すれば、より強固な多層配線基板を形成することができる。含浸樹脂の他にシリカゾル、シルセスキオキサン、ポリシラザンなどから生成されるシリカなどの無機物質を充填してももちろんよい。圧着前に含浸樹脂を含浸しておき、圧着しながら含浸樹脂を硬化させてもよいが、ビア端面が含浸樹脂で被覆されてしまうおそれがある。
【０２２９】
配線パターンを多孔質フィルム状の絶縁体と複合化した形で形成することによって、配線部と非配線部との段差を非常に小さくすることができる。場合によっては、そうした段差をなくすことができるため、複数の複合部材を容易に積層することができる。さらに、複合部材の膜厚を薄くしたり、多層配線基板における積層数を多くすることも可能となる。特に、多孔質フィルム状の絶縁体の厚さが数μｍ程度と薄い場合には、こうした効果が顕著に現れる。
【０２３０】
以上、配線パターンが形成された複合部材と、ビアが形成された複合部材とを積層することにより多層配線基板を製造する方法を説明したが、これに限定されるものではない。配線パターンとビアとが形成された複合部材を用いて、多層配線基板を製造することもできる。
【０２３１】
こうした複合部材の断面図を、図５に示す。図５に示す複合部材においては、シート状の多孔質の絶縁体５１中に深さの異なる導電部５２を形成することによって、配線パターンとビアとが１つの部材中に作り込まれている。こうした複合部材を用いて多層配線基板を製造することにより、積層数を低減して工程を簡略化することができる。
【０２３２】
このとき、シート状の多孔質の絶縁体中に深さの異なる導電部を作り込むには、シート状の多孔質の絶縁体（以下多孔質絶縁体シート）の露光波長に対する吸光度の調節などによって、露光光の多孔質絶縁体シート内への侵入長を、そのシート厚の内部にとどめるよう制御する。こうした露光光を用いて、一方の面から配線パターンを露光し、他方の面からビアのパターンを露光する。その後、無電解めっき等を施すことによって、配線パターンとビアとを有する複合部材を得ることができる。あるいは、多孔質の絶縁体にあまり吸収されない波長の露光光を用いて、ビアパターンを露光してもよい。これらの手法を用いることによって、インナービアを非常に簡便に作製することが可能となる。すなわち、基本的に配線パターンとビアとを同じ工程で作製することが可能となるため、製造工程が簡略化される。配線パターンを絶縁体の両面に露光すれば、両面配線基板を作製することもできる。
【０２３３】
以上説明したように、本発明の方法によれば、微細なビアや配線が自由にかつ精度よく形成された複合部材を製造することができる。得られる複合部材は、機械的特性や電気絶縁性といった特性も優れている。
【０２３４】
なお、複合部材が積層された多層配線基板においては、図３に示したように、各複合部材の導電部３２，３３の最表面には、絶縁体成分を含まない導電体からなる層３５が形成されていることが好ましい。このように、基板の導電部３２，３３の最表面には絶縁体成分を含まない導電体からなる層３５が存在することによって、導電部間の接触が良好となる。したがって、導電部の低抵抗化に有効である。
【０２３５】
導電部の最表面に形成される絶縁体成分を含まない導電体からなる層３５としては、具体的には、低抵抗な銅などの金属からなる層が好ましい。絶縁体成分を含まないとは、導電体中の前記絶縁体成分の含有率が体積分率で５％以下であることをさす。層の厚さとしては、各層の平坦性を考慮し、２０μｍ以下、特に１０μｍ以下が望ましい。また、絶縁体成分を含む多孔質体中に形成された導電体からなる層の厚さの１〜５０％、さらには５〜２０％に設定されることが望まれる。厚さが厚すぎると導電部の段差が大きくなり、積層が困難となる。一方、薄すぎる場合には、導電部の低抵抗化の効果が十分でない。
【０２３６】
導電体からなる層３５は、前記工程（１）にあたる無電解めっきを長時間行なうことによって形成することができる。あるいは、絶縁体内部にパターン状導電部を形成した後、再度めっき浴に浸漬して、導電体層３５を形成してもよい。導電部最表面の形状に自由度を持たせるためには、金属箔を導電部端面に貼り合わせるのが望ましい。
【０２３７】
このような構成の多層配線基板を得るためには、まず、多孔質体シートに露光、めっきして配線部、ビア部からなる導電部を形成する。その後、導電部以外の多孔質シート表面にエポキシ樹脂やポリイミド（ポリアミド酸）などの接着剤を塗布し、金属箔の接着と導電部と金属箔の接続を行なう。
【０２３８】
接着剤の塗布は、シルクスクリーン法などで行なってもよいが、インクジェット法などで塗布してもよい。この際、導電部端面をはんだめっきしておくことが好ましい。
【０２３９】
接着後、両面の金属箔をサブストラクト的手法のような常法により加工して、回路パターンを形成する。各々の複合部材に対して適当な含浸樹脂を注入した後、ホットプレスで積層することによって、多層配線基板を製造することができる。
【０２４０】
あるいは、多孔質体フィルムの片面に金属箔を接着し、露光、めっきによって望みのパターンで多孔質フィルム内に導電部を形成する。しかる後に、上面に金属箔を接着して導電部と金属箔の接続を行ない、上下の銅箔をパターニングして回路パターンを形成して、複合部材を得る。これを、前述と同様の手法により多層化することによって、多層配線基板を製造することもできる。
【０２４１】
さらにまた、金属箔の代わりに予めパターン状に形成した金属配線パターンを転写させることにより多孔質フィルムと接着する手法を用いるなど、種々の方法を採用して、導電体からなる層を形成することができる。
【０２４２】
もちろん、こうした導電体からなる層は段差の原因となり、積層する際に問題となる。しかしながら、多孔質体内部に形成された導電部と共同で導電の役を担うため、その膜厚を薄くすることが可能となる。特に、高周波用途の配線においては、表皮効果によって配線表面の導電率が配線全体の導電特性を左右する。そのため、膜厚が薄くとも十分な効果が期待できる。図３に示されるような構造の多層配線基板は、こうした用途に最適である。
【０２４３】
本発明に係る複合部材の製造方法は、多層配線基板や３次元配線基板の形成以外にも、半導体装置の多層チップの層間の配線の形成に適用することも可能である。具体的には、上下にパッドが存在する半導体チップを積層する際の層間配線の形成である。例えば、半導体チップのパッドの配置に合わせた、あるいは特に合わせずに柱状配線などをシート状の絶縁体の多孔質体の膜厚方向に形成する。こうして柱状配線が形成されたシートを、２枚の半導体チップの間に挿入して積層することによって、隣接する２つの半導体チップ間の配線を形成することができる。またこの後、シートを酸素アッシングや熱分解などの手法により除去してもよい。さらに多孔質体シートを除去した後、電解めっき、無電解めっき等によって多孔質化している配線を緻密化することもできる。
【０２４４】
さらには、本発明の方法により製造された複合部材を、ガラスエポキシ基板などの配線基板と複合化することもできる。用いられる配線基板は、例えば、公知の製法によって作製されたガラスクロスやアラミド繊維の不織布などの強化繊維に、含浸樹脂を含浸した樹脂シートから作製されたものなどが挙げられる。このように複合化することによって、曲げ強度を簡単に確保することが可能となる。
【０２４５】
以下、実施例に基づいて本発明を具体的に説明するが、本発明はこれらの実施例のみに限定されるものではない。
【０２４６】
（実施例１）絶縁体表面への配線パターンの形成
絶縁体として、ビスマレイミド−トリアジン樹脂シートを用意した。一方、ナフトキノンジアジド含有フェノール樹脂（ナフトキノンジアジド含有率；３３当量ｍｏｌ％）をアセトンに溶解して、１ｗｔ％の濃度の感光性組成物溶液を調製した。ここで用いたフェノール樹脂の分子量は、２５００である。得られた溶液を、前述の樹脂シート上に厚み０．１μｍとなるようスピンコートして塗膜を得た。さらに、室温で３０ｍｉｎ乾燥させて、感光性組成物層を形成した。
【０２４７】
このシートに対して、ＣＡＮＯＮ ＰＬＡ５０１を用いて、ライン幅１０μｍ、スペース３０μｍのマスクを介して光量５００ｍＪ／ｃｍ²（波長４３６ｎｍ）の条件で露光し、インデンカルボン酸からなる潜像を形成させた。
【０２４８】
パターン潜像が形成されたシートを、０．５Ｍに調整した硫酸銅水溶液に５ｍｉｎ浸漬後、蒸留水による洗浄を３回繰り返した。用いた硫酸銅水溶液のｐＨは４．１であった。洗浄後のシートを、水素化ホウ素ナトリウム０．０１Ｍ水溶液に３０ｍｉｎ浸漬後、蒸留水で洗浄して、複合部材を製造した。得られた複合部材には、ライン幅１０μｍ、スペース３０μｍのマスクどおりのＣｕからなる導電部が形成されていた。
【０２４９】
図６に、本実施例で得られた複合部材における導電部の表面から観察した光学顕微鏡写真を示す。この写真は、倍率１８０倍にて撮影した反射型光学顕微鏡写真である。
【０２５０】
なお、本実施例で得られた複合部材の断面に関して、テトラブロモフェノールブルーを用いた酸染色試験を行なったところ、導電部と絶縁体との界面にはインデンカルボン酸に由来するカルボン酸が存在していることが確認された。
【０２５１】
この複合部材において、絶縁体と導電部の界面以外の部位では、前述のインデンカルボン酸は観察されなかった。
【０２５２】
このようにして得た複合部材（導電パターン形成シート）を、さらに無電解めっき液ＰＳ−５０３に３０ｍｉｎ浸漬して、導電部に銅めっきを施すことにより配線パターンを形成した。
【０２５３】
導電部と絶縁体との密着性の評価は、次のとおりである。従来品では、めっき金属の室温でのピール強度として１．０ｋＮ／ｍ前後の多層配線板が数多く市販されている。上述と同様の条件で得られたＢＴ樹脂シート−Ｃｕ層からなる複合部材において、ＢＴ樹脂シートを固定し、Ｃｕ部について９０°方向、５０ｎｍ／ｍｉｎの条件下でのピール強度を測定した。その結果、１．９ｋＮ／ｍとなり、従来品と比較して、導電部と絶縁体との密着性は良好であることが確認された。本発明の方法により製造された複合部材においては、有機感光性化合物が接着層として十分機能していることがわかる。
【０２５４】
（実施例２）多孔質体の絶縁体への配線パターンの形成
絶縁体として、ＰＴＦＥ多孔質フィルム（空孔径５００ｎｍ、膜厚２０μｍ）を用い、実施例１で用いた感光性組成物溶液を、ディップ法にてフィルム全表面にコーティングした。この操作により、多孔質フィルムの内部空孔表面がナフトキノンジアジド含有フェノール樹脂で被覆された。その後、ドット径５０μｍ、スペース５０μｍのマスクを用いて、実施例１と同様の操作を行なって複合部材（導電パターン形成シート）を製造した。得られた複合部材においては、ドット径５０μｍ、スペース５０μｍの導電部が、絶縁体の内部にわたって形成されていた。
【０２５５】
（実施例３）無電解めっき処理
実施例２で得られた導電パターン形成シートを、無電解銅めっき液ＰＳ−５０３に３０ｍｉｎ浸漬し、導電部に銅めっきを施して配線パターンを形成した。フィルム裏面についても同様のパターン形状が形成されていた。
【０２５６】
図７に、本実施例で得られた複合部材における配線パターンの表面から観察した光学顕微鏡写真を示す。この写真は、倍率１８０倍にて撮影した反射型光学顕微鏡写真である。
【０２５７】
本実施例で得られた複合部材において、導電部と絶縁体との界面、および前記絶縁体と導電部の界面以外に存在するインデンカルボン酸由来のカルボン酸を実施例１と同様の手法を用いて観察した。その結果、インデンカルボン酸由来のカルボン酸は、絶縁体と導電部の界面のみに観察された。また、導電部と絶縁体との密着性は良好であった。
【０２５８】
（実施例４）両面プリント配線基板
下記式で表わされるポリアミド酸とポリエチレンオキシドとのグラフトコポリマー、およびビス（４−マレイミドフェニルメタン）の混合物を含有するＮＭＰ溶液を調製した。ただし、ポリエチレン鎖の分子量は約２万、ポリアミド酸成分とポリエチレンオキシド成分との重量比は２：５とし、グラフトコポリマーとビス（４−マレイミドフェニルメタン）との混合比は重量比で７：１とした。
【０２５９】
【化５】

【０２６０】
この溶液から、キャスト法によりシートを作製した。得られたシートを窒素気流下、室温から３０分かけて１５０℃に昇温し、この温度で１時間加熱した。次に、３０分かけて２５０℃に昇温して、この温度で１時間加熱した。さらに、３０分かけて３５０℃に昇温し、この温度で１時間加熱処理して、厚さ１０μｍのポリイミド多孔質体シートが得られた。
【０２６１】
加熱後のフィルムを透過型電子顕微鏡で観察したところ、孔径約０．２μｍの三次元的に連続な空孔が形成されていた。
【０２６２】
一方、感光性組成物溶液として、ナフトキノンジアジド含有フェノール樹脂（ナフトキノンジアジド含有率：３３当量ｍｏｌ％）をアセトンに溶解して、１ｗｔ％の溶液を調製した。ここで用いたフェノール樹脂の分子量は、２５００であった。この溶液を、前述のポリイミド多孔質体シートの全表面に、ディップ法にてコーティングした。この操作により、多孔質体シートの内部空孔表面がナフトキノンジアジド含有フェノール樹脂で被覆された。
【０２６３】
このポリイミド多孔質シートに対して、ＣＡＮＯＮ ＰＬＡ５０１で、ドット径５０μｍ、スペース５０μｍのマスクを介して光量 ３Ｊ／ｃｍ²（波長４３６ｎｍ）の条件で露光して、インデンカルボン酸からなる潜像を形成させた。
【０２６４】
パターン潜像が形成されたシートを、０．５Ｍに調製した硫酸銅水溶液に５ｍｉｎ浸漬後、蒸留水による洗浄を３回繰り返した。用いた硫酸銅水溶液のｐＨは４．１である。洗浄後のシートを、水素化ホウ素ナトリウム０．０１Ｍ水溶液に３０ｍｉｎ浸漬後、蒸留水で洗浄した。洗浄後、無電解銅めっき液ＰＳ−５０３に３０ｍｉｎ浸漬し、導電部に銅めっきを施して、複合部材を製造した。得られた複合部材には、ドット径５０μｍ、スペース５０μｍのマスクどおりのＣｕからなる導電部が形成されていた。
【０２６５】
（実施例５）両面プリント配線基板
前述の実施例４と同様の手法により、厚さ１０μｍのポリイミド多孔質体シートを作製した。このポリイミド多孔質体シートには、孔径約０．２μｍの連続な空孔が三次元的に形成されていた。
【０２６６】
得られた多孔質体シートに対して、ビア径として５０μｍのパターンのマスクでビアシートを実施例４と同様の方法で形成した。その後、ビア端面にははんだめっきを施して、ビアシートを得た。また、同様の多孔質体シートを用いて、上述と同様の手法により、ライン幅３０μｍの配線シートを作製した。
【０２６７】
そして、ビアと配線とが導通する位置でビアシート／配線シート／ビアシートの配列で位置合わせをして、熱プレス機により加熱、加圧して積層し多層配線基板を得た。
【０２６８】
（実施例６）
前述の実施例４と同様の手法により、厚さ４０μｍのポリイミド多孔質体シートを作製した。このポリイミド多孔質体シートには、孔径約０．２μｍの連続な空孔が三次元的に形成されていた。
【０２６９】
得られた多孔質体シートに対して、ビア径として５０μｍのパターンのマスクでビアシートを実施例４と同様の方法で形成した。その後、ビア端面にははんだめっきを施して、ビアシートを得た。また、同様の多孔質体シートを用いて、上述と同様の手法により、ライン幅３０μｍの配線シートを得た。この配線シートに対しても、ビアシートの場合と同様の方法で導電部を形成した後、はんだめっきを施した。
【０２７０】
ビアシートおよび配線シートにおける導電部以外の表面部分には、ポリイミドワニスをシルクスクリーン法により塗布した。
【０２７１】
また一方で、０．３ｍｍ厚のステンレス板上に市販のポジ型フォトレジストをスピンコート法により膜厚２μｍに塗布してフォトレジスト膜を形成した。得られたフォトレジスト膜に対して、露光、現像を行ない、ビア転写用の基板および配線パターン転写用の基板を作製した。なお、ビア転写用の基板の作製に当たっては、ビア径５５μｍのマスクを用いて露光を行ない、配線パターン転写用基板の作製に当たっては、ライン幅３３μｍのマスクを用いて露光を行なった。いずれのマスクも、前述の多孔質シートに形成されたビアおよび配線パターンと同じピッチである。
【０２７２】
こうして得られた転写用基板と銅電極とを対向し、硫酸銅めっき浴に浸漬することにより電解めっきを施した（電流密度２Ａ／ｄｍ²、１５ｍｉｎ）。用いた硫酸銅のｐＨは４．１である。各転写用基板におけるフォトレジスト除去部位には、膜厚約５μｍの銅が析出して金属パターンが形成され、これを金属転写原板とした。
【０２７３】
多孔質体シートに形成された導電部が金属転写原板の金属パターンに対向するよう、パターン形状の対応したビアシートと金属転写原板とを１５０℃で圧着して、転写原板の金属部を多孔質体シートへ転写した。配線シートについても、同様にして転写原板の金属部を転写した。
【０２７４】
その後、実施例５と同様の手法により、ビアと配線とが導通する位置でビアシート／配線シート／ビアシートの配列で位置合わせをして、熱プレス機で加熱、加圧して積層した。その結果、図３に示すような多層配線基板が得られた。
【０２７５】
積層シートの上端と下端の抵抗を測定したところ、１ｍΩであった。
【０２７６】
（実施例７）異方性導電シート
実施例２および３で作製された導電パターン形成ＰＴＦＥ多孔質シートに対し、銅カラムの端面にＣｕ／Ｎｉ系共晶めっきをして高さ２〜３μｍの剣山状の構造を形成した。この銅カラムが形成されたＰＴＦＥ多孔質体シートに含浸する樹脂組成物を、以下のように調製した。
【０２７７】
当量の３，３’，４，４’−ベンゾフェノンテトラカルボン酸二無水物と２，２’−ビス［４−（ｐ−アミノフェノキシ）フェニル］プロパンとを、ジメチルアセトアミド中で反応させて、ポリアミド酸ワニスを調製した。このポリアミド酸ワニスに、３０重量％の２，２−ビス［４−（４−マレイミドフェノキシ）フェニルを加えて、含浸溶液とした。
【０２７８】
得られた含浸溶液を、銅カラムが形成されたＰＴＦＥ多孔質体シートに含浸した後、熱風乾燥して溶媒を除去した。次いで、２００℃で３０分間加熱して、接着性の異方性導電フィルムを作製した。
【０２７９】
（実施例８）多孔質の絶縁体への配線パターンの形成
式（II）で表わされる化合物（分子量１０，０００）５ｇと、酸発生剤としてＮ−ヒドロキシナフチルイミドトリフルオロメタンスルホネート０．１ｇおよびシクロヘキシルアミン０．０４ｇとを、メトキシメチルプロピオネート１００ｇに溶解して、有機感光性組成物溶液を調製した。
【０２８０】
【化６】

【０２８１】
絶縁体としては、ＰＴＦＥ多孔質フィルム（空孔径５００ｎｍ、膜厚２０μｍ）を用意した。前述の有機感光性組成物溶液をディップ法にてフィルム全面にコーティングした後、１００℃、９０秒間のベーキングを施した。さらに、ライン幅＝５０μｍ、スペース幅＝１００μｍのマスクを用いて、実施例１と同様の条件にて露光した。次いで、１４０℃で１５分ＰＥＢを施した後、実施例１と同様の導電パターン形成プロセスを行なって、複合部材を製造した。得られた複合部材には、Ｌライン幅＝１００μｍ、スペース幅＝５０μｍの導電部が内部にわたって形成されていた。
【０２８２】
（実施例９）
有機感光性組成物溶液として、ナフトキノンジアジド含有フェノール樹脂（ナフトキノンジアジド含有率；３３当量ｍｏｌ％）０．９ｇとポリ（エチレン−カルボジイミド）樹脂０．５ｇとをアセトン１００ｍｌに溶解して溶液を調製した。ここで用いたフェノール樹脂の分子量は２５００である。この溶液を用いて、実施例１と同様の手法により複合部材を製造した。得られた複合部材には、実施例１と同様に良好なパターンが形成されていた。
【０２８３】
この複合部材に対し、８０℃で１時間加熱処理を加えた後、ピール強度評価を行なったところ、２．６ｋＮ／ｍであった。
【０２８４】
（実施例１０）
有機感光性組成物溶液として、ポリ（ｐ−ニトロベンジル−ｐ−ビニルベンゼンカルボネート−ｃｏ−スチレン）をトルエンに溶解して、１重量％の濃度の溶液を調製した。用いた樹脂の分子量は、１５，０００である。この溶液を用いた以外は実施例２と同様の手法により、ＰＴＦＥ多孔質フィルムに配線パターンを形成した。その結果、マスクどおりに良好な導電パターンが得られた。
【０２８５】
（実施例１１）
まず、ポリ（ビニルスチレン）とポリメチルメタクリレートとのジブロックコポリマーを、リビングアニオン重合法により合成した。重量平均分子量Ｍｗ＝２８７０００（ポリ（ビニルエチレン）分子量＝９１０００、ポリメチルメタクリレート分子量＝１９６０００）、Ｍｗ／Ｍｎ＝１．１０であった。このジブロックコポリマーに、ラジカル発生剤としての３，３’，４，４’−テトラ−（ｔ−ブチルぺルオキシカルボニル）ベンゾフェノンを１．７重量％添加して混合物を得、この混合物をシクロヘキサノンに溶解して、１０重量％の濃度の溶液を調製した。
【０２８６】
得られたシクロヘキサノン溶液を、アプリケータを用いてＰＴＦＥ板上に塗布し、乾燥して厚さ１５μｍのフィルムを作製した。このフィルムを窒素気流下、１３５℃で２４時間加熱処理した。加熱処理後、加速電圧２ＭＶのβ線を１６０ＫＧｙ照射した。照射後、乳酸エチルで洗浄して、架橋ポリ（ビニルエチレン）の多孔質フィルムを作製した。
【０２８７】
得られたフィルムを透過型電子顕微鏡で観察したところ、孔径約５０ｎｍの三次元的に連続な空孔が形成されていた。
【０２８８】
一方、ナフトキノンジアジド含有フェノール樹脂（ナフトキノンジアジド含有率；３３当量ｍｏｌ％）をアセトンに溶解して０．５ｗｔ％濃度の溶液を調製し、感光性組成物溶液とした。このアセトン溶液を、前述の多孔質フィルムに含浸した後、室温で乾燥した。このシートに対し、ＣＡＮＯＮ ＰＬＡ５０１を用いて、マスクを介して配線パターンおよびビアパターンをそれぞれ露光して、インデンカルボン酸からなる潜像を形成した。配線パターンは、ライン幅２０μｍ、スペース３０μｍであり、ビア径は１０μｍである。露光は、光量５００ｍＪ／ｃｍ²（波長４３６ｎｍ）の条件で行なった。
【０２８９】
パターン潜像が形成されたシートを、０．５Ｍに調整した硫酸銅水溶液に５ｍｉｎ浸漬後、蒸留水による洗浄を３回繰り返した。用いた硫酸銅水溶液のｐＨは４．１であった。洗浄後のシートを、水素化ホウ素ナトリウム０．０１Ｍ水溶液に３０ｍｉｎ浸漬後、蒸留水で洗浄した。さらに、無電解銅めっき液ＰＳ−５０３に３０ｍｉｎ浸漬して、導電部に銅めっきを施した。これにより、Ｃｕからなる配線パターンおよびビアパターンがそれぞれ形成された多孔質シートが得られた。
【０２９０】
配線パターンが形成された多孔質シート（配線シート）には、さらに無電解めっきを施すことにより、配線パターンの端面にＣｕのみからなる厚さ２μｍの層を形成した。また、ビアパターンが形成された多孔質シート（ビアシート）には、端面にＣｕ／Ｎｉ系共晶めっきをして高さ２〜３ミクロンの剣山状の突起構造を形成した。
【０２９１】
こうして得られた配線シート２枚の間に、ビアシート１枚を挟んで積層した後、樹脂溶液を含浸した。用いた含浸樹脂溶液は、ベンゾシクロブテン樹脂溶液（ダウケミカル社製、商品名：ＸＵ１３００５）１００重量部に、５０重量部のメチルイソブチルケトンを加えて調製した。シートの積層体は、圧着してから溶媒を除去した。さらに、窒素気流下、２４０℃で１時間加熱硬化させることにより、両面配線基板を作製した。
【０２９２】
同様の手法により、配線シート４枚とビアシート３枚とを交互に積層して４層の多層配線基板を作製した。また、４層のＦＲ−４ガラスエポキシ基板（配線幅７５μｍ）の両面に、それぞれビアシートおよび配線シート１枚ずつを積層して、６層の多層配線基板を作製した。さらに、ビアシートおよび配線シートを２枚ずつ用いて８層の多層配線基板も作製できた。
【０２９３】
以上のように作製した多層配線基板は、配線シートの導電部の端面にＣｕのみからなる層が形成されているため、端面にＣｕのみからなる層を形成しないものに比べて低抵抗であった。また、ガラスエポキシ基板をコア層に有する多層配線基板は、曲げ強度に優れていた。
【０２９４】
（実施例１２）
前述の実施例４と同様の手法により、厚さ２０μｍのポリイミド多孔質体シートを作製した。このポリイミド多孔質体シートには、孔径約０．２μｍの連続な空孔が三次元的に形成されていた。
【０２９５】
一方、ＯＨ基をｔｅｒｔ−ブトキシカルボニルメチル基でキャップしたフェノールノボラック樹脂誘導体１０ｇと、酸発生剤として、ＤＴＢＰＩ−ＴＦ（ビス（４−ｔｅｒｔ−ブチルフェニル）ヨードニウムトリフルオロメタンスルホネート）０．５ｇおよびアクリジンオレンジ（Ｃ．Ｉ．４６００５）０．０８ｇとをメチルセロソルブ２００ｇに溶解して、有機感光性組成物溶液を調製した。
【０２９６】
前述のようにして得られたポリイミド多孔質体シートを、この有機感光性組成物溶液に含浸した後、８０℃、１０ｍｉｎ乾燥させて、有機感光性組成物被覆ポリイミド多孔質体シートを作製した。
【０２９７】
このシートに対して、低圧水銀ランプで、ライン幅５０μｍ、スペース５０μｍの配線パターンのマスクを介して光量１０ｍＪ／ｃｍ²（波長２５４ｎｍ）の条件で露光し、その後、１００℃で５分間の条件で加熱処理を施すことにより、カルボキシル基含有フェノールノボラック樹脂からなる潜像を形成させた。この条件におけるパターンのシートに対する侵入深さは、約５μｍであった。
【０２９８】
引き続いて、このシートの裏面にビアパターンマスクを配置して、露光を施した。用いたビアパターンマスクには、５０μｍφのビア部が１００μｍピッチに並んでいる。このビア部を、前述のシート下部に描いたライン露光部に貫通するよう配置した。これらに対し、ＣＡＮＯＮ ＰＬＡ５０１で、光量５００ｍＪ／ｃｍ²（波長５４６ｎｍ）の条件で長波長露光して、前述と同様にカルボキシル基含有フェノールノボラック樹脂からなる潜像を形成させた。
【０２９９】
露光後のシートにおいては、ビア露光部がライン露光部まで到達した潜像を形成していた。
【０３００】
パターン潜像が形成されたシートを蒸留水により洗浄し、０．５Ｍに調整した硫酸銅水溶液に５ｍｉｎ浸漬後、蒸留水による洗浄を３回繰り返した。用いた硫酸銅水溶液のｐＨは４．１である。洗浄後のシートを、水素化ホウ素ナトリウム０．０１Ｍ水溶液に３０ｍｉｎ浸漬後、蒸留水で洗浄した。さらに、無電解銅めっき液ＰＳ−５０３に３０ｍｉｎ浸漬して、導電部に銅めっきを施した。その結果、図５に示されるようなＣｕからなる配線パターンが形成された複合部材が得られた。
【０３０１】
【発明の効果】
以上詳述したように、本発明によれば、導電回路設計への自由度が高く、また露光により絶縁体の劣化を生じず、かつ絶縁体への金属の異常析出がなく微細なパターンを有する導電部を容易に形成することが可能となる。
【０３０２】
また、本発明によれば、導電回路設計の自由度が高く、低コストで絶縁部の材料選択性や成形加工性に影響を及ぼさず、かつ絶縁体への金属の異常析出がなく、微細なパターンを有する導電部を容易に形成することが可能となる。
【０３０６】
さらに本発明によれば、上述した方法により製造された複合部材を用いた電子パッケージが提供される。
【０３０７】
本発明は、各種光機能性装置や多層配線基板等、多くの用途に好適に用いることができ、その工業的価値は絶大である。
【図面の簡単な説明】
【図１】本発明の複合部材の製造方法を示す断面概略図。
【図２】本発明の複合部材を示す概略図。
【図３】本発明の多層配線基板を示す概略図。
【図４】多層配線基板の製造に用いられる複合部材の斜視図及び断面図。
【図５】多層配線基板の製造に用いられる複合部材の断面図。
【図６】実施例１で得られた複合部材の導電部を示す写真。
【図７】実施例３で得られた複合部材の配線パターンを示す写真。
【符号の説明】
１…絶縁体
２…感光性組成物層
３…マスク
４…感光部
５…無電解めっき[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a method of manufacturing a composite member that is used for a wiring board or the like in the fields of electricity, electronics, communication, and the like and in which a conductive portion such as wiring is formed on an insulator. The present invention also provides,Composite member manufactured by such a methodIncludeIt relates to electronic packages.
[0002]
[Prior art]
In recent years, high integration and miniaturization of various electric and electronic parts including semiconductors have been progressing. It is certain that this trend will intensify in the future. In connection with this, fine wiring of metal wiring, fine pitch, three-dimensional wiring, and the like have been attempted in order to perform high-density mounting on a printed wiring board.
[0003]
In particular, three-dimensional wiring is indispensable for high-density mounting, and various methods have been proposed for manufacturing a wiring board having three-dimensional wiring.
[0004]
However, according to the conventional method for manufacturing a wiring board, it is difficult to easily form a fine three-dimensional wiring having a three-dimensional free shape.
[0005]
When forming a three-dimensional wiring on a wiring board, a multilayer wiring board structure is configured by stacking two-dimensional wiring boards, as represented by, for example, a build-up wiring board. In such a multilayer wiring board structure, adjacent wiring layers are coupled by conductive columns called vias.
[0006]
Conventionally, such vias have been formed by the following method. First, through holes (via holes) are provided in the insulator by a photolithography process using photosensitive polyimide, resist, or the like. Then, vias are formed by selectively plating or filling the holes with conductive paste. In order to form vias by such a method, steps of resist application, exposure, and etching are required. For this reason, it takes time and it is difficult to improve the yield.
[0007]
Other examples of via formation methods include drills and CO on insulators.₂A method of providing a via hole of a predetermined size using a laser or the like and plating the hole or filling a conductive paste can be mentioned.
[0008]
However, with such a method of drilling an insulator, it is difficult to freely form a fine via of several tens of microns or less at a desired position.
[0009]
In the method described in JP-A-7-207450, a compound having a hydrophilic group is allowed to enter the pores of a three-dimensional porous film such as PTFE, and in this state, a low-pressure mercury lamp (wavelengths of 185 nm and 254 nm) is used. Perform pattern exposure. Thereby, a hydrophilic group is formed on the three-dimensional porous film. Furthermore, metal plating is performed on the three-dimensional porous film.
[0010]
However, in the above-described method, since the exposure is performed with light having a short wavelength, the material constituting the three-dimensional porous film is deteriorated. In addition, the exposure light is absorbed by the three-dimensional porous film so that the exposure light does not penetrate into the porous body and fine vias cannot be formed.
[0011]
Further, in the above-described method, PTFE constituting the three-dimensional porous film reacts with the exposure light to selectively generate a hydrophilic group, but this PTFE has poor molding processability and high cost. And so on.
[0012]
  Also,Another way to form viasAlso suggestHas been. In this method, first, the entire surface of the insulator made of a porous material is impregnated with a photosensitive composition containing a photosensitive reducing agent and a metal salt. Next, post pattern exposure is performed to reduce the cation of the metal salt in the exposed portion to a metal nucleus. Thereafter, the photosensitive composition in the unexposed area is washed and removed, and further, electroless plating or solder is applied to the remaining metal core, thereby forming a via having a desired pattern.
[0013]
However, in this method, the entire surface of the porous insulator is impregnated with the photosensitive composition containing the metal salt, so that the metal salt adsorbed on the portion corresponding to the unexposed portion is completely removed after exposure. Is difficult. Therefore, in the subsequent reduction process, a phenomenon occurs in which metal nuclei are deposited in an undesired portion. Such abnormal deposition of metal nuclei causes a problem in insulating characteristics between adjacent vias and wiring layers as the pattern becomes finer.
[0014]
In addition, the via formed in the insulator substrate by the conventional method for manufacturing a wiring substrate has a structure in which the insulator and the conductive portion are in direct contact with each other. In that case, since both are inferior in adhesiveness, the problem that an electroconductive part will peel from an insulator board | substrate will arise in use.
[0015]
Furthermore, when a multilayer wiring board is configured by laminating a plurality of wiring boards formed by a conventional wiring board manufacturing method, the electrical connection between the wiring layers of each wiring board and the electrical conductivity of the wiring are further improved. Was demanded.
[0016]
[Problems to be solved by the invention]
The present invention has a high degree of freedom in designing a conductive circuit, does not cause deterioration of the insulator due to exposure, and can easily form a conductive portion having a fine pattern without abnormal metal deposition on the insulator. It aims at providing the manufacturing method of a composite member.
[0017]
In addition, the present invention has a high degree of freedom in the design of conductive circuits, has a low cost, does not affect the material selectivity and molding processability of the insulating portion, and has a fine pattern without abnormal metal deposition on the insulator. It aims at providing the manufacturing method of the composite member which can form a part easily.
[0021]
  Furthermore, the present invention provides a composite member produced by the method described above.TheAn object is to provide an electronic package used.
[0022]
[Means for Solving the Problems]
  In order to solve the above problems, the present invention provides:Sheet or porousA method for producing a composite member in which a conductive part is selectively formed on an insulator, comprising: (1) a photosensitive composition layer containing a compound that generates an ion-exchange group by irradiation with light having a wavelength of 280 nm or more., All surfaces are hydrophilicThe insulatorInside or surfaceAnd (2) a second step in which the photosensitive composition is subjected to pattern exposure with exposure light having a wavelength of 280 nm or more to generate an ion-exchange group in the exposed portion, and (3) the pattern. To the pattern of ion-exchangeable groups formed by exposureBy contacting an aqueous solution of a metal salt with the ion exchange groupMetal ionsAndAnd a third step of forming the conductive portion by bonding to provide a method of manufacturing a composite member.
[0023]
  The present invention also providesSheet or porousA method for producing a composite member in which a conductive part is selectively formed on an insulator, comprising: (1) a photosensitive composition layer containing a compound having an ion-exchange group;, All surfaces are hydrophilicThe insulatorInside or surfaceAnd (2) pattern exposure of the photosensitive composition layer with exposure light having a wavelength of 280 nm or more to eliminate the ion-exchangeable group in the exposed portion, and the ion-exchangeable group in the unexposed portion. And (3) the ion-exchangeable group left in the unexposed portion by the pattern exposure.By contacting an aqueous solution of a metal salt with the ion exchange groupMetal ionsAndAnd a third step of forming the conductive portion by bonding to provide a method of manufacturing a composite member.
[0024]
  The present invention also providesSheet or porousA method for producing a composite member in which a conductive part is selectively formed on an insulator, comprising: (1) an onium salt derivative, a sulfonium ester derivative, a carboxylic acid derivative, and a naphthoic acid that generate an ion-exchangeable group upon irradiation with light. A photosensitive composition layer containing at least one derivative of quinonediazide derivatives or a compound capable of disappearing an ion-exchangeable group upon irradiation with light.Inside or surfaceAnd (2) a second step in which the photosensitive composition is subjected to pattern exposure, and an ion exchange group is generated or eliminated in the exposed portion, and (3) the pattern exposure is performed.Or obtained by disappearingIon exchange group patternBy contacting an aqueous solution of a metal salt with the ion exchange groupMetal ionsAndAnd a third step of forming the conductive portion by bonding to provide a method of manufacturing a composite member.
[0025]
In the manufacturing method of this invention, it is desirable to provide the process of electroless-plating to the electroconductive part surface formed at the said 3rd process.
[0030]
  Furthermore, the present invention comprises a composite member obtained by the above-described method for manufacturing a composite member.On the wiring boardThere is provided an electronic package characterized in that at least one electronic component is electrically connected.
[0031]
  Furthermore, the present invention providesPorousA method for producing a composite member in which a conductive portion is selectively formed on an insulator, comprising: (1) a photosensitive composition layer;All surfaces are hydrophilicA first step of forming in or on the insulator; and (2) a second step of generating an ion-exchange group in the exposed portion by pattern exposure of the photosensitive composition layer with light and heating. And (3) the ion exchange group formed in the exposed portion by the pattern exposure.By contacting an aqueous solution of a metal salt with the ion exchange groupMetal ionsAndAt least a third step of bonding to form the conductive portion, wherein the photosensitive composition layer includes at least a compound that generates an ion-exchange group in the presence of an acid and a photoacid generator. A method for producing a composite member is provided.
[0033]
The present invention will be described in detail below.
[0034]
The method for producing the composite member of the present invention will be described with reference to FIG. 1, taking as an example the case of forming a conductive portion extending in the planar direction and thickness direction of a sheet-like insulator.
[0035]
FIG. 1 is a schematic sectional view showing a method for producing a composite member of the present invention.
[0036]
In the present invention, at least the steps (1) to (3) and, if necessary, the following (4) and (5) are performed to form a conductive portion having a fine pattern on the insulator. Here, the case where the photosensitive composition containing the compound which produces | generates an ion exchange group by light irradiation is used is shown. Each step will be described below.
[0037]
Step (1): First, as shown in FIG. 1A, a photosensitive composition layer 2 containing a compound that generates an ion-exchange group by light irradiation is formed on the insulator 1. In the case where the pattern of the conductive portion is formed in the planar direction and the thickness direction of the insulator 1, the insulator 1 can be easily and accurately formed by using a porous body.
[0038]
Step (2): Next, as shown in FIG. 1B, the photosensitive composition layer 2 formed on the insulator 1 is subjected to pattern exposure through a mask 3 to expose the photosensitive composition layer 2. An ion exchange group is generated in part 4. When the insulator 1 is a porous body, the inside of the insulator 1 is also exposed.
[0039]
Step (3): Thereafter, a metal ion or a metal is bonded to the ion-exchangeable group generated in the exposed portion 4 by pattern exposure in the step (2) as shown in FIG.
[0040]
Step (4): If necessary, the conductivity is improved by reducing the metal ions bound to the ion exchange groups of the exposed portion 4 to metallize the metal ions as shown in FIG. 1 (d). Let
[0041]
Step (5): Further, if necessary, electroless plating 5 is applied to the conductive portion formed in the exposed portion 4 as shown in FIG.
[0042]
In addition, when the photosensitive composition containing the compound which lose | disappears an ion exchange group by exposure is used, the ion exchange group of an exposure part lose | disappears in a 2nd process, and an ion exchange group remains in an unexposed part. As a result, a negative pattern is formed.
[0043]
In steps (1) to (3) (if necessary (4) and (5)) relating to the method for producing a composite member of the present invention, complicated procedures such as resist coating, etching, and resist peeling are required. No process is required. Therefore, the process is simplified as compared with a conventional method for manufacturing a wiring substrate in which a through hole is formed using photolithography or a mechanical technique. In addition, if a porous body is used as the insulator, there is no step of selectively filling plating or a conductive paste to form a conductive portion, and the work becomes easy.
[0044]
In addition, the accuracy of the pattern shape of the conductive portion can be improved, and a fine pattern controlled to several tens of μm or less can be easily formed. For this reason, the degree of freedom in designing the conductive portion formed in the insulator is also improved.
[0045]
  In the present invention,The phenomenon that metal nuclei are deposited in an undesired portion does not occur. As a result, it is possible to form a conductive portion having a fine pattern shape with high accuracy only in a desired portion.
[0046]
In the first and second embodiments of the present invention, as a compound that generates or disappears an ion-exchange group by light irradiation, a compound that generates an ion-exchange group by light irradiation with a wavelength of 280 nm or more is used as exposure light. Light having a wavelength of 280 nm or more is used. Thereby, damage caused to the insulator by exposure is reduced, and deterioration of the insulator is reduced. Further, the absorption of exposure light in the insulator is reduced. For this reason, it becomes advantageous when forming the electroconductive part penetrated in the film thickness direction especially using the insulator which consists of a porous body. In particular, for use in a wiring board, when the insulator is a polymer, it is necessary to use a heat resistant polymer. Many heat-resistant polymers often have an aromatic / heterocyclic structure such as a benzene ring in the main chain or side chain, and the aromatic / heterocyclic structure absorbs light in the ultraviolet region. For example, the benzene ring has an absorption peak near 254 nm. For this reason, light with a short wavelength of 280 nm or less is almost absorbed, and it is difficult to expose through the film thickness direction. By using light having a long wavelength with little absorption of an aromatic / heterocyclic structure as exposure light, a conductive part having a fine pattern with higher accuracy can be formed.
[0047]
In the third aspect of the present invention, at least one selected from an onium salt derivative, a sulfonium ester derivative, a carboxylic acid derivative, and a naphthoquinonediazide derivative is used as the compound that generates an ion-exchange group by light irradiation. Photosensitive compounds containing derivatives are used. The compound group enumerated here is rich in versatility, and easily generates an ion exchange group by light irradiation. For this reason, the conductive part having a fine pattern can be formed with high accuracy. Furthermore, they can be applied to any insulator such as ceramic or organic insulating material. Therefore, it is possible to use an insulator having a low cost and high moldability.
[0048]
In the method using PTFE described in JP-A-7-207450, a liquid such as water or alcohol is usually used as a compound having a hydrophilic group, and exposure is performed in a state in which these liquids are wet in a porous film. Need to do. For this reason, there existed problems, such as a process and an exposure apparatus becoming complicated. However, according to the present invention, such a problem does not occur, and the conductive portion can be easily formed.
[0049]
In the production method of the present invention, a photosensitive composition containing at least a naphthoquinone diazide derivative and a carbodiimide derivative is preferably used.
[0050]
The naphthoquinone diazide derivative acts as a photosensitive component, and it is preferable to use a derivative added to a compound having a high molecular weight, such as a phenol resin addition type, in consideration of film forming properties. At this time, the naphthoquinonediazide derivative easily generates an ion-exchangeable carboxyl group with a high resolution by irradiating light having a wavelength longer than the wavelength of i-line (365 nm). The only product produced as a by-product during the reaction is nitrogen, which is easily discharged out of the system as a gas. Therefore, it does not affect the subsequent metal ion substitution reaction and the electroless plating process performed as necessary.
[0051]
In addition, the polycarbodiimide derivative has a carbodiimide structure showing high reactivity with active hydrogen compounds contained in alcohol, thiol, amine and the like. By blending such a polycarbodiimide derivative, it can be easily reacted with a naphthoquinonediazide derivative. Thus, by reacting both derivatives, the photosensitive composition layer has a three-dimensional gelled structure. For this reason, it becomes insoluble in both water-based and organic solvent-based solvents, and heat resistance can be improved. As a result, the adhesive strength between the conductive portion and the insulator can be improved, and the chemical resistance and heat resistance of the entire composite member can be improved.
[0052]
In the present invention, a porous body is preferably used as the insulator. In particular, when the photosensitive composition containing a naphthoquinone diazide derivative is coated on the surface of the internal pores of the porous body, conducting the process (2) as described above allows highly accurate pattern shape conductivity. The part can be formed.
[0053]
When a conductive part is formed by the method of the present invention using a sheet-like insulator in the planar direction and the thickness direction, the resulting composite member is preferably configured as follows. This will be described with reference to FIG.
[0054]
In FIG. 2, the schematic of an example of the composite member manufactured by the method of this invention is shown. As shown in FIG. 2, a photosensitive composition layer 22 containing a compound that generates an ion-exchange group by exposure exists on the surface of the porous insulator 21. By performing exposure, an organic compound 24 containing an ion exchange group is formed in the exposed portion. The ion exchange group of the organic compound 24 carries metal ions and metal fine particles by an ion exchange reaction or an adsorption reaction. By subsequently performing electroless plating, a conductive portion 23 having a thickness is formed. Thus, a composite member is produced by the method of the present invention. Here, the organic compound 24 is firmly bonded to both the insulator 21 and the conductive portion 23 to improve the adhesion between them. Thus, in the composite member in which the organic compound 24 exists between the insulator 21 and the conductive portion 23, the amount of the organic compound 24 on the surface of the insulator 21 preferably satisfies the following conditions. That is, it is desirable that the amount of the organic compound 24 present without contacting the conductive portion 23 is smaller than the amount of the organic compound 24 present at the interface between the insulator 21 and the conductive portion 23. The hydrophilic ion exchange group contributes to the improvement of the adhesion between the conductive portion 23 and the insulator 21. However, when a hydrophilic group of an organic compound is present in addition to the portion where the conductive portion 23 is formed, metal migration is likely to occur between the adjacent conductive portions 23. In addition, the hygroscopicity is increased and the insulating properties are lowered.
[0055]
A multilayer wiring board can be produced using the composite member produced by the method of the present invention. First, a conductive part is formed by the method of the present invention over the planar direction and the thickness direction of a sheet-like insulator to manufacture a composite member. A multilayer wiring board produced by laminating a plurality of composite members obtained in this way will be described with reference to FIG.
[0056]
FIG. 3 is a schematic view showing an example of a multilayer wiring board using a composite member manufactured by the method of the present invention. As shown in FIG. 3, the multilayer wiring board 31 is configured by laminating a plurality of porous films made of an insulator 34 having conductive portions such as vias 32 and wirings 33. The via 32 and the wiring 33 are formed by filling a metal in the surface or inside of the fine hole of the porous film. A conductive portion 35 made of only a conductive material such as metal is formed on the end face of such a conductive portion.
[0057]
That is, in the multilayer wiring board 31 shown in FIG. 3, a layer 35 made of a conductor containing no insulator component exists on the outermost surface of the conductive portions 32 and 33 in each porous film. For this reason, the resistance of the conductive portion can be reduced. Particularly in a high frequency region, the impedance characteristics can be improved by the skin effect of these structures.
[0058]
The composite member produced by the method of the present invention can be used as a wiring board in a single layer without being laminated. An electronic package can be obtained by electrically connecting an electronic component on such a wiring board or a multilayer wiring board as described above.
[0059]
Since the conductive part having a fine pattern is formed with high precision on the wiring board in the electronic package thus configured, high-density mounting is possible. Specific examples of the wiring board or multilayer wiring board described above are suitable for multilayer wiring boards, interposers, 3D wiring, etc., which are indispensable for high-density mounting such as portable devices and micromachines, flip chip, and spherical semiconductor mounting. Multi-layer wiring, three-dimensional wiring, etc. that can be used in
[0060]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
[0061]
In the present invention, the insulator on which conductive portions such as wirings and vias are formed may be made of any insulator material, and specific examples thereof include resins and ceramics.
[0062]
Examples of the resin include glass epoxy resin, bismaleimide-triazine resin and PPE resin, which are conventionally used as insulators for printed wiring boards, and other polyethers such as polyolefins, acrylic polymers, and polyallyl ethers. And resins generally called engineering plastics, such as polyesters such as polyarylate, polyamide, and polyethersulfone.
[0063]
Examples of the ceramic include glass, alumina, and aluminum nitride.
[0064]
In particular, when the conductive portion is formed three-dimensionally in the present invention, that is, for example, when the conductive portion is formed not only in the planar direction but also in the thickness direction on the sheet-like insulator, a porous body made of an insulating material is used. By using it, an accurate conductive part can be easily formed.
[0065]
A porous body made of a resin can be easily produced by a method such as a wet method or a dry method.
[0066]
For example, when producing a porous resin sheet by a wet method, first, an inorganic fine powder and an organic solvent, which are pore forming agents, are added to a resin and kneaded to prepare a mixture. Subsequently, after forming this into a film, an inorganic fine powder and an organic solvent are extracted with a solvent. Then, it extends | stretches as needed.
[0067]
For example, when producing a porous resin sheet by a dry method, a mixture prepared in the same manner as in the wet method is extruded into a sheet. Next, after heat treatment as necessary, this is uniaxially or biaxially stretched.
[0068]
Even when the porous resin sheet is produced by any of these wet methods and dry methods, if necessary, the stretched resin sheet may be subjected to heat treatment for dimensional stability. In addition, a desired porous resin sheet can be easily produced by forming the resin sheet and then making it porous after forming the resin sheet without adding the above-described additives.
[0069]
Moreover, as a porous body made of ceramics, for example, alumina can be produced by anodizing aluminum in an electrolytic solution.
[0070]
In the manufacturing method of the composite member according to the present invention, when the conductive portion is three-dimensionally formed, that is, for example, when the conductive portion is formed not only in the planar direction but also in the thickness direction on the sheet-like insulator, The inside of the body is also exposed. At this time, in order to prevent exposure light from being scattered, the pore size of the porous body is preferably sufficiently small with respect to the exposure wavelength. However, if the pore diameter is too small, the photosensitive composition may be difficult to impregnate or exposure light may not be transmitted. Especially when wiring is formed, the filled metal needs to be well continuous in the pores, but if the pore diameter is too small, the metal may be in a fine particle state separated from each other in the pores. There is. In order to avoid such inconvenience, the pore diameter of the porous body is preferably 30 to 2000 nm, more preferably 50 to 1000 nm, and most preferably set in the range of 100 to 500 nm.
[0071]
Even when the pore diameter deviates from the above-mentioned range and is considerably larger than the exposure wavelength, a liquid having a refractive index close to or the same as that of the porous body or an amorphous solid having a low boiling point is filled in the pores to prevent scattering. For example, scattering during exposure can be prevented. However, if the pore diameter becomes too large, it will be difficult to sufficiently fill the pores with metal by plating or the like, and it will be difficult to reduce the width of the conductive portion to several tens of μm or less. Further, when a multilayer wiring board is manufactured, a short circuit between layers tends to occur. Taking these into consideration, it is desirable that the pore size of the porous body be set to 5 μm or less even when a liquid for preventing scattering is used during exposure.
[0072]
In addition, the porous body is a porous material having three-dimensionally continuous pores in order to produce a composite member having a pattern in the film thickness direction, in particular, a line-shaped part continuously connected in the two-dimensional direction. The body is desirable.
[0073]
Furthermore, it is preferable that the continuous pores existing in the porous body are regularly and uniformly formed in order to prevent scattering of exposure light. This is also effective for miniaturization of the conductive line.
[0074]
In addition, the continuous pores in the porous body need to be opened to the outside of the porous body, and it is desirable that the number of closed cells having no open end is as small as possible. Further, in order to improve the electrical conductivity of the wiring, it is desirable that the porosity is high in a range where the mechanical strength of the porous body is maintained. Specifically, the porosity is preferably 40% or more, and more preferably 60% or more.
[0075]
The porous body having three-dimensionally continuous pores as described above can be produced by various methods. For example, beads laminated, green sheets, porous bodies prepared using a laminated structure of beads as a template, porous bodies formed using a laminate of bubbles or liquid bubbles as a template, silica obtained by supercritical drying of silica sol A porous body made by removing an appropriate phase from a phase-separated structure such as an airgel, a porous body formed from a microphase-separated structure of a polymer, a co-continuous structure generated by spinodal decomposition of a mixture of polymer or silica, A porous material produced by an emulsion templating method or the like; H. Cumpston et al. (Nature, vol. 398, 51, 1999) and M.C. A porous body produced using a three-dimensional stereolithography as reported by Campbell et al. (Nature, vol. 404, 53, 2000) can be used.
[0076]
Examples of the porous body prepared by filling the voids of the laminated structure of beads with resin or metal oxide gel and then curing the beads and then removing the beads are, for example, Y. A. Vlasov et al. (Adv. Mater. 11, No. 2, 165, 1999) and S. A. Johnson et al. (Science Vol. 283,963, 1999) have reported.
[0077]
In addition, since a porous body having a regular and high porosity can be produced at low cost, a porous body such as a polymer formed using a laminate of bubbles or liquid bubbles as a template is preferable. For example, S. H. Park et al. (Adv. Mater. 10, No. 13, 1045, 1998) and S. A. Jenekhe et al. (Science Vol. 283, 372, 1999).
[0078]
A silica airgel having continuous pores with a porosity of 90% or more and a pore diameter of about 100 nm or less obtained by supercritical drying of silica sol is preferable because of its high porosity and excellent transparency.
[0079]
A porous body formed from a phase-separated structure represented by a polymer or the like is most preferable because the pore diameter can be easily controlled and can be produced at low cost.
[0080]
The porous body produced from the microphase separation structure can easily control the state of the inner surface of the pores. That is, when one phase of the microphase separation structure is removed, it is not completely removed but partially remains on the inner surface of the pore. Thereby, the surface state of the inner surface of the hole can be changed. For example, in the case where an ABC type triblock copolymer having a sufficiently large molecular weight of A and C as compared with B is used to remove the C phase and form a porous body composed of the A phase. The B phase is disposed on the inner surface of the pores. Therefore, the properties of the inner surface of the pores can be changed without greatly changing the properties of the entire porous body. Therefore, the adhesiveness between the impregnating resin and the porous body can be improved. In this case, since the B phase is completely bonded to the A phase by chemical bonding, it is superior to a normal surface adsorption type surface treatment agent.
[0081]
The phase separation structure exhibited by the polymer is not particularly limited, and examples thereof include a phase separation structure formed by spinodal decomposition exhibited by the polymer blend, and a micro phase separation structure exhibited by the block copolymer and graft copolymer. The microphase-separated structure exhibited by the block copolymer or graft copolymer is the best because the pore size can be easily controlled and a regular porous structure can be formed.
[0082]
Among the microphase-separated structures, the co-continuous structure is a phase-separated structure composed of two phases that are three-dimensionally continuous, and is porous with three-dimensionally continuous pores by selectively removing one phase. It is preferable because a solid body can be formed. Of these co-continuous structures, an OBDD structure or a Gyroid structure is preferable. Moreover, it is preferable that the weight fraction in the copolymer of the polymer chain which comprises a porous body is set to the range of 30 to 70%.
[0083]
The pore diameter of the obtained porous body can be controlled by the molecular weight of the polymer chain constituting the phase to be removed from the phase separation structure. In addition, the pore diameter of the porous body can be controlled by mixing such a homopolymer having good compatibility with the polymer chain. By using a method of mixing homopolymers, a porous body having a pore diameter of 100 nm or more that is difficult to form with only a copolymer can be produced relatively easily. However, when the amount of the homopolymer mixed is too large, the regularity of the phase separation structure is lowered. Therefore, the mixing amount of the homopolymer is preferably 10% or less by weight with respect to the copolymer.
[0084]
A three-dimensional porous body made of a co-continuous structure has continuous pores having correlation distances of 2√3 times and 4 times the radius of rotation of the cross section of the microdomain constituting the three-dimensional porous structure. . This can be confirmed by a small angle X-ray scattering method or a light scattering method. Note that having a correlation distance means that the existence probability of a surrounding domain with respect to a distance r from the center of a predetermined domain (at the point of the distance r, the point forms a domain instead of a hole) This means that there is a distance at which the existence probability is maximum when the probability of being a filling region is measured.
[0085]
The method for selectively removing one phase from the microphase separation structure is not particularly limited, and various methods can be employed. For example, there is a method of chemically cutting two bonding sites using a telechelic polymer and then etching one polymer chain. Further, a method of selectively decomposing and removing one phase by ozone oxidation, or a method of removing it by oxygen plasma or photolysis may be used. Furthermore, it is also possible to selectively decompose and remove one phase by irradiating energy rays such as β rays.
[0086]
The polymer material for producing the porous body from the phase separation structure is not particularly limited, and any material can be used. Examples thereof include polyolefins, acrylic polymers, polyethers such as polyallyl ethers, polyesters such as polyarylates, polyamides, polyimides, polyethers, and polyether sulfones.
[0087]
When a porous body is used as the substrate for wiring formation, a heat resistant polymer such as polyimide, polyamide, polyallyl ether, polyarylate, and polyethersulfone is particularly preferable. In addition, a polymer having a double bond in a side chain or main chain obtained by polymerizing a conjugated diene monomer such as 1,2-bond type or 1,4-bond type polybutadiene may be used.
[0088]
A porous body made of polyimide can be produced, for example, by the following method. First, polyamic acid, which is a polyimide precursor, and a thermally decomposable polymer such as polyethylene oxide, polypropylene oxide, and polymethyl methacrylate are mixed. At this time, phase separation may be performed as a block copolymer or a graft copolymer. Next, heat treatment is performed to convert the polyamic acid into polyimide, and at the same time, the thermally decomposable polymer is volatilized and removed.
[0089]
From the viewpoint of the regularity of the structure, it is preferable to use a block copolymer or a graft copolymer. However, when pores of 100 nm or more are formed, the molecular weight of the thermally decomposable polymer chain is about 100,000 or more, so that it is relatively difficult to synthesize a block copolymer. Therefore, for example, it is preferable to introduce a bonding group at the end of the thermally decomposable polymer chain and then synthesize a graft copolymer. A homopolymer may be added to the block copolymer or graft copolymer to adjust the pore size of the porous body. However, when the amount of the homopolymer mixed is too large, the regularity of the phase separation structure is lowered. Therefore, the mixing amount of the homopolymer is preferably 10% or less by weight with respect to the copolymer. At this time, the addition of a crosslinkable plasticizer such as bismaleimides promotes the formation of a microphase separation structure and improves the heat resistance and mechanical strength of the porous body.
[0090]
In addition, 1,2-bonded polybutadiene, that is, poly (vinylethylene) is three-dimensionally cross-linked by the addition of a radical generator or a cross-linking agent, resulting in a cured polymer having excellent heat resistance, electrical properties, moisture resistance, and mechanical properties. . In addition, since poly (vinylethylene) can be polymerized by living, it is possible to produce a block copolymer having a high molecular weight and a uniform molecular weight distribution. Therefore, when a block copolymer of poly (vinylethylene) and polymethacrylic acid ester that can be decomposed and removed by β-rays is used, a regular porous body having a desired pore size composed of a crosslinked poly (vinylethylene) is formed. can do. Also in this case, the pore diameter of the porous body can be controlled by adding a homopolymer.
[0091]
As the radical generator, organic peroxides such as general dicumyl peroxide and azonitriles such as azobisisobutyronitrile can be used. Among them, generation of polyfunctional radicals such as 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane and 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone The agent is preferable because it also acts as a crosslinking agent.
[0092]
The amount of radical generator added is preferably 0.1 to 20% by weight, more preferably 1 to 5% by weight, based on the polymer chain to be crosslinked. If the radical generator is too small, the crosslinking density is small, and if it is too large, the crosslinked product may become porous or the microphase separation structure may be disturbed.
[0093]
Examples of the crosslinking agent include bis (4-maleimidophenyl) methane, bis (4-maleimidophenyl) ether, 2,2′-bis [4- (paraaminophenoxy) phenyl] propane, and 2,2′-bis [4- Bismaleimides such as (paraaminophenoxy) phenyl] hexafluoropropane are preferred. The addition amount is preferably 0.1 to 20% by weight, more preferably 1 to 5% by weight, based on the polymer chain to be crosslinked. If it is too small, the crosslinking density is small, and if it is too large, the microphase separation structure may be disturbed.
[0094]
If the crosslinking reaction proceeds before the microphase separation structure is formed, the formation of the microphase separation structure is inhibited. Therefore, it is preferable that the crosslinking reaction is started after the microphase separation structure is sufficiently formed. The formation of the microphase-separated structure proceeds above the glass transition temperature of each polymer chain forming the copolymer. Therefore, it is preferable that the glass transition temperature of the polymer chain is sufficiently lower than the radical generation temperature of the radical generator.
[0095]
Examples of the most preferable composition include diblock copolymer or triblock copolymer of poly (vinylethylene) chain, poly (methyl methacrylate) chain, and poly α-methylstyrene chain, and 2,2- Bis (4,4-di-t-butylperoxycyclohexyl) propane or 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone in weight percent with respect to the poly (vinylethylene) chain 1 to 5% added. In particular, it is best to use 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone as the radical generator.
[0096]
First, after heating at a temperature equal to or higher than the glass transition temperature of each polymer chain to form a microphase separation structure, the temperature may be gradually raised and heated above the thermal decomposition temperature of the radical generator to be crosslinked and cured. However, if the temperature is too high at this time, the order-disorder transition temperature may be passed before sufficient crosslinking is performed, and there is a possibility that the material will melt and become uniform. In that respect, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone is advantageous because it generates radicals by ultraviolet irradiation without thermal decomposition.
[0097]
A diblock copolymer or triblock copolymer of poly (vinylethylene) chain and polymethyl methacrylate chain has a sufficiently high microphase separation structure because the glass transition temperature of polymethyl methacrylate is relatively high at around 105 ° C. Cross-linking reaction is likely to occur before However, since polymethyl methacrylate is easily vaporized by β-ray irradiation, it can be made porous by solvent washing or heat treatment at a relatively low temperature. Since the glass transition temperature of polymethylmethacrylate is close to the crosslinking initiation temperature, a microphase separation structure may be formed by slowly evaporating the solvent from the solution to form a cast film. In this case, if the solvent is evaporated at a temperature sufficiently lower than the thermal decomposition temperature of the radical generator, the formation of the microphase molecular structure is not hindered by crosslinking. However, the production of such a cast film takes a relatively long time and the productivity is not high. The same can be said when poly α-methylstyrene is used instead of polymethyl methacrylate.
[0098]
Instead of polymethyl methacrylate and poly α-methyl styrene, polymethacrylates substituted with alkyl groups having 3 to 6 carbon atoms, and substituted poly α-methyl styrenes with phenyl groups substituted with similar alkyl groups Since the glass transition temperature is lowered, the above-described problems can be avoided. That is, the microphase separation structure can be rapidly formed by heat-treating the copolymer film (or molded product) at a temperature equal to or higher than the glass transition temperature. For example, poly n-propyl methacrylate and poly n-butyl methacrylate have low glass transition temperatures of 35 ° C. and 25 ° C., respectively. Similarly, poly α-methylstyrene butylated at the 4-position shows a low glass transition temperature. When the number of simple primes of the alkyl group is more than 6, although a lower glass transition temperature is exhibited, at the same time, a crosslinking reaction is easily caused by β-ray irradiation. Poly n-propyl methacrylate, poly n-butyl methacrylate, and poly s-butyl methacrylate are exemplified as those having both a low glass transition temperature and an effect of promoting decomposition by β-ray irradiation, particularly poly n-butyl methacrylate, poly Most preferred is s-butyl methacrylate.
[0099]
When an alkyl group is branched like a 2-ethylhexyl group, it is excellent in that the effect of promoting decomposition by β-ray irradiation is hardly suppressed even when the number of carbon atoms increases. However, it is inferior to the above poly n-butyl methacrylate and poly s-butyl methacrylate in terms of practicality from the viewpoint of easy availability of monomers.
[0100]
Furthermore, polyisobutylene, polypropylene, or the like can be used as a polymer chain that achieves both a low glass transition temperature and a decomposition promoting effect by β-ray irradiation.
[0101]
Although there is no restriction | limiting in particular as an irradiation amount of (beta) ray, It is preferable to set to the range of 100Gy-10MGy, Furthermore, it is preferable to set to 1KGy-1MGy, More desirably, 10KGy-200KGy. If the irradiation amount is too small, the degradable polymer chain will not be sufficiently decomposed. Conversely, if the irradiation amount is too large, the degradation product of the degradable polymer chain may be cured by three-dimensional crosslinking, etc. This is because the chain may be broken down. The acceleration voltage varies depending on the thickness of the copolymer molded body, that is, the penetration length of β-rays into the molded body. For example, in the case of a thin film of about several tens of μm or less, about 20 kV to 2 MV is preferable. In the case of a film having a thickness of 100 μm or more, a bulk molded body, etc., about 500 kV to 10 MV is preferable. When the molded body contains a metal molded body or the like, the accelerating voltage can be increased.
[0102]
When the β-ray irradiation is performed, the 1,2-bonded polybutadiene chain is cross-linked, so that the amount of the radical generator may be reduced or may not be added at all. In this case, it is not always necessary to reduce the glass transition temperature. Poly (vinylethylene) cross-linked products have been tried to be used for wiring boards because of their excellent properties, but there is a problem that the adhesiveness of the wiring to copper is not good.
[0103]
However, in the composite member of the present invention, such a problem is avoided because wiring and vias such as copper are integrated with the porous body.
[0104]
Next, the manufacturing method of the composite member which concerns on this invention is demonstrated for each process with reference to FIG.
[0105]
<Step 1>
Step (1): First, a photosensitive composition layer 2 containing a compound that generates or disappears an ion exchange group by exposure is formed on an insulator 1 as shown in FIG. In addition, in FIG. 1, the example using the photosensitive composition containing the compound which produces | generates an ion exchange group by exposure is shown.
[0106]
When the conductive portion is formed in the planar direction and the thickness direction of the insulator 1, the conductive portion can be easily and accurately formed by using the insulator 1 as a porous body.
[0107]
The photosensitive composition used in the manufacturing method of the composite member which concerns on this invention contains the compound which produces | generates an ion exchange group by light irradiation, or the compound which lose | disappears an ion exchange group by light irradiation. However, the compound which produces | generates an ion exchange group by exposure may produce an ion exchange group by the multistep reaction triggered by the chemical reaction by exposure. Such a compound first generates a chemical reaction by exposure to generate a precursor of some ion-exchange group, and this precursor further generates a chemical reaction to generate an ion-exchange group.
[0108]
As a compound which produces | generates an ion exchange group by exposure, the compound which generate | occur | produces the functional group which has ion exchange ability by exposure (i) is mentioned.
[0109]
In addition, as a compound that loses an ion-exchange group by exposure, (ii) a functional group having a functional group having ion exchange ability before exposure and having a hydrophobic property that hardly dissolves or swells in water after exposure. And compounds that generate groups.
[0110]
Examples of the functional group having ion exchange properties in the above (i) and (ii) include hydrophilic functional groups such as a —COOX group, —SO_ThreeX group, -PO_ThreeX₂A group (X is selected from a hydrogen atom, an alkali metal or alkaline earth metal, a typical metal belonging to Groups 1 and 2 of the periodic table, and an ammonium group) and -NH₂OH etc. are mentioned.
[0111]
In particular, in (i) and (ii), as the functional group having ion exchange ability, a functional group having a cation exchange ability is desirable because it can easily exchange ions with metal ions. Such cation exchange groups include -COOX group, -SO_ThreeX group or -PO_ThreeX₂An acidic group such as a group (where X is a hydrogen atom, an alkali metal or an alkaline earth metal, a typical metal belonging to groups I and II of the periodic table, or an ammonium group) is particularly preferable. If these are contained, after the metal ion exchange, which is a subsequent step, stable adsorption with the reduced metal or metal fine particles can be obtained.
[0112]
Of the above-described cation exchange groups, those having a pKa value of 7.2 or less determined from ion dissociation properties in water are more preferable. When the pKa value exceeds 7.2, the number of bonds per unit area is small in the subsequent step of bonding metal ions or metals (step (3)). Therefore, there is a possibility that desired conductive properties may not be obtained in the conductive portions formed thereafter.
[0113]
In the first and second embodiments of the present invention, a compound that generates or disappears an ion-exchange group when irradiated with light having a wavelength of 280 nm or longer is used as the compound that generates or disappears an ion-exchange group when irradiated with light.
[0114]
Specific examples of compounds that generate ion-exchangeable groups upon irradiation with light having a wavelength of 280 nm or more include naphthoquinone diazide derivatives, o-nitrobenzyl ester derivatives, p-nitrobenzyl ester sulfonate derivatives, and naphthyl or phthalimide trifluorosulfonates. Derivatives and the like.
[0115]
In particular, when a naphthoquinone diazide derivative is used, sufficiently fine patterning is possible in a short time with light having a wavelength of 280 nm or more with low energy. Further, the naphthoquinonediazide derivative causes light bleaching during exposure and becomes transparent in a wavelength region of about 300 nm or more. Therefore, it is possible to expose deeply in the film thickness direction, which is very suitable for exposure through the film thickness direction of the porous sheet.
[0116]
For example, the exposure reaction when naphthoquinonediazide is used as a compound that generates an ion-exchange group is shown in the following chemical formula (1).
[0117]
[Chemical 1]

[0118]
As shown in the chemical formula (1), the naphthoquinone diazide formed on the insulator generates —COOH groups by exposure to water and the presence of water in the next step.
[0119]
In addition, the photosensitive composition layer is exposed to a metal ion-containing aqueous solution or an alkali or acidic aqueous solution in a subsequent step. Since the photosensitive composition ionized by the ion exchange reaction is easily dissolved in the aqueous solution, it is more easily peeled off than the insulator as the base material. Therefore, in order to prevent peeling from the substrate, it is preferable that a group that generates an ion-exchange group is supported or bonded to a polymer compound such as a polymer, and the group that generates an ion-exchange group is shared by the polymer compound. Most preferably it is chemically bonded by a bond.
[0120]
In this case, the molecular weight of the polymer or polymer compound is preferably 1000 or more, and more preferably 2000 or more. In the case of a polymer having a molecular weight of 1000 or less, applicability to an insulator as a base material is deteriorated, and uniform application may be difficult. Moreover, it becomes easy to produce deterioration by exposure to the alkali or acidic aqueous solution in a plating process.
[0121]
To simply prevent peeling from the substrate, a low molecular monomolecular film having both a group capable of chemically bonding to the substrate and an ion-exchange group may be formed on the surface of the substrate. For example, JP-A-6-202343 discloses a method for forming a monomolecular film of a silane coupling agent having a naphthoquinonediazide group that is exposed to an ion-exchange group on the surface of a glass substrate.
[0122]
However, in the case of a monomolecular layer, the inventors have found that the adsorption amount of the plating nucleus is small and sufficient plating cannot be performed. By using the polymeric photosensitive composition as described above, the substrate surface can be coated with a certain thickness. Therefore, since a sufficient amount of plating nuclei are adsorbed, good plating can be performed.
[0123]
From such a viewpoint, in the present invention, the compound that generates an ion-exchange group by irradiation with light having a wavelength of 280 nm or more includes 1,2-naphthoquinonediazidosulfonyl-substituted phenol resin derivative, 1,2-naphthoquinonediazidesulfonyl-substituted polystyrene derivative. Etc. are suitable.
[0124]
Another example of a compound that generates an ion-exchange group by irradiation with light having a wavelength of 280 nm or longer is a compound in which a protective group is introduced into an ion-exchange group such as a carboxyl group contained in the polymer structure. It is done. When this compound is used, a photoacid generator that generates an acid by irradiation with light having a wavelength of 280 nm or more is added to the photosensitive composition. An acid is generated from the photoacid generator by subsequent exposure, and the protecting group is decomposed by the generated acid to generate an ion-exchange group. Examples of the polymer include phenolic resins such as phenol novolac resin, xylenol novolak resin, vinylphenol resin, and cresol novolac resin, and carboxyl group-containing polymers such as polyamic acid, polyacrylic acid, and polymethacrylic acid.
[0125]
Examples of the protecting group for the phenolic resin include tert-butyl ester derivative substituents such as a tert-butoxycarbonylmethyl group and a tert-butoxycarbonylethyl group.
[0126]
On the other hand, in polyamic acid, polyacrylic acid, etc., as a protective group for the carboxyl group in the structure, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, tert-butyl group Group, benzylalkoxy group, 2-acetoxyethyl group, 2-methoxyethyl group, methoxymethyl group, 2-ethoxyethyl group, 3-methoxy-1-propyl group and other alkoxy groups, trimethylsilyl group, triethylsilyl group, triphenyl Examples include alkylsilyl groups such as silyl groups.
[0127]
Moreover, o-nitrobenzyl ester group is mentioned as a protective group which produces | generates ion exchange groups, such as carboxylic acid, only by light irradiation, without using a photo-acid generator.
[0128]
Suitable photoacid generators for the deprotection of such protecting groups include CF._ThreeSO_Three ^-, P-CH_ThreePhSO_Three ^-, P-NO₂PhSO_Three ^-And the like, and salts such as onium salts, diazonium salts, phosphonium salts, iodonium salts, etc., organic halogen compounds, and orthoquinone-diazide sulfonic acid esters.
[0129]
By using a composition that generates an ion-exchange group by such chemical amplification, high sensitivity to light can be achieved. The use of these compositions becomes effective as the pattern becomes finer, particularly when light transmittance in the film thickness direction is required, such as the formation of a three-dimensional pattern on a porous substrate. come.
[0130]
On the other hand, irradiation with light having a wavelength of 280 nm or more eliminates the ion-exchangeable group, that is, generates a functional group that has an ion-exchange ability before exposure and has a hydrophobic property that hardly dissolves or swells in water after exposure. As the compound, the following compounds can be used. That is, -COOX group which is an ion-exchange group, -SO_ThreeX group or -PO_ThreeX₂Having an acidic group such as a group (where X is a hydrogen atom, an alkali metal or alkaline earth metal and a typical metal belonging to the periodic table groups I and II, an ammonium group) in the composition skeleton, It is a compound that loses ion exchange capacity.
[0131]
As a compound that generates a functional group that has an ion exchange capacity before exposure and has a hydrophobic property that hardly dissolves or swells in water after exposure, a decarboxylation reaction is performed by light irradiation in the presence of a basic substance. Examples thereof include a carboxyl group-containing compound that can be generated and decomposed. In this case, in addition to the aforementioned carboxyl group-containing compound, a photoacid generator and a basic compound are added to the photosensitive composition. In such a composition, the acid generated by exposure neutralizes the basic compound involved in the decarboxylation reaction. For this reason, the ion exchange ability of the exposed portion disappears due to a mechanism in which the carboxyl group remains in the exposed portion and the decarboxylation reaction proceeds in the unexposed portion.
[0132]
As the carboxyl group-containing compound that can be decomposed by causing a decarboxylation reaction, any compound can be selected, but a compound in which the decarboxylation reaction easily proceeds with a basic compound is preferable. Examples of such a compound include those having an electron-withdrawing group or an unsaturated bond at the α-position or β-position of the carboxyl group. Here, the electron withdrawing group is preferably a carboxyl group, a cyano group, a nitro group, an aryl group, a carbonyl group, or a halogen.
[0133]
Specific examples of such a carboxyl group-containing compound include α-cyanocarboxylic acid derivatives, α-nitrocarboxylic acid derivatives, α-phenylcarboxylic acid derivatives, β, γ-olefin carboxylic acids and the like.
[0134]
Examples of the photoacid generator to be added include the photoacid generators described above, and those that generate an acid at a wavelength of 280 nm or more are particularly preferable.
[0135]
As the basic compound to be added, any compound can be used as long as it is neutralized by the acid released from the photoacid generator and acts as a catalyst for the decarboxylation reaction of the carboxyl group-containing compound. The basic compound may be either an organic compound or an inorganic compound, but a nitrogen-containing compound is preferred. Specific examples include ammonia, primary amines, secondary amines, and tertiary amines. The content of these basic compounds is 0.1 to 30% by weight, preferably 0.5 to 15% by weight in the photosensitive composition. When the amount is less than 0.1% by weight, the decarboxylation reaction does not proceed sufficiently. When the amount exceeds 30% by weight, the carboxyl group-containing compound remaining in the unexposed area may be deteriorated.
[0136]
In addition, since the photosensitive composition layer is exposed to a metal ion-containing aqueous solution or an alkali or acidic aqueous solution in a later step, a group that causes an ion-exchangeable group disappearance reaction is prevented from dissolving in the polymer or polymer compound. Those supported or bonded to each other are preferred. As already explained, it is most preferable that the group causing the ion exchange group disappearance reaction is chemically bonded to a polymer or a polymer compound having a molecular weight of 1000 or more.
[0137]
In the third aspect of the present invention, at least one selected from the group consisting of an onium salt derivative, a sulfonium ester derivative, a carboxylic acid derivative, and a naphthoquinonediazide derivative is used as the compound that generates an ion exchange group upon exposure. Derivatives are used.
[0138]
As onium salt derivatives, CF_ThreeSO_Three ^-, P-CH_ThreePhSO_Three ^-, P-NO₂PhSO_Three ^-And the like as a counter anion, and the like. More specifically, trifluoroacetate derivatives such as diphenyliodonium, 4,4′-dibutylphenyliodonium, triphenylsulfonium, naphthylsulfonium, trifluoromethanesulfonate derivatives, and toluenesulfonic acid derivatives are exemplified.
[0139]
Examples of the sulfonium ester derivatives include benzoin tosylate derivatives, o-nitrobenzyl tosylate derivatives, p-nitrobenzyl ester derivatives of arylsulfonic acid, p-nitrobenzyl-9,10-diethoxyanthracene-2- Examples thereof include sulfonate derivatives.
[0140]
Examples of the carboxylic acid derivative include the above-described phenol resin, a hydroxyl group of polyamic acid or polyacrylic acid, or a polymer in which a carboxyl group is protected. Examples of the polymer include a phenol novolak resin derivative, a xylenol novolac resin derivative, a vinyl. Examples thereof include phenolic resin derivatives such as phenol resin derivatives and cresol novolak resin derivatives, and carboxyl group-containing polymer derivatives such as polyamic acid derivatives, polyacrylic acid derivatives, and polymethacrylic acid derivatives.
[0141]
Examples of the protecting group for the phenolic resin derivative include tert-butyl ester derivative substituents such as a tert-butoxycarbonylmethyl group and a tert-butoxycarbonylethyl group.
[0142]
On the other hand, in polyamic acid, polyacrylic acid, etc., a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group, a tert-butyl group as a protecting group for the carboxyl group in the structure. , Alkoxy groups such as benzylalkoxy group, 2-acetoxyethyl group, 2-methoxyethyl group, methoxymethyl group, 2-ethoxyethyl group, 3-methoxy-1-propyl group, trimethylsilyl group, triethylsilyl group, triphenylsilyl And alkylsilyl groups such as groups. These generate carboxyl groups by acting with a suitable photoacid generator.
[0143]
Examples of naphthoquinone diazide derivatives include naphthoquinone diazide-4-sulfonic acid derivatives, naphthoquinone diazide-5-sulfonic acid derivatives, naphthoquinone diazide sulfonyl halide derivatives, and esterified products thereof.
[0144]
In addition, since the photosensitive composition layer containing a compound as described above is exposed to a metal ion-containing aqueous solution or an alkali or acidic aqueous solution in a later step, an ion-exchange group generation reaction is performed so as not to be dissolved therein. A group in which the generated group is supported or bonded to a polymer or a polymer compound is preferable. As already explained, it is most preferable that the group causing the ion exchange group disappearance reaction is chemically bonded to a polymer or a polymer compound having a molecular weight of 1000 or more.
[0145]
From such a viewpoint, 1,2-naphthoquinonediazidosulfonyl-substituted phenol resin derivative, 1,2-naphthoquinonediazidesulfonyl-substituted polystyrene derivative, etc., or ion exchange by deprotection using a photoacid generator of a polymer functional group protecting group Sex group generation is preferred.
[0146]
In the fourth aspect of the present invention, a functional group having a hydrophobic property of disappearing an ion-exchangeable group by exposure, that is, having an ion-exchange ability before exposure but hardly dissolved or swollen in water after exposure. A photosensitive composition containing the generated compound is used. Such a compound is a compound having an ion exchange group in its skeleton and extinguishing the ion exchange ability by light irradiation. Examples of the ion exchange group include -COOX group, -SO_ThreeX group or -PO_ThreeX₂And an acidic group such as a group (where X is a hydrogen atom, an alkali metal or alkaline earth metal, a typical metal belonging to Periodic Tables I and II, an ammonium group).
[0147]
Carboxyl group-containing compounds that can be decomposed by a decarboxylation reaction as compounds that generate hydrophobic functional groups that have ion-exchange ability before exposure and are difficult to dissolve or swell in water after exposure Is mentioned. In this case, in addition to the above-mentioned carboxyl group-containing compound, it is added to the photoacid generator, the basic compound and the photosensitive composition. In such a composition, the acid generated by exposure neutralizes the basic compound involved in the decarboxylation reaction. For this reason, the ion exchange ability of the exposed portion disappears due to a mechanism in which the carboxyl group remains in the exposed portion and the decarboxylation reaction proceeds in the unexposed portion.
[0148]
As the carboxyl group-containing compound that can be decomposed by causing a decarboxylation reaction, any compound can be selected, but a compound in which the decarboxylation reaction easily proceeds with a basic compound is preferable. Examples of such a compound include those having an electron-withdrawing group or an unsaturated bond at the α-position or β-position of the carboxyl group. Here, the electron-withdrawing group is preferably a carboxyl group, a cyano group, a nitro group, an aryl group, a carbonyl group, or a halogen.
[0149]
Specific examples of such a carboxyl group-containing compound include α-cyanocarboxylic acid derivatives, α-nitrocarboxylic acid derivatives, α-phenylcarboxylic acid derivatives, β, γ-olefin carboxylic acids, and the like.
[0150]
Examples of the photoacid generator to be added include the above-mentioned photoacid generators, and those that generate an acid at a wavelength of 280 nm or more are particularly preferable.
[0151]
As the basic compound to be added, any compound can be used as long as it is neutralized by the acid released from the photoacid generator and acts as a catalyst for the decarboxylation reaction of the carboxyl group-containing compound. The basic compound may be either an organic compound or an inorganic compound, but a nitrogen-containing compound is preferred. Specific examples include ammonia, primary amines, secondary amines, and tertiary amines. The content of these basic compounds is 0.1 to 30% by weight, preferably 0.5 to 15% by weight in the photosensitive composition. When the amount is less than 0.1% by weight, the decarboxylation reaction does not proceed sufficiently. When the amount exceeds 30% by weight, the carboxyl group-containing compound remaining in the unexposed area may be deteriorated.
[0152]
In addition, since the photosensitive composition layer is exposed to a metal ion-containing aqueous solution or an alkali or acidic aqueous solution in a later step, a group that causes an ion-exchangeable group disappearance reaction is prevented from being dissolved in the polymer or the polymer. Those supported or bonded to molecular compounds are preferred. As already explained, it is most preferable that the group causing the ion exchange group disappearance reaction is chemically bonded to a polymer or a polymer compound having a molecular weight of 1000 or more.
[0153]
As described above, according to the method of the present invention, first, by performing pattern exposure, ion exchange groups are selectively arranged in the exposed or unexposed area of the photosensitive composition layer. A region having such an ion exchange group is hydrophilic, but a region not including the ion exchange group is likely to be hydrophobic in many cases. However, in this invention, it is preferable that the area | region where the ion exchange group of a photosensitive composition layer does not exist is also hydrophilic and has the wettability with respect to water. When the hydrophobicity of the region where no ion-exchange group is present is too strong, in the plating step of <Step (5)> described later, the contact between the plating solution and the substrate becomes insufficient, and bubbles are formed on the substrate. It becomes easy. When bubbles are attached, the portion remains without being plated, so that a good metal pattern cannot be formed. In particular, when a porous body is used as the substrate, the plating solution is less likely to penetrate into the porous body. For this reason, when the hydrophobicity of the area | region which does not have an ion exchange group is too strong, it becomes difficult to plate inside a porous body.
[0154]
JP-A-6-202343 discloses a method of forming a metal pattern by forming a pattern comprising a hydrophilic region and a hydrophobic region and selectively plating the hydrophilic region. . At this time, in order to improve the selectivity of plating, the hydrophobic region is selectively fluorinated to increase the hydrophobicity of the region. By fluorination, the difference in wettability of the hydrophilic region and the hydrophobic region with respect to water increases. Thereby, the plating solution is selectively brought into contact with the hydrophilic region to enhance the selectivity of plating.
[0155]
However, for the reasons described above, in such a method, bubbles are likely to adhere to the hydrophobic region, so that satisfactory plating cannot be performed. Furthermore, since it is difficult for the plating solution to penetrate into the porous body, it is extremely difficult to plate the inside of the porous body.
[0156]
On the other hand, in the method of the present invention, it is not necessary to form a hydrophilic region and a hydrophobic region. Rather, by making all the surfaces of the insulator as the base material hydrophilic, the base material and the plating solution can be brought into sufficient contact and good plating can be performed.
[0157]
The wettability with water can be easily measured by a contact angle when a water droplet is dropped on a flat surface. In the present invention, the contact angle is preferably 60 ° or less, more preferably 40 ° or less, even in a region where no ion-exchange group is present.
[0158]
The photosensitive composition used in the production method of the present invention can contain additives depending on the purpose in addition to the compound that generates an ion-exchange group by exposure.
[0159]
For example, you may mix | blend the photosensitizer for improving resolution, film thickness permeability, etc. The photosensitizer is not particularly limited as long as it can photosensitize a compound that generates an ion-exchange group by exposure, and is appropriately selected according to the type of compound used, the light source, and the like.
[0160]
Specific examples of the photosensitizer include aromatic hydrocarbons and derivatives thereof, benzophenone and derivatives thereof, o-benzoylbenzoate and derivatives thereof, acetophenone and derivatives thereof, benzoin and benzoin ethers and derivatives thereof, xanthone and derivatives thereof. Thioxanthone and derivatives thereof, disulfide compounds, quinone compounds, halogenated hydrocarbon-containing compounds and amines, eosin B (CI No. 45400), eosin J (CI No. 45380), cyanocin (C I. No. 45410), Bengalrose, erythrosine (C.I. No. 45430), 2,3,7-trihydroxy-9-phenylxanthen-6-one, xanthene dyes such as rhodamine 6G, thionine (C I. No. 2000), Azure A (C.I.No. 52005), thiazine dyes such as Azure C (C.I.No. 52002), pyronin B (C.I.No. 45005), pyronin GY (C.I. No. 45005) and coumarin dyes such as 3-acetylcoumarin and 3-acetyl-7-diethylaminocoumarin.
[0161]
The blending ratio of such a photosensitizer is usually 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the compound that generates or disappears an ion exchange group upon exposure.
[0162]
Moreover, when the above-mentioned naphthoquinone diazide derivative is used as the compound that generates an ion-exchange group by exposure, it is preferable to add a carbodiimide derivative or an amine derivative as a crosslinking agent. The photosensitive composition can be cured by heat treatment after the conductive portion is formed, and heat resistance can be imparted to the resulting insulator.
[0163]
The blending ratio of such a crosslinking agent is appropriately determined from the equivalent amounts of functional groups that react with each other.
[0164]
As the photosensitive composition used in the method for producing a composite member of the present invention, a photosensitive composition containing a naphthoquinone diazide derivative and a polycarbodiimide derivative is particularly preferable. When such a photosensitive composition is used, the polycarbodiimide derivative and the ion exchange group generated from the naphthoquinonediazide derivative are cross-linked with each other by performing a heat treatment after forming the conductive portion. Thereby, the contact property between the conductive portion and the insulator is improved. In this way, it is possible to obtain a composite member having high heat resistance and a conductive portion having a fine pattern.
[0165]
Further, in the photosensitive composition as described above, a hydrophilic ion-exchange group is selectively generated in the exposed portion, so that a difference in solubility occurs between the exposed portion and the unexposed portion of the photosensitive composition layer. By utilizing this difference in solubility, a pattern of the photosensitive composition can be easily formed.
[0166]
In addition, such a photosensitive composition is an optical color used for an interlayer insulating film for a build-up substrate, a color liquid crystal display device, an electroluminescence display, a color fluorescent display device, a plasma display panel, an OA sensor, a solid-state image sensor, and the like. It can use for uses, such as a light-shielding photosensitive resin composition suitable for manufacture of a filter. Since this photosensitive composition has characteristics such as chemical resistance, water resistance, heat resistance, and high adhesion to a substrate, it is a useful photosensitive composition.
[0167]
As the naphthoquinonediazide derivative contained in the photosensitive composition described above, 1,2-naphthoquinonediazidesulfonyl-substituted phenol resin, 1,2-naphthoquinonediazidesulfonyl-substituted polystyrene resin, and the like are particularly preferable. When these are contained, the film formability is good and a thin film can be formed. In particular, the 1,2-naphthoquinonediazide sulfonyl-substituted phenolic resin is most excellent in heat resistance because the phenolic hydroxyl group of the phenolic resin crosslinks and cures with the polycarbodiimide derivative.
[0168]
Moreover, as a polycarbodiimide derivative contained in the photosensitive composition mentioned above, the compound represented by following General formula (1) is preferable.
[0169]
[Chemical formula 2]

(In the formula, R1 represents an organic group having 1 to 20 carbon atoms represented by a methylene group, an ethylene group, a propyl group, an isoprene group, a butadiene group, etc.)
[0170]
Thus, when the polycarbodiimide derivative is composed of an aliphatic skeleton, the composition can be set to a low viscosity. Therefore, in the case of coating with a solvent by a spin coating method, a dip coating method or the like, it is particularly preferably used for thinning the organic photosensitive composition.
[0171]
Further, in the photosensitive composition as described above, the naphthoquinone diazide derivative and the polycarbodiimide derivative each take into consideration the functional group equivalent of each other to react, and the ratio of the reactive group to 1 mol of the carbodiimide group is 0.00. It is desirable to contain from 01 mol to 1 mol. When the ratio of the reactive group is less than 0.01 mol, the reactivity is poor and it becomes difficult to obtain the desired heat resistance. On the other hand, when the ratio of the reactive group exceeds 1 mol, the storage stability at room temperature is lowered, and the process of the present invention may be hindered. By adjusting to the said range, reaction temperature can be made into about 100 degreeC, and it is desirable to advance reaction after completion | finish of this process.
[0172]
The photosensitive composition used in the method for producing a composite member of the present invention may be formed into a sheet by molding a mixture of components, or may be in solution by dissolving the mixture of components in an appropriate solvent.
[0173]
In order to form the photosensitive composition layer on the insulator, the photosensitive composition layer can be formed on the surface of the insulator by attaching the sheet-like photosensitive composition to the insulator. Alternatively, the photosensitive composition in solution may be coated on the insulator to form a photosensitive composition layer on the surface of the insulator. Considering the durability of the composite member after forming the conductive portion, it is preferable to form a photosensitive composition layer by coating the insulator with a solution-like photosensitive composition.
[0174]
In addition, when a conductive portion is formed in a three-dimensional manner using a porous insulator, the porous insulator is impregnated or coated on the inner surface of the porous insulator, and the surface to the inner portion is coated. The photosensitive composition layer is formed over the entire area.
[0175]
As a coating method, any method such as a dipping method, a spin coating method, a spray method, a vacuum deposition method, and a laminating method may be used.
[0176]
In the method for producing a composite member of the present invention, it is preferable to use an insulator in which a photosensitive composition layer is previously formed in order to improve productivity.
[0177]
Examples of the insulator in which the photosensitive composition layer is formed in advance include a porous insulator in which the inner pore surface is coated with a photosensitive composition containing a naphthoquinonediazide derivative. Thus, by using a porous insulator whose inner pore surface is coated with a naphthoquinonediazide derivative, a conductive portion with a high pattern shape can be formed in a three-dimensional shape.
[0178]
<Step (2)>
Next, the photosensitive composition layer 2 formed on the insulator 1 in the step (1) is subjected to pattern exposure to a desired conductive pattern as shown in FIG. The ion-exchanging group is generated or disappeared in the exposure unit 4 of 2.
[0179]
In FIG. 1B, pattern exposure is performed through the mask 3 on which the conductive pattern is formed, but the present invention is not limited to this. Using a mask on which a negative image of the conductive pattern is formed, ion-exchange groups in portions other than the conductive pattern portion may be generated or eliminated.
[0180]
In the exposure, it is not always necessary to use a mask. For example, the exposure may be performed by drawing according to a conductive pattern using a laser beam or the like. Further, the periodic pattern may be exposed using a periodic light intensity pattern such as an interference fringe generated by light interference.
[0181]
Furthermore, the exposure pattern may be not only a two-dimensional pattern but also a three-dimensional pattern. To expose a three-dimensional pattern, various Kochi three-dimensional exposure methods, such as condensing exposure light with a lens, and drawing the pattern by three-dimensionally scanning the spot of the collected light Can be used.
[0182]
In the first and second embodiments of the present invention, exposure light having a wavelength of 280 nm or more is irradiated. In order to suppress degradation of the insulator due to exposure to a low level, the wavelength of the exposure light is preferably 300 nm or more, and more preferably 350 nm or more.
[0183]
In particular, when the porous body has an aromatic compound structure, such as when exposing in the thickness direction inside the porous body, it is important to use exposure light having a long wavelength. When the porous body is composed of aromatic polyimide or the like, there are many cases where the absorption edge of polyimide absorption is 450 nm or more. In such a case, it is preferable to perform pattern exposure at a longer wavelength of 500 nm or more.
[0184]
In the third and fourth aspects of the present invention, the wavelength of the exposure light is not particularly limited.
[0185]
As the exposure light source used in the step (2), in addition to an ultraviolet light source and a visible light source, a light source that generates exposure light of a predetermined wavelength may be selected from among light sources such as β rays (electron beams) and X rays. it can. The ultraviolet light source or visible light source is specifically selected from hydrogen discharge tubes, rare gas discharge tubes, continuous spectrum light sources such as tungsten lamps and halogen lamps, various lasers, and discontinuous spectrum light sources such as mercury lamps. Use.
[0186]
In the step (2), in order to increase the binding amount of metal ions in the subsequent step (3) with respect to the ion exchange group of the photosensitive composition layer, You may swell the part which formed the ion exchange group. For this purpose, the insulator is brought into contact with the acid or alkali solution by a technique such as spraying or dipping. In particular, hydroxides such as lithium hydroxide, potassium hydroxide and sodium hydroxide as alkali solutions, alkali metal salts such as lithium carbonate, potassium carbonate and sodium carbonate, metal alkoxides such as sodium methoxide and potassium ethoxide and hydrogenation It is preferable to use at least one kind of aqueous solution such as sodium boron and soak in these solutions. These aqueous solutions may be used alone or in combination.
[0187]
<Step (3)>
Next, metal ions or metal fine particles are selectively bonded to the formed ion-exchangeable group to form a conductive portion as shown in FIG. In FIG.1 (c), the exposure part 4 becomes an electroconductive part.
[0188]
The ion exchange group generated in the exposed portion undergoes an exchange reaction with metal ions. An example of an exchange reaction between an ion exchange group and a metal ion is shown in the following chemical formula (2).
[0189]
[Chemical Formula 3]

[0190]
In order to cause an exchange reaction between the ion-exchange group and the metal ion, it can be easily carried out simply by immersing the insulator after pattern exposure in an aqueous solution containing a metal salt, for example.
[0191]
Examples of the metal element used as the metal ion include copper, silver, palladium, nickel, cobalt, tin, titanium, lead, platinum, gold, chromium, molybdenum, iron, iridium, tungsten, and rhodium.
[0192]
These metal elements are contained in the solution as metal salts such as sulfates, acetates, nitrates, chlorides, carbonates and the like. In particular, copper sulfate is preferable. It is appropriate to mix such metal salts so that the concentration of metal ions in the solution is 0.001 to 10M, preferably 0.01 to 1M. The solvent for dissolving the metal salt may be water or an organic solvent system such as methanol or isopropanol.
[0193]
The pH of the metal salt-containing liquid used here is preferably 7 or less, and more preferably 6.5 or less. As the ion exchange group used in the present invention, those having a pKa value of 7.2 or less determined from an ion dissociation constant in water are preferably used. In this case, as the pH of the aqueous solution containing the metal salt becomes around 7, the ion exchange amount hardly changes.
[0194]
When the pH of the metal salt-containing solution exceeds 7, metal ions are adsorbed to polar groups other than the target ion-exchange group, such as phenolic hydroxyl groups and silanol groups. As a result, a good pattern cannot be obtained. For example, when a photosensitive agent is applied to a glass substrate by spin coating or the like, hydroxyl groups are exposed on the back surface where the photosensitive agent is not applied. When such a substrate is immersed in an aqueous solution containing a metal salt exceeding pH 7, metal ions are adsorbed on the hydroxyl group. For this reason, metallization occurs in the subsequent process, and the back surface where the photosensitive agent is not applied is plated.
[0195]
Therefore, it is desirable that the metal salt-containing solution used in the present invention is in the above-described range in both concentration and pH.
[0196]
In the present invention, a solution in which metal fine particles are dispersed can also be used. The ion-exchange group and the colloidal metal fine particles are selectively bonded by electrostatic interaction or the like. Therefore, the bond between the ion exchange group and the metal fine particles can be easily generated only by immersing the insulator in the solution in which the metal fine particles are dispersed.
[0197]
For example, a palladium-tin colloid used as a catalyst for electroless plating prepared by mixing palladium chloride and tin chloride in an acidic aqueous solution of hydrochloric acid, or an insulator in a dispersion of palladium halide, oxide, or acetylated complex Soak. Thereby, metal fine particles are easily bonded to the ion-exchange group in a position-selective manner.
[0198]
As described above, the composite member can be obtained by forming the conductive portion in the insulator by the method of the present invention. In order to further improve the conductivity of the conductive portion of the composite member, it is desirable to perform either or both of the following step (4) and step (5).
[0199]
<Process (4)>
In order to improve the conductivity of the conductive portion 4 formed by ion exchange, as shown in FIG. 1D, metal ions bonded to the ion exchange group are brought into contact with a reducing agent to be metallized.
[0200]
An example of a metallization reaction between an ion exchange group and a metal ion is shown in the following chemical formula (3).
[0201]
[Formula 4]

[0202]
The reducing agent used is not particularly limited, and examples thereof include dimethylamine borane, trimethylamine borane, hydrazine, formalin, sodium borohydride, hypophosphite such as sodium hypophosphite, and the like. The conductive portion 4 can be metallized by immersing the insulator in a solution containing such a reducing agent.
[0203]
<Step (5)>
In order to improve the conductivity of the conductive portion 4, electroless plating 5 is applied as shown in FIG. Thereby, the inside of the void | hole of the electroconductive part 4 can be filled up with a metal to some extent.
[0204]
The metal is most preferably copper with low electrical resistance and relatively low corrosion. Specifically, the electroconductive part obtained in the previous step is used as a catalyst core and brought into contact with the electroless plating solution.
[0205]
Examples of the electroless plating solution include those containing metal ions such as copper, silver, palladium, nickel, cobalt, platinum, gold, and rhodium.
[0206]
In addition to the metal salt aqueous solution described above, this electroless plating solution includes reducing agents such as formaldehyde, hydrazine, sodium hypophosphite, sodium borohydride, ascorbic acid, glyoxylic acid, sodium acetate, EDTA, tartaric acid, malic acid. In addition, complexing agents such as citric acid and glycine, precipitation control agents, and the like are included, and many of these are commercially available and can be easily obtained. Therefore, the member may be immersed until the desired conductive film thickness of the electroless plating solution or the filling of the porous interior is completed.
[0207]
In addition, when a porous body is used as the insulator, it is desirable to further perform the following step (6) in order to improve the electrical insulation and mechanical strength of the composite.
[0208]
<Step (6)>
The pores of the porous body are filled with an impregnating resin or an inorganic substance. Examples of the impregnating resin include those made of a curable resin such as epoxy resin, polyimide, BT resin, benzocyclobutene resin, and cross-linked polybutadiene resin. Silica or the like can be used.
[0209]
If there are pores in the insulator, the inner surface of the pores may absorb moisture and the electrical insulation may be impaired. However, if the void is a closed cell which is sufficiently smaller than the size of the conductive portion, that is, the via diameter if it is a via, and the wiring width and wiring pitch if it is a wiring, it is possible to maintain a certain degree of insulation.
[0210]
Examples of the material to be filled include the above-described impregnating resin and the inorganic substance, and are not particularly limited. However, an impregnating resin is most preferable in consideration of filling properties, adhesiveness, and the like.
[0211]
In some cases, the impregnating resin may be mixed with an inorganic filler of nanometer order.
[0212]
Examples of the inorganic filler include metal oxides such as silica and alumina, metal nitrides such as silicon nitride and aluminum nitride, and ultrafine metal particles such as platinum and palladium. The inorganic filler can be preliminarily mixed with the impregnating resin and impregnated with the mixture. Or after impregnating the mixture of an inorganic filler precursor and an impregnation resin, you may produce | generate an inorganic filler in a void | hole. As such an inorganic filler precursor, silsesquioxane, polysilazane and the like are preferably used.
[0213]
In the production method of the present invention, it is necessary to avoid the formation of an ion-exchange group-containing organic compound in the photosensitive composition layer other than the target site for forming the conductive portion as much as possible. For this reason, it is preferable to perform the operation up to the plating in a yellow room where light having a short wavelength is blocked.
[0214]
In the method for manufacturing a composite member according to the present invention, an easily removable insulator such as thermal decomposability can also be used. In this case, first, a conductive portion is formed in a predetermined region of the insulator. Next, the porous body is removed by means such as heating before being impregnated with the impregnating resin by the above-described technique and cured. Thereby, a wiring board in which vias and wirings are formed in a cured product of the impregnating resin may be formed. In this case, the conductive portion is finally formed in a material different from the insulator used for forming the conductive portion.
[0215]
Note that when the insulator is pressurized and compressed during the curing of the impregnating resin, the void formed by removing the porous body of the conductive portion is crushed, and the conductive substances adhere to each other. As a result, the conductivity of the conductive column can be improved, which is preferable.
[0216]
In the composite member produced by the method of the present invention, the organic compound layer derived from the photosensitive composition remains at the interface between the insulator and the conductive part. In this case, as described with reference to FIG. 2, it is preferable to adjust the content of the organic compound per unit surface area on the insulator surface. As a result, the adhesion between the conductive portion and the insulator can be improved, and the electrical characteristics of the conductive portion can also be improved.
[0217]
That is, as shown in FIG. 2, a composite member in which the conductive portion 23 is partially formed on the surface or inside of the porous insulator 21 via the organic compound 24, and the unit surface area on the surface of the insulator 21. It is preferable that the content of per organic compound 24 satisfies the following relationship. That is, the amount of the organic compound 24 that exists between the insulator 21 and the conductive portion 23 is larger than the content of the organic compound 24 that exists other than between the insulator 21 and the conductive portion 23.
[0218]
In order to improve the moisture resistance of the composite member, prevent migration, etc., the organic compound 24 content between the insulator 21 and the conductive portion 23 is present between the insulator 21 and the conductive portion 23. The content is preferably 5 times or more, more preferably 10 times or more.
[0219]
In this case, the organic compound 24 may be derived from the photosensitive composition used in the method for producing a composite member according to the present invention, or may be other than that. In particular, it is desirable that the insulator 21 and the photosensitive composition have different structures in that the insulator is not deteriorated by light irradiation and the material selection of the insulator is not limited.
[0220]
For example, when the present invention is used for a multilayer wiring board, versatile resins such as epoxy resin, phenol resin, bismaleimide-triazine (BT) resin, polyimide, polyamide, polyallyl ether conventionally used for insulating parts , Heat resistant polymers such as polyarylate and polyethersulfone can be used. Further, if it is desired to lower the dielectric constant, materials such as polytetrafluoroethylene (PTFE) -based polymer and benzocyclobutene (BCB) resin can be selected depending on the application. Furthermore, as described above, since the insulator is not easily damaged by light degradation during exposure, the thickness and the like can be set freely.
[0221]
A multilayer wiring board can be produced using the composite member produced by the method of the present invention. This will be described with reference to FIG.
[0222]
In FIG. 4, the perspective view and sectional drawing of the composite member used for manufacture of a multilayer wiring board are shown. First, a composite member is manufactured according to the method of the present invention. As shown in FIG. 4, in the sheet-like composite members a, b, and c, a conductive portion 42 serving as a wiring pattern is formed on the surface of the porous insulator 41, inside, or both. In the sheet-like composite member d, a conductive portion 42 serving as a via pattern is formed on the surface of the porous insulator 41 and / or inside thereof. Like the composite member b, the via pattern and the wiring pattern may be formed on the same sheet.
[0223]
As shown in the composite member d in which the via pattern is formed, it is desirable that the end surface of the conductive portion 42 that is a via has an acute angle structure such as a sword mountain shape protruding from the sheet surface. Thereby, it is possible to improve the connection between the via and the wiring.
[0224]
It is also possible to coat the end face of the via with solder, but in this case also, it is more preferable to have an acute angle structure. However, since solder tends to cause voids and the like when the flux evaporates, it is preferable to form an acute angle structure on the end face of the via with a relatively hard metal such as a nickel alloy. When the via end face is flat, the end face is covered with the impregnating resin and electrical connection is likely to be hindered. The sword mountain-like structure can be formed, for example, by applying Cu / Ni eutectic acicular plating.
[0225]
A multilayer wiring board on which a three-dimensional wiring is formed is obtained by alternately laminating a plurality of composite members a, b, c formed with wiring patterns formed in this way and a composite member d formed with via patterns. can get.
[0226]
A multilayer wiring board can be manufactured by preparing a plurality of composite members in which wiring patterns and via patterns are formed in advance and laminating them in a lump. Alternatively, a porous body on which a wiring pattern or via pattern is not yet formed is overlaid on a composite member on which a wiring pattern or via pattern is formed, and then exposed and plated to form a wiring pattern, which is sequentially repeated. Thus, a multilayer wiring board can be obtained.
[0227]
It is desirable that the composite members in the multilayer wiring board are laminated by pressure bonding. When the pressure bonding is performed, an adhesive layer may be inserted between adjacent sheets.
[0228]
Further, after the pressure bonding, if a porous body is filled with an impregnation resin such as an epoxy resin, polyimide, BT resin, or benzocyclobutene resin and cured, a stronger multilayer wiring board can be formed. Of course, inorganic substances such as silica produced from silica sol, silsesquioxane, polysilazane and the like may be filled in addition to the impregnating resin. The impregnating resin may be impregnated before the pressure bonding, and the impregnating resin may be cured while being pressure bonded, but the via end face may be covered with the impregnating resin.
[0229]
By forming the wiring pattern in a composite form with a porous film-like insulator, the step between the wiring portion and the non-wiring portion can be made extremely small. In some cases, such a step can be eliminated, so that a plurality of composite members can be easily laminated. Furthermore, it is possible to reduce the film thickness of the composite member or increase the number of layers in the multilayer wiring board. In particular, when the thickness of the porous film-like insulator is as thin as about several μm, such an effect is remarkable.
[0230]
As described above, the method of manufacturing the multilayer wiring board by laminating the composite member in which the wiring pattern is formed and the composite member in which the via is formed has been described. However, the present invention is not limited to this. A multilayer wiring board can also be manufactured using a composite member in which wiring patterns and vias are formed.
[0231]
A cross-sectional view of such a composite member is shown in FIG. In the composite member shown in FIG. 5, a wiring pattern and a via are formed in one member by forming conductive portions 52 having different depths in a sheet-like porous insulator 51. By manufacturing a multilayer wiring board using such a composite member, the number of stacks can be reduced and the process can be simplified.
[0232]
At this time, in order to create conductive portions having different depths in the sheet-like porous insulator, by adjusting the absorbance with respect to the exposure wavelength of the sheet-like porous insulator (hereinafter referred to as porous insulator sheet). The penetration length of the exposure light into the porous insulator sheet is controlled so as to remain within the sheet thickness. Using such exposure light, the wiring pattern is exposed from one surface, and the via pattern is exposed from the other surface. Then, the composite member which has a wiring pattern and a via can be obtained by performing electroless plating etc. Alternatively, the via pattern may be exposed using exposure light having a wavelength that is not so much absorbed by the porous insulator. By using these methods, the inner via can be manufactured very simply. That is, since the wiring pattern and the via can basically be manufactured in the same process, the manufacturing process is simplified. If the wiring pattern is exposed on both sides of the insulator, a double-sided wiring board can be produced.
[0233]
As described above, according to the method of the present invention, a composite member in which fine vias and wirings are freely and accurately formed can be manufactured. The resulting composite member is also excellent in properties such as mechanical properties and electrical insulation.
[0234]
In the multilayer wiring board in which the composite members are laminated, as shown in FIG. 3, a layer 35 made of a conductor that does not contain an insulator component is formed on the outermost surfaces of the conductive portions 32 and 33 of each composite member. Preferably it is formed. As described above, the presence of the layer 35 made of a conductor containing no insulator component on the outermost surfaces of the conductive portions 32 and 33 of the substrate makes the contact between the conductive portions good. Therefore, it is effective for reducing the resistance of the conductive portion.
[0235]
Specifically, the layer 35 made of a conductor not including an insulator component formed on the outermost surface of the conductive portion is preferably a layer made of a metal such as low resistance copper. “Not containing an insulator component” means that the content of the insulator component in the conductor is 5% or less in terms of volume fraction. The thickness of the layer is preferably 20 μm or less, particularly 10 μm or less in consideration of the flatness of each layer. In addition, it is desired that the thickness is set to 1 to 50%, more preferably 5 to 20% of the thickness of the layer made of the conductor formed in the porous body containing the insulator component. If the thickness is too thick, the step of the conductive portion becomes large, and stacking becomes difficult. On the other hand, if it is too thin, the effect of reducing the resistance of the conductive portion is not sufficient.
[0236]
The layer 35 made of a conductor can be formed by performing electroless plating corresponding to the step (1) for a long time. Alternatively, the conductor layer 35 may be formed by forming a patterned conductive portion inside the insulator and then immersing it again in a plating bath. In order to give flexibility to the shape of the outermost surface of the conductive part, it is desirable to bond the metal foil to the end face of the conductive part.
[0237]
In order to obtain a multilayer wiring board having such a configuration, first, a conductive part including a wiring part and a via part is formed by exposing and plating the porous sheet. Thereafter, an adhesive such as an epoxy resin or polyimide (polyamic acid) is applied to the surface of the porous sheet other than the conductive portion, and adhesion of the metal foil and connection between the conductive portion and the metal foil are performed.
[0238]
The adhesive may be applied by a silk screen method or the like, but may be applied by an ink jet method or the like. At this time, it is preferable to solder-plat the end face of the conductive part.
[0239]
After bonding, the metal foils on both sides are processed by a conventional method such as a subtractive method to form a circuit pattern. A multilayer wiring board can be manufactured by injecting an appropriate impregnating resin into each composite member and then laminating with a hot press.
[0240]
Alternatively, a metal foil is bonded to one side of the porous film, and a conductive portion is formed in the porous film in a desired pattern by exposure and plating. Thereafter, a metal foil is bonded to the upper surface to connect the conductive portion and the metal foil, and the upper and lower copper foils are patterned to form a circuit pattern to obtain a composite member. A multilayer wiring board can be manufactured by multilayering this by the same method as described above.
[0241]
Furthermore, a layer made of a conductor is formed by employing various methods such as using a technique of bonding a porous film by transferring a metal wiring pattern formed in advance in a pattern instead of a metal foil. Can do.
[0242]
Of course, the layer made of such a conductor causes a step, which causes a problem in stacking. However, since it plays a role of conduction in cooperation with the conductive portion formed inside the porous body, the film thickness can be reduced. Particularly in high-frequency wiring, the electrical conductivity on the surface of the wiring affects the conductive characteristics of the entire wiring due to the skin effect. Therefore, even if the film thickness is thin, a sufficient effect can be expected. A multilayer wiring board having a structure as shown in FIG. 3 is optimal for such applications.
[0243]
The method for manufacturing a composite member according to the present invention can be applied to formation of wiring between layers of a multilayer chip of a semiconductor device in addition to formation of a multilayer wiring board or a three-dimensional wiring board. Specifically, it is the formation of interlayer wiring when stacking semiconductor chips having pads on the upper and lower sides. For example, a columnar wiring or the like is formed in the thickness direction of the porous body of the sheet-like insulator in accordance with the arrangement of the pads of the semiconductor chip, or not in particular. By inserting and laminating the sheet on which the columnar wiring is formed in this manner between two semiconductor chips, wiring between two adjacent semiconductor chips can be formed. Thereafter, the sheet may be removed by a technique such as oxygen ashing or thermal decomposition. Further, after removing the porous sheet, the wiring made porous by electrolytic plating, electroless plating, or the like can be densified.
[0244]
Furthermore, the composite member manufactured by the method of the present invention can be combined with a wiring substrate such as a glass epoxy substrate. Examples of the wiring board used include those prepared from a resin sheet obtained by impregnating a reinforcing fiber such as a glass cloth or an aramid fiber nonwoven fabric prepared by a known manufacturing method with an impregnating resin. By compounding in this way, it is possible to easily ensure the bending strength.
[0245]
EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited only to these Examples.
[0246]
(Example 1) Formation of wiring pattern on insulator surface
A bismaleimide-triazine resin sheet was prepared as an insulator. On the other hand, a naphthoquinone diazide-containing phenol resin (naphthoquinone diazide content; 33 equivalent mol%) was dissolved in acetone to prepare a photosensitive composition solution having a concentration of 1 wt%. The molecular weight of the phenol resin used here is 2500. The obtained solution was spin-coated on the above resin sheet so as to have a thickness of 0.1 μm to obtain a coating film. Further, the photosensitive composition layer was formed by drying at room temperature for 30 minutes.
[0247]
A light amount of 500 mJ / cm is applied to this sheet using a CANON PLA 501 through a mask having a line width of 10 μm and a space of 30 μm.²Exposure was carried out under the conditions of (wavelength 436 nm) to form a latent image made of indenecarboxylic acid.
[0248]
The sheet on which the pattern latent image was formed was immersed in an aqueous copper sulfate solution adjusted to 0.5 M for 5 min, and then washed with distilled water three times. The pH of the copper sulfate aqueous solution used was 4.1. The washed sheet was immersed in a 0.01 M aqueous solution of sodium borohydride for 30 minutes and then washed with distilled water to produce a composite member. In the obtained composite member, a conductive portion made of Cu as a mask having a line width of 10 μm and a space of 30 μm was formed.
[0249]
In FIG. 6, the optical microscope photograph observed from the surface of the electroconductive part in the composite member obtained by the present Example is shown. This photograph is a reflection optical microscope photograph taken at a magnification of 180 times.
[0250]
In addition, regarding the cross section of the composite member obtained in this example, an acid dyeing test using tetrabromophenol blue was performed. As a result, carboxylic acid derived from indenecarboxylic acid was present at the interface between the conductive part and the insulator. It was confirmed that
[0251]
In this composite member, the above-mentioned indenecarboxylic acid was not observed at a site other than the interface between the insulator and the conductive part.
[0252]
The composite member (conductive pattern forming sheet) thus obtained was further immersed in an electroless plating solution PS-503 for 30 minutes, and a conductive pattern was plated with copper to form a wiring pattern.
[0253]
Evaluation of adhesion between the conductive part and the insulator is as follows. In the conventional products, many multilayer wiring boards having a peel strength of plated metal at room temperature of about 1.0 kN / m are commercially available. In the composite member composed of the BT resin sheet-Cu layer obtained under the same conditions as described above, the BT resin sheet was fixed, and the peel strength of the Cu part was measured at 90 ° direction and 50 nm / min. As a result, it was 1.9 kN / m, and it was confirmed that the adhesion between the conductive portion and the insulator was better than that of the conventional product. In the composite member manufactured by the method of the present invention, it can be seen that the organic photosensitive compound functions sufficiently as an adhesive layer.
[0254]
(Example 2) Formation of wiring pattern on insulator of porous body
A PTFE porous film (pore diameter: 500 nm, film thickness: 20 μm) was used as an insulator, and the photosensitive composition solution used in Example 1 was coated on the entire surface of the film by a dipping method. By this operation, the inner pore surface of the porous film was coated with the naphthoquinonediazide-containing phenol resin. Thereafter, the same operation as in Example 1 was performed using a mask having a dot diameter of 50 μm and a space of 50 μm to produce a composite member (conductive pattern forming sheet). In the obtained composite member, a conductive portion having a dot diameter of 50 μm and a space of 50 μm was formed over the inside of the insulator.
[0255]
(Example 3) Electroless plating treatment
The conductive pattern forming sheet obtained in Example 2 was immersed in an electroless copper plating solution PS-503 for 30 min, and the conductive portion was plated with copper to form a wiring pattern. A similar pattern shape was formed on the back side of the film.
[0256]
In FIG. 7, the optical microscope photograph observed from the surface of the wiring pattern in the composite member obtained by the present Example is shown. This photograph is a reflection optical microscope photograph taken at a magnification of 180 times.
[0257]
In the composite member obtained in this example, a carboxylic acid derived from indene carboxylic acid existing at the interface between the conductive part and the insulator and other than the interface between the insulator and the conductive part was used in the same manner as in Example 1. And observed. As a result, carboxylic acid derived from indenecarboxylic acid was observed only at the interface between the insulator and the conductive part. Further, the adhesion between the conductive part and the insulator was good.
[0258]
(Example 4) Double-sided printed wiring board
An NMP solution containing a mixture of polyamic acid and polyethylene oxide represented by the following formula and a mixture of bis (4-maleimidophenylmethane) was prepared. However, the molecular weight of the polyethylene chain is about 20,000, the weight ratio of the polyamic acid component and the polyethylene oxide component is 2: 5, and the mixing ratio of the graft copolymer and bis (4-maleimidophenylmethane) is 7: 1 by weight. It was.
[0259]
[Chemical formula 5]

[0260]
A sheet was produced from this solution by a casting method. The obtained sheet was heated from room temperature to 150 ° C. over 30 minutes under a nitrogen stream, and heated at this temperature for 1 hour. Next, the temperature was raised to 250 ° C. over 30 minutes and heated at this temperature for 1 hour. Furthermore, the temperature was raised to 350 ° C. over 30 minutes, and heat treatment was performed at this temperature for 1 hour, to obtain a polyimide porous sheet having a thickness of 10 μm.
[0261]
When the heated film was observed with a transmission electron microscope, three-dimensionally continuous pores having a pore diameter of about 0.2 μm were formed.
[0262]
On the other hand, a naphthoquinone diazide-containing phenol resin (naphthoquinone diazide content: 33 equivalent mol%) was dissolved in acetone as a photosensitive composition solution to prepare a 1 wt% solution. The molecular weight of the phenol resin used here was 2500. This solution was coated on the entire surface of the polyimide porous sheet described above by the dipping method. By this operation, the inner pore surface of the porous sheet was coated with the naphthoquinonediazide-containing phenol resin.
[0263]
With respect to this polyimide porous sheet, the amount of light is 3 J / cm with a CANON PLA 501 through a mask having a dot diameter of 50 μm and a space of 50 μm.²Exposure was performed under the condition of (wavelength 436 nm) to form a latent image made of indenecarboxylic acid.
[0264]
The sheet on which the pattern latent image was formed was immersed in an aqueous copper sulfate solution adjusted to 0.5 M for 5 minutes, and then washed with distilled water three times. The pH of the aqueous copper sulfate solution used is 4.1. The washed sheet was immersed in a 0.01 M aqueous solution of sodium borohydride for 30 minutes and then washed with distilled water. After washing, the composite member was manufactured by immersing in electroless copper plating solution PS-503 for 30 minutes and copper plating the conductive part. In the obtained composite member, a conductive portion made of Cu according to a mask having a dot diameter of 50 μm and a space of 50 μm was formed.
[0265]
(Example 5) Double-sided printed wiring board
A polyimide porous sheet having a thickness of 10 μm was produced in the same manner as in Example 4 described above. In this porous polyimide sheet, continuous pores having a pore diameter of about 0.2 μm were formed three-dimensionally.
[0266]
For the obtained porous sheet, a via sheet was formed in the same manner as in Example 4 using a mask having a pattern with a via diameter of 50 μm. Thereafter, the via end face was subjected to solder plating to obtain a via sheet. Further, a wiring sheet having a line width of 30 μm was produced using the same porous sheet by the same method as described above.
[0267]
And it aligned by the arrangement | sequence of a via sheet / wiring sheet / via sheet | seat in the position which a via | veer and wiring conduct | electrically_connect, and it heated and pressurized with the hot press machine and laminated | stacked, and the multilayer wiring board was obtained.
[0268]
(Example 6)
A polyimide porous sheet having a thickness of 40 μm was produced in the same manner as in Example 4 described above. In this porous polyimide sheet, continuous pores having a pore diameter of about 0.2 μm were formed three-dimensionally.
[0269]
For the obtained porous sheet, a via sheet was formed in the same manner as in Example 4 using a mask having a pattern with a via diameter of 50 μm. Thereafter, the via end face was subjected to solder plating to obtain a via sheet. In addition, a wiring sheet having a line width of 30 μm was obtained using the same porous sheet by the same method as described above. Also on this wiring sheet, the conductive part was formed by the same method as in the case of the via sheet, and then solder plating was performed.
[0270]
Polyimide varnish was applied to the surface portion of the via sheet and the wiring sheet other than the conductive portion by a silk screen method.
[0271]
On the other hand, a commercially available positive photoresist was applied to a film thickness of 2 μm on a 0.3 mm thick stainless steel plate by a spin coating method to form a photoresist film. The obtained photoresist film was exposed and developed to produce a via transfer substrate and a wiring pattern transfer substrate. It should be noted that exposure was performed using a mask having a via diameter of 55 μm in the production of the via transfer substrate, and exposure was performed using a mask having a line width of 33 μm in the production of the wiring pattern transfer substrate. Both masks have the same pitch as the vias and wiring patterns formed in the porous sheet.
[0272]
The transfer substrate thus obtained and the copper electrode were opposed to each other and immersed in a copper sulfate plating bath to perform electroplating (current density 2 A / dm).², 15 min). The pH of the copper sulfate used is 4.1. A copper pattern with a film thickness of about 5 μm was deposited on the photoresist removal portion of each transfer substrate to form a metal pattern, which was used as a metal transfer original plate.
[0273]
The via sheet corresponding to the pattern shape and the metal transfer original plate are pressure-bonded at 150 ° C. so that the conductive portion formed on the porous sheet faces the metal pattern of the metal transfer original plate, and the metal portion of the transfer original plate is porous. Transferred to a sheet. For the wiring sheet, the metal portion of the transfer original plate was similarly transferred.
[0274]
Thereafter, by the same method as in Example 5, alignment was performed in the via sheet / wiring sheet / via sheet arrangement at a position where the via and the wiring were conducted, and the laminate was heated and pressed with a hot press machine. As a result, a multilayer wiring board as shown in FIG. 3 was obtained.
[0275]
When the resistance of the upper end and the lower end of the laminated sheet was measured, it was 1 mΩ.
[0276]
(Example 7) Anisotropic conductive sheet
The conductive pattern-formed PTFE porous sheet produced in Examples 2 and 3 was subjected to Cu / Ni eutectic plating on the end face of the copper column to form a sword-like structure having a height of 2 to 3 μm. A resin composition to be impregnated into the PTFE porous sheet on which the copper column was formed was prepared as follows.
[0277]
An equivalent amount of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and 2,2′-bis [4- (p-aminophenoxy) phenyl] propane are reacted in dimethylacetamide to form a polyamide. An acid varnish was prepared. 30% by weight of 2,2-bis [4- (4-maleimidophenoxy) phenyl was added to the polyamic acid varnish to obtain an impregnation solution.
[0278]
The obtained impregnating solution was impregnated into a PTFE porous sheet on which a copper column was formed, and then dried with hot air to remove the solvent. Subsequently, it heated at 200 degreeC for 30 minute (s), and produced the adhesive anisotropic conductive film.
[0279]
(Example 8) Formation of a wiring pattern on a porous insulator
5 g of a compound represented by the formula (II) (molecular weight 10,000), 0.1 g of N-hydroxynaphthylimide trifluoromethanesulfonate and 0.04 g of cyclohexylamine as an acid generator are dissolved in 100 g of methoxymethyl propionate. Thus, an organic photosensitive composition solution was prepared.
[0280]
[Chemical 6]

[0281]
As the insulator, a PTFE porous film (pore diameter: 500 nm, film thickness: 20 μm) was prepared. The entire surface of the film was coated with the above-mentioned organic photosensitive composition solution by a dip method, and then baked at 100 ° C. for 90 seconds. Further, exposure was performed under the same conditions as in Example 1 using a mask having a line width = 50 μm and a space width = 100 μm. Next, PEB was performed at 140 ° C. for 15 minutes, and then a conductive pattern forming process similar to that in Example 1 was performed to manufacture a composite member. In the obtained composite member, a conductive portion having an L line width = 100 μm and a space width = 50 μm was formed over the inside.
[0282]
Example 9
As an organic photosensitive composition solution, 0.9 g of naphthoquinonediazide-containing phenol resin (naphthoquinonediazide content; 33 equivalent mol%) and 0.5 g of poly (ethylene-carbodiimide) resin were dissolved in 100 ml of acetone to prepare a solution. . The molecular weight of the phenol resin used here is 2500. Using this solution, a composite member was produced in the same manner as in Example 1. A good pattern was formed on the obtained composite member in the same manner as in Example 1.
[0283]
When this composite member was heat-treated at 80 ° C. for 1 hour and then peel strength was evaluated, it was 2.6 kN / m.
[0284]
(Example 10)
As an organic photosensitive composition solution, poly (p-nitrobenzyl-p-vinylbenzene carbonate-co-styrene) was dissolved in toluene to prepare a solution having a concentration of 1% by weight. The resin used has a molecular weight of 15,000. A wiring pattern was formed on the PTFE porous film by the same method as in Example 2 except that this solution was used. As a result, a good conductive pattern was obtained according to the mask.
[0285]
(Example 11)
First, a diblock copolymer of poly (vinyl styrene) and polymethyl methacrylate was synthesized by a living anionic polymerization method. Weight average molecular weight Mw = 287000 (poly (vinylethylene) molecular weight = 91000, polymethylmethacrylate molecular weight = 196000), Mw / Mn = 1.10. To this diblock copolymer, 1.7% by weight of 3,3 ′, 4,4′-tetra- (t-butylperoxycarbonyl) benzophenone as a radical generator was added to obtain a mixture, and this mixture was added to cyclohexanone. A solution having a concentration of 10% by weight was prepared.
[0286]
The obtained cyclohexanone solution was applied on a PTFE plate using an applicator and dried to prepare a film having a thickness of 15 μm. This film was heat-treated at 135 ° C. for 24 hours under a nitrogen stream. After the heat treatment, 160 KGy was irradiated with β rays having an acceleration voltage of 2 MV. After irradiation, the film was washed with ethyl lactate to produce a porous film of crosslinked poly (vinylethylene).
[0287]
When the obtained film was observed with a transmission electron microscope, three-dimensionally continuous pores having a pore diameter of about 50 nm were formed.
[0288]
On the other hand, a naphthoquinone diazide-containing phenol resin (naphthoquinone diazide content: 33 equivalent mol%) was dissolved in acetone to prepare a 0.5 wt% concentration solution, which was used as a photosensitive composition solution. This acetone solution was impregnated into the porous film described above, and then dried at room temperature. The sheet was exposed to the wiring pattern and via pattern through a mask using CANON PLA 501 to form a latent image made of indenecarboxylic acid. The wiring pattern has a line width of 20 μm, a space of 30 μm, and a via diameter of 10 μm. Exposure is 500mJ / cm²The measurement was performed under the condition of a wavelength of 436 nm.
[0289]
The sheet on which the pattern latent image was formed was immersed in an aqueous copper sulfate solution adjusted to 0.5 M for 5 min, and then washed with distilled water three times. The pH of the copper sulfate aqueous solution used was 4.1. The washed sheet was immersed in a 0.01 M aqueous solution of sodium borohydride for 30 minutes and then washed with distilled water. Furthermore, it was immersed in electroless copper plating solution PS-503 for 30 minutes, and the copper plating was given to the electroconductive part. Thereby, the porous sheet in which the wiring pattern and via pattern made of Cu were respectively formed was obtained.
[0290]
The porous sheet (wiring sheet) on which the wiring pattern was formed was further subjected to electroless plating to form a 2 μm-thick layer made of only Cu on the end face of the wiring pattern. Further, the porous sheet (via sheet) on which the via pattern was formed was subjected to Cu / Ni eutectic plating on the end face to form a sword-like projection structure having a height of 2 to 3 microns.
[0291]
After laminating one via sheet between two thus obtained wiring sheets, the resin solution was impregnated. The impregnating resin solution used was prepared by adding 50 parts by weight of methyl isobutyl ketone to 100 parts by weight of a benzocyclobutene resin solution (manufactured by Dow Chemical Co., Ltd., trade name: XU13005). The laminated body of the sheets was subjected to pressure bonding, and then the solvent was removed. Furthermore, the double-sided wiring board was produced by heat-curing at 240 degreeC under nitrogen stream for 1 hour.
[0292]
In the same manner, four wiring sheets and three via sheets were alternately laminated to produce a four-layer multilayer wiring board. In addition, a via sheet and a wiring sheet were laminated on both sides of a four-layer FR-4 glass epoxy substrate (wiring width 75 μm) to prepare a six-layer multilayer wiring board. Further, an eight-layer multilayer wiring board could be fabricated using two via sheets and two wiring sheets.
[0293]
Since the multilayer wiring board produced as described above has a layer made of only Cu on the end face of the conductive portion of the wiring sheet, the resistance is lower than that in which the layer made only of Cu is not formed on the end face. . Moreover, the multilayer wiring board which has a glass epoxy board | substrate in a core layer was excellent in bending strength.
[0294]
Example 12
A polyimide porous sheet having a thickness of 20 μm was produced in the same manner as in Example 4 described above. In this porous polyimide sheet, continuous pores having a pore diameter of about 0.2 μm were formed three-dimensionally.
[0295]
On the other hand, 10 g of phenol novolak resin derivative capped with tert-butoxycarbonylmethyl group, 0.5 g of DTBPI-TF (bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate) and acridine orange as an acid generator (C.I. 46005) 0.08 g was dissolved in 200 g of methyl cellosolve to prepare an organic photosensitive composition solution.
[0296]
The polyimide porous body sheet obtained as described above was impregnated in this organic photosensitive composition solution, and then dried at 80 ° C. for 10 minutes to prepare an organic photosensitive composition-coated polyimide porous body sheet.
[0297]
The sheet is irradiated with a low-pressure mercury lamp through a wiring pattern mask having a line width of 50 μm and a space of 50 μm, and a light amount of 10 mJ / cm.²Exposure was performed under the conditions of (wavelength 254 nm), and then a heat treatment was performed at 100 ° C. for 5 minutes to form a latent image made of a carboxyl group-containing phenol novolac resin. The penetration depth of the pattern into the sheet under these conditions was about 5 μm.
[0298]
Subsequently, a via pattern mask was placed on the back side of the sheet and exposed. The used via pattern mask has 50 μmφ via portions arranged at a pitch of 100 μm. The via portion was disposed so as to penetrate the line exposure portion drawn at the lower part of the sheet. On the other hand, with CANON PLA501, the light quantity is 500 mJ / cm.²Long wavelength exposure was performed under the condition of (wavelength 546 nm), and a latent image made of a carboxyl group-containing phenol novolak resin was formed in the same manner as described above.
[0299]
In the exposed sheet, a latent image in which the via exposure portion reached the line exposure portion was formed.
[0300]
The sheet on which the pattern latent image was formed was washed with distilled water, immersed in an aqueous copper sulfate solution adjusted to 0.5 M for 5 min, and then washed with distilled water three times. The pH of the aqueous copper sulfate solution used is 4.1. The washed sheet was immersed in a 0.01 M aqueous solution of sodium borohydride for 30 minutes and then washed with distilled water. Furthermore, it was immersed in electroless copper plating solution PS-503 for 30 minutes, and the copper plating was given to the electroconductive part. As a result, a composite member having a wiring pattern made of Cu as shown in FIG. 5 was obtained.
[0301]
【The invention's effect】
As described above in detail, according to the present invention, the degree of freedom in designing a conductive circuit is high, the insulator is not deteriorated by exposure, and there is no abnormal deposition of metal on the insulator, thus having a fine pattern. The conductive part can be easily formed.
[0302]
In addition, according to the present invention, the degree of freedom in the design of the conductive circuit is high, the material selectivity of the insulating portion and the molding processability are not affected at low cost, and there is no abnormal deposition of metal on the insulator, which is fine. It becomes possible to easily form a conductive portion having a pattern.
[0306]
  Furthermore, the present inventionAccording toManufactured by the method described aboveComposite partsThe electronic package used is provided.
[0307]
The present invention can be suitably used for many applications such as various optical functional devices and multilayer wiring boards, and its industrial value is tremendous.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a method for producing a composite member of the present invention.
FIG. 2 is a schematic view showing a composite member of the present invention.
FIG. 3 is a schematic view showing a multilayer wiring board according to the present invention.
4A and 4B are a perspective view and a cross-sectional view of a composite member used for manufacturing a multilayer wiring board.
FIG. 5 is a cross-sectional view of a composite member used for manufacturing a multilayer wiring board.
6 is a photograph showing a conductive portion of the composite member obtained in Example 1. FIG.
7 is a photograph showing a wiring pattern of a composite member obtained in Example 3. FIG.
[Explanation of symbols]
1 ... Insulator
2 ... Photosensitive composition layer
3 ... Mask
4 ... Sensitive area
5. Electroless plating

Claims (7)

A method for producing a composite member in which a conductive portion is selectively formed on a sheet-like or porous insulator,
(1) a first step of forming a photosensitive composition layer containing a compound that generates an ion-exchange group by irradiation with light having a wavelength of 280 nm or more in or on the surface of the insulator having a hydrophilic surface ; ,
(2) a second step of pattern-exposing the photosensitive composition with exposure light having a wavelength of 280 nm or more, and generating an ion-exchange group in the exposed portion;
(3) a third step of forming the conductive portion by bringing an aqueous solution of a metal salt into contact with the pattern of ion-exchangeable groups formed by the pattern exposure to bond the ion-exchangeable groups and metal ions. A method for producing a composite member, comprising: A method for producing a composite member in which a conductive portion is selectively formed on a sheet-like or porous insulator,
(1) a first step of forming a photosensitive composition layer containing a compound having an ion-exchange group in or on the surface of the insulator having a hydrophilic surface ;
(2) pattern exposure of the photosensitive composition layer with an exposure light having a wavelength of 280 nm or longer, the second step of eliminating the ion-exchange group in the exposed portion and leaving the ion-exchange group in the unexposed portion;
(3) A metal salt aqueous solution is brought into contact with the ion-exchangeable group left in the unexposed part by the pattern exposure , thereby bonding the ion-exchangeable group and the metal ion to form the conductive part. The manufacturing method of the composite member characterized by including 3 processes. A method for producing a composite member in which a conductive portion is selectively formed on a sheet-like or porous insulator,
(1) Onium salt derivatives, sulfonium ester derivatives, carboxylic acid derivatives, and naphthoquinonediazide derivatives that generate ion-exchangeable groups upon light irradiation, or compounds that lose ion-exchangeable groups upon light irradiation A first step of forming a photosensitive composition layer containing the material in or on the insulator;
(2) a second step of pattern-exposing the photosensitive composition and generating or eliminating ion-exchange groups in the exposed portion;
(3) The conductive portion is formed by bonding the ion-exchange group and the metal ion by bringing an aqueous solution of the metal salt into contact with the pattern of the ion-exchange group obtained or disappeared by the pattern exposure. And a third step of manufacturing a composite member.   4. The method for manufacturing a composite member according to claim 1, further comprising a step of performing electroless plating on the surface of the conductive portion formed in the third step. . At least one electronic component is electrically connected to a wiring board made of a composite member obtained by the composite member manufacturing method according to claim 1, claim 2, or claim 3. electronic package. A method of manufacturing a composite member in which a conductive portion is selectively formed on a sheet-like or porous insulator,
(1) a first step of forming a photosensitive composition layer on or in the insulator having the entire surface hydrophilic;
(2) a second step of pattern-exposing the photosensitive composition layer with light and heating to generate an ion-exchange group in the exposed portion;
(3) An aqueous solution of a metal salt on the ion-exchangeable group formed in the exposed portion by the pattern exposure. At least a third step of bonding the ion-exchange group and metal ion to form the conductive portion by contacting
The method for producing a composite member, wherein the photosensitive composition layer includes at least a compound that generates an ion-exchange group in the presence of an acid and a photoacid generator. The method for producing a composite member according to claim 6, wherein the photosensitive composition further contains a photosensitizer.

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