JP2002226552A - Epoxy resin composition and application thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition for a semiconductor sealing material excellent in low warpage, crack resistance and electrical properties for use in sealing a package of such a type as to hold semiconductor chips such as ball grid arrays on a resin substrate, to provide a cured product of the above composition, and to provide a semiconductor device using the above cured product. SOLUTION: This epoxy resin composition is characterized by comprising a curing promoter, an epoxy resin and a curing agent; wherein a phosphine oxide compound is the essential component for the curing promoter, the epoxy resin includes 5-100 wt.% of an epoxy resin of general formula (2), and the curing agent is a bifunctional or higher functional ester-containing compound or ester-containing resin where 10-100 mol% of the hydroxy groups are esterified with aromatic acyl groups.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device in which a semiconductor integrated circuit is sealed with an epoxy resin, and has various physical properties sufficient for the purpose, particularly low moisture absorption and melting of a resin composition. The present invention relates to an epoxy resin composition excellent in flowability and the like and excellent in crack resistance as a whole, a cured product thereof, and a semiconductor device obtained by using the resin composition.

[0002]

2. Description of the Related Art Conventionally, integrated circuits (ICs) and large-scale integrated circuits (LSIs) have been protected from dust and dust in the external atmosphere, malfunctions due to heat, moisture, or light by a sealing material that protects them. Has been put to practical use. As a sealing material, a transition has been made from metal and ceramics to resin sealing in recent years. At present, epoxy resin sealing is mainly used. Particularly, an epoxy resin composition using a phenol resin as a curing agent is often used in view of a balance between cost and physical properties. Encapsulants using these epoxy resin compositions are required to improve not only mechanical properties but also the following problems.

[0003] That is, the problem is that when exposed to the soldering conditions in order to absorb moisture in the outside air, cracks occur due to explosive vaporization of moisture due to high temperatures. As a side reaction at the time of curing, due to partial occurrence of epoxy homopolymerization, the hydroxyl groups of the phenol resin become excessive, resulting in poor moisture resistance and electrical characteristics. The presence of a polymerized portion or an excess phenol resin portion may cause a decrease in mechanical properties. Free metal ions, particularly halogen ions, cause corrosion of metal parts of the semiconductor and electric leakage. And so on. Of these, the ionic impurities are not essential because they are problems of purification and purity of the epoxy resin.
By modifying the resin and suppressing the side reaction, it is possible to sufficiently bring out the physical properties of the original epoxy resin composition.

However, as for the moisture absorption of the resin, as long as the curing reaction is caused by the reaction between the epoxy group and the hydroxyl group, the resin always generates a hydroxyl group as represented by the following reaction formula (5). In addition, the hydrophilicity increases due to the hydroxyl group, and there is a limit in reducing the overall moisture absorption rate even if the basic skeleton is made hydrophobic.

[0005]

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(In the formula, A represents an epoxy residue and B represents a phenol residue.) One method for solving these problems is disclosed in Japanese Patent Application Laid-Open No. Sho 62-53327 filed by Nishikubo et al. A reaction between an epoxy group and an ester group has been proposed. The publication discloses quaternary onium salts and crown ether complexes as preferable catalysts, and further discloses a paper disclosed in the same publication [Organic Synthetic Chemistry, Vol. 49, pp. 218-233 (1991); Addition reaction and its application to polymer synthesis], the yield is shown when using each catalyst as a unit reaction. Up to 91% of tetrabutylammonium chloride
However, the yield is generally low. In addition, if these quaternary onium salts and crown ether complexes remain contained in the resin used as the encapsulant for semiconductor integrated circuits, they not only cause undesired results such as electrical short-circuits, but also cause undesired results. Needless to say, it also causes corrosion of metal parts that come into contact with it, causing serious defects as products.

On the other hand, in a general addition reaction between an epoxy resin and a phenol resin, phosphines such as trialkylphosphines and triarylphosphines, imidazoles, tertiary amines, and the like are used as catalysts. For the purpose, imidazoles and phosphines are frequently used. Of these, imidazoles have a reaction activity, but are liable to cause the epoxy homopolymerization which is a side reaction described above, and the above-mentioned problem is large. On the other hand, phosphines do not have these problems, but have a low curing rate. When imidazoles are used as catalysts in epoxy / ester curing reactions, according to Nishikubo et al., The reaction yield of an addition reaction of an ester group to an epoxy group is about 50%, and the other is a single epoxy resin. Considering that it is a side reaction such as polymerization, it is not a catalyst from which a sufficient cured product can be obtained.

Furthermore, in the follow-up test of the present inventors, when these imidazoles and phosphines are used as a curing catalyst, the ester by the aromatic acyl group in the present invention does not substantially cause a curing reaction of the epoxy resin. I understood. Specifically, gelling usually does not occur for 10 minutes or more in the range of 150 to 200 ° C., which is the temperature used for curing.
In reality, this is a situation in which the resin composition flows out before a cured product is obtained (see a comparative example described later).

Further, the epoxy resin is cured with an ester,
For use as a sealing material for semiconductor integrated circuits, a method has been proposed in which 10 to 90% of a phenol resin is esterified and used as a curing agent (JP-A-9-235451). This method is used to produce ester resin.
The idea of leaving a part of the phenolic hydroxyl group of the phenolic resin, which is the raw material, to form a crosslinked part by the phenol part which is easy to react in the initial stage of curing, and to make the ester group act on the epoxy group by the after-cure. It is based on.

However, the curing catalysts disclosed in the publication are phosphines, imidazoles and diazabicyclos, and phosphines have a sufficient curing catalyst activity for epoxy groups and ester groups as shown in Comparative Examples of the present application. In addition, imidazoles and diazabicyclos, as evident from the previous paper by Nishikubo et al., Frequently undergo epoxy homopolymerization, making it difficult to control the molar ratio between the epoxy group and the functional group of the curing agent. Is also not preferred.

In recent years, as semiconductors have become higher in density and smaller in size, resins, rather than conventional metals, have been increasingly used as substrates for holding semiconductor chips in packages such as ball grid arrays. However, at this time, since the resin sealing is performed only on one surface of the substrate as shown in FIG. 1, the package often warps due to cooling and shrinkage after molding. Therefore, in order to reduce the warpage, a semiconductor encapsulant is represented by the formula (2)
Epoxy resin (trade name: EPPN-501,
Nippon Kayaku Co., Ltd.) and a phenolic resin (trade name: MEH-7500, Meiwa Kasei) represented by (chemical formula 7), an epoxy resin represented by formula (3) (chemical formula 8) (trade name: Epicoat 1031S, made of Yuka Shell Epoxy,
Etc.) and 4,4 ', 4 ", 4'"-(1,2-ethanedylidene) tetrakisphenol resin (trade name: Tecp-
E, manufactured by Honshu Chemical Co., Ltd.), formula (4) (chemical formula 9)
The combination of an epoxy resin (trade name: VG3101, manufactured by Mitsui Chemicals, Inc.) and a trisphenol resin (trade name: Tris PPA, manufactured by Honshu Chemical Co., Ltd.) is often used. These methods raise the glass transition point of the cured product above the molding temperature by increasing the number of reaction points between the epoxy group and the phenolic OH group, and consequently reduce the shrinkage accompanying cooling after molding below the glass transition point. The object is to reduce the warpage of the package by performing the process in the low linear expansion coefficient region (α1).

[0012]

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[0013]

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[0014]

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[0015]

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However, even when such a resin is used, the number of reaction points eventually increases, the strength of the molded product increases, and the flexibility is lost. . Accordingly, in addition to the above-mentioned problems (1) and (2), package warpage is large for such a package sealing material. There is a problem to be improved.

[0017]

SUMMARY OF THE INVENTION The present invention is directed to a semiconductor encapsulant having low warpage, crack resistance and excellent electrical properties for encapsulating a package in which a semiconductor chip such as a ball grid array is held by a resin substrate. An object of the present invention is to provide an epoxy resin composition, a cured product thereof, and a semiconductor device.

[0018]

Means for Solving the Problems As a result of intensive studies, the present inventors have completed the present invention. That is, the present invention relates to (1) an epoxy containing 5 to 100% by weight of (A) a phosphine oxide compound represented by the general formula (1) and (B) a compound having three or more glycidyl groups. An epoxy resin composition comprising: a resin; (C) a bifunctional or more functional ester-containing compound or an ester-containing resin in which 10 to 100 mol% of hydroxyl groups are esterified by an aromatic and / or aliphatic acyl group. object.

[0019]

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(Wherein, R1 to R6 are a hydrogen atom and a carbon atom of 1)
A linear, branched or cyclic alkyl group of 10 to 10 or an aryl group or aralkyl group having 6 to 10 carbon atoms;
They may all be the same or different. (2) The epoxy resin composition according to (1), wherein the compound having three or more glycidyl groups is a compound represented by the general formula (2).

[0021]

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(Wherein, R1 to R7 are a hydrogen atom, carbon number 1)
A linear, branched or cyclic alkyl group of 10 to 10 or an aryl group or aralkyl group having 6 to 10 carbon atoms;
They may all be the same or different. n
Represents an integer of 0 to 100. (3) The epoxy resin composition according to (1), wherein the compound having three or more glycidyl groups is a compound represented by the following general formula (3).

[0023]

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(Wherein, R1 to R18 represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms or an aryl or aralkyl group having 6 to 10 carbon atoms, all of which are the same). (4) The epoxy resin composition according to (1), wherein the compound having three or more glycidyl groups is a compound represented by the following general formula (4):

[0025]

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(Wherein R1 to R19 represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms or an aryl group or aralkyl group having 6 to 10 carbon atoms, all of which are the same). (5) (D) The organic and / or inorganic filler may be replaced with (B +
C) 100 parts by weight or more, 100 parts by weight, 1900
The epoxy resin composition according to any one of (1) to (4), which is contained in a range of not more than part by weight. (6) A cured epoxy resin obtained by thermally curing the epoxy resin composition according to any one of (1) to (5). (7) A semiconductor device characterized by sealing a semiconductor integrated circuit with the epoxy resin composition according to any one of (1) to (5). (8) The semiconductor device according to (7), which is a ball grid array. About.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin composition of the present invention comprises:
The phosphine oxide compound represented by the above general formula (1) is an essential component as a curing accelerator, and (B) an epoxy resin having 3 or more glycidyl groups as an epoxy resin containing 5 to 100% by weight in the epoxy resin. And (C) an epoxy resin composition containing a bifunctional or more functional ester-containing compound or ester-containing resin.
The epoxy resin composition of the present invention makes it possible to cause an epoxy group and an ester to react quickly and selectively by using the phosphine oxide compound as a curing accelerator. Even when the semiconductor chip such as a ball grid array is held in a resin substrate by solving the problems of the above-mentioned, even if it is used for a package of a type in which cooling after molding does not occur, higher mechanical properties, especially flexibility, are not generated. It is possible to give a cured product having excellent crack resistance and electrical properties.

The phosphine oxide compound (A) represented by the general formula (1), which is a curing accelerator in the epoxy resin composition of the present invention, will be described. General formula (1)
In formula (I), all of the substituents R1 to R6 may be the same or different, and may have a hydrogen atom, a carbon number of 1 to 10
Linear, branched or cyclic alkyl group or carbon number 6
To 10 aryl groups or aralkyl groups.

Specific examples include a hydrogen atom; methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, 1-pentyl, 2-pentyl, 3-pentyl group, 2-methyl-1-butyl group, isopentyl group, tert-pentyl group, 3-methyl-2-butyl group, neopentyl group, n-
Hexyl group, 4-methyl-2-pentyl group, cyclopentyl group, cyclohexyl group, 1-heptyl group, 3-heptyl group, 1-octyl group, 2-octyl group, 2-ethyl-1-hexyl group, nonyl group or Straight chain such as decyl group,
A branched or cyclic alkyl group; an aryl group such as a phenyl group; an aralkyl group such as a toluyl group, a benzyl group, a 1-phenylethyl or a 2-phenylethyl group. Of these, preferred are a methyl group,
An aliphatic hydrocarbon group having 1 to 6 carbon atoms, such as an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group or a cyclohexyl group, more preferably a methyl group or an ethyl group.

Such a phosphine oxide compound is
G. FIG. N. Koian et al. Journal of
General Chemistry of Th
e Can be synthesized by reacting phosphorus oxytrichloride with three molecules of iminotrisamino (unsubstituted, monosubstituted, disubstituted) phosphorane as described in USSR, 55, 1453 (1985). Further, if purification is necessary, it can be purified by a commonly used method such as column chromatography, distillation, recrystallization and the like. The phosphine oxide compound thus obtained is usually a solid.

In the epoxy resin composition of the present invention, the amount of the phosphine oxide compound used as a curing accelerator is
The total weight of the epoxy resin composition (resin component: the sum of the epoxy resin and the curing agent) is in the range of 0.001 to 25% (0.001 to 25 g / 100 g), preferably 0.01 to 15%. % Or less, more preferably 0.1%
It is used in the range of at least 5%. In terms of molar equivalent, 1.5 × 10 ^-6 or more and 4.5 × 10 ^-2 mol / 100 g
Or less, preferably from 1.5 × 10 ^{−5 to} 2.5 × 10 ⁻² mol / 100 g, more preferably from 1.5 × 10 ^{−4 to} 1.0 × 10 ⁻² mol / 100 g. .

Further, in the epoxy resin composition of the present invention, other commonly used curing accelerators other than the phosphine oxide compound, for example, imidazoles such as 2-methylimidazole, phosphines such as triphenylphosphine and the like can be used. The phosphine oxide compound may be used in combination within a range from 0.5% by weight to 500% by weight. If the amount exceeds 500% by weight (5 equivalents), the features of the present invention may be lost.

In the epoxy resin composition of the present invention,
The component (B) is a compound having three or more glycidyl groups, and is, for example, an epoxy resin represented by the general formulas (2), (3) and (4) (hereinafter referred to as an epoxy resin). In the formula, R1 to R18 are the substituents R1 to R6 in the above formula (1).
The same groups can be exemplified. For example, it is commercially available from Nippon Kayaku under the trade name of EPPN-501, Yuka Shell under the trade name of Epikote 1031S, and Mitsui Chemicals under the trade name of VG-3101. The addition amount of the component (B) in the epoxy resin is desirably 5% by weight or more. Still more preferably, 5
0% by weight or more. If it is less than 5% by weight, the effect of reducing the warpage of the package may not be obtained. The epoxy resin other than the component (A) is an epoxy resin having two or more epoxy groups in one molecule, and the epoxy resin has a molecular weight as long as it can be cured with various curing agents as described below. There are no particular restrictions on the structure, molecular weight, etc., and various conventionally known ones can be used. For example, epoxy resins synthesized from various bisphenols such as epichlorohydrin and bisphenol A and novolak resins, alicyclic epoxy resins, epoxy resins into which halogen atoms such as chlorine and bromine are introduced, and the like can be used. Of these, substituted and unsubstituted novolak epoxy resins, biphenyl epoxy resins, and the like are preferably used. The above epoxy resins may be used alone or in combination of two or more.

In the epoxy resin composition of the present invention,
As the curing agent of the component (C), a hydroxyl group of 10 to 100
It is a bifunctional or more functional ester-containing compound or ester-containing resin in which at most mol% is esterified with an aromatic and / or aliphatic acyl group. Specific examples of phenol resins that can be esterified are as follows.

That is, a phenolic resin represented by Chemical Formula 14 (trade name: MEH-7500, manufactured by Meiwa Kasei Co., Ltd.)
4,4 ', 4'',
4 ′ ″-(1,2-ethanedylidene) tetrakisphenol resin, 1- [α-methyl-
α- (4-hydroxyphenyl) ethyl] -4- [α,
α-bis (4-hydroxyphenyl) ethyl] benzene, a novolak resin such as a phenol novolak resin or a cresol novolak resin represented by the general formula (6) (Formula 17); residue obtained by removing the bisphenol compound from the novolak resin (Triphenol or more: hereinafter abbreviated as VR);
Phenol aralkyl resins represented by general formula (7) (formula 18); phenol-dicyclopetadiene copolymer resin (DPR resin) represented by general formula (8) (formula 19); general formula (9) And naphthol aralkyl resins represented by the following formula (20). Among them, a phenol novolak resin represented by the formula (6), 4,4 ′, 4 ″, 4 ′ ″-(1,2-ethanedylidene) tetrakisphenol resin, which can suppress shrinkage after molding to a small extent, -[Α-methyl-α- (4-hydroxyphenyl) ethyl] -4-
[Α, α-bis (4-hydroxyphenyl) ethyl] benzene is preferred.

[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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[0042]

Embedded image [In the formulas (6) to (9), R is a hydrogen atom and has 1 to 10 carbon atoms.
A linear, branched or cyclic alkyl group having 6 to 6 carbon atoms
Represents 10 aryl groups or aralkyl groups, all of which may be the same or different. m represents an integer of 0 to 3 and n represents an integer of 0 to 100]

As a method for esterifying these phenolic resins, known methods are used, and the details are as follows. That is, the esterifying agent used for esterifying the above-mentioned hydroxyl group may be any of organic carboxylic anhydride, organic carboxylic halide, and organic carboxylic acid. What is necessary is just to select suitably according to the characteristic of the esterifying agent according to the carbon number of the ester to be induced. Specific examples of this esterifying agent include benzoic anhydride, benzoic acid chloride, benzoic acid bromide, benzoic acid, o-methylbenzoic acid chloride, m-methylbenzoic acid chloride, p
-Methylbenzoic acid chloride, o-methylbenzoic acid, m
-Methylbenzoic acid, p-methylbenzoic acid, 2,3-dimethylbenzoic acid, 2,4-dimethylbenzoic acid, 2,5-dimethylbenzoic acid, 2,6-dimethylbenzoic acid, 3,4-
Dimethylbenzoic acid, 3,5-dimethylbenzoic acid, acetic anhydride, acetyl chloride, acetyl bromide, acetic acid,
Propionic anhydride, propionic chloride, propionic bromide, propionic acid, butyric anhydride, butyric chloride, butyric acid, valeric anhydride, valeric chloride, citrate bromide, valeric acid, pivalic chloride, pivalic acid, phenylacetic acid, phenylacetic acid Examples thereof include chloride, 2-phenylpropionic acid, 3-phenylpropionic acid, o-tolylacetic acid, m-tolylacetic acid, p-tolylacetic acid, and cumene acid. Among them, preferred are benzoic anhydride and benzoic acid chloride. These esterifying agents can be used alone or in combination of two or more.

The amount used is 10 mol% based on the hydroxyl groups.
The upper limit is not particularly limited, and when the esterification is sufficiently advanced by using the excess, the excess esterifying agent may be removed after the completion of the reaction. From the viewpoints of cost, cost, etc., the molar amount is preferably 10 times or less, preferably 5 times or less, more preferably 3 times or less with respect to the hydroxyl group.

The specific reaction varies depending on the kind of the esterifying agent, but if each is described, the reaction generally used may be used for the organic carboxylic anhydride. That is, after reacting an arbitrary amount of an organic carboxylic acid anhydride to be esterified to a hydroxyl group, the by-product organic carboxylic acid and excess organic carboxylic acid anhydride are distilled under normal pressure, reduced pressure distillation, water washing, and carbonate. The desired ester compound can be obtained by removal by an arbitrary method such as washing with a weak base water, etc., or a combination thereof. When partial esterification is performed, an esterified product obtained by esterifying an arbitrary amount based on the hydroxyl group, that is, 10 mol% or more in the resin composition of the present invention is used. In the case of complete esterification using a product, the upper limit thereof is not particularly limited as long as the solvent is used in an equimolar amount or more with respect to the hydroxyl group. It may be used at a molar ratio of not more than twice. This amount is the same in the case of a reaction using an organic carboxylic acid described later.

In general, the ester reaction is often carried out in the presence of an organic base which is inert to the reaction of pyridine, piperidine, triethylamine or the like.
When the epoxy resin composition of the present invention is used in the electric and electronic fields such as a sealing material for a semiconductor integrated circuit, it is necessary to prevent the nitrogen-containing organic base from remaining. For this reason, it is desirable to finally introduce a washing step. However, the reaction proceeds sufficiently even without using these organic bases, so that it is most desirable not to use an organic base.

The reaction temperature ranges from 60 ° C. to 200 ° C., preferably from 80 ° C. to 180 ° C., particularly preferably 100 ° C.
It is desirable to be in the range of ℃ to 160 ℃. The reaction time largely depends on the type of the reactants and the reaction temperature, but is about 1 hour to 2 hours.
In reality, it is desirable to determine the end point while tracking the disappearance of the esterifying agent, the disappearance of the hydroxyl group, and the like by high performance liquid chromatography, gas chromatography, or the like.

The solvent used in the reaction may or may not be used. If the hydroxyl group-containing substance is sufficiently molten at the reaction temperature and the esterifying agent is liquid, or if it melts at the reaction temperature or if it dissolves in the resin and does not interfere with the reaction, the reaction is carried out without solvent. Should be performed.

If a solvent is required, any solvent which is inert to the reaction can be used. Examples thereof include aromatic hydrocarbons such as benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene and diphenyl ether; N, N-dimethylformamide, N,
Aprotic polar solvents such as N-dimethylacetamide, N-methyl-2-pyrrolidone, N, N-dimethyl-2-imidazolidinone, dimethylsulfoxide, sulfolane, ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether And the like; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and the like can be used alone or in any combination.

The reaction is carried out under normal pressure, pressure (in an autoclave),
Any of reduced pressure may be used.
Any of inert gases such as nitrogen, argon and helium may be used, but preferably under a nitrogen atmosphere.

Next, the reaction when an organic carboxylic acid halide is used as the esterifying agent will be described.
Also in this case, a generally used technique can be used.

That is, an arbitrary amount of an organic carboxylic acid halide to be esterified with a hydroxyl group may be reacted. In this case, the by-produced hydrogen halide is trapped in the system in the presence of a required amount of a base inert to the reaction of pyridine, piperazine, triethylamine, etc., and is discharged out of the system as a gas sequentially and quickly during the reaction. However, it is conceivable that the water is trapped using water or an alkali trap installed outside the reaction system.
In order to avoid the contamination of nitrogen-containing compounds and ionic compounds, a method is preferred in which the hydrogen halide gas is discharged out of the system immediately during the reaction. At this time, it is more preferable to carry out the reaction under a gas flow of a gas which is also inert to the reaction.

When the partial esterification is carried out, the amount of the organic carboxylic acid halide to be used is an arbitrary amount with respect to the hydroxyl group, that is, in the resin composition of the present invention, an esterified product having an esterification of 10 mol% or more is used. Since it is used, an organic carboxylic acid halide of 10 mol% or more is used, and in the case of complete esterification, an equimolar or small excess with respect to the hydroxyl group may be used, and the use of a large excess is not particularly limited. Considering the economic efficiency, the volumetric efficiency of the reaction, and the complexity of the processing steps after the reaction, it is preferable to use the compound in an amount of 10 times or less, preferably 5 times or less, more preferably 3 times or less with respect to the hydroxyl group. Good. The reaction temperature, the use of a solvent in the reaction, and the form of the reaction may be in accordance with the case of the organic carboxylic anhydride.

When an organic carboxylic acid is used as the esterifying agent, an organic carboxylic acid anhydride may be used, but an acid catalyst is required for the reaction. For example, mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and polyphosphoric acid;
Organic sulfonic acids such as p-toluenesulfonic acid, methanesulfonic acid, ethanesulfonic acid, dimethylsulfonic acid, and diethylsulfonic acid; super strong acids represented by trifluoromethanesulfonic acid; and acidic ion exchange resins represented by alkanesulfonic acid type A super-acid type ion exchange resin represented by a perfluoroalkanesulfonic acid type;

The amount of the superacid used is 0.00001-5% by weight, preferably 0.00.05% by weight, based on the weight of the raw material.
001 to 1% by weight, more preferably 0.001 to 0.1
In the range of 1 to 100% by weight, preferably 10 to 50% by weight in the case of ion exchange resins, and 0.01 to 10% by weight, preferably 0.1 to 5% by weight in other cases. Range. If the temperature falls below this range, the reaction rate decreases, and the reaction is not completed in a practical reaction time. On the other hand, if it is larger than this range, the side reaction cannot be ignored, or the cost increases, including the complicated process of removing the catalyst.

The reactions of the three types of esterifying agents have been described above. In any case, if it is necessary to obtain an esterified compound having a higher degree of purification, a water washing step may be introduced after the completion of the reaction. Good. In that case, toluene,
Washing may be performed using a water-washable solvent such as xylene, methyl isobutyl ketone, methyl ethyl ketone, or ethyl acetate until the washing wastewater is free of acidic components and ionic impurities.

In the present invention, the esterification ratio is in the range of 10 to 100 mol%, preferably 50 to 100 mol%, more preferably 80 to 100 mol%, and still more preferably 90 to 100 mol%. More than 100
Mol% or less.

The esterified product having an esterification ratio of 10 to 100 mol% obtained as described above can be used as a curing agent for an epoxy resin in the same manner as a conventional phenol resin. In other words, by using as a curing agent for bifunctional or higher epoxy resin,
It can be used in the same field as a thermosetting resin like a conventional epoxy-phenol cured product.

The mixing ratio of the epoxy resin and the curing agent is such that the ester group or the total of the ester group and the hydroxyl group is 1 mole equivalent of the epoxy group, that is, the active group for the epoxy group is 0.5 to 1.5 mole equivalent. , Preferably in the range of 0.7 to 1.3 molar equivalents, and more preferably used by adjusting the molar ratio at which the optimum physical properties of the cured product are obtained.

In the epoxy resin composition of the present invention,
If necessary, an organic and / or inorganic filler and other additives may be added to the epoxy resin composition as the component (C). In particular, when used as an encapsulant for semiconductor integrated circuits, use organic and / or inorganic fillers to improve the mechanical properties and reduce the overall cost, and colorants such as carbon black to prevent malfunction due to light. It is desirable to use a release agent, a coupling agent, a flame retardant, and the like.

The amount of the organic and / or inorganic filler used is in the range of 100 parts by weight or more and 1900 parts by weight or less based on 100 parts by weight of (A + B), and is preferably from the viewpoint of moisture resistance and mechanical strength. It is at least 250 parts by weight, more preferably at least 550 parts by weight. Organic and / or inorganic fillers used include, for example, silica, alumina, silicon nitride, silicon carbide, talc, calcium silicate,
Examples thereof include powders such as calcium carbonate, mica, clay, and titanium white; and fibrous bodies such as glass fiber, carbon fiber, and aramid fiber. Among these, crystalline silica and / or fused silica are preferred for use as a sealing material. Further, in consideration of fluidity during molding of the resin composition, the shape is spherical or spherical and irregular. Mixtures are desirable.

In the epoxy resin composition of the present invention, it is preferable to add various additives in consideration of mechanical strength and heat resistance. For example, it is desirable to use a coupling agent in order to improve the adhesion between the resin and the inorganic filler, and examples of such a coupling agent include silane-based, titanate-based, aluminate-based, and zirco-aluminate-based. Can be. Among them, a silane coupling agent is preferable, and a silane coupling agent having a functional group that reacts with an epoxy group is most preferable.

Examples of such a coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, N
-(2-aminomethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-anilinopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxy Silane and the like can be mentioned, and these can be used alone or in combination of two or more. It is desirable that these coupling agents are fixed on the surface of the inorganic filler by adsorption or reaction in advance.

As a method for sealing a semiconductor integrated circuit using the epoxy resin composition of the present invention to produce a semiconductor device, low-pressure transfer molding can be said to be the most common method, but other methods, such as injection molding, can be used. , Compression molding, casting, etc. are also possible, and special methods such as using a solvent are also possible.

The warpage of the semiconductor device after molding is desirably as small as possible because it is difficult to make a contact when the semiconductor device is mounted on a substrate. Specifically, the amount of warpage per semiconductor device is desirably 50 μm or less. As a method of measuring the warpage, as shown in FIG. 3, it is common to measure several semiconductor devices which are molded at once.

[0066]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. (Curing Agent Synthesis Example 1) A phenolic resin represented by Chemical Formula 21 (trade name: MEH-7500, hydroxyl equivalent 97 g / eq) was placed in a glass container equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser. : Nippon Kayaku Co., Ltd.) 291 g (l
mol) and 1500 g of toluene, and the internal temperature was 100
The temperature was raised to ° C., and the mixture was stirred in a slurry. While maintaining the internal temperature at the same temperature, while stirring, 464.0 g of benzoic acid chloride.
(3.3 mol) was added dropwise over 4 hours. Thereafter, the temperature was gradually raised, and the reaction was carried out for 8 hours under reflux of toluene. Hydrochloric acid by-produced by the reaction was quickly released out of the system by a nitrogen stream, and neutralized by an alkali trap. Add 1000 g of toluene to the reaction solution, and add 1%
Washed with 2500 g of aqueous sodium carbonate solution. Then, after washing with hot water at 60 to 70 ° C. until the waste water becomes neutral, toluene is distilled off under conditions of a maximum of 150 ° C./5 mmHg to remove a compound having a completely benzoylated hydroxyl group in 508.
g was obtained. The hydroxyl equivalent of this compound was 3000 g / eq or more (not detectable).

[0067]

Embedded image

(Synthesis Example 2 of Curing Agent) In a glass container equipped with a thermometer, a stirrer, a dropping funnel and a reflux condenser,
4 ', 4 ", 4'"-(1,2-ethanedilidene) tetrakisphenol resin (trade name: Tecp-E, hydroxyl equivalent 102 g / e)
q: 408 g (1 mol) of Honshu Chemical Co., Ltd.) and 1500 g of toluene were charged, the internal temperature was raised to 100 ° C., and the mixture was stirred in a slurry. While maintaining the internal temperature at the same temperature, while stirring, 464.0 g (3.3 mol) of benzoic acid chloride.
Was added dropwise over 4 hours. Thereafter, the temperature was gradually raised, and the reaction was carried out for 8 hours under reflux of toluene. Hydrochloric acid by-produced by the reaction was quickly released out of the system by a nitrogen stream, and neutralized by an alkali trap. Toluene 10
An additional 00 g was added, and the mixture was washed at 700 ° C. with 2500 g of a 1% aqueous sodium carbonate solution. Thereafter, hot water was washed at 60 to 70 ° C. until the waste water became neutral, and toluene was distilled off under conditions of a maximum of 150 ° C./5 mmHg to obtain 728 g of a compound in which hydroxyl groups were completely benzoylated. The hydroxyl equivalent of this compound was 3000 g / eq or more (not detectable). (Curing agent synthesis example 3) 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] -4- was placed in a glass container equipped with a thermometer, stirrer, dropping funnel and reflux condenser.
[Α, α-bis (4-hydroxyphenyl) ethyl] benzene (trade name: Tris PPA, hydroxyl equivalent 141 g / eq: manufactured by Honshu Chemical Co., Ltd.) 424 g (1 mol), toluene 1500 g
Was charged, the internal temperature was raised to 100 ° C., and the mixture was stirred in a slurry state. While maintaining the internal temperature at the same temperature, 464.0 g (3.3 mol) of benzoic acid chloride was added dropwise over 4 hours while stirring. Thereafter, the temperature was gradually raised, and the reaction was carried out for 8 hours under reflux of toluene. Hydrochloric acid by-produced by the reaction
It was quickly released from the system by a nitrogen stream and neutralized by an alkali trap. 1000 g of toluene was added to the reaction solution, and 2500 g of a 1% aqueous solution of sodium carbonate was added at 700 ° C.
And washed. Then 60-70 ° C until the wastewater becomes neutral
After washing with hot water in
The residue was distilled off under the condition of mmHg to obtain 728 g of a compound in which hydroxyl groups were completely benzoylated. The hydroxyl equivalent of this compound was 3000 g / eq or more (not detectable). Example 1 An epoxy resin represented by the general formula (2) (R1
R7 is a hydrogen atom in all epoxy resins (trade name: EPPN-501, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 1)
167 parts by weight (67 g / eq) and 206 parts by weight of the phenol benzoylated resin (ester equivalent: 206 g / eq = calculated value) obtained in Synthesis Example 1 as a curing agent were sufficiently melt-kneaded at 80 ° C. to obtain a uniform resin mixture. did. In the resin mixture, R1 of the general formula (1) is used as a curing accelerator.
A phosphine oxide compound (PZO) in which R6 is all methyl groups was added in an amount of 0.0055 mol and kneaded at 50 ° C. for 1 minute to obtain a resin composition.

A filler and other additives were blended in the following proportions with 200 g of the resin composition, and heated and kneaded with a roll to obtain a molding material for a sealing material. Inorganic filler: 720 parts by weight [50 parts by weight of spherical fused silica (Halimic S-CO, manufactured by Micron Corporation) and 50 parts by weight of amorphous fused silica (Huzrex RD-8, manufactured by Tatsumori) Parts mixture] Silane coupling agent: 62 parts by weight (SZ-608
3, manufactured by Toray Dow Corning Silicone Co., Ltd.) Carnauba wax: 45 parts by weight Carbon black: 3 parts by weight Antimony oxide: 10 parts by weight A part of this molding material was used, and 150 ° C. → 185 ° C./5 m
After obtaining a cured product under the conditions of 150 kg / cm ² at 185 ° C./5 min, 185 ° C./8 hr (nitrogen atmosphere)
After-cure was applied under the conditions described above to sufficiently advance the curing. Each physical property was measured using this cured product. The results are shown in Table 1. The symbols in the table represent the following.

E: Esterification rate PZO: phosphine oxide TPP: triphenylphosphine UDI: 2-undecylimidazole The gel time of the resin composition before kneading the rolls was 150 ° C.
Was measured. (Example 2) Each test was performed in the same manner as in Example 1, except that 50% by weight of the epoxy resin was changed to biphenyl epoxy (trade name: YX-4000, manufactured by Yuka Shell Epoxy). The results are shown in Table 1. (Example 3) The epoxy resin in Example 1 was replaced with a tetraphenylolethane type epoxy resin (trade name: Epicoat 10).
31S, Yuka Shell Epoxy, epoxy equivalent 205g / e
q), the curing agent was 4,4 ′, 4 ″, obtained in Synthesis Example 2.
Each test was performed in the same manner except that the resin was replaced with 4 ′ ″-(1,2-ethanedylidene) tetrakisphenol benzoylated resin (ester equivalent: 206 g / eq = calculated value).
The results are shown in Table 1. (Example 4) Each test was carried out in the same manner as in Example 3, except that 50% by weight of the epoxy resin was changed to biphenyl epoxy (trade name: YH-4000, manufactured by Yuka Shell Epoxy). The results are shown in Table 1. (Example 5) The epoxy resin in Example 1 was replaced with 1- [α-
Methyl-α- (4-hydroxyphenyl) ethyl] -4
-[Α, α-bis (4-hydroxyphenyl) ethyl]
Glycidylated benzene (trade name: VG-3101, manufactured by Mitsui Chemicals, epoxy equivalent 210 g / eq), and a curing agent, 1- [α-methyl-α- (4-hydroxyphenyl) ethyl obtained in Synthesis Example 3 ] -4- [α, α-bis (4-hydroxyphenyl) ethyl] benzenebenzoylated resin (ester equivalent 245.3 g / eq = calculated value)
Each test was performed in the same manner. The results are shown in Table 1. (Example 6) Each test was conducted in the same manner as in Example 5, except that 50% by weight of the epoxy resin was changed to biphenyl epoxy (trade name: YH-4000, manufactured by Yuka Shell Epoxy). The results are shown in Table 1.

[0071]

[Table 1]

(Comparative Example 1) A resin composition was obtained in the same manner as in Example 1 except that the curing accelerator was changed to 0.015 mol of triphenylphosphine (TPP). A cured product was not obtained. The gel time was also measured at 150 ° C and 200 ° C for 20 minutes.
The test was stopped because no gelling tendency was observed. (Comparative Example 2) A resin composition was obtained in the same manner as in Example 1 except that the curing accelerator was changed to 0.015 mol of 2-undecylimidazole (UDI), and subsequent tests were performed. Nothing was obtained. Also the gel time is 1
The measurement was carried out at 50 ° C. and 200 ° C. for 20 minutes, but the test was stopped because no tendency for gelation was observed. (Comparative Example 3) A phenol resin represented by Chemical Formula 21 (trade name: MEH-7500, hydroxyl equivalent: 97 g / eq: manufactured by Meiwa Kasei Co., Ltd.) in Example 1 was used as a curing agent, and triphenylphosphine was used as a curing accelerator. Each test was performed in the same manner except that (TPP) was changed to 0.015 mol. Table 2 shows the results. (Comparative Example 4) Each test was carried out in the same manner as in Example 1, except that 96% by weight of the epoxy resin was changed to biphenyl epoxy (trade name: YX-4000, manufactured by Yuka Shell Epoxy). Table 2 shows the results. (Comparative Example 5) Except that the curing accelerator in Example 3 was changed to 0.015 mol of triphenylphosphine (TPP),
In the same manner, a resin composition was obtained, and subsequent tests were conducted, but no cured product was obtained. Gel time is also 150
The test was stopped at 20 ° C. and 200 ° C. for 20 minutes because no gelling tendency was observed.

[0073]

[Table 2]

Comparative Example 6 A resin composition was obtained in the same manner as in Example 3 except that the curing accelerator was changed to 0.015 mol of 2-undecylimidazole (UDI), and the subsequent tests were performed. However, no cured product was obtained. The gel time was also measured at 150 ° C. and 200 ° C. for 20 minutes, but the test was stopped because there was no tendency for gelation. (Comparative Example 7) The curing agent in Example 3 was changed to 4,4 ′,
4 '', 4 '''-(1,2-ethanedilidene) tetrakisphenol resin (trade name: Tekp-E, hydroxyl equivalent 102g / e
q: manufactured by Honshu Chemical Co., Ltd.), and each test was performed in the same manner except that the curing accelerator was changed to 0.015 mol of triphenylphosphine (TPP). The results are shown in Table-3. (Comparative Example 8) Each test was performed in the same manner as in Example 3 except that 96% by weight of the epoxy resin was changed to biphenyl epoxy (trade name: YX-4000, manufactured by Yuka Shell Epoxy). The results are shown in Table-3. (Comparative Example 9) Except that the curing accelerator in Example 5 was changed to 0.015 mol of triphenylphosphine (TPP),
In the same manner, a resin composition was obtained, and subsequent tests were conducted, but no cured product was obtained. Gel time is also 150
The test was stopped at 20 ° C. and 200 ° C. for 20 minutes because no gelling tendency was observed. (Comparative Example 10) A resin composition was obtained in the same manner as in Example 5 except that the curing accelerator was changed to 0.015 mol of 2-undecylimidazole (UDI), and the subsequent tests were carried out. Nothing was obtained. The gel time was also measured at 150 ° C. and 200 ° C. for 20 minutes, but the test was stopped because there was no tendency for gelation.

[0075]

[Table 3]

(Comparative Example 11) The curing agent in Example 5 was changed to 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] -4- [α, α-bis (4-hydroxyphenyl) ethyl] benzene (Product name: Tris PPA, MW = 424,
Hydroxyl equivalent: 141.3 g / eq: manufactured by Honshu Chemical Co., Ltd.) The curing accelerator is triphenylphosphine (TPP) 0.015.
Each test was performed in the same manner except that the moles were used. The results are shown in Table-3. (Comparative Example 12) Each test was performed in the same manner as in Example 5, except that 96% by weight of the epoxy resin was changed to biphenyl epoxy (trade name: YX-4000, manufactured by Yuka Shell Epoxy). The results are shown in Table-3.

[0077]

[Table 4]

The test methods for various physical properties are as follows. . Tg (glass transition temperature): TMA needle penetration method (Shimadzu TM
A-DRW DT-30). -Flexural strength and modulus: according to JIS K-6911. Boiling water absorption: The weight increase after boiling for 2 hours in boiling water at 100 ° C. was measured. * V. P. S test: The test semiconductor device shown in FIG. 2 was molded and left in a constant temperature and humidity chamber of 85 ° C. and 85% for 168 hours, and immediately thereafter, a Fluorinert solution at 240 ° C. (manufactured by Sumitomo 3M Ltd., FC -70), and the number of semiconductors having cracks in the package resin was counted. The test value is shown as a fraction, and the numerator is the number of semiconductors with cracks,
The denominator is the number of subjects. Package warpage: A package as shown in FIG. 2 was molded, and the warpage was measured by a method as shown in FIG. As described above, the phosphine oxide compound is an essential component as a curing accelerator of the present invention, and a glycidyl group represented by the general formula (2), (3) or (4) is 3 to A bifunctional or more ester-containing compound or ester in which 5 to 100% by weight of an epoxy resin having 5 epoxy resins is contained in the epoxy resin and 10 mol% to 100 mol% of hydroxyl groups are esterified by an aromatic acyl group as a curing agent; The epoxy resin composition characterized in that it contains a resin-containing resin and has a large hygroscopic property and excellent flexibility as compared with a conventional epoxy resin-phenol resin cured product, and has a crack resistance and a low resistance. Very advantageous in warpage. For this reason, it can be seen that it is excellent in crack resistance and low warpage especially in a sealing material for a package in which a semiconductor chip such as a ball grid array is held by a resin substrate.

When triphenylphosphine (TPP), a conventional curing accelerator, was used, Comparative Examples 1 and 2
As shown in 6, 7, 11, and 12, it can be seen that triphenylphosphine does not cause a curing reaction of a portion esterified by an aromatic acyl group. This indicates that an esterified curing agent and a phosphine oxide compound are essential components for obtaining high physical properties as a sealing material in the present invention.

[0080]

The epoxy resin composition obtained by the present invention can be used in industrial fields where epoxy resin compositions have conventionally been used. Particularly, a semiconductor chip such as a ball grid array is held by a resin substrate. When used as a sealing material for a package of a type, a package excellent in crack resistance and low warpage can be provided as compared with a conventional epoxy resin-phenol resin cured product.

[Brief description of the drawings]

FIG. 1 is an example of a cross-sectional view of a BGA package.

FIG. 2 is a schematic diagram of a package for measuring warpage.

FIG. 3 is a conceptual diagram of a package warpage measuring method.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/29 H01L 23/30 R 23/31 F term (Reference) 4J002 CD041 CD061 CD071 CL062 DA016 DE146 DE236 DJ006 DJ016 DJ036 DJ046 DJ056 DL006 FA042 FA046 FD012 FD016 4J036 AA02 AC03 AE05 AF06 AJ14 DD07 FA01 FB08 JA07 4M109 AA01 BA03 CA21 EA04 EB03 EB04 EC03 EC04 EC07

Claims (8)

[Claims] 1. A phosphine oxide compound represented by the following general formula (1):
An epoxy resin containing 5 to 100% by weight of a compound having at least one compound, (C) a bifunctional or more functional ester-containing compound in which 10 to 100 mol% of hydroxyl groups are esterified with an aromatic and / or aliphatic acyl group, or An epoxy resin composition comprising an ester-containing resin. Embedded image (Wherein, R1 to R6 are a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms or a carbon atom having 6 to 1 carbon atoms)
0 represents an aryl group or an aralkyl group, which may be the same or different. ) 2. The compound having three or more glycidyl groups is a compound represented by the general formula (2).
The epoxy resin composition described in the above (Wherein, R1 to R7 are a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms or a carbon atom having 6 to 1 carbon atoms)
0 represents an aryl group or an aralkyl group, which may be the same or different. n is 0 to 100
Represents an integer. ) 3. The compound having three or more glycidyl groups is a compound represented by the general formula (3).
The epoxy resin composition described in the above (Wherein, R1 to R18 represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms or a carbon atom having 6 to 1 carbon atoms)
0 represents an aryl group or an aralkyl group, which may be the same or different. ) 4. The compound having three or more glycidyl groups is a compound represented by the general formula (4).
The epoxy resin composition described in the above (Wherein, R1 to R19 represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms or a carbon atom having 6 to 1 carbon atoms)
0 represents an aryl group or an aralkyl group, which may be the same or different. ) 5. (D) 100 parts by weight or more of an organic and / or inorganic filler per 100 parts by weight of (B + C);
The epoxy resin composition according to any one of claims 1 to 4, wherein the content is not more than 900 parts by weight. 6. An epoxy resin cured product obtained by thermally curing the epoxy resin composition according to claim 1. 7. A semiconductor device, wherein a semiconductor integrated circuit is encapsulated with the epoxy resin composition according to claim 1. 8. The semiconductor device according to claim 7, wherein the semiconductor device is a ball grid array.