JPH1045879A

JPH1045879A - Epoxy resin composition for sealing optical semiconductor

Info

Publication number: JPH1045879A
Application number: JP20690596A
Authority: JP
Inventors: Keiichi Sakumichi; 慶一作道
Original assignee: Sumitomo Bakelite Co Ltd
Current assignee: Sumitomo Bakelite Co Ltd
Priority date: 1996-08-06
Filing date: 1996-08-06
Publication date: 1998-02-17
Anticipated expiration: 2016-08-06
Also published as: JP3714568B2

Abstract

PROBLEM TO BE SOLVED: To obtain a composition comprising an epoxy resin, an acid anhydride curing agent and a specific curing accelerator, little in thermal discoloration at high temperatures, especially little in the lowering of light transmission on the side of low wavelengths, and capable of exhibiting excellent transparency. SOLUTION: This epoxy resin composition comprises (A) an epoxy resin such as a bisphenol type epoxy resin or an alicyclic epoxy resin, (B) an acid anhydride curing agent such as phthalic anhydride, trimellitic anhydride, nadic anhydride or cinnamic anhydride, and (C) a curing accelerator containing (C1 ) a compound of the formula: Zn(Cn H2n+1 COO)2 [(n) is 1-21] in an amount of 70-99mol.% based on the whole amount of the curing accelerator (e.g. the mixture of a tertiary amine, an organic phosphine or an imidazole with the component C1 ). In the composition, the component B is preferably compounded in an amount of 0.5-1.2 equivalents per equivalent of the component A. The epoxy resin composition can exhibit excellent moldability.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、透明性に優れた光
半導体封止用エポキシ樹脂組成物に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for encapsulating an optical semiconductor having excellent transparency.

【０００２】[0002]

【従来の技術】オプトエレクトロニクスの分野に於い
て、酸無水物硬化タイプの光半導体封止用エポキシ樹脂
組成物（以下、樹脂組成物という）は、透明性に優れて
おり、特に無色透明のエポキシ樹脂を用いると、可視光
領域でも高い光透過率が得られるため、フォトセンサ
ー、ＬＥＤ等に使用されている。しかし、この樹脂組成
物の硬化物は、成形時及びポストキュアー時の熱履歴に
より変色し易いため、光透過率が低下してしまう。この
ため、従来は成形時及びポストキュアー時の温度を低く
し、熱変色を抑えてきたが、生産の効率化のためには、
高温・短時間の熱処理が可能な材料が求められている。
又、熱変色による光透過率の低下は、低波長領域で顕著
であるため、今後必要とされる青色レーザー等の低波長
デバイスへの対応が困難となっている。熱変色の原因
は、硬化物中に存在する硬化促進剤の酸化である。とこ
ろが、樹脂組成物の硬化物中に粒子があると白濁し光透
過率が低下してしまうので、これまでは硬化促進剤とし
て、エポキシ樹脂、酸無水物との溶解性が良好で無色の
イミダゾールが用いられてきた。しかし、イミダゾール
は酸化を受け易いため、硬化物全体の熱変色を引き起こ
す。従来、この熱変色を抑えるために、酸化防止剤の添
加等が試みられてきたが、いずれも１５０℃以上の高い
温度に耐え得るものではなく、充分な耐熱性を持つもの
は得られていない。2. Description of the Related Art In the field of optoelectronics, an acid anhydride-curable epoxy resin composition for encapsulating an optical semiconductor (hereinafter referred to as a resin composition) is excellent in transparency, and particularly colorless and transparent epoxy resin. When a resin is used, a high light transmittance can be obtained even in a visible light region, and thus it is used for a photo sensor, an LED, and the like. However, the cured product of this resin composition is easily discolored due to the heat history at the time of molding and at the time of post-curing, so that the light transmittance is reduced. For this reason, in the past, the temperature during molding and post-curing was lowered to suppress thermal discoloration.
There is a need for a material that can be heat-treated at high temperature for a short time.
Further, since the decrease in light transmittance due to thermal discoloration is remarkable in a low wavelength region, it is difficult to cope with a low wavelength device such as a blue laser which will be required in the future. The cause of the thermal discoloration is oxidation of the curing accelerator present in the cured product. However, if particles are present in the cured product of the resin composition, it becomes cloudy and the light transmittance is reduced.So far, as a curing accelerator, epoxy resins and acid anhydrides have good solubility and colorless imidazole. Has been used. However, imidazole is susceptible to oxidation, causing thermal discoloration of the entire cured product. Conventionally, in order to suppress this thermal discoloration, addition of an antioxidant and the like have been tried, but none of them can withstand a high temperature of 150 ° C. or more, and those having sufficient heat resistance have not been obtained. .

【０００３】[0003]

【発明が解決しようとする課題】本発明は、高温での熱
変色、特に低波長側での光透過率の低下が少ない透明性
に優れた樹脂組成物を提供するものである。The object of the present invention is to provide a resin composition which is excellent in transparency with little heat discoloration at a high temperature, in particular, a decrease in light transmittance on a low wavelength side.

【０００４】[0004]

【課題を解決するための手段】本発明は、（Ａ）エポキ
シ樹脂、（Ｂ）酸無水物系硬化剤、及び（Ｃ）式（１）
の化合物を全硬化促進剤中に７０〜９９ｍｏｌ％含む硬
化促進剤からなることを特徴とする光半導体封止用エポ
キシ樹脂組成物である。Ｚｎ（Ｃ_nＨ_2n+1ＣＯＯ）₂ （式中、ｎ＝１〜２１）（１）The present invention provides (A) an epoxy resin, (B) an acid anhydride-based curing agent, and (C) a compound represented by the formula (1):
An epoxy resin composition for encapsulating an optical semiconductor, comprising a curing accelerator containing 70 to 99 mol% of the above compound in the total curing accelerator. _{_{Zn (C n H 2n + 1}} COO) 2 ( wherein, n = 1~21) (1)

【０００５】[0005]

【発明の実施の形態】本発明で用いるエポキシ樹脂とし
ては、例えば、ビスフェノール型エポキシ樹脂、脂環式
エポキシ樹脂等が挙げられ、これらは単独でも混合して
用いてもよい。本発明で用いる酸無水物系硬化剤として
は、例えば、フタル酸無水物、トリメリット酸無水物、
ピロメリット酸無水物、ナジック酸無水物、コハク酸無
水物等のカルボン酸無水物及びその誘導体等が挙げら
れ、これらは単独でも混合して用いてもよい。配合量と
しては、エポキシ樹脂１当量に対して酸無水物系硬化剤
を０．５〜１．２当量が望ましい。この範囲外だと、成
形性に欠陥を起こす場合がある。DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin used in the present invention includes, for example, bisphenol type epoxy resin and alicyclic epoxy resin, and these may be used alone or in combination. As the acid anhydride-based curing agent used in the present invention, for example, phthalic anhydride, trimellitic anhydride,
Examples thereof include carboxylic anhydrides such as pyromellitic anhydride, nadic anhydride, and succinic anhydride and derivatives thereof, and these may be used alone or in combination. The compounding amount is desirably 0.5 to 1.2 equivalents of the acid anhydride-based curing agent to 1 equivalent of the epoxy resin. Outside this range, defects may occur in the moldability.

【０００６】本発明で用いる式（１）で示す化合物は、
無色であり、エポキシ樹脂、酸無水物に対する溶解
性が良好であり、高温での耐変色性に優れている。こ
のため、硬化物中に存在しても光透過率の低下を引き起
こさない。式（１）中のｎは、ｎ＝１〜２１で、より好
ましくはｎ＝３〜１７である。ｎ＝２１を越えると、エ
ポキシ樹脂、酸無水物に対する溶解性が低下し、硬化物
中に粒子ができ、光透過率が低下してしまう。式（１）
の配合量としては、全硬化促進剤中、７０〜９９ｍｏｌ
％が好ましい。７０ｍｏｌ％未満だと、熱変色が起こり
光透過率が低下してしまう。一方、９９ｍｏｌ％を越え
ると、硬化が不充分で満足な熱時硬度が得られない。式
（１）と併用する硬化促進剤としては、例えば、トリメ
チルアミン、トリメタノールアミン等の第３級アミン
類、トリフェニルホスフィン、トリシクロヘキシルホス
フィン等の有機ホスフィン類、２−メチルイミダゾール
等のイミダゾール類等が挙げられ、これらは単独でも混
合して用いてもよい。The compound represented by the formula (1) used in the present invention is
It is colorless, has good solubility in epoxy resins and acid anhydrides, and has excellent resistance to discoloration at high temperatures. Therefore, even if it is present in the cured product, it does not cause a decrease in light transmittance. N in the formula (1) is n = 1 to 21, and more preferably n = 3 to 17. If n exceeds 21, the solubility in the epoxy resin and the acid anhydride decreases, particles are formed in the cured product, and the light transmittance decreases. Equation (1)
As the compounding amount of the total curing accelerator, 70 to 99 mol
% Is preferred. If it is less than 70 mol%, thermal discoloration occurs and the light transmittance decreases. On the other hand, if it exceeds 99 mol%, curing is insufficient and satisfactory hot hardness cannot be obtained. Examples of the curing accelerator used in combination with the formula (1) include tertiary amines such as trimethylamine and trimethanolamine, organic phosphines such as triphenylphosphine and tricyclohexylphosphine, and imidazoles such as 2-methylimidazole. And these may be used alone or as a mixture.

【０００７】本発明の樹脂組成物は、（Ａ）〜（Ｃ）成
分の他、必要に応じて、アゾ系、キノン系の染料、モン
タン酸等の離型剤、及び酸化防止剤等を添加してもよ
い。本発明の樹脂組成物は、（Ａ）〜（Ｃ）成分、及び
各種添加剤等を混合し、加熱ロールを用いて５０〜９０
℃で混練し冷却固化後粉砕して成形材料とすることがで
きる。The resin composition of the present invention further comprises, if necessary, an azo or quinone dye, a releasing agent such as montanic acid, an antioxidant, etc., in addition to the components (A) to (C). May be. The resin composition of the present invention is obtained by mixing the components (A) to (C), various additives, and the like, and using a heating roll to prepare a mixture of 50 to 90.
C., kneaded, cooled and solidified, and then pulverized to obtain a molding material.

【０００８】実施例１ビスフェノールＡ型エポキシ（軟化点７０℃、エポキシ当量４８０）１００．００重量部テトラヒドロフタル酸無水物３２．００重量部Ｚｎ（Ｃ₁₇Ｈ₃₅ＣＯＯ）₂ ６．００重量部２−メチルイミダゾール０．０３重量部グリセリンモノベヘネート３．００重量部以上を粉砕後混合し７０〜９０℃の加熱ロールを用いて
加熱混練を行い、冷却固化後粉砕して成形材料を得た。
この成形材料を低圧トランスファー成形機を用いて１５
０℃、７０kg／cm²、３分間の条件で１０×３０×１mm
（厚さ）のテストピースを成形後、１７５℃、２時間の
ポストキュアーを行い、光透過率測定用テストピースと
した。得られたテストピースを、分光光度計（（株）日
立製作所・製３３０型自記分光光度計）を用いて、４９
０nmの光透過率を測定した。又、キュラストメータを用
いて、１５０℃、２分間の樹脂組成物のトルク値を測定
し、熱時硬度の目安とした。結果を表１に示す。Example 1 Bisphenol A type epoxy (softening point 70 ° C., epoxy equivalent 480) 100.00 parts by weight Tetrahydrophthalic anhydride 32.00 parts by weight Zn (C ₁₇ H ₃₅ COO) ₂ 6.00 parts by weight 2 -Methylimidazole 0.03 parts by weight Glycerin monobehenate 3.00 parts by weight After grinding and mixing, the mixture was heated and kneaded using a heating roll at 70 to 90 ° C, solidified by cooling, and then ground to obtain a molding material.
The molding material is transferred to a low pressure transfer molding machine for 15 minutes.
10 × 30 × 1 mm under the conditions of 0 ° C., 70 kg / cm ² and 3 minutes
After forming the (thickness) test piece, post-curing was performed at 175 ° C. for 2 hours to obtain a light transmittance measurement test piece. Using a spectrophotometer (Hitachi, Ltd., 330-type self-recording spectrophotometer), the obtained test piece was subjected to a test.
The light transmittance at 0 nm was measured. Moreover, the torque value of the resin composition at 150 ° C. for 2 minutes was measured using a curast meter, and was used as a measure of the hardness when heated. Table 1 shows the results.

【０００９】実施例２〜５、比較例１〜５表１及び表２の配合に従って、実施例１と同様にしてテ
ストピースを得、実施例１と同様にして評価した。結果
を表１及び表２に示す。Examples 2 to 5 and Comparative Examples 1 to 5 Test pieces were obtained in the same manner as in Example 1 according to the formulations in Tables 1 and 2, and evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

【表１】 [Table 1]

【００１０】[0010]

【表２】 [Table 2]

【００１１】[0011]

【発明の効果】本発明によると透明性、熱安定性に優れ
た光半導体封止用エポキシ樹脂組成物が得られ、又、成
形及びポストキュアーを高温・短時間で行えるため、生
産コストを大幅に削減できる。According to the present invention, an epoxy resin composition for encapsulating an optical semiconductor having excellent transparency and thermal stability can be obtained, and molding and post-curing can be performed at a high temperature in a short time, so that the production cost is greatly increased. Can be reduced.

Claims

【特許請求の範囲】[Claims]

【請求項１】（Ａ）エポキシ樹脂、（Ｂ）酸無水物系
硬化剤、及び（Ｃ）式（１）の化合物を全硬化促進剤中
に７０〜９９ｍｏｌ％含む硬化促進剤からなることを特
徴とする光半導体封止用エポキシ樹脂組成物。Ｚｎ（Ｃ_nＨ_2n+1ＣＯＯ）₂ （式中、ｎ＝１〜２１）（１）1. A curing accelerator comprising (A) an epoxy resin, (B) an acid anhydride-based curing agent, and (C) a curing accelerator containing 70 to 99 mol% of a compound of the formula (1) in the total curing accelerator. An epoxy resin composition for encapsulating optical semiconductors, which is characterized by the following. _{_{Zn (C n H 2n + 1}} COO) 2 ( wherein, n = 1~21) (1)