JP4565212B2 - Photosensitive transfer film, dielectric and electronic parts - Google Patents

Description

【００４５】
（式中、Ｒ¹ およびＲ⁴ は、それぞれ、同一または異なる炭素数１〜３０のアルキル基を示し、Ｒ² およびＲ³ は、それぞれ、同一または異なるメチレン基または炭素数２〜３０のアルキレン基を示し、ｓは０〜５の整数であり、ｔは１〜１０の整数である。）
【００４６】
【化２】

【００４７】
（式中、Ｒ⁵ は炭素数１〜３０の炭化水素基を示す。）
上記式（１）において、Ｒ¹ またはＲ⁴ で示されるアルキル基、並びにＲ² またはＲ³ で示されるアルキレン基は、直鎖状であっても分岐状であってもよく、また、飽和基であっても不飽和基であってもよい。Ｒ¹ またはＲ⁴ で示されるアルキル基の炭素数は、１〜３０であり、好ましくは２〜２０、さらに好ましくは４〜１０であることが望ましい。Ｒ² またはＲ³ で示されるアルキレン基の炭素数は、２〜３０であり、好ましくは２〜２０、さらに好ましくは４〜１０とされることが望ましい。当該アルキル基およびアルキレン基の炭素数が３０を超える場合には、溶剤に対する可塑剤の溶解性が低下し、転写フィルムの良好な可撓性が得られない場合がある。
【００４８】
上記式（１）で示される化合物の具体例としては、ジブチルアジペート、ジイソブチルアジペート、ジ−２−エチルヘキシルアジペート、ジ−２−エチルヘキシルアゼレート、ジブチルセバケート、ジブチルジグリコールアジペートなどが挙げられる。好ましくは、ｔが２〜６で表される化合物である。
上記式（２）において、Ｒ⁵ で示される炭化水素基は、直鎖状であっても分岐状であってもよく、また、飽和基であっても不飽和基であってもよい。Ｒ⁵ で示される炭化水素基は、炭素数が、１〜３０、好ましくは２〜２０、さらに好ましくは１０〜１８であることが好ましく、また、特にアルキル基またはアルケニル基であることが好ましい。
【００４９】
上記式（２）で示される化合物の具体例としては、プロピレングリコールモノラウレート、プロピレングリコールモノオレートなどが挙げられる。
感光性組成物における可塑剤の含有割合としては、誘電体用複合粒子（Ａ）１００重量部に対して、０．１〜２０重量部、好ましくは０．５〜１０重量部であることが望ましい。
▲２▼接着助剤
接着助剤としては、下記式（３）で示される化合物などのシランカップリング剤〔飽和アルキル基含有（アルキル）アルコキシシラン〕が好適に用いられる。
【００５０】
【化３】

【００５１】
（式中、ｐは３〜２０の整数、ｍは１〜３の整数、ｎは１〜３の整数、ａは１〜３の整数である。）
上記式（３）において、飽和アルキル基の炭素数を示すｐは３〜２０の整数とされ、好ましくは４〜１６の整数とされる。
上記式（３）で示されるシランカップリング剤の具体例としては、ｎ−プロピルジメチルメトキシシラン、ｎ−ブチルジメチルメトキシシラン、ｎ−デシルジメチルメトキシシラン、ｎ−ヘキサデシルジメチルメトキシシラン、ｎ−イコサンジメチルメトキシシランなどの飽和アルキルジメチルメトキシシラン類（ａ＝１，ｍ＝１，ｎ＝１）；
ｎ−プロピルジエチルメトキシシラン、ｎ−ブチルジエチルメトキシシラン、ｎ−デシルジエチルメトキシシラン、ｎ−ヘキサデシルジエチルメトキシシラン、ｎ−イコサンジエチルメトキシシランなどの飽和アルキルジエチルメトキシシラン類（ａ＝１，ｍ＝１，ｎ＝２）；
ｎ−ブチルジプロピルメトキシシラン、ｎ−デシルジプロピルメトキシシラン、ｎ−ヘキサデシルジプロピルメトキシシラン、ｎ−イコサンジプロピルメトキシシランなどの飽和アルキルジプロピルメトキシシラン類（ａ＝１，ｍ＝１，ｎ＝３）；
ｎ−プロピルジメチルエトキシシラン、ｎ−ブチルジメチルエトキシシラン、ｎ−デシルジメチルエトキシシラン、ｎ−ヘキサデシルジメチルエトキシシラン、ｎ−イコサンジメチルエトキシシランなどの飽和アルキルジメチルエトキシシラン類（ａ＝１，ｍ＝２，ｎ＝１）；
ｎ−プロピルジエチルエトキシシラン、ｎ−ブチルジエチルエトキシシラン、ｎ−デシルジエチルエトキシシラン、ｎ−ヘキサデシルジエチルエトキシシラン、ｎ−イコサンジエチルエトキシシランなどの飽和アルキルジエチルエトキシシラン類（ａ＝１，ｍ＝２，ｎ＝２）；
ｎ−ブチルジプロピルエトキシシラン、ｎ−デシルジプロピルエトキシシラン、ｎ−ヘキサデシルジプロピルエトキシシラン、ｎ−イコサンジプロピルエトキシシランなどの飽和アルキルジプロピルエトキシシラン類（ａ＝１，ｍ＝２，ｎ＝３）；
ｎ−プロピルジメチルプロポキシシラン、ｎ−ブチルジメチルプロポキシシラン、ｎ−デシルジメチルプロポキシシラン、ｎ−ヘキサデシルジメチルプロポキシシラン、ｎ−イコサンジメチルプロポキシシランなどの飽和アルキルジメチルプロポキシシラン類（ａ＝１，ｍ＝３，ｎ＝１）；
ｎ−プロピルジエチルプロポキシシラン、ｎ−ブチルジエチルプロポキシシラン、ｎ−デシルジエチルプロポキシシラン、ｎ−ヘキサデシルジエチルプロポキシシラン、ｎ−イコサンジエチルプロポキシシランなどの飽和アルキルジエチルプロポキシシラン類（ａ＝１，ｍ＝３，ｎ＝２）；
ｎ−ブチルジプロピルプロポキシシラン、ｎ−デシルジプロピルプロポキシシラン、ｎ−ヘキサデシルジプロピルプロポキシシラン、ｎ−イコサンジプロピルプロポキシシランなどの飽和アルキルジプロピルプロポキシシラン類（ａ＝１，ｍ＝３，ｎ＝３）；
ｎ−プロピルメチルジメトキシシラン、ｎ−ブチルメチルジメトキシシラン、ｎ−デシルメチルジメトキシシラン、ｎ−ヘキサデシルメチルジメトキシシラン、ｎ−イコサンメチルジメトキシシランなどの飽和アルキルメチルジメトキシシラン類（ａ＝２，ｍ＝１，ｎ＝１）；
ｎ−プロピルエチルジメトキシシラン、ｎ−ブチルエチルジメトキシシラン、ｎ−デシルエチルジメトキシシラン、ｎ−ヘキサデシルエチルジメトキシシラン、ｎ−イコサンエチルジメトキシシランなどの飽和アルキルエチルジメトキシシラン類（ａ＝２，ｍ＝１，ｎ＝２）；
ｎ−ブチルプロピルジメトキシシラン、ｎ−デシルプロピルジメトキシシラン、ｎ−ヘキサデシルプロピルジメトキシシラン、ｎ−イコサンプロピルジメトキシシランなどの飽和アルキルプロピルジメトキシシラン類（ａ＝２，ｍ＝１，ｎ＝３）
ｎ−プロピルメチルジエトキシシラン、ｎ−ブチルメチルジエトキシシラン、ｎ−デシルメチルジエトキシシラン、ｎ−ヘキサデシルメチルジエトキシシラン、ｎ−イコサンメチルジエトキシシランなどの飽和アルキルメチルジエトキシシラン類（ａ＝２，ｍ＝２，ｎ＝１）；
ｎ−プロピルエチルジエトキシシラン、ｎ−ブチルエチルジエトキシシラン、ｎ−デシルエチルジエトキシシラン、ｎ−ヘキサデシルエチルジエトキシシラン、ｎ−イコサンエチルジエトキシシランなどの飽和アルキルエチルジエトキシシラン類（ａ＝２，ｍ＝２，ｎ＝２）；
ｎ−ブチルプロピルジエトキシシラン、ｎ−デシルプロピルジエトキシシラン、ｎ−ヘキサデシルプロピルジエトキシシラン、ｎ−イコサンプロピルジエトキシシランなどの飽和アルキルプロピルジエトキシシラン類（ａ＝２，ｍ＝２，ｎ＝３）；
ｎ−プロピルメチルジプロポキシシラン、ｎ−ブチルメチルジプロポキシシラン、ｎ−デシルメチルジプロポキシシラン、ｎ−ヘキサデシルメチルジプロポキシシラン、ｎ−イコサンメチルジプロポキシシランなどの飽和アルキルメチルジプロポキシシラン類 （ａ＝２，ｍ＝３，ｎ＝１）；
ｎ−プロピルエチルジプロポキシシラン、ｎ−ブチルエチルジプロポキシシラン、ｎ−デシルエチルジプロポキシシラン、ｎ−ヘキサデシルエチルジプロポキシシラン、ｎ−イコサンエチルジプロポキシシランなどの飽和アルキルエチルジプロポキシシラン類 （ａ＝２，ｍ＝３，ｎ＝２）；
ｎ−ブチルプロピルジプロポキシシラン、ｎ−デシルプロピルジプロポキシシラン、ｎ−ヘキサデシルプロピルジプロポキシシラン、ｎ−イコサンプロピルジプロポキシシランなどの飽和アルキルプロピルジプロポキシシラン類（ａ＝２，ｍ＝３，ｎ＝３）；
ｎ−プロピルトリメトキシシラン、ｎ−ブチルトリメトキシシラン、ｎ−デシルトリメトキシシラン、ｎ−ヘキサデシルトリメトキシシラン、ｎ−イコサントリメトキシシランなどの飽和アルキルトリメトキシシラン類（ａ＝３，ｍ＝１）；
ｎ−プロピルトリエトキシシラン、ｎ−ブチルトリエトキシシラン、ｎ−デシルトリエトキシシラン、ｎ−ヘキサデシルトリエトキシシラン、ｎ−イコサントリエトキシシランなどの飽和アルキルトリエトキシシラン類（ａ＝３，ｍ＝２）；
ｎ−プロピルトリプロポキシシラン、ｎ−ブチルトリプロポキシシラン、ｎ−デシルトリプロポキシシラン、ｎ−ヘキサデシルトリプロポキシシラン、ｎ−イコサントリプロポキシシランなどの飽和アルキルトリプロポキシシラン類（ａ＝３，ｍ＝３）などを挙げることができ、これらは、単独でまたは２種以上を組み合わせて使用することができる。
【００５２】
これらのうち、ｎ−ブチルトリメトキシシラン、ｎ−デシルトリメトキシシラン、ｎ−ヘキサデシルトリメトキシシラン、ｎ−デシルジメチルメトキシシラン、ｎ−ヘキサデシルジメチルメトキシシラン、ｎ−ブチルトリエトキシシラン、ｎ−デシルトリエトキシシラン、ｎ−ヘキサデシルトリエトキシシラン、ｎ−デシルエチルジエトキシシラン、ｎ−ヘキサデシルエチルジエトキシシラン、ｎ−ブチルトリプロポキシシラン、ｎ−デシルトリプロポキシシラン、ｎ−ヘキサデシルトリプロポキシシランなどが特に好ましい。
【００５３】
感光性組成物における接着助剤の含有割合としては、誘電体用複合粒子（Ａ）１００重量部に対して、０．００１〜１０重量部、好ましくは０．００１〜５重量部であることが望ましい。
▲３▼分散剤
誘電体用複合粒子（Ａ）の分散剤としては、脂肪酸が好ましく用いられ、特に、炭素数３〜３０、好ましくは炭素数４〜３０、さらに好ましくは４〜２０の脂肪酸が好ましい。上記脂肪酸の好ましい具体例としては、
マロン酸、オクタン酸、ウンデシル酸、ラウリン酸、ミリスチン酸、パルミチン酸、ペンタデカン酸、ステアリン酸、アラキン酸等の飽和脂肪酸；
フマル酸、イタコン酸、シトラコン酸、エライジン酸、オレイン酸、リノール酸、リノレン酸、アラキドン酸等の不飽和脂肪酸；
フタル酸等の芳香族脂肪酸；
などを挙げることができ、これらは、単独でまたは２種以上を組み合わせて使用することができる。
【００５４】
感光性組成物における分散剤の含有割合としては、誘電体用複合粒子（Ａ）１００重量部に対して、０．００１〜１０重量部、好ましくは０．０１〜５重量部であることが望ましい。
▲４▼充填剤
本発明の感光性転写フィルムを構成する感光性組成物は、（Ａ）〜（Ｅ）成分の他に、さらに、充填剤を含有することができる。このような充填剤として、誘電率を向上させる添加剤としては、たとえばカーボン微粉（例：アセチレンブラック、ケッチェンブラックなど）、黒鉛微粉などの導電性微粒子、たとえば炭化ケイ素微粉などの半導体性の微粒子などが挙げられる。これらの誘電率向上用の充填剤を添加する場合には、誘電体用複合粒子（Ａ）に対し、好ましくは０〜１０重量％、さらに好ましくは０．５〜１０重量％、特に好ましくは１〜５重量％の量で使用することが望ましい。
【００５５】
［誘電体］
上記感光性転写フィルムを用いることにより、５００℃以下の加熱で、誘電率が３０以上、誘電正接が０．１以下の誘電体を形成することができる。以下、本発明の誘電体の形成方法および誘電体の物性について詳述する。
＜誘電体層パターンの形成方法＞
本発明の感光性転写フィルムを用いたパターンの形成方法は、〔１〕感光性転写層の転写工程、〔２〕感光性転写層の露光工程、〔３〕感光性転写層の現像工程、〔４〕感光性転写層パターンの焼成工程の各工程を有する。
〔１〕感光性転写層の転写工程
転写工程では、本発明の感光性転写フィルムを使用し、当該感光性転写フィルムを構成する感光性転写層を基板上に転写する。
【００５６】
基板材料としては、例えばプリント基板、ガラス、シリコーン、アルミナなどからなる板状部材が用いられる。この板状部材の表面に予め所望のパターンを形成したものを用いても差し支えない。基板表面に対しては、必要に応じて、シランカップリング剤などによる薬品処理；プラズマ処理；イオンプレーティング法、スパッタリング法、気相反応法、真空蒸着法などによる薄膜形成処理のような前処理を適宜施していてもよい。
【００５７】
転写工程の一例を示せば以下のとおりである。必要に応じて使用される感光性転写フィルムの保護フィルムを剥離した後、基板上に、感光性転写層の表面が当接されるように感光性転写フィルムを重ね合わせ、この感光性転写フィルムを加熱ローラなどにより熱圧着する。これにより、基板上に感光性転写層が転写されて密着した状態となる。ここで、転写条件としては、例えば、加熱ローラの表面温度が２０〜１４０℃、加熱ローラによるロール圧が１〜５ｋｇ／ｃｍ² 、加熱ローラの移動速度が０．１〜１０．０ｍ／分であるような条件を示すことができる。また、基板は予熱されていてもよく、予熱温度としては例えば４０〜１００℃とすることができる。
〔２〕感光性転写層の露光工程
露光工程においては、感光性転写層の表面に、露光用マスクを介して、放射線を選択的照射（露光）して、感光性転写層のパターンの潜像を形成する。なお、感光性転写層上の支持フィルムは露光工程の前に剥離除去してもよく、また、露光工程の後、後述する現像工程の前に剥離除去してもよい。感度上昇の観点から、感光性転写層上の支持フィルムは露光工程の後、後述する現像工程の前に剥離除去することが好ましい。
【００５８】
露光工程において選択的照射（露光）される放射線としては、たとえば可視光線、紫外線、遠紫外線、電子線あるいはＸ線等が挙げられ、好ましくは可視光線、紫外線および遠紫外線が、さらに好ましくは紫外線が用いられる。
露光用マスクの露光パターンは目的によって異なるが、例えば、１０〜１０００μｍ幅のドットパターンが用いられる。
【００５９】
放射線照射装置としては、たとえばフォトリソグラフィー法で使用されている紫外線照射装置、半導体および液晶表示装置を製造する際に使用されている露光装置などが挙げられるが、特にこれらに限定されるものではない。
〔３〕感光性転写層の現像工程
現像工程においては、露光された感光性転写層を現像処理することにより、感光性転写層のパターン（潜像）を顕在化させる。
【００６０】
感光性転写層の現像工程で使用される現像液としては、アルカリ現像液を使用することができる。これにより、感光性転写層に含有されるアルカリ可溶性樹脂を容易に溶解除去することができる。
なお、感光性転写層に含有される誘電体用複合粒子は、アルカリ可溶性樹脂により均一に分散されているため、バインダーであるアルカリ可溶性樹脂を溶解させ、洗浄することにより、誘電体用複合粒子も同時に除去される。
【００６１】
アルカリ現像液の有効成分としては、例えば
水酸化リチウム、水酸化ナトリウム、水酸化カリウム、リン酸水素ナトリウム、リン酸水素二アンモニウム、リン酸水素二カリウム、リン酸水素二ナトリウム、リン酸二水素アンモニウム、リン酸二水素カリウム、リン酸二水素ナトリウム、ケイ酸リチウム、ケイ酸ナトリウム、ケイ酸カリウム、炭酸リチウム、炭酸ナトリウム、炭酸カリウム、ホウ酸リチウム、ホウ酸ナトリウム、ホウ酸カリウム、アンモニアなどの無機アルカリ性化合物；
テトラメチルアンモニウムヒドロキシド、トリメチルヒドロキシエチルアンモニウムヒドロキシド、モノメチルアミン、ジメチルアミン、トリメチルアミン、モノエチルアミン、ジエチルアミン、トリエチルアミン、モノイソプロピルアミン、ジイソプロピルアミン、エタノールアミンなどの有機アルカリ性化合物；
などを挙げることができる。
【００６２】
感光性転写層の現像工程で使用されるアルカリ現像液は、前記アルカリ性化合物の１種または２種以上を水などの溶媒に溶解させることにより調製することができる。ここに、アルカリ性現像液におけるアルカリ性化合物の濃度は、通常０．００１〜１０質量％であり、好ましくは０．０１〜５質量％である。アルカリ現像液には、ノニオン系界面活性剤または有機溶剤などの添加剤が含有されていてもよい。
【００６３】
なお、アルカリ現像液による現像処理がなされた後は、通常、水洗処理が施される。また、必要に応じて現像処理後に感光性転写層パターン側面および基板露出部に残存する不要分を擦り取る工程を含んでもよい。
現像処理条件としては、現像液の種類・組成・濃度、現像時間、現像温度、現像方法（例えば浸漬法、揺動法、シャワー法、スプレー法、パドル法）、現像装置などを目的に応じて適宜選択することができる。
【００６４】
この現像工程により、感光性転写層残留部と、感光性転写層除去部とから構成される感光性転写層パターン（露光用マスクに対応するパターン）が形成される。
〔４〕感光性転写層パターンの硬化工程
この工程においては、誘電体層パターンを熱硬化処理して、パターンを形成する。このような加熱温度は、５００℃以下で行うことが可能であり、好ましくは１００〜５００℃、さらに好ましくは１５０〜３００℃で行うことが望ましい。加熱時間は、好ましくは１分〜２４時間、さらに好ましくは１０分〜１２時間の範囲で行うことが望ましい。
【００６５】
感光性転写層を加熱して硬化する場合、加熱方法としては、たとえば、オーブン、赤外線ランプ、ホットプレート等により加熱することができる。
＜誘電体の物性＞
このような本発明の感光性転写フィルムから得られる誘電体は、誘電率が３０以上、好ましくは１００以上、さらに好ましくは１５０以上、特に好ましくは２００以上であることが望ましい。誘電率の上限は特に限定されないが、たとえば３００００程度であってもよい。また、誘電正接が０．１以下、好ましくは０．０８以下、さらに好ましくは０．０６以下であることが望ましい。誘電正接の下限は特に限定されないが、たとえば０．００１程度であってもよい。
【００６６】
なお、本明細書において、誘電率、誘電正接は、ＪＩＳ Ｋ６４８１（周波数１ＭＨｚ）に記載の方法により測定した値である。
また、このような誘電体の体積抵抗率は好ましくは１０¹¹Ω・ｃｍ以上、より好ましくは１０¹²Ω・ｃｍ以上のものとすることができる。
なお、この誘電体の厚さは、好ましくは１００μｍ以下、より好ましくは３０μｍ以下であることが望ましい。フィルム厚さの下限は特に限定されないが、通常は１μｍ以上である。
【００６７】
［電子部品］
本発明の誘電体は、５００℃以下という低い温度で加熱焼成して得ることができ、誘電率が３０以上かつ誘電正接が０．１以下であり、薄膜で静電容量の大きなコンデンサ等を形成することができる。また、この誘電体を備えたプリント回路基板、半導体パッケージ、コンデンサ、高周波用アンテナ等の電子部品は、小型でかつ高密度のものとすることができる。
【００６８】
【発明の効果】
本発明に係る感光性転写フィルムを用いると、前記のように５００℃以下という低い加熱温度で、しかも０．１以下という低い誘電正接かつ３０以上という高い誘電率の誘電体を形成することができる。
本発明の誘電体は、薄膜で高誘電率であるので、プリント回路基板、半導体パッケージ、コンデンサ、高周波用アンテナ等の電子部品等において好適に利用される。
【００６９】
本発明の電子部品は、前記誘電体を備えることから、小型化、薄膜化することができる。
【００７０】
【実施例】
以下、本発明の実施例について説明するが、本発明はこれらによって限定されるものではない。なお、以下において「部」は「質量部」を示す。
また、重量平均分子量（Ｍｗ）は、東ソー株式会社製ゲルパーミィエーションクロマトグラフィー（ＧＰＣ）（商品名ＨＬＣ−８０２Ａ）により測定したポリスチレン換算の平均分子量である。
【００７１】
【実施例１】
（１）誘電体用複合粒子の製造
チタン酸バリウム粒子（商品名「ＨＰＢＴ−１」、富士チタン株式会社製、平均粒子径０．６μｍ、誘電率２０００）を無電解銀メッキ法により表面に銀をコートして、誘電体用複合粒子（ａ）を得た。
【００７２】
得られた粉体のＳＥＭ（走査形電子顕微鏡）観察から、粒子表面に銀の微粒子が部分的に付着していることを確認した。また、ＳＩＭＳ（二次イオン形質量分析法）によりチタン酸バリウム表面に銀が重量比換算で１０％付着していることを確認した。一方、粉末の比表面積は３．８ｍ²／ｇであった。
（２）感光性組成物の調製
（Ａ）誘電体用複合粒子として、前記誘電体用複合粒子（ａ）１００部、（Ｂ）アルカリ可溶性樹脂として、メタクリル酸ｎ−ブチル／メタクリル酸３−ヒドロキシプロピル／メタクリル酸＝６０／２０／２０（質量％）共重合体（Ｍｗ＝５０，０００）２０部、（Ｃ）エチレン性不飽和基含有化合物として、トリメチロールプロパントリアクリレート１０部、（Ｄ）光重合開始剤として、２−ベンジル−２−ジメチルアミノ−１−（４−モルフォリノフェニル）−ブタン−１−オン２部、（Ｅ）溶剤として、プロピレングリコールモノメチルエーテル１００部および（Ｆ）分散剤としてオレイン酸１部、充填剤としてアセチレンブラック０．５部をビーズミルで混練りした後、ステンレスメッシュ（５００メッシュ）でフィルタリングすることにより、感光性組成物を調製した。
（３）感光性転写フィルムの作製
下記（イ）の操作により、感光性転写層が支持フィルム上に形成されてなる本発明の感光性転写フィルムを作製した。
（イ）上記のようにして得られた感光性組成物を予め離型処理したＰＥＴフィルムよりなる支持フィルム（幅２００ｍｍ、長さ３０ｍ、厚さ３８μｍ）上にブレードコーターを用いて塗布し、塗膜を１００℃で５分間乾燥して溶剤を完全に除去し、厚さ２０μｍの感光性樹脂層を支持フィルム上に形成した。
（４）感光性転写層の転写工程
プリント配線基板の表面に、感光性転写層の表面が当接されるように感光性転写フィルムを重ね合わせ、この感光性転写フィルムを加熱ローラにより熱圧着した。ここで、圧着条件としては、加熱ローラの表面温度を１２０℃、ロール圧を４ｋｇ／ｃｍ² 、加熱ローラの移動速度を０．５ｍ／分とした。これにより、ガラス基板の表面に感光性転写層が転写されて密着した状態となった。この感光性転写層について膜厚を測定したところ、２０μｍ±１μｍの範囲にあった。
（５）誘電体層の露光工程・現像工程
感光性転写層に対して、露光用マスク（５００μｍ角のドットパターン）を介して、超高圧水銀灯により、ｉ線（波長３６５ｎｍの紫外線）を照射した。ここに、照射量は４００ｍＪ／ｃｍ²とした。
【００７３】
露光工程の終了後、露光処理された感光性転写層に対して、０．５質量％の炭酸ナトリウム水溶液（３０℃）を現像液とするシャワー法による現像処理を１分かけて行った。次いで超純水による水洗処理を行い、これにより、紫外線が照射されていない未硬化の感光性転写層を除去し、パターンを形成した。
（６）誘電体層パターンの硬化工程：
感光性転写層パターンが形成されたプリント配線基板をオーブン内で２００℃の温度雰囲気下で３０分間にわたり硬化処理を行った。これにより、プリント配線基板の表面に誘電体パターンが得られた。
【００７４】
得られた誘電体パターンのパターニング特性および誘電体特性については、後述の方法により評価した。結果を表１に示す。
【００７５】
【実施例２】
（Ｂ）アルカリ可溶性樹脂として、メタクリル酸ｎ−ブチル／メタクリル酸３−ヒドロキシプロピル／メタクリル酸＝６０／２０／２０（質量％）共重合体（Ｍｗ＝１００，０００）１０部、（Ｃ）エチレン性不飽和基含有化合物として、トリメチロールプロパントリアクリレート５部を用いたこと以外は実施例１と同様にして、感光性組成物を調製した。当該感光性組成物を用いたこと以外は実施例１と同様にして、厚さ２０μｍの感光性転写層を有する感光性転写フィルムを形成後、転写・露光・現像・硬化工程を行い、誘電体パターンを作製し、評価を行った。結果を表１に示す。
【００７６】
【実施例３】
チタン酸バリウム粒子（商品名「ＢＴ−０２」、堺化学株式会社製、平均粒子径０．２μｍ、誘電率２０００）を無電解銀メッキ法により表面に銀をコートして、誘電体用複合粒子（ｂ）を得た。
得られた粉体のＳＥＭ観察から、粒子表面に銀の微粒子が部分的に付着していることを確認した。また、ＳＩＭＳによりチタン酸バリウム表面に銀が重量比換算で２０％付着していることを確認した。一方、粉末の比表面積は４．０ｍ²／ｇであった。
【００７７】
（Ａ）誘電体用複合粒子として、前記誘電体用複合粒子（ｂ）１００部を用いたこと以外は実施例１と同様にして、感光性組成物を調製した。当該感光性組成物を用いたこと以外は実施例１と同様にして、厚さ２０μｍの感光性誘電体層を有する感光性フィルムを形成後、転写・露光・現像・硬化工程を行い、誘電体パターンを作製し、評価を行った。結果を表１に示す。
【００７８】
【実施例４】
チタン酸カルシウム粒子（平均粒子径２μｍ、誘電率１４０）を無電解リン−ニッケルメッキ法により表面にニッケルをコートして、誘電体用複合粒子（ｃ）を得た。
得られた粉体のＳＥＭ観察から、粒子表面にニッケルの微粒子が部分的に付着していることを確認した。また、ＳＩＭＳによりチタン酸カルシウム表面にニッケルが重量比換算で１０％付着していることを確認した。一方、粉末の比表面積は２．０ｍ²／ｇであった。
【００７９】
（Ａ）誘電体用複合粒子として、前記誘電体用複合粒子（ｃ）１００部を用いたこと以外は実施例１と同様にして、感光性組成物を調製した。当該感光性組成物を用いたこと以外は実施例１と同様にして、厚さ２０μｍの感光性誘電体層を有する感光性転写フィルムを形成後、転写・露光・現像・硬化工程を行い、誘電体パターンを作製し、評価を行った。結果を表１に示す。
【００８０】
【参考例１】
（Ｃ）エチレン性不飽和基含有化合物として、トリメチロールプロパントリアクリレート１部を用いたこと以外は実施例１と同様にして、感光性組成物を調製した。当該感光性組成物を用いたこと以外は実施例１と同様にして、厚さ２０μｍの感光性誘電体層を有する感光性転写フィルムを形成後、転写・露光・現像・硬化工程を行い、誘電体パターンを作製し、評価を行った。結果を表１に示す。
【００８１】
【参考例２】
（Ｃ）エチレン性不飽和基含有化合物として、トリメチロールプロパントリアクリレート５０部を用いたこと以外は実施例１と同様にして、感光性組成物を調製した。当該感光性組成物を用いたこと以外は実施例１と同様にして、厚さ２０μｍの感光性誘電体層を有する感光性フィルムを形成後、転写・露光・現像・硬化工程を行い、誘電体パターンを作製し、評価を行った。結果を表１に示す。
【００８２】
【参考例３】
（Ｂ）アルカリ可溶性樹脂として、メタクリル酸ｎ−ブチル／メタクリル酸３−ヒドロキシプロピル／メタクリル酸＝６０／２０／２０（質量％）共重合体（Ｍｗ＝１００，０００）３部を用いたこと以外は実施例１と同様にして、感光性組成物を調製した。当該感光性組成物を用いたこと以外は実施例１と同様にして、厚さ２０μｍの感光性誘電体層を有する感光性フィルムを形成後、基板上に転写したが転写不良となった。結果を表１に示す。
〔転写性〕
感光性フィルムをプリント配線基板の表面に転写した際、転写が良好であった場合を○、転写不良が生じた場合を×として評価した。
〔パターニング特性〕
得られた誘電体パターンについて、走査型電子顕微鏡（ＳＥＭ）を用いて、当該誘電体パターンの幅および高さの測定を行い、幅の精度について、５００μｍ±１０μｍの範囲にあるものを○、それ以外のものを×として評価した。また、パターンの欠落についての観察を行い、欠落のないものについて○、欠落のあるものについて×として評価した。
〔誘電率、誘電正接および体積抵抗率〕
ＪＩＳ Ｋ６４８１に準拠して測定した。
【００８３】
誘電率、誘電正接は周波数１ＭＨｚの測定値である。
〔耐湿熱性（ＨＡＳＴ試験）〕
硬化フィルムについて、１２１℃、湿度１００％、２気圧の条件下で、７２時間耐湿熱性試験を行って、試験の前後で赤外線分光測定を実施し、その変化の程度により、耐湿熱性を下記基準で評価した。
【００８４】
○・・・変化がなく耐性が認められる
×・・・変化が大きく耐性が認められない
【００８５】
【表１】

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photosensitive transfer film that can be suitably used to form a pattern with high dimensional accuracy, and a dielectric and an electronic component formed from the photosensitive transfer film.
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
In recent years, a technique in which a layer having a high dielectric constant is provided on a multilayer printed wiring board or the like and this layer is used for a capacitor or the like is known. This high dielectric constant layer is obtained by, for example, adding a high dielectric constant inorganic powder to an organic solvent made of a thermosetting resin to a fiber reinforcing material such as glass fiber to compensate for the brittleness of the thermosetting resin. It is prepared by a method such as impregnation, scattering of the solvent by baking or the like and curing. However, in the conventional method, it is usually difficult to obtain a layer having a high dielectric constant such as 30 or more or 50 or more.
[0003]
Attempts have also been made to obtain a dielectric layer having a high dielectric constant using various inorganic powders. For example, Fe is used as an inorganic powder in polystyrene._ThreeO_FourIt is known that a dielectric layer having a high dielectric constant can be obtained by adding ZnO + carbon or the like. However, in such a system, even if the dielectric constant can be increased, the dielectric loss tangent of the obtained dielectric layer becomes large, so that heat generation in the dielectric layer in an AC electric field increases, and a dielectric film is provided. In addition, there is a problem that the reliability and durability of the semiconductor substrate are likely to deteriorate due to deterioration of the multilayer printed wiring board and the like, and failure of the joint due to thermal stress.
[0004]
On the other hand, in order to obtain a high dielectric constant, a method is generally known in which a dielectric layer is formed by heating and baking high dielectric constant inorganic powder at a high temperature. However, since this method needs to be fired at a high temperature of about 1000 ° C., for example, it cannot be applied to the case where a dielectric layer is provided in a state where electronic components are mounted on a wiring board. There was a problem that it could not be applied universally to the process.
[0005]
Furthermore, a screen printing method or the like is known as a method for forming a dielectric layer, but with the increase in size and definition of the substrate, the requirement for pattern position accuracy becomes very strict and cannot be handled by normal printing. There was a problem. In addition, film thickness fluctuations and film defects are likely to occur depending on paste properties and printing conditions, and there is a problem that process management for obtaining a pattern with high dimensional accuracy is difficult.
[0006]
For this reason, the appearance of a photosensitive transfer film capable of providing a dielectric layer having a high dielectric constant and low heat loss by low-temperature firing and capable of forming a pattern with high dimensional accuracy has been desired.
Accordingly, the present inventors have intensively studied to solve the above problems, and use a photosensitive transfer film containing particles in which a conductive metal or organic compound is attached to a part of the surface of specific inorganic particles. Thus, it has been found that a dielectric having a pattern with a high dielectric constant, a low dielectric loss tangent, and a high dimensional accuracy can be formed at a low temperature of 500 ° C. or lower, and the present invention has been completed. It was.
[0007]
OBJECT OF THE INVENTION
The present invention is intended to solve the problems associated with the prior art as described above, and is a photosensitive transfer that can form a high-dielectric constant dielectric layer with low dimensional accuracy and low heat loss. It is an object to provide films and dielectrics and electronic components formed from this composition.
[0008]
SUMMARY OF THE INVENTION
The photosensitive transfer film according to the present invention is
(A) Composite particles for dielectrics in which a conductive metal or a compound thereof, a conductive organic compound or a conductive inorganic substance is attached to a part of the surface of an inorganic particle having a dielectric constant of 30 or more,
(B) an alkali-soluble resin,
(C) an ethylenically unsaturated group-containing compound, and
(D) A photosensitive transfer layer containing a photopolymerization initiator and having a film thickness of 5 to 100 μm is provided on a support film.
[0009]
According to the photosensitive transfer film of the present invention, it is possible to form a dielectric having a dielectric constant of 30 or more and a dielectric loss tangent of 0.1 or less by heating at 500 ° C. or lower.
The inorganic particles constituting the composite particles for dielectric (A) are preferably titanium metal oxides. Further, a conductive metal or a compound thereof, a conductive organic compound, or a conductive inorganic substance can be attached by an electroless plating method.
[0010]
The alkali-soluble resin (B) is preferably any one of (meth) acrylic resin, hydroxystyrene resin, novolac resin, or polyester resin.
The ethylenically unsaturated group-containing compound (C) is preferably a (meth) acrylate compound, and the ethylenically unsaturated group-containing compound (C) is (based on 100 parts by mass of the alkali-soluble resin (B)). It is preferably contained in the range of 20 to 500 parts by mass.
[0011]
The dielectric of the present invention can be formed by heating and curing the photosensitive transfer film at 500 ° C. or lower, and preferably has a dielectric constant of 30 or more and a dielectric loss tangent of 0.1 or less.
The electronic component according to the present invention is formed using the photosensitive transfer film.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the details of the photosensitive transfer film of the present invention will be described.
[Photosensitive transfer film]
The photosensitive transfer film of the present invention is
(A) Composite particles for dielectrics in which a conductive metal or a compound thereof, a conductive organic compound or a conductive inorganic substance is attached to a part of the surface of an inorganic particle having a dielectric constant of 30 or more,
(B) an alkali-soluble resin,
(C) an ethylenically unsaturated group-containing compound, and
(D) Photopolymerization initiator
And a photosensitive transfer layer having a thickness of 5 to 100 μm is essential.
[0013]
The photosensitive transfer film of the present invention comprises a support film and a photosensitive transfer layer formed on the support film, and a protective film is provided on the surface of the photosensitive transfer layer. Good.
<Supporting film and protective film>
The support film constituting the photosensitive transfer film of the present invention is preferably a resin film having heat resistance and solvent resistance and flexibility. Since the support film has flexibility, a photosensitive transfer layer can be formed by applying a paste-like composition by a roll coater, and the photosensitive transfer layer is stored in a roll shape, Can be supplied. Examples of the resin forming the support film include polyethylene terephthalate, polyester, polyethylene, polypropylene, polystyrene, polyimide, polyvinyl alcohol, fluorine-containing resin (eg, polyfluoroethylene), nylon, and cellulose. The thickness of the support film is preferably 20 to 100 μm, for example.
[0014]
The surface of the support film is preferably subjected to a release treatment. This is because when the mold release treatment is performed, the support film can be easily peeled off in the pattern forming process described later.
As the mold release process, for example, a process of applying a silicon release agent, a fluorine release agent, a silicon-fluorine release agent, or the like is preferably used.
[0015]
In addition, about a protective film, the thing similar to a support film can be used. Further, the surface of the protective film is usually subjected to a release treatment, and the peel strength between the protective film / photosensitive transfer layer is required to be smaller than the peel strength between the support film / photosensitive transfer layer.
<Photosensitive transfer layer>
The photosensitive transfer layer constituting the photosensitive transfer film of the present invention is usually
(A) Composite particles for dielectrics in which a conductive metal or a compound thereof, a conductive organic compound or a conductive inorganic substance is attached to a part of the surface of an inorganic particle having a dielectric constant of 30 or more,
(B) an alkali-soluble resin,
(C) an ethylenically unsaturated group-containing compound, and
(D) Photopolymerization initiator
As an essential component, and if necessary,
(E) a solvent, and
(F) It can form by apply | coating the paste-form photosensitive composition containing various additives on a support film, drying a coating film, and removing a part or all of a solvent.
[0016]
As a method of applying a photosensitive composition on a support film to obtain a photosensitive transfer layer, a film having a large thickness (for example, 1 μm or more) excellent in film thickness uniformity can be efficiently formed. Specifically, a coating method using a roll coater, a coating method using a blade coater, a coating method using a slit coater, a coating method using a curtain coater, a coating method using a wire coater, and the like can be mentioned as preferable examples.
[0017]
The drying condition of the coating film is 50 to 150 ° C. and about 0.5 to 30 minutes, and the residual ratio of the solvent after drying (content in the photosensitive transfer layer) is usually 2% by mass or less, preferably Is desirably 1% by mass or less.
The film thickness of the photosensitive transfer layer formed on at least one side of the support film as described above is desirably 5 to 100 μm, preferably 8 to 70 μm, and more preferably 10 to 50 μm.
[0018]
The content of the dielectric forming composite particles (A) in the photosensitive transfer layer is 30 to 90% by mass, preferably 40 to 80% by mass, based on the entire photosensitive transfer layer in the transfer film. It is desirable. By having such a photosensitive transfer layer, it is possible to obtain a photosensitive transfer film that has excellent adhesion to the substrate and can form a pattern with high dimensional accuracy.
<Photosensitive composition>
The photosensitive composition used for forming the photosensitive transfer layer constituting the photosensitive transfer film of the present invention comprises (A) a conductive metal on a part of the surface of inorganic particles having a dielectric constant of 30 or more. Or a composite particle for dielectric material to which the compound or a conductive organic compound or a conductive inorganic substance is attached, (B) an alkali-soluble resin, (C) an ethylenically unsaturated group-containing compound, (D) a photopolymerization initiator, If necessary, (E) a solvent and (F) various additives can be prepared by kneading using a kneader such as a roll kneader, a mixer, a homomixer, a ball mill, or a bead mill.
[0019]
The photosensitive composition prepared as described above is a paste-like composition having fluidity suitable for coating, and its viscosity is usually 100 to 100,000 mPa · s, preferably 500 to 10 1,000 mPa · s.
Hereinafter, each component constituting the photosensitive composition will be described.
(A) Composite particles for dielectric
<Inorganic particles>
The inorganic particles used in the present invention have a dielectric constant of 30 or more, preferably 50 or more, more preferably 70 or more. There is no problem with the high dielectric constant, and the upper limit is not limited, but it may be about 30000, for example.
[0020]
As such inorganic particles, those composed of metal oxides are preferably used, and titanium-based metal oxides are particularly preferable. Here, the “titanium metal oxide” refers to a compound containing a titanium element and an oxygen element as essential elements. As such a titanium-based metal oxide, a titanium-based single metal oxide containing a single titanium as a metal element constituting a crystal structure, and a titanium-based double oxide containing titanium and other metal elements as a metal element Can be preferably used.
[0021]
Examples of the titanium-based single metal oxide include titanium dioxide-based metal oxide. Examples of such titanium dioxide-based metal oxides include titanium dioxide-based metal oxides having an anatase structure or a rutile structure.
Examples of the titanium complex oxide include metal oxides such as barium titanate, lead titanate, strontium titanate, bismuth titanate, magnesium titanate, neodymium titanate, and calcium titanate. Is mentioned.
[0022]
The “titanium dioxide-based metal oxide” means a system containing only titanium dioxide or a system containing a small amount of other additives in titanium dioxide, and the crystal structure of titanium dioxide as a main component is retained. The same applies to other metal oxides.
The “titanium-based complex oxide” is an oxide formed by combining a titanium-based single metal oxide and a metal oxide composed of at least one other metal element. An oxoacid ion does not exist.
[0023]
In the present invention, the titanium-based metal oxide constituting such inorganic particles is preferably a titanium dioxide-based metal oxide having a rutile structure among the titanium-based single metal oxides. Among them, a barium titanate metal oxide can be preferably used.
Of these, barium titanate-based metal oxides can be particularly preferably used.
[0024]
Moreover, in order to improve the dispersibility to an aqueous medium, the particle | grains which modified | denatured the surface of the said inorganic particle with silica, an alumina, etc. can also be used suitably.
The average particle size of such inorganic particles is preferably 0.1 to 5.0 μm, more preferably 0.1 to 3.0 μm, more preferably 0.1 to 2.0 μm, and particularly preferably 0.2 to It is desirable that the thickness is 1.0 μm. If the average particle diameter exceeds 5 μm, the composition of the dielectric layer tends to be non-uniform when the film thickness is reduced. If the average particle size is less than 0.1 μm, the cohesive force between the powders becomes strong and coarse particles may be generated.
[0025]
The shape of the inorganic particle of the present invention is not particularly limited, and examples thereof include a spherical shape, a granular shape, a plate shape, a flake shape, a whisker shape, a rod shape, and a filament shape. Among these shapes, a spherical shape, a granular shape, a flake shape, and a scaly shape are preferable. These types of inorganic particles can be used singly or in combination of two or more.
<Composite particles for dielectrics>
In the composite particles for dielectric used in the present invention, a part of the surface of the inorganic particles is coated with a conductive substance. Examples of such a conductive substance include a conductive metal or a compound thereof, a conductive organic compound, or a conductive inorganic substance. These conductive substances may be attached to a part of the surface of the inorganic particles either singly or in combination.
[0026]
Examples of the conductive metal include at least one metal selected from gold, silver, copper, tin, platinum, palladium, ruthenium, Fe, Ni, Co, Ge, Si, Zn, Ti, Mg, Al, and the like. Can be used. These metals can also be used as the metal.
As the conductive metal compound, the conductive metal nitride can be used.
[0027]
As the conductive organic compound, at least one compound selected from TCNQ (7,7,8,8-tetracyanoquinodimethane), polypyrrole, polyaniline, polythiophene, and the like can be used.
As the conductive inorganic substance, at least one selected from carbon, graphite and the like other than the metal or metal compound can be used.
[0028]
The proportion of the inorganic particles contained in the dielectric composite particles used in the present invention is preferably 60 to 99% by weight, more preferably 65 to 95% by weight, and particularly preferably, with respect to the total weight of the dielectric composite particles Preferably, it is contained in an amount of 70 to 90% by weight. Further, the ratio of the conductive metal or their compounds or the conductive organic compound or the conductive inorganic substance, that is, the amount of the conductive substance attached is preferably 1 to the total weight of the composite particles for dielectric. It is desirable that it is contained in an amount of 40% by weight, more preferably 5 to 35% by weight, particularly preferably 10 to 30% by weight.
[0029]
When the proportion of the inorganic particle component exceeds 99% by weight, a high dielectric constant may not be obtained when a dielectric is used. Moreover, when the proportion of the inorganic particle component is less than 60% by weight, the dielectric insulation may be deteriorated.
The average particle size of the composite particles for dielectric used in the present invention is preferably 0.1 to 5.0 μm, more preferably 0.1 to 3.0 μm, more preferably 0.1 to 2.0 μm, particularly preferably. Is preferably 0.2 to 1.0 μm. If the average particle diameter exceeds 5 μm, the composition of the dielectric layer tends to be non-uniform when the film thickness is reduced. The average particle size of the dielectric composite particles is particularly preferably 2 μm or less in order to make the composition of the dielectric layer uniform even when the film thickness is reduced.
[0030]
The specific surface area of the composite particles for dielectric used in the present invention is preferably 1 to 20 m.²/ G, more preferably 1.2 to 15 m²/ G, more preferably 1.5 to 10 m²/ G, particularly preferably 1.5 to 8 m²/ G is desirable. When the specific surface area is in the above range, a dielectric having a high dielectric constant and a low dielectric loss tangent can be obtained.
Such dielectric composite particles used in the present invention can be prepared using a known method, and the production method is not limited.
[0031]
For example, when a conductive metal is coated on the surface of inorganic particles by plating or the like, it can be performed by electroless plating (chemical plating) or the like.
Moreover, as a method for obtaining the composite particles for dielectric having the average particle diameter as described above, specifically, the particles are composed of inorganic particles to which 1 to 40% by weight of a metal component (for example, copper) is adhered by electroless plating or the like. A powder having an average particle size of 0.1 to 10 μm is collected from the composite particles for dielectric using a classifier, and the powder is sufficiently dispersed by ultrasonic dispersion in pure water. By eluting only the Cu content on the surface in the sulfuric acid bath, it is possible to obtain composite particles for dielectric having such an average particle diameter.
(B) Alkali-soluble resin
Various resins can be used as the alkali-soluble resin used in the photosensitive composition. Here, “alkali-soluble” means a property of being dissolved by an alkaline developer, and specifically, it should be soluble to such an extent that the intended development processing is performed.
[0032]
Specific examples of such alkali-soluble resins include (meth) acrylic resins, hydroxystyrene resins, novolac resins, and polyester resins.
Among such alkali-soluble resins, (meth) acrylic resins are preferable, and particularly preferable ones include, for example,
Among such alkali-soluble resins, (meth) acrylic resins are preferable, and particularly preferable ones include, for example,
Copolymers of carboxyl group-containing monomers (a) (hereinafter also referred to as “monomer (a)”) and other copolymerizable monomers (c) (hereinafter also referred to as “monomer (c)”), or
Mention may be made of (meth) acrylic resins such as copolymers of monomer (ii) and OH group-containing monomers (b) (hereinafter also referred to as “monomer (b)”) and monomer (c).
[0033]
Examples of the monomer (I) (carboxyl group-containing monomers) include acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, mesaconic acid, cinnamic acid, and succinic acid mono (2). -(Meth) acryloyloxyethyl), ω-carboxy-polycaprolactone mono (meth) acrylate and the like.
[0034]
As the monomer (b) (OH group-containing monomers), for example,
Hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate;
phenolic hydroxyl group-containing monomers such as o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene;
Etc.
[0035]
Examples of the monomer (c), which is another copolymerizable monomer, include:
Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, n-lauryl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, dicyclopentanyl ( (Meth) acrylic acid esters other than the monomer (a) such as (meth) acrylate (when the monomer (b) is included, the monomers (b) and (b));
Aromatic vinyl monomers such as styrene and α-methylstyrene;
Conjugated dienes such as butadiene and isoprene;
A macromonomer having a polymerizable unsaturated group such as a (meth) acryloyl group at one end of a polymer chain such as polystyrene, poly (meth) acrylate methyl, poly (meth) ethyl acrylate, poly (meth) acrylate benzyl, etc. Kind;
Etc.
[0036]
The copolymer of the monomer (a) and the monomer (c) or the copolymer of the monomer (a), the monomer (b) and the monomer (c) is the monomer (b) and / or the monomer (b). Due to the presence of the copolymer component derived from the carboxyl group- or phenolic hydroxyl group-containing monomer, it becomes alkali-soluble. Among these, a copolymer of the monomer (A), the monomer (B), and the monomer (C) is particularly preferable from the viewpoint of dispersion stability of the dielectric composite particles (A) and solubility in an alkali developer described later. The content of the copolymer component unit derived from the monomer (a) in this copolymer is preferably 1 to 50% by mass, particularly preferably 5 to 30% by mass, and the copolymer component derived from the monomer (b). The content of the unit is preferably 1 to 50% by mass, particularly preferably 5 to 30% by mass, and the content of the copolymer component unit derived from the monomer (c) is preferably 1 to 98% by mass, particularly Preferably it is 40-90 mass%. Moreover, as a monomer (b) component, hydroxyl-containing monomers, such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, are preferable.
[0037]
The molecular weight of the alkali-soluble resin (B) constituting the photosensitive composition is a weight-average molecular weight in terms of polystyrene by GPC (hereinafter also simply referred to as “weight-average molecular weight (Mw)”), and is 5,000 to 5,000, 000, preferably 10,000 to 300,000.
The content ratio of the alkali-soluble resin (B) in the photosensitive composition is usually 5 to 500 parts by mass, preferably 10 to 500 parts by mass, particularly preferably 10 to 100 parts by mass of the dielectric composite particles (A). It is desirable that it is -200 mass parts. The photosensitive transfer film may contain a resin other than an alkali-soluble resin such as a polyimide resin, a bismaleimide resin, or an epoxy resin.
(C) Ethylenically unsaturated group-containing compound
The ethylenically unsaturated group-containing compound (C) constituting the photosensitive composition is not particularly limited as long as it is a compound that contains an ethylenically unsaturated group and can undergo a radical polymerization reaction with a photopolymerization initiator described later. Usually, a (meth) acrylate compound is used.
[0038]
Specific examples of such (meth) acrylate compounds include
Di (meth) acrylates of alkylene glycol such as ethylene glycol and propylene glycol; di (meth) acrylates of polyalkylene glycol such as polyethylene glycol and polypropylene glycol; hydroxypolybutadiene at both ends, hydroxypolyisoprene at both ends, hydroxypoly at both ends Di (meth) acrylates of hydroxylated polymers at both ends such as caprolactone; trivalent or higher polyvalent such as glycerin, 1,2,4-butanetriol, trimethylolalkane, tetramethylolalkane, pentaerythritol, dipentaerythritol Poly (meth) acrylates of alcohols; poly (meth) acrylates of polyalkylene glycol adducts of trihydric or higher polyhydric alcohols; 1,4-cyclohexanedio Le, poly (meth) acrylates of cyclic polyols such as 1,4-benzene diol;
List oligo (meth) acrylates such as polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, alkyd resin (meth) acrylate, silicone resin (meth) acrylate, and spiraline resin (meth) acrylate. Can do. As the (meth) acrylate compound, in addition to the compounds described above, the compounds shown in the monomers (A), (B) and (C) constituting the alkali-soluble resin (B) described above may be used. .
[0039]
The ethylenically unsaturated group-containing compound (C) containing these (meth) acrylate compounds can be used singly or in combination of two or more, and is usually added to 100 parts by mass of the alkali-soluble resin (B) described above. It is used in an amount of 20 to 500 parts by weight, preferably 40 to 250 parts by weight, more preferably 40 to 200 parts by weight.
(D) Photopolymerization initiator
Especially as a photoinitiator (D) which comprises a photosensitive composition, as long as it is a compound which generate | occur | produces a radical in the exposure process mentioned later and starts the polymerization reaction of the ethylenically unsaturated group containing compound (C) mentioned above. There is no limitation.
[0040]
Specific examples of the photopolymerization initiator (D) include
Benzyl, benzoin, benzophenone, Michler's ketone, 4,4'-bisdiethylaminobenzophenone, camphorquinone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy- 2-phenylacetophenone, 2-methyl- [4 ′-(methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1- Carbonyl compounds such as ON, 2,4-diethylthioxanthone, isopropylthioxanthone;
Phosphine oxide compounds such as bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide;
Azo compounds or azide compounds such as azoisobutyronitrile and 4-azidobenzaldehyde;
Organic sulfur compounds such as mercaptan disulfide;
Organic peroxides such as benzoyl peroxide, di-tert-butyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, paraffin hydroperoxide;
2,4-bis (trichloromethyl) -6- (2'-chlorophenyl) -1,3,5-triazine, 2- [2- (2-furanyl) ethylenyl] -4,6-bis (trichloromethyl)- Trihalomethanes such as 1,3,5-triazine;
Imidazole dimers such as 2,2'-bis (2-chlorophenyl) -4,5,4 ', 5'-tetraphenyl 1,2'-biimidazole;
These can be used alone or in combination of two or more. In addition to such a photopolymerization initiator (D), a sensitizer, a sensitization aid, a hydrogen donor, a chain transfer agent and the like may be used in combination.
[0041]
As a content rate of a photoinitiator (D), it is 0.1-100 mass parts normally with respect to 100 mass parts of total amounts of the said alkali-soluble resin (B) and an ethylenically unsaturated group containing compound (C). Preferably, it is 1 to 50 parts by mass.
(E) Solvent
The photosensitive composition contains a solvent (E) as necessary. As said solvent (E), affinity with the composite particle for dielectrics (A), alkali-soluble resin (B), ethylenically unsaturated group-containing compound (C), photopolymerization initiator (D), and necessary Accordingly, it has good solubility with various additives (F) described later, can impart a suitable viscosity to the photosensitive composition, and can be easily removed by evaporation by drying. preferable.
[0042]
Specific examples of such solvents include ketones such as diethyl ketone, methyl butyl ketone, dipropyl ketone, and cyclohexanone;
alcohols such as n-pentanol, 4-methyl-2-pentanol, cyclohexanol, diacetone alcohol;
Ether alcohols such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether;
Saturated aliphatic monocarboxylic acid alkyl esters such as n-butyl acetate and amyl acetate;
Lactate esters such as ethyl lactate and lactate-n-butyl;
Ether esters such as methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, ethyl-3-ethoxypropionate;
Etc., and these can be used alone or in combination of two or more.
[0043]
The content ratio of the solvent (E) in the photosensitive composition can be appropriately selected within a range in which good photosensitive transfer layer forming performance (fluidity or plasticity) is obtained. Usually, composite particles for dielectrics are used. (A) It is 1-10,000 mass parts with respect to 100 mass parts, Preferably it is 10-1,000 mass parts.
(F) Various additives
In addition to the components (A) to (E), the photosensitive composition constituting the photosensitive transfer film includes a plasticizer, an adhesion assistant, a dispersant, a filler, a storage stabilizer, an antifoaming agent, and an antioxidant. Various additives such as an agent, an ultraviolet absorber, a leveling agent, and a development accelerator may be contained as optional components.
(1) Plasticizer
The plasticizer is added in order to develop good flexibility in the formed photosensitive transfer layer. Specifically, the compound represented by the following formula (1) or (2) is preferably used because it is easily decomposed and removed by heat and does not adversely affect the performance of the resulting pattern.
[0044]
[Chemical 1]

[0045]
(Wherein R¹And R^FourEach represents the same or different alkyl group having 1 to 30 carbon atoms, R²And R^ThreeRespectively represent the same or different methylene groups or alkylene groups having 2 to 30 carbon atoms, s is an integer of 0 to 5, and t is an integer of 1 to 10. )
[0046]
[Chemical 2]

[0047]
(Wherein R^FiveRepresents a hydrocarbon group having 1 to 30 carbon atoms. )
In the above formula (1), R¹Or R^FourAn alkyl group represented by²Or R^ThreeThe alkylene group represented by may be linear or branched, and may be a saturated group or an unsaturated group. R¹Or R^FourThe carbon number of the alkyl group represented by is 1 to 30, preferably 2 to 20, and more preferably 4 to 10. R²Or R^ThreeThe number of carbon atoms of the alkylene group represented by is from 2 to 30, preferably from 2 to 20, and more preferably from 4 to 10. When the number of carbon atoms of the alkyl group and alkylene group exceeds 30, the solubility of the plasticizer in the solvent may be reduced, and good transfer film flexibility may not be obtained.
[0048]
Specific examples of the compound represented by the above formula (1) include dibutyl adipate, diisobutyl adipate, di-2-ethylhexyl adipate, di-2-ethylhexyl azelate, dibutyl sebacate, dibutyl diglycol adipate and the like. Preferably, t is a compound represented by 2-6.
In the above formula (2), R^FiveThe hydrocarbon group represented by may be linear or branched, and may be a saturated group or an unsaturated group. R^FiveIs preferably 1 to 30, preferably 2 to 20, and more preferably 10 to 18, and particularly preferably an alkyl group or an alkenyl group.
[0049]
Specific examples of the compound represented by the formula (2) include propylene glycol monolaurate and propylene glycol monooleate.
The content of the plasticizer in the photosensitive composition is 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the composite particles for dielectric (A). .
(2) Adhesion aid
As the adhesion assistant, a silane coupling agent [saturated alkyl group-containing (alkyl) alkoxysilane] such as a compound represented by the following formula (3) is preferably used.
[0050]
[Chemical Formula 3]

[0051]
(In the formula, p is an integer of 3 to 20, m is an integer of 1 to 3, n is an integer of 1 to 3, and a is an integer of 1 to 3.)
In the above formula (3), p indicating the carbon number of the saturated alkyl group is an integer of 3 to 20, and preferably an integer of 4 to 16.
Specific examples of the silane coupling agent represented by the above formula (3) include n-propyldimethylmethoxysilane, n-butyldimethylmethoxysilane, n-decyldimethylmethoxysilane, n-hexadecyldimethylmethoxysilane, and n-ico. Saturated alkyldimethylmethoxysilanes such as sundimethylmethoxysilane (a = 1, m = 1, n = 1);
Saturated alkyldiethylmethoxysilanes such as n-propyldiethylmethoxysilane, n-butyldiethylmethoxysilane, n-decyldiethylmethoxysilane, n-hexadecyldiethylmethoxysilane, n-icosanediethylmethoxysilane (a = 1, m = 1, n = 2);
Saturated alkyldipropylmethoxysilanes such as n-butyldipropylmethoxysilane, n-decyldipropylmethoxysilane, n-hexadecyldipropylmethoxysilane, n-icosanedipropylmethoxysilane (a = 1, m = 1, n = 3);
Saturated alkyldimethylethoxysilanes such as n-propyldimethylethoxysilane, n-butyldimethylethoxysilane, n-decyldimethylethoxysilane, n-hexadecyldimethylethoxysilane, n-icosanedimethylethoxysilane (a = 1, m = 2, n = 1);
Saturated alkyldiethylethoxysilanes such as n-propyldiethylethoxysilane, n-butyldiethylethoxysilane, n-decyldiethylethoxysilane, n-hexadecyldiethylethoxysilane, n-icosanediethylethoxysilane (a = 1, m = 2, n = 2);
Saturated alkyldipropylethoxysilanes (a = 1, m = 2, n-butyldipropylethoxysilane, n-decyldipropylethoxysilane, n-hexadecyldipropylethoxysilane, n-icosanedipropylethoxysilane) n = 3);
Saturated alkyldimethylpropoxysilanes such as n-propyldimethylpropoxysilane, n-butyldimethylpropoxysilane, n-decyldimethylpropoxysilane, n-hexadecyldimethylpropoxysilane, n-icosanedimethylpropoxysilane (a = 1, m = 3, n = 1);
Saturated alkyl diethylpropoxysilanes such as n-propyldiethylpropoxysilane, n-butyldiethylpropoxysilane, n-decyldiethylpropoxysilane, n-hexadecyldiethylpropoxysilane, n-icosanediethylpropoxysilane (a = 1, m = 3, n = 2);
Saturated alkyldipropylpropoxysilanes such as n-butyldipropylpropoxysilane, n-decyldipropylpropoxysilane, n-hexadecyldipropylpropoxysilane, n-icosanedipropylpropoxysilane (a = 1, m = 3, n = 3);
Saturated alkylmethyldimethoxysilanes such as n-propylmethyldimethoxysilane, n-butylmethyldimethoxysilane, n-decylmethyldimethoxysilane, n-hexadecylmethyldimethoxysilane, n-icosanemethyldimethoxysilane (a = 2, m = 1, n = 1);
Saturated alkylethyldimethoxysilanes such as n-propylethyldimethoxysilane, n-butylethyldimethoxysilane, n-decylethyldimethoxysilane, n-hexadecylethyldimethoxysilane, n-icosaneethyldimethoxysilane (a = 2, m = 1, n = 2);
Saturated alkylpropyldimethoxysilanes such as n-butylpropyldimethoxysilane, n-decylpropyldimethoxysilane, n-hexadecylpropyldimethoxysilane, n-icosanepropyldimethoxysilane (a = 2, m = 1, n = 3)
Saturated alkylmethyldiethoxysilanes such as n-propylmethyldiethoxysilane, n-butylmethyldiethoxysilane, n-decylmethyldiethoxysilane, n-hexadecylmethyldiethoxysilane, n-icosanemethyldiethoxysilane (A = 2, m = 2, n = 1);
Saturated alkylethyldiethoxysilanes such as n-propylethyldiethoxysilane, n-butylethyldiethoxysilane, n-decylethyldiethoxysilane, n-hexadecylethyldiethoxysilane, n-icosaneethyldiethoxysilane (A = 2, m = 2, n = 2);
Saturated alkylpropyldiethoxysilanes (a = 2, m = 2) such as n-butylpropyldiethoxysilane, n-decylpropyldiethoxysilane, n-hexadecylpropyldiethoxysilane, n-icosanepropyldiethoxysilane , N = 3);
Saturated alkylmethyldipropoxysilanes such as n-propylmethyldipropoxysilane, n-butylmethyldipropoxysilane, n-decylmethyldipropoxysilane, n-hexadecylmethyldipropoxysilane, n-icosanemethyldipropoxysilane (A = 2, m = 3, n = 1);
Saturated alkylethyldipropoxysilanes such as n-propylethyldipropoxysilane, n-butylethyldipropoxysilane, n-decylethyldipropoxysilane, n-hexadecylethyldipropoxysilane, n-icosaneethyldipropoxysilane (A = 2, m = 3, n = 2);
Saturated alkylpropyl dipropoxysilanes such as n-butylpropyldipropoxysilane, n-decylpropyldipropoxysilane, n-hexadecylpropyldipropoxysilane, n-icosanepropyldipropoxysilane (a = 2, m = 3) , N = 3);
Saturated alkyltrimethoxysilanes such as n-propyltrimethoxysilane, n-butyltrimethoxysilane, n-decyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-icosanetrimethoxysilane (a = 3, m = 1);
Saturated alkyltriethoxysilanes such as n-propyltriethoxysilane, n-butyltriethoxysilane, n-decyltriethoxysilane, n-hexadecyltriethoxysilane, n-icosanetriethoxysilane (a = 3, m = 2);
Saturated alkyltripropoxysilanes such as n-propyltripropoxysilane, n-butyltripropoxysilane, n-decyltripropoxysilane, n-hexadecyltripropoxysilane, n-icosanetripropoxysilane (a = 3, m = 3) etc. can be mentioned, These can be used individually or in combination of 2 or more types.
[0052]
Among these, n-butyltrimethoxysilane, n-decyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-decyldimethylmethoxysilane, n-hexadecyldimethylmethoxysilane, n-butyltriethoxysilane, n- Decyltriethoxysilane, n-hexadecyltriethoxysilane, n-decylethyldiethoxysilane, n-hexadecylethyldiethoxysilane, n-butyltripropoxysilane, n-decyltripropoxysilane, n-hexadecyltripropoxy Silane and the like are particularly preferable.
[0053]
The content ratio of the adhesion assistant in the photosensitive composition is 0.001 to 10 parts by weight, preferably 0.001 to 5 parts by weight, with respect to 100 parts by weight of the composite particles for dielectric (A). desirable.
(3) Dispersant
As the dispersant for the composite particles for dielectric (A), a fatty acid is preferably used, and a fatty acid having 3 to 30 carbon atoms, preferably 4 to 30 carbon atoms, and more preferably 4 to 20 carbon atoms is particularly preferable. As a preferable specific example of the fatty acid,
Saturated fatty acids such as malonic acid, octanoic acid, undecyl acid, lauric acid, myristic acid, palmitic acid, pentadecanoic acid, stearic acid, arachidic acid;
Unsaturated fatty acids such as fumaric acid, itaconic acid, citraconic acid, elaidic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid;
Aromatic fatty acids such as phthalic acid;
These may be used alone or in combination of two or more.
[0054]
The content ratio of the dispersant in the photosensitive composition is 0.001 to 10 parts by weight, preferably 0.01 to 5 parts by weight, with respect to 100 parts by weight of the composite particles for dielectric (A). .
(4) Filler
The photosensitive composition constituting the photosensitive transfer film of the present invention can further contain a filler in addition to the components (A) to (E). As such fillers, additives for improving the dielectric constant include, for example, carbon fine powder (eg, acetylene black, ketjen black, etc.), conductive fine particles such as graphite fine powder, and semiconductive fine particles such as silicon carbide fine powder. Etc. When these fillers for improving the dielectric constant are added, it is preferably 0 to 10% by weight, more preferably 0.5 to 10% by weight, particularly preferably 1 to the dielectric composite particles (A). It is desirable to use in an amount of ˜5% by weight.
[0055]
[Dielectric]
By using the photosensitive transfer film, a dielectric having a dielectric constant of 30 or more and a dielectric loss tangent of 0.1 or less can be formed by heating at 500 ° C. or lower. Hereinafter, the dielectric forming method and the physical properties of the dielectric according to the present invention will be described in detail.
<Method for forming dielectric layer pattern>
The pattern forming method using the photosensitive transfer film of the present invention includes: [1] a photosensitive transfer layer transfer step, [2] a photosensitive transfer layer exposure step, [3] a photosensitive transfer layer development step, [ 4) It has each process of the baking process of the photosensitive transfer layer pattern.
[1] Photosensitive transfer layer transfer process
In the transfer step, the photosensitive transfer film of the present invention is used, and the photosensitive transfer layer constituting the photosensitive transfer film is transferred onto the substrate.
[0056]
As the substrate material, for example, a plate-shaped member made of a printed circuit board, glass, silicone, alumina or the like is used. A plate having a desired pattern previously formed on the surface of the plate member may be used. For substrate surface, chemical treatment with silane coupling agent, etc. as necessary; plasma treatment; pretreatment such as thin film formation treatment by ion plating method, sputtering method, gas phase reaction method, vacuum deposition method, etc. May be applied as appropriate.
[0057]
An example of the transfer process is as follows. After removing the protective film of the photosensitive transfer film used as necessary, the photosensitive transfer film is overlaid on the substrate so that the surface of the photosensitive transfer layer is in contact with the photosensitive transfer film. Thermocompression bonding with a heating roller. As a result, the photosensitive transfer layer is transferred onto and in close contact with the substrate. Here, as the transfer conditions, for example, the surface temperature of the heating roller is 20 to 140 ° C., and the roll pressure by the heating roller is 1 to 5 kg / cm.²The condition that the moving speed of the heating roller is 0.1 to 10.0 m / min can be shown. Moreover, the board | substrate may be preheated and can be 40-100 degreeC as preheating temperature, for example.
[2] Exposure process of photosensitive transfer layer
In the exposure step, the surface of the photosensitive transfer layer is selectively irradiated (exposed) with radiation through an exposure mask to form a latent image of the pattern of the photosensitive transfer layer. The support film on the photosensitive transfer layer may be peeled off before the exposure step, or may be peeled off after the exposure step and before the development step described later. From the viewpoint of increasing sensitivity, the support film on the photosensitive transfer layer is preferably peeled off after the exposure step and before the development step described below.
[0058]
Examples of the radiation that is selectively irradiated (exposed) in the exposure step include visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray, and the like, preferably visible light, ultraviolet light, and far ultraviolet light, more preferably ultraviolet light. Used.
Although the exposure pattern of the exposure mask varies depending on the purpose, for example, a dot pattern having a width of 10 to 1000 μm is used.
[0059]
Examples of the radiation irradiation apparatus include, but are not limited to, an ultraviolet irradiation apparatus used in a photolithography method, an exposure apparatus used in manufacturing a semiconductor and a liquid crystal display device, and the like. .
[3] Photosensitive transfer layer development process
In the development step, the exposed photosensitive transfer layer is developed to reveal the pattern (latent image) of the photosensitive transfer layer.
[0060]
As the developer used in the development process of the photosensitive transfer layer, an alkali developer can be used. Thereby, the alkali-soluble resin contained in the photosensitive transfer layer can be easily dissolved and removed.
In addition, since the composite particles for dielectric contained in the photosensitive transfer layer are uniformly dispersed by the alkali-soluble resin, the composite particles for dielectric can be obtained by dissolving and washing the alkali-soluble resin as a binder. Removed at the same time.
[0061]
As an active ingredient of an alkaline developer, for example
Lithium hydroxide, sodium hydroxide, potassium hydroxide, sodium hydrogen phosphate, diammonium hydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, ammonium dihydrogen phosphate, potassium dihydrogen phosphate, diphosphate phosphate Inorganic alkaline compounds such as sodium hydrogen, lithium silicate, sodium silicate, potassium silicate, lithium carbonate, sodium carbonate, potassium carbonate, lithium borate, sodium borate, potassium borate, ammonia;
Organic alkaline compounds such as tetramethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, ethanolamine;
And so on.
[0062]
The alkaline developer used in the developing process of the photosensitive transfer layer can be prepared by dissolving one or more of the alkaline compounds in a solvent such as water. Here, the density | concentration of the alkaline compound in an alkaline developing solution is 0.001-10 mass% normally, Preferably it is 0.01-5 mass%. The alkaline developer may contain an additive such as a nonionic surfactant or an organic solvent.
[0063]
In addition, after the development process with an alkali developer is performed, a washing process is usually performed. Moreover, you may include the process of scraping the unnecessary part which remain | survives in the photosensitive transfer layer pattern side surface and board | substrate exposed part after a development process as needed.
As development processing conditions, the type, composition, and concentration of the developer, development time, development temperature, development method (for example, dipping method, rocking method, shower method, spray method, paddle method), development device, etc., are selected depending on the purpose. It can be selected appropriately.
[0064]
By this development process, a photosensitive transfer layer pattern (pattern corresponding to an exposure mask) composed of a photosensitive transfer layer remaining portion and a photosensitive transfer layer removal portion is formed.
[4] Photosensitive transfer layer pattern curing step
In this step, the dielectric layer pattern is thermally cured to form a pattern. Such heating temperature can be performed at 500 ° C. or less, preferably 100 to 500 ° C., more preferably 150 to 300 ° C. The heating time is preferably 1 minute to 24 hours, more preferably 10 minutes to 12 hours.
[0065]
When the photosensitive transfer layer is cured by heating, the heating method can be performed by, for example, an oven, an infrared lamp, a hot plate, or the like.
<Physical properties of dielectrics>
The dielectric obtained from the photosensitive transfer film of the present invention desirably has a dielectric constant of 30 or more, preferably 100 or more, more preferably 150 or more, and particularly preferably 200 or more. Although the upper limit of a dielectric constant is not specifically limited, For example, about 30000 may be sufficient. The dielectric loss tangent is 0.1 or less, preferably 0.08 or less, more preferably 0.06 or less. The lower limit of the dielectric loss tangent is not particularly limited, but may be about 0.001, for example.
[0066]
In this specification, the dielectric constant and dielectric loss tangent are values measured by the method described in JIS K6481 (frequency 1 MHz).
Also, the volume resistivity of such a dielectric is preferably 10¹¹Ω · cm or more, more preferably 10¹²It can be Ω · cm or more.
The thickness of the dielectric is preferably 100 μm or less, more preferably 30 μm or less. Although the minimum of film thickness is not specifically limited, Usually, it is 1 micrometer or more.
[0067]
[Electronic parts]
The dielectric of the present invention can be obtained by heating and firing at a temperature as low as 500 ° C. or less, and has a dielectric constant of 30 or more and a dielectric loss tangent of 0.1 or less, thereby forming a thin film capacitor having a large capacitance. can do. In addition, electronic components such as a printed circuit board, a semiconductor package, a capacitor, and a high frequency antenna provided with this dielectric can be small and have high density.
[0068]
【The invention's effect】
When the photosensitive transfer film according to the present invention is used, a dielectric having a low dielectric loss tangent of 0.1 or less and a high dielectric constant of 30 or more can be formed at a low heating temperature of 500 ° C. or less as described above. .
Since the dielectric of the present invention is a thin film and has a high dielectric constant, it is suitably used in electronic parts such as printed circuit boards, semiconductor packages, capacitors, and high frequency antennas.
[0069]
Since the electronic component of the present invention includes the dielectric, the electronic component can be reduced in size and thickness.
[0070]
【Example】
Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following, “part” means “part by mass”.
Moreover, a weight average molecular weight (Mw) is an average molecular weight of polystyrene conversion measured by Tosoh Corporation gel permeation chromatography (GPC) (brand name HLC-802A).
[0071]
[Example 1]
(1) Manufacture of dielectric composite particles
Barium titanate particles (trade name “HPBT-1”, manufactured by Fuji Titanium Co., Ltd., average particle size 0.6 μm, dielectric constant 2000) are coated with silver on the surface by an electroless silver plating method, and composite particles for dielectrics (A) was obtained.
[0072]
From SEM (scanning electron microscope) observation of the obtained powder, it was confirmed that silver fine particles partially adhered to the particle surface. Further, it was confirmed by SIMS (secondary ion mass spectrometry) that 10% of silver was adhered to the barium titanate surface in terms of weight ratio. On the other hand, the specific surface area of the powder is 3.8 m.²/ G.
(2) Preparation of photosensitive composition
(A) As composite particles for dielectric, 100 parts of composite particles for dielectric (a), (B) As alkali-soluble resin, n-butyl methacrylate / 3-hydroxypropyl methacrylate / methacrylic acid = 60/20 / 20 (mass%) copolymer (Mw = 50,000) 20 parts, (C) 10 parts of trimethylolpropane triacrylate as an ethylenically unsaturated group-containing compound, (D) 2-benzyl as a photopolymerization initiator 2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2 parts as (E) solvent, 100 parts of propylene glycol monomethyl ether and 1 part of oleic acid as dispersant (F), filler After kneading 0.5 parts of acetylene black with a bead mill, it is filtered with a stainless mesh (500 mesh). By and to prepare a photosensitive composition.
(3) Production of photosensitive transfer film
The photosensitive transfer film of the present invention in which a photosensitive transfer layer was formed on a support film was prepared by the following operation (a).
(A) A photosensitive film obtained as described above was applied on a support film (width 200 mm, length 30 m, thickness 38 μm) made of a PET film, which had been subjected to release treatment in advance, using a blade coater. The film was dried at 100 ° C. for 5 minutes to completely remove the solvent, and a photosensitive resin layer having a thickness of 20 μm was formed on the support film.
(4) Photosensitive transfer layer transfer process
A photosensitive transfer film was superposed on the surface of the printed wiring board so that the surface of the photosensitive transfer layer was in contact with the surface, and this photosensitive transfer film was thermocompression bonded with a heating roller. Here, as pressure bonding conditions, the surface temperature of the heating roller is 120 ° C., and the roll pressure is 4 kg / cm.² The moving speed of the heating roller was 0.5 m / min. As a result, the photosensitive transfer layer was transferred and adhered to the surface of the glass substrate. The film thickness of this photosensitive transfer layer was measured and found to be in the range of 20 μm ± 1 μm.
(5) Dielectric layer exposure / development process
The photosensitive transfer layer was irradiated with i rays (ultraviolet light having a wavelength of 365 nm) with an ultrahigh pressure mercury lamp through an exposure mask (500 μm square dot pattern). Here, the irradiation amount is 400 mJ / cm²It was.
[0073]
After completion of the exposure process, the exposed photosensitive transfer layer was developed by a shower method using a 0.5% by mass aqueous sodium carbonate solution (30 ° C.) as a developer over 1 minute. Subsequently, a water washing treatment with ultrapure water was performed, whereby the uncured photosensitive transfer layer not irradiated with ultraviolet rays was removed to form a pattern.
(6) Curing process of dielectric layer pattern:
The printed wiring board on which the photosensitive transfer layer pattern was formed was cured in an oven at 200 ° C. for 30 minutes. Thereby, a dielectric pattern was obtained on the surface of the printed wiring board.
[0074]
The patterning characteristics and dielectric characteristics of the obtained dielectric pattern were evaluated by the method described later. The results are shown in Table 1.
[0075]
[Example 2]
(B) As alkali-soluble resin, n-butyl methacrylate / 3-hydroxypropyl methacrylate / methacrylic acid = 60/20/20 (mass%) copolymer (Mw = 100,000) 10 parts, (C) ethylene A photosensitive composition was prepared in the same manner as in Example 1 except that 5 parts of trimethylolpropane triacrylate was used as the compound containing a polymerizable unsaturated group. In the same manner as in Example 1 except that the photosensitive composition was used, after forming a photosensitive transfer film having a photosensitive transfer layer having a thickness of 20 μm, a transfer / exposure / development / curing step was performed to obtain a dielectric. A pattern was prepared and evaluated. The results are shown in Table 1.
[0076]
[Example 3]
Barium titanate particles (trade name “BT-02”, manufactured by Sakai Chemical Industry Co., Ltd., average particle size 0.2 μm, dielectric constant 2000) are coated with silver by an electroless silver plating method, and composite particles for dielectrics (B) was obtained.
From SEM observation of the obtained powder, it was confirmed that silver fine particles were partially attached to the particle surface. Moreover, it confirmed that 20% of silver adhered to the barium titanate surface by SIMS by SIMS. On the other hand, the specific surface area of the powder is 4.0 m.²/ G.
[0077]
(A) A photosensitive composition was prepared in the same manner as in Example 1 except that 100 parts of the composite particle for dielectric (b) was used as the composite particle for dielectric. In the same manner as in Example 1 except that the photosensitive composition was used, after forming a photosensitive film having a photosensitive dielectric layer having a thickness of 20 μm, a transfer / exposure / development / curing step was performed to obtain a dielectric. A pattern was prepared and evaluated. The results are shown in Table 1.
[0078]
[Example 4]
Calcium titanate particles (average particle size 2 μm, dielectric constant 140) were coated with nickel on the surface by an electroless phosphorus-nickel plating method to obtain dielectric composite particles (c).
From SEM observation of the obtained powder, it was confirmed that nickel fine particles partially adhered to the particle surface. Further, it was confirmed by SIMS that 10% of nickel was attached to the calcium titanate surface in terms of weight ratio. On the other hand, the specific surface area of the powder is 2.0 m²/ G.
[0079]
(A) A photosensitive composition was prepared in the same manner as in Example 1 except that 100 parts of the dielectric composite particles (c) were used as the composite particles for dielectric. A photosensitive transfer film having a photosensitive dielectric layer having a thickness of 20 μm was formed in the same manner as in Example 1 except that the photosensitive composition was used, and then a transfer / exposure / development / curing step was performed. A body pattern was prepared and evaluated. The results are shown in Table 1.
[0080]
[Reference Example 1]
(C) A photosensitive composition was prepared in the same manner as in Example 1 except that 1 part of trimethylolpropane triacrylate was used as the ethylenically unsaturated group-containing compound. A photosensitive transfer film having a photosensitive dielectric layer having a thickness of 20 μm was formed in the same manner as in Example 1 except that the photosensitive composition was used, and then a transfer / exposure / development / curing step was performed. A body pattern was prepared and evaluated. The results are shown in Table 1.
[0081]
[Reference Example 2]
(C) A photosensitive composition was prepared in the same manner as in Example 1 except that 50 parts of trimethylolpropane triacrylate was used as the ethylenically unsaturated group-containing compound. In the same manner as in Example 1 except that the photosensitive composition was used, after forming a photosensitive film having a photosensitive dielectric layer having a thickness of 20 μm, a transfer / exposure / development / curing step was performed to obtain a dielectric. A pattern was prepared and evaluated. The results are shown in Table 1.
[0082]
[Reference Example 3]
(B) As alkali-soluble resin, except using 3 parts of n-butyl methacrylate / 3-hydroxypropyl methacrylate / methacrylic acid = 60/20/20 (mass%) copolymer (Mw = 100,000). A photosensitive composition was prepared in the same manner as in Example 1. A photosensitive film having a photosensitive dielectric layer having a thickness of 20 μm was formed and then transferred onto the substrate in the same manner as in Example 1 except that the photosensitive composition was used. The results are shown in Table 1.
[Transferability]
When the photosensitive film was transferred to the surface of the printed wiring board, the case where the transfer was good was evaluated as ◯, and the case where transfer failure occurred was evaluated as X.
[Patterning characteristics]
About the obtained dielectric pattern, the width | variety and height of the said dielectric pattern are measured using a scanning electron microscope (SEM), and the thing which exists in the range of 500 micrometers +/- 10 micrometers about the precision of the width, it Those other than were evaluated as x. Moreover, the lack of pattern was observed, and it evaluated as (circle) about the thing with no missing, and x with the missing.
[Dielectric constant, dielectric loss tangent and volume resistivity]
Measurement was performed in accordance with JIS K6481.
[0083]
The dielectric constant and dielectric loss tangent are measured values at a frequency of 1 MHz.
[Moisture and heat resistance (HAST test)]
The cured film was subjected to a moisture and heat resistance test for 72 hours under the conditions of 121 ° C., humidity 100%, and 2 atmospheres, and before and after the test, infrared spectroscopic measurement was performed. evaluated.
[0084]
○ ・ ・ ・ There is no change and tolerance is recognized
X: Change is large and tolerance is not recognized
[0085]
[Table 1]

Claims (9)

(A) Composite particles for dielectrics in which a conductive metal or a compound thereof, a conductive organic compound or a conductive inorganic substance is attached to a part of the surface of an inorganic particle having a dielectric constant of 30 or more,
(B) an alkali-soluble resin,
A photosensitive transfer layer containing (C) an ethylenically unsaturated group-containing compound and (D) a photopolymerization initiator and having a thickness of 5 to 100 μm,
A photosensitive transfer film provided on a support film. The photosensitive transfer film according to claim 1, wherein a dielectric having a dielectric constant of 30 or more and a dielectric loss tangent of 0.1 or less can be formed by heating at 500 ° C. or less. The photosensitive transfer film according to claim 1, wherein the inorganic particles constituting the dielectric composite particles (A) are titanium-based metal oxides. In the composite particles for dielectric (A), a conductive metal or a compound thereof, a conductive organic compound or a conductive inorganic substance is attached by an electroless plating method. The photosensitive transfer film according to any one of the above. The photosensitive transfer film according to claim 1, wherein the alkali-soluble resin (B) is any one of a (meth) acrylic resin, a hydroxystyrene resin, a novolak resin, or a polyester resin. . The photosensitive transfer film according to claim 1, wherein the ethylenically unsaturated group-containing compound (C) is a (meth) acrylate compound. The said ethylenically unsaturated group containing compound (C) is contained in the range of 20-500 mass parts with respect to 100 mass parts of alkali-soluble resin (B), The any one of Claims 1-6 characterized by the above-mentioned. The photosensitive transfer film according to 1. It is formed by heating and curing the photosensitive transfer film according to any one of claims 1 to 7 at 500 ° C or lower, and having a dielectric constant of 30 or more and a dielectric loss tangent of 0.1 or less. Dielectric. An electronic component formed using the photosensitive transfer film according to claim 1.