Resin composition

Abstract

Provided is a resin composition or the like with which it is possible to form a cured product in which the amount of warping is suppressed, the dielectric loss tangent is low, and the reflow resistance is exceptional. This resin composition contains: (A-1) an epoxy resin represented by formula (1); and (B) a polymer that has a glass transition temperature Tg of 25°C or less or is liquid at 25°C or less, the weight-average molecular weight of the component (B) being 5,000-1,000,000.

Description

resin composition

[0001] The present invention relates to a resin composition, and further to a resin sheet, a cured product, a circuit board, and a semiconductor device.

[0002] Circuit boards such as printed wiring boards are widely used in various electronic devices. A known method for manufacturing a circuit board is a build-up method in which insulating layers and conductor layers are alternately stacked on an inner layer substrate. The insulating layer is formed, for example, from a cured product of a resin composition. Specifically, a resin composition layer containing a resin composition is formed, and the resin composition layer is cured to form an insulating layer containing a cured product of the resin composition (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2022-161968

[0004] In recent years, there has been an increasing demand for larger circuit boards. The present inventors have found that when a resin composition such as that described in Patent Document 1 is used as an insulating layer for a larger circuit board, the amount of warpage tends to increase. To reduce the amount of warpage, for example, it is conceivable to include a high-molecular-weight polymer in the resin composition to relieve stress. However, including a high-molecular-weight polymer in the resin composition induces localized curing of a thermosetting resin such as an epoxy resin. This localized curing tends to result in poor reflow resistance and an increased dielectric loss tangent.

[0005] The present invention has been made in view of the above-mentioned problems, and aims to provide a resin composition capable of forming a cured product that suppresses the amount of warping and has a low dielectric tangent and excellent reflow resistance; a resin sheet containing the resin composition; a cured product of the resin composition; a circuit board containing the cured product of the resin composition; and a semiconductor device that includes the circuit board.

[0006] As a result of extensive investigations, the present inventors have found that the above-mentioned problems can be solved by incorporating an epoxy resin having the following structure as the epoxy resin, even when a specific polymer is incorporated, and have thus completed the present invention.

[0007] That is, the present invention includes the following: [1] A resin composition comprising: (A-1) an epoxy resin represented by formula (1), and (B) a polymer having a glass transition temperature Tg of 25°C or less or being liquid at 25°C or less, and having a weight average molecular weight of more than 5,000 and 1,000,000 or less. (In formula (1), R １ each independently represents a monovalent aliphatic group; each L independently represents a divalent linking group; R Ｓ each independently represent a substituent, each m independently represent an integer of 0 to 3, and n represents an integer of 0 to 5. [2] The resin composition according to [1], further comprising (C) an inorganic filler. [3] The resin composition according to [2], wherein the content of the component (C) is 40% by mass or more, when the total nonvolatile components in the resin composition is 100% by mass. [4] The resin composition according to any one of [1] to [3], wherein the content of the component (A-1) is 0.5% by mass or more and 20% by mass or less, when the total nonvolatile components in the resin composition is 100% by mass. [5] R １ [6] The resin composition according to any one of [1] to [4], wherein R each independently represents an alkyl group. １each independently represent an alkyl group having 1 to 6 carbon atoms. [7] The resin composition according to any one of [1] to [5], wherein L each independently represent a divalent aliphatic group. [8] The resin composition according to any one of [1] to [7], wherein L each independently represent a divalent group consisting of an alkylene group, a cycloalkylene group, or a combination thereof. [9] The resin composition according to any one of [1] to [8], wherein component (B) comprises one or more selected from the group consisting of a polybutadiene structure, a polycarbonate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyisoprene structure, a polyisobutylene structure, and a polystyrene structure.

[10] The resin composition according to [9], wherein the resin comprising a polyalkylene structure comprises a resin comprising a carbon skeleton derived from a dimer acid.

[11] The resin composition according to any one of [1] to

[10] , wherein the component (B) has a functional group capable of reacting with an epoxy resin.

[12] The epoxy group equivalent of the component (A-1) in the resin composition is E Ａ１ The functional group equivalent capable of reacting with the epoxy resin of component (B) in the resin composition is E Ｂ When this is done, E Ａ１ / E Ｂ The resin composition according to

[11] , wherein the content of the component (A-1) when the nonvolatile components in the resin composition are 100 mass % is M Ａ１ The content of component (B) when the nonvolatile components in the resin composition are taken as 100% by mass is M Ｂ When M Ａ１ / M Ｂ

[14] The resin composition according to any one of [1] to

[13] , wherein the ρ is 0.2 or more and 3.5 or less.

[15] A resin sheet comprising a support and a layer of the resin composition according to any one of [1] to

[14] provided on the support.

[16] A cured product of the resin composition according to any one of [1] to

[14] .

[17] A circuit board comprising an insulating layer made of a cured product of the resin composition according to any one of [1] to

[14] .

[18] A semiconductor device comprising the circuit board according to

[17] .

[0008] According to the present invention, it is possible to provide a resin composition capable of forming a cured product that suppresses the amount of warping and has a low dielectric tangent and excellent reflow resistance; a resin sheet containing the resin composition; a cured product of the resin composition; a circuit board containing the cured product of the resin composition; and a semiconductor device including the circuit board.

[0009] <Explanation of Terms> In this specification, the term "optionally substituted" used in reference to a compound or group means both a case where the hydrogen atoms of the compound or group are not substituted with substituents, and a case where some or all of the hydrogen atoms of the compound or group are substituted with substituents.

[0010] In this specification, unless otherwise specified, the term "substituent" means a halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an alkoxy group, a cycloalkyloxy group, an aryl group, an aryloxy group, an arylalkyl group, an arylalkoxy group, a monovalent heterocyclic group, an alkylidene group, an acyl group, an acyloxy group, an amino group, a silyl group, a carboxy group, a sulfo group, a cyano group, a nitro group, a mercapto group, or an oxo group.

[0011] Examples of halogen atoms used as substituents include fluorine, chlorine, bromine, and iodine atoms. The alkyl group used as a substituent may be either linear or branched. The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 3. The alkenyl group used as a substituent may be either linear or branched. The alkenyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6, and even more preferably 2 or 3 carbon atoms. The cycloalkyl group used as a substituent preferably has 3 to 12 carbon atoms, more preferably 3 to 6 carbon atoms. The alkoxy group used as a substituent may be either linear or branched. The alkoxy group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms. The cycloalkyloxy group used as a substituent preferably has 3 to 12 carbon atoms, more preferably 3 to 6 carbon atoms. The aryl group used as a substituent preferably has 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms. The aryloxy group used as a substituent preferably has 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms. The arylalkyl group used as a substituent preferably has 7 to 15 carbon atoms, more preferably 7 to 11. The arylalkoxy group used as a substituent preferably has 7 to 15 carbon atoms, more preferably 7 to 11. The monovalent heterocyclic group used as a substituent refers to a group obtained by removing one hydrogen atom from the heterocycle of a heterocyclic compound. The monovalent heterocyclic group preferably has 3 to 15 carbon atoms, more preferably 3 to 9 carbon atoms. The monovalent heterocyclic group also includes a monovalent aromatic heterocyclic group (heteroaryl group). The alkylidene group used as a substituent refers to a group obtained by removing two hydrogen atoms from the same carbon atom of an alkane. The alkylidene group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 3 carbon atoms. The acyl group used as a substituent refers to a group represented by the formula: -C(=O)-R (wherein R is an alkyl group or an aryl group). The alkyl group represented by R may be either linear or branched. The acyl group preferably has 2 to 13 carbon atoms, more preferably 2 to 7 carbon atoms.The acyloxy group used as a substituent is a group represented by the formula: -O-C(=O)-R (wherein R is as defined above). The number of carbon atoms in the acyloxy group is preferably 2 to 13, more preferably 2 to 7. The above-mentioned substituent may further have a substituent (sometimes referred to as a "secondary substituent"). Unless otherwise specified, the same secondary substituent as the above-mentioned substituent may be used.

[0012] As used herein, the term "aliphatic group" refers to a group obtained by removing one or more hydrogen atoms bonded to an aliphatic carbon of an aliphatic compound. Specifically, a monovalent aliphatic group refers to a group obtained by removing one hydrogen atom bonded to an aliphatic carbon of an aliphatic compound, and a divalent aliphatic group refers to a group obtained by removing two hydrogen atoms bonded to an aliphatic carbon of an aliphatic compound. Examples of monovalent aliphatic groups include optionally substituted alkyl groups, optionally substituted cycloalkyl groups, optionally substituted alkenyl groups, optionally substituted cycloalkenyl groups, and optionally substituted alkapolyenyl groups (the number of double bonds is preferably 2 to 10, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2). Examples of divalent aliphatic groups include alkylene groups which may have a substituent, cycloalkylene groups which may have a substituent, alkenylene groups which may have a substituent, cycloalkenylene groups which may have a substituent, and alkapolyenylene groups which may have a substituent (the number of double bonds is preferably 2 to 10, more preferably 2 to 6, even more preferably 2 to 4, and still more preferably 2). Here, the alkyl group, alkenyl group, alkapolyenyl group, alkylene group, alkenylene group, and alkapolyenylene group may be either linear or branched. In this specification, unless otherwise specified, the number of carbon atoms in the aliphatic group is preferably 1 or more, more preferably 2 or more, or 3 or more, and is preferably 30 or less, more preferably 20 or less, even more preferably 18 or less, 16 or less, 14 or less, 12 or less, 10 or less, 8 or less, or 6 or less. The number of carbon atoms in the substituent is not included in this number of carbon atoms.

[0013] In this specification, "C ｐ ~C ｑThe term "(p and q are positive integers, and p<q)" indicates that the number of carbon atoms in the organic group described immediately after this term is p to q. For example, "C １ ~C ６ "Alkyl group" refers to an alkyl group having 1 to 6 carbon atoms, ６ ~C １０ The term "cycloalkyl group" refers to a cycloalkyl group having 6 to 10 carbon atoms.

[0014] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and can be implemented with any modifications within the scope of the claims of the present invention and their equivalents.

[0015] [Resin Composition] The resin composition of the present invention comprises (A-1) an epoxy resin represented by formula (1), and (B) a polymer having a glass transition temperature Tg of 25° C. or less, or being liquid at 25° C. or less, and having a weight average molecular weight of more than 5,000 and 1,000,000 or less. By containing component (A-1) and component (B) in combination, it is possible to obtain a cured product that is less likely to warp, has a low dielectric loss tangent, and has excellent reflow resistance. In formula (1), R １ each independently represents a monovalent aliphatic group; each L independently represents a divalent linking group; R Ｓ each independently represents a substituent; each m independently represents an integer of 0 to 3; and n independently represents an integer of 0 to 5.

[0016] The resin composition of the present invention may contain (A-2) another epoxy resin in addition to (A-1) the epoxy resin represented by formula (1). Hereinafter, the epoxy resin represented by formula (1) above will be referred to as "(A-1) the epoxy resin represented by formula (1)" or simply "component (A-1)," and the other epoxy resin will be referred to as "(A-2) another epoxy resin" or simply "component (A-2)." Furthermore, component (A-1) and component (A-2) will be collectively referred to as "(A) epoxy resin" or simply "epoxy resin" or "component (A)."

[0017] The resin composition may further contain optional components such as (C) an inorganic filler, (D) a curing agent, (E) a radical polymerizable resin, (F) an organic filler, (G) a curing accelerator, (H) other additives, and (I) a solvent, as necessary. Each component that can be contained in the resin composition will be described below.

[0018] <(A-1) Epoxy Resin Represented by Formula (1)> The resin composition of the present invention contains an epoxy resin represented by formula (1) as the component (A-1). In formula (1), R １ each independently represents a monovalent aliphatic group; each L independently represents a divalent linking group; R Ｓ each independently represents a substituent; each m independently represents an integer of 0 to 3; and n independently represents an integer of 0 to 5.

[0019] As mentioned above, in the past, studies have been conducted to incorporate high-molecular-weight polymers into resin compositions to suppress the amount of warping. However, when such polymers are incorporated into resin compositions, localized curing is induced with thermosetting resins such as epoxy resins, and this localized curing results in poor reflow resistance and an increased dielectric dissipation factor. In the present invention, component (A-1) is included as the epoxy resin. By incorporating component (A-1), it is possible to form a cured product that suppresses the amount of warping, has a low dielectric dissipation factor, and has excellent reflow resistance, even when component (B) is incorporated.

[0020] In formula (1), R １ R each independently represents a monovalent aliphatic group. １ The monovalent aliphatic group represented by the formula (I) is preferably an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a cycloalkyl group which may have a substituent, and more preferably an alkyl group having 1 to 12 carbon atoms which may have a substituent, an alkenyl group having 2 to 12 carbon atoms which may have a substituent, or a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent.

[0021] Among these, from the viewpoint of obtaining the remarkable effect of the present invention, R １The monovalent aliphatic group represented by the formula (I) is preferably an alkyl group which may have a substituent, and more preferably an alkyl group. The number of carbon atoms in the alkyl group is as described above for the aliphatic group, but is preferably 1 to 10, more preferably 1 to 8, and even more preferably 1 to 6 or 1 to 4.

[0022] Thus, in one preferred embodiment, R １ each independently represents an alkyl group, more preferably an alkyl group having 1 to 6 carbon atoms.

[0023] In formula (1), L's each independently represent a divalent linking group. Examples of the divalent linking group represented by L include divalent organic groups consisting of one or more (e.g., 1 to 50, 1 to 20, or 1 to 10) skeletal atoms selected from carbon atoms, oxygen atoms, nitrogen atoms, and sulfur atoms, and among these, divalent aliphatic groups are preferred. Therefore, in a preferred embodiment, L's each independently represent a divalent aliphatic group.

[0024] As the divalent aliphatic group represented by L, as described above, an alkylene group which may have a substituent, an alkenylene group which may have a substituent, a cycloalkylene group which may have a substituent, or a divalent group consisting of a combination thereof is preferred, and an alkylene group having 1 to 12 carbon atoms, an alkenylene group having 2 to 12 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, or a divalent group consisting of a combination thereof is preferred.

[0025] Among these, from the viewpoint of significantly achieving the effects of the present invention, the divalent aliphatic group represented by L is preferably an alkylene group which may have a substituent, a cycloalkylene group which may have a substituent, or a divalent group consisting of a combination thereof, more preferably an alkylene group, a cycloalkylene group, or a divalent group consisting of a combination thereof, and even more preferably an alkylene group or a cycloalkylene group. The number of carbon atoms in the alkylene group is as described above for the aliphatic group, but is preferably 1 to 10, more preferably 1 to 8, and even more preferably 1 to 6 or 1 to 4. The number of carbon atoms in the cycloalkylene group is as described above for the aliphatic group, but is preferably 6 to 12, more preferably 6 to 10.

[0026] Therefore, in a preferred embodiment, each L independently represents a divalent group selected from an alkylene group, a cycloalkylene group, or a combination thereof, and more preferably represents a divalent group selected from an alkylene group having 1 to 6 carbon atoms, a cycloalkylene group having 6 to 10 carbon atoms, or a combination thereof.

[0027] From the viewpoint of significantly achieving the effects of the present invention, L is preferably each independently a divalent group represented by the following formula (2). In formula (2), R ３ and R ４ each independently represents a hydrogen atom or an alkyl group which may have a substituent, and R ３ and R ４ may be united to form a ring.

[0028] R ３ and R ４ The alkyl group in R preferably has 1 to 6 carbon atoms. ３ and R ４ and R form a ring, the ring formed is preferably a 4- to 10-membered saturated carbocyclic ring, more preferably a 6- to 10-membered saturated carbocyclic ring. ３ and R ４ It may have a substituent derived from:

[0029] R ３ and R４ The substituents that the alkyl group may have in the formula (I) are as described above, but a halogen atom or an alkyl group is preferred because the effects of the present invention can be more effectively enjoyed.

[0030] For example, R ３ and R ４ When both R and R represent hydrogen atoms, the divalent group represented by formula (2) is a methylene group. ３ and R ４ When both R and R represent a methyl group, the divalent group represented by formula (2) is a propylene group (propane-2,2-diyl group). ３ and R ４ When both R and R represent trifluoromethyl groups, the divalent group represented by formula (2) is a hexafluoropropylene group (hexafluoropropane-2,2-diyl group). ３ and R ４ When R ３ and R ４ and examples of substituted 6-membered saturated carbocyclic rings include trimethylcyclohexylene groups (such as 3,3,5-trimethylcyclohexane-1,1-diyl groups).

[0031] In formula (1), R Ｓ R each independently represents a substituent. Ｓ As the substituent represented by the formula (I), as described above, from the viewpoint of being able to enjoy the effects of the present invention more, a halogen atom, an alkoxy group, or an aryl group is preferable, and a halogen atom is more preferable.

[0032] In formula (1), each m independently represents an integer of 0 to 3. Each m independently represents preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0. In formula (1), n ​​represents an integer of 0 to 5. n is preferably an integer of 1 or greater, and preferably an integer of 5 or less. The epoxy resin represented by formula (1) is preferably a mixture containing compounds in which n is an integer of 0 to 5, and more preferably a mixture containing compounds in which n is an integer of 1 to 5.

[0033] From the viewpoint of achieving the effects of the present invention remarkably, particularly preferred examples of the epoxy resin represented by formula (1) are shown below.

[0034] In one preferred embodiment, in formula (1), R １ each independently represents an alkyl group which may have a substituent; each L independently represents an alkylene group which may have a substituent, an alkenylene group which may have a substituent, a cycloalkylene group which may have a substituent, or a divalent group consisting of a combination thereof; R Ｓ each independently represents a halogen atom, an alkoxy group, or an aryl group, each m independently represents 0 or 1, and n represents an integer of 0 to 5. In this case, the epoxy resin represented by formula (1) is preferably a mixture containing compounds in which n is an integer of 0 to 5, and more preferably a mixture containing compounds in which n is an integer of 1 to 5.

[0035] In a more preferred embodiment, in formula (1), R １ each independently represents an alkyl group having 1 to 6 carbon atoms; each L independently represents an alkylene group having 1 to 6 carbon atoms, a cycloalkylene group having 6 to 10 carbon atoms, or a divalent group formed by a combination thereof; R Ｓeach independently represents a halogen atom, each m independently represents 0 or 1 (more preferably 0), and n represents an integer of 0 to 5. In this case, the epoxy resin represented by formula (1) is preferably a mixture containing compounds in which n is an integer of 0 to 5, and more preferably a mixture containing compounds in which n is an integer of 1 to 5.

[0036] In a further preferred embodiment, in formula (1), R １ each independently represent an alkyl group having 1 to 6 carbon atoms, each L independently represent a divalent group represented by the above formula (2), each m independently represent 0 or 1 (more preferably 0), and n represents an integer of 0 to 5. In this case, the epoxy resin represented by formula (1) is preferably a mixture containing each compound in which n is an integer of 0 to 5, and more preferably a mixture containing each compound in which n is an integer of 1 to 5.

[0037] In order to obtain the effects of the present invention more remarkably, the bonding position of L to the benzene ring shown in formula (1) is preferably an oxygen atom (R １ In relation to the bonding position of the oxygen atom bonded to the aryl group at the ortho position relative to the aryl group, the para position is preferred.

[0038] The epoxy group equivalent of component (A-1) is preferably 600 g / eq. or less, more preferably 500 g / eq. or less, 400 g / eq. or less, 300 g / eq. or less, or 250 g / eq. or less. The lower limit is preferably 160 g / eq. or more, more preferably 170 g / eq. or more, 175 g / eq. or more, or 180 g / eq. or more. The epoxy group equivalent is the mass of the epoxy resin containing one equivalent of epoxy groups and can be measured in accordance with JIS K7236. By using component (A-1) having an epoxy group equivalent within this range, the crosslink density of the cured product of the resin composition is increased. This suppresses the amount of warping and makes it possible to obtain a cured product with a low dielectric tangent and excellent reflow resistance.

[0039] An example of the synthesis procedure for component (A-1), i.e., the epoxy resin represented by formula (1), is shown below.

[0040] In one embodiment, the component (A-1) is a reaction product (epoxidation product) of: (x1) a divalent hydroxy compound represented by the following general formula (x1); and (x2) an epihalohydrin: (In the formula, R １ , L, R Ｓ , m is the same as above.)

[0041] -(x1) Divalent Hydroxy Compound- The divalent hydroxy compound (x1) may be appropriately determined so as to achieve the desired structure of the component (A-1). Suitable examples of the structure of the component (A-1), i.e., the structure represented by formula (1), are as described above. For example, the divalent hydroxy compound (x1) may include a divalent hydroxy compound having R at the ortho position relative to the hydroxy group. １ A biphenyl compound having R bonded to it, and R in the ortho position relative to the hydroxy group. １ Specifically, bisphenol compounds having R １ is C １ ~C ６ 4,4'-methylenebis(2-C １ ~C ６ alkylphenol) can be used, and R １ is C １ ~C ６ 2,2-bis(4-hydroxy-3-C alkyl group), L is a propane-2,2-diyl group, and m is 0. １ ~C ６ alkylphenyl)propane, １ is C １ ~C ６ 1,1-bis(4-hydroxy-3-C alkyl group), L is a cyclohexane-1,1-diyl group, and m is 0. １ ~C ６ (Alkylphenyl)cyclohexane may be used.

[0042] -(x2) Epihalohydrin- As the epihalohydrin (x2), epichlorohydrin or epibromohydrin may be used.

[0043] The reaction of components (x1) and (x2) may be carried out by a conventionally known epoxidation reaction using a divalent hydroxy compound and epihalohydrin. The reaction may proceed in a solvent-free system without using a solvent, or in an organic solvent system using an organic solvent. Examples of organic solvents used in the reaction include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; acetate-based solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol-based solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; and amide-based solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. The organic solvents may be used alone or in combination of two or more.

[0044] A base may be used in the reaction. Examples of the base include alkali metal hydroxides such as sodium hydroxide (caustic soda) and potassium hydroxide; and tertiary amines such as triethylamine, pyridine, and N,N-dimethyl-4-aminopyridine (DMAP). The base may be used alone or in combination of two or more. A condensing agent or a phase transfer catalyst may also be used in the reaction. Any conventionally known condensing agent or phase transfer catalyst may be used.

[0045] The reaction temperature is not particularly limited as long as the reaction proceeds, and may be, for example, in the range of 50 to 150° C. The reaction time is also not particularly limited as long as the desired structure of component (A-1) is achieved, and may be, for example, in the range of 1 to 10 hours.

[0046] In such a reaction, by adjusting the ratio of the amounts of the component (x1) and the component (x2), it is possible to adjust the degree of polymerization (n in formula (1); the smaller the amount of the component (x2), the larger the value of n tends to be), and it is also possible to adjust the epoxy group equivalent of the resulting component (A-1). To efficiently achieve the structure of formula (1), the amount of the component (x2) must be greater than the amount of the component (x1), and typically the amount of the component (x2) is 2 moles or more, preferably 3 moles or more, per mole of the component (x1).

[0047] After the reaction, excess component (x2) can be distilled off to obtain component (A-1). The component (A-1) may also be purified. For example, after the reaction, a purification step such as washing with water or microfiltration may be carried out to remove by-product salts and excess starting materials from the system. Specifically, the component (A-1) may be purified by dissolving the residue obtained by distilling off excess component (x2) in an organic solvent, filtering, washing with water to remove by-product salts, and then distilling off the organic solvent.

[0048] The content of component (A-1) in the resin composition, i.e., the epoxy resin represented by formula (1), is preferably 0.5% by mass or more, more preferably 0.8% by mass or more, even more preferably 1% by mass or more, 1.5% by mass or more, 2% by mass or more, 2.5% by mass or more, or 3% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, or 8% by mass or less, when the total amount of non-volatile components in the resin composition is taken as 100% by mass.

[0049] The content of the component (A-1) is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, or 10% by mass or more, and is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, or 25% by mass or less, when the resin component in the resin composition is taken as 100% by mass.

[0050] In the present invention, the content of each component in the resin composition is a value when the nonvolatile components in the resin composition are taken as 100 mass %, unless otherwise specified, and the nonvolatile components refer to all nonvolatile components in the resin composition excluding the solvent. Furthermore, in the present invention, the "resin components" in the resin composition refer to the nonvolatile components constituting the resin composition excluding the inorganic filler (C) described below.

[0051] <(A-2) Other Epoxy Resins> The resin composition may contain (A-2) other epoxy resins as the epoxy resin (A), as long as it contains the above-mentioned (A-1) component. The (A-2) other epoxy resins do not include those that fall under the above-mentioned (A-1) component. One type of (A-2) component may be used alone, or two or more types may be used in combination.

[0052] There are no particular restrictions on the type of component (A-2), so long as it has one or more (preferably two or more) epoxy groups in one molecule. Examples of the component (A-2) include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, bisphenol E type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthol type epoxy resins, naphthalene type epoxy resins, naphthylene ether type epoxy resins, glycidylamine type epoxy resins, glycidyl ester type epoxy resins, cresol novolac type epoxy resins, biphenyl type epoxy resins, phenol aralkyl type epoxy resins, biphenyl aralkyl type epoxy resins, fluorene skeleton type epoxy resins, dicyclopentadiene type epoxy resins, anthracene type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexanedimethanol type epoxy resins, trimethylol type epoxy resins, and halogenated epoxy resins.

[0053] The component (A-2) can be classified into epoxy resins that are liquid at a temperature of 20°C (hereinafter referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter referred to as "solid epoxy resins"). When the resin composition contains the component (A-2), it may further contain only a liquid epoxy resin, or only a solid epoxy resin, or it may further contain a combination of a liquid epoxy resin and a solid epoxy resin.

[0054] The liquid epoxy resin used as component (A-2) is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0055] The liquid epoxy resin as component (A-2) is preferably a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol AF type epoxy resin, a bisphenol E type epoxy resin, a naphthalene type epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin, a phenol novolac type epoxy resin, an alicyclic epoxy resin having an ester skeleton, a cyclohexane type epoxy resin, a cyclohexane dimethanol type epoxy resin, a glycidyl amine type epoxy resin, an epoxy resin having a butadiene structure, a glycidyl cyclohexane type epoxy resin, a phenolphthalimidine type epoxy resin, or an alkyl diglycidyl ether type epoxy resin; more preferably a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a naphthalene type epoxy resin; and even more preferably a bisphenol A type epoxy resin or a bisphenol F type epoxy resin.

[0056] Specific examples of liquid epoxy resins as component (A-2) include "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resins) manufactured by DIC Corporation; "828US", "jER828EL", "825", and "Epikote 828EL" (bisphenol A type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER807" and "1750" (bisphenol F type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630" and "630LSD" (glycidylamine type epoxy resins) manufactured by Mitsubishi Chemical Corporation; and " Examples of epoxy resins include ZX1059 (a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin); EX-721 (glycidyl ester epoxy resin) manufactured by Nagase ChemteX Corporation; CELLOXIDE 2021P (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation; PB-3600 (epoxy resin having a butadiene structure) manufactured by Daicel Corporation; ZX1658 and ZX1658GS (liquid 1,4-glycidylcyclohexane epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; YED216D (alkyl diglycidyl ether epoxy resin) manufactured by Mitsubishi Chemical Corporation; and EPOX MK R710 and EPOX MK R1710 (bisphenol E epoxy resin) manufactured by Printec Co., Ltd. These may be used alone or in combination of two or more.

[0057] As the solid epoxy resin for component (A-2), a solid epoxy resin having two or more epoxy groups per molecule is preferred, a solid epoxy resin having three or more epoxy groups per molecule is more preferred, and an aromatic solid epoxy resin having three or more epoxy groups per molecule is even more preferred.

[0058] The solid epoxy resin as component (A-2) is preferably a bixylenol-type epoxy resin, a naphthalene-type epoxy resin, a naphthalene-type tetrafunctional epoxy resin, a cresol novolac-type epoxy resin, a dicyclopentadiene-type epoxy resin, a trisphenol-type epoxy resin, a naphthol-type epoxy resin, a biphenyl-type epoxy resin, a naphthylene ether-type epoxy resin, an anthracene-type epoxy resin, a bisphenol A-type epoxy resin, a bisphenol AF-type epoxy resin, or a tetraphenylethane-type epoxy resin, more preferably a naphthol-type epoxy resin, a bixylenol-type epoxy resin, or a biphenyl-type epoxy resin, and even more preferably a biphenyl-type epoxy resin.

[0059] Specific examples of solid epoxy resins as component (A-2) include "HP4032H" (naphthalene-type epoxy resin), "HP-4700", "HP-4710" (naphthalene-type tetrafunctional epoxy resin), "N-690" (cresol novolac-type epoxy resin), "N-695" (cresol novolac-type epoxy resin), "HP-7200", "HP-7200HH", and "HP-7200H" (dicyclopentadiene-type epoxy resin), all manufactured by DIC Corporation. ene-type epoxy resins), "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000", and "HP6000L" (naphthylene ether-type epoxy resins); "EPPN-502H" (trisphenol-type epoxy resin), "NC7000L" (naphthol novolac-type epoxy resin), "NC3000H", "NC3000", and "NC30" manufactured by Nippon Kayaku Co., Ltd. 00L" and "NC3100" (biphenyl-type epoxy resin); "ESN475V" (naphthalene-type epoxy resin) and "ESN485" (naphthol novolac-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YL6121" (biphenyl-type epoxy resin), "YX4000HK" (bixylenol-type epoxy resin), and "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; Osaka Gas Co., Ltd. Examples of epoxy resins include "PG-100" and "CG-500" manufactured by Mitsubishi Chemical Corporation, "YL7760" (bisphenol AF type epoxy resin), "YL7800" (fluorene type epoxy resin), "jER1010" (solid bisphenol A type epoxy resin), and "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation, and "WHR-991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd. These may be used alone or in combination of two or more.

[0060] When a liquid epoxy resin and a solid epoxy resin are used in combination as component (A-2), the ratio by mass between them (liquid epoxy resin:solid epoxy resin) is preferably 1:0.1 to 1:20, more preferably 1:0.15 to 1:10, and particularly preferably 1:0.2 to 1:5.

[0061] From the viewpoint of achieving remarkable effects of the present invention, the epoxy group equivalent of the component (A-2) is preferably 50 g / eq. to 2000 g / eq., more preferably 60 g / eq. to 1000 g / eq., and even more preferably 80 g / eq. to 500 g / eq.

[0062] From the viewpoint of significantly achieving the effects of the present invention, the weight average molecular weight (Mw) of the component (A-2) is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The Mw of the epoxy resin can be measured as a polystyrene-equivalent value by the GPC method.

[0063] When the resin composition contains component (A-2), i.e., other epoxy resin, the content of component (A-1) is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, 40% by mass or more, or 45% by mass or more, when the entire component (A) (total of non-volatile components) is taken as 100% by mass. The lower limit is preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less, 80% by mass or less, 75% by mass or less, 70% by mass or less, 65% by mass or less, or 60% by mass or less.

[0064] The content of the component (A-2), when the total amount of non-volatile components in the resin composition is taken as 100% by mass, is preferably 1% by mass or more, more preferably 1.5% by mass or more, even more preferably 1.8% by mass or more, 2% by mass or more, or 3% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, or 8% by mass or less.

[0065] The content of the (A-2) component, when the resin component in the resin composition is taken as 100% by mass, is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, 6% by mass or more, 10% by mass or more, or 15% by mass or more, and is preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less.

[0066] The total content of the component (A) may be appropriately determined so as to satisfy the preferred ranges for the content of the component (A-1) and the content of the component (A-1) relative to the total amount of the component (A). For example, the total content of the component (A) in the resin composition is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, and is preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less, when the total amount of non-volatile components in the resin composition is taken as 100% by mass.

[0067] The total content of the (A) component is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more, and is preferably 60% by mass or less, more preferably 55% by mass or less, and even more preferably 50% by mass or less, when the resin components in the resin composition are taken as 100% by mass.

[0068] <(B) Polymer Having a Glass Transition Temperature Tg of 25°C or Less, or Being Liquid at 25°C or Less, and Having a Weight-Average Molecular Weight of More than 5,000 and Less than 1,000,000> The resin composition includes, as component (B), a polymer (B) having a glass transition temperature Tg of 25°C or less, or Being liquid at 25°C or less, and Having a weight-average molecular weight of more than 5,000 and less than 1,000,000. Since the present invention includes component (A-1), even when component (B) is contained, it is possible to form a cured product that suppresses the amount of warpage, has a low dielectric loss tangent, and exhibits excellent reflow resistance. Component (B) does not include those that fall under the aforementioned component (A). One type of component (B) may be used alone, or two or more types may be used in combination.

[0069] The component (B) has a glass transition temperature Tg of 25°C or lower, or is liquid at 25°C or lower. When the component (B) has a glass transition temperature Tg of 25°C or lower, the glass transition temperature Tg is preferably 20°C or lower, more preferably 15°C or lower. The lower limit of the glass transition temperature Tg is not particularly limited, but is preferably -30°C or higher, more preferably -20°C or higher, even more preferably -15°C or higher, or -10°C or higher. When the component (B) is liquid at 25°C or lower, the component (B) is preferably liquid at 25°C, more preferably liquid at 20°C, and even more preferably liquid at 15°C. The glass transition temperature Tg can be measured by DSC (differential scanning calorimetry) at a heating rate of 5°C / min.

[0070] Since component (B) is a polymer, it usually has a large weight-average molecular weight. The weight-average molecular weight Mw of component (B) is greater than 5,000, preferably 8,000 or more, and more preferably 10,000 or more. The upper limit is 1,000,000 or less, preferably 500,000 or less, more preferably 300,000 or less, and even more preferably 200,000 or less, 100,000 or less, 50,000 or less, or 30,000 or less. The weight-average molecular weight can be measured as a polystyrene-equivalent value by GPC.

[0071] Component (B) has a low elastic modulus. Therefore, component (B) is preferably a low-elasticity polymer. Specifically, when a tensile test is performed in accordance with Japanese Industrial Standards (JIS K7161) at a temperature of 25°C and a humidity of 40% RH, component (B) typically exhibits an elastic modulus of 1 GPa or less. The range of the elastic modulus of component (B) is, in detail, typically 1 GPa or less, preferably 0.9 GPa or less, more preferably 0.8 GPa or less, and even more preferably 0.7 GPa or less, and is preferably 0.01 GPa or more, more preferably 0.03 GPa or more, even more preferably 0.05 GPa or more, and particularly preferably 0.1 GPa or more.

[0072] As component (B), a resin containing one or more structures selected from the group consisting of a polybutadiene structure, a polycarbonate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyisoprene structure, a polyisobutylene structure, and a polystyrene structure within the molecule is preferred. The term "(meth)acrylate" encompasses acrylates, methacrylates, and combinations thereof. These structures may be contained in the main chain or in the side chain. These structures typically have little restriction on atomic movement due to the interatomic bonds contained in the structure, allowing for a wide range of bond angle changes and rotations, and therefore can function as a flexible molecular skeleton. Therefore, component (B) can be easily obtained as a resin containing these structures. Among these, a resin containing one or more structures selected from the group consisting of a polybutadiene structure, a polycarbonate structure, and a polyalkylene structure is more preferred.

[0073] A resin containing a polybutadiene structure is sometimes referred to as a "polybutadiene resin." The polybutadiene structure may be partially or completely hydrogenated. Examples of polybutadiene resins include hydrogenated polybutadiene skeleton-containing resins, hydroxy group-containing polybutadiene resins, phenolic hydroxy group-containing polybutadiene resins, carboxy group-containing polybutadiene resins, acid anhydride group-containing polybutadiene resins, epoxy group-containing polybutadiene resins, isocyanate group-containing polybutadiene resins, urethane group-containing polybutadiene resins, and polyphenylene ether-polybutadiene resins.

[0074] Specific examples of polybutadiene resins include "Ricon 130MA8," "Ricon 130MA13," "Ricon 130MA20," "Ricon 131MA5," "Ricon 131MA10," "Ricon 131MA17," "Ricon 131MA20," and "Ricon 184MA6" (acid anhydride group-containing polybutadienes) manufactured by Cray Valley Corporation; "GQ-1000" (hydroxyl- and carboxyl-group-introduced polybutadiene), "G-1000," "G-2000," and "G-3000" (polybutadiene having hydroxyl groups at both ends), "GI-1000," "GI-2000," and "GI-3000" (hydrogenated polybutadiene having hydroxyl groups at both ends) manufactured by Nippon Soda Co., Ltd.; and "FCA-061L" (hydrogenated polybutadiene skeleton epoxy resin) manufactured by Nagase ChemteX Corporation.

[0075] Specific examples of polybutadiene resins include polyimide resins having a polybutadiene structure, a urethane structure, and an imide structure in the molecule. The polyimide resin can be produced as a linear polyimide resin (such as the polyimides described in JP 2006-37083 A and WO 2008 / 153208 A) using hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride as raw materials. The content of the butadiene structure in the polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. For details of the polyimide resin, please refer to the descriptions in JP 2006-37083 A and WO 2008 / 153208 A, the contents of which are incorporated herein by reference.

[0076] Resins containing a polycarbonate structure are sometimes referred to as “polycarbonate resins.” Examples of polycarbonate resins include hydroxy group-containing carbonate resins, phenolic hydroxy group-containing carbonate resins, carboxy group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, and urethane group-containing carbonate resins.

[0077] Specific examples of polycarbonate resins include "FPC0220" manufactured by Mitsubishi Gas Chemical Company, Inc.; "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Corporation; and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) manufactured by Kuraray Co., Ltd.

[0078] Specific examples of polycarbonate resins include polyimide resins having an imide structure, a urethane structure, and a polycarbonate structure within the molecule. The polyimide resin can be produced as a linear polyimide resin using a hydroxyl-terminated polycarbonate, a diisocyanate compound, and a tetrabasic acid anhydride as raw materials. The carbonate structure content of the polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. Details of the polyimide resin can be found in International Publication No. WO 2016 / 129541, the contents of which are incorporated herein by reference.

[0079] A resin containing a polyalkylene structure is sometimes referred to as a "polyalkylene resin." As the polyalkylene resin, a resin containing an alkylene chain in the repeating unit can be used. The number of carbon atoms in the alkylene chain is preferably 2 or more, more preferably 3 or more, even more preferably 5 or more, and still more preferably 7 or more. The upper limit may be, for example, 36 or less, 15 or less, 10 or less, 8 or less, etc. As this polyalkylene resin, a resin containing a carbon skeleton derived from a dimer acid in the repeating unit is preferred.

[0080] The carbon skeleton derived from dimer acid refers to the skeleton of a divalent group remaining after removing the two terminal carboxyl groups (—COOH) of a dimer acid. Dimer acids are known compounds obtained by dimerizing unsaturated fatty acids (preferably those having 11 to 22 carbon atoms, more preferably those having 18 carbon atoms), and their industrial production process is largely standardized in the industry. Dimer acids are particularly readily available, primarily consisting of 36-carbon dimer acids obtained by dimerizing 18-carbon unsaturated fatty acids such as oleic acid and linoleic acid, which are inexpensive and readily available. Furthermore, dimer acids may contain arbitrary amounts of monomer acids, trimer acids, other polymerized fatty acids, etc., depending on the production method and degree of purification. Furthermore, although double bonds remain after the polymerization reaction of unsaturated fatty acids, in this specification, hydrogenated products obtained by further hydrogenation to reduce the degree of unsaturation are also encompassed in the term dimer acid.

[0081] A polyalkylene resin containing a carbon skeleton derived from a dimer acid generally contains a divalent hydrocarbon group, and this divalent hydrocarbon group contains a carbon skeleton derived from a dimer acid. This divalent hydrocarbon group containing a carbon skeleton derived from a dimer acid usually has a long aliphatic carbon chain having 7 or more carbon atoms, and this long aliphatic carbon chain contains an alkylene chain. The divalent hydrocarbon group containing a carbon skeleton derived from a dimer acid may have 36 carbon atoms.

[0082] A specific example of a polyalkylene resin containing a carbon skeleton derived from a dimer acid is a polyimide resin containing a carbon skeleton derived from a dimer acid. This polyimide resin can be, for example, a resin obtained by an imidization reaction between a dimer acid type diamine and a tetracarboxylic acid anhydride. A dimer acid type diamine is a diamine in which two terminal carboxy groups (-COOH) of a dimer acid are replaced by aminomethyl groups (-CH ２ -NH ２ ) or amino group (-NH ２) is substituted. Examples of dimer acid diamines include "PRIAMINE 1073," "PRIAMINE 1074," and "PRIAMINE 1075" manufactured by Croda Japan; and "VERSAMINE 551" and "VERSAMINE 552" manufactured by Cognis Japan. Furthermore, as the tetracarboxylic acid anhydride, an aliphatic tetracarboxylic acid dianhydride may be used, an aromatic tetracarboxylic acid dianhydride may be used, or a combination of these may be used.

[0083] A resin containing a polyalkyleneoxy structure is sometimes referred to as a "polyalkyleneoxy resin." The number of carbon atoms in the alkyleneoxy structure contained in the polyalkyleneoxy resin is preferably 2 to 15, more preferably 3 to 10, and even more preferably 5 to 8. Specific examples of alkyleneoxy resins include "EXA-4850-150," "EXA-4816," and "EXA-4822" manufactured by DIC Corporation; "EP-4000," "EP-4003," "EP-4010," and "EP-4011" manufactured by ADEKA Corporation; "BEO-60E" and "BPO-20E" manufactured by New Japan Chemical Co., Ltd.; and "YL7175" and "YL7410" manufactured by Mitsubishi Chemical Corporation.

[0084] Resins containing a polysiloxane structure are sometimes referred to as “polysiloxane resins.” Examples of polysiloxane resins include “SMP-2006,” “SMP-2003PGMEA,” and “SMP-5005PGMEA” manufactured by Shin-Etsu Silicones Co., Ltd.; and linear polyimides made from amine-terminated polysiloxanes and tetrabasic acid anhydrides (see, for example, WO 2010 / 053185, JP 2002-12667 A, and JP 2000-319386 A).

[0085] A resin containing a poly(meth)acrylate structure may be referred to as a “poly(meth)acrylate resin.” Examples of poly(meth)acrylic resins include Teisan Resin manufactured by Nagase ChemteX Corporation; ME-2000, W-116.3, W-197C, KG-25, and KG-3000 manufactured by Negami Chemical Industrial Co., Ltd.; and ARUFON UH-2000 manufactured by Toagosei Co., Ltd.

[0086] Resins containing polyisoprene structures are sometimes called “polyisoprene resins.” Specific examples of polyisoprene resins include “KL-610” and “KL613” manufactured by Kuraray Co., Ltd.

[0087] Resins containing a polyisobutylene structure are sometimes called "polyisobutylene resins." Specific examples of polyisobutylene resins include "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer), both manufactured by Kaneka Corporation.

[0088] A resin containing a polystyrene structure is sometimes referred to as a "polystyrene resin." The polystyrene resin may be a copolymer containing, in combination with a styrene unit, any repeating unit different from the styrene unit, or may be a hydrogenated polystyrene resin. Examples of polystyrene resins include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-butadiene-butylene-styrene block copolymer (SBBS), styrene-butadiene diblock copolymer, hydrogenated styrene-butadiene copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-butadiene random copolymer, and styrene-maleic anhydride copolymer.

[0089] Specific examples of polystyrene resins include hydrogenated styrene-based thermoplastic elastomers "S1606," "H1041," "Tuftec H1043," "Tuftec P2000," and "Tuftec MP10" (manufactured by Asahi Kasei Corporation); epoxidized styrene-butadiene thermoplastic elastomers "Epofriend AT501" and "CT310" (manufactured by Daicel Corporation); modified styrene-based elastomers having hydroxyl groups "Septon HG252" (manufactured by Kuraray Co., Ltd.); and carboxyl Examples of such elastomers include "Tuftec N503M" modified styrene elastomers having an alkyl group, "Tuftec N501" modified styrene elastomers having an amino group, and "Tuftec M1913" modified styrene elastomers having an acid anhydride group (manufactured by Asahi Kasei Corporation); "Septon S8104" unmodified styrene elastomers (manufactured by Kuraray Co., Ltd.); "FG1924" styrene-ethylene / butylene-styrene block copolymers (manufactured by Kraton Corporation), and "EF-40" (manufactured by CRAY VALLEY).

[0090] Component (B) may have a functional group capable of reacting with an epoxy resin. The epoxy resin is preferably an epoxy resin (A), more preferably either an epoxy resin (A-1) or an epoxy resin (A-2), and even more preferably component (A-1). When component (B) is capable of reacting with an epoxy resin, the mechanical strength of the cured product of the resin composition can be increased. Functional groups capable of reacting with an epoxy resin include functional groups that appear upon heating. Examples of such functional groups include hydroxyl groups, carboxyl groups, acid anhydride groups, phenolic hydroxyl groups, epoxy groups, isocyanate groups, urethane groups, and maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups). Of these, hydroxyl groups, acid anhydride groups, phenolic hydroxyl groups, epoxy groups, isocyanate groups, urethane groups, and maleimide groups are preferred, with phenolic hydroxyl groups being more preferred.

[0091] When component (B) has a functional group, the functional group equivalent is preferably 100 g / eq. or more, more preferably 200 g / eq. or more, even more preferably 300 g / eq. or more, and preferably 200,000 g / eq. or less, more preferably 150,000 g / eq. or less, even more preferably 50,000 g / eq. or less, 10,000 g / eq. or less, or 5,000 g / eq. or less. The functional group equivalent is the number of grams of resin containing 1 gram equivalent of functional group. For example, the epoxy group equivalent can be measured according to JIS K7236. The hydroxyl group equivalent can be calculated by dividing the molecular weight of KOH by the hydroxyl value measured according to JIS K1557-1. When multiple types of functional groups are present, the functional group equivalent can be calculated by calculating the functional groups reactive with the epoxy resin contained in component (B) as a whole from the calculated values ​​for each.

[0092] The epoxy group equivalent of component (A-1) in the resin composition is E Ａ１ The functional group equivalent capable of reacting with the epoxy resin of component (B) in the resin composition is E Ｂ When this is done, E Ａ１ / E Ｂ is preferably 0.01 or more, more preferably 0.1 or more, even more preferably 0.5 or more, 1.0 or more, 1.2 or more, or 1.5 or more, and is preferably 50 or less, more preferably 40 or less, even more preferably 20 or less, 10 or less, or 5 or less. Ａ１ / E Ｂ By adjusting the equivalents of the component (A-1) and the component (B) so that the equivalents fall within this range, it becomes possible to obtain a cured product that is further suppressed in warping, has a lower dielectric tangent, and is more excellent in reflow resistance.

[0093] The content of component (B) is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 1.5% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, when the total amount of non-volatile components in the resin composition is 100% by mass.

[0094] The content of component (B) is preferably 1% by mass or more, more preferably 3% by mass or more, even more preferably 5% by mass or more, or 8% by mass or more, and is preferably 50% by mass or less, more preferably 45% by mass or less, even more preferably 40% by mass or less, or 35% by mass or less, when the resin component in the resin composition is 100% by mass.

[0095] The content of component (A-1) when the nonvolatile components in the resin composition are taken as 100% by mass is M Ａ１ The content of component (B) when the nonvolatile components in the resin composition are taken as 100% by mass is M Ｂ When M Ａ１ / M Ｂ is preferably 0.2 or more, more preferably 0.3 or more, even more preferably 0.4 or more, 0.5 or more, or 0.6 or more, and is preferably 3.5 or less, more preferably 3 or less, even more preferably 2.5 or less, 2 or less, 1.5 or less, 1.3 or less, 1.2 or less, or 1.1 or less. Ａ１ / M Ｂ By adjusting the contents of the (A-1) component and the (B) component so that the (A-2) value falls within this range, it is possible to obtain a cured product that is more effectively prevented from warping, has a lower dielectric tangent, and is more excellent in reflow resistance.

[0096] <(C) Inorganic Filler> The resin composition may contain (C) an inorganic filler as an optional component in combination with the above-described components (A) and (B). By including component (C), the dielectric loss tangent can be further reduced. The component (C) may be used alone or in combination of two or more types.

[0097] Examples of materials for component (C) include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum silicate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Furthermore, spherical silica is preferred.

[0098] Examples of commercially available products of component (C) include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", "YA010C", "SC2500SQ", "SO-C4", "SO-C2", and "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30", "DAW-03", and "FB-105FD" manufactured by Denka Company, Limited; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama Corporation; and "CellSpheres" and "MGH-005" manufactured by Taiheiyo Cement Corporation.

[0099] The average particle size of component (C) is not particularly limited, but is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, 2 μm or less, 1 μm or less, or 0.7 μm or less. The lower limit of the average particle size is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.07 μm or more, 0.1 μm or more, or 0.2 μm or more.

[0100] The average particle size of component (C) can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, a particle size distribution of the inorganic filler is prepared on a volume basis using a laser diffraction / scattering particle size distribution measuring device, and the median diameter is used as the average particle size. The measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the mixture ultrasonically for 10 minutes. The measurement sample is measured using a laser diffraction particle size distribution measuring device, with blue and red light source wavelengths used, using a flow cell system to measure the volume-based particle size distribution of the inorganic filler, and the average particle size is calculated as the median diameter from the obtained particle size distribution. An example of a laser diffraction particle size distribution measuring device is the "LA-960" manufactured by Horiba, Ltd.

[0101] The specific surface area of ​​component (C) is not particularly limited, but is preferably 0.1 m ２ / g or more, more preferably 0.5m ２ / g or more, more preferably 1m ２ / g or more, 3m ２ / g or more or 5m ２ The upper limit of the specific surface area is not particularly limited, but is preferably 100 m ２ / g or less, more preferably 80m ２ / g or less, more preferably 60m ２ / g or less, 50m ２ / g or less or 40m ２ The specific surface area of ​​component (C) is determined in accordance with the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) and calculating the specific surface area using the BET multipoint method.

[0102] Component (C) is preferably surface-treated with an appropriate surface treatment agent. Surface treatment can enhance the moisture resistance and dispersibility of component (C). Examples of surface treatment agents include silane coupling agents such as vinyl silane coupling agents, epoxy silane coupling agents, styryl silane coupling agents, (meth)acrylic silane coupling agents, amino silane coupling agents, isocyanurate silane coupling agents, ureido silane coupling agents, mercapto silane coupling agents, isocyanate silane coupling agents, and acid anhydride silane coupling agents; non-silane coupling alkoxysilane compounds such as methyltrimethoxysilane and phenyltrimethoxysilane; and silazane compounds. One type of surface treatment agent may be used alone, or two or more types may be used in combination.

[0103] Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd.

[0104] The degree of surface treatment with the surface treatment agent is preferably within a predetermined range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2 to 5% by mass of the surface treatment agent.

[0105] The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of ​​the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of ​​the inorganic filler is 0.02 mg / m ２ More than 0.1 mg / m ２ More preferably, 0.2 mg / m or more ２On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition or the melt viscosity in the form of a sheet, it is more preferable that the content be 1.0 mg / m ２ Preferably, 0.8 mg / m or less ２ More preferably, 0.5 mg / m or less ２ The following is more preferable. The carbon amount per unit surface area of ​​component (C) can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the carbon amount per unit surface area of ​​the inorganic filler can be measured using a carbon analyzer. An "EMIA-320V" manufactured by Horiba, Ltd., or the like, can be used as the carbon analyzer.

[0106] The content of component (C) is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, 65% by mass or more, or 70% by mass or more, and is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, when the total amount of non-volatile components in the resin composition is 100% by mass.

[0107] <(D) Curing Agent> The resin composition may contain a (C) curing agent as an optional component in combination with the above-described (A) and (B) components. This (D) curing agent as component (D) excludes those that fall under components (A) to (C). Component (D) usually has the function of reacting with component (A) to cure the resin composition. Component (D) may be used alone or in combination of two or more types in any ratio.

[0108] As the component (D), a compound capable of reacting with the component (A) to cure the resin composition can be used, and examples thereof include active ester curing agents, phenolic curing agents, benzoxazine curing agents, carbodiimide curing agents, acid anhydride curing agents, amine curing agents, cyanate ester curing agents, etc. Among these, the component (D) preferably contains any one of an active ester curing agent, a phenolic curing agent, and a carbodiimide curing agent, and more preferably contains an active ester curing agent and a phenolic curing agent.

[0109] Examples of active ester curing agents include curing agents having one or more active ester groups per molecule. Among these, preferred active ester curing agents are compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. The active ester curing agent is preferably one obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, active ester curing agents obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester curing agents obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound are more preferred.

[0110] Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0111] Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, phenol novolak, etc. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0112] Specific preferred examples of the active ester curing agent include dicyclopentadiene-type active ester curing agents, naphthalene-type active ester curing agents containing a naphthalene structure, active ester curing agents containing an acetylated product of phenol novolac, active ester curing agents containing a benzoylated product of phenol novolac, active ester curing agents that are acetylated products of phenol novolac, and active ester curing agents containing a styryl group and a naphthalene structure. As the dicyclopentadiene-type active ester curing agent, an active ester curing agent containing a dicyclopentadiene-type diphenol structure is preferred. The "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0113] Among these, the active ester curing agent is preferably at least one selected from the group consisting of an active ester curing agent containing a styryl group and a naphthalene structure, and a naphthalene-type active ester curing agent containing a naphthalene structure.

[0114] Commercially available active ester curing agents include active ester curing agents containing a dicyclopentadiene-type diphenol structure, such as "EXB9451," "EXB9460," "EXB9460S," "HPC-8000-65T," "HPC-8000H-65TM," and "EXB-8000L-65TM" (manufactured by DIC Corporation); naphthalene-type active ester curing agents containing a naphthalene structure, such as "HP-B-8151-62T," "EXB9416-70BK," "EXB-8100L-65T," "EXB-8150L-65T," "EXB-8150-65T," "HPC-8150-60T," and "HPC-8151-62T" (manufactured by DIC Corporation); phosphorus-containing active ester compounds, such as "EXB9401" (manufactured by DIC Corporation); and phenol novolak compounds. Examples of such curing agents include "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester-based curing agent containing an acetylated product of phenol novolac; "YLH1026" (manufactured by Mitsubishi Chemical Corporation) as an active ester-based curing agent containing a benzoylated product of phenol novolac; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester-based curing agent which is an acetylated product of phenol novolac; "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester-based curing agents which are benzoylated products of phenol novolac; "EXB-8500-65T" (manufactured by DIC Corporation); and "PC1300-02-65MA" (manufactured by Air Water Inc.) as an active ester-based curing agent containing a styryl group and a naphthalene structure.

[0115] Examples of phenolic curing agents include curing agents having one or more, preferably two or more, hydroxyl groups bonded to an aromatic ring (such as a benzene ring or a naphthalene ring) per molecule. Among these, compounds having a hydroxyl group bonded to a benzene ring are preferred. Furthermore, from the viewpoint of heat resistance and water resistance, phenolic curing agents having a novolac structure are preferred. Furthermore, from the viewpoint of adhesion, nitrogen-containing phenolic curing agents are preferred, and triazine skeleton-containing phenolic curing agents are more preferred. In particular, from the viewpoint of achieving high levels of heat resistance, water resistance, and adhesion, triazine skeleton-containing phenolic novolac curing agents are preferred.

[0116] Specific examples of phenol-based curing agents and naphthol-based curing agents include "MEH-7700", "MEH-7810", and "MEH-8000H" manufactured by Meiwa Chemical Industry Co., Ltd.; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170", "SN-180", "SN-190", "SN-475", "SN-495", "SN-495V", "SN-375", and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; Examples thereof include "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", and "KA-1165" manufactured by DIC Corporation; and "GDP-6115L", "GDP-6115H", and "ELPC75" manufactured by Gun-ei Chemical Co., Ltd.

[0117] Specific examples of carbodiimide curing agents include "V-03", "V-05", "V-07", and "V-11S" manufactured by Nisshinbo Chemical Inc.; and Stavaxol (registered trademark) P manufactured by Lanxess AG.

[0118] Specific examples of benzoxazine-based curing agents include "ODA-BOZ" manufactured by JFE Chemical Corporation, "HFB2006M" manufactured by Showa Highpolymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Chemicals Corporation.

[0119] Examples of acid anhydride curing agents include curing agents having one or more acid anhydride groups in one molecule. Specific examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenone. Examples of the acid anhydride include polymeric acid anhydrides such as tetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and styrene-maleic acid resins obtained by copolymerizing styrene and maleic acid. Commercially available acid anhydride curing agents may be used, and examples thereof include "MH-700" manufactured by New Japan Chemical Co., Ltd.

[0120] Examples of the amine-based curing agent include curing agents having one or more amino groups in one molecule, such as aliphatic amines, polyether amines, alicyclic amines, and aromatic amines. Among these, aromatic amines are preferred from the viewpoint of achieving the desired effects of the present invention. The amine-based curing agent is preferably a primary amine or a secondary amine, and more preferably a primary amine. Specific examples of the amine-based curing agent include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxybenzidine), and 2,2-bis(3-amino-4-hydroxybenzidine). bis(4-aminophenoxy)biphenyl)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, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, and the like. Commercially available amine-based curing agents may be used, and examples thereof include "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD A-A," "KAYAHARD A-B," and "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd., and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

[0121] Examples of cyanate ester curing agents include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)thioether, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins are partially triazine converted. Specific examples of cyanate ester curing agents include "PT30" and "PT60" manufactured by Arxada (both are phenol novolac type polyfunctional cyanate ester resins); "ULL-950S" (polyfunctional cyanate ester resin); "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazinated to form a trimer); and the like.

[0122] When the number of epoxy groups in component (A-1) is taken to be 1, the number of active groups in the (D) curing agent is preferably 0.1 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. Here, "the number of epoxy groups in component (A-1)" refers to the total value obtained by dividing the mass of the non-volatile components of component (A-1) present in the resin composition by the epoxy equivalent. Furthermore, "the number of active groups in (D) curing agent" refers to the total value obtained by dividing the mass of the non-volatile components of the (D) curing agent present in the resin composition by the active group equivalent.

[0123] When the number of epoxy groups in component (A) is taken to be 1, the number of active groups in the (D) curing agent is preferably 0.1 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and is preferably 10 or less, more preferably 5 or less, and even more preferably 3 or less. Here, the "number of epoxy groups in component (A)" refers to the total value obtained by dividing the mass of the non-volatile components of component (A) present in the resin composition by the epoxy equivalent.

[0124] The content of the (D) curing agent is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 1.5% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, based on 100% by mass of the non-volatile components in the resin composition.

[0125] The content of the (D) curing agent is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and is preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, based on 100% by mass of the resin component in the resin composition.

[0126] <(E) Radically Polymerizable Resin> The resin composition may contain a radically polymerizable resin (E) as an optional component in combination with the above-described components (A) and (B). This radically polymerizable resin (E) as component (E) excludes those corresponding to components (A) to (D). The component (E) may be used alone, or two or more types may be used in combination at any ratio.

[0127] The type of radical polymerizable resin (E) is not particularly limited as long as it has one or more (preferably two or more) radical polymerizable unsaturated groups in one molecule. Examples of the radical polymerizable resin include resins having one or more radical polymerizable unsaturated groups selected from maleimide group, vinyl group, allyl group, styryl group, vinylphenyl group, acryloyl group, methacryloyl group, fumaroyl group, and maleoyl group. Among them, from the viewpoint of obtaining a cured product exhibiting better dielectric properties, the radical polymerizable resin is preferably one or more selected from maleimide resin, (meth)acrylic resin, and styryl resin.

[0128] The type of maleimide resin is not particularly limited as long as it has one or more (preferably two or more) maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) in one molecule. Examples of maleimide resins include: (1) maleimide resins containing an aliphatic skeleton (preferably an aliphatic skeleton having 36 carbon atoms derived from dimer diamine), such as "BMI-3000J," "BMI-5000," "BMI-1400," "BMI-1500," "BMI-1700," and "BMI-689" (all manufactured by Designer Molecules), and "SLK6895-T90" (manufactured by Shin-Etsu Chemical Co., Ltd.); (2) maleimide resins containing an indane skeleton, as described in the Japan Institute of Invention and Innovation Disclosure Technical Bulletin No. 2020-500211; and (3) maleimide resins containing an aromatic ring skeleton directly bonded to the nitrogen atom of the maleimide group, such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Daiwa Kasei Co., Ltd.), and "BMI-80" (manufactured by Keiai Kasei Co., Ltd.).

[0129] The (meth)acrylic resin may be of any type, and may be a monomer or oligomer, as long as it has one or more (preferably two or more) (meth)acryloyl groups in one molecule. Here, the term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups. Examples of methacrylic resins include (meth)acrylate monomers, as well as (meth)acrylic resins such as "A-DOG" (manufactured by Shin-Nakamura Chemical Co., Ltd.), "DCP-A" (manufactured by Kyoeisha Chemical Co., Ltd.), "NPDGA," "FM-400," "R-687," "THE-330," "PET-30," and "DPHA" (all manufactured by Nippon Kayaku Co., Ltd.).

[0130] The styryl resin is not particularly limited in type, and may be a monomer or oligomer, as long as it has one or more (preferably two or more) styryl groups or vinylphenyl groups in one molecule. Examples of the styryl resin include styrene monomers and styryl resins such as "OPE-2St," "OPE-2St 1200," and "OPE-2St 2200" (all manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0131] The content of component (E) is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, or 5% by mass or more, and is preferably 20% by mass or less, more preferably 15% by mass or less, even more preferably 10% by mass or less, or 8% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

[0132] The content of component (E) is, for example, 1% by mass or more, preferably 3% by mass or more, more preferably 5% by mass or more, and preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, assuming that the resin components in the resin composition are 100% by mass.

[0133] <(F) Organic Filler> The resin composition may contain an (F) organic filler as an optional component in combination with the above-described components (A) and (B). The (F) organic filler as component (F) does not include those corresponding to the above-described components (A) to (E). The (F) organic filler is usually incompatible with resin components other than the (F) organic filler and is contained in the resin composition in the form of particles, and is contained in the cured product while maintaining this particulate state. Furthermore, one type of (F) organic filler may be used alone, or two or more types may be used in combination.

[0134] As the (F) organic filler, particles of an organic material may be used. A rubber component is preferred as the organic material contained in the (F) organic filler. Examples of rubber components include silicone-based elastomers such as polydimethylsiloxane; olefin-based thermoplastic elastomers such as polybutadiene, polyisoprene, polychlorobutadiene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-diene terpolymer, and ethylene-propylene-butene terpolymer; and thermoplastic elastomers such as acrylic thermoplastic elastomers such as polypropyl(meth)acrylate, polybutyl(meth)acrylate, polycyclohexyl(meth)acrylate, and polyoctyl(meth)acrylate. Furthermore, silicone-based rubbers such as polyorganosiloxane rubber may be mixed into the rubber component. The rubber component contained in the rubber particles has a glass transition temperature of, for example, 0°C or lower, preferably -10°C or lower, more preferably -20°C or lower, and even more preferably -30°C or lower.

[0135] The (F) organic filler may be a core-shell type rubber particle consisting of a core particle containing the above-mentioned rubber component and a shell portion obtained by graft copolymerization of a monomer component copolymerizable with the rubber component contained in the core particle. Here, the term "core-shell type" does not necessarily refer only to those in which the core particle and the shell portion are clearly distinguishable, but also includes those in which the boundary between the core particle and the shell portion is unclear, and the core particle does not necessarily have to be completely covered with the shell portion.

[0136] Specific examples of the organic filler (F) include "CHT" manufactured by Samsung SDI; "B602" manufactured by Techno UMG; "Paraloid EXL-2602", "Paraloid EXL-2603", "Paraloid EXL-2655", "Paraloid EXL-2311", "Paraloid-EXL2313", "Paraloid EXL-2315", "Paraloid KM-330", "Paraloid KM-336P", and "Paraloid KCZ-201" manufactured by Dow; and "Metablen C-223A" and "Metablen E- 901," "Metablen S-2001," "Metablen W-450A," "Metablen SRK-200," "Kane Ace M-511," "Kane Ace M-600," "Kane Ace M-400," "Kane Ace M-580," and "Kane Ace MR-01" manufactured by Kaneka Corporation, and "Staphyloid AC3355," "Staphyloid AC3816," "Staphyloid AC3816N," "Staphyloid AC3832," "Staphyloid AC4030," and "Staphyloid AC3364" manufactured by Aica Kogyo Co., Ltd.

[0137] The content of the (F) organic filler is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, relative to 100% by mass of the non-volatile components in the resin composition, and is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less, or 1.5% by mass or less.

[0138] The content of the (F) organic filler is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, relative to 100% by mass of the resin component in the resin composition, and is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

[0139] <(G) Curing Accelerator> The resin composition may contain a (G) curing accelerator as an optional component in combination with the (A) and (B) components. The (G) curing accelerator as the (G) component does not include those corresponding to the above-mentioned (A) to (F) components. The (G) curing accelerator acts as a catalyst for the reaction of the (A) epoxy resin, and can accelerate the curing of the resin composition.

[0140] Examples of the (G) curing accelerator include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, amine-based curing accelerators, etc. One type of (G) curing accelerator may be used alone, or two or more types may be used in combination.

[0141] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hydrogenhexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, and tetraphenylphosphonium bromide. aromatic phosphonium salts such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone addition products such as triphenylphosphine-p-benzoquinone addition products; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine aromatic phosphines such as phenylphosphine, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2′-bis(diphenylphosphino)diphenyl ether;

[0142] Examples of the urea-based curing accelerator include 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. aromatic dimethylureas such as N,N-(1,4-phenylene)bis(N',N'-dimethylurea), N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea], and the like.

[0143] Examples of guanidine curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

[0144] Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-methylimidazole. Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl -(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct imidazole compounds such as 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. Commercially available imidazole curing accelerators include, for example, "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A" manufactured by Shikoku Chemicals Corporation; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0145] Examples of metal-based curing accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organic copper complexes such as copper(II) acetylacetonate, organic zinc complexes such as zinc(II) acetylacetonate, organic iron complexes such as iron(III) acetylacetonate, organic nickel complexes such as nickel(II) acetylacetonate, and organic manganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0146] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. Commercially available amine curing accelerators may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0147] The content of the (G) curing accelerator, relative to 100% by mass of the non-volatile components in the resin composition, is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and is preferably 5% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less.

[0148] The content of the (G) curing accelerator, relative to 100% by mass of the resin component in the resin composition, is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, and is preferably 10% by mass or less, more preferably 6% by mass or less, even more preferably 3% by mass or less.

[0149] <(H) Optional Additives> The resin composition may further contain an optional additive (H) as an optional component. The optional additive (H) as component (H) does not include those corresponding to the above-mentioned components (A) to (G). Examples of the optional additive (H) include thermoplastic resins; organometallic compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silanes; triazole-based adhesion imparting agents, tetrazole-based adhesion imparting agents, triazine-based Examples of the additives include adhesion promoters such as adhesion promoters; antioxidants such as hindered phenol antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; and stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers. One type of optional additive (H) may be used alone, or two or more types may be used in combination.

[0150] <(I) Solvent> The resin composition may further contain (I) a solvent as an optional volatile component in addition to the non-volatile components such as the above-mentioned components (A) to (H). An organic solvent is typically used as the (I) solvent. Examples of the organic solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol-based solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples of the solvent include ether ester solvents such as ethyl acetate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. (I) The solvent may be used alone or in combination of two or more.

[0151] (I) The content of the solvent, relative to 100% by mass of all components in the resin composition, may be, for example, 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less, or may be 0% by mass.

[0152] <Method for producing resin composition> The resin composition can be produced, for example, by mixing components that can be contained in the resin composition. The above-mentioned components may be mixed partially or entirely at the same time, or may be mixed sequentially. In the process of mixing each component, the temperature may be appropriately set, and thus heating and / or cooling may be performed temporarily or throughout. Furthermore, stirring or shaking may be performed in the process of mixing each component.

[0153] <Physical Properties of Resin Composition> As described above, the resin composition of the present invention containing the component (A-1) and the component (B) in combination can provide a cured product that is less prone to warping, has a low dielectric loss tangent, and is excellent in reflow resistance.

[0154] The cured product obtained by heating the resin composition at 200°C for 90 minutes exhibits the characteristic of a low dielectric loss tangent (Df). Therefore, an insulating layer with a low dielectric loss tangent is obtained. The dielectric loss tangent is preferably less than 0.0045, more preferably 0.004 or less, and even more preferably less than 0.004. There is no particular lower limit, but it can be 0.00001 or more. The dielectric loss tangent can be measured by the method described in the examples below.

[0155] The cured product obtained by heating the resin composition at 100°C for 30 minutes and then at 200°C for 90 minutes exhibits the characteristic of suppressing the amount of warping. Thus, an insulating layer with suppressed amount of warping is obtained. The amount of warping is preferably less than 2500 μm, more preferably 2000 μm or less, and even more preferably less than 2000 μm. There is no particular lower limit, but it can be 0 μm or more. The amount of warping can be evaluated by the method described in the examples below.

[0156] The cured product obtained by heating the resin composition at 200°C for 90 minutes exhibits excellent reflow resistance. This results in an insulating layer with excellent reflow resistance. For example, a resin composition layer is formed on both sides of an inner layer substrate. The resin composition layer is thermally cured at 200°C for 90 minutes to form an insulating layer. CZ copper foil is then laminated on the insulating layer, and five evaluation pieces are obtained by cutting the evaluation pieces into 100 mm x 50 mm pieces. These evaluation pieces are then passed 10 times through a reflow device that reproduces a solder reflow temperature with a peak temperature of 260°C (the reflow temperature profile conforms to IPC / JEDEC J-STD-020C). In this case, the number of test pieces exhibiting abnormalities such as swelling is preferably one, and more preferably zero. Reflow resistance can be evaluated by the method described in the Examples below.

[0157] The resin composition of the present invention can provide a cured product having a low dielectric loss tangent, suppressed warpage, and excellent reflow resistance. Therefore, the resin composition of the present invention can be suitably used as a resin composition for forming an insulating layer of a printed wiring board (resin composition for an insulating layer of a printed wiring board), and more suitably used as a resin composition for forming an interlayer insulating layer of a printed wiring board (resin composition for an insulating interlayer of a printed wiring board). The resin composition of the present invention can also be suitably used when the printed wiring board is a circuit board with built-in components. The resin composition of the present invention can also be suitably used as a resin composition for forming an insulating layer of a rewiring board for a semiconductor package (resin composition for an insulating layer of a rewiring board). In the present invention, printed wiring boards and rewiring boards are collectively referred to as "circuit boards," and therefore the resin composition of the present invention can be suitably used for an insulating layer of a circuit board.

[0158] The resin composition of the present invention can further be used in a wide range of applications requiring a resin composition, such as sheet-like laminate materials such as resin sheets and prepregs, solder resists, underfill materials, die bonding materials, hole filling resins, sealing resins, and component embedding resins.

[0159] [Sheet-like Laminated Material (Resin Sheet, Prepreg)] The resin composition of the present invention can be used as it is, but may also be used in the form of a sheet-like laminated material containing the resin composition.

[0160] As the sheet-like laminate material, the following resin sheets and prepregs are preferred.

[0161] In one embodiment, the resin sheet includes a support and a layer of a resin composition (hereinafter simply referred to as a "resin composition layer") provided on the support, and is characterized in that the resin composition layer is formed from the resin composition of the present invention.

[0162] The thickness of the resin composition layer varies depending on the application, and may be appropriately determined depending on the application. For example, from the viewpoint of thinning printed wiring boards and semiconductor packages, the thickness of the resin composition layer is preferably 100 μm or less, more preferably 90 μm or less, and even more preferably 80 μm or less, or 60 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 1 μm or more, 5 μm or more, etc.

[0163] Examples of the support include a thermoplastic resin film, a metal foil, and a release paper, and a thermoplastic resin film or a metal foil is preferred. Therefore, in a preferred embodiment, the support is a thermoplastic resin film or a metal foil.

[0164] When a thermoplastic resin film is used as the support, examples of the thermoplastic resin include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0165] When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of a single metal, such as copper, or a foil made of an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0166] The support may be subjected to a matte treatment, a corona treatment, or an antistatic treatment on the surface that will be bonded to the resin composition layer. Alternatively, a support with a release layer, which has a release layer on the surface that will be bonded to the resin composition layer, may be used as the support. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available products may be used as the support with a release layer. Examples include "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Uni-Peel" manufactured by Unitika Ltd., which are PET films having a release layer primarily composed of an alkyd resin-based release agent.

[0167] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is in the above range.

[0168] When a metal foil is used as the support, a metal foil with a support substrate may be used, which is a thin metal foil with a peelable support substrate attached thereto. In one embodiment, the metal foil with a support substrate includes a support substrate, a release layer provided on the support substrate, and a metal foil provided on the release layer. When a metal foil with a support substrate is used as the support, the resin composition layer is provided on the metal foil.

[0169] In the metal foil with a supporting substrate, the material of the supporting substrate is not particularly limited, and examples thereof include copper foil, aluminum foil, stainless steel foil, titanium foil, copper alloy foil, etc. When copper foil is used as the supporting substrate, it may be electrolytic copper foil or rolled copper foil. Furthermore, the release layer is not particularly limited as long as it can release the metal foil from the supporting substrate, and examples thereof include an alloy layer of an element selected from the group consisting of Cr, Ni, Co, Fe, Mo, Ti, W, and P; an organic coating, etc.

[0170] In the metal foil with a supporting substrate, the material of the metal foil is preferably, for example, copper foil or copper alloy foil.

[0171] In the metal foil with a supporting substrate, the thickness of the supporting substrate is not particularly limited, but is preferably in the range of 10 μm to 150 μm, more preferably in the range of 10 μm to 100 μm. The thickness of the metal foil may be, for example, in the range of 0.1 μm to 10 μm.

[0172] In one embodiment, the resin sheet may further include an optional layer as needed. Examples of such optional layers include a protective film provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, adhesion of dust and the like to the surface of the resin composition layer and scratches can be suppressed.

[0173] The resin sheet can be produced, for example, by preparing a liquid resin composition as is or a resin varnish by dissolving the resin composition in an organic solvent, applying this onto a support using a die coater or the like, and then drying to form a resin composition layer.

[0174] The organic solvent may be the same as the organic solvent described as a component of the resin composition. The organic solvent may be used alone or in combination of two or more.

[0175] Drying may be carried out by known methods such as heating or hot air blowing. Drying conditions are not particularly limited, but drying is carried out so that the content of organic solvent in the resin composition layer becomes 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the organic solvent in the resin composition or resin varnish, for example, when a resin composition or resin varnish containing 30% by mass to 60% by mass of organic solvent is used, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0176] The resin sheet can be stored in a rolled state. When the resin sheet has a protective film, it can be used by peeling off the protective film.

[0177] In one embodiment, the prepreg is formed by impregnating a sheet-like fiber substrate with the resin composition of the present invention.

[0178] The sheet-like fiber substrate used for the prepreg is not particularly limited, and commonly used prepreg substrates such as glass cloth, aramid nonwoven fabric, and liquid crystal polymer nonwoven fabric can be used. From the viewpoint of thinning printed wiring boards and semiconductor chip packages, the thickness of the sheet-like fiber substrate is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. The lower limit of the thickness of the sheet-like fiber substrate is not particularly limited. It is usually 10 μm or more.

[0179] The prepreg can be produced by a known method such as a hot melt method or a solvent method.

[0180] The thickness of the prepreg may be in the same range as that of the resin composition layer in the resin sheet described above.

[0181] The sheet-like laminate material of the present invention can be suitably used to form an insulating layer of a printed wiring board (for the insulating layer of a printed wiring board), and can be more suitably used to form an interlayer insulating layer of a printed wiring board (for the insulating interlayer of a printed wiring board). The sheet-like laminate material of the present invention can also be suitably used to form an insulating layer of a rewiring board of a semiconductor package (for the insulating layer of a rewiring board). That is, the sheet-like laminate material of the present invention can be suitably used as an insulating layer of a circuit board.

[0182] [Circuit Board] The resin composition of the present invention can be used to form an insulating layer for a circuit board. The present invention also provides such a circuit board, i.e., a circuit board including an insulating layer made of a cured product of the resin composition of the present invention.

[0183] <Printed Wiring Board> In one embodiment, the circuit board of the present invention is a printed wiring board.

[0184] A printed wiring board can be produced, for example, by using the above-mentioned resin sheet by a method including the following steps (I) and (II): (I) a step of laminating a resin sheet on an inner layer substrate so that the resin composition layer of the resin sheet is bonded to the inner layer substrate; and (II) a step of curing (e.g., thermally curing) the resin composition layer to form an insulating layer.

[0185] The "inner layer substrate" used in step (I) is a member that will become the substrate of a printed wiring board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may have a conductor layer on one or both sides, and this conductor layer may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate is sometimes referred to as an "inner layer circuit board." Furthermore, intermediate products on which an insulating layer and / or a conductor layer is to be further formed during the production of a printed wiring board are also included in the "inner layer substrate" of the present invention. When the printed wiring board is a circuit board with built-in components, an inner layer substrate with built-in components may be used.

[0186] The lamination of the inner layer substrate and the resin sheet can be carried out, for example, by thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of a member for thermocompression bonding the resin sheet to the inner layer substrate (hereinafter also referred to as a "thermocompression bonding member") include a heated metal plate (such as a SUS panel) or a metal roll (such as a SUS roll). The thermocompression bonding member may be pressed directly onto the resin sheet, or may be pressed via an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently conform to the surface irregularities of the inner layer substrate.

[0187] The lamination of the inner layer substrate and the resin sheet may be carried out by a vacuum lamination method. In the vacuum lamination method, the thermocompression temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, the thermocompression pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa to 1.47 MPa, and the thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. The lamination may be carried out under reduced pressure conditions, preferably a pressure of 26.7 hPa or less.

[0188] The lamination can be performed using a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., or a batch-type vacuum pressure laminator.

[0189] After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression member from the support side. The pressing conditions for the smoothing treatment may be the same as the thermocompression conditions for lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

[0190] The support may be removed between step (I) and step (II), or may be removed after step (II). When a metal foil is used as the support, the conductor layer may be formed using the metal foil without peeling off the support. When a metal foil with a supporting substrate is used as the support, the supporting substrate (and the release layer) may be peeled off. Then, the conductor layer can be formed using the metal foil.

[0191] In step (II), the resin composition layer is cured (for example, by heat curing) to form an insulating layer made of a cured product of the resin composition. The curing conditions for the resin composition layer are not particularly limited, and conditions typically employed for forming insulating layers for printed wiring boards may be used.

[0192] For example, the heat curing conditions for the resin composition layer vary depending on the type of resin composition, but in one embodiment, the curing temperature is preferably 140° C. to 250° C., more preferably 150° C. to 240° C., and even more preferably 180° C. to 230° C. The curing time is preferably 5 minutes to 240 minutes, more preferably 10 minutes to 150 minutes, and even more preferably 15 minutes to 120 minutes.

[0193] Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 140°C, preferably 60°C to 135°C, more preferably 70°C to 130°C for 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

[0194] When manufacturing a printed wiring board, the following steps may be further performed: (III) drilling holes in the insulating layer; (IV) roughening the insulating layer; and (V) forming a conductor layer. These steps (III) to (V) may be performed according to various methods known to those skilled in the art for use in manufacturing printed wiring boards. When the support is removed after step (II), the support may be removed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). Furthermore, if necessary, the formation of the insulating layer and the conductor layer in steps (I) to (V) may be repeated to form a multilayer wiring board.

[0195] In another embodiment, the printed wiring board of the present invention can be produced using the above-mentioned prepreg. The production method is basically the same as when a resin sheet is used.

[0196] Step (III) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (III) may be performed using, for example, a drill, a laser, plasma, or the like, depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be determined appropriately depending on the design of the printed wiring board.

[0197] Step (IV) is a step of roughening the insulating layer. Usually, in this step (IV), smear removal (desmear) is also performed. The procedure and conditions of the roughening treatment are not particularly limited, and known procedures and conditions that are usually used when forming an insulating layer of a printed wiring board can be adopted. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order.

[0198] The swelling liquid used in the roughening treatment is not particularly limited, but examples thereof include alkaline solutions and surfactant solutions, and is preferably an alkaline solution, with sodium hydroxide solution and potassium hydroxide solution being more preferred. Commercially available swelling liquids include "Swelling Dip Securigance P" and "Swelling Dip Securigance SBU" manufactured by Atotech Japan. The swelling treatment using a swelling liquid is not particularly limited, but can be carried out by, for example, immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40°C to 80°C for 5 to 15 minutes.

[0199] The oxidizing agent used in the roughening treatment is not particularly limited, but examples thereof include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0200] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan is an example.

[0201] The treatment with the neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30° C. to 80° C. for 5 to 30 minutes. From the viewpoint of workability, etc., a method in which the object that has been roughened with an oxidizing agent is immersed in a neutralizing solution at 40° C. to 70° C. for 5 to 20 minutes is preferred.

[0202] Step (V) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer may be a single metal layer or an alloy layer. Examples of the alloy layer include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among these, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

[0203] The conductor layer may have a single layer structure or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are stacked. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

[0204] The thickness of the conductor layer depends on the desired design of the printed wiring board, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0205] In one embodiment, the conductor layer may be formed by plating. From the viewpoint of facilitating the formation of fine wiring, it is preferable to form the conductor layer by a semi-additive method. An example of forming the conductor layer by a semi-additive method will be described below.

[0206] First, a plating seed layer is formed on the surface of an insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary plating seed layer is removed by etching or the like, thereby forming a conductor layer having the desired wiring pattern.

[0207] In another embodiment, the conductor layer may be formed using a metal foil. When forming the conductor layer using a metal foil, it is preferable to perform step (V) between step (I) and step (II). For example, after step (I), the support is removed and a metal foil is laminated on the exposed surface of the resin composition layer. The lamination of the resin composition layer and the metal foil may be performed by a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Thereafter, a conductor layer having a desired wiring pattern can be formed using the metal foil on the insulating layer by a conventional known technique such as a modified semi-additive method.

[0208] The metal foil can be produced by a known method such as an electrolytic method, a rolling method, etc. Examples of commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Nippon Mining & Smelting Corporation, and 3EC-III foil and TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd.

[0209] Alternatively, when a metal foil or a metal foil with a supporting substrate is used as the support for the resin sheet, the conductor layer may be formed using the metal foil, as described above.

[0210] <Rewiring Substrate of Semiconductor Package> In one embodiment, the circuit board of the present invention is a rewiring substrate (rewiring layer) of a semiconductor package. Hereinafter, a method for manufacturing a semiconductor package will be described.

[0211] The semiconductor package includes an insulating layer made of a cured product of the resin composition of the present invention as an insulating layer of a rewiring substrate. The semiconductor package may also include a sealing layer made of a cured product of the resin composition of the present invention.

[0212] A semiconductor package can be manufactured, for example, by a method including the following steps (1) to (6) using the resin composition and resin sheet of the present invention. The resin composition and resin sheet of the present invention can be used to form a rewiring formation layer (insulating layer for forming a rewiring substrate) in step (5) or a sealing layer in step (3). An example of forming a rewiring formation layer or a sealing layer using a resin composition or a resin sheet will be shown below. However, techniques for forming a rewiring formation layer or a sealing layer for a semiconductor package are known, and a person skilled in the art can manufacture a semiconductor package using the resin composition and resin sheet of the present invention according to known techniques. (1) A step of laminating a temporary fixing film on a substrate; (2) A step of temporarily fixing a semiconductor chip on the temporary fixing film; (3) A step of forming a sealing layer on the semiconductor chip; (4) A step of peeling the substrate and the temporary fixing film from the semiconductor chip; (5) A step of forming a rewiring formation layer as an insulating layer on the surface of the semiconductor chip from which the substrate and the temporary fixing film have been peeled; and (6) A step of forming a rewiring layer as a conductor layer on the rewiring formation layer.

[0213] -Step (1)- The material used for the substrate is not particularly limited. Examples of the substrate include semiconductor wafers such as silicon wafers, glass wafers, glass substrates, metal substrates such as copper, titanium, stainless steel, and cold-rolled steel plate (SPCC), substrates in which glass fibers are impregnated with epoxy resin or the like and subjected to a thermosetting treatment (e.g., FR-4 substrates), and substrates made of bismaleimide triazine resin (BT resin).

[0214] The material of the temporary fixing film is not particularly limited as long as it can be peeled off from the semiconductor chip in step (4) and can temporarily fix the semiconductor chip. Commercially available products can be used as the temporary fixing film. Examples of commercially available products include Riva Alpha manufactured by Nitto Denko Corporation.

[0215] -Step (2)- The semiconductor chips can be temporarily fixed using known devices such as a flip chip bonder, a die bonder, etc. The layout and number of semiconductor chips to be arranged can be set appropriately depending on the shape and size of the temporary fixing film, the number of semiconductor packages to be produced, etc. For example, the semiconductor chips can be temporarily fixed by arranging them in a matrix of multiple rows and multiple columns.

[0216] -Step (3)- A resin composition layer of the resin sheet of the present invention is laminated on a semiconductor chip, or the resin composition of the present invention is applied to a semiconductor chip and cured (for example, thermally cured) to form a sealing layer.

[0217] For example, lamination of a semiconductor chip and a resin sheet can be performed by removing the protective film from the resin sheet and then thermocompressing the resin sheet to the semiconductor chip from the support side. Examples of a member for thermocompressing the resin sheet to the semiconductor chip (hereinafter also referred to as a "thermocompression member") include a heated metal plate (such as a SUS panel) or a metal roll (such as a SUS roll). It is preferable to press the thermocompression member not directly onto the resin sheet, but via an elastic material such as heat-resistant rubber, so that the resin sheet can adequately conform to the surface irregularities of the semiconductor chip. The semiconductor chip and the resin sheet can also be laminated by a vacuum lamination method, and the lamination conditions and preferred ranges are the same as those described in connection with the method for manufacturing a printed wiring board.

[0218] After lamination, the resin composition is thermally cured to form the sealing layer under the same conditions as those described in relation to the method for producing a printed wiring board.

[0219] The support of the resin sheet may be peeled off after the resin sheet is laminated on the semiconductor chip and thermally cured, or the support may be peeled off before the resin sheet is laminated on the semiconductor chip.

[0220] When forming a sealing layer by applying the resin composition of the present invention, the application conditions are the same as the application conditions when forming the resin composition layer described in relation to the resin sheet of the present invention, and the preferred ranges are also the same.

[0221] -Step (4)- The method for peeling off the substrate and the temporary fixing film can be changed as appropriate depending on the material of the temporary fixing film, etc., and examples thereof include a method in which the temporary fixing film is heated and foamed (or expanded) to peel off, and a method in which ultraviolet light is irradiated from the substrate side to reduce the adhesive strength of the temporary fixing film and then peel it off.

[0222] In the method of heating and foaming (or expanding) the temporary fixing film to peel it off, the heating conditions are usually 100 to 250°C for 1 to 90 seconds or 5 to 15 minutes. In the method of irradiating ultraviolet light from the substrate side to reduce the adhesive strength of the temporary fixing film to peel it off, the irradiation dose of ultraviolet light is usually 10 mJ / cm. ２ ~1000mJ / cm ２ is.

[0223] -Step (5)- A rewiring formation layer (insulating layer of a rewiring substrate) is formed using the resin composition and resin sheet of the present invention.

[0224] After forming the redistribution layer, via holes may be formed in the redistribution layer to connect the semiconductor chip to a conductor layer (described later). The via holes may be formed by a known method depending on the material of the redistribution layer.

[0225] Step (6)—The formation of a conductor layer on the rewiring formation layer may be carried out in the same manner as step (V) described in relation to the method for producing a printed wiring board. Steps (5) and (6) may be repeated to alternately stack (build up) conductor layers (rewiring layers) and rewiring formation layers (insulating layers).

[0226] In manufacturing the semiconductor package, the steps of (7) forming a solder resist layer on the conductor layer (rewiring layer), (8) forming bumps, and (9) dicing the plurality of semiconductor packages into individual semiconductor packages may be further performed. These steps may be performed according to various methods used in manufacturing semiconductor packages and known to those skilled in the art.

[0227] Even when a composition contributing to good dielectric properties is employed, the resin composition and resin sheet of the present invention can provide a cured product that exhibits good adhesion to a conductor layer when exposed to a high-temperature, high-humidity environment. By forming a rewiring formation layer (insulating layer) using the resin composition and resin sheet of the present invention, a semiconductor package with extremely low transmission loss can be realized without concern for reduced conductor adhesion, regardless of whether the semiconductor package is a fan-in (Fan-In) package or a fan-out (Fan-Out) package. In one embodiment, the semiconductor package of the present invention is a fan-out (Fan-Out) package. The resin composition and resin sheet of the present invention can be applied to both fan-out panel level packages (FOPLPs) and fan-out wafer level packages (FOWLPs). In one embodiment, the semiconductor package of the present invention is a fan-out panel level package (FOPLP) or a fan-out wafer level package (FOWLP).

[0228] [Semiconductor Device] The semiconductor device of the present invention includes a layer made of a cured product of the resin composition layer of the present invention. The semiconductor device of the present invention can be produced using the circuit board of the present invention.

[0229] Examples of semiconductor devices include various semiconductor devices used in electrical appliances (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircraft).

[0230] The present invention will be described in more detail below with reference to examples. The present invention is not limited to these examples. In the following, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

[0231] Synthesis Example 1: Synthesis of Epoxy Resin A 100 g of 2,2-bis(4-hydroxy-3-methylphenyl)propane was dissolved in 1,050 g of epichlorohydrin, 0.25 g of benzyltriethylammonium chloride was added, and 90 g of 48% aqueous sodium hydroxide solution was added dropwise over 5 hours at 70°C under reduced pressure. The water produced was removed from the system by azeotropy with epichlorohydrin, and the distilled epichlorohydrin was returned to the system. After the dropwise addition, the reaction was continued for 2 hours, and then the produced salt was removed by filtration. After further washing with water, the epichlorohydrin was distilled off. The resulting epoxy resin was dissolved in 400 g of methyl isobutyl ketone, and 10 g of 10% aqueous sodium hydroxide solution was added at 85°C and reacted for 2 hours. After the reaction, the mixture was filtered, washed with water, and the methyl isobutyl ketone was distilled off, yielding 129 g of pale yellow liquid epoxy resin. The epoxy equivalent was 191 g / eq. Epoxy resin A was a mixture of compounds having a structure represented by the following formula (A) (wherein n is an integer of 0 to 5).

[0232] Synthesis Example 2: Synthesis of Epoxy Resin B 90 g of 4,4'-methylenebis(2-methylphenol) was dissolved in 1,050 g of epichlorohydrin, 0.25 g of benzyltriethylammonium chloride was added, and 90 g of 48% aqueous sodium hydroxide solution was added dropwise over 5 hours at 70°C under reduced pressure. The water produced was removed from the system by azeotropy with epichlorohydrin, and the distilled epichlorohydrin was returned to the system. After the dropwise addition, the reaction was continued for 2 hours, and then the produced salt was removed by filtration. After further washing with water, the epichlorohydrin was distilled off. The resulting epoxy resin was dissolved in 400 g of methyl isobutyl ketone, and 10 g of 10% aqueous sodium hydroxide solution was added at 85°C and reacted for 2 hours. After the reaction, the mixture was filtered, washed with water, and the methyl isobutyl ketone was distilled off, yielding 145 g of pale yellow liquid epoxy resin. The epoxy equivalent was 184 g / eq. Epoxy resin B was a mixture of compounds having a structure represented by the following formula (B) (wherein n is an integer of 0 to 5).

[0233] Synthesis Example 3: Synthesis of Epoxy Resin C: 116 g of 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane was dissolved in 1,050 g of epichlorohydrin, 0.25 g of benzyltriethylammonium chloride was added, and 90 g of 48% aqueous sodium hydroxide solution was added dropwise over 5 hours at 70°C under reduced pressure. The water produced was removed from the system by azeotropy with epichlorohydrin, and the distilled epichlorohydrin was returned to the system. After the dropwise addition, the reaction was continued for 2 hours, and then the produced salt was removed by filtration. After further washing with water, the epichlorohydrin was distilled off. The resulting epoxy resin was dissolved in 400 g of methyl isobutyl ketone, and 10 g of 10% aqueous sodium hydroxide solution was added at 85°C and reacted for 2 hours. After the reaction, the mixture was filtered, washed with water, and the methyl isobutyl ketone was distilled off, yielding 155 g of pale yellow solid epoxy resin. The epoxy equivalent was 220 g / eq. Epoxy resin C was a mixture of compounds having a structure represented by the following formula (C) (wherein n is an integer of 0 to 5).

[0234] Synthesis Example 4: Synthesis of Polymer A 69 g of bifunctional hydroxyl group-terminated polybutadiene ("G-3000" manufactured by Nippon Soda Co., Ltd., number average molecular weight = 3000, hydroxyl group equivalent = 1800 g / eq.), 40 g of PGMEA (propylene glycol monomethyl ether acetate manufactured by Showa Denko K.K.), and 0.005 g of dibutyltin laurate were placed in a reaction vessel and mixed to dissolve uniformly. Once uniform, the temperature was raised to 60°C, and 8 g of isophorone diisocyanate ("IPDI" manufactured by Evonik Degussa Japan Co., Ltd., isocyanate group equivalent = 113 g / eq.) was added with further stirring, and the reaction was carried out for approximately 3 hours.

[0235] Next, 23 g of cresol novolak resin ("KA-1160" manufactured by DIC Corporation, hydroxyl group equivalent weight = 117 g / eq.) and 60 g of PGMEA were added to the reaction mixture, and the mixture was refluxed at 150°C with stirring, and the reaction was carried out for about 10 hours. －１The disappearance of the NCO peak was confirmed. The disappearance of the NCO peak was considered to be the end point of the reaction, and the reaction mixture was cooled to room temperature. The reaction mixture was then filtered through a 100-mesh filter cloth to obtain a polymer having a butadiene structure and a phenolic hydroxyl group (phenolic hydroxyl group-containing butadiene resin: non-volatile components 50% by mass). The weight-average molecular weight of Polymer A was 27,000, the hydroxyl group equivalent was 467 g / eq., and the glass transition temperature was -7°C.

[0236] Synthesis Example 5: Synthesis of Polymer B A flask equipped with a stirrer, a thermometer, and a condenser was charged with 368.41 g of ethyl diglycol acetate and 368.41 g of ExxonMobil Corp.'s "Solvesso 150 (registered trademark)" (aromatic solvent). Furthermore, 100.1 g (0.4 mol) of diphenylmethane diisocyanate and 400 g (0.2 mol) of polycarbonate diol ("C-2015N" manufactured by Kuraray Co., Ltd., number average molecular weight: approximately 2000, hydroxyl equivalent: 1000 g / eq., non-volatile components: 100% by mass) were charged to the flask, and the reaction was carried out at 70°C for 4 hours. This yielded a first reaction solution.

[0237] Next, 195.9 g (0.2 mol) of nonylphenol novolak resin (hydroxyl group equivalent: 229.4 g / eq, average 4.27 functional groups, average calculated molecular weight: 979.5 g / mol) and 41.0 g (0.1 mol) of ethylene glycol bisanhydrotrimellitate were further charged into the flask, and the temperature was raised to 150°C over 2 hours and the reaction was carried out for 12 hours. This resulted in a second reaction solution. －１ The disappearance of the NCO peak was confirmed. The disappearance of the NCO peak was considered to be the end point of the reaction, and the temperature of the second reaction solution was lowered to room temperature. The second reaction solution was then filtered through a 100-mesh filter cloth. As a result, a dispersion solution (non-volatile component 50% by mass) containing polymer B (phenolic hydroxyl group-containing polycarbonate resin) as a non-volatile component was obtained as the filtrate. The weight-average molecular weight of polymer B was 20,000, the hydroxyl group equivalent was 339 g / eq., and the glass transition temperature was 5°C.

[0238] Synthesis Example 6: Synthesis of Polymer C Into a 1 L separable flask equipped with an oil bath and a stirring rod, 200 g of cyclohexanone was added while introducing nitrogen gas. 149.4 g of dimer diamine ("PRIAMINE 1075" manufactured by Croda Japan) as a diamine and 4.7 g of m-aminophenol as a monoamine compound were added with stirring. Subsequently, 67.3 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride as a tetracarboxylic acid was added and stirred at room temperature for 30 minutes. The mixture was heated to 100°C and stirred for 3 hours. After stirring, the oil bath was removed and the temperature was returned to room temperature to obtain a varnish-like polyimide precursor. Thereafter, while removing the distilled water from the system using a Dean-Stark trap, the mixture was heated at 170°C for 10 hours, and imidized to obtain Polymer C (50% by mass of non-volatile components) having a carbon skeleton derived from dimer acid. The weight average molecular weight of the obtained Polymer C was 10,000, and the hydroxyl group equivalent was 3,900 g / eq. , and the glass transition temperature was -1°C.

[0239] Synthesis Example 7 Synthesis of Maleimide A An MEK solution (62% by mass of non-volatile components) of maleimide A synthesized by the method described in Synthesis Example 1 of Japan Institute of Invention and Innovation Disclosure Technical Bulletin No. 2020-500211 was prepared. This maleimide A had an Mw / Mn of 1.81, t″ in formula (1) of 1.47 (mainly 1, 2, or 3), and a weight-average molecular weight of 2,000.

[0240] Examples 1 to 15, Comparative Examples 1 to 5 Each component was weighed out in the number of parts by mass shown in the table, and then 15 parts of MEK and 15 parts of cyclohexanone were added and mixed together. The mixture was uniformly dispersed using a high-speed rotary mixer to obtain a resin composition (resin varnish). *1: Indicates the content when the non-volatile components in the resin composition are taken as 100% by mass. *1: Indicates the content when the non-volatile components in the resin composition are taken as 100% by mass.

[0241] Details of each component listed in the table are as follows: Component (A-1) Synthesis Example 1: Epoxy resin A synthesized in Synthesis Example 1 Synthesis Example 2: Epoxy resin B synthesized in Synthesis Example 2 Synthesis Example 3: Epoxy resin C synthesized in Synthesis Example 3 Component (A-2) ESN-4100V: methoxy group-containing naphthol aralkyl resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent: 363 g / eq., MEK solution with 75% solids) ZX-1059: bisphenol-type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., 1:1 mixture of bisphenol A type and bisphenol F type, epoxy equivalent: 165 g / eq.) NC3000: biphenyl-type epoxy resin (manufactured by Nippon Chemical Industry Co., Ltd., epoxy equivalent: approximately 271 g / eq.) HP4032SS: naphthalene-type epoxy resin (manufactured by DIC Corporation, epoxy equivalent: approximately 144 g / eq.) YX4000H: bixylenol-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: approximately 194 g / eq.) Component (B) Polymer A: Polymer A synthesized in Synthesis Example 4 Polymer B: Polymer B synthesized in Synthesis Example 5 Polymer C: Polymer C synthesized in Synthesis Example 6 S1606: hydrogenated styrene-based thermoplastic elastomer (manufactured by Asahi Kasei Corporation, glass transition temperature: -13°C (measured by DSC at a heating rate of 5°C / min), weight average molecular weight: approximately 225,000 (value calculated as polystyrene by GPC), having a non-hydrogenated double bond as a functional group, and a functional group equivalent of 1,000 g / eq. to 100,000g / eq.) Component (C) SO-C2: spherical silica (average particle size 0.5µm, manufactured by Admatechs Co., Ltd.) surface-treated with an aminosilane coupling agent (KBM573 manufactured by Shin-Etsu Chemical Co., Ltd.) Component (D) HPC-8000-65T: activated ester compound (manufactured by DIC Corporation, active group equivalent of approximately 223g / eq., toluene solution with 65% by mass of non-volatile components) LA-3018-50P: triazine skeleton-containing phenolic curing agent (manufactured by DIC Corporation, hydroxyl group equivalent of approximately 151g / eq., 1-methoxy-2-propanol solution with 50% solids) V-03: carbodiimide resin (manufactured by Nisshinbo Chemical Inc., carbodiimide group equivalent of approximately 216g / eq., toluene solution with 50% solids) BA230S75: bisphenol A dicyanate prepolymer (manufactured by Arxada, cyanate equivalent of approximately 235 g / eq., MEK solution with a solid content of 75%) PT30: phenol novolac-type multifunctional cyanate ester resin (manufactured by Arxada, cyanate equivalent of approximately 124 g / eq., MEK solution with a solid content of 80%) Component (E) OPE-2St 1200: vinylbenzyl-modified polyphenylene ether (manufactured by Mitsubishi Gas Chemical Co., Ltd., toluene solution with a non-volatile content of 65%) SLK-6895-T90: bismaleimide resin (manufactured by Shin-Etsu Chemical Co., Ltd., maleimide equivalent of approximately 345 g / eq., toluene solution with a solid content of 90%) Maleimide A: maleimide A synthesized in Synthesis Example 7 Component (F) EXL2655: organic filler (manufactured by DOW Corporation) (G) component 2P4MZ: 2-phenyl-4-methylimidazole (manufactured by Shikoku Chemical Industry Co., Ltd.) Co(acac)3: cobalt(III) acetylacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.),

[0242] <Preparation of Resin Sheet> A polyethylene terephthalate film ("Lumirror R80" manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130° C.) that had been subjected to a release treatment with an alkyd resin-based release agent ("AL-5" manufactured by Lintec Corporation) was prepared as a support.

[0243] Each resin composition was uniformly applied onto the support using a die coater so that the thickness of the resin composition layer after drying would be 50 μm, and the resulting coating was dried at 70°C to 100°C for 3 minutes to form a resin composition layer on the support.

[0244] Next, the rough surface of a polypropylene film ("Alphan MA-411" manufactured by Oji F-Tex Co., Ltd., thickness 15 μm) was attached as a protective film to the surface of the resin composition layer that was not bonded to the support, thereby obtaining a resin sheet having the support, the resin composition layer, and the protective film in this order.

[0245] Test Example 1: Measurement of dielectric loss tangent The protective film was peeled off from the resin sheet, and the resin composition layer was thermally cured by heating at 200°C for 90 minutes, and then the support was peeled off. The obtained cured product was cut into a piece 2 mm wide and 80 mm long to prepare a test piece for evaluation.

[0246] The dielectric loss tangent of each test piece was measured by the cavity resonance perturbation method using an Agilent Technologies HP8362B at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. Measurements were performed on three test pieces, and the average value was calculated. ◯: Dielectric loss tangent less than 0.0040 △: Dielectric loss tangent 0.0040 or more but less than 0.0045 ×: Dielectric loss tangent 0.0045 or more

[0247] <Test Example 2: Warpage Measurement> A resin sheet was laminated onto one entire side of a 12-inch silicon wafer (thickness 775 μm) using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator "CVP700"). This lamination was performed so that the resin composition layer and the silicon wafer were bonded. The polyethylene terephthalate film of the resin sheet was peeled off to expose the resin composition layer. A resin sheet was similarly laminated on the surface of this exposed resin composition layer, and the polyethylene terephthalate film was peeled off to form two resin composition layers (total thickness 100 μm) on one side of the 12-inch silicon wafer. The lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, and then pressing at 100 ° C. and a pressure of 0.74 MPa for 30 seconds.

[0248] The sample was heated in an oven at 100°C for 30 minutes, and then further heated at 200°C for 90 minutes to cure the resin composition layer, thereby obtaining a sample laminate having a layer structure of "silicon wafer / cured product layer." The obtained sample laminate was placed on the top surface of a horizontal table. The edge of the sample laminate was pressed against the top surface of the table. The distance between the edge of the silicon wafer opposite the pressed edge and the top surface of the table was measured as the amount of warpage, and the amount of warpage was evaluated according to the following criteria. The smaller the amount of warpage, the more effectively the warpage was suppressed. ○: Amount of warpage is 0 μm or more and 2000 μm or less △: Amount of warpage is more than 2000 μm and less than 2500 μm ×: Amount of warpage is 2500 μm or more

[0249] Test Example 3: Evaluation of reflow resistance (1) Copper foil substrate treatment The shiny side of "3EC-III" (electrolytic copper foil, 35 μm) manufactured by Mitsui Mining & Smelting Co., Ltd. was etched to a depth of 1 μm with a microetching agent ("CZ8101" manufactured by MEC Co., Ltd.) to roughen the copper surface, and then an anti-rust treatment (CL8300) was applied. Furthermore, the foil was heated in an oven at 130° C. for 30 minutes. This copper foil is referred to as CZ copper foil.

[0250] (2) Preparation of Inner Layer Substrate Both sides of a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.4 mm, Panasonic "R1515A") on which an inner layer circuit had been formed were etched by 1 μm with a microetching agent (MEC "CZ8101") to roughen the copper surface.

[0251] (3) Lamination of copper foil and formation of insulating layer Using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator "CVP700"), the resin sheet was laminated on both sides of the inner layer substrate so that the resin composition layer was in contact with the inner layer substrate. Lamination was performed by reducing the pressure for 30 seconds to adjust the air pressure to 13 hPa or less, and then pressing at 120 ° C. and a pressure of 0.74 MPa for 30 seconds. Next, a heat press was performed at 100 ° C. and a pressure of 0.5 MPa for 60 seconds. The treated surface of the CZ copper foil was laminated on the resin composition layer under the same conditions as above. Then, an evaluation substrate was produced by curing the resin composition layer at 200 ° C. for 90 minutes to form an insulating layer.

[0252] (4) Measurement of reflow resistance The evaluation board was cut into small pieces of 100 mm x 50 mm, and passed through a reflow device ("HAS-6116" manufactured by Nippon Antom Co., Ltd.) that reproduces a solder reflow temperature of a peak temperature of 260°C 10 times (the reflow temperature profile conforms to IPC / JEDEC J-STD-020C). Evaluation was performed on five small pieces, and pieces that had abnormalities such as swelling in the conductor layer by visual observation in two or more small pieces were judged as "X", pieces that had abnormalities such as swelling in the conductor layer in one small piece were judged as "△", and pieces that had no abnormalities at all were judged as "O".

[0253]

Claims

1. A resin composition comprising: (A-1) an epoxy resin represented by formula (1); and (B) a polymer having a glass transition temperature Tg of 25°C or less, or being liquid at 25°C or less, and having a weight average molecular weight of more than 5,000 and not more than 1,000,000. (In formula (1), R １ each independently represents a monovalent aliphatic group; each L independently represents a divalent linking group; R Ｓ each independently represents a substituent, each m independently represents an integer of 0 to 3, and n independently represents an integer of 0 to 5.

2. The resin composition according to claim 1, further comprising (C) an inorganic filler.

3. A resin composition according to claim 2, wherein the content of component (C) is 40% by mass or more when the non-volatile components in the resin composition are 100% by mass.

4. The resin composition according to claim 1, wherein the content of component (A-1) is 0.5% by mass or more and 20% by mass or less, when the non-volatile components in the resin composition are 100% by mass.

5. R １ The resin composition according to claim 1 , wherein each independently represents an alkyl group.

6. R １ The resin composition according to claim 1, wherein each independently represents an alkyl group having 1 to 6 carbon atoms.

7. The resin composition according to claim 1, wherein each L independently represents a divalent aliphatic group.

8. The resin composition according to claim 1, wherein each L independently represents a divalent group consisting of an alkylene group, a cycloalkylene group, or a combination thereof.

9. The resin composition according to claim 1, wherein component (B) comprises one or more selected from the group consisting of a polybutadiene structure, a polycarbonate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyisoprene structure, a polyisobutylene structure, and a polystyrene structure.

10. The resin composition according to claim 9, wherein the resin containing a polyalkylene structure includes a resin containing a carbon skeleton derived from a dimer acid.

11. The resin composition according to claim 1, wherein component (B) has a functional group capable of reacting with an epoxy resin.

12. The epoxy group equivalent of component (A-1) in the resin composition is E Ａ１ The functional group equivalent capable of reacting with the epoxy resin of component (B) in the resin composition is E Ｂ When this is done, E Ａ１ / E Ｂ The resin composition according to claim 11, wherein is 0.01 or more and 50 or less.

13. The content of component (A-1) when the nonvolatile components in the resin composition are 100% by mass is M Ａ１ The content of component (B) when the nonvolatile components in the resin composition are taken as 100% by mass is M Ｂ When M Ａ１ / M Ｂ The resin composition according to claim 1, wherein the σ is 0.2 or more and 3.5 or less.

14. The resin composition according to claim 1, which is used for an insulating layer of a circuit board.

15. A resin sheet comprising a support and a layer of the resin composition according to any one of claims 1 to 14 provided on the support.

16. A cured product of the resin composition according to any one of claims 1 to 14.

17. A circuit board comprising an insulating layer made of a cured product of the resin composition according to any one of claims 1 to 14.

18. A semiconductor device comprising the circuit board according to claim 17.

Images