Sealing resin composition and electronic component device

Abstract

This sealing resin composition contains epoxy resin, a curing agent, and an inorganic filler containing alumina. The moisture content of the alumina is 0.190 mass% or less.

Description

Encapsulating resin composition and electronic component device

[0001] The present invention relates to an encapsulating resin composition and an electronic component device.

[0002] In recent years, electronic devices such as smartphones have become lighter, thinner, shorter, and smaller, and their functionality has increased. This has led to an increase in the amount of heat generated by electronic devices that handle large amounts of information at high speeds, potentially causing malfunctions. Therefore, there is a demand for efficient heat dissipation of heat generated from within electronic devices, i.e., high heat dissipation (high thermal conductivity). Device structures with high heat dissipation properties have been investigated, as well as improvements to the heat dissipation properties of the encapsulant itself. To achieve this, the use of inorganic fillers such as alumina, which have excellent heat dissipation properties, and increasing the packing density of inorganic fillers have been considered (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2022-97508

[0004] However, encapsulating resin compositions that are highly filled with an inorganic filler such as alumina, which has excellent heat dissipation properties, have the problem that their hardness decreases when heated, and they are not necessarily materials with excellent continuous moldability.

[0005] An object of one aspect of the present invention is to provide an encapsulating resin composition having excellent hot hardness and thermal conductivity, and an electronic component device including an element encapsulated with the same.

[0006] <1> An encapsulating resin composition comprising an epoxy resin, a curing agent, and an inorganic filler containing alumina, wherein the alumina has a moisture content of 0.190% by mass or less. <2> The encapsulating resin composition according to <1>, wherein the proportion of alumina contained in the inorganic filler is 50% by mass to 100% by mass relative to the total amount of the inorganic filler. <3> The encapsulating resin composition according to <1> or <2>, wherein the inorganic filler consists solely of alumina. <4> The encapsulating resin composition according to any one of <1> to <3>, further comprising a curing accelerator. <5> The encapsulating resin composition according to <4>, wherein the curing accelerator includes at least one selected from the group consisting of alkyldiarylphosphines, dialkylarylphosphines, triarylphosphines, and adducts of triarylphosphines and benzoquinone. <6> An electronic component device comprising an element and a cured product of the encapsulating resin composition according to any one of <1> to <5>, which encapsulates the element.

[0007] According to one embodiment of the present invention, it is possible to provide an encapsulating resin composition having excellent hot hardness and thermal conductivity, and an electronic component device including an element encapsulated with the same.

[0008] Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention 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 invention.

[0009] 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 present disclosure, numerical ranges described in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. Furthermore, in the numerical ranges described in the present 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 corresponding substances. When multiple substances corresponding to each component are present in the composition, the content of each component means the total content of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, 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. In the present disclosure, one or more types of alumina may be contained. When two or more aluminas are included in the composition, the moisture content of the alumina means the weighted average of the moisture contents of the two or more aluminas.

[0010] [Encapsulating Resin Composition] The encapsulating resin composition of the present disclosure comprises an epoxy resin, a curing agent, and an inorganic filler containing alumina, wherein the moisture content of the alumina is 0.190 mass% or less. Generally, encapsulating resin compositions highly filled with inorganic fillers such as alumina, which have excellent heat dissipation properties, tend to have reduced hardness when heated. On the other hand, in the present disclosure, by adjusting the moisture content of the alumina, even when alumina is used as the inorganic filler, the reduction in hardness when heated can be suppressed, thereby providing an encapsulating resin composition with high heat dissipation properties. Furthermore, the encapsulating resin composition of the present disclosure is used, for example, to encapsulate electronic component devices.

[0011] [Epoxy Resin] The encapsulating resin composition of the present disclosure contains an epoxy resin. The type of the epoxy resin is not particularly limited as long as it has an epoxy group in the molecule.

[0012] Specific examples of epoxy resins include novolac epoxy resins (phenol novolac epoxy resins, orthocresol novolac epoxy resins, etc.) obtained by epoxidizing novolac 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, etc., and naphthol compounds such as α-naphthol, β-naphthol, dihydroxynaphthalene, etc., with an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, propionaldehyde, etc., under an acidic catalyst; and triphenylmethane phenolic compounds obtained by condensing or co-condensing the above phenolic compounds with an aromatic aldehyde compound such as benzaldehyde, salicylaldehyde, etc., under an acidic catalyst. triphenylmethane-type epoxy resins obtained by epoxidizing novolak resins; copolymer epoxy resins obtained by epoxidizing novolak resins obtained by co-condensing the above-mentioned phenol compounds and naphthol compounds with aldehyde compounds such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde under an acidic catalyst; diphenylmethane-type epoxy resins which are diglycidyl ethers of bisphenol A, bisphenol AD, bisphenol F, and the like; 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 phenol compounds; sulfur-containing epoxy resins which are diglycidyl ethers of bisphenol S, and the like; butanediol, polyethylene glycol glycidyl ester-type epoxy resins which are glycidyl esters of polycarboxylic acid compounds such as phthalic acid, isophthalic acid, tetrahydrophthalic acid, and dimer acid; glycidylamine-type epoxy resins in which active hydrogen bonded to nitrogen atoms of aniline, diaminodiphenylmethane, isocyanuric acid, and the like is substituted with a glycidyl group; dicyclopentadiene-type epoxy resins which are epoxidized co-condensation resins of dicyclopentadiene and phenol 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 an intramolecular olefin bond; 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.

[0013] The epoxy equivalent (molecular weight / number of epoxy groups) of the epoxy resin is not particularly limited, but from the viewpoint of a balance of various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 100 g / eq to 1000 g / eq, and more preferably 150 g / eq to 500 g / eq.

[0014] The epoxy equivalent of the epoxy resin is a value measured by a method in accordance with JIS K 7236:2009.

[0015] The melting point or softening point of the epoxy resin is not particularly limited, but is preferably 40°C to 180°C from the viewpoint of moldability and reflow resistance, and more preferably 50°C to 130°C from the viewpoint of handleability during preparation of the encapsulating resin composition.

[0016] The melting point or softening point of the epoxy resin is a value measured by the single cylinder rotational viscometer method described in JIS K 7234:1986 and JIS K 7233:1986.

[0017] The content of the epoxy resin in the encapsulating resin composition is preferably 2% by mass to 10% by mass, more preferably 2.5% by mass to 7.5% by mass, and even more preferably 3% by mass to 6.5% by mass, from the viewpoints of strength, fluidity, heat resistance, moldability, and the like.

[0018] [Curing Agent] The encapsulating resin composition of the present disclosure contains a curing agent. The type of curing agent is not particularly limited and can be selected depending on the type of epoxy resin, the desired properties of the encapsulating resin composition, and the like.

[0019] Specific examples of the curing agent include phenol curing agents, amine curing agents, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, blocked isocyanate curing agents, etc. From the viewpoint of improving heat resistance, the curing agent is preferably a phenol curing agent.

[0020] Specific examples of the phenolic curing agent include 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 resorcinol, catechol, bisphenol A, bisphenol F, phenol, cresol, xylenol, phenylphenol, and aminophenol, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene, with an aldehyde compound such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde, under an acidic catalyst; Examples of suitable phenol curing agents include aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins synthesized from methoxy-paraxylene, bis(methoxymethyl)biphenyl, etc.; paraxylylene-modified phenolic resins; 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-mentioned phenolic compounds with dicyclopentadiene; cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified phenolic resins; and biphenyl-type phenolic resins. For example, from the viewpoint of improving reflow resistance, phenol aralkyl resins are preferred, and biphenyl aralkyl-type phenolic resins are more preferred. These phenol curing agents may be used alone or in combination of two or more.

[0021] When the phenol curing agent contains a phenol aralkyl resin (preferably a biphenyl aralkyl phenol resin), the proportion of the phenol aralkyl resin may be 50% by mass or more, 60% by mass or more, 80% by mass or less, or 70% by mass or less, based on the total amount of the phenol curing agent.

[0022] The functional group equivalent of the curing agent (hydroxyl group equivalent in the case of a phenolic curing agent) is not particularly limited, but from the viewpoint of the balance of various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 70 g / eq to 1000 g / eq, and more preferably 80 g / eq to 500 g / eq.

[0023] The hydroxyl group equivalent of the phenol curing agent is a value measured by a method in accordance with JIS K 0070:1992.

[0024] The melting point or softening point of the curing agent is not particularly limited, but is preferably 40°C to 180°C from the viewpoint of moldability and reflow resistance, and more preferably 50°C to 130°C from the viewpoint of handleability during production of the encapsulating resin composition.

[0025] The melting point or softening point of the curing agent is a value measured by the single cylinder rotational viscometer method described in JIS K 7234:1986 and JIS K 7233:1986.

[0026] 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 functional groups in the epoxy resin (number of functional groups in the curing agent / number of functional groups in the epoxy resin), is not particularly limited. From the viewpoint of minimizing the amount of unreacted components, it is preferably set in the range of 0.5 to 1.5, more preferably in the range of 0.6 to 1.3, and even more preferably in the range of 0.7 to 1.2.

[0027] [Curing Accelerator] The encapsulating resin composition of the present disclosure may contain a curing accelerator. The type of curing accelerator is not particularly limited and can be selected depending on the type of epoxy resin, the desired properties of the encapsulating resin composition, and the like. Furthermore, from the viewpoints of the electrical reliability of the encapsulating resin composition and fluidity during molding, a phosphorus-based curing accelerator is preferred as the curing accelerator.

[0028] Specific examples of the curing accelerator include 1,8-diaza-bicyclo(5,4,0)undecene-7, 1,5-diaza-bicyclo(4,3,0)nonene, 5,6-dibutylamino- tertiary amines such as 1,8-diaza-bicyclo(5,4,0)undecene-7, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol, and derivatives thereof; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and derivatives thereof; organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine, and phosphorus compounds having intramolecular polarization obtained by adding a compound having a π bond such as maleic anhydride, benzoquinone, or diazophenylmethane to these phosphines; tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, 2-ethyl-4-methylimidazole tetraphenylborate, N-methylmo-tetraphenylphosphonium tetraphenylborate, an adduct of triphenylphosphine and benzoquinone, an adduct of tri-para-tolylphosphine and benzoquinone, and triphenylphosphonium triphenylborane. These curing accelerators may be used alone or in combination of two or more.

[0029] The curing accelerator may include at least one selected from the group consisting of alkyldiarylphosphines, dialkylarylphosphines, triarylphosphines, and adducts of triarylphosphines and benzoquinone, or may include an adduct of triarylphosphine and benzoquinone, or may include an adduct of triphenylphosphine and benzoquinone. When the encapsulating resin composition includes such a curing accelerator, the curing accelerator is likely to decompose in the presence of moisture and a curing agent (e.g., a phenolic curing agent), and the hot hardness of the encapsulating resin composition is likely to decrease. On the other hand, by adjusting the moisture content of the alumina as disclosed herein, even when the above-mentioned curing accelerator is used, side reactions that decompose the curing accelerator are less likely to occur, and a decrease in hot hardness tends to be suppressed.

[0030] The content of the curing accelerator in the encapsulating resin composition is not particularly limited as long as the curing acceleration effect is obtained. The content of the curing accelerator in the encapsulating resin composition is preferably 0.1% by mass to 8.0% by mass, more preferably 0.5% by mass to 5.0% by mass, and even more preferably 1.0% by mass to 3.0% by mass, relative to the total amount of the epoxy resin and the curing agent. When the content of the curing accelerator is 0.1% by mass or more relative to the total amount of the epoxy resin and the curing agent, the curing time tends to be shortened, and when it is 8.0% by mass or less, the curing speed is not too fast and a good molded product tends to be obtained.

[0031] [Inorganic Filler] The encapsulating resin composition of the present disclosure contains an inorganic filler containing alumina. By including the inorganic filler, it is possible to reduce moisture absorption and improve strength when the composition is cured. The moisture content of the alumina contained in the encapsulating resin composition is 0.190 mass% or less. The moisture content (mass%) of the alumina can be measured by the method described in the Examples below.

[0032] The moisture content (% by mass) of the alumina is preferably 0.185% by mass or less, more preferably 0.180% by mass or less. The lower limit of the moisture content (% by mass) of the alumina is not particularly limited, and may be 0.100% by mass or more.

[0033] Furthermore, the proportion of alumina contained in the inorganic filler is preferably 50% by mass to 100% by mass, more preferably 75% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, and particularly preferably 85% by mass to 100% by mass, based on the total amount of the inorganic filler. By including 50% by mass or more of alumina, an encapsulating resin composition having excellent thermal conductivity can be obtained.

[0034] From the viewpoint of obtaining an encapsulating resin composition in which a decrease in hardness upon heating is suppressed, the proportion of alumina contained in the inorganic filler is preferably 98 mass % or less, and more preferably 95 mass % or less, based on the total amount of the inorganic filler.

[0035] The inorganic filler may consist of only alumina, or may contain an inorganic filler other than alumina. In the encapsulating resin composition of the present disclosure, since the moisture content of the alumina is 0.190 mass% or less, even when the proportion of alumina is high, for example, when the inorganic filler consists of only alumina, a decrease in hot hardness tends to be suppressed.

[0036] Examples of inorganic fillers other than alumina (hereinafter also referred to as "other inorganic fillers") include fused silica, crystalline silica, silicon nitride, boron nitride, magnesium oxide, zinc oxide, silicon carbide, aluminum nitride, zircon, calcium silicate, calcium carbonate, potassium titanate, beryllia, zirconia, fosterite, steatite, spinel, mullite, titania, and other powders or beads obtained by spheroidizing these, single crystal fibers such as potassium titanate, glass fibers, aramid fibers, and carbon fibers. Furthermore, examples of other inorganic fillers include aluminum hydroxide, zinc borate, and magnesium hydroxide, from the viewpoint of flame retardant effect. One type of other inorganic filler may be used alone, or two or more types may be used in combination.

[0037] From the viewpoint of thermal conductivity, the inorganic filler preferably contains at least one inorganic filler selected from the group consisting of silicon nitride, boron nitride, magnesium oxide, zinc oxide, silicon carbide, and aluminum nitride as an inorganic filler other than alumina, with silicon carbide being more preferred.

[0038] The content of inorganic fillers other than alumina may be 50% by mass or less, 25% by mass or less, 20% by mass or less, or 10% by mass or less, based on the total amount of inorganic fillers.

[0039] The content of the inorganic filler in the encapsulating resin composition (which may be read as the content of alumina) is preferably 83% by mass to 97% by mass, more preferably 85% by mass to 95% by mass, and even more preferably 88% by mass to 94% by mass, based on the total amount of the encapsulating resin composition, from the viewpoints of moisture absorption, reduction in the linear expansion coefficient, improvement in strength, and solder heat resistance.

[0040] The content of the inorganic filler in the encapsulating resin composition (which may be read as the content of alumina) is preferably 70% by volume to 90% by volume, more preferably 72% by volume to 85% by volume, and even more preferably 75% by volume to 82% by volume, based on the total amount of the encapsulating resin composition, from the viewpoints of moisture absorption, reduction in the linear expansion coefficient, improvement in strength, and solder heat resistance.

[0041] The shape of the inorganic filler is not particularly limited, and examples thereof include powder, spheres, fibers, etc. Among these, a spherical shape is preferred from the viewpoints of flowability during molding of the encapsulating resin composition and mold abrasion resistance.

[0042] When the inorganic filler is particulate, its average particle size is not particularly limited. For example, the volume average particle size is preferably 0.05 μm to 35 μm, and more preferably 0.1 μm to 30 μm. When the volume average particle size of the inorganic filler is 0.05 μm or more, the increase in viscosity of the encapsulating resin composition tends to be further suppressed. When the volume average particle size is 35 μm or less, the filling ability into narrow gaps tends to be further improved. The volume average particle size of the inorganic filler can be measured as the particle size (D50) at which the cumulative volume from the small diameter side reaches 50% in the volume-based particle size distribution obtained using a laser scattering diffraction particle size distribution analyzer.

[0043] The inorganic filler may contain two types of inorganic fillers with different average particle sizes, or may contain two types of alumina with different average particle sizes. For example, it is preferable to contain a first inorganic filler with a volume average particle size of 10 μm to 35 μm, preferably 15 μm to 30 μm, and a second inorganic filler with a volume average particle size of 0.05 μm to 2 μm, preferably 0.1 μm to 1 μm.

[0044] When the inorganic filler contains two types of inorganic fillers having different average particle sizes, the content of the first inorganic filler may be 50% by mass to 95% by mass, 70% by mass to 90% by mass, or 80% by mass to 85% by mass, relative to the total amount of the inorganic filler.

[0045] When the inorganic filler contains two types of inorganic fillers with different average particle sizes, the content of the second inorganic filler may be 5% by mass to 50% by mass, 10% by mass to 30% by mass, or 15% by mass to 20% by mass, relative to the total amount of the inorganic filler.

[0046] The specific surface area of ​​alumina is 0.3 m from the viewpoint of filling narrow gaps. ２ / g or more, and 0.5m ２ / g or more, and more preferably 0.6m ２ Further, the specific surface area of ​​alumina is preferably 15 m / g or more from the viewpoint of suppressing an increase in viscosity. ２ / g or less, and ２ / g or less is more preferable, ２ / g or less is more preferable, ２ / g or less is particularly preferred, and ２ It is highly preferred that the SiO2 content is 1 / g or less.

[0047] When two types of alumina with different average particle sizes are included, the specific surface area of ​​the alumina corresponding to the first inorganic filler is 0.3 m ２ / g or more, and ２ / g or more is more preferable, and 0.6m ２ The specific surface area of ​​the alumina corresponding to the first inorganic filler is more preferably 2.0 m / g or more. ２ / g or less, and 1.5m ２ / g or less, and more preferably 1.2m ２ The specific surface area of ​​alumina corresponding to the second inorganic filler is preferably 2.0 m / g or less. ２ / g or more, and ２ / g or more is more preferable, and 2.5m ２ The specific surface area of ​​the alumina corresponding to the second inorganic filler is more preferably 15 m / g or more. ２ / g or less, and ２ / g or less is more preferable, ２ / g or less is more preferable, ２ / g or less is particularly preferred, ２ The specific surface area of ​​alumina is calculated by the BET method by measuring nitrogen adsorption at liquid nitrogen temperature (77K) by a multipoint method.

[0048] [Other Components] The encapsulating resin composition of the present disclosure may contain other components in addition to the above-described epoxy resin, curing agent, curing accelerator, and inorganic filler. The other components are not particularly limited, and include various additives such as a mold release agent; a coupling agent; a flame retardant such as a brominated epoxy resin or a phosphorus compound; a flame retardant aid such as antimony trioxide or antimony tetroxide; a colorant; a stress relaxation agent; and an antioxidant. Specific examples of the other components, such as the mold release agent, coupling agent, colorant, and stress relaxation agent, will be described below.

[0049] (Mold Release Agent) The encapsulating resin composition may further contain a mold release agent from the viewpoint of obtaining good mold releasability 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, paraffin wax, fatty acid 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.

[0050] When the encapsulating resin composition contains a release agent, the content of the release agent is preferably 10% by mass or less, and from the viewpoint of exerting its effect, preferably 0.5% by mass or more, based on the total amount of the epoxy resin and the curing agent.

[0051] (Coupling Agent) The encapsulating resin composition 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. The coupling agents may be used alone or in combination of two or more.

[0052] 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-aminopropyltriethoxysilane, trimethoxysilane, γ-(β-aminoethyl)aminopropyldimethoxymethylsilane, N-(trimethoxysilylpropyl)ethylenediamine, N-(dimethoxymethylsilylisopropyl)ethylenediamine, methyltrimethoxysilane, methyltriethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, γ-anilinopropyltrimethoxysilane, vinyltrimethoxysilane, and γ-mercaptopropylmethyldimethoxysilane.

[0053] 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.

[0054] When the encapsulating resin composition contains a coupling agent, the content of the coupling agent is preferably 3 mass% or less based on the total encapsulating resin composition, and from the viewpoint of exerting its effects, it is preferably 0.1 mass% or more.

[0055] (Colorant) The encapsulating resin composition may further contain a colorant. Examples of the colorant include known colorants such as carbon black, organic dyes, organic pigments, iron 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.

[0056] When conductive particles such as carbon black are used in combination as a colorant, it is preferable to use particles with a particle size of 10 μm or more in an amount of 1 mass % or less based on the total amount of conductive particles, and the content of carbon black is preferably 3 mass % or less based on the total amount of epoxy resin and curing agent.

[0057] (Stress Relaxant) The encapsulating resin composition may further contain a stress relaxation agent such as silicone oil, silicone rubber particles, or synthetic rubber. By including a stress relaxation agent, package warpage and package cracking can be further reduced. Examples of the stress relaxation agent 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 agent may be used alone or in combination of two or more.

[0058] The hot hardness of the encapsulating resin composition when cured is preferably 70 or more, more preferably 73 or more, and even more preferably 75 or more. A higher hot hardness is preferable, and there is no particular upper limit, and it may be, for example, 95 or less. The method for measuring the hot hardness of the cured product is as follows. The encapsulating resin composition is molded using a transfer molding machine under conditions of a mold temperature of 175°C to 180°C, a molding pressure of 6.9 MPa, and a curing time of 150 seconds into a test piece for measuring the hot hardness (a disk having a diameter of 50 mm and a thickness of 3 mm). Immediately after molding, the hot hardness of the test piece is measured using a Shore D hardness tester.

[0059] [Method for Preparing Encapsulating Resin Composition] The method for preparing the encapsulating resin composition is not particularly limited. A common method includes thoroughly mixing predetermined amounts of 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, a method includes stirring and mixing predetermined amounts of 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.

[0060] [Electronic Component Device] The electronic component device of the present disclosure includes an element and a cured product of the above-described encapsulating resin composition that encapsulates the element. Examples of the electronic component device include an element (e.g., active elements such as semiconductor chips, transistors, diodes, and thyristors, or passive elements such as capacitors, resistors, and coils) mounted 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 the resulting element portion is encapsulated with the encapsulating resin composition. More specifically, general resin-sealed integrated circuits (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 terminals of the element such as bonding pads are connected to leads by wire bonding, bumps, or the like, and then sealed using a sealing resin composition by transfer molding or the like. Examples of suitable packages include TCP (Tape Carrier Package) in which elements connected to a tape carrier by bumps are sealed with an encapsulating resin composition; COB (Chip On Board) modules, hybrid ICs, multi-chip modules, etc. in which elements connected to wiring formed on a support member by wire bonding, flip chip bonding, solder, etc. are sealed with an encapsulating resin composition; and BGA (Ball Grid Array), CSP (Chip Size Package), MCP (Multi Chip Package), etc. in which elements are mounted on the surface of a support member having terminals for wiring board connection formed on the back surface, and the elements and wiring formed on the support member are connected by bumps or wire bonding, and then the elements are sealed with an encapsulating resin composition. The encapsulating resin composition can also be suitably used in printed wiring boards.

[0061] Methods for encapsulating electronic component devices using an encapsulating resin composition include low-pressure transfer molding, injection molding, compression molding, etc. Among these, low-pressure transfer molding is commonly used.

[0062] The present invention will be specifically explained below with reference to examples, but the scope of the present invention is not limited to these examples.

[0063] [Preparation of Encapsulating Resin Composition] The components shown below were premixed (dry blended) in the blending ratios (parts by mass) shown in Table 1, and then kneaded in a twin-screw kneader and cooled and pulverized to prepare encapsulating resin compositions of Examples and Comparative Examples.

[0064] (Epoxy resin) A1... Biphenyl type epoxy resin, epoxy equivalent: 192 g / eq, softening point: 104 to 110°C (Curing agent) B1... Phenol novolac type phenolic resin, hydroxyl equivalent: 106 g / eq, softening point: 80 to 88°C, viscosity (150°C): 0.25 to 0.30 Pa·s B2... Biphenyl aralkyl type phenolic resin, hydroxyl equivalent: 199 g / eq, softening point: 64 to 69°C, viscosity (150°C): 0.06 to 0.10 Pa·s (Curing accelerator) C1... Adduct of triphenylphosphine and benzoquinone (Inorganic filler) D1... Alumina filler, average particle size D50: 26.1 μm, specific surface area: 0.8 m ２ / g D2: Alumina filler, average particle size D50: 0.3 μm, specific surface area: 11 m ２ / g D3...Alumina filler, average particle size D50: 0.24 μm, specific surface area: 10.8 m ２ / g D4...Alumina filler, average particle size D50: 0.5 μm, specific surface area: 6.0 m ２ / g D5...Alumina filler, average particle size D50: 0.6 μm, specific surface area: 5.3 m ２ / g D6...Alumina filler, average particle size D50: 0.6 μm, specific surface area: 8.6 m ２ / g D7...Alumina filler, average particle size D50: 0.3 μm, specific surface area: 7.4 m ２ / g D8...Fused silica filler, average particle size D50: 0.5 μm, specific surface area: 6.3 m ２ / g

[0065] (Evaluation of Hot Hardness) The hot hardness of the encapsulating resin composition was evaluated as follows. The encapsulating resin composition prepared as described above was molded into test pieces (disks with a diameter of 50 mm and a thickness of 3 mm) for measuring hot hardness using a transfer molding machine under conditions of a mold temperature of 175°C to 180°C, a molding pressure of 6.9 MPa, and a curing time of 150 seconds. Immediately after molding, the hot hardness of the test pieces was measured using a Shore D hardness tester. The results are shown in Table 1.

[0066] (Measurement of Moisture Content) The moisture content of alumina was measured as follows. The mass of a container (made of aluminum, upper diameter (mm) × lower diameter (mm) × height (mm) = 54 × 47 × 72) was measured. After approximately 30 g of alumina was placed in the container, the mass of the alumina + container was measured, and the container was heated in a constant temperature dryer at a temperature of 175°C for 15 hours. Immediately after heating was completed, the mass of the alumina + container was measured. The moisture content (mass %) of the alumina was calculated using the following formula: [(mass of alumina + container before heating) - (mass of alumina + container after heating)] / (mass of alumina + container before heating - mass of container) × 100. The results are shown in Table 1.

[0067]

[0068] As shown in Table 1, Examples 1 to 4, in which the moisture content of the alumina was 0.190 mass % or less, had higher hot hardness than Comparative Examples 1 to 3, and were excellent in continuous formability.

[0069] The disclosure of Japanese Patent Application No. 2024-145882 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. An encapsulating resin composition comprising an epoxy resin, a curing agent, and an inorganic filler containing alumina, wherein the moisture content of the alumina is 0.190 mass % or less.

2. The encapsulating resin composition according to claim 1, wherein the proportion of alumina contained in the inorganic filler is 50% by mass to 100% by mass based on the total amount of the inorganic filler.

3. The encapsulating resin composition according to claim 1, wherein the inorganic filler consists solely of alumina.

4. The encapsulating resin composition according to claim 1, further comprising a curing accelerator.

5. The encapsulating resin composition according to claim 4, wherein the curing accelerator comprises at least one selected from the group consisting of alkyldiarylphosphines, dialkylarylphosphines, triarylphosphines, and adducts of triarylphosphines and benzoquinone.

6. An electronic component device comprising an element and a cured product of the encapsulating resin composition according to any one of claims 1 to 5, which encapsulates the element.

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