JP4106972B2 - Composition for forming photosensitive dielectric, dielectric and electronic component - Google Patents

Description

【００２６】
（式（１）において、Ｘ₁〜Ｘ₁₀は、それぞれ相互に同一または異なってもよく、水素原子、炭素数１〜４のアルキル基、炭素数１〜４のアルコキシ基または水酸基である。但し、Ｘ₁〜Ｘ₅の少なくとも１つは水酸基である。また、Ａは単結合、Ｏ、Ｓ、ＣＨ₂、Ｃ（ＣＨ₃）₂、Ｃ（ＣＦ₃）₂、Ｃ＝Ｏ、またはＳＯ₂である。）
【００２７】
【化２】

【００２８】
（式（２）において、Ｘ₁₁〜Ｘ₂₄は、それぞれ相互に同一または異なってもよく、前記Ｘ₁〜Ｘ₁₀の場合と同様である。但し、Ｘ₁₁〜Ｘ₁₅の少なくとも１つは水酸基である。また、Ｒ₁〜Ｒ₄は、水素原子または炭素数１〜４のアルキル基である。）
【００２９】
【化３】

【００３０】
（式（３）において、Ｘ₂₅〜Ｘ₃₉は、それぞれ相互に同一または異なってもよく、前記Ｘ₁〜Ｘ₁₀の場合と同様である。但し、Ｘ₂₅〜Ｘ₂₉において少なくとも１つは水酸基であり、Ｘ₃₀〜Ｘ₃₄において少なくとも１つは水酸基である。また、Ｒ₅は、水素原子または炭素数１〜４のアルキル基である。）
【００３１】
【化４】

【００３２】
（式（４）において、Ｘ₄₀〜Ｘ₅₈は、それぞれ相互に同一または異なってもよく、前記Ｘ₁〜Ｘ₁₀の場合と同様である。但し、Ｘ₄₀〜Ｘ₄₄において少なくとも１つは水酸基であり、Ｘ₄₅〜Ｘ₄₉において少なくとも１つは水酸基であり、Ｘ₅₀〜Ｘ₅₄において少なくとも１つは水酸基である。また、Ｒ₆〜Ｒ₈は、水素原子または炭素数１〜４のアルキル基である。）
【００３３】
【化５】

【００３４】
（式（５）において、Ｘ₅₉〜Ｘ₇₂は、それぞれ相互に同一または異なってもよく、前記Ｘ₁〜Ｘ₁₀と同様である。但し、Ｘ₅₉〜Ｘ₆₂において少なくとも１つは水酸基であり、Ｘ₆₃〜Ｘ₆₇において少なくとも１つは水酸基である。）
このようなキノンジアジド化合物（Ｃ）の具体例としては、以下のものが挙げられる。4,4'-ジヒドロキシジフェニルメタン、4,4'-ジヒドロキシジフェニルエーテル、2,3,4-トリヒドロキシベンゾフェノン、2,3,4,4'-テトラヒドロキシベンゾフェノン、2,3,4,2',4'-ペンタヒドロキシベンゾフェノン、トリス（4-ヒドロキシフェニル）メタン、トリス（4-ヒドロキシフェニル）エタン、1,1-ビス（4-ヒドロキシフェニル）-1-フェニルエタン、1,3-ビス［1-（4-ヒドロキシフェニル）-1-メチルエチル］ベンゼン、1,4-ビス［1-（4-ヒドロキシフェニル）-1-メチルエチル］ベンゼン、4,6-ビス［1-（4-ヒドロキシフェニル）-1-メチルエチル］-1,3-ジヒドロキシベンゼン、1,1-ビス（4-ヒドロキシフェニル）-1-［4-｛1-（4-ヒドロキシフェニル）-1-メチルエチル｝フェニル］エタンなどの1,2-ナフトキノンジアジド-4-スルホン酸または1,2-ナフトキノンジアジド-5-スルホン酸エステル化合物。
【００３５】
本発明の感光性誘電体形成用組成物においては、キノンジアジド化合物（Ｃ）は、フェノール樹脂（Ｂ）１００質量部に対して１０〜５０質量部、好ましくは１５〜３０質量部である。キノンジアジド化合物（Ｃ）の配合量が１０質量部未満では未露光部の残膜率が低下したり、マスクパターンに忠実な像が得られないことがある。また、キノンジアジド化合物（Ｃ）の配合量が５０質量部を超えるとパターン形状が劣化したり、硬化時に発泡することがある。
【００３６】
（Ｄ）分子中に少なくとも２つ以上のアルキルエーテル化されたアミノ基を有する化合物（硬化剤）；
本発明において用いられる分子中に少なくとも２つ以上のアルキルエーテル化されたアミノ基を有する化合物（以下、「硬化剤（Ｄ）」ともいう。）は、前記フェノール樹脂（Ｂ）と反応する架橋剤（硬化剤）として作用するものである。硬化剤（Ｄ）としては（ポリ）メチロール化メラミン、（ポリ）メチロール化グリコールウリル、（ポリ）メチロール化ベンゾグアナミン、（ポリ）メチロール化ウレアなどの活性メチロール基の全部または一部をアルキルエーテル化した含窒素化合物を挙げることができる。ここで、アルキル基としてはメチル基、エチル基、ブチル基、またはこれらを混合したものを挙げることができ、一部自己縮合してなるオリゴマー成分を含有していてもよい。具体的にはヘキサメトキシメチル化メラミン、ヘキサブトキシメチル化メラミン、テトラメトキシメチル化グリコールウリル、テトラブトキシメチル化グリコールウリルなどを用いることができ、これらの硬化剤（Ｄ）は１種単独または２種以上を併用しても構わない。
【００３７】
本発明における硬化剤（Ｄ）の配合量は前記フェノール樹脂（Ｂ）１００質量部に対して、１〜１００質量部、好ましくは５〜５０質量部である。配合量が１質量部未満では硬化が不十分になり、得られる硬化物の電気絶縁性が低下したりすることがあり、１００質量部を越えるとパターニング特性が低下したり、耐熱性が低下することがある。
【００３８】
（Ｅ）熱感応性酸発生剤
本発明において用いられる熱感応性酸発生剤（以下、「酸発生剤（Ｅ）」という。）は、適当な熱を加える、たとえば５０〜２５０℃に加熱することによって酸を発生する化合物ならば特に制限されないが、例えばスルホニウム塩やジアゾニウム塩、ハロゲン含有化合物、スルホン酸エステル化合物などが挙げられる。
【００３９】
酸発生剤（Ｅ）の例としては、たとえばベンジルメチルフェニルスルホニウムヘキサフルオロアンチモネート、ベンジルメチルフェニルスルホニウムヘキサフルオロホスフェート、ベンジルメチルフェニルスルホニウムテトラフルオロボレート、ベンジルメチルフェニルスルホニウムトリフルオロメタンスルホネート、ベンジル（4-ヒドロキシフェニル）メチルスルホニウムヘキサフルオロアンチモネート、ベンジル（4-ヒドロキシフェニル）メチルスルホニウムヘキサフルオロホスフェート、ベンジル（4-ヒドロキシフェニル）メチルスルホニウムテトラフルオロボレート、ベンジル（4-ヒドロキシフェニル）メチルスルホニウムトリフルオロメタンスルホネート、ベンゼンジアゾニウムヘキサフルオロアンチモネート、ベンゼンジアゾニウムヘキサフルオロホスフェート、ベンゼンジアゾニウムテトラフルオロボレート、ベンゼンジアゾニウムトリフルオロメタンスルホネート、ナフタレンジアゾニウムヘキサフルオロアンチモネート、ナフタレンジアゾニウムトリフルオロメタンスルホネートなどが挙げられる。
【００４０】
本発明における酸発生剤（Ｅ）の配合量は前記フェノール樹脂（Ｂ）１００質量部に対して、０．１〜１０質量部、好ましくは０．５〜５質量部である。酸発生剤（Ｅ）の配合量が０．１質量部未満では得られる硬化物の耐溶剤性が低下したりすることがあり、１０質量部を越えると電気絶縁性が低下することがある。
（Ｆ）架橋微粒子
本発明において用いられる架橋微粒子（Ｆ）は、該粒子を構成する重合体のＴｇが０℃以下であれば特に限定されるものではないが、不飽和重合性基を２個以上有する架橋性モノマー（以下、「架橋性モノマー」ともいう。）と、架橋微粒子（Ｆ）を構成する共重合体のＴｇが０℃以下となるように選択される１種以上のその他のモノマー（以下、「その他のモノマー」ともいう。）を共重合したものが好ましく、さらに、その他のモノマーとして架橋微粒子（Ｆ）を構成する共重合体のＴｇが０℃以下となるようなものであって、重合性基以外の官能基、たとえば、カルボキシル基、エポキシ基、アミノ基、イソシアネート基、水酸基等の官能基を有するモノマーを共重合したものが好ましく用いられる。
【００４１】
架橋性モノマーの例としては、ジビニルベンゼン、ジアリルフタレート、エチレングリコールジ（メタ）アクリレート、プロピレングリコールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ポリエチレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレートなどの重合性不飽和基を複数有する化合物を挙げることができる。なかでも、ジビニルベンゼンが好ましい。
【００４２】
本発明において用いられる架橋微粒子（Ｆ）を製造する際に用いられる架橋性モノマーは、共重合に用いられる全モノマーに対して１〜２０質量％の範囲、より好ましくは２〜１０質量％の範囲で用いられる。
その他のモノマーの例としては、ブタジエン、イソプレン、ジメチルブタジエン、クロロプレン、1,3-ペンタジエンなどのジエン化合物、（メタ）アクリロニトリル、α-クロロアクリロニトリル、α-クロロメチルアクリロニトリル、α-メトキシアクリロニトリル、α-エトキシアクリロニトリル、クロトン酸ニトリル、ケイ皮酸ニトリル、イタコン酸ジニトリル、マレイン酸ジニトリル、フマル酸ジニトリルなどの不飽和ニトリル化合物類、（メタ）アクリルアミド、N,N'-メチレンビス（メタ）アクリルアミド、N,N'-エチレンビス（メタ）アクリルアミド、N,N'-ヘキサメチレンビス（メタ）アクリルアミド、N-ヒドロキシメチル（メタ）アクリルアミド、N-（2-ヒドロキシエチル）（メタ）アクリルアミド、N,N-ビス（2-ヒドロキシエチル）（メタ）アクリルアミド、クロトン酸アミド、ケイ皮酸アミド等の不飽和アミド類、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸ブチル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸ラウリル、ポリエチレングリコール（メタ）アクリレート、ポリプロピレングリコール（メタ）アクリレートなどの（メタ）アクリル酸エステル類、スチレン、α-メチルスチレン、ｏ-メトキシスチレン、ｐ-ヒドロキシスチレン、ｐ-イソプロペニルフェノールなどの芳香族ビニル化合物、ビスフェノールＡのジグリシジルエーテル、グリコールのジグリシジルエーテルなどと（メタ）アクリル酸、ヒドロキシアルキル（メタ）アクリレートなどとの反応によって得られるエポキシ（メタ）アクリレートおよび、ヒドロキシアルキル（メタ）アクリレートとポリイソシアナートとの反応によって得られるウレタン（メタ）アクリレート類、グリシジル（メタ）アクリレート、（メタ）アリルグリシジルエーテルなどのエポキシ基含有不飽和化合物、（メタ）アクリル酸、イタコン酸、コハク酸-β-（メタ）アクリロキシエチル、マレイン酸-β-（メタ）アクリロキシエチル、フタル酸-β-（メタ）アクリロキシエチル、ヘキサヒドロフタル酸-β-（メタ）アクリロキシエチルなどの不飽和酸化合物、ジメチルアミノ（メタ）アクリレート、ジエチルアミノ（メタ）アクリレート等のアミノ基含有不飽和化合物、（メタ）アクリルアミド、ジメチル（メタ）アクリルアミド等のアミド基含有不飽和化合物、ヒドロキシエチル（メタ）アクリレート、ヒドロキシプロピル（メタ）アクリレート、ヒドロキシブチル（メタ）アクリレート等の水酸基含有不飽和化合物などを例示することができる。これらのその他のモノマーとしては、ブタジエン、イソプレン、（メタ）アクリロニトリル、（メタ）アクリル酸アルキルエステル類、スチレン、ｐ-ヒドロキシスチレン、ｐ-イソプロペニルフェノール、グリシジル（メタ）アクリレート、（メタ）アクリル酸、ヒドロキシアルキル（メタ）アクリレート類などが好ましく用いられる。
【００４３】
このようなその他のモノマーとしては、少なくとも１種のジエン化合物、具体的にはブタジエンを用いることが好ましい。このようなジエン化合物は、共重合に用いる全モノマーに対して２０〜８０質量％、好ましくは３０〜７０質量％の量で用いられることが望ましい。
本発明で用いられる架橋微粒子（Ｆ）は、その他のモノマーとしてブタジエンなどのジエン化合物が全モノマーに対して上記のような量で共重合されていると、ゴム状の軟らかい微粒子となり、特に得られる硬化膜にクラック（割れ）が生ずるのを防止でき、耐久性に優れた硬化膜を得ることができる。
【００４４】
本発明において架橋微粒子（Ｆ）の平均粒子径は、通常３０〜５００ｎｍ、好ましくは４０〜２００ｎｍ、さらに好ましくは５０〜１２０ｎｍであることが好ましい。架橋微粒子（Ｆ）の粒径コントロール方法は、特に限定されるものではないが、乳化重合により架橋微粒子（Ｆ）を合成する場合、使用する乳化剤の量により、乳化重合中のミセルの数を制御し、粒径をコントロールする方法が例示できる。
【００４５】
また、架橋微粒子（Ｆ）の配合量は前記フェノール樹脂（Ｂ）１００質量部に対して、０〜５０質量部、好ましくは１〜５０質量部、さらに好ましくは５〜３０質量部である。架橋微粒子（Ｆ）の配合量が５０質量部を越えると解像性や得られる硬化膜の耐熱性が低下したり、他成分との相溶性、分散性が低下することがある。感光性誘導体形成用組成物が架橋微粒子を含有すると、得られる硬化膜の熱衝撃性が向上する。
【００４６】
（Ｇ）溶剤
本発明において用いられる溶剤（Ｇ）は、感光性誘電体形成用組成物の取り扱い性を向上させたり、粘度や保存安定性を調節するために添加される。このような溶剤（Ｇ）の種類は、特に制限されるものではないが、たとえば、エチレングリコールモノメチルエーテルアセテート、エチレングリコールモノエチルエーテルアセテート等のエチレングリコールモノアルキルエーテルアセテート類；プロピレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテル、プロピレングリコールモノプロピルエーテル、プロピレングリコールモノブチルエーテル等のプロピレングリコールモノアルキルエーテル類；プロピレングリコールジメチルエーテル、プロピレングリコールジエチルエーテル、プロピレングリコールジプロピルエーテル、プロピレングリコールジブチルエーテル等のプロピレングリコールジアルキルエーテル類；プロピレングリコールモノメチルエーテルアセテート、プロピレングリコールモノエチルエーテルアセテート、プロピレングリコールモノプロピルエーテルアセテート、プロピレングリコールモノブチルエーテルアセテート等のプロピレングリコールモノアルキルエーテルアセテート類；エチルセロソルブ、ブチルセロソルブ等のセロソルブ類、ブチルカルビトール等のカルビトール類；乳酸メチル、乳酸エチル、乳酸n-プロピル、乳酸イソプロピル等の乳酸エステル類；酢酸エチル、酢酸n-プロピル、酢酸イソプロピル、酢酸n-ブチル、酢酸イソブチル、酢酸n-アミル、酢酸イソアミル、プロピオン酸イソプロピル、プロピオン酸n-ブチル、プロピオン酸イソブチル等の脂肪族カルボン酸エステル類；3-メトキシプロピオン酸メチル、3-メトキシプロピオン酸エチル、3-エトキシプロピオン酸メチル、3-エトキシプロピオン酸エチル、ピルビン酸メチル、ピルビン酸エチル等の他のエステル類；トルエン、キシレン等の芳香族炭化水素類；2-ヘプタノン、3-ヘプタノン、4-ヘプタノン、シクロヘキサノン等のケトン類；N-ジメチルホルムアミド、N-メチルアセトアミド、N,N-ジメチルアセトアミド、N-メチルピロリドン等のアミド類；γ-ブチロラクン等のラクトン類などを挙げることができる。これらの溶剤（Ｆ）は、１種単独あるいは２種以上を混合して使用することもできる。
【００４７】
その他の添加剤
本発明の感光性誘電体形成用組成物中には、その他の添加剤としてエポキシ化合物、密着助剤およびレベリング剤などを含有することができる。また、エポキシ化合物としてはたとえば、ノボラック型エポキシ樹脂、ビスフェノール型エポキシ樹脂、脂環式エポキシ樹脂、脂肪族エポキシ樹脂などが挙げられる。これらのその他添加剤は得られる感光性誘電体形成用組成物の特性を損なわない程度に含有することができる。
【００４８】
［誘電体］
本発明の感光性誘電体形成用組成物を用いることにより、５００℃以下の加熱で、誘電率が５以上、好ましくは１０以上、誘電正接が０．１以下、静電容量５ｎＦ／ｃｍ²以上の誘電体を形成することができる。以下に、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。
【００４９】
本発明にかかる感光性誘電体形成用組成物を配線パターン等が施されたシリコンウエハーなどの基板に塗工し、乾燥して溶剤などを揮発させて塗膜を形成する。上記基板材料としては、特に限定されないが、たとえばプリント配線基板、銅張積層板（ＣＣＬ）、ＳＵＳ基板、銅箔付きポリイミド基板、セラミクス基板、シリコーンウエハー（Ｗ−ＣＳＰなど）、アルミナ基板などからなる板状部材が挙げられる。その後所望のマスクパターンを介して露光し、次いで、アルカリ性現像液により現像して、露光部を溶解、除去することにより所望のパターンが形成された塗膜を得ることができる。さらに、コンデンサ特性を発現させるために現像後に加熱処理を行うことにより、硬化膜を得ることができる。
【００５０】
感光性誘電体形成用組成物を基板に塗工する方法としては、たとえば、ディッピング法、スプレー法、バーコート法、ロールコート法、スピンコート法、カーテンコート法スクリーン印刷法などの塗布方法を用いることができ、塗布の厚さは、塗布手段、感光性誘電体形成用組成物の固形分濃度や粘度を調節することにより、適宜制御することができる。
【００５１】
露光に用いられる放射線としては、たとえば、低圧水銀灯、高圧水銀灯、メタルハライドランプ、ｇ線ステッパー、ｉ線ステッパーなどの紫外線や電子線、レーザー光線などが挙げられ、露光量としては使用する光源や誘電体層の膜厚などによって適宜選定されるが、例えば高圧水銀灯からの紫外線照射の場合、誘電体層の膜厚０．５〜５０μｍでは、１,０００〜２０,０００Ｊ／ｍ²程度である。
【００５２】
その後、アルカリ性現像液により現像して、露光部を溶解、除去することによって所望のパターンを形成する。誘電体層に含有される無機粒子は、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、アルカリ可溶性樹脂が溶解した部分に存在する無機粒子も同時に除去される。この場合の現像方法としては、シャワー現像法、スプレー現像法、浸漬現像法、パドル現像法などを挙げることができ、現像条件としては通常、２０〜４０℃で１〜１０分程度である。
【００５３】
前記アルカリ性現像液としては、たとえば、水酸化ナトリウム、水酸化カリウム、アンモニア水、テトラメチルアンモニウムヒドロキシド、コリンなどのアルカリ性化合物を濃度が０．１〜１０質量％程度になるように水に溶解したアルカリ性水溶液を挙げることができる。前記アルカリ性水溶液には、たとえば、メタノール、エタノールなどの水溶性の有機溶剤や界面活性剤などを適量添加することもできる。なお、アルカリ性現像液で現像した後は、水で洗浄し、乾燥する。
【００５４】
さらに、現像後に絶縁膜としての特性を十分に発現させるために加熱処理を行うことによって硬化させることができる。この際、酸発生剤（Ｅ）が分解し、酸を発生する。この酸の触媒作用によって硬化剤（Ｄ）とフェノール樹脂（Ｂ）との硬化反応が促進される。このような硬化条件は特に制限されるものではないが、硬化物の用途に応じて、１００〜２５０℃の温度で、３０分〜１０時間程度加熱し、塗膜を硬化させることができる。また、硬化を十分に進行させたり、得られたパターン形状の変形を防止するために二段階で加熱することもでき、例えば、第一段階では、５０〜１００℃の温度で、１０分〜２時間程度加熱し、さらに１００〜２５０℃の温度で、２０分〜８時間程度加熱して硬化させることもできる。このような硬化条件であれば、加熱設備として一般的なオーブンや、赤外線炉などを使用することができる。
【００５５】
＜誘電体の物性＞
本発明に係る感光性誘電体形成用組成物から得られる誘電体は、誘電率が５以上、好ましくは１０以上、さらに好ましくは１５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２００程度であってもよい。また、本発明に係る感光性誘電体形成用組成物から得られる誘電体は、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。本発明に係る感光性誘電体形成用組成物から得られる誘電体は、静電容量が静電容量５ｎＦ／ｃｍ²以上、好ましくは１０ｎＦ／ｃｍ²以上、さらに好ましくは１５ｎＦ／ｃｍ²以上であることが望ましい。静電容量の上限は特に限定されないが、たとえば５０ｎＦ／ｃｍ²以上程度であってもよい。
【００５６】
なお、本明細書において、誘電率、誘電正接、静電容量は、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、このような誘電体をコンデンサとして使用する場合のリーク電流は好ましくは１０^-8Ａ/cm²以下、より好ましくは１０^-9Ａ/cm²以下、更に好ましくは１０^-10Ａ/cm²以下であることが望ましい。
【００５７】
なお、この誘電体の厚さは、好ましくは５０μｍ以下、より好ましくは２０μｍ以下、さらに好ましくは５μｍ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０．５μｍ以上である。
［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５以上であり、かつ誘電正接が０．１以下であり、かつ静電容量４ｎＦ／ｃｍ²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。
【００５８】
【発明の効果】
本発明に係る感光性誘電体形成用組成物を用いると、前記のように５００℃以下という低い加熱温度で、しかも０．１以下という誘電正接かつ５ｎＦ／ｃｍ²以上という高い静電容量の誘電体を形成することができる。
本発明に係る誘電体は、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。
【００５９】
本発明に係る電子部品は、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。
【００６０】
【実施例】
以下、実施例に基づいて本発明をさらに具体的に説明するが、本発明はこれらの実施例に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、「％」は「質量％」を示す。
【００６１】
【実施例１】
（１）感光性誘電体形成用組成物の調製
表１に示すとおり、（A-1）無機粒子としてチタン酸バリウム粒子１５０質量部、（B-1）フェノール樹脂１００質量部、（C-1）キノンジアジド化合物１５質量部、(D-1)硬化剤２３質量部、(E-1)酸発生剤２質量部、(F-1)架橋微粒子１０質量部、(G-1)乳酸エチル９００質量部に溶解し、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）および孔径１μｍのフィルターで濾過することにより、感光性誘電体形成用組成物を調製した。
【００６２】
（２）感光性誘電体形成用組成物の塗布工程
感光性誘電体形成用組成物をＣｕスパッタ付きシリコンウェハー上にスピンナーを用いて塗布し、塗膜を１００℃で５分間乾燥して溶剤を完全に除去し、厚さ１μｍの感光性誘電体層を形成した。
（３）誘電体層の露光工程・現像工程
感光性誘電体層に対して、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。照射量は５００ｍＪ／ｃｍ²とした。
【００６３】
露光工程の終了後、露光処理された感光性誘電体層に対して、２．３８質量％のテトラメチルアンモニウムヒドロキシド水溶液（２５℃）を現像液とするシャワー法による現像処理を２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可溶化された感光性誘電体層を除去し、パターンを形成した。
【００６４】
（４）誘電体層パターンの硬化工程
感光性誘電体層パターンが形成されたシリコンウェハーをオーブン内で２００℃の温度雰囲気下で６０分間にわたり硬化処理を行った。これにより、シリコンウェハー基板の表面に誘電体パターンが得られた。
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。
【００６５】
【実施例２〜５】
実施例１と同様にして、表１に示した組成の感光性誘電体形成用組成物を調製し、これらの特性を実施例１と同様に測定した。得られた結果を表１に示す。
【００６６】
【比較例１〜５】
表２に示す各組成物を調製し、実施例１と同様に物性を測定した。結果を表２に示す。
なお、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以下のようにして評価した。
【００６７】
〔パターニング特性〕
実施例１〜５、および比較例１〜５：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±５μｍ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。
【００６８】
〔誘電率、誘電正接およびリーク電流〕
実施例１〜５、および比較例１〜５：得られた誘電体パターン上面にアルミ蒸着法により上面電極（厚み；0.5μｍ）を形成した。
Ｃｕスパッタ付きシリコンウェハー基板側と上面電極の間でＬＣＲメーター（ＨＰ４２８４Ａ、ヒューレットパッカード社製）により１ＭＨｚでの誘電率、誘電正接を１０点測定してその平均値を求めた。また、銅箔側と電極の間でのリーク電流を絶縁抵抗計（アドバンテスト製）で１０点測定してその平均値を求めた。
【００６９】
〔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。
○・・・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
【００７０】
【表１】

【００７１】
【表２】

【００７２】
注）表１に記載の組成は、以下のとおりである。
無機粒子
Ａ−１：チタン酸バリウム粒子（商品名「ＢＴ−０１」、堺化学工業社製、平均粒子径０．１μｍ）
Ａ−２：チタン酸バリウム粒子（商品名「ＢＴ−０２」、堺化学工業社製、平均粒子径０．２μｍ）
フェノール樹脂；
Ｂ−１：ｍ−クレゾール／ｐ−クレゾール＝６０／４０（モル比）からなるクレゾールノボラック樹脂（ポリスチレン換算重量平均分子量＝８,７００）
Ｂ−２：ｍ−クレゾール／ｐ−クレゾール＝５０／５０（モル比）からなるクレゾールノボラック樹脂（ポリスチレン換算重量平均分子量＝７,５００）
Ｂ−３：ポリヒドロキシスチレン（丸善石油化学（株）製、商品名；マルカリンカー Ｓ−２Ｐ）
フェノール化合物；
ｂ−１：1,1-ビス（4-ヒドロキシフェニル）-1-[4-｛1-（4-ヒドロキシフェニル）-1-メチルエチル｝フェニル]エタン
キノンジアジド化合物；
Ｃ−１：1,1-ビス（4-ヒドロキシフェニル）-1-［4-[1-（4-ヒドロキシフェニル）-1-メチルエチル]フェニル］エタンと1,2-ナフトキノンジアジド-5-スルホン酸との2.0モル縮合物
Ｃ−２：1,1-ビス（4-ヒドロキシフェニル）-1-フェニルエタンと1,2-ナフトキノンジアジド-5-スルホン酸との1.5モル縮合物
硬化剤；
Ｄ−１：ヘキサメトキシメチル化メラミン（三井サイテック（株）製、商品名；サイメル３００）
Ｄ−２：テトラメトキシメチルグルコールウリル（三井サイテック（株）製、商品名；サイメル１１７４）
酸発生剤；
Ｅ−１：ベンジル（4-ヒドロキシフェニル）メチルスルホニウムヘキサフルオロアンチモネート
Ｅ−２：ベンジル（4-ヒドロキシフェニル）メチルスルホニウムヘキサフルオロホスフェート
架橋微粒子；
Ｆ−１：ブタジエン／ヒドロキシブチルメタクリレート／メタクリル酸／ジビニルベンゼン＝６０／３２／６／２（重量％）、平均粒径＝６５ｎｍ
溶剤；
Ｇ−１：乳酸エチル
Ｇ−２：2-ヘプタノン[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a composition for forming a photosensitive dielectric material that can be suitably used to form a pattern with high dimensional accuracy, and a dielectric material and an electronic component formed therefrom.
[0002]
TECHNICAL BACKGROUND OF THE INVENTION
In recent years, a technique in which a high dielectric constant layer 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 made of, for example, a fiber reinforced fiber glass or the like in which an organic solvent in which a thermosetting resin is dissolved is added with an inorganic powder having a high dielectric constant to compensate for the brittleness of the thermosetting resin. It is prepared by a method of impregnating a material and then dispersing and curing the solvent by baking or the like. However, in the conventional method, it is usually difficult to obtain a layer having a high dielectric constant of, for example, 20 or more and having a low leakage current even in a thin film.
[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.
For this reason, there has been a demand for the appearance of a composition for forming a photosensitive dielectric capable of providing a dielectric layer having a high dielectric constant and a small heat loss by low-temperature firing and capable of forming a pattern with high dimensional accuracy.
[0006]
Therefore, as a result of intensive studies to solve the above problems, the present inventors can perform firing at a low temperature of 500 ° C. or lower by using a photosensitive dielectric forming composition containing a specific resin composition. Thus, the inventors have found that a dielectric having a high dielectric constant and a low dielectric loss tangent, a thin film with a low leakage current, and a pattern with high dimensional accuracy can be formed, and the present invention has been completed.
[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 material that can form a high dielectric constant dielectric layer with low dimensional accuracy and that can be manufactured by low-temperature firing. It is an object of the present invention to provide a composition for forming a dielectric material, and a dielectric and an electronic component formed from the composition.
[0008]
SUMMARY OF THE INVENTION
The composition for forming a photosensitive dielectric according to the present invention is:
(A) inorganic particles, (B) an alkali-soluble resin having a phenolic hydroxyl group, (C) a compound having a quinonediazide group, (D) a compound having at least two alkyl etherified amino groups in the molecule, and It is characterized by containing (E) a heat-sensitive acid generator and, if necessary, (F) crosslinked fine particles.
[0009]
According to the composition for forming a photosensitive dielectric according to the present invention, the dielectric constant is 5 or more, preferably 10 or more, the dielectric loss tangent is 0.1 or less, and the capacitance is 5 nF / cm by heating at 500 ° C. or less.²It is possible to form the above dielectric.
The electronic component according to the present invention includes a dielectric formed using the photosensitive dielectric forming composition.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described.
First, the details of the composition for forming a photosensitive dielectric according to the present invention will be described.
[Composition for forming photosensitive dielectric]
The composition for forming a photosensitive dielectric according to the present invention comprises (A) inorganic particles, (B) an alkali-soluble resin having a phenolic hydroxyl group, (C) a compound having a quinonediazide group, and (D) at least two in the molecule. It comprises the above compound having an alkyl etherified amino group, (E) a heat-sensitive acid generator, (F) crosslinked fine particles, and (G) a solvent. Moreover, the composition for photosensitive dielectric formation of this invention can also contain other additives, such as an epoxy compound, a close_contact | adherence adjuvant, a leveling agent, etc. as needed. The photosensitive dielectric composition can be prepared by kneading using a kneader such as a roll kneader, a mixer, a homomixer, a ball mill, or a bead mill.
[0011]
The composition for forming a photosensitive dielectric prepared as described above is a paste-like composition having fluidity suitable for coating, and its viscosity is usually 10 to 50,000 mPa · s, preferably Is preferably 20 to 10,000 mPa · s.
Hereinafter, each component constituting the photosensitive dielectric forming composition will be described.
[0012]
(A) 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 particularly limited, but may be about 30000, for example.
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.
[0013]
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.
[0014]
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.
[0015]
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.
[0016]
The average particle size of such inorganic particles is preferably 0.005 to 2.0 μm, more preferably 0.02 to 1.0 μm, more preferably 0.02 to 0.8 μm, and particularly preferably 0.02 to 0.02 μm. It is desirable that the thickness is 0.3 μm. Further, at this time, Dw / Dn comprising the ratio of the weight average particle diameter (Dw) to the number average particle diameter (Dn) is preferably 1.05 or more, more preferably 1.1 or more, more preferably 1.2 or more. Particularly preferably, it is desirable that it is 1.25 or more. When Dw / Dn is smaller than 1.05, when the film thickness is reduced, the packing of the dielectric particles may be poor and the leakage current may increase.
[0017]
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.
[0018]
The inorganic particles used in the present invention can be synthesized by, for example, a gas phase method, a sol-gel method, an RF plasma method, or the like. In order to disperse the inorganic particles synthesized by the gas phase method in a solvent, they can be dispersed to primary particles by a known dispersing method, bead mill, kneading method, high-pressure homogenizer, etc. in combination with a dispersant.
The amount of the inorganic particles (A) in the composition for forming a photosensitive dielectric material is 20 to 20 when (A) + (B) + (C) + (D) + (E) + (F) is 100% by mass. It is desirable that it is 85 mass%, Preferably it is 30-85 mass%, More preferably, it is 40-85 mass%.
[0019]
( B ) An alkali-soluble resin having a phenolic hydroxyl group;
The alkali-soluble resin having a phenolic hydroxyl group (hereinafter, also referred to as “phenol resin (B)”) used in the present invention is not particularly limited, but a novolac resin is preferable. Such a novolak resin can be obtained by condensing phenols and aldehydes in the presence of a catalyst.
[0020]
Examples of phenols used at this time include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p- Butylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4 , 5-trimethylphenol, catechol, resorcinol, pyrogallol, α-naphthol, β-naphthol and the like.
[0021]
Examples of aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, and benzaldehyde. Specific examples of such novolak resins include phenol / formaldehyde condensed novolak resins, cresol / formaldehyde condensed novolak resins, phenol-naphthol / formaldehyde condensed novolak resins, and the like.
[0022]
Examples of phenol resins (B) other than novolak resins include polyhydroxystyrene and copolymers thereof, phenol-xylylene glycol condensation resins, cresol-xylylene glycol condensation resins, phenol-dicyclopentadiene condensation resins, and the like. Can do.
In the present invention, besides the alkali-soluble resin having a phenolic hydroxyl group, a phenolic low molecular compound (hereinafter also referred to as “phenol compound (b)”) can be used in combination. For example, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, tris (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, tris (4-hydroxyphenyl) ) Ethane, 1,3-bis [1- (4-hydroxyphenyl) -1-methylethyl] benzene, 1,4-bis [1- (4-hydroxyphenyl) -1-methylethyl] benzene, 4,6 -Bis [1- (4-hydroxyphenyl) -1-methylethyl] -1,3-dihydroxybenzene, 1,1-bis (4-hydroxyphenyl) -1- [4- {1- (4-hydroxyphenyl) ) -1-methylethyl} phenyl] ethane, 1,1,2,2-tetra (4-hydroxyphenyl) ethane and the like. These phenol compounds (b) can be contained in the phenol resin (B) as a part of the component (B) in the range of 0 to 40% by mass, particularly 0 to 30% by mass.
[0023]
The phenol resin (B) needs to have a weight average molecular weight of 2,000 or more, particularly from 2,000 to 20,000, from the viewpoints of resolution, thermal shock resistance, heat resistance, and the like of the obtained insulating film. A range of about 000 is preferred.
In the composition for forming a photosensitive dielectric of the present invention, the content of the phenol resin (B) (the total amount when the phenol compound (b) is used in combination) is the entire composition ((A) + (B) + ( C) + (D) + (E) + (F)) is 10 to 50% by mass, preferably 13 to 45% by mass. When the proportion of the phenol resin (B) is within this range, the film formed using the resulting photosensitive insulating resin composition has sufficient developability with an alkaline aqueous solution.
[0024]
(C) Compound having quinonediazide group
The compound having a quinonediazide group (hereinafter also referred to as “quinonediazide compound (C)”) used in the present invention is a compound having one or more phenolic hydroxyl groups and 1,2-naphthoquinonediazide-4-sulfonic acid or 1,1. It is an ester compound with 2-naphthoquinonediazide-5-sulfonic acid. The compound having one or more phenolic hydroxyl groups is not particularly limited, but specifically, a compound having the structure shown below is preferable.
[0025]
[Chemical 1]

[0026]
(In Formula (1), X₁~ X_TenMay be the same or different from each other, and are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a hydroxyl group. However, X₁~ X_FiveAt least one of these is a hydroxyl group. A is a single bond, O, S, CH₂, C (CH_Three)₂, C (CF_Three)₂, C = O, or SO₂It is. )
[0027]
[Chemical 2]

[0028]
(In Formula (2), X₁₁~ X_{twenty four}May be the same or different from each other, and the X₁~ X_TenIt is the same as the case of. However, X₁₁~ X₁₅At least one of these is a hydroxyl group. R₁~ R_FourIs a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. )
[0029]
[Chemical Formula 3]

[0030]
(In Formula (3), X_{twenty five}~ X₃₉May be the same or different from each other, and the X₁~ X_TenIt is the same as the case of. However, X_{twenty five}~ X₂₉In which at least one is a hydroxyl group, X₃₀~ X₃₄At least one is a hydroxyl group. R_FiveIs a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. )
[0031]
[Formula 4]

[0032]
(In Formula (4), X₄₀~ X₅₈May be the same or different from each other, and the X₁~ X_TenIt is the same as the case of. However, X₄₀~ X₄₄In which at least one is a hydroxyl group, X₄₅~ X₄₉In which at least one is a hydroxyl group, X₅₀~ X₅₄At least one is a hydroxyl group. R₆~ R₈Is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. )
[0033]
[Chemical formula 5]

[0034]
(In Formula (5), X₅₉~ X₇₂May be the same or different from each other, and the X₁~ X_TenIt is the same. However, X₅₉~ X₆₂In which at least one is a hydroxyl group, X₆₃~ X₆₇At least one is a hydroxyl group. )
Specific examples of such a quinonediazide compound (C) include the following. 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3,4,2 ', 4' -Pentahydroxybenzophenone, Tris (4-hydroxyphenyl) methane, Tris (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,3-bis [1- (4 -Hydroxyphenyl) -1-methylethyl] benzene, 1,4-bis [1- (4-hydroxyphenyl) -1-methylethyl] benzene, 4,6-bis [1- (4-hydroxyphenyl) -1 1 such as -methylethyl] -1,3-dihydroxybenzene, 1,1-bis (4-hydroxyphenyl) -1- [4- {1- (4-hydroxyphenyl) -1-methylethyl} phenyl] ethane 1,2-naphthoquinonediazide-4-sulfonic acid or 1,2-naphthoquinonediazide-5-sulfuric acid Phosphate ester compound.
[0035]
In the composition for forming a photosensitive dielectric of the present invention, the quinonediazide compound (C) is 10 to 50 parts by mass, preferably 15 to 30 parts by mass with respect to 100 parts by mass of the phenol resin (B). If the compounding amount of the quinonediazide compound (C) is less than 10 parts by mass, the remaining film ratio in the unexposed area may be lowered, or an image faithful to the mask pattern may not be obtained. Moreover, when the compounding quantity of a quinonediazide compound (C) exceeds 50 mass parts, a pattern shape may deteriorate or it may foam at the time of hardening.
[0036]
(D) a compound (curing agent) having at least two or more alkyl etherified amino groups in the molecule;
The compound having at least two or more alkyl etherified amino groups in the molecule used in the present invention (hereinafter also referred to as “curing agent (D)”) is a crosslinking agent that reacts with the phenol resin (B). It acts as a (curing agent). As the curing agent (D), all or a part of active methylol groups such as (poly) methylolated melamine, (poly) methylolated glycoluril, (poly) methylolated benzoguanamine, (poly) methylolated urea are alkyletherified. A nitrogen-containing compound can be mentioned. Here, examples of the alkyl group include a methyl group, an ethyl group, a butyl group, or a mixture thereof, and may contain an oligomer component that is partially self-condensed. Specifically, hexamethoxymethylated melamine, hexabutoxymethylated melamine, tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril and the like can be used, and these curing agents (D) can be used alone or in combination of two. You may use the above together.
[0037]
The compounding quantity of the hardening | curing agent (D) in this invention is 1-100 mass parts with respect to 100 mass parts of said phenol resins (B), Preferably it is 5-50 mass parts. If the blending amount is less than 1 part by mass, curing may be insufficient, and the electrical insulation of the resulting cured product may decrease, and if it exceeds 100 parts by mass, patterning characteristics may decrease or heat resistance may decrease. Sometimes.
[0038]
(E) Heat sensitive acid generator
The heat-sensitive acid generator (hereinafter referred to as “acid generator (E)”) used in the present invention is a compound that generates an acid by applying appropriate heat, for example, heating to 50 to 250 ° C. Although it does not restrict | limit in particular, For example, a sulfonium salt, a diazonium salt, a halogen containing compound, a sulfonic acid ester compound etc. are mentioned.
[0039]
Examples of the acid generator (E) include benzylmethylphenylsulfonium hexafluoroantimonate, benzylmethylphenylsulfonium hexafluorophosphate, benzylmethylphenylsulfonium tetrafluoroborate, benzylmethylphenylsulfonium trifluoromethanesulfonate, benzyl (4-hydroxy Phenyl) methylsulfonium hexafluoroantimonate, benzyl (4-hydroxyphenyl) methylsulfonium hexafluorophosphate, benzyl (4-hydroxyphenyl) methylsulfonium tetrafluoroborate, benzyl (4-hydroxyphenyl) methylsulfonium trifluoromethanesulfonate, benzenediazonium Hexafluoroantimonate, benzenediazonium Hexafluorophosphate, tetrafluoroborate, benzenediazonium trifluoromethanesulfonate, naphthalene diazonium hexafluoroantimonate, and the like naphthalene diazonium trifluoromethanesulfonate.
[0040]
The compounding quantity of the acid generator (E) in this invention is 0.1-10 mass parts with respect to 100 mass parts of said phenol resins (B), Preferably it is 0.5-5 mass parts. If the blending amount of the acid generator (E) is less than 0.1 parts by mass, the solvent resistance of the resulting cured product may be lowered, and if it exceeds 10 parts by mass, the electrical insulation may be lowered.
(F) Cross-linked fine particles
The crosslinked fine particles (F) used in the present invention are not particularly limited as long as the Tg of the polymer constituting the particles is 0 ° C. or lower, but the crosslinkable monomer having two or more unsaturated polymerizable groups. (Hereinafter also referred to as “crosslinkable monomer”) and one or more other monomers (hereinafter referred to as “others”) selected so that the Tg of the copolymer constituting the crosslinked fine particles (F) is 0 ° C. or less. In which the Tg of the copolymer constituting the crosslinked fine particles (F) is 0 ° C. or lower, and is a polymerizable group. Those obtained by copolymerizing a monomer having a functional group other than the above, for example, a functional group such as a carboxyl group, an epoxy group, an amino group, an isocyanate group, or a hydroxyl group are preferably used.
[0041]
Examples of crosslinkable monomers include divinylbenzene, diallyl phthalate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, polyethylene glycol di Examples thereof include compounds having a plurality of polymerizable unsaturated groups such as (meth) acrylate and polypropylene glycol di (meth) acrylate. Of these, divinylbenzene is preferable.
[0042]
The crosslinkable monomer used in producing the crosslinked fine particles (F) used in the present invention is in the range of 1 to 20% by mass, more preferably in the range of 2 to 10% by mass, based on the total monomers used for copolymerization. Used in
Examples of other monomers include diene compounds such as butadiene, isoprene, dimethylbutadiene, chloroprene, 1,3-pentadiene, (meth) acrylonitrile, α-chloroacrylonitrile, α-chloromethylacrylonitrile, α-methoxyacrylonitrile, α- Unsaturated nitrile compounds such as ethoxyacrylonitrile, crotonic acid nitrile, cinnamic nitrile, itaconic acid dinitrile, maleic acid dinitrile, fumarate dinitrile, (meth) acrylamide, N, N'-methylenebis (meth) acrylamide, N, N '-Ethylenebis (meth) acrylamide, N, N'-hexamethylenebis (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N, N-bis ( 2-hydroxyethyl) (meth) a Unsaturated amides such as chloramide, crotonic acid amide, and cinnamic acid amide, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid Hexyl, (meth) acrylic acid esters such as lauryl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, styrene, α-methylstyrene, o-methoxystyrene, p-hydroxystyrene, p -Epoxy (meth) acrylate obtained by reaction of aromatic vinyl compounds such as isopropenyl phenol, diglycidyl ether of bisphenol A, diglycidyl ether of glycol, etc. with (meth) acrylic acid, hydroxyalkyl (meth) acrylate, etc. And epoxy group-containing unsaturated compounds such as urethane (meth) acrylates, glycidyl (meth) acrylate, and (meth) allyl glycidyl ether obtained by reaction of hydroxyalkyl (meth) acrylate with polyisocyanate, (meth) acrylic Acid, itaconic acid, succinic acid-β- (meth) acryloxyethyl, maleic acid-β- (meth) acryloxyethyl, phthalic acid-β- (meth) acryloxyethyl, hexahydrophthalic acid-β- (meta ) Unsaturated acid compounds such as acryloxyethyl, amino group-containing unsaturated compounds such as dimethylamino (meth) acrylate and diethylamino (meth) acrylate, and amide group-containing unsaturated compounds such as (meth) acrylamide and dimethyl (meth) acrylamide , Hydroxyethyl (meth) acrylate, Rokishipuropiru (meth) acrylate, hydroxybutyl (meth) hydroxyl group-containing unsaturated compounds such as acrylate and the like can be exemplified. These other monomers include butadiene, isoprene, (meth) acrylonitrile, (meth) acrylic acid alkyl esters, styrene, p-hydroxystyrene, p-isopropenylphenol, glycidyl (meth) acrylate, (meth) acrylic acid. Hydroxyalkyl (meth) acrylates and the like are preferably used.
[0043]
As such other monomers, it is preferable to use at least one diene compound, specifically, butadiene. Such a diene compound is desirably used in an amount of 20 to 80% by mass, preferably 30 to 70% by mass, based on all monomers used for copolymerization.
The crosslinked fine particles (F) used in the present invention are particularly obtained as rubber-like soft fine particles when a diene compound such as butadiene is copolymerized in the above amount with respect to all monomers as other monomers. Cracks can be prevented from occurring in the cured film, and a cured film having excellent durability can be obtained.
[0044]
In the present invention, the average particle diameter of the crosslinked fine particles (F) is usually 30 to 500 nm, preferably 40 to 200 nm, more preferably 50 to 120 nm. The particle size control method of the crosslinked fine particles (F) is not particularly limited, but when the crosslinked fine particles (F) are synthesized by emulsion polymerization, the number of micelles during emulsion polymerization is controlled by the amount of emulsifier used. In addition, a method for controlling the particle size can be exemplified.
[0045]
Moreover, the compounding quantity of crosslinked fine particle (F) is 0-50 mass parts with respect to 100 mass parts of said phenol resins (B), Preferably it is 1-50 mass parts, More preferably, it is 5-30 mass parts. If the blended amount of the crosslinked fine particles (F) exceeds 50 parts by mass, the resolution and heat resistance of the resulting cured film may be reduced, and compatibility with other components and dispersibility may be reduced. When the composition for forming a photosensitive derivative contains crosslinked fine particles, the thermal shock resistance of the resulting cured film is improved.
[0046]
(G) Solvent
The solvent (G) used in the present invention is added to improve the handleability of the composition for forming a photosensitive dielectric, and to adjust the viscosity and storage stability. The type of the solvent (G) is not particularly limited, but examples thereof include ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; propylene glycol monomethyl ether, propylene Propylene glycol monoalkyl ethers such as glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether; propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether ; Propylene glycol monomethyl ether Tate, propylene glycol monoalkyl ether acetates such as propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate; cellosolves such as ethyl cellosolve and butyl cellosolve; carbitols such as butyl carbitol; Lactic acid esters such as methyl, ethyl lactate, n-propyl lactate, isopropyl lactate; ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, isopropyl propionate, propionate Aliphatic carboxylic acid esters such as n-butyl acid and isobutyl propionate; methyl 3-methoxypropionate, ethyl 3-methoxypropionate, 3-ethoxypropion Other esters such as methyl, ethyl 3-ethoxypropionate, methyl pyruvate and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; ketones such as 2-heptanone, 3-heptanone, 4-heptanone and cyclohexanone Amides such as N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide and N-methylpyrrolidone; lactones such as γ-butyrolacun. These solvent (F) can also be used individually by 1 type or in mixture of 2 or more types.
[0047]
Other additives
In the composition for forming a photosensitive dielectric of the present invention, an epoxy compound, an adhesion assistant, a leveling agent and the like can be contained as other additives. Examples of the epoxy compound include novolak type epoxy resins, bisphenol type epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins. These other additives can be contained to such an extent that the characteristics of the resulting photosensitive dielectric forming composition are not impaired.
[0048]
[Dielectric]
By using the photosensitive dielectric forming composition of the present invention, the dielectric constant is 5 or more, preferably 10 or more, the dielectric loss tangent is 0.1 or less, and the capacitance is 5 nF / cm by heating at 500 ° C. or less.²The above dielectric can be formed. The dielectric forming method and physical properties of the dielectric according to the present invention will be described in detail below.
[0049]
The composition for forming a photosensitive dielectric according to the present invention is applied to a substrate such as a silicon wafer on which a wiring pattern or the like has been applied, and dried to evaporate a solvent and form a coating film. Although it does not specifically limit as said board | substrate material, For example, it consists of a printed wiring board, a copper clad laminated board (CCL), a SUS board | substrate, a polyimide board with copper foil, a ceramics board | substrate, a silicone wafer (W-CSP etc.), an alumina board | substrate etc. A plate-like member is mentioned. Thereafter, the film is exposed through a desired mask pattern, then developed with an alkaline developer, and the exposed portion is dissolved and removed to obtain a coating film on which the desired pattern is formed. Furthermore, a cured film can be obtained by performing a heat treatment after development in order to develop capacitor characteristics.
[0050]
As a method for applying the photosensitive dielectric forming composition to the substrate, for example, a coating method such as a dipping method, a spray method, a bar coating method, a roll coating method, a spin coating method, a curtain coating method or a screen printing method is used. The thickness of the coating can be appropriately controlled by adjusting the solid content concentration and viscosity of the coating means and the photosensitive dielectric forming composition.
[0051]
Examples of radiation used for exposure include low-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, g-line steppers, i-line steppers, and other ultraviolet rays, electron beams, laser beams, and the like. For example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, when the dielectric layer has a thickness of 0.5 to 50 μm, 1,000 to 20,000 J / m.²Degree.
[0052]
Thereafter, development is performed with an alkaline developer, and a desired pattern is formed by dissolving and removing the exposed portion. Since the inorganic particles contained in the dielectric layer are uniformly dispersed by the alkali-soluble resin, the inorganic particles present in the portion where the alkali-soluble resin is dissolved by dissolving and washing the alkali-soluble resin as the binder Are also removed at the same time. Examples of the developing method in this case include a shower developing method, a spray developing method, an immersion developing method, a paddle developing method, and the like. The developing conditions are usually 20 to 40 ° C. for about 1 to 10 minutes.
[0053]
As the alkaline developer, for example, an alkaline compound such as sodium hydroxide, potassium hydroxide, ammonia water, tetramethylammonium hydroxide, choline, etc. was dissolved in water so as to have a concentration of about 0.1 to 10% by mass. Alkaline aqueous solution can be mentioned. An appropriate amount of a water-soluble organic solvent such as methanol or ethanol, a surfactant, or the like can be added to the alkaline aqueous solution. In addition, after developing with an alkaline developer, it is washed with water and dried.
[0054]
Furthermore, it can be cured by performing a heat treatment in order to sufficiently develop the characteristics as an insulating film after development. At this time, the acid generator (E) is decomposed to generate an acid. The curing reaction between the curing agent (D) and the phenol resin (B) is promoted by the catalytic action of the acid. Such curing conditions are not particularly limited, but the coating film can be cured by heating at a temperature of 100 to 250 ° C. for about 30 minutes to 10 hours depending on the use of the cured product. Moreover, in order to fully advance hardening and to prevent the deformation | transformation of the obtained pattern shape, it can also heat in two steps, for example, at the temperature of 50-100 degreeC in a 1st step, 10 minutes-2 It can also be heated for about an hour and further cured by heating at a temperature of 100 to 250 ° C. for about 20 minutes to 8 hours. Under such curing conditions, a general oven, an infrared furnace, or the like can be used as heating equipment.
[0055]
<Physical properties of dielectrics>
The dielectric obtained from the composition for forming a photosensitive dielectric according to the present invention desirably has a dielectric constant of 5 or more, preferably 10 or more, more preferably 15 or more. The upper limit of the dielectric constant is not particularly limited, but may be about 200, for example. The dielectric obtained from the composition for forming a photosensitive dielectric according to the present invention desirably has a dielectric loss tangent of 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. The dielectric obtained from the composition for forming a photosensitive dielectric according to the present invention has a capacitance of 5 nF / cm.²Or more, preferably 10 nF / cm²Or more, more preferably 15 nF / cm²The above is desirable. The upper limit of the capacitance is not particularly limited, but for example 50 nF / cm²It may be about the above.
[0056]
In this specification, the dielectric constant, dielectric loss tangent, and capacitance are values measured by the method described in JIS K6481 (frequency 1 MHz).
In addition, when such a dielectric is used as a capacitor, the leakage current is preferably 10^-8A / cm²Or less, more preferably 10^-9A / cm²Or less, more preferably 10^-TenA / cm²The following is desirable.
[0057]
The thickness of the dielectric is preferably 50 μm or less, more preferably 20 μm or less, and even more preferably 5 μm or less. Although the minimum of film thickness is not specifically limited, Usually, it is 0.5 micrometer or more.
[Electronic parts]
The dielectric of the present invention can be obtained by heating and firing at a low temperature of 500 ° C. or less, the dielectric constant is 5 or more, the dielectric loss tangent is 0.1 or less, and the capacitance is 4 nF / cm.²Thus, a capacitor having a large capacitance with a thin film can be formed. 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.
[0058]
【The invention's effect】
When the composition for forming a photosensitive dielectric according to the present invention is used, the dielectric loss tangent of 0.1 or less and 5 nF / cm at a heating temperature as low as 500 ° C. or less as described above.²A dielectric having a high capacitance as described above can be formed.
Since the dielectric according to the present invention is a thin film and has a high dielectric constant, it is suitably used in electronic parts such as a printed circuit board, a semiconductor package, a capacitor, and a high frequency antenna.
[0059]
Since the electronic component according to the present invention includes the dielectric, it can be reduced in size and thickness.
[0060]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples. In the following, “part” means “part by mass”, and “%” means “% by mass”.
[0061]
[Example 1]
(1) Preparation of photosensitive dielectric composition
As shown in Table 1, (A-1) 150 parts by mass of barium titanate particles as inorganic particles, (B-1) 100 parts by mass of phenol resin, (C-1) 15 parts by mass of quinonediazide compound, (D-1) curing Dissolved in 23 parts by weight of agent, 2 parts by weight of (E-1) acid generator, 10 parts by weight of (F-1) crosslinked fine particles, and 900 parts by weight of (G-1) ethyl lactate, kneaded in a bead mill, then stainless steel A composition for forming a photosensitive dielectric was prepared by filtering through a mesh (500 mesh) and a filter having a pore diameter of 1 μm.
[0062]
(2) Coating process of photosensitive dielectric composition
The composition for forming a photosensitive dielectric is applied onto a silicon wafer with Cu sputter using a spinner, the coating film is dried at 100 ° C. for 5 minutes to completely remove the solvent, and a photosensitive dielectric layer having a thickness of 1 μm. Formed.
(3) Dielectric layer exposure and development processes
The photosensitive dielectric 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). Irradiation amount is 500mJ / cm²It was.
[0063]
After the exposure process, the exposed photosensitive dielectric layer is subjected to a developing process by a shower method using a 2.38 mass% tetramethylammonium hydroxide aqueous solution (25 ° C.) as a developing solution over 2 minutes. went. Subsequently, a water washing treatment with ultrapure water was performed, whereby the photosensitive dielectric layer solubilized by irradiation with ultraviolet rays was removed to form a pattern.
[0064]
(4) Dielectric layer pattern curing process
The silicon wafer on which the photosensitive dielectric layer pattern was formed was cured in an oven at 200 ° C. for 60 minutes. Thereby, a dielectric pattern was obtained on the surface of the silicon wafer substrate.
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.
[0065]
[Examples 2 to 5]
In the same manner as in Example 1, a composition for forming a photosensitive dielectric having the composition shown in Table 1 was prepared, and these characteristics were measured in the same manner as in Example 1. The obtained results are shown in Table 1.
[0066]
[Comparative Examples 1-5]
Each composition shown in Table 2 was prepared, and the physical properties were measured in the same manner as in Example 1. The results are shown in Table 2.
The patterning characteristics and dielectric characteristics of the dielectric pattern were evaluated as follows.
[0067]
[Patterning characteristics]
Examples 1 to 5 and Comparative Examples 1 to 5: With respect to the obtained dielectric pattern, the width and height of the dielectric pattern were measured using a scanning electron microscope (SEM), and the accuracy of the width was measured. In the range of 500 μm ± 5 μm, the evaluation was evaluated as “◯”, and the others 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.
[0068]
[Dielectric constant, dielectric loss tangent and leakage current]
Examples 1 to 5 and Comparative Examples 1 to 5: An upper surface electrode (thickness: 0.5 μm) was formed on the upper surface of the obtained dielectric pattern by an aluminum vapor deposition method.
An average value was obtained by measuring 10 points of dielectric constant and dielectric loss tangent at 1 MHz with an LCR meter (HP4284A, manufactured by Hewlett Packard) between the silicon wafer substrate with Cu sputter and the upper surface electrode. Further, the leakage current between the copper foil side and the electrode was measured at 10 points with an insulation resistance meter (manufactured by Advantest), and the average value was obtained.
[0069]
[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.
○ ・ ・ ・ There is no change and tolerance is recognized
X: Change is large and tolerance is not recognized
[0070]
[Table 1]

[0071]
[Table 2]

[0072]
Note) The composition described in Table 1 is as follows.
Inorganic particles
A-1: Barium titanate particles (trade name “BT-01”, manufactured by Sakai Chemical Industry Co., Ltd., average particle size 0.1 μm)
A-2: Barium titanate particles (trade name “BT-02”, manufactured by Sakai Chemical Industry Co., Ltd., average particle size 0.2 μm)
Phenolic resin;
B-1: Cresol novolak resin composed of m-cresol / p-cresol = 60/40 (molar ratio) (polystyrene equivalent weight average molecular weight = 8,700)
B-2: Cresol novolak resin consisting of m-cresol / p-cresol = 50/50 (molar ratio) (polystyrene equivalent weight average molecular weight = 7,500)
B-3: Polyhydroxystyrene (manufactured by Maruzen Petrochemical Co., Ltd., trade name: Marcalinker S-2P)
Phenolic compounds;
b-1: 1,1-bis (4-hydroxyphenyl) -1- [4- {1- (4-hydroxyphenyl) -1-methylethyl} phenyl] ethane
Quinonediazide compounds;
C-1: 1,1-bis (4-hydroxyphenyl) -1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethane and 1,2-naphthoquinonediazide-5-sulfone 2.0 molar condensate with acid
C-2: 1.5 molar condensate of 1,1-bis (4-hydroxyphenyl) -1-phenylethane and 1,2-naphthoquinonediazide-5-sulfonic acid
Curing agent;
D-1: Hexamethoxymethylated melamine (Mitsui Cytec Co., Ltd., trade name: Cymel 300)
D-2: Tetramethoxymethyl glycoluril (Mitsui Cytec Co., Ltd., trade name: Cymel 1174)
Acid generator;
E-1: Benzyl (4-hydroxyphenyl) methylsulfonium hexafluoroantimonate
E-2: benzyl (4-hydroxyphenyl) methylsulfonium hexafluorophosphate
Crosslinked fine particles;
F-1: butadiene / hydroxybutyl methacrylate / methacrylic acid / divinylbenzene = 60/32/6/2 (% by weight), average particle diameter = 65 nm
solvent;
G-1: Ethyl lactate
G-2: 2-Heptanone

Claims (6)

  (A) inorganic particles, (B) an alkali-soluble resin having a phenolic hydroxyl group, (C) a compound having a quinonediazide group, (D) a compound having at least two alkyl etherified amino groups in the molecule, and (E) A composition for forming a photosensitive dielectric, comprising a heat-sensitive acid generator. 10 to 50 parts by mass of the quinonediazide group-containing compound (C) with respect to 100 parts by mass of the alkali-soluble resin (B) having a phenolic hydroxyl group, and at least two alkyl etherified amino acids in the molecule The photosensitive compound according to claim 1, comprising 1 to 100 parts by mass of the group-containing compound (D) and 0.1 to 10 parts by mass of the heat-sensitive acid generator (E). Composition for forming a dielectric material.   (A) inorganic particles, (B) an alkali-soluble resin having a phenolic hydroxyl group, (C) a compound having a quinonediazide group, (D) a compound having at least two alkyl etherified amino groups in the molecule, E) A composition for forming a photosensitive dielectric, comprising a heat-sensitive acid generator and (F) crosslinked fine particles. The composition for forming a photosensitive dielectric according to claim 3 , wherein the crosslinked fine particles (F) have an average particle size of 30 to 500 nm. The dielectric formed using the composition for photosensitive dielectric formation in any one of Claims 1-4 . An electronic component comprising the dielectric according to claim 5 .