Epoxy resin composition and semiconductor device

Abstract

To provide an epoxy resin composition capable of reducing wire sweep and wire opening.SOLUTION: An epoxy resin composition has a disc flow length of 100 mm or more. In terms of a cured product, a content of chloride ion in the cured product is 20 ppm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to an epoxy resin composition and a semiconductor device. [Background technology]

[0002] A structure in which a semiconductor element and a substrate are electrically connected is called a wire bonding structure in which the semiconductor element and the substrate are connected via wires. In the wire bonding structure, the semiconductor element, the substrate, and the wires electrically connecting them are sealed with a resin composition to form a semiconductor device. While gold has been the mainstream wire material in recent years, due to factors such as rising gold prices, copper has increasingly been used as the wire material. Meanwhile, epoxy resin compositions containing epoxy resins are widely used as encapsulating compositions for encapsulating semiconductor devices. However, epoxy resins are often synthesized using epichlorohydrin, and epoxy resin compositions containing such epoxy resins tend to contain residual bases derived from the epoxy resin as impurities corrosive to wires. Furthermore, decomposition of the epichlorohydrin remaining in the epoxy resin can sometimes result in the generation of new residual bases.

[0003] Copper is more chemically reactive than gold and is therefore more susceptible to corrosion by chlorine. This corrosion can lead to wire breaks between the wire and the electrode pad of the semiconductor element or between the wire and the substrate (wire opens), reducing the reliability of the semiconductor device. Therefore, in order to improve the reliability of semiconductor devices using copper wires, attempts have been made to incorporate a hydrotalcite compound into an epoxy resin composition as an ion trapping agent that traps impurity ions (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-1902 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-29919 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the inclusion of an ion-trapping agent such as a hydrotalcite compound in an epoxy resin composition tends to increase the viscosity of the epoxy resin composition when sealing a semiconductor package, which can cause the epoxy resin composition to flow, which can apply pressure to the wires and lead to displacement of the wires (wire sweep). One aspect of the present disclosure has been made in view of the above-described conventional circumstances, and an object of the present disclosure is to provide an epoxy resin composition capable of suppressing wire sweep and wire open, and a semiconductor device using the same. [Means for solving the problem]

[0006] Specific means for achieving the above object are as follows. <1> The disk flow length is 100 mm or more, An epoxy resin composition, which when cured has a chloride ion content of 20 ppm or less. <2> Epoxy resin, A hardener; a salt of a cation derived from an addition reaction product of a phosphine compound and a quinone compound and an anion derived from a carboxylic acid compound having a structure in which two adjacent carbon atoms are both substituted with carboxy groups; Contains <1> The epoxy resin composition according to claim 1. <3> The salt contains a phosphonium compound represented by the following general formula (I): <2> The epoxy resin composition according to claim 1.

[0007] [ka]

[0008] (In general formula (I), R 1A Each of R independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. 1A Two Rs are arbitrarily selected from 1A are connected to each other, R 1A may form a ring structure together with the phosphorus atom to which R is attached. 1B each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms, and n represents an integer of 0 to 3. When n is 2 or 3, two R 1B may be linked together to form a cyclic structure. a represents 1 or 2. When a is 1, X a- represents a monovalent anion represented by the following general formula (IA), and when a is 2, X a- represents a divalent anion represented by the following general formula (IB):

[0009] [ka]

[0010] (In general formula (IA), R 1C Each of R independently represents an alkyl group, a hydroxyl group, an amino group, or an alkoxy group. p represents an integer of 0 to 4. In general formula (IB), R 1D each independently represents an alkyl group, a hydroxyl group, an amino group, or an alkoxy group, and q represents an integer of 0 to 2. <4> Contains inorganic fillers <2> or <3> The epoxy resin composition according to claim 1. <5> A semiconductor element and a device that encapsulates the semiconductor element. <1> ~ <4> and a cured product of the epoxy resin composition according to any one of the above items. [Effects of the Invention]

[0011] According to one embodiment of the present disclosure, it is possible to provide an epoxy resin composition capable of suppressing wire sweep and wire open, and a semiconductor device using the same. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present disclosure. In the present disclosure, the term "process" includes not only a process that is independent of other processes, but also a process that cannot be clearly distinguished from other processes as long as the purpose of the process is achieved. In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple substances corresponding to the component. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, particles corresponding to each component may contain multiple types of particles. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0013] <Epoxy resin composition> The epoxy resin composition of the present disclosure has a disk flow length of 100 mm or more, and when cured, the content of chloride ions in the cured product is 20 ppm or less. Use of the epoxy resin composition of the present disclosure makes it possible to suppress wire sweep and wire open when forming a semiconductor device.

[0014] In the present disclosure, the disk flow length of an epoxy resin composition is a value measured using a flat plate mold for disk flow measurement, which has an upper mold measuring 200 mm (W) × 200 mm (D) × 25 mm (H) and a lower mold measuring 200 mm (W) × 200 mm (D) × 15 mm (H). Specifically, 5 g of the epoxy resin composition was placed in the center of the lower mold heated to 180°C. After 5 seconds, the upper mold, also heated to 180°C, was closed and compression-molded under a load of 78 N for a curing time of 90 seconds. The major and minor axes (mm) of the molded product were measured with calipers, and the average value (mm) calculated from these values ​​was used to define the disk flow length. In the present disclosure, the disk flow length of the epoxy resin composition is 100 mm or more, preferably 105 mm or more, and may be 160 mm or less.

[0015] The chloride ion content in the cured product of the epoxy resin composition is measured as follows. 50 g of ion-exchanged water and 5 g of a cured epoxy resin composition are placed in a pressure vessel and left at 121°C and 2 atmospheres for 20 hours. After leaving the vessel, the chloride ion concentration in the water is measured using ion chromatography. The chloride ion content is 20 ppm or less, preferably 15 ppm or less, and more preferably 10 ppm or less. The lower limit of the chloride ion content is 0 ppm.

[0016] Each component constituting the epoxy resin composition of the present disclosure will be described below. The epoxy resin composition of the present disclosure may contain an epoxy resin, a curing agent, and a curing accelerator, and may further contain other components such as an inorganic filler as necessary.

[0017] -Epoxy resin- The epoxy resin composition of the present disclosure contains an epoxy resin. The type of epoxy resin is not particularly limited, and known epoxy resins can be used. Specifically, for example, novolac resins obtained by condensing or co-condensing at least one selected from the group consisting of phenolic compounds (e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, and bisphenol F) and naphthol compounds (e.g., α-naphthol, β-naphthol, and dihydroxynaphthalene) with an aldehyde compound (e.g., formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde) under an acidic catalyst are epoxidized (e.g., phenol novolac epoxy resins and orthocresol novolac epoxy resins); bisphenols (e.g., bisphenol A, bisphenol AD, bisphenol F, and bisphenol S). and biphenols (e.g., alkyl-substituted or unsubstituted biphenols); epoxidized phenol-aralkyl resins; epoxidized adducts or polyadducts of phenols with at least one selected from the group consisting of dicyclopentadiene and terpene compounds; glycidyl ester-type epoxy resins obtained by reacting polybasic acids (e.g., phthalic acid and dimer acid) with epichlorohydrin; glycidylamine-type epoxy resins obtained by reacting polyamines (e.g., diaminodiphenylmethane and isocyanuric acid) with epichlorohydrin; linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids (e.g., peracetic acid); and alicyclic epoxy resins. Epoxy resins also include those obtained by epoxidizing phenol-aralkyl resins, biphenyl-aralkyl resins, or naphthol-aralkyl resins. The epoxy resins may be used alone or in combination of two or more.

[0018] From the viewpoint of preventing corrosion of aluminum wiring or copper wiring on elements such as ICs, the epoxy resin preferably has a high purity and a low hydrolyzable chlorine content. From the viewpoint of improving the moisture resistance of the epoxy resin composition, the hydrolyzable chlorine content is preferably 500 ppm by mass or less.

[0019] Here, the amount of hydrolyzable chlorine is a value determined by dissolving 1 g of a sample epoxy resin in 30 mL of dioxane, adding 5 mL of 1N-KOH methanol solution, refluxing for 30 minutes, and then performing potentiometric titration.

[0020] The content of the epoxy resin in the epoxy resin composition is preferably 2.5 to 10 mass %, more preferably 3.0 to 8.0 mass %, and even more preferably 3.5 to 7.5 mass %. The content of the epoxy resin in the epoxy resin composition excluding the inorganic filler used as needed is preferably 40% by mass to 99% by mass, more preferably 45% by mass to 98% by mass, and even more preferably 48% by mass to 97% by mass.

[0021] - Hardener - The epoxy resin composition of the present disclosure may contain a curing agent. The type of curing agent is not particularly limited, and known curing agents can be used. Specific examples include novolak resins obtained by condensing or co-condensing at least one selected from the group consisting of phenolic compounds (e.g., phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, and bisphenol F) and naphthol compounds (e.g., α-naphthol, β-naphthol, and dihydroxynaphthalene) with an aldehyde compound (e.g., formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde) under an acidic catalyst; phenol-aralkyl resins; biphenyl-aralkyl resins; and naphthol-aralkyl resins. One curing agent may be used alone, or two or more may be used in combination.

[0022] The curing agent is preferably blended so that the equivalent of the functional group of the curing agent (for example, a phenolic hydroxyl group in the case of a novolac resin) is 0.5 to 1.5 equivalents per equivalent of the epoxy group of the epoxy resin, and it is particularly preferable that the curing agent be blended so that the equivalent is 0.7 to 1.2 equivalents.

[0023] -Curing accelerator- The epoxy resin composition of the present disclosure may contain a curing accelerator. The curing accelerator is not particularly limited as long as it accelerates the curing reaction between the epoxy resin and the curing agent. At least a portion of the chloride ions in the cured product of the epoxy resin composition are generated by the action of a curing accelerator on epichlorohydrin remaining in the epoxy resin, which was used in synthesizing the epoxy resin. Therefore, when a curing accelerator is used, it is desirable to select a curing accelerator with low activity toward epichlorohydrin. By selecting a material with low activity toward epichlorohydrin as a curing accelerator, the chloride ion content in the cured product can be reduced. If the chloride ion content in the cured product is low, the need to include an ion-trapping agent such as a hydrotalcite compound in the epoxy resin composition is eliminated or reduced. As a result, it is believed that the viscosity of the epoxy resin composition when sealing a semiconductor package can be lowered compared to when an ion-trapping agent is included. As a result of intensive studies by the present inventors, the present inventors have found that a salt (hereinafter sometimes referred to as a specific salt) of a cation derived from an addition reaction product of a phosphine compound and a quinone compound (hereinafter sometimes referred to as a specific addition reaction product) and an anion derived from a carboxylic acid compound (hereinafter sometimes referred to as a specific carboxylic acid compound) having a structure in which two adjacent carbon atoms are both substituted with carboxy groups is preferable as a curing accelerator having low activity against epichlorohydrin.

[0024] The specific addition reactant that is the source of the cation contained in the specific salt is not particularly limited. Examples of the phosphine compound that constitutes the specific addition reactant include alkylphosphine compounds and arylphosphine compounds. Examples of the quinone compound that constitutes the specific addition reactant include benzoquinone and naphthoquinone, which may have a substituent. The specific addition reaction product that is the source of the cation contained in the specific salt may include, for example, a compound represented by the following general formula (IC).

[0025] [ka]

[0026] In general formula (IC), R 1A Each of R independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. 1A Two Rs are arbitrarily selected from 1A are connected to each other, R 1A may form a ring structure together with the phosphorus atom to which R is attached. 1B each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms, and n represents an integer of 0 to 3. When n is 2 or 3, two R 1B may be linked together to form a ring structure.

[0027] In general formula (IC), R 1A or R 1B The substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms, represented by the formula (I), is a hydrocarbon group having 1 to 18 carbon atoms, and includes aliphatic hydrocarbon groups having a substituent, aliphatic hydrocarbon groups having no substituent, aromatic hydrocarbon groups having a substituent, and aromatic hydrocarbon groups having no substituent. When the hydrocarbon group has a substituent, the number of carbon atoms in the hydrocarbon group does not include the number of carbon atoms contained in the substituent.

[0028] The aliphatic hydrocarbon group may be a linear or branched saturated aliphatic hydrocarbon group, or a linear or branched unsaturated aliphatic hydrocarbon group. It has 1 to 18 carbon atoms, but from the viewpoint of storage stability, it preferably has 1 to 12 carbon atoms, and more preferably has 3 to 8 carbon atoms. More specific examples of the aliphatic hydrocarbon group include saturated aliphatic hydrocarbon groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, and an octadecyl group; and unsaturated aliphatic hydrocarbon groups such as an allyl group and a vinyl group.

[0029] The aliphatic hydrocarbon group may be an alicyclic hydrocarbon group. The alicyclic hydrocarbon group may be a saturated alicyclic hydrocarbon group or an unsaturated alicyclic hydrocarbon group. Specific examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, and a cyclohexenyl group.

[0030] The aliphatic hydrocarbon group may have a substituent. Examples of the substituent in the aliphatic hydrocarbon group include an alkoxy group, an aryl group, a hydroxyl group, an amino group, and a halogen atom. When the aliphatic hydrocarbon group has a substituent, the position and the number of the substituent are not particularly limited. When the aliphatic hydrocarbon group has two or more substituents, the substituents may be the same or different.

[0031] The aromatic hydrocarbon group preferably has 6 to 18 carbon atoms, more preferably 6 to 14 carbon atoms. Specific examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and an anthracenyl group. The aromatic hydrocarbon group may have a substituent. Examples of the substituent in the aromatic hydrocarbon group include an alkyl group, an alkoxy group, an aryl group, a hydroxyl group, an amino group, and a halogen atom. When the aromatic hydrocarbon group has a substituent, the position and the number of the substituent are not particularly limited. When the aromatic hydrocarbon group has two or more substituents, the substituents may be the same or different.

[0032] More specific examples of the substituted or unsubstituted aromatic hydrocarbon group include aryl groups such as phenyl and naphthyl; alkyl-substituted aryl groups such as tolyl, dimethylphenyl, ethylphenyl, n-butylphenyl, and t-butylphenyl; and alkoxy-substituted aryl groups such as methoxyphenyl, ethoxyphenyl, n-butoxyphenyl, and t-butoxyphenyl. These groups may be further substituted with an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an amino group, a halogen atom, or the like.

[0033] The three R in general formula (IC) 1A Two Rs are arbitrarily selected from1A are connected together to form R 1A may form a ring structure together with the phosphorus atom to which they are attached. 1A When the and the phosphorus atom form a cyclic structure, the number of rings formed may be one or more, and the cyclic structure may include a bridged ring structure. R that can form a ring structure together with the phosphorus atom 1A Specific examples of the alkylene group include alkylene groups such as ethylene, propylene, butylene, pentylene, and hexylene; alkenyl groups such as ethylenyl, propylene, and butylenyl; aralkylene groups such as methylenephenylene; and arylene groups such as phenylene, naphthylene, and anthracenylene. These may be substituted with an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an amino group, a hydroxyl group, a halogen atom, or the like.

[0034] R 1A From the viewpoint of availability of raw materials, is preferably a monovalent group selected from the group consisting of unsubstituted aryl groups and substituted aryl groups, such as a phenyl group, p-tolyl group, m-tolyl group, o-tolyl group, p-methoxyphenyl group, m-methoxyphenyl group, o-methoxyphenyl group, p-hydroxyphenyl group, m-hydroxyphenyl group, o-hydroxyphenyl group, 2,5-dihydroxyphenyl group, 4-(4-hydroxyphenyl)phenyl group, 1-naphthyl group, 2-naphthyl group, 1-(2-hydroxynaphthyl) group, and 1-(4-hydroxynaphthyl) group, as well as linear, branched, and cyclic alkyl groups, such as a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, octyl group, and cyclohexyl group. Furthermore, it is more preferably a monovalent group selected from the group consisting of unsubstituted aryl groups and substituted aryl groups, such as a phenyl group, a p-tolyl group, a m-tolyl group, an o-tolyl group, a p-methoxyphenyl group, a m-methoxyphenyl group, an o-methoxyphenyl group, a p-hydroxyphenyl group, a m-hydroxyphenyl group, an o-hydroxyphenyl group, a 2,5-dihydroxyphenyl group, a 4-(4-hydroxyphenyl)phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-(2-hydroxynaphthyl) group, and a 1-(4-hydroxynaphthyl) group.

[0035] In formula (IC), n represents an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0. When n is 2 or 3, two R 1B may be linked to each other to form a ring structure. When n is 3, three R 1B Two Rs are arbitrarily selected from 1B may form a cyclic structure. The Two R's 1B When forms a cyclic structure, the number of rings formed may be one or more, and the cyclic structure may contain a bridged ring structure. R capable of forming a cyclic structure 1B Specific examples of R that can form a ring structure together with the phosphorus atom are 1A This is similar to the specific example above.

[0036] The specific addition reaction product may be produced by any method. For example, P(R 1A An addition reaction product of the phosphine compound and the p-quinone compound can be obtained by stirring a solution of the phosphine compound represented by formula (3) and a solution of the p-quinone compound at a temperature of from room temperature to 80°C, and filtering out the precipitated yellow-brown crystals. In this case, the organic solvent that can be used may be methanol, a mixed solvent of methanol and water, acetone, a mixed solvent of acetone and toluene, or the like. Other examples of the production method include a method of reacting a phosphine compound with a halogen-substituted diphenol compound having two hydroxyl groups substituted on an aromatic ring and a halogen atom substituted on an aromatic ring in the same molecule, using a coupling catalyst or ultraviolet light, if necessary, and then carrying out a dehydrohalogenation reaction using a basic compound, if necessary; and a method of reacting a phosphine dihalide compound with a halogen-substituted diphenol compound, and then carrying out a dehydrohalogenation reaction thereon.

[0037] The specific carboxylic acid compound that is the source of the anion contained in the specific salt is not particularly limited as long as it has a structure in which two adjacent carbon atoms are both substituted with carboxy groups, and may be an aromatic carboxylic acid or an aliphatic carboxylic acid. Examples of the aliphatic carboxylic acid include saturated aliphatic carboxylic acids, unsaturated aliphatic carboxylic acids, and alicyclic carboxylic acids.

[0038] The specific carboxylic acid compound may be, for example, at least one selected from the group consisting of compounds represented by the following general formula (II) to compounds represented by the following general formula (V).

[0039] [ka]

[0040] In the general formulas (II) to (V), R 2 ~R 5 each independently represents a hydrogen atom, an alkyl group, a hydroxyl group, an amino group, a carboxyl group, or an alkoxy group, and R 6 ~R 13 each independently represents a hydrogen atom, an alkyl group, or a carboxy group; R 14 represents an alkylene group, and R 15 ~R 18 each independently represents a hydrogen atom, an alkyl group, a hydroxyl group, an amino group, a carboxy group, or a carboxyalkyl group.

[0041] In general formula (II), R 2 ~R 5 The alkyl group represented by the formula (I) is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, and a t-butyl group, and a methyl group is preferred. In general formula (II), R 2 ~R 5 The alkoxy group represented by the formula (I) is preferably a linear or branched alkoxy group having 1 to 4 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an s-butoxy group, an isobutoxy group, and a t-butoxy group, with a methoxy group being preferred. Examples of the compound represented by general formula (II) include phthalic acid, 4-methylphthalic acid, 4-hydroxyphthalic acid, 4-aminophthalic acid, 4-methoxyphthalic acid, and pyromellitic acid.

[0042] In general formula (III) or general formula (IV), R 6 ~R 13 The alkyl group represented by the formula (I) is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, and a t-butyl group, and a methyl group is preferred. In general formula (IV), R 14 Examples of the alkylene group represented by the formula (I) include a methylene group and an ethylene group, with a methylene group being preferred.

[0043] Examples of the compound represented by general formula (III) or general formula (IV) include bicyclo[2.2.1]heptane-2,3-dicarboxylic acid, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic acid, and 1,2,4,5-cyclohexanetetracarboxylic acid.

[0044] In general formula (V), R 15 ~R 18The alkyl group represented by the formula (I) is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, and a t-butyl group, and a methyl group is preferred. In general formula (V), R 15 ~R 18 Examples of the carboxyalkyl group represented by the formula (I) include a 2-carboxyethyl group, a 3-carboxypropyl group, a 4-carboxybutyl group, and a carboxymethyl group.

[0045] Examples of the compound represented by general formula (V) include succinic acid, malic acid, citric acid, and butane-1,2,3,4-tetracarboxylic acid.

[0046] In the present disclosure, the specific carboxylic acid compound is preferably phthalic acid or pyromellitic acid, and more preferably phthalic acid.

[0047] The specific salt of the present disclosure may be a phosphonium compound represented by the following general formula (I):

[0048] [ka]

[0049] In general formula (I), R 1A Each of R independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. 1A Two Rs are arbitrarily selected from 1A are connected to each other, R 1A may form a ring structure together with the phosphorus atom to which R is attached. 1B each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms, and n represents an integer of 0 to 3. When n is 2 or 3, two R 1B may be linked together to form a cyclic structure. a represents 1 or 2. When a is 1, X a- represents a monovalent anion represented by the following general formula (IA), and when a is 2, X a-represents a divalent anion represented by the following general formula (IB).

[0050] [ka]

[0051] In general formula (IA), R 1C Each of R independently represents an alkyl group, a hydroxyl group, an amino group, or an alkoxy group. p represents an integer of 0 to 4. In general formula (IB), R 1D each independently represents an alkyl group, a hydroxyl group, an amino group or an alkoxy group, and q represents an integer of 0 to 2.

[0052] R in general formula (I) 1A 、 R 1B and n have the same meanings as in formula (IC), and the preferred specific examples are also the same.

[0053] In general formula (IA), R 1C The alkyl group represented by the formula (I) is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an isobutyl group, and a t-butyl group, and a methyl group is preferred. In general formula (IA), R 1C The alkoxy group represented by the formula (I) is preferably a linear or branched alkoxy group having 1 to 4 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an s-butoxy group, an isobutoxy group, and a t-butoxy group, with a methoxy group being preferred. In formula (IA), p is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0. Examples of compounds that can be used to generate the monovalent anion represented by general formula (IA) include phthalic acid, 4-methylphthalic acid, 4-hydroxyphthalic acid, 4-aminophthalic acid, and 4-methoxyphthalic acid.

[0054] In general formula (IB), R 1D Specific and preferred examples of the alkyl group represented by R 1C The same applies to the alkyl group represented by the formula: In general formula (IB), R 1D Specific and preferred examples of the alkoxy group represented by R 1C The same applies to the alkoxy group represented by the formula: In general formula (IB), q is preferably 0 or 1, and more preferably 0. Examples of compounds that serve as the source of the divalent anion represented by general formula (IB) include pyromellitic acid.

[0055] X a- As a compound that serves as a source of the monovalent or divalent anion represented by the formula (I), phthalic acid or pyromellitic acid is preferred, and phthalic acid is more preferred.

[0056] Specific salts used in the present disclosure include 2,5-dihydroxyphenyl(triphenyl)phosphonium hydrogen phthalate, 2,5-dihydroxyphenyl(triphenyl)phosphonium hydrogen 4-methyl phthalate, 2,5-dihydroxyphenyl(triphenyl)phosphonium hydrogen 4-hydroxyphthalate, 2,5-dihydroxyphenyl(tri-p-tolyl)phosphonium hydrogen phthalate, 2,5-dihydroxyphenyl(tri-p-tolyl)phosphonium hydrogen 4-methyl phthalate, 2,5-dihydroxyphenyl(tri-p-tolyl)phosphonium hydrogen 4-hydroxyphthalate, 2,5-dihydroxyphenyl(tri-n-butyl)phosphonium hydrogen phthalate, 2,5-dihydroxyphenyl(tri-n-butyl)phosphonium hydrogen 4-methyl phthalate, 2,5-dihydroxyphenyl(tri-n-butyl)phosphonium hydrogen 4-hydroxyphthalate, bis[2 ,5-dihydroxyphenyl(triphenyl)phosphonium]dihydrogenpyromellitate, bis[2,5-dihydroxyphenyl(tri-p-tolyl)phosphonium]dihydrogenpyromellitate, bis[2,5-dihydroxyphenyl(tri-n-butyl)phosphonium]dihydrogenpyromellitate, 1,4-dihydroxynaphthalenyl(triphenyl)phosphonium hydrogenphthalate, 1,4-dihydroxynaphthalenyl(tri-p-tolyl)phosphonium hydrogen phthalate, 1,4-dihydroxynaphthalenyl(tri-n-butyl)phosphonium hydrogen phthalate, bis[1,4-dihydroxynaphthalenyl(triphenyl)phosphonium]dihydrogen pyromellitate, bis[1,4-dihydroxynaphthalenyl(tri-p-tolyl)phosphonium]dihydrogen pyromellitate, bis[1,4-dihydroxynaphthalenyl(tri-n-butyl)phosphonium]dihydrogen pyromellitate, and the like.

[0057] The method for producing the specific salt is not particularly limited. The specific salt can be produced, for example, by adding an acid to the specific addition reactant to form an intermolecular salt, and then reacting this intermolecular salt with an alkali metal salt of a specific carboxylic acid compound while heating and stirring, thereby causing an exchange reaction of the anion portion of the intermolecular salt. When a compound represented by general formula (IC) is used as the specific addition reactant and phthalic acid is used as the specific carboxylic acid compound, concentrated hydrochloric acid is added to a slurry of the compound represented by general formula (IC) suspended in an alcohol solvent such as methanol, followed by addition of water and potassium hydrogen phthalate, and the mixture is stirred while heated. After the reaction mixture is allowed to cool, the precipitated crystals are filtered and washed with water to obtain crude crystals. An alcohol solvent such as methanol and water are added to the crude crystals, and the reaction mixture is stirred while heated and cooled. The precipitated crystals are filtered, washed with water, and dried to obtain the phosphonium compound represented by general formula (I).

[0058] The content of the specific salt is preferably 0.1% by mass to 20% by mass, more preferably 0.5% by mass to 15% by mass, and even more preferably 1.0% by mass to 10% by mass, relative to the total amount of the epoxy resin and the curing agent.

[0059] The epoxy resin composition of the present disclosure may further contain a curing accelerator other than the specific salt. Specific examples of other curing accelerators include cycloamidine compounds such as 1,8-diaza-bicyclo[5.4.0]undecene-7, 1,5-diaza-bicyclo[4.3.0]nonene, and 5,6-dibutylamino-1,8-diaza-bicyclo[5.4.0]undecene-7; cycloamidine compounds with maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, and 2,3-dibenzoquinone; Quinone compounds such as methoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone; compounds with intramolecular polarization formed by adding compounds with π bonds such as diazophenylmethane and phenolic resins; tertiary amine compounds such as benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of tertiary amine compounds; 2-methylimidazolinone; Examples of suitable curing accelerators include imidazole compounds such as 2-phenylimidazole and 2-phenyl-4-methylimidazole, derivatives of imidazole compounds, organic phosphine compounds such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, tris(4-methylphenyl)phosphine, diphenylphosphine, and phenylphosphine, phosphorus compounds having intramolecular polarization obtained by adding a compound having a π bond such as diazophenylmethane or a phenolic resin to an organic phosphine compound, tetraphenylborate salts such as tetraphenylphosphonium tetraphenylborate, triphenylphosphonium tetraphenylborate, 2-ethyl-4-methylimidazolium tetraphenylborate, and N-methylmorpholinium tetraphenylborate, derivatives of tetraphenylborate salts, and triphenylborane complexes such as triphenylphosphine-triphenylborane complex and morpholine-triphenylborane complex. These curing accelerators may be used singly or in combination of two or more.

[0060] When the epoxy resin composition contains other curing accelerators, the content of the other curing accelerators is preferably 0.1% by mass to 15% by mass based on the total amount of the epoxy resin and the curing agent. The ratio of the specific salt in the curing accelerator is preferably 50% by mass to 100% by mass, and more preferably 90% by mass to 100% by mass.

[0061] -Inorganic filler- The epoxy resin composition of the present disclosure may contain an inorganic filler. When the epoxy resin composition contains an inorganic filler, the moisture absorption of the epoxy resin composition tends to be reduced and the strength of the epoxy resin composition in a cured state tends to be improved.

[0062] The inorganic fillers may be used alone or in combination of two or more. When two or more inorganic fillers are used in combination, for example, two or more inorganic fillers with different components, average particle diameters, shapes, etc. are used. The shape of the inorganic filler is not particularly limited, and examples thereof include angular, powdery, spherical, fibrous, etc. From the viewpoints of flowability and mold wear during molding of the epoxy resin composition, spherical shapes are preferred.

[0063] The inorganic filler preferably contains at least one of alumina and silica, and more preferably contains alumina from the viewpoint of high thermal conductivity. Examples of silica include spherical silica and crystalline silica. Other inorganic fillers that can be used in combination with at least one of alumina and silica include zircon, magnesium oxide, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, boron nitride, aluminum nitride, beryllia, zirconia, etc. Furthermore, inorganic fillers with flame retardant effect include aluminum hydroxide, zinc borate, etc.

[0064] The content of the inorganic filler is preferably 50% by volume or more, more preferably 70% by volume or more, and even more preferably 75% by volume or more, based on the total volume of the epoxy resin composition, from the viewpoints of moisture absorption, reduction of the linear expansion coefficient, improvement of strength, and solder heat resistance. The content of the inorganic filler may be 95% by volume or less.

[0065] When alumina is used as the inorganic filler, the average particle size is preferably 4 μm or more, more preferably 7 μm or more, and even more preferably 10 μm or more, from the viewpoint of high thermal conductivity. The thermal conductivity of the cured product of the epoxy resin composition tends to increase as the average particle size of the inorganic filler increases. From the viewpoint of narrow gap filling properties, the average particle size of the inorganic filler is preferably 75 μm or less, more preferably 55 μm or less, and even more preferably 45 μm or less. The average particle size of the inorganic filler can be measured by the following method.

[0066] The inorganic filler to be measured is added to a solvent (pure water) in a range of 1% to 5% by mass together with 1% to 8% by mass of surfactant, and the mixture is vibrated in a 110W ultrasonic cleaner for 30 seconds to 5 minutes to disperse the inorganic filler. Approximately 3 mL of the dispersion is poured into a measurement cell and measured at 25°C. A laser diffraction particle size analyzer (HORIBA, Ltd., LA920) is used to measure the volumetric particle size distribution. The average particle size is calculated as the particle size (D50%) at which the cumulative total from the smallest diameter side in the volumetric particle size distribution reaches 50%.

[0067] The specific surface area of ​​the inorganic filler is set to 0.7 m from the viewpoint of fluidity and moldability. 2 / g~6.0m 2 / g, and 0.9m 2 / g~5.5m 2 / g, more preferably 1.0m 2 / g~5.0m 2 / g is more preferred. The fluidity of the epoxy resin composition tends to increase as the specific surface area of ​​the inorganic filler decreases. In the present disclosure, the specific surface area of ​​an inorganic filler refers to the specific surface area of ​​a mixture of inorganic fillers when at least two types of inorganic fillers are used in combination. The specific surface area (BET specific surface area) of the inorganic filler can be measured from the nitrogen adsorption capacity in accordance with JIS Z 8830:2013. As the evaluation apparatus, AUTOSORB-1 (trade name) manufactured by QUANTACHROME can be used. Since it is considered that the moisture adsorbed on the sample surface and in the structure affects the gas adsorption capacity, it is preferable to first perform a pretreatment for removing moisture by heating when measuring the BET specific surface area. In the pretreatment, a measurement cell into which 0.05 g of the measurement sample is introduced is depressurized to 10 Pa or less with a vacuum pump, then heated at 110 °C, held for 3 hours or more, and then naturally cooled to room temperature (25 °C) while maintaining the depressurized state. After performing this pretreatment, the evaluation temperature is set to 77 K, and the measurement is performed with the evaluation pressure range being less than 1 in terms of relative pressure (equilibrium pressure with respect to the saturated vapor pressure).

[0068] (Ion trap agent) In the epoxy resin composition of the present disclosure, by selecting a curing accelerator having low activity with respect to epichlorohydrin such as the above-mentioned specific salt as the curing accelerator, it is possible to reduce the content of chloride ions in the cured product. Therefore, for example, by using a curing accelerator containing a specific salt, the necessity of including an ion trap agent in the epoxy resin composition is reduced, but the epoxy resin composition of the present disclosure may further contain an ion trap agent as necessary. The ion trap agent that can be used in the present disclosure is not particularly limited as long as it is an ion trap agent generally used in a sealing material used for manufacturing semiconductor devices. Examples of the ion trap agent include compounds represented by the following general formula (VI-1) or the following general formula (VI-2). The compound represented by the general formula (VI-1) may be natural or synthetic hydrotalcite.

[0069] Mg 1-a Al a (OH)2(CO3) a / 2 ·uH2O (VI-1) (In the general formula (VI-1), a is 0 < a ≤ 0.5, and u is a positive number.) BiO b (OH)c (NO3) d (VI-2) (In general formula (VI-2), b is 0.9≦b≦1.1, c is 0.6≦c≦0.8, and d is 0.2≦d≦0.4.)

[0070] Ion trapping agents are commercially available. For example, "DHT-4A" (Kyowa Chemical Industry Co., Ltd., trade name) is a commercially available compound represented by general formula (VI-1). For example, "IXE500" (Toagosei Co., Ltd., trade name) is a commercially available compound represented by general formula (VI-2).

[0071] Other examples of ion trapping agents include hydrous oxides of elements selected from magnesium, aluminum, titanium, zirconium, antimony, and the like. The ion trapping agent may be used alone or in combination of two or more types.

[0072] When the epoxy resin composition contains an ion trapping agent, the content of the ion trapping agent may be 0.1 parts by mass or more, or 0.5 parts by mass or more, relative to 100 parts by mass of the epoxy resin, from the viewpoint of realizing sufficient moisture resistance reliability. From the viewpoint of fully exhibiting the effects of other components, the content of the ion trapping agent may be 10 parts by mass or less, or 5 parts by mass or less, relative to 100 parts by mass of the epoxy resin.

[0073] The average particle size of the ion trapping agent is preferably 0.1 μm to 3.0 μm, and the maximum particle size is preferably 10 μm or less. The average particle size of the ion trapping agent can be measured in the same manner as in the case of the inorganic filler.

[0074] (coupling agent) The epoxy resin composition of the present disclosure may further contain a coupling agent. The type of coupling agent is not particularly limited, and known coupling agents can be used. Examples of the coupling agent include silane coupling agents and titanium coupling agents. One type of coupling agent may be used alone, or two or more types may be used in combination.

[0075] Examples of silane coupling agents include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-[bis(β-hydroxyethyl)]aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, Examples of suitable silanes include methyltriethoxysilane, γ-(β-aminoethylamino)propyldimethoxymethylsilane, N-(dimethoxymethylsilylisopropyl)ethylenediamine, methyltrimethoxysilane, methyltriethoxysilane, N-(β-(N-vinylbenzylamino)ethyl)-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, γ-anilinopropyltrimethoxysilane (N-phenyl-3-aminopropyltrimethoxysilane), vinyltrimethoxysilane, and γ-mercaptopropylmethyldimethoxysilane.

[0076] Examples of titanium coupling agents include isopropyl triisostearoyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate)oxyacetate titanate, bis(dioctyl pyrophosphate)ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl tridodecyl benzenesulfonyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, and tetraisopropyl bis(dioctyl phosphite) titanate.

[0077] When the epoxy resin composition contains a coupling agent, the content of the coupling agent is preferably 10% by mass or less based on the total epoxy resin composition, and from the viewpoint of exerting its effects, it is preferably 0.1% by mass or more.

[0078] (mold release agent) The epoxy resin composition of the present disclosure may further contain a release agent. The type of release agent is not particularly limited, and known release agents can be used. Specific examples include higher fatty acids, carnauba wax, and polyethylene wax. One type of release agent may be used alone, or two or more types may be used in combination. When the epoxy resin composition contains a release agent, the content of the release agent is preferably 10% by mass or less, based on the total amount of the epoxy resin and the curing agent, and from the viewpoint of exerting its effect, it is preferably 0.5% by mass or more.

[0079] (Colorants and modifiers) The epoxy resin composition of the present disclosure may contain a colorant (e.g., carbon black). The epoxy resin composition may also contain a modifier (e.g., silicone resin and silicone rubber). The colorant and modifier may each be used alone or in combination of two or more.

[0080] When conductive particles such as carbon black are used as the colorant, the content of particles with a particle diameter of 10 μm or more is preferably 1% by mass or less of the total conductive particles. When the epoxy resin composition contains conductive particles, the content of the conductive particles is preferably 3 mass % or less based on the total amount of the epoxy resin and the curing agent.

[0081] <Method for producing epoxy resin composition> The method for preparing the epoxy resin composition is not particularly limited and can be performed by a known method. For example, the epoxy resin composition can be prepared by thoroughly mixing a mixture of raw materials in predetermined amounts using a mixer or the like, kneading the mixture using a hot roll, extruder, or grinder, and then cooling and pulverizing the mixture. The state of the epoxy resin composition is not particularly limited and may be in a powder, solid, liquid, or other form.

[0082] <Semiconductor device> The semiconductor device of the present disclosure includes a semiconductor element and a cured product of the epoxy resin composition of the present disclosure that encapsulates the semiconductor element.

[0083] The method for encapsulating a semiconductor element using an epoxy resin composition is not particularly limited, and any known method can be applied. For example, transfer molding is common, but compression molding, injection molding, etc. may also be used.

[0084] The semiconductor device of the present disclosure is suitable for use as an IC, an LSI (Large-Scale Integration), or the like. [Example]

[0085] The present disclosure will be described below based on examples, but the present disclosure is not limited to the following examples. In the following examples, parts and % represent parts by mass and % by mass unless otherwise specified.

[0086] (Example 1 and Comparative Examples 1 to 3) The components were blended to obtain the compositions shown in Table 1, and the components were kneaded and dispersed using a triple roll mill and a vacuum kneading mill to prepare the epoxy resin compositions of Example 1 and Comparative Examples 1 to 3. In the table, the blending units are parts by mass, and "-" indicates "not blended." The materials used in preparing the epoxy resin composition and their abbreviations are listed below.

[0087] Epoxy resin: Biphenyl aralkyl type epoxy resin with an epoxy equivalent weight of 265g / eq to 285g / eq Hardener: Biphenyl aralkyl phenolic resin with a hydroxyl group equivalent of 201g / eq to 220g / eq Silane compound: γ-glycidoxypropyltrimethoxysilane Pigment: Carbon black Additive (ion trap): Hydrotalcite Silica particles A: average particle size 0.5 μm Silica particles B: average particle size 10 μm

[0088] -Production of Curing Accelerator A- 370 g of an addition reaction product of triphenylphosphine and 1,4-benzoquinone, synthesized by the method described in JP-A-9-157497, was suspended in 2000 mL of methanol to prepare a slurry, to which 104 g of 35% hydrochloric acid was added dropwise over 30 minutes, followed by the addition of 2000 mL of water and 204 g of potassium hydrogen phthalate, followed by heating and stirring for 1 hour at 80° C. After the reaction solution was cooled to 10° C., the precipitated crystals were filtered and washed twice with 1000 mL of purified water. To the obtained crude crystals, 1200 mL each of methanol and purified water was added, and the mixture was heated and stirred at 80°C for 1 hour. After the reaction solution was cooled to 10°C, the precipitated crystals were filtered and washed twice with 1000 mL of purified water. The obtained crystals were dried under reduced pressure to obtain 387 g (yield 72.1%) of 2,5-dihydroxyphenyl(triphenyl)phosphonium hydrogen phthalate (hardening accelerator A).

[0089] Curing Accelerator B: Triphenylphosphine-benzoquinone adduct Curing Accelerator C: Triparatolylphosphine-benzoquinone adduct Curing Accelerator D: Tri-n-butylphosphine-benzoquinone adduct

[0090] <Liquidity> (Spiral Flow (SF) Evaluation) Using a spiral flow measurement mold conforming to EMMI-1-66, the prepared epoxy resin compositions were molded in a transfer molding machine under conditions of a mold temperature of 180°C, a molding pressure of 22.5 MPa, and a curing time of 300 seconds, and the flow distance was determined. The SF of the epoxy resin composition of Example 1 was defined as 100%, and the relative SF values ​​of the epoxy resin compositions of each comparative example were calculated. The results are shown in Table 1.

[0091] (Disk Flow (DF) Evaluation) DF was measured using a flat mold for disk flow measurement, consisting of an upper mold measuring 200 mm (W) × 200 mm (D) × 25 mm (H) and a lower mold measuring 200 mm (W) × 200 mm (D) × 15 mm (H). Specifically, 5 g of the obtained epoxy resin composition of each Example and Comparative Example was placed in the center of the lower mold heated to 180°C. After 5 seconds, the upper mold, also heated to 180°C, was closed and compression molded under a load of 78 N and a cure time of 90 seconds. The major and minor axes of the molded product were measured with calipers, and the average value (mm) of the major and minor axes was taken as the disk flow length. The results are shown in Table 1.

[0092] (Wire sweep evaluation) The prepared epoxy resin composition was used in a compression molding machine (TOWA, PMC-1040S) to seal a package at 175°C for 120 seconds, followed by post-curing at 175°C for 5 hours to obtain a semiconductor device. This semiconductor device is a ball grid array (BGA) package (resin-sealed portion size: 228mm x 67mm x 1mm thick) with a chip size of 7.5mm x 7.5mm. The copper wire diameter is 18µm and the average copper wire length is 5mm. The fabricated package was examined using a soft X-ray analyzer to observe the deformation state of the copper wires and to check for the presence or absence of deformation. The results are shown in Table 1.

[0093] The evaluation was carried out according to the following criteria. AA: Wire sweep rate is less than 3% A: The occurrence rate of wire sweep is 3% or more but less than 5% B: Wire sweep rate is 5% or more but less than 7% C: Wire sweep rate is 7% or more

[0094] <Reliability> (Chloride ion content (amount of chlorine in the extract)) 50 g of ion-exchanged water and 5 g of pulverized powder of the cured epoxy resin composition prepared were placed in a pressure vessel and left at 121°C and 2 atmospheres for 20 hours. After leaving the vessel, the chloride ion concentration in the water was measured using ion chromatography. The results are shown in Table 1.

[0095] (HAST test) The prepared epoxy resin composition was used in a transfer molding machine at a mold temperature of 175°C and a molding pressure of 70 kgf / cm. 2The semiconductor element was encapsulated under conditions of a pressure of approximately 6.86 MPa and a curing time of 120 seconds to produce an evaluation substrate. The electrodes of the evaluation substrate used 60 μm-wide pads composed of Al / Si / Cu=98.9% / 0.8% / 0.3%, and pure copper wires. This evaluation substrate was placed in a high-temperature, high-humidity chamber at 130°C and 85% humidity, and a voltage of 5 V was applied. A highly accelerated temperature and humidity stress test (HAST) was then performed in the chamber for a cumulative total of 24, 48, 96, 168, and 336 hours. For the five packages of each example and comparative example, electrical characteristics were evaluated after each of the above-mentioned time periods, and the presence or absence of short-circuited wires was confirmed among the four pairs of wires in each package (a total of 20 pairs of wires). The results are shown in Table 1.

[0096] The evaluation was carried out according to the following criteria. AA: After 336 hours, no short circuits occurred in any of the wires. A: At 336 hours, a short circuit occurred in one of the wires. B: After 192 hours, a short circuit occurred in one of the wires. C: After 168 hours, a short circuit occurred in one of the wires.

[0097] [Table 1]

[0098] As is clear from the evaluation results in Table 1, the epoxy resin composition of Example 1 suppresses wire sweep more effectively than the epoxy resin compositions of Comparative Examples 1 to 3. Furthermore, the epoxy resin composition of Example 1 exhibits superior HAST test results to the epoxy resin compositions of Comparative Examples 2 and 3. The superior HAST test results indicate that the epoxy resin composition of Example 1 is able to suppress wire open more effectively than the epoxy resin compositions of Comparative Examples 2 and 3. From the above, it is clear that the epoxy resin composition of Example 1 can suppress wire sweep and wire open.

Claims

1. The disk flow length is 100 mm or more, An epoxy resin composition, which when cured has a chloride ion content of 20 ppm or less.

2. Epoxy resin, A hardener; a salt of a cation derived from an addition reaction product of a phosphine compound and a quinone compound and an anion derived from a carboxylic acid compound having a structure in which two adjacent carbon atoms are both substituted with carboxy groups; The epoxy resin composition according to claim 1, comprising:

3. 3. The epoxy resin composition according to claim 2, wherein the salt comprises a phosphonium compound represented by the following general formula (I): 【Chemistry 1】 (In general formula (I), R １Ａ Each of R independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms. １Ａ Two R arbitrarily selected from １Ａ are connected to each other, R １Ａ may form a ring structure together with the phosphorus atom to which R is attached. １Ｂ each independently represents a substituted or unsubstituted hydrocarbon group having 1 to 18 carbon atoms; n represents an integer of 0 to 3; when n is 2 or 3, two R １Ｂ may be linked together to form a cyclic structure. a represents 1 or 2. When a is 1, X ａ－ represents a monovalent anion represented by the following general formula (IA), and when a is 2, X ａ－ represents a divalent anion represented by the following general formula (IB): 【Chemistry 2】 (In general formula (IA), R １Ｃ each independently represents an alkyl group, a hydroxyl group, an amino group, or an alkoxy group, and p represents an integer of 0 to 4. In general formula (IB), R １Ｄ each independently represents an alkyl group, a hydroxyl group, an amino group, or an alkoxy group; and q represents an integer of 0 to 2.

4. 4. The epoxy resin composition according to claim 2, further comprising an inorganic filler.

5. A semiconductor device comprising: a semiconductor element; and a cured product of the epoxy resin composition according to any one of claims 1 to 4, which encapsulates the semiconductor element.

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