Epoxy resin composition, cured product, and electronic component device

Abstract

To provide an epoxy resin composition which allows the manufacture of an electronic component device excellent in electrical reliability, a cured product thereof, and an electronic component device using the epoxy resin composition.SOLUTION: The epoxy resin composition contains: an epoxy resin; a curing agent containing a compound having a constituent unit of formula (B1) and a constituent unit of formula (B2); an inorganic filler; and a specific hydrotalcite compound. In the formula (B1) and the formula (B2), R2-R5 each independently represent a C1-6 monovalent organic group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to an epoxy resin composition, a cured product, and an electronic component device. [Background technology]

[0002] Sealing compositions containing epoxy resins are widely used to seal semiconductor packages. However, epoxy resins are often synthesized using epichlorohydrin, and encapsulating compositions containing such epoxy resins tend to contain residual impurity ions, such as chloride ions, derived from the epichlorohydrin. When semiconductor packages are produced using such encapsulating compositions, the presence of impurity ions tends to promote wire corrosion. Therefore, in order to improve the moisture resistance reliability of semiconductor packages, attempts have been made to incorporate hydrotalcite compounds into epoxy resin compositions as ion trapping agents that capture impurity ions (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-44898 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, there is room for improvement in electrical reliability when an epoxy resin composition containing a hydrotalcite compound is used in an electronic component device. The present disclosure relates to an epoxy resin composition and a cured product thereof that can be used to prepare an electronic component device with excellent electrical reliability, as well as an electronic component device using the epoxy resin composition. [Means for solving the problem]

[0005] Means for solving the above problems include the following aspects. <1> Epoxy resin, a curing agent containing a compound having a structural unit of the following formula (B1) and a structural unit of the following formula (B2); an inorganic filler; a hydrotalcite compound containing a hydrotalcite compound having a molar ratio of Mg to Al (Mg / Al) of 2.4 or more; An epoxy resin composition comprising:

[0006] [ka]

[0007] In formula (B1) and formula (B2), R 2 ~R 5 each independently represents a monovalent organic group having 1 to 6 carbon atoms, X2 and X3 each independently represent an integer of 0 to 4, X4 and X5 each independently represent an integer of 0 to 3, n1 represents a number from 1 to 10, n2 represents a number from 1 to 10, The structural unit of formula (B2) exists separately from the structural unit of formula (B1). <2> the content of the compound having the structural unit of formula (B1) and the structural unit of formula (B2) relative to the total mass of the curing agent is 30% by mass to 100% by mass; <1> The epoxy resin composition according to claim 1. <3> The content of the inorganic filler is 50% by volume to 95% by volume relative to the total volume of the epoxy resin composition. <1> or <2> The epoxy resin composition according to claim 1. <4> The hydrotalcite compound having a molar ratio of Mg to Al (Mg / Al) of 2.4 or more has a volume average particle size of 20 μm or less. <1> ~ <3> 10. The epoxy resin composition according to claim 1, wherein the epoxy resin composition is <5> the content of the hydrotalcite compound having a molar ratio of Mg to Al (Mg / Al) of 2.4 or more is 0.01% by mass or more relative to the total mass of the epoxy resin; <1> ~ <4> 10. The epoxy resin composition according to claim 1, wherein the epoxy resin composition is <6> <1> ~ <5> A cured product of the epoxy resin composition according to any one of claims 1 to 10. <7> In a pressure cooker test, the water absorption rate after 20 hours at 121°C and 2.1 atmospheres is 0.30% by mass or less. <6> The cured product according to claim 1. <8> An element and a device for sealing the element <6> or <7> and an electronic component device comprising the cured product according to claim 1. [Effects of the Invention]

[0008] According to the present disclosure, there are provided an epoxy resin composition capable of producing electronic component devices with excellent electrical reliability, a cured product thereof, and an electronic component device using the epoxy resin composition. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, modes for carrying out embodiments of the present disclosure will be described in detail. However, the embodiments of the present disclosure are 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 they do not limit the embodiments of the present disclosure.

[0010] 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, multiple types of particles corresponding to each component may be contained. 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.

[0011] In the present disclosure, the "resin component" in the epoxy resin composition means the components of the epoxy resin composition excluding the inorganic filler. In this disclosure, the content or content ratio of each component in the epoxy resin composition refers to the content or content ratio based on the amount excluding volatile components such as solvents, if any, present in the epoxy resin composition. "Volatile components" refer to components that volatilize when heated at 150°C for 1 hour.

[0012] <Epoxy resin composition> The epoxy resin composition contains an epoxy resin, a curing agent including a compound having a structural unit of the following formula (B1) and a structural unit of the following formula (B2) (hereinafter also referred to as the "specific curing agent"), an inorganic filler, and a hydrotalcite compound including a hydrotalcite compound having a molar ratio of Mg to Al (Mg / Al) of 2.4 or more (hereinafter also referred to as the "specific hydrotalcite compound").

[0013] [ka]

[0014] In formula (B1) and formula (B2), R 2 ~R 5 each independently represents a monovalent organic group having 1 to 6 carbon atoms, X2 and X3 each independently represent an integer of 0 to 4, X4 and X5 each independently represent an integer of 0 to 3, n1 represents a number from 1 to 10, n2 represents a number from 1 to 10, The structural unit of formula (B2) exists separately from the structural unit of formula (B1).

[0015] The epoxy resin composition of the present disclosure makes it possible to produce electronic component devices with excellent electrical reliability. The reason for this is not entirely clear, but is thought to be as follows: The specific hydrotalcite compound has good impurity ion-trapping ability, but is prone to aggregation in the presence of moisture, making it difficult to achieve good dispersibility. On the other hand, the epoxy resin composition of the present disclosure containing the specific curing agent is thought to be able to suppress water absorption by the resin material, allowing the specific hydrotalcite compound to be well dispersed within the resin material. As a result, the ion-trapping ability of the specific hydrotalcite compound is particularly well exhibited, and good electrical reliability is thought to be achieved. Each component of the epoxy resin composition will be described in detail below.

[0016] <Epoxy resin> The epoxy resin composition contains an epoxy resin. The type of epoxy resin is not particularly limited as long as it has two or more epoxy groups in one molecule. The epoxy resin may be solid or liquid at 25°C and atmospheric pressure, and is preferably solid. Specifically, novolac epoxy resins (phenol novolac epoxy resins, orthocresol novolac epoxy resins, etc.) are obtained by epoxidizing novolac resins obtained by condensing or co-condensing, under an acid catalyst, at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, etc., and naphthol compounds such as α-naphthol, β-naphthol, dihydroxynaphthalene, etc., with an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, propionaldehyde, etc.; triphenylmethane epoxy resins are obtained by epoxidizing triphenylmethane phenolic resins obtained by condensing or co-condensing, under an acid catalyst, the above phenolic compounds with aromatic aldehyde compounds such as benzaldehyde, salicylaldehyde, etc.; and epoxidized novolac resins obtained by co-condensing, under an acid catalyst, the above phenolic compounds and naphthol compounds with an aldehyde compound. diphenylmethane-type epoxy resins, which are diglycidyl ethers of bisphenol A, bisphenol F, etc.; biphenyl-type epoxy resins, which are diglycidyl ethers of alkyl-substituted or unsubstituted biphenols; stilbene-type epoxy resins, which are diglycidyl ethers of stilbene-based phenolic compounds; sulfur-containing epoxy resins, which are diglycidyl ethers of bisphenol S, etc.; glycidyl ether-type epoxy resins, which are glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ester-type epoxy resins, which are glycidyl esters of polycarboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidylamine-type epoxy resins, in which the active hydrogen bonded to the nitrogen atom of aniline, diaminodiphenylmethane, isocyanuric acid, etc. is substituted with a glycidyl group; and dicyclopentadiene-type epoxy resins, which are epoxidized co-condensation resins of dicyclopentadiene and phenolic compounds.Alicyclic epoxy resins such as vinylcyclohexene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, which are produced by epoxidizing the olefin bonds in the molecule; paraxylylene-modified epoxy resins, which are glycidyl ethers of paraxylylene-modified phenolic resins; metaxylylene-modified epoxy resins, which are glycidyl ethers of metaxylylene-modified phenolic resins; terpene-modified epoxy resins, which are glycidyl ethers of terpene-modified phenolic resins; and dicyclopentadiene-modified phenolic resins, which are glycidyl ethers of dicyclopentadiene-modified phenolic resins. Examples of suitable epoxy resins include pentadiene-modified epoxy resins, cyclopentadiene-modified epoxy resins which are glycidyl ethers of cyclopentadiene-modified phenolic resins, polycyclic aromatic ring-modified epoxy resins which are glycidyl ethers of polycyclic aromatic ring-modified phenolic resins, naphthalene-type epoxy resins which are glycidyl ethers of naphthalene ring-containing phenolic resins, halogenated phenol novolac-type epoxy resins, hydroquinone-type epoxy resins, trimethylolpropane-type epoxy resins, linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid, and aralkyl-type epoxy resins obtained by epoxidizing aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins. Further examples of suitable epoxy resins include epoxidized silicone resins and epoxidized acrylic resins. These epoxy resins may be used alone or in combination of two or more.

[0017] Among the above epoxy resins, from the viewpoint of a balance between reflow resistance and fluidity, epoxy resins selected from the group consisting of biphenyl-type epoxy resins, stilbene-type epoxy resins, diphenylmethane-type epoxy resins, sulfur-containing epoxy resins, novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, triphenylmethane-type epoxy resins, copolymer-type epoxy resins, and aralkyl-type epoxy resins (these are referred to as "specific epoxy resins"). The specific epoxy resins may be used alone or in combination of two or more.

[0018] When the epoxy resin contains a specific epoxy resin, the total content of the specific epoxy resin is preferably 30% by mass or more, and more preferably 50% by mass or more, of the total epoxy resin, from the viewpoint of exhibiting the performance of the specific epoxy resin.

[0019] Among the specific epoxy resins, biphenyl-type epoxy resins, stilbene-type epoxy resins, diphenylmethane-type epoxy resins, and sulfur-atom-containing epoxy resins are more preferred from the viewpoint of fluidity, and dicyclopentadiene-type epoxy resins, triphenylmethane-type epoxy resins, and aralkyl-type epoxy resins are preferred from the viewpoint of heat resistance.

[0020] In one embodiment, the epoxy resin may include a copolymerized epoxy resin obtained by epoxidizing a novolak resin obtained by co-condensing a phenol compound and a naphthol compound with an aldehyde compound in the presence of an acid catalyst. When the epoxy resin contains a copolymerized epoxy resin obtained by epoxidizing a novolak resin obtained by co-condensing a phenol compound and a naphthol compound with an aldehyde compound in the presence of an acid catalyst, the content of the copolymerized epoxy resin may be 50% by mass to 100% by mass, 70% by mass to 100% by mass, or 90% by mass to 100% by mass, based on the total mass of the epoxy resin.

[0021] The copolymerized epoxy resin obtained by epoxidizing a novolac resin obtained by co-condensing a naphthol compound, a phenol compound, and an aldehyde compound under an acidic catalyst is not particularly limited as long as it is an epoxy resin made from a compound having a naphthol skeleton and a compound having a phenol skeleton. For example, an epoxy resin obtained by glycidyl etherifying a novolac phenolic resin using a compound having a naphthol skeleton and a compound having a phenol skeleton is preferred, and an epoxy resin represented by the following general formula (IX) is more preferred. Among the epoxy resins represented by the following general formula (IX), R 21is a methyl group, i is 1, j is 0, and k is 0, and NC-7300 (trade name, Nippon Kayaku Co., Ltd.) is available as a commercially available product.

[0022] [ka]

[0023] In formula (IX), R 19 ~R 21 represents a monovalent organic group having 1 to 18 carbon atoms (preferably an alkyl group or an aryl group), and may all be the same or different. Each i independently represents an integer of 0 to 3, each j independently represents an integer of 0 to 2, and each k independently represents an integer of 0 to 4. Each l and m represents an average value and is a number greater than 0 and not greater than 10, and (l + m) is a number greater than 0 and not greater than 10. The terminal of the epoxy resin represented by formula (IX) is represented by the following formula (IX-1) or (IX-2). In formulas (IX-1) and (IX-2), R 19 ~R 21 , i, j and k are defined as R 19 ~R 21 has the same definition as i, j, and k. n is 1 (when bonding via a methylene group) or 0 (when bonding not via a methylene group).

[0024] [ka]

[0025] Examples of the epoxy resin represented by the general formula (IX) include random copolymers containing l structural units and m structural units randomly, alternating copolymers containing them alternately, copolymers containing them regularly, block copolymers containing them in block form, etc. Any of these may be used alone or in combination of two or more.

[0026] Another preferred copolymerized epoxy resin is Epiclon HP-5000 (trade name, DIC Corporation), a methoxynaphthalene-cresol-formaldehyde co-condensation epoxy resin containing the following two structural units in a random, alternating, or block order, and represented by the following general formula: In the following general formula, n and m each represent an average value and are numbers greater than 0 and less than 10, and (n+m) represents a number greater than 0 and less than 10; preferably, n and m each represent an average value and are numbers from 1 to 9, and (n+m) represents a number from 2 to 10.

[0027] [ka]

[0028] The epoxy equivalent of the epoxy resin is not particularly limited. From the viewpoint of a balance of various properties such as moldability, reflow resistance, and electrical reliability, the epoxy equivalent of the epoxy resin is preferably 100 g / eq to 1000 g / eq, more preferably 150 g / eq to 500 g / eq, and even more preferably 160 g / eq to 300 g / eq. The epoxy equivalent of the epoxy resin is a value measured by a method in accordance with JIS K 7236:2009.

[0029] When the epoxy resin is solid, its softening point or melting point is not particularly limited, but the softening point or melting point of the epoxy resin is preferably 40°C to 180°C from the viewpoints of moldability and reflow resistance, and more preferably 50°C to 130°C from the viewpoint of handleability during preparation of the epoxy resin composition. The melting point of the epoxy resin is a value measured by differential scanning calorimetry (DSC), and the softening point of the epoxy resin is a value measured by a method (ring and ball method) in accordance with JIS K 7234:1986.

[0030] From the viewpoints of strength, fluidity, heat resistance, moldability, etc., the content of the epoxy resin in the epoxy resin composition is preferably 0.5% by mass to 50% by mass, and more preferably 2% by mass to 30% by mass.

[0031] <Curing agent> The epoxy resin composition contains a curing agent that includes a compound having a structural unit of the following formula (B1) and a structural unit of the following formula (B2) (i.e., a specific curing agent).

[0032] [ka]

[0033] In formula (B1) and formula (B2), R 2 ~R 5 each independently represents a monovalent organic group having 1 to 6 carbon atoms, X2 and X3 each independently represent an integer of 0 to 4, X4 and X5 each independently represent an integer of 0 to 3, n1 represents a number from 1 to 10, n2 represents a number from 1 to 10, The structural unit of formula (B2) exists separately from the structural unit of formula (B1).

[0034] Hereinafter, the structural unit of formula (B1) will also be referred to as a (B1) unit, and the structural unit of formula (B2) will also be referred to as a (B2) unit. The phrase "the structural unit of formula (B2) exists separately from the structural unit of formula (B1)" means that the (B2) unit is not part of the (B1) unit, but is a structural unit based on a polymerization component separate from the component that forms the (B1) unit. The specific curing agent has n1 (B1) units and n2 (B2) units. The linking mode between the (B1) units and the (B2) units is not particularly limited. When the specific curing agent has a plurality of (B1) units and a plurality of (B2) units, the linking mode between the (B1) units and the (B2) units may be, for example, block copolymerization or random copolymerization, with block copolymerization being preferred.

[0035] The specific curing agent is preferably a compound represented by the following formula (B).

[0036] [ka]

[0037] In formula (B), R 1 ~R 5 each independently represents a monovalent organic group having 1 to 6 carbon atoms, X1 to X3 each independently represent an integer of 0 to 4, X4 and X5 each independently represent an integer of 0 to 3, n1 represents a number from 1 to 10, n2 represents a number from 1 to 10.

[0038] In formula (B1), formula (B2) and formula (B), R 1 ~R 5 are each independently a monovalent organic group having 1 to 6 carbon atoms, and preferably a monovalent organic group having 1 to 3 carbon atoms. 1 ~R 5 Examples of the monovalent organic group having 1 to 6 carbon atoms represented by the formula include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, a pentyl group, a hexyl group, an isopropyl group, an isobutyl group, and a t-butyl group.

[0039] In formula (B1), formula (B2) and formula (B), X1 to X3 are each independently preferably 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0040] In formula (B1), formula (B2) and formula (B), X4 and X5 each independently represent preferably 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0041] In formula (B1), formula (B2) and formula (B), n1 and n2 are the average values ​​of the repeating numbers of the structural units in parentheses.

[0042] The hydroxyl equivalent of the specific curing agent is preferably 130 g / eq to 200 g / eq, and more preferably 150 g / eq to 180 g / eq. The hydroxyl equivalent of the specific curing agent is measured by the method described below.

[0043] When the specific curing agent is solid, its softening point or melting point is not particularly limited, and from the viewpoints of moldability and reflow resistance, it is preferably 40°C to 180°C, and from the viewpoint of handleability during production of the epoxy resin composition, it is more preferably 50°C to 130°C. From the viewpoints of improving flowability and reducing the high-temperature elastic modulus of the cured product of the epoxy resin composition and improving reflow resistance, the softening point or melting point of the specific curing agent is preferably 50°C to 100°C, more preferably 50°C to 75°C, and even more preferably 50°C to 70°C.

[0044] The specific curing agent may be used alone or in combination of two or more kinds. As the curing agent, other curing agents may be used in combination with the specific curing agent. The content of the specific curing agent relative to the total mass of the curing agents is preferably 30% by mass to 100% by mass, more preferably 40% by mass to 100% by mass, may be 50% by mass to 100% by mass, or may be 70% by mass to 100% by mass.

[0045] Examples of curing agents other than the specific curing agent include phenolic curing agents (compounds having a phenolic hydroxyl group in the molecule; excluding the specific curing agent), amine curing agents, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, and blocked isocyanate curing agents. From the viewpoint of improving heat resistance, the curing agent is preferably a phenolic curing agent. The curing agent may be solid or liquid at 25°C and atmospheric pressure, and is preferably solid.

[0046] Specific examples of the phenolic curing agent include polyhydric phenolic compounds such as resorcinol, catechol, bisphenol A, bisphenol F, and substituted or unsubstituted biphenols; novolak-type phenolic resins obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene, with an aldehyde compound such as formaldehyde, acetaldehyde, or propionaldehyde, under an acidic catalyst; and novolak-type phenolic resins synthesized from the above-mentioned phenolic compounds and dimethoxyparaxylene, bis(methoxymethyl)biphenyl, or the like. Examples of suitable phenolic curing agents include aralkyl phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins (excluding specific curing agents); paraxylylene and / or metaxylylene-modified phenolic resins; melamine-modified phenolic resins; terpene-modified phenolic resins; dicyclopentadiene-type phenolic resins and dicyclopentadiene-type naphthol resins synthesized by copolymerization of the above phenolic compounds with dicyclopentadiene; cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified phenolic resins; biphenyl-type phenolic resins; triphenylmethane-type phenolic resins obtained by condensation or co-condensation of the above phenolic compounds with aromatic aldehyde compounds such as benzaldehyde and salicylaldehyde under an acidic catalyst; and phenolic resins obtained by copolymerization of two or more of these. The phenolic curing agents may be used singly or in combination of two or more.

[0047] Among phenolic curing agents, from the viewpoint of reflow resistance, at least one selected from the group consisting of aralkyl phenolic resins, dicyclopentadiene phenolic resins, triphenylmethane phenolic resins, copolymerized phenolic resins of benzaldehyde phenolic resins and aralkyl phenolic resins, and novolac phenolic resins is preferred. These phenolic curing agents may be used alone or in combination of two or more.

[0048] The functional group equivalent weight (hydroxyl group equivalent weight for phenolic curing agents, active hydrogen equivalent weight for amine curing agents) of curing agents other than the specific curing agent is not particularly limited. From the viewpoint of the balance of various properties such as moldability, reflow resistance, and electrical reliability, the functional group equivalent weight of curing agents other than the specific curing agent is preferably 70 g / eq to 1000 g / eq, and more preferably 80 g / eq to 500 g / eq.

[0049] The hydroxyl equivalent weight for phenolic curing agents is a value calculated based on the hydroxyl value measured in accordance with JIS K0070:1992, and the active hydrogen equivalent weight for amine curing agents is a value calculated based on the amine value measured in accordance with JIS K7237:1995.

[0050] When the curing agent is solid, its softening point or melting point is not particularly limited. From the viewpoints of moldability and reflow resistance, the softening point or melting point of the curing agent is preferably 40°C to 180°C, and from the viewpoint of handleability during production of the epoxy resin composition, it is more preferably 50°C to 130°C. The melting point or softening point of the curing agent is a value measured in the same manner as the melting point or softening point of the epoxy resin.

[0051] The equivalent ratio between the epoxy resin and the curing agent, i.e., the ratio of the number of functional groups in the curing agent to the number of epoxy groups in the epoxy resin (number of functional groups in the curing agent / number of epoxy groups in the epoxy resin), is not particularly limited. In order to minimize the amount of unreacted components, the equivalent ratio between the epoxy resin and the curing agent is preferably set in the range of 0.5 to 2.0, and more preferably in the range of 0.6 to 1.3. In terms of moldability and reflow resistance, the equivalent ratio between the epoxy resin and the curing agent is more preferably set in the range of 0.8 to 1.2.

[0052] <Inorganic filler> The epoxy resin composition contains an inorganic filler, and the material of the inorganic filler is not particularly limited. Specific examples of inorganic filler materials include silica such as fused silica and crystalline silica, glass, alumina, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, magnesium oxide, silicon carbide, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, talc, clay, and mica. Inorganic fillers having flame retardant properties may also be used. Examples of inorganic fillers having flame retardant properties include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as composite hydroxides of magnesium and zinc, and zinc borate. Among inorganic fillers, silica such as fused silica is preferred from the viewpoint of reducing the linear expansion coefficient, and alumina is preferred from the viewpoint of high thermal conductivity.

[0053] The shape of the inorganic filler is not particularly limited, but from the viewpoints of filling properties and mold wear, a spherical shape is preferred.

[0054] The inorganic filler may be used alone or in combination of two or more. The term "use of two or more inorganic fillers" refers to, for example, the use of two or more inorganic fillers having the same components but different average particle sizes, the use of two or more inorganic fillers having the same average particle size but different components, and the use of two or more inorganic fillers having different average particle sizes and types.

[0055] When the inorganic filler is particulate, its average particle diameter is not particularly limited. For example, the volume average particle diameter of the entire inorganic filler is preferably 80 μm or less, and may be 50 μm or less, 40 μm or less, 30 μm or less, or 20 μm or less. Furthermore, the volume average particle diameter of the entire inorganic filler is preferably 0.1 μm or more, more preferably 0.2 μm or more, and even more preferably 0.3 μm or more. When the volume average particle diameter of the inorganic filler is 0.1 μm or more, an increase in the viscosity of the epoxy resin composition tends to be suppressed. When the volume average particle diameter of the inorganic filler is 80 μm or less, the filling ability into narrow gaps tends to be further improved. The volume average particle diameter of the inorganic filler can be measured as the particle diameter (D50) at which the cumulative total from the small diameter side reaches 50% in the volume-based particle size distribution measured using a laser diffraction / scattering particle size distribution analyzer (e.g., HORIBA, Ltd., product name: LA920).

[0056] The inorganic filler preferably has a controlled maximum particle size in order to improve filling properties in narrow gaps. The maximum particle size of the inorganic filler may be adjusted as appropriate, and from the viewpoint of filling properties, it is preferably 105 μm or less, more preferably 75 μm or less, and may be 60 μm or less, or may be 40 μm or less. The maximum particle size is the particle size (D90) at which the cumulative percentage from the small diameter side reaches 90% in the volume-based particle size distribution measured using a laser diffraction / scattering particle size distribution analyzer (e.g., Horiba, Ltd., product name: LA920).

[0057] The content of the inorganic filler is not particularly limited. The content of the inorganic filler is preferably 50% by volume or more, more preferably 60% by volume or more, even more preferably 70% by volume or more, particularly preferably 75% by volume or more, and extremely preferably 80% by volume or more, based on the total volume of the epoxy resin composition. By making the content of the inorganic filler 50% by volume or more of the entire epoxy resin composition, it tends to be possible to suitably improve the properties of the cured product, such as the thermal expansion coefficient, thermal conductivity, and elastic modulus. Furthermore, the content of the inorganic filler is preferably 95% by volume or less, more preferably 90% by volume or less, and even more preferably 87% by volume or less, based on the total volume of the epoxy resin composition. When the content of the inorganic filler is 95% by volume or less of the total volume of the epoxy resin composition, an increase in viscosity of the epoxy resin composition is suppressed, and the flowability is further improved, tending to result in better moldability. From the above viewpoints, the content of the inorganic filler is preferably 50% by volume to 95% by volume, more preferably 60% by volume to 95% by volume, even more preferably 70% by volume to 95% by volume, particularly preferably 75% by volume to 90% by volume, and extremely preferably 80% by volume to 87% by volume, relative to the total volume of the epoxy resin composition.

[0058] The content of inorganic filler in a cured product of an epoxy resin composition can be measured as follows. First, the total mass of the cured product is measured, and the cured product is baked at 400°C for 2 hours and then at 700°C for 3 hours to evaporate the resin component, and the mass of the remaining inorganic filler is measured. The volumes are calculated from the obtained masses and their specific gravities, and the ratio of the volume of the inorganic filler to the total volume of the cured product is determined as the inorganic filler content.

[0059] <Hydrotalcite compounds> The epoxy resin composition contains a hydrotalcite compound, and the hydrotalcite compound contains Mg and Al as elements and includes a hydrotalcite compound (i.e., a specific hydrotalcite compound) having a molar ratio of Mg to Al (Mg / Al) (hereinafter also referred to as "Mg / Al ratio") of 2.4 or more.

[0060] In the present disclosure, the hydrotalcite compound may be a natural hydrotalcite or a synthetic hydrotalcite (hydrotalcite-like compound). The hydrotalcite compound may be an uncalcined hydrotalcite compound, a calcined hydrotalcite compound, or a combination of both.

[0061] The hydrotalcite compound may be used alone or in combination of two or more. Examples of the case of using two or more hydrotalcite compounds include the case of using two or more types of hydrotalcite compounds having different Mg / Al ratios, average particle diameters, specific surface areas, etc.

[0062] The specific hydrotalcite compound contains Mg and Al as elements, and its structure is not particularly limited as long as the Mg / Al ratio is 2.4 or more. Examples of the specific hydrotalcite compound include the compound represented by the following formula (1).

[0063] Mg (1-X) Al X (OH)2(CO3) X / 2 ·mH2O ……(1) (0 < X ≦ 0.29, m is a positive number)

[0064] In formula (1), X is a positive number representing the substitution amount of Mg for Al, 0 < X ≦ 0.29, and more preferably 0.20 ≦ X ≦ 0.29. m represents a positive number exceeding 0, and preferably 0 < m ≦ 2.

[0065] The Mg / Al ratio of the specific hydrotalcite compound is 2.4 or more, preferably 2.5 or more, more preferably 2.6 or more, further preferably 2.7 or more, and particularly preferably 2.8 or more. Also, the Mg / Al ratio is preferably 4.0 or less, may be 3.5 or less, or may be 3.2 or less. From the above viewpoints, the Mg / Al ratio may be 2.4 to 4.0, may be 2.5 to 4.0, may be 2.6 to 4.0, may be 2.7 to 3.5, or may be 2.8 to 3.2. The larger the Mg / Al ratio, the longer the interlayer distance in the crystal tends to be. When the Mg / Al ratio is 2.4 or more, it is considered that the interlayer distance does not become too narrow and impurities ions can be efficiently captured. Also, when the Mg / Al ratio is 4.0 or less, it is considered that an appropriate layered structure is maintained and impurities ions can be efficiently captured. The Mg / Al ratio can be measured by energy dispersive X-ray analysis.

[0066] The method for producing the specific hydrotalcite compound is not particularly limited, and the specific hydrotalcite compound can be synthesized by a conventional method. The Mg / Al ratio of the specific hydrotalcite compound can be set to a desired value, for example, by adjusting the molar ratio of the Mg salt and the Al salt used as raw materials.

[0067] The shape of the specific hydrotalcite compound is not particularly limited, but is preferably particulate. The particulate shape may be, for example, spherical or polyhedral.

[0068] When the specific hydrotalcite compound is in a particulate form, the volume average particle diameter is not particularly limited. The volume average particle diameter of the specific hydrotalcite compound may be, for example, 0.01 μm to 20 μm. In one embodiment, the volume average particle diameter of the specific hydrotalcite compound may be 20 μm or less, 15 μm or less, or 10 μm or less. The volume average particle diameter of the specific hydrotalcite compound may be 0.01 μm or more, 0.05 μm or more, or 0.1 μm or more. When the volume average particle diameter is 20 μm or less, excellent electrical reliability tends to be obtained. When the volume average particle diameter is 0.1 μm or more, dispersibility in the resin composition tends to be good. From the above viewpoints, the volume average particle diameter may be 0.01 μm to 20 μm, 0.05 μm to 15 μm, or 0.1 μm to 10 μm. In the present disclosure, when the volume average particle size of a specific hydrotalcite compound is mentioned, the particle size refers to the volume average particle size of secondary particles. In the present disclosure, the volume average particle diameter of the hydrotalcite compound can be measured as the particle diameter (D50) at which the cumulative amount from the small diameter side reaches 50% in a volume-based particle size distribution measured using a laser scattering diffraction particle size distribution measuring device.

[0069] The specific surface area of ​​the specific hydrotalcite compound is not particularly limited, and is 5 m 2 / g~300m 2 / g, and 10m 2 / g~250m 2 / g, more preferably 15m 2 / g~200m 2 The specific surface area of ​​the hydrotalcite compound is a value measured by the BET method.

[0070] The content of the specific hydrotalcite compound is preferably 0.01% by mass to 15% by mass, more preferably 0.03% by mass to 15% by mass, and even more preferably 0.1% by mass to 15% by mass, relative to the total mass of the epoxy resin. Furthermore, since the epoxy resin composition of the present disclosure can suppress aggregation of the hydrotalcite compound, the content of the specific hydrotalcite compound may be increased in anticipation of improved ion-trapping ability. For example, the content of the specific hydrotalcite compound may be 2.0% by mass or more, 2.5% by mass or more, or 3.0% by mass or more, relative to the total mass of the epoxy resin.

[0071] The specific hydrotalcite compound may be used in combination with a hydrotalcite compound other than the specific hydrotalcite compound. From the viewpoint of suitably exhibiting the excellent electrical reliability provided by the specific hydrotalcite compound, the content of the specific hydrotalcite compound relative to the total mass of the hydrotalcite compounds is preferably 50 mass% or more, more preferably 70 mass% or more, and even more preferably 90 mass% or more.

[0072] The hydrotalcite compound other than the specific hydrotalcite compound is not particularly limited, and examples thereof include compounds represented by the following formula (2) (excluding the specific hydrotalcite compound).

[0073] [M 1 1-x M 2 x (OH)2(A x / n mH2O) (2)

[0074] In formula (2), M 1 represents a divalent metal. M 2 represents a trivalent metal. x and m each independently represent a positive number. A represents CO3, HPO3, or a saturated aliphatic monocarboxylic acid. n represents the valence of A.

[0075] In formula (1), M 1 Examples of the divalent metal represented by include Mg, Fe, Zn, Ca, Cu, Co, etc., preferably Mg, Zn or Ca, and more preferably Mg. M 2 Examples of the trivalent metal represented by include Al, Ce, Fe, Mn, In, Cr, etc., preferably Al or Ce, and more preferably Al. x represents a positive number, preferably 0 < x ≤ 0.50, and more preferably 0.20 ≤ x ≤ 0.33. m represents a positive number, preferably 0 < m ≤ 2. A represents CO3, HPO3, or a saturated aliphatic monocarboxylic acid, and preferably CO3.

[0076] The total content of the hydrotalcite compound is not particularly limited as long as it is sufficient to capture ions such as halogen ions. The total content of the hydrotalcite compound is preferably 0.01% to 15% by mass, more preferably 0.03% to 15% by mass, and even more preferably 0.1% to 15% by mass based on the total mass of the epoxy resin.

[0077] <Various Additives> In addition to the above components, the epoxy resin composition may contain various additives such as a curing accelerator, a coupling agent, an ion exchanger, a mold release agent, a flame retardant, a coloring agent, a stress reliever, etc. The epoxy resin composition may also contain various additives generally used in the art as needed in addition to the additives exemplified below.

[0078] (Curing Accelerator) The epoxy resin composition may contain a curing accelerator. The type of curing accelerator is not particularly limited, and examples thereof include diazabicycloalkenes such as 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), cyclic amidine compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-heptadecylimidazole; derivatives of the cyclic amidine compounds; phenol novolac salts of the cyclic amidine compounds or their derivatives; and combinations of these compounds with maleic anhydride, quinone compounds such as 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone. compounds having intramolecular polarization obtained by adding a compound having a π bond, such as diazophenylmethane; cyclic amidinium compounds such as the tetraphenylborate salt of DBU, the tetraphenylborate salt of DBN, the tetraphenylborate salt of 2-ethyl-4-methylimidazole, and the tetraphenylborate salt of N-methylmorpholine; tertiary amine compounds such as pyridine, triethylamine, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of the above tertiary amine compounds; ammonium salt compounds such as tetra-n-butylammonium acetate, tetra-n-butylammonium phosphate, tetraethylammonium acetate, tetra-n-hexylammonium benzoate, and tetrapropylammonium hydroxide;organic phosphines such as primary phosphines such as ethylphosphine and phenylphosphine; secondary phosphines such as dimethylphosphine and diphenylphosphine; and tertiary phosphines such as triphenylphosphine, diphenyl(p-tolyl)phosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, tris(alkylalkoxyphenyl)phosphine, tris(dialkylphenyl)phosphine, tris(trialkylphenyl)phosphine, tris(tetraalkylphenyl)phosphine, tris(dialkoxyphenyl)phosphine, tris(trialkoxyphenyl)phosphine, tris(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiarylphosphine, trinaphthylphosphine, and tris(benzyl)phosphine; phosphine compounds such as complexes of the above organic phosphines with organoborons; and complexes of the above organic phosphines or the above phosphine compounds with maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, compounds having intramolecular polarization obtained by adding a compound having a π bond, such as quinone compounds, such as 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, and anthraquinone, or diazophenylmethane; compounds having intramolecular polarization obtained by adding the above organic phosphines or the above phosphine compounds with 4-bromophenol, 3-bromophenol, 2-bromophenol, 4-chlorophenol, 3-chlorophenol, 2-chlorophenol, and 4-iodophenol; compounds with intramolecular polarization obtained by reacting halogenated phenol compounds such as phenol, 3-iodophenol, 2-iodophenol, 4-bromo-2-methylphenol, 4-bromo-3-methylphenol, 4-bromo-2,6-dimethylphenol, 4-bromo-3,5-dimethylphenol, 4-bromo-2,6-di-t-butylphenol, 4-chloro-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol, and 4-bromo-4'-hydroxybiphenyl, followed by a dehydrohalogenation step;Examples of the curing accelerator include tetra-substituted phosphonium compounds such as tetraphenylphosphonium, tetraphenylborate salts of tetra-substituted phosphonium such as tetraphenylphosphonium tetra-p-tolylborate, and salts of tetra-substituted phosphonium with phenolic compounds; phosphobetaine compounds; and adducts of phosphonium compounds with silane compounds. One type of curing accelerator may be used alone, or two or more types may be used in combination.

[0079] Particularly suitable curing accelerators include triphenylphosphine, and adducts of triphenylphosphine and quinone compounds.

[0080] The content of the curing accelerator is preferably 0.1 to 30 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the resin component. When the amount of the curing accelerator is 0.1 part by mass or more per 100 parts by mass of the resin component, good curing tends to occur in a short time. When the amount of the curing accelerator is 30 parts by mass or less per 100 parts by mass of the resin component, the curing speed is not too fast, and good molded products tend to be obtained.

[0081] (coupling agent) The epoxy resin composition may 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, titanium coupling agents, aluminum chelate compounds, and aluminum / zirconium compounds. One type of coupling agent may be used alone, or two or more types may be used in combination.

[0082] Examples of the silane coupling agent include silane compounds such as epoxy silane, mercapto silane, amino silane, alkyl silane, ureido silane, and vinyl silane. Specific examples include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-(2-aminoethyl)aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, octenyltrimethoxysilane, glycidoxyoctyltrimethoxysilane, and methacryloxyoctyltrimethoxysilane.

[0083] 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.

[0084] When the epoxy resin composition contains a coupling agent, the amount of the coupling agent is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, per 100 parts by mass of the inorganic filler. When the amount of the coupling agent is 0.05 parts by mass or more per 100 parts by mass of the inorganic filler, adhesion to metal members tends to be improved. When the amount of the coupling agent is 20 parts by mass or less per 100 parts by mass of the inorganic filler, moldability tends to be improved.

[0085] (ion exchanger) The epoxy resin composition may contain an ion exchanger other than the hydrotalcite compound. The ion exchanger is not particularly limited, and conventionally known ion exchangers can be used. Specific examples include hydrous oxides of at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium, and bismuth.

[0086] When the epoxy resin composition contains an ion exchanger other than the hydrotalcite compound, the total amount of the hydrotalcite compound and the other ion exchanger is preferably 0.01% by mass to 15% by mass, more preferably 0.03% by mass to 15% by mass, and even more preferably 0.1% by mass to 15% by mass, based on the total mass of the epoxy resin.

[0087] (mold release agent) The epoxy resin composition may contain a mold release agent from the viewpoint of obtaining good releasability from the mold during molding. There are no particular limitations on the mold release agent, and conventionally known ones can be used. Specific examples include carnauba wax, higher fatty acids such as montanic acid and stearic acid, higher fatty acid metal salts, ester waxes such as montanic acid esters, and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene. One type of mold release agent may be used alone, or two or more types may be used in combination.

[0088] When the epoxy resin composition contains a release agent, the amount thereof is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the resin component. When the amount of the release agent is 0.01 part by mass or more per 100 parts by mass of the resin component, sufficient release properties tend to be obtained. When the amount of the release agent is 10 parts by mass or less per 100 parts by mass of the resin component, good adhesion and curability tend to be obtained.

[0089] (Flame retardant) The epoxy resin composition may contain a flame retardant. There are no particular limitations on the flame retardant, and conventionally known flame retardants can be used. Specific examples include organic or inorganic compounds containing halogen atoms, antimony atoms, nitrogen atoms, or phosphorus atoms, and metal hydroxides. The flame retardants may be used alone or in combination of two or more.

[0090] When the epoxy resin composition contains a flame retardant, the amount thereof is not particularly limited as long as it is an amount sufficient to obtain the desired flame retardant effect. For example, the amount of the flame retardant is preferably 1 to 30 parts by mass, more preferably 2 to 20 parts by mass, per 100 parts by mass of the resin component.

[0091] (coloring agent) The epoxy resin composition may further contain a colorant. Examples of the colorant include known colorants such as carbon black, organic dyes, organic pigments, titanium oxide, red lead, and red iron oxide. The content of the colorant can be appropriately selected depending on the purpose, etc. The colorant may be used alone or in combination of two or more.

[0092] (Stress reliever) The epoxy resin composition may contain a stress relaxation agent such as silicone oil or silicone rubber particles. The inclusion of a stress relaxation agent can further reduce package warpage and package cracking. Examples of stress relaxation agents include commonly used known stress relaxation agents (flexibilizers). Specific examples include thermoplastic elastomers such as silicone, styrene, olefin, urethane, polyester, polyether, polyamide, and polybutadiene elastomers; rubber particles such as NR (natural rubber), NBR (acrylonitrile-butadiene rubber), acrylic rubber, urethane rubber, and silicone powder; and rubber particles having a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS), methyl methacrylate-silicone copolymer, and methyl methacrylate-butyl acrylate copolymer. The stress relaxation agents may be used alone or in combination of two or more.

[0093] [Method for preparing epoxy resin composition] The method for preparing the epoxy resin composition is not particularly limited. A typical method includes thoroughly mixing the components using a mixer or the like, melt-kneading the mixture using a mixing roll, extruder, or the like, cooling, and pulverizing the mixture. More specifically, the method includes stirring and mixing the components described above, kneading the mixture using a kneader, roll, extruder, or the like that has been preheated to 70°C to 140°C, cooling, and pulverizing the mixture.

[0094] The epoxy resin composition may be solid or liquid at 25°C under atmospheric pressure, and is preferably solid. When the epoxy resin composition is solid, its shape is not particularly limited, and examples include powder, granules, and tablets. When the epoxy resin composition is in tablet form, it is preferable that the dimensions and mass of the tablet be set to suit the molding conditions of the package, from the viewpoint of ease of handling.

[0095] <Cured product of epoxy resin composition> The cured product in one embodiment of the present disclosure is a cured product of the above-described epoxy resin composition.

[0096] [Water absorption rate] The lower the water absorption of the cured product of the epoxy resin composition, the better. The water absorption of the cured product measured under the following conditions is preferably 0.50% by mass or less, more preferably 0.40% by mass or less, and even more preferably 0.30% by mass or less. The cured product is placed in a pressure cooker test device at 121°C and 2.1 atmospheres, and removed after 20 hours. The mass increase (%) from the mass of the cured product immediately before placement is calculated and used as the water absorption rate. The water absorption rate can be calculated using the following formula: Water absorption rate (mass%) = {(mass after water absorption - mass before water absorption) / mass before water absorption} x 100 When measuring the water absorption of a cured product of an epoxy resin composition before curing, the composition is molded at 175°C for 90 seconds and then post-cured at 175°C for 5 hours to produce a cured product, and the water absorption is measured. Specifically, the water absorption can be measured by the method described in the examples.

[0097] <Electronic component devices> An electronic component device according to one aspect of the present disclosure includes an element and a cured product of the epoxy resin composition described above that encapsulates the element. Examples of electronic component devices include devices obtained by mounting elements (active elements such as semiconductor chips, transistors, diodes, and thyristors, and passive elements such as capacitors, resistors, and coils) on a support member such as a lead frame, a pre-wired tape carrier, a wiring board, glass, a silicon wafer, or an organic substrate, and then sealing the resulting element part with an epoxy resin composition. More specifically, typical resin-sealed ICs such as DIP (Dual Inline Package), PLCC (Plastic Leaded Chip Carrier), QFP (Quad Flat Package), SOP (Small Outline Package), SOJ (Small Outline J-lead package), TSOP (Thin Small Outline Package), and TQFP (Thin Quad Flat Package) have a structure in which an element is fixed on a lead frame, and terminal portions of the element such as bonding pads and leads are connected by wire bonding, bumps, or the like, and then sealed using an epoxy resin composition by transfer molding or the like; TCP (Tape Carrier Package) has a structure in which an element connected to a tape carrier by bumps is sealed with an epoxy resin composition; and COB (Chip On Board) has a structure in which an element is connected to wiring formed on a support member by wire bonding, flip chip bonding, solder, or the like, and then sealed with an epoxy resin composition. Examples of suitable printed wiring boards include BGA (Ball Grid Array), CSP (Chip Size Package), and MCP (Multi Chip Package), which have a structure in which elements are mounted on the surface of a support member having terminals for connecting a wiring board formed on the back surface thereof, the elements are connected to wiring formed on the support member by bump or wire bonding, and the elements are then sealed with an epoxy resin composition. Epoxy resin compositions can also be suitably used in printed wiring boards.

[0098] Methods for encapsulating electronic component devices using epoxy resin compositions include low-pressure transfer molding, injection molding, and compression molding. [Example]

[0099] Next, embodiments of the present disclosure will be described in detail using examples, but the embodiments of the present disclosure are not limited to these examples.

[0100] [Preparation of Epoxy Resin Composition] The following ingredients were prepared: Epoxy resin: Methoxynaphthalene-cresol-formaldehyde co-condensation epoxy resin (HP-5000 (trade name), DIC Corporation, epoxy equivalent 250 g / eq, softening point 58°C) Curing agent 1: A compound in which, in formula (B), x1 to x5 are all 0, n1 is 1 to 10, and n2 is 1 to 10 (MEHC-7841 (trade name), Meiwa Chemical Industry Co., Ltd., hydroxyl group equivalent 164 g / eq to 168 g / eq, softening point 58°C to 65°C) Curing agent 2: Phenol novolac phenolic resin (H-4 (trade name), Meiwa Kasei Co., Ltd., hydroxyl equivalent 103 g / eq to 107 g / eq, softening point 67°C to 75°C) Curing agent 3: Aralkyl phenolic resin (MEH-7800 (trade name), Meiwa Kasei Co., Ltd., hydroxyl equivalent 167g / eq to 180g / eq, softening point 61℃ to 90℃) Hardener 4: Triphenylmethane phenolic resin (product name: MEH-7500, Meiwa Kasei Co., Ltd., hydroxyl equivalent 95g / eq to 99g / eq, softening point 107°C to 113°C) Curing accelerator: adduct of tributylphosphine and 1,4-benzoquinone Coupling agent 1: 3-glycidoxypropyltrimethoxysilane Coupling agent 2: N-phenyl-3-aminopropyltrimethoxysilane Release agent: Carnauba wax Pigment: Carbon black Hydrotalcite compound 1: (NAOX-41A (trade name), Mg / Al = 3.0, volume average particle size (secondary particle size) 20 μm or less, specific surface area 50 m 2 / g) Hydrotalcite compound 2: Mg 4.3 Al2(OH) 12.6 CO₃·mH₂O (DHT-4A (registered trademark), Kyowa Chemical Industry Co., Ltd., Mg / Al = 2.15, volume average particle size (secondary particle size) 20 μm or less, specific surface area 10.1 m 2 / g) Inorganic filler 1: Spherical silica (volume average particle size 19.0 μm) Inorganic filler 2: Spherical silica (volume average particle size 0.5 μm)

[0101] The components shown in Table 1 were blended in the amounts shown in the table (units are parts by mass unless otherwise specified) and thoroughly mixed in a mixer, then melt-kneaded in a twin-screw kneader under conditions such that the average temperature in the kneading zone was approximately 100°C. The molten mixture was then cooled, and the solid was pulverized into powder to prepare the desired powdered epoxy resin composition. Blank spaces in the table indicate that no component was blended.

[0102] [Measurement of water absorption rate] The epoxy resin composition was molded at 175°C for 90 seconds and then post-cured at 175°C for 5 hours to produce a cured product. Immediately after production, a plate-shaped cured product with a diameter of 50 mm and a thickness of 3 mm was placed in a pressure cooker tester at 121°C and 2.1 atmospheres. After 20 hours, it was removed and the mass increase (%) from the mass of the cured product immediately before placement was determined. The water absorption was calculated using the following formula: Water absorption rate (mass%) = {(mass after water absorption - mass before water absorption) / mass before water absorption} x 100

[0103] [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. 2 The semiconductor element was encapsulated under conditions of a pressure of approximately 6.86 MPa and a curing time of 120 seconds to produce an SOP package for evaluation. Post-curing was performed at 175°C for 5 hours. The package electrodes used 60μm-wide pads made of Al / Si / Cu=98.9% / 0.8% / 0.3%, and pure copper wires. This evaluation board was placed in a high-temperature, high-humidity chamber at 130°C and a relative humidity of 85%, and a voltage of 5V was applied to perform an in-chamber HAST test (Highly Accelerated temperature and humidity Stress Test). The time until a break in the copper wire occurred was measured for each package.

[0104] The evaluation was carried out according to the following criteria. A: The time until the defect occurs is over 1500 hours. B: Time until defect occurs is more than 1000 hours but less than 1500 hours C: Time until defect occurs is more than 500 hours but less than 1000 hours D: Time until defect occurs is more than 100 hours but less than 500 hours E: Time until defect occurs is 100 hours or less

[0105] [Table 1]

[0106] As shown in the table, the time until failure occurred in the HAST test was long and electrical reliability was excellent in Example 1. This is presumably because the water absorption of the cured product in Example 1 was low, and hydrotalcite compound 1 was well dispersed, effectively demonstrating its ion-trapping ability.

Claims

1. Epoxy resin, a curing agent containing a compound having a structural unit represented by the following formula (B1) and a structural unit represented by the following formula (B2); an inorganic filler; a hydrotalcite compound containing a hydrotalcite compound having a molar ratio of Mg to Al (Mg / Al) of 2.4 or more; An epoxy resin composition comprising: 【Chemical 1】 In formula (B1) and formula (B2), R ２ ~R ５ each independently represents a monovalent organic group having 1 to 6 carbon atoms, X2 and X3 each independently represent an integer of 0 to 4, X4 and X5 each independently represent an integer of 0 to 3, n1 represents a number from 1 to 10, n2 represents a number from 1 to 10, The structural unit of formula (B2) exists separately from the structural unit of formula (B1).

2. 2. The epoxy resin composition according to claim 1, wherein the content of the compound having the structural unit of formula (B1) and the structural unit of formula (B2) relative to the total mass of the curing agent is 30% by mass to 100% by mass.

3. 3. The epoxy resin composition according to claim 1, wherein the content of the inorganic filler is 50% by volume to 95% by volume based on the total volume of the epoxy resin composition.

4. 4. The epoxy resin composition according to claim 1, wherein the hydrotalcite compound has a molar ratio of Mg to Al (Mg / Al) of 2.4 or more and has a volume average particle size of 20 μm or less.

5. 5. The epoxy resin composition according to claim 1, wherein the content of the hydrotalcite compound having a molar ratio of Mg to Al (Mg / Al) of 2.4 or more is 0.01 mass% or more, based on the total mass of the epoxy resin.

6. The epoxy resin composition according to any one of claims 1 to 5, wherein in the compound having a structural unit of formula (B1) and a structural unit of formula (B2), the structural unit of formula (B1) and the structural unit of formula (B2) are linked by block copolymerization or random copolymerization.

7. An epoxy resin composition described in any one of claims 1 to 6, wherein the compound having a structural unit of formula (B1) and a structural unit of formula (B2) is a compound represented by the following formula (B): 【Chemistry 2】 In formula (B), R 1 to R 5 each independently represent a monovalent organic group having 1 to 6 carbon atoms; X1 to X3 each independently represent an integer of 0 to 4, X4 and X5 each independently represent an integer of 0 to 3, n1 represents a number from 1 to 10, n2 represents a number from 1 to 10.

8. A cured product of the epoxy resin composition according to any one of claims 1 to 7.

9. 9. The cured product according to claim 8, which has a water absorption of 0.30% by mass or less after 20 hours at 121°C and 2.1 atmospheres in a pressure cooker test.

10. An electronic component device comprising: an element; and the cured product according to claim 8 or 9 that seals the element.

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