Resin composition

Abstract

Provided is a resin composition which is capable of forming an insulating layer having a low dielectric loss tangent and which has low viscosity. A resin composition includes (A) a combination of specific bismaleimide compounds, (B) a thermosetting resin, and (C) an inorganic filler.

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 Art

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

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-138996. Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] The insulating layer generally requires a low dielectric loss tangent. Thus, the present inventors have tried to form an insulating layer having a low dielectric loss tangent by a resin composition containing a maleimide resin. However, the resin composition used in such a forming method tends to have an excessive viscosity.

[0008] For example, in the case of forming an insulating layer by a lamination method using a resin sheet having a resin composition layer, it is sometimes required to bury wirings and components through the resin composition layer during lamination. At this time, in order to obtain good embedability, the composition of the resin composition is sometimes adjusted to reduce the melt viscosity of the resin composition. However, in such an adjusted composition, the viscosity of the resin composition sometimes becomes large. If the viscosity is too large, the peelability of the protective film of the resin sheet becomes insufficient, the workability is reduced, or it becomes a cause of voids in the laminated insulating layer.

[0009] The present invention has been made in view of the above problems, and an object thereof is to provide: a resin composition capable of forming an insulating layer having a low dielectric loss tangent and having a low viscosity; a resin sheet containing the resin composition; a cured product of the resin composition; a circuit board containing the cured product of the resin composition; and a semiconductor device including the circuit board.

[0010] Means for Solving the Problems

[0011] The inventors of the present invention have conducted in-depth research to solve the above problems. As a result, the inventors have found that a resin composition containing a combination of specific bismaleimide compounds, a thermosetting resin, and an inorganic filler can solve the above problems, and thus completed the present invention.

[0012] That is, the present invention includes the following content.

[0013] <1> A resin composition comprising:

[0014] (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 in this combination, 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 based on 100% by mass of this combination;

[0015] (B) A thermosetting resin; and

[0016] (C) An inorganic filler,

[0017]

[0018] In formula (1-i),

[0019] X i Each independently represents a tetravalent organic group,

[0020] R i Represents a divalent aliphatic hydrocarbon group having the same structure,

[0021] m i Represents an integer of 0 or more;

[0022] In formula (1-ii),

[0023] X ii Each independently represents a tetravalent organic group,

[0024] R ii Represents a divalent aliphatic hydrocarbon group having the same structure as R i The same structure,

[0025] m ii Represents an integer of 0 or more,

[0026] n ii Represents 1 or 2;

[0027] Except for the bond orientation of R i And the bond orientation of R ii The part represented by the following formula (1-i-a) of formula (1-i) and the part represented by the following formula (1-ii-a) of formula (1-ii) have the same structure,

[0028]

[0029] <2><1> The resin composition according to the above, wherein R i and R ii include one or more selected from alkyl groups having 5 or more carbon atoms and alkylene groups having 5 or more carbon atoms.

[0030] <3><1> or <2> The resin composition according to the above, wherein R i and R ii represent a divalent aliphatic hydrocarbon group containing a dimer acid skeleton.

[0031] <4><1> to <3> The resin composition according to any one of the above, wherein R i and R ii are both represented by the following formula (2),

[0032]

[0033] In formula (2), * represents the bonding site.

[0034] <5><1> to <4> The resin composition according to any one of the above, wherein the bismaleimide compound represented by formula (1-i) is represented by the following formula (3-i),

[0035] The bismaleimide compound represented by formula (1-ii) is represented by the following formula (3-ii),

[0036]

[0037] In formula (3-i),

[0038] R i represents a divalent aliphatic hydrocarbon group having the same structure,

[0039] m i represents an integer of 0 or more;

[0040] In formula (3-ii),

[0041] R ii represents a divalent aliphatic hydrocarbon group having the same structure as R i and the same structure,

[0042] m ii represents the same integer of 0 or more as m i and the same,

[0043] n ii represents 1 or 2.

[0044] <6><1> to <5> The resin composition according to any one of the above, wherein mi and m ii are both 0.

[0045] <7> The resin composition according to any one of <1> to <6>, wherein the (B) thermosetting resin contains an epoxy resin.

[0046] <8> The resin composition according to any one of <1> to <7>, wherein the amount of the (C) inorganic filler is 50% by mass or more with respect to the non-volatile components of 100% by mass of the resin composition.

[0047] <9> The resin composition according to any one of <1> to <8>, which further contains a (D) elastomer.

[0048] <10> The resin composition according to <9>, wherein the (D) elastomer has a weight-average molecular weight of more than 5,000.

[0049] <11> The resin composition according to <9> or <10>, wherein the (D) elastomer contains one or more selected from the following structures: polybutadiene structure, polycarbonate structure, polyalkylene structure, polyalkyleneoxy structure, polysiloxane structure, poly(meth)acrylate structure, polyisoprene structure, polyisobutylene structure, and polystyrene structure.

[0050] <12> The resin composition according to any one of <1> to <11> for forming an insulating layer.

[0051] <13> A resin sheet comprising: a support and a resin composition layer provided on the support,

[0052] The resin composition layer contains the resin composition according to any one of <1> to <12>.

[0053] <14> A cured product of the resin composition according to any one of <1> to <12>.

[0054] <15> A circuit board comprising a cured product of the resin composition according to any one of <1> to <12>.

[0055] <16> A semiconductor device comprising the circuit board according to <15>.

[0056] Advantages of the Invention

[0057] According to the present invention, there can be provided: a resin composition capable of forming an insulating layer having a low dielectric loss tangent and having low viscosity; 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 containing the circuit board. Detailed Description

[0058] Hereinafter, embodiments and examples will be shown to describe the present invention. However, the present invention is not limited to the embodiments and examples shown below, and can be implemented with modifications within the scope not exceeding the claims and their equivalents.

[0059] In this specification, the term "may have a substituent" when referring to a compound or a group means both the case where the hydrogen atom of the compound or group is not substituted with a substituent and the case where a part or all of the hydrogen atoms of the compound or group are substituted with a substituent.

[0060] <Summary of the resin composition>

[0061] The resin composition according to one embodiment of the present invention contains: (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), and the amount of the bismaleimide compound represented by the formula (1-ii) in this 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 the formula (1-i)" contained in the component (A) may sometimes be referred to as the "first bismaleimide compound". In addition, the "bismaleimide compound represented by the formula (1-ii)" contained in the component (A) may sometimes be referred to as the "second bismaleimide compound". Moreover, the "(A) combination of the first bismaleimide compound represented by the formula (1-i) and the second bismaleimide compound represented by the following formula (1-ii)" as the component (A) may sometimes be referred to as the "(A) specific bismaleimide resin".

[0062]

[0063] In the formula (1-i), X i each independently represents a tetravalent organic group; R i represents a divalent aliphatic hydrocarbon group having the same structure; m i represents an integer of 0 or more. In the formula (1-ii), X ii each independently represents a tetravalent organic group; R ii represents a divalent aliphatic hydrocarbon group having the same structure as R i ; m ii represents an integer of 0 or more; n ii represents 1 or 2. Except for the orientation of the bond of R i and the orientation of the bond of R ii , the part represented by the following formula (1-i-a) of the formula (1-i) and the part represented by the following formula (1-ii-a) of the formula (1-ii) have the same structure.

[0064]

[0065] In Formula (1-i-a) and Formula (1-ii-a), the meanings of the symbols are the same as those in Formula (1-i) and Formula (1-ii); * represents a bonding site.

[0066] The resin composition may have low viscosity and can form an insulating layer having a low dielectric loss tangent. Moreover, the resin composition generally may have a low minimum melt viscosity. In addition, by using the resin composition, a circuit board with suppressed warpage can be manufactured.

[0067] The present inventors presume the mechanism for obtaining such excellent effects as follows. However, the technical scope of the present invention is not limited by the following mechanism.

[0068] (A) The first bismaleimide compound and the second bismaleimide compound contained in the specific bismaleimide resin contain a maleimide group (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl). Since this maleimide group reacts to form a bond, the resin composition can be cured to form a cured product. Generally, polar groups such as hydroxyl groups are not generated due to the reaction of the maleimide group during the curing of the resin composition. Therefore, the cured product can have a small polarity, so when an insulating layer is formed of the cured product, the insulating layer can have a small polarity. Therefore, the insulating layer can have a low dielectric loss tangent.

[0069] In addition, in a combination of a first bismaleimide compound and a second bismaleimide compound containing the same or a similar structure, the first bismaleimide compound has good compatibility with other resin components contained in the resin composition. When the compatibility of the resin components in the resin composition is good, the viscosity generally tends to increase. In particular, when the resin composition contains an (D) elastomer, this tendency is significant. Specifically, the (B) thermosetting resin generally has a tendency of low compatibility with the (D) elastomer. Therefore, the viscosity of the conventional resin composition containing the (B) thermosetting resin and the (D) elastomer is good. However, in order to reduce the dielectric loss tangent, when the first bismaleimide compound is further combined with the (B) thermosetting resin and the (D) elastomer, since the first bismaleimide compound has high compatibility with the (D) elastomer, the viscosity increases and becomes excessive. In contrast, the second bismaleimide compound contained in the resin composition of the present embodiment in combination with the first bismaleimide compound has poor compatibility with resin components other than the first bismaleimide compound and the second bismaleimide compound. For example, compared with the compatibility between the (D) elastomer and the first bismaleimide compound, the compatibility between the (D) elastomer and the second bismaleimide compound is low. It is presumed that this is due to the fact that compared with the overall low polarity of the structure of the first bismaleimide compound, the secondary amino group of the second bismaleimide compound has high polarity, resulting in the change of the overall polarity of the molecule. That is, when the 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 caused by the first bismaleimide compound. On the other hand, if the compatibility is excessively reduced, the uniformity of the resin composition is reduced, and phase separation may occur, or the film-forming property is reduced. Therefore, by combining the second bismaleimide compound and the first bismaleimide compound in an appropriate ratio, a resin composition excellent in both viscosity and uniformity can be obtained.

[0070] Moreover, the first bismaleimide compound contains a divalent aliphatic hydrocarbon group R i , and the second bismaleimide compound contains a divalent aliphatic hydrocarbon group R ii . These divalent aliphatic hydrocarbon groups R i and R ii are different from rigid structures such as arylene groups and can function as flexible molecular structures. Therefore, the resin composition containing a combination of the first bismaleimide compound and the second bismaleimide compound can reduce the minimum melt viscosity.

[0071] In addition, the flexible molecular structures of the first bismaleimide compound and the second bismaleimide compound are also included in the cured product of the resin composition, and can play a role in absorbing stress. Therefore, when the cured product containing elements capable of absorbing stress is provided on a circuit board, deformation caused by stress can be suppressed, and thus warpage can be suppressed.

[0072] <(A) Specific bismaleimide resin (combination of the first bismaleimide compound and the second bismaleimide compound)>

[0073] The resin composition according to this embodiment contains (A) a specific bismaleimide resin which is a combination of a first bismaleimide compound represented by formula (1-i) and a second bismaleimide compound represented by formula (1-ii).

[0074]

[0075] In formula (1-i), X i each independently represents a tetravalent organic group. The tetravalent organic group preferably consists of 5 or more skeletal atoms and non-skeletal atoms. The 5 or more skeletal atoms are preferably selected from carbon atoms, nitrogen atoms (not forming imide), oxygen atoms, and sulfur atoms. The number of skeletal atoms is usually 5 or more, preferably 5 to 200, more preferably 5 to 100, and further preferably 5 to 50. In addition, the non-skeletal atoms are usually selected from hydrogen atoms and halogen atoms. The tetravalent organic group represented by X i may be a tetravalent organic group without an aromatic ring or a tetravalent organic group with an aromatic ring. When formula (1-i) contains a plurality of X i , the plurality of X i may be the same or different.

[0076] The tetravalent organic group represented by X i is preferably represented by the following formula (X1).

[0077]

[0078] 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-; a x each independently represents an integer of 0 or 1 or more; b x each independently represents 0, 1 or 2; cx represents 0 or 1; * represents the binding site. a x Each unit of the unit may be the same or different.

[0079] In formula (X1), R x1 each independently represents a substituent. As the substituent, for example, the following can be cited: alkyl, alkenyl, aryl, aryl-alkyl, alkyl-oxy, alkenyl-oxy, aryl-oxy, alkyl-carbonyl, alkenyl-carbonyl, aryl-carbonyl, alkyl-oxy-carbonyl, alkenyl-oxy-carbonyl, aryl-oxy-carbonyl, alkyl-carbonyl-oxy, alkenyl-carbonyl-oxy, aryl-carbonyl-oxy, etc. Among them, alkyl is preferred. As the alkyl, an alkyl having 1 to 14 carbon atoms is preferred. As specific examples of the alkyl, the following can be cited: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, cyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, trimethylcyclohexyl, cyclopentylmethyl, cyclohexylmethyl, etc.

[0080] 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. Among them, an aromatic ring which may have a substituent is preferred.

[0081] The aromatic ring means a ring that follows Hückel's rule and has 4p + 2 electrons (p is a natural number) in the π electron system on the ring. The aromatic ring may be an aromatic carbocyclic ring having carbon atoms as ring-forming atoms, or may be an aromatic heterocyclic ring having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms in addition to carbon atoms as ring-forming atoms. Among them, an aromatic carbocyclic ring is preferred. The aromatic ring is preferably an aromatic ring having 5 to 14 members, more preferably an aromatic ring having 5 to 10 members, and further preferably an aromatic ring having 5 or 6 members. As specific examples of the aromatic ring, the following can be cited: benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, etc. More preferably, it is a benzene ring or a naphthalene ring, and further preferably a benzene ring.

[0082] The non-aromatic ring means a ring other than the aromatic ring. The non-aromatic ring may be a non-aromatic carbocyclic ring having carbon atoms as ring-forming atoms, or may be a non-aromatic heterocyclic ring having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms in addition to carbon atoms as ring-forming atoms. Among them, 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 non-aromatic ring having 4 to 14 members. As specific examples of the non-aromatic ring, the following can be cited: monocyclic alkane rings such as cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring; monocyclic olefin rings such as cyclobutene ring, cyclopentene ring, cyclohexene ring, cycloheptene ring, cyclooctene ring, cyclopentadiene ring, cyclohexadiene ring; aromatic ring-non-aromatic ring fused rings such as indane ring, indene ring, tetrahydronaphthalene ring, fluorene ring, etc.

[0083] In formula (X1), Z x1 and Z x2 each independently represents a single bond, an alkylene group, -O-, -CO-, -S-, -SO-, -SO2-, -CONH-, -NHCO-, -COO- or -OCO-. As the alkylene group, an alkylene group having 1 to 14 carbon atoms is preferred. Specific examples of the alkylene group include: linear alkylene groups such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene; ethylidene (-CH(CH3)-), propylidene (-CH(CH2CH3)-), isopropylidene (-C(CH3)2-), ethylmethylmethylene (-C(CH3)(CH2CH3)-), diethylmethylene (-C(CH2CH3)2-) and other branched alkylene groups, etc.

[0084] In formula (X1), a x each independently represents an integer of 0 or more, preferably an integer of 0 to 5, more preferably 0, 1 or 2, still more preferably 0 or 1, and particularly preferably 0.

[0085] In formula (X1), b x each independently represents 0, 1 or 2, preferably 0.

[0086] In formula (X1), c x represents 0 or 1, preferably 1.

[0087] Examples of the tetravalent organic group represented by formula (X1) include: groups represented by the following formulas (x-1) to (x-25). Among these, the group represented by formula (x-8) is preferred. In the following formulas, * represents the bonding site.

[0088]

[0089] In formula (1-i), R i all represent divalent aliphatic hydrocarbon groups having the same structure. The R i contained in formula (1-i) all have the same structure, and the orientation of the bond of R i can be the same or different. Here, the "orientation of the bond" of R i means the orientation in formula (1-i) of the two bonding bonds that R i has. For example, taking the R i contained in the m i unit as an example for illustration. R i representing a divalent aliphatic hydrocarbon group has two bonding bonds. Here, one of the two bonding bonds is referred to as the "first bonding bond", and the other is referred to as the "second bonding bond". The R i contained in the m iThe orientation of the bond can be considered as the orientation in which the first bonding bond is bonded to the maleimide group on the left side of the formula and the second bonding bond is bonded to the imide ring on the right side of the formula, and the orientation in which the first bonding bond is bonded to the imide ring on the right side of the formula and the second bonding bond is bonded to the maleimide group on the left side of the formula. R i The orientation of the bond can be any of them.

[0090] R i The divalent aliphatic hydrocarbon group represented by R is a divalent hydrocarbon group that does not contain an aromatic ring, and can be any of linear, branched, cyclic, and combinations thereof. In addition, the divalent aliphatic hydrocarbon group can be a divalent saturated aliphatic hydrocarbon group or a divalent unsaturated aliphatic hydrocarbon group. R i The number of carbon atoms of the divalent aliphatic hydrocarbon group represented by R is preferably 5 or more, more preferably 6 or more, still more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and still more preferably 40 or less.

[0091] R i Preferably, it contains one or more selected from an alkyl group having 5 or more carbon atoms and an alkylene group having 5 or more carbon atoms. When using such an R i In the case of the first bismaleimide compound, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0092] The number of carbon atoms of the alkyl group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and still more preferably 40 or less. The alkyl group can be any of linear, branched, cyclic, and combinations thereof, and among them, a linear alkyl group is preferred. Examples of the alkyl group include pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc.

[0093] The number of carbon atoms of the alkylene group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and still more preferably 40 or less. The alkylene group can be any of linear, branched, cyclic, and combinations thereof, and among them, a linear alkylene group is preferred. Examples of the alkylene group include pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, heptadecylene, hexatriacontylene, octyl-cyclohexylene, octyl-cyclohexylene-octyl, propyl-cyclohexylene-octyl, etc.

[0094] From the viewpoint of particularly effectively reducing the dielectric loss tangent and the minimum melt viscosity, R i Preferably, it contains both an alkyl group having 5 or more carbon atoms and an alkylene group having 5 or more carbon atoms.

[0095] R iMore preferably, it 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 two terminal carboxyl groups (-COOH) of dimer acid. Dimer acid is a known compound obtained by dimerizing unsaturated fatty acids (preferably unsaturated fatty acids having 11 to 22 carbon atoms, more preferably unsaturated fatty acids having 18 carbon atoms), and its industrial manufacturing process has almost been standardized in the industry. It can be easily obtained: dimer acid mainly composed of dimer acid having 36 carbon atoms obtained by dimerizing unsaturated fatty acids having 18 carbon atoms such as oleic acid and linoleic acid, which are particularly inexpensive and easily available. In addition, depending on the manufacturing method and purification degree, dimer acid sometimes contains an arbitrary amount of monomeric acid, trimeric acid, other polymeric fatty acids, etc. In addition, double bonds usually remain after the polymerization reaction of unsaturated fatty acids, but in this specification, hydrides obtained by further hydrogenation reaction to reduce the degree of unsaturation are also included in dimer acid. The divalent aliphatic hydrocarbon group containing a dimer acid skeleton usually has a long aliphatic carbon chain having 7 or more carbon atoms, and thus may contain one or more groups selected from the above-mentioned alkyl groups having 5 or more carbon atoms and alkylene groups having 5 or more carbon atoms.

[0096] As the divalent aliphatic hydrocarbon group containing a dimer acid skeleton, for example, a group represented by the following formula (R1) containing a long aliphatic carbon chain having 7 or more carbon atoms can be cited.

[0097]

[0098] In formula (R1), R r each 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 represents 0 or 1; * represents a bonding site.

[0099] In formula (R1), R r each independently represents a linear or branched alkylene group, or a linear or branched alkenylene group. The number of carbon atoms of the alkylene group is usually 7 to 200, preferably 7 to 100, more preferably 7 to 50. In addition, the number of carbon atoms of the alkenylene group is usually 7 to 200, preferably 7 to 100, more preferably 7 to 50.

[0100] In formula (R1), ring Z rIt represents a cycloalkane ring which may have a group selected from linear or branched alkyl groups and linear or branched alkenyl groups, or a cycloalkene ring which may have a group selected from linear or branched alkyl groups and linear or branched alkenyl groups. Among them, a cycloalkane ring which may have a group selected from linear or branched alkyl groups and linear or branched alkenyl groups is preferred, and a cyclohexane ring which may have a linear or branched alkyl group is more preferred.

[0101] In formula (R1), k r represents 0 or 1.

[0102] As the divalent aliphatic hydrocarbon group containing a dimer acid skeleton, a group represented by the following formula (R2) or (R3) is preferred.

[0103]

[0104] In formula (R2), m1, n1, p1 and q1 each represent an integer of 1 or more. Among them, m1 + n1 is 6 or more and 17 or less, and p1 + q1 is 8 or more and 19 or less. In addition, in formula (R3), m2, n2, p2 and q2 each represent an integer of 1 or more. Among them, m2 + n2 is 6 or more and 17 or less, and p2 + q2 is 8 or more and 19 or less. Moreover, in formula (R2) and (R3), the dotted lines each independently represent a carbon-carbon single bond or a carbon-carbon double bond, and * represents a bonding site.

[0105] Among the groups represented by formula (R2), a group represented by the following formula (R4) is more preferred.

[0106]

[0107] In formula (R4), the meanings of the symbols are the same as above.

[0108] Among them, as a more preferred example of the divalent aliphatic hydrocarbon group containing a dimer acid skeleton, a group represented by any one of the following formulas (R2-1) to (R2-2) and formulas (R3-1) to (R3-2) can be cited.

[0109]

[0110] In formulas (R2-1) to (R2-2) and formulas (R3-1) to (R3-2), the meanings of the symbols are the same as above.

[0111] Among these preferred examples, as a further preferred example of the divalent aliphatic hydrocarbon group containing a dimer acid skeleton, a group represented by any one of the following formulas (R2-3), (R2-4), (R3-3) and (R3-4) can be cited.

[0112]

[0113] In formulas (R2-3), (R2-4), (R3-3) and (R3-4), * represents a bonding site.

[0114] 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 further preferred.

[0115]

[0116] In formula (2), * represents a bonding site.

[0117] In formula (1-i), m i represents an integer of 0 or more. Therefore, m i can be 0 or an integer of 1 or more. m i is preferably an integer of 0 to 100, more preferably an integer of 0 to 50, further preferably an integer of 0 to 20, further preferably an integer of 0 to 10, further preferably 0 or 1, and particularly preferably 0.

[0118] In formula (1-ii), X ii each independently represents a tetravalent organic group. The range of X ii in formula (1-ii) can be the same as the range of X i in formula (1-i). In the case where formula (1-ii) contains a plurality of X ii , the plurality of X ii can be the same or different.

[0119] In formula (1-ii), R ii represents a divalent aliphatic hydrocarbon group having the same structure as R i . Similar to R i contained in formula (1-i), R ii in formula (1-ii) all have the same structure, and the orientations of the bonds of R ii can be the same or different. Here, the "orientation of the bond" of R ii refers to the orientation in formula (1-ii) of the two bonding bonds that R ii has. For example, since R ii contained in the m ii unit represents a divalent aliphatic hydrocarbon group, it has two bonding bonds. Here, one of the two bonding bonds is referred to as the "third bonding bond" and the other is referred to as the "fourth bonding bond". The orientation of the bond of R ii contained in the m ii unit can be considered such that the third bonding bond is bonded to the imide ring in the n ii unit on the left side of the formula and the fourth bonding bond is bonded to the m on the right side of the formula.ii The orientation of the imide ring bonding in the unit, and the third bonding bond and m on the right side in the formula ii The imide ring in the unit is bonded and the fourth bonding bond and n on the left side in the formula ii The orientation of the imide ring bonding in the unit. R ii The orientation of the bond of can be any of them.

[0120] In formula (1-ii), m ii represents an integer of 0 or more. m in formula (1-ii) ii The range of can be the same as that of m in formula (1-i) i In particular, when m i is 0, it is particularly preferred that m ii is 0.

[0121] In formula (1-ii), n ii represents 1 or 2.

[0122] Moreover, except for the orientation of the bond of R i and the orientation of the bond of R ii the part represented by the following formula (1-i-a) of formula (1-i) and the part represented by the following formula (1-ii-a) of formula (1-ii) have the same structure. R in formula (1-i-a) i has the same structure as R in formula (1-ii-a) ii but there is no restriction on the orientation of its bond. That is, the orientation of the bond of R in formula (1-i-a) i and the orientation of the bond of R in formula (1-ii-a) ii can be the same or different. In addition, when m i is 2 or more, the orientations of the multiple Rs contained in formula (1-i-a) i can be the same or different. Moreover, when m ii is 2 or more, the orientations of the multiple Rs contained in formula (1-ii-a) ii can be the same or different. Therefore, for example, when one of the two bonding bonds of R i is called the "first bonding bond" and the other is called the "second bonding bond", in formula (1-i-a), the orientation of the bond of R i can be independently the orientation in which the first bonding bond of the R i ]>has is bonded to the imide ring on the right side in the formula, or can be the orientation in which the second bonding bond of the R i has is bonded to the imide ring on the right side in the formula. In addition, for example, when one of the two bonding bonds of R iiWhen one of the two binding keys is called the "third binding key" and the other is called the "fourth binding key", R ii The orientations of the bonds can be, independently of each other, the orientation in which the third binding key possessed by this R ii is bonded to the imide ring on the right side of the formula, or can also be the orientation in which the fourth binding key possessed by this R ii is bonded to the imide ring on the right side of the formula.

[0123]

[0124] In formula (1-i-a) and formula (1-ii-a), the meanings of the symbols are the same as those in formula (1-i) and formula (1-ii); * represents the binding site.

[0125] Among the above, it is preferred 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, (A) the specific bismaleimide resin preferably contains a combination of the first bismaleimide compound represented by formula (3-i) and the second bismaleimide compound represented by formula (3-ii). (A) The specific bismaleimide resin may contain only a combination of the first bismaleimide compound represented by formula (3-i) and the second bismaleimide compound represented by formula (3-ii). <s

[0126]

[0127] In formula (3-i) and formula (3-ii), the meanings of the symbols are the same as those in formula (1-i) and formula (1-ii). At this time, since the parts represented by formula (1-i-a) and the parts represented by formula (1-ii-a) have the same structure except for the orientation of the bond of R i and the orientation of the bond of R ii , the m in formula (3-i) i and the m in formula (3-ii) ii represent the same number. In formula (3-i) and formula (3-ii), R i and R ii both represent a divalent aliphatic hydrocarbon group having the same structure, preferably a divalent aliphatic hydrocarbon group containing a dimer acid skeleton, and more preferably the group represented by formula (2).

[0128] (A) The specific bismaleimide resin is a composition containing a first bismaleimide compound as a main component and combined with a second bismaleimide compound. Moreover, based on the amounts of the first bismaleimide compound and the second bismaleimide compound which are the combination in the (A) specific bismaleimide resin, the amount of the second bismaleimide compound is within a specific range. Here, the amounts of the first bismaleimide compound and the second bismaleimide compound are the amounts in the combination of the first bismaleimide compound and the second bismaleimide compound. Therefore, when the resin composition contains any bismaleimide compound represented by formula (1-i) and the resin composition does not contain the bismaleimide compound represented by formula (1-ii) which should be combined with the any bismaleimide compound, the amount of the any bismaleimide compound is not included in the amount of the first bismaleimide compound. In addition, when the resin composition contains any bismaleimide compound represented by formula (1-ii) and the resin composition does not contain the bismaleimide compound represented by formula (1-i) which should be combined with the any bismaleimide compound, the amount of the any bismaleimide compound is not included in the amount of the second bismaleimide compound.

[0129] Specifically, with respect to 100% by mass of the (A) component (i.e., the combination of the first bismaleimide compound represented by formula (1-i) and the second bismaleimide compound represented by formula (1-ii)), the amount range of the second bismaleimide compound represented by formula (1-ii) is generally 8% by mass or more, preferably 10% by mass or more, more preferably 12% by mass or more, generally 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less. Unless otherwise specified, when the resin composition contains two or more groups of the combination of the first bismaleimide compound and the second bismaleimide compound, the amount of the first bismaleimide compound represents the sum of the amounts of all the first bismaleimide compounds contained in their combination; the amount of the second bismaleimide compound represents the sum of the amounts of all the second bismaleimide compounds contained in their combination; the amount of the (A) component represents the sum of the amounts of all the first bismaleimide compounds and the second bismaleimide compounds contained in their combination. When the amount of the second bismaleimide compound is within the above range, the viscosity and the dielectric loss tangent can be reduced, and generally the minimum melt viscosity and warpage can be decreased. On the contrary, when the amount of the second bismaleimide compound exceeds 50% by mass, the minimum melt viscosity of the resin composition becomes high.

[0130] With respect to 100% by mass of component (A), the amount of the first bismaleimide compound is generally 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, generally 92% by mass or less, preferably 90% by mass or less, and further preferably 88% by mass or less. The first bismaleimide compound can be particularly effective in helping to reduce the dielectric loss tangent and the minimum melt viscosity. Moreover, when the amount of the first bismaleimide compound is within the above range, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0131] n ii The amount of the second bismaleimide compound with n ii = 1 (i.e., n ii = 1 unit) is generally less than the amount of the first bismaleimide compound. With respect to 100% by mass of component (A), the amount of the second bismaleimide compound with n ii = 1 is preferably 3% by mass or more, more preferably 4% by mass or more, further preferably 5% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 25% by mass or less, further preferably 20% by mass or less, further preferably 10% by mass or less, and particularly preferably 8% by mass or less. When the amount of the second bismaleimide compound with n

[0132] n ii = 2 (i.e., n ii = 2 units) is generally less than the amount of the second bismaleimide compound with n ii = 1 (i.e., n ii = 1 unit). With respect to 100% by mass of component (A), the amount of the second bismaleimide compound with n ii = 2 is preferably 1% by mass or more, more preferably 2% by mass or more, further preferably 3% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, further preferably 10% by mass or less, further preferably 9% by mass or less, further preferably 8% by mass or less, further preferably 6% by mass or less, and particularly preferably 5% by mass or less. When the amount of the second bismaleimide compound with n ii = 2 is within the above range, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0133] The first bismaleimide compound, n ii the second bismaleimide compound with n iiThe amount of the second bismaleimide compound with n being 2 relative to 100% by mass of the component (A) can be determined by gel permeation chromatography (GPC). The GPC measurement can be carried out under the following measurement apparatus and measurement conditions.

[0134] Measurement apparatus: "GPC-101" manufactured by Shoko Kagaku Co., Ltd.;

[0135] Column: Guard column "GPC KF-G 4A" manufactured by Shoko Kagaku Co., Ltd., reference column "KF-800RH" manufactured by Shoko Kagaku Co., Ltd.;

[0136] Detector: RI (differential refractometer)

[0137] Measurement conditions: Column temperature 40 °C

[0138] Developing solvent: Tetrahydrofuran

[0139] Flow rate: 1.0 ml / min

[0140] Standard: Monodisperse polystyrene with known molecular weight is used.

[0141] Sample: The (A) specific bismaleimide resin is dissolved in a tetrahydrofuran solution to a concentration of 0.1% by mass and filtered through a microfilter to obtain (50 μL).

[0142] The first bismaleimide compound, n ii The second bismaleimide compound with n being 1 and n ii The amount of the second bismaleimide compound with n being 2 relative to 100% by mass of the component (A) can be calculated based on the peak areas of the GPC chromatogram obtained by the above GPC measurement. Specifically, calculate the peak area ratios of the first bismaleimide compound, n ii The second bismaleimide compound with n being 1 and n ii The second bismaleimide compound with n being 2 in the GPC chromatogram respectively, and the content (% by mass) based on the mass can be obtained as the peak area ratio.

[0143] The (A) specific bismaleimide resin as a combination of the first bismaleimide compound and the second bismaleimide compound can be produced, for example, by a method including reacting a diamine containing a divalent aliphatic hydrocarbon group with maleic anhydride. As the diamine containing a divalent aliphatic hydrocarbon group, for example, NH2-R i -NH2 (R iThe compound represented by (the meaning is the same as above), preferably a dimer acid type diamine. The dimer acid type diamine refers to a diamine compound having a structure in which two terminal carboxyl groups (-COOH) of dimer acid are substituted by aminomethyl (-CH2-NH2) or amino (-NH2). In addition, the (A) specific bismaleimide resin can be produced by a production method including reacting the diamine with a tetracarboxylic dianhydride. According to the production method including the reaction of diamine and tetracarboxylic dianhydride, a first bismaleimide compound having the m in the formula (1-i) and a second bismaleimide compound having the m in the formula (1-ii) are usually obtained. In the production method of the (A) specific bismaleimide resin, sometimes the first bismaleimide compound is generated as the main product and the second bismaleimide compound is generated as a by-product. In the (A) specific bismaleimide resin contained in the (A) specific bismaleimide resin produced by this production method, the part represented by the formula (1-i-a) of the first bismaleimide compound and the part represented by the formula (1-ii-a) of the second bismaleimide compound may be parts formed by the reaction of a common diamine and a common tetracarboxylic dianhydride. Therefore, except for the orientation of the bond of R and the orientation of the bond of R, they may have the same structure. Since such a (A) specific bismaleimide resin usually can omit the process of purifying and separating by-products, the production of the (A) specific bismaleimide resin can be simplified. Moreover, when using the (A) specific bismaleimide resin containing such by-products, the excellent effects as described above can be obtained. i units of the first bismaleimide compound and the m in the formula (1-ii) ii units of the second bismaleimide compound. In the production method of the (A) specific bismaleimide resin, sometimes the first bismaleimide compound is generated as the main product and the second bismaleimide compound is generated as a by-product. In the (A) specific bismaleimide resin contained in the (A) specific bismaleimide resin produced by this production method, the part represented by the formula (1-i-a) of the first bismaleimide compound and the part represented by the formula (1-ii-a) of the second bismaleimide compound may be parts formed by the reaction of a common diamine and a common tetracarboxylic dianhydride. Therefore, except for the orientation of the bond of R i and the orientation of the bond of R ii , they may have the same structure. Since such a (A) specific bismaleimide resin usually can omit the process of purifying and separating by-products, the production of the (A) specific bismaleimide resin can be simplified. Moreover, when using the (A) specific bismaleimide resin containing such by-products, the excellent effects as described above can be obtained.

[0144] As the (A) specific bismaleimide resin, commercially available products can be used. As the commercially available (A) specific bismaleimide resin, for example, "SLK-6893-T90" manufactured by Shin-Etsu Chemical Co., Ltd. (represented by the formula (3-i) and m i is 0, R i is a combination of the first bismaleimide compound represented by the formula (2) and the second bismaleimide compound represented by the formula (3-ii) and m ii is 0, R ii is a combination of the second bismaleimide compound represented by the formula (2)); "SLK-1500" manufactured by Shin-Etsu Chemical Co., Ltd. (represented by the formula (3-i) and m i is 1 to 10, R i is a combination of the first bismaleimide compound represented by the formula (2) and the second bismaleimide compound represented by the formula (3-ii) and m ii is 1 to 10, R ii is a combination of the second bismaleimide compound represented by the formula (2)), etc.

[0145] (A) The range of the maleimide group equivalent of the specific bismaleimide resin is preferably 200 g / eq. or more, more preferably 300 g / eq. or more, preferably 2500 g / eq. or less, more preferably 2000 g / eq. or less, and further preferably 1500 g / eq. or less. The maleimide group equivalent represents the mass of the resin per 1 equivalent of the maleimide group.

[0146] (A) The range of the weight average molecular weight of the specific bismaleimide resin is preferably 400 or more, more preferably 500 or more, further preferably 600 or more, preferably 10,000 or less, more preferably 7,000 or less, and further preferably 5,000 or less. The weight average molecular weight can be measured by gel permeation chromatography (GPC) as a polystyrene conversion value.

[0147] With respect to the non-volatile components of the resin composition at 100% by mass, 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, particularly preferably 2% by mass or more, preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 10% by mass or less. The non-volatile components of the resin composition represent the components remaining after removing the (G) solvent from the components contained in the resin composition. When the amount of the combination of the first bismaleimide compound and the second bismaleimide compound is within the above range, the viscosity, the dielectric loss tangent, the minimum melt viscosity, and the warpage can be effectively reduced.

[0148] With respect to the resin components of the resin composition at 100% by mass, 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, particularly preferably 10% by mass or more, 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 represent the components remaining after removing the (C) inorganic filler from the non-volatile components of the resin composition. When the amount of the combination of the first bismaleimide compound and the second bismaleimide compound is within the above range, the viscosity, the dielectric loss tangent, the minimum melt viscosity, and the warpage can be effectively reduced.

[0149] With respect to the amount of the (D) elastomer of 100% by mass, the amount of the (A) component (i.e., the combination of the first bismaleimide compound and the second bismaleimide compound) preferably ranges from 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, preferably 1000% by mass or less, more preferably 500% by mass or less, and still more preferably 200% by mass or less. When the amount of the combination of the first bismaleimide compound and the second bismaleimide compound is within the above range, the viscosity, the dielectric loss tangent, the minimum melt viscosity, and the warpage can be effectively reduced.

[0150] With respect to the non-volatile components of the resin composition of 100% by mass, the amount of the second bismaleimide compound preferably ranges from 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, preferably 5% by mass or less, more preferably 2% by mass or less, and still more preferably 1% by mass or less. When the amount of the second bismaleimide compound is within the above range, the viscosity and the dielectric loss tangent can be reduced, and generally, the minimum melt viscosity and the warpage can be decreased.

[0151] With respect to the amount of the (D) elastomer of 100% by mass, the amount of the second bismaleimide compound preferably ranges from 0.1% by mass or more, more preferably 1% by mass or more, particularly preferably 2% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less. When the amount of the second bismaleimide compound is within the above range, the viscosity and the dielectric loss tangent can be reduced, and generally, the minimum melt viscosity and the warpage can be decreased.

[0152] <(B) Thermosetting resin>

[0153] The resin composition according to the present embodiment contains a (B) thermosetting resin as the (B) component. The (B) thermosetting resin can form bonds through a thermal reaction to cure the resin composition. The (B) thermosetting resin does not include a substance corresponding to the above (A) component. The (B) thermosetting resin can be used alone as one kind, or two or more kinds can be used in combination.

[0154] Examples of the (B) thermosetting resin include: epoxy resins, active ester resins, phenolic resins, carbodiimide resins, acid anhydride resins, benzo azine resins, cyanate ester resins, amine resins, thiol resins, and polymerizable unsaturated resins, etc.

[0155] (B) The thermosetting resin preferably contains an epoxy resin. In particular, (B) the thermosetting resin more preferably contains, in combination, an epoxy resin and a resin that can react with and bond to the epoxy resin to cure (B) the thermosetting resin. Hereinafter, the resin that can react with and bond to the epoxy resin may sometimes be referred to as a "curing agent".

[0156] An epoxy resin means a curable resin having an epoxy group. Examples of the epoxy resin include: bisxylenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol novolac type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing a spiro ring, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, naphthalene ether type epoxy resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin, isocyanurate type epoxy resin, phenol phthalimide type epoxy resin, etc. The epoxy resin may be used alone or in combination of two or more.

[0157] From the viewpoint of obtaining a cured product having excellent heat resistance, the epoxy resin preferably contains an epoxy resin having an aromatic structure. The aromatic structure means a chemical structure that is generally defined as aromatic and also includes polycyclic aromatic and aromatic heterocycles. Examples of the epoxy resin having an aromatic structure include: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol novolac type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, bisxylenol type epoxy resin, glycidylamine type epoxy resin having an aromatic structure, glycidyl ester type epoxy resin having an aromatic structure, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin having an aromatic structure, epoxy resin having a butadiene structure and having an aromatic structure, alicyclic epoxy resin having an aromatic structure, heterocyclic epoxy resin, epoxy resin containing a spiro ring and having an aromatic structure, cyclohexanedimethanol type epoxy resin having an aromatic structure, naphthalene ether type epoxy resin, trimethylol type epoxy resin having an aromatic structure, tetraphenylethane type epoxy resin having an aromatic structure, etc. Among them, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin and bisxylenol type epoxy resin are preferred.

[0158] (B) The thermosetting resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. 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 further preferably 70% by mass or more with respect to the non-volatile components of the entire epoxy resin of 100% by mass.

[0159] The epoxy resin contains an epoxy resin that is liquid at 20°C (hereinafter sometimes referred to as "liquid epoxy resin") and an epoxy resin that is solid at 20°C (hereinafter sometimes referred to as "solid epoxy resin"). (B) The thermosetting resin may contain only the liquid epoxy resin, only the solid epoxy resin, or a combination of the liquid epoxy resin and the solid epoxy resin.

[0160] As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferred.

[0161] As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, and epoxy resin having a butadiene structure are preferred; bisphenol A type epoxy resin, bisphenol F type epoxy resin, and naphthalene type epoxy resin are more preferred.

[0162] As specific examples of the liquid epoxy resin, the following can be cited: "HP-4032", "HP-4032-D", "HP-4032-SS" (naphthalene-type epoxy resin) manufactured by DIC Corporation; "828US", "828EL", "jER828EL", "825", "Epikote 828EL" (bisphenol A-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER807", "1750" (bisphenol F-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD", "604" (glycidylamine-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycerol-type epoxy resin) manufactured by ADEKA Corporation; "EP-3950L", "EP-3980S" (glycidylamine-type epoxy resin) manufactured by ADEKA Corporation; "EP-4088S" (dicyclopentadiene-type epoxy resin) manufactured by ADEKA Corporation; "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" (an alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation; "PB-3600" manufactured by Daicel Corporation; "JP-100", "JP-200" (epoxy resins having a butadiene structure) manufactured by Nippon Soda Co., Ltd.; "ZX1658", "ZX1658GS" (liquid 1,4-glycidylcyclohexane-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd., etc.

[0163] As the solid epoxy resin, a solid epoxy resin having 3 or more epoxy groups in 1 molecule is preferred, and an aromatic solid epoxy resin having 3 or more epoxy groups in 1 molecule is more preferred.

[0164] As the solid epoxy resin, xylenol-type epoxy resin, naphthalene-type epoxy resin, naphthalene-type tetrafunctional epoxy resin, naphthol novolac-type epoxy resin, cresol novolac-type epoxy resin, dicyclopentadiene-type epoxy resin, triphenol-type epoxy resin, naphthol-type epoxy resin, biphenyl-type epoxy resin, naphthalene ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, bisphenol AF-type epoxy resin, phenol aralkyl-type epoxy resin, tetraphenylethane-type epoxy resin, phenol phthalimide-type epoxy resin are preferred.

[0165] As specific examples of the solid epoxy resin, the following can be cited: "HP4032H" (naphthalene-type epoxy resin) manufactured by DIC Corporation; "HP-4700", "HP-4710" (naphthalene-type tetrafunctional epoxy resin) manufactured by DIC Corporation; "N-690" (cresol novolak-type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolak-type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", "HP-7200L" (dicyclopentadiene-type epoxy resin) manufactured by DIC Corporation; "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000", "HP6000L" (naphthalene ether-type epoxy resin) manufactured by DIC Corporation; "EPPN-502H" (triphenol-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolak-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V", "ESN4100V" (naphthalene-type epoxy resin) manufactured by Nippon Steel Chemical Co., Ltd.; "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", "YL7890" (xylenol-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; "YX7700" (phenol aralkyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "PG-100", "CG-500" manufactured by Osaka Gas Chemical 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; "WHR991S" (phenol phthalimide-type epoxy resin) manufactured by Nippon Kayaku Co., Ltd., etc.

[0166] When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, their mass ratio (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.

[0167] 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., further 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 1 equivalent of epoxy groups. This epoxy equivalent can be measured in accordance with JIS K7236.

[0168] The weight-average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and further preferably 400 to 1,500. The weight-average molecular weight can be measured by gel permeation chromatography (GPC) as a polystyrene conversion value.

[0169] With respect to the resin component of the resin composition of 100% by mass, the amount of the epoxy resin preferably ranges from 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, preferably 80% by mass or less, more preferably 60% by mass or less, and further preferably 40% by mass or less. When the amount of the epoxy resin is within the above range, the viscosity, the dielectric loss tangent, the minimum melt viscosity, and the warpage can be effectively reduced.

[0170] Examples of the curing agent include: active ester resins, phenolic resins, carbodiimide resins, acid anhydride resins, benz azine resins, cyanate ester resins, amine resins, mercaptan resins, etc. The curing agent can be used alone as one kind, or two or more kinds can be used in combination.

[0171] As the active ester resin, a resin having one or more, preferably two or more active ester groups in one molecule can be used. Among them, as the active ester resin, resins 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 are preferred.

[0172] The active ester resin is preferably a resin obtained by a condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, 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, pyromellitic acid, etc. Examples of the phenol compound or naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, 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, phloroglucinol, benzenetriol, dicyclopentadiene-type diphenol compound, phenol novolac, etc. Herein, the "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing 2 molecules of phenol with 1 molecule of dicyclopentadiene.

[0173] Specifically, as the active ester resin, 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, and an active ester resin containing a benzoylated product of phenol novolac are preferred, and among them, 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.

[0174] Examples of commercially available active ester resins include, for example, as active ester resins containing a dicyclopentadiene-type diphenol structure, "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", "HPC-8000-65T", "EXB-8000H" (manufactured by DIC Corporation); as active ester resins containing a naphthalene structure, "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", "EXB-9416-70BK", "HPC-8150-62T", "EXB-8" (manufactured by DIC Corporation); as phosphorus-containing active ester resins, "EXB9401" (manufactured by DIC Corporation); as active ester resins that are acetates of novolak phenol resins, "DC808" (manufactured by Mitsubishi Chemical Corporation); as active ester resins that are benzoylates of novolak phenol resins, "YLH1026", "YLH1030", "YLH1048" (manufactured by Mitsubishi Chemical Corporation); as active ester resins containing a styryl group and a naphthalene structure, "PC1300-02-65MA" (manufactured by AIRWATER Corporation), etc.

[0175] With respect to the resin component of the resin composition at 100% by mass, the amount of the active ester resin preferably ranges from 1% by mass or more, more preferably 2% by mass or more, further preferably 5% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less. When the amount of the active ester resin is within the above range, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0176] 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 in one molecule can be used. From the viewpoints of heat resistance and water resistance, a phenolic resin having a novolak structure is preferred. In addition, from the viewpoint of adhesion, a nitrogen-containing phenolic resin can be used, for example, a phenolic resin containing a triazine skeleton can be used. As a specific example, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a phenolic novolak resin containing a triazine skeleton can be used.

[0177] As specific examples of the phenolic resin, the following can be cited: "MEH-7700", "MEH-7810", "MEH-7851", "MEH-8000H" manufactured by Meiwafosis Co., Ltd.; "NHN", "CBN", "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-495V", "SN-375", "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", "TD-2090-60M", "KA-1160" manufactured by DIC Corporation; "GDP-6115L", "GDP-6115H", "ELPC75", etc. manufactured by Gunei Chemical Industry Co., Ltd.

[0178] With respect to the resin component of the resin composition of 100% by mass, the amount of the phenolic resin preferably ranges from 1% by mass or more, more preferably 2% by mass or more, still more preferably 3% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less. When the amount of the phenolic resin is within the above range, the viscosity, the dielectric loss tangent, the minimum melt viscosity, and the warpage can be effectively reduced.

[0179] 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(tert-butylcarbodiimide) and cyclohexane bis(methylene-tert-butylcarbodiimide); biscarbodiimides such as phenyl-bis(xylenylcarbodiimide); aliphatic polycarbodiimides such as polyhexamethylene carbodiimide, polytrimethylhexamethylene carbodiimide, polycyclohexylene carbodiimide, poly(methylenebiscyclohexylene carbodiimide), and poly(isophorone carbodiimide); aromatic polycarbodiimides such as poly(phenylcarbodiimide), poly(naphthylcarbodiimide), poly(tolylene carbodiimide), poly(methyldiisopropylphenylcarbodiimide), poly(triethylphenylcarbodiimide), poly(diethylphenylcarbodiimide), poly(triisopropylphenylcarbodiimide), poly(diisopropylphenylcarbodiimide), poly(xylenylcarbodiimide), poly(tetramethylxylenylcarbodiimide), poly(methylenediphenylcarbodiimide), and poly[methylenebis(methylphenyl)carbodiimide]. As commercially available products of the carbodiimide resin, 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.; "Stabaxol P", "Stabaxol P400", "Hycasyl510", etc. manufactured by LANXESS Corporation can be cited.

[0180] With respect to the resin component of the resin composition of 100% by mass, the amount of the carbodiimide resin preferably ranges from 0.1% by mass or more, more preferably from 1% by mass or more, still more preferably from 2% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and still more preferably 5% by mass or less. When the amount of the carbodiimide resin is within the above range, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0181] 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, dodecenylsuccinic anhydride, 5-(2,5-dioxotetrahydro-3-furyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, dicarboxylic anhydride, and the like. Polymer-type acid anhydrides such as benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(trimellitic anhydride), and styrene-maleic acid resin obtained by copolymerization of styrene and maleic acid. Examples of commercially available acid anhydride resins include "HNA-100," "MH-700," "MTA-15," "DDSA," and "OSA" manufactured by Shin Nippon Chemical Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Corporation; "HN-2200" and "HN-5500" manufactured by Resonac; and "EF-30," "EF-40," "EF-60," and "EF-80" manufactured by Cray Valley Corporation.

[0182] As benzo Azoline resins can be used which have one or more, preferably two or more, benzophenones in one molecule. As a benzophenone Specific examples of the oxazine-based resin include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Co., Ltd.; "HFB2006M" manufactured by Showa Highpolymer Co., Ltd.; and "Pd" and "Fa" manufactured by Shikoku Chemicals Co., Ltd.

[0183] As the cyanate ester resin, a resin having one or more, preferably two or more cyanate ester groups in one molecule can be used. Examples of the cyanate ester resin include: bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylen-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanatephenyl)propane, 1,1-bis(4-cyanatephenyl)methane, bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylene))benzene, bis(4-cyanatephenyl) sulfide, and bis(4-cyanatephenyl) ether, etc., difunctional cyanate ester resins; polyfunctional cyanate ester resins derived from phenol novolac and cresol novolac, etc.; prepolymers formed by partial triazine formation of these cyanate ester resins, etc. Specific examples of the cyanate ester resin include: "PT30" and "PT60" (phenol novolac type polyfunctional cyanate ester resins), "BA230", "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate is triazine-formed to become a trimer), etc. manufactured by arxada (formerly Lonza).

[0184] As the amine-based resin, a resin having one or more, preferably two or more amino groups in one molecule can be used. As the amine-based resin, for example, aliphatic amines, polyether amines, alicyclic amines, aromatic amines, etc. can be cited. Among them, aromatic amines are preferred. The amine-based resin is preferably a primary amine or a secondary amine, and more preferably a primary amine. As specific examples of the amine-based resin, 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, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc. can be cited. As commercially available products of the amine-based resin, for example, "SEIKACURE-S" manufactured by SEIKA Corporation; "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARDA-A", "KAYAHARD A-B", "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd.; "EPICURE W" manufactured by Mitsubishi Chemical Corporation; "DTDA" manufactured by Sumitomo Seika Chemicals Co., Ltd., etc. can be cited.

[0185] As the thiol-based resin, for example, trimethylolpropane tris(3-mercapto propionate), pentaerythritol tetra(3-mercapto butyrate), tris(3-mercaptopropyl) isocyanurate, etc. can be cited.

[0186] 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., still 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 1 equivalent of the active group.

[0187] In one example, the range of the weight average molecular weight (Mw) of the curing agent can be the same as the range of the weight average molecular weight (Mw) of the epoxy resin.

[0188] With respect to the resin component of the resin composition of 100% by mass, the amount of the curing agent preferably ranges from 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less. When the amount of the curing agent is within the above range, the viscosity, dissipation factor, minimum melt viscosity, and warpage can be effectively reduced.

[0189] When the resin composition contains an epoxy resin and a curing agent, with respect to 1 epoxy group number of the epoxy resin, the range of the active group number of the curing agent is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.4 or more, particularly preferably 0.5 or more, preferably 3.0 or less, more preferably 2.5 or less, still more preferably 2.0 or less, still more preferably 1.5 or less, and particularly preferably 1.0 or less. The "epoxy group number of the epoxy resin" of the resin composition means the value obtained by summing up all the values obtained by dividing the mass of the non-volatile component of the epoxy resin present in the resin composition by the epoxy equivalent. In addition, the "active group number of the curing agent" of the resin composition means the value obtained by summing up all the values obtained by dividing the mass of the non-volatile component of the curing agent present in the resin composition by the active group equivalent.

[0190] As the polymerizable unsaturated resin, a resin containing a non-aromatic carbon-carbon unsaturated bond can be used. Therefore, the polymerizable unsaturated resin usually can have a polymerizable unsaturated group containing a non-aromatic carbon-carbon unsaturated bond. As the polymerizable unsaturated group, for example, the following can be mentioned: unsaturated hydrocarbon groups such as vinyl, allyl, 1-propenyl, 3-cyclohexenyl, 3-cyclopentenyl, 2-vinylphenyl, 3-vinylphenyl, 4-vinylphenyl; α,β-unsaturated carbonyls such as acryloyl, methacryloyl, maleimide group. The polymerizable unsaturated resin having these polymerizable unsaturated groups usually can react by free radical polymerization. The polymerizable unsaturated resin preferably has 2 or more polymerizable unsaturated groups.

[0191] As the polymerizable unsaturated resin, for example, the following can be mentioned: (meth)acrylic polymerizable unsaturated resin, styrene polymerizable unsaturated resin, allyl polymerizable unsaturated resin, maleimide polymerizable unsaturated resin, etc. The polymerizable unsaturated resin can be used alone or in combination of 2 or more.

[0192] 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. As the (meth)acrylic polymerizable unsaturated resin, for example, the following can be mentioned: 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-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, glycerol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate and other low molecular weight (molecular weight less than 1000) aliphatic (meth)acrylate resins; di alkylene glycol di(meth)acrylate, 3,6-dioxa-1,8-octanediol di(meth)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, propoxylated bisphenol A di(meth)acrylate and other low molecular weight (molecular weight less than 1000) ether-containing (meth)acrylate resins; tris(3-hydroxypropyl)isocyanurate group tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate group tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate and other low molecular weight (molecular weight less than 1000) isocyanurate group-containing (meth)acrylate resins; (meth)acrylic acid-modified polyphenylene ether resin and other high molecular weight (molecular weight 1000 or more) (meth)acrylate resins, etc. The term "(meth)acrylic acid" includes acrylic acid, methacrylic acid and their combinations. As commercially available products of the (meth)acrylic polymerizable unsaturated resin, for example, the following can be mentioned: "A-DOG" (di alkylene glycol diacrylate) manufactured by Shin-Nakamura Chemical Co., Ltd.; "DCP-A" (tricyclodecane dimethanol diacrylate), "DCP" (tricyclodecane dimethanol dimethacrylate), "BPE-1300N" (ethoxylated bisphenol A dimethacrylate) manufactured by Kyoeisha Chemical Co., Ltd.; "KAYARAD R-684" (tricyclodecane dimethanol diacrylate), "KAYARAD R-604" (di alkylene glycol diacrylate) manufactured by Nippon Kayaku Co., Ltd.; "SA9000", "SA9000-111" (methacrylic acid-modified polyphenylene ether) manufactured by SABIC Co., etc.

[0193] As the styrene-based polymerizable unsaturated resin, a resin having one or more, preferably two or more vinyl groups directly bonded to aromatic carbon atoms in one molecule can be used. 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, bis(4-vinylphenyl)ether; high molecular weight (molecular weight 1000 or more) styrene-based resins such as vinylbenzyl-modified polyphenylene ether resin, styrene-divinylbenzene copolymer, etc. Examples of commercially available products of the styrene-based polymerizable unsaturated resin include: "ODV-XET(X03)", "ODV-XET(X04)", "ODV-XET(X05)" (styrene-divinylbenzene copolymer) manufactured by Nippon Steel Chemical Co., Ltd.; "OPE-2St", "OPE-2St1200", "OPE-2St 2200" (vinylbenzyl-modified polyphenylene ether resin) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0194] As the allyl-based polymerizable unsaturated resin, a resin having one or more, preferably two or more allyl groups in one molecule can be used. Examples of the allyl-based polymerizable unsaturated resin include: aromatic carboxylic acid allyl ester resins such as diallyl phthalate, diallyl isophthalate, diallyl terephthalate, diallyl 2,6-naphthalate, diallyl 2,3-naphthalate; allyl isocyanurate resins such as 1,3,5-triallyl isocyanurate, 1,3-diallyl-5-glycidyl isocyanurate; aromatic allyl resins containing epoxy groups such as 2,2-bis[3-allyl-4-(glycidyloxy)phenyl]propane; containing benz oxazine-3-yl)phenyl]methane, etc. containing benz Aromatic allyl resins of triazines; Ether-containing aromatic allyl resins such as 1,3,5-triallyl ether benzene; Allyl silane resins such as diallyl diphenyl silane, etc. As commercially available products of allyl-based polymerizable unsaturated resins, for example, "TAIC" (1,3,5-triallyl isocyanurate) manufactured by Nippon Kayaku Co., Ltd.; "DAD" (diallyl phthalate) manufactured by Nisshu Techno Fine Chemical Co., Ltd.; "TRIAM-705" (triallyl trimellitate) manufactured by Fujifilm Wako Pure Chemical Corporation; The trade name "DAND" (diallyl 2,3-naphthalenedicarboxylate) manufactured by Nisshu Techno Fine Chemical Co., Ltd.; "ALP-d" (bis[3-allyl-4-(3,4-dihydro-2H-1,3-benzoxazin-3-yl)phenyl]methane) manufactured by Shikoku Kasei Kogyo Co., Ltd.; "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 Kasei Kogyo Co., Ltd.; "NE-V-1100-70T" manufactured by DIC Corporation, etc.

[0195] As the maleimide-based polymerizable unsaturated resin, a resin having one or more, preferably two or more maleimide groups in one molecule can be used. 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 not having a maleimide group directly bonded to an aromatic ring. As commercially available products of maleimide-based free-radical polymerizable resins, for example, 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 KI Kasei Co., Ltd.), "BMI-6100" (manufactured by Designer Molecules Inc.), etc. In addition, as the maleimide-based polymerizable unsaturated resin, the maleimide resin (maleimide compound containing an indane ring skeleton) disclosed in Japanese Invention Association Public Technical Report Public Technical Number 2020-500211 can be used.

[0196] 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., further 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 1 equivalent of the polymerizable unsaturated group.

[0197] The weight average molecular weight (Mw) of the polymerizable unsaturated resin is preferably 40,000 or less, more preferably 10,000 or less, still more preferably 5,000 or less, and particularly preferably 3,000 or less. There is no particular limitation on the lower limit, and for example, it may be 150 or more, etc.

[0198] With respect to the resin component of the resin composition of 100% by mass, the amount of the polymerizable unsaturated resin preferably ranges from 1% by mass or more, more preferably 2% by mass or more, still more preferably 5% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less. When the amount of the polymerizable unsaturated resin is within the above range, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0199] With respect to the non-volatile component of the resin composition of 100% by mass, the amount of the (B) thermosetting resin preferably ranges from 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, still more preferably 20% by mass or less, and particularly preferably 18% by mass or less. When the amount of the (B) thermosetting resin is within the above range, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0200] With respect to the resin component of the resin composition of 100% by mass, the amount of the (B) thermosetting resin preferably ranges from 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, preferably 90% by mass or less, more preferably 80% by mass or less, and still more preferably 70% by mass or less. When the amount of the (B) thermosetting resin is within the above range, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0201] <(C) Inorganic filler>

[0202] The resin composition according to this embodiment includes a (C) inorganic filler as the (C) component. The (C) inorganic filler is particles of an inorganic material. Therefore, the (C) inorganic filler is contained in the resin composition in a particulate state and is usually contained in the cured product while maintaining the particulate state. The (C) inorganic filler does not include substances equivalent to the above (A) to (B) components.

[0203] As the inorganic material for forming the (C) inorganic filler, an inorganic compound is generally used. Examples of the material 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 zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium phosphotungstate. Among these, silica and alumina are suitable, and silica is particularly suitable. Therefore, the (C) inorganic filler preferably contains silica, and may also contain only silica. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. In addition, spherical silica is preferred as silica. The (C) inorganic filler may be used alone or in combination of two or more kinds.

[0204] Examples of commercially available products of the (C) inorganic filler include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical 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 Co., Ltd.; "SILFIL NSS-3N", "SILFIL NSS-4N", and "SILFIL NSS-5N" manufactured by Tokuyama Corporation; "CellSpheres" and "MGH-005" manufactured by Taiheiyo Cement Corporation, etc.

[0205] The average particle size of the (C) inorganic filler is preferably 0.01 μm or more, more preferably 0.05 μm or more, further preferably 0.1 μm or more, preferably 10 μm or less, more preferably 5 μm or less, further preferably 3 μm or less, and further preferably 1 μm or less.

[0206] (C) The average particle diameter of the inorganic filler can be measured by the laser diffraction / scattering method based on the Mie scattering theory. Specifically, the particle diameter distribution of the inorganic filler can be produced on a volume basis by a laser diffraction / scattering type particle diameter distribution measuring device, and the median particle diameter thereof can be used as the average particle diameter for measurement. As the measurement sample, a sample obtained by weighing 100 mg of the inorganic filler and 10 g of methyl ethyl ketone into a test tube and dispersing them ultrasonically for 10 minutes can be used. For the measurement sample, using a laser diffraction type particle diameter distribution measuring device, the light source wavelengths used are set to blue and red, and the particle diameter distribution on a volume basis of the inorganic filler is measured in a flow cell manner, and the average particle diameter as the median particle diameter is calculated from the obtained particle diameter distribution. As the laser diffraction type particle diameter distribution measuring device, for example, "LA-960" manufactured by Horiba, Ltd. can be mentioned.

[0207] (C) The specific surface area of the inorganic filler is preferably 0.1 m 2 / g or more, more preferably 0.5 m 2 / g or more, further preferably 1 m 2 / g or more, particularly preferably 3 m 2 / g or more, preferably 100 m 2 / g or less, more preferably 70 m 2 / g or less, further preferably 50 m 2 / g or less, particularly preferably 40 m 2 / g or less. (C) The specific surface area of the inorganic filler can be measured by the following method: According to the BET method, using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.), nitrogen is adsorbed on the surface of the sample, and the specific surface area is calculated by the BET multi-point method.

[0208] From the viewpoint of improving moisture resistance and dispersibility, (C) the inorganic filler is preferably treated with a surface treatment agent. As the surface treatment agent, for example, fluorine-containing silane coupling agents, amino-silane-based coupling agents, epoxy-silane-based coupling agents, mercapto-silane-based coupling agents, silane-based coupling agents, alkoxysilanes, organosilazane compounds, titanate-based coupling agents, etc. can be mentioned. The surface treatment agent can be used alone as 1 kind, or 2 or more kinds can be arbitrarily combined and used.

[0209] Examples of commercially available surface treatment agents include: "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.; "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.; "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.; "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.; "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd.; "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd.; "KBM-4803" (long-chain epoxy type silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd.; "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., etc.

[0210] From the viewpoint of improving the dispersibility of the inorganic filler, the degree of surface treatment with the surface treatment agent is preferably limited to a specific range. 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 surface-treated with 0.2% to 3% by mass of the surface treatment agent, and still more preferably surface-treated with 0.3% to 2% by mass of the surface treatment agent.

[0211] The degree of surface treatment with the surface treatment agent can be evaluated by the carbon amount per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the carbon amount per unit surface area of the inorganic filler is preferably 0.02 mg / m 2 or more, more preferably 0.1 mg / m 2 or more, and still more preferably 0.2 mg / m 2 or more. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin composition layer, it is preferably 1.0 mg / m 2 or less, more preferably 0.8 mg / m 2 or less, and still more preferably 0.5 mg / m 2 or less.

[0212] After the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)), the carbon amount per unit surface area of the (C) inorganic filler can be measured. Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with the surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid component, the carbon amount per unit surface area of the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, "EMIA-320V" manufactured by Horiba, Ltd. can be used, etc.

[0213] With respect to the non-volatile components of the resin composition of 100% by mass, the amount of the (C) inorganic filler preferably ranges from 50% by mass or more, more preferably 55% by mass or more, further preferably 60% by mass or more, further preferably 65% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, further preferably 80% by mass or less, and further preferably 77% by mass or less. When the amount of the (C) inorganic filler is within the above range, the viscosity, the dielectric loss tangent, the minimum melt viscosity, and the warpage can be effectively reduced.

[0214] With respect to the non-volatile components of the resin composition of 100% by mass, the total amount of the (A) specific bismaleimide resin, the (B) thermosetting resin, and the (C) inorganic filler preferably ranges from 60% by mass or more, more preferably 70% by mass or more, and further preferably 80% by mass or more. The upper limit is usually 100% by mass or less, but may be 99.9% by mass or less.

[0215] <(D) Elastomer>

[0216] The resin composition according to the present embodiment may further contain a (D) elastomer as an optional component. The (D) elastomer as the (D) component does not include substances corresponding to the above (A) to (C) components. Since the (D) elastomer is a flexible component, the minimum melt viscosity and the warpage can be effectively reduced. Generally, the (D) elastomer is contained in the resin composition in a state compatible with resin components such as the (A) to (B) components, and is contained in the cured product while maintaining this compatible state. The (D) elastomer may be used alone or in combination of two or more.

[0217] (D) The elastomer generally has a low elastic modulus. Specifically, according to Japanese Industrial Standard (JIS K7161), when a tensile test is performed at a temperature of 25°C and a humidity of 40% RH, the (D) elastomer generally exhibits an elastic modulus of 1 GPa or less. In detail, the elastic modulus of the (D) elastomer generally ranges from 1 GPa or less, preferably 0.9 GPa or less, more preferably 0.8 GPa or less, further preferably 0.7 GPa or less, preferably 0.01 GPa or more, more preferably 0.03 GPa or more, further preferably 0.05 GPa or more, and particularly preferably 0.1 GPa or more.

[0218] As the (D) elastomer, it is preferable to include in the molecule one or more resins selected from the following structures: polybutadiene structure, polycarbonate structure, polyalkylene structure, polyalkyleneoxy structure, polysiloxane structure, poly(meth)acrylate structure, polyisoprene structure, polyisobutene structure, and polystyrene structure. The term “(meth)acrylate” includes acrylate and methacrylate and combinations thereof. These structures may be included in the main chain or in the side chain. These structures generally have little restriction on atomic motion caused by the interatomic bonds contained in the structure and have a wide range of bond angle changes and rotations, so they can function as a flexible molecular backbone. Therefore, as the resin containing these structures, the (D) elastomer can be easily obtained. Among them, it is further preferable to select one or more resins from the polybutadiene structure, polycarbonate structure, and polyalkylene structure.

[0219] Sometimes, the resin containing the polybutadiene structure is called “polybutadiene resin”. The polybutadiene structure may be partially or completely hydrogenated. As the polybutadiene resin, for example, resins containing a hydrogenated polybutadiene skeleton, polybutadiene resins containing a hydroxyl group, polybutadiene resins containing a phenolic hydroxyl group, polybutadiene resins containing a carboxyl group, polybutadiene resins containing an acid anhydride group, polybutadiene resins containing an epoxy group, polybutadiene resins containing an isocyanate group, polybutadiene resins containing a urethane group, polyphenylene ether-polybutadiene resins, etc. can be cited.

[0220] Specific examples of the polybutadiene resin include: “Ricon 130MA8”, “Ricon 130MA13”, “Ricon 130MA20”, “Ricon131MA5”, “Ricon 131MA10”, “Ricon131MA17”, “Ricon 131MA20”, “Ricon 184MA6” (acid anhydride group-containing polybutadiene) manufactured by Cray Valley; “GQ-1000” (hydroxyl group- and carboxyl group-introduced polybutadiene), “G-1000”, “G-2000”, “G-3000” (two-terminal hydroxyl polybutadiene), “GI-1000”, “GI-2000”, “GI-3000” (two-terminal hydroxyl hydrogenated polybutadiene) manufactured by Nippon Soda Co., Ltd.; “FCA-061L” (hydrogenated polybutadiene skeleton epoxy resin) manufactured by Nagase ChemteX Corporation, etc.

[0221] In addition, as a specific example of the polybutadiene resin, a polyimide resin having a polybutadiene structure, a urethane structure, and an imide structure in the molecule can be mentioned. This polyimide resin can be made into a linear polyimide resin using hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetracarboxylic dianhydride as raw materials (the polyimide described in Japanese Patent Laid-Open No. 2006-37083 and International Publication No. 2008 / 153208). The content of the butadiene structure in this polyimide resin is preferably 60% by mass to 95% by mass, more preferably 75% by mass to 85% by mass. For details of this polyimide resin, reference can be made to the descriptions in Japanese Patent Laid-Open No. 2006-37083 and International Publication No. 2008 / 153208, and this content is incorporated into this specification.

[0222] Sometimes, a resin containing a polycarbonate structure is referred to as a "polycarbonate resin". As the polycarbonate resin, for example, a hydroxyl-containing carbonate resin, a phenolic hydroxyl-containing carbonate resin, a carboxyl-containing carbonate resin, an acid anhydride group-containing carbonate resin, an isocyanate group-containing carbonate resin, a urethane group-containing carbonate resin, etc. can be mentioned.

[0223] As a specific example of the polycarbonate resin, "FPC0220" manufactured by Mitsubishi Gas Chemical Company; "T6002", "T6001" (polycarbonate diol) manufactured by Asahi Kasei Corporation; "C-1090", "C-2090", "C-3090" (polycarbonate diol) manufactured by Kuraray Co., Ltd., etc. can be mentioned.

[0224] In addition, as a specific example of the polycarbonate resin, a polyimide resin having an imide structure, a urethane structure, and a polycarbonate structure in the molecule can be mentioned. This polyimide resin can be made into a linear polyimide resin using hydroxyl-terminated polycarbonate, a diisocyanate compound, and a tetracarboxylic dianhydride as raw materials. The content of the carbonate structure in this polyimide resin is preferably 60% by mass to 95% by mass, more preferably 75% by mass to 85% by mass. For details of this polyimide resin, reference can be made to the description in International Publication No. 2016 / 129541, and this content is incorporated into this specification.

[0225] Sometimes, a resin containing a polyalkylene structure is 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 this alkylene chain is preferably 2 or more, more preferably 3 or more, further preferably 5 or more, and further preferably 7 or more. The upper limit can 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.

[0226] As described above, the dimer acid skeleton represents the skeleton of a divalent group obtained by removing the two terminal carboxyl groups (-COOH) of the dimer acid. The polyalkylene resin containing the dimer acid skeleton usually contains a divalent hydrocarbon group, and this divalent hydrocarbon group contains the dimer acid skeleton. The divalent hydrocarbon group containing the dimer acid skeleton usually has a long aliphatic carbon chain with 7 or more carbon atoms, and an alkylene chain is included in this long aliphatic carbon chain. The number of carbon atoms of the divalent hydrocarbon group containing the dimer acid skeleton may be 36.

[0227] As a specific example of the polyalkylene resin containing the dimer acid skeleton, a polyimide resin containing the dimer acid skeleton can be cited. Regarding this polyimide resin, for example, a resin obtained by an imidization reaction of a dimer acid type diamine and a tetracarboxylic dianhydride can be cited. The dimer acid type diamine refers to a diamine compound having a structure in which the two terminal carboxyl groups (-COOH) of the dimer acid are replaced by aminomethyl (-CH2-NH2) or amino (-NH2). Examples of the dimer acid type diamine include "PRIAMINE 1073", "PRIAMINE 1074", "PRIAMINE 1075" manufactured by Croda Japan; "Versamine 551", "Versamine 552" manufactured by Cognis Japan, etc. In addition, as the tetracarboxylic dianhydride, an aliphatic tetracarboxylic dianhydride can be used, an aromatic tetracarboxylic dianhydride can be used, or they can be used in combination.

[0228] Sometimes a resin containing a polyalkyleneoxy structure is called a "polyalkyleneoxy resin". The number of carbon atoms of the alkyleneoxy structure contained in the polyalkyleneoxy resin is preferably 2 to 15, more preferably 3 to 10, and still more preferably 5 to 8. As specific examples of the alkyleneoxy resin, "EXA-4850-150", "EXA-4816", "EXA-4822" manufactured by DIC; "EP-4000", "EP-4003", "EP-4010", "EP-4011" manufactured by ADEKA; "BEO-60E", "BPO-20E" manufactured by Shin Nippon Rika; "YL7175", "YL7410" manufactured by Mitsubishi Chemical, etc. can be cited.

[0229] Sometimes a resin containing a polysiloxane structure is called a "polysiloxane resin". As the polysiloxane resin, for example, "SMP-2006", "SMP-2003PGMEA", "SMP-5005PGMEA" manufactured by Shin-Etsu Silicone; a linear polyimide using an amino-terminated polysiloxane and a tetracarboxylic dianhydride (International Publication No. 2010 / 053185, Japanese Patent Laid-Open No. 2002-12667, Japanese Patent Laid-Open No. 2000-319386, etc.) can be cited.

[0230] Sometimes, a resin containing a poly(meth)acrylate structure is referred to as a "poly(meth)acrylate resin". Examples of the poly(meth)acrylate resin include TEISAN resin manufactured by Nagase ChemteX Corporation; "ME-2000", "W-116.3", "W-197C", "KG-25", "KG-3000" manufactured by Negami Kogyo Co., Ltd.; "ARUFON UH-2000" manufactured by Toagosei Co., Ltd., etc.

[0231] Sometimes, a resin containing a polyisoprene structure is referred to as a "polyisoprene resin". Specific examples of the polyisoprene resin include "KL-610", "KL613", etc. manufactured by Kuraray Co., Ltd.

[0232] Sometimes, a resin containing a polyisobutene structure is referred to as a "polyisobutene resin". Specific examples of the polyisobutene resin include "SIBSTAR-073T" (styrene-isobutene-styrene triblock copolymer), "SIBSTAR-042D" (styrene-isobutene diblock copolymer), etc. manufactured by Kaneka Corporation.

[0233] Sometimes, a resin containing a polystyrene structure is referred to as a "polystyrene resin". The polystyrene resin may be a copolymer containing any repeating unit different from the styrene unit in combination with the styrene unit, or a hydrogenated polystyrene resin. Examples of the polystyrene resin include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-butadiene-butene-styrene block copolymer (SBBS), styrene-butadiene diblock copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-butadiene random copolymer, styrene-maleic anhydride copolymer, etc.

[0234] As specific examples of the polystyrene resin, the following can be cited: hydrogenated styrene-based thermoplastic elastomers "H1041", "Tuftec H1043", "Tuftec P2000", "Tuftec MP10" (manufactured by Asahi Kasei Corporation); epoxidized styrene-butadiene thermoplastic elastomers "EPOFRIEND AT501", "CT310" (manufactured by Daicel Corporation); modified styrene-based elastomers having a hydroxyl group "SEPTON HG252" (manufactured by Kuraray Co., Ltd.); modified styrene-based elastomers having a carboxyl group "TuftecN503M"; modified styrene-based elastomers having an amino group "Tuftec N501"; modified styrene-based elastomers having an acid anhydride group "Tuftec M1913" (manufactured by Asahi Kasei Corporation); unmodified styrene-based elastomers "SEPTON S8104" (manufactured by Kuraray Co., Ltd.); styrene-ethylene / butene-styrene block copolymers "FG1924" (manufactured by Kraton Corporation); "EF-40" (manufactured by CRAY VALLEY Corporation).

[0235] (D) The elastomer generally has a relatively large weight-average molecular weight. The weight-average molecular weight Mw of the (D) elastomer preferably ranges greater than 5,000, more preferably 8,000 or more, and still more preferably 10,000 or more. The upper limit is preferably 1,000,000 or less, more preferably 500,000 or less, still more preferably 200,000 or less, still more preferably 100,000 or less, still more preferably 50,000 or less, and still more preferably 30,000 or less.

[0236] (D) The elastomer preferably has a glass transition temperature Tg of 25°C or lower, or is in a liquid state 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, and more preferably 15°C or lower. There is no particular limitation on the lower limit of the glass transition temperature Tg, and it can be preferably -15°C or higher. When the (D) elastomer is in a liquid state at 25°C or lower, the (D) elastomer is preferably in a liquid state at 25°C, more preferably in a liquid state at 20°C, and still more preferably in a liquid state at 15°C. The glass transition temperature Tg can be measured by DSC (differential scanning calorimetry) at a heating rate of 5°C / minute.

[0237] (D) The elastomer may have functional groups capable of reacting with (A) a specific bismaleimide resin or (B) a thermosetting resin. When (D) the elastomer is capable of reacting with (A) a specific bismaleimide resin or (B) a thermosetting resin, the mechanical strength of the cured product of the resin composition can be improved. The functional groups capable of reacting with (A) a specific bismaleimide resin or (B) a thermosetting resin include functional groups that appear upon heating. Examples of such functional groups include: hydroxyl group, carboxyl group, acid anhydride group, phenolic hydroxyl group, epoxy group, isocyanate group, urethane group, and maleimide group. Among them, hydroxyl group, acid anhydride group, phenolic hydroxyl group, epoxy group, isocyanate group, urethane group, and maleimide group are preferred, and phenolic hydroxyl group is more preferred.

[0238] With respect to the non-volatile components of the resin composition of 100% by mass, the amount of (D) the elastomer preferably ranges from 0.1% by mass or more, more preferably from 1% by mass or more, further preferably from 2% by mass or more, further preferably from 3% by mass or more, further preferably from 4% by mass or more, further preferably from 5% by mass or more, preferably from 30% by mass or less, more preferably from 20% by mass or less, and further preferably from 15% by mass or less. When the amount of (D) the elastomer is within the above range, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0239] With respect to the resin components of the resin composition of 100% by mass, the amount of (D) the elastomer preferably ranges from 1% by mass or more, more preferably from 5% by mass or more, further preferably from 10% by mass or more, preferably from 70% by mass or less, more preferably from 60% by mass or less, further preferably from 50% by mass or less, and further preferably from 40% by mass or less. When the amount of (D) the elastomer is within the above range, the viscosity, dielectric loss tangent, minimum melt viscosity, and warpage can be effectively reduced.

[0240] <(E) Curing catalyst>

[0241] The resin composition according to the present embodiment may further contain (E) a curing catalyst as an optional component, and the (E) curing catalyst promotes the reaction of curable resins such as (A) a specific bismaleimide resin and (B) a thermosetting resin. The substance equivalent to the above components (A) to (D) is not included in the (E) curing catalyst as the (E) component. The (E) curing catalyst as the (E) component may be used alone in one kind, or two or more kinds may be used in combination.

[0242] As the (E) curing catalyst, for example, the following can be cited: a curing accelerator that is a catalyst for promoting the reaction of an epoxy resin. As the curing accelerator, for example, the following can be cited: a phosphorus-based curing accelerator, a urea-based curing accelerator, a guanidine-based curing accelerator, an imidazole-based curing accelerator, a metal-based curing accelerator, an amine-based curing accelerator, etc. The curing accelerator can be used alone as one kind, or two or more kinds can be used in combination.

[0243] 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)pyromellitic acid salt, tetrabutylphosphonium hexahydrophthalate, 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, and tetraphenylphosphonium bromide. Aromatic phosphonium salts such as phosphonium, p-tolyltriphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone addition reactants such as triphenylphosphine-p-benzoquinone addition reactants; tributylphosphine, tri-tert-butylphosphine , trioctylphosphine, di-tert-butyl (2-butenyl) phosphine, di-tert-butyl (3-methyl-2-butenyl) phosphine, tricyclohexylphosphine and other aliphatic phosphines; dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tri(4-ethylphenyl)phosphine, tri(4-propylphenyl)phosphine, tri(4-isopropylphenyl)phosphine, tri(4-butylphenyl)phosphine, tri(4-tert-butylphenyl)phosphine, tri(2,4-dimethylphenyl)phosphine, tri(2,5-dimethylphenyl)phosphine, tri( Aromatic phosphines such as tris(2,6-dimethylphenyl)phosphine, 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 are mentioned. Examples of commercially available phosphorus-based curing accelerators include "TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.

[0244] As the urea-based curing accelerator, for example, the following can be cited: 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, 3-cyclooctyl-1,1-dimethylurea; aromatic dimethylureas such as 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, 3-(3,4-dimethylphenyl)-1,1-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), N,N-(4-methyl-1,3-phenylene)bis(N’,N’-dimethylurea) (toluene bisdimethylurea), etc.

[0245] As the guanidine-based curing accelerator, for example, the following can be cited: 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, 1-(o-tolyl)biguanide, etc.

[0246] As imidazole-based curing accelerators, for example, the following can be cited: 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, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 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, 2-phenylimidazoline and other imidazole compounds, and adducts of imidazole compounds and epoxy resins. As commercially available products of imidazole-based curing accelerators, for example, the following can be cited: "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", "C11Z-A" manufactured by Shikoku Kasei Kogyo Co., Ltd.; "P200-H50" manufactured by Mitsubishi Chemical Corporation, etc.

[0247] As metal-based curing accelerators, for example, the following can be cited: organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organocopper complexes such as copper(II) acetylacetonate, organozinc complexes such as zinc(II) acetylacetonate, organoiron complexes such as iron(III) acetylacetonate, organonickel complexes such as nickel(II) acetylacetonate, organomanganese complexes such as manganese(II) acetylacetonate, etc. As organometallic salts, for example, the following can be cited: zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, zinc stearate, etc.

[0248] As amine-based curing accelerators, for example, the following can be cited: trialkylamines such as triethylamine and tributylamine; 4-dimethylaminopyridine; benzyldimethylamine; 2,4,6-tris(dimethylaminomethyl)phenol; 1,8-diazabicyclo(5,4,0)-undecene, etc. As commercially available products of amine-based curing accelerators, for example, the following can be cited: "MY-25" manufactured by Ajinomoto Fine-techno Co., Inc., etc.

[0249] With respect to the resin component of the resin composition of 100% by mass, the amount range of the curing accelerator is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, preferably 5% by mass or less, more preferably 2% by mass or less, and still more preferably 1% by mass or less.

[0250] As the (E) curing catalyst, for example, the following can be cited: radical polymerization initiators as catalysts for radical reactions. The radical polymerization initiators can be used alone or in combination of two or more. As radical polymerization initiators, for example, the following can be cited: peroxide-based radical polymerization initiators, azo-based radical polymerization initiators, etc.

[0251] As peroxide-based radical polymerization initiators, for example, the following can be cited: hydrogen peroxide compounds such as 1,1,3,3-tetramethylbutyl hydroperoxide; dialkyl peroxide compounds such as tert-butyl cumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, di-tert-amyl peroxide, diisopropylbenzene peroxide, 1,4-bis(1-tert-butylperoxy-1-methylethyl)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane; diacyl peroxide compounds such as dilauroyl peroxide, didecanoyl peroxide, dicyclohexyl peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate; peroxyester compounds such as tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butyl isopropylmonocarbonate, tert-butyl 2-ethylhexylperoxide, tert-butyl neodecanoate, tert-hexyl isopropylmonocarbonate, tert-butyl laurate, 1,1-dimethylpropyl 2-ethylhexylperoxide, tert-butyl 2-ethylhexylperoxide, tert-butyl 3,5,5-trimethylhexylperoxide, tert-butyl 2-ethylhexylmonocarbonate, tert-butyl peroxymaleate, etc.

[0252] As an azo-based radical polymerization initiator, examples include: azo nitrile 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, 2-phenylazo-4-methoxy-2,4-dimethyl-valeronitrile; azo amide compounds such as 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propanamide], 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propanamide], 2,2'-azobis[2-methyl-N-[2-(1-hydroxybutyl)]-propanamide], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propanamide], 2,2'-azobis(2-methylpropanamide) dihydrate, 2,2'-azobis[N-(2-propenyl)-2-methylpropanamide], 2,2'-azobis(N-butyl-2-methylpropanamide), 2,2'-azobis(N-cyclohexyl-2-methylpropanamide); alkyl azo compounds such as 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2-methylpropane), etc.

[0253] Examples of commercially available products of radical polymerization initiators include: "PERBUTYL C", "PERBUTYL A", "PERBUTYL P", "PERBUTYL L", "PERBUTYL O", "PERBUTYL ND", "PERBUTYLZ", "PERBUTYL I", "PERCUMYL P", "PERCUMYL D", "PERHEXYL D", "PERHEXYL A", "PERHEXYLI", "PERHEXYL Z", "PERHEXYL ND", "PERHEXYL O", "PERHEXYL PV" manufactured by NOF Corporation; "LUPEROX DTA" manufactured by ARKEMA Kishima Co., Ltd., etc.

[0254] With respect to the resin component of the resin composition of 100% by mass, the amount of the radical polymerization initiator preferably ranges from 0.01% by mass or more, more preferably from 0.1% by mass or more, further preferably from 0.2% by mass or more, preferably 5% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less.

[0255] With respect to the non-volatile components of the resin composition at 100% by mass, the amount of the (E) curing catalyst preferably ranges from 0.01% by mass or more, more preferably 0.02% by mass or more, still more preferably 0.05% by mass or more, preferably 2% by mass or less, more preferably 1% by mass or less, and still more preferably 0.5% by mass or less.

[0256] With respect to the resin component of the resin composition at 100% by mass, the amount of the (E) curing catalyst preferably ranges from 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.2% by mass or more, preferably 5% by mass or less, more preferably 2% by mass or less, and still more preferably 1% by mass or less.

[0257] <(F) Optional Additives>

[0258] The resin composition according to this embodiment may further contain (F) optional additives as optional components. The (F) optional additives as the (F) component do not include substances equivalent to the above-mentioned (A) to (E) components. Examples of the (F) optional additives include: organometallic compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; homogenizers such as organosilicon-based homogenizers and acrylic polymer-based homogenizers; thickeners such as Benton and montmorillonite; defoamers such as organosilicon-based defoamers, acrylic-based defoamers, fluorine-based defoamers, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as ureidosilanes; adhesion imparting agents such as triazole-based adhesion imparting agents, tetrazole-based adhesion imparting agents, and triazine-based adhesion imparting agents; antioxidants such as hindered phenol-based antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and organosilicon-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate compounds, phosphonitrile compounds, hypophosphorous acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, organosilicon-based dispersants, anionic dispersants, and cationic dispersants; stabilizers such as borate ester-based stabilizers, titanate ester-based stabilizers, aluminate ester-based stabilizers, zirconate ester-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic anhydride-based stabilizers, etc. The (F) optional additives can be used alone or in combination of two or more.

[0259] <(G) Solvent>

[0260] The resin composition according to the present embodiment may further include a (G) solvent as an optional volatile component in combination with the non-volatile components such as the above-mentioned (A) to (F) components. As the (G) solvent, an organic solvent is generally used. Examples of the organic solvent include: ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; tetrahydropyran, tetrahydrofuran, 1,4-dimethoxybenzene, and the like. Ether solvents such as alkane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, anisole; alcohol solvents such as methanol, ethanol, propanol, butanol, ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, carbitol acetate (ethyl diglycol (G) solvents may be used alone or in combination of two or more.

[0261] The amount of (G) solvent can be set to obtain a desired minimum melt viscosity. For example, when using a low-viscosity resin such as a liquid epoxy resin, a resin combination with a low melt viscosity can sometimes be obtained. However, when such a low-viscosity resin is less or no low-viscosity resin is used, the melt viscosity of the resin combination can sometimes increase. Therefore, (G) solvent can also be mixed in the resin combination with a high melt viscosity to reduce the melt viscosity of the resin combination. In the past, the viscosity of the resin combination with a low melt viscosity may become larger. In contrast, in the resin combination involved in the present embodiment, for example, even when the minimum melt viscosity is reduced using (G) solvent, the viscosity can be reduced.

[0262] The amount of the (G) solvent relative to 100% by mass of the total components of the resin composition may be, for example, 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, or 5% by mass or less, or may be 0% by mass. The specific amount of the (G) solvent can be adjusted so as to obtain a desired minimum melt viscosity.

[0263] <Method for producing resin composition>

[0264] The resin composition according to this embodiment can be produced, for example, by mixing the components that can be included in the resin composition. Some or all of the above components can be mixed simultaneously, or can be mixed sequentially. During the mixing of each component, the temperature can be appropriately set, and thus, heating and / or cooling can be performed temporarily or throughout the process. In addition, during the mixing of each component, stirring or oscillation can be performed.

[0265] <Properties of the Resin Composition and Its Cured Product>

[0266] The resin composition according to this embodiment can have low viscosity. For example, as described in the examples below, a resin sheet including a resin composition layer containing the resin composition and a protective film joined to the resin composition layer is prepared. In the case of performing a tack evaluation test of stretching and peeling the protective film, the tack can be reduced to such an extent that zipping marks remain on the surface of the resin sheet. Here, "zipping" means a phenomenon in which the protective film peels off repeatedly or stops when the protective film is stretched and peeled off with a certain force and speed. In addition, "zipping marks" means marks formed on the resin composition layer at the position where zipping occurs and the peeling of the protective film stops. Generally, when the tack is low enough, zipping does not occur. Therefore, when zipping does not occur, it can be judged that the tack is low. Due to having such low tack, according to the resin composition according to this embodiment, peeling defects of the protective film from the resin sheet can generally be suppressed, or the generation of voids in the insulating layer can be suppressed. Specifically, the tack evaluation test can be performed as described in <Test Example 2: Tack Evaluation Test> of the examples below.

[0267] Since the resin composition according to this embodiment can generally have a low minimum melt viscosity, both low tack and low minimum melt viscosity can be achieved. Moreover, since the resin composition according to this embodiment has such a low minimum melt viscosity, for example, when forming a resin composition layer on an inner layer substrate having wirings on its surface, the wirings on the surface of the inner layer substrate can be well buried 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 further preferably 4,500 poise or less. The lower limit can be, for example, 500 poise or more, 1,000 poise or more, etc.

[0268] The minimum melt viscosity of the resin composition can be measured using a dynamic viscoelasticity measuring device. Under the measurement conditions of starting temperature 60°C to 200°C, heating rate 5°C / minute, measurement interval temperature 2.5°C, frequency 1 Hz, and strain 5 deg, the dynamic viscoelastic modulus is measured while heating, and the lowest value of the measured melt viscosity can be obtained as the minimum melt viscosity. The specific measurement method can adopt the method of <Test Example 4: Measurement Test of Melt Viscosity> of the examples below.

[0269] By curing the resin composition, a cured product of the resin composition can be obtained. Moreover, an insulating layer can be formed from the cured product. Generally, since heating is performed during the curing of the resin composition, among the components contained in the resin composition, volatile components such as (G) solvents can be volatilized by 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.

[0270] The cured product of the resin composition according to this embodiment can have excellent dielectric properties. Specifically, it can have a low dissipation factor Df. In one example, the dissipation factor Df of the cured product is preferably 0.0050 or less, more preferably 0.0049 or less, and still more preferably 0.0048 or less. There is no particular limitation on the lower limit of the dissipation factor Df, and for example, it can be 0.0010 or more.

[0271] The dissipation factor Df of the cured product of the resin composition can be measured by the cavity resonator perturbation method under the measurement conditions of a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. In the case where the sample is the resin composition before curing, the resin composition can also be cured under the curing conditions of 200°C for 90 minutes to obtain a cured product, and the dissipation factor Df of the cured product can be measured. The specific measurement method can adopt the method of <Test Example 1: Measurement Test of Dissipation Factor Df> in the following examples.

[0272] When the cured product of the resin composition according to this embodiment is provided on a circuit board, warping of the circuit board can be suppressed. In one example, when the warpage amount is measured by the method described in <Test Example 3: Warpage Measurement Test> of the following examples, the range of the warpage amount is preferably less than 2,500 μm, and more preferably 2,000 μm or less.

[0273] <Use of the resin composition>

[0274] The resin composition according to this embodiment can be used for the formation of an insulating layer, and is particularly preferably used for the formation of an insulating layer of a circuit board. In addition, the resin composition can also be used for manufacturing a resin sheet. Generally, the resin sheet is used for the formation of an insulating layer. In addition, the resin composition can also be used for other uses. For example, it can also be used for solder resist, underfill material, chip bonding material, via filling resin, encapsulation resin, component embedding resin, etc.

[0275] <Resin sheet>

[0276] A resin sheet according to an embodiment of the present invention includes a support and a resin composition layer formed on the support. The resin composition layer contains the above resin composition and preferably contains only the above resin composition.

[0277] From the viewpoint of thinning, the thickness of the resin composition layer included in the resin sheet is preferably 200 μm or less, more preferably 150 μm or less, and still 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.

[0278] Examples of the support include a film of a plastic material, a metal foil, and a release paper, and a film of a plastic material and a metal foil are preferred.

[0279] When using a film of a plastic material as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes simply referred to as "PET"), polyethylene naphthalate (hereinafter sometimes simply referred to as "PEN"), polycarbonate (hereinafter sometimes simply referred to as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyethersulfide (PES), polyether ketone, polyimide, etc. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0280] When using a metal foil as the support, examples of the metal foil include a copper foil, an aluminum foil, etc., and a copper foil is preferred. As the copper foil, a foil made of single metal of copper or a foil made of an alloy of copper and other metals (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) can be used.

[0281] Surface treatments such as a matting treatment, a corona treatment, and an antistatic treatment can be performed on the surface of the support that is joined to the resin composition layer.

[0282] As the support, a support with a release layer having a release layer on the surface joined to the resin composition layer can be used. Examples of the release agent in the release layer of the support with a release layer include one or more release agents selected from alkyd-based release agents, polyolefin-based release agents, urethane-based release agents, and silicone-based release agents. Commercially available products can be used as the support with a release layer, and examples include "PET501010", "SK-1", "AL-5", "AL-7" manufactured by Lintec Corporation as PET films having a release layer mainly composed of a silicone-based release agent or an alkyd resin-based release agent; "Lumirror T60" manufactured by Toray Industries, Inc.; "Purex" manufactured by Teijin Limited; "Unipeel" manufactured by UNITIKA Ltd., etc.

[0283] There is no particular limitation on the thickness of the support, and it is preferably 1 μm or more, more preferably 5 μm or more, still more preferably 10 μm or more, preferably 75 μm or less, more preferably 60 μm or less, and still more preferably 50 μm or less. When using a support with a release layer, it is preferred that the overall thickness of the support with the release layer is within the above range.

[0284] As needed, the resin sheet may have optional components. For example, the resin sheet may have a protective film that protects the resin composition layer. The protective film is usually provided on the surface of the resin composition layer that is not joined to the support (i.e., the surface on the side opposite to the support). There is no particular limitation on the thickness of the protective film, and it is, for example, 1 μm to 40 μm. When the protective film is provided, it is possible to suppress dust from adhering to the surface of the resin composition layer and to prevent damage to the surface of the resin composition layer.

[0285] The resin sheet can be manufactured, for example, by a method including forming a resin composition layer on a support. As a specific example, a liquid (varnish-like) resin composition is directly coated on the support, or a solvent and a resin composition are mixed to prepare a liquid (varnish-like) resin composition, which is then coated on the support, and further dried as needed to form a resin composition layer, whereby the resin sheet can be manufactured. As the solvent, the same solvent as the (G) solvent described as a component of the resin composition can be used.

[0286] The coating of the resin composition can be carried out using a coating device such as a die coater. In addition, drying can be carried out, for example, by drying methods such as heating and blowing hot air. There is no particular limitation on the drying conditions, and drying is carried out so that the content of the solvent in the resin composition layer usually reaches 10% by mass or less, preferably 5% by mass or less. Although it may vary depending on the boiling point of the solvent, for example, when using a resin composition containing 30% to 60% by mass of the solvent, a resin composition layer can be formed by drying at 50°C to 150°C for 3 minutes to 10 minutes.

[0287] The manufactured resin sheet can be wound into a roll for storage. When the resin sheet has a protective film, the resin sheet can usually be used by peeling off the protective film.

[0288] <Circuit board>

[0289] The circuit board according to one embodiment of the present invention includes a cured product of the above resin composition. Usually, the circuit board has an insulating layer that includes a cured product of the resin composition. The insulating layer may consist only of a cured product of the resin composition. There is no particular limitation on the thickness of the insulating layer, and for example, it may be in the same range as the thickness of the resin composition layer included in the resin sheet. In addition, the insulating layer usually has the same characteristics as the cured product of the above resin composition.

[0290] The circuit substrate preferably includes an inner substrate, on which the insulating layer is provided. Alternatively, the circuit substrate may include a conductive layer. For example, the conductive layer may be provided on the insulating layer. An example of a preferred method for manufacturing the circuit substrate is described below.

[0291] The method for manufacturing a circuit substrate according to a preferred embodiment includes the following steps:

[0292] Step (I), forming a resin composition layer on the inner substrate; and

[0293] In step (II), the resin composition layer is cured.

[0294] The "inner layer substrate" is a component that serves as the base material of the circuit substrate, and examples thereof include: a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, and the like. In addition, the inner layer substrate may have a conductor layer on one or both sides thereof. In addition, the conductor layer possessed by 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 referred to as an "inner layer circuit substrate." In addition, when manufacturing a circuit substrate, an intermediate product on which an insulating layer and / or a conductor layer is to be further formed is also included in the term "inner layer substrate." In addition, an inner layer substrate with built-in components may be used.

[0295] Regarding the formation of the resin composition layer on the inner substrate, for example, it can be carried out by a formation method including applying a resin composition on the inner substrate and drying it as needed, but it is preferably carried out using a resin sheet. The formation method of the resin composition layer using a resin sheet generally includes laminating a resin sheet and an inner substrate. The lamination of the resin sheet and the inner substrate is carried out in a manner that the resin composition layer of the resin sheet is bonded to the inner substrate. The lamination can be carried out, for example, by heat-pressing the resin sheet to the inner substrate from the support side. As a component for heat-pressing the resin sheet to the inner substrate (hereinafter also referred to as a "heat-pressing component"), for example, a heated metal plate (SUS end plate, etc.) or a metal roller (SUS roller, etc.) can be cited. It should be noted that it is preferred not to directly press the heat-pressing component and the resin sheet, but to press them through an elastic material such as heat-resistant rubber so that the resin sheet fully follows the surface unevenness of the inner substrate.

[0296] The lamination of the inner substrate and the resin sheet can be carried out by a vacuum lamination method. In the vacuum lamination method, the heating and pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heating and pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa, and the heating and pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination is preferably carried out under a reduced pressure condition of 26.7 hPa or less.

[0297] The lamination can be carried out by a commercially available vacuum laminator. As a commercially available vacuum laminator, for example, a vacuum pressure type laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko-Materials Co., Ltd., an intermittent vacuum pressure laminator, etc. can be cited.

[0298] The method for manufacturing a circuit board may include: after lamination, by pressing the heating and pressing member from the support side under normal pressure (atmospheric pressure), the resin sheet is smoothed. The pressing conditions for the smoothing treatment can be set to the same conditions as the heating and pressing conditions for the above lamination. The smoothing treatment can be carried out using a commercially available laminator. The lamination and the smoothing treatment can be continuously carried out using the above-mentioned commercially available vacuum laminator.

[0299] The method for manufacturing a circuit board according to this example includes: after step (I), step (II) of curing the resin composition layer. By curing the resin composition layer in step (II), an insulating layer containing a cured product of the resin composition can be formed.

[0300] The curing of the resin composition layer is usually carried out by thermal curing. The thermal curing conditions of the resin composition layer may vary depending on the type of the resin composition. For example, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and further preferably 170°C to 210°C. In addition, the curing time can be preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and further preferably 15 minutes to 100 minutes.

[0301] The manufacturing method of a circuit board may include: before the thermal curing of the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, before the resin composition layer is thermally cured, the resin composition layer may be preheated at a temperature generally of 50°C to 150°C, preferably 60°C to 140°C, more preferably 70°C to 130°C for generally more than 5 minutes, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and further preferably 15 minutes to 100 minutes. The preheating is generally carried out after process (I). In addition, when a smoothing process is carried out after the lamination of the inner layer substrate and the resin sheet, the preheating can generally be carried out after this smoothing process.

[0302] When using a resin sheet, the manufacturing method of a circuit board may include: after the lamination of the inner layer substrate and the resin sheet, a process of peeling off the support of the resin sheet. The peeling of the support can be carried out between process (I) and process (II), or can be carried out after process (II). In addition, as described later, when the manufacturing method of a circuit board includes a process (III) of forming holes in the insulating layer, a process (IV) of roughening the insulating layer, and a process (V) of forming a conductor layer, the peeling of the support can be carried out between process (II) and process (III), between process (III) and process (IV), or between process (IV) and process (V).

[0303] The manufacturing method of a circuit board may include: after process (II), a process (III) of forming holes such as vias and through-holes in the insulating layer. The method of forming the holes can be selected according to factors such as the composition of the resin composition used to form the insulating layer. For example, the holes can be formed by processing methods such as drilling, laser processing, and plasma processing, among which laser processing is preferred. For example, the holes can be formed by irradiating the insulating layer with laser after peeling off the support, or the holes can be formed by irradiating the insulating layer with laser through the support. The size and shape of the holes can be appropriately determined according to the design of the circuit board.

[0304] The manufacturing method of a circuit board may include: a process (IV) of roughening the insulating layer. According to the roughening process, the surface of the insulating layer can be roughened. In addition, according to the roughening process, contaminants (resin residues) can be removed from the insulating layer. Therefore, this roughening process is sometimes referred to as a "decontamination process". For example, if holes are formed in process (III), contaminants may be formed in the holes, so it is preferred to carry out the roughening process of process (IV) after process (III) to remove the said contaminants.

[0305] There are no particular limitations on the steps and conditions for the roughening treatment, and known steps and conditions commonly used in forming the insulating layer of the circuit board can be adopted. For example, the roughening treatment can be implemented by sequentially performing a swelling treatment based on a swelling liquid, an oxidation treatment based on an oxidizing agent, and a neutralization treatment based on a neutralizing liquid on the insulating layer.

[0306] Examples of the swelling liquid for the roughening treatment include an alkali solution, a surfactant solution, etc., and an alkali solution is preferred. As the alkali solution, a sodium hydroxide solution or a potassium hydroxide solution is more preferred. Examples of commercially available swelling liquids include "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan Co., Ltd. The swelling treatment based on the swelling liquid can be carried out, for example, by immersing the insulating layer in the swelling liquid at 30°C to 90°C for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferred to immerse the insulating layer in the swelling liquid at 40°C to 80°C for 5 minutes to 15 minutes.

[0307] Examples of the oxidizing agent for the roughening treatment include an alkaline permanganic acid solution obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. The oxidation treatment based on an oxidizing agent such as the alkaline permanganic acid solution is preferably carried out by immersing the insulating layer in the oxidizing agent solution heated to 60°C to 100°C for 10 minutes to 30 minutes. In addition, the concentration of the permanganate in the alkaline permanganic acid solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganic acid solutions such as "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by Atotech Japan Co., Ltd.

[0308] As the neutralizing liquid for the roughening treatment, an acidic aqueous solution is preferred, and examples of commercially available products include "Reduction Solution Securiganth P" manufactured by Atotech Japan Co., Ltd. The neutralization treatment based on the neutralizing liquid can be carried out by immersing the treated surface that has undergone the oxidation treatment based on the oxidizing agent in the neutralizing liquid at 30°C to 80°C for 5 minutes to 30 minutes. From the viewpoint of operability, a method of immersing the object that has undergone the oxidation treatment based on the oxidizing agent in the neutralizing liquid at 40°C to 70°C for 5 minutes to 20 minutes is preferred.

[0309] The manufacturing method of the circuit board may include: a step (V) of forming a conductor layer on the insulating layer. When the manufacturing method of the circuit board includes step (III) or (IV), it is preferred that the step (V) of forming the conductor layer is usually carried out after step (III) and (IV).

[0310] There is no particular limitation on the conductor material for the conductor layer. In a suitable embodiment, the conductor layer contains one or more metals selected from 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. As the alloy layer, for example, a layer formed of an alloy of two or more metals selected from the above (for example, nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy) can be cited. Among them, from the viewpoints of the versatility of forming the conductor layer, cost, ease of patterning, etc., a single-metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of 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 nickel-chromium alloy is more preferred, and a single-metal layer of copper is further preferred.

[0311] The conductor layer may have a single-layer structure or a multilayer structure including two or more single-metal layers or alloy layers composed of different kinds of metals or alloys. In the case where the conductor layer has a multilayer structure, it is preferred that the layer in contact with the insulating layer is a single-metal layer of chromium, zinc, or titanium, or an alloy layer of nickel-chromium alloy.

[0312] 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.

[0313] The conductor layer can be formed by electroplating. For example, the surface of the insulating layer can be electroplated by a conventionally known technique such as the semi-additive method or the full-additive method to form a conductor layer having a desired wiring pattern. From the viewpoint of manufacturing simplicity, the semi-additive method is preferred. Hereinafter, an example of forming a conductor layer by the semi-additive method is shown.

[0314] First, an electroless plating layer (electroplating seed layer) is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern corresponding to the desired wiring pattern is formed on the formed electroless plating layer to expose a part of the electroless plating layer. After forming an electroplating layer by electroplating on the exposed electroless plating layer, the mask pattern is removed. After that, the unnecessary electroless plating layer is removed by etching, and a conductor layer having a desired wiring pattern can be formed.

[0315] As another example, the conductor layer can be formed using a metal foil. In the case of forming the conductor layer using a metal foil, step (V) is suitably carried out between step (I) and step (II). For example, after step (I), the support is removed, and a metal foil is laminated on the surface of the exposed resin composition layer. The lamination of the resin composition layer and the metal foil can be carried out by a vacuum lamination method. The lamination conditions can be the same as those described with respect to step (I). Then, step (II) is carried out to form the insulating layer. After that, using the metal foil on the insulating layer, a conductor layer having a desired wiring pattern can be formed 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. As commercially available products of the metal foil, for example, there can be mentioned: HLP foil, JXUT-III foil manufactured by JX Metals Co., Ltd.; 3EC-III foil, TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd., etc.

[0316] In the case of forming the conductor layer on the insulating layer, the method for manufacturing the circuit board may include: performing an annealing treatment after forming the conductor layer. According to the annealing treatment, the adhesion between the insulating layer and the conductor layer can be improved. The annealing treatment can be carried out, for example, by heating at 150°C to 210°C for 20 minutes to 180 minutes.

[0317] In the method for manufacturing the circuit board, each of the above steps can be carried out only once, or can be repeated two or more times. For example, steps (I) to (V) can also be repeatedly carried out 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.

[0318] In the method for manufacturing the circuit board, optional steps can be further included in combination with the above steps. For example, the method for manufacturing the circuit board can include: a step of providing a semiconductor chip in a manner to be joined to the conductor layer. As a specific example, in the case of manufacturing a circuit board for a semiconductor chip package having a semiconductor chip, the method for manufacturing the circuit board can include: a step of providing a semiconductor chip. The semiconductor chip can adopt appropriate conditions capable of making a conductor connection between the terminal electrodes of the semiconductor chip and the conductor layer formed on the insulating layer. For example, the conditions used in flip chip mounting can be adopted. In addition, the semiconductor chip can be joined via an insulating adhesive, or can be joined by reflow soldering. Moreover, if necessary, the provided semiconductor chip can be filled with a molding underfill material. In addition, the method for manufacturing the circuit board can include, for example: a step of forming a sealing layer; a step of forming a solder resist layer; a step of cutting the manufactured circuit board into individual pieces, etc.

[0319] Examples of the circuit board include printed wiring boards and semiconductor chip packages. Examples of the semiconductor chip package 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. Among these semiconductor chip packages, a cured product formed by curing the above resin composition is preferably used to form a rewiring formation layer as an insulating layer. However, the circuit board is not limited to the substrates exemplified herein.

[0320] <Semiconductor Device>

[0321] The circuit board can be used to manufacture a semiconductor device. The semiconductor device includes the above circuit board. Examples of the semiconductor device include various semiconductor devices for electrical products (such as computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical devices, and televisions) and transportation means (such as motorcycles, automobiles, trams, ships, and airplanes).

[0322] Examples

[0323] Hereinafter, examples will be shown to specifically describe the present invention. However, the present invention is not limited to these examples.

[0324] In the following description, unless otherwise specified, "parts" and "%" indicating amounts refer to "parts by mass" and "% by mass", respectively. In addition, the temperature conditions and pressure conditions are room temperature (23°C) and atmospheric pressure (1 atm) when not specifically specified.

[0325] <Synthesis Example 1: Synthesis of Elastomer (D1)>

[0326] 69 g of difunctional hydroxyl-terminated polybutadiene ("G-3000" manufactured by Nippon Soda Co., Ltd., number average molecular weight = 3000, hydroxyl equivalent = 1800 g / eq.), 40 g of PGMEA (propylene glycol monomethyl ether acetate manufactured by Showa Denko K.K.), and 0.005 g of dibutyltin dilaurate were charged into a reaction vessel and mixed to dissolve them uniformly. When it became uniform, the temperature was raised to 60°C, and 8 g of isophorone diisocyanate ("IPDI" manufactured by Evonik Degussa Japan Co., Ltd., isocyanate group equivalent = 113 g / eq.) was further added with stirring, and the reaction was carried out for about 3 hours.

[0327] Next, 23 g of cresol novolac resin (“KA-1160” manufactured by DIC Corporation, hydroxyl equivalent = 117 g / eq.) and 60 g of PGMEA were added to the reactants, and the mixture was refluxed with stirring while heating up to 150 °C, and the reaction was carried out for about 10 hours. The disappearance of the NCO peak at 2250 cm -1 was confirmed by FT-IR. The disappearance of the NCO peak was regarded as the end point of the reaction, and the reactants were cooled to room temperature. Moreover, the reactants were filtered through a 100-mesh filter cloth to obtain an elastomer (D1) having a butadiene structure and phenolic hydroxyl groups (butadiene resin containing phenolic hydroxyl groups: non-volatile content 50% by mass). The weight-average molecular weight of the elastomer (D1) was 27,000, and the glass transition temperature was -7 °C.

[0328] The elastic modulus of the obtained elastomer (D1) was measured by the following elastic modulus measurement method. That is, a polyethylene terephthalate film (“Lumirror R80” manufactured by Toray Industries, Inc., thickness 38 μm, softening point 130 °C) subjected to a demolding treatment with an alkyd resin-based mold release agent (“AL-5” manufactured by Lintec Corporation) was prepared. Using a die coater, the elastomer (D1) was uniformly coated on the polyethylene terephthalate film so that the thickness of the dried elastomer layer was 50 μm, and it was dried at 70 °C to 120 °C for 10 minutes to form an elastomer layer. The elastomer layer was peeled off from the polyethylene terephthalate, and the elastic modulus was measured by a tensile test (temperature 25 °C, humidity 40% RH) according to JIS K7161, and it was confirmed that the elastic modulus of the elastomer (D1) was 0.05 GPa.

[0329] <Synthesis Example 2: Synthesis of Elastomer (D2)>

[0330] Into a flask equipped with a stirring device, a thermometer, and a condenser, 368.41 g of carbitol acetate and 368.41 g of an aromatic solvent (“Solvesso 150 (registered trademark)” manufactured by Exxon Mobil Corporation) were charged as solvents. Moreover, 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: about 2000, hydroxyl equivalent: 1000 g / eq., non-volatile content: 100% by mass) were charged into the flask, and the reaction was carried out at 70 °C for 4 hours. Thus, a first reaction solution was obtained.

[0331] Next, 195.9 g (0.2 mol) of novolac resin of nonylphenol (hydroxyl equivalent: 229.4 g / eq, average functionality 4.27, average calculated molecular weight: 979.5 g / mol) and 41.0 g (0.1 mol) of ethylene glycol bis(trimellitate) 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. Thus, the second reaction solution was obtained. Confirmation of the disappearance of the NCO peak at 2250 cm -1 was carried out by FT-IR. The disappearance of the NCO peak was regarded as the end point of the reaction, and the second reaction solution was cooled to room temperature. Further, the second reaction solution was filtered through a 100-mesh filter cloth. Thus, as the filtrate, an elastomer (D2) having phenolic hydroxyl groups (polycarbonate resin containing phenolic hydroxyl groups: non-volatile content 50 mass%) was obtained. The weight-average molecular weight of the elastomer (D2) was 20,000, and the glass transition temperature was 5 °C. By the same method for measuring the elastic modulus as that of the elastomer (D1), it was confirmed that the elastic modulus of the elastomer (D2) measured by the tensile test according to JIS K7161 (temperature 25 °C, humidity 40% RH) was 0.5 GPa.

[0332] <Synthesis Example 3: Synthesis of Elastomer (D3)>

[0333] In a 1-L separable flask equipped with an oil bath and a stirrer bar, 200 g of cyclohexanone was added while introducing nitrogen, and 149.4 g of a dimer acid type diamine (“PRIAMINE 1075” manufactured by Croda Japan Co., Ltd.) as a diamine and 4.7 g of m-aminophenol as a monoamine compound were added with stirring. Then, 67.3 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride as a tetracarboxylic acid was added, and the mixture was stirred at room temperature for 30 minutes. The temperature was raised to 100 °C, and after stirring for 3 hours, it was taken out of the oil bath and returned to room temperature to obtain a varnish-like polyimide precursor. Thereafter, using a Dean-Stark trap, the distilled water was removed from the system, and at the same time, heating was carried out at 170 °C for 10 hours for imidization to obtain an elastomer (D3) having a dimer acid skeleton (non-volatile content 50 mass%). The weight-average molecular weight of the obtained elastomer (D3) was 10,000. By the same method for measuring the elastic modulus as that of the elastomer (D1), it was confirmed that the elastic modulus of the elastomer (D3) measured by the tensile test according to JIS K7161 (temperature 25 °C, humidity 40% RH) was 0.2 GPa.

[0334] <Synthesis Example 4: Synthesis of Maleimide Resin (B)>

[0335] A MEK solution (nonvolatile component: 60% by mass) of a maleimide resin (B) synthesized by the method described in Synthesis Example 1 of Japanese Invention Association Publication No. 2020-500211 was prepared. The maleimide resin (B) has a structure represented by the following formula (b-1) and a weight-average molecular weight of 2,000.

[0336]

[0337] <Examples 1 to 8 and Comparative Examples 1 to 9>

[0338] (1) Preparation of resin composition:

[0339] Each component was weighed and mixed in the amounts (parts by mass) shown in Tables 1 to 4. Further, 15 parts of MEK and 15 parts of cyclohexanone were mixed, and the mixture was uniformly dispersed using a high-speed rotary mixer to obtain a resin composition (resin varnish). The details of each component shown in Tables 1 to 4 are as follows.

[0340] (A) component:

[0341] "SLK-6893-T90": A flexible backbone bismaleimide resin (manufactured by Shin-Etsu Chemical Co., Ltd., toluene solution with nonvolatile component of 90%), containing 90% by mass of a first bismaleimide compound represented by formula (3-i) (m i = 0, R i represented by formula (2)), 6% by mass of a second bismaleimide compound represented by formula (3-ii) (m ii = 0, n ii = 1, R ii represented by formula (2)), and 4% by mass of a second bismaleimide compound represented by formula (3-ii) (m ii = 0, n ii = 2, R ii represented by formula (2)).

[0342] (B) component:

[0343] "ZX-1059": A bisphenol type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., a 1:1 mixture of bisphenol A type and bisphenol F type, epoxy equivalent: 169 g / eq.).

[0344] "NC3000": A biphenyl aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 275 g / eq.).

[0345] "HP4032SS": A naphthalene type epoxy resin (manufactured by DIC Corporation, epoxy equivalent: approximately 144 g / eq.).

[0346] "YX4000HK": Biphenol type epoxy resin (manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: approximately 185 g / eq.).

[0347] "HPC-8000-65T": Activated ester resin (manufactured by DIC Corporation, active group equivalent: approximately 223 g / eq., toluene solution with 65 mass% non-volatile content).

[0348] "KA-1160": Cresol novolak type phenolic resin (manufactured by DIC Corporation, hydroxyl equivalent: 117 g / eq.).

[0349] "V-03": Carbodiimide resin (manufactured by Nisshinbo Chemical Inc., active group equivalent: 216 g / eq., toluene solution with 50% non-volatile content).

[0350] "OPE-2St": Vinylbenzyl modified polyphenylene ether (manufactured by Mitsubishi Gas Chemical Company, toluene solution with 65% non-volatile content rate).

[0351] "Maleimide resin B": Maleimide resin (B) synthesized in Synthesis Example 4 (non-volatile content: 60 mass%).

[0352] "BMI-689": Flexible backbone bismaleimide resin (manufactured by Designer molecules, non-volatile content: 100%), containing 93 mass% of any bismaleimide compound represented by formula (3-i) (m i =0, R i represented by formula (2)), 4 mass% of any bismaleimide compound represented by formula (3-ii) (m ii =0, n ii =1, R ii represented by formula (2)) and 3 mass% of any bismaleimide compound represented by formula (3-ii) (m ii =0, n ii =2, R ii represented by formula (2)). Since the amount of any bismaleimide compound represented by formula (1-ii) is not within a specific range, it is classified as component (B) in Comparative Examples 1 and 4-9.

[0353] (C) component:

[0354] "SO-C2": Spherical silica (average particle size: 0.5 μm, manufactured by Admatechs) surface-treated with an amino-silane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0355] "LHP-208": Silica (average particle size 0.5 μm, manufactured by Ube Exsymo Co., Ltd.) surface-treated with an amino-silane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0356] Component (D)

[0357] "Elastomer D1": Elastomer (D1) synthesized in Synthesis Example 1, non-volatile content 50% by mass.

[0358] "Elastomer D2": Elastomer (D2) synthesized in Synthesis Example 2, non-volatile content 50% by mass.

[0359] "Elastomer D3": Elastomer (D3) synthesized in Synthesis Example 3, non-volatile content 50% by mass.

[0360] Component (E):

[0361] "2P4MZ": 2-Phenyl-4-methylimidazole (manufactured by Shikoku Chemicals Corporation)

[0362] "LUPEROX DTA": Di-tert-amyl peroxide (manufactured by Arkema Kishima Co., Ltd.)

[0363] (2) Manufacture of the resin sheet:

[0364] 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. Using a die coater, the resin composition was uniformly coated on this support such that the thickness of the dried resin composition layer was 50 μm, and it was dried at 70°C to 100°C for 3 minutes to make the residual solvent content 2% by mass, thereby forming a resin composition layer. Next, the rough surface of a polypropylene film ("ALPHAN MA-411" manufactured by Oji F-TEX Corporation, thickness 15 μm) was adhered to the surface of the resin composition layer that was not joined to the support. Thus, a resin sheet having a support, a resin composition layer, and a protective film in that order was obtained.

[0365] <Test Example 1: Measurement test of dielectric loss tangent Df>

[0366] The protective film was peeled off from the resin sheet. After heat-curing the resin composition layer by heating at 200°C for 90 minutes, 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 test pieces for evaluation.

[0367] For the test pieces, the dielectric loss tangent was measured at a measurement frequency of 5.8 GHz and a measurement temperature of 23 °C by the cavity resonator perturbation method using a measuring device ("HP8362B" manufactured by Agilent Technologies, Inc.). Three test pieces were measured and the average value was calculated. Based on this average value, the dielectric loss tangent was evaluated according to the following evaluation criteria.

[0368] Evaluation Criteria for Dielectric Loss Tangent

[0369] "Good": The dielectric loss tangent is 0.005 or less;

[0370] "Bad": The dielectric loss tangent is greater than 0.005.

[0371] <Test Example 2: Adhesion Evaluation Test>

[0372] When there are zipper marks remaining on the surface of the resin sheet when the protective film of the resin sheet is peeled off by hand, it is judged that the adhesion is too strong and evaluated as "bad". The case where the protective film can be peeled off without forming zipper marks is evaluated as "good".

[0373] <Test Example 3: Warpage Measurement Test>

[0374] Using an intermittent vacuum pressure laminator (two-stage laminator "CVP700" manufactured by Nikko-Materials Co., Ltd.), the resin sheet with the protective film peeled off was laminated on the entire single surface of a 12-inch silicon wafer (thickness 775 μm). This lamination was carried out in such a way that the resin composition layer was joined to the silicon wafer. The support of the resin sheet was peeled off to expose the resin composition layer. On the surface of this exposed resin composition layer, the resin sheet with the protective film peeled off was further laminated in the same way, and the support was peeled off to form two resin composition layers (total thickness 100 μm) on the single surface of the 12-inch silicon wafer. It should be noted that the lamination was carried out by reducing the pressure for 30 seconds to make the air pressure 13 hPa or less, and then pressing for 30 seconds at 100 °C and a pressure of 0.74 MPa.

[0375] It was heated at 100 °C for 30 minutes in an oven, and then further heated at 200 °C for 90 minutes to cure the resin composition layer, obtaining a sample laminate having a layer structure of "silicon wafer / cured layer". The warpage amount of the obtained sample laminate was measured using a Shadow Moire measuring device ("Thermoire AXP" manufactured by Akorometrix). The measurement was carried out in accordance with JEITA EDX-7311-24 of the Japan Electronics and Information Technology Industries Association standard. Specifically, the imaginary plane obtained by using the least squares method for all the data of the evaluation substrate surface (the surface of the cured layer opposite to the silicon wafer) in the measurement area was used as the reference plane, and the difference between the minimum value and the maximum value of the height in the vertical direction from this reference plane to the evaluation substrate surface was obtained as the warpage amount. The measured values of the obtained warpage amount were evaluated according to the following criteria.

[0376] Warpage evaluation criteria:

[0377] "Excellent": The warpage amount is 0 μm or more and 2000 μm or less;

[0378] "Good": The warpage amount exceeds 2000 μm and is less than 2500 μm.

[0379] "Poor": The warpage amount is 2500 μm or more.

[0380] <Test Example 4: Measurement Test of Melt Viscosity>

[0381] A sample of the resin composition was obtained by peeling a part of the resin composition layer from the resin sheet, and the melt viscosity was measured using a dynamic viscoelasticity measuring device ("Rheosol-G3000" manufactured by UBM). Specifically, for a 1 g sample of the resin composition, a parallel plate with a diameter of 18 mm was used, and the temperature was raised from the starting temperature of 60 °C to 200 °C at a rate of 5 °C / minute. The dynamic viscoelastic modulus was measured under the measurement conditions of a measurement interval temperature of 2.5 °C, a frequency of 1 Hz, and a strain of 5 deg, and the minimum melt viscosity (poise) was calculated. The measured minimum melt viscosity was evaluated according to the following criteria.

[0382] Minimum melt viscosity evaluation criteria:

[0383] "Good": The minimum melt viscosity is 6000 poise or less;

[0384] "Poor": The minimum melt viscosity is greater than 6000 poise.

[0385] <Results>

[0386] The results of the above-mentioned examples and comparative examples are shown in the following table. In the following table, the meanings of the abbreviations are as described below.

[0387] NVC: Non-volatile component concentration.

[0388] (A) component amount: The amount of component (A) relative to the non-volatile components of 100% by mass of the resin composition.

[0389] (B) component amount: The amount of component (B) relative to the non-volatile components of 100% by mass of the resin composition.

[0390] (C) component amount: The amount of component (C) relative to the non-volatile components of 100% by mass of the resin composition.

[0391] (D) component amount: The amount of component (D) relative to the non-volatile components of 100% by mass of the resin composition.

[0392] (E) component amount: The amount of component (E) relative to the non-volatile components of 100% by mass of the resin composition.

[0393] (A) component / (D) component: The amount of component (A) relative to the non-volatile components of 100% by mass of component (D).

[0394] Amount of the second bismaleimide compound: The amount of the second bismaleimide compound relative to the non-volatile components of 100% by mass of the resin composition.

[0395] Df: Dielectric dissipation factor.

[0396] [Table 1]

[0397] [Results of Examples 1 to 5 in Table 1]

[0398]

[0399] [Table 2]

[0400] [Results of Examples 6 to 8 and Comparative Examples 1 to 2 in Table 2]

[0401]

[0402] [Table 3]

[0403] [Results of Comparative Examples 3 to 7 in Table 3]

[0404]

[0405] [Table 4]

[0406] [Results of Comparative Examples 8 to 9 in Table 4]

[0407]

Claims

1. A resin composition comprising: (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 in this combination, 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 based on 100% by mass of this combination; (B) A thermosetting resin; and (C) An inorganic filler, In formula (1-i), X i each independently represents a tetravalent organic group R i represents a divalent aliphatic hydrocarbon group 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 represents a divalent aliphatic hydrocarbon group that all have the same structure as R i and the same structure, m ii represents an integer of 0 or more, n ii represents 1 or 2; Except for the key orientation of R i and the key orientation of R ii except for the key orientation, the part represented by the following formula (1-i-a) of formula (1-i) and the part represented by the following formula (1-ii-a) of formula (1-ii) have the same structure, 2. The resin composition according to claim 1, wherein, R i and R ii include one or more selected from alkyl groups having 5 or more carbon atoms and alkylene groups having 5 or more carbon atoms.

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

4. The resin composition according to claim 1, wherein, R i and R ii are both represented by the following formula (2), In formula (2), * represents a bonding site.

5. The resin composition according to claim 1, wherein, 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), In formula (3-i), R i represents a divalent aliphatic hydrocarbon group having the same structure m i represents an integer of 0 or more; In formula (3-ii), R ii represents a divalent aliphatic hydrocarbon group that all have the same structure as R i and the same structure, m ii represents an integer greater than or equal to 0 that is the same as m i ​ n ii represents 1 or 2.

6. The resin composition according to claim 1, wherein, m i and m ii are both 0.

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

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

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

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

11. The resin composition according to claim 9, wherein, (D) The elastomer contains one or more selected from the following structures: polybutadiene structure, polycarbonate structure, polyalkylene structure, polyalkyleneoxy structure, polysiloxane structure, poly(meth)acrylate structure, polyisoprene structure, polyisobutylene structure, and polystyrene structure.

12. The resin composition according to claim 1, which is used for forming an insulating layer.

13. A resin sheet comprising: a support and a resin composition layer provided on the support, The resin composition layer contains 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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