JP3624499B2 - Epoxy resin molding material for sealing electronic parts and semiconductor device - Google Patents

Description

【０００５】
【発明の実施の形態】
本発明において用いられる（Ａ）成分の１分子中に２個以上のエポキシ基を有するエポキシ樹脂としては、電子部品封止用エポキシ樹脂成形材料で一般に使用されているものであれば制限はなく、フェノールノボラック型エポキシ樹脂、オルソクレゾールノボラック型エポキシ樹脂をはじめとするフェノール類とアルデヒド類のノボラック樹脂をエポキシ化したもの、ビスフェノールＡ、ビスフェノールＦ、ビスフェノールＳ、アルキル置換又は非置換のビフェノールなどのジグリシジルエーテル、ジアミノジフェニルメタン、イソシアヌル酸などのポリアミンとエピクロルヒドリンの反応により得られるグリシジルアミン型エポキシ樹脂、オレフィン結合を過酢酸などの過酸で酸化して得られる線状脂肪族エポキシ樹脂、及び飽和脂肪族環を有するエポキシ樹脂（脂環族エポキシ樹脂）などがある。また、臭素化エポキシ樹脂など、これらのエポキシ樹脂をハロゲン化したハロゲン化エポキシ樹脂、例えば臭素化ビスフェノールＡのジグリシジルエーテル、臭素化フェノールノボラック型エポキシ樹脂等も難燃性を向上させるために用いられる。具体的には臭素化ビスフェノールＡ型エポキシ樹脂が好適に用いられ、その配合量はエポキシ樹脂全体に対して好ましくは５〜４０重量％、更に好ましくは１０〜３０重量％配合される。
【０００６】
（Ａ）成分のエポキシ樹脂において特に優れた接着性を示すものとして、アルキル置換又は非置換のビフェニル骨格型エポキシ樹脂があり、本発明のエポキシ樹脂成形材料に特に優れた接着性を付与するためには、使用エポキシ樹脂全量に対し２０重量％以上、好ましくは６０重量以上％使用することが望ましい。アルキル置換ビフェニル骨格型エポキシ樹脂とは、ビフェニル環がアルキル基で置換されたものであり、アルキル基としては、メチル基等の炭素数１〜４のものが好ましい。このようなエポキシ樹脂の具体例としては、例えば、４，４′−ビスヒドロキシビフェニルや４，４′−ジヒドロキシ−３，３′，５，５′−テトラアルキルビフェニル等のアルキル置換又は非置換４，４′−ジヒドロキシビフェニルをエピクロルヒドリンを用いてエポキシ化したもの、すなわち、アルキル置換又は非置換の４，４′−ビス（２，３−エポキシプロポキシ）ビフェニル等が挙げられる。
【０００７】
（Ａ）成分のエポキシ樹脂は適宜何種類でも併用することができるが、純度、特に加水分解性塩素量はＩＣなど素子上のアルミ配線腐食に係わるため少ない方がよく、耐湿性の優れた電子部品封止用エポキシ樹脂成形材料を得るためには５００ｐｐｍ以下であることが好ましい。ここで、加水分解性塩素量とは試料のエポキシ樹脂１ｇをジオキサン３０ｍｌに溶解し、１Ｎ−ＫＯＨメタノール溶液５ｍｌを添加して３０分間リフラックス後、電位差滴定により求めた値を尺度としたものである。
【０００８】
本発明において用いられる（Ｂ）成分の１分子中に２個以上のフェノール性水酸基を有する化合物としては、フェノール、クレゾール、キシレノール、レゾルシン、カテコール、ビスフェノールＡ、ビスフェノールＦなどのフェノール類又はα−ナフトール、β−ナフトール、ジヒドロキシナフタレン等のナフトール類とホルムアルデヒド、アセトアルデヒド、プロピオンアルデヒド、ベンズアルデヒド、サリチルアルデヒド等のアルデヒド類とを酸性触媒下で縮合又は共縮合させて得られる樹脂、ポリパラビニルフェノール樹脂、フェノール類とジメトキシパラキシレンから合成されるキシリレン基を有するフェノール・アラルキル樹脂、飽和脂肪族環を分子中に有する化合物などがあり、単独で又は２種類以上併用してもよい。また、難燃性付与の目的で、ハロゲン化フェノール類、例えば臭素化ビスフェノールＡなどを併用してもよく、その配合量は（Ｂ）成分総量中、５〜４０重量％、好ましくは１０〜３０重量％が適当である。
【０００９】
本発明における（Ａ）成分のエポキシ樹脂と（Ｂ）成分のフェノール性水酸基を有する化合物において、接着性に優れるものとしては、樹脂又は化合物の構造中に特定の飽和脂肪族環を有するものが挙げられる。これを例示すれば、ジシクロペンタジエンや、リモネンなどのテルペン化合物に酸触媒等を用いてフェノール類を付加させた樹脂、又はこれをエポキシ化した樹脂があげられる。これらの樹脂又は化合物の添加量としては、（Ａ）成分＋（Ｂ）成分の合計重量に対し、飽和脂肪族環の重量が２０％〜４０％であることが好ましい。２０重量％未満では従来のオルソクレゾールノボラック型エポキシ樹脂／フェノールノボラック樹脂系のエポキシ樹脂成形材料と比較し高接着性の効果が不十分となることがある。更に、これらの構造を有するエポキシ樹脂又はフェノール性水酸基を有する化合物は前出のビフェニル骨格型エポキシ樹脂と併用することで、更に優れた接着性を発揮できる。
【００１０】
エポキシ樹脂成形材料中の（Ａ）成分のエポキシ樹脂の配合割合は、通常５ 〜３０重量％、好ましくは７〜２０重量％、（Ｂ）成分のフェノール性水酸基を有する化合物の配合割合は、通常３〜３０重量％、好ましくは５〜１５重量％が適当である。
【００１１】
また、（Ａ）成分のエポキシ樹脂中のエポキシ基と、（Ｂ）成分のフェノール性水酸基を有する化合物中のフェノール性水酸基及び（Ｃ）成分の共重合体中に存在するフェノール性水酸基の当量比（（Ｂ）及び（Ｃ）成分のフェノール性水酸基数／（Ａ）成分のエポキシ基数）は、特に限定はされないが、それぞれの未反応分を少なく抑えるために０．７〜１．３の範囲に設定することが好ましい。
【００１２】
本発明の電子部品封止用エポキシ樹脂成形材料には、エポキシ樹脂とフェノール性水酸基を有する化合物の硬化反応を促進する硬化促進剤を配合することができる。この硬化促進剤としては、例えば、トリエチレンジアミン、ベンジルジメチルアミン、トリエタノールアミン、ジメチルアミノエタノール、トリス（ジメチルアミノメチル）フェノール、１，６−ジアザビシクロ（４，３，０）ウンデセン−５、１，８−ジアザビシクロ（５，４，０）ウンデセン−７などの三級アミン類、２−メチルイミダゾール、２−フェニルイミダゾール、２−フェニル−４−メチルイミダゾール、２−ヘプタデシルイミダゾールなどのイミダゾール類、トリブチルホスフィン、メチルジフェニルホスフィン、トリフェニルホスフィン、ジフェニルホスフィン、フェニルホスフィンなどの有機ホスフィン類、テトラフェニルホスホニウムテトラフェニルボレート、トリフェニルホスフィンテトラフェニルボレート、２−エチル−４−メチルイミダゾールテトラフェニルボレート、Ｎ−メチルモルホリンテトラフェニルボレートなどのテトラフェニルボロン塩などがあり、単独で又は２種以上併用してもよい。硬化促進剤総量の好ましい配合割合は（Ａ）成分のエポキシ樹脂１００重量部に対して０．３〜２０重量部、更に好ましくは０．６〜１０重量部である。
【００１３】
本発明の（Ｃ）成分、すなわちフェノール性水酸基と反応する官能基を有するポリオレフィン（Ｃ−１）とヒドロキシフェニレン基を構造単位として有する重合体（Ｃ−２）との共重合体は、本発明の電子部品封止用エポキシ樹脂成形材料の接着性を阻害することなく、優れた離型性を発現させるための成分である。従来の高級脂肪酸、高級脂肪酸金属塩、高級脂肪酸エステル、パラフィンワックス、ポリオレフィンワックス等では添加量を多くすることで離型性を良くすることはできるが、接着性も低下していまい、この両立が困難である。そこで本発明者らは従来の離型剤成分とベース樹脂の共重合体を各種合成し、接着性と離型性との関係について鋭意検討を行った結果、上記の共重合体を使用することで離型性と接着性の両立を図ることができることを見出した。ここで、フェノール性水酸基と反応する官能基を有するポリオレフィン（Ｃ−１）のポリオレフィン部を例示するとポリエチレン、ポリプロピレン、１，２−ポリブタジエン又は１，４−ポリブタジエン更にはこれらポリブタジエン類の不飽和二重結合を水添したものなどが挙げられる。フェノール性水酸基と反応する官能基を有するポリオレフィンは、ポリオレフィン主鎖の末端又は分子内に、エポキシ基、カルボキシル基などの官能基を有しているものが用いられる。
【００１４】
上記官能基を有するポリオレフィン（Ｃ−１）の好ましい例として、エポキシ基を両末端に有する水添１，２−ポリブタジエン、カルボキシル基を両末端に有する水添１，２−ポリブタジエン、エポキシ基を両末端に有するポリエチレンなどを挙げることができる。これらのポリオレフィンは官能基を有することでフェノール樹脂等のヒドロキシフェニレン基を有する重合体（Ｃ−２）と容易にブロック共重合体又はグラフト共重合体等の共重合体を生成することができる。すなわちエポキシ基を有する場合は前述のエポキシ基とフェノール性水酸基の反応を促進する硬化促進剤の存在下で付加反応を行えば（Ｃ）成分の共重合体を得ることができる。また、カルボキシル基を有する場合は酸触媒を用いることで縮合反応により（Ｃ）成分の共重合体を得ることができる。何れの場合も重合体（Ｃ−２）としてフェノール樹脂類を用いる場合は、ゲル化を避けるために、ポリオレフィン（Ｃ−１）の官能基１当量当たり、フェノール樹脂類のフェノール性水酸基３〜２０倍当量、好ましくは５〜１０倍当量の割合で反応させることが望ましい。
【００１５】
なお、（Ｃ）成分の共重合体の製造に用いられる重合体（Ｃ−１）の具体例としては、例えば
【００１６】
【化３】

低分子量ポリエチレンの部分酸化物
等が挙げられる。
【００１７】
また、上記共重合体（（Ｃ）成分）の製造に用いられるポリオレフィン（Ｃ−１）の分子量は特に限定するものではないが、重量平均分子量で、５００〜５０００の範囲が好ましく、更には１０００〜３０００の範囲が好ましい。この理由としては分子量がこの範囲より小さくなると離型性に対して効果が無く、大きい場合は（Ｃ）成分の共重合体の軟化点が高くなり、成形材料中への分散が悪くなるため離型性に対する効果が低下するおそれがあるためである。
【００１８】
本発明の電子部品封止用エポキシ樹脂成形材料には、（Ｃ）成分以外の離型剤として一般的に使用される高級脂肪酸、高級脂肪酸金属塩、エステル系ワックス、ポリエチレン系ワックスなどを同時に何種類でも使用することができる。（Ｃ）成分以外の離型剤の配合割合としては、通常、（Ａ）成分のエポキシ樹脂１００重量部に対して０．１〜３重量部、好ましくは０．５〜１．５重量部が適当である。
【００１９】
また、本発明の電子部品封止用エポキシ樹脂成形材料には、無機質充填剤として、溶融シリカ、結晶シリカ、アルミナ、ジルコン、珪酸カルシウム、炭酸カルシウム、炭化珪素、窒化ホウ素、ベリリア、ジルコニアなどの粉体、又はこれらを球形化したビーズ、チタン酸カリウム、炭化珪素、窒化珪素、アルミナなどの単結晶繊維、ガラス繊維などを１種類以上配合することができる。無機質充填剤の配合量としては、吸湿性、線膨張係数の低減及び強度向上の観点からエポキシ樹脂成形材料全体に対して５０〜９５重量％、好ましくは７０〜９０重量％とすることが適当である。上記の無機質充填剤の中で、線膨張係数低減の観点からは溶融シリカが、高熱伝導性の観点からはアルミナが好ましく、充填剤形状は成形時の流動性及び金型摩耗性の点から球形が好ましい。
【００２０】
また、本発明の電子部品封止用エポキシ樹脂成形材料にはカーボンブラック、有機染料などの着色剤、エポキシシラン、アミノシラン、アルキルシラン、ビニルシラン、有機チタネート、アルミニウムアルコレートなどのカップリング剤を使用することができる。カップリング剤の好ましい配合割合は（Ａ）成分のエポキシ樹脂１００重量部に対して１〜１５重量部、更に好ましくは２〜８重量部である。
【００２１】
更に、本発明の電子部品封止用エポキシ樹脂成形材料には、上記のハロゲン化物以外の難燃剤として、三酸化アンチモン、五酸化アンチモン、水酸化アルミニウムなどの難燃剤を使用することができる。これらの難燃剤の好ましい配合割合は（Ａ）成分のエポキシ樹脂１００重量部に対して１〜３０重量部、更に好ましくは２〜１５重量部である。
【００２２】
以上のような原材料を用いて成形材料を作製する一般的な方法としては、所定の配合量の原材料混合物をミキサー等によって充分混合した後、熱ロール、押出機等によって混練し、冷却、粉砕することによって、成形材料を得ることができる。
【００２３】
本発明で得られる成形材料を用いて電子部品を封止する方法としては、低圧トランスファ成形法が最も一般的であるが、インジェクション成形、圧縮成形、注型などの方法によっても可能である。
【００２４】
【実施例】
以下、本発明の実施例及びその比較例によって本発明を更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。
【００２５】
実施例１〜１１、比較例１〜１３
表２及び表３に示す実施例及び比較例の成形材料を作製するにあたり、（Ａ）成分及び（Ｂ）成分の各種エポキシ樹脂及び硬化剤としては次に示すものを使用した。
【００２６】
【化４】

＊１：ｏ−クレゾールノボラック型エポキシ樹脂（エポキシ当量＝２００）、住友化学工業（株）製、ＥＳＣＮ−１９５
【００２７】
【化５】

＊２： テトラメチルビフェニル型ジエポキシ樹脂（エポキシ当量＝１８８）、油化シェルエポキシ（株）製、ＹＸ−４０００Ｈ
【００２８】
【化６】

【００２９】
【化７】

（Ｃ）成分の共重合体としては表１に示すもの使用した。
【００３０】
【表１】

前記したエポキシ樹脂、硬化剤、表１に示す共重合体、エポキシ当量３７５、軟化点８０℃、臭素含量４８重量％の臭素化ビスフェノールＡ型エポキシ樹脂、１，８−ジアザビシクロ（５，４，０）ウンデセン−７、カルナバワックス、 重量平均分子量３０００の非酸化ポリエチレンワックス、三酸化アンチモン、カーボンブラック、カップリング剤としてγ−グリシドキシプロピルトリメトキシシラン、石英ガラス粉を原材料とし、表２、表３に示す重量比で配合を行い、混練温度８０〜９０℃、混練時間１０分の条件でロール混練を行い、実施例及び比較例の成形材料を作製した。なお、表２及び表３中、成分の量は重量部で示した。表４、表５に実施例及び比較例の成形材料特性を、表６に特性評価法の詳細を示す。表４、表５に示すように比較例と比べ実施例１〜１１は離型性とマーキング性を両立した優れた性能を有している。更に、実施例１〜１１は優れた離型性を発揮すると共に、ベース樹脂本来の接着性を維持する能力が高いため、表面実装型ＩＣの最重要特性である耐リフロークラック性にも優れていることが分かる。
【００３１】
【表２】

＊７：１，８−ジアザビシクロ（５，４，０）ウンデセン−７
＊８：γ−グリシドキシプロピルトリメトキシシラン
＊９：非酸化型ポリエチレンワックス（分子量３０００）
【００３２】
【表３】

【００３３】
【表４】

【００３４】
【表５】

【００３５】
【表６】

【００３６】
【発明の効果】
本発明によって得られたエポキシ樹脂成形材料は耐クラック性が従来のものと比べ大きく改善できる。電子部品の分野、特にＦＰ（フラットパッケージ）、ＳＯＰ（スモールアウトラインパッケージ）などのＩＣではパッケージが薄形、小形になり、素子の大型化と相俟って耐パッケージクラック性が強く要求されており、これらの製品へ広く適用でき、その工業的価値は大きい。
【図面の簡単な説明】
【図１】離型性の測定法を示す斜視図。
【符号の説明】
１ 金型
２ 成形品[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an epoxy resin molding material for encapsulating electronic components that has good adhesion to insert components and excellent releasability, and particularly for encapsulating electronic components such as LSIs with large element sizes and thin shapes. The present invention relates to an epoxy resin molding material.
[0002]
[Prior art]
Conventionally, epoxy resin molding materials have been widely used as sealing materials in the field of sealing electronic components such as coils, capacitors, transistors, and ICs. This is because the epoxy resin is balanced in various characteristics such as electrical characteristics, heat resistance, mechanical strength, and adhesion to insert parts. In addition, a release agent is added to these epoxy resin molding materials for sealing electronic parts in order to obtain good release properties from the mold during molding. Conventionally used release agents include higher fatty acids, higher fatty acid esters or polyolefins. As the former, natural waxes such as carnauba wax, higher fatty acids such as stearic acid and montanic acid, and esterified products thereof are used. As the latter, low molecular weight substances such as polyethylene and polypropylene and partial oxides thereof are used.
[0003]
[Problems to be solved by the invention]
In recent years, surface mount ICs have become mainstream as IC packages, and small thin packages such as TSOP (Thin Small Outline Package) are increasing. In these packages, the thickness of the sealing resin on the IC chip is thin, and high adhesiveness is required for the epoxy resin molding material for sealing the electronic component for sealing the package in order to ensure reliability. However, when the adhesiveness is increased, it is natural that mold release at the time of molding tends to deteriorate. This tendency is remarkable in the novel base resin material from the viewpoint of improving adhesiveness. That is, many problems relating to releasability have occurred in biphenyl-based and dicyclopentadiene-based materials that are becoming more mainstream than orthocresol novolac-type epoxy resin systems that are conventional base resin systems. In order to solve these problems, the present invention provides an epoxy resin molding material for encapsulating electronic components that has good adhesion to an IC chip and a lead frame and is excellent in mold releasability.
[0004]
The epoxy resin molding material for electronic component sealing of the present invention is
(A) an epoxy resin having two or more epoxy groups in one molecule;
(B) Compound having two or more phenolic hydroxyl groups in one molecule and (C) Epoxy resin having two or more epoxy groups in one molecule, (B) Two or more phenolic hydroxyl groups in one molecule (C) Hydrogenated 1,2-polybutadiene having an epoxy group, hydrogenated 1,2-polybutadiene having a carboxyl group, polybutadiene having an epoxy group represented by the following formula, and a weight average molecular weight of 1000 to 3000 A copolymer of polyolefin selected from partial oxides of low molecular weight polyethylene, (C-1), and a polymer (C-2) having a hydroxyphenylene group as a structural unit is an essential component. is there.
[Chemical formula 2]

[0005]
DETAILED DESCRIPTION OF THE INVENTION
As the epoxy resin having two or more epoxy groups in one molecule of the component (A) used in the present invention, there is no limitation as long as it is generally used in an epoxy resin molding material for electronic component sealing, Diglycidyl such as phenol novolac epoxy resin, epoxidized phenol and aldehyde novolac resin such as orthocresol novolac epoxy resin, bisphenol A, bisphenol F, bisphenol S, alkyl-substituted or unsubstituted biphenol Glycidylamine type epoxy resin obtained by reaction of polyamine such as ether, diaminodiphenylmethane, isocyanuric acid and epichlorohydrin, linear aliphatic epoxy resin obtained by oxidizing olefin bond with peracid such as peracetic acid, and saturated aliphatic ring There is an epoxy resin (alicyclic epoxy resin) having. Further, halogenated epoxy resins obtained by halogenating these epoxy resins such as brominated epoxy resins, for example, diglycidyl ether of brominated bisphenol A, brominated phenol novolac type epoxy resins, etc. are used for improving flame retardancy. . Specifically, brominated bisphenol A type epoxy resin is suitably used, and the blending amount thereof is preferably 5 to 40% by weight, more preferably 10 to 30% by weight, based on the entire epoxy resin.
[0006]
In order to give particularly excellent adhesiveness to the epoxy resin molding material of the present invention, there is an alkyl-substituted or unsubstituted biphenyl skeleton-type epoxy resin that exhibits particularly excellent adhesiveness in the (A) component epoxy resin. Is preferably 20% by weight or more, preferably 60% by weight or more, based on the total amount of the epoxy resin used. The alkyl-substituted biphenyl skeleton-type epoxy resin is one in which a biphenyl ring is substituted with an alkyl group, and the alkyl group is preferably one having 1 to 4 carbon atoms such as a methyl group. Specific examples of such an epoxy resin include alkyl-substituted or unsubstituted 4 such as 4,4′-bishydroxybiphenyl and 4,4′-dihydroxy-3,3 ′, 5,5′-tetraalkylbiphenyl. , 4'-dihydroxybiphenyl obtained by epoxidation using epichlorohydrin, that is, alkyl-substituted or unsubstituted 4,4'-bis (2,3-epoxypropoxy) biphenyl and the like.
[0007]
Any number of (A) component epoxy resins can be used in combination, but the purity, especially the amount of hydrolyzable chlorine, is better because it relates to the corrosion of aluminum wiring on devices such as ICs, and has excellent moisture resistance. In order to obtain an epoxy resin molding material for component sealing, it is preferably 500 ppm or less. Here, the amount of hydrolyzable chlorine is a value obtained by dissolving 1 g of an epoxy resin of a sample in 30 ml of dioxane, adding 5 ml of a 1N-KOH methanol solution and refluxing for 30 minutes, and then obtaining by potentiometric titration. is there.
[0008]
As the compound having two or more phenolic hydroxyl groups in one molecule of the component (B) used in the present invention, phenols such as phenol, cresol, xylenol, resorcin, catechol, bisphenol A, bisphenol F, or α-naphthol , Resins obtained by condensation or cocondensation of naphthols such as β-naphthol and dihydroxynaphthalene with aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde and salicylaldehyde under an acidic catalyst, polyparavinylphenol resin, phenol And aralkyl resins having a xylylene group synthesized from dimethoxyparaxylene and compounds having a saturated aliphatic ring in the molecule, and may be used alone or in combination of two or more. Further, for the purpose of imparting flame retardancy, halogenated phenols such as brominated bisphenol A may be used in combination, and the blending amount thereof is 5 to 40% by weight, preferably 10 to 30% in the total amount of component (B). Weight percent is appropriate.
[0009]
In the compound having an epoxy resin as the component (A) and a phenolic hydroxyl group as the component (B) in the present invention, those having excellent adhesiveness include those having a specific saturated aliphatic ring in the structure of the resin or compound. It is done. For example, a resin obtained by adding a phenol to a terpene compound such as dicyclopentadiene or limonene using an acid catalyst or the like, or a resin obtained by epoxidizing the resin can be given. As the addition amount of these resins or compounds, the weight of the saturated aliphatic ring is preferably 20% to 40% with respect to the total weight of the component (A) + the component (B). If it is less than 20% by weight, the effect of high adhesiveness may be insufficient as compared with a conventional ortho-cresol novolac type epoxy resin / phenol novolac resin type epoxy resin molding material. Furthermore, the epoxy resin which has these structures or the compound which has a phenolic hydroxyl group can exhibit the further outstanding adhesiveness by using together with the above-mentioned biphenyl frame | skeleton type epoxy resin.
[0010]
The blending ratio of the epoxy resin of the component (A) in the epoxy resin molding material is usually 5 to 30% by weight, preferably 7 to 20% by weight, and the blending ratio of the compound having the phenolic hydroxyl group of the component (B) is usually 3 to 30% by weight, preferably 5 to 15% by weight is suitable.
[0011]
Moreover, the equivalent ratio of the epoxy group in the epoxy resin of (A) component, the phenolic hydroxyl group in the compound which has the phenolic hydroxyl group of (B) component, and the phenolic hydroxyl group which exists in the copolymer of (C) component (Number of phenolic hydroxyl groups in components (B) and (C) / number of epoxy groups in component (A)) is not particularly limited, but is in the range of 0.7 to 1.3 in order to suppress each unreacted component to a small extent. It is preferable to set to.
[0012]
The epoxy resin molding material for electronic component sealing of the present invention may contain a curing accelerator that accelerates the curing reaction of the epoxy resin and the compound having a phenolic hydroxyl group. Examples of the curing accelerator include triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, 1,6-diazabicyclo (4,3,0) undecene-5, 1, Tertiary amines such as 8-diazabicyclo (5,4,0) undecene-7, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, tributyl Organic phosphines such as phosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine, tetraphenylphosphonium tetraphenylborate, triphenylphosphinetetraphenylborate, 2- Chill-4-methylimidazole tetraphenylborate, include tetraphenyl boron salts such as N- methylmorpholine tetraphenylborate may be used alone or in combination. A preferable blending ratio of the total amount of the curing accelerator is 0.3 to 20 parts by weight, more preferably 0.6 to 10 parts by weight with respect to 100 parts by weight of the epoxy resin as the component (A).
[0013]
The component (C) of the present invention, that is, a copolymer of a polyolefin (C-1) having a functional group that reacts with a phenolic hydroxyl group and a polymer (C-2) having a hydroxyphenylene group as a structural unit is the present invention. It is a component for exhibiting excellent releasability without hindering the adhesiveness of the epoxy resin molding material for electronic component sealing. Conventional higher fatty acids, higher fatty acid metal salts, higher fatty acid esters, paraffin waxes, polyolefin waxes, etc. can improve releasability by increasing the amount added, but the adhesiveness also decreases, and this compatibility is achieved. Have difficulty. Therefore, the present inventors synthesized various copolymers of a conventional release agent component and a base resin, and as a result of earnestly examining the relationship between adhesiveness and release properties, the above-mentioned copolymer was used. It has been found that both releasability and adhesiveness can be achieved. Here, the polyolefin part of the polyolefin (C-1) having a functional group that reacts with a phenolic hydroxyl group is exemplified by polyethylene, polypropylene, 1,2-polybutadiene, or 1,4-polybutadiene, and further unsaturated double of these polybutadienes. Examples include hydrogenated bonds. As the polyolefin having a functional group that reacts with a phenolic hydroxyl group, one having a functional group such as an epoxy group or a carboxyl group at the end of the polyolefin main chain or in the molecule is used.
[0014]
Preferred examples of the above-mentioned polyolefin (C-1) having a functional group include hydrogenated 1,2-polybutadiene having an epoxy group at both ends, hydrogenated 1,2-polybutadiene having a carboxyl group at both ends, and both epoxy groups. Examples thereof include polyethylene at the end. Since these polyolefins have a functional group, it is possible to easily form a copolymer such as a block copolymer or a graft copolymer with a polymer (C-2) having a hydroxyphenylene group such as a phenol resin. That is, when it has an epoxy group, a copolymer of component (C) can be obtained by carrying out an addition reaction in the presence of a curing accelerator that promotes the reaction between the epoxy group and the phenolic hydroxyl group. Moreover, when it has a carboxyl group, the copolymer of (C) component can be obtained by a condensation reaction by using an acid catalyst. In any case, when a phenol resin is used as the polymer (C-2), in order to avoid gelation, the phenolic hydroxyl group 3-20 of the phenol resin per equivalent of the functional group of the polyolefin (C-1). It is desirable to react at a ratio of double equivalent, preferably 5 to 10 equivalents.
[0015]
Specific examples of the polymer (C-1) used for the production of the copolymer of the component (C) include, for example,
[Chemical 3]

Examples thereof include partial oxides of low molecular weight polyethylene.
[0017]
Further, the molecular weight of the polyolefin (C-1) used for the production of the copolymer (component (C)) is not particularly limited, but the weight average molecular weight is preferably in the range of 500 to 5000, and more preferably 1000 A range of ˜3000 is preferred. The reason for this is that if the molecular weight is smaller than this range, there is no effect on the releasability, and if it is larger, the softening point of the copolymer of component (C) becomes higher and the dispersion in the molding material becomes worse, so that the release. This is because the effect on moldability may be reduced.
[0018]
The epoxy resin molding material for encapsulating electronic components of the present invention contains, at the same time, higher fatty acids, higher fatty acid metal salts, ester waxes, polyethylene waxes and the like that are generally used as mold release agents other than the component (C). It can be used with any type. (C) As a mixture ratio of mold release agents other than component, 0.1-3 weight part normally with respect to 100 weight part of epoxy resin of (A) component, Preferably 0.5-1.5 weight part is. Is appropriate.
[0019]
In addition, the epoxy resin molding material for sealing electronic parts of the present invention includes powders such as fused silica, crystalline silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, boron nitride, beryllia, zirconia as inorganic fillers. One or more kinds of spheres, beads obtained by spheroidizing these, single crystal fibers such as potassium titanate, silicon carbide, silicon nitride, and alumina, and glass fibers can be blended. The blending amount of the inorganic filler is suitably 50 to 95% by weight, preferably 70 to 90% by weight, based on the entire epoxy resin molding material, from the viewpoint of hygroscopicity, reduction of linear expansion coefficient and improvement of strength. is there. Among the above inorganic fillers, fused silica is preferable from the viewpoint of reducing the linear expansion coefficient, and alumina is preferable from the viewpoint of high thermal conductivity, and the filler shape is spherical from the viewpoint of fluidity and mold wear during molding. Is preferred.
[0020]
The epoxy resin molding material for sealing electronic parts of the present invention uses a colorant such as carbon black and organic dye, and a coupling agent such as epoxy silane, amino silane, alkyl silane, vinyl silane, organic titanate and aluminum alcoholate. be able to. A preferable blending ratio of the coupling agent is 1 to 15 parts by weight, and more preferably 2 to 8 parts by weight with respect to 100 parts by weight of the epoxy resin as the component (A).
[0021]
Furthermore, flame retardants such as antimony trioxide, antimony pentoxide, and aluminum hydroxide can be used in the epoxy resin molding material for sealing electronic parts of the present invention as a flame retardant other than the above-mentioned halides. A preferable blending ratio of these flame retardants is 1 to 30 parts by weight, and more preferably 2 to 15 parts by weight with respect to 100 parts by weight of the epoxy resin as the component (A).
[0022]
As a general method for producing a molding material using the raw materials as described above, a raw material mixture having a predetermined blending amount is sufficiently mixed by a mixer or the like, then kneaded by a hot roll or an extruder, cooled and pulverized. Thus, a molding material can be obtained.
[0023]
As a method for sealing an electronic component using the molding material obtained in the present invention, a low-pressure transfer molding method is the most common, but it can also be performed by a method such as injection molding, compression molding or casting.
[0024]
【Example】
Hereinafter, the present invention will be described more specifically with reference to examples of the present invention and comparative examples thereof, but the present invention is not limited to these examples.
[0025]
Examples 1-11, Comparative Examples 1-13
In producing the molding materials of Examples and Comparative Examples shown in Tables 2 and 3, the following compounds were used as various epoxy resins and curing agents of the component (A) and the component (B).
[0026]
[Formula 4]

* 1: o-cresol novolac type epoxy resin (epoxy equivalent = 200), manufactured by Sumitomo Chemical Co., Ltd., ESCN-195
[0027]
[Chemical formula 5]

* 2: Tetramethylbiphenyl diepoxy resin (epoxy equivalent = 188), manufactured by Yuka Shell Epoxy Co., Ltd., YX-4000H
[0028]
[Chemical 6]

[0029]
[Chemical 7]

As the copolymer of component (C), those shown in Table 1 were used.
[0030]
[Table 1]

Epoxy resin, curing agent, copolymer shown in Table 1, epoxy equivalent 375, softening point 80 ° C., brominated bisphenol A type epoxy resin having a bromine content of 48% by weight, 1,8-diazabicyclo (5,4,0 ) Undecene-7, carnauba wax, non-oxidized polyethylene wax having a weight average molecular weight of 3000, antimony trioxide, carbon black, γ-glycidoxypropyltrimethoxysilane as a coupling agent, and quartz glass powder as raw materials. The mixture was blended at a weight ratio shown in FIG. In Tables 2 and 3, the amounts of the components are shown in parts by weight. Tables 4 and 5 show the molding material characteristics of Examples and Comparative Examples, and Table 6 shows details of the characteristic evaluation method. As shown in Tables 4 and 5, Examples 1 to 11 have excellent performances that are compatible with releasability and marking properties as compared with Comparative Examples. Further, Examples 1 to 11 exhibit excellent releasability and high ability to maintain the original adhesiveness of the base resin, so that they are excellent in reflow crack resistance, which is the most important characteristic of surface mount ICs. I understand that.
[0031]
[Table 2]

* 7: 1,8-diazabicyclo (5,4,0) undecene-7
* 8: γ-glycidoxypropyltrimethoxysilane * 9: Non-oxidized polyethylene wax (molecular weight 3000)
[0032]
[Table 3]

[0033]
[Table 4]

[0034]
[Table 5]

[0035]
[Table 6]

[0036]
【The invention's effect】
The epoxy resin molding material obtained by the present invention can be greatly improved in crack resistance as compared with the conventional one. In the field of electronic parts, especially in ICs such as FP (flat package) and SOP (small outline package), the package has become thin and small, and along with the increase in size of the device, package crack resistance is strongly required. It can be widely applied to these products, and its industrial value is great.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a method for measuring releasability.
[Explanation of symbols]
1 Mold 2 Molded product

Claims (7)

(A) an epoxy resin having two or more epoxy groups in one molecule, (B) a compound having two or more phenolic hydroxyl groups in one molecule, and (C) a hydrogenated 1,2-polybutadiene having an epoxy group Polyolefin (C-1) and hydroxy selected from hydrogenated 1,2-polybutadiene having a carboxyl group, polybutadiene having an epoxy group represented by the following formula, and a partial oxide of low molecular weight polyethylene having a weight average molecular weight of 1000 to 3000 An epoxy resin molding material for encapsulating electronic parts, comprising as an essential component a copolymer with a polymer (C-2) having a phenylene group as a structural unit.

2. The epoxy resin molding material for sealing electronic parts according to claim 1, wherein the polyolefin used for the production of component (C) has a weight average molecular weight of 1000 to 3000. The epoxy resin molding material for electronic component sealing according to claim 1 or 2, wherein the polymer (C-2) having a hydroxyphenylene group as a structural unit used for the production of the component (C) is a phenol novolac resin. The epoxy resin molding material for electronic component sealing according to any one of claims 1 to 3 , wherein the epoxy resin as component (A) is alkyl-substituted or unsubstituted 4,4'-bis (2,3-epoxypropoxy) biphenyl. The epoxy for electronic component sealing according to any one of claims 1 to 4 , wherein the epoxy resin as component (A) or the compound having a phenolic hydroxyl group as component (B) is an epoxy resin or compound having a saturated aliphatic ring in the molecule. Resin molding material. The epoxy resin molding material for electronic component sealing in any one of Claims 1-5 which further contains brominated epoxy resin as an epoxy resin of (A) component. The semiconductor device which consists of a sealing resin of the epoxy resin molding material for electronic component sealing in any one of Claims 1-6 which seals a semiconductor element.

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