JP4765150B2 - Epoxy resin composition and semiconductor device - Google Patents

Description

式（２）中、ｎは３〜１０００の整数であり、Ｒとしては、例えば、アルキル基、アルケニル基、アルコキシ基、アリール基、アリールオキシ基等が一般的であるが、又、アミノ基、メルカプト基、ヒドロキシ基、フルオロアルキル基等に代表される様に、Ｎ、Ｓ、Ｏ、Ｆ原子等を含有していても差し支えない。これらのホスファゼン化合物は、単独でも混合して用いてもよい。
ホスファゼン化合物の難燃機構は、その含有しているリンによる炭化促進効果、即ち、硬化物の表面に不燃性の炭化層を形成することにより、硬化物表面の保護、及び酸素を遮断する効果が得られること、又、含有している窒素により、熱分解時に窒素ガスが発生し、気相においても酸素を遮断することによる。この固相と気相の両方で働く難燃効果から、ホスファゼン化合物は高い難燃性を付与することができる。
【００１０】
好ましいホスファゼン化合物としては、本発明のエポキシ樹脂組成物の流動性の点から、環状ホスファゼン化合物である。
環状ホスファゼン化合物としては、例えば、式（１）で示される環状ホスファゼン化合物
【化３】

（式中、ｎは３〜７の整数、Ｒは互いに同一もしくは異なる有機基を示す。）
等があり、式（１）中のＲはアルキル基、アルケニル基、アルコキシ基、アリール基、アリールオキシ基等が一般的であるが、又、アミノ基、メルカプト基、ヒドロキシ基、フルオロアルキル基等に代表される様に、Ｎ、Ｓ、Ｏ、Ｆ原子等を含有していても差し支えない。これらの環状ホスファゼン化合物は、単独でも混合して用いてもよい。更に、３量体の６員環を主成分としていることがより好ましい。
式（１）で示される環状ホスファゼン化合物としては、具体的には、例えば、ヘキサプロピルシクロトリホスファゼン、テトラエトキシジプロポキシシクロトリホスファゼン、ヘキサフェノキシシクロトリホスファゼン、ヘキサアニリノシクロトリホスファゼン、ヘキサキス（３−メルカプトプロピル）シクロトリホスファゼン、ヘキサキス（ヘプタフルオロプロピルオキシ）シクロトリホスファゼン等が一例として挙げられる。
式（２）、式（１）中のＲとしては、耐熱性、耐湿性の観点からはアリールオキシ基が好ましく、エポキシ樹脂との相溶性やエポキシ樹脂組成物の流動性の観点から、２ｎ個のＲのうち、少なくともｎ個がフェノキシ基であることが、より好ましい。
【００１１】
又、別の環状ホスファゼン化合物の例として、難燃性を高めるために、一つの環状ホスファゼンが別の有機基を介して他の環状ホスファゼンと結合した形態の化合物も好ましい。この場合、環状ホスファゼンは同じ種類でもよく、異なった種類でもよい。例えば、式（１）で示される一つの環状ホスファゼンのＲの一部が他の環状ホスファゼンのＲの一部との間で別の有機基又はＲを介して結合した形態の化合物でもよく、これらの別の有機基は、単独の基だけではなく、他の基との複合の基でもよい。例えば、有機基の両末端にホスファゼン基を有している化合物でもよい。これらの環状ホスファゼン同士を結合する別の有機基としては、例えば、１，６−ジオキシヘキサン等の様にジオール化合物の水酸基から水素原子を除いた有機基、あるいはハイドロキノン、４，４’−ビフェノール、ビスフェノールＦ等の２官能フェノール化合物等のジヒドロキシ化合物から水素原子を除いた基等を好ましく用いることができる。
【００１２】
本発明のホスファゼン化合物の配合量は、全エポキシ樹脂組成物中に０．０１〜１５重量％が好ましく、更に好ましくは０．１〜１０重量％である。０．０１重量％未満だと難燃性が不足し、１５重量％を越えると硬化性、耐熱性及び強度が低下し、吸水率が増加するので好ましくない。
【００１３】
本発明に用いる水酸化マグネシウムは、ホスファゼン化合物と同様に、難燃剤として作用し、その難燃機構としては、燃焼時に水酸化マグネシウムが脱水を開始し、吸熱することによって燃焼反応を阻害するものである。
水酸化マグネシウムの平均粒径としては１〜３０μｍが好ましく、より好ましくは５〜２０μｍである。
水酸化マグネシウムの配合量としては、全エポキシ樹脂組成物中に０．５〜２０重量％が好ましく、更に好ましくは０．５〜１０重量％である。０．５重量％未満だと難燃性が不足し、２０重量％を越えると耐湿信頼性、成形性が低下するので好ましくない。
【００１４】
ホスファゼン化合物及び水酸化マグネシウムは、各々単独でも難燃性を付与する性質があるが、十分な難燃性を発現させるには、多量の配合量が必要となる。しかし多量に配合すると、成形性及び強度の低下、吸水率の増加を引き起こす傾向にあり、耐半田クラック性が低下する。これらの諸物性の低下を防ぐためにも配合量は極力少なくする必要がある。
本発明者は、ホスファゼン化合物と水酸化マグネシウムとを併用することにより、その相乗効果として更に難燃性が向上し、配合量を低減できることを見出した。
前述した様に、ホスファゼン化合物は、燃焼時にポリ燐酸層と炭化層を形成することによって燃焼反応を阻害するものであり、更に水酸化マグネシウムは、硬化した樹脂成分の炭化を促進させる作用がある。両者を併用することにより、互いの能力を補い合い、その相乗効果として高い難燃性を得ることができる。その結果として、配合量をを少なくしても難燃性を維持し、成形性及び強度の低下、吸水率の増加等を防ぐことができる。
【００１５】
本発明のエポキシ樹脂組成物は、（Ａ）〜（Ｆ）成分の他、必要に応じて臭素化エポキシ樹脂、三酸化アンチモン等の難燃剤を含有することは差し支えないが、半導体装置の１５０〜２００℃の高温下での電気特性の安定性が要求される用途では、臭素原子、アンチモン原子の含有量が、それぞれ全エポキシ樹脂組成物中に０．１重量％未満であることが好ましく、完全に含まれない方がより好ましい。臭素原子、アンチモン原子のいずれかが０．１重量％以上だと、高温下に放置したときに半導体装置の抵抗値が時間と共に増大し、最終的には半導体素子の金線が断線する不良が発生する可能性がある。又、環境保護の観点からも、臭素原子、アンチモン原子のそれぞれの含有量が０．１重量％未満で、極力含有されていないことが望ましい。臭素原子の含有量は、蛍光Ｘ線分析法、イオンクロマトグラフ分析法等の元素分析で測定することができる。アンチモン原子の含有量は、原子吸光分析法、発光分析法、蛍光Ｘ線分光法、イオンクロマトグラフ分析法等の元素分析で測定することができる。
本発明のエポキシ樹脂組成物は、（Ａ）〜（Ｆ）成分を必須成分とするが、これ以外に必要に応じてシランカップリング剤、カーボンブラック等の着色剤、天然ワックス、合成ワックス等の離型剤、及びシリコーンオイル、ゴム等の低応力添加剤等の種々の添加剤を適宜配合しても差し支えない。
又、本発明のエポキシ樹脂組成物は、（Ａ）〜（Ｆ）成分、及びその他の添加剤等をミキサー等を用いて充分に均一に混合した後、更に熱ロール又はニーダー等で溶融混練し、冷却後粉砕して得られる。
本発明のエポキシ樹脂組成物を用いて、半導体素子等の各種の電子部品を封止し、半導体装置を製造するには、トランスファーモールド、コンプレッションモールド、インジェクションモールド等の従来からの成形方法で硬化成形すればよい。
【００１６】
【実施例】
以下に本発明の実施例を示すが、本発明はこれらに限定されるものではない。配合割合は重量部とする。
なお、実施例、及び比較例で用いたエポキシ樹脂、フェノール樹脂の略号を以下にまとめて示す。
エポキシ樹脂（Ｅ−１）：ビフェニル型エポキシ樹脂［４，４’−ビス（２，３−エポキシプロポキシ）−３，３’，５，５’−テトラメチルビフェニルを主成分とする。エポキシ当量１９０ｇ／ｅｑ、融点１０５℃］、
エポキシ樹脂（Ｅ−２）：ジシクロペンタジエン変性フェノール型エポキシ樹脂（エポキシ当量２６５ｇ／ｅｑ、軟化点６０℃）、
フェノール樹脂（Ｈ−１）：フェノールアラルキル樹脂（水酸基当量１６５ｇ／ｅｑ、軟化点６２℃）、
フェノール樹脂（Ｈ−２）：フェノールノボラック樹脂（水酸基当量１０４ｇ／ｅｑ、軟化点８０℃）
【００１７】

【化４】

を常温でスーパーミキサーを用いて混合し、７０〜１００℃でロール混練し、冷却後粉砕してエポキシ樹脂組成物とした。得られたエポキシ樹脂組成物を以下の方法で評価した。結果を表１に示す。
【００１８】
評価方法
硬化性：（株）オリエンテック・製、ＪＳＲキュラストメーターＩＶＰＳを用いて、ダイスの直径３５ｍｍ、振幅角１°、成形温度１７５℃、成形開始９０秒後のトルク値を測定した。数値が大きいほど硬化が速い。単位はＮ・ｍ。
難燃性：低圧トランスファー成形機を用いて、成形温度１７５℃、圧力７ＭＰａ、硬化時間１２０秒で試験片（１２７ｍｍ×１２．７ｍｍ×３．２ｍｍ）を成形し、アフターベークとして１７５℃、８時間処理した後、ＵＬ−９４垂直法に準じてΣＦ、Ｆmaxを測定し、難燃性を判定した。
熱時強度：低圧トランスファー成形機を用いて、成形温度１７５℃、圧力７ＭＰａ、硬化時間１２０秒で試験片（８０ｍｍ×１０ｍｍ×４ｍｍ）を成形し、アフターベークとして１７５℃、８時間処理した後、２４０℃での曲げ強度をＪＩＳ Ｋ ６９１１に準じて測定した。単位はＮ／ｍｍ²。
吸水率：低圧トランスファー成形機を用いて、成形温度１７５℃、圧力７ＭＰａ、硬化時間１２０秒で円盤（直径５０ｍｍ、厚さ４ｍｍ）を成形し、アフターベークとして１７５℃、８時間処理した後、１５０℃で１６時間乾燥処理を行い、８５℃、相対湿度８５％で１６８時間吸水処理を行ったものについて、初期重量に対する増加重量の百分率を求めた。単位は％。
耐半田クラック性：低圧トランスファー成形機を用いて、成形温度１７５℃、圧力７ＭＰａ、硬化時間１２０秒で８０ｐＱＦＰ（２ｍｍ厚、チップサイズ９．０ｍｍ×９．０ｍｍ）を成形し、アフターベークとして１７５℃、８時間処理した後、８５℃、相対湿度８５％で９６時間の処理を行い、ＩＲリフロー処理（２４０℃、１０秒）を行った。超音波探傷機を用いて、パッケージ内部の剥離、クラック等の不良を観察した。６個のパッケージ中の不良パッケージ数を示す。
高温保管特性：低圧トランスファー成形機を用いて、成形温度１７５℃、圧力７ＭＰａ、硬化時間１２０秒で１６ｐＤＩＰ（チップサイズ３．０ｍｍ×３．５ｍｍ）を成形し、アフターベークとして１７５℃、８時間処理した後、高温保管試験（１８５℃、１０００時間）を行い、配線間の電気抵抗値が初期値に対し２０％増加したパッケージを不良と判定した。１５個のパッケージ中の不良率を百分率で示した。単位は％。
Ｂｒ原子、Ｓｂ原子の含有量：圧力５．９ＭＰａで直径４０ｍｍ、厚さ５〜７ｍｍに圧縮成形し、蛍光Ｘ線分析装置を用いて、全エポキシ樹脂組成物中の臭素原子、アンチモン原子の含有量を定量した。単位は重量％。
【００１９】
実施例２〜６、比較例１〜６
表１の配合に従い、実施例１と同様にしてエポキシ樹脂組成物を得て、実施例１と同様にして評価した。結果を表１に示す。
比較例１に用いた臭素化ビスフェノールＡ型エポキシ樹脂のエポキシ当量は、３６５ｇ／ｅｑ．。
実施例６に用いた環状ホスファゼン化合物は、式（４）で示される。
【化５】

【００２０】
【表１】

【００２１】
【発明の効果】
本発明に従うと、ハロゲン系難燃剤、アンチモン化合物を含まず、成形性に優れた半導体封止用エポキシ樹脂組成物が得られ、これを用いた半導体装置は難燃性、高温保管特性、耐湿信頼性、及び耐半田クラック性に優れる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a halogen-containing flame retardant, an epoxy resin composition for semiconductor encapsulation that does not contain an antimony compound and has excellent flame retardancy, and a semiconductor device.
[0002]
[Prior art]
Conventionally, electronic components such as diodes, transistors, and integrated circuits are mainly sealed with an epoxy resin composition. In these epoxy resin compositions, a halogen-based flame retardant and an antimony compound are blended in order to impart flame retardancy. However, development of an epoxy resin composition excellent in flame retardancy is required without using halogen-based flame retardants and antimony compounds from the viewpoint of environment and hygiene.
In addition, when a semiconductor device sealed with an epoxy resin composition containing a halogen-based flame retardant and an antimony compound is stored at a high temperature, the thermally decomposed halide is liberated from these flame retardant components, and the junction of the semiconductor element Epoxy resin which is known to corrode the semiconductor device and impair the reliability of the semiconductor device, and can achieve V-0 of UL-94 flame retardant without using halogenated flame retardant and antimony compound as flame retardant There is a need for a composition.
In this way, the corrosion resistance of the semiconductor element junction (bonding pad) after storing the semiconductor device at a high temperature (for example, 185 ° C.) is called the high temperature storage characteristic, and this high temperature storage characteristic is improved. As a technique for achieving this, a method using diantimony pentoxide (Japanese Patent Laid-Open No. 55-146950), a method of combining antimony oxide and an organic phosphine (Japanese Patent Laid-Open No. 61-53321), and the like have been proposed. However, there are some types of epoxy resin compositions that are unsatisfactory for the required level of high-temperature storage characteristics for recent semiconductor devices.
Therefore, by using a cyclic phosphazene compound as proposed in JP-A-10-259292, sufficient flame retardancy could be achieved without using a bromine compound and an antimony compound. There has been a problem that the moisture resistance reliability is lowered due to a decrease, mold stain due to occurrence of bleeding, a decrease in strength, an increase in water absorption, and the like. For this reason, the epoxy resin composition which can obtain a flame retardance even if the addition amount of a cyclic phosphazene compound is decreased is desired.
As a technique for improving the above disadvantages, there has been a proposal for solving flame retardancy and moisture resistance reliability by using magnesium hydroxide and a specific metal oxide in combination (Japanese Patent Application No. 11-342914, etc.). In order to exhibit sufficient flame retardancy, a large amount of addition is required, and there is a problem that the moldability and solder crack resistance are lowered.
That is, there is a need for an epoxy resin composition that maintains flame retardancy, is excellent in moldability, high-temperature storage characteristics, moisture resistance reliability, and solder crack resistance and does not use a halogen-based flame retardant and an antimony compound.
[0003]
[Problems to be solved by the invention]
The present invention does not contain a halogen-based flame retardant and an antimony compound, and has an epoxy resin composition for semiconductor encapsulation excellent in moldability, flame retardancy, high-temperature storage characteristics, moisture resistance reliability, and solder crack resistance, and The semiconductor device used is provided.
[0004]
[Means for Solving the Problems]
The present invention includes (A) an epoxy resin, (B) a phenol resin, (C) a curing accelerator, (D) an inorganic filler, (E) a phosphazene compound, and (F) magnesium hydroxide as essential components. An epoxy resin composition for semiconductor encapsulation, which is characterized.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The epoxy resin used in the present invention refers to monomers, oligomers, and polymers in general having two or more epoxy groups in one molecule, and the molecular weight and molecular structure thereof are not particularly limited. For example, biphenyl type epoxy resins, Bisphenol type epoxy resin, stilbene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triphenolmethane type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, triazine nucleus-containing epoxy resin, dicyclopentadiene modified phenol type An epoxy resin, a phenol aralkyl type epoxy resin (having a phenylene skeleton, a biphenylene skeleton, etc.), a naphthol type epoxy resin, and the like can be used. These may be used alone or in combination.
[0006]
The phenol resin used in the present invention refers to a nomer, oligomer, or polymer generally having two or more phenolic hydroxyl groups in one molecule, and its molecular weight and molecular structure are not particularly limited. For example, a phenol novolac resin, Examples include cresol novolac resin, dicyclopentadiene-modified phenol resin, terpene-modified phenol resin, triphenolmethane type resin, phenol aralkyl resin (having phenylene skeleton, biphenylene skeleton, etc.), naphthol aralkyl resin, and the like. Can be used. In particular, phenol novolac resin, dicyclopentadiene modified phenol resin, phenol aralkyl resin, naphthol aralkyl resin, terpene modified phenol resin and the like are preferable.
As these compounding quantities, 0.8-1.3 are preferable by the ratio of the number of epoxy groups of all the epoxy resins, and the number of phenolic hydroxyl groups of all the phenol resins.
[0007]
As a hardening accelerator used for this invention, what is necessary is just to accelerate | stimulate the hardening reaction of an epoxy group and a phenolic hydroxyl group, and what is generally used for a sealing material can be used. Examples thereof include 1,8-diazabicyclo (5,4,0) undecene-7, triphenylphosphine, 2-methylimidazole, tetraphenylphosphonium / tetraphenylborate and the like, and these may be used alone or in combination. Absent.
[0008]
As the inorganic filler used in the present invention, those generally used for sealing materials can be used. Examples thereof include fused silica, crystalline silica, talc, alumina, silicon nitride and the like, and these may be used alone or in combination. Among these, it is preferable to use the total amount of fused silica having a high sphericity or partially crushed silica. The average particle size of the inorganic filler is preferably 5 to 30 μm, and the maximum particle size is preferably 74 μm or less. In addition, the filling amount can be increased by mixing particles having different particle sizes. The inorganic filler that has been surface-treated with a silane coupling agent or the like in advance may be used.
As the blending amount, the total amount of magnesium hydroxide and the inorganic filler is preferably 60 to 95% by weight in the total epoxy resin composition from the balance between moldability and solder crack resistance. If it is less than 60% by weight, the resistance to solder cracking accompanying an increase in water absorption rate is lowered, and if it exceeds 95% by weight, there are problems in moldability such as wire sweep and pad shift, which is not preferable.
[0009]
The phosphazene compound used in the present invention may be any compound having a phosphazene structure in the compound, and examples thereof include a compound having a structure represented by the formula (2) and acts as a flame retardant.
[Chemical 2]

In the formula (2), n is an integer of 3 to 1000, and as R, for example, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, an aryloxy group and the like are common, but an amino group, As represented by a mercapto group, a hydroxy group, a fluoroalkyl group, etc., it may contain N, S, O, F atoms, etc. These phosphazene compounds may be used alone or in combination.
The flame retardant mechanism of the phosphazene compound has the effect of promoting carbonization by phosphorus contained therein, that is, the effect of protecting the surface of the cured product and blocking oxygen by forming a non-combustible carbonized layer on the surface of the cured product. This is because nitrogen gas is generated during pyrolysis due to the nitrogen contained, and oxygen is blocked even in the gas phase. Due to the flame retardant effect that works in both the solid phase and the gas phase, the phosphazene compound can impart high flame retardancy.
[0010]
A preferable phosphazene compound is a cyclic phosphazene compound from the viewpoint of fluidity of the epoxy resin composition of the present invention.
Examples of the cyclic phosphazene compound include a cyclic phosphazene compound represented by the formula (1):

(In the formula, n represents an integer of 3 to 7, and R represents the same or different organic groups.)
R in formula (1) is generally an alkyl group, an alkenyl group, an alkoxy group, an aryl group, an aryloxy group, etc., but also an amino group, a mercapto group, a hydroxy group, a fluoroalkyl group, etc. As represented by N, S, O, F atoms and the like may be contained. These cyclic phosphazene compounds may be used alone or in combination. Furthermore, it is more preferable that the main component is a trimer 6-membered ring.
Specific examples of the cyclic phosphazene compound represented by the formula (1) include hexapropylcyclotriphosphazene, tetraethoxydipropoxycyclotriphosphazene, hexaphenoxycyclotriphosphazene, hexaanilinocyclotriphosphazene, hexakis (3- Examples include mercaptopropyl) cyclotriphosphazene and hexakis (heptafluoropropyloxy) cyclotriphosphazene.
R in formula (2) and formula (1) is preferably an aryloxy group from the viewpoint of heat resistance and moisture resistance, and 2n from the viewpoint of compatibility with the epoxy resin and fluidity of the epoxy resin composition. It is more preferable that at least n of R in the formulas are phenoxy groups.
[0011]
In addition, as an example of another cyclic phosphazene compound, a compound in which one cyclic phosphazene is bonded to another cyclic phosphazene through another organic group in order to enhance flame retardancy is also preferable. In this case, the cyclic phosphazenes may be of the same type or different types. For example, a compound in a form in which a part of R of one cyclic phosphazene represented by the formula (1) is bonded to a part of R of another cyclic phosphazene via another organic group or R may be used. The other organic group may be not only a single group but also a complex group with other groups. For example, a compound having a phosphazene group at both ends of the organic group may be used. As another organic group for bonding these cyclic phosphazenes, for example, an organic group obtained by removing a hydrogen atom from a hydroxyl group of a diol compound, such as 1,6-dioxyhexane, hydroquinone, 4,4′-biphenol A group obtained by removing a hydrogen atom from a dihydroxy compound such as a bifunctional phenol compound such as bisphenol F can be preferably used.
[0012]
The blending amount of the phosphazene compound of the present invention is preferably 0.01 to 15% by weight, more preferably 0.1 to 10% by weight in the total epoxy resin composition. If it is less than 0.01% by weight, the flame retardancy is insufficient, and if it exceeds 15% by weight, the curability, heat resistance and strength are lowered and the water absorption rate is increased.
[0013]
Magnesium hydroxide used in the present invention acts as a flame retardant, like phosphazene compounds, and its flame retardant mechanism is that magnesium hydroxide starts dehydration during combustion and inhibits the combustion reaction by absorbing heat. is there.
As an average particle diameter of magnesium hydroxide, 1-30 micrometers is preferable, More preferably, it is 5-20 micrometers.
As a compounding quantity of magnesium hydroxide, 0.5-20 weight% is preferable in all the epoxy resin compositions, More preferably, it is 0.5-10 weight%. If it is less than 0.5% by weight, the flame retardancy is insufficient, and if it exceeds 20% by weight, the moisture resistance reliability and moldability deteriorate, which is not preferable.
[0014]
The phosphazene compound and magnesium hydroxide each have a property of imparting flame retardancy, but a large amount is required to develop sufficient flame retardancy. However, when it mix | blends abundantly, it exists in the tendency which causes the fall of a moldability and intensity | strength, and the increase in a water absorption, and solder crack resistance falls. In order to prevent the deterioration of these various physical properties, it is necessary to reduce the blending amount as much as possible.
The present inventor has found that the combined use of a phosphazene compound and magnesium hydroxide further improves the flame retardancy as a synergistic effect and can reduce the blending amount.
As described above, the phosphazene compound inhibits the combustion reaction by forming a polyphosphoric acid layer and a carbonized layer at the time of combustion, and magnesium hydroxide has an action of promoting carbonization of the cured resin component. By using both in combination, it is possible to supplement each other's ability and obtain high flame retardancy as a synergistic effect. As a result, even if the blending amount is decreased, flame retardancy can be maintained, and a decrease in moldability and strength, an increase in water absorption, and the like can be prevented.
[0015]
Although the epoxy resin composition of the present invention may contain flame retardants such as brominated epoxy resin and antimony trioxide as required in addition to the components (A) to (F), it may be 150 to 150 of the semiconductor device. In applications where stability of electrical characteristics at a high temperature of 200 ° C. is required, the content of bromine atoms and antimony atoms is preferably less than 0.1% by weight in the total epoxy resin composition. It is more preferable that it is not included in. If either the bromine atom or the antimony atom is 0.1% by weight or more, the resistance value of the semiconductor device increases with time when left at high temperature, and finally the defect that the gold wire of the semiconductor element breaks. May occur. From the viewpoint of environmental protection, it is desirable that the content of each bromine atom and antimony atom is less than 0.1% by weight and is not contained as much as possible. The bromine atom content can be measured by elemental analysis such as fluorescent X-ray analysis or ion chromatography analysis. The content of antimony atoms can be measured by elemental analysis such as atomic absorption analysis, emission analysis, fluorescent X-ray spectroscopy, ion chromatography analysis and the like.
The epoxy resin composition of the present invention has components (A) to (F) as essential components, but in addition to this, a silane coupling agent, a colorant such as carbon black, natural wax, synthetic wax, etc. Various additives such as a release agent and low stress additives such as silicone oil and rubber may be appropriately blended.
In addition, the epoxy resin composition of the present invention is sufficiently kneaded with a hot roll or a kneader after the components (A) to (F) and other additives are sufficiently uniformly mixed using a mixer or the like. It is obtained by pulverizing after cooling.
The epoxy resin composition of the present invention is used to encapsulate various electronic components such as semiconductor elements, and to manufacture semiconductor devices by conventional molding methods such as transfer molding, compression molding, and injection molding. do it.
[0016]
【Example】
Examples of the present invention are shown below, but the present invention is not limited thereto. The blending ratio is parts by weight.
In addition, the abbreviations of the epoxy resin and the phenol resin used in Examples and Comparative Examples are collectively shown below.
Epoxy resin (E-1): Biphenyl type epoxy resin [4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5,5′-tetramethylbiphenyl as a main component. Epoxy equivalent 190 g / eq, melting point 105 ° C.]
Epoxy resin (E-2): dicyclopentadiene-modified phenol type epoxy resin (epoxy equivalent 265 g / eq, softening point 60 ° C.),
Phenol resin (H-1): Phenol aralkyl resin (hydroxyl equivalent 165 g / eq, softening point 62 ° C.),
Phenol resin (H-2): Phenol novolac resin (hydroxyl equivalent: 104 g / eq, softening point: 80 ° C.)
[0017]

[Formula 4]

Were mixed at room temperature using a supermixer, roll kneaded at 70 to 100 ° C., cooled and pulverized to obtain an epoxy resin composition. The obtained epoxy resin composition was evaluated by the following methods. The results are shown in Table 1.
[0018]
Evaluation method Curability: Using a JSR Clastometer IVPS manufactured by Orientec Co., Ltd., the diameter of the die was 35 mm, the amplitude angle was 1 °, the molding temperature was 175 ° C., and the torque value after 90 seconds from the start of molding was measured. The larger the value, the faster the cure. The unit is N · m.
Flame retardancy: Using a low-pressure transfer molding machine, a test piece (127 mm × 12.7 mm × 3.2 mm) was molded at a molding temperature of 175 ° C., a pressure of 7 MPa, and a curing time of 120 seconds, and afterbaked at 175 ° C. for 8 hours. After the treatment, ΣF and Fmax were measured according to the UL-94 vertical method to determine flame retardancy.
Strength during heat: Using a low-pressure transfer molding machine, a test piece (80 mm × 10 mm × 4 mm) was molded at a molding temperature of 175 ° C., a pressure of 7 MPa, and a curing time of 120 seconds, and after-baking at 175 ° C. for 8 hours, The bending strength at 240 ° C. was measured according to JIS K 6911. The unit is N / mm ² .
Water absorption: Using a low-pressure transfer molding machine, a disk (diameter: 50 mm, thickness: 4 mm) was molded at a molding temperature of 175 ° C., a pressure of 7 MPa, and a curing time of 120 seconds. After baking at 175 ° C. for 8 hours, 150 The percentage of increase in weight with respect to the initial weight was determined for those subjected to a drying treatment at 85 ° C. for 16 hours and a water absorption treatment at 85 ° C. and a relative humidity of 85% for 168 hours. Units%.
Solder crack resistance: Using a low-pressure transfer molding machine, 80 pQFP (2 mm thickness, chip size 9.0 mm × 9.0 mm) was molded at a molding temperature of 175 ° C., a pressure of 7 MPa, and a curing time of 120 seconds, and after baking at 175 ° C. After 8 hours of treatment, a treatment of 85 hours at 85 ° C. and a relative humidity of 85% was conducted for 96 hours, followed by an IR reflow treatment (240 ° C., 10 seconds). Using an ultrasonic flaw detector, defects such as peeling and cracks inside the package were observed. The number of defective packages among the six packages is shown.
High-temperature storage characteristics: Using a low-pressure transfer molding machine, 16pDIP (chip size: 3.0mm x 3.5mm) was molded at a molding temperature of 175 ° C, pressure of 7MPa, and curing time of 120 seconds, and afterbaked at 175 ° C for 8 hours. After that, a high-temperature storage test (185 ° C., 1000 hours) was performed, and a package in which the electrical resistance value between the wirings increased by 20% with respect to the initial value was determined to be defective. The defect rate in 15 packages is shown as a percentage. Units%.
Content of Br atom and Sb atom: compression molding to a diameter of 40 mm and a thickness of 5 to 7 mm at a pressure of 5.9 MPa, and use of a fluorescent X-ray analyzer to contain bromine atom and antimony atom in all epoxy resin compositions The amount was quantified. The unit is% by weight.
[0019]
Examples 2-6, Comparative Examples 1-6
According to the composition of Table 1, an epoxy resin composition was obtained in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table 1.
The epoxy equivalent of the brominated bisphenol A type epoxy resin used in Comparative Example 1 was 365 g / eq. .
The cyclic phosphazene compound used in Example 6 is represented by the formula (4).
[Chemical formula 5]

[0020]
[Table 1]

[0021]
【The invention's effect】
According to the present invention, an epoxy resin composition for semiconductor encapsulation that does not contain a halogen-based flame retardant and an antimony compound and is excellent in moldability is obtained. A semiconductor device using the composition has flame resistance, high-temperature storage characteristics, and moisture resistance reliability. And excellent solder crack resistance.

Claims (3)

(A) Epoxy resin, (B) phenol resin, (C) curing accelerator, (D) inorganic filler, (E) phosphazene compound, and (F) magnesium hydroxide as essential components An epoxy resin composition for sealing, wherein the phosphazene compound is a cyclic phosphazene compound represented by the formula (1) or a part of R of the cyclic phosphazene compound represented by the formula (1) is represented by the other formula (1) The compound of the form couple | bonded via R between some R of cyclic phosphazene compound shown , The compounding quantity of a phosphazene compound is 0.1 to 10 weight% in all the epoxy resin compositions, and water The epoxy resin composition for semiconductor sealing whose compounding quantity of magnesium oxide is 0.5 to 10 weight% in all the epoxy resin compositions.

(In the formula, n represents an integer of 3, R represents the same or different organic group selected from an alkyl group, an alkenyl group, an alkoxy group, an aryl group, and an aryloxy group, and among R, at least three are phenoxy groups. is there.)   The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein bromine atoms and antimony atoms contained in all epoxy resin compositions are each less than 0.1% by weight. Wherein a obtained by encapsulating a semiconductor element with claim 1 or 2 semiconductor encapsulating epoxy resin composition.