JP2008081683A - Epoxy resin composition, semiconductor sealing epoxy resin composition, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition capable of being cured into a product of reduced modulus, to provide a semiconductor sealing epoxy resin composition using the same, and to provide a semiconductor device of excellent reliability. <P>SOLUTION: What is disclosed is an epoxy resin composition comprising (A) a compound having two or more epoxy groups in the molecule, (B) a compound having two or more phenolic hydroxyl groups in the molecule, and (C) a monofunctional (monohydric) phenolic compound, an epoxy resin composition wherein the monofunctional phenolic compound (C) is one having a pKa value of 7.5-9.8, a semiconductor sealing epoxy resin composition further containing an inorganic filler (D) in addition to the epoxy resin composition, and a semiconductor device formed by sealing an electronic component with a cured product of the semiconductor sealing epoxy resin composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition, an epoxy resin composition for semiconductor encapsulation, and a semiconductor device.

  Many attempts have been made to lower the elastic modulus of the epoxy resin composition for semiconductor encapsulation for the purpose of improving the reliability of the semiconductor package. It is known that the epoxy resin for semiconductor encapsulation causes peeling due to the difference in coefficient of linear expansion between each other at the interface with the metal frame or other resin substrate as the base material, causing a semiconductor defect. Yes. As countermeasures, methods such as reducing the elastic modulus of the resin to relieve stress generated at the interface and inside the molded product, and improving the filler ratio to reduce the difference in linear expansion coefficient are known. It has been.

  As a technique for reducing the elastic modulus, use of a low stress agent is common. A technique for adding a high molecular weight silane component, a thermoplastic oligomer, or the like as a low stress agent is known (for example, see Patent Documents 1 and 2). The stress agent itself oozes out from the resin and causes mold stains, and there are moldability problems due to an increase in the melt viscosity of the resin composition.

  Also known is a method of obtaining a cured product having a low elastic modulus by lowering the degree of curing of the resin with a specific curing accelerator. As such a curing accelerator, an adduct of triarylphosphine and quinones is typical, but a cured product using these accelerators has many unreacted functional groups and has a bad influence on water absorption. May give. Moreover, the control of the elastic modulus of the cured product is very difficult, and the desired elastic modulus may not be obtained.

  Furthermore, a technique of mixing a curable resin component having liquid crystallinity and causing phase separation in the system after curing to form a sea-island structure having islands with a low elastic modulus (see, for example, Patent Document 3) is also disclosed. However, there is a problem that the degree of freedom in selecting the resin and the mixing ratio of the composition components is low, and it is not always possible to obtain a desired elastic modulus, and it is necessary to use an expensive raw material in terms of cost.

  On the other hand, a technique for imparting adhesiveness and flexibility using allylnaphthol has been disclosed (for example, see Patent Document 4). In this technique, allyl groups constituting the allylnaphthol compound are bonded to each other. It is a technology to improve the crosslink density by reaction, and it is the opposite of the approach of reducing the elastic modulus of the cured product, so depending on the properties of the resin used, the resin cured product becomes brittle due to overcrowding of the crosslink density Reliability could be adversely affected.

JP 2001-288336 A (page 1-3) JP 2001-207021 (page 1-3) JP-A-9-194687 (page 1-2) JP-A-7-138201 (page 2-3)

  An object of the present invention is to provide an epoxy resin composition capable of reducing the elastic modulus of a cured product, an epoxy resin composition for semiconductor encapsulation using the same, and a semiconductor device having excellent reliability.

That is, the present invention
(1) An epoxy resin composition comprising a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and a monofunctional phenol compound (C),
(2) The epoxy resin composition according to item (1), wherein the monofunctional phenol compound (C) has a pKa value of 7.5 to 9.8.
(3) The epoxy resin composition according to (1) or (2), wherein the monofunctional phenol compound (C) is a compound represented by the following general formula (1):

［式中、Ｒ₁およびＲ₈は、いずれか一方が水酸基であり、もう一方は水素原子、炭素数１〜８の炭化水素基及びハロゲン基から選ばれるものである。Ｒ₂〜Ｒ₇は、水素原子、炭素数１〜８の炭化水素基及びハロゲン基から選ばれるものであり、これらは同一又は異なるものである。］

[In the formula, _one of R ₁ and R ₈ is a hydroxyl group, and the other is selected from a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, and a halogen group. R _{2 to} R ₇ are selected from a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, and a halogen group, and these are the same or different. ]

(4) An epoxy resin composition for semiconductor encapsulation, further comprising an inorganic filler (D) in the epoxy resin composition according to any one of items (1) to (3),
(5) The epoxy resin composition for semiconductor encapsulation according to item (4), wherein the inorganic filler (E) is contained in the semiconductor epoxy resin composition in an amount of 50 to 95% by weight,
(6) A semiconductor device in which an electronic component is sealed with a cured product of the epoxy resin composition for sealing a semiconductor according to (5),
It is.

  The epoxy resin composition of the present invention can reduce the elastic modulus of a cured product, and a semiconductor device obtained from an epoxy resin composition for semiconductor encapsulation containing the epoxy resin composition has excellent solder crack resistance.

  Hereinafter, preferred embodiments of the epoxy resin composition, the epoxy resin composition for semiconductor encapsulation and the semiconductor device of the present invention will be described.

  The epoxy resin composition of the present invention comprises a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and a monofunctional phenol compound (C This can reduce the elastic modulus of the cured product, and is obtained by sealing an electronic component with a cured product of the epoxy resin composition for semiconductor encapsulation containing the epoxy resin composition. The semiconductor device provides excellent reliability.

  The compound (A) having two or more epoxy groups in one molecule used in the present invention is a monomer, oligomer or polymer in general having two or more epoxy groups in one molecule, and its molecular weight and molecular structure are particularly limited. For example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, hydroquinone type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, stilbene type epoxy resin, triphenol Methane type epoxy resin, alkyl-modified triphenol methane type epoxy resin, triazine nucleus-containing epoxy resin, dicyclopentadiene modified phenol type epoxy resin, phenol aralkyl type epoxy resin having phenylene and / or biphenylene skeleton Naphthol-type epoxy resin, copolymerized epoxy resin of naphthols and phenols, naphthalene-type epoxy resin, naphthol aralkyl-type epoxy resin having phenylene and / or biphenylene skeleton, sulfur atom-containing epoxy resin, salicylaldehyde-type epoxy resin, These may be used alone or in combination. Among these, phenol aralkyl type epoxy resins having a phenylene and / or biphenylene skeleton, and naphthol having a phenylene and / or biphenylene skeleton from the viewpoint of excellent reliability of the semiconductor package when used as an epoxy resin for semiconductor encapsulation. It is preferable to use an aralkyl type epoxy resin or the like.

  The compound (B) having two or more phenolic hydroxyl groups in one molecule used in the present invention is not limited as long as it has two or more phenolic hydroxyl groups in one molecule, and an epoxy group in one molecule. It functions as a hardening | curing agent of the compound (A) which has 2 or more.

  The compound (B) having two or more phenolic hydroxyl groups in one molecule includes monomers, oligomers and polymers in general having two or more phenolic hydroxyl groups in one molecule, and its molecular weight and molecular structure are particularly limited. For example, phenol novolak resin, cresol novolak resin, triphenolmethane type phenol resin, terpene modified phenol resin, dicyclopentadiene modified phenol resin, aralkyl type phenol resin, phenol aralkyl resin having phenylene and / or biphenylene skeleton , Naphthol aralkyl resin having phenylene and / or biphenylene skeleton, salicylaldehyde type phenol resin, copolymer type resin of benzaldehyde type phenol resin and aralkyl type phenol resin, bisphenol Compounds, include dihydroxynaphthalene compounds and the like, these are no problem be used singly or in admixture. Of these, phenol aralkyl resins having a phenylene and / or biphenylene skeleton and naphthol aralkyl resins having a phenylene and / or biphenylene skeleton from the viewpoint of excellent reliability of the semiconductor package when used as an epoxy resin for semiconductor encapsulation. Etc. are preferably used.

  The compound (A) having two or more epoxy groups in one molecule and the compound (B) having two or more phenolic hydroxyl groups in one molecule used in the present invention both have two or more reactive groups (epoxy groups, Or a phenolic hydroxyl group), preferably, each compound preferably contains three or more reactive groups, and either one contains three or more reactive groups. It may contain what has. As a specific example, at least one of the compound (A) having two or more epoxy groups in one molecule or the compound (B) having two or more phenolic hydroxyl groups in one molecule is three. It is preferable to contain 30% by weight or more of those having the above reactive groups. For example, in the compound (A) having two or more epoxy groups in one molecule, 70% by weight of a compound having two epoxy groups in one molecule %, And a mixture of 30% by weight of a compound having 3 or more epoxy groups in one molecule. Furthermore, at least one of the compound (A) having two or more epoxy groups in one molecule or the compound (B) having two or more phenolic hydroxyl groups in one molecule is three or more reactive groups. It is more preferable that 40% by weight or more is included. A plurality of these compounds containing three or more reactive groups may be mixed. That is, in the case of the compound (A) having two or more epoxy groups in one molecule, a single compound having three epoxy groups may be used, and three, four, five or more epoxy groups may be formed. It may be a mixture of compounds. Moreover, the sum total of the compound which has 3 or more reactive groups contained in the compound (A) which has 2 or more of epoxy groups in 1 molecule, and the compound (B) which has 2 or more of phenolic hydroxyl groups in 1 molecule is The above ratio may be exceeded.

  In the present invention, the compound (A) having two or more epoxy groups in one molecule or the compound (B) having two or more phenolic hydroxyl groups in one molecule does not have three or more reactive groups. Can be used, but those having 3 or more reactive groups are outside the above range, the crosslink density of the cured resin becomes low, and the monofunctional phenolic compound (C) further reduces the crosslink density and cures. May become insufficient.

  The monofunctional phenol compound (C) used in the present invention is a phenol compound having substantially no reactive substituent other than one phenolic hydroxyl group, and conventionally known compounds can be used. Here, the reactive substituent is a compound (A) having two or more epoxy groups in one molecule and a phenolic in one molecule in the curing reaction of the epoxy resin composition of the present invention and the temperature history of the production process. When a substituent capable of chemically reacting with the compound (B) having two or more hydroxyl groups or the monofunctional phenol compound (C) has the substituent, a chemical reaction occurs between these substituents. Specifically, a substituent that includes a group consisting of an oxirane ring such as an epoxy group or an oxetane group or a group consisting of an oxirane ring, a phenolic hydroxyl group, a thiol group, a carboxyl group, And a group having an active hydrogen atom such as an amino group or a group that reacts with an epoxy group or a phenolic hydroxyl group such as a substituent containing it, a vinyl group, an allyl group, a maleimide group Any such capable of reacting with a substituent group among groups or substituents containing products thereof. These substituents are not suitable for the purpose of the present invention because the crosslink density of the resin is improved by reaction and the elastic modulus cannot be reduced.

  The monofunctional phenolic compound (C) used in the present invention has no reactive substituent other than one phenolic hydroxyl group, thereby effectively reducing the crosslink density of the cured resin and reducing the elastic modulus. can do. The monofunctional phenol compound (C) may have a substituent other than the reactive substituent. Examples of the substituent other than the reactive substituent include an alkyl group, an allyl group, an organic group having an alcoholic hydroxyl group, a halogen group, an oxyalkyl group, an oxyaryl group, an aralkyl group, a nitro group, and an ester group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a tertiary butyl group. Examples of the halogen group include a chloro group, a bromo group, and an iodo group. Examples of the alkyl group include a methoxy group, an ethoxy group, and propoxy. Examples of the aralkyl group include a phenylmethyl group and a phenylisopropyl group. Examples of the oxyaryl group include a phenoxy group and a 1-naphthoxy group. Examples of the organic group having an alcoholic hydroxyl group include hydro Shimechiru group, such as 2-hydroxyethyl group and the like, examples of the ester group, and an organic group represented by organic radicals and the general formula represented by the following general formula (2) (3).

Wherein, R ₉ and R ₁₀ represents a hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group is an organic group composed of carbon atoms and hydrogen atoms, and may be linear, branched or cyclic, and the bond between carbon and carbon is a single bond, It is a double bond or a triple bond. Specific examples include an alkyl group, a cycloalkyl group, an alkylene group, and an aryl group.

  The monofunctional phenol compound (C) used in the present invention is phenol; 2-chlorophenol, 3-chlorophenol, 4-chlorophenol, 2-bromophenol, 3-bromophenol, 4-bromophenol, 2-iodo. Halogen substituted phenol compounds such as phenol, 3-iodophenol, 4-iodophenol, 2,5-dichlorophenol, 2,5-dibromophenol, 2,5-diiodophenol and pentachlorophenol; 2-methylphenol ( Orthocresol), 3-methylphenol (metacresol), 4-methylphenol (paracresol), 2,5-dimethylphenol, 2-ethylphenol, 3-ethylphenol, 4-ethylphenol, 2-propylphenol, 3 -Propylfe Phenol compounds having an alkyl substituent such as 4-propylphenol, 2-butylphenol, 3-butylphenol, 4-butylphenol and 4-tertiarybutylphenol; 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol Phenol compounds having an oxyalkyl substituent such as 2-ethoxyphenol, 3-ethoxyphenol, 4-ethoxyphenol, 2-propoxyphenol, 2,5-dimethoxyphenol and 2,5-diethoxyphenol; Phenol compounds having aryl substituents such as phenol, 3-phenylphenol and 4-phenylphenol; phenol compounds having nitro substituents such as 3-nitrophenol and 4-nitrophenol Phenol compounds having an aralkyl substituent such as 4- (phenylmethyl) phenol (common name: p-benzylphenol) and 4- (phenylisopropyl) phenol (common name: p-cumylphenol); 1-naphthol 1-hydroxyanthracene having a substituent other than the above-mentioned reactive substituents such as 2-naphthol, 2-chloro-1-naphthol and 1-methoxy-2-naphthol, or unsubstituted naphthols; And monohydroxyanthracenes.

  The monofunctional phenol compound (C) used in the present invention can release protons of phenolic hydroxyl groups, and the ease of proton release has a correlation with the reactivity with epoxy groups. As the pKa value indicating the proton releasing property of the monofunctional phenol compound (C) used in the present invention, a phenolic hydroxyl group is present in one molecule as a typical curing agent for a compound having two or more epoxy groups in one molecule. Compared to 9.8 to 10.3 which is a pKa value of a compound having two or more compounds, it is desirable that the value is lower.

  A preferable range of the pKa value of the monofunctional phenol compound (C) is 7.5 or more and 9.8 or less, and more preferably 8.8 or more and 9.5 or less. In this range, the effect of reducing the viscosity reduction at the time of melting of the resin composition and the volatilization of the monofunctional phenol compound (C) becomes the best. Although the pKa value can be used even outside the above range, if it exceeds this range, a monofunctional phenol may be used in the latter half of the curing reaction in which the viscosity of the resin composition cannot be sufficiently reduced or the system temperature is exposed to a high temperature. The compound (C) becomes a volatile component and may cause voids in the cured product. On the other hand, when the pKa value is significantly below this range, such a monofunctional phenolic compound (C) has a very high ability as an acid, which inhibits the curing accelerating action or the epoxy resin composition as a semiconductor. When used as a sealing material, the semiconductor to be sealed may be corroded.

  In the present invention, the pKa value of the monofunctional phenol compound (C) can be measured by a conventionally known method, and literature values can also be used. For example, the monofunctional phenolic compound (C) is adjusted to a dilute aqueous solution, the solution temperature is set to 25 ° C., and a strong alkaline aqueous solution such as an aqueous sodium hydroxide solution is added until the pH value changes greatly (equivalent point). To neutralize and titrate. When the amount of the alkali solution added up to the equivalence point is x, the pH value when the amount of alkali dropped is x / 2 is equal to the pKa value. It is preferable to prepare a solution as dilute as possible for the measurement. Measurement is performed with a plurality of dilute solutions, and a plot is created based on the pKa value and the solution concentration as a result of the measurement. It can also be obtained by extrapolation. The pKa values of typical phenolic compounds measured by such a method include 2-methylphenol (10.28), phenol (9.82), 1-naphthol (9.14), 3-chlorophenol. (8.78), 2-bromophenol (8.22), and the like. These literature values are summarized in the acid-base dissociation constants of aromatic compounds (page 637) in Asakura Shoten's “Daily Organic Chemistry, Vol. 2, Handbook of Organic Chemical Constants” and can be referred to.

When the monofunctional phenol compound (C) used in the present invention is selected such that the boiling point exceeds the molding temperature of the epoxy resin composition or the post-curing (post-cure) temperature, the unreacted monofunctional phenol compound (C) This is preferable because it can be suppressed from causing vaporization of the cured product and peeling at the interface between the metal frame and the resin when used as an epoxy resin for semiconductor encapsulation. When the pKa value of the monofunctional phenol compound (C) is outside the above range, and when the amount of the monofunctional phenol compound (C) added is excessive, it is preferable that the boiling point is high. What has a boiling point exceeding 150-175 degreeC which is the curing temperature of a novel epoxy resin is preferable.
Further, when a phenol compound having no sublimation property is selected as the phenol compound of the present invention, it is also preferable because the unreacted phenol compound is hardly vaporized.

  As the monofunctional phenol compound (C) used in the present invention, a compound having a structure represented by the general formula (1) is preferably used. Thereby, the above-mentioned pKa value falls within a preferable range, the boiling point of the monofunctional phenol compound (C) is increased, and voids in the cured product due to vaporization are hardly generated.

Here, in the compound represented by the general formula (1), as the substituents R ₁ and R ₈ , either one has a hydroxyl group, the other is a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, and It has what is chosen from a halogen group. Examples of the hydrocarbon group having 1 to 8 carbon atoms include a saturated or unsaturated aliphatic group having 1 to 8 carbon atoms, an aromatic group, and a group formed by combining them. Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tertiary butyl group, hexyl group, cyclohexyl group, heptyl group, cycloheptyl group, octyl group and cyclooctyl group, etc. A linear or branched saturated aliphatic group, and an unsaturated aliphatic group in which the saturated aliphatic group has one or more double bonds or triple bonds at any position; an aromatic group such as a phenyl group; And a group in which an aliphatic group and an aromatic group such as a benzyl group and a 4-methylphenyl group are combined. Among these substituents, those having a hydrogen atom as any one of R ₁ and R ₈ are preferable because the pKa value of the monofunctional phenol compound (C) falls within a suitable range.

Further, the compound represented by the general formula (1) is, as substituents R ₂ to R _7, a hydrogen atom, those selected from the group consisting of hydrocarbon radicals and halogen radicals having 1 to 8 carbon atoms, these radicals They may be the same or different. Examples of the hydrocarbon group having 1 to 8 carbon atoms include the same groups as the substituents R ₁ and R ₈ . Among these substituents, those having a hydrogen atom as R _{2 to} R ₇ are preferable because the pKa value of the monofunctional phenol compound (C) falls within a suitable range.

  Preferable examples of the compound represented by the general formula (1) include 1-naphthol (pKa = 9.14) and 2-naphthol (pKa = 9.31).

  Suitable addition amount of the monofunctional phenol compound (C) used in the present invention is a compound (A) having two or more epoxy groups in one molecule and a compound (B) having two or more phenolic hydroxyl groups in one molecule. The compound (A) having two or more epoxy groups in one molecule and the compound (B) having two or more phenolic hydroxyl groups in one molecule are different depending on the ratio, functional group equivalent and average number of functional groups. In the range of the combination, specifically, the total amount of the compound (A) having two or more epoxy groups in one molecule and the compound (B) having two or more phenolic hydroxyl groups in one molecule is 0.5%. It is preferably used between ˜15% by weight. The amount of decrease in the percentage of the cured product tends to be proportional to the amount added, and can be arbitrarily adjusted during use. Although the addition amount can be used even outside the above range, if it exceeds this range, a sufficient crosslinking density necessary for gelation cannot be obtained, and resin curing failure may occur. Moreover, if it is less than this range, the effect of reducing the elastic modulus may not be sufficiently obtained.

  An inorganic filler (D) can be used for the resin composition of this invention as needed. In particular, inorganic fillers are effective for use in fields requiring high heat resistance, such as epoxy resin compositions for semiconductor encapsulation. There is no restriction | limiting in particular about the kind of inorganic filler (D), What is generally used as a resin additive can be used.

  As this inorganic filler (D), what is generally used for the epoxy resin composition for semiconductor sealing can be used. For example, fused spherical silica, fused crushed silica, crystalline silica, talc, alumina, titanium white, silicon nitride and the like can be mentioned, and most preferably used are spherical fused silica and crushed fused silica. These inorganic fillers may be used alone or in combination. These may be surface-treated with a coupling agent. The shape of the inorganic filler is preferably as spherical as possible and the particle size distribution is broad in order to improve fluidity. Although the compounding quantity of an inorganic filler is not specifically limited, 50 to 95 weight% is preferable in all the epoxy resin compositions. Although it can be used outside the above range, if it is below the lower limit value, sufficient solder resistance may not be obtained, and if it exceeds the upper limit value, sufficient fluidity may not be obtained.

  Further, the content (blending amount) of the inorganic filler (D) is the compound (A) having two or more epoxy groups in one molecule, and the compound (B) having two or more phenolic hydroxyl groups in one molecule. ) And the specific gravity of the inorganic filler (D) may be taken into consideration, and weight% may be converted to volume% and handled.

  The content (blending) ratio of the compound (A) having two or more epoxy groups in one molecule and the compound (B) having two or more phenolic hydroxyl groups in one molecule is not particularly limited, The phenolic hydroxyl group of the compound (B) having two or more phenolic hydroxyl groups in one molecule is 0.5 to 2 with respect to 1 mol of the epoxy group of the compound (A) having two or more epoxy groups in one molecule. It is preferably used so as to be about a mole, and more preferably used so as to be about 0.7 to 1.5 mole. Thereby, various characteristics improve more, maintaining the balance of the various characteristics of an epoxy resin composition to a suitable thing.

  In this invention, a hardening accelerator can be used arbitrarily and there will be no restriction | limiting if it has a function which accelerates | stimulates hardening reaction of the compound (A) which has 2 or more of epoxy groups in 1 molecule. Specifically, organic phosphine compounds such as triphenylphosphine and tritertiary butylphosphine, amine compounds such as tributylamine and benzyldimethylamine, imidazole compounds such as 2-methylimidazole and 2-phenylimidazole, tetraphenylphosphonium tetra Addition of phenylborate, tetraphenylphosphonium bromide, molecular compounds of tetraphenylphosphonium and bisphenol A, and phosphonium salts such as tetraphenylphosphonium / tetranaphthoic acid borate, 2- (triphenylphosphonio) phenolate, triphenylphosphine and benzoquinone Phosphonium inner salt compounds such as 1,8-diazabicyclo (5,4,0) -7-undecene Ruken compounds, known curing accelerators can be used. These curing accelerators can also be used after being finely divided, microcapsuled (core shell), mechano-fusion treated, or the like.

  Of these, when phosphonium molecular compounds and phosphonium inner salts are used, a compound having two or more epoxy groups in one molecule (A), a compound having two or more phenolic hydroxyl groups in one molecule (B) And the monofunctional phenol compound (C) is favorably promoted and sufficient crosslinking is formed. Such curing accelerators include tetraphenylphosphonium and 2,3-dihydroxynaphthalene molecular compounds, tetraphenylphosphonium and bisphenol F molecular compounds, 2- (triphenylphosphonio) phenolate, addition of triphenylphosphine and benzoquinone. Such as things.

  In the epoxy resin composition of the present invention, the content (blending amount) of the curing accelerator is not particularly limited, but the compound (A) having two or more epoxy groups in one molecule and a phenolic hydroxyl group in one molecule. The amount is preferably about 0.01 to 10% by weight, more preferably about 0.1 to 5% by weight, based on the resin component comprising two or more compounds (B) and the monofunctional phenol compound (C). More preferable. Thereby, the sclerosis | hardenability, fluidity | liquidity, and hardened | cured material characteristic of an epoxy resin composition are expressed with sufficient balance.

  In addition, the epoxy resin composition of the present invention includes a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and a monofunctional phenol compound ( C) In addition to silane coupling agents such as epoxy silane, mercapto silane, amino silane, alkyl silane, ureido silane and vinyl silane, titanate coupling agent, aluminum coupling agent, aluminum / zirconium coupling agent Coupling agents such as carbon black and bengara; natural waxes such as carnauba wax; synthetic waxes such as polyethylene wax; higher fatty acids such as stearic acid and zinc stearate and metal salts thereof or paraffins Molding agent; Silicone oil and shi Low stress components such as corn rubber; Flame retardants such as brominated epoxy resin, antimony trioxide, aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate and phosphazene; Inorganic ion exchange such as bismuth oxide hydrate Various additives such as body, etc. may be appropriately blended.

  The epoxy resin composition of the present invention comprises a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and a monofunctional phenol compound (C), If necessary, other additives and the like are sufficiently uniformly mixed using a mixer, then melt-kneaded with a kneader, cooled and pulverized. The mixer is not particularly limited, and examples thereof include blenders such as a ball mill, a Henschel mixer, a V blender, a double cone blender, a concrete mixer, and a ribbon blender. The kneader is not particularly limited, but a hot roll, a heating kneader, a uniaxial or biaxial screw type kneader, or the like is preferably used.

  The epoxy resin composition for semiconductor encapsulation of the present invention comprises a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and a monofunctional phenol compound. (C) and the inorganic filler (D) can be obtained by the same method as the above epoxy resin composition using other additives as required.

  The epoxy resin composition of the present invention is used to encapsulate various electronic components such as semiconductor elements, and to manufacture semiconductor devices by conventional molding methods such as transfer molding, compression molding, and injection molding. do it.

The form of the semiconductor device of the present invention is not particularly limited. For example, SIP (Single Inline Package), HSIP (SIP with Heatsink), ZIP (Zig-zag Inline Package), DIP (Dual Inline Package), SDIP (Shrink) Dual Inline Package), SOP (Small Outline Package), SSOP (Shrink Small Outline Package), TSOP (Thin Small Outline Package), SOJ (Small Outline J-leaded Package), QFP (Quad Flat Package), QFP (FP) ( QFP Fine Pitch), TQFP (Thin Quad Flat Package), QFJ (PLCC) (Quad Flat J-leaded Package), BGA (Ball Grid Array), and the like.
The semiconductor device of the present invention thus obtained is excellent in solder resistance during moisture absorption.

  In the present embodiment, the case where the epoxy resin composition of the present invention is used as a sealing material for a semiconductor device has been described. However, the use of the epoxy resin composition of the present invention is not limited thereto. .

  Next, specific examples of the present invention will be described, but the present invention is not limited thereto.

  In carrying out the present invention, a commercially available reagent was used as it was for the monofunctional phenol compound (component (C)). Component (C) used in the examples was methacresol (pKa = 10.09), 2-methoxyphenol (pKa = 9.98), 2-chloro-1-naphthol (pKa = 7.73), 1- Hydroxyanthracene (pKa = 9.88), 2-naphthol (pKa = 9.31), 1-naphthol (pKa = 9.23), 3-bromophenol (pKa = 9.11), 4-nitrophenol (pKa = 7.14), and as components used in the comparative examples, 1,4-hydroquinone (pKa = 9.96), 3-methylcatechol (pKa = 9.28), 4-aminophenol (pKa = 9) .83), pyrogallol (pKa = 8.94). The pKa value of the polyfunctional phenols used in the comparative examples describes the tendency of the first hydroxyl group to release protons, that is, the pKa1 value.

(Synthesis of curing accelerator C1)
In a separable flask (volume: 200 mL) equipped with a condenser and a stirrer, 10.4 g (0.060 mol) of 2-bromophenol, 17.3 g (0.066 mol) of triphenylphosphine, 0.65 g (5 mmol) of nickel chloride And 40 mL of ethylene glycol was charged, and the reaction was carried out at 160 ° C. with stirring. After cooling the reaction solution, 40 mL of pure water was added dropwise, and the precipitated powder was washed with toluene, filtered and dried to obtain a white powder.
Next, the obtained powder was dissolved in 100 ml of methanol, and 60 ml of 1 mol / L sodium hydroxide aqueous solution and 500 ml of pure water were sequentially added. The obtained crystals were filtered and washed to obtain 12.7 g of pale yellow crystals.
This compound was designated C1. Compound C1 was analyzed by ¹ H-NMR, mass spectrum, and elemental analysis, and as a result, it was confirmed to be the target triphenyl (2-hydroxyphenyl) phosphonium. The yield of the obtained curing accelerator C1 was 83%.

(Synthesis of curing accelerator C2)
A separable flask (volume: 200 mL) equipped with a condenser and a stirrer was charged with 6.49 g (0.060 mol) of benzoquinone, 17.3 g (0.066 mol) of triphenylphosphine and 40 mL of acetone, and reacted at room temperature with stirring. . The precipitated crystals were washed with acetone, filtered and dried to obtain 20.0 g of brown crystals.
This compound was designated C2. Compound C2 was analyzed by ¹ H-NMR, mass spectrum, and elemental analysis, and as a result, it was confirmed to be the target triphenyl (2,5-dihydroxyphenyl) phosphobetaine. The yield of the obtained curing accelerator C2 was 84%.

(Synthesis of curing accelerator C3)
A beaker with a stirrer (capacity: 1000 mL) is charged with 25.2 g (0.060 mol) of tetraphenylphosphonium bromide, 17.28 g (0.120 mol) of 2,3-dihydroxynaphthalene, and 200 mL of methanol, and may be stirred. After dissolution, 60 ml of a 1 mol / L sodium hydroxide aqueous solution and 600 mL of pure water were sequentially added. The precipitated powder was washed with pure water, filtered and dried to obtain a white powder.

This compound was designated as C3. Compound C3 was analyzed by ¹ H-NMR, mass spectrum, and elemental analysis, and as a result, it was confirmed to be a molecular compound of target tetraphenylphosphonium and 2,3-dihydroxynaphthalene. The yield of the obtained compound C3 was 83%.

[Preparation of epoxy resin composition and manufacture of semiconductor device]
An epoxy resin composition containing a monofunctional phenol compound (D), a non-monofunctional phenol compound, and the compounds C1 to C3 to 1,8-diazabicyclo- (5,4,0) -7-undecene as follows. A semiconductor device was manufactured.

(Example 1)
First, as a compound (A) having two or more epoxy groups in one molecule (component (A)), a biphenyl type epoxy resin (YX-4000HK manufactured by Japan Epoxy Resin Co., Ltd., melting point: 105 ° C., epoxy equivalent: 193, ICI melt viscosity at 150 ° C .: 0.15 poise) Phenol aralkyl resin (XLC-LL manufactured by Mitsui Chemicals, Inc.) as compound (B) (component (B)) having two or more phenolic hydroxyl groups in one molecule, softening Point: 77 ° C., hydroxyl equivalent weight: 172, ICI melt viscosity at 150 ° C .: 3.6 poise), monofunctional phenol compound (C) (component (C)) as metacresol, curing accelerator as curing accelerator C1, inorganic filling Material (D) (component (D)) as fused spherical silica (average particle size 15 μm), other additives as carbon black, brominated bis The phenol A type epoxy resin and carnauba wax were prepared, respectively.

  Next, the biphenyl type epoxy resin: 52 parts by weight, the phenol aralkyl resin: 44 parts by weight, the curing accelerator C1: 1.8 parts by weight, metacresol: 2.6 parts by weight, fused spherical silica: 700 parts by weight, Carbon black: 2 parts by weight, brominated bisphenol A type epoxy resin: 2 parts by weight, carnauba wax: 2 parts by weight are first mixed at room temperature, then kneaded at 95 ° C. for 8 minutes using a hot roll, and then cooled and pulverized Thus, an epoxy resin composition (thermosetting resin composition) was obtained.

  Next, using the epoxy resin composition obtained above as an epoxy resin composition for semiconductor encapsulation, eight 100-pin TQFP packages (semiconductor devices) and 15 16-pin DIP packages (semiconductor devices) , Each manufactured.

  The 100-pin TQFP was manufactured by transfer molding at a mold temperature of 175 ° C., an injection pressure of 7.4 MPa and a curing time of 2 minutes, and post-cured at 175 ° C. for 8 hours.

  The package size of the 100-pin TQFP was 14 × 14 mm, the thickness was 1.4 mm, the silicon chip (semiconductor element) size was 8.0 × 8.0 mm, and the lead frame was 42 alloy.

  The 16-pin DIP was manufactured by transfer molding at a mold temperature of 175 ° C., an injection pressure of 6.8 MPa and a curing time of 2 minutes, and post-cured at 175 ° C. for 8 hours.

  The package size of the 16-pin DIP is 6.4 × 19.8 mm, the thickness is 3.5 mm, the silicon chip (semiconductor element) size is 3.5 × 3.5 mm, and the lead frame is made of 42 alloy. .

(Example 2)
Example 1 except that instead of the curing accelerator C1, a curing accelerator C2: 1.9 parts by weight, and metacresol: 2.6 parts by weight, 2-methoxyphenol: 3.1 parts by weight were used. Similarly, an epoxy resin composition (thermosetting resin composition) was obtained, and a package (semiconductor device) was manufactured in the same manner as in Example 1 using this epoxy resin composition.

(Example 3)
Instead of curing accelerator C1, curing accelerator C3: 3.4 parts by weight, metacresol: 2.6 parts by weight, 2-chloro-1-naphthol: 5.0 parts by weight, XLC-LL: 44 parts by weight XLC-LL: An epoxy resin composition (thermosetting resin composition) was obtained in the same manner as in Example 1 except that 40 parts by weight was used, and this epoxy resin composition was used to carry out the above-described implementation. A package (semiconductor device) was manufactured in the same manner as in Example 1.

Example 4
Instead of curing accelerator C1, curing accelerator C3: 3.4 parts by weight, metacresol: 2.6 parts by weight, 1-hydroxyanthracene: 5.4 parts by weight, XLC-LL: 44 parts by weight instead of XLC -LL: An epoxy resin composition (thermosetting resin composition) was obtained in the same manner as in Example 1 except that 40 parts by weight were used. Using this epoxy resin composition, Similarly, a package (semiconductor device) was manufactured.

(Example 5)
Instead of the curing accelerator C1, 1,8-diazabicyclo- (5,4,0) -7-undecene (manufactured by San Apro Co., Ltd., trade name: DBU): 1.0 part by weight, metacresol: 2.6 weight In the same manner as in Example 1 except that 2-naphthol: 7.0 parts by weight and XLC-LL: 40 parts by weight were used instead of 44 parts by weight, an epoxy resin composition ( A thermosetting resin composition) was obtained, and a package (semiconductor device) was manufactured in the same manner as in Example 1 using this epoxy resin composition.

(Example 6)
First, as component (A), a biphenyl aralkyl type epoxy resin (NC-3000 manufactured by Nippon Kayaku Co., Ltd., softening point: 60 ° C., epoxy equivalent: 272, ICI melt viscosity at 150 ° C .: 1.3 poise), component (B ) As a biphenyl aralkyl type phenol resin (MEH-7851SS manufactured by Meiwa Kasei Co., Ltd., softening point: 68 ° C., hydroxyl equivalent: 199, ICI melt viscosity at 150 ° C .: 0.9 poise), 1-naphthol as component (C), Curing accelerator C1 was prepared as a curing accelerator, fused spherical silica (average particle size 15 μm) was prepared as component (D), and carbon black, brominated bisphenol A type epoxy resin and carnauba wax were prepared as other additives.

  Next, the biphenyl aralkyl type epoxy resin: 58 parts by weight, the biphenyl aralkyl type phenol resin: 38 parts by weight, the curing accelerator C1: 1.8 parts by weight, 1-naphthol: 3.2 parts by weight, fused spherical silica: 700 parts by weight, carbon black: 2 parts by weight, brominated bisphenol A type epoxy resin: 2 parts by weight, carnauba wax: 2 parts by weight are first mixed at room temperature and then kneaded at 105 ° C. for 8 minutes using a hot roll. Thereafter, the mixture was cooled and pulverized to obtain an epoxy resin composition (thermosetting resin composition).

  Next, a package (semiconductor device) was manufactured in the same manner as in Example 1 using the epoxy resin composition obtained above as an epoxy resin composition for semiconductor encapsulation.

(Example 7)
Curing accelerator C1: Instead of 1.8 parts by weight, curing accelerator C2: 1.9 parts by weight, 1-naphthol: Instead of 3.2 parts by weight, 3-bromophenol: 7.3 parts by weight, MEH-7851SS : An epoxy resin composition (thermosetting resin composition) was obtained in the same manner as in Example 6 except that 34 parts by weight was used instead of 38 parts by weight. A package (semiconductor device) was manufactured in the same manner as in Example 1.

(Example 8)
Curing accelerator C1: Instead of 1.8 parts by weight, curing accelerator C3: 3.5 parts by weight, 1-naphthol: instead of 3.2 parts by weight, 3-nitrophenol: 2.9 parts by weight, MEH-7851SS : An epoxy resin composition (thermosetting resin composition) was obtained in the same manner as in Example 6 except that MEH-7851SS: 34 parts by weight was used instead of 38 parts by weight, and this epoxy resin composition was used. In the same manner as in Example 1, a package (semiconductor device) was manufactured.

Example 9
Curing accelerator C1: in place of 1.8 parts by weight, DBU: 1.0 part by weight, 1-naphthol: in place of 3.2 parts by weight, except that 4-nitrophenol: 3.1 parts by weight was used. An epoxy resin composition (thermosetting resin composition) was obtained in the same manner as in Example 6, and a package (semiconductor device) was produced in the same manner as in Example 1 using this epoxy resin composition.

(Comparative Example 1)
An epoxy resin composition (thermosetting resin composition) was prepared in the same manner as in Example 1 except that 1,4-hydroquinone: 1.4 parts by weight was used instead of 2.6 parts by weight of metacresol. Using this epoxy resin composition, a package (semiconductor device) was manufactured in the same manner as in Example 1.

(Comparative Example 2)
Curing accelerator C1: Instead of 1.8 parts by weight, curing accelerator C2: 1.9 parts by weight, metacresol: 2.6 parts by weight, 3-methylcatechol: 3.0 parts by weight, XLC-LL: An epoxy resin composition (thermosetting resin composition) was obtained in the same manner as in Example 1 except that 40 parts by weight of XLC-LL was used instead of 44 parts by weight, and this epoxy resin composition was used. A package (semiconductor device) was manufactured in the same manner as in Example 1.

(Comparative Example 3)
Curing accelerator C1: In place of 1.8 parts by weight, DBU: 1.0 part by weight, 1-naphthol: in place of 3.2 parts by weight, 3-aminophenol: 4.6 parts by weight, MEH-7851SS: 38 parts by weight An epoxy resin composition (thermosetting resin composition) was obtained in the same manner as in Example 6 except that MEH-7851SS: 34 parts by weight was used instead of the parts, and using this epoxy resin composition, A package (semiconductor device) was manufactured in the same manner as in Example 1.

(Comparative Example 4)
Curing accelerator C1: Instead of 1.8 parts by weight, curing accelerator C3: 3.4 parts by weight, 1-naphthol: instead of 3.2 parts by weight, pyrogallol: 0.9 parts by weight, MEH-7851SS: 38 parts by weight An epoxy resin composition (thermosetting resin composition) was obtained in the same manner as in Example 6 except that MEH-7851SS: 34 parts by weight was used instead of the parts, and using this epoxy resin composition, A package (semiconductor device) was manufactured in the same manner as in Example 1.

(Comparative Example 5)
In the same manner as in Example 1 except that the component corresponding to component (C) was not used and XLC-LL: 48 parts by weight was used instead of XLC-LL: 44 parts by weight, an epoxy resin composition (heat A curable resin composition) was obtained, and a package (semiconductor device) was manufactured in the same manner as in Example 1 using this epoxy resin composition.

(Comparative Example 6)
In the same manner as in Example 6 except that the component corresponding to component (C) was not used and MEH-7851SS: 42 parts by weight was used instead of 38 parts by weight of MEH-7851SS: the epoxy resin composition (heat A curable resin composition) was obtained, and a package (semiconductor device) was manufactured in the same manner as in Example 1 using this epoxy resin composition.

[Characteristic evaluation]
Characteristic evaluation (1) to (3) of the epoxy resin composition obtained in each example and each comparative example, and characteristic evaluation (4) and (5) of the semiconductor device obtained in each example and each comparative example ) Was performed as follows.

(1): Spiral flow Using a mold for spiral flow measurement according to EMMI-I-66, measurement was performed at a mold temperature of 175 ° C, an injection pressure of 6.8 MPa, and a curing time of 2 minutes.

  This spiral flow is a parameter of fluidity, and the larger the value, the better the fluidity.

(2): Curing torque Using a curast meter (Orientec Co., Ltd., JSR curast meter IV PS type), the torque after 175 ° C. and 90 seconds was measured.
This hardening torque shows that curability is so favorable that a numerical value is large.

(3) Thermal elastic modulus Using a mold from which a molded product having a size of 500 × 10 × 3 mm was obtained, a test piece formed by molding at a mold temperature of 175 ° C., an injection pressure of 6.8 MPa, and a curing time of 5 minutes was 175 ° C. After being stored in a warm air dryer for 4 hours, using a rheometer Rheopolymer made by Jusco International, the storage elastic modulus at 260 ° C. was measured at an oscillation strain control measurement mode, frequency 1 Hz, strain 0.03. It was measured. The elastic modulus at high temperature affects the solder crack resistance when the semiconductor is sealed with resin, and the lower the value, the better the solder crack resistance.

(4) Solder resistance 100 pin TQFP was allowed to stand for 168 hours in an environment of 85 ° C. and 85% relative humidity, and then immersed in a solder bath at 260 ° C. for 10 seconds.

  Then, the presence or absence of the occurrence of external cracks was observed under a microscope, and displayed as a percentage (%) as crack generation rate = (number of packages in which cracks occurred) / (total number of packages) × 100.

  Further, the ratio of the peeled area between the silicon chip and the cured epoxy resin composition was measured using an ultrasonic flaw detector, and the peel rate = (peeled area) / (silicon chip area) × 100. The average value of the package was obtained and expressed as a percentage (%).

  These crack generation rate and peeling rate indicate that the smaller the numerical value, the better the solder resistance at the time of moisture absorption, and the higher the reliability of the obtained package.

  As shown in Table 1, the epoxy resin compositions obtained in Examples 1 to 9 (the epoxy resin composition of the present invention and the epoxy resin composition for semiconductor encapsulation) all impair the curability and fluidity. The package of each example (semiconductor device of the present invention) with reduced elastic modulus and sealed with this cured product has good solder resistance during moisture absorption and excellent reliability. It was a thing.

  On the other hand, the epoxy resin compositions obtained in Comparative Examples 1 to 4 use a phenol component that is not monofunctional, but both have improved elastic modulus, and the packages obtained in these Comparative Examples are Both were inferior in solder resistance. In addition, the epoxy resin compositions obtained in Comparative Example 5 and Comparative Example 6 do not include those corresponding to the phenol component, and similarly to Comparative Examples 1 to 4, the packages obtained in these Comparative Examples All were inferior in solder resistance.

Claims (6)

An epoxy resin composition comprising a compound (A) having two or more epoxy groups in one molecule, a compound (B) having two or more phenolic hydroxyl groups in one molecule, and a monofunctional phenol compound (C). The epoxy resin composition according to claim 1, wherein the monofunctional phenol compound (C) has a pKa value of 7.5 or more and 9.8 or less. The epoxy resin composition according to claim 1 or 2, wherein the monofunctional phenol compound (C) is a compound represented by the following general formula (1).

[In the formula, _one of R ₁ and R ₈ is a hydroxyl group, and the other is selected from a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, and a halogen group. R _{2 to} R ₇ are selected from a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, and a halogen group, and these are the same or different. ] The epoxy resin composition for semiconductor sealing which further contains an inorganic filler (D) in the epoxy resin composition of any one of Claims 1 thru | or 3. The epoxy resin composition for semiconductor encapsulation according to claim 4, wherein the inorganic filler (E) is contained in the semiconductor epoxy resin composition in an amount of 50 to 95% by weight. The semiconductor device which sealed the electronic component with the hardened | cured material of the epoxy resin composition for semiconductor sealing of Claim 5.