Resin composition

Abstract

To provide a resin composition which allows formation of an insulating layer with a low dielectric dissipation factor and exhibits low tack property.SOLUTION: The resin composition includes (A) a combination of specific bismaleimide compounds, (B) a thermosetting resin, and (C) an inorganic filler.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Circuit boards such as printed wiring boards are widely used in various electronic devices. A known method for manufacturing circuit boards 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 then the resin composition layer is cured to form an insulating layer containing a cured product of the resin composition (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-138996 Summary of the Invention [Problem to be solved by the invention]

[0004] Insulating layers are generally required to have a low dielectric loss tangent. Therefore, the present inventors attempted to form an insulating layer with a low dielectric loss tangent using a resin composition containing a maleimide resin. However, the resin composition used in such a formation method tends to have excessively high tackiness.

[0005] For example, when forming an insulating layer by a lamination method using a resin sheet having a resin composition layer, it may be necessary to embed wiring and components with the resin composition layer during lamination. In this case, in order to obtain good embeddability, the composition of the resin composition may be adjusted to lower the melt viscosity of the resin composition. However, the tackiness of the resin composition adjusted in this manner may be increased. If the tackiness is excessively high, the peelability of the protective film on the resin sheet may be insufficient, resulting in poor handling or causing voids in the insulating layer after lamination.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide a resin composition capable of forming an insulating layer having a low dielectric tangent and having low tackiness; a resin sheet including the resin composition; a cured product of the resin composition; a circuit board including the cured product of the resin composition; and a semiconductor device including the circuit board. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result, have found that a resin composition containing a specific combination of a bismaleimide compound, a thermosetting resin, and an inorganic filler can solve the above-mentioned problems, thereby completing the present invention. That is, the present invention includes the following.

[0008] <1> (A) A combination of a bismaleimide compound represented by the following formula (1-i) and a bismaleimide compound represented by the following formula (1-ii), in which the amount of the bismaleimide compound represented by the following formula (1-ii) is 8% by mass or more and 50% by mass or less, relative to 100% by mass of the combination; (B) a thermosetting resin; and (C) an inorganic filler; and a resin composition comprising the same. [ka] (In formula (1-i), X i each independently represents a tetravalent organic group, R i represent divalent aliphatic hydrocarbon groups having the same structure, m i represents an integer greater than or equal to 0; In formula (1-ii), X ii each independently represents a tetravalent organic group, R ii are all R i represents a divalent aliphatic hydrocarbon group having the same structure as m ii represents an integer greater than or equal to 0, n ii represents 1 or 2; The moiety represented by the following formula (1-ia) in formula (1-i) and the moiety represented by the following formula (1-ii-a) in formula (1-ii) are R i The bond direction and R ii They have the same structure except for the orientation of the bond.) [ka] <2> R i and R ii contains at least one selected from the group consisting of an alkyl group having 5 or more carbon atoms and an alkylene group having 5 or more carbon atoms, <1> The resin composition according to claim 1. <3> R i and R ii represents a divalent aliphatic hydrocarbon group containing a dimer acid skeleton, <1> or <2> The resin composition according to claim 1. <4> R i and R ii However, both are expressed by the following formula (2): <1> ~ <3> The resin composition according to any one of claims 1 to 10. [ka] (In formula (2), * represents a binding site.) <5> The bismaleimide compound represented by formula (1-i) is represented by the following formula (3-i): The bismaleimide compound represented by formula (1-ii) is represented by the following formula (3-ii): <1> ~ <4> The resin composition according to any one of claims 1 to 10. [ka] (In formula (3-i), R i represent divalent aliphatic hydrocarbon groups having the same structure, m i represents an integer greater than or equal to 0; In formula (3-ii), R ii are all R i represents a divalent aliphatic hydrocarbon group having the same structure as m ii is m i represents an integer equal to or greater than 0, n ii represents 1 or 2.) <6> m i and m ii But both are 0. <1> ~ <5> The resin composition according to any one of claims 1 to 10. <7> (B) the thermosetting resin includes an epoxy resin; <1> ~ <6> The resin composition according to any one of claims 1 to 10. <8> (C) The amount of the inorganic filler is 50% by mass or more relative to 100% by mass of the nonvolatile components of the resin composition; <1> ~ <7> The resin composition according to any one of claims 1 to 10. <9> (D) further comprising an elastomer; <1> ~ <8> The resin composition according to any one of claims 1 to 10. <10> (D) the elastomer has a weight average molecular weight greater than 5,000; <9> The resin composition according to claim 1. <11> (D) the elastomer 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; <9> or <10> The resin composition according to claim 1. <12> For forming an insulating layer, <1> ~ <11> The resin composition according to any one of claims 1 to 10. <13> A support and a resin composition layer provided on the support, The resin composition layer is <1> ~ <12> A resin sheet comprising the resin composition according to any one of claims 1 to 4. <14> <1> ~ <12> A cured product of the resin composition according to any one of claims 1 to 4. <15> <1> ~ <12> A circuit board comprising a cured product of the resin composition according to any one of claims 1 to 4. <16> <15> A semiconductor device comprising the circuit board according to claim 1. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a resin composition that can form an insulating layer having a low dielectric tangent and has low tackiness; 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. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be modified and implemented within the scope of the claims and their equivalents.

[0011] As used herein, the term "optionally substituted" 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.

[0012] <Outline of Resin Composition> A resin composition according to one embodiment of the present invention comprises: (A) a combination of a bismaleimide compound represented by the following formula (1-i) and a bismaleimide compound represented by the following formula (1-ii), wherein the amount of the bismaleimide compound represented by formula (1-ii) in the combination is in a specific range of 8% by mass or more and 50% by mass or less; (B) a thermosetting resin; and (C) an inorganic filler. In the following description, the "bismaleimide compound represented by formula (1-i)" contained in component (A) may be referred to as the "first bismaleimide compound." Furthermore, the "bismaleimide compound represented by formula (1-ii)" contained in component (A) may be referred to as the "second bismaleimide compound." Furthermore, the "combination of (A) the first bismaleimide compound represented by formula (1-i) and the second bismaleimide compound represented by formula (1-ii)" as component (A) may be referred to as the "(A) specific bismaleimide resin."

[0013] [ka]

[0014] (In formula (1-i), X i each independently represents a tetravalent organic group; R i represent divalent aliphatic hydrocarbon groups having the same structure; m i represents an integer of 0 or more. In formula (1-ii), X ii each independently represents a tetravalent organic group; R ii are all R i represents a divalent aliphatic hydrocarbon group having the same structure as ii represents an integer greater than or equal to 0; n ii represents 1 or 2. The moiety represented by the following formula (1-ia) in formula (1-i) and the moiety represented by the following formula (1-ii-a) in formula (1-ii) are R i The bond direction and R ii They have the same structure except for the orientation of the bond.)

[0015] [ka]

[0016] (In formula (1-ia) and formula (1-ii-a), the symbols have the same meanings as in formula (1-i) and formula (1-ii); * represents a binding site.)

[0017] The resin composition can have low tackiness and can form an insulating layer with a low dielectric loss tangent. Furthermore, the resin composition can usually have a low minimum melt viscosity. Furthermore, by using the resin composition, a circuit board with reduced warpage can be produced. The inventors of the present invention speculate that the mechanism by which such excellent effects are obtained is as follows: However, the technical scope of the present invention is not limited by the mechanism below.

[0018] The first bismaleimide compound and the second bismaleimide compound contained in the (A) specific bismaleimide resin contain a maleimide group (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl group). This maleimide group reacts to form a bond, allowing the resin composition to cure and form a cured product. Normally, the reaction of the maleimide group during curing of the resin composition does not produce polar groups such as hydroxyl groups. Therefore, the cured product can have low polarity, and when an insulating layer is formed using the cured product, the insulating layer can have low polarity. Therefore, the insulating layer can have a low dielectric loss tangent.

[0019] Furthermore, among combinations of a first bismaleimide compound and a second bismaleimide compound having the same or similar structure, the first bismaleimide compound has good compatibility with other resin components contained in the resin composition. When the resin components in a resin composition have good compatibility, the tackiness generally tends to be high, and this tendency is particularly pronounced when the resin composition contains a (D) elastomer. Specifically, (B) thermosetting resins generally tend to have low compatibility with (D) elastomers. Therefore, conventional resin compositions containing a (B) thermosetting resin and a (D) elastomer have good tackiness. However, when a first bismaleimide compound is further combined with a (B) thermosetting resin and a (D) elastomer to reduce the dielectric loss tangent, the high compatibility between the first bismaleimide compound and the (D) elastomer results in excessively high tackiness. In contrast, the second bismaleimide compound contained in the resin composition of this embodiment in combination with the first bismaleimide compound exhibits poor compatibility with resin components other than the first bismaleimide compound and the second bismaleimide compound. For example, the compatibility between the (D) elastomer and the second bismaleimide compound is lower than the compatibility between the (D) elastomer and the first bismaleimide compound. This is presumably due to the fact that the structure of the first bismaleimide compound is generally low in polarity, while the secondary amino group of the second bismaleimide compound has high polarity, resulting in a change in the polarity of the entire molecule. In other words, when a resin composition contains a combination of the first bismaleimide compound and the second bismaleimide compound, the second bismaleimide compound can suppress the increase in compatibility due to the first bismaleimide compound. On the other hand, excessively low compatibility can reduce the homogeneity of the resin composition, potentially resulting in phase separation and reduced film formability. Therefore, by combining and using the second bismaleimide compound and the first bismaleimide compound in an appropriate ratio, a resin composition with excellent tackiness and homogeneity can be obtained.

[0020] Furthermore, the first bismaleimide compound contains a divalent aliphatic hydrocarbon group R i and the second bismaleimide compound contains a divalent aliphatic hydrocarbon group R iiThese divalent aliphatic hydrocarbon groups R i and R ii can function as a flexible molecular structure, unlike a rigid structure such as an arylene group. Therefore, a resin composition containing a combination of the first bismaleimide compound and the second bismaleimide compound can have a reduced minimum melt viscosity.

[0021] Furthermore, the flexible molecular structures of the first bismaleimide compound and the second bismaleimide compound are also contained in the cured product of the resin composition, and can play a role in absorbing stress. Therefore, when a cured product containing such an element capable of absorbing stress is provided on a circuit board, deformation due to stress can be suppressed, and therefore warpage can be suppressed.

[0022] <(A) Specific Bismaleimide Resin (Combination of First Bismaleimide Compound and Second Bismaleimide Compound)> The resin composition according to the present embodiment contains (A) a specific bismaleimide resin as a combination of a first bismaleimide compound represented by formula (1-i) and a second bismaleimide compound represented by formula (1-ii).

[0023] [ka]

[0024] In formula (1-i), X i each independently represents a tetravalent organic group. The tetravalent organic group preferably comprises five or more skeletal atoms and non-skeletal atoms. The five or more skeletal atoms are preferably selected from carbon atoms, nitrogen atoms (not forming imides), oxygen atoms, and sulfur atoms. The number of skeletal atoms is usually five or more, preferably 5 to 200, more preferably 5 to 100, and even more preferably 5 to 50. The non-skeletal atoms are usually selected from hydrogen atoms and halogen atoms. X i The tetravalent organic group represented by the formula (1-i) may be a tetravalent organic group having no aromatic ring, or may be a tetravalent organic group having an aromatic ring. iIf multiple Xs are included, multiple Xs are included. i may be the same or different.

[0025] X i The tetravalent organic group represented by the formula: is preferably represented by the following formula (X1).

[0026] [ka]

[0027] (In formula (X1), R x1 each independently represents a substituent; ring Z x each independently represents a non-aromatic ring which may have a substituent, or an aromatic ring which may have a substituent; Z x1 and Z x2 each independently represents a single bond, an alkylene group, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, -NHCO-, -COO-, or -OCO-; x each independently represents an integer of 0 or 1 or more; b x each independently represents 0, 1, or 2; c x represents 0 or 1; * indicates a binding site. x The units may be the same for each unit or may be different.)

[0028] In formula (X1), R x1each independently represents a substituent. Examples of the substituent include an alkyl group, an alkenyl group, an aryl group, an aryl-alkyl group, an alkyl-oxy group, an alkenyl-oxy group, an aryl-oxy group, an alkyl-carbonyl group, an alkenyl-carbonyl group, an aryl-carbonyl group, an alkyl-oxy-carbonyl group, an alkenyl-oxy-carbonyl group, an aryl-oxy-carbonyl group, an alkyl-carbonyl-oxy group, an alkenyl-carbonyl-oxy group, and an aryl-carbonyl-oxy group, among which an alkyl group is preferred. As the alkyl group, an alkyl group having 1 to 14 carbon atoms is preferred. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a trimethylcyclohexyl group, a cyclopentylmethyl group, and a cyclohexylmethyl group.

[0029] In formula (X1), ring Z x each independently represents a non-aromatic ring which may have a substituent, or an aromatic ring which may have a substituent, and among these, an aromatic ring which may have a substituent is preferred.

[0030] The aromatic ring refers to a ring conforming to Hückel's rule, in which the number of electrons contained in the π-electron system on the ring is 4p+2 (p is a natural number). The aromatic ring may be an aromatic carbocycle having carbon atoms as ring-constituting atoms, or an aromatic heterocycle having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms as ring-constituting atoms in addition to carbon atoms. Among these, aromatic carbocycles are preferred. The aromatic ring is preferably a 5- to 14-membered aromatic ring, more preferably a 5- to 10-membered aromatic ring, and even more preferably a 5- or 6-membered aromatic ring. Specific examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring, more preferably a benzene ring or a naphthalene ring, and even more preferably a benzene ring.

[0031] A non-aromatic ring refers to a ring other than an aromatic ring. The non-aromatic ring may be a non-aromatic carbocyclic ring having carbon atoms as ring-constituting atoms, or a non-aromatic heterocyclic ring having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms in addition to carbon atoms as ring-constituting atoms. Among these, a non-aromatic carbocyclic ring is preferred. The non-aromatic ring may be a saturated ring or an unsaturated non-aromatic ring, but a saturated ring is preferred. The non-aromatic ring is preferably a 4- to 14-membered non-aromatic ring. Specific examples of the non-aromatic ring include monocycloalkane rings such as a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, and a cyclooctane ring; monocycloalkene rings such as a cyclobutene ring, a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, a cyclooctene ring, a cyclopentadiene ring, and a cyclohexadiene ring; and aromatic-non-aromatic ring fused rings such as an indane ring, an indene ring, a tetralin ring, and a fluorene ring.

[0032] In formula (X1), Z x1 and Z x2 are each independently a single bond, an alkylene group, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, -NHCO-, -COO-, or -OCO-. The alkylene group is preferably an alkylene group having 1 to 14 carbon atoms. Specific examples of alkylene groups include straight-chain alkylene groups such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, and decamethylene; and branched-chain alkylene groups such as ethylidene (-CH(CH3)-), propylidene (-CH(CH2CH3)-), isopropylidene (-C(CH3)2-), ethylmethylmethylene (-C(CH3)(CH2CH3)-), and diethylmethylene (-C(CH2CH3)2-).

[0033] In formula (X1), a x are each independently an integer of 0 or 1 or more, preferably an integer of 0 to 5, more preferably 0, 1 or 2, even more preferably 0 or 1, and particularly preferably 0.

[0034] In formula (X1), b x are each independently 0, 1 or 2, preferably 0.

[0035] In formula (X1), c x represents 0 or 1, preferably 1.

[0036] Examples of the tetravalent organic group represented by formula (X1) include groups represented by the following formulae (x-1) to (x-25). Among these, the group represented by formula (x-8) is preferred. In the following formulae, * represents a bonding site.

[0037] [ka]

[0038] In formula (1-i), R i Each of R in formula (1-i) represents a divalent aliphatic hydrocarbon group having the same structure. i have the same structure, and R i The bond directions of R may be the same or different. i The "bond direction" of R i represents the direction of the two bonds in formula (1-i). For example, m i R included in the unit i This will be explained using the following example. R represents a divalent aliphatic hydrocarbon group. i has two bonds. Here, one of these two bonds is called the "first bond" and the other is called the "second bond." m i R included in the unit i The bonding direction of R is considered to be such that the first bond is bonded to the maleimide group on the left side of the formula and the second bond is bonded to the imide ring on the right side of the formula, or the first bond is bonded to the imide ring on the right side of the formula and the second bond is bonded to the maleimide group on the left side of the formula. i The bond direction may be any of these directions.

[0039] R iThe divalent aliphatic hydrocarbon group represented by R is a divalent hydrocarbon group that does not contain an aromatic ring and may be linear, branched, cyclic, or a combination thereof. The divalent aliphatic hydrocarbon group may be a divalent saturated aliphatic hydrocarbon group or a divalent unsaturated aliphatic hydrocarbon group. i The divalent aliphatic hydrocarbon group represented by is preferably 5 or more, more preferably 6 or more, even more preferably 8 or more, and is preferably 50 or less, more preferably 45 or less, even more preferably 40 or less.

[0040] R i Preferably, R contains at least one group selected from the group consisting of an alkyl group having 5 or more carbon atoms and an alkylene group having 5 or more carbon atoms. i When a first bismaleimide compound having the formula (I) is used, it is possible to effectively reduce tackiness, dielectric loss tangent, minimum melt viscosity, and warpage.

[0041] The number of carbon atoms in an alkyl group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, and preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. The alkyl group may be linear, branched, cyclic, or a combination thereof, with linear being preferred. Examples of this alkyl group include pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups.

[0042] The number of carbon atoms in the alkylene group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, and preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. The alkylene group may be linear, branched, cyclic, or a combination thereof, with linear being preferred. Examples of this alkylene group include a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, a dodecylene group, a tridecylene group, a heptadecylene group, a hexatriacontylene group, an octylene-cyclohexylene group, an octylene-cyclohexylene-octylene group, and a propylene-cyclohexylene-octylene group.

[0043] From the viewpoint of particularly effectively reducing the dielectric loss tangent and the minimum melt viscosity, R i Preferably, the alkyl group contains both an alkyl group having 5 or more carbon atoms and an alkylene group having 5 or more carbon atoms.

[0044] R i represents a divalent aliphatic hydrocarbon group containing a dimer acid skeleton. The dimer acid skeleton represents the skeleton of a divalent group formed by 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 has been largely standardized in the industry. Dimer acids are particularly readily available, with the main component being a 36-carbon dimer acid obtained by dimerizing unsaturated fatty acids having 18 carbon atoms, such as oleic acid and linoleic acid, which are inexpensive and readily available. Dimer acids may contain arbitrary amounts of monomer acids, trimer acids, other polymerized fatty acids, etc., depending on the production method and the degree of purification. Furthermore, although double bonds usually 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 included in the term dimer acid. A divalent aliphatic hydrocarbon group containing a dimer acid skeleton generally has a long aliphatic carbon chain having 7 or more carbon atoms, and therefore may contain one or more groups selected from the group consisting of the above-mentioned alkyl groups having 5 or more carbon atoms and alkylene groups having 5 or more carbon atoms.

[0045] Examples of the divalent aliphatic hydrocarbon group containing a dimer acid skeleton include groups represented by the following formula (R1) that contain a long aliphatic carbon chain having 7 or more carbon atoms.

[0046] [ka]

[0047] (In formula (R1), R reach independently represents a linear or branched alkylene group or a linear or branched alkenylene group; ring Z r represents a cycloalkane ring which may have a group selected from a linear or branched alkyl group and a linear or branched alkenyl group, or a cycloalkene ring which may have a group selected from a linear or branched alkyl group and a linear or branched alkenyl group; k r indicates 0 or 1; * indicates a binding site.)

[0048] In formula (R1), R r are each independently a linear or branched alkylene group or a linear or branched alkenylene group. The alkylene group has usually 7 to 200 carbon atoms, preferably 7 to 100 carbon atoms, and more preferably 7 to 50 carbon atoms. The alkenylene group has usually 7 to 200 carbon atoms, preferably 7 to 100 carbon atoms, and more preferably 7 to 50 carbon atoms.

[0049] In formula (R1), ring Z r represents a cycloalkane ring optionally having a group selected from a linear or branched alkyl group and a linear or branched alkenyl group, or a cycloalkene ring optionally having a group selected from a linear or branched alkyl group and a linear or branched alkenyl group. Among these, a cycloalkane ring optionally having a group selected from a linear or branched alkyl group and a linear or branched alkenyl group is preferred, and a cyclohexane ring optionally having a linear or branched alkyl group is more preferred.

[0050] In formula (R1), k r indicates 0 or 1.

[0051] The divalent aliphatic hydrocarbon group containing a dimer acid skeleton is preferably a group represented by the following formula (R2) or (R3).

[0052] [ka]

[0053] (In formula (R2), m1, n1, p1, and q1 each represent an integer of 1 or greater, with the proviso that m1+n1 is 6 or greater and 17 or less, and p1+q1 is 8 or greater and 19 or less. In formula (R3), m2, n2, p2, and q2 each represent an integer of 1 or greater, with the proviso that m2+n2 is 6 or greater and 17 or less, and p2+q2 is 8 or greater and 19 or less. In formulas (R2) and (R3), each dashed line independently represents a carbon-carbon single bond or a carbon-carbon double bond, and * represents a bonding site.)

[0054] Among the groups represented by formula (R2), groups represented by the following formula (R4) are more preferred.

[0055] [ka]

[0056] (In formula (R4), the symbols have the same meanings as described above.)

[0057] Among these, more preferred examples of the divalent aliphatic hydrocarbon group containing a dimer acid skeleton include groups represented by any of the following formulae (R2-1) to (R2-2) and (R3-1) to (R3-2).

[0058] [ka]

[0059] (In formulas (R2-1) to (R2-2) and formulas (R3-1) to (R3-2), the symbols have the same meanings as described above.)

[0060] Among these preferred examples, more preferred examples of the divalent aliphatic hydrocarbon group containing a dimer acid skeleton include groups represented by any of the following formulae (R2-3), (R2-4), (R3-3), and (R3-4).

[0061] [ka]

[0062] (In formulas (R2-3), (R2-4), (R3-3) and (R3-4), * indicates a binding site.)

[0063] Among these, as the divalent aliphatic hydrocarbon group containing a dimer acid skeleton, the group of formula (R2-3) and the group of formula (R3-3) are preferred, the group of formula (R2-3) is more preferred, and the group represented by the following formula (2) is even more preferred.

[0064] [ka]

[0065] (In formula (2), * represents a binding site.)

[0066] In formula (1-i), m i represents an integer greater than or equal to 0. Therefore, m i may be 0 or an integer equal to or greater than 1. i is preferably an integer of 0 to 100, more preferably an integer of 0 to 50, even more preferably an integer of 0 to 20, even more preferably an integer of 0 to 10, still more preferably 0 or 1, and particularly preferably 0.

[0067] In formula (1-ii), X ii Each of X in formula (1-ii) independently represents a tetravalent organic group. ii The range of X in formula (1-i) i The range of X in formula (1-ii) can be the same as ii If multiple Xs are included, multiple Xs are included. ii may be the same or different.

[0068] In formula (1-ii), R ii are all R i R in formula (1-i) represents a divalent aliphatic hydrocarbon group having the same structure asi Similarly, R in formula (1-ii) ii have the same structure, and R ii The bond directions of R may be the same or different. ii The "bond direction" of R ii represents the direction of the two bonds in formula (1-ii). For example, m ii R included in the unit ii represents a divalent aliphatic hydrocarbon group, and therefore has two bonds. Here, one of these two bonds is referred to as the "third bond" and the other as the "fourth bond." m ii R included in the unit ii The direction of the bond is such that the third bond is n on the left side of the formula. ii The fourth bond is attached to the imide ring in the unit, and the m ii The direction of bonding to the imide ring in the unit and the third bond to the right side of the formula ii The fourth bond is attached to the imide ring in the unit, and the n ii It is thought that the direction of bonding to the imide ring in the unit is ii The bond direction may be any of these directions.

[0069] In formula (1-ii), m ii represents an integer of 0 or more. m in formula (1-ii) ii The range of m in formula (1-i) i In particular, the range of m i If is 0, then m ii It is particularly preferred that is 0.

[0070] In formula (1-ii), n ii represents 1 or 2.

[0071] Furthermore, the moiety represented by the following formula (1-ia) in formula (1-i) and the moiety represented by the following formula (1-ii-a) in formula (1-ii) are R i The bond direction and R ii The R in formula (1-ia) has the same structure as the R in formula (1-ia) except for the bond direction. i and R in formula (1-ii-a)ii has the same structure as the R in formula (1-ia), but the bond orientation is not restricted. i The bond direction and R in formula (1-ii-a) ii The bond directions of m may be the same or different. i When R is 2 or more, the plurality of R included in formula (1-ia) i The bond directions of m may be the same or different. ii When R is 2 or more, the plurality of R included in formula (1-ii-a) ii The bond directions of R may be the same or different. i When one of the two bonds of R is referred to as the "first bond" and the other as the "second bond," i The bond direction of each R i The first bond of R may be oriented in a direction that bonds to the imide ring on the right side of the formula, i The second bond of R may be oriented so as to bond to the imide ring on the right side of the formula. ii When one of the two bonds in is called the "third bond" and the other is called the "fourth bond," R ii The bond direction of each R ii The third bond of R may be oriented in a direction that bonds to the imide ring on the right side of the formula, ii The fourth bond of the formula may be oriented so as to bond to the imide ring on the right side of the formula.

[0072] [ka]

[0073] (In formula (1-ia) and formula (1-ii-a), the meanings of the symbols are the same as in formula (1-i) and formula (1-ii); * represents a binding site.)

[0074] Among the above, it is preferable that the first bismaleimide compound is represented by the following formula (3-i) and the second bismaleimide compound is represented by the following formula (3-ii). Therefore, it is preferable that the (A) specific bismaleimide resin contains a combination of the first bismaleimide compound represented by formula (3-i) and the second bismaleimide compound represented by formula (3-ii). The (A) specific bismaleimide resin may contain only the combination of the first bismaleimide compound represented by formula (3-i) and the second bismaleimide compound represented by formula (3-ii).

[0075] [ka]

[0076] In formula (3-i) and formula (3-ii), the meanings of the symbols are the same as in formula (1-i) and formula (1-ii). In this case, the moiety represented by formula (1-ia) and the moiety represented by formula (1-ii-a) are R i The bond direction and R ii Since they have the same structure except for the bond direction, m i and m in equation (3-ii) ii In formula (3-i) and formula (3-ii), R i and R ii represent divalent aliphatic hydrocarbon groups having the same structure, and are preferably divalent aliphatic hydrocarbon groups containing a dimer acid skeleton, more preferably groups represented by formula (2).

[0077] The (A) specific bismaleimide resin is a composition containing a first bismaleimide compound as a main component and further containing a second bismaleimide compound. The amount of the second bismaleimide compound is within a specific range, based on the total amount of the first bismaleimide compound and the second bismaleimide compound combined to form the (A) specific bismaleimide resin. The amounts of the first bismaleimide compound and the second bismaleimide compound refer to the amounts within the total amount of the first bismaleimide compound and the second bismaleimide compound combined. Therefore, when a resin composition contains a bismaleimide compound represented by formula (1-i) but does not contain a bismaleimide compound represented by formula (1-ii) to be combined with the bismaleimide compound, the amount of the bismaleimide compound is not included in the amount of the first bismaleimide compound. Furthermore, when an optional bismaleimide compound represented by formula (1-ii) is contained in the resin composition and a bismaleimide compound represented by formula (1-i) to be combined with the optional bismaleimide compound is not contained in the resin composition, the amount of the optional bismaleimide compound is not included in the amount of the second bismaleimide compound.

[0078] Specifically, the amount of the second bismaleimide compound represented by Formula (1-ii) relative to 100% by mass of component (A) (i.e., the combination of the first bismaleimide compound represented by Formula (1-i) and the second bismaleimide compound represented by Formula (1-ii)) is usually 8% by mass or more, preferably 10% by mass or more, more preferably 12% by mass or more, and usually 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. When two or more combinations of first bismaleimide compounds and second bismaleimide compounds are contained in the resin composition, unless otherwise specified, the amount of the first bismaleimide compound represents the total amount of all first bismaleimide compounds contained in those combinations; the amount of the second bismaleimide compound represents the total amount of all second bismaleimide compounds contained in those combinations; and the amount of component (A) represents the total amount of all first bismaleimide compounds and second bismaleimide compounds contained in those combinations. When the amount of the second bismaleimide compound is within the above range, tackiness and dielectric loss tangent can be reduced, and further, usually, minimum melt viscosity and warpage can be reduced. Conversely, when the amount of the second bismaleimide compound exceeds 50 mass%, the minimum melt viscosity of the resin composition becomes high.

[0079] The amount of the first bismaleimide compound relative to 100% by mass of component (A) is usually 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and usually 92% by mass or less, preferably 90% by mass or less, and even more preferably 88% by mass or less. The first bismaleimide compound can particularly effectively contribute to reducing the dielectric loss tangent and minimum melt viscosity. When the amount of the first bismaleimide compound is within the above range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0080] n ii The second bismaleimide compound in which n is 1 (i.e., ii The amount of n (=1 unit) is usually less than the amount of the first bismaleimide compound. iiThe amount of the second bismaleimide compound in which n is 1 is preferably 3% by mass or more, more preferably 4% by mass or more, even more preferably 5% by mass or more, and is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, and particularly preferably 8% by mass or less. ii When the amount of the second bismaleimide compound in which R is 1 is within the above range, it is possible to effectively reduce tackiness, dielectric loss tangent, minimum melt viscosity, and warpage.

[0081] n ii The second bismaleimide compound in which n is 2 (i.e., ii = 2 bodies), the amount is usually n ii The second bismaleimide compound in which n is 1 (i.e., ii (=1 unit) is less than the amount of n ii The amount of the second bismaleimide compound in which n is 2 is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, and is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 9% by mass or less, even more preferably 8% by mass or less, even more preferably 6% by mass or less, and particularly preferably 5% by mass or less. ii When the amount of the second bismaleimide compound in which M is 2 is within the above range, it is possible to effectively reduce tackiness, dielectric loss tangent, minimum melt viscosity, and warpage.

[0082] First bismaleimide compound, n ii a second bismaleimide compound in which n is 1; and ii The amount of the second bismaleimide compound in which R is 2 relative to 100% by mass of the component (A) can be measured by gel permeation chromatography (GPC). GPC measurement can be performed using the following measuring device and under the following measuring conditions.

[0083] Measuring device: Shoko Science Co., Ltd. "GPC-101" Column: Guard column "GPC KF-G 4A" manufactured by Shoko Science Co., Ltd., Reference column "KF-800RH" manufactured by Shoko Science Co., Ltd. Detector: RI (differential refractometer) Measurement conditions: Column temperature 40°C Developing solvent: Tetrahydrofuran Flow rate 1.0ml / min Standard: Use monodisperse polystyrene with known molecular weight. Sample: (A) A specific bismaleimide resin was dissolved in a tetrahydrofuran solution to a concentration of 0.1% by mass, and the solution was filtered through a microfilter (50 μL).

[0084] First bismaleimide compound, n ii a second bismaleimide compound in which n is 1; and ii The amount of the second bismaleimide compound in which n is 2 relative to 100% by mass of the component (A) can be calculated from the peak area in the GPC chart obtained by the GPC measurement described above. ii a second bismaleimide compound in which n is 1; and ii The peak area ratio of each second bismaleimide compound having a value of 2 can be calculated, and the peak area ratio can be obtained as the mass content (mass %).

[0085] The specific bismaleimide resin (A) as a combination of the first bismaleimide compound and the second bismaleimide compound can be produced, for example, by a method comprising reacting a diamine containing a divalent aliphatic hydrocarbon group with maleic anhydride. Examples of the diamine containing a divalent aliphatic hydrocarbon group include NH-R i -NH2(R iThe meaning of is the same as that described above. ) can be mentioned, and dimer acid type diamines are preferred. Dimer acid type diamines refer to diamine compounds having a structure in which the two terminal carboxy groups (-COOH) of a dimer acid are substituted with aminomethyl groups (-CH2-NH2) or amino groups (-NH2). The (A) specific bismaleimide resin may also be produced by a production method including reacting the above-mentioned diamine with a tetracarboxylic dianhydride. According to a production method including the reaction of a diamine with a tetracarboxylic dianhydride, m in formula (1-i) can usually be produced. i a first bismaleimide compound having a unit, and m in formula (1-ii) ii In the method for producing the specific bismaleimide resin (A) described above, the first bismaleimide compound is produced as a main product, and the second bismaleimide compound is produced as a by-product. The moiety represented by formula (1-ia) of the first bismaleimide compound and the moiety represented by formula (1-ii-a) of the second bismaleimide compound contained in the specific bismaleimide resin (A) produced by this method can be moieties formed by the reaction of a common diamine and a common tetracarboxylic dianhydride, and therefore, R i The bond direction and R ii The specific bismaleimide resin (A) may have the same structure as the specific bismaleimide resin (A) except for the orientation of the bond. Since such a specific bismaleimide resin (A) typically does not require the step of separating by-products through purification, the production of the specific bismaleimide resin (A) can be simplified. Furthermore, when the specific bismaleimide resin (A) containing such by-products is used, the excellent effects described above can be obtained.

[0086] As the (A) specific bismaleimide resin, a commercially available product may be used. An example of a commercially available (A) specific bismaleimide resin is "SLK-6893-T90" manufactured by Shin-Etsu Chemical Co., Ltd. (a first bismaleimide compound represented by formula (3-i), m i is 0, R i is a first bismaleimide compound represented by formula (2) and a second bismaleimide compound represented by formula (3-ii), iiis 0, R ii a combination of a second bismaleimide compound represented by formula (2) and m; "SLK-1500" manufactured by Shin-Etsu Chemical Co., Ltd. (a first bismaleimide compound represented by formula (3-i), i is 1 to 10, R i is a first bismaleimide compound represented by formula (2) and a second bismaleimide compound represented by formula (3-ii), ii is 1 to 10, R ii and a second bismaleimide compound represented by formula (2);

[0087] The range of the maleimide group equivalent of the (A) specific bismaleimide resin is preferably 200 g / eq. or more, more preferably 300 g / eq. or more, and preferably 2500 g / eq. or less, more preferably 2000 g / eq. or less, and even more preferably 1500 g / eq. or less. The maleimide group equivalent represents the mass of the resin per equivalent of maleimide group.

[0088] The weight-average molecular weight of the (A) specific bismaleimide resin is preferably at least 400, more preferably at least 500, and even more preferably at least 600, and is preferably at most 10,000, more preferably at most 7,000, and even more preferably at most 5,000. The weight-average molecular weight can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0089] The amount of component (A) (i.e., the combination of the first bismaleimide compound and the second bismaleimide compound) is preferably 0.1% by mass or more, more preferably 1% by mass or more, and particularly preferably 2% by mass or more, relative to 100% by mass of the nonvolatile components of the resin composition, and is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less. The nonvolatile components of the resin composition refer to the components contained in the resin composition excluding the solvent (G). When the amount of the combination of the first bismaleimide compound and the second bismaleimide compound is within the above range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0090] The amount of component (A) (i.e., the combination of the first bismaleimide compound and the second bismaleimide compound) is preferably 1% by mass or more, more preferably 5% by mass or more, and particularly preferably 10% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less. The resin components of the resin composition refer to the non-volatile components of the resin composition excluding the inorganic filler (C). When the amount of the combination of the first bismaleimide compound and the second bismaleimide compound is within the above range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0091] The amount of component (A) (i.e., the combination of the first bismaleimide compound and the second bismaleimide compound) is preferably 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 20% by mass or more, relative to 100% by mass of the elastomer (D). When the amount of the combination of the first bismaleimide compound and the second bismaleimide compound is within the above range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0092] The amount of the second bismaleimide compound is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, relative to 100% by mass of the nonvolatile components of the resin composition. When the amount of the second bismaleimide compound is within the above range, tackiness and dielectric loss tangent can be reduced, and usually, the minimum melt viscosity and warpage can be reduced.

[0093] The amount of the second bismaleimide compound is preferably at least 0.1% by mass, more preferably at least 1% by mass, and particularly preferably at least 2% by mass, relative to 100% by mass of the elastomer (D), and is preferably at most 40% by mass, more preferably at most 30% by mass, and even more preferably at most 20% by mass. When the amount of the second bismaleimide compound is within the above range, tackiness and dielectric loss tangent can be reduced, and usually, the minimum melt viscosity and warpage can be reduced.

[0094] <(B) Thermosetting resin> The resin composition according to this embodiment includes a (B) thermosetting resin as component (B). The (B) thermosetting resin reacts with heat to form bonds, thereby curing the resin composition. The (B) thermosetting resin does not include those corresponding to the above-mentioned component (A). One type of (B) thermosetting resin may be used alone, or two or more types may be used in combination.

[0095] Examples of (B) thermosetting resins include epoxy resins, active ester resins, phenolic resins, carbodiimide resins, acid anhydride resins, benzoxazine resins, cyanate ester resins, amine resins, thiol resins, and polymerizable unsaturated resins.

[0096] The (B) thermosetting resin preferably contains an epoxy resin. In particular, the (B) thermosetting resin more preferably contains a combination of an epoxy resin and a resin that can react with and bond to the epoxy resin to cure the (B) thermosetting resin. Hereinafter, the resin that can react with and bond to the epoxy resin may be referred to as a "curing agent."

[0097] The epoxy resin refers to a curable resin having an epoxy group. Examples of epoxy resins include bixylenol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol AF-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, phenol aralkyl-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexane dimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, isocyanurate-type epoxy resins, and phenolphthalimidine-type epoxy resins. The epoxy resin may be used alone or in combination of two or more.

[0098] From the viewpoint of obtaining a cured product having excellent heat resistance, the epoxy resin preferably contains an epoxy resin containing an aromatic structure. The aromatic structure is a chemical structure generally defined as aromatic, and also includes polycyclic aromatic rings and aromatic heterocycles. Examples of epoxy resins containing an aromatic structure include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol novolac type epoxy resins, phenol novolac type epoxy resins, tert-butyl-catechol type epoxy resins, naphthalene type epoxy resins, naphthol type epoxy resins, anthracene type epoxy resins, bisxyleneol type epoxy resins, glycidylamine type epoxy resins having an aromatic structure, glycidyl ester type epoxy resins having an aromatic structure, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins having an aromatic structure, epoxy resins having a butadiene structure having an aromatic structure, alicyclic epoxy resins having an aromatic structure, heterocyclic epoxy resins, spiro ring-containing epoxy resins having an aromatic structure, cyclohexanedimethanol type epoxy resins having an aromatic structure, naphthylene ether type epoxy resins, trimethylol type epoxy resins having an aromatic structure, and tetraphenylethane type epoxy resins having an aromatic structure. Among these, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, and bisphenol N type epoxy resin are preferred.

[0099] The (B) thermosetting resin preferably contains an epoxy resin having two or more epoxy groups in one molecule, and the proportion of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, relative to 100% by mass of the nonvolatile components of the entire epoxy resin.

[0100] Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). (B) Thermosetting resin may contain only liquid epoxy resin, only solid epoxy resin, or a combination of liquid epoxy resin and solid epoxy resin.

[0101] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0102] Preferred liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexanedimethanol type epoxy resins, and epoxy resins having a butadiene structure; more preferred are bisphenol A type epoxy resins, bisphenol F type epoxy resins, and naphthalene type epoxy resins.

[0103] Specific examples of liquid epoxy resins include "HP-4032", "HP-4032-D", and "HP-4032-SS" (naphthalene type epoxy resins) manufactured by DIC Corporation; "828US", "828EL", "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", "630LSD", and "604" (glycidylamine type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycirol type epoxy resin) manufactured by ADEKA Corporation; and "EP-3950L" and "EP-3980" manufactured by ADEKA Corporation. Examples include "EP-4088S" (glycidylamine type epoxy resin) manufactured by ADEKA Corporation; "EP-4088S" (dicyclopentadiene type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation; "Celloxide 2021P" (alicyclic epoxy resin with an ester skeleton) manufactured by Daicel Corporation; "PB-3600" manufactured by Daicel Corporation, "JP-100" and "JP-200" (epoxy resins with a butadiene structure) manufactured by Nippon Soda Co., Ltd.; and "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.

[0104] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferred.

[0105] Preferred solid epoxy resins include bixylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, naphthol novolac-type epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, phenol aralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, and phenolphthalimidine-type epoxy resins.

[0106] Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resins) manufactured by DIC Corporation; "N-690" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene type epoxy resins) manufactured by DIC Corporation; and "EXA-7311" and "E" manufactured by DIC Corporation. XA-7311-G3, EXA-7311-G4, EXA-7311-G4S, HP6000, HP6000L (naphthylene ether type epoxy resin); Nippon Kayaku Co., Ltd.'s "EPPN-502H" (trisphenol type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC7000L" (naphthol novolac type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin); Nippon Steel Chemical & Material Co., Ltd.'s "ESN475V", "ESN4100V" (naphthalene-type epoxy resin); "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", and "YL7890" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation. Examples include "YX7700" (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YX7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.

[0107] When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, the mass ratio thereof (liquid epoxy resin:solid epoxy resin) is preferably 20:1 to 1:20, more preferably 10:1 to 1:10, and particularly preferably 7:1 to 1:7. In particular, from the viewpoint of effectively reducing the melt viscosity, it is preferable to use more liquid epoxy resin than solid epoxy resin.

[0108] The epoxy equivalent of the epoxy resin is preferably 50 g / eq. to 5,000 g / eq., more preferably 60 g / eq. to 3,000 g / eq., even more preferably 80 g / eq. to 2,000 g / eq., and particularly preferably 110 g / eq. to 1,000 g / eq. The epoxy equivalent represents the mass of the resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0109] The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight can be measured by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

[0110] The amount of the epoxy resin is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, and is preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 40% by mass or less, relative to 100% by mass of the resin components of the resin composition. When the amount of the epoxy resin is within the above range, it is possible to effectively reduce tackiness, dielectric loss tangent, minimum melt viscosity, and warpage.

[0111] Examples of the curing agent include active ester resins, phenol resins, carbodiimide resins, acid anhydride resins, benzoxazine resins, cyanate ester resins, amine resins, thiol resins, etc. One type of curing agent may be used alone, or two or more types may be used in combination.

[0112] The active ester resin may be a resin having one or more, preferably two or more, active ester groups in one molecule. Among them, preferred active ester resins are those having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds.

[0113] The active ester resin 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. From the viewpoint of improving heat resistance in particular, an active ester resin obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferred. 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. 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, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0114] Specifically, the active ester resin is preferably a dicyclopentadiene-type active ester resin, a naphthalene-type active ester resin containing a naphthalene structure, an active ester resin containing an acetylated product of phenol novolac, or an active ester resin containing a benzoylated product of phenol novolac, and among these, a dicyclopentadiene-type active ester resin is more preferred. As the dicyclopentadiene-type active ester resin, an active ester resin containing a dicyclopentadiene-type diphenol structure is preferred.

[0115] Commercially available active ester resins include, for example, "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", "HPC-8000-65T", and "EXB-8000H" (manufactured by DIC Corporation) as active ester resins containing a dicyclopentadiene-type diphenol structure; and "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", and "EXB-8150H" as active ester resins containing a naphthalene structure. Examples of such active ester resins include XB-9416-70BK, HPC-8150-62T, and EXB-8 (manufactured by DIC Corporation); an active ester resin containing phosphorus, such as EXB9401 (manufactured by DIC Corporation); an active ester resin which is an acetylated product of phenol novolac, such as DC808 (manufactured by Mitsubishi Chemical Corporation); active ester resins which are benzoylated products of phenol novolac, such as YLH1026, YLH1030, and YLH1048 (manufactured by Mitsubishi Chemical Corporation); and an active ester resin containing a styryl group and a naphthalene structure, such as PC1300-02-65MA (manufactured by Air Water Inc.).

[0116] The amount of the active ester resin is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 5% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. When the amount of the active ester resin is within the above range, it is possible to effectively reduce tackiness, dielectric loss tangent, minimum melt viscosity, and warpage.

[0117] As the phenolic resin, a resin having one or more, preferably two or more, hydroxyl groups (phenolic hydroxyl groups) bonded to an aromatic ring such as a benzene ring or a naphthalene ring per molecule can be used. From the viewpoint of heat resistance and water resistance, a phenolic resin having a novolac structure is preferred. From the viewpoint of adhesion, a nitrogen-containing phenolic resin may be used, for example, a phenolic resin containing a triazine skeleton. As a specific example, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a phenolic novolac resin containing a triazine skeleton may be used.

[0118] Specific examples of phenolic resins include "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000H" manufactured by Meiwa Kasei Co., Ltd.; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", and "SN-375" manufactured by Nippon Steel Chemical & Material Co., Ltd. Examples include "SN-395"; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", "TD-2090-60M", and "KA-1160" manufactured by DIC Corporation; and "GDP-6115L", "GDP-6115H", and "ELPC75" manufactured by Gun-ei Chemical Co., Ltd.

[0119] The amount of the phenolic resin 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 components of the resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. When the amount of the phenolic resin is within the above range, it is possible to effectively reduce tackiness, dielectric loss tangent, minimum melt viscosity, and warpage.

[0120] As the carbodiimide resin, a resin having one or more, preferably two or more, carbodiimide structures in one molecule can be used. Specific examples of the carbodiimide resin include aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexanebis(methylene-t-butylcarbodiimide); aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide); poly(phenylenecarbodiimide), poly(naphthalenecarbodiimide); Examples of polycarbodiimides include aromatic polycarbodiimides such as poly(methylenediphenylenecarbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide]. Commercially available carbodiimide resins include, for example, "Carbodilite V-02B," "Carbodilite V-03," "Carbodilite V-04K," "Carbodilite V-05," "Carbodilite V-07," and "Carbodilite V-09" manufactured by Nisshinbo Chemical Inc.; and "Stavaxol P," "Stavaxol P400," and "Hykasil 510" manufactured by Lanxess AG.

[0121] The amount of the carbodiimide resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more, and is preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, based on 100% by mass of the resin components of the resin composition. When the amount of the carbodiimide resin is within the above range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0122] As the acid anhydride resin, a resin having one or more, preferably two or more, acid anhydride groups in one molecule can be used. Specific examples of the acid anhydride resin include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. Examples of suitable anhydrides include anhydrides, 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 polymeric anhydrides such as styrene-maleic acid resins, which are copolymers of styrene and maleic acid. Commercially available acid anhydride resins include, for example, "HNA-100," "MH-700," "MTA-15," "DDSA," and "OSA" manufactured by New Japan Chemical Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Corporation; "HN-2200" and "HN-5500" manufactured by Resonac Corporation; and "EF-30," "EF-40," "EF-60," and "EF-80" manufactured by Cray Valley Chemical Industries, Ltd.

[0123] The benzoxazine resin may be a resin having one or more, preferably two or more, benzoxazine rings in one molecule. Specific examples of the benzoxazine resin include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation, "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "Pd" and "Fa" manufactured by Shikoku Chemical Industry Co., Ltd.

[0124] As the cyanate ester resin, a resin having one or more, preferably two or more, cyanate groups in one molecule can be used. Examples of cyanate ester resins include bifunctional cyanate ester 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; multifunctional cyanate ester resins derived from phenol novolac, cresol novolac, and the like; and prepolymers in which these cyanate ester resins are partially triazine converted. Specific examples of cyanate ester resins include "PT30" and "PT60" (phenol novolac type multifunctional cyanate ester resins) manufactured by Arxada (formerly Lonza), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazine converted to a trimer).

[0125] The amine resin may be a resin having one or more, preferably two or more, amino groups in one molecule. Examples of the amine resin include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines, with aromatic amines being preferred. The amine resin is preferably a primary amine or secondary amine, with primary amines being more preferred. Specific examples of the amine resin include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxyphenyl)propanol. Examples of suitable bis(4-aminophenoxy)benzene include bis(4-aminophenyl)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, and bis(4-(3-aminophenoxy)phenyl)sulfone. Commercially available amine-based resins include, for example, "SEIKACURE-S" manufactured by Seika Corporation; "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD AA," "KAYAHARD AB," and "KAYAHARD AS" manufactured by Nippon Kayaku Co., Ltd.; "Epicure W" manufactured by Mitsubishi Chemical Corporation; and "DTDA" manufactured by Sumitomo Seika Chemicals Co., Ltd.

[0126] Examples of thiol-based resins include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate.

[0127] The active group equivalent of the curing agent is preferably 50 g / eq. to 3000 g / eq., more preferably 100 g / eq. to 1000 g / eq., even more preferably 100 g / eq. to 500 g / eq., and particularly preferably 100 g / eq. to 300 g / eq. The active group equivalent represents the mass of the resin per equivalent of the active group.

[0128] In one example, the weight average molecular weight (Mw) range of the curing agent may be the same as the weight average molecular weight (Mw) range of the epoxy resin.

[0129] The amount of the 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, relative to 100% by mass of the resin component of the resin composition, and is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less. When the amount of the curing agent is within the above range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0130] When a resin composition contains a combination of an epoxy resin and a curing agent, the range of the number of active groups in the curing agent relative to the number of epoxy groups in the epoxy resin is preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.4 or more, particularly preferably 0.5 or more, and preferably 3.0 or less, more preferably 2.5 or less, even more preferably 2.0 or less, even more preferably 1.5 or less, particularly preferably 1.0 or less, relative to the number of epoxy groups in the epoxy resin (1). The "number of epoxy groups in the epoxy resin" of a resin composition refers to the sum of all values obtained by dividing the mass of the non-volatile components of the epoxy resin present in the resin composition by the epoxy equivalent. Furthermore, the "number of active groups in the curing agent" of a resin composition refers to the sum of all values obtained by dividing the mass of the non-volatile components of the curing agent present in the resin composition by the active group equivalent.

[0131] The polymerizable unsaturated resin may be a resin containing a non-aromatic carbon-carbon unsaturated bond. Therefore, the polymerizable unsaturated resin typically has a polymerizable unsaturated group containing a non-aromatic carbon-carbon unsaturated bond. Examples of the polymerizable unsaturated group include unsaturated hydrocarbon groups such as vinyl, allyl, 1-propenyl, 3-cyclohexenyl, 3-cyclopentenyl, 2-vinylphenyl, 3-vinylphenyl, and 4-vinylphenyl; and α,β-unsaturated carbonyl groups such as acryloyl, methacryloyl, and maleimide. Polymerizable unsaturated resins containing these polymerizable unsaturated groups typically undergo radical polymerization. Preferably, the polymerizable unsaturated resin has two or more polymerizable unsaturated groups.

[0132] Examples of the polymerizable unsaturated resin include (meth)acrylic polymerizable unsaturated resins, styrene polymerizable unsaturated resins, allyl polymerizable unsaturated resins, maleimide polymerizable unsaturated resins, etc. One type of polymerizable unsaturated resin may be used alone, or two or more types may be used in combination.

[0133] As the (meth)acrylic polymerizable unsaturated resin, a resin having one or more, preferably two or more, acryloyl groups and / or methacryloyl groups in one molecule can be used. Examples of the (meth)acrylic polymerizable unsaturated resin include cyclohexane-1,4-dimethanol di(meth)acrylate, cyclohexane-1,3-dimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonane diol di(meth)acrylate, and the like. Low molecular weight (molecular weight less than 1000) aliphatic (meth)acrylic acid ester resins such as diol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, glycerin tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate; dioxane glycol di(meth)acrylate, 3,6-dioxa-1,8-octanediol di(meth)acrylate Examples of the ether-containing (meth)acrylic acid ester resins include low molecular weight (molecular weight less than 1000) acrylates, such as acrylate, 3,6,9-trioxaundecane-1,11-diol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, ethoxylated bisphenol A di(meth)acrylate, and propoxylated bisphenol A di(meth)acrylate; low molecular weight (molecular weight less than 1000) isocyanurate-containing (meth)acrylic acid ester resins, such as tris(3-hydroxypropyl)isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, and ethoxylated isocyanuric acid tri(meth)acrylate; and high molecular weight (molecular weight 1000 or more) (meth)acrylic acid ester resins, such as (meth)acrylic-modified polyphenylene ether resins. The term "(meth)acrylic acid" includes acrylic acid, methacrylic acid, and combinations thereof.Commercially available (meth)acrylic polymerizable unsaturated resins include, for example, "A-DOG" (dioxane glycol diacrylate) manufactured by Shin-Nakamura Chemical Co., Ltd., "DCP-A" (tricyclodecane dimethanol diacrylate), "DCP" (tricyclodecane dimethanol dimethacrylate), and "BPE-1300N" (ethoxylated bisphenol A dimethacrylate) manufactured by Kyoeisha Chemical Co., Ltd., "KAYARAD R-684" (tricyclodecane dimethanol diacrylate) and "KAYARAD R-604" (dioxane glycol diacrylate) manufactured by Nippon Kayaku Co., Ltd., and "SA9000" and "SA9000-111" (methacrylic-modified polyphenylene ether) manufactured by SABIC.

[0134] The styrene-based polymerizable unsaturated resin may be a resin having one or more, preferably two or more, vinyl groups directly bonded to an aromatic carbon atom in one molecule. Examples of the styrene-based polymerizable unsaturated resin include low-molecular-weight (molecular-weight less than 1000) styrene-based resins such as divinylbenzene, 2,4-divinyltoluene, 2,6-divinylnaphthalene, 1,4-divinylnaphthalene, 4,4'-divinylbiphenyl, 1,2-bis(4-vinylphenyl)ethane, 2,2-bis(4-vinylphenyl)propane, and bis(4-vinylphenyl)ether; and high-molecular-weight (molecular-weight 1000 or more) styrene-based resins such as vinylbenzyl-modified polyphenylene ether resin and styrene-divinylbenzene copolymer. Commercially available styrene-based polymerizable unsaturated resins include, for example, "ODV-XET(X03)", "ODV-XET(X04)", and "ODV-XET(X05)" (styrene-divinylbenzene copolymers) manufactured by Nippon Steel Chemical & Material Co., Ltd., and "OPE-2St", "OPE-2St 1200", and "OPE-2St 2200" (vinylbenzyl-modified polyphenylene ether resins) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0135] As the allylic polymerizable unsaturated resin, a resin having one or more, preferably two or more, allyl groups in one molecule can be used. Examples of allyl-based polymerizable unsaturated resins include aromatic carboxylic acid allyl ester resins such as diallyl diphenate, triallyl trimellitate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalenedicarboxylate, and diallyl 2,3-naphthalenecarboxylate; isocyanuric acid allyl ester resins such as 1,3,5-triallyl isocyanurate and 1,3-diallyl-5-glycidyl isocyanurate; epoxy-containing aromatic allyl resins such as 2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane; benzoxazine-containing aromatic allyl resins such as bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane; ether-containing aromatic allyl resins such as 1,3,5-triallyl ether benzene; and allyl silane resins such as diallyldiphenylsilane. Commercially available allyl polymerizable unsaturated resins include, for example, "TAIC" (1,3,5-triallyl isocyanurate) manufactured by Nippon Kasei Chemical Co., Ltd., "DAD" (diallyl diphenate) manufactured by Nisshoku Techno Fine Chemical Co., Ltd., "TRIAM-705" (triallyl trimellitate) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., "DAND" (2,3-diallyl naphthalenecarboxylate) manufactured by Nisshoku Techno Fine Chemical Co., Ltd., and " Examples include "ALP-d" (bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane), "RE-810NM" (2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane) manufactured by Nippon Kayaku Co., Ltd., "DA-MGIC" (1,3-diallyl-5-glycidyl isocyanurate) manufactured by Shikoku Chemicals Corporation, and "NE-V-1100-70T" manufactured by DIC Corporation.

[0136] The maleimide-based polymerizable unsaturated resin may be a resin having one or more, preferably two or more, maleimide groups per molecule. The maleimide-based polymerizable unsaturated resin may be an aromatic maleimide resin having a maleimide group directly bonded to an aromatic ring, or an aliphatic maleimide resin having no maleimide group directly bonded to an aromatic ring. Commercially available maleimide-based radically polymerizable resins include aromatic maleimide resins such as "MIR-3000-70MT" (manufactured by Nippon Kayaku Co., Ltd.), "BMI-4000" (manufactured by Daiwa Kasei Co., Ltd.), "BMI-80" (manufactured by Keiai Kasei Co., Ltd.), and "BMI-6100" (manufactured by Designer Molecules Inc.). Furthermore, the maleimide-based polymerizable unsaturated resin may be a maleimide resin (maleimide compound containing an indane ring skeleton) disclosed in the Japan Institute of Invention and Innovation's Disclosure Technical Bulletin No. 2020-500211.

[0137] The polymerizable unsaturated group equivalent of the polymerizable unsaturated resin is preferably 20 g / eq. to 3,000 g / eq., more preferably 50 g / eq. to 2,500 g / eq., even more preferably 70 g / eq. to 2,000 g / eq., and particularly preferably 90 g / eq. to 1,500 g / eq. The polymerizable unsaturated group equivalent represents the mass of the resin per equivalent of the polymerizable unsaturated group.

[0138] The weight average molecular weight (Mw) of the polymerizable unsaturated resin is preferably 40,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, and particularly preferably 3,000 or less. The lower limit is not particularly limited, but may be, for example, 150 or more.

[0139] The amount of the polymerizable unsaturated resin is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 5% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. When the amount of the polymerizable unsaturated resin is within the above range, it is possible to effectively reduce tackiness, dielectric loss tangent, minimum melt viscosity, and warpage.

[0140] The amount of (B) thermosetting resin is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and particularly preferably 18% by mass or less, relative to 100% by mass of the nonvolatile components of the resin composition. When the amount of (B) thermosetting resin is within the above range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0141] The amount of (B) thermosetting resin is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less. When the amount of (B) thermosetting resin is within the above range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0142] <(C) Inorganic filler> The resin composition according to this embodiment includes a (C) inorganic filler as component (C). The (C) inorganic filler is particles of an inorganic material. Therefore, the (C) inorganic filler is included in the resin composition in the form of particles, and is usually included in the cured product while maintaining this particulate state. The (C) inorganic filler does not include those corresponding to the above-mentioned components (A) and (B).

[0143] Inorganic compounds are typically used as the inorganic material forming the (C) inorganic filler. Examples of materials for the (C) inorganic filler include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, 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 and alumina are preferred, with silica being particularly preferred. Therefore, the (C) inorganic filler preferably contains silica, or may contain only silica. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Moreover, the silica is preferably spherical silica.The inorganic filler (C) may be used alone or in combination of two or more kinds.

[0144] (C) Examples of commercially available inorganic fillers 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.

[0145] The average particle size of the (C) inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and is preferably 10 μm or less, more preferably 5 μm or less, even more preferably 3 μm or less, even more preferably 1 μm or less.

[0146] (C) The average particle size of an inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, a volumetric particle size distribution of the inorganic filler is created using a laser diffraction / scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A 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 volumetric particle size distribution of the inorganic filler is measured using a laser diffraction particle size distribution analyzer with blue and red light source wavelengths using a flow cell system, and the average particle size can be calculated as the median diameter from the particle size distribution obtained. Examples of laser diffraction particle size distribution analyzers include the LA-960 manufactured by Horiba, Ltd.

[0147] (C) The specific surface area of the inorganic filler is preferably 0.1 m 2 / g or more, more preferably 0.5m 2 / g or more, more preferably 1m 2 / g or more, particularly preferably 3m 2 / g or more, preferably 100m 2 / g or less, more preferably 70m 2 / g or less, more preferably 50m 2 / g or less, particularly preferably 40m 2 (C) The specific surface area of the inorganic filler can be measured 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.

[0148] The (C) inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a mercaptosilane coupling agent, a silane coupling agent, an alkoxysilane, an organosilazane compound, and a titanate coupling agent. One type of surface treatment agent may be used alone, or two or more types may be used in any combination.

[0149] Examples of commercially available surface treatment agents include Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd.'s "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM-4803" (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical Co., Ltd.'s "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane).

[0150] The degree of surface treatment with the surface treatment agent preferably falls within a specific 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, more preferably with 0.2% to 3% by mass of the surface treatment agent, and even more preferably with 0.3% to 2% by mass of the surface treatment agent.

[0151] 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 set to 0.02 mg / m 2 More than 0.1 mg / m is preferable. 2More preferably, 0.2 mg / m or more 2 On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition layer, it is more preferable that the amount of the resin composition layer is 1.0 mg / m 2 Preferably less than 0.8 mg / m 2 Less than 0.5 mg / m is more preferable. 2 The following is even more preferred:

[0152] (C) The amount of carbon per unit surface area of the inorganic filler 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 amount of carbon 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.

[0153] The amount of (C) inorganic filler is preferably 50% by mass or more, more preferably 55% by mass or more, even more preferably 60% by mass or more, even more preferably 65% 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, even more preferably 77% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of (C) inorganic filler is within the above range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0154] The total amount of the (A) specific bismaleimide resin, (B) thermosetting resin, and (C) inorganic filler is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, based on 100% by mass of the nonvolatile components of the resin composition. The upper limit is usually 100% by mass or less, but may be 99.9% by mass or less.

[0155] <(D) Elastomer> The resin composition according to this embodiment may further contain an (D) elastomer as an optional component. The (D) elastomer as the (D) component does not include those corresponding to the above-mentioned (A) to (C) components. The (D) elastomer is a flexible component, and therefore can effectively reduce the minimum melt viscosity and warpage. The (D) elastomer is usually contained in the resin composition in a state compatible with the resin components (A) to (B), and is contained in the cured product while maintaining this compatible state. One type of (D) elastomer may be used alone, or two or more types may be used in combination.

[0156] The (D) elastomer typically has a low modulus of elasticity. 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, the (D) elastomer typically exhibits a modulus of elasticity of 1 GPa or less. The range of the modulus of elasticity of the (D) elastomer is, in detail, typically 1 GPa or less, preferably 0.9 GPa or less, more preferably 0.8 GPa or less, 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.

[0157] As the (D) elastomer, 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, allowing them to function as flexible molecular skeletons. Therefore, the (D) elastomer can be easily obtained from a resin containing such a structure. 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 even more preferred.

[0158] 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.

[0159] Specific examples of polybutadiene resins include "Ricon 130MA8," "Ricon 130MA13," "Ricon 130MA20," "Ricon 131MA5," "Ricon 131MA10," "Ricon 131MA17," "Ricon 131MA20," and "Ricon 184MA6" (anhydride-containing polybutadienes) manufactured by Cray Valley Corporation; "GQ-1000" (hydroxyl- and carboxyl-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" (a hydrogenated polybutadiene-based epoxy resin) manufactured by Nagase ChemteX Corporation.

[0160] 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 (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.

[0161] 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.

[0162] 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.

[0163] Specific examples of polycarbonate resins include polyimide resins having an imide structure, a urethane structure, and a polycarbonate structure in 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. For details of the polyimide resin, please refer to the description in International Publication No. 2016 / 129541, the contents of which are incorporated herein by reference.

[0164] 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 even 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 dimer acid skeleton in the repeating unit is preferred.

[0165] As described above, the dimer acid skeleton refers to the skeleton of a divalent group remaining after removing the two terminal carboxy groups (—COOH) of a dimer acid. A polyalkylene resin containing a dimer acid skeleton generally contains a divalent hydrocarbon group, and this divalent hydrocarbon group contains a dimer acid skeleton. The divalent hydrocarbon group containing the dimer acid skeleton 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 the dimer acid skeleton may have 36 carbon atoms.

[0166] A specific example of a polyalkylene resin containing a dimer acid skeleton is a polyimide resin containing a dimer acid skeleton. Examples of this polyimide resin include resins obtained by the imidization reaction of a dimer acid diamine with a tetracarboxylic acid anhydride. The dimer acid diamine refers to a diamine compound having a structure in which the two terminal carboxyl groups (-COOH) of a dimer acid are substituted with an aminomethyl group (-CH-NH) or an amino group (-NH). 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, the tetracarboxylic acid anhydride may be an aliphatic tetracarboxylic acid dianhydride, an aromatic tetracarboxylic acid dianhydride, or a combination thereof.

[0167] 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.

[0168] Resins containing polysiloxane structures 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, International Publication No. 2010 / 053185, Japanese Patent Application Laid-Open No. 2002-12667, and Japanese Patent Application Laid-Open No. 2000-319386).

[0169] Resins containing a poly(meth)acrylate structure are sometimes referred to as “poly(meth)acrylate resins.” 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.

[0170] Resins containing polyisoprene structures are sometimes called “polyisoprene resins.” Specific examples of polyisoprene resins include “KL-610” and “KL613” manufactured by Kuraray Co., Ltd.

[0171] Resins containing polyisobutylene structures are sometimes called "polyisobutylene resins." Specific examples of polyisobutylene resins include Kaneka Corporation's "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer).

[0172] 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 block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-butadiene random copolymer, and styrene-maleic anhydride copolymer.

[0173] Specific examples of polystyrene resins include hydrogenated styrene-based thermoplastic elastomers "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.); modified styrene-based elastomers having carboxyl groups "Tuftec N503M," modified styrene-based elastomers having amino groups "Tuftec N501," modified styrene-based elastomers having acid anhydride groups "Tuftec M1913" (manufactured by Asahi Kasei Corporation); unmodified styrene-based elastomers "Septon S8104" (manufactured by Kuraray Co., Ltd.); and styrene-ethylene / butylene-styrene block copolymers "FG1924" (manufactured by Kraton) and "EF-40" (manufactured by Cray Valley).

[0174] The (D) elastomer usually has a large weight-average molecular weight. The weight-average molecular weight Mw of the (D) elastomer is preferably greater than 5,000, more preferably 8,000 or more, and even more preferably 10,000 or more. The upper limit is preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 200,000 or less, even more preferably 100,000 or less, even more preferably 50,000 or less, and even more preferably 30,000 or less.

[0175] The (D) elastomer preferably has a glass transition temperature Tg of 25°C or lower, or is liquid at 25°C or lower. When the (D) elastomer 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 -15°C or higher. When the (D) elastomer is liquid at 25°C or lower, the (D) elastomer 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.

[0176] The (D) elastomer may have a functional group capable of reacting with the (A) specific bismaleimide resin or the (B) thermosetting resin. When the (D) elastomer is capable of reacting with the (A) specific bismaleimide resin or the (B) thermosetting resin, the mechanical strength of the cured product of the resin composition can be increased. Functional groups capable of reacting with the (A) specific bismaleimide resin or the (B) thermosetting 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. Among 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.

[0177] The amount of (D) elastomer is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, even more preferably 3% by mass or more, even more preferably 4% by mass or more, even more preferably 5% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, based on 100% by mass of the non-volatile components of the resin composition. When the amount of (D) elastomer is within this range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0178] The amount of (D) elastomer is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and is preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, even more preferably 40% by mass or less, based on 100% by mass of the resin components of the resin composition. When the amount of (D) elastomer is within this range, tackiness, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0179] <(E) Curing catalyst> The resin composition according to the present embodiment may further contain, as an optional component, a curing catalyst (E) that promotes the reaction of the curable resin, such as the specific bismaleimide resin (A) and the thermosetting resin (B). The curing catalyst (E) as the component (E) does not include those corresponding to the above-mentioned components (A) to (D). The curing catalyst (E) as the component (E) may be used alone or in combination of two or more.

[0180] (E) The curing catalyst may, for example, be a curing accelerator that accelerates the reaction of the epoxy resin. Examples of the curing accelerator include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators. One type of curing accelerator may be used alone, or two or more types may be used in combination.

[0181] 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 tetra-p-tolylborate. 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 adducts such as triphenylphosphine-p-benzoquinone adduct; 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 Examples of suitable phosphorus-based curing accelerators include aromatic phosphines such as 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. Commercially available phosphorus-based curing accelerators include "TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.

[0182] 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 toluene bis(dimethylurea), 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea].

[0183] 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.

[0184] 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-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium 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 Examples of imidazole compounds include 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 "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.

[0185] 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.

[0186] 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. Examples of commercially available amine curing accelerators include "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0187] The range of the amount of the curing accelerator 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, relative to 100% by mass of the resin component of the resin composition, and is preferably 5% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less.

[0188] (E) The curing catalyst may be, for example, a radical polymerization initiator as a catalyst for a radical reaction. One type of radical polymerization initiator may be used alone, or two or more types may be used in combination. Examples of the radical polymerization initiator include a peroxide-based radical polymerization initiator and an azo-based radical polymerization initiator.

[0189] Examples of the peroxide radical polymerization initiator include hydroperoxide compounds such as 1,1,3,3-tetramethylbutyl hydroperoxide; dialkyl peroxide compounds such as tert-butylcumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, di-tert-amyl peroxide, dicumyl peroxide, 1,4-bis(1-tert-butylperoxy-1-methylethyl)benzene, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; and diacid compounds such as dilauroyl peroxide, didecanoyl peroxide, dicyclohexyl peroxydicarbonate, and bis(4-tert-butylcyclohexyl)peroxydicarbonate. peroxide compounds; and peroxyester compounds such as tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyneodecanoate, tert-hexylperoxyisopropyl monocarbonate, tert-butyl peroxylaurate, (1,1-dimethylpropyl) 2-ethylperhexanoate, tert-butyl 2-ethylperhexanoate, tert-butyl 3,5,5-trimethylperhexanoate, tert-butylperoxy-2-ethylhexyl monocarbonate, and tert-butylperoxymaleic acid.

[0190] Examples of the azo radical polymerization initiator include azonitrile compounds such as 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, and 2-phenylazo-4-methoxy-2,4-dimethyl-valeronitrile; 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide], and 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide]. azoamide compounds such as 2,2'-azobis[2-methyl-N-[2-(1-hydroxybutyl)]-propionamide], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide], 2,2'-azobis(2-methylpropionamide) dihydrate, 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(N-cyclohexyl-2-methylpropionamide); alkyl azo compounds such as 2,2'-azobis(2,4,4-trimethylpentane) and 2,2'-azobis(2-methylpropane); and the like.

[0191] Commercially available radical polymerization initiators include, for example, "Perbutyl C," "Perbutyl A," "Perbutyl P," "Perbutyl L," "Perbutyl O," "Perbutyl ND," "Perbutyl Z," "Perbutyl I," "Percumyl P," "Percumyl D," "Perhexyl D," "Perhexyl A," "Perhexyl I," "Perhexyl Z," "Perhexyl ND," "Perhexyl O," and "Perhexyl PV," all manufactured by NOF Corporation; and "Luperox DTA" manufactured by Arkema Yoshitomi Co., Ltd.

[0192] The amount of the radical polymerization initiator is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.2% by mass or more, relative to 100% by mass of the resin component of the resin composition, and is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less.

[0193] The amount of the (E) curing catalyst is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.05% by mass or more, and is preferably 2% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less, relative to 100% by mass of the non-volatile components of the resin composition.

[0194] The amount of the (E) curing catalyst is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.2% by mass or more, relative to 100% by mass of the resin component of the resin composition, and is preferably 5% by mass or less, more preferably 2% by mass or less, even more preferably 1% by mass or less.

[0195] <(F) Optional Additives> The resin composition according to this embodiment may further contain an optional additive (F) as an optional component. The optional additive (F) as component (F) does not include those corresponding to the above-mentioned components (A) to (E). Examples of the optional additive (F) include organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt 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 promoters, tetrazole-based adhesion promoters, and triazine-based adhesion promoters. Examples of the additives include adhesion-imparting agents 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, and 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. (F) Optional additives may be used singly or in combination of two or more.

[0196] <(G) Solvent> The resin composition according to this embodiment may further contain a (G) solvent as an optional volatile component in addition to the non-volatile components (A) to (F) described above. Typically, an organic solvent is used as the (G) 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 suitable solvents 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. (G) Solvents may be used singly or in combination of two or more.

[0197] The amount of (G) solvent may be set so as to obtain a desired minimum melt viscosity. For example, when a low-viscosity resin such as a liquid epoxy resin is used, a resin composition with a low melt viscosity may be obtained. However, when such a low-viscosity resin is used in small amounts or not at all, the melt viscosity of the resin composition may be high. Therefore, a (G) solvent may be mixed with a resin composition with a high melt viscosity to reduce the melt viscosity of the resin composition. Conventionally, resin compositions with such low melt viscosities may have increased tackiness. In contrast, the resin composition according to this embodiment can reduce tackiness even when the minimum melt viscosity is lowered using, for example, a (G) solvent.

[0198] The amount of (G) solvent 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, 10% by mass or less, or 5% by mass or less, based on 100% by mass of all components of the resin composition. The specific amount of (G) solvent may be adjusted so as to obtain a desired minimum melt viscosity.

[0199] <Method of manufacturing resin composition> The resin composition according to the present embodiment can be produced, for example, by mixing components that can be contained in the resin composition. The above-mentioned components may be mixed in part or all 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.

[0200] <Characteristics of the resin composition and its cured product> The resin composition according to the present embodiment can have low tackiness. For example, as described in the examples below, a resin sheet including a resin composition layer containing a resin composition and a protective film bonded to the resin composition layer is prepared. When a tackiness evaluation test is performed in which the protective film is pulled and peeled off, the tackiness can be reduced to such an extent that no zipping marks remain on the surface of the resin sheet. Here, "zipping" refers to the phenomenon in which the protective film repeatedly peels off and stops when peeled off by pulling with a certain force and speed. Furthermore, "zipping marks" refer to marks formed on the resin composition layer at positions where zipping occurs and peeling of the protective film stops. Usually, when tackiness is sufficiently low, zipping does not occur. Therefore, when zipping does not occur, it can be determined that the tackiness is low. Because the resin composition according to the present embodiment has such low tackiness, it is usually possible to suppress poor peeling of the protective film from the resin sheet and suppress the occurrence of voids in the insulating layer. Specifically, the tackiness evaluation test can be carried out as described in <Test Example 2: Tackiness Evaluation Test> in the Examples section below.

[0201] The resin composition according to this embodiment can generally have a low minimum melt viscosity, and thus can achieve both low tackiness and a low minimum melt viscosity. Furthermore, because the resin composition according to this embodiment has such a low minimum melt viscosity, when a resin composition layer is formed on an inner layer substrate having wiring on its surface, the wiring on the surface of the inner layer substrate can be satisfactorily embedded in the resin composition layer. The specific range of the minimum melt viscosity of the resin composition is preferably 6,000 poise or less, more preferably 5,000 poise or less, and even more preferably 4,500 poise or less. The lower limit can be, for example, 500 poise or more, 1,000 poise or more, etc.

[0202] The minimum melt viscosity of the resin composition can be determined by measuring the dynamic viscoelastic modulus while raising the temperature from a starting temperature of 60°C to 200°C under the following measurement conditions: a heating rate of 5°C / min, a measurement interval temperature of 2.5°C, a vibration frequency of 1 Hz, and a strain of 5 deg, using a dynamic viscoelasticity measuring device, and obtaining the minimum melt viscosity as the minimum value of the measured melt viscosities. A specific measurement method that can be used is the method described in <Test Example 4: Melt Viscosity Measurement Test> in the Examples below.

[0203] By curing the resin composition, a cured product of the resin composition can be obtained. An insulating layer can be formed from this cured product. Since heat is usually applied when curing a resin composition, volatile components, such as (G) solvent, contained in the resin composition can volatilize due to the heat during curing. Therefore, the cured product obtained by curing the resin composition can contain non-volatile components, such as components (A) to (F), or reaction products thereof.

[0204] The cured product of the resin composition according to this embodiment can have excellent dielectric properties, specifically, a low dielectric loss tangent Df. In one example, the dielectric loss tangent Df of the cured product is preferably 0.0050 or less, more preferably 0.0049 or less, and even more preferably 0.0048 or less. There is no particular lower limit to the dielectric loss tangent Df, and it can be, for example, 0.0010 or more.

[0205] The dielectric loss tangent Df of the cured resin composition can be measured by the cavity resonance perturbation method at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. When the sample is an uncured resin composition, the resin composition may be cured at 200°C for 90 minutes to obtain a cured product, and the dielectric loss tangent Df of the cured product may be measured. A specific measurement method may be the method described in <Test Example 1: Measurement of Dielectric Loss Tangent Df> in the Examples section below.

[0206] When a cured product of the resin composition according to this embodiment is provided on a circuit board, warpage of the circuit board can be suppressed. In one example, when the amount of warpage is measured by the method described in <Test Example 3: Warpage Measurement Test> in the Examples section below, the range of the amount of warpage is preferably less than 2,500 μm, more preferably 2,000 μm or less.

[0207] <Applications of resin composition> The resin composition according to this embodiment can be used to form an insulating layer, and is particularly preferably used to form an insulating layer for a circuit board. The resin composition may also be used to manufacture a resin sheet. Typically, an insulating layer is formed using this resin sheet. The resin composition may also be used for other purposes, such as solder resist, underfill material, die bonding material, hole filling resin, sealing resin, and component embedding resin.

[0208] <Resin sheet> A resin sheet according to one embodiment of the present invention includes a support and a resin composition layer formed on the support. The resin composition layer contains the resin composition described above, and preferably contains only the resin composition described above.

[0209] From the viewpoint of thinning, the thickness of the resin composition layer provided in the resin sheet is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less. The lower limit of the thickness of the resin composition layer can be, for example, 1 μm or more, 3 μm or more, 5 μm or more, etc.

[0210] Examples of the support include plastic film, metal foil, and release paper, with plastic film and metal foil being preferred.

[0211] When a film of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

[0212] 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, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0213] The surface of the support that is to be bonded to the resin composition layer may be subjected to a surface treatment such as matte treatment, corona treatment, or antistatic treatment.

[0214] The support may be a support with a release layer, which has a release layer on the surface that bonds with the resin composition layer. 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-based release agents, polyolefin-based release agents, urethane-based release agents, and silicone-based release agents. Commercially available products may be used as the support with a release layer, including PET films having a release layer primarily composed of a silicone-based release agent or an alkyd resin-based release agent, such as "PET501010," "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 Limited.

[0215] The thickness of the support is not particularly limited, but is preferably 1 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, and is preferably 75 μm or less, more preferably 60 μm or less, even more preferably 50 μm or less. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is within the above range.

[0216] The resin sheet may include any optional member as needed. For example, the resin sheet may include a protective film for protecting the resin composition layer. The protective film is usually provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite to the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. When the protective film is provided, adhesion of dust and scratches to the surface of the resin composition layer can be suppressed.

[0217] The resin sheet can be produced, for example, by a method including forming a resin composition layer on a support. Specifically, the resin sheet can be produced by applying a liquid (varnish-like) resin composition directly or by mixing a solvent and the resin composition to prepare a liquid (varnish-like) resin composition, applying the liquid (varnish-like) resin composition to a support, and then drying it as necessary to form a resin composition layer. The solvent may be the same as the (G) solvent described as a component of the resin composition.

[0218] The resin composition can be applied using a coating device such as a die coater. Drying can be performed by a drying method such as heating or hot air blowing. The drying conditions are not particularly limited, but drying is typically performed so that the solvent content in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Although this may vary depending on the boiling point of the solvent, for example, when a resin composition containing 30% by mass to 60% by mass of solvent is used, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0219] The produced resin sheet can be stored by being wound up in a roll. When the resin sheet has a protective film, the resin sheet can usually be used by peeling off the protective film.

[0220] <Circuit board> A circuit board according to one embodiment of the present invention includes a cured product of the resin composition described above. Typically, the circuit board includes an insulating layer, and this insulating layer includes a cured product of the resin composition. The insulating layer may include only a cured product of the resin composition. The thickness of the insulating layer is not particularly limited and may be, for example, in the same range as the thickness of the resin composition layer included in the resin sheet. Furthermore, the insulating layer may typically have properties similar to those of the cured product of the resin composition described above.

[0221] Preferably, the circuit board includes an inner layer substrate and the insulating layer is provided on the inner layer substrate. The circuit board may also include a conductor layer. For example, the conductor layer may be provided on an insulating layer. An example of a preferred method for manufacturing a circuit board will be described below.

[0222] A preferred example of a method for manufacturing a circuit board includes the steps of: Step (I) of forming a resin composition layer on an inner layer substrate; a step (II) of curing the resin composition layer; Includes:

[0223] An "inner layer substrate" is a member that serves as the base material of a circuit board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The inner layer substrate may have a conductor layer on one or both sides. The conductor layer of the inner layer substrate may be patterned. An inner layer substrate having a conductor layer (circuit) formed on one or both sides of the substrate is sometimes called an "inner layer circuit board." The term "inner layer substrate" also includes intermediate products on which insulating layers and / or conductor layers are to be further formed during the production of a circuit board. In addition, inner layer substrates with built-in components may also be used.

[0224] The resin composition layer may be formed on the inner layer substrate by, for example, a method including applying a resin composition to the inner layer substrate and drying it as necessary, but is preferably formed using a resin sheet. The method for forming a resin composition layer using a resin sheet typically includes laminating the resin sheet and the inner layer substrate. The resin sheet and the inner layer substrate are laminated so that the resin composition layer of the resin sheet and the inner layer substrate are bonded. This lamination may be performed, 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). It is preferable to press the thermocompression bonding member not directly against the resin sheet but through 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.

[0225] 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 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. The lamination is preferably carried out under reduced pressure conditions of 26.7hPa or less.

[0226] The lamination may 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.

[0227] The method for manufacturing a circuit board may include smoothing the resin sheet after lamination under normal pressure (atmospheric pressure), for example, by pressing the resin sheet from the support side with a thermocompression member. The pressing conditions for the smoothing may be the same as those for the thermocompression bonding of the lamination. The smoothing may be performed using a commercially available laminator. The lamination and smoothing may be performed consecutively using the commercially available vacuum laminator.

[0228] The method for producing a circuit board according to this example includes a step (II) of curing the resin composition layer after the step (I). By curing the resin composition layer in the step (II), an insulating layer containing a cured product of the resin composition can be formed.

[0229] The resin composition layer is usually cured by thermal curing. The thermal curing conditions for the resin composition layer may vary depending on the type of resin composition. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0230] The method for producing a circuit board may include preheating the resin composition layer at a temperature lower than the curing temperature before thermally curing the resin composition layer. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated for typically 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, at a temperature of typically 50°C to 150°C, preferably 60°C to 140°C, and more preferably 70°C to 130°C. Preheating is typically carried out after step (I). Furthermore, when a smoothing treatment is carried out after laminating the inner layer substrate and the resin sheet, preheating can typically be carried out after the smoothing treatment.

[0231] When a resin sheet is used, the method for producing a circuit board may include a step of peeling off the support of the resin sheet after laminating the inner layer substrate and the resin sheet. The peeling off of the support may be performed between steps (I) and (II), or after step (II). Furthermore, when the method for producing a circuit board includes step (III) of forming holes in the insulating layer, step (IV) of roughening the insulating layer, and step (V) of forming a conductor layer, as described below, the peeling off of the support may be performed between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V).

[0232] The method for producing a circuit board may include, after step (II), step (III) of forming holes such as via holes or through holes in the insulating layer. The method for forming the holes may be selected depending on factors such as the composition of the resin composition used to form the insulating layer. For example, holes may be formed by processing methods such as drilling, laser processing, and plasma processing, with laser processing being preferred. For example, holes may be formed by irradiating the insulating layer with laser light after peeling off the support, or by irradiating the insulating layer with laser light through the support. The dimensions and shape of the holes may be determined appropriately depending on the design of the circuit board.

[0233] The method for manufacturing a circuit board may include a step (IV) of roughening the insulating layer. The roughening treatment can roughen the surface of the insulating layer. The roughening treatment can also remove smears (resin residues) from the insulating layer. Therefore, this roughening treatment is sometimes called a "desmear treatment." For example, when holes are formed in step (III), smears may form in the holes. Therefore, it is preferable to perform the roughening treatment of step (IV) after step (III) to remove the smears.

[0234] The procedure and conditions for the roughening treatment are not particularly limited, and known procedures and conditions that are commonly used when forming an insulating layer for a circuit board can be adopted. For example, the roughening treatment may be performed by subjecting the insulating layer to a swelling treatment using a swelling liquid, an oxidation treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid in this order.

[0235] Examples of swelling liquids used in the roughening treatment include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Sodium hydroxide solutions and potassium hydroxide solutions are more preferred as alkaline solutions. Commercially available swelling liquids include "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan. Swelling treatment using a swelling liquid can be performed, for example, by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes. To keep the 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.

[0236] Examples of oxidizing agents used in the roughening treatment include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Oxidation treatment using an oxidizing agent such as 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.

[0237] 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 can be cited as an example. Neutralization treatment using a neutralizing solution can be carried out by immersing the surface that has been oxidized with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, a preferred method is to immerse the object that has been oxidized with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

[0238] The method for producing a circuit board may include step (V) of forming a conductor layer on the insulating layer. When the method for producing a circuit board includes step (III) or (IV), step (V) of forming a conductor layer is usually preferably carried out after steps (III) and (IV).

[0239] The conductive 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 alloy layers 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, and the like, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, copper-nickel alloy, or 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.

[0240] The conductor layer may have a single layer structure or a multi-layer structure including two or more single metal or alloy layers made of different types of metals or alloys. 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.

[0241] The thickness of the conductor layer depends on the design of the circuit board, but is preferably 3 μm to 35 μm, and more preferably 5 μm to 30 μm.

[0242] The conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of the insulating layer using a conventionally known technique such as a semi-additive method or a full-additive method. From the viewpoint of ease of production, the semi-additive method is preferred. An example of forming a conductor layer by a semi-additive method will be described below.

[0243] First, an electroless plated layer (plating seed layer) is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed electroless plated layer, exposing a portion of the electroless plated layer corresponding to the desired wiring pattern. After forming an electroless plated layer on the exposed electroless plated layer by electrolytic plating, the mask pattern is removed. Thereafter, unnecessary electroless plated layer is removed by etching, thereby forming a conductor layer having the desired wiring pattern.

[0244] As another example, the conductor layer may be formed using a metal foil. When a metal foil is used to form the conductor layer, step (V) is preferably performed between steps (I) and (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 known technique such as a subtractive method or a modified semi-additive method. The metal foil can be manufactured by a known method such as an electrolytic method or a rolling method. Commercially available metal foils include, for example, HLP foil and JXUT-III foil manufactured by JX Nippon Mining & Smelting Co., Ltd., and 3EC-III foil and TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd.

[0245] When a conductor layer is formed on an insulating layer, the method for manufacturing a circuit board may include performing an annealing treatment after the formation of the conductor layer. The annealing treatment can improve the adhesion between the insulating layer and the conductor layer. The annealing treatment can be performed, for example, by heating at 150°C to 210°C for 20 to 180 minutes.

[0246] In the method for manufacturing a circuit board, each of the above steps may be performed only once or may be repeated two or more times. For example, steps (I) to (V) may be performed repeatedly to form a circuit board having a multilayer structure, such as a multilayer printed wiring board having a plurality of insulating layers and conductor layers.

[0247] The method for manufacturing a circuit board may include any additional steps in addition to the steps described above. For example, the method for manufacturing a circuit board may include a step of providing a semiconductor chip so that the semiconductor chip is bonded to the conductor layer. Specifically, when manufacturing a circuit board for a semiconductor chip package including a semiconductor chip, the method for manufacturing a circuit board may include a step of providing the semiconductor chip. The semiconductor chip may be bonded under appropriate conditions that allow conductive connection between the terminal electrodes of the semiconductor chip and the conductor layer formed on the insulating layer. For example, conditions used in flip-chip mounting may be used. The semiconductor chip may be bonded via an insulating adhesive or by reflow bonding. If necessary, the provided semiconductor chip may be filled with a mold underfill material. The method for manufacturing a circuit board may also include, for example, a step of forming a sealing layer, a step of forming a solder resist layer, and a step of dicing the manufactured circuit board into individual pieces.

[0248] Examples of circuit boards include printed wiring boards and semiconductor chip packages. Examples of semiconductor chip packages include FC-CSP, MIS-BGA package, ETS-BGA package, fan-out type WLP (Wafer Level Package), fan-in type WLP, fan-out type PLP (Panel Level Package), and fan-in type PLP. In these semiconductor chip packages, it is preferable to form a rewiring formation layer as an insulating layer using a cured product obtained by curing the above-mentioned resin composition. However, the circuit board is not limited to those exemplified here.

[0249] <Semiconductor device> The circuit board can be used to manufacture a semiconductor device. The semiconductor device includes the circuit board described above. Examples of the semiconductor device include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical equipment, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft). [Example]

[0250] The present invention will be specifically described below with reference to examples, although the present invention is not limited to these examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Unless otherwise specified, the temperature and pressure conditions were room temperature (23°C) and atmospheric pressure (1 atm).

[0251] <Synthesis Example 1: Synthesis of elastomer (D1)> A reaction vessel was charged with 69 g of bifunctional hydroxy-terminated polybutadiene ("G-3000" manufactured by Nippon Soda Co., Ltd., number average molecular weight = 3000, hydroxy group equivalent weight = 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, which were mixed and dissolved uniformly. Once homogeneous, the mixture was heated to 60°C, and 8 g of isophorone diisocyanate ("IPDI" manufactured by Evonik Degussa Japan Co., Ltd., isocyanate group equivalent weight = 113 g / eq.) was added with further stirring, and the reaction was carried out for approximately 3 hours.

[0252] Next, 23 g of cresol novolak resin (DIC Corporation "KA-1160", hydroxyl group equivalent = 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 reacted for about 10 hours. -1 The disappearance of the NCO peak was confirmed. The disappearance of the NCO peak was considered to be the end 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 an elastomer (D1) having a butadiene structure and phenolic hydroxyl groups (phenolic hydroxyl group-containing butadiene resin: non-volatile components 50% by mass). The weight-average molecular weight of the elastomer (D1) was 27,000, and the glass transition temperature was -7°C.

[0253] The modulus of elasticity of the resulting elastomer (D1) was measured using the following modulus measurement method. Specifically, a polyethylene terephthalate film (Toray Industries, Inc.'s "Lumirror R80," 38 μm thick, softening point 130°C) was prepared, which had been subjected to a release treatment with an alkyd resin-based release agent (Lintec Corporation's "AL-5"). The elastomer (D1) was uniformly applied to the polyethylene terephthalate film using a die coater so that the dried elastomer layer would be 50 μm thick. The film was then dried at 70°C to 120°C for 10 minutes to form an elastomer layer. The elastomer layer was peeled from the polyethylene terephthalate, and the modulus was measured using a tensile test (temperature 25°C, humidity 40% RH) in accordance with JIS K7161. The modulus of elasticity of the elastomer (D1) was confirmed to be 0.05 GPa.

[0254] <Synthesis Example 2: Synthesis of elastomer (D2)> A flask equipped with a stirrer, thermometer, and condenser was charged with 368.41 g of ethyl diglycol acetate and 368.41 g of an aromatic solvent ("Solvesso 150 (registered trademark)" manufactured by ExxonMobil Corporation) as a 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 produced a first reaction solution.

[0255] Next, 195.9 g (0.2 mol) of nonylphenol novolac 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. FT-IR showed a peak at 2250 cm -1 The disappearance of the NCO peak was confirmed. The disappearance of the NCO peak was considered to be the end of the reaction, and the second reaction solution was cooled to room temperature. The second reaction solution was then filtered through a 100-mesh filter cloth. As a result, an elastomer (D2) having phenolic hydroxyl groups (phenolic hydroxyl group-containing polycarbonate resin: non-volatile components 50% by mass) was obtained as a filtrate. The weight-average molecular weight of the elastomer (D2) was 20,000, and the glass transition temperature was 5°C. The elastic modulus of the elastomer (D2) was confirmed to be 0.5 GPa as measured by a tensile test (temperature 25°C, humidity 40% RH) in accordance with JIS K7161 using the same elastic modulus measurement method as for the elastomer (D1).

[0256] <Synthesis Example 3: Synthesis of elastomer (D3)> A 1-L separable flask equipped with an oil bath and a stirrer was charged with 200 g of cyclohexanone while introducing nitrogen gas. Then, 149.4 g of a dimer acid diamine ("PRIAMINE 1075" manufactured by Croda Japan) and 4.7 g of m-aminophenol were added with stirring. Subsequently, 67.3 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride were added and stirred at room temperature for 30 minutes. The mixture was heated to 100°C and stirred for 3 hours. After that, the oil bath was removed and the mixture was returned to room temperature to obtain a varnish-like polyimide precursor. The mixture was then heated at 170°C for 10 hours while removing the distilled water using a Dean-Stark trap. This resulted in imidization, yielding elastomer (D3) with a dimer acid skeleton (50% nonvolatiles). The resulting elastomer (D3) had a weight-average molecular weight of 10,000. Using the same elastic modulus measurement method as for elastomer (D1), the elastic modulus of elastomer (D3) was confirmed to be 0.2 GPa as measured by a tensile test (temperature 25°C, humidity 40% RH) in accordance with JIS K7161.

[0257] <Synthesis Example 4: Synthesis of Maleimide Resin (B)> An MEK solution (60% by mass of non-volatile components) of maleimide resin (B) was prepared using the method described in Synthesis Example 1 of Japan Institute of Invention and Innovation Disclosure Technical Bulletin No. 2020-500211. This maleimide resin (B) had a structure represented by the following formula (b-1) and a weight-average molecular weight of 2,000.

[0258] [ka]

[0259] <Examples 1 to 8 and Comparative Examples 1 to 9> (1) Preparation of resin composition: Each component was weighed and mixed in the amount (parts by mass) shown in Tables 1 to 4, and then 15 parts of MEK and 15 parts of cyclohexanone were added and uniformly dispersed using a high-speed rotating mixer to obtain a resin composition (resin varnish). Details of each component shown in Tables 1 to 4 are as follows.

[0260] (A) Component: "SLK-6893-T90": flexible skeleton bismaleimide resin (manufactured by Shin-Etsu Chemical Co., Ltd., toluene solution with 90% non-volatile components), a first bismaleimide compound represented by formula (3-i) (m i =0, R i 90% by mass of a second bismaleimide compound (m ii =0, n ii =1, R ii 6% by mass of a second bismaleimide compound (m ii =0, n ii =2, R ii A resin containing 4% by mass of a compound represented by formula (2).

[0261] (B) Ingredients: "ZX-1059": Bisphenol epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., a 1:1 mixture of bisphenol A and bisphenol F, epoxy equivalent weight 169g / eq.). "NC3000": Biphenyl aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 275g / eq.). "HP4032SS": Naphthalene-type epoxy resin (manufactured by DIC, epoxy equivalent weight approximately 144g / eq.). "YX4000HK": Bixylenol-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent weight approximately 185g / eq.). "HPC-8000-65T": Active ester resin (manufactured by DIC Corporation, active group equivalent weight approximately 223 g / eq., toluene solution with 65% non-volatile content by mass). "KA-1160": Cresol novolac phenolic resin (manufactured by DIC Corporation, hydroxyl group equivalent weight 117g / eq.). "V-03": Carbodiimide resin (manufactured by Nisshinbo Chemical Inc., active group equivalent weight 216 g / eq., toluene solution with 50% non-volatile components). "OPE-2St": vinylbenzyl-modified polyphenylene ether (manufactured by Mitsubishi Gas Chemical Co., Ltd., toluene solution with a non-volatile content of 65%). "Maleimide resin B": Maleimide resin (B) synthesized in Synthesis Example 4, non-volatile component 60% by mass. "BMI-689": Flexible backbone bismaleimide resin (manufactured by Designer Molecules, 100% non-volatile component), any bismaleimide compound represented by formula (3-i) (m i =0, R i 93% by mass of any bismaleimide compound represented by formula (3-ii) (m ii =0, n ii =1, R ii 4% by mass of an arbitrary bismaleimide compound (m ii =0, n ii =2, R ii A resin containing 3% by mass of the optional bismaleimide compound represented by formula (1-ii) (represented by formula (2)). Since the amount of the optional bismaleimide compound represented by formula (1-ii) is not within a specific range, Comparative Examples 1 and 4 to 9 are classified as component (B).

[0262] (C) Ingredients: "SO-C2": Spherical silica (average particle size 0.5 μm, manufactured by Admatechs Co., Ltd.) surface-treated with an aminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.). "LHP-208": Silica (average particle size 0.5 μm, manufactured by Ube Exsymo Co., Ltd.) surface-treated with an aminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0263] (D) Component "Elastomer D1": Elastomer (D1) synthesized in Synthesis Example 1, non-volatile component 50% by mass. "Elastomer D2": Elastomer (D2) synthesized in Synthesis Example 2, non-volatile component 50% by mass. "Elastomer D3": Elastomer (D3) synthesized in Synthesis Example 3, non-volatile component 50% by mass.

[0264] (E) Ingredients: "2P4MZ": 2-phenyl-4-methylimidazole (manufactured by Shikoku Chemicals Corporation) "Luperox DTA": Di-t-amyl peroxide (manufactured by Arkema Yoshitomi Co., Ltd.)

[0265] (2) Resin sheet manufacturing: As a support, 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. The resin composition was uniformly applied to the support using a die coater so that the thickness of the resin composition layer after drying would be 50 μm, and the film was dried at 70 to 100°C for 3 minutes so that the residual solvent content was 2% by mass, forming a resin composition layer. 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 side of the resin composition layer that was not bonded to the support. This resulted in a resin sheet having a support, a resin composition layer, and a protective film in this order.

[0266] <Test Example 1: Measurement test of dielectric loss tangent Df> The protective film was peeled off from the resin sheet. The resin composition layer was thermally cured by heating at 200°C for 90 minutes, and then the support was peeled off to obtain a cured product. The obtained cured product was cut into a width of 2 mm and a length of 80 mm to obtain a test piece for evaluation.

[0267] The dielectric loss tangent of each test piece was measured by a cavity resonance perturbation method using a measuring device ("HP8362B" manufactured by Agilent Technologies) 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. Based on this average value, the dielectric loss tangent was evaluated according to the following evaluation criteria.

[0268] Evaluation criteria for dielectric loss tangent "Good": Dielectric tangent is 0.005 or less "Poor": The dissipation factor is greater than 0.005.

[0269] <Test Example 2: Tack Evaluation Test> When the protective film of the resin sheet was peeled off by hand, if a zipping mark remained on the surface of the resin sheet, it was judged that the tackiness was too strong and was evaluated as "poor." If the resin sheet could be peeled off without leaving a zipping mark, it was evaluated as "good."

[0270] <Test Example 3: Warpage measurement test> The resin sheet from which the protective film had been peeled off was laminated over the entire surface of one side of a 12-inch silicon wafer (775 μm thick) 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 support of the resin sheet was peeled off to expose the resin composition layer. A resin sheet from which the protective film had been peeled off was similarly laminated on the surface of this exposed resin composition layer, and the support was peeled off, forming 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 to 13 hPa or less for 30 seconds, followed by pressure bonding at 100°C and a pressure of 0.74 MPa for 30 seconds.

[0271] The sample was heated in an oven at 100°C for 30 minutes, followed by further heating at 200°C for 90 minutes to cure the resin composition layer, yielding a sample laminate having a layer structure of "silicon wafer / cured product layer." The amount of warpage of the resulting sample laminate was measured using a shadow moiré measurement device ("Thermoire AXP" manufactured by Akorometrix). Measurements were performed in accordance with JEITA EDX-7311-24, a standard of the Japan Electronics and Information Technology Industries Association. Specifically, a virtual plane calculated using the least squares method for all data on the evaluation substrate surface (the surface of the cured product layer opposite the silicon wafer) in the measurement area was used as the reference plane. The difference between the minimum and maximum vertical heights from this reference plane to the evaluation substrate surface was calculated as the amount of warpage. The measured values of the amount of warpage were evaluated according to the following criteria.

[0272] Warpage evaluation criteria: "Excellent": Warpage is between 0 μm and 2000 μm. "Good": Warpage is over 2000 μm and less than 2500 μm. "Poor": Warpage is 2500 μm or more.

[0273] <Test Example 4: Melt Viscosity Measurement Test> A portion of the resin composition layer was peeled off from the resin sheet to obtain a resin composition sample, and the melt viscosity was measured using a dynamic viscoelasticity measuring device (Rheosol-G3000, manufactured by UBM). Specifically, a 1g sample of the resin composition was heated from an initial temperature of 60°C to 200°C at a heating rate of 5°C / min using parallel plates with a diameter of 18mm. The dynamic viscoelasticity was measured under the following measurement conditions: measurement interval temperature 2.5°C, frequency 1Hz, and strain 5°C, and the minimum melt viscosity (poise) was calculated. The measured minimum melt viscosity was evaluated according to the following criteria.

[0274] Minimum melt viscosity rating criteria: "Good": Minimum melt viscosity is 6000 Poise or less "Poor": The minimum melt viscosity is greater than 6000 Poise.

[0275] <Result> The results of the above-mentioned Examples and Comparative Examples are shown in the following table. In the table, the meanings of the abbreviations are as follows: NVC: Non-volatile content concentration. Amount of component (A): Amount of component (A) relative to 100% by mass of the nonvolatile components of the resin composition. Amount of component (B): Amount of component (B) relative to 100% by mass of the nonvolatile components of the resin composition. Amount of component (C): Amount of component (C) relative to 100% by mass of the nonvolatile components of the resin composition. Amount of component (D): Amount of component (D) relative to 100% by mass of the nonvolatile components of the resin composition. Amount of component (E): Amount of component (E) relative to 100% by mass of the nonvolatile components of the resin composition. Component (A) / Component (D): Amount of component (A) relative to 100% by mass of the nonvolatile components of component (D). Amount of second bismaleimide compound: Amount of second bismaleimide compound relative to 100% by mass of the nonvolatile components of the resin composition. Df: dielectric loss tangent.

[0276]

Table 1

[0277]

Table 2

[0278]

Table 3

[0279]

Table 4

Claims

1. (A) A combination of a bismaleimide compound represented by the following formula (1-i) and a bismaleimide compound represented by the following formula (1-ii), in which the amount of the bismaleimide compound represented by the following formula (1-ii) is 8% by mass or more and 50% by mass or less, relative to 100% by mass of the combination; (B) a thermosetting resin; and (C) an inorganic filler; and a resin composition comprising the same. 【Chemical 1】 (In formula (1-i), X ｉ each independently represents a tetravalent organic group, R ｉ represent divalent aliphatic hydrocarbon groups having the same structure, m ｉ represents an integer of 0 or greater; In formula (1-ii), X ｉｉ each independently represents a tetravalent organic group, R ｉｉ are all R ｉ represents a divalent aliphatic hydrocarbon group having the same structure as m ｉｉ represents an integer of 0 or greater, n ｉｉ represents 1 or 2; The moiety represented by the following formula (1-ia) in formula (1-i) and the moiety represented by the following formula (1-ii-a) in formula (1-ii) are R ｉ The bond direction and R ｉｉ They have the same structure except for the orientation of the bond.) 【Chemistry 2】

2. R ｉ and R ｉｉ The resin composition according to claim 1 , wherein the alkyl group has at least 5 carbon atoms and the alkylene group has at least 5 carbon atoms.

3. R ｉ and R ｉｉ The resin composition according to claim 1 , wherein represents a divalent aliphatic hydrocarbon group containing a dimer acid skeleton.

4. R ｉ and R ｉｉ The resin composition according to claim 1, wherein each of the above is represented by the following formula (2): 【Chemistry 3】 (In formula (2), * represents a binding site.)

5. The bismaleimide compound represented by formula (1-i) is represented by the following formula (3-i): The resin composition according to claim 1, wherein the bismaleimide compound represented by formula (1-ii) is represented by the following formula (3-ii): 【Chemistry 4】 (In formula (3-i), R ｉ represent divalent aliphatic hydrocarbon groups having the same structure, m ｉ represents an integer of 0 or greater; In formula (3-ii), R ｉｉ are all R ｉ represents a divalent aliphatic hydrocarbon group having the same structure as m ｉｉ is m ｉ represents an integer equal to or greater than 0, n ｉｉ represents 1 or 2.)

6. m ｉ and m ｉｉ The resin composition according to claim 1 , wherein both of

7. The resin composition according to claim 1 , wherein the thermosetting resin (B) comprises an epoxy resin.

8. The resin composition according to claim 1, wherein the amount of the inorganic filler (C) is 50% by mass or more relative to 100% by mass of the nonvolatile components of the resin composition.

9. The resin composition according to claim 1, further comprising (D) an elastomer.

10. The resin composition according to claim 9, wherein the elastomer (D) has a weight average molecular weight of greater than 5,000.

11. 10. The resin composition according to claim 9, wherein the elastomer (D) 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.

12. The resin composition according to claim 1 for forming an insulating layer.

13. A support and a resin composition layer provided on the support, A resin sheet, wherein the resin composition layer comprises the resin composition according to any one of claims 1 to 12.

14. A cured product of the resin composition according to any one of claims 1 to 12.

15. A circuit board comprising a cured product of the resin composition according to any one of claims 1 to 12.

16. A semiconductor device comprising the circuit board according to claim 15.

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