JPH065741A - Epoxy resin composition for sealing semiconductor - Google Patents

Abstract

PURPOSE:To provide excellent solder heat resistance, moistureproof reliability and low stressfulness by incorporating special phenol compound in curing agent as an indispensable ingredient in epoxy resin composition containing epoxy resin, the agent, filler in such a manner that a ratio of the filler is 70-95% of the entirety. CONSTITUTION:Epoxy resin composition contains epoxy resin, curing agent containing phenol compound represented by a formula as an indispensable ingredient and filler. A mixing amount of the epoxy resin contained in the composition is normally 4-20wt.% and desirably 5 to 15wt.%. The phenol compound is normally contained 5-100wt.% or desirably 20-80wt.% as an indispensable ingredient in the agent. A mixing amount of the agent is normally 2-10wt.% or desirably 3-8wt.%. A ratio of the filler is 70-95wt.% of the entirety. Thus, moistureproof reliability of the composition to be used for a large-sized chip can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for semiconductor encapsulation which is excellent in solder heat resistance, moisture resistance reliability and low stress.

[0002]

2. Description of the Related Art Epoxy resins are excellent in heat resistance, moisture resistance, electrical characteristics, adhesiveness, etc., and can be given various characteristics by blending formulation, so they are used as industrial materials such as paints, adhesives and electrical insulation materials. Has been done.

For example, as a method of sealing electronic circuit parts such as semiconductor devices, hermetic seals made of metal or ceramics and phenol resin, silicone resin, etc. have hitherto been used.
Resin encapsulation with an epoxy resin or the like has been proposed. However, resin sealing with an epoxy resin is mainly used from the viewpoint of the balance of economy, productivity and physical properties.

In recent years, densification and automation have also been promoted in mounting components on a printed circuit board. Instead of the conventional "insertion mounting method" in which lead pins are inserted into holes in the substrate, components are soldered to the surface of the substrate. "Surface mounting method" has become popular. Along with this, the package is shifting from the conventional DIP (dual in-line package) to a thin FPP (flat plastic package) suitable for high-density mounting and surface mounting.

With the shift to the surface mounting system, the soldering process, which has not been a problem so far, has become a big problem. In the conventional pin insertion mounting method, the lead portion is only partially heated in the soldering process, but in the surface mounting method, the entire package is immersed in a heating medium and heated. As the soldering method in the surface mounting method, immersion in a solder bath, heating with a saturated vapor of an inert gas (vapor phase method), infrared reflow method, etc. are used. In either method, the entire package is heated to a high temperature of 210 to 270 ° C. It will be heated. Therefore, the package sealed with the conventional sealing resin has a problem that the resin part is cracked during soldering or peeling occurs between the chip and the resin, which reduces reliability and cannot be used as a product. Occurs.

The occurrence of cracks in the soldering process is
It is said that moisture absorbed between the post-curing and the mounting process explosively vaporizes and expands during soldering heating.As a countermeasure against this, the post-cured package is completely dried and sealed. The method of storing and shipping is used.

Various improvements have been made to the sealing resin. For example, a method of blending a phenol aralkyl resin as a curing agent (JP-A-59-67660) and a method of blending a trifunctional phenol-based curing agent (JP-A 1-1712).
No. 32) is proposed.

On the other hand, when a semiconductor is sealed with an epoxy resin, the coefficient of linear expansion of the epoxy resin is considerably larger than that of the semiconductor, so that thermal stress is applied to the semiconductor element due to temperature changes, which causes aluminum wiring. There is a problem in that the current is leaked by sliding, or cracks are generated in the passivation film or the sealing resin itself, which lowers reliability.

In order to solve this problem and reduce the stress of the sealing resin, it is necessary to lower the linear expansion coefficient of the sealing resin,
It is effective to lower the elastic modulus.

In order to reduce the linear expansion coefficient of the sealing resin,
A method of selecting the type of filler and a method of highly filling the filler are known.

Further, in order to lower the elastic modulus of the sealing resin, it is effective to add an elastomer component. For example, a method of adding silicone rubber, carboxyl group-modified nitrile rubber, polystyrene block copolymer, etc. JP-A-60-18145, JP-A-58-21921
No. 8, JP-A-59-96122, JP-A-58.
-108220, JP-A-59-75922, JP-A-60-1220).

[0012]

However, the method of enclosing the dry package in the container has a drawback that the manufacturing process and the handling work of the product are complicated and the product price is high.

Further, resins improved by various methods have been gradually effective, but they are still insufficient. A method of blending a phenol aralkyl resin as a curing agent (JP-A-59-67660) and a method of blending a trifunctional phenolic curing agent (JP-A 1-1712).
No. 32) is effective in preventing cracks in the resin portion during soldering, but when a large chip is used, there is a problem in that the interface between the chip and the resin peels off and moisture resistance reliability decreases.

On the other hand, in order to lower the elastic modulus of the sealing resin, a method of lowering the stress of the epoxy resin by adding an elastomer component (Japanese Patent Publication No. Sho 60-18145,
JP-A-58-219218, JP-A-59-961
No. 22, JP-A-58-108220, JP-A-59-75922, and JP-A-60-1220), increase of the addition amount causes mold stains and deterioration of fluidity. Therefore, the addition amount was limited, and sufficient stress reduction could not be achieved.

The object of the present invention is to solve the problem of peeling of the interface between the chip and the resin, which occurs in the soldering process, of the package using such a large chip, and the reliability is not deteriorated.
It is an object of the present invention to provide an epoxy resin composition for semiconductor encapsulation, which is small in thermal stress applied to a semiconductor element due to temperature change, that is, excellent in solder heat resistance, moisture resistance reliability and low stress resistance.

[0016]

Means for Solving the Problems The present inventors have found that the addition of a curing agent having a specific structure achieves the above-mentioned object and that an epoxy resin composition meeting the purpose can be obtained. The invention was reached.

That is, the present invention relates to an epoxy resin (A),
An epoxy resin composition comprising a curing agent (B) and a filler (C), wherein the curing agent (B) has the following general formula (I):

[Chemical 2] (In the formula, R ^{1 to} R ⁶ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, a phenyl group, a benzyl group or a cyclohexyl group. R ¹ and R ² are hydrogen atoms, and R ¹ and R ² are methyl groups and R ^{3 to} R ⁶ are hydrogen atoms, except for a phenol compound (b) having a skeleton represented by It is an epoxy resin composition for semiconductor encapsulation, which is contained as an essential component, and the proportion of the filler (C) is 70 to 95% by weight of the whole.

The structure of the present invention will be described in detail below.

The epoxy resin (A) in the present invention is 1
Although it is not particularly limited as long as it has two or more epoxy groups in the molecule, a polyglycidyl ether type epoxy resin of polyfunctional phenol is usually used. Specific examples of the polyglycidyl ether type epoxy resin of polyfunctional phenol include various novolak type epoxy resins such as cresol novolac type epoxy resin and phenol novolac type epoxy resin, bisphenol A type epoxy resin, and bisphenol F type epoxy resin. Of these epoxy resins, a cresol novolac type epoxy resin is usually preferably used from the viewpoint of moisture resistance reliability, heat resistance and productivity.

In the present invention, the epoxy resin (A) has the following general formula (II)

[Chemical 3] (Wherein R ^{7 to} R ¹⁴ represent a hydrogen atom, a C _{1 to} C ₄ lower alkyl group or a halogen atom), and an epoxy resin (a ₁ ) represented by the following general formula (III)

[Chemical 4] (However, two of R ¹⁵ to R ²² is a 2,3-epoxypropoxy group and the remainder is a hydrogen atom, a lower alkyl group or a halogen atom C ₁ ~C _4.) Epoxy resin represented by It is more preferable to contain one or both of (a ₂ ) as an essential component. Epoxy resin (a ₁ )
Further, by containing an epoxy resin having a bifunctional and rigid skeleton such as (a ₂ ), the effect of preventing the occurrence of cracks in the soldering process is further improved.

Preferred specific examples of the epoxy resin (a ₁ ) in the present invention include 4,4'-bis (2,3-epoxypropoxy) biphenyl and 4,4'-bis (2,3).
-Epoxypropoxy) -3,3 ', 5,5'-tetramethylbiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3', 5,5'-tetramethyl-2
-Chlorobiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'-tetramethyl-
2-bromobiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'-tetraethylbiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3, 3 ', 5,5'-tetrabutylbiphenyl and the like can be mentioned, and 4,4'-bis (2,3-epoxypropoxy) biphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 Particularly preferred is', 5,5'-tetramethylbiphenyl.

Further, preferred specific examples of the epoxy resin (a ₂ ) in the present invention include 1,5-bis (2,3-epoxypropoxy) naphthalene and 1,5-
Bis (2,3-epoxypropoxy) -7-methylnaphthalene, 1,6-bis (2,3-epoxypropoxy)
Naphthalene, 1,6-bis (2,3-epoxypropoxy) -2-methylnaphthalene, 1,6-bis (2,3-
Epoxypropoxy) -8-methylnaphthalene, 1,6
-Bis (2,3-epoxypropoxy) -4,8-dimethylnaphthalene, 2-bromo-1,6-bis (2,3-)
Epoxypropoxy) naphthalene, 8-bromo-1,6
-Bis (2,3-epoxypropoxy) naphthalene,
2,7-bis (2,3-epoxypropoxy) naphthalene and the like, 1,5-bis (2,3-epoxypropoxy) naphthalene, 1,6-bis (2,3-epoxypropoxy) naphthalene, 2 , 7-Bis (2,3-epoxypropoxy) naphthalene is particularly preferred.

The ratio of the epoxy resins (a ₁ ) and (a ₂ ) contained in the epoxy resin (A) is not particularly limited, but in order to exert a more sufficient effect, the epoxy resin (a ₁₎ ), (A ₂ ) in epoxy resin (A)
It is preferable to contain 0% by weight or more.

In the present invention, the compounding amount of the epoxy resin (A) is usually 4 to 20% by weight, preferably 5 to 15% by weight.
Is. If the content of the epoxy resin (A) is less than 4% by weight, moldability and adhesiveness are insufficient, and if it exceeds 20% by weight, the coefficient of linear expansion becomes large and it becomes difficult to reduce stress, which is not preferable.

The curing agent (B) in the present invention has the above formula
It is important to contain the phenol compound (b) represented by (I) as an essential component. Phenolic compound (b)
If it does not contain, the effect of improving the solder heat resistance and the effect of improving the moisture resistance reliability cannot be exhibited.

Preferred specific examples of the phenol compound (b) in the present invention include 4,4 '-(1-α-methylbenzylidene) bisphenol and 4,4'-(1-methylethylidene) bis (2-methylphenol). ), 4, 4
′ -Ethylidene bisphenol, 4,4′-cyclohexylidene bisphenol, 4,4 ′-(1-α-methylbenzylidene) bis (2-methylphenol), 4,4
′-(1-Methylethylidene) bis (2-allylphenol), 4,4 ′-(1-α-methylbenzylidene) bis (2-ethylphenol), 4,4 ′-(1-methylethylidene) bis ( 2-phenylphenol), 4,4
′-(1-α-Methylbenzylidene) bis (2-phenylphenol), 4,4 ′-(1-α-methylbenzylidene) bis (2-t-butylphenol), 4,4′-
(1-α-methylbenzylidene) bis (2-allylphenol), 4,4 ′-(cyclohexylidene) bis (2
-Methylphenol), 4,4 '-(cyclohexylidene) bis (2-allylphenol), 4,4'-(cyclohexylidene) bis (2-phenylphenol) and the like, and 4,4'- (1-α-Methylbenzylidene) bisphenol, 4,4 ′-(1-methylethylidene) bis (2-methylphenol), 4,4′-ethylidenebisphenol, and 4,4′-cyclohexylidenebisphenol are preferable. Among them, 4,4 '-(1-methylethylidene) bis (2-methylphenol), 4,
4'-ethylidene bisphenol, 4,4 '-(1-α
-Methylbenzylidene) bisphenol and 4,4'-cyclohexylidenebisphenol are preferred, and 4,4 '-(1-methylethylidene) bis (2
-Methylphenol) and 4,4'-ethylidene bisphenol.

Further, as the curing agent (B) in the present invention, it is preferable to use a polyfunctional curing agent other than the above-mentioned phenol compound (b) as a crosslinking agent. Examples of the curing agent that can be used in combination include, for example, phenol novolac resin, cresol novolac resin, and the following general formula (IV)

[Chemical 5] (In the formula, R may be the same or different and each represents a hydrogen atom, an allyl group or a C ₁ -C ₄ alkyl group. M represents an integer of 0 or more.), A phenol compound represented by the formula: (V)

[Chemical 6] (In the formula, R ′ may be the same or different and each represents a hydrogen atom, a C _{1 to} C ₄ alkyl group or an aryl group, and n represents an integer of 0 or more.), Examples thereof include acid anhydrides such as maleic anhydride, phthalic anhydride and pyromellitic anhydride, and aromatic amines such as metaphenylenediamine, diaminodiphenylmethane and diaminodiphenylsulfone. Among them, from the viewpoint of moisture resistance reliability, a phenol novolac resin or a phenol compound (b) represented by the above formula (IV) or the above formula (V) is used.
′) Is preferred.

The ratio of the phenol compound (b) contained in the curing agent (B) is not particularly limited, and the effect of the present invention can be exhibited if the phenol compound (b) is contained as an essential component. In order to exert a sufficient effect, the phenol compound (b) is usually added to the curing agent (B) in an amount of 5
.About.100% by weight, preferably 20 to 80% by weight.

In the present invention, the compounding amount of the curing agent (B) is usually 2 to 10% by weight, preferably 3 to 8% by weight.
Further, the compounding ratio of the epoxy resin (A) and the curing agent (B) is such that the chemical equivalent ratio of (B) to (A) is 0.5 to 1.5, especially from the viewpoint of mechanical properties and moisture resistance reliability. 0.8 ~
It is preferably in the range of 1.2.

Further, in the present invention, the epoxy resin (A)
A curing catalyst may be used to accelerate the curing reaction of the curing agent (B). The curing catalyst is not particularly limited as long as it accelerates the curing reaction, and for example, 2-methylimidazole,
Imidazole compounds such as 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzyl Tertiary amine compounds such as dimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo (5,4,0) undecene-7, zirconium tetra Organometallic compounds such as methoxide, zirconium tetrapropoxide, tetrakis (acetylacetonato) zirconium, tri (acetylacetonato) aluminum and triphenylphosphine, trimethylphosphine,
Examples thereof include organic phosphine compounds such as triethylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine and tri (nonylphenyl) phosphine. Among them, organic phosphine compounds are preferable, and triphenylphosphine is particularly preferably used, from the viewpoint of moisture resistance. Two or more kinds of these curing catalysts may be used in combination depending on the use, and the addition amount thereof is the epoxy resin (A).
The range of 0.1 to 10 parts by weight is preferable with respect to 100 parts by weight.

As the filler (C) in the present invention, fused silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide, antimony oxide, asbestos, glass fiber, etc. Among them, fused silica is particularly preferably used because it has a large effect of lowering the linear expansion coefficient and is effective in reducing stress.

The fused silica referred to herein means an amorphous silica having a true specific gravity of 2.3 or less. The production does not necessarily have to go through the molten state, and any production method can be used. For example, a method of melting crystalline silica, a method of synthesizing from various raw materials, and the like can be mentioned.

The shape and particle size of the fused silica are not particularly limited, but crushed fused silica 99 having an average particle size of 10 μm or less is used.
~ 50 wt% and spherical fused silica having an average particle size of 4 μm or less 1
Fused silica composed of ˜50% by weight is preferably used because the effect of improving solder heat resistance is large. Among them, crushed fused silica having an average particle size of 10 μm or less, particularly 3 μm or more 1
Fractured fused silica of 0 μm or less 99 to 50% by weight, especially 9
9 to 70% by weight and an average particle size of 4 μm or less, particularly 0.1 μm
The average particle size of the spherical fused silica is smaller than the average particle size of the crushed fused silica, and the fused silica of ½ or less is most preferable. It is preferably used. The average particle size as used herein means a particle size (median size) with a cumulative weight of 50%, and when two types of abnormally crushed or spherical fused silica having different average particle sizes are used together, the mixture is crushed or spherical. It means the average particle size of fused silica.

In the present invention, the proportion of the filler (C) is 75 to 95% by weight of the whole from the viewpoint of moldability and low stress. 7 if fused silica is used as the filler (C)
5 to 90% by weight is preferable, and 75 to 88% by weight is particularly preferable.

In the present invention, it is preferable in terms of reliability that the filler is surface-treated in advance with a coupling agent such as a silane coupling agent or a titanate coupling agent. As the coupling agent, silane coupling agents such as epoxysilane, aminosilane, mercaptosilane and the like are preferably used.

In the present invention, a modified styrene block copolymer (E) obtained by copolymerizing or graft-reacting an unsaturated carboxylic acid or its derivative with the styrene block copolymer (D) and / or the styrene block copolymer (E). ) Is preferable in terms of solder heat resistance and moisture resistance reliability.

The styrene block copolymer (D) has an aromatic vinyl hydrocarbon polymer block having a glass transition temperature of usually 25 ° C. or higher, preferably 50 ° C. or higher, and a glass transition temperature of 0 ° C. or lower, preferably -25. Included are linear, radial, and branched block copolymers composed of conjugated diene polymer blocks having a temperature of not higher than 0 ° C. Examples of the aromatic vinyl hydrocarbon include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, 1,3-dimethylstyrene and vinylnaphthalene, and among them, styrene is preferably used.

As the above-mentioned conjugated diene, butadiene,
(1,3-butadiene), isoprene (2-methyl-
1,3-Butadiene), methylisoprene (2,3-dimethyl-1,3-butadiene), 1,3-pentadiene and the like. Among them, butadiene and isoprene are preferably used. The proportion of the aromatic vinyl hydrocarbon polymer block which is the glass phase block in the styrene block copolymer is 10 to 50% by weight, and the proportion of the conjugated diene polymer block which is the rubber phase block is 90 to 50% by weight.
Is preferred. There are many combinations of the glass phase block and the rubber phase block, and any of them may be used, but a triblock copolymer in which the glass phase block is bonded to both ends of the intermediate rubber phase block is preferable. The number average molecular weight of the glass phase block in this case is preferably 3,000 to 150,000,
It is particularly preferably 5000 to 60,000. The number average molecular weight of the rubber phase block is preferably 5,000 to 3.
00000, particularly preferably 10,000 to 150,000
Is.

The styrene block copolymer can be produced by a known living anion polymerization method, but is not particularly limited thereto, and can be produced by a cationic polymerization method or a radical polymerization method. The styrene-based block copolymer also includes a hydrogenated block copolymer in which a part of the unsaturated bonds of the block copolymer described above is reduced by hydrogenation. Here, 25% or less of the aromatic double bonds of the aromatic vinyl hydrocarbon polymer block and 80% or more of the aliphatic double bonds of the conjugated diene polymer block are preferably hydrogenated. Specific preferred examples of the styrene block copolymer include polystyrene / polybutadiene / polystyrene triblock copolymer (S
BS), polystyrene / polyisoprene / polystyrene triblock copolymer (SIS), hydrogenated copolymer of SBS (SEBS) and hydrogenated copolymer of SIS. Among them, SBS hydrogenated copolymer (S
Hydrogenated copolymers of EBS) and SIS are particularly preferably used.

The modified styrenic block copolymer (E) in the present invention is obtained by copolymerizing or graft-reacting an unsaturated carboxylic acid or its derivative with a styrene-based block copolymer, which is usually produced by a graft reaction. . Here, as the unsaturated carboxylic acid, acrylic acid, methacrylic acid, ethacrylic acid, crotonic acid, maleic acid,
Fumaric acid, itaconic acid, citraconic acid and butenedicarboxylic acid are preferably used. Further, as the derivative thereof, alkyl ester, glycidyl ester, acid anhydride, imide and the like are preferably used. Preferred specific examples include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylic acid, diglycidyl itaconic acid, citraconic acid. Diglycidyl ester, butene dicarboxylic acid diglycidyl ester, butene dicarboxylic acid monoglycidyl ester, maleic anhydride, itaconic anhydride, citraconic anhydride, maleic acid imide, N-phenyl maleic acid imide, itaconic acid imide, citraconic acid imide, etc. Of these, glycidyl methacrylate, maleic anhydride, N-phenylmaleic acid imide, and maleic acid imide are preferably used. Two or more of these unsaturated carboxylic acids or their derivatives may be used in combination depending on the application.

The graft reaction amount of the unsaturated carboxylic acid or its derivative is 0.01 to 10% by weight in terms of solder heat resistance.
Is preferred, and 0.05 to 5% by weight is particularly preferred. The term "graft reaction" used herein means that the unsaturated carboxylic acid or its derivative is chemically bonded to the styrene block copolymer.

The modified styrenic block copolymer (E) can be prepared by a known method, for example, a styrene block copolymer and an unsaturated carboxylic acid or a derivative thereof in a molten state or a solution state in the presence of a radical initiator or It can be obtained by graft-reacting an unsaturated carboxylic acid or its derivative with a styrenic block copolymer in the absence. Preferably, it can be produced by melt-kneading at 100 to 350 ° C. using a melt-kneading device such as a single-screw or twin-screw extruder, Banbury mixer, kneader, and roll. Further, when an organic peroxide is added as a radical initiator during the melt-kneading, the graft reaction can be more effectively performed. Examples of the organic peroxide include benzoyl peroxide, 1,1-bis-tert-butylperoxy-3,
3,5-trimethylcyclohexane, n-butyl-4,
4-bis-tert-butyl peroxyvalate, te
rt-butylcumyl peroxide, dicumyl peroxide, tert-butylperoxybenzoate, di-tert-butylperoxide, di (tert-butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5-di ( Examples include tert-butylperoxy) hexane, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3, tert-butylperoxycumene and the like. The addition amount of the organic peroxide is preferably 0.001 to 1 part by weight based on 100 parts by weight of the styrene block copolymer.

The addition amount of the styrene block copolymer (D) and / or the modified styrene block copolymer (E) is 0.1 to 10 in the epoxy resin composition for encapsulating a semiconductor device from the viewpoint of solder heat resistance. % By weight is preferred, 1-6% by weight
Is particularly preferable.

The epoxy resin composition of the present invention includes a halogen compound such as a halogenated epoxy resin, a flame retardant such as a phosphorus compound, a flame retardant aid such as antimony trioxide, a colorant such as carbon black and iron oxide, and a silicone rubber. , Olefin copolymers, modified nitrile rubber, modified polybutadiene rubber, modified silicone oil and other elastomers,
Thermoplastic resins such as polyethylene, long-chain fatty acids, metal salts of long-chain fatty acids, esters of long-chain fatty acids, amides of long-chain fatty acids, mold release agents such as paraffin wax, and crosslinking agents such as organic peroxides are added arbitrarily. can do.

The epoxy resin composition of the present invention is preferably melt-kneaded, for example, by melt-kneading using a known kneading method such as Banbury mixer, kneader, roll, single-screw or twin-screw extruder and cokneader. Manufactured.

[0046]

EXAMPLES The present invention will be specifically described below with reference to examples. In addition,% in an Example shows weight%.

Examples 1 to 19 and Comparative Examples 1 to 8 The components shown in Tables 1, 2, 3, and 4 were dry blended with a mixer in the composition ratios shown in Table 5. The mixture was heated and kneaded for 5 minutes using a mixing roll having a roll surface temperature of 90 ° C., cooled and pulverized to produce an epoxy resin composition for semiconductor encapsulation.

[0048]

[Table 1]

[Chemical 7]

[0049]

[Table 2]

[0050]

[Table 3]

[0051]

[Table 4]

[0052]

[Table 5]

This composition was molded by a low pressure transfer molding method under the conditions of 175 ° C. × 2 minutes and 180 ° C. ×
Post cure was carried out under the condition of 5 hours, and the physical properties of the respective compositions were measured by the following physical property measuring methods.

Solder heat resistance: 160 pin with a chip size of 12 × 12 mm mounted with a simulated element having Al vapor deposited on the surface
20 QFP are molded and post-cured, 85 ℃ / 8
After humidifying at 5% RH for 72 hours, heat treatment was performed in an IR reflow furnace having a maximum temperature of 240 ° C., and the presence or absence of peeling between the chip and the resin interface was examined with an ultrasonic flaw detector. As the failure rate, the rate of QFP in which peeling occurred was determined.

Moisture resistance reliability: Using QFP after solder heat resistance evaluation, under PCT conditions of 121 ° C./100% RH, the time at which the cumulative failure rate becomes 50% when the disconnection of the Al wiring becomes a failure was determined as the life.

Low stress: 160 equipped with a dummy chip
Mold 20 pieces of pinQFP, post cure, -6
The number of cycles in which cracks occurred was determined in a temperature cycle test of 5 ° C to 150 ° C.

Table 6 shows the results of these evaluations.

[0058]

[Table 6]

As shown in Table 6, the epoxy resin compositions (Examples 1 to 19) of the present invention are excellent in solder heat resistance, humidity resistance reliability and low stress resistance. On the other hand, Comparative Examples 1 to 7, in which the curing agent (B) does not contain the curing agent (b),
Solder heat resistance, moisture resistance reliability, and low stress resistance are inferior.

Further, in Comparative Example 8 in which the amount of the filler added is 70% by weight or less, the solder heat resistance and the moisture resistance reliability are improved despite the addition of the curing agent (b) and the styrene block copolymer. Inferior in low stress.

[0061]

The epoxy resin composition for semiconductor encapsulation of the present invention is excellent in solder heat resistance, moisture resistance reliability, and low stress because it contains a bifunctional curing agent having a specific structure. .

Claims (1)

[Claims] 1. An epoxy resin composition comprising an epoxy resin (A), a curing agent (B) and a filler (C),
The curing agent (B) has the following general formula (I): (In the formula, R ^{1 to} R ⁶ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, a phenyl group, a benzyl group or a cyclohexyl group. R ¹ and R ² are hydrogen atoms, and R ¹ and R ² are methyl groups and R ^{3 to} R ⁶ are hydrogen atoms, except for a phenol compound (b) having a skeleton represented by An epoxy resin composition for semiconductor encapsulation, which comprises as an essential component, and the proportion of the filler (C) is 70 to 95% by weight of the whole.