Molding resin composition and electronic component device

Abstract

To provide a resin composition for molding which achieves both high dielectric constant and low dielectric loss tangent in a cured product after molding.SOLUTION: A resin composition for molding contains a curable resin, and an inorganic filler containing calcium titanate particles.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to a resin composition for molding and an electronic component device. [Background technology]

[0002] In recent years, the demand for more advanced, lighter, and smaller electronic devices has led to increased density integration and even higher density mounting of electronic components. As a result, semiconductor packages used in these electronic devices are becoming smaller and smaller than ever before. Furthermore, the radio frequencies used for communication in electronic devices are also increasing.

[0003] High dielectric constant resin compositions for use in encapsulating semiconductor devices have been proposed in order to miniaturize semiconductor packages and to handle high frequencies (see, for example, Japanese Patent Publication No. 2015-036410, Japanese Patent Publication No. 2017-057268, and Japanese Patent Publication No. 2018-141052). [Overview of the initiative] [Problems that the invention aims to solve]

[0004] Examples of materials used to encapsulate electronic components such as semiconductor elements include molding resin compositions comprising a curable resin and an inorganic filler. By using a molding resin composition that yields a cured product with a high dielectric constant, it becomes possible to miniaturize semiconductor packages.

[0005] On the other hand, materials with a high dielectric constant generally also have a high dielectric loss tangent. When materials with a high dielectric loss tangent are used, the transmitted signal is converted into heat due to transmission loss, which tends to reduce communication efficiency. Here, the amount of transmission loss that occurs when radio waves transmitted for communication are converted into heat in a dielectric is expressed as the product of the frequency, the square root of the relative permittivity, and the dielectric loss tangent. In other words, the transmission signal is more easily converted into heat in proportion to the frequency. Furthermore, especially in recent years, in order to cope with the increase in the number of channels due to the diversification of information, radio waves used for communication have become higher in frequency, so there is a demand for molding resin compositions that can achieve both a high dielectric constant and a low dielectric loss tangent in the cured product after molding.

[0006] The object of this disclosure is to provide a molding resin composition that achieves both a high dielectric constant and a low dielectric loss tangent in the cured product after molding, and an electronic component device using the same. [Means for solving the problem]

[0007] The following embodiments are included as specific means for solving the aforementioned problems. <1> Curable resin and An inorganic filler containing calcium titanate particles, A molding resin composition containing the following: <2> The curable resin contains an epoxy resin, and the molding resin composition further contains a curing agent. <1> The molding resin composition described above. <3> The curing agent comprises an active ester compound. <2> The molding resin composition described above. <4> The curing agent comprises at least one other curing agent selected from the group consisting of phenol curing agents, amine curing agents, acid anhydride curing agents, polymer captan curing agents, polyaminoamide curing agents, isocyanate curing agents, and blocked isocyanate curing agents, and an active ester compound. <2> or <3> The molding resin composition described above. <5> The curing agent comprises an aralkyl-type phenolic resin and an activated ester compound. <2> or <3> The molding resin composition described above. <6> The inorganic filler further contains at least one other inorganic filler selected from the group consisting of silica particles and alumina particles. <1> ~ <5> A molding resin composition as described in any one of the following. <7> The volume-average particle size of the aforementioned other inorganic fillers is 3 μm or larger. <6> The molding resin composition described above. <8> The content of the calcium titanate particles is 30% to 80% by volume relative to the total inorganic filler. <1> ~ <7> A molding resin composition as described in any one of the following. <9> The relative permittivity of the entire inorganic filler at 10 GHz is 80 or less. <1> ~ <8> A molding resin composition as described in any one of the following. <10> The total content of the inorganic filler is 40% to 85% by volume relative to the total volume of the molding resin composition. <1> ~ <9> A molding resin composition as described in any one of the following. <11> The volume-average particle size of the calcium titanate particles is 0.2 μm to 80 μm. <1> ~ <10> A molding resin composition as described in any one of the following. <12> Further comprising a curing accelerator containing an organic phosphine, <1> ~ <11> A molding resin composition as described in any one of the following. <13> The inorganic filler contains spherical calcium titanate particles, <1> ~ <12> A molding resin composition according to any one of the items. <14> The total content of the inorganic filler is 70% to 85% by volume relative to the total volume of the molding resin composition. <13> The molding resin composition described above. <15> The relative permittivity of the cured product of the molding resin composition is 9 to 40, and the dielectric loss tangent of the cured product is 0.020 or less. <1> ~ <14> A molding resin composition according to any one of the items. <16> Used in high-frequency devices, <1> ~ <15> A molding resin composition as described in any one of the following. <17> Used for sealing electronic components in high-frequency devices, <16> The molding resin composition described above. <18> Used in antenna-in-package, <1> ~ <17> A molding resin composition as described in any one of the following. <19> Support member and An electronic component arranged on the support member, The aforementioned electronic component is sealed <1> ~ <18> A cured product of a molding resin composition described in any one of the following, An electronic component device equipped with the following features. <20> The aforementioned electronic component includes an antenna. <19> The electronic component device described above. [Effects of the Invention]

[0008] This disclosure provides a molding resin composition that achieves both a high dielectric constant and a low dielectric loss tangent in a cured product after molding, and an electronic component device using the same. [Brief explanation of the drawing]

[0009] [Figure 1] This is an SEM image of calcium titanate particles that have undergone spheroidization treatment. [Figure 2] This is an SEM image of calcium titanate particles before spheroidization treatment. [Modes for carrying out the invention]

[0010] In this 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, provided that the purpose of such process is achieved. In this disclosure, the numerical range indicated using "~" includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in numerical ranges described within this disclosure, the upper or lower limit of that range may be replaced with the values ​​shown in the examples. In the present disclosure, each component may contain a plurality of corresponding substances. When there are a plurality of substances corresponding to each component in the composition, the content rate or content of each component means the total content rate or content of the plurality of substances present in the composition, unless otherwise specified. In the present disclosure, the particles corresponding to each component may contain a plurality of types. When there are a plurality of types of particles corresponding to each component in the composition, the particle diameter of each component means a value for the mixture of the plurality of types of particles present in the composition, unless otherwise specified. In the present disclosure, when simply described as "calcium titanate particles", it means calcium titanate particles having any shape such as spherical, elliptical, amorphous, or a mixture thereof.

[0011] Hereinafter, embodiments for implementing the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps, etc.) are not essential unless specifically specified. The same applies to numerical values and their ranges, which do not limit the present disclosure.

[0012] <Molding resin composition> The molding resin composition according to one embodiment of the present invention includes a curable resin and an inorganic filler containing calcium titanate particles.

[0013] As described above, in the molding resin composition, it is required to achieve both a high dielectric constant and a low dielectric tangent in the cured product after molding. As a material that can obtain a high dielectric constant, for example, barium titanate can be considered. However, when using barium titanate, not only the dielectric constant but also the dielectric tangent tends to increase.

[0014] On the other hand, it has been found that when using calcium titanate, it is possible to suppress the increase in the dielectric tangent compared to the case of using barium titanate while increasing the dielectric constant. That is, in the present embodiment, by using an inorganic filler containing calcium titanate particles, a cured product having both a high dielectric constant and a low dielectric tangent can be obtained compared to the case of using barium titanate.

[0015] The following describes each component constituting the molding resin composition. The molding resin composition of this embodiment contains a curable resin and an inorganic filler, and may contain other components as needed.

[0016] (curable resin) The molding resin composition in this embodiment includes a curable resin. The curable resin may be either a thermosetting resin or a photocurable resin, but from the viewpoint of mass production, a thermosetting resin is preferable. 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 it may contain two or more types. Below, epoxy resin will be described as an example of a curable resin.

[0017] -Epoxy resin- The molding resin composition preferably contains an epoxy resin as the curable resin. When the molding resin composition contains epoxy resin as the curable resin, the epoxy resin content relative to the total 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 epoxy resin content relative to the total curable resin may also be 100% by mass. The type of epoxy resin is not particularly limited as long as it has epoxy groups in its molecule.

[0018] Specifically, the epoxy resins include: novolac-type epoxy resins (phenol novolac-type epoxy resins, orthocresol novolac-type epoxy resins, etc.) which are obtained by condensing or co-condensing a novolac resin obtained by condensing or co-condensing a novolac resin obtained by phenol compounds selected from the group consisting of phenol compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene, with an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, or propionaldehyde, under an acidic catalyst; triphenylmethane-type epoxy resins which are obtained by condensing or co-condensing a triphenylmethane-type phenol resin obtained by condensing or co-condensing the above phenol compound with an aromatic aldehyde compound such as benzaldehyde or salicylaldehyde, under an acidic catalyst; and novolac resins obtained by co-condensing the above phenol compound and naphthol compound with an aldehyde compound under an acidic catalyst. Copolymer epoxy resins, which are resins that have been epoxidized; diphenylmethane-type epoxy resins, which are diglycidyl ethers of bisphenol A, bisphenol F, etc.; biphenyl-type epoxy resins, which are diglycidyl ethers of alkyl-substituted or unsubstituted biphenols; stilbene-type epoxy resins, which are diglycidyl ethers of stilbene-based phenol compounds; sulfur atom-containing epoxy resins, which are diglycidyl ethers of bisphenol S, etc.; 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 acid compounds such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidylamine-type epoxy resins, in which the active hydrogen bonded to the nitrogen atom of aniline, diaminodiphenylmethane, isocyanuric acid, etc., is replaced with a glycidyl group; dicyclopentadiene-type epoxy resins, which are co-condensed resins of dicyclopentadiene and phenol compounds that have been 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 have epoxidized olefin bonds within the molecule; paraxylylene-modified epoxy resins, which are glycidyl ethers of paraxylylene-modified phenol resins; metaxylylene-modified epoxy resins, which are glycidyl ethers of metaxylylene-modified phenol resins; terpene-modified epoxy resins, which are glycidyl ethers of terpene-modified phenol resins; and dicyclopentadiene-modified phenol resins, which are glycidyl ethers of dicyclo Examples of 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, which are epoxidized aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins. Furthermore, epoxides of acrylic resins can also be cited as epoxy resins. These epoxy resins may be used individually or in combination of two or more types.

[0019] The epoxy equivalent (molecular weight / number of epoxy groups) of the epoxy resin is not particularly limited. From the viewpoint of balancing 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 shall be the value measured according to the method conforming to 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. From the viewpoint of moldability and reflow resistance, the softening point or melting point of the epoxy resin is preferably 40°C to 180°C, and from the viewpoint of ease of handling when preparing the resin composition for molding, it is more preferably 50°C to 130°C. The melting point or softening point of the epoxy resin shall be the value measured by differential scanning calorimetry (DSC) or by a method (ring-sphere method) in accordance with JIS K 7234:1986.

[0021] When a molding resin composition contains epoxy resin as a curable resin, the mass percentage of epoxy resin in the total amount of the molding resin composition is preferably 0.5% to 30% by mass, more preferably 2% to 20% by mass, and even more preferably 3.5% to 13% by mass, from the viewpoint of strength, fluidity, heat resistance, moldability, etc.

[0022] -Hardening agent- If the molding resin composition contains an epoxy resin as the curable resin, the molding resin composition may further contain a curing agent. Preferably, the molding resin composition contains a curable resin containing an epoxy resin, a curing agent, and an inorganic filler containing calcium titanate particles. The type of curing agent is not particularly limited.

[0023] The curing agent preferably contains an active ester compound. The active ester compound may be used alone or in combination of two or more types. Here, an active ester compound refers to a compound that has one or more ester groups that react with epoxy groups in one molecule and has a curing effect on epoxy resins. When the curing agent contains an active ester compound, the curing agent may also contain other curing agents, or may not contain other curing agents.

[0024] When an active ester compound is used as a curing agent, the dielectric loss tangent of the cured product can be kept lower compared to when a phenol curing agent or an amine curing agent is used. The reason for this is presumed to be as follows. In the reaction of epoxy resin with a phenol curing agent or an amine curing agent, secondary hydroxyl groups are generated. In contrast, in the reaction of epoxy resin with an activated ester compound, ester groups are generated instead of secondary hydroxyl groups. Since ester groups have lower polarity than secondary hydroxyl groups, a molding resin composition containing an activated ester compound as a curing agent can suppress the dielectric loss tangent of the cured product to a lower level compared to a molding resin composition containing only a curing agent that generates secondary hydroxyl groups. Furthermore, since polar groups in the cured product increase its water absorption, using an active ester compound as a curing agent can reduce the concentration of polar groups in the cured product, thereby suppressing its water absorption. By suppressing the water absorption of the cured product, that is, by reducing the content of H2O, a polar molecule, 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 is a compound that has one or more ester groups in its molecule that react with epoxy groups. Examples of active ester compounds include phenol ester compounds, thiophenol ester compounds, N-hydroxyamine ester compounds, and esterified heterocyclic hydroxy compounds.

[0026] Examples of active ester compounds include ester compounds obtained from at least one aliphatic carboxylic acid and an aromatic carboxylic acid, and at least one aliphatic hydroxy compound and an aromatic hydroxy compound. Ester compounds in which an aliphatic compound is the polycondensation component tend to have excellent compatibility with epoxy resins due to the presence of an aliphatic chain. Ester compounds in which an aromatic compound is the 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 aromatic carboxylic acids and phenolic hydroxyl groups. In particular, aromatic esters obtained by the condensation reaction of aromatic carboxylic acids and phenolic hydroxyl groups using a mixture of aromatic carboxylic acid components in which 2 to 4 hydrogen atoms of the aromatic ring are substituted with carboxyl groups (such as benzene, naphthalene, biphenyl, diphenylpropane, diphenylmethane, diphenyl ether, and diphenylsulfonic acid), monohydric phenols in which 1 hydrogen atom of the aforementioned aromatic ring is substituted with a hydroxyl group, and polyhydric phenols in which 2 to 4 hydrogen atoms of the aforementioned aromatic ring are substituted with hydroxyl groups as raw materials are preferred. That is, aromatic esters having structural units derived from the above aromatic carboxylic acid component, structural units derived from the above monohydric phenol, and structural units derived from the above polyhydric phenol are preferred.

[0028] Specific examples of active ester compounds include active ester resins having a structure obtained by reacting a phenol resin having a molecular structure in which a phenol compound is bonded via an aliphatic cyclic hydrocarbon group, as described in Japanese Patent Publication No. 2012-246367, with an aromatic dicarboxylic acid or its halide and an aromatic monohydroxy compound. The compound represented by the following structural formula (1) is preferred as the active ester resin.

[0029] [ka]

[0030] In structural formula (1), R 1 X is an alkyl group having 1 to 4 carbon atoms, X is an unsubstituted benzene ring, an unsubstituted naphthalene ring, a benzene or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, or a biphenyl group, Y is a benzene ring, a naphthalene ring, or a benzene or 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 repeats, ranging from 0.25 to 10.

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

[0032] [ka]

[0033] [ka]

[0034] Other specific examples of active ester compounds include the compound represented by the following structural formula (2) and the compound represented by the following structural formula (3), as described in Japanese Patent Publication No. 2014-114352.

[0035] [ka]

[0036] In structural formula (2), R 1 and R 2 Each of these is independently a hydrogen atom, a C1-C4 alkyl group, or a C1-C4 alkoxy group, and Z is an ester-forming structural site (z1) selected from the group consisting of an unsubstituted benzoyl group, an unsubstituted naphthoyl group, a benzoyl or naphthoyl group substituted with a C1-C4 alkyl group, and a C2-C6 acyl group, or a hydrogen atom (z2), and at least one of Z is an ester-forming structural site (z1).

[0037] In structural formula (3), R 1 and R 2Each of these is independently a hydrogen atom, a C1-C4 alkyl group, or a C1-C4 alkoxy group, and Z is an ester-forming structural site (z1) selected from the group consisting of an unsubstituted benzoyl group, an unsubstituted naphthoyl group, a benzoyl or naphthoyl group substituted with a C1-C4 alkyl group, and a C2-C6 acyl group, or a hydrogen atom (z2), and at least one of Z is an ester-forming structural site (z1).

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

[0039] [ka]

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

[0041] [ka]

[0042] Commercially available active ester compounds may be used. 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 phenol novolac; and "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing a benzoylated 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 balancing various properties such as moldability, reflow resistance, and electrical reliability, 150 g / eq to 400 g / eq is preferred, 170 g / eq to 300 g / eq is more preferred, and 200 g / eq to 250 g / eq is even more preferred. The ester equivalent of the active ester compound shall be the value measured by the method in accordance with JIS K 0070:1992.

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

[0045] The curing agent may include curing agents other than active ester compounds. The type of other curing agent is not particularly limited and can be selected according to the desired properties of the molding resin composition. Examples of other curing agents include phenol curing agents, amine curing agents, acid anhydride curing agents, polymer captan curing agents, polyaminoamide curing agents, isocyanate curing agents, and blocked isocyanate curing agents.

[0046] Specifically, as phenol curing agents, polyhydric phenol compounds such as resorcinol, catechol, bisphenol A, bisphenol F, and substituted or unsubstituted biphenols; novolac-type phenolic resins obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenol compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, aminophenol, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene, with aldehyde compounds such as formaldehyde, acetaldehyde, and propionaldehyde under an acidic catalyst; and those synthesized from the above phenolic compounds with dimethoxyp-xylene, bis(methoxymethyl)biphenyl, etc. Examples 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 phenolic compounds and dicyclopentadiene; cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified phenolic resins; biphenyl-type phenolic resins; triphenylmethane-type phenolic resins obtained by condensation or co-condensation of the above phenolic compounds and aromatic aldehyde compounds such as benzaldehyde and salicylaldehyde under an acidic catalyst; and phenolic resins obtained by copolymerizing two or more of these. These phenolic curing agents may be used individually or in combination of two or more.

[0047] The functional group equivalents of other curing agents (hydroxyl group equivalents in the case of phenol curing agents) are not particularly limited. From the viewpoint of balancing various properties such as moldability, reflow resistance, and electrical reliability, the functional group equivalents of other curing agents are preferably 70 g / eq to 1000 g / eq, and more preferably 80 g / eq to 500 g / eq. The functional group equivalents of other curing agents (hydroxyl group equivalents in the case of phenol curing agents) shall be values ​​measured according to the 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 viewpoint 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 handling during the manufacture of the molding resin composition, it is more preferably 50°C to 130°C. The melting point or softening point of the curing agent shall be a value measured in the same manner as the melting point or softening point of the epoxy resin.

[0049] The equivalent ratio of epoxy resin to curing agent (all curing agents if multiple types 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 curing agent / number of functional groups in epoxy resin), is not particularly limited. From the viewpoint of minimizing unreacted components, it is preferable to set it in the range of 0.5 to 2.0, and more preferably in the range of 0.6 to 1.3. From the viewpoint of moldability and reflow resistance, it is even more preferable to set it in the range of 0.8 to 1.2.

[0050] The curing agent may include at least one other curing agent selected from the group consisting of phenol curing agents, amine curing agents, acid anhydride curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, and blocked isocyanate curing agents, and an active ester compound. From the viewpoint of having excellent flexural toughness after curing the molding resin composition, the curing agent may include a phenol curing agent and an active ester compound, or it may include an aralkyl type phenol resin and an active ester compound. In the following text, "other curing agents" may be interpreted as "phenol curing agents."

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

[0052] When the curing agent contains an active ester compound and other curing agents, the total mass ratio of the epoxy resin and the active ester compound to the total amount of epoxy resin and curing agent is preferably 40% by mass or more, more preferably 60% by mass, even more preferably 80% by mass or more, particularly preferably 85% by mass or more, and extremely preferably 90% by 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 other curing agents, the mass ratio of the active ester compound to the total amount of the active ester compound and other curing agents is preferably 40% to 90% by mass, more preferably 50% to 80% by mass, and even more preferably 55% to 70% by mass, from the viewpoint of having excellent flexural toughness after curing the molding resin composition and 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 ratio of the other curing agents to the total amount of the active ester compound and other curing agents is preferably 10% to 60% by mass, more preferably 20% to 50% by mass, and even more preferably 30% to 45% by mass, from the viewpoint of having excellent flexural toughness after curing the molding resin composition and keeping the dielectric loss tangent of the cured product low.

[0055] When a 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, based on the total amount of the molding resin composition.

[0056] -Polyimide resin- The molding resin composition may also contain a polyimide resin as a curable resin. Polyimide resins are not particularly limited as long as they are polymer compounds having imide bonds. 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, the compound having two or more N-substituted maleimide groups will also be called a "polymaleimide compound," and the compound having two or more amino groups will also be called a "polyamino compound." Bismaleimide resins may be polymers 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, compounds having a group containing two or more ethylenically unsaturated double bonds will also be referred to as "ethylenic compounds."

[0058] The polymaleimide compound is not limited to any compound having two or more N-substituted maleimide groups; it 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, it is preferable that the polymaleimide compound is a compound having two N-substituted maleimide groups.

[0059] Specific examples of polymaleimide compounds include bis(4-maleimidophenyl)methane, bis(3-maleimidophenyl)methane, polyphenylmethanemaleimide, bis(4-maleimidophenyl) ether, bis(4-maleimidophenyl) sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, m-phenylenebismaleimide, p-phenylenebismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 1,2-bismaleimideethane, 1,6-bismaleimidehexane, 1,12-bismaleimidodecane, 1,6-bismaleimide-(2,2,4-trimethyl)hexane, and 1,6-bismaleimide-(2,4,4-trimethyl)hexane. These polymaleimide compounds may be used individually or in combination of two or more.

[0060] The polyamino compound is not limited to compounds having two or more amino groups; it may be a compound having two amino groups, or a compound having three or more amino groups. From the viewpoint of availability, it is preferable that the polyamino compound is a compound having two amino groups.

[0061] Specific examples of polyamino compounds 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 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 individually or in combination of two or more.

[0062] Examples of "groups containing ethylenically unsaturated double bonds" found in ethylenically active compounds include vinyl groups, allyl groups, vinyloxy groups, allyloxy groups, acryloyl groups, and methacryloyl groups. Ethylenely active compounds may have only one group containing an ethylenically unsaturated double bond in a single molecule, or they may have two or more such groups. Ethylene compounds may have other groups in addition to the group containing the ethylenically unsaturated double bond. Examples of other groups include amino groups, ether groups, and sulfide groups. Specific examples of ethylenic compounds include diallylamine, diallyl ether, diallyl sphide, and triallyl isocyanurate.

[0063] In 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 ethylenically active compound, the equivalent ratio (Ta3 / Ta1) of the number of ethylenically unsaturated double bonds (Ta3) of the ethylenically active compound to the number of N-substituted maleimide groups (Ta1) of the polymaleimide compound in the bismaleimide resin can be, 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 in the range of 800 to 1500, 800 to 1300, or 800 to 1100.

[0065] The weight-average molecular weight of bismaleimide resin can be determined by gel permeation chromatography (GPC) and conversion from a calibration curve using standard polystyrene. The calibration curve is approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Type: A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Corporation]. The equipment used for GPC includes: Pump: L-6200 (Hitachi High-Technologies Corporation), Detector: L-3300 RI (Hitachi High-Technologies Corporation), Column Oven: L-655A-52 (Hitachi High-Technologies Corporation), Guard Column: TSK Guardcolumn HHR-L (Tosoh Corporation, column size 6.0 x 40 mm), Column: TSK gel-G4000HHR+gel-G2000HHR (Tosoh Corporation, column size 7.8 x 300 mm). The measurement conditions for GPC include: eluent: tetrahydrofuran, sample concentration: 30 mg / 5 mL, injection volume: 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 percentage of the polyimide resin in the total amount of the molding resin composition can be, for example, 0.5% to 30% by mass, preferably 2% to 20% by mass, and more preferably 3.5% to 13% by mass.

[0067] (Curing accelerator) The molding resin composition in this embodiment may optionally contain a curing accelerator. The type of curing accelerator is not particularly limited and can be selected according to the type of curable resin, the desired properties of the molding resin composition, etc.

[0068] Examples of curing accelerators used in a molding resin composition containing at least one selected from the group consisting of epoxy resins and polyimide resins as a 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 ruimidazole and 2-heptadecylimidazole; derivatives of the cyclic amidine compounds; phenol novolac salts of the cyclic amidine compounds or their derivatives; and these compounds with 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, and 2,3-dimethoxy Compounds having intramolecular polarization obtained by adding compounds with π bonds, such as quinone compounds like -1,4-benzoquinone and phenyl-1,4-benzoquinone, and diazophenylmethane; cyclic amidinium compounds such as tetraphenylborate salt of DBU, tetraphenylborate salt of DBN, tetraphenylborate salt of 2-ethyl-4-methylimidazole, and tetraphenylborate salt of N-methylmorpholine; tertiary amine compounds such as pyridine, triethylamine, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of the above tertiary amine compounds; ammonium salt compounds such as tetra-n-butylammonium acetate, tetra-n-butylammonium phosphate, tetraethylammonium acetate, tetra-n-hexylammonium benzoate, and tetrapropylammonium hydroxide;Organic phosphines such as primary phosphines like ethylphosphine and phenylphosphine, secondary phosphines like dimethylphosphine and diphenylphosphine, 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, tris(benzyl)phosphine, and other tertiary phosphines; phosphine compounds such as complexes of the above organic phosphines with organoborons; and the above organic phosphines or the above phosphine compounds containing maleic anhydride, 1,4-benzoquinone, 2,5-tholquinone, 1,4-naphthoquinone, and 2,3-dimethylbenzoquinone. Compounds having intramolecular polarization obtained by adding compounds having π bonds, such as quinone compounds like 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, anthraquinone, and diazophenylmethane; the organophosphine or the phosphine compound and 4-bromophenol, 3-bromophenol, 2-bromophenol, 4-chlorophenol, 3-chlorophenol, 2-chlorophenol, 4-iodidephenol, 3 Compounds having intramolecular polarization obtained by reacting halogenated phenol compounds such as -iodide phenol, 2-iodide phenol, 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, and 4-bromo-4'-hydroxybiphenyl with a dehalogenation step;Examples include tetrasubstituted phosphonium compounds such as tetraphenylphosphonium, tetraphenylborate salts of tetrasubstituted phosphoniums such as tetraphenylphosphonium tetra-p-tolylborate, and salts of tetrasubstituted phosphonium with phenolic compounds; salts of tetraalkylphosphonium with partially hydrolyzed aromatic carboxylic acid anhydrides; phosphobetaine compounds; and adducts of phosphonium compounds with silane compounds. The hardening accelerator may be used alone or in combination of two or more types.

[0069] Among these, the curing accelerator is preferably one that contains an organophosphine. Examples of curing accelerators containing organophosphines include the organophosphine, phosphine compounds such as complexes of the organophosphine and organoborons, and compounds having intramolecular polarization obtained by adding a compound having a π bond to the organophosphine or the phosphine compound. Among these, particularly suitable curing accelerators include triphenylphosphine, adducts of triphenylphosphine and quinone compounds, adducts of tributylphosphine and quinone compounds, and adducts of tri-p-tolylphosphine and quinone compounds.

[0070] When a molding resin composition contains a curing accelerator, the amount is preferably 0.1 to 30 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the resin component. When the amount of curing accelerator is 0.1 parts by mass or more per 100 parts by mass of the resin component, it tends to cure well in a short time. When the amount of curing accelerator is 30 parts by mass or less per 100 parts by mass of the resin component, it tends to result in a good molded product with a curing speed that is not too fast. Here, "resin components" refers to the curable resin and the curing agent used as needed. Furthermore, 100 parts by mass of resin components means that the total amount of the curable resin and the curing agent used as needed is 100 parts by mass.

[0071] (Curing initiator) If the molding resin composition contains a polyimide resin as the curable resin, the molding resin composition may optionally contain a curing initiator. Examples of curing initiators include radical polymerization initiators that generate free radicals upon heat. Specifically, examples of curing initiators include inorganic peroxides, organic peroxides, and azo compounds. Examples of inorganic peroxides include potassium persulfate (dipotassium peroxosulfate), sodium persulfate, and ammonium persulfate. 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, as well as α,α'-di(t-butylperoxy)diisopropylbenzene, dicumyl peroxide, and 2,5-dimethyl-2,5-di(t-butylperoxy) Examples include hexane, t-butylcumyl peroxide, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexine-3, di-t-butyl peroxide, and other dialkyl peroxides; dibenzoyl peroxide, di(4-methylbenzoyl) peroxide, and other diacyl peroxides; 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-butyl peroxy 2-ethylhexanonate. Examples of azo compounds include azobisisobutyronitrile, azobis-4-methoxy-2,4-dimethylvaleronitrile, azobiscyclohexanone-1-carbonitride, and azodibenzoyl.

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

[0073] (Inorganic filler) The molding resin composition in this embodiment includes an inorganic filler containing calcium titanate particles. The inorganic filler contains at least calcium titanate particles and may optionally contain other fillers besides calcium titanate particles.

[0074] -Calcium titanate particles- The shape of the calcium titanate particles is not particularly limited and may include spherical, elliptical, or irregular shapes. Furthermore, the calcium titanate particles may be crushed. The calcium titanate particles may be surface-treated.

[0075] The inorganic filler may contain spherical calcium titanate particles. Alternatively, the inorganic filler may contain both spherical calcium titanate particles and non-spherical calcium titanate particles (e.g., amorphous calcium titanate particles). By including spherical calcium titanate particles in the inorganic filler, it is possible to achieve high fluidity while simultaneously obtaining a high dielectric constant and a low dielectric loss tangent in the cured product after molding. Specifically, when the inorganic filler includes spherical calcium titanate particles, high fluidity can be obtained even if the proportion of inorganic filler in the molding resin composition is increased. By increasing the proportion of inorganic filler, the proportion of curable resin, which has a relatively higher dielectric loss tangent than the inorganic filler, decreases, making it possible to further reduce the overall dielectric loss tangent of the cured product after molding. Therefore, it is considered possible to achieve both high fluidity, a high dielectric constant, and an even lower dielectric loss tangent.

[0076] Here, the spherical calcium titanate particles are particles that have undergone a spheroidization treatment by heating and melting. Figure 1 shows an SEM image of the spheroidized calcium titanate particles. Figure 2 shows an SEM image of the calcium titanate particles before the spheroidization treatment. The SEM images in Figures 1 and 2 were obtained using a scanning electron microscope (JEOL Ltd., product name: JSM-7800F) at a magnification of 1000x and under high vacuum conditions. The shape of calcium titanate particles before spheroidization is usually irregular, as shown in Figure 2. By spheroidizing these irregularly shaped calcium titanate particles, spherical calcium titanate particles are obtained, as shown in Figure 1. The above spheroidizing treatment is carried out by heating and melting at a temperature of 1000°C to 1400°C for a period of 1 to 2 hours. Note that this spheroidizing treatment differs from the calcination process described later in that it is performed without the addition of a dopant compound and for a shorter heating time. Therefore, when uncalcined, amorphous calcium titanate particles are subjected to this spheroidizing treatment, spherical calcium titanate particles are obtained without calcination.

[0077] The volume-average particle size of the calcium titanate particles is preferably 0.1 μm to 100 μm, more preferably 0.2 μm to 80 μm, even more preferably 0.5 μm to 30 μm, particularly preferably 0.5 μm to 10 μm, and most preferably 0.5 μm to 8 μm. The volume-average particle size of calcium 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 ash. The resulting ash is observed using a scanning electron microscope (SEM), separated by shape, and the particle size distribution is determined from the observed images. The volume-average particle size (D50) of the calcium titanate particles can then be determined from this particle size distribution. Alternatively, the volume-average particle size of calcium titanate particles may be determined by measurement using a laser diffraction / scattering particle size distribution analyzer (e.g., LA920, Horiba, Ltd.). Furthermore, the calcium titanate particles may be a mixture of two or more types of calcium titanate particles with different volume-average particle sizes.

[0078] The content of calcium titanate particles is preferably 30% to 80% by volume relative to the total inorganic filler. In particular, from the viewpoint of obtaining a cured product with a high dielectric constant, the content of calcium titanate particles is preferably 30% or more by volume, more preferably 35% or more by volume, even more preferably 40% or more by volume, particularly preferably 60% or more by volume, extremely preferably 63% or more by volume, and most preferably 65% ​​or more by volume. On the other hand, from the viewpoint of obtaining a cured product with suppressed void formation, the content of calcium titanate particles is preferably 80% or less by volume, more preferably 77% or less by volume, and even more preferably 75% or less by volume. Furthermore, from the viewpoint of obtaining a high fluidity of the molding resin composition, it is particularly preferably less than 60% by volume, extremely preferably 55% or less by volume, and most preferably 50% or less by volume.

[0079] The content of calcium titanate particles is preferably 30% to 80% by volume, more preferably 35% to 77% by volume, and even more preferably 40% to 75% by volume, relative to the total inorganic filler. From the viewpoint of obtaining a cured product with a high dielectric constant, low dielectric loss tangent, and suppressed void generation, the content of calcium titanate particles is preferably 60% to 80% by volume, more preferably 63% to 77% by volume, and even more preferably 65% ​​to 75% by volume, relative to the total inorganic filler. From the viewpoint of achieving both a high dielectric constant and a low dielectric loss tangent in the cured product, and obtaining high fluidity in the molding resin composition, the content of calcium titanate particles is preferably 30% or more and less than 60% by volume, more preferably 35% to 55% by volume, and even more preferably 40% to 50% by volume, relative to the total inorganic filler.

[0080] When the inorganic filler contains spherical calcium titanate particles, it is possible to increase the proportion of the inorganic filler in the entire molding resin composition. Specifically, by including spherical calcium titanate particles in the inorganic filler, high fluidity can be obtained even if the total proportion of the inorganic filler in the molding resin composition is increased. Therefore, without changing the proportion of calcium titanate particles in the entire molding resin composition, it is possible to increase the proportion of other fillers with relatively low dielectric loss tangents and decrease the proportion of curable resins with relatively high dielectric loss tangents, thereby lowering the dielectric loss tangent while maintaining a high dielectric constant.

[0081] The percentage (by volume) of calcium titanate particles relative to the total inorganic filler can be determined by the following method. Thin sections of cured resin compositions for molding are 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 filler contained in area S is determined. Next, using an SEM-EDX (energy-dispersive X-ray spectrometer), the elements of the inorganic filler are identified, and the total area B of calcium titanate particles contained within the total area A of the inorganic filler is determined. The total area B of calcium titanate particles is divided by the total area A of the inorganic filler and converted to a percentage (%), and this value is taken as the content (volume %) of calcium titanate particles relative to the total inorganic filler. The area S should be sufficiently large relative to the size of the inorganic filler. For example, it should be large enough to contain 100 or more inorganic fillers. The area S may also be the sum of multiple cross-sections.

[0082] The content of calcium titanate particles is preferably 15% to 70% by volume relative to the entire molding resin composition. In particular, from the viewpoint of obtaining a cured product with a high dielectric constant, the content of calcium titanate particles is preferably 15% or more by volume, more preferably 25% or more by volume, even more preferably 27% or more by volume, particularly preferably 40% or more by volume, extremely preferably 42% or more by volume, and most preferably 45% or more by volume. On the other hand, from the viewpoint of obtaining a cured product with suppressed void formation, the content of calcium titanate particles is preferably 70% or less by volume, more preferably 60% or less by volume, even more preferably 55% or less by volume, and from the viewpoint of obtaining high fluidity of the molding resin composition, it is particularly preferably less than 40% by volume, extremely preferably 35% or less by volume, and most preferably 33% or less by volume.

[0083] The content of calcium titanate particles is preferably 15% to 70% by volume, more preferably 25% to 60% by volume, and even more preferably 27% to 55% by volume, relative to the entire molding resin composition. From the viewpoint of obtaining a cured product with a high dielectric constant, low dielectric loss tangent, and suppressed void generation, the content of calcium titanate particles is preferably 40% to 70% by volume, more preferably 42% to 60% by volume, and even more preferably 45% to 55% by volume, relative to the entire molding resin composition. From the viewpoint of achieving both a high dielectric constant and a low dielectric loss tangent in the cured product, and obtaining high fluidity in the molding resin composition, the content of calcium titanate particles is preferably 15% or more and less than 40% by volume, more preferably 25% to 35% by volume, and even more preferably 27% to 33% by volume, relative to the entire molding resin composition.

[0084] In the molding resin composition, the mass ratio of calcium titanate particles to the total of the epoxy resin and curing agent (calcium titanate particles / total of epoxy resin and curing agent) is preferably 1 to 10, more preferably 1.5 to 8, even more preferably 2 to 6, and particularly preferably 2.5 to 5, from the viewpoint of balancing dielectric constant and fluidity.

[0085] -Other fillers- Other types of fillers are not particularly limited. Specific examples of other filler materials include inorganic materials such as fused silica, crystalline silica, glass, alumina, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, fossilite, steatite, spinel, mullite, titania, talc, clay, and mica. Other fillers may be inorganic fillers with flame-retardant properties. Examples of inorganic fillers with flame-retardant properties include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as magnesium-zinc composite hydroxides, and zinc borate. Other fillers may be used individually or in combination of two or more types.

[0086] Among these, the other fillers preferably contain at least one selected from the group consisting of silica particles and alumina particles, from the viewpoint of reducing dielectric loss tangent. The other fillers may contain only silica particles and alumina particles, or both silica particles and alumina particles. If the other filler contains at least one selected from the group consisting of silica particles and alumina particles, the total content of silica particles and alumina particles is preferably 20% to 70% by volume, more preferably 23% to 65% by volume, even more preferably 25% to 60% by volume, and from the viewpoint of balancing fluidity and dielectric constant, it is particularly preferably 30% to 60% by volume, and extremely preferably 35% to 50% by volume.

[0087] Other fillers preferably contain alumina particles from the viewpoint of improving the fluidity of the molding resin composition. If other fillers contain alumina particles, the alumina particle content is preferably 20% to 70% by volume, more preferably 23% to 65% by volume, even more preferably 25% to 60% by volume, and from the viewpoint of balancing fluidity and dielectric constant, particularly preferably 30% to 60% by volume, and extremely preferably 35% to 50% by volume.

[0088] Other fillers may include titanate compound particles other than calcium titanate particles. Examples of titanate compound particles other than calcium titanate particles include strontium titanate particles, barium titanate particles, potassium titanate particles, magnesium titanate particles, lead titanate particles, aluminum titanate particles, and lithium titanate particles. However, from the viewpoint of keeping the dielectric loss tangent of the cured product low, the content of barium titanate particles is preferably less than 1 volume%, more preferably less than 0.5 volume%, and even more preferably less than 0.1 volume%, 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-mentioned content. Furthermore, the total content of titanate compound particles other than calcium titanate particles may be less than 1 volume%, less than 0.5 volume%, or less than 0.1 volume% of the total inorganic filler. In other words, the inorganic filler does not have to contain titanate compound particles other than calcium titanate particles, or it may contain titanate compound particles other than calcium titanate particles in the above-mentioned content.

[0089] The volume-average particle size of the other fillers is not particularly limited. Preferably, the volume-average particle size of the other fillers is 0.2 μm to 100 μm, and more preferably 0.5 μm to 50 μm. When the volume-average particle size of the other fillers 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 of the other fillers is 100 μm or less, the filling performance of the molding resin composition tends to be further improved. The average particle size of other inorganic fillers can be determined by placing the molding resin composition in a crucible and leaving it at 800°C for 4 hours to ashify. The resulting ash is observed using a scanning electron microscope (SEM), separated by shape, and the particle size distribution is determined from the observed images. The volume-average particle size (D50) of the other fillers can then be determined from this particle size distribution. Alternatively, the volume-average particle size of the other fillers may be determined by measurement using a laser diffraction / scattering particle size distribution analyzer (e.g., LA920, Horiba, Ltd.). The other fillers may be a mixture of two or more fillers with different volume-average particle sizes.

[0090] The volume-average particle size of the other fillers may be 3 μm or more, or 5 μm or more, from the viewpoint of the viscosity of the molding resin composition, and may be 10 μm or more, or 20 μm or more, from the viewpoint of the fluidity of the molding resin composition.

[0091] The ratio of the volume-average particle size (μm) of other fillers to the volume-average particle size (μm) of calcium titanate, known as the volume-average particle size of other fillers / volume-average particle size of calcium titanate, is preferably greater than 1 and 20 or less, more preferably 1.5 to 15, and even more preferably 3 to 10, from the viewpoint of the fluidity and filling properties of the molding resin composition.

[0092] The shape of the other filler material is not particularly limited and may include spherical, elliptical, or irregular shapes. Furthermore, the other filler material may be crushed. The shape of the other fillers is preferably spherical from the viewpoint of improving the fluidity of the molding resin composition.

[0093] -Total content and characteristics of inorganic fillers- From the viewpoint of controlling the fluidity and strength of the cured product of the molding resin composition, the total content of inorganic fillers in the molding resin composition is preferably 40% to 90% by volume, more preferably 40% to 85% by volume, even more preferably 45% to 85% by volume, particularly preferably 50% to 82% by volume, and most preferably 55% to 80% by volume.

[0094] When the inorganic filler contains spherical calcium titanate particles, high fluidity can be obtained even if the overall content of the inorganic filler in the molding resin composition is high. Furthermore, by increasing the overall content of the inorganic filler in the molding resin composition, the content of the curable resin in the molding resin composition decreases, making it easier to obtain a cured product with a low dielectric loss tangent. From this perspective, when the inorganic filler contains spherical calcium titanate particles, the total content of the inorganic filler in the molding resin composition is preferably 70% by volume or more, more preferably 73% by volume or more, even more preferably 75% by volume or more, and particularly preferably 77% by volume or more.

[0095] The content (volume %) of inorganic fillers in a molding resin composition can be determined by the following method. Thin sections of cured molded resin compositions are 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 filler contained in area S is determined. The total area A of the inorganic filler is divided by area S and converted to a percentage (%), and this value is taken as the inorganic filler content (volume %) in the molded resin composition. The area S should be sufficiently large relative to the size of the inorganic filler. For example, it should be large enough to contain 100 or more inorganic fillers. The area S may also be the sum of multiple cross-sections. Inorganic fillers may exhibit uneven distribution in the direction of gravity during the curing of the molding resin composition. In such cases, when imaging with a scanning electron microscope (SEM), the entire direction of gravity of the cured material is imaged, and the area S encompassing the entire direction of gravity of the cured material is identified.

[0096] For example, the relative permittivity at 10 GHz for the entire inorganic filler material can be in the range of 80 or less. Hereafter, the relative permittivity at 10 GHz will also be simply referred to as "permittivity". Furthermore, in the case of inorganic fillers, it is preferable that the dielectric constant of the entire inorganic filler is 80 or less, and that the content of calcium titanate particles is 30 volume% or more of the total inorganic filler. One method for ensuring that the calcium titanate particle content is 30% or more by volume relative to the total inorganic filler, and that the dielectric constant of the total inorganic filler is 80 or less, is to use unfired calcium titanate particles as the calcium titanate particles. Here, unfired calcium titanate particles refer to calcium titanate particles that have not undergone the firing process described below.

[0097] Here, the "calcination process" refers to the process of adding a dopant compound containing other elements (i.e., elements other than titanium and calcium) to calcium titanate particles and heating them at a temperature of 1000°C or higher for 3 hours or more. The dielectric constant of calcium titanate particles increases significantly after undergoing the above-mentioned firing process. For example, the dielectric constant of unfired calcium titanate particles after firing at 1000°C for 3 hours is several times greater than that of calcium titanate before firing. Therefore, when adjusting the dielectric constant of the entire inorganic filler to 80 or less while using calcium titanate particles that have been calcined as calcium titanate particles, the content of calcium titanate particles in the entire inorganic filler is reduced. In a molding resin composition using an inorganic filler that contains calcined calcium titanate particles at a low content and has an overall dielectric constant of 80 or less, a cured product with a high dielectric constant can be obtained, but unevenness in the dielectric constant of the cured product is likely to occur. In contrast, in a molding resin composition using an inorganic filler that contains uncalcined calcium titanate particles at a content of 30 volume% or more and has an overall dielectric constant of 80 or less, a cured product with a high dielectric constant and high uniformity of dielectric constant can be obtained.

[0098] The dielectric constant of the entire inorganic filler is preferably 50 or less, more preferably 40 or less, and even more preferably 30 or less, from the viewpoint of suppressing dielectric loss. The dielectric constant of the entire inorganic filler is preferably 5 or more, more preferably 10 or more, and even more preferably 15 or more, from the viewpoint of miniaturizing electronic components such as antennas. The dielectric constant of the entire inorganic filler is preferably 5 to 50, more preferably 10 to 40, and even more preferably 15 to 30, from the viewpoint of suppressing dielectric loss and miniaturizing electronic components such as antennas.

[0099] Here, the dielectric constant of the entire inorganic filler can be determined, for example, as follows. Specifically, the following are prepared: three or more measurement resin compositions containing an inorganic filler to be measured and a specific curable resin, each with a different inorganic filler content; and a measurement resin composition containing the specific curable resin but without the inorganic filler. An example of a measurement resin composition containing an inorganic filler to be measured and a specific curable resin is a measurement resin composition containing a biphenyl aralkyl type epoxy resin, a phenol curing agent which is a phenol aralkyl type phenol resin, a curing accelerator containing an organic phosphine, and the inorganic filler to be measured. An example of three or more measurement resin compositions with different inorganic filler content is a measurement resin composition in which the inorganic filler content relative to the total measurement resin composition is 10% by volume, 20% by volume, and 30% by volume. Each prepared resin composition for measurement is molded by compression molding under the conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 600 seconds to obtain a cured product for measurement. The relative permittivity at 10 GHz is measured for each of the obtained cured products, and a graph is created with the inorganic filler content on the x-axis and the measured relative permittivity on the y-axis. Linear approximation is performed from the obtained graph using the least squares method, and the relative permittivity when the inorganic filler content is 100 volume% is extrapolated and defined as the "dielectric constant of the entire inorganic filler."

[0100] [Various additives] The molding resin composition in this embodiment may include, in addition to the components described above, various additives such as coupling agents, ion exchangers, mold release agents, flame retardants, colorants, and stress relievers, as exemplified below. The molding resin composition in this embodiment may also include, as necessary, various additives well known in the art, in addition to the additives exemplified below.

[0101] (Coupling agent) The resin composition for molding in this embodiment may contain a coupling agent. From the viewpoint of enhancing the adhesion between the resin component and the inorganic filler, it is preferable that the resin composition for molding contains a coupling agent. Examples of the coupling agent include known coupling agents such as silane-based compounds such as epoxy silane, mercapto silane, amino silane, alkyl silane, ureido silane, vinyl silane, and disilazane, titanium-based compounds, aluminum chelate-based compounds, and aluminum / zirconium-based compounds.

[0102] When the resin composition for molding contains a coupling agent, the amount of the coupling agent is preferably 0.05 parts by mass to 5 parts by mass, more preferably 0.1 parts by mass to 2.5 parts by mass, based on 100 parts by mass of the inorganic filler. When the amount of the coupling agent is 0.05 parts by mass or more based on 100 parts by mass of the inorganic filler, the adhesion to the frame tends to be further improved. When the amount of the coupling agent is 5 parts by mass or less based on the inorganic filler 100 parts by mass, the moldability of the package tends to be further improved.

[0103] (Ion exchanger) The resin composition for molding in this embodiment may contain an ion exchanger. From the viewpoint of improving the moisture resistance and high-temperature storage characteristics of an electronic component device including an electronic component to be sealed, it is preferable that the resin composition for molding contains an ion exchanger. The ion exchanger is not particularly limited, and conventionally known ones can be used. Specifically, 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 exchanger may be used alone or in combination of two or more. Among them, hydrotalcite represented by the following general formula (A) is preferable.

[0104] Mg (1-X) Al X (OH)2(CO3) X / 2 ·mH2O ……(A) (0 < X ≦ 0.5, m is a positive number)

[0105] When a molding resin composition contains an ion exchanger, there are no particular restrictions on its content as long as it is sufficient to capture ions such as halogen ions. 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.

[0106] (Release agent) The molding resin composition in this embodiment may contain a release agent from the viewpoint of obtaining good release properties from the mold during molding. The release agent is not particularly limited, and conventionally known ones can be used. Specifically, 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. The release agent may be used alone or in combination of two or more types.

[0107] When a molding resin composition contains a release agent, the amount is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the resin component. When the amount of release agent is 0.01 parts by mass or more per 100 parts by mass of the resin component, sufficient release properties tend to be obtained. When it is 10 parts by mass or less, better adhesion tends to be obtained.

[0108] (Flame retardant) The molding resin composition in this embodiment may contain a flame retardant. The flame retardant is not particularly limited, and conventionally known ones can be used. Specifically, examples include organic or inorganic compounds containing halogen atoms, antimony atoms, nitrogen atoms, or phosphorus atoms, metal hydroxides, etc. The flame retardant may be used alone or in combination of two or more types.

[0109] If the molding resin composition contains a flame retardant, the amount is not particularly limited as long as it is sufficient to obtain the desired flame retardant effect. For example, the amount of 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.

[0110] (Coloring agent) The molding resin composition in this embodiment may contain a colorant. Examples of known colorants include carbon black, organic dyes, organic pigments, titanium dioxide, red lead, and red iron oxide. The amount of colorant can be appropriately selected depending on the purpose. One colorant may be used alone, or two or more colorants may be used in combination.

[0111] (Stress reliever) The molding resin composition in this embodiment may contain a stress-relieving agent. Including a stress-relieving agent can further reduce package warping deformation and package cracking. Examples of stress-relieving agents include commonly used and known stress-relieving agents (flexible agents). Specifically, examples include thermoplastic elastomers such as silicone-based, styrene-based, olefin-based, urethane-based, polyester-based, polyether-based, polyamide-based, and polybutadiene-based; 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-relieving agent may be used alone or in combination of two or more types. Among stress relaxants, silicone-based stress relaxants are preferred. Examples of silicone-based stress relaxants include those having epoxy groups, those having amino groups, and those modified with polyethers, with silicone compounds such as epoxy-grouped silicone compounds and polyether-based silicone compounds being more preferred.

[0112] If the molding resin composition contains a stress-relieving agent, the amount 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.

[0113] (Method for preparing a resin composition for molding) The method for preparing the molding resin composition is not particularly limited. A common method involves thoroughly mixing predetermined amounts of components using a mixer or the like, then melt-kneading them using a mixing roll, extruder, or the like, followed by cooling and pulverization. More specifically, for example, a method involves stirring and mixing predetermined amounts of the above-mentioned components, then kneading them using a kneader, roll, extruder, or the like that has been preheated to 70°C to 140°C, followed by cooling and pulverization.

[0114] In this embodiment, the molding resin composition is preferably solid at room temperature and atmospheric pressure (for example, 25°C and atmospheric pressure). The shape of the molding resin composition when it is solid is not particularly limited and can be powder, granular, tablet, etc. When the molding resin composition is in tablet form, the dimensions and mass should preferably be such that they are suitable for the molding conditions of the package, from the viewpoint of handling.

[0115] (Properties of molding resin compositions) The relative permittivity at 10 GHz of the cured product obtained by compression molding the molding resin composition in this embodiment under the 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, 9 to 40. From the viewpoint of miniaturizing electronic components such as antennas, the relative permittivity at 10 GHz of the cured product is preferably 10 to 35, and more preferably 13 to 30. The relative permittivity described above is measured using a dielectric constant measuring device (for example, Agilent Technologies, product name "Network Analyzer N5227A") at a temperature of 25±3°C.

[0116] The dielectric loss tangent at 10 GHz of the cured product obtained by compression molding the molding resin composition in this embodiment under the 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, 0.020 or less. From the viewpoint of reducing transmission loss, the dielectric loss tangent at 10 GHz of the cured product is preferably 0.018 or less, more preferably 0.015 or less, and even more preferably 0.010 or less. The lower limit of the dielectric loss tangent at 10 GHz of the cured product is not particularly limited, and for example, 0.005. The above dielectric loss tangent measurement is performed using a dielectric constant measuring device (for example, Agilent Technologies, product name "Network Analyzer N5227A") at a temperature of 25±3°C.

[0117] When a molding resin composition is molded using a spiral flow measurement mold conforming to EMMI-1-66 under the conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds, the flow distance is preferably 80 cm or more, more preferably 100 cm or more, and even more preferably 120 cm or more. Hereinafter, the above flow distance will also be referred to as "spiral flow". The upper limit of the spiral flow is not particularly limited, and for example, 200 cm can be cited.

[0118] The gel time of the molding resin composition at 175°C is preferably 30 to 100 seconds, and more preferably 40 to 70 seconds. The gel time at 175°C is measured as follows. Specifically, a 3g sample of the molding resin composition is measured at 175°C using a Curlastometer from JSR Trading Co., Ltd., and the time until the torque curve rises is defined as the gel time (sec).

[0119] (Applications of molding resin compositions) The molding resin composition in this embodiment can be applied, for example, to the manufacture of electronic component devices, particularly high-frequency devices, as described later. The molding resin composition in this embodiment may also be used for encapsulating 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 components and devices are becoming more sophisticated and smaller. Along with the miniaturization and increased functionality of PKGs, the development of antenna-in-packages (AiPs), which are PKGs with antenna functionality, is also progressing. In AiPs, in order to cope with the increase in the number of channels due to the diversification of information, the radio waves used for communication are becoming higher in frequency, and the sealing material is required to have both a high dielectric constant and a low dielectric loss tangent. As described above, the molding resin composition in this embodiment yields a cured product that achieves both a high dielectric constant and a low dielectric loss tangent. Therefore, it is particularly suitable for antenna-in-package (AiP) applications in high-frequency devices, where an antenna placed on a support member is sealed with the molding resin composition.

[0120] <Electronic Components and Devices> An electronic component device according to one embodiment of the present disclosure comprises a support member, an electronic component disposed on the support member, and a cured product of the aforementioned molding resin composition that encapsulates the electronic component. Examples of electronic component devices include those in 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 on support members such as lead frames, pre-wired tape carriers, wiring boards, glass, silicon wafers, and organic substrates, and the resulting electronic component region is sealed with a molding resin composition (e.g., a high-frequency device).

[0121] The type of support member is not particularly limited, and any support member commonly used in the manufacture of electronic component devices can be used. The above electronic components may include an antenna, or may include an antenna and elements other than an antenna. The above antenna is not limited to anything that performs the function of an antenna, and may be an antenna element or wiring.

[0122] Furthermore, in the electronic component device of this embodiment, other electronic components may be arranged on the side of the support member opposite to the side on which the above-mentioned electronic components are arranged, if necessary. The other electronic components may be sealed with the aforementioned molding resin composition, or with another resin composition, or may not be sealed at all.

[0123] (Manufacturing method for electronic component devices) The method for manufacturing an electronic component device according to this embodiment includes the steps of arranging an electronic component on a support member and sealing the electronic component with the aforementioned molding resin composition. The method for carrying out each of the above steps is not particularly limited and can be carried out using general methods. Furthermore, the types of support members and electronic components used in the manufacture of electronic component devices are not particularly limited and can be those commonly used in the manufacture of electronic component devices.

[0124] Methods for encapsulating electronic components using the aforementioned molding resin composition include low-pressure transfer molding, injection molding, and compression molding. Among these, low-pressure transfer molding is the most common. [Examples]

[0125] The above embodiments will be described in detail below with reference to examples, but the scope of the above embodiments is not limited to these examples.

[0126] <Preparation of resin composition for molding> The components listed below were mixed in the proportions (parts by mass) shown in Tables 1 to 3 to prepare the molding resin compositions for the examples and comparative examples. These molding resin compositions were solid at room temperature and pressure. In Tables 1 through 3, blank spaces indicate that the ingredient is not included. Furthermore, Tables 1 to 3 also show the results obtained by determining the content of calcium titanate particles relative to the total inorganic filler used ("Particle percentage (volume %)" in the table), the content of the inorganic filler relative to the total molding resin composition ("Content (volume %)" in the table), and the relative permittivity of the total inorganic filler at 10 GHz ("Filler permittivity" in the table) using the method described above.

[0127] • Epoxy resin 1: Triphenylmethane type epoxy resin, epoxy equivalent 167 g / eq (Mitsubishi Chemical Corporation, product name "1032H60") • Epoxy resin 2: Biphenyl aralkyl type epoxy resin, epoxy equivalent 274 g / eq (Nippon Kayaku Co., Ltd., product name "NC-3000") • Epoxy resin 3: Biphenyl-type epoxy resin, epoxy equivalent 192 g / eq (Mitsubishi Chemical Corporation, product name "YX-4000")

[0128] • Hardener 1: Active ester compound, DIC Corporation, Product name "EXB-8" • Curing agent 2: Phenolic curing agent, aralkyl-type phenolic resin, hydroxyl group equivalent 170g / eq (Meiwa Chemicals Co., Ltd., product name "MEH7800 series")

[0129] • Inorganic filler 1: Silica particles, other fillers, volume-average particle size: 11 μm, shape: spherical • Inorganic filler 2: Alumina particles, other fillers, volume-average particle size: 45 μm, shape: spherical • Inorganic filler 3: Alumina particles, other fillers, volume-average particle size: 7 μm, shape: spherical • Inorganic filler 4: Unfired calcium titanate particles, volume-average particle size: 6 μm, shape: irregular. • Inorganic filler 5: Unfired calcium titanate particles, volume-average particle size: 0.2 μm, shape: irregular. • Inorganic filler 6: Unfired barium titanate particles, volume-average particle size: 6.6 μm, shape: spherical • Inorganic filler 7: Unfired calcium titanate particles, volume-average particle size: 9 μm, shape: spherical

[0130] • Curing accelerator: Triphenylphosphine / 1,4-benzoquinone adduct • Coupling agent: N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., product name "KBM-573") • Release agent: Montane ester wax (Clariant Japan Co., Ltd., product name "HW-E") • Coloring agent: Carbon black (Mitsubishi Chemical Corporation, product name "MA600") • Silicone 1: Polyether-based silicone compound (Momentive Performance Materials, product name "SIM768E") • Silicone 2: Silicone compound containing an epoxy group (Dow Toray Industries, Ltd., product name "AY42-119")

[0131] The volume-average particle size of each of the inorganic fillers mentioned above was obtained by the following measurements. Specifically, first, an inorganic filler was added to a dispersion medium (water) in an amount ranging from 0.01% to 0.1% by mass, and then dispersed in a bath-type ultrasonic cleaner for 5 minutes. 5 ml of the obtained dispersion was injected 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 50% of the cumulative value (by volume) in the obtained particle size distribution was defined as the volume-average particle size.

[0132] <Evaluation of molding resin compositions> (Relative permittivity and dielectric loss tangent) The molding resin composition was placed in a vacuum hand press machine and molded under the 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, and 0.2 mm thick). Using this plate-shaped cured product as a test specimen, the relative permittivity and dielectric loss tangent were measured at 10 GHz at a temperature of 25 ± 3°C using a dielectric constant measuring device (Agilent Technologies, product name "Network Analyzer N5227A"). The results are shown in Tables 1 to 3 ("Relative Permittivity" and "Dielectric Loss Tangent" in the tables).

[0133] (Liquidity: spiral flow) Using a spiral flow measurement mold conforming to EMMI-1-66, the molding resin composition was molded under the conditions of a mold temperature of 180°C, a molding pressure of 6.9 MPa, and a curing time of 120 seconds, and the flow distance (cm) was determined. The results are shown in Tables 1 to 3 ("Flow distance (cm)" in the tables).

[0134] (Geltime) Measurements were performed at 175°C using a Curlastometer from JSR Trading Co., Ltd. for 3g of the molding resin composition, and the time until the torque curve rose was defined as the gel time (seconds). The results are shown in Tables 1 to 3 ("Gel Time (seconds)" in the tables). In the table, "Not possible" means that the gel time is so short that the rise of the torque curve cannot be observed.

[0135] [Table 1]

[0136] [Table 2]

[0137] [Table 3]

[0138] As shown in Tables 1 to 3, the molding resin compositions of the examples achieve both a high relative permittivity and a low dielectric loss tangent in the cured product after molding, compared to the molding resin compositions of the comparative examples.

[0139] [Examples 15 and 16] The molding resin compositions of Examples 15 and 16 were prepared by mixing the materials in the proportions (parts by mass) shown in Table 4. These molding resin compositions were solid at room temperature and pressure. In Example 15, curing agents 1 and 3 were used in combination, while silicone was not used in Examples 15 and 16. In Table 4, the blank cells mean that the corresponding components are not included. Also, each item in Table 4 is the same as each item in Tables 1 to 3. Incidentally, the curing agent 3 used in Example 15 is as follows. · Curing agent 3: Phenolic curing agent, aralkyl type phenolic resin, hydroxyl equivalent 202 g / eq (Meiwa Kasei Co., Ltd., product name "MEH7851SS"))

[0140]

Table 4

[0141] As shown in Table 4, the molding resin compositions of Examples 15 and 16 achieve both a high relative permittivity and a low dielectric loss tangent in the cured product after molding, as compared with the molding resin compositions of the comparative examples shown in Table 3.

[0142] <Evaluation of molding resin composition> (Flexural strength) Using the molding resin compositions obtained in each example and each comparative example, cured products of the molding resin compositions were obtained under the same conditions as (relative permittivity and dielectric loss tangent). The cured product was cut into a rectangular parallelepiped of 4.0 mm × 10.0 mm × 80 mm, and test pieces for flexural strength evaluation were prepared. Using these test pieces, a flexural test was conducted on a Tensilon universal material testing machine (Instron 5948, manufactured by Instron Corporation) under the conditions of a support span of 64 mm, a crosshead speed of 10 mm / min, and a temperature of 25°C. Using the measured results, a flexural stress-displacement curve was created from Equation (A), and the maximum stress was taken as the flexural strength. σ = 3FL / 2bh 2 ··· Equation (A) σ: Flexural stress (MPa) F: Flexural load (N)​​​​​​​​​​​​​The bending toughness was evaluated by measuring the fracture toughness. Test specimens for evaluating bending toughness were prepared by cutting the hardened material into rectangular parallelepipeds measuring 4.0 mm × 10.0 mm × 80 mm. The size of the crack defects in the test specimens for evaluating bending toughness was set to 4.0 mm × 2.0 mm × 1.0 mm. The fracture toughness value was calculated by three-point bending measurement using a Tensilon universal material tester (Instron 5948, Instron Corporation) and the test specimens for evaluating bending toughness, based on ASTM D5045.

[0144] Table 5 shows the measurement results of bending strength and fracture toughness values ​​for each example and comparative example.

[0145] [Table 5]

[0146] As shown in Table 5, the molding resin compositions of Examples 7, 9, and 15 showed better flexural toughness after curing compared to the molding resin compositions of each example and each comparative example. Table 5 shows that when only an active ester compound was used as a curing agent, the evaluation of flexural toughness tended to worsen compared to when only a phenol curing agent was used. On the other hand, in the molding resin composition of Example 15, the evaluation of flexural toughness after curing was better when both an active ester compound and a phenol curing agent were used as curing agents compared to when only a phenol curing agent was used. Thus, in Example 15, it was confirmed that the flexural toughness after curing was synergistically improved by using both an active ester compound and a phenol curing agent as curing agents. Improved flexural toughness tends to suppress the occurrence of cracks in the cured product.

[0147] [Examples 17-19] The molding resin compositions of Examples 17-19 were prepared by mixing the materials in the proportions (parts by mass) shown in Table 6. These molding resin compositions were solid at room temperature and pressure. In Table 6, blank spaces indicate that the component is not included. Furthermore, each item in Table 6 is the same as the items in Tables 1 through 4. The inorganic filler 7 used in Examples 17 to 19 is as follows. • Inorganic filler 7: Unfired calcium titanate particles, volume-average particle size: 8.9 μm, shape: spherical; irregularly shaped calcium titanate particles subjected to spheroidization treatment at 1200°C for 2 hours.

[0148] [Table 6]

[0149] As shown in Table 6, the molding resin compositions of Examples 17-19 achieve both a high relative permittivity and a low dielectric loss tangent in the cured product after molding, compared to the molding resin compositions of the comparative examples shown in Table 3. Furthermore, the molding resin compositions of Examples 18-19 have the same inorganic filler content relative to the total molding resin composition and have a longer flow distance compared to the molding resin compositions of Examples 1-2, which do not contain spherical calcium titanate particles, and also achieve both a high relative permittivity and a low dielectric loss tangent, similar to Examples 1-2.

[0150] The disclosures of PCT / JP2020 / 046412, filed on 11 December 2020, and PCT / JP2021 / 017047, filed on 28 April 2021, are incorporated herein by reference in their entirety. All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted as being incorporated by reference.

Claims

1. A thermosetting resin containing an epoxy resin, An inorganic filler containing calcium titanate particles, Hardener and Includes, The curing agent comprises an active ester compound, wherein the active ester compound is a compound represented by the following structural formula (1), and is a resin composition for molding. 【Chemistry 1】 In structural formula (1), R １ x is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, x is an unsubstituted benzene ring, an unsubstituted naphthalene ring, a benzene or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, or a biphenyl group, x is a benzene ring, a naphthalene ring, or a benzene or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, x is 0 or 1, and x represents the average number of repetitions, ranging from 0.25 to 10.

2. Thermosetting resins containing epoxy resin, An inorganic filler containing calcium titanate particles, Hardener and A molding resin composition comprising, The epoxy resin includes a biphenyl aralkyl type epoxy resin and / or a biphenyl type epoxy resin. The curing agent comprises an active ester compound and a phenol curing agent, wherein the active ester compound is a compound represented by the following structural formula (1), A molding resin composition wherein the content of calcium titanate particles relative to the entire molding resin composition is (380 / 1466) × 100% by mass or more. 【Chemistry 2】 In structural formula (1), R １ x is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, x is an unsubstituted benzene ring, an unsubstituted naphthalene ring, a benzene or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, or a biphenyl group, x is a benzene ring, a naphthalene ring, or a benzene or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, x is 0 or 1, and x represents the average number of repetitions, ranging from 0.25 to 10.

3. Thermosetting resins containing epoxy resin, An inorganic filler containing calcium titanate particles, Hardener and A molding resin composition comprising, The epoxy resin comprises at least one selected from the group consisting of diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, naphthalene-type epoxy resin, dicyclopentadiene-type epoxy resin, glycidylamine-type epoxy resin, naphthol aralkyl-type epoxy resin, and phenol aralkyl-type epoxy resin. The curing agent comprises an active ester compound, or comprises the active ester compound and a phenol curing agent, wherein the active ester compound is a compound represented by the following structural formula (1), A molding resin composition wherein the content of calcium titanate particles relative to the entire molding resin composition is [(759 + 127) / 1488] × 100% by mass or more. 【Transformation 3】 In structural formula (1), R １ x is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, x is an unsubstituted benzene ring, an unsubstituted naphthalene ring, a benzene or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, or a biphenyl group, x is a benzene ring, a naphthalene ring, or a benzene or naphthalene ring substituted with an alkyl group having 1 to 4 carbon atoms, x is 0 or 1, and x represents the average number of repetitions, ranging from 0.25 to 10.

4. The molding resin composition according to any one of claims 1 to 3, wherein the active ester compound is any of the following compounds (1-1) to (1-10). 【Chemistry 4】 【Transformation 5】

5. The molding resin composition according to any one of claims 1 to 4, wherein the curing agent comprises an aralkyl-type phenolic resin and the active ester compound.

6. The molding resin composition according to any one of claims 1 to 5, wherein the inorganic filler further contains at least one other inorganic filler selected from the group consisting of silica particles and alumina particles.

7. The molding resin composition according to claim 6, wherein the volume average particle size of the other inorganic filler is 3 μm or more.

8. The molding resin composition according to any one of claims 1 to 7, wherein the inorganic filler comprises at least one selected from the group consisting of strontium titanate particles, barium titanate particles, potassium titanate particles, magnesium titanate particles, lead titanate particles, aluminum titanate particles, and lithium titanate particles.

9. The molding resin composition according to any one of claims 1 to 8, wherein the inorganic filler comprises magnesium titanate particles together with the calcium titanate particles.

10. The molding resin composition according to any one of claims 1 to 9, wherein the content of the calcium titanate particles is 30% to 80% by volume relative to the total inorganic filler.

11. The molding resin composition according to any one of claims 1 to 10, wherein the relative permittivity at 10 GHz in the entire inorganic filler is 80 or less.

12. The molding resin composition according to any one of claims 1 to 11, wherein the total content of the inorganic filler is 40% to 85% by volume relative to the entire molding resin composition.

13. A molding resin composition according to any one of claims 1 to 12, further comprising a curing accelerator containing an organic phosphine.

14. The molding resin composition according to claim 13, wherein the total content of the inorganic filler is 70% to 85% by volume relative to the entire molding resin composition.

15. A molding resin composition according to any one of claims 1 to 14, wherein the relative permittivity at 10 GHz of the cured product of the molding resin composition is 9 to 40, and the dielectric loss tangent at 10 GHz of the cured product is 0.020 or less.

16. A molding resin composition according to any one of claims 1 to 15, used in high-frequency devices.

17. A molding resin composition according to claim 16, used for sealing electronic components in high-frequency devices.

18. A molding resin composition according to any one of claims 1 to 17, used in an antenna-in-package.

19. Support member and An electronic component arranged on the support member, A cured product of the molding resin composition according to any one of claims 1 to 18, which is used to seal the aforementioned electronic component, An electronic component device equipped with the following features.

20. The electronic component device according to claim 19, wherein the aforementioned electronic component includes an antenna.

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