Liquid resin composition for sealing, and electronic component device

Abstract

This liquid resin composition for sealing contains a compound having a vinylphenyl group and a compound having a maleimide group.

Description

Liquid resin composition for sealing and electronic component device

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

[0002] Liquid resin compositions are widely used in electronic component devices in which semiconductor elements are bare-chip mounted, such as COB (Chip on Board), COG (Chip on Glass), and TCP (Tape Carrier Package). Furthermore, in semiconductor devices (also known as flip chips) in which semiconductor elements are directly bump-connected to a wiring substrate, liquid resin compositions are used as underfill materials to fill the gaps between the bump-connected semiconductor elements and the wiring substrate. These liquid resin compositions play an important role in protecting electronic components from temperature, humidity, mechanical external forces, and the like.

[0003] Liquid resin compositions containing epoxy resins are widely used as liquid resin compositions for underfill materials, and contain a liquid epoxy resin, a curing agent, an inorganic filler such as silica, and the like. For example, Patent Document 1 discloses a liquid epoxy resin composition further containing a dispersant having a phosphate group or a phosphate salt group as an adsorption group, and the inorganic filler is surface-treated with phenylsilane. Patent Document 2 discloses an underfill material containing an epoxy resin, a curing agent, a filler, and a nitrogen-containing compound that is at least one of a guanidine compound or a biguanide compound having a specific structure.

[0004] JP 2021-172725 A JP 2019-081835 A

[0005] In recent years, in order to cope with the increase in the number of channels accompanying the diversification of information, the radio waves used for communication in electronic devices equipped with semiconductor devices have become higher in frequency. As radio waves become higher in frequency, there is a demand for encapsulating resin compositions with low dielectric loss tangents. When a material with a high dielectric loss tangent is used, the transmission signal is converted into heat due to dielectric loss, which tends to reduce communication efficiency. The amount of dielectric loss generated 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 dielectric constant, and the dielectric loss tangent. Transmission signals are more likely to be converted into heat in proportion to the frequency. Therefore, to keep dielectric loss low in high-frequency radio waves, it is desirable to lower the dielectric loss tangent.

[0006] The present disclosure has been made in consideration of the above-described conventional circumstances, and an object of the present disclosure is to provide a liquid resin composition for sealing that can form a cured product exhibiting a low dielectric tangent while maintaining filling properties for sealing, and an electronic component device using the same.

[0007] The present disclosure includes the following embodiments: <1> A liquid encapsulating resin composition containing a compound having a vinylphenyl group and a compound having a maleimide group. <2> The liquid encapsulating resin composition according to <1>, wherein the compound having a vinylphenyl group includes a compound represented by the following formula (b1): (In the formula, X ｂ１ represents an organic group, B's each independently represent a group containing a vinylphenyl group, and 1 represents an integer of 1 to 5. <3> The encapsulating liquid resin composition according to <1> or <2>, wherein the compound having a vinylphenyl group includes a compound having two or more vinylphenyl groups. <4> The encapsulating liquid resin composition according to any one of <1> to <3>, wherein the compound having a vinylphenyl group includes a compound represented by the following formula (b3): (In the formula, B ｈｂ each independently represents a hydrogen atom or a group represented by the following formula (Bz), and at least one B ｈｂ is a group represented by the following formula (Bz). (wherein * represents a bonding position.) <5> The encapsulating liquid resin composition according to any one of <1> to <4>, wherein the compound having a vinylphenyl group includes a polymer having a vinylphenyl group. <6> The encapsulating liquid resin composition according to any one of <1> to <5>, wherein the compound having a vinylphenyl group includes a polymer having a structural unit represented by the following formula (Bb): (wherein X represents an organic group, B each independently represents a group containing a vinylphenyl group, R each independently represents a substituent, l represents an integer of 1 to 5, m represents an integer of 0 to 10, and * represents a bonding position to another atom.) <7> The encapsulating liquid resin composition according to any one of <1> to <6>, wherein the compound having a vinylphenyl group includes at least one selected from the group consisting of a polymer represented by the following formula (B3-3) and a polymer represented by the following formula (B3-7): (In the formula, B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5. The benzene ring may each independently have a substituent at a substitutable position. (In the formula, B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5. The benzene ring may each independently have a substituent at a substitutable position. (wherein * represents a bonding position.) <8> The encapsulating liquid resin composition according to any one of <1> to <7>, wherein the compound having a maleimide group is liquid at 25°C. <9> The encapsulating liquid resin composition according to any one of <1> to <8>, wherein the compound having a maleimide group includes a compound having two maleimide groups. <10> The encapsulating liquid resin composition according to any one of <1> to <9>, wherein the molar ratio of maleimide groups to vinylphenyl groups (maleimide groups / vinylphenyl groups) is 0.05 to 5.0. <11> The encapsulating liquid resin composition according to any one of <1> to <10>, which is a radically polymerizable encapsulating liquid resin composition. <12> The encapsulating liquid resin composition according to any one of <1> to <11>, further comprising at least one selected from the group consisting of a radical polymerization initiator and a polymerization inhibitor. <13> The encapsulating liquid resin composition according to any one of <1> to <12>, further comprising a filler. <14> The encapsulating liquid resin composition according to any one of <1> to <13>, wherein the dielectric loss tangent of the cured product when cured at 150°C for 1 hour is 0.0050 or less. <15> An electronic component device comprising: an electronic component; and a cured product of the encapsulating liquid resin composition according to any one of <1> to <14>, which encapsulates at least a part of the electronic component.

[0008] According to the present disclosure, there are provided a liquid resin composition for encapsulation that can form a cured product exhibiting a low dielectric loss tangent while maintaining filling properties for encapsulation, and an electronic component device using the same.

[0009] Embodiments of the present disclosure will be described. The present disclosure is not limited to the following embodiments. The following embodiments can be implemented alone or in combination. Combinations of multiple embodiments are also included in the present disclosure.

[0010] In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in the present disclosure, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of another numerical range. The upper or lower limit of a numerical range described in the present disclosure may be replaced with a value shown in the Examples. A stepped numerical range may be created by selecting a numerical value from the upper and lower limit numerical values ​​described in stages in the present disclosure. The upper and lower limit numerical values ​​described in the present disclosure may be replaced with a value shown in the Examples. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, each structure in the polymer may contain multiple corresponding structures. When a polymer contains multiple structures corresponding to each structure, the content or amount of each structure refers to the total content or amount of the multiple structures present in the polymer, unless otherwise specified. In the present disclosure, the particles corresponding to each component may contain multiple types of particles. When a composition contains multiple types of particles corresponding to each component, the particle size of each component refers to the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0011] <Sealing Liquid Resin Composition> The encapsulating liquid resin composition contains a compound having a vinylphenyl group (hereinafter also referred to as a "vinylphenyl compound") and a compound having a maleimide group (hereinafter also referred to as a "maleimide compound"). By configuring the encapsulating liquid resin composition as described above, it is possible to form a cured product exhibiting a low dielectric loss tangent while maintaining the filling properties for encapsulation. The reason for this is presumed to be as follows. In conventionally widely used epoxy resin compositions, the curing reaction causes the ring opening of epoxy groups to produce hydroxyl groups. Because hydroxyl groups are polar groups, the dielectric loss tangent of the cured product is high. In contrast, the curing reaction of vinylphenyl compounds and maleimide compounds does not produce polar groups such as hydroxyl groups, and therefore the dielectric loss tangent of the cured product can be kept low. Furthermore, because it is a liquid resin composition, the filling properties are maintained at the same level as conventional epoxy resin compositions.

[0012] Since the vinylphenyl compound and the maleimide compound have excellent reactivity, it is possible to keep the heating temperature lower than when a cured product is obtained by polymerizing only the vinylphenyl compound.Furthermore, the sealing liquid composition of the present disclosure also allows the heating temperature for curing to be kept lower than that of conventional general epoxy resin compositions.

[0013] A cured product obtained using the encapsulating liquid resin composition can be used as an encapsulant for encapsulating electronic components such as semiconductor elements. The encapsulating liquid resin composition may contain other components. The encapsulating liquid resin composition may be a radical-polymerizable encapsulating liquid resin composition that can be polymerized by a radical polymerization reaction to form a cured product.

[0014] [Compound Having a Vinylphenyl Group] The vinylphenyl compound is a compound having at least one vinylphenyl group. The vinylphenyl compound has, for example, 1 to 20, 1 to 15, or 1 to 10 vinylphenyl groups. The vinylphenyl compound may be used alone or in combination of two or more types.

[0015] The vinylphenyl group can be represented by any of the following formulas: From the viewpoint of obtaining a cured product with a low dielectric constant and dielectric loss tangent, the vinylphenyl compound preferably contains a compound having a group represented by formula (p): * indicates the bonding position to other atoms.

[0016] The proportion of groups represented by formula (p) relative to the total amount of groups represented by formula (p), groups represented by formula (m), and groups represented by formula (o) in the total amount of the vinylphenyl compound is preferably 40 mol% or more, may be 50 mol% or more, may be 60 mol% or more, or may be 70 mol% or more. Moreover, the proportion of groups represented by formula (p) may be 10 mol% or more, may be 20 mol% or more, or may be 30 mol% or more. The greater the proportion of groups represented by formula (p), the lower the dielectric constant and dielectric loss tangent of the cured product tend to be.

[0017] In the total amount of the vinylphenyl compound contained in the encapsulating liquid resin composition, the molar ratio of the group represented by formula (p), the group represented by formula (m), and the group represented by formula (o) (group represented by formula (p):group represented by formula (m):group represented by formula (o)) is, for example, 40 to 100:0 to 60:0 to 60, 70 to 90:0:10 to 30, or 40 to 60:40 to 60:0.

[0018] The vinylphenyl compound may be a compound having a vinylphenylmethyl group (also referred to as a "vinylbenzyl group"). In the present disclosure, a compound having a vinylbenzyl group may be referred to as a "vinylbenzyl compound". The vinylbenzyl compound is an example of a vinylphenyl compound. The vinylphenyl compound may be a compound having a vinylphenylmethyloxy group (also referred to as a "vinylbenzyl ether group"). In the present disclosure, a compound having a vinylbenzyl ether group may be referred to as a "vinylbenzyl ether compound". The vinylbenzyl ether compound is an example of a vinylbenzyl compound and a vinylphenyl compound.

[0019] The vinylphenyl compound may further have an aromatic ring in addition to the vinylphenyl group. The vinylphenyl compound may have only one aromatic ring or two or more aromatic rings. The aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. The aromatic ring may be a monocyclic ring or a condensed polycyclic ring. Examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, tetracene, fluorene, phenanthrene, indene, indane, and biphenylene. Examples of aromatic heterocyclic rings include pyridine, pyrazine, quinoline, isoquinoline, acridine, phenanthroline, furan, pyrrole, thiophene, carbazole, oxazole, oxadiazole, thiadiazole, triazole, benzoxazole, benzoxadiazole, benzothiadiazole, benzotriazole, and benzothiophene. From the viewpoint of the dielectric properties of the cured product, the aromatic ring may be an aromatic hydrocarbon ring or a condensed polycyclic aromatic hydrocarbon ring. In terms of dielectric constant and dielectric loss tangent, examples of aromatic rings include fluorene and indene, and indene is preferred. When the vinylphenyl compound contains indene, a cured product exhibiting a lower dielectric constant and dielectric loss tangent tends to be obtained.

[0020] In some embodiments, the vinyl phenyl compound includes a compound having two or more vinyl phenyl groups. The compound having two or more vinyl phenyl groups may be a monomer or a polymer.

[0021] The vinylphenyl compound may be a monomer or polymer capable of radical polymerization. The vinylphenyl compound includes, for example, a monomer having a vinylphenyl group. In the present disclosure, a monomer having a vinylphenyl group may be referred to as a "vinylphenyl group-containing monomer." The vinylphenyl compound includes, for example, a polymer having a vinylphenyl group. In the present disclosure, a polymer having a vinylphenyl group may be referred to as a "vinylphenyl group-containing polymer." In the present disclosure, a monomer may be a compound that does not contain a repeating structural unit. A polymer may be a compound that contains a repeating structural unit. A polymer may be a polymer with a low degree of polymerization (i.e., an oligomer) or a polymer with a high degree of polymerization.

[0022] Examples of the vinylphenyl compound include compounds represented by the following formula (b1).

[0023]

[0024] In formula (b1), X ｂ１ represents an organic group, B each independently represents a group containing a vinylphenyl group, and l represents an integer of 1 to 5. "Independently each" means that when l is 2 or more and there are multiple Bs, the multiple Bs may be the same "group containing a vinylphenyl group", or some or all of the Bs may be different "groups containing a vinylphenyl group". "Independently each" does not preclude l from being 1, and the structural unit represented by formula (b1) may have one "group containing a vinylphenyl group". The same applies to "independently each" in the present disclosure.

[0025] X ｂ１ The organic group represented by formula (b1) may be a group containing at least one carbon atom. When the compound represented by formula (b1) is a vinylphenyl group-containing monomer, X ｂ１Examples of the organic group represented by formula (b1) include aromatic ring groups. Examples of the aromatic ring contained in the aromatic ring group are as described above. When the compound represented by formula (b1) is a vinylphenyl group-containing monomer, l may be 1 to 3. When the compound represented by formula (b1) is a vinylphenyl group-containing polymer, X ｂ１ The organic group represented by is a polymer.

[0026] (Vinylphenyl Group-Containing Monomer) In some embodiments, the vinylphenyl compound includes a vinylphenyl group-containing monomer. In some embodiments, the vinylphenyl group-containing monomer includes a monomer having two vinylphenyl groups and may further include at least one selected from the group consisting of a monomer having one vinylphenyl group and a monomer having three vinylphenyl groups; or may include a monomer having two vinylphenyl groups, a monomer having one vinylphenyl group, and a monomer having three vinylphenyl groups. When the vinylphenyl group-containing monomer includes two or more vinylphenyl group-containing monomers, the average number of vinylphenyl groups in the vinylphenyl group-containing monomer is, for example, 1.4 to 2.8, 1.6 to 2.7, or 1.8 to 2.6.

[0027] The vinylphenyl group-containing monomer may further have an aromatic ring other than the benzene ring contained in the vinylphenyl group. The vinylphenyl group-containing monomer may have only one aromatic ring or may have two or more aromatic rings. Examples of aromatic rings are as described above.

[0028] The vinylphenyl group-containing monomer may include, for example, a monomer having one aromatic ring other than the benzene ring contained in the vinylphenyl group and 1 to 3 vinylphenyl groups bonded to the aromatic ring directly or via a linking group; a monomer having one aromatic hydrocarbon and 1 to 3 vinylphenyl groups bonded to the aromatic hydrocarbon directly or via a linking group; or a monomer having one indene ring and 1 to 3 vinylphenyl groups bonded to the indene ring directly or via a linking group. The linking group may be, for example, a group selected from the group consisting of an alkylene group having 1 to 5 carbon atoms, an oxy group, a thio group, a sulfonyl group, a sulfinyl group, a carbonyl group, a carbonyloxy group, an imino group, and a group formed by combining two or more selected from these. Note that "having one aromatic ring and 1 to 3 vinylphenyl groups bonded to the aromatic ring via a linking group" means "having one aromatic ring and 1 to 3 linking groups bonded to the aromatic ring and 1 to 3 vinylphenyl groups bonded to the linking group."

[0029] The vinylphenyl group-containing monomer may have a saturated or unsaturated aliphatic hydrocarbon group, a saturated or unsaturated alicyclic hydrocarbon group, a group containing a hetero atom, or the like, instead of or in addition to the aromatic ring.

[0030] The weight average molecular weight (Mw) of the vinylphenyl group-containing monomer is, for example, 200 to 2,000, 200 to 1,000, 200 to 800, 250 to 750, or 300 to 700 from the viewpoint of curability and handleability. In the present disclosure, the weight average molecular weight (Mw) and number average molecular weight (Mn) refer to values ​​measured in polystyrene equivalent by gel permeation chromatography (GPC). Specifically, the weight average molecular weight (Mw) in the present disclosure can be measured by the method described in the Examples. The number average molecular weight (Mn) in the present disclosure can be measured in the same manner as the Mw measurement method described in the Examples.

[0031] When the vinylphenyl group-containing monomer contains a compound represented by formula (b1), it may contain a compound in which l is 2 in formula (b1) and may further contain at least one compound selected from the group consisting of a compound in which l is 1 and a compound in which l is 3; or it may contain a compound in which l is 2, a compound in which l is 1, and a compound in which l is 3. When the vinylphenyl group-containing monomer contains multiple types of compounds represented by formula (b1), the average value of l in the compounds represented by formula (b1) is, for example, 1.4 to 2.8, 1.6 to 2.7, or 1.8 to 2.6.

[0032] In some embodiments, the vinyl phenyl compound includes a compound represented by the following formula (b2): When the vinyl phenyl compound includes a compound represented by the following formula (b2), better heat resistance and a lower coefficient of linear thermal expansion tend to be obtained.

[0033]

[0034] In formula (b2), X ｂ２ represents an aromatic hydrocarbon group; B ｐ each independently represents a group represented by the following formula (Ph); each L independently represents a direct bond or a linking group; and 1 represents an integer of 1 to 3.

[0035] In formula (Ph), * represents a bonding position.

[0036] Examples of the aromatic hydrocarbon ring contained in the aromatic hydrocarbon ring group are as described above. ｂ２may be, for example, a fused polycyclic aromatic hydrocarbon ring group. Examples of the linking group are as described above. The linking group may be, for example, an alkylene group or a methylene group. The vinylphenyl group-containing monomer may, for example, in formula (b2), include a compound where l is 2, and may further include at least one selected from the group consisting of a compound where l is 1 and a compound where l is 3; or may include a compound where l is 2, a compound where l is 1, and a compound where l is 3. When the vinylphenyl group-containing monomer includes multiple types of compounds represented by formula (b2), the average value of l in the compounds represented by formula (b2) is, for example, 1.4 to 2.8, 1.6 to 2.7, or 1.8 to 2.6. Note that L being a "direct bond" means that X ｂ２ and B ｐ The same applies to "direct bond" in the present disclosure.

[0037] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Ph) may include a group represented by formula (p) above.

[0038] In some embodiments, the vinyl phenyl compound includes a compound represented by the following formula (b3): ​​When the vinyl phenyl compound includes a compound represented by the following formula (b3), better heat resistance and a lower coefficient of linear thermal expansion are obtained, and further, a low dielectric constant and a low dielectric loss tangent tend to be obtained.

[0039]

[0040] In formula (b3), B ｈｂ each independently represents a hydrogen atom or a group represented by the following formula (Bz), and at least one B ｈｂ is a group represented by the following formula (Bz).

[0041] In formula (Bz), * represents a bonding position.

[0042] The vinylphenyl group-containing monomer includes a compound in which, in formula (b3), the number of groups represented by formula (Bz) is 2, and may further include at least one selected from the group consisting of compounds in which the number of groups represented by formula (Bz) is 1 and compounds in which the number of groups represented by formula (Bz) is 3; or may include a compound in which the number of groups represented by formula (Bz) is 2, a compound in which the number is 1, and a compound in which the number is 3. When the vinylphenyl group-containing monomer includes multiple types of compounds represented by formula (b3), the average number of groups represented by formula (Bz) in the compounds represented by formula (b3) is, for example, 1.4 to 2.8, 1.6 to 2.7, or 1.8 to 2.6.

[0043] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Bz) may include a group in which the bonding position of the vinyl group to the benzene ring is para to the bonding position of the methylene group to the benzene ring.

[0044] The method for synthesizing the vinylphenyl group-containing monomer is not particularly limited. For example, when the vinylphenyl group-containing monomer is a compound represented by formula (b2), a method of reacting an aromatic hydrocarbon with a styrene having a halogenated methyl group in the presence of a basic compound can be mentioned. When synthesized by this method, the compound represented by formula (b2) has a methylene group as a linking group.

[0045] Examples of styrenes having a halogenated methyl group include o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene, and these can be used alone or in combination of two or more. Examples of basic compounds include alkali metal hydroxides and alkali metal alkoxides. A phase transfer catalyst may be used in this reaction. Examples of phase transfer catalysts include tetrabutylphosphonium bromide and tetra-n-butylammonium bromide. The reaction can be carried out in a solvent. The reaction may be carried out under heating and stirring. A polymerization inhibitor may be added to the reaction system. The resulting product may be purified, as necessary, by known methods such as concentration, reprecipitation, and washing.

[0046] (Vinylphenyl Group-Containing Polymer) In some embodiments, the vinylphenyl compound includes a vinylphenyl group-containing polymer. The vinylphenyl compound may include a polymer having two vinylphenyl groups; or a polymer having three or more vinylphenyl groups. Examples of the vinylphenyl group-containing polymer include a polymer having a hydrocarbon chain skeleton and a vinylphenyl group; a polymer having a phenolic resin skeleton and a vinylphenyl group, and the like. Examples of polymers having a hydrocarbon chain skeleton include polyolefins, vinyl-based polymers, acrylic polymers, polydicyclopentadiene, and the like. Examples of phenolic resins include novolac-type phenolic resins, aralkyl-type phenolic resins, dicyclopentadiene-type phenolic resins, triphenylmethane-type phenolic resins, and resins containing a naphthol structure instead of or in addition to the phenol structure in these phenolic resins.

[0047] From the viewpoint of ease of handling, the weight average molecular weight (Mw) of the vinylphenyl group-containing polymer is, for example, 300 to 50,000, 500 to 30,000, 1,000 to 10,000, or more than 2,000 to 10,000. From the viewpoint of improving the fluidity of the encapsulating liquid resin composition, the weight average molecular weight (Mw) may be 5,000 or less, or 2,500 or less.

[0048] In some embodiments, the vinyl phenyl compound may include a polymer including a structure represented by formula (Bb):

[0049]

[0050] In formula (Bb), X represents an organic group, each B independently represents a group containing a vinylphenyl group, each R independently represents a substituent, l represents an integer of 1 to 5, and m represents an integer of 0 to 10. * represents the bonding position to another atom.

[0051] The organic group represented by X may be a group containing at least one carbon atom, for example, a group containing at least one selected from the group consisting of saturated aliphatic hydrocarbon groups, unsaturated aliphatic hydrocarbon groups, saturated alicyclic hydrocarbon groups, unsaturated alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups. The organic group represented by X may further contain a linking group containing a heteroatom, a substituent containing a heteroatom, etc. Examples of the substituent represented by R include alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. m represents, for example, an integer of 0 to 5, an integer of 0 to 2, or 0.

[0052] In some embodiments, the vinyl phenyl compound comprises a polymer comprising a structure represented by formula (B1):

[0053]

[0054] In formula (B1), X Ｂ１ represents an organic group, B represents a group containing a vinylphenyl group, R each independently represents a substituent, and m represents an integer of 0 to 10. * represents the bonding position to other atoms. X Ｂ１ has the same meaning as X in formula (Bb). Also, B, R, and m in formula (B1) have the same meaning as B, R, and m in formula (Bb), respectively.

[0055] In some embodiments, the vinyl phenyl compound includes a polymer represented by the following formula (B2): When the vinyl phenyl compound includes a polymer represented by the following formula (B2), better heat resistance and a lower coefficient of linear thermal expansion tend to be obtained.

[0056]

[0057] In formula (B2), X Ｂ２ each independently represents a benzene ring or a naphthalene ring; each Y independently represents an organic group; B ｐeach independently represent a group represented by the following formula (Ph); each L independently represents a direct bond or a linking group; each R independently represents a substituent; each m independently represents an integer of 0 to 5; and n represents a number of 2 to 10.

[0058] In formula (Ph), * represents a bonding position.

[0059] The organic group represented by Y may be a group containing at least one carbon atom, and examples thereof include substituted or unsubstituted alkylene groups such as a methylene group or an ethylene group; substituted or unsubstituted cycloalkylene groups such as tetrahydrodicyclopentadiene; substituted or unsubstituted arylalkylene groups such as a phenylmethylene group; and substituted or unsubstituted divalent organic groups containing an alkylene group and an arylene group.

[0060] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Ph) may include a group represented by formula (p) above.

[0061] Examples of the linking group represented by L include an alkylene group, an oxy group, a thio group, a sulfonyl group, a sulfinyl group, a carbonyl group, a carbonyloxy group, an imino group, and a group formed by combining two or more selected from these.

[0062] Examples of the substituent represented by R include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl. The substituent may be an alkyl group having 1 to 5 carbon atoms or a methyl group. Each m independently represents, for example, an integer of 0 to 4, an integer of 0 to 2, or 0.

[0063] n is an average value in the polymer represented by formula (B2), and n is, for example, a number from 2 to 8, or a number from 3 to 5.

[0064] In some embodiments, the vinyl phenyl compound may comprise at least one selected from the group consisting of polymers represented by the formula:

[0065]

[0066]

[0067] In each of the above formulas, B ｐ each independently represent a group represented by the above formula (Ph), each L independently represents a direct bond or a linking group, and n represents a number of 2 to 10. The benzene ring and the naphthalene ring may each independently have a substituent at a substitutable position.

[0068] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Ph) may include a group represented by formula (p) above.

[0069] Examples of the linking group represented by L in each formula include an alkylene group, an oxy group, a thio group, a sulfonyl group, a sulfinyl group, a carbonyl group, a carbonyloxy group, an imino group, and a group formed by combining two or more selected from these. The linking group may contain an oxy group from the viewpoint of obtaining good tracking resistance. The linking group may contain, for example, a methyleneoxy group, and in this case, the polymer represented by the above formula may contain B ｐ -CH ２ The structure includes a structure represented by -O-* (* represents the bonding position to another atom).

[0070] When the benzene ring and naphthalene ring in each formula have a substituent, examples of the substituent include an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. The substituent may be an alkyl group having 1 to 5 carbon atoms, or may be a methyl group. Alternatively, the benzene ring and naphthalene ring in each formula are unsubstituted, or may be a group represented by the formula *-L-B ｐ (* indicates the bonding position to another atom) and may have no other substituents.

[0071] n is an average value in the polymer represented by each formula, and n is, for example, a number from 2 to 8, or a number from 3 to 5.

[0072] When the vinylphenyl compound contains at least one selected from the group consisting of polymers represented by formulas (B2-1) to (B2-11), excellent heat resistance and a low coefficient of linear thermal expansion tend to be readily obtained. When the vinylphenyl compound contains at least one selected from the group consisting of polymers represented by formulas (B2-3) and (B2-7), a low dielectric constant and dielectric loss tangent tend to be readily obtained. In particular, when the vinylphenyl compound contains a polymer represented by formula (B2-3), an even lower dielectric constant and dielectric loss tangent tend to be readily obtained. In particular, when the vinylphenyl compound contains a polymer represented by formula (B2-7), good tracking resistance tends to be readily obtained, and the encapsulating liquid resin composition tends to exhibit good fluidity.

[0073] In some embodiments, the vinylphenyl compound includes at least one selected from the group consisting of a polymer represented by the following formula (B3-3) and a polymer represented by the following formula (B3-7):

[0074]

[0075] In formula (B3-3), B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5.

[0076]

[0077] In formula (B3-7), B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5.

[0078] In formula (Bz), * represents a bonding position.

[0079] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Bz) may include a group in which the bonding position of the vinyl group to the benzene ring is para to the bonding position of the methylene group to the benzene ring.

[0080] The method for synthesizing the vinylphenyl group-containing polymer is not particularly limited. For example, when the vinylphenyl group-containing polymer is a compound represented by formula (B2-1), a method of reacting a phenol resin with a styrene having a halogenated methyl group in the presence of a basic compound can be mentioned. When synthesized by this method, the compound represented by formula (B2-1) has a methyleneoxy group as a linking group.

[0081] Examples of the styrene having a halogenated methyl group, the basic compound, and the phase transfer catalyst are as described above. The reaction can be carried out in a solvent. The reaction can be carried out under heating and stirring. A polymerization inhibitor can be added to the reaction system. The resulting product can be purified, if necessary, by known methods such as concentration, reprecipitation, and washing.

[0082] Examples of phenolic resins include novolac-type phenolic resins, aralkyl-type phenolic resins, dicyclopentadiene-type phenolic resins, biphenyl-type phenolic resins, triphenylmethane-type phenolic resins, and resins containing a naphthol structure instead of or in addition to the phenol structure in these phenolic resins. Commercially available phenolic resins can be used.

[0083] The weight average molecular weight (Mw) of the phenolic resin is, for example, 300 to 30,000, 500 to 10,000, or 1,000 to 5,000 from the viewpoint of handleability of the encapsulating liquid resin composition. The number average molecular weight (Mn) of the phenolic resin is, for example, 200 to 10,000, 500 to 5,000, or 1,000 to 2,000 from the viewpoint of handleability. The hydroxyl equivalent of the phenolic resin is, for example, 50 to 500 g / eq, 100 to 400 g / eq, or 150 to 300 g / eq from the viewpoint of the heat resistance and linear thermal expansion coefficient of the cured product. The hydroxyl equivalent can be measured by a method in accordance with JIS K 0070:1992.

[0084] The vinylphenyl compounds may be used alone or in combination of two or more.

[0085] When the vinylphenyl compound contains a vinylbenzyl compound, the content of the vinylbenzyl compound is, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more, based on the total mass of the vinylphenyl compounds. The upper limit of the content of the vinylbenzyl compound may be 100% by mass. When the vinylphenyl compound contains a vinylbenzyl ether compound, the content of the vinylbenzyl ether compound is, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more, based on the mass of the vinylphenyl compounds. The upper limit of the content of the vinylbenzyl ether compound may be 100% by mass. When the encapsulating liquid resin composition contains a vinylbenzyl ether compound, tracking resistance tends to be improved.

[0086] The total content of the vinylphenyl compound and the maleimide compound in the encapsulating liquid resin composition is, for example, 70 to 100 mass%, 80 to 99 mass%, or 90 to 98 mass%, based on the mass of the encapsulating liquid resin composition (excluding the mass of the filler if the encapsulating liquid resin composition contains a filler). When the total content is 70 mass% or more, the cured product tends to exhibit better heat resistance and a lower linear thermal expansion coefficient. The upper limit of the total content of the vinylphenyl compound and the maleimide compound may be 100 mass%, and taking into account the addition of optional components such as a polymerization initiator and a colorant, the total content may be less than 100 mass%.

[0087] [Compound Having a Maleimide Group] The maleimide compound is a compound having at least one maleimide group. The maleimide compound has, for example, 1 to 20, 1 to 15, or 1 to 10 maleimide groups. The maleimide compounds may be used alone or in combination of two or more.

[0088] The maleimide compound is preferably in a liquid state at 25° C. The liquid state may be in a range that can be measured with a viscometer. The maleimide compound may be a radically polymerizable monomer or polymer.

[0089] From the viewpoint of obtaining a liquid encapsulating resin composition that is liquid at 25° C., the maleimide compound preferably contains an aliphatic hydrocarbon group having 10 or more carbon atoms, more preferably an aliphatic hydrocarbon group having 15 or more carbon atoms, and even more preferably an aliphatic hydrocarbon group having 30 or more carbon atoms. The upper limit of the number of carbon atoms in the aliphatic hydrocarbon group is not particularly limited, but may be, for example, 3,000 or less.

[0090] In some embodiments, the maleimide compound includes a compound having two maleimide groups. In the present disclosure, a compound having two maleimide groups may be referred to as a "bismaleimide." In some embodiments, the maleimide compound includes a compound having three or more maleimide groups.

[0091] The maleimide group can be represented by the following formula: * indicates the bonding position to other atoms. In the formula, R １ and R ２ each independently represents a hydrogen atom, an alkyl group, or a halogen atom.

[0092] In some embodiments, the maleimide compound comprises a compound represented by formula (m):

[0093] In formula (m), X ｍ represents an organic group, and M represents a maleimide group.

[0094] X ｍ The organic group represented by the formula (I) may be a group containing at least one carbon atom, for example, a group containing at least one selected from the group consisting of a saturated aliphatic hydrocarbon group, an unsaturated aliphatic hydrocarbon group, a saturated alicyclic hydrocarbon group, and an unsaturated alicyclic hydrocarbon group. The organic group may further contain a linking group containing a hetero atom, a substituent containing a hetero atom, or the like.

[0095] From the viewpoint of obtaining a liquid encapsulating resin composition that is liquid at 25° C., the maleimide compound preferably contains a compound represented by the following formula (m-1).

[0096]

[0097] In formula (m-2), R１ ~R ４ R each independently represents a hydrogen atom, an alkyl group or a halogen atom, and Y represents an aliphatic hydrocarbon group. １ ~R ４ are each independently preferably a hydrogen atom. The number of carbon atoms in the aliphatic hydrocarbon group represented by Y is preferably 10 or more, more preferably 15 or more, and even more preferably 30 or more. The upper limit of the number of carbon atoms in the aliphatic hydrocarbon group represented by Y is not particularly limited, but may be, for example, 3,000 or less.

[0098] When using a maleimide compound A represented by formula (m-1) in which the aliphatic hydrocarbon group represented by Y has 500 or more carbon atoms, it is preferable to use it in combination with a maleimide compound B represented by formula (m-1) in which the aliphatic hydrocarbon group represented by Y has less than 500 carbon atoms. By using maleimide compounds in such a combination, an increase in the thermal expansion coefficient of the cured product tends to be suppressed.

[0099] Examples of the maleimide compound include compounds having the following structure:

[0100]

[0101] In the above structural formula, n1 is preferably an average value of 1 to 3, more preferably 1 to 2. n2 may be an average value of 1 to 10. In addition, -C in the above structural formula ３６ H ７０ The - may be changed to an aliphatic hydrocarbon group having 10 or more carbon atoms other than 36 carbon atoms.

[0102] Commercially available maleimide compounds can be used. Examples of commercially available maleimide compounds include "BMI-689," "BMI-1500," and "BMI-1700" manufactured by DMI Corporation. Alternatively, maleimide compounds may be synthesized. The method for synthesizing a maleimide compound is not particularly limited. For example, a synthesis method using a primary amine and maleic anhydride as raw materials to form a maleamic acid or maleamic acid ester as a maleimide precursor, followed by ring closure by dehydration or dealcoholization, can be used. The alkyl group of the primary amine may be, for example, a group containing at least one selected from the group consisting of saturated aliphatic hydrocarbon groups, unsaturated aliphatic hydrocarbon groups, saturated alicyclic hydrocarbon groups, and unsaturated alicyclic hydrocarbon groups.

[0103] The content of the maleimide compound may be, for example, 5% by mass or more, 10% by mass or more, or 20% by mass or more, based on the mass of the encapsulating liquid resin composition (excluding the mass of the filler when the encapsulating liquid resin composition contains a filler). When the content of the maleimide compound is 5% by mass or more, the cured product tends to exhibit better heat resistance. Furthermore, the content of the maleimide compound may be 80% by mass or less, 65% by mass or less, or 50% by mass or less. When the content of the maleimide compound is 50% by mass or less, the linear thermal expansion coefficient of the cured product can be kept low.

[0104] The content of the maleimide compound may be, for example, 10% by mass or more, 15% by mass or more, or 25% by mass or more, based on the total mass of the vinylphenyl compound and the maleimide compound. When the content of the maleimide compound is 10% by mass or more, the cured product tends to exhibit better heat resistance. Furthermore, the content of the maleimide compound may be 80% by mass or less, 70% by mass or less, or 60% by mass or less. When the content of the maleimide compound is 60% by mass or less, the linear thermal expansion coefficient of the cured product can be kept low.

[0105] From the viewpoints of dielectric properties, curability, and conductor adhesion, the molar ratio of maleimide groups to vinylphenyl groups (maleimide groups / vinylphenyl groups) in the encapsulating liquid resin composition is preferably 0.05 or more, more preferably 0.10 or more, more preferably 0.30 or more, even more preferably 0.50 or more, and particularly preferably 0.70 or more. Furthermore, from the viewpoints of dielectric properties, curability, and conductor adhesion, the molar ratio (maleimide groups / vinylphenyl groups) is preferably 5.0 or less, more preferably 2.0 or less, and even more preferably 1.5 or less. The molar ratio (maleimide groups / vinylphenyl groups) may be, for example, 1.0 or less, 0.6 or less, 0.4 or less, or 0.3 or less. From the above viewpoints, the molar ratio (maleimide groups / vinylphenyl groups) may be 0.05 to 5.0.

[0106] [Optional Components] The encapsulating liquid resin composition may further contain at least one selected from the group consisting of a radical polymerization initiator and a polymerization inhibitor, and may further contain other optional components. Optional components include various additives such as fillers, coupling agents, mold release agents, colorants, ion exchangers, flame retardants, and stress relaxation agents. The encapsulating liquid resin composition may contain various additives as needed, in addition to the following examples.

[0107] (Radical Polymerization Initiator) The encapsulating liquid resin composition may contain a radical polymerization initiator. When the encapsulating liquid resin composition is cured by heating, the radical polymerization initiator may be a thermal radical polymerization initiator that generates free radicals by heating. The thermal radical polymerization initiator may be, for example, an organic peroxide such as peroxyketal or dialkyl peroxide, or an azo compound such as azobisbutyronitrile or azobispropionitrile.

[0108] Examples of organic peroxides include 1,1,3,3-tetramethylbutylperoxyneodecanoate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, cumylperoxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, and t-butylperoxyneodecanoate. Pivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneoheptanoate, t-amylperoxy-2-ethylhexanoate, di-t-butylperoxyhexahydroterephthalate, t-amylperoxy-3,5, 5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, t-amylperoxyneodecanoate, di(3-methylbenzoyl) peroxide, dibenzoyl peroxide, di(4-methylbenzoyl) peroxide, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2, Examples of such peroxyalkylene compounds include 5-dimethyl-2,5-di(3-methylbenzoylperoxy)hexane, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxybenzoate, dibutyl peroxytrimethyl adipate, t-amyl peroxy normal octoate, t-amyl peroxy isononanoate, and t-amyl peroxybenzoate.

[0109] Examples of azo compounds include 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(1-acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 4,4'-azobis(4-cyanovaleric acid), and 1,1'-azobis(1-cyclohexanecarbonitrile).

[0110] When the encapsulating liquid resin composition contains a radical polymerization initiator, the radical polymerization initiator may be used alone or in combination of two or more. When the encapsulating liquid resin composition contains a radical polymerization initiator, the content of the radical polymerization initiator may be 0.1% by mass to 30% by mass, 0.1% by mass to 10% by mass, or 0.2% by mass to 3% by mass based on the total mass of the vinylphenyl compound and any vinyl compound other than the vinylphenyl compound that is optionally contained (which may be 0% by mass).

[0111] (Filler) The encapsulating liquid resin composition may contain a filler. Examples of fillers include inorganic fillers and organic fillers. In some embodiments, the encapsulating liquid resin composition contains an inorganic filler.

[0112] The average particle size of the filler is not particularly limited, and is preferably 0.1 μm to 10 μm, and more preferably 0.3 μm to 5 μm. When the average particle size of the filler is 0.1 μm or more, dispersibility in the resin components (epoxy resin and curing agent) improves, and the flow properties of the encapsulating liquid resin composition tend to be further improved. When the average particle size is 10 μm or less, sedimentation of the filler is more easily suppressed, and permeability and flowability into fine gaps improve, which tends to further suppress the occurrence of voids or unfilled portions.

[0113] The average particle size of the inorganic filler can be determined by the following method. A thin section sample is prepared from the encapsulating liquid resin composition or a cured product of the encapsulating liquid resin composition. 100 particles of the inorganic filler are randomly selected from an image of the thin section sample taken with a scanning electron microscope. The major axis of each particle is measured, and the arithmetic mean value is used as the average particle size of the inorganic filler.

[0114] The type of inorganic filler is not particularly limited. Examples include silica such as fused silica and crystalline silica; alumina, zirconia, titania, glass, talc, clay, and mica. The inorganic filler may be an inorganic filler having a flame retardant effect. Examples of inorganic fillers having a flame retardant effect include aluminum hydroxide; magnesium hydroxide; composite metal hydroxides such as a composite hydroxide of magnesium and zinc; and zinc borate.

[0115] The inorganic filler may contain silica to reduce the linear expansion coefficient, or alumina to improve thermal conductivity. The inorganic filler may be in the form of powder, spherical beads formed from powder, or fibers.

[0116] When the encapsulating liquid resin composition contains a filler, the filler may be used alone or in combination of two or more types. When the encapsulating liquid resin composition contains a filler, the content of the filler (excluding carbon black) may be 25 parts by mass or more, 50 parts by mass or more, or 100 parts by mass or more per 100 parts by mass of the total mass of the vinylphenyl compound and the maleimide compound. Furthermore, the content may be 2000 parts by mass or less, 1500 parts by mass or less, or 1000 parts by mass or less per 100 parts by mass of the total mass of the vinylphenyl compound and the maleimide compound. When the filler content is 25 parts by mass or more, the properties of the cured product, such as the thermal expansion coefficient, thermal conductivity, and elastic modulus, tend to be further improved. When the filler content is 2000 parts by mass or less, the increase in viscosity of the encapsulating liquid resin composition is suppressed, and the fluidity is further improved, tending to improve penetration and dispensability.

[0117] When the encapsulating liquid resin composition contains an inorganic filler, the content of the inorganic filler (excluding carbon black) may be, for example, 20 mass % or more, 35 mass % or more, 40 mass % or more, or 50 mass % or more based on the mass of the encapsulating liquid resin composition. The content of the inorganic filler (excluding carbon black) may be 95 mass % or less, 90 mass % or less, 85 mass % or less, or 80 mass % or less.

[0118] When the encapsulating liquid resin composition contains an inorganic filler, the content of the inorganic filler (excluding carbon black) may be, for example, 15% by volume or more, 35% by volume or more, 40% by volume or more, or 50% by mass or more, based on the volume of the encapsulating liquid resin composition. The content of the inorganic filler (excluding carbon black) may be 90% by volume or less, 85% by volume or less, 80% by volume or less, or 75% by volume or less. When the content of the inorganic filler is 15% by volume or more, the properties of the cured product, such as the thermal expansion coefficient, thermal conductivity, and elastic modulus, tend to be further improved. When the content of the inorganic filler is 90% by volume or less, the increase in viscosity of the encapsulating liquid resin composition is suppressed, and the fluidity is further improved, tending to improve penetration and dispensability.

[0119] (Coupling Agent) The encapsulating liquid resin composition may contain a coupling agent. When the encapsulating liquid resin composition contains a coupling agent, the adhesiveness of the cured product or the adhesiveness between the resin components (vinylphenyl compound, vinyl compound included as needed, etc.) and the inorganic filler tends to be improved. Examples of coupling agents include silane coupling agents, titanate coupling agents, aluminum chelate coupling agents, and aluminum-zirconium coupling agents. Examples of silane coupling agents include epoxy silane coupling agents, mercapto silane coupling agents, amino silane coupling agents, alkyl silane coupling agents, ureido silane coupling agents, vinyl silane coupling agents, (meth)acrylic silane coupling agents, and disilazane coupling agents. In the present disclosure, coupling agents having a vinylphenyl group are excluded from the scope of the above-mentioned vinylphenyl compounds. In other words, vinylphenyl compounds are compounds other than compounds that fall under the category of coupling agents.

[0120] Examples of silane coupling agents include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and N-phenyl-3-aminopropyl Trimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-anilinopropyltrimethoxysilane, γ-anilinopropyltriethoxysilane, γ-(N,N-dimethyl)aminopropyltrimethoxysilane, γ-(N,N-diethyl)aminopropyltrimethoxysilane, γ-(N,N-dibutyl)aminopropyltrimethoxysilane, γ-(N-methyl)anilinopropyltrimethoxysilane, γ-(N-ethyl)anilinopropyltrimethoxysilane γ-(N,N-dimethyl)aminopropyltrimethoxysilane, γ-(N,N-diethyl)aminopropyltriethoxysilane, γ-(N,N-dibutyl)aminopropyltriethoxysilane, γ-(N-methyl)anilinopropyltriethoxysilane, γ-(N-ethyl)anilinopropyltriethoxysilane, γ-(N,N-dimethyl)aminopropylmethyldimethoxysilane, γ-(N,N-diethyl)aminopropylmethyldimethoxysilane, γ-(N,N-dibutyl)aminopropyl Examples of such silane include methyldimethoxysilane, γ-(N-methyl)anilinopropylmethyldimethoxysilane, γ-(N-ethyl)anilinopropylmethyldimethoxysilane, N-(trimethoxysilylpropyl)ethylenediamine, N-(dimethoxymethylsilylisopropyl)ethylenediamine, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, vinyltrimethoxysilane, and γ-mercaptopropylmethyldimethoxysilane.

[0121] When the encapsulating liquid resin composition contains a coupling agent, the coupling agent may be used alone or in combination of two or more. When the encapsulating liquid resin composition contains an inorganic filler and a coupling agent, the amount is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 2.5 parts by mass, per 100 parts by mass of the filler. When the content of the coupling agent is 0.05% by mass or more, the adhesiveness of the cured product tends to be improved.

[0122] (Mold Release Agent) The encapsulating liquid resin composition may contain a mold release agent. When the encapsulating liquid resin composition contains a mold release agent, good releasability from the mold during molding is easily obtained. Examples of the mold release agent include known mold release agents such as 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.

[0123] When the encapsulating liquid resin composition contains a release agent, the release agent may be used alone or in combination of two or more. When the encapsulating liquid resin composition contains a release agent, the content of the release agent may be, for example, 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more, based on the total mass of the vinylphenyl compound and the maleimide compound contained as needed, and may be 10% by mass or less, 5% by mass or less, or 2% by mass or less. When the content of the release agent is 0.01% by mass or more, sufficient release properties tend to be obtained. When the content of the release agent is 10% by mass or less, better adhesion tends to be obtained.

[0124] (Colorant) The encapsulating liquid resin composition may contain a colorant. Examples of the colorant include known colorants such as carbon black, organic dyes, organic pigments, titanium oxide, red lead, and red iron oxide. The content of the colorant can be appropriately selected depending on the purpose, etc. The colorant may also function as a filler.

[0125] When the encapsulating liquid resin composition contains a colorant, the colorant may be used alone or in combination of two or more. When the encapsulating liquid resin composition contains a colorant, the content of the colorant is, for example, 0.01 to 10 mass % or 0.1 to 5 mass % based on the total mass of the vinylphenyl compound and the maleimide compound contained as needed.

[0126] (Polymerization inhibitor) The encapsulating liquid resin composition may contain a polymerization inhibitor. Examples of the polymerization inhibitor include phenolic compounds such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; and hindered amine compounds.

[0127] (Ion Exchanger) The encapsulating liquid resin composition may contain an ion exchanger. When the encapsulating liquid resin composition contains an ion exchanger, the moisture resistance and high-temperature storage characteristics of the electronic component device tend to be improved. Examples of the ion exchanger 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 also function as a filler. The encapsulating liquid resin composition may use one type of ion exchanger alone or two or more types in combination.

[0128] (Flame retardant) The encapsulating liquid resin composition may contain a flame retardant. Examples of the flame retardant include organic or inorganic compounds containing a halogen atom, an antimony atom, a nitrogen atom, or a phosphorus atom, and metal hydroxides. The encapsulating liquid resin composition may contain one flame retardant alone or two or more flame retardants in combination.

[0129] (Stress Relaxant) The encapsulating liquid resin composition may contain a stress relaxation agent. When the encapsulating liquid resin composition contains a stress relaxation agent, warpage and cracking of electronic component devices tend to be reduced. Examples of stress relaxation agents include silicone oil; thermoplastic elastomers such as silicone, styrene, olefin, urethane, polyester, polyether, polyamide, and polybutadiene elastomers; rubber particles such as NR (natural rubber), NBR (acrylonitrile-butadiene rubber), acrylic rubber, urethane rubber, and silicone powder; and rubber particles having a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS), methyl methacrylate-silicone copolymer, and methyl methacrylate-butyl acrylate copolymer (excluding compounds having a vinyl group in the molecule). When the encapsulating liquid resin composition contains a stress relaxation agent, the encapsulating liquid resin composition may contain one type of stress relaxation agent alone or two or more types in combination. Commercially available flexibility-imparting agents can be used as the stress relaxation agent.

[0130] [Viscosity] In some embodiments, the viscosity of the encapsulating liquid resin composition at 25°C is, for example, 1000 Pa·s or less, 100 Pa·s or less, or 50 Pa·s or less. When the viscosity can be kept low, the encapsulating liquid resin composition has excellent filling properties. In the present disclosure, the viscosity is a value measured at 25°C using an E-type viscometer.

[0131] [Storage Modulus of Cured Product] In some embodiments, the encapsulating liquid resin composition, when cured, has a storage modulus at 40°C measured by DMA (dynamic mechanical analysis) of, for example, 3.5 GPa or less, 3.0 GPa or less, or 2.6 GPa or less. If the storage modulus can be kept low, warping, breakage, etc., at the location where the encapsulant is applied tends to be suppressed.

[0132] The cured product used for measuring the storage modulus is a liquid encapsulating resin composition cured for 1 hour at 150° C. The measurement can be performed using a dynamic viscoelasticity measuring device (e.g., the "DMA7100" manufactured by Hitachi High-Technologies Corporation) under the conditions of a tensile mode, a sine wave of 10 kHz, and a temperature rise rate of 10° C. / min.

[0133] [Dielectric Properties of Cured Product] In some embodiments, the encapsulating liquid resin composition has a dielectric loss tangent (Df) at 10 GHz of, for example, 0.0050 or less, 0.0025 or less, or 0.0020 or less when cured. A cured product with a low dielectric loss tangent suppresses a decrease in communication efficiency in electronic devices that use high-frequency radio waves for communication.

[0134] In some embodiments, the encapsulating liquid resin composition has a relative dielectric constant (Dk) at 10 GHz when cured of, for example, 3.00 or less, 2.90 or less, or 2.85 or less.

[0135] The cured product for measuring Df and Dk is a liquid encapsulating resin composition cured for 1 hour at 150° C. The measurement can be performed using a dielectric constant measuring device (for example, Agilent Technologies, product name "Network Analyzer N5227A") at a temperature of 25±3° C. and 10 GHz.

[0136] [Uses of the encapsulating liquid resin composition] The encapsulating liquid resin composition of the present disclosure is suitable as a sealant for electronic component devices that use high-frequency radio waves for communication. The method for applying the encapsulating liquid resin composition of the present disclosure to electronic component devices is not particularly limited, and examples include a dispensing method, a casting method, and a printing method. The encapsulating liquid resin composition can be applied to the gap between the electronic component and the substrate by any method, such as a post-injection method or a pre-application method. By increasing the viscosity, the encapsulating liquid resin composition can also be used for compression molding.

[0137] In some embodiments, the electronic component device includes, for example, an electronic component and a cured product of the sealing liquid resin composition of the present disclosure that seals at least a portion of the electronic component. The electronic component device may be, for example, an electronic component module including a plurality of electronic components and electronic component devices and the sealing material of the above embodiment that seals at least a portion of the plurality of electronic components.

[0138] Examples of electronic components include active elements or components such as diodes, transistors, integrated circuits, and relays; passive elements or components such as resistors, capacitors, and coils; connectors, support members, terminals, and switches. Examples of electronic component devices include electronic component devices having the electronic components; and modules having one or both of the electronic components and the electronic component devices. The electronic component device may have a support member. Examples of support members include lead frames, pre-wired tape carriers, wiring boards, glass, silicon wafers, and organic substrates.

[0139] For example, a method for manufacturing an electronic component device includes placing an electronic component on a support member and encapsulating at least a portion of the electronic component using the encapsulating liquid resin composition of the present disclosure. For example, the temperature when injecting the encapsulating liquid resin composition into the gap between the electronic component and the substrate can be 60°C to 130°C. The curing temperature can be 100°C to 200°C, and the curing time can be 0.5 hours to 5 hours. Because the encapsulating liquid resin composition of the present disclosure has excellent reactivity, it is possible to set the curing temperature as low as described above.

[0140] The embodiments of the present disclosure will be specifically described with reference to examples, but the embodiments of the present disclosure are not limited to the following examples.

[0141] <Synthesis of Vinylphenyl Compound> A 500 mL reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet was charged with 35.6 parts by mass of indene, 99.1 parts by mass of chloromethylstyrene, 7.1 parts by mass of tetra-n-butylammonium bromide as a phase transfer catalyst, 0.1 parts by mass of phenothiazine as a polymerization inhibitor, and 76.4 parts by mass of toluene as a solvent. The resulting composition was stirred at 40°C while blowing in nitrogen at a flow rate of 50 mL / min. The chloromethylstyrene used was a mixture of o-chloromethylstyrene and p-chloromethylstyrene (Wujin Linchuan Chemical Co., Ltd., o-chloromethylstyrene content 17% by mass, p-chloromethylstyrene content 83% by mass).

[0142] Next, 46.5 parts by mass of a sodium hydroxide aqueous solution (concentration 48% by mass) as a basic compound was added dropwise over 20 minutes, and the mixture was further stirred at 60°C for 9 hours. Nitrogen was continuously blown in during the reaction. The composition was cooled to room temperature (25°C), neutralized with a 10% by mass aqueous hydrochloric acid solution, and then washed twice with pure water. Thereafter, toluene was distilled off under reduced pressure, and the resulting viscous liquid was washed with methanol and then vacuum-dried to obtain a vinylphenyl compound.

[0143] Vinylphenyl compounds are １ H-nuclear magnetic resonance ( １ H-NMR analysis confirmed that the compound had a structure in which substantially all of the two hydrogen atoms directly bonded to the carbon atom at position 1 of indene were substituted with vinylbenzyl groups (vinylphenylmethyl groups). GPC analysis confirmed that the vinylphenyl compound was a mixture of a compound having two vinylbenzyl groups and a compound having three vinylbenzyl groups, and that the average number of vinylbenzyl groups was in the range of 1.8 to 2.6. The weight-average molecular weight (Mw) of the vinylphenyl compound was 500.

[0144]

[0145] In the examples, the weight average molecular weight (Mw) was calculated by gel permeation chromatography (GPC) using a calibration curve prepared using standard polystyrene. The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Types: A-2500, A-5000, F-20, F-80) (Tosoh Corporation). Apparatus: High-speed GPC apparatus HLC-8320GPC (Tosoh Corporation) Detector: Ultraviolet absorption detector UV-8320 (Tosoh Corporation) Columns: Guard column; TSKgel guard column Super (HZ)-M + Column; TSKgel SuperMultipore HZ-M (2 columns), Reference column; TSKgel Super H-RC (2 columns) (all Tosoh Corporation) Column size: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 1 mL Injection volume: 20 μL or 2 μL Flow rate: 0.35 mL / min Measurement temperature: 40°C

[0146] <Preparation of Liquid Sealing Resin Composition> The vinylphenyl compounds obtained above were each placed in a metal tray and left to stand in a vacuum dryer at 0.1 MPa or less and at a temperature of 70° C. for 5 hours to remove the solvent.

[0147] Examples 1 and 2 and Comparative Examples 1 to 4 The vinylphenyl compound after removing the solvent was mixed with the compounds shown in Table 1 to prepare liquid compositions.

[0148] The compounds listed in Table 1 are as follows. In Table 1, the unit of each compound is "parts by mass," and the content of the inorganic filler is "% by mass" relative to the total amount of the encapsulating liquid resin composition. The average particle size of the inorganic filler was measured by the method described above.

[0149] Vinylphenyl compound: the vinylphenyl compound (vinylbenzyl compound) obtained above, which is liquid at room temperature. Maleimide compound: hexatriacontane bismaleimide. Radical polymerization initiator: t-butyl peroxy isopropyl monocarbonate, NOF Corporation "Perbutyl I". Epoxy resin: bisphenol F type epoxy resin, epoxy equivalent 159, liquid at room temperature, weight average molecular weight approximately 310. Curing agent: liquid amine resin with an active hydrogen equivalent of 63 g / eq. Curing accelerator: imidazole compound. Acrylic compound: 1,9-nonanediol dimethacrylate, Shin-Nakamura Kogyo Co., Ltd. "NOD-N". Inorganic filler: silica product name "SE2200", spherical silica with a volume average particle size of 0.5 μm, Admatechs Co., Ltd.

[0150] <Preparation of Cured Product> A cured product was prepared using the encapsulating liquid resin composition, and the viscosity, storage modulus at 40° C., and dielectric properties (Df and Dk) were measured. The measurement results are shown in Table 1.

[0151] (Penetration) A 50 μm thick SUS spacer was sandwiched between two pieces of glass to create a 5 mm wide flow path. This was placed horizontally on a hot plate at 110° C., and then a liquid resin composition was dropped onto the end of the flow path so that the liquid resin composition would penetrate into the gap between the two pieces of glass from the inlet to a length of 20 mm. This was evaluated as A, and this was evaluated as B.

[0152] (Measurement of storage modulus at 40°C) A cured product was obtained under the above conditions. The size of the measurement sample was 30 mm x 4 mm x 1 mm. Measurement was carried out under the above conditions using a dynamic viscoelasticity measuring device ("DMA7100" manufactured by Hitachi High-Technologies Corporation).

[0153] (Measurement of Dielectric Properties (Df and Dk)) A cured product was obtained under the above conditions. The size of the measurement sample was 1 mm × 1 mm × 50 mm. Measurement was carried out under the above conditions using a dielectric constant measurement device (Agilent Technologies, product name "Network Analyzer N5227A").

[0154]

[0155] Comparative Example 3 did not cure under the above conditions, and could not be evaluated. As shown in Table 1, Examples 1 and 2, which contain a vinylphenyl compound and a maleimide compound, have excellent dielectric properties, particularly a significantly lower dielectric loss tangent, compared to Comparative Examples 1 to 4, which do not contain at least one of a vinylphenyl compound and a maleimide compound. It can also be seen that Examples 1 and 2 have sufficiently low viscosity and excellent penetration. Furthermore, it can also be seen that Examples 1 and 2 have a lower storage modulus at 40°C compared to Comparative Examples 1 to 4.

Claims

1. A liquid encapsulating resin composition containing a compound having a vinylphenyl group and a compound having a maleimide group.

2. The encapsulating liquid resin composition according to claim 1, wherein the compound having a vinylphenyl group includes a compound represented by the following formula (b1): (In the formula, X ｂ１ represents an organic group, each B independently represents a group containing a vinylphenyl group, and l represents an integer of 1 to 5.

3. The encapsulating liquid resin composition according to claim 1 or 2, wherein the compound having a vinylphenyl group includes a compound having two or more vinylphenyl groups.

4. The encapsulating liquid resin composition according to any one of claims 1 to 3, wherein the compound having a vinylphenyl group includes a compound represented by the following formula (b3): (In the formula, B ｈｂ each independently represents a hydrogen atom or a group represented by the following formula (Bz), ｈｂ is a group represented by the following formula (Bz). (In the formula, * represents a bonding position.) 5. The encapsulating liquid resin composition according to any one of claims 1 to 4, wherein the compound having a vinylphenyl group includes a polymer having a vinylphenyl group.

6. The encapsulating liquid resin composition according to any one of claims 1 to 5, wherein the compound having a vinylphenyl group includes a polymer having a structural unit represented by the following formula (Bb): (In the formula, X represents an organic group, each B independently represents a group containing a vinylphenyl group, each R independently represents a substituent, l represents an integer of 1 to 5, and m represents an integer of 0 to 10. * represents a bonding position to another atom.) 7. The encapsulating liquid resin composition according to any one of claims 1 to 6, wherein the compound having a vinylphenyl group comprises at least one selected from the group consisting of a polymer represented by the following formula (B3-3) and a polymer represented by the following formula (B3-7): (In the formula, B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number from 3 to 5. The benzene rings may each independently have a substituent at a substitutable position. (In the formula, B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number from 3 to 5. The benzene rings may each independently have a substituent at a substitutable position. (In the formula, * represents a bonding position.) 8. The encapsulating liquid resin composition according to any one of claims 1 to 7, wherein the compound having a maleimide group is liquid at 25°C.

9. The encapsulating liquid resin composition according to any one of claims 1 to 8, wherein the compound having a maleimide group includes a compound having two maleimide groups.

10. The encapsulating liquid resin composition according to any one of claims 1 to 9, wherein the molar ratio of maleimide groups to vinylphenyl groups (maleimide groups / vinylphenyl groups) is 0.05 to 5.

0.

11. The encapsulating liquid resin composition according to any one of claims 1 to 10, which is a radically polymerizable encapsulating liquid resin composition.

12. The encapsulating liquid resin composition according to any one of claims 1 to 11, further comprising at least one selected from the group consisting of a radical polymerization initiator and a polymerization inhibitor.

13. The encapsulating liquid resin composition according to any one of claims 1 to 12, further comprising a filler.

14. The encapsulating liquid resin composition according to any one of claims 1 to 13, wherein the dielectric tangent of the cured product when cured at 150°C for 1 hour is 0.0050 or less.

15. An electronic component device comprising an electronic component and a cured product of the sealing liquid resin composition according to any one of claims 1 to 14, which seals at least a part of the electronic component.

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