JP3582771B2 - Epoxy resin composition and semiconductor device - Google Patents

Description

（Ｒ_１は、水素原子、メチル基、エチル基、ブチル基、又はハロゲン原子であって、Ｒ_１は互いに同じであっても異なっていてもよい。）
【０００６】
【化４】

【０００７】
【発明の実施の形態】
本発明に用いられる式（１）で示されるビフェニル型エポキシ樹脂は、メソゲン骨格を主鎖に持ち、比較的低分子であるため結晶性を有し、１分子内にエポキシ基を２個有するジエポキシ化合物であるため、融点未満の温度では固体であるが、融点以上の温度で低粘度の液状物質となる。このため式（１）のエポキシ樹脂を用いたエポキシ樹脂組成物は、溶融状態で低粘度を示し、成形時の流動性が高く、薄型パッケージへの充填性に優れ、成形性が良好である。又、式（１）のエポキシ樹脂は２官能であるため、これを用いた樹脂組成物の硬化物は架橋密度が低く抑えられ、高温での弾性率が抑えられるため、半田処理時等の応力緩和に適しており、成形性と耐半田クラック性とを向上できる。
又、式（１）のエポキシ樹脂の特性を損なわない範囲で、例えば、ビスフェノール型エポキシ樹脂、スチルベン型エポキシ樹脂、オルソクレゾールノボラック型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、ナフタレン型エポキシ樹脂、トリフェノールメタン型エポキシ樹脂、アルキル変性トリフェノールメタン型エポキシ樹脂、トリアジン核含有エポキシ樹脂、ジシクロペンタジエン変性フェノール型エポキシ樹脂等の他のエポキシ樹脂を併用してもよい。これらのエポキシ樹脂は、単独でも混合して用いてもよい。融点又は軟化点、エポキシ当量等も特に限定するものではないが、エポキシ樹脂中の塩素含有量は極力低い方が長期信頼性の点から好ましい。
【０００８】
本発明に用いられるフェノール樹脂としては、１分子内に２個以上のフェノール性水酸基を有するモノマー、オリゴマー、ポリマー全般を指し、例えば、フェノールノボラック樹脂、フェノールアラルキル樹脂、ナフトールアラルキル樹脂、テルペン変性フェノール樹脂、ジシクロペンタジエン変性フェノール樹脂等が挙げられ、これらは単独でも混合して用いてもよい。軟化点、水酸基当量等も特に限定するものではないが、フェノール樹脂中の塩素含有量は極力低い方が長期信頼性の点から好ましい。
全エポキシ樹脂と全フェノール樹脂の配合割合としては、成形性と耐半田クラック性との兼ね合いから、フェノール性水酸基数に対しエポキシ基数が１．１〜１．４の割合が最もバランスが良く、好ましい。更に好ましくは、１．２〜１．３である。１．１未満だと、耐半田クラック性が低下し、１．４を越えると、硬化性が低下するので好ましくない。
【０００９】
本発明に用いられる硬化促進剤は、式（２）で示される化合物であり、この化合物は常温では活性が低く、１００℃以上の高温では活性が高く、又、融点が２００℃〜２５０℃の範囲内にあるため、混練時の分散性、常温保存性、反応性の点で優れている。式（２）の化合物の配合量としては、全硬化促進剤中に５０〜１００重量％が好ましい。５０重量％未満だと、常温保存性が悪いので好ましくない。
又、式（２）の化合物のみだと、材料の混練温度域での反応性が極端に低くなり、混練時の低分子量成分の反応まで抑制され、成形時にウスバリが発生しやすくなるおそれがある。そこで、式（２）の化合物に比べると常温保存性や流動性の点では劣るものの、低温での反応促進作用に優れたトリフェニルホスフィンを併用すると、反応性のバランスをとることができるため、より好ましい。この場合の配合量としては、全硬化促進剤中に式（２）の化合物が５０〜９０重量％、トリフェニルホスフィンが１０〜５０重量％である割合が好ましい。式（２）の化合物が５０重量％未満だと、上記の効果が十分に発現されず、従来の硬化促進剤系と同様の効果しか得られないので好ましくない。トリフェニルホスフィンが１０重量％未満だと、成形時にウスバリが多くなるので好ましくない。
又、これらの硬化促進剤の特性を損なわない範囲で、例えばテトラフェニルホスホニウム・テトラフェニルボレート、２−メチルイミダゾール、１，８−ジアザビシクロ（５，４，０）ウンデセン−７等の他の硬化促進剤と併用してもよい。
【００１０】
本発明に用いられる溶融球状シリカは、溶融球状シリカ中に粒径６０μｍ以上のものが１重量％以下、且つ粒径４０μｍ以上のものが１０〜１００重量％が好ましく、特に、流動性の点から１０〜３０重量％が好ましい。粒径６０μｍ以上のものが１重量％を越えると、金型内の狭流路での樹脂組成物の流動性が低下し、アイランドシフトが発生するので好ましくない。又、粒径４０μｍ以上のものが１０重量％未満だと、ウスバリが多くなるので好ましくない。
又、本発明の溶融球状シリカの特性を損なわない範囲で、例えば、溶融破砕シリカ、結晶シリカ、２次凝集シリカ、アルミナ、チタンホワイト、水酸化アルミニウム、タルク、クレー、ガラス繊維等の他の無機充填材を併用してもよい。
なお、メモリー系の半導体素子等では、放射性物質による誤動作が問題となるため、全樹脂組成物中のウラン（以下、Ｕという）及びトリウム（以下、Ｔｈという）の合計量が２ｐｐｂ以下であることが好ましい。Ｕ、Ｔｈの定量方法としては、樹脂組成物を秤量、灰化後、弗酸を用いて溶融球状シリカを溶解、除去し、更に塩酸を用いてアンチモンを溶解、除去した残渣水溶液をＩＣＰ−ＭＳ（高周波誘導結合プラズマ質量分析）を用いて測定する。
【００１１】
本発明の樹脂組成物は、（Ａ）〜（Ｄ）成分の他、必要に応じてγ−グリシドキシプロピルトリメトキシシラン等のカップリング剤、カーボンブラック等の着色剤、臭素化エポキシ樹脂、酸化アンチモン、リン化合物等の難燃剤、シリコーンオイル、シリコーンゴム等の低応力成分、天然ワックス、合成ワックス、高級脂肪酸及びその金属塩類もしくはパラフィン等の離型剤、酸化防止剤等の各種添加剤を配合することができる。
本発明の樹脂組成物は、（Ａ）〜（Ｄ）成分、及びその他の添加剤等をミキサーを用いて常温混合し、ニーダ、ロール、押出機等の混練機で加熱混練し、冷却後粉砕して得られる。
本発明の樹脂組成物を用いて、半導体素子等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成形方法で硬化成形すればよい。
【００１２】
【実施例】
以下、本発明を実施例で具体的に説明する。配合割合は重量部とする。
実施例１
式（３）の構造を主成分とするビフェニル型エポキシ樹脂（油化シェルエポキシ（株）・製ＹＸ−４０００Ｈ、融点１０５℃、エポキシ当量１９５）１３．２重量部
【化５】

【００１３】
式（４）のフェノールノボラック樹脂（軟化点８０℃、水酸基当量１０５）
５．６重量部
【化６】

【００１４】
式（５）の硬化促進剤 ０．３０重量部
【化７】

【００１５】
トリフェニルホスフィン ０．１０重量部
溶融球状シリカＩ（Ｕ含有量０．１ｐｐｂ、Ｔｈ含有量０．１ｐｐｂ、粒径６
０μｍ以上が０．７重量％、粒径４０μｍ以上が１６重量％）８０．０重量部
カーボンブラック ０．３重量部
カルナバワックス ０．５重量部
をミキサーを用いて混合し、表面温度が９０℃と４５℃の２本ロールを用いて混練し、冷却後粉砕して、樹脂組成物を得た。得られた樹脂組成物を以下の方法で評価した。結果を表１に示す。
【００１６】
評価方法
スパイラルフロー：ＥＭＭＩ−Ｉ−６６に準じたスパイラルフロー測定用の金型を用い、金型温度１７５℃、注入圧力７０ｋｇ／ｃｍ^２、硬化時間２分で測定した。単位はｃｍ。
常温保存性：２５℃で１週間保存した後、スパイラルフローを測定し、調製直後のスパイラルフローに対する百分率として表した。単位は％。
硬化性：ショアＤ硬度計を用い、金型温度１７５℃、注入圧力７０ｋｇ／ｃｍ^２、硬化時間２分で成形し、型開き１０秒後に測定したショアＤ硬度の値を硬化性とする。
ウスバリ特性：トランスファー成形機を用いて金型温度１７５℃、圧力７０ｋｇ／ｃｍ^２、硬化時間２分で１６ｐＤＩＰ（チップサイズ３００×３００ミル）を成形し、ベントのバリ長さを測定した。単位はｍｍ。
アイランドシフト特性：トランスファー成形機を用い、金型温度１８０℃、圧力１００ｋｇ／ｃｍ^２、硬化時間１分で４４ｐＴＳＯＰ（ＬＯＣ構造：ＬＥＡＤＯＮ ＣＨＩＰ構造）を成形し、パッケージの中央を切断、研磨した後、拡大投影機を用いて、ゲート側の半導体素子表面〜パッケージ上面間の距離と、ベント側の半導体素子表面〜パッケージ上面間の距離との差を、アイランドシフト量と定義し測定した。単位はμｍ。
耐半田性：トランスファー成形機を用い、金型温度１７５℃、圧力７０ｋｇ／ｃｍ^２、硬化時間２分で８０ｐＱＦＰ（厚さ１．５ｍｍ）を８個成形し、１７５℃で８時間アフターキュア後、８５℃、相対湿度６０％の環境下に１６８時間放置し、その後ＩＲリフロー（２４０℃）で１０秒間処理した。得られたパッケージを目視及び超音波探傷機で観察し、外部クラック、チップ上剥離、及びパッド下剥離の発生したパッケージ個数をそれぞれｎ／８と表示した。
Ｕ、Ｔｈ量：樹脂組成物を灰化後、弗酸を用いて溶融球状シリカを溶解、除去し、更に塩酸を用いてアンチモンを溶解、除去した残渣水溶液をＩＣＰ−ＭＳ（高周波誘導結合プラズマ質量分析）で測定した。単位は、全樹脂組成物中の重量比でｐｐｂ。
【００１７】
実施例２〜９、比較例１〜７
表１、表２の配合に従い、実施例１と同様にして樹脂組成物を得、実施例１と同様にして評価した。結果を表１、表２に示す。
実施例及び比較例で使用した式（６）の硬化促進剤、式（７）のクレゾールノボラック型エポキシ樹脂（軟化点５５℃、エポキシ当量２０１）、溶融球状シリカＩＩ〜Ｖの構造及び性状を以下に示す。
【化８】

【００１８】
【化９】

【００１９】
溶融球状シリカＩＩ（Ｕ含有量１．１ｐｐｂ、Ｔｈ含有量１．６ｐｐｂ、粒径６０μｍ以上が０．７重量％、粒径４０μｍ以上が１６重量％）、
溶融球状シリカＩＩＩ（Ｕ含有量０．１ｐｐｂ、Ｔｈ含有量０．１ｐｐｂ、粒径６０μｍ以上が１．７重量％、粒径４０μｍ以上が６重量％）、
溶融球状シリカＩＶ（Ｕ含有量０．１ｐｐｂ、Ｔｈ含有量０．１ｐｐｂ、粒径６０μｍ以上が３．２重量％、粒径４０μｍ以上が２５重量％）、
溶融球状シリカＶ（Ｕ含有量０．１ｐｐｂ、Ｔｈ含有量０．１ｐｐｂ、粒径６０μｍ以上が０．５重量％、粒径４０μｍ以上が４重量％）。
【表１】

【００２０】
【表２】

【００２１】
【発明の効果】
本発明の半導体封止用エポキシ樹脂組成物は、常温保存性に優れ、成形時の硬化性、及びウスバリ特性、アイランドシフト特性を改善し、これを用いた半導体装置は耐半田クラック性に優れる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a surface-mountable epoxy resin composition for semiconductor encapsulation, which has excellent storage stability at room temperature, moldability, and reliability, and a semiconductor device obtained by encapsulating a semiconductor element using the same.
[0002]
[Prior art]
2. Description of the Related Art Epoxy resin compositions for semiconductor encapsulation (hereinafter referred to as resin compositions) have been developed and produced to protect semiconductor element bodies from mechanical and chemical actions. The items required for this resin composition are changing depending on the type of semiconductor element, the structure of the package to be sealed, the environment in which it is used, and the like. Package crack. In response to this requirement, the use of a biphenyl type epoxy resin, which is a crystalline epoxy resin, and the use of, for example, a phenol resin, which is a curing agent, in an amount greater than the theoretical equivalent amount of the epoxy resin significantly improves the solder crack resistance. Was. However, the biphenyl type epoxy resin is crystalline at room temperature when used alone, but when used in a resin composition, the viscosity increases due to a crosslinking reaction at the time of kneading and storage at room temperature of the material, and the crystallinity is partially impaired. Therefore, in the encapsulation step, there is a problem in moldability such as a defect (island shift) in which the island of the semiconductor element is tilted, or the biphenyl-type epoxy resin is used in excess of the stoichiometric equivalent with respect to, for example, a phenol resin as a curing agent. As a result, the curability was reduced, and workability was hindered.
[0003]
In order to solve the above problems, for example, when using triphenylphosphine as a curing accelerator, a method of suppressing the addition amount to prevent a decrease in storage stability at room temperature, or a method of suppressing addition of tetraphenylphosphonium / tetraphenylborate (hereinafter, referred to as TPP-K) has been proposed to improve the storage stability at room temperature and the curability (Japanese Patent Publication No. 51-24399), but these properties cannot be achieved at the same time and are insufficient. .
[0004]
[Problems to be solved by the invention]
The present invention is an epoxy resin composition for semiconductor encapsulation, which has excellent solder crack resistance, improves curability at room temperature while maintaining curability at the time of molding, has improved fluidity, and improved burrs, and uses the same. To provide a semiconductor device in which a semiconductor element is sealed.
[0005]
[Means for Solving the Problems]
The present inventor uses a specific curing accelerator for the biphenyl type epoxy resin, and increases the mixing ratio of all epoxy resins and all phenolic resins, by increasing the ratio of the number of epoxy groups to the number of phenolic hydroxyl groups, The inventors have found that the above-mentioned excellent properties are exhibited, and based on this finding, have completed the present invention.
That is, the present invention provides (A) an epoxy resin represented by the formula (1), (B) a phenolic resin, and (C) a curing accelerator containing the compound represented by the formula (2) in an amount of 50 to 100% by weight in the total curing accelerator. And (D) fused spherical silica as essential components, wherein the number of epoxy groups of all epoxy resins is 1.1 to 1.4 with respect to the number of phenolic hydroxyl groups of all phenolic resins, and the particle size of fused spherical silica is 60 μm or more. 1% by weight or less, and those having a particle size of 40 μm or more are 10 to 100% by weight. In particular, the curing accelerator contains a compound represented by the formula (2) in all the curing accelerators. An epoxy resin composition for semiconductor encapsulation containing 50 to 90% by weight and 10 to 50% by weight of triphenylphosphine, wherein the total amount of uranium and thorium in all epoxy resin compositions is 2 ppb or less, and using the same. A semiconductor device characterized by being sealed.
Embedded image

(R ₁ is a hydrogen atom, a methyl group, an ethyl group, a butyl group, or a halogen atom, and R ₁ may be the same or different.)
[0006]
Embedded image

[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
The biphenyl type epoxy resin represented by the formula (1) used in the present invention has a mesogen skeleton in the main chain, is relatively low in molecular weight, has crystallinity, and has two epoxy groups in one molecule. Since it is a compound, it is a solid at a temperature lower than the melting point, but becomes a low-viscosity liquid material at a temperature higher than the melting point. For this reason, the epoxy resin composition using the epoxy resin of the formula (1) exhibits a low viscosity in a molten state, has a high fluidity at the time of molding, has excellent filling properties into a thin package, and has good moldability. Further, since the epoxy resin of the formula (1) is bifunctional, a cured product of the resin composition using the epoxy resin has a low crosslinking density and a low elastic modulus at a high temperature. It is suitable for relaxation and can improve moldability and solder crack resistance.
Further, as long as the properties of the epoxy resin of the formula (1) are not impaired, for example, bisphenol type epoxy resin, stilbene type epoxy resin, orthocresol novolak type epoxy resin, phenol novolak type epoxy resin, naphthalene type epoxy resin, triphenol methane Other epoxy resins, such as epoxy resin, alkyl-modified triphenolmethane-type epoxy resin, epoxy resin containing triazine nucleus, and dicyclopentadiene-modified phenol-type epoxy resin may be used in combination. These epoxy resins may be used alone or in combination. The melting point, softening point, epoxy equivalent and the like are not particularly limited, but the chlorine content in the epoxy resin is preferably as low as possible from the viewpoint of long-term reliability.
[0008]
The phenolic resin used in the present invention refers to all monomers, oligomers and polymers having two or more phenolic hydroxyl groups in one molecule, for example, phenol novolak resin, phenol aralkyl resin, naphthol aralkyl resin, terpene-modified phenol resin And a dicyclopentadiene-modified phenol resin. These may be used alone or as a mixture. The softening point, hydroxyl equivalent and the like are not particularly limited, but the chlorine content in the phenol resin is preferably as low as possible from the viewpoint of long-term reliability.
As the compounding ratio of all epoxy resins and all phenol resins, the ratio of the number of epoxy groups to the number of phenolic hydroxyl groups is preferably 1.1 to 1.4, which is the best, because of the balance between moldability and solder crack resistance. . More preferably, it is 1.2 to 1.3. If it is less than 1.1, the solder crack resistance is reduced, and if it exceeds 1.4, the curability is undesirably reduced.
[0009]
The curing accelerator used in the present invention is a compound represented by the formula (2). This compound has low activity at room temperature, high activity at a high temperature of 100 ° C. or higher, and has a melting point of 200 ° C. to 250 ° C. Since it is within the range, it is excellent in dispersibility during kneading, storage stability at room temperature, and reactivity. The compounding amount of the compound of the formula (2) is preferably 50 to 100% by weight in the total curing accelerator. If it is less than 50% by weight, the storage stability at room temperature is poor, which is not preferable.
When only the compound of the formula (2) is used, the reactivity of the material in the kneading temperature range becomes extremely low, the reaction of the low molecular weight components during kneading is suppressed, and there is a possibility that burrs are easily generated during molding. . Therefore, the use of triphenylphosphine, which is inferior to the compound of formula (2) in storage stability at normal temperature and fluidity, but is excellent in promoting the reaction at low temperatures, can balance the reactivity. More preferred. In this case, the compounding amount is preferably such that the total amount of the curing accelerator is 50 to 90% by weight of the compound of the formula (2) and 10 to 50% by weight of triphenylphosphine. If the amount of the compound of the formula (2) is less than 50% by weight, the above-mentioned effects are not sufficiently exhibited, and only the same effects as those of the conventional curing accelerator system can be obtained. If the content of triphenylphosphine is less than 10% by weight, undesirably, the amount of burrs increases during molding.
Further, other curing accelerators such as tetraphenylphosphonium tetraphenylborate, 2-methylimidazole, 1,8-diazabicyclo (5,4,0) undecene-7 can be used within the range not impairing the properties of these curing accelerators. You may use together with an agent.
[0010]
In the fused spherical silica used in the present invention, those having a particle diameter of 60 μm or more are preferably 1% by weight or less, and those having a particle diameter of 40 μm or more are preferably 10 to 100% by weight, particularly from the viewpoint of fluidity. 10-30% by weight is preferred. If the particle size exceeds 60 μm, the flowability of the resin composition in the narrow flow path in the mold is reduced, and an island shift occurs. If the particle size is 40 μm or more and less than 10% by weight, undesired burrs increase.
Further, within the range not impairing the properties of the fused spherical silica of the present invention, for example, other inorganic materials such as fused silica, crystalline silica, secondary aggregated silica, alumina, titanium white, aluminum hydroxide, talc, clay, and glass fiber. A filler may be used in combination.
In a memory-based semiconductor element or the like, a malfunction due to a radioactive substance poses a problem. Therefore, the total amount of uranium (hereinafter, referred to as U) and thorium (hereinafter, referred to as Th) in all resin compositions is 2 ppb or less. Is preferred. As a method for quantifying U and Th, the resin composition was weighed, and after incineration, the fused spherical silica was dissolved and removed using hydrofluoric acid, and antimony was further dissolved and removed using hydrochloric acid. (High frequency inductively coupled plasma mass spectrometry).
[0011]
In addition to the components (A) to (D), the resin composition of the present invention may further include, if necessary, a coupling agent such as γ-glycidoxypropyltrimethoxysilane, a coloring agent such as carbon black, a brominated epoxy resin, Flame retardants such as antimony oxide and phosphorus compounds, low stress components such as silicone oil and silicone rubber, release agents such as natural wax, synthetic wax, higher fatty acids and their metal salts or paraffin, and various additives such as antioxidants. Can be blended.
The resin composition of the present invention is obtained by mixing the components (A) to (D) and other additives at room temperature using a mixer, kneading with a kneader such as a kneader, a roll, an extruder, and cooling, followed by pulverization. Is obtained.
In order to manufacture an electronic component such as a semiconductor element by encapsulating an electronic component using the resin composition of the present invention, it is only necessary to cure and mold by a molding method such as a transfer mold, a compression mold, and an injection mold.
[0012]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples. The mixing ratio is by weight.
Example 1
13.2 parts by weight of a biphenyl type epoxy resin having a structure represented by the formula (3) as a main component (YX-4000H manufactured by Yuka Shell Epoxy Co., Ltd., melting point: 105 ° C., epoxy equivalent: 195)

[0013]
Phenol novolak resin of formula (4) (softening point 80 ° C., hydroxyl equivalent 105)
5.6 parts by weight

[0014]
0.30 parts by weight of a curing accelerator of the formula (5)

[0015]
Triphenylphosphine 0.10 parts by weight fused spherical silica I (U content 0.1 ppb, Th content 0.1 ppb, particle size 6
0.7% by weight is 0 μm or more, 16% by weight is 40 μm or more) 80.0 parts by weight Carbon black 0.3 part by weight Carnauba wax 0.5 part by weight is mixed using a mixer, and the surface temperature is 90 ° C. The mixture was kneaded with two rolls at 45 ° C., cooled and pulverized to obtain a resin composition. The obtained resin composition was evaluated by the following method. Table 1 shows the results.
[0016]
Evaluation method Spiral flow: Measurement was performed using a mold for spiral flow measurement according to EMMI-I-66 at a mold temperature of 175 ° C., an injection pressure of 70 kg / cm ² , and a curing time of 2 minutes. The unit is cm.
Room-temperature storage property: After storing at 25 ° C. for one week, the spiral flow was measured and expressed as a percentage of the spiral flow immediately after preparation. Units%.
Curability: Using a Shore D hardness meter, molding was performed at a mold temperature of 175 ° C., an injection pressure of 70 kg / cm ² , and a curing time of 2 minutes, and the value of Shore D hardness measured 10 seconds after the mold opening was taken as the curability.
Usbari characteristics: Using a transfer molding machine, a 16pDIP (tip size 300 × 300 mil) was molded at a mold temperature of 175 ° C., a pressure of 70 kg / cm ² and a curing time of 2 minutes, and the burr length of the vent was measured. The unit is mm.
Island shift characteristics: Using a transfer molding machine, a 44pTSOP (LOC structure: LEADON CHIP structure) was molded at a mold temperature of 180 ° C., a pressure of 100 kg / cm ² , and a curing time of 1 minute, and the center of the package was cut and polished. Using a magnifying projector, the difference between the distance between the semiconductor element surface on the gate side and the upper surface of the package and the distance between the semiconductor element surface on the vent side and the upper surface of the package was defined and measured as an island shift amount. The unit is μm.
Solder Resistance: Using a transfer molding machine, eight 80pQFP (1.5 mm thick) were molded at a mold temperature of 175 ° C., a pressure of 70 kg / cm ² and a curing time of 2 minutes, and after-cured at 175 ° C. for 8 hours. The substrate was left in an environment of 85 ° C. and a relative humidity of 60% for 168 hours, and then treated by IR reflow (240 ° C.) for 10 seconds. The obtained packages were visually observed and observed with an ultrasonic flaw detector, and the number of packages in which external cracks, peeling on the chip, and peeling under the pad occurred was indicated as n / 8.
U and Th amounts: After ashing of the resin composition, the fused spherical silica was dissolved and removed using hydrofluoric acid, and antimony was further dissolved and removed using hydrochloric acid. The residual aqueous solution was subjected to ICP-MS (high-frequency inductively coupled plasma mass). Analysis). The unit is ppb by weight ratio in the whole resin composition.
[0017]
Examples 2 to 9, Comparative Examples 1 to 7
According to the formulations in Tables 1 and 2, a 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 Tables 1 and 2.
The structures and properties of the curing accelerator of the formula (6), the cresol novolak type epoxy resin of the formula (7) (softening point of 55 ° C., epoxy equivalent of 201) and the fused spherical silicas II to V used in Examples and Comparative Examples are as follows. Shown in
Embedded image

[0018]
Embedded image

[0019]
Fused spherical silica II (U content 1.1 ppb, Th content 1.6 ppb, particle size 60 μm or more 0.7% by weight, particle size 40 μm or more 16% by weight),
Fused spherical silica III (U content 0.1 ppb, Th content 0.1 ppb, particle size 60 μm or more 1.7% by weight, particle size 40 μm or more 6% by weight),
Fused spherical silica IV (U content 0.1 ppb, Th content 0.1 ppb, particle size 60 μm or more is 3.2% by weight, particle size 40 μm or more is 25% by weight),
Fused spherical silica V (U content 0.1 ppb, Th content 0.1 ppb, particle size 60 μm or more 0.5% by weight, particle size 40 μm or more 4% by weight).
[Table 1]

[0020]
[Table 2]

[0021]
【The invention's effect】
ADVANTAGE OF THE INVENTION The epoxy resin composition for semiconductor sealing of this invention is excellent in the storability at normal temperature, and improves the curability at the time of shaping | molding, a Usbari characteristic, and an island shift characteristic, and the semiconductor device using this is excellent in solder crack resistance.

Claims (4)

(A) an epoxy resin represented by the formula (1), (B) a phenolic resin, (C) a curing accelerator containing 50 to 100% by weight of the compound represented by the formula (2) in the total curing accelerator, and (D) 1) Melt spherical silica is an essential component, and the number of epoxy groups in all epoxy resins is 1.1 to 1.4 with respect to the number of phenolic hydroxyl groups in all phenolic resins, and 1% by weight of fused spherical silica has a particle size of 60 μm or more. An epoxy resin composition for encapsulating a semiconductor, wherein the content of the epoxy resin is 40 to 100% by weight and the particle size is 40 μm or more.

(R ₁ is a hydrogen atom, a methyl group, an ethyl group, a butyl group, or a halogen atom, and R ₁ may be the same or different.)

The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the curing accelerator contains 50 to 90% by weight of the compound represented by the formula (2) and 10 to 50% by weight of triphenylphosphine in the total curing accelerator. . The epoxy resin composition for semiconductor encapsulation according to claim 1 or 2, wherein the total amount of uranium and thorium in all epoxy resin compositions is 2 ppb or less. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition for semiconductor encapsulation according to claim 1.