Resin composition for molding and electronic component device

Abstract

This resin composition for molding comprises a curable resin and an inorganic filler containing alumina particles and at least one of calcium titanate particles and strontium titanate particles. The total content of the calcium titanate particles and the strontium titanate particles is 5.0 vol% to 15.0 vol% with respect to the whole inorganic filler, and the content of the whole inorganic filler exceeds 60 vol% with respect to the whole resin composition for molding.

Description

Molding resin composition and electronic component device

[0001] The present disclosure relates to a molding resin composition and an electronic component device.

[0002] In recent years, with the demand for electronic devices to be more highly functional and lighter, thinner, shorter, and smaller, the integration and even higher density of electronic components have progressed, and the semiconductor packages used in these electronic devices have become smaller than ever before.Furthermore, the radio waves used for communication in electronic devices have become higher in frequency.

[0003] BACKGROUND ART In order to reduce the size of semiconductor packages and to accommodate high frequencies, high-dielectric-constant resin compositions have been proposed for use in encapsulating semiconductor elements.

[0004] JP 2015-036410 A JP 2017-057268 A JP 2018-141052 A

[0005] Examples of materials for encapsulating electronic components such as semiconductor devices include molding resin compositions containing a curable resin and an inorganic filler. When a material with a high dielectric loss tangent is used as the molding resin composition, transmission signals are converted into heat due to transmission loss, which tends to reduce communication efficiency. The amount of transmission loss caused by heat conversion of radio waves transmitted for communication in a dielectric is expressed as the product of the square root of the frequency, the dielectric constant, and the dielectric loss tangent. In other words, the transmission signal is more likely to be converted into heat in proportion to its frequency. In particular, in recent years, radio waves used for communication have become higher in frequency to accommodate an increase in the number of channels due to the diversification of information. This has created a demand for molding resin compositions capable of molding cured products with low dielectric constants and low dielectric loss tangents. Meanwhile, a higher dielectric constant allows for the miniaturization of substrates and semiconductor packages. Therefore, from the perspective of suppressing transmission loss and miniaturizing substrates, etc., it is desirable to maintain the dielectric constant while suppressing excessive increases and decreases in the dielectric constant and ensuring a low dielectric loss tangent.

[0006] An object of the present disclosure is to provide a molding resin composition that can mold a cured product having a low dielectric loss tangent while maintaining a relative dielectric constant, and an electronic component device using the same.

[0007] Specific means for solving the above problems include the following aspects. <1> A molding resin composition comprising: a curable resin; and an inorganic filler comprising alumina particles and at least one of calcium titanate particles and strontium titanate particles, wherein the total content of the calcium titanate particles and strontium titanate particles is 5.0 volume % to 15.0 volume % based on the total inorganic filler, and the total content of the inorganic filler is more than 60 volume % based on the total molding resin composition. <2> The molding resin composition according to <1>, wherein the curable resin comprises an epoxy resin and the molding resin composition further comprises a curing agent. <3> The molding resin composition according to <2>, wherein the curing agent comprises an active ester compound. <4> The molding resin composition according to <3>, wherein the curing agent further comprises a phenolic curing agent. <5> The molding resin composition according to <4>, wherein the phenolic curing agent comprises an aralkyl phenolic resin and a melamine-modified phenolic resin. <6> The molding resin composition according to any one of <1> to <5>, further comprising a stress relaxation agent. <7> The molding resin composition according to <6>, wherein the stress relaxation agent comprises at least one of an indene-styrene-coumarone copolymer, a trialkylphosphine oxide, and a triarylphosphine oxide. <8> The molding resin composition according to any one of <1> to <7>, wherein the inorganic filler comprises calcium titanate particles. <9> The molding resin composition according to any one of <2> to <8>, wherein the total mass ratio of the calcium titanate particles and the strontium titanate particles to the total mass of the epoxy resin and the curing agent is 0.8 to 1.5. <10> The molding resin composition according to any one of <1> to <9>, which is used for a high-frequency device. <11> The molding resin composition according to <10>, which is used for encapsulating electronic components in a high-frequency device. <12> The molding resin composition according to any one of <1> to <9>, which is used for an antenna-in-package. <13> An electronic component device comprising: a support member, an electronic component placed on the support member, and a cured product of the molding resin composition according to any one of <1> to <9> that seals the electronic component. <14> The electronic component device according to <13>, wherein the electronic component includes an antenna.

[0008] According to the present disclosure, there are provided a molding resin composition that can be molded into a cured product having a low dielectric loss tangent while maintaining a relative dielectric constant, and an electronic component device using the same.

[0009] In the present disclosure, the term "process" includes not only processes that are independent of other processes, but also processes 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 numerical ranges described in stages in the present disclosure, 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 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 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, 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, the "total content of calcium titanate particles and strontium titanate particles" may be read as either "the content of calcium titanate particles" or "the content of strontium titanate particles." In the present disclosure, the "total of calcium titanate particles and strontium titanate particles" may be read as either "calcium titanate particles" or "strontium titanate particles."

[0010] Hereinafter, embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present disclosure.

[0011] <Molding Resin Composition> The molding resin composition of the present embodiment comprises a curable resin, alumina particles, and an inorganic filler containing at least one of calcium titanate particles and strontium titanate particles, wherein the total content of the calcium titanate particles and strontium titanate particles is 5.0 vol % to 15.0 vol % based on the total inorganic filler, and the total content of the inorganic filler exceeds 60 vol % based on the total molding resin composition.

[0012] As described above, molding resin compositions are required to suppress transmission loss in the cured product after molding. From the viewpoint of suppressing transmission loss, it is desirable to achieve a low dielectric loss tangent. From the viewpoint of suppressing transmission loss and miniaturizing substrates and semiconductor packages, it is preferable to balance the dielectric constant by suppressing excessive increases and decreases in the dielectric constant. In the molding resin composition of this embodiment, by combining alumina particles with at least one of calcium titanate particles and strontium titanate particles, setting the total content of calcium titanate particles and strontium titanate particles to 5.0% by volume to 15.0% by volume relative to the total inorganic filler, and setting the total content of inorganic fillers to more than 60% by volume relative to the total molding resin composition, it is possible to mold a cured product having a low dielectric loss tangent while maintaining a dielectric constant suitable for suppressing transmission loss and miniaturizing substrates and semiconductor packages, etc.

[0013] Furthermore, in the molding resin composition of this embodiment, by using at least one of calcium titanate particles and strontium titanate particles, it is possible to mold a cured product having a lower dielectric tangent than when barium titanate or the like is used.

[0014] Each component constituting the molding resin composition will be described below. The molding resin composition of this embodiment contains a curable resin and an inorganic filler, and may contain other components as necessary.

[0015] (Curable Resin) The molding resin composition of this embodiment contains a curable resin. The curable resin may be either a thermosetting resin or a photocurable resin, and from the viewpoint of mass production, a thermosetting resin is preferred. Examples of thermosetting resins include epoxy resins, phenolic resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, urethane resins, polyimide resins such as bismaleimide resins, polyamide resins, polyamideimide resins, silicone resins, and acrylic resins. From the viewpoint of moldability and electrical properties, the thermosetting resin is preferably at least one selected from the group consisting of epoxy resins and polyimide resins, more preferably at least one selected from the group consisting of epoxy resins and bismaleimide resins, and even more preferably an epoxy resin. The molding resin composition may contain only one type of curable resin, or may contain two or more types. Hereinafter, an epoxy resin will be described as an example of a curable resin.

[0016] -Epoxy Resin- The molding resin composition preferably contains an epoxy resin as the curable resin. When the molding resin composition contains an epoxy resin as the curable resin, the content of the epoxy resin relative to the entire curable resin is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. The content of the epoxy resin relative to the entire curable resin may be 100% by mass. There are no particular restrictions on the type of epoxy resin, as long as it has an epoxy group in the molecule.

[0017] Specific examples of epoxy resins include novolac epoxy resins (phenol novolac epoxy resins, o-cresol novolac epoxy resins, etc.) 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 obtained by epoxidizing triphenylmethane phenolic resins obtained by condensing or co-condensing, under an acid catalyst, the above-mentioned phenolic compound with an aromatic aldehyde compound such as benzaldehyde, salicylaldehyde, etc.; and novolac resins obtained by co-condensing, under an acid catalyst, the above-mentioned phenolic compound and naphthol compound with an aldehyde compound. diphenylmethane-type epoxy resins which are diglycidyl ethers of bisphenol A, bisphenol F, or 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 phenolic compounds; sulfur-containing epoxy resins which are diglycidyl ethers of bisphenol S, or the like; 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 active hydrogen bonded to nitrogen atoms of aniline, diaminodiphenylmethane, isocyanuric acid, or the like is substituted with a glycidyl group; dicyclopentadiene-type epoxy resins in which a co-condensation resin of dicyclopentadiene and a phenolic compound is epoxidized;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. Epoxidized acrylic resins are also suitable as epoxy resins. These epoxy resins may be used alone or in combination of two or more.

[0018] The epoxy resin preferably contains at least one of an o-cresol novolac epoxy resin and a biphenyl epoxy resin, and more preferably contains an o-cresol novolac epoxy resin and a biphenyl epoxy resin. The total content of the o-cresol novolac epoxy resin and the biphenyl epoxy resin is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and even more preferably 90% by mass to 100% by mass, based on the total amount of the epoxy resin.

[0019] The epoxy equivalent (molecular weight / number of epoxy groups) 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, and more preferably 150 g / eq to 500 g / eq. The epoxy equivalent of the epoxy resin is a value measured by a method in accordance with JIS K 7236:2009.

[0020] When the epoxy resin is solid, the softening point or melting point of the epoxy resin is not particularly limited. The softening point or melting point of the epoxy resin 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 molding resin composition. The melting point or softening point of the epoxy resin is a value measured by differential scanning calorimetry (DSC) or a method in accordance with JIS K 7234:1986 (ring and ball method).

[0021] When the molding resin composition contains an epoxy resin as the curable resin, the mass proportion of the epoxy resin in the entire molding resin composition is preferably 0.5% by mass to 30% by mass, more preferably 2% by mass to 20% by mass, and even more preferably 3.5% by mass to 13% by mass, from the viewpoints of strength, fluidity, heat resistance, moldability, and the like.

[0022] - Curing Agent - When the molding resin composition contains an epoxy resin as the curable resin, the molding resin composition may further contain a curing agent. The molding resin composition preferably contains a curable resin containing an epoxy resin, a curing agent, and an inorganic filler containing alumina particles and at least one of calcium titanate particles and strontium titanate. The type of curing agent is not particularly limited.

[0023] The curing agent preferably contains an active ester compound. The active ester compounds may be used alone or in combination of two or more. Here, the active ester compound refers to a compound that has one or more ester groups per molecule that react with epoxy groups and has the ability to harden epoxy resins. Note that when the curing agent contains an active ester compound, the curing agent may contain a curing agent other than the active ester compound, or may not contain a curing agent other than the active ester compound.

[0024] When an active ester compound is used as a curing agent, the dielectric loss tangent of the cured product can be kept lower than when a phenolic or amine curing agent is used as the curing agent. The reason for this is presumed to be as follows: In the reaction between an epoxy resin and a phenolic or amine curing agent, secondary hydroxyl groups are generated. In contrast, in the reaction between an epoxy resin and an active ester compound, ester groups are generated instead of secondary hydroxyl groups. Since ester groups have lower polarity than secondary hydroxyl groups, molding resin compositions containing an active ester compound as a curing agent can keep the dielectric loss tangent of the cured product lower than molding resin compositions containing only a curing agent that generates secondary hydroxyl groups. Furthermore, while polar groups in a cured product increase the water absorption of the cured product, using an active ester compound as a curing agent can reduce the concentration of polar groups in the cured product, thereby suppressing the water absorption of the cured product. Furthermore, suppressing the water absorption of the cured product, in other words, reducing the polar molecule H ２ By reducing the O content, the dielectric loss tangent of the cured product can be further reduced.

[0025] The type of active ester compound is not particularly limited as long as it has one or more ester groups in the molecule that react with an epoxy group. Examples of the active ester compound include phenol ester compounds, thiophenol ester compounds, N-hydroxyamine ester compounds, and esterified products of heterocyclic hydroxy compounds.

[0026] Examples of active ester compounds include ester compounds obtained from at least one of an aliphatic carboxylic acid and an aromatic carboxylic acid and at least one of an aliphatic hydroxy compound and an aromatic hydroxy compound. Ester compounds using an aliphatic compound as a polycondensation component tend to have excellent compatibility with epoxy resins due to the presence of an aliphatic chain. Ester compounds using an aromatic compound as a polycondensation component tend to have excellent heat resistance due to the presence of an aromatic ring.

[0027] Specific examples of active ester compounds include aromatic esters obtained by the condensation reaction of an aromatic carboxylic acid with a phenolic hydroxyl group. Among these, aromatic esters obtained by the condensation reaction of an aromatic carboxylic acid with a phenolic hydroxyl group using a mixture of raw materials: an aromatic carboxylic acid component in which 2 to 4 hydrogen atoms on the aromatic ring of benzene, naphthalene, biphenyl, diphenylpropane, diphenylmethane, diphenyl ether, diphenylsulfonic acid, etc. are substituted with carboxy groups; a monohydric phenol in which one hydrogen atom on the aromatic ring is substituted with a hydroxyl group; and a polyhydric phenol in which 2 to 4 hydrogen atoms on the aromatic ring are substituted with hydroxyl groups. That is, aromatic esters having structural units derived from the aromatic carboxylic acid component, structural units derived from the monohydric phenol, and structural units derived from the polyhydric phenol are preferred.

[0028] Specific examples of the active ester compound include an active ester resin having a structure obtained by reacting a phenolic resin having a molecular structure in which phenolic compounds are bonded via alicyclic hydrocarbon groups with an aromatic dicarboxylic acid or a halide thereof, and an aromatic monohydroxy compound, as described in JP 2012-246367 A. As the active ester resin, a compound represented by the following structural formula (1) is preferred.

[0029]

[0030] In structural formula (1), R １represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group; X represents an unsubstituted benzene ring, an unsubstituted naphthalene ring, a benzene ring or a naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, or a biphenyl group; Y represents a benzene ring, a naphthalene ring, or a benzene ring or a naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms; k is 0 or 1; and n represents the average number of repetitions and is 0 to 5.

[0031] Specific examples of the compound represented by structural formula (1) include the following exemplary compounds (1-1) to (1-10): In the structural formula, t-Bu is a tert-butyl group.

[0032]

[0033]

[0034] Other specific examples of the active ester compound include a compound represented by the following structural formula (2) and a compound represented by the following structural formula (3), which are described in JP 2014-114352 A.

[0035]

[0036] In structural formula (2), R １ and R ２ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; Z is an ester-forming structural moiety (z1) selected from the group consisting of an unsubstituted benzoyl group, an unsubstituted naphthoyl group, a benzoyl group or naphthoyl group substituted with an alkyl group having 1 to 4 carbon atoms, and an acyl group having 2 to 6 carbon atoms, or a hydrogen atom (z2); and at least one of Z is an ester-forming structural moiety (z1).

[0037] In structural formula (3), R １ and R ２are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; Z is an ester-forming structural moiety (z1) selected from the group consisting of an unsubstituted benzoyl group, an unsubstituted naphthoyl group, a benzoyl group or naphthoyl group substituted with an alkyl group having 1 to 4 carbon atoms, and an acyl group having 2 to 6 carbon atoms, or a hydrogen atom (z2); and at least one of Z is an ester-forming structural moiety (z1).

[0038] Specific examples of the compound represented by structural formula (2) include the following exemplary compounds (2-1) to (2-6).

[0039]

[0040] Specific examples of the compound represented by structural formula (3) include the following exemplary compounds (3-1) to (3-6).

[0041]

[0042] Commercially available products may be used as the active ester compound. Examples of commercially available active ester compounds include "EXB9451", "EXB9460", "EXB9460S", and "HPC-8000-65T" (manufactured by DIC Corporation) as active ester compounds containing a dicyclopentadiene-type diphenol structure; "EXB9416-70BK", "EXB-8", and "EXB-9425" (manufactured by DIC Corporation) as active ester compounds containing an aromatic structure; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated product of phenol novolac; and "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing a benzoylated product of phenol novolac.

[0043] The ester equivalent (molecular weight / number of ester groups) of the active ester compound is not particularly limited. From the viewpoint of a balance of various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 150 g / eq to 400 g / eq, more preferably 170 g / eq to 300 g / eq, and even more preferably 200 g / eq to 250 g / eq. The ester equivalent of the active ester compound is a value measured by a method in accordance with JIS K 0070:1992.

[0044] The equivalent ratio (ester group / epoxy group) between the epoxy resin and the active ester compound is preferably 0.9 or more, more preferably 0.95 or more, and even more preferably 0.97 or more, from the viewpoint of keeping the dielectric loss tangent of the cured product low. The equivalent ratio (ester group / epoxy group) between the epoxy resin and the active ester compound is preferably 1.1 or less, more preferably 1.05 or less, and even more preferably 1.03 or less, from the viewpoint of keeping the unreacted active ester compound low.

[0045] The curing agent may contain other curing agents in addition to the active ester compound. The type of other curing agent is not particularly limited and can be selected depending on the desired properties of the molding resin composition. Examples of other curing agents include phenol curing agents, amine curing agents, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, and blocked isocyanate curing agents.

[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, and propionaldehyde, under an acidic catalyst; and resins synthesized from the above phenolic compounds and dimethoxyparaxylene, bis(methoxymethyl)biphenyl, or the like. Examples of the phenolic curing agent include aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins; paraxylylene-modified phenolic resins and 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; biphenyl-type phenolic resins; triphenylmethane-type phenolic resins obtained by condensation or co-condensation of the above-mentioned 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. These phenolic curing agents may be used alone or in combination of two or more.

[0047] The functional group equivalent of the other curing agent (hydroxyl group equivalent in the case of a phenolic 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 of the other curing agent is preferably 70 g / eq to 1000 g / eq, and more preferably 80 g / eq to 500 g / eq. The functional group equivalent of the other curing agent (hydroxyl group equivalent in the case of a phenolic curing agent) is a value measured by a method in accordance with JIS K 0070:1992.

[0048] The softening point or melting point of the curing agent 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 molding 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.

[0049] The equivalent ratio between the epoxy resin and the curing agent (all curing agents when multiple curing agents are used), 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 unreacted components, it is preferably set in the range of 0.5 to 2.0, more preferably in the range of 0.6 to 1.3. From the viewpoint of moldability and reflow resistance, it is even more preferably set in the range of 0.8 to 1.2.

[0050] The curing agent may contain at least one other curing agent selected from the group consisting of a phenolic curing agent, an amine curing agent, an acid anhydride curing agent, a polymercaptan curing agent, a polyaminoamide curing agent, an isocyanate curing agent, and a blocked isocyanate curing agent, and an active ester compound. From the viewpoint of excellent flexural toughness after curing of the molding resin composition, the curing agent may contain a phenolic curing agent and an active ester compound, an aralkyl phenolic resin and an active ester compound, or an aralkyl phenolic resin, a melamine-modified phenolic resin, and an active ester compound. Hereinafter, the term "other curing agent" may be read as "phenolic curing agent."

[0051] When the curing agent contains an active ester compound and other curing agents, the mass proportion of the active ester compound in the total amount of the active ester compound and other curing agents is, from the viewpoint of keeping the dielectric dissipation factor of the cured product low, preferably 40 mass % or more, more preferably 60 mass % or more, even more preferably 80 mass % or more, particularly preferably 85 mass % or more, and extremely preferably 90 mass % or more.

[0052] When the curing agent contains an active ester compound and another curing agent, the total mass proportion of the epoxy resin and the active ester compound in the total amount of the epoxy resin and the curing agent is preferably 40 mass % or more, more preferably 60 mass % or more, even more preferably 80 mass % or more, particularly preferably 85 mass % or more, and extremely preferably 90 mass % or more, from the viewpoint of keeping the dielectric loss tangent of the cured product low.

[0053] When the curing agent contains an active ester compound and another curing agent, the mass proportion of the active ester compound in the total amount of the active ester compound and the other curing agent is preferably 40% by mass to 90% by mass, more preferably 50% by mass to 80% by mass, and even more preferably 55% by mass to 70% by mass, from the viewpoint of excellent flexural toughness after curing of the molding resin composition and of keeping the dielectric loss tangent of the cured product low.

[0054] When the curing agent contains an active ester compound and other curing agents, the mass proportion of the other curing agents in the total amount of the active ester compound and other curing agents is preferably 10% by mass to 60% by mass, more preferably 20% by mass to 50% by mass, and even more preferably 30% by mass to 45% by mass, from the viewpoint of excellent flexural toughness after curing of the molding resin composition and of keeping the dielectric loss tangent of the cured product low.

[0055] When the molding resin composition contains an epoxy resin and a curing agent, the content of curable resins other than the epoxy resin may be less than 5% by mass, 4% by mass or less, or 3% by mass or less, relative to the entire molding resin composition.

[0056] -Polyimide Resin- The molding resin composition may contain a polyimide resin as a curable resin. The polyimide resin is not particularly limited as long as it is a polymer compound having an imide bond. Examples of polyimide resins include bismaleimide resins.

[0057] Examples of bismaleimide resins include copolymers of a compound having two or more N-substituted maleimide groups and a compound having two or more amino groups. Hereinafter, a compound having two or more N-substituted maleimide groups will also be referred to as a "polymaleimide compound," and a compound having two or more amino groups will also be referred to as a "polyamino compound." The bismaleimide resin may be a polymer obtained by polymerizing a composition containing a polymaleimide compound and a polyamino compound, and may contain units derived from compounds other than the polymaleimide compound and the polyamino compound. Examples of other compounds include compounds having a group containing two or more ethylenically unsaturated double bonds. Hereinafter, a compound having a group containing two or more ethylenically unsaturated double bonds will also be referred to as an "ethylenic compound."

[0058] The polymaleimide compound is not limited as long as it has two or more N-substituted maleimide groups, and may be a compound having two N-substituted maleimide groups or a compound having three or more N-substituted maleimide groups. From the viewpoint of availability, the polymaleimide compound is preferably a compound having two N-substituted maleimide groups.

[0059] Specific examples of the polymaleimide compound include bis(4-maleimidophenyl)methane, bis(3-maleimidophenyl)methane, polyphenylmethane maleimide, bis(4-maleimidophenyl)ether, bis(4-maleimidophenyl)sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, m-phenylene bismaleimide, p-phenylene bismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 1,2-bismaleimidoethane, 1,6-bismaleimidohexane, 1,12-bismaleimidododecane, 1,6-bismaleimido-(2,2,4-trimethyl)hexane, and 1,6-bismaleimido-(2,4,4-trimethyl)hexane. These polymaleimide compounds may be used alone or in combination of two or more.

[0060] The polyamino compound is not limited as long as it has two or more amino groups, and may be a compound having two amino groups or a compound having three or more amino groups. From the viewpoint of availability, the polyamino compound is preferably a compound having two amino groups.

[0061] Specific examples of the polyamino compound include 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyl-diphenylmethane, 4,4'-diamino-3,3'-diethyl-diphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ketone, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3 -bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 1,3-bis[1-(4-(4-aminophenoxy)phenyl)-1-methylethyl]benzene, 1,4-bis[1-(4-(4-aminophenoxy)phenyl)-1-methylethyl]benzene, 4,4'-[1, Examples of the polyamino compounds include 3-phenylenebis(1-methylethylidene)]bisaniline, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 3,3'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, and 9,9-bis(4-aminophenyl)fluorene. These polyamino compounds may be used alone or in combination of two or more.

[0062] Examples of the "group containing an ethylenically unsaturated double bond" contained in the ethylenic compound include a vinyl group, an allyl group, a vinyloxy group, an allyloxy group, an acryloyl group, and a methacryloyl group. The ethylenic compound may contain only one type of group containing an ethylenically unsaturated double bond in one molecule, or may contain two or more types. The ethylenic compound may further contain other groups in addition to the group containing an ethylenically unsaturated double bond. Examples of other groups include an amino group, an ether group, and a sulfide group. Specific examples of the ethylenic compound include diallylamine, diallyl ether, diallyl sulfide, and triallyl isocyanurate.

[0063] In the bismaleimide resin, the equivalent ratio (Ta1 / Ta2) of the number of N-substituted maleimide groups (Ta1) of the polymaleimide compound to the number of amino groups (Ta2) of the polyamino compound is preferably in the range of 1.0 to 10.0, and more preferably in the range of 2.0 to 10.0. Furthermore, when the bismaleimide resin contains units derived from an ethylenic compound, the equivalent ratio (Ta3 / Ta1) of the number of ethylenically unsaturated double bonds (Ta3) of the ethylenic compound to the number of N-substituted maleimide groups (Ta1) of the polymaleimide compound in the bismaleimide resin is, for example, in the range of 0.05 to 0.2.

[0064] The weight average molecular weight of the bismaleimide resin is not particularly limited, and may be, for example, in the range of 800 to 1500, 800 to 1300, or 800 to 1100.

[0065] The weight-average molecular weight of the bismaleimide resin can be determined by gel permeation chromatography (GPC) using a calibration curve calculated from standard polystyrene. The calibration curve is approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Types: A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Corporation]. The apparatus used for GPC includes pump: L-6200 type (manufactured by Hitachi High-Technologies Corporation), detector: L-3300 type RI (manufactured by Hitachi High-Technologies Corporation), column oven: L-655A-52 (manufactured by Hitachi High-Technologies Corporation), guard column: TSK Guardcolumn HHR-L (manufactured by Tosoh Corporation, column size 6.0 × 40 mm), column: TSK gel-G4000HHR + gel-G2000HHR (manufactured by Tosoh Corporation, column size 7.8 × 300 mm). GPC measurement conditions include eluent: tetrahydrofuran, sample concentration: 30 mg / 5 mL, injection amount: 20 μL, flow rate: 1.00 mL / min, and measurement temperature: 40 ° C.

[0066] When the molding resin composition contains a polyimide resin as a curable resin, the mass proportion of the polyimide resin in the entire molding resin composition is, for example, 0.5% by mass to 30% by mass, preferably 2% by mass to 20% by mass, and more preferably 3.5% by mass to 13% by mass.

[0067] (Curing Accelerator) The molding resin composition of the present embodiment may contain a curing accelerator as needed. The type of curing accelerator is not particularly limited and can be selected depending on the type of curable resin, the desired properties of the molding resin composition, and the like.

[0068] Examples of the curing accelerator used in the molding resin composition containing at least one resin selected from the group consisting of epoxy resins and polyimide resins as the curable resin include diazabicycloalkenes such as 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-ethyl-4-methylimidazole. cyclic amidine compounds such as benzoquinone, 2-heptadecylimidazole, etc.; derivatives of the above cyclic amidine compounds; phenol novolak salts of the above cyclic amidine compounds or their derivatives; compounds having intramolecular polarization obtained by adding to these compounds quinone compounds such as maleic anhydride, 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, phenyl-1,4-benzoquinone, etc., or compounds having a π bond such as diazophenylmethane; tetraphenylborate salts of DBU, Cyclic amidinium compounds such as tetraphenylborate salts, tetraphenylborate salts of 2-ethyl-4-methylimidazole, and tetraphenylborate salts 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(alkyl alkoxyphenyl)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 organic phosphines with organic borons; and the organic phosphines or the phosphine compounds, which may be combined with maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone. 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, and compounds having intramolecular polarization obtained by adding a compound having a π bond such as diazophenylmethane; a compound having intramolecular polarization, which is obtained by reacting a halogenated phenol compound such as 1-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-tert-butylphenol, 4-chloro-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol, or 4-bromo-4'-hydroxybiphenyl with the halogenated phenol compound, 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; salts of tetraalkylphosphonium with partial hydrolysates of aromatic carboxylic acid anhydrides; 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.

[0069] Among these, the curing accelerator is preferably a curing accelerator containing an organic phosphine. Examples of the curing accelerator containing an organic phosphine include the above-mentioned organic phosphines, phosphine compounds such as complexes of the above-mentioned organic phosphines and organoborons, and compounds having intramolecular polarization formed by adding a compound having a π bond to the above-mentioned organic phosphines or the above-mentioned phosphine compounds. Among these, particularly suitable curing accelerators include trialkylphosphines, triphenylphosphine, adducts of triphenylphosphine and a quinone compound, such as adducts of trialkylphosphines and a quinone compound, and adducts of tri-p-tolylphosphine and a quinone compound.

[0070] When the molding resin composition contains a curing accelerator, the amount thereof is preferably 0.1 to 30 parts by mass, 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 parts by mass or more per 100 parts by mass of the resin component, the composition tends to cure well 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 rate is not too fast and a good molded product tends to be obtained. Here, the resin component refers to the curable resin and the curing agent used as needed. Furthermore, 100 parts by mass of the resin component means that the total amount of the curable resin and the curing agent used as needed is 100 parts by mass.

[0071] (Curing Initiator) When the molding resin composition contains a polyimide resin as the curable resin, the molding resin composition may contain a curing initiator as needed. Examples of the curing initiator include radical polymerization initiators that generate free radicals by heat. Specific examples of the curing initiator include inorganic peroxides, organic peroxides, azo compounds, etc. Examples of inorganic peroxides include potassium persulfate (dipotassium peroxosulfate), sodium persulfate, and ammonium persulfate. Examples of organic peroxides include ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide, peroxyketals such as 1,1-di(t-butylperoxy)cyclohexane and 2,2-di(4,4-di(t-butylperoxy)cyclohexyl)propane, hydroperoxides such as p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide and t-butyl hydroperoxide, α,α'-di(t-butylperoxy)diisopropylbenzene, dicumyl peroxide and 2,5-dimethyl-2,5-di(t-butylperoxy)cyclohexyl dialkyl peroxides such as dibenzoyl peroxide, di(4-methylbenzoyl) peroxide, diacyl peroxides such as dibenzoyl peroxide and di(4-methylbenzoyl) peroxide, peroxydicarbonates such as di-n-propyl peroxydicarbonate and diisopropyl peroxydicarbonate, and peroxyesters such as 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-hexyl peroxybenzoate, t-butyl peroxybenzoate, and t-butylperoxy 2-ethylhexanoate. Examples of azo compounds include azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitrile, and azodibenzoyl.

[0072] When the molding resin composition contains a curing initiator, the content of the curing initiator is, for example, 0.1 to 8.0 parts by mass per 100 parts by mass of the polyimide compound, and from the viewpoint of curability, 0.5 to 6.0 parts by mass is more preferable. When the content of the curing initiator is 8.0 parts by mass or less, volatile matter is less likely to be generated, and the occurrence of voids during curing tends to be further suppressed. Furthermore, when the content of the curing initiator is 1 part by mass or more, curability tends to be better.

[0073] (Inorganic Filler) The molding resin composition of the present embodiment contains an inorganic filler containing alumina particles and at least one of calcium titanate particles and strontium titanate particles. The inorganic filler may contain fillers other than alumina particles, calcium titanate particles, or strontium titanate particles.

[0074] -Alumina Particles- The inorganic filler contains alumina particles. One type of alumina particles may be used alone, or two or more types may be used in combination. The alumina particles may also be a mixture of two or more types of fillers having different volume average particle sizes.

[0075] The shape of the alumina particles is not particularly limited, and examples thereof include spherical, elliptical, and irregular shapes. The alumina particles may be crushed or surface-treated.

[0076] The content of the alumina particles is preferably 50 to 95% by volume, more preferably 85 to 95% by volume, and even more preferably 90 to 95% by volume, based on the total volume of the inorganic filler.

[0077] The content (volume %) of alumina particles and the total content (volume %) of calcium titanate particles and strontium titanate particles relative to the entire inorganic filler can be determined by the following method. A thin slice sample of a cured molding resin composition is imaged using a scanning electron microscope (SEM). An arbitrary area S is identified in the SEM image, and the total area A of the inorganic fillers contained in area S is determined. Next, an SEM-EDX (energy dispersive X-ray spectrometer) is used to identify the elements of the inorganic filler, thereby determining the total area B of specific particles such as alumina particles, calcium titanate particles, and strontium titanate particles contained within the total area A of the inorganic filler. The total area B of the specific particles is divided by the total area A of the inorganic filler, and converted to a percentage (%), which is used as the content (volume %) of the specific particles relative to the entire inorganic filler. The area S is set to be sufficiently large relative to the size of the inorganic filler. For example, it is set to be large enough to contain 100 or more inorganic fillers. The area S may be the sum of multiple cross-sections.

[0078] In the molding resin composition, the mass ratio of the alumina particles to the total of the epoxy resin and the curing agent (alumina particles / total of the epoxy resin and the curing agent) is preferably 1 to 25, more preferably 2 to 20, even more preferably 3 to 15, and particularly preferably 4 to 12, from the viewpoint of the balance between the dielectric loss tangent and the fluidity.

[0079] The volume average particle size of the alumina particles is not particularly limited. The volume average particle size of the alumina particles is preferably 0.2 μm to 100 μm, more preferably 0.5 μm to 50 μm, and even more preferably 1.0 μm to 10 μm. When the volume average particle size is 0.2 μm or more, the increase in viscosity of the molding resin composition tends to be further suppressed. When the volume average particle size is 100 μm or less, the filling property of the molding resin composition tends to be further improved. The volume average particle size of the alumina particles can be determined by placing the molding resin composition in a crucible and leaving it at 800°C for 4 hours to incinerate it. The resulting ash is observed with an SEM, separated by shape, and the particle size distribution is determined from the observed image. From the particle size distribution, the volume average particle size of the alumina particles can be determined as the volume average particle size (D50). Alternatively, the volume average particle size of the alumina particles may be determined by measurement using a laser diffraction / scattering particle size distribution analyzer (e.g., HORIBA, Ltd., LA920).

[0080] -Calcium titanate particles and strontium titanate- The shape of the calcium titanate particles or strontium titanate is not particularly limited, and examples thereof include spherical, elliptical, and irregular shapes. The calcium titanate particles or strontium titanate particles may be crushed. The calcium titanate particles or strontium titanate particles may be surface-treated. The calcium titanate particles or strontium titanate particles may be a mixture of two or more fillers having different volume average particle sizes.

[0081] The volume average particle size of the calcium titanate particles or the volume average particle size of the strontium titanate may be 0.1 μm to 100 μm, 0.2 μm to 80 μm, 0.5 μm to 30 μm, 0.5 μm to 10 μm, or 0.5 μm to 8 μm. The volume average particle size of the calcium titanate particles and the volume average particle size of the strontium titanate particles can be measured as follows. A molding resin composition is placed in a crucible and left at 800°C for 4 hours to be incinerated. The resulting ash is observed with an SEM, separated by shape, and the particle size distribution is determined from the observed image. From the particle size distribution, the volume average particle size of the calcium titanate particles and the volume average particle size of the strontium titanate particles can be determined as the volume average particle size (D50). The volume average particle size of calcium titanate particles and the volume average particle size of strontium titanate particles may be determined by measurement using a laser diffraction / scattering particle size distribution measuring device (for example, LA920 manufactured by Horiba, Ltd.).

[0082] From the viewpoint of the balance between the dielectric constant and the dielectric loss tangent, the total content of the calcium titanate particles and the strontium titanate particles is 5.0 to 15.0% by volume, preferably 5.5 to 13.0% by volume, more preferably 6.0 to 12.0% by volume, even more preferably 6.0 to 10.0% by volume, and particularly preferably 6.0 to 9.0% by volume, relative to the total inorganic filler. The total content of the alumina, calcium titanate particles, and strontium titanate particles may be 70 to 100% by volume, or may be 90 to 100% by volume, relative to the total inorganic filler.

[0083] In the molding resin composition, the total mass ratio of the calcium titanate particles and strontium titanate particles to the total of the epoxy resin and curing agent (total of the calcium titanate particles and strontium titanate particles / total of the epoxy resin and curing agent) is preferably 0.5 to 5, more preferably 0.7 to 2, even more preferably 0.8 to 1.5, and particularly preferably 0.9 to 1.2, from the viewpoint of the balance between the dielectric loss tangent and the fluidity.

[0084] -Other Fillers- The inorganic filler may contain fillers other than alumina particles, calcium titanate particles, or strontium titanate. The shape of the other fillers is not particularly limited, and examples include spherical, elliptical, and irregular shapes. The other fillers may also be crushed. The other fillers may also be surface-treated. One type of other filler may be used alone, or two or more types may be used in combination. The other filler may also be a mixture of two or more fillers having different volume average particle sizes.

[0085] The type of other filler is not particularly limited. Specific examples of the material of the other filler include inorganic materials such as silica, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, talc, clay, and mica. Inorganic fillers having a flame-retardant effect may also be used as the other filler. Examples of inorganic fillers having a flame-retardant effect include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as composite hydroxides of magnesium and zinc, and zinc borate.

[0086] The other filler may contain titanium compound particles other than calcium titanate particles or strontium titanate. Examples of titanium compound particles other than calcium titanate particles or strontium titanate include barium titanate particles, potassium titanate particles, magnesium titanate particles, lead titanate particles, aluminum titanate particles, lithium titanate, and titanium oxide particles. However, from the viewpoint of keeping the dielectric tangent of the cured product low, the content of barium titanate particles is preferably less than 1 vol%, more preferably less than 0.5 vol%, and even more preferably less than 0.1 vol% relative to the total inorganic filler. In other words, it is preferable that the inorganic filler does not contain barium titanate particles or contains barium titanate particles at the above content. Furthermore, the total content of titanium compound particles other than calcium titanate particles or strontium titanate particles may be less than 1 vol%, less than 0.5 vol%, or less than 0.1 vol% relative to the total inorganic filler. That is, the inorganic filler may not contain any titanium compound particles other than calcium titanate particles or strontium titanate particles, or may contain any titanium compound particles other than calcium titanate particles or strontium titanate particles in the above content.

[0087] The preferred ranges of the volume average particle diameters of the other fillers are the same as the preferred ranges of the volume average particle diameter of the alumina particles.

[0088] - Total inorganic filler content and properties - From the viewpoint of controlling the fluidity and strength of a cured product of the molding resin composition, the total inorganic filler content contained in the molding resin composition exceeds 60% by volume, and is preferably more than 60% by volume and not more than 90% by volume, more preferably 62% by volume to 85% by volume, even more preferably 65% ​​by volume to 85% by volume, particularly preferably 68% by volume to 80% by volume, and extremely preferably 70% by volume to 78% by volume, relative to the total molding resin composition.

[0089] The content (volume %) of inorganic filler in a molding resin composition can be determined by the following method. A thin section sample of the cured molding resin composition is imaged using a scanning electron microscope (SEM). An arbitrary area S is identified in the SEM image, and the total area A of the inorganic fillers contained in area S is determined. The total area A of the inorganic fillers is divided by area S to convert it to a percentage (%), and this value is used as the content (volume %) of inorganic filler in the molding resin composition. Area S is set to an area sufficiently large relative to the size of the inorganic filler. For example, it is set to a size that contains 100 or more inorganic fillers. Area S may be the sum of multiple cross sections. The inorganic filler may have a bias in its presence in the direction of gravity when the molding resin composition is cured. In this case, when imaging with an SEM, the entire cured product is imaged in the direction of gravity, and the area S containing the entire cured product in the direction of gravity is determined.

[0090] [Various Additives] In addition to the components described above, the molding resin composition of this embodiment may contain various additives such as coupling agents, ion exchangers, release agents, flame retardants, colorants, and stress relaxation agents, as exemplified below. The molding resin composition of this embodiment may contain various additives known in the art, as needed, in addition to the additives exemplified below.

[0091] (Coupling Agent) The molding resin composition in this embodiment may contain a coupling agent. From the viewpoint of improving the adhesion between the resin component and the inorganic filler, the molding resin composition preferably contains a coupling agent. Examples of the coupling agent include known coupling agents such as silane-based compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, vinylsilane, and disilazane, titanium-based compounds, aluminum chelate-based compounds, and aluminum / zirconium-based compounds.

[0092] When the molding resin composition contains a coupling agent, the amount of the coupling agent is preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 2.5 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 the frame tends to be further improved. When the amount of the coupling agent is 5 parts by mass or less per 100 parts by mass of the inorganic filler, moldability of the package tends to be further improved.

[0093] (Ion Exchanger) The molding resin composition in this embodiment may contain an ion exchanger. It is preferable that the molding resin composition contain an ion exchanger from the viewpoint of improving the moisture resistance and high-temperature storage characteristics of an electronic component device including an encapsulated electronic component. The ion exchanger is not particularly limited, and conventionally known ion exchangers can be used. Specific examples include hydrotalcite compounds and hydrous oxides of at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium, and bismuth. The ion exchangers may be used alone or in combination of two or more. Among these, hydrotalcites represented by the following general formula (A) are preferred:

[0094] Mg （１－Ｘ） Al Ｘ (OH) ２ (CO ３ ) Ｘ／２ ・mH ２ O ……(A) (0<X≦0.5, m is a positive number)

[0095] When the molding resin composition contains an ion exchanger, the content thereof is not particularly limited as long as it is an amount sufficient to capture ions such as halogen ions, etc. For example, the content of the ion exchanger is preferably 0.1 to 30 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the resin component.

[0096] (Mold Release Agent) The molding resin composition of this embodiment may contain a mold release agent from the viewpoint of obtaining good releasability from the mold during molding. There are no particular restrictions on the mold release agent, and conventionally known mold release agents 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.

[0097] When the molding 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 is 10 parts by mass or less, better adhesion tends to be obtained.

[0098] (Flame Retardant) The molding resin composition of the present embodiment 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 a halogen atom, an antimony atom, a nitrogen atom, or a phosphorus atom, and metal hydroxides. The flame retardants may be used alone or in combination of two or more.

[0099] When the molding 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, and more preferably 2 to 20 parts by mass, per 100 parts by mass of the resin component.

[0100] (Colorant) The molding resin composition of the present embodiment may 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 types.

[0101] (Stress Relaxant) The molding resin composition of this embodiment may contain a stress relaxation agent. By including a stress relaxation agent, warpage deformation of the package and the occurrence of package cracks can be further reduced. Examples of stress relaxation agents include commonly used known stress relaxation agents (flexibilizers). Specific examples include thermoplastic elastomers such as silicone-based, styrene-based, olefin-based, urethane-based, polyester-based, polyether-based, polyamide-based, and polybutadiene-based elastomers; indene-styrene-coumarone copolymers; triarylphosphine oxides such as trialkylphosphine oxide and triphenylphosphine oxide; organic phosphorus compounds such as phosphate esters; 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. One type of stress relaxation agent may be used alone, or two or more types may be used in combination. Examples of silicone-based stress relaxation agents include those having an epoxy group, those having an amino group, and polyether-modified versions of these, with silicone compounds such as epoxy-group-containing silicone compounds and polyether-based silicone compounds being more preferred.

[0102] From the viewpoint of the dielectric loss tangent, the stress relaxation agent preferably contains at least one of an indene-styrene-coumarone copolymer, a trialkylphosphine oxide, and a triarylphosphine oxide.

[0103] When the molding resin composition contains a stress relaxation agent, the amount thereof is, for example, preferably 1 part by mass to 30 parts by mass, and more preferably 2 parts by mass to 20 parts by mass, per 100 parts by mass of the resin component. When the stress relaxation agent contains at least one of an indene-styrene-coumarone copolymer, a trialkylphosphine oxide, and a triarylphosphine oxide, the total amount thereof is, for example, preferably 1 part by mass to 30 parts by mass, and more preferably 2 parts by mass to 20 parts by mass, per 100 parts by mass of the resin component. The content of the indene-styrene-coumarone copolymer may be, for example, 1 part by mass to 20 parts by mass, or may be 2 parts by mass to 10 parts by mass, per 100 parts by mass of the resin component. The content of the trialkylphosphine oxide or the content of the triarylphosphine oxide may be, for example, 1 part by mass to 20 parts by mass, or may be 2 parts by mass to 10 parts by mass, per 100 parts by mass of the resin component. The content of the silicone-based stress relaxation agent may be, for example, 2 parts by mass or less, or 1 part by mass or less, per 100 parts by mass of the resin component. The molding resin composition may not contain a silicone-based stress relaxation agent. From the viewpoint of dielectric loss tangent, it is preferable that the molding resin composition contains at least one of an indene-styrene-coumarone copolymer, a trialkylphosphine oxide, and a triarylphosphine oxide (preferably, an indene-styrene-coumarone copolymer and a trialkylphosphine oxide or a triarylphosphine oxide), and does not contain a silicone-based stress relaxation agent. The lower limit of the content of the silicone-based stress relaxation agent is not particularly limited, and may be 0 parts by mass or 0.1 parts by mass.

[0104] From the viewpoint of dielectric loss tangent, the content of the silicone-based stress relaxation agent is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 7% by mass or less, particularly preferably 5% by mass or less, extremely preferably 0.5% by mass or less, and extremely preferably 0.1% by mass or less, relative to the entire molding resin composition. The lower limit of the content of the silicone-based stress relaxation agent is not particularly limited, and may be 0% by mass or 0.1% by mass.

[0105] (Method for preparing molding resin composition) The method for preparing the molding 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.

[0106] The molding resin composition in this embodiment is preferably solid at room temperature and normal pressure (for example, 25°C and atmospheric pressure). When the molding resin composition is solid, its shape is not particularly limited, and examples include powder, granules, tablets, etc. When the molding resin composition is in tablet form, it is preferable from the viewpoint of handleability that the dimensions and mass of the tablet-shaped molding resin composition are set to dimensions and mass that are suitable for the molding conditions of the package.

[0107] (Characteristics of Molding Resin Composition) The molding resin composition of this embodiment is compression molded under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 600 seconds, and the cured product has a relative dielectric constant at 10 GHz of 7.0 to 10.0, 7.0 to 9.0, or 7.0 to 8.0, from the viewpoint of antenna size design when combined with a package substrate such as a high dielectric substrate or a ceramic substrate. The relative dielectric constant is measured at a temperature of 25±3°C using a dielectric constant measuring device (for example, Agilent Technologies, product name "Network Analyzer N5227A").

[0108] The dielectric loss tangent at 10 GHz of the cured product obtained by compression molding the molding resin composition of this embodiment under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 600 seconds is, for example, 0.015 or less. From the viewpoint of reducing transmission loss, the dielectric loss tangent at 10 GHz of the cured product is preferably 0.010 or less, more preferably 0.008 or less, and even more preferably 0.007 or less. The lower limit of the dielectric loss tangent at 10 GHz of the cured product is not particularly limited, and may be, for example, 0.001. The dielectric loss tangent is measured at a temperature of 25±3°C using a dielectric constant measuring device (e.g., Agilent Technologies, product name "Network Analyzer N5227A").

[0109] (Uses of Molding Resin Composition) The molding resin composition of this embodiment can be applied, for example, to the production of electronic component devices, particularly high-frequency devices, as described below. The molding resin composition of this embodiment may be used to seal electronic components in high-frequency devices. In particular, with the recent spread of fifth-generation mobile communication systems (5G), semiconductor packages (PKGs) used in electronic component devices have become more highly functional and smaller. As PKGs become smaller and more functional, development of antenna-in-package (AiP), which is a PKG with antenna functionality, is also progressing. In AiP, radio waves used for communication are becoming higher in frequency to accommodate the increase in the number of channels associated with the diversification of information, and sealing materials are required to have both a high dielectric constant and a low dielectric loss tangent. As described above, the molding resin composition of this embodiment can produce a cured product that has both a high dielectric constant and a low dielectric loss tangent. Therefore, in high-frequency devices, the molding resin composition is particularly suitable for antenna-in-package (AiP) applications in which an antenna placed on a support member is encapsulated with the molding resin composition. In electronic component devices including an antenna, such as an antenna-in-package, heat is generated by power supply when a power supply amplifier is provided on the opposite side of the antenna. From the viewpoint of improving heat dissipation, the molding resin composition used in manufacturing electronic component devices preferably contains alumina particles as an inorganic filler.

[0110] An electronic component device according to an embodiment of the present disclosure includes a support member, an electronic component disposed on the support member, and a cured product of the molding resin composition encapsulating the electronic component. Examples of the electronic component device include a support member such as a lead frame, a pre-wired tape carrier, a wiring board, glass, a silicon wafer, or an organic substrate, on which electronic components (active elements such as semiconductor chips, transistors, diodes, and thyristors, passive elements such as capacitors, resistors, and coils, and antennas) are mounted, and the resulting electronic component region is encapsulated with the molding resin composition (e.g., a high-frequency device).

[0111] The type of the support member is not particularly limited, and a support member generally used in the manufacture of electronic component devices can be used. The electronic component may include an antenna, or may include an antenna and an element other than an antenna. The antenna is not limited as long as it functions as an antenna, and may be an antenna element or wiring.

[0112] In the electronic component device of the present embodiment, if necessary, another electronic component may be disposed on the surface of the support member opposite to the surface on which the electronic component is disposed. The other electronic component may be encapsulated with the molding resin composition described above, or with another resin composition, or may not be encapsulated.

[0113] (Method for manufacturing an electronic component device) The method for manufacturing an electronic component device according to this embodiment includes the steps of placing electronic components on a support member and encapsulating the electronic components with the molding resin composition. The method for carrying out each of the above steps is not particularly limited, and can be carried out by a general method. Furthermore, the types of support member and electronic components used in manufacturing the electronic component device are not particularly limited, and support members and electronic components commonly used in manufacturing electronic component devices can be used.

[0114] Methods for encapsulating electronic components using the molding resin composition include low-pressure transfer molding, injection molding, compression molding, etc. Among these, low-pressure transfer molding is the most common.

[0115] The above-described embodiment will be specifically described below using examples, but the scope of the above-described embodiment is not limited to these examples.

[0116] <Preparation of molding resin composition> Molding resin compositions of Examples and Comparative Examples were prepared by mixing the components shown below in the blending ratios (parts by mass) shown in Tables 1 and 2. This molding resin composition was solid at room temperature and normal pressure.

[0117] Epoxy resin 1: o-cresol novolac type epoxy resin, epoxy equivalent 200 g / eq. Epoxy resin 2: biphenyl type epoxy resin, epoxy equivalent 192 g / eq.

[0118] Curing agent 1: active ester compound, DIC Corporation, product name "EXB-8" Curing agent 2: phenolic curing agent, aralkyl phenolic resin, hydroxyl group equivalent 170 g / eq Curing agent 3: melamine-modified phenolic resin, reactive group equivalent 120 g / eq

[0119] Curing accelerator: Trialkylphosphine / 1,4-benzoquinone adduct Coupling agent: N-phenyl-3-aminopropyltrimethoxysilane Mold release agent: Montan acid ester wax Colorant: Carbon black Stress relaxation agent 1: Indene-styrene-coumarone copolymer Stress relaxation agent 2: Triarylphosphine oxide

[0120] Inorganic filler 1: alumina particles, volume average particle size: 5.7 μm, shape: spherical Inorganic filler 2: alumina particles, volume average particle size: 0.7 μm, shape: spherical Inorganic filler 3: calcium titanate particles, volume average particle size: 0.2 μm, shape: irregular

[0121] The volume-average particle size of each inorganic filler was a value obtained by the following measurement. Specifically, the inorganic filler was first added to a dispersion medium (water) in an amount ranging from 0.01% by mass to 0.1% by mass, and the mixture was dispersed in a bath-type ultrasonic cleaner for 5 minutes. Five milliliters of the resulting dispersion was poured into a cell, and the particle size distribution was measured at 25°C using a laser diffraction / scattering particle size distribution analyzer (HORIBA, Ltd., LA920). The particle size at an integrated value of 50% (volume basis) in the resulting particle size distribution was taken as the volume-average particle size.

[0122] <Evaluation of Molding Resin Composition> (Dielectric Constant and Dielectric Loss Tangent) The molding resin composition was charged into a vacuum hand press and molded under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 600 seconds. Post-curing was carried out at 175°C for 6 hours to obtain a plate-shaped cured product (12.5 mm long, 25 mm wide, 0.2 mm thick). This plate-shaped cured product was used as a test piece and the dielectric constant and dielectric loss tangent were measured at a temperature of 25±3°C and 10 GHz using a dielectric constant measuring device (Agilent Technologies, product name "Network Analyzer N5227A"). The results are shown in Tables 1 to 3 ("Dielectric Constant" and "Dielectric Loss Tangent" in the tables).

[0123]

[0124]

[0125] As shown in Tables 1 and 2, the molding resin compositions of the Examples tended to give cured products having a higher relative dielectric constant and a reduced dielectric loss tangent to the same extent as the molding resin compositions of the Comparative Examples.

[0126] The disclosure of Japanese Patent Application No. 2023-117870, filed on July 19, 2023, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described 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. A molding resin composition comprising: a curable resin; and an inorganic filler containing alumina particles and at least one of calcium titanate particles and strontium titanate particles, wherein the total content of the calcium titanate particles and strontium titanate particles is 5.0 volume % to 15.0 volume % based on the total inorganic filler, and the total content of the inorganic filler exceeds 60 volume % based on the total molding resin composition.

2. The molding resin composition according to claim 1, wherein the curable resin comprises an epoxy resin, and the molding resin composition further comprises a curing agent.

3. The molding resin composition according to claim 2, wherein the curing agent comprises an active ester compound.

4. The molding resin composition according to claim 3, wherein the curing agent further comprises a phenolic curing agent.

5. The molding resin composition according to claim 4, wherein the phenolic hardener comprises an aralkyl type phenolic resin and a melamine modified phenolic resin.

6. The molding resin composition according to claim 5, further comprising a stress relaxation agent.

7. The molding resin composition according to claim 6, wherein said stress relaxation agent comprises at least one of an indene-styrene-coumarone copolymer, a trialkylphosphine oxide, and a triarylphosphine oxide.

8. The molding resin composition according to claim 1, wherein the inorganic filler comprises calcium titanate particles.

9. The molding resin composition according to claim 2, wherein the combined mass ratio of the calcium titanate particles and the strontium titanate particles to the combined mass of the epoxy resin and the curing agent is 0.8 to 1.

5.

10. The molding resin composition according to any one of claims 1 to 9, which is used in a high-frequency device.

11. The molding resin composition according to claim 10, which is used for sealing electronic parts in a high frequency device.

12. The molding resin composition according to any one of claims 1 to 9, which is used for an antenna-in-package.

13. An electronic component device comprising: a support member; an electronic component placed on the support member; and a cured product of the molding resin composition according to any one of claims 1 to 9, encapsulating the electronic component.

14. The electronic component device of claim 13, wherein the electronic component includes an antenna.

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