JP3622950B2 - Liquid encapsulating resin composition and semiconductor device using the same - Google Patents

Description

（ｎは１から５０までの整数）
【０００８】
また、半導体素子が上記の液状封止樹脂組成物を用いて封止された半導体装置である。
【０００９】
【発明の実施の態様】
本発明に用いられる式（１）で示されるエポキシ樹脂（Ａ）を用いると、硬化物が低弾性率化され、液状封止樹脂に求められる低応力性を有することを見いだした。また、信頼性の優れた液状封止樹脂組成物を得るために、硬化剤のＮａ^＋、Ｃｌ⁻等のイオン性不純物はできるだけ少ないものが好ましい。
【００１０】
（Ｂ）硬化剤としてはアルキル化ジアミノジフェニルメタンである。アルキル化ジアミノジフェニルメタンの例としては、エチル化ジアミノジフェニルメタン、メチル化ジアミノジフェニルメタン等がある。これを用いた場合、特に金属、ソルダーレジスト等ＢＧＡパッケージに必須の被着体への接着性が、式（１）で示されるエポキシ樹脂との組み合わせにおいて特に優れるからである。また、信頼性の優れた液状封止樹脂組成物を得るために、硬化剤のNa⁺、Cl^-等のイオン性不純物はできるだけ少ないものが好ましい。
【００１１】
主剤である全エポキシ樹脂（Ａ）と、硬化剤との配合モル比は０．８〜１．２が望ましい。０．８未満の場合は、過剰に未反応の硬化剤の反応基が残存することとなり、耐湿性の低下、信頼性の低下に繋がる。逆に１．２を越えると硬化が不十分となり、信頼性の低下に繋がる。
【００１２】
（Ｃ）の無機フィラーとしては、樹脂の充填に用いることができるものなら何れも使用できる。その中でもシリカが好ましく、例えば、結晶シリカ、溶融シリカ等が用いられる。形状は一般に球状、破砕状、フレーク状等があるが、充填材をより多く添加することにより線膨張係数の低減化が図られ、その効果をあげるためには球状の無機充填材が最も良い。
【００１３】
添加量は、最終硬化物に対し、６０ｗｔ％〜９０ｗｔ％が望ましい。６０ｗｔ％未満だと、硬化物の線膨張係数が大きくなり、硬化後のパッケージへの応力蓄積やＴ／Ｃ試験での樹脂クラックを起こす恐れがある。一方、９０ｗｔ％を越えると結果として得られる液状封止樹脂組成物の粘度が高くなり過ぎ、実用レベルではないため好ましくない。
【００１４】
本発明の液状封止樹脂組成物には、前記の必須成分の他に必要に応じて、硬化促進剤、希釈剤、顔料、カップリング剤、難燃剤、レベリング剤、消泡剤等の添加物を用いても差し支えない。液状封止樹脂組成物は、各成分、添加物等を３本ロールにて分散混練し、真空下で脱泡処理して製造する。
【００１５】
本発明の液状封止樹脂組成物を用いて半導体装置を製作すると、従来より信頼性の高い半導体装置を得ることが出来る。半導体装置の製造方法は公知の方法を用いることが出来る。
【００１６】
【実施例】
本発明を実施例及び比較例で説明する。
＜実施例１＞
式（１）で示されたエポキシ樹脂（等量２２５）１００重量部、硬化剤としてエチル化ジアミノジフェニルメタン（カヤハードＡ−Ａ、日本化薬社製、当量６５）３０重量部、密着性助剤としてγ−グリシジルトリメトキシシラン６重量部、平均粒径６μｍ、最大粒径５０μｍの球状シリカ３２０重量部、希釈剤として、ブチルセロソルブアセテート７．５重量部、カーボンブラック１重量部を秤量し、これらの原材料を３本ロールにて分散混練し、真空下脱泡処理をして液状封止樹脂組成物を得た。次に、得られた液状封止樹脂組成物を用いて接着性、靱性値の尺度として破壊エネルギー及び信頼性試験を行った。
【００１８】
＜比較例１＞
ビスフェノールＦ型エポキシ樹脂（当量１６５）１００重量部、硬化剤としてエチル化ジアミノジフェニルメタン（カヤハードＡ−Ａ、日本化薬社製、当量６５）４０重量部、密着性助剤としてγ−グリシジルトリメトキシシラン６重量部、平均粒径６μｍ、最大粒径５０μｍの球状シリカ３５０重量部、希釈剤としてブチルセロソルブアセテート７．５重量部、カーボンブラック１重量部を秤量し、これらの原材料を３本ロールにて、分散混練し真空下脱泡処理をして液状封止樹脂組成物を得た。次に、得られた液状封止樹脂組成物を用いて接着性、靱性値の尺度として破壊エネルギー及び信頼性試験を行った。
【００１９】
＜比較例２＞
ビスフェノールＦ型エポキシ樹脂（当量１６５）１００重量部、硬化剤としてアリルフェノールノボラック（ＭＥＨ−８０００、明和化成製、水酸基１４１）８３重量部、密着性助剤としてγ−グリシジルトリメトキシシラン６重量部、平均粒径６μｍ、最大粒径５０μｍの球状シリカ４４５重量部、希釈剤としてブチルセロソルブアセテート７．５重量部、カーボンブラック１重量部を秤量し、これらの原材料を３本ロールにて分散混練し、真空下脱泡処理をして液状封止樹脂組成物を得た。次に、得られた液状封止樹脂組成物を用いて接着性、靱性値の尺度として破壊エネルギー及び信頼性試験を行った。
【００２０】
各試験の方法は次のとおりである。
１）接着性；ソルダーレジスト（太陽インキ社製、ＰＳＲ４０００ＡＵＳ０５／ＣＡ−４０ＡＵＳ２）が塗布されたガラス−エポキシ基板に液状封止樹脂組成物を塗布し、上から６ｘ６ｍｍのチップをマウントし、１５０℃、３時間で硬化させ、２００℃のホットプレートに載置しダイシェアー強度を測定した。
２）弾性率；幅１０ｍｍ、厚み４ｍｍ、長さ１３ｍｍの試験片を作製し（試験片の硬化条件：１５０℃，３時間）、万能試験機を用いて曲げ試験を行い、ひずみ−応力グラフより計算し求めた。
【００２１】
３）信頼性−１；ＢＴ基板製の１５ｍｍ角のシリコンチップがマウントされたＢＧＡ基板に液状封止樹脂組成物を塗布し（キャビティサイズ：２５ｍｍｘ２５ｍｍｘ１ｍｍｔ）、１５０℃、３時間の条件で硬化させて、試験片を作製した。次に、Ｔ／Ｃ処理（−５５℃／３０分←→１２５℃／３０分、１０００サイクル）を施した後、超音波探傷機（ＳＡＴ）にて半導体チップとプリント基板界面との剥離、クラックの有無を確認した。試験に用いたサンプル数は１０個である。
【００２２】
４）信頼性−２；上記の信頼性−１と同じ条件で作製したテストピース１０個を、８５℃、８５％ＲＨの条件で７２時間の湿度処理を施したのち、ＩＲリフロー（最大温度２４０℃、９０秒）にて２回処理した後、ＳＡＴにて剥離、クラックの有無を確認した。
【００２３】
測定した結果を表１に示す。
【表１】

【００２４】
【発明の効果】
本発明による液状封止樹脂組成物は、低応力性を有し、よって耐半田クラック性試験、Ｔ／Ｃ試験等を満足し、信頼性の高い液状封止樹脂組成物であり、半導体装置である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid sealing resin composition used for sealing a semiconductor, and a semiconductor device using the resin composition.
[0002]
[Prior art]
In recent years, with the increase in size of semiconductor chips, the increase in the number of pins of packages, and the diversification, the requirement for reliability of resin materials as peripheral materials has become severe year by year. Conventionally, a package in which a semiconductor chip is bonded to a lead frame and sealed with a mold resin has been mainstream, but packages such as a ball grid array (BGA) have increased considerably due to the limit of the number of pins.
[0003]
BGA is sealed with a mold resin or a liquid resin, but since it is composed of a substrate, a solder resist, and a plated portion such as gold or nickel, adhesion to them is important. In addition, solder crack resistance is required for joining to the motherboard by surface mounting. Furthermore, there is a temperature cycle test (T / C test) as a part of reliability, and high reliability is required for the package.
[0004]
For example, the required reliability condition is as follows:
Solder crack resistance: The package is moisture-absorbed for one week under the conditions of 30 ° C. and 60% RH and then reflowed to prevent peeling and cracking. T / C test: −55 ° C. to 125 ° C. (each temperature exposure time 30 Min), after 1000 cycles or more of treatment, no peeling or cracking.
[0005]
However, more stringent requirements are, for example,
・ Solder crack resistance: Moisture absorption of package at 85 ° C. and 85% RH for one week, reflow treatment and no peeling or crack ・ T / C test: −65 ° C. to 150 ° C. (each exposure time 30 minutes), After processing for 1000 cycles or more, more severe conditions equivalent to those of the lead frame type package are required, such as no peeling or cracking.
However, there is no material satisfying such reliability in the liquid sealing resin composition for sealing the semiconductor.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a highly reliable liquid sealing resin composition satisfying a solder crack resistance test, a T / C test and the like in the liquid sealing resin composition.
[0007]
[Means for Solving the Problems]
The present inventors have found that have conducted extensive studies to solve the prior art of such a problem, an epoxy resin represented by the formula (1), a curing agent, Ri Do silica, the curing agent is an alkylating diamino diphenylmethane der Ru liquid encapsulating resin composition and completed the present invention found that the excellent reliability has a low stress property.
[Chemical formula 2]

(N is an integer from 1 to 50)
[0008]
Also, the semiconductor device is a semiconductor device encapsulated using the above liquid sealing resin composition.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
It has been found that when the epoxy resin (A) represented by the formula (1) used in the present invention is used, the cured product has a low elastic modulus and has low stress required for a liquid sealing resin. Moreover, in order to obtain a liquid sealing resin composition having excellent reliability, it is preferable that the ionic impurities such as Na ⁺ and Cl ⁻ of the curing agent are as small as possible.
[0010]
(B) The curing agent is alkylation diaminodiphenylmethane. Examples of alkylated diaminodiphenylmethane include ethylated diaminodiphenylmethane, methylated diaminodiphenylmethane, and the like. This is because the adhesion to an adherend essential for BGA packages such as metal and solder resist is particularly excellent in combination with the epoxy resin represented by the formula (1). Further, in order to obtain a reliable good liquid sealing resin composition, the curing agent Na ^+, Cl ^- ionic impurities such as those as small as possible is preferable.
[0011]
The blending molar ratio of the main epoxy resin (A) and the curing agent is preferably 0.8 to 1.2. If it is less than 0.8, the reactive group of the unreacted curing agent will remain excessively, leading to a decrease in moisture resistance and a decrease in reliability. On the other hand, if it exceeds 1.2, curing will be insufficient, leading to a decrease in reliability.
[0012]
As the inorganic filler (C), any filler that can be used for filling the resin can be used. Among these, silica is preferable, and for example, crystalline silica, fused silica, and the like are used. There are generally spherical shapes, crushed shapes, flake shapes, and the like, but the addition of more fillers can reduce the linear expansion coefficient, and spherical inorganic fillers are the best for increasing the effect.
[0013]
The addition amount is desirably 60 wt% to 90 wt% with respect to the final cured product. If it is less than 60 wt%, the linear expansion coefficient of the cured product increases, and there is a risk of causing stress accumulation in the package after curing and resin cracking in the T / C test. On the other hand, if it exceeds 90 wt%, the resulting liquid encapsulating resin composition has an excessively high viscosity, which is not practical and not preferred.
[0014]
In addition to the above essential components, the liquid sealing resin composition of the present invention includes additives such as a curing accelerator, a diluent, a pigment, a coupling agent, a flame retardant, a leveling agent, and an antifoaming agent as necessary. Can be used. The liquid encapsulating resin composition is produced by dispersing and kneading each component, additive and the like with three rolls and defoaming under vacuum.
[0015]
When a semiconductor device is manufactured using the liquid encapsulating resin composition of the present invention, a semiconductor device with higher reliability than before can be obtained. A known method can be used as a method of manufacturing the semiconductor device.
[0016]
【Example】
The present invention will be described with reference to examples and comparative examples.
<Example 1>
100 parts by weight of the epoxy resin (equal amount 225) represented by the formula (1), 30 parts by weight of ethylated diaminodiphenylmethane (Kayahard AA, Nippon Kayaku Co., Ltd., equivalent 65) as a curing agent, as an adhesion aid Weigh 6 parts by weight of γ-glycidyltrimethoxysilane, 320 parts by weight of spherical silica having an average particle size of 6 μm and a maximum particle size of 50 μm, 7.5 parts by weight of butyl cellosolve acetate and 1 part by weight of carbon black as diluents. Was dispersed and kneaded with three rolls and defoamed under vacuum to obtain a liquid sealing resin composition. Next, using the obtained liquid sealing resin composition, fracture energy and reliability tests were performed as measures of adhesiveness and toughness.
[0018]
<Comparative Example 1>
100 parts by weight of a bisphenol F type epoxy resin (equivalent 165), 40 parts by weight of ethylated diaminodiphenylmethane (Kayahard AA, Nippon Kayaku Co., Ltd., equivalent 65) as a curing agent, and γ-glycidyltrimethoxysilane as an adhesion assistant Weighing 6 parts by weight, 350 parts by weight of spherical silica having an average particle diameter of 6 μm, a maximum particle diameter of 50 μm, 7.5 parts by weight of butyl cellosolve acetate as a diluent, and 1 part by weight of carbon black, these raw materials are in three rolls, Dispersion kneading and defoaming treatment under vacuum gave a liquid sealing resin composition. Next, using the obtained liquid sealing resin composition, fracture energy and reliability tests were performed as measures of adhesiveness and toughness.
[0019]
<Comparative example 2>
100 parts by weight of a bisphenol F type epoxy resin (equivalent 165), 83 parts by weight of allylphenol novolak (MEH-8000, manufactured by Meiwa Kasei, hydroxyl group 141) as a curing agent, 6 parts by weight of γ-glycidyltrimethoxysilane as an adhesion assistant, 445 parts by weight of spherical silica having an average particle diameter of 6 μm and a maximum particle diameter of 50 μm, 7.5 parts by weight of butyl cellosolve acetate as a diluent, and 1 part by weight of carbon black are weighed, and these raw materials are dispersed and kneaded with three rolls, and vacuumed. A bottom sealing process was performed to obtain a liquid sealing resin composition. Next, using the obtained liquid sealing resin composition, fracture energy and reliability tests were performed as measures of adhesiveness and toughness.
[0020]
The method of each test is as follows.
1) Adhesiveness: A liquid sealing resin composition was applied to a glass-epoxy substrate coated with a solder resist (manufactured by Taiyo Ink, PSR4000AUS05 / CA-40AUS2), a 6 × 6 mm chip was mounted from above, and 150 ° C. It was cured in 3 hours and placed on a 200 ° C. hot plate to measure the die shear strength.
2) Elastic modulus: A test piece having a width of 10 mm, a thickness of 4 mm, and a length of 13 mm was prepared (curing condition of the test piece: 150 ° C., 3 hours), and a bending test was performed using a universal testing machine. Calculated and determined.
[0021]
3) Reliability-1: A liquid sealing resin composition was applied to a BGA substrate mounted with a 15 mm square silicon chip made of a BT substrate (cavity size: 25 mm × 25 mm × 1 mmt), and cured under conditions of 150 ° C. for 3 hours. A test piece was prepared. Next, after T / C treatment (-55 ° C / 30 minutes ← → 125 ° C / 30 minutes, 1000 cycles), peeling and cracking between the semiconductor chip and the printed circuit board interface with an ultrasonic flaw detector (SAT) The presence or absence was confirmed. The number of samples used for the test is ten.
[0022]
4) Reliability-2: Ten test pieces manufactured under the same conditions as the above reliability-1 were subjected to humidity treatment for 72 hours under the conditions of 85 ° C. and 85% RH, and then IR reflow (maximum temperature 240 (C, 90 seconds), and the presence or absence of peeling or cracking was confirmed by SAT.
[0023]
The measured results are shown in Table 1.
[Table 1]

[0024]
【The invention's effect】
The liquid encapsulating resin composition according to the present invention is a highly reliable liquid encapsulating resin composition having a low stress and thus satisfying a solder crack resistance test, a T / C test, etc. is there.

Claims (2)

Epoxy resin represented by the formula (A) (1), (B) a curing agent, (C) Ri Do inorganic filler, liquid sealing resin composition curing agent characterized alkylated diaminodiphenylmethane der Rukoto .

(N is an integer from 1 to 50) A semiconductor device manufactured by sealing a semiconductor element using the liquid sealing resin composition according to claim 1.