JPWO2008153208A1 - Resin composition for interlayer insulation of multilayer printed wiring board - Google Patents

Abstract

A resin composition suitable for interlayer insulation of a flexible multilayer printed wiring board is provided. Resin composition for interlayer insulation of multilayer printed wiring board containing the following components (A), (B) and (C): (A) It has a polybutadiene structure, a urethane structure, an imide structure in the molecule, and a molecular terminal A polyimide resin having a phenol structure, (B) an epoxy resin, and (C) an inorganic filler having a specific surface area of 18 to 50 m <2> / g.

Description

  The present invention relates to a resin composition suitable for interlayer insulation of multilayer printed wiring boards, particularly for interlayer insulation of flexible multilayer printed wiring boards. The present invention also relates to an adhesive film for forming an interlayer insulating layer of a multilayer printed wiring board prepared from the resin composition, and a multilayer printed wiring board having an interlayer insulating layer formed from the resin composition.

  A flexible multilayer printed wiring board can be bent and mounted even in a narrow space, and thus is indispensable for media devices and the like that are becoming smaller and thinner. As a material used for interlayer insulation of a flexible multilayer printed wiring board, for example, JP-A-2006-037083 discloses a resin composition comprising a polyimide having a polybutadiene structure and an epoxy resin, etc. It is disclosed that the interlayer insulating layer is excellent in flexibility, mechanical strength, dielectric properties and the like.

  An object of the present invention is to provide a resin composition suitable for interlayer insulation of a flexible multilayer printed wiring board.

The polyimide contained in the resin composition of JP-A-2006-037083 is terminated with an acid anhydride group or a carboxyl group, but these groups react with an epoxy group to generate an ester bond that is easily hydrolyzed. Considering application to precise electronic parts, it is desired to reduce or eliminate the abundance of these groups in the resin composition from the viewpoint of insulation reliability and the like. In view of the above points, the present inventors have evaluated a resin composition using a polyimide resin having a phenol structure introduced at the end thereof in order to reduce or eliminate carboxyl groups in a polyimide resin having a polybutadiene structure. Similarly, it was found that an interlayer insulating layer having excellent flexibility, mechanical strength, dielectric properties and the like can be obtained. On the other hand, when using the resin composition as an interlayer insulating layer, a method of containing an inorganic filler typified by silica for the purpose of suppressing the coefficient of thermal expansion and tack is known. In the composition containing an epoxy resin, the inorganic filler easily settled, and it was difficult to obtain a uniform resin composition. As a result of further intensive studies, the inventors of the present invention can easily disperse the inorganic filler by using a material having a specific surface area far smaller than that of the normally used inorganic filler, and a uniform resin composition can be obtained. It was found that it can be obtained.
The present inventors completed the present invention based on the above findings. That is, the present invention includes the following contents.
[1] Resin composition for interlayer insulation of multilayer printed wiring board containing the following components (A), (B) and (C):
(A) a polyimide resin having a polybutadiene structure, a urethane structure, an imide structure in the molecule, and a phenol structure at the molecular end;
(B) epoxy resin,
(C) An inorganic filler having a specific surface area of 18 to 50 m ² / g.
[2] Resin composition for interlayer insulation of multilayer printed wiring board containing the following components (A), (B) and (C):
(A) [a] A polybutadiene polyol compound having two or more alcoholic hydroxyl groups in one molecule and [b] a diisocyanate compound are reacted to form a diisocyanate prepolymer, and [c] tetrabasic acid dianhydride, and [D] a polyimide resin having a phenol structure at the molecular end, which can be obtained by reacting a polyfunctional phenol compound having two or more phenolic hydroxyl groups in one molecule;
(B) epoxy resin,
(C) An inorganic filler having a specific surface area of 18 to 50 m ² / g.
[3] The resin composition according to the above [1] or [2], wherein the inorganic filler of the component (C) has a specific surface area of 18 to 40 m ² / g.
[4] The resin composition according to [1] or [2] above, wherein the specific surface area of the inorganic filler of component (C) is 18 to 35 m ² / g.
[5] The resin composition according to the above [1] or [2], wherein the inorganic filler of the component (C) has a specific surface area of 20 to 30 m ² / g.
[6] The resin composition according to the above [1] or [2], wherein the inorganic filler is silica.
[7] The resin composition according to the above [1] or [2], wherein the phenolic compound is a phenol novolac resin.
[8] The resin composition according to the above [1] or [2], wherein the polybutadiene polyol compound is a hydrogenated polybutadiene polyol compound.
[9] In the component (A) polyimide resin, the reaction component [a] functional group equivalent of the isocyanate group of the diisocyanate compound to the hydroxyl group of the polybutadiene polyol having two or more alcoholic hydroxyl groups in one molecule The resin composition according to [2], wherein the ratio is reacted at a ratio of 1: 1.5 to 1: 2.5.
[10] The resin composition according to [1] or [2] above, further comprising a polyfunctional phenol compound having two or more phenolic hydroxyl groups in one molecule of component [D].
[11] The component (A) is 40 to 85% by weight with respect to 100% by weight in total of the component (A) polyimide resin, the component (B) epoxy resin and the component (D) polyfunctional phenol compound, The resin composition according to the above [10], wherein B) is contained at 15 to 40% by weight and component (D) is contained at 0 to 20% by weight.
[12] An adhesive film for forming an interlayer insulating layer of a multilayer printed wiring board in which the resin composition according to [1] or [2] is formed on a support.
[13] A multilayer printed wiring board in which an interlayer insulating layer is formed from the resin composition according to [1] or [2].

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition which is excellent in a softness | flexibility, mechanical strength, a dielectric characteristic, etc. and suitable for the interlayer insulation of a flexible multilayer printed wiring board is provided.

（Ｒ１はポリブタジエン構造を有する２価の有機基を表す。）
反応成分［ｂ］のジイソシアネート化合物は、以下の式（ｂ）で表すことができる。

（Ｒ２は２価の有機基を示す。）
反応成分［ｃ］の四塩基酸二無水物は、以下の式（ｃ）で表すことができる。

（Ｒ３は４価の有機基を表す。）
上記分子末端に水酸基を有するポリブタジエンポリオールとジイソシアネート化合物を反応させて得られるジイソシアネートプレポリマーは、以下の式（ａ’−ｂ）で表すことができる。

（Ｒ１及びＲ２は上記と同義であり、ｎは１以上１００以下（１≦ｎ≦１００）の整数を示す。ｎは好ましくは１以上１０以下（１≦ｎ≦１０）の整数を示す。）
次に、上記反応で得られるジイソシアネートプレポリマーに反応成分［ｃ］の四塩基酸二無水物及び反応成分［ｄ］の多官能フェノール化合物を反応させる。反応割合は特に限定されないが組成物中にイソシアネート基を極力残さないようにするのが好ましい。反応系中のイソシアネート基を極力残さないようにするために、反応中において、ＦＴ−ＩＲ等でイソシアネート基の消失を確認するのが好ましい。反応順により、まず四塩基酸二無水物を反応させた後に、多官能フェノール化合物を反応させる方法と、四塩基酸二無水物及び多官能フェノール化合物を同時に添加して反応させる方法が挙げられる。同時に添加する場合、酸無水物基が優先的にイソシアネート基と反応し、イミド結合を形成すると考えられる。そして残りのイソシアネート基は多官能フェノール化合物と反応し、末端にフェノール構造を導入することができる。
反応成分［ａ］のポリブタジエンポリオールの水酸基の官能基当量をＷ、反応成分［ｂ］のジイソシアネート化合物のイソシアネート基の官能基当量をＸ、反応成分［ｃ］の四塩基酸二無水物の官能基当量をＹ、反応成分［ｄ］の多官能フェノール化合物の官能基当量をＺとした場合、反応成分［ｃ］及び［ｄ］は、Ｙ＜Ｘ−Ｗ＜Ｙ＋Ｚの関係を満たす比率で使用するのが好ましい。
反応成分［ａ］として分子末端に水酸基を有するポリブタジエンジオールを使用した場合、本発明における成分（Ａ）のポリイミドは以下の式（１−ａ）及び（１−ｂ）の構造を有する。

具体的な反応条件は、例えば、反応成分［ａ］のポリブタジエンポリオールと反応成分［ｂ］のジイソシアネート化合物の反応は、有機溶媒中、反応温度が８０℃以下、反応時間が通常２〜８時間の条件で行うことができる。また必要により触媒存在下に行ってもよい。次に該反応溶液中に四塩基酸二無水物及び多官能フェノール化合物を添加し、反応温度１２０〜１６０℃、反応時間５〜２４時間の条件で反応を行うことができる。反応は通常触媒存在下に行われる。また有機溶媒を更に添加して行ってもよい。
この反応においては、イソシアネート基と酸無水物基の反応によるイミド結合形成とともに炭酸ガスが発生するため、反応前後での重量減少量を測定し、炭酸ガスのモル数を求めることで、形成したイミド基のモル数を計算することができる。
反応終了後、必要により不溶物を除くため反応溶液の濾過を行ってもよい。このようにして、本発明におけるポリイミド樹脂をワニス状で得ることができる。ワニス中の溶媒量は、反応時の溶媒量を調整する、又は反応後に溶媒を添加するなどして適宜調整することできる。本発明におけるポリイミド樹脂は、通常上記ワニス状のまま組成物の調製に用いることができる。単離する場合は、例えば、貧溶媒のメタノール中に得られたワニスを少しずつ添加していくことでポリイミドを沈殿させて、固体として得ることができる。
上記各反応に使用される有機溶媒としては、例えば、Ｎ，Ｎ’−ジメチルホルムアミド、Ｎ，Ｎ’−ジエチルホルムアミド、Ｎ，Ｎ’−ジメチルアセトアミド、Ｎ，Ｎ’−ジエチルアセトアミド、ジメチルスルホキシド、ジエチルスルホキシド、Ｎ−メチル−２−ピロリドン、テトラメチルウレア、γ−ブチロラクトン、シクロヘキサノン、ジグライム、トリグライム、カルビトールアセテート、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などの極性溶媒を挙げることができる。これらの溶媒は２種以上を混合して用いてもよい。また、必要により芳香族炭化水素などの非極性溶媒を適宜混合して用いることもできる。
上記各反応に使用される触媒としては、例えば、テトラメチルブタンジアミン、ベンジルジメチルアミン、トリエタノールアミン、トリエチルアミン、Ｎ，Ｎ’−ジメチルピペリジン、α−メチルベンジルジメチルアミン、Ｎ−メチルモルホリン、トリエチレンジアミン等の三級アミンや、ジブチル錫ラウレート、ジメチル錫ジクロライド、ナフテン酸コバルト、ナフテン酸亜鉛等の有機金属触媒などを挙げることができる。これらの触媒は２種以上を混合して用いてもよい。触媒としては、特に、トリエチレンジアミンを使用するのが最も好ましい。
本発明におけるエポキシ樹脂としては、例えば、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、ビスフェノールＳ型エポキシ樹脂、アルキルフェノールノボラック型エポキシ樹脂、ビフェノール型エポキシ樹脂、ナフタレン型エポキシ樹脂、ジシクロペンタジエン型エポキシ樹脂、フェノールとフェノール性ヒドロキシル基を有する芳香族アルデヒドとの縮合物のエポキシ化物、トリグリシジルイソシアヌレート、脂環式エポキシ樹脂等などの１分子中に２つ以上の官能基を有するエポキシ樹脂を挙げることができる。これらのエポキシ樹脂は２種以上を混合して用いてもよい。更に、ビスフェノールＡ型エポキシを用いるのが好ましい。
本発明の組成物においては、必要に応じてエポキシ硬化剤を配合してもよい。エポキシ硬化剤としては、例えば、アミン系硬化剤、グアニジン系硬化剤、イミダゾール系硬化剤、フェノール系硬化剤、酸無水物系硬化剤、又はこれらのエポキシアダクトやマイクロカプセル化したもの等を挙げることができる。特に樹脂組成物をワニスにしたときの粘度安定性などの観点からフェノール系硬化剤が好ましい。エポキシ硬化剤は２種以上を混合して用いてもよい。
エポキシ硬化剤の具体例としては、例えば、アミン系硬化剤としてジシアンジアミド、イミダゾール系硬化剤としてイミダゾールシラン、２−フェニル−４−メチル−５−ヒドロキシメチルイミダゾール、２，４−ジアミノ−６−〔２’−メチルイミダゾリル−（１’）〕−エチル−ｓ−トリアジンイソシアヌル酸付加物、フェノール系硬化剤としてトリアジン構造含有フェノールノボラック樹脂（例えば、フェノライト７０５０シリーズ：大日本インキ化学工業（株）社製）などを挙げることができる。
本発明のポリイミド樹脂組成物としては、成分（Ａ）のポリイミド樹脂と成分（Ｂ）のエポキシ樹脂の硬化時の架橋密度等の制御のため、成分（Ｄ）１分子中に２個以上のフェノール性水酸基を有する多官能フェノール化合物を併用することが好ましい。成分（Ａ）と成分（Ｂ）での架橋密度を、成分（Ｄ）を併用することで高めることが可能であり、これによりガラス転移点以上の温度における熱膨張等を低下させることが可能である。前記架橋密度を高め、熱膨張等を低下させるため、樹脂組成物中の成分（Ａ）と成分（Ｂ）と成分（Ｄ）の配合比率は、これらの合計１００重量％に対して、成分（Ａ）が４０〜８５重量％、成分（Ｂ）が１５〜４０重量％、成分（Ｄ）が０〜２０重量％であることが好ましい。また、成分（Ａ）中のフェノール性水酸基（ｘ）と成分（Ｄ）中のフェノール性水酸基（ｚ）の合計と、成分（Ｂ）中のエポキシ基（ｙ）のモル比（ｘ＋ｚ）／（ｙ）としては、０．７〜１．３であることが好ましい。
成分（Ｄ）の１分子中に２個以上のフェノール性水酸基を有する多官能フェノール化合物の例としては、上述した反応成分［ｄ］と同じものを上げることができる。
本発明の熱硬化性ポリイミド樹脂組成物は、必要に応じて硬化促進剤を併用することが出来る。例えば、メラミン、ジシアンジアミド、グアナミンやその誘導体、アミン類、水酸基を１個有するフェノール類、有機ホスフィン類、ホスホニウム塩類、４級アンモニウム塩類、多塩基酸無水物、光カチオン触媒、シアネート化合物、イソシアネート化合物、ブロックイソシアネート化合物等が挙げられる。
本発明の樹脂組成物には比表面積が１８〜５０ｍ^２／ｇの無機充填材が含有される。無機充填材の例としては、シリカ、アルミナなどが挙げられる。特にシリカが好ましい。無機充填材は２種以上を混合して用いることもできる。無機充填材の配合量は特に限定されないが、好ましくは、樹脂組成物中、１０〜５０質量％の範囲で添加することができる。１０質量％未満であると、熱膨張率及びタック改善等の効果が得られにくい傾向にある。５０質量％を超えると、レーザー加工性が悪くなるばかりでなく、更に硬化物の弾性率も高くなり、硬く脆い材料となる傾向にある。
また無機充填材の比表面積は、１８〜５０ｍ^２／ｇの範囲で用いられる。この範囲外であると、フィラーが沈降する傾向があり、ワニスを長時間安定に保つことが困難になる。比表面積の範囲の下限は、２０ｍ^２／ｇ以上がより好ましい。比表面積の範囲の上限は、４０ｍ^２／ｇが好ましく、３５ｍ^２／ｇがより好ましく、３０ｍ^２／ｇ以下がさらに好ましい。例えば、比表面積の範囲は、１８〜４０ｍ^２／ｇが好ましく、１８〜３５ｍ^２／ｇの範囲がより好ましく、２０〜３０ｍ^２／ｇの範囲がさらに好ましい。
比表面積の分析は，粉体粒子表面に吸着占有面積の分かった分子を液体窒素の温度で吸着させ，その量から試料の比表面積を求めるという、いわゆるＢＥＴ法で求めることが出来る。最も良く利用されるのが不活性気体の低温低湿物理吸着によるＢＥＴ法である。
発明の樹脂組成物には本発明の効果が発揮される範囲において、各種樹脂添加剤や成分（Ａ）及び（Ｂ）以外の樹脂成分等を配合することができる。樹脂添加剤の例としては、オルベン、ベントン等の増粘剤、シリコン系、フッ素系又はアクリル系の消泡剤、レベリング剤、イミダゾール系、チアゾール系、トリアゾール系等の密着付与剤、シランカップリング剤等の表面処理剤、フタロシアニン・ブルー、フタロシアニン・グリーン、アイオジン・グリーン、ジスアゾイエロー、カーボンブラック等の着色剤、リン含有化合物、臭素含有化合物、水酸化アルミニウム、水酸化マグネシウム等難燃剤、リン系酸化防止剤、フェノール系酸化防止剤等の酸化防止剤を挙げることができる。
本発明の樹脂組成物は、特に多層フレキシブルプリント配線板の層間絶縁層用として好適に用いられる。特に、樹脂組成物層（Ａ層）及び支持体フィルム（Ｂ層）からなる接着フィルム及び樹脂組成物層（Ａ層）が銅箔上に形成されているＲＣＣタイプの接着フィルムの形態で好適に使用することができる。
接着フィルムは、当業者に公知の方法に従って、例えば、本発明の熱硬化性樹脂組成物を有機溶剤に溶解した樹脂ワニスを調製し、支持体フィルム及び銅箔にこの樹脂ワニスを塗布し、加熱又は熱風吹きつけ等により有機溶剤を乾燥させて熱硬化性樹脂組成物層を形成させることにより製造することができる。
支持体フィルム（Ｂ層）は、接着フィルムを製造する際の支持体となるものであり、多層プリント配線板の製造において、最終的には剥離または除去されるものである。支持体フィルムとしては、例えば、ポリエチレン、ポリ塩化ビニル等のポリオレフィン、ポリエチレンテレフタレート（以下、「ＰＥＴ」と略称することがある。）、ポリエチレンナフタレート等のポリエステル、ポリカーボネート、更には離型紙や銅箔等の金属箔などを挙げることができる。ポリイミド、ポリアミド、ポリアミドイミド、液晶ポリマー等の耐熱樹脂も使用することができる。なお、銅箔を支持体フィルムとして使用する場合は、塩化第二鉄、塩化第二銅等のエッチング液でエッチングすることにより除去することができる。支持フィルムはマット（ｍａｔ）処理、コロナ処理の他、離型処理を施してあってもよいが、剥離性を考慮すると離型処理が施されている方がより好ましい。支持フィルムの厚さは特に限定されないが、通常１０〜１５０μｍであり、好ましくは２５〜５０μｍの範囲で用いられる。
ＲＣＣタイプの場合は、銅箔は多層プリント配線板の導体層の一部として使用することになる。一般的には電解銅箔、圧延銅箔が挙げられ、極薄銅箔を用いることも出来る。極薄銅箔はキャリア銅箔が付いていても良い。銅箔の厚さは特に限定されないが、ファインピッチな配線形成には極薄銅箔を用いるのが好ましい。
ワニスを調製するための有機溶剤としては、例えば、アセトン、メチルエチルケトン、シクロヘキサノン等のケトン類、酢酸エチル、酢酸ブチル、セロソルブアセテート、プロピレングリコールモノメチルエーテルアセテート、カルビトールアセテート等の酢酸エステル類、セロソルブ、ブチルカルビトール等のカルビトール類、トルエン、キシレン等の芳香族炭化水素類、ジメチルホルムアミド、ジメチルアセトアミド、Ｎ−メチルピロリドン等を挙げることができる。有機溶剤は２種以上を組み合わせて用いてもよい。
乾燥条件は特に限定されないが、接着フィルムの接着能力を保持するため、乾燥時に熱硬化性樹脂組成物の硬化をできる限り進行させないことが重要となる。また、接着フィルム内に有機溶剤が多く残留すると、硬化後に膨れが発生する原因となるため、熱硬化性樹脂組成物中への有機溶剤の含有割合が通常５質量％以下、好ましくは３質量％以下となるように乾燥させる。具体的な乾燥条件は、熱硬化性樹脂組成物の硬化性やワニス中の有機溶媒量によっても異なるが、例えば３０〜６０質量％の有機溶剤を含むワニスにおいては、通常８０〜１２０℃で３〜１３分程度乾燥させることができる。当業者は、簡単な実験により適宜、好適な乾燥条件を設定することができる。
樹脂組成物層（Ａ層）の厚さは通常５〜５００μｍの範囲とすることができる。Ａ層の厚さの好ましい範囲は接着フィルムの用途により異なり、ビルドアップ工法により多層プリント配線板の製造に用いる場合は、回路を形成する導体層の厚みが通常５〜７０μｍであるので、層間絶縁層に相当するＡ層の厚さは１０〜１００μｍの範囲であるのが好ましい。
Ａ層は保護フィルムで保護されていてもよい。保護フィルムで保護することにより、樹脂組成物層表面へのゴミ等の付着やキズを防止することができる。保護フィルムはラミネートの際に剥離される。保護フィルムとしては支持フィルムと同様の材料を用いることができる。保護フィルムの厚さは特に限定されないが、好ましくは１〜４０μｍの範囲である。
本発明の接着フィルムは真空ラミネーターにより好適に回路基板にラミネートすることができる。ここで使用する内層回路基板は、主として、ポリエステル基板、ポリイミド基板、ポリアミドイミド基板、液晶ポリマー基板等の内層回路基板が挙げられる。また本発明の接着フィルムは多層プリント配線板をさらに多層化するために使用することもできる。なお回路表面は過酸化水素／硫酸、メックエッチボンド（メック（株）社製）等の表面処理剤により予め粗化処理が施されていた方が絶縁層の回路基板への密着性の観点から好ましい。
市販されている真空ラミネーターとしては、例えば、ニチゴー・モートン（株）製 バキュームアップリケーター、（株）名機製作所製 真空加圧式ラミネーター、日立テクノエンジニアリング（株）製 ロール式ドライコータ、日立エーアイーシー（株）製真空ラミネーター等を挙げることができる。
ラミネートにおいて、接着フィルムが保護フィルムを有している場合には該保護フィルムを除去した後、接着フィルムを加圧及び加熱しながら回路基板に圧着する。ラミネートの条件は、接着フィルム及び回路基板を必要によりプレヒートし、圧着温度を好ましくは７０〜１４０℃、圧着圧力を好ましくは１〜１１ｋｇｆ／ｃｍ^２とし、空気圧２０ｍｍＨｇ以下の減圧下でラミネートするのが好ましい。また、ラミネートの方法はバッチ式であってもロールでの連続式であってもよい。
樹脂組成物層（Ａ層）及び支持体フィルム（Ｂ層）からなる接着フィルムの場合、以下のような工程をたどる。接着フィルムを回路基板にラミネートした後、室温付近に冷却し支持体フィルムを剥離する。次いで、回路基板にラミネートされた熱硬化性樹脂組成物を加熱硬化させる。加熱硬化の条件は通常１５０℃〜２２０℃で２０分〜１８０分の範囲で選択され、より好ましくは１６０℃〜２００℃で３０〜１２０分の範囲で選択される。なお支持体フィルムが離型処理やシリコン等の剥離層を有する場合は、熱硬化性樹脂組成物の加熱硬化後あるいは加熱硬化及び穴開け後に支持体フィルムを剥離することもできる。
樹脂組成物の硬化物である絶縁層が形成された後、必要に応じて回路基板にドリル、レーザー、プラズマ、又はこれらの組み合わせ等の方法により穴開けを行いビアホールやスルーホールを形成してもよい。特に炭酸ガスレーザーやＹＡＧレーザー等のレーザーによる穴開けが一般的に用いられる。
次いで絶縁層の表面処理を行う。表面処理はデスミアプロセスで用いられる方法を採用することができ、デスミアプロセスを兼ねた形で行うことができる。デスミアプロセスに用いられる薬品としては酸化剤が一般的である。酸化剤としては、例えば、過マンガン酸塩（過マンガン酸カリウム、過マンガン酸ナトリウム等）、重クロム酸塩、オゾン、過酸化水素／硫酸、硝酸等が挙げられる。好ましくはビルドアップ工法による多層プリント配線板の製造における絶縁層の粗化に汎用されている酸化剤である、アルカリ性過マンガン酸溶液（例えば過マンガン酸カリウム、過マンガン酸ナトリウムの水酸化ナトリウム水溶液）を用いて処理を行うのが好ましい。酸化剤で処理する前に、膨潤剤による処理を行うこともできる。また酸化剤による処理の後は、通常、還元剤による中和処理が行われる。
上記のようなデスミアプロセスは、メッキにより形成される導体層のピール強度を上げるため、絶縁層表面を粗化し凹凸を設ける目的を兼ねる
表面処理を行った後、絶縁層表面にメッキにより導体層を形成する。導体層形成は無電解メッキと電解メッキを組み合わせた方法で実施することができる。また導体層とは逆パターンのメッキレジストを形成し、無電解メッキのみで導体層を形成することもできる。導体層形成後、１５０〜２００℃で２０〜９０分アニール（ａｎｎｅａｌ）処理することにより、導体層のピール強度をさらに向上、安定化させることができる。
導体層をパターン加工し回路形成する方法としては、例えば当業者に公知のサブトラクティブ法、セミアディディブ法などを用いることができる。サブトラクティブ法の場合、無電解銅メッキ層の厚みは０．１乃至３μｍ、好ましくは０．３乃至２μｍである。その上に電気メッキ層（パネルメッキ層）を３乃至３５μｍ、好ましくは５乃至２０μｍの厚みで形成した後、エッチングレジストを形成し、塩化第二鉄、塩化第二銅等のエッチング液でエッチングすることにより導体パターンを形成した後、エッチングレジストを剥離することにより、回路基板を得ることが出来る。また、セミアディティブ法の場合には、無電解銅メッキ層の厚みを０．１乃至３μｍ、好ましくは０．３乃至２μｍで無電解銅メッキ層を形成後、パターンレジストを形成し、次いで電気銅メッキ後に剥離することにより、回路基板を得ることができる。
樹脂組成物層（Ａ層）が銅箔上に形成されているＲＣＣタイプの接着フィルムの場合、以下のような工程をたどる。接着フィルムを回路基板にラミネートし、上記のように熱硬化性樹脂組成物を加熱硬化させる。次いで穴あけを上記のように行い、ソフトエッチングによりビアの表面処理を行う。次いで、無電解メッキを行い、上記のようにサブトラクティブ法などを用いて回路基板を得ることが出来る。用いられる銅箔としては、通常、１２又は１８μｍ品の電解銅箔が使用されており、例えば、三井金属鉱業（株）製「ＤＦＦ」、「ＮＳ−ＶＬＰ」、日鉱金属（株）製「ＪＴＣ」等が挙げられる。また、ファインラインの要求に従い極薄銅箔を使用することも出来、例えば、三井金属鉱業（株）製「Ｍｉｃｒｏ Ｔｈｉｎ Ｅｘ」、日本電解（株）製「ＹＳＭＡＰ」等が挙げられる。The polyimide resin of component (A) in the present invention has a polybutadiene structure, a urethane structure, and an imide structure in the molecule, and a phenol structure at the molecular end. The polyimide resin having a phenol structure at the molecular end can be obtained by the following method using the reaction components [a] to [d]. That is,
[A] a polybutadiene polyol compound having two or more alcoholic hydroxyl groups in one molecule, and
[B] A diisocyanate compound is reacted to form a diisocyanate prepolymer;
[C] tetrabasic acid dianhydride, and
[D] a polyfunctional phenol compound having two or more phenolic hydroxyl groups in one molecule;
React.
[A] As a polybutadiene polyol compound having two or more alcoholic hydroxyl groups in one molecule, those having a number average molecular weight of 300 to 5,000 are preferable. When the number average molecular weight is 300 or less, the modified polyimide resin tends to lack flexibility. In the case of 5,000 or more, the modified polyimide resin tends to lack compatibility with the thermosetting resin, and also tends to lack heat resistance and chemical resistance.
In the present invention, the number average molecular weight is a value measured by a gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the number average molecular weight by the GPC method is Shodex GPC System 21 manufactured by Showa Denko KK as a measuring device, and Shodex LF-804 / KF-803 / KF-804 manufactured by Showa Denko KK as a column. Measured at a column temperature of 40 ° C. using NMP as a mobile phase, and can be calculated using a standard polystyrene calibration curve. As the polybutadiene polyol, hydrogenated polybutadiene polyol in which unsaturated bonds in the molecule are hydrogenated may be used alone or in combination. The polybutadiene polyol is preferably a polybutadiene diol having a hydroxyl group at the molecular end. The alcoholic hydroxyl group means a hydroxyl group present in a form in which a hydrogen atom of an aliphatic hydrocarbon structure is substituted with a hydroxyl group (hydroxyl group). Specific examples of the polybutadiene polyol include, for example, G-1000, G-2000, G-3000, GI-1000, GI-2000 (manufactured by Nippon Soda Co., Ltd.), R-45EPI (Idemitsu Petrochemical ( Etc.).
[B] The diisocyanate compound is a compound having two isocyanate groups in the molecule. For example, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone. And diisocyanates such as diisocyanate.
[C] Tetrabasic acid dianhydride is a compound having two acid anhydride groups in the molecule. For example, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic acid Anhydride, naphthalenetetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-cyclohexene-1,2-dicarboxylic anhydride, 3,3′-4,4′-diphenyl Sulfonetetracarboxylic dianhydride, 1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-C] furan-1, 3-dione etc. are mentioned.
[D] Polyfunctional phenol compounds having two or more phenolic hydroxyl groups in one molecule include, for example, bisphenol A, bisphenol F, bisphenol S, biphenol, phenol novolac resin, alkylphenol novolac resin, bisphenol A type novolac resin, Examples thereof include a dicyclopentadiene structure-containing phenol novolak resin, a triazine structure-containing phenol novolak resin, a biphenyl skeleton-containing phenol novolak resin, a phenyl group-containing phenol novolak resin, a terpene-modified phenol resin, and polyvinylphenols. In particular, an alkylphenol novolac resin is preferable. The phenolic hydroxyl group means a hydroxyl group present in a form in which a hydrogen atom of an aromatic ring structure is substituted with a hydroxyl group (hydroxyl group).
In order to obtain the polyimide resin in the present invention efficiently, it is preferable to follow the following procedure. First, the polybutadiene polyol of the reaction component [a] and the diisocyanate compound of the reaction component [b] are reacted at a ratio in which the functional group equivalent of the isocyanate group of the diisocyanate compound to the hydroxyl group of the polybutadiene polyol exceeds 1. The reaction ratio between the polybutadiene polyol and the diisocyanate compound is preferably such that the functional group equivalent ratio of the isocyanate group of the diisocyanate compound to the hydroxyl group of the polybutadiene is 1: 1.5 to 1: 2.5.
When the reaction component [a] is a polybutadiene diol having a hydroxyl group at the molecular end, the polybutadiene diol can be represented by the following formula (a ′).

(R1 represents a divalent organic group having a polybutadiene structure.)
The diisocyanate compound of the reaction component [b] can be represented by the following formula (b).

(R2 represents a divalent organic group.)
The tetrabasic acid dianhydride of the reaction component [c] can be represented by the following formula (c).

(R3 represents a tetravalent organic group.)
The diisocyanate prepolymer obtained by reacting the polybutadiene polyol having a hydroxyl group at the molecular terminal with a diisocyanate compound can be represented by the following formula (a′-b).

(R1 and R2 are as defined above, and n represents an integer of 1 to 100 (1 ≦ n ≦ 100). N preferably represents an integer of 1 to 10 (1 ≦ n ≦ 10).)
Next, the diisocyanate prepolymer obtained by the above reaction is reacted with a tetrabasic acid dianhydride as a reaction component [c] and a polyfunctional phenol compound as a reaction component [d]. The reaction ratio is not particularly limited, but it is preferable to keep the isocyanate group from remaining in the composition as much as possible. In order not to leave the isocyanate group in the reaction system as much as possible, it is preferable to confirm the disappearance of the isocyanate group by FT-IR or the like during the reaction. According to the order of reaction, first, after reacting the tetrabasic acid dianhydride, a method of reacting the polyfunctional phenol compound and a method of simultaneously adding and reacting the tetrabasic acid dianhydride and the polyfunctional phenol compound are mentioned. When added simultaneously, the acid anhydride group preferentially reacts with the isocyanate group to form an imide bond. The remaining isocyanate groups can react with the polyfunctional phenol compound to introduce a phenol structure at the terminal.
The functional group equivalent of the hydroxyl group of the polybutadiene polyol of the reaction component [a] is W, the functional group equivalent of the isocyanate group of the diisocyanate compound of the reaction component [b] is X, and the functional group of the tetrabasic acid dianhydride of the reaction component [c]. When the equivalent is Y and the functional group equivalent of the polyfunctional phenol compound of the reaction component [d] is Z, the reaction components [c] and [d] are used in a ratio satisfying the relationship of Y <X−W <Y + Z. Is preferred.
When a polybutadiene diol having a hydroxyl group at the molecular end is used as the reaction component [a], the polyimide of the component (A) in the present invention has the structures of the following formulas (1-a) and (1-b).

Specific reaction conditions are, for example, the reaction of the polybutadiene polyol of the reaction component [a] and the diisocyanate compound of the reaction component [b], in an organic solvent, the reaction temperature is 80 ° C. or less, and the reaction time is usually 2 to 8 hours. Can be done under conditions. Moreover, you may carry out in catalyst presence if needed. Next, a tetrabasic acid dianhydride and a polyfunctional phenol compound are added to the reaction solution, and the reaction can be carried out under conditions of a reaction temperature of 120 to 160 ° C. and a reaction time of 5 to 24 hours. The reaction is usually performed in the presence of a catalyst. Moreover, you may carry out by adding an organic solvent further.
In this reaction, carbon dioxide gas is generated along with imide bond formation by reaction of isocyanate group and acid anhydride group. Therefore, the weight loss before and after the reaction is measured, and the number of moles of carbon dioxide gas is obtained to determine the formed imide. The number of moles of the group can be calculated.
After completion of the reaction, the reaction solution may be filtered if necessary to remove insoluble matters. Thus, the polyimide resin in the present invention can be obtained in a varnish form. The amount of solvent in the varnish can be appropriately adjusted by adjusting the amount of solvent during the reaction or adding a solvent after the reaction. The polyimide resin in this invention can be normally used for preparation of a composition with the said varnish form. In the case of isolation, for example, by adding the varnish obtained in methanol as a poor solvent little by little, the polyimide can be precipitated and obtained as a solid.
Examples of the organic solvent used in the above reactions include N, N′-dimethylformamide, N, N′-diethylformamide, N, N′-dimethylacetamide, N, N′-diethylacetamide, dimethylsulfoxide, diethyl Examples include polar solvents such as sulfoxide, N-methyl-2-pyrrolidone, tetramethylurea, γ-butyrolactone, cyclohexanone, diglyme, triglyme, carbitol acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. These solvents may be used as a mixture of two or more. Further, if necessary, a nonpolar solvent such as an aromatic hydrocarbon can be appropriately mixed and used.
Examples of the catalyst used in each of the above reactions include tetramethylbutanediamine, benzyldimethylamine, triethanolamine, triethylamine, N, N′-dimethylpiperidine, α-methylbenzyldimethylamine, N-methylmorpholine, triethylenediamine. And organic metal catalysts such as dibutyltin laurate, dimethyltin dichloride, cobalt naphthenate, and zinc naphthenate. These catalysts may be used in combination of two or more. In particular, it is most preferable to use triethylenediamine as the catalyst.
As the epoxy resin in the present invention, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, bisphenol S type epoxy resin, alkylphenol novolac type epoxy resin, biphenol type epoxy resin, naphthalene type epoxy resin, Two or more functional groups in one molecule such as dicyclopentadiene type epoxy resin, epoxidized product of condensate of phenol and aromatic aldehyde having phenolic hydroxyl group, triglycidyl isocyanurate, alicyclic epoxy resin, etc. The epoxy resin which has can be mentioned. Two or more of these epoxy resins may be mixed and used. Furthermore, it is preferable to use a bisphenol A type epoxy.
In the composition of this invention, you may mix | blend an epoxy hardening | curing agent as needed. Examples of the epoxy curing agent include an amine curing agent, a guanidine curing agent, an imidazole curing agent, a phenol curing agent, an acid anhydride curing agent, or an epoxy adduct or a microencapsulated one thereof. Can do. In particular, a phenol-based curing agent is preferable from the viewpoint of viscosity stability when the resin composition is made into a varnish. Two or more epoxy curing agents may be mixed and used.
Specific examples of the epoxy curing agent include dicyandiamide as the amine curing agent, imidazole silane, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and 2,4-diamino-6- [2 as the imidazole curing agent. '-Methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adduct, a phenol novolak resin containing a triazine structure as a phenolic curing agent (for example, Phenolite 7050 series: manufactured by Dainippon Ink & Chemicals, Inc.) ) And the like.
The polyimide resin composition of the present invention includes two or more phenols in one molecule of component (D) in order to control the crosslinking density at the time of curing of the polyimide resin of component (A) and the epoxy resin of component (B). It is preferable to use a polyfunctional phenol compound having a functional hydroxyl group in combination. It is possible to increase the crosslinking density of the component (A) and the component (B) by using the component (D) in combination, thereby reducing the thermal expansion at a temperature above the glass transition point. is there. In order to increase the crosslinking density and reduce thermal expansion and the like, the blending ratio of the component (A), the component (B), and the component (D) in the resin composition is 100% by weight of these components ( It is preferable that A) is 40 to 85% by weight, component (B) is 15 to 40% by weight, and component (D) is 0 to 20% by weight. Moreover, the molar ratio (x + z) / () of the total of the phenolic hydroxyl group (x) in the component (A) and the phenolic hydroxyl group (z) in the component (D) and the epoxy group (y) in the component (B). y) is preferably 0.7 to 1.3.
As an example of the polyfunctional phenol compound having two or more phenolic hydroxyl groups in one molecule of the component (D), the same compounds as the reaction component [d] described above can be raised.
The thermosetting polyimide resin composition of this invention can use a hardening accelerator together as needed. For example, melamine, dicyandiamide, guanamine and derivatives thereof, amines, phenols having one hydroxyl group, organic phosphines, phosphonium salts, quaternary ammonium salts, polybasic acid anhydrides, photocationic catalysts, cyanate compounds, isocyanate compounds, Examples include blocked isocyanate compounds.
The resin composition of the present invention has a specific surface area of 18 to 50 m. ² / G of inorganic filler. Examples of inorganic fillers include silica and alumina. Silica is particularly preferable. Two or more inorganic fillers can be mixed and used. Although the compounding quantity of an inorganic filler is not specifically limited, Preferably, it can add in the range of 10-50 mass% in a resin composition. If it is less than 10% by mass, it tends to be difficult to obtain effects such as thermal expansion coefficient and tack improvement. When it exceeds 50% by mass, not only the laser processability is deteriorated, but also the elastic modulus of the cured product is increased, and it tends to be a hard and brittle material.
The specific surface area of the inorganic filler is 18 to 50 m. ² / G in the range. Outside this range, the filler tends to settle and it becomes difficult to keep the varnish stable for a long time. The lower limit of the specific surface area range is 20 m. ² / G or more is more preferable. The upper limit of the specific surface area is 40 m. ² / G is preferred, 35 m ² / G is more preferable, 30 m ² / G or less is more preferable. For example, the specific surface area ranges from 18 to 40 m. ² / G is preferred, 18-35 m ² / G range is more preferable, 20-30m ² The range of / g is more preferable.
The analysis of the specific surface area can be obtained by a so-called BET method in which molecules having a known adsorption occupation area are adsorbed on the powder particle surface at the temperature of liquid nitrogen and the specific surface area of the sample is obtained from the amount. The BET method by low-temperature low-humidity physical adsorption of an inert gas is most often used.
Various resin additives, resin components other than components (A) and (B), and the like can be blended in the resin composition of the invention within the range where the effects of the present invention are exhibited. Examples of resin additives include thickeners such as olben and benton, silicone, fluorine or acrylic antifoaming agents, leveling agents, imidazole, thiazole and triazole adhesion promoters, silane couplings Surface treatment agents such as phthalocyanine, phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, carbon black and other colorants, phosphorus containing compounds, bromine containing compounds, flame retardants such as aluminum hydroxide and magnesium hydroxide, phosphorus Antioxidants such as antioxidants and phenolic antioxidants can be mentioned.
The resin composition of the present invention is particularly suitably used for an interlayer insulating layer of a multilayer flexible printed wiring board. In particular, an adhesive film composed of a resin composition layer (A layer) and a support film (B layer) and an RCC type adhesive film in which a resin composition layer (A layer) is formed on a copper foil are suitable. Can be used.
For the adhesive film, according to a method known to those skilled in the art, for example, a resin varnish prepared by dissolving the thermosetting resin composition of the present invention in an organic solvent is prepared, and this resin varnish is applied to a support film and a copper foil and heated. Or it can manufacture by drying an organic solvent by hot air spraying etc. and forming a thermosetting resin composition layer.
The support film (B layer) serves as a support when the adhesive film is produced, and is finally peeled off or removed in the production of the multilayer printed wiring board. Examples of the support film include polyolefins such as polyethylene and polyvinyl chloride, polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”), polyesters such as polyethylene naphthalate, polycarbonate, and release paper and copper foil. The metal foil etc. can be mentioned. Heat-resistant resins such as polyimide, polyamide, polyamideimide, and liquid crystal polymer can also be used. In addition, when using copper foil as a support body film, it can remove by etching with etching liquid, such as ferric chloride and cupric chloride. The support film may be subjected to a release treatment in addition to a mat treatment and a corona treatment, but it is more preferable that the release treatment is performed in consideration of releasability. Although the thickness of a support film is not specifically limited, Usually, it is 10-150 micrometers, Preferably it is used in 25-50 micrometers.
In the case of the RCC type, the copper foil is used as a part of the conductor layer of the multilayer printed wiring board. Generally, an electrolytic copper foil and a rolled copper foil are mentioned, and an ultrathin copper foil can also be used. The ultrathin copper foil may have a carrier copper foil. The thickness of the copper foil is not particularly limited, but it is preferable to use an ultrathin copper foil for fine pitch wiring formation.
Examples of organic solvents for preparing varnish include ketones such as acetone, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, acetate esters such as carbitol acetate, cellosolve, butyl Examples thereof include carbitols such as carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Two or more organic solvents may be used in combination.
The drying conditions are not particularly limited, but in order to maintain the adhesive ability of the adhesive film, it is important not to allow the thermosetting resin composition to cure as much as possible during drying. In addition, if a large amount of organic solvent remains in the adhesive film, it may cause swelling after curing. Therefore, the content of the organic solvent in the thermosetting resin composition is usually 5% by mass or less, preferably 3% by mass. Dry to: The specific drying conditions vary depending on the curability of the thermosetting resin composition and the amount of the organic solvent in the varnish. For example, in a varnish containing 30 to 60% by mass of an organic solvent, it is usually 3 at 80 to 120 ° C. It can be dried for about 13 minutes. Those skilled in the art can appropriately set suitable drying conditions by simple experiments.
The thickness of the resin composition layer (A layer) can usually be in the range of 5 to 500 μm. The preferred range of the thickness of the A layer varies depending on the use of the adhesive film, and when used for the production of multilayer printed wiring boards by the build-up method, the thickness of the conductor layer forming the circuit is usually 5 to 70 μm. The thickness of the A layer corresponding to the layer is preferably in the range of 10 to 100 μm.
The A layer may be protected with a protective film. By protecting with a protective film, it is possible to prevent dust and the like from being attached to the surface of the resin composition layer and scratches. The protective film is peeled off during lamination. As the protective film, the same material as the support film can be used. Although the thickness of a protective film is not specifically limited, Preferably it is the range of 1-40 micrometers.
The adhesive film of the present invention can be suitably laminated on a circuit board with a vacuum laminator. Examples of the inner layer circuit board used here include inner layer circuit boards such as a polyester substrate, a polyimide substrate, a polyamideimide substrate, and a liquid crystal polymer substrate. The adhesive film of the present invention can also be used for further multilayering a multilayer printed wiring board. In addition, from the viewpoint of adhesion of the insulating layer to the circuit board, the surface of the circuit should have been previously roughened with a surface treatment agent such as hydrogen peroxide / sulfuric acid or MEC Etch Bond (MEC Co., Ltd.). preferable.
Commercially available vacuum laminators include, for example, a vacuum applicator manufactured by Nichigo Morton Co., Ltd., a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a roll type dry coater manufactured by Hitachi Techno Engineering Co., Ltd., Hitachi AIC ( A vacuum laminator manufactured by Co., Ltd. can be mentioned.
In the lamination, when the adhesive film has a protective film, the protective film is removed, and then the adhesive film is pressure-bonded to the circuit board while being pressurized and heated. The laminating conditions are as follows: adhesive film and circuit board are preheated as necessary, pressure bonding temperature is preferably 70 to 140 ° C., pressure bonding pressure is preferably 1 to 11 kgf / cm. ² And laminating under reduced pressure with an air pressure of 20 mmHg or less. The laminating method may be a batch method or a continuous method using a roll.
In the case of an adhesive film composed of a resin composition layer (A layer) and a support film (B layer), the following steps are followed. After laminating the adhesive film on the circuit board, it is cooled to around room temperature and the support film is peeled off. Next, the thermosetting resin composition laminated on the circuit board is cured by heating. The conditions for heat curing are usually selected in the range of 150 to 220 ° C. for 20 to 180 minutes, more preferably in the range of 160 to 200 ° C. for 30 to 120 minutes. When the support film has a release layer or a release layer such as silicon, the support film can be peeled after the thermosetting resin composition is heat-cured or after heat-curing and punching.
After the insulating layer, which is a cured product of the resin composition, is formed, a via hole or a through hole may be formed by drilling the circuit board by a method such as drill, laser, plasma, or a combination thereof as necessary. Good. In particular, drilling with a laser such as a carbon dioxide laser or a YAG laser is generally used.
Next, the surface treatment of the insulating layer is performed. The surface treatment can employ a method used in a desmear process, and can be performed in a form that also serves as a desmear process. As a chemical used in the desmear process, an oxidizing agent is generally used. Examples of the oxidizing agent include permanganate (potassium permanganate, sodium permanganate, etc.), dichromate, ozone, hydrogen peroxide / sulfuric acid, nitric acid, and the like. Preferably, an alkaline permanganate solution (for example, potassium permanganate, sodium hydroxide aqueous solution of sodium permanganate), which is an oxidizer widely used for roughening the insulating layer in the production of multilayer printed wiring boards by the build-up method. It is preferable to carry out the treatment using A treatment with a swelling agent can also be performed before the treatment with the oxidizing agent. Further, after the treatment with an oxidizing agent, neutralization treatment with a reducing agent is usually performed.
The desmear process as described above also serves the purpose of roughening the surface of the insulating layer and providing irregularities in order to increase the peel strength of the conductor layer formed by plating.
After the surface treatment, a conductor layer is formed by plating on the surface of the insulating layer. The conductor layer can be formed by a method combining electroless plating and electrolytic plating. Alternatively, a plating resist having a pattern opposite to that of the conductor layer can be formed, and the conductor layer can be formed only by electroless plating. After the conductor layer is formed, the peel strength of the conductor layer can be further improved and stabilized by annealing at 150 to 200 ° C. for 20 to 90 minutes.
As a method for forming a circuit by patterning the conductor layer, for example, a subtractive method or a semi-additive method known to those skilled in the art can be used. In the case of the subtractive method, the thickness of the electroless copper plating layer is 0.1 to 3 μm, preferably 0.3 to 2 μm. An electroplating layer (panel plating layer) is formed thereon with a thickness of 3 to 35 μm, preferably 5 to 20 μm, an etching resist is formed, and etching is performed with an etching solution such as ferric chloride or cupric chloride. After forming a conductor pattern by this, a circuit board can be obtained by peeling an etching resist. In the case of the semi-additive method, after forming the electroless copper plating layer with an electroless copper plating layer thickness of 0.1 to 3 μm, preferably 0.3 to 2 μm, a pattern resist is formed, and then the electrolytic copper A circuit board can be obtained by peeling after plating.
In the case of an RCC type adhesive film in which the resin composition layer (A layer) is formed on a copper foil, the following steps are followed. The adhesive film is laminated on the circuit board, and the thermosetting resin composition is cured by heating as described above. Next, drilling is performed as described above, and via surface treatment is performed by soft etching. Next, electroless plating is performed, and a circuit board can be obtained using the subtractive method or the like as described above. As the copper foil used, 12 or 18 μm electrolytic copper foil is usually used. For example, “DFF”, “NS-VLP” manufactured by Mitsui Mining & Smelting Co., Ltd., “JTC” manufactured by Nikko Metal Co., Ltd. Or the like. Moreover, ultra-thin copper foil can also be used according to the requirements of fine lines, for example, “Micro Thin Ex” manufactured by Mitsui Mining & Smelting Co., Ltd., “YSMAP” manufactured by Nippon Electrolytic Co., Ltd., and the like.

＜実施例１３＞
銅箔との密着力（その１）
実施例７で得られた接着フィルムを銅箔（日鉱金属（株）製 ＪＴＣ箔）のＳ面及びＭ面にそれぞれ（株）名機製作所製真空ラミネーターにより、温度１００℃、圧力７ｋｇｆ／ｃｍ^２、気圧５ｍｍＨｇ以下の条件で片面にラミネートし、銅箔／接着フィルム／ＰＥＴの３層品をそれぞれ用意した。次いで離型処理ＰＥＴフィルムを剥離し、メックエッチボンドＣＺ−８１００処理済銅張積層板上に同様にラミネートした。そして１２０℃３０分、さらに１８０℃で９０分加熱硬化させた。得られた基板を用いて樹脂／銅箔の界面のピール強度を測定したところ、Ｓ面のピールが０．６６ｋｇｆ／ｃｍ、Ｍ面のピールが１．２２ｋｇｆ／ｃｍであった。またピール強度測定はＪＩＳ Ｃ６４８１に準じて評価し、銅箔厚は１８μｍとした。
＜実施例１４＞
銅箔との密着力（その２）
実施例８で得られた接着フィルムを用いて実施例１３と同様にして樹脂／銅箔の界面のピール強度を測定したところ、Ｓ面のピールが０．７３ｋｇｆ／ｃｍ、Ｍ面のピールが１．０５ｋｇｆ／ｃｍであった。
＜実施例１５＞
銅箔との密着力（その３）
実施例９で得られた接着フィルムを用いて実施例１３と同様にして樹脂／銅箔の界面のピール強度を測定したところ、Ｓ面のピールが０．５０ｋｇｆ／ｃｍ、Ｍ面のピールが１．０４ｋｇｆ／ｃｍであった。
＜実施例１６＞
銅箔との密着力（その４）
実施例１０で得られた接着フィルムを用いて実施例１３と同様にして樹脂／銅箔の界面のピール強度を測定したところ、Ｓ面のピールが０．６７ｋｇｆ／ｃｍ、Ｍ面のピールが０．９４ｋｇｆ／ｃｍであった。
＜実施例１７＞
銅箔との密着力（その５）
実施例１１で得られた接着フィルムを用いて実施例１３と同様にして樹脂／銅箔の界面のピール強度を測定したところ、Ｓ面のピールが０．４６ｋｇｆ／ｃｍ、Ｍ面のピールが１．１３ｋｇｆ／ｃｍであった。
＜実施例１８＞
銅箔との密着力（その６）
実施例１２で得られた接着フィルムを用いて実施例１３と同様にして樹脂／銅箔の界面のピール強度を測定したところ、Ｓ面のピールが０．４４ｋｇｆ／ｃｍ、Ｍ面のピールが１．０６ｋｇｆ／ｃｍであった。
＜比較例２＞
エポキシ樹脂製の層間絶縁材料（味の素ファインテクノ（株）社製ＡＢＦ−ＧＸｃｏｄｅ１３）を用いて実施例１３と同様にして樹脂／銅箔の界面のピール強度を測定したところ、Ｓ面のピールが０．２９ｋｇｆ／ｃｍ、Ｍ面のピールが１．４４ｋｇｆ／ｃｍであった。
実施例１３〜１８、比較例２の結果を表２にまとめる。実施例のものは銅箔のＳ面のような平滑な表面に対しても良好な密着性を示すことがわかる。

＜実施例１９＞
メッキピールについて（その１）
実施例８で得られた接着フィルムをメックエッチボンドＣＺ−８１００処理済銅張積層板上に（株）名機製作所製真空ラミネーターにより、温度１００℃、圧力７ｋｇｆ／ｃｍ^２、気圧５ｍｍＨｇ以下の条件で両面にラミネートした。次いで離型処理ＰＥＴフィルムを剥離し、１８０℃で３０分加熱硬化させ絶縁層を形成した。デスミアプロセスを兼ねた絶縁層の表面処理プロセスは、アトテックジャパン社製の以下の薬液を使用した。膨潤剤「スウェリング・ディップ・セキュリガンス Ｐ（Ｓｗｅｌｌｉｎｇ Ｄｉｐ Ｓｅｃｕｒｉｇａｎｔｈ Ｐ）」、酸化剤「コンセントレイト・コンパクト ＣＰ（Ｃｏｎｃｅｎｔｒａｔｅ Ｃｏｍｐａｃｔ ＣＰ）」（過マンガン酸アルカリ溶液）、還元剤「リダクション・ソルーション・セキュリガンス（Ｒｅｄｕｃｔｉｏｎ ｓｏｌｕｔｉｏｎ Ｓｅｃｕｒｉｇａｎｔｈ Ｐ−５００）」
温度８０℃で５分間膨潤剤溶液で表面処理し、次いで温度８０℃で５分間酸化剤で表面処理し、最後に４０℃で５分間還元剤溶液で中和処理を行った。次に絶縁層表面に無電界銅メッキの触媒付与を行なった後、無電界銅メッキ液に３２℃で３０分浸漬して、１．５μｍの無電界銅メッキ皮膜を形成させた。これを、１５０℃３０分で乾燥後、酸洗浄し、含リン銅板をアノードとし、陰極電流密度２．０Ａ／ｄｍ^２で１２分間電気銅メッキを行ない、銅メッキ皮膜を形成させた。その後、更に１８０℃で３０分アニール処理を行った。得られた導体層のピール強度は０．７１ｋｇｆ／ｃｍであった。またピール強度測定はＪＩＳ Ｃ６４８１に準じて評価し、導体メッキ厚は約２５μｍとした。
＜比較例３＞
エポキシ樹脂製の層間絶縁材料（味の素ファインテクノ（株）社製ＡＢＦ−ＧＸｃｏｄｅ１３）を用いて実施例１９と同様にして絶縁層を形成した。アトテックジャパン社製の薬液を用いて同様に表面処理を行った。
温度６０℃で５分間、膨潤剤溶液により表面処理し、次いで温度８０℃で１５分間、酸化剤により表面処理し、最後に４０℃で５分間、還元剤溶液により中和処理を行った。また得られた導体層のピール強度は０．６ｋｇｆ／ｃｍであった。
＜製造例３＞
＜線状変性ポリイミド樹脂の製造（線状変性ポリイミド樹脂ワニスＣ）＞
反応容器にＧ−３０００（２官能性ヒドロキシル基末端ポリブタジエン、数平均分子量＝５０４７（ＧＰＣ法）、ヒドロキシル基当量＝１７９８ｇ／ｅｑ．、固形分１００ｗ％：日本曹達（株）製）５０ｇと、イプゾール１５０ ２３．５ｇ、ジブチル錫ラウレート０．００５ｇを混合し均一に溶解させた。均一になったところで５０℃に昇温し、更に撹拌しながら、トルエン−２，４−ジイソシアネート（イソシアネート基当量＝８７．０８ｇ／ｅｑ．）４．８ｇを添加し約３時間反応を行った。次いで、この反応物を室温まで冷却してから、これにベンゾフェノンテトラカルボン酸二無水物（酸無水物当量＝１６１．１ｇ／ｅｑ．）８．９６ｇと、トリエチレンジアミン０．０７ｇと、エチルジグリコールアセテート（ダイセル化学工業（株）社製）４０．４ｇを添加し、攪拌しながら１３０℃まで昇温し、約４時間反応を行った。ＦＴ−ＩＲより２２５０ｃｍ^−１のＮＣＯピークの消失の確認を行った。ＮＣＯピーク消失の確認をもって反応の終点とみなし、反応物を室温まで降温してから１００メッシュの濾布で濾過して線状変性ポリイミド樹脂（線状変性ポリイミド樹脂ワニスＣ）を得た。
線状変性ポリイミド樹脂ワニスＡの性状：粘度＝７．５Ｐａ・ｓ（２５℃、Ｅ型粘度計）
酸価＝１６．９ｍｇＫＯＨ／ｇ
固形分＝５０ｗ％
＜参考例５＞
成分（Ａ）として製造例３で得られたポリイミド樹脂ワニスＣ３５部、成分（Ｂ）としてビスフェノールＡノボラック型エポキシ樹脂のＥＤＧＡｃ及びイプゾール１５０混合ワニス（固形分５０％、エポキシ当量２１０、ジャパンエポキシレジン（株）製「１５７Ｓ７０」）１０．９部、フェノールノボラック（大日本インキ化学工業（株）製「ＴＤ２０９０−６０Ｍ」）４．５部、球形シリカ（比表面積４．１ｍ^２／ｇ）６部、さらにトルエン１０部、γブチロラクトン２部を添加してワニス状の樹脂組成物を調製した。
＜分散性＞
比較例４において、ワニスを室温で１２時間ほど静置しておいてもフィラーが均一に分散されたまま維持された。
＜物性値＞
比較例４で得られたワニスについて、実施例７と同様にしてＰＥＴ上に樹脂組成物層を形成し接着フィルムを得て、１８０℃で９０分加熱硬化した。硬化物の特性値を表３に示す。また、比較例４から得られた接着フィルムを用いて実施例１３と同様にして樹脂／銅箔の界面のピール強度を測定したところ、Ｓ面のピールが０．５５ｋｇｆ／ｃｍ、Ｍ面のピールが０．６７ｋｇｆ／ｃｍであった。

The content of the present invention will be specifically described below with reference to examples, but the present examples are not intended to limit the present invention.
<Production Example 1>
<Manufacture of polyimide resin (polyimide resin varnish A)>
A flask equipped with a stirrer, a thermometer and a condenser was charged with 203.07 g of γ-butyrolactone and 304.60 g of Solvesso 150 as solvents, 88.8 g (0.4 mol) of isophorone diisocyanate and hydrogenated polybutadienediol (hydroxyl group). Charged 48.5 KOH-mg / g, molecular weight 2313) 231.3 g (0.1 mol) and polybutadiene diol (hydroxyl value 52.6 KOH-mg / g, molecular weight 2133) 213.3 g (0.1 mol) Reaction was performed at 70 degreeC for 4 hours. Subsequently, 195.9 g (0.2 mol) of nonylphenol novolac resin (hydroxyl equivalent 229.4 g / eq, average 4.27 functionality, average calculated molecular weight 979.5 g / mol) and ethylene glycol bisanhydro trimellitate 41.0 g ( 0.1 mol), the temperature was raised to 150 ° C. over 2 hours, and the reaction was allowed to proceed for 12 hours.
After the reaction, a transparent brown liquid was obtained, and a polyimide resin solution having a nonvolatile content of 60% and a viscosity of 15 Pa · s (25 ° C.) was obtained. The obtained polyimide resin solution was coated on a KBr plate and the infrared absorption spectrum of the sample in which the solvent component was volatilized was measured. As a result, 2270 cm ^−1, which is the characteristic absorption of the isocyanate group, was completely disappeared, and 725 cm Absorption of the imide ring was confirmed at ⁻¹ , 1780 cm ⁻¹ and 1720 cm ⁻¹ . Absorption of urethane bonds was confirmed at 1540 cm ⁻¹ . The amount of carbon dioxide generated with the progress of imidization was 8.8 g (0.2 mol), which was traced by the change in the weight charged to the flask. The functional group equivalent of the acid anhydride of ethylene glycol bisanhydro trimellitate is 0.2 mol, the amount of carbon dioxide generated is also 0.2 mol, and all of the acid anhydride is used for imide formation. It is concluded that no anhydride is present.
As a result, 0.2 mol of the isocyanate group is converted into an imide bond, and the remaining isocyanate group forms a urethane bond together with the hydroxyl group of hydrogenated polybutadiene diol and polybutadiene diol and the phenolic hydroxyl group in the nonylphenol novolac resin. Thus, it is concluded that a polyurethaneimide resin having a phenolic hydroxyl group of a nonylphenol novolak resin and having a part of the phenolic hydroxyl group modified with a urethane bond was obtained.
<Production Example 2>
<Manufacture of polyimide resin (polyimide resin varnish B)>
A flask equipped with a stirrer, a thermometer and a condenser was charged with 292.09 g of ethyl diglycol acetate and 292.09 g of Solvesso 150 as solvents, 88.8 g (0.4 mol) of isophorone diisocyanate and polybutadiene diol (hydroxyl value). 52.6 KOH-mg / g, molecular weight 2133) 426.6 g (0.2 mol) was charged, and the reaction was carried out at 70 ° C. for 4 hours. Subsequently, 195.9 g (0.2 mol) of nonylphenol novolac resin (hydroxyl equivalent 229.4 g / eq, average 4.27 functionality, average calculated molecular weight 979.5 g / mol) and ethylene glycol bisanhydro trimellitate 41.0 g ( 0.1 mol), the temperature was raised to 150 ° C. over 2 hours, and the reaction was allowed to proceed for 12 hours.
After the reaction, a transparent brown liquid was obtained, and a polyimide resin solution having a nonvolatile content of 56% and a viscosity of 12 Pa · s (25 ° C.) was obtained. The obtained polyimide resin solution was coated on a KBr plate and the infrared absorption spectrum of the sample in which the solvent component was volatilized was measured. As a result, 2270 cm ^−1, which is the characteristic absorption of the isocyanate group, was completely disappeared, and 725 cm Absorption of the imide ring was confirmed at ⁻¹ , 1780 cm ⁻¹ and 1720 cm ⁻¹ . Absorption of urethane bonds was confirmed at 1540 cm ⁻¹ . The amount of carbon dioxide generated with the progress of imidization was 8.8 g (0.2 mol), which was traced by the change in the weight charged to the flask. The functional group equivalent of the acid anhydride of ethylene glycol bisanhydro trimellitate is 0.2 mol, the amount of carbon dioxide generated is also 0.2 mol, and all of the acid anhydride is used for imide formation. It is concluded that no anhydride is present. As a result, 0.2 mol of the isocyanate group is converted into an imide bond, and the remaining isocyanate group forms a urethane bond together with the hydroxyl group of polybutadiene diol and the phenolic hydroxyl group in the nonylphenol novolac resin, whereby the phenol novolac is added to the resin. It is concluded that a polyimide urethane resin having a phenolic hydroxyl group of the resin and having some phenolic hydroxyl groups modified with urethane bonds was obtained.
<Reference Example 1>
40 parts of polyimide resin varnish A obtained in Production Example 1 as component (A), diethylene glycol monoethyl ether acetate (hereinafter referred to as EDGAc) of bisphenol A novolak type epoxy resin and ipsol 150 (aromatic hydrocarbon) as component (B) Mixed solvent: manufactured by Idemitsu Petrochemical Co., Ltd.) mixed varnish (solid content 50%, epoxy equivalent 210, “157S70” manufactured by Japan Epoxy Resin Co., Ltd.), imidazole derivative (produced by Japan Epoxy Resin Co., Ltd.) “P200H50”) 0.5 part, spherical silica (specific surface area 80 m ² / g) 6 parts, toluene 10 parts and γ-butyrolactone 5.5 parts were added to prepare a varnish-like resin composition.
<Reference Example 2>
40 parts of polyimide resin varnish A obtained in Production Example 1 as component (A), EDGAc of bisphenol A novolac type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70") 10.9 parts, imidazole derivative (Japan Epoxy Resin "P200H50" 0.5 parts), spherical silica (specific surface area 6.2 m ² / g) 6 parts, toluene 10 parts Was added to prepare a varnish-like resin composition.
<Reference Example 3>
40 parts of polyimide resin varnish B obtained in Production Example 2 as component (A), EDGAc of bisphenol A novolak type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70") 10.9 parts, imidazole derivative (Japan Epoxy Resin "P200H50") 0.5 parts, spherical silica (specific surface area 80 m ² / g) 6 parts, further toluene 10 parts, γ A varnish-like resin composition was prepared by adding 5.5 parts of butyrolactone.
<Reference Example 4>
40 parts of polyimide resin varnish B obtained in Production Example 2 as component (A), EDGAc of bisphenol A novolak type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70") 10.9 parts, imidazole derivative (Japan Epoxy Resin "P200H50" 0.5 parts), spherical silica (specific surface area 6.2 m ² / g) 6 parts, toluene 10 parts Was added to prepare a varnish-like resin composition.
<Example 1>
40 parts of polyimide resin varnish A obtained in Production Example 1 as component (A), EDGAc of bisphenol A novolac type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70") 10.9 parts, imidazole derivative (Japan Epoxy Resin "P200H50" 0.5 parts), spherical silica (specific surface area 30 m ² / g) 6 parts, further toluene 10 parts, γ A varnish-like resin composition was prepared by adding 2 parts of butyrolactone.
<Example 2>
40 parts of polyimide resin varnish B obtained in Production Example 2 as component (A), EDGAc of bisphenol A novolak type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70") 10.9 parts, imidazole derivative (Japan Epoxy Resin "P200H50" 0.5 parts), spherical silica (specific surface area 30 m ² / g) 6 parts, further toluene 10 parts, γ A varnish-like resin composition was prepared by adding 2 parts of butyrolactone.
<Example 3>
40 parts of polyimide resin varnish A obtained in Production Example 1 as component (A), EDGAc of bisphenol A novolac type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70") 10.9 parts, imidazole derivative (Japan Epoxy Resin "P200H50" 0.5 parts), spherical silica (specific surface area 20 m ² / g) 6 parts, further toluene 10 parts, γ A varnish-like resin composition was prepared by adding 4 parts of butyrolactone.
<Example 4>
40 parts of polyimide resin varnish B obtained in Production Example 2 as component (A), EDGAc of bisphenol A novolak type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70") 10.9 parts, imidazole derivative (Japan Epoxy Resin "P200H50" 0.5 parts), spherical silica (specific surface area 20 m ² / g) 6 parts, further toluene 10 parts, γ A varnish-like resin composition was prepared by adding 4 parts of butyrolactone.
<Example 5>
40 parts of polyimide resin varnish A obtained in Production Example 1 as component (A), EDGAc of bisphenol A novolac type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70" manufactured by Co., Ltd.) 10.9 parts, 0.5 parts of imidazole derivative ("P200H50" manufactured by Japan Epoxy Resin Co., Ltd.), 6 parts of spherical alumina (specific surface area 22 m ² / g), and 10 parts of toluene are added. Thus, a varnish-like resin composition was prepared.
<Example 6>
40 parts of polyimide resin varnish B obtained in Production Example 2 as component (A), EDGAc of bisphenol A novolak type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70" manufactured by Co., Ltd.) 10.9 parts, 0.5 parts of imidazole derivative ("P200H50" manufactured by Japan Epoxy Resin Co., Ltd.), 6 parts of spherical alumina (specific surface area 22 m ² / g), and 10 parts of toluene are added. Thus, a varnish-like resin composition was prepared.
<Dispersibility>
In Reference Examples 1 to 4, when the varnish is allowed to stand at room temperature for about 12 hours, the filler settles and the varnish is separated, but in Examples 1 to 6, the filler is maintained uniformly dispersed. It was.
<Example 7>
About the varnish obtained in Example 1, the resin composition was applied on a release-treated polyethylene terephthalate (thickness 38 μm, hereinafter abbreviated as PET) with an applicator so that the resin thickness after drying was 60 μm. , Dried at 80 to 120 ° C. (average 100 ° C.) for 12 minutes to form a resin composition layer to obtain an adhesive film.
<Example 8>
About the varnish obtained in Example 2, the resin composition layer was formed on PET similarly to Example 7, and the adhesive film was obtained.
<Example 9>
About the varnish obtained in Example 3, the resin composition layer was formed on PET similarly to Example 7, and the adhesive film was obtained.
<Example 10>
About the varnish obtained in Example 4, the resin composition layer was formed on PET similarly to Example 7, and the adhesive film was obtained.
<Example 11>
About the varnish obtained in Example 5, the resin composition layer was formed on PET similarly to Example 7, and the adhesive film was obtained.
<Example 12>
About the varnish obtained in Example 6, the resin composition layer was formed on PET similarly to Example 7, and the adhesive film was obtained.
The adhesive films obtained from Examples 7 to 12 were heat-cured at 180 ° C. for 90 minutes. Table 1 shows the characteristics of the cured product of each resin composition. The tensile strength at break was measured in accordance with Japanese Industrial Standard (JIS) K7127. The dielectric characteristics were evaluated by a cavity resonance perturbation method (E8362B manufactured by Agilent Technologies). The characteristic values are shown in Table 1.
<Comparative Example 1>
As Comparative Example 1, an epoxy resin interlayer insulating material (ABF-GXcode 13 manufactured by Ajinomoto Fine Techno Co., Ltd.) was obtained by heating and curing at 180 ° C. for 90 minutes. The characteristic values of the cured product are shown in Table 1 as described above.

<Example 13>
Adhesion with copper foil (part 1)
The adhesive film obtained in Example 7 was subjected to a vacuum laminator manufactured by Meiki Seisakusho on the S and M surfaces of copper foil (JTC foil manufactured by Nikko Metal Co., Ltd.), respectively, at a temperature of 100 ° C. and a pressure of 7 kgf / cm ^2. The laminate was laminated on one side under the conditions of an atmospheric pressure of 5 mmHg or less to prepare three-layer products of copper foil / adhesive film / PET. Next, the release-treated PET film was peeled off and laminated in the same manner on a MEC-etch bond CZ-8100-treated copper clad laminate. Then, it was cured by heating at 120 ° C. for 30 minutes and further at 180 ° C. for 90 minutes. When the peel strength of the resin / copper foil interface was measured using the obtained substrate, the peel on the S surface was 0.66 kgf / cm and the peel on the M surface was 1.22 kgf / cm. The peel strength measurement was evaluated according to JIS C6481, and the copper foil thickness was 18 μm.
<Example 14>
Adhesion with copper foil (Part 2)
When the peel strength of the resin / copper foil interface was measured in the same manner as in Example 13 using the adhesive film obtained in Example 8, the peel on the S surface was 0.73 kgf / cm, and the peel on the M surface was 1. 0.05 kgf / cm.
<Example 15>
Adhesion with copper foil (part 3)
When the peel strength of the resin / copper foil interface was measured in the same manner as in Example 13 using the adhesive film obtained in Example 9, the peel on the S surface was 0.50 kgf / cm, and the peel on the M surface was 1. 0.04 kgf / cm.
<Example 16>
Adhesive strength with copper foil (4)
Using the adhesive film obtained in Example 10, the peel strength at the resin / copper foil interface was measured in the same manner as in Example 13. The peel on the S surface was 0.67 kgf / cm, and the peel on the M surface was 0. It was 94 kgf / cm.
<Example 17>
Adhesion with copper foil (part 5)
Using the adhesive film obtained in Example 11, the peel strength at the resin / copper foil interface was measured in the same manner as in Example 13. As a result, the peel on the S surface was 0.46 kgf / cm, and the peel on the M surface was 1. .13 kgf / cm.
<Example 18>
Adhesive strength with copper foil (6)
Using the adhesive film obtained in Example 12, the peel strength at the resin / copper foil interface was measured in the same manner as in Example 13. As a result, the peel on the S surface was 0.44 kgf / cm, and the peel on the M surface was 1. 0.06 kgf / cm.
<Comparative example 2>
When the peel strength of the resin / copper foil interface was measured in the same manner as in Example 13 using an epoxy resin interlayer insulating material (ABF-GXcode 13 manufactured by Ajinomoto Fine Techno Co., Ltd.), the peel on the S surface was 0. The peel of the M surface was 1.44 kgf / cm.
The results of Examples 13 to 18 and Comparative Example 2 are summarized in Table 2. It turns out that the thing of an Example shows favorable adhesiveness also to the smooth surface like the S surface of copper foil.

<Example 19>
About Plating Peel (Part 1)
The adhesive film obtained in Example 8 was subjected to conditions of 100 ° C., pressure 7 kgf / cm ² and atmospheric pressure 5 mmHg or less on a Mec Etch Bond CZ-8100 treated copper clad laminate using a vacuum laminator manufactured by Meiki Seisakusho. Laminated on both sides. Next, the release-treated PET film was peeled off and heated and cured at 180 ° C. for 30 minutes to form an insulating layer. The following chemical solution manufactured by Atotech Japan was used for the surface treatment process of the insulating layer that also served as the desmear process. Swelling agent “Swelling Dip Securigans P”, oxidizing agent “Concentrate Compact CP” (alkaline permanganate solution), reducing agent “Reduction Solution Securigans ( "Reduction solution Security P-500)"
Surface treatment was performed with a swelling agent solution at a temperature of 80 ° C. for 5 minutes, followed by surface treatment with an oxidizing agent at a temperature of 80 ° C. for 5 minutes, and finally a neutralization treatment was performed with a reducing agent solution at 40 ° C. for 5 minutes. Next, an electroless copper plating catalyst was applied to the surface of the insulating layer, and then immersed in an electroless copper plating solution at 32 ° C. for 30 minutes to form a 1.5 μm electroless copper plating film. This was dried at 150 ° C. for 30 minutes, washed with acid, and a phosphorous copper plate was used as an anode, and electroplating was performed at a cathode current density of 2.0 A / dm ² for 12 minutes to form a copper plating film. Thereafter, an annealing treatment was further performed at 180 ° C. for 30 minutes. The peel strength of the obtained conductor layer was 0.71 kgf / cm. The peel strength measurement was evaluated according to JIS C6481, and the conductor plating thickness was about 25 μm.
<Comparative Example 3>
An insulating layer was formed in the same manner as in Example 19 using an interlayer insulating material made of epoxy resin (ABF-GXcode 13 manufactured by Ajinomoto Fine Techno Co., Ltd.). Surface treatment was similarly performed using a chemical solution manufactured by Atotech Japan.
Surface treatment was performed with a swelling agent solution at a temperature of 60 ° C. for 5 minutes, followed by a surface treatment with an oxidizing agent at a temperature of 80 ° C. for 15 minutes, and finally a neutralization treatment was performed with a reducing agent solution at 40 ° C. for 5 minutes. The peel strength of the obtained conductor layer was 0.6 kgf / cm.
<Production Example 3>
<Production of linear modified polyimide resin (linear modified polyimide resin varnish C)>
In a reaction vessel, 50 g of G-3000 (bifunctional hydroxyl group-terminated polybutadiene, number average molecular weight = 5047 (GPC method), hydroxyl group equivalent = 1798 g / eq., Solid content: 100 w%, manufactured by Nippon Soda Co., Ltd.), ipzol 150 23.5 g and dibutyltin laurate 0.005 g were mixed and dissolved uniformly. When the temperature became uniform, the temperature was raised to 50 ° C., and while further stirring, 4.8 g of toluene-2,4-diisocyanate (isocyanate group equivalent = 87.08 g / eq.) Was added and the reaction was carried out for about 3 hours. The reaction was then cooled to room temperature before 8.96 g benzophenonetetracarboxylic dianhydride (acid anhydride equivalent = 161.1 g / eq.), 0.07 g triethylenediamine, and ethyl diglycol. 40.4 g of acetate (manufactured by Daicel Chemical Industries, Ltd.) was added, the temperature was raised to 130 ° C. with stirring, and the reaction was carried out for about 4 hours. The disappearance of the NCO peak at 2250 cm ⁻¹ was confirmed by FT-IR. The confirmation of the disappearance of the NCO peak was regarded as the end point of the reaction, and the reaction product was cooled to room temperature and then filtered through a 100 mesh filter cloth to obtain a linear modified polyimide resin (linear modified polyimide resin varnish C).
Properties of linear modified polyimide resin varnish A: Viscosity = 7.5 Pa · s (25 ° C., E-type viscometer)
Acid value = 16.9 mgKOH / g
Solid content = 50w%
<Reference Example 5>
35 parts of polyimide resin varnish obtained in Production Example 3 as component (A), EDGAc of bisphenol A novolak type epoxy resin and ipsol 150 mixed varnish as component (B) (solid content 50%, epoxy equivalent 210, Japan epoxy resin ( "157S70") 10.9 parts, phenol novolac (Dainippon Ink & Chemicals "TD2090-60M") 4.5 parts, spherical silica (specific surface area 4.1 m ² / g) 6 parts, Furthermore, 10 parts of toluene and 2 parts of γ-butyrolactone were added to prepare a varnish-like resin composition.
<Dispersibility>
In Comparative Example 4, even when the varnish was allowed to stand at room temperature for about 12 hours, the filler was maintained uniformly dispersed.
<Physical property values>
For the varnish obtained in Comparative Example 4, a resin composition layer was formed on PET in the same manner as in Example 7 to obtain an adhesive film, which was heat cured at 180 ° C. for 90 minutes. Table 3 shows the characteristic values of the cured product. Further, when the peel strength of the resin / copper foil interface was measured in the same manner as in Example 13 using the adhesive film obtained from Comparative Example 4, the peel on the S surface was 0.55 kgf / cm, and the peel on the M surface. Was 0.67 kgf / cm.

Claims (13)

Interlayer insulation resin composition for multilayer printed wiring boards containing the following components (A), (B) and (C):
(A) a polyimide resin having a polybutadiene structure, a urethane structure, an imide structure in the molecule, and a phenol structure at the molecular end;
(B) epoxy resin,
(C) An inorganic filler having a specific surface area of 18 to 50 m ² / g. Interlayer insulation resin composition for multilayer printed wiring boards containing the following components (A), (B) and (C):
(A) [a] A polybutadiene polyol compound having two or more alcoholic hydroxyl groups in one molecule and [b] a diisocyanate compound are reacted to form a diisocyanate prepolymer, and [c] tetrabasic acid dianhydride, and [D] a polyimide resin having a phenol structure at the molecular end, which can be obtained by reacting a polyfunctional phenol compound having two or more phenolic hydroxyl groups in one molecule;
(B) epoxy resin,
(C) An inorganic filler having a specific surface area of 18 to 50 m ² / g. The resin composition of Claim 1 or 2 whose specific surface area of the inorganic filler of a component (C) is 18-40 m < ² > / g. The resin composition of Claim 1 or 2 whose specific surface area of the inorganic filler of a component (C) is 18-35 m < ² > / g. The resin composition of Claim 1 or 2 whose specific surface area of the inorganic filler of a component (C) is 20-30 m < ² > / g.   The resin composition according to claim 1 or 2, wherein the inorganic filler is silica.   The resin composition according to claim 1 or 2, wherein the phenolic compound is a phenol novolac resin.   The resin composition according to claim 1 or 2, wherein the polybutadiene polyol compound is a hydrogenated polybutadiene polyol compound. In the polyimide resin of component (A), the functional group equivalent ratio of the isocyanate group of the reaction component [b] diisocyanate compound to the hydroxyl group of the polybutadiene polyol having two or more alcoholic hydroxyl groups in one molecule of the reaction component [a] The resin composition according to claim 2, which is reacted at a ratio of 1: 1.5 to 1: 2.5.   Furthermore, the resin composition of Claim 1 or 2 containing the polyfunctional phenol compound which has a 2 or more phenolic hydroxyl group in component [D] 1 molecule.   Component (A) is 40 to 85% by weight and Component (B) is 100% by weight of the total of the polyimide resin of Component (A), the epoxy resin of Component (B) and the polyfunctional phenol compound of Component (D). The resin composition according to claim 10, wherein 15 to 40% by weight and component (D) are contained at 0 to 20% by weight.   The adhesive film for interlayer insulation layer formation of the multilayer printed wiring board by which the resin composition of Claim 1 or 2 was layer-formed on the support body.   A multilayer printed wiring board in which an interlayer insulating layer is formed from the resin composition according to claim 1.