Resin composition, prepreg, resin film, metal-clad laminated plate, printed wiring board, and semiconductor package

Abstract

Disclosed is a resin composition which comprises a thermosetting resin (A), a phosphorus-based compound (B) having a phosphazene structure and a biphenyl structure, and a filler (C) in an amount of 30 mass% or more relative to the solid content of the resin composition. Also disclosed are a prepreg, a resin film, a metal-clad laminated plate, a printed wiring board, and a semiconductor package.

Description

Resin composition, prepreg, resin film, metal-clad laminate, printed wiring board, and semiconductor package

[0001] The present disclosure relates to a resin composition, a prepreg, a resin film, a metal-clad laminate, a printed wiring board, and a semiconductor package.

[0002] In recent years, miniaturization and high performance of electronic devices have been progressing. Along with this, in semiconductor packages used in electronic devices, suppression of warpage during assembly and the like has become an issue.

[0003] One of the factors causing warpage of a semiconductor package is the difference in the coefficient of thermal expansion between members of the semiconductor package. Specifically, the difference in the coefficient of thermal expansion between a semiconductor element and a printed wiring board can be cited. Generally, the coefficient of thermal expansion of a printed wiring board tends to be larger than that of a semiconductor element.

[0004] Patent Document 1 describes that in a resin composition containing an epoxy resin or the like, in order to reduce the coefficient of thermal expansion, a filler such as silica is highly filled.

[0005] Japanese Patent Application Laid-Open No. 5-148343

[0006] As one method for suppressing warpage of a semiconductor package, a method of reducing the difference in the coefficient of thermal expansion from that of a semiconductor element by making the coefficient of thermal expansion of a printed wiring board small can be considered. On the other hand, in the design of a resin composition for manufacturing a product having a desired coefficient of thermal expansion, it is desirable that the coefficient of thermal expansion is less affected and the change in the coefficient of thermal expansion is small, for example, by adding an additive to the resin composition. An object of the present disclosure is to provide a resin composition suitable for manufacturing a product having a desired coefficient of thermal expansion, and a prepreg, a resin film, a metal-clad laminate, a printed wiring board, and a semiconductor package using the same.

[0007] The present invention includes, but is not limited to, the following embodiments. One embodiment relates to a resin composition comprising a thermosetting resin (A), a phosphorus-based compound (B) having a phosphazene structure and a biphenyl structure, and a filler (C) in an amount of 30% by mass or more relative to the solid content of the resin composition. Another embodiment relates to a prepreg comprising the above-mentioned resin composition or a semi-cured product of the above-mentioned resin composition. Another embodiment relates to a resin film comprising the above-mentioned resin composition or a semi-cured product of the above-mentioned resin composition. Another embodiment relates to a metal-clad laminate comprising a cured product of the above-mentioned resin composition and a metal foil. Another embodiment relates to a printed circuit board comprising a cured product of the above-mentioned resin composition. Another embodiment relates to a semiconductor package comprising the above-mentioned printed circuit board and a semiconductor element.

[0008] This disclosure provides a resin composition suitable for manufacturing products having a desired coefficient of thermal expansion, as well as prepregs, resin films, metal-clad laminates, printed circuit boards, and semiconductor packages using this resin composition.

[0009] Figure 1 is a GPC chart of the indene composition (1) produced in Example 1.

[0010] The embodiments of the present invention will be described in detail below. The present invention is not limited to the embodiments described below.

[0011] In this disclosure, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described stepwise in this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. Furthermore, the upper or lower limits of numerical ranges described in this disclosure may be replaced with the values ​​shown in the examples. In this disclosure, each component may contain one or more of the corresponding substances unless otherwise specified. In this disclosure, the content of each component in the resin composition means the total amount of the multiple substances present in the resin composition if there are multiple substances corresponding to each component, unless otherwise specified. In this disclosure, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are measured values ​​according to the following measurement methods unless otherwise specified.

[0012] The weight-average molecular weight and number-average molecular weight are calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The calibration curve is approximated by a cubic equation using standard polystyrene: TSK standard POLYSTYRENE (Type; A-2500, A-5000, F-20, F-80) (Tosoh Corporation, product name)). The GPC conditions are shown below.

[0013] Instrument: High-speed GPC instrument "HLC-8320GPC" (Tosoh Corporation, product name) Detector: Ultraviolet absorption detector "UV-8320" (Tosoh Corporation, product name) Columns: Guard column; TSKgel guardcolumn Super(HZ)-M+, Column; TSKgel SuperMultipore HZ-M (2), Reference column; TSKgel SuperH-RC (2) (all Tosoh Corporation, product names) Column size: 4.6 × 20 mm (guard column), 4.6 × 150 mm (column), 6.0 × 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 1 mL Injection volume: 20 μL or 2 μL Flow rate: 0.35 mL / min Measurement temperature: 40°C

[0014] [Resin Composition] A resin composition according to one embodiment of the present disclosure comprises a thermosetting resin (A), a phosphorus-based compound (B) having a phosphazene structure and a biphenyl structure, and a filler (C) in an amount of 30% by mass or more relative to the solid content of the resin composition. Hereinafter, "thermosetting resin (A)" may be referred to as "component (A)". Also, "phosphorus-based compound (B) having a phosphazene structure and a biphenyl structure" may be referred to as "phosphorus-based compound (B)" or "component (B)". Also, "filler (C)" may be referred to as "component (C)".

[0015] <Thermosetting resin (A)> As thermosetting resin (A), a compound having a reactive group can be used. For example, thermosetting resin (A) may be a compound having a reactive group that is self-curing or curable in combination with a curing agent.

[0016] The thermosetting resin (A) is not particularly limited and includes, for example, epoxy resins, phenolic resins, maleimide compounds, polyarylene ether compounds having polymerizable groups, compounds having vinyl groups, thermosetting polyimide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, melamine resins, and compounds having vinylbenzyl groups. The thermosetting resin can undergo polymerization and / or curing reactions when heated in the presence of a polymerization initiator or the like, as needed. For example, compounds having vinylbenzyl groups, maleimide compounds, polyarylene ether compounds having polymerizable groups, and compounds having vinyl groups may be monomers, oligomers, prepolymers, etc., and these can also be used as thermosetting resin (A).

[0017] Component (A) may be, for example, a compound having a polymerizable group. Examples of polymerizable groups include maleimide groups, vinyl groups, vinyloxy groups, allyl groups, allyloxy groups, (meth)acryloyl groups, (meth)acryloyloxy groups, vinylbenzyl groups, vinylbenzyloxy groups, etc. Examples of compounds having a polymerizable group include maleimide compounds, polyarylene ether compounds having a polymerizable group, compounds having a vinyl group, compounds having a vinylbenzyl group, etc.

[0018] (A) One component may be used alone, or two or more components may be used in combination.

[0019] Among these, epoxy resins, phenolic resins, maleimide compounds, polyarylene ether compounds having polymerizable groups, compounds having vinyl groups, and compounds having vinylbenzyl groups are preferred from the viewpoint of thermosetting properties and dielectric properties. The thermosetting resin (A) may include, for example, at least one selected from the group consisting of maleimide compounds, polyarylene ether compounds having polymerizable groups, compounds having vinyl groups, and compounds having vinylbenzyl groups.

[0020] Epoxy resins preferably have two or more epoxy groups in one molecule. Examples of epoxy resins include glycidyl ether type epoxy resins, glycidylamine type epoxy resins, and glycidyl ester type epoxy resins. Within each of these types of epoxy resins, epoxy resins can be further classified into bisphenol type epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, novolac type epoxy resins, stilbene type epoxy resins, naphthalene skeleton-containing epoxy resins, biphenyl type epoxy resins, xylylene type epoxy resins, and dihydroanthracene type epoxy resins.

[0021] Epoxy resins may be used individually or in combination of two or more types.

[0022] Examples of maleimide compounds include compounds having one or more N-substituted maleimide groups, and derivatives thereof. As maleimide compounds, for example, at least one selected from the group consisting of compounds having two or more N-substituted maleimide groups and derivatives thereof may be used.

[0023] Examples of compounds having one or more N-substituted maleimide groups include aromatic maleimide compounds, which have an N-substituted maleimide group directly bonded to an aromatic ring; aromatic bismaleimide compounds, which have two N-substituted maleimide groups directly bonded to an aromatic ring; aromatic polymaleimide compounds, which have three or more N-substituted maleimide groups directly bonded to an aromatic ring; and aliphatic maleimide compounds, which have an N-substituted maleimide group directly bonded to an aliphatic hydrocarbon.

[0024] Examples of derivatives of compounds having one or more N-substituted maleimide groups include aminomaleimide compounds containing structural units derived from the above-mentioned compound having one or more N-substituted maleimide groups and structural units derived from a diamine compound.

[0025] Specific examples of bismaleimide compounds having two N-substituted maleimide groups include, for example, N,N'-ethylenebismaleimide, N,N'-hexamethylenebismaleimide, N,N'-(1,3-phenylene)bismaleimide, N,N'-[1,3-(2-methylphenylene)]bismaleimide, N,N'-[1,3-(4-methylphenylene)]bismaleimide, N,N'-(1,4-phenylene)bismaleimide, bis(4-maleimidophenyl)methane, bis(3-methyl-4-maleimidophenyl)methane, 3,3'- Dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, bis(4-maleimidophenyl) ether, bis(4-maleimidophenyl) sulfone, bis(4-maleimidophenyl) sulfide, bis(4-maleimidophenyl) ketone, bis(4-maleimidocyclohexyl)methane, 1,4-bis(4-maleimidophenyl)cyclohexane, 1,4-bis(maleimidomethyl)cyclohexane, 1,4-bis(maleimidomethyl)benzene, 1,3-bis(4-maleimidophenoxy)benzene, 1 ,3-bis(3-maleimidophenoxy)benzene, bis[4-(3-maleimidophenoxy)phenyl]methane, bis[4-(4-maleimidophenoxy)phenyl]methane, 1,1-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,1-bis[4-(4-maleimidophenoxy)phenyl]ethane, 1,2-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,2-bis[4-(4-maleimidophenoxy)phenyl]ethane, 2,2-bis[4-(3-maleimidophenoxy)phenyl] Propane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4-bis(3-maleimidophenoxy)biphenyl, 4,4-bis(4-maleimidophenoxy)biphenyl, bis[4-(3-maleimidophenoxy)phenyl]ketone, bis[4-(4-maleimidophenoxy)phenyl]ketone, bis(4-maleimidophenoxy)disulfide, bis[4-(3-maleimidophenoxy)phenyl]sulfide, bis[4-(4-maleimidophenoxy)phenyl]sulfide, bis[4-(3-maleimidophenoxy)phenyl] Sulfoxide, bis[4-(4-maleimidophenoxy)phenyl]sulfoxide, bis[4-(3-maleimidophenoxy)phenyl]sulfone, bis[4-(4-maleimidophenoxy)phenyl]sulfone, bis[4-(3-maleimidophenoxy)phenyl]ether, bis[4-(4-maleimidophenoxy)phenyl]ether, 1,4-bis[4-(4-maleimidophenoxy)-α,α-dimethyl [Benzyl]benzene, 1,3-bis[4-(4-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(4-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene Examples include 1,3-bis[4-(4-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleimidophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, and aromatic bismaleimide compounds containing an indane ring, as described later.

[0026] Examples of maleimide compounds include polyphenylmethanemaleimide, maleimide compounds containing fused rings of aromatic and aliphatic rings, and biphenylaralkyl maleimide resins.

[0027] As maleimide compounds containing a fused ring of an aromatic ring and an aliphatic ring, aromatic maleimide compounds containing a fused ring of an aromatic ring and an aliphatic ring and having two or more N-substituted maleimide groups are preferred, and aromatic bismaleimide compounds containing a fused ring of an aromatic ring and an aliphatic ring and having two N-substituted maleimide groups are more preferred. Examples of fused rings of aromatic rings and aliphatic rings include indan rings. Examples of maleimide compounds containing a fused ring of an aromatic ring and an aliphatic ring include the aforementioned aromatic bismaleimide compounds containing indan rings.

[0028] Aromatic bismaleimide compounds containing an indane ring include, for example, those represented by the following formula (1).

[0029] [R in equation (1)] ５ is a hydrogen atom or a methyl group, and l is an integer of 1 or more. In formula (1), l may be, for example, 1 or more and 10 or less.

[0030] Examples of biphenylaralkyl-type maleimide resins include those represented by the following formula (2).

[0031]

[0032] [In equation (2), m is an integer greater than or equal to 1.]

[0033] Maleimide compounds may be used individually or in combination of two or more.

[0034] Regarding polyarylene ether compounds having polymerizable groups, the arylene group is not particularly limited and examples include phenylene groups, naphthylene groups, and structures in which one or more alkyl groups, alkyloxy groups, halogen atoms, etc., are substituted on the aromatic carbons thereof. A polyarylene ether compound having polymerizable groups may be, for example, a polyphenylene ether compound having polymerizable groups. Regarding polyarylene ether compounds having polymerizable groups, examples of polymerizable groups include vinyl groups, vinyloxy groups, isopropenyl groups, allyl groups, allyloxy groups, 1-methylallyl groups, 3-butenyl groups, (meth)acryloyl groups, (meth)acryloyloxy groups, vinylbenzyl groups, vinylbenzyloxy groups, etc. A polyarylene ether compound having polymerizable groups may have structural parts other than the polyarylene ether structure. Specifically, it may have acrylic polymerization sites, (poly)urethane sites, (poly)ester sites, etc., in its molecular chain. The number of polymerizable groups in a single molecule of a polyarylene ether compound is not particularly limited, nor are the substitution positions of the polymerizable groups particularly limited. For example, a polyarylene ether compound may have polymerizable groups at the molecular ends, or it may have polymerizable groups at both ends. Examples of polyarylene ether compounds having polymerizable groups include polyphenylene ether compounds having polymerizable groups such as (meth)acryloyl groups and vinylbenzyl groups at the ends.

[0035] Specific examples of polyphenylene ether compounds having polymerizable groups include, for example, the compound represented by the following formula (3).

[0036]

[0037] [In formula (3), R ６ [where p is a hydrogen atom or a methyl group; p and q are integers greater than or equal to 1; and X is a divalent organic group.]

[0038] In formula (3), X is a divalent organic group, and its specific structure is not particularly limited, but examples include hydrocarbon groups having 1 to 6 carbon atoms, halogenated hydrocarbon groups, oxygen atoms, sulfur atoms, carbonyl groups, sulfonyl groups, etc.

[0039] The molecular weight of the polyarylene ether compound having polymerizable groups is not particularly limited, but for example, the number average molecular weight (Mn) may be in the range of 1,000 to 5,000.

[0040] The compound having a vinyl group may be a polymer compound having a vinyl group. Preferably, the compound having a vinyl group is a polymer compound having multiple structural units. The compound having a vinyl group may be a homopolymer or a copolymer. For example, the compound having a vinyl group may be a random copolymer, a block copolymer, etc.

[0041] A compound having a vinyl group may, for example, contain one or more structural units having a vinyl group. A compound having a vinyl group may, for example, contain one or more structural units having a vinyl group and one or more structural units not having a vinyl group. A compound having a vinyl group may, for example, be a homopolymer of monomers having a vinyl group, or a copolymer of two or more monomers including a monomer having a vinyl group. A compound having a vinyl group may, for example, be a copolymer of monomers containing one or more monomers having a vinyl group and one or more monomers not having a vinyl group. A compound having a vinyl group may, for example, have a long-chain portion. Examples of long chains include alkyl chains.

[0042] The weight-average molecular weight (Mw) of a compound having a vinyl group may be 6,500 or more, 10,000 or more, 25,000 or more, or 30,000 or more. The weight-average molecular weight of a compound having a vinyl group may be, for example, 50,000 or more. The weight-average molecular weight of a compound having a vinyl group may be, for example, 100,000 or less, or 50,000 or less. The weight-average molecular weight of a compound having a vinyl group may be, for example, 30,000 or less. The weight-average molecular weight of a compound having a vinyl group may be, for example, 6,500 to 100,000, 10,000 to 100,000, 25,000 to 100,000, or 30,000 to 50,000. The weight-average molecular weight of a compound having a vinyl group may be, for example, 6,500 to 30,000, 25,000 to 50,000, 30,000 to 50,000, or 50,000 to 100,000.

[0043] The number-average molecular weight (Mn) of the compound having a vinyl group may be 2,000 or more, 3,000 or more, or 4,000 or more from the viewpoint of adhesion strength with metal foil. The number-average molecular weight of the compound having a vinyl group may be, for example, 10,000 or more. The number-average molecular weight of the compound having a vinyl group may be, for example, 20,000 or less, or 10,000 or less. The number-average molecular weight of the compound having a vinyl group may be, for example, 4,000 or less. The number-average molecular weight of the compound having a vinyl group may be, for example, 2,000 to 20,000, 3,000 to 10,000, or 4,000 to 10,000. The number-average molecular weight of the compound having a vinyl group may be, for example, 2,000 to 4,000, 4,000 to 10,000, or 10,000 to 20,000.

[0044] The vinyl group equivalent of a compound having a vinyl group may be 150 g / eq or more, 200 g / eq or more, or 250 g / eq or more, from the viewpoint of adhesion strength with metal foil and dielectric properties. The vinyl group equivalent of a compound having a vinyl group may be, for example, 500 g / eq or more. The vinyl group equivalent of a compound having a vinyl group may be, for example, 2,300 g / eq or less, 2,100 g / eq or less, 1,000 g / eq or less, or 500 g / eq or less. The vinyl group equivalent of a compound having a vinyl group may be, for example, 150 g / eq to 2,300 g / eq, 150 g / eq to 2,100 g / eq, 200 to 1,000 g / eq, or 250 g / eq to 500 g / eq. The vinyl group equivalent of a compound having a vinyl group may be, for example, 150 g / eq to 250 g / eq, 250 g / eq to 500 g / eq, or 500 g / eq to 1,000 g / eq.

[0045] The glass transition temperature (Tg) of a compound having a vinyl group is preferably 150°C or higher, more preferably 170°C or higher, and even more preferably 200°C or higher, from the viewpoint of the heat resistance of the cured resin composition. The upper limit of the glass transition temperature (Tg) of the resin is not particularly limited, but may be, for example, 300°C or lower.

[0046] In this disclosure, unless otherwise specified, the glass transition temperature (Tg) of compounds having a vinyl group is a measurement value obtained by the following measurement method. The glass transition temperature of compounds having a vinyl group is measured by differential scanning calorimeter (DSC). For example, the "DSC Q200" (product name) from T.A. Instruments Japan Co., Ltd. can be used as the measuring device.

[0047] The specific procedure involves first drying the compound containing the vinyl group, then cooling it to prepare the sample for measurement. A 10 mg sample is then measured using a differential scanning calorimeter in nitrogen (N2). ２ Under the specified atmosphere, the temperature is increased at a rate of 10°C / min in the temperature range of 25°C to 400°C, and then cooled to 25°C. The temperature at which the baseline shifts during the subsequent heating under the same conditions is defined as the glass transition temperature.

[0048] A compound having a vinylbenzyl group (hereinafter sometimes referred to as "vinylbenzyl compound") may have one or more vinylbenzyl groups, or two or more vinylbenzyl groups. By having one or more vinylbenzyl groups in a single molecule, a cured product can be obtained by promoting the reaction of the vinylbenzyl groups intramolecularly or intermolecularly using heating or other means. A vinylbenzyl compound may be used alone or in combination of two or more types.

[0049] The vinylbenzyl compound may be a monomer, oligomer, or prepolymer, and combinations of two or more of these may be included in the resin composition.

[0050] When the vinylbenzyl compound is a monomer, one or more vinylbenzyl groups may be introduced into the base compound. The oligomer may be a low-degree-of-polymerization compound obtained by polymerizing two or more of these monomers. The prepolymer may have one or more vinylbenzyl groups introduced into the resin skeleton, and may be a polymer of a monomer, oligomer, or combination thereof having one or more vinylbenzyl groups. In this disclosure, the oligomer and prepolymer are those in which some of the polymerizable groups in the monomer remain without undergoing polymerization, and have curability due to the remaining polymerizable groups.

[0051] In the monomer of the vinylbenzyl compound, the number of vinylbenzyl groups may be one or more, or two or more, for example, 2 to 4 or 2 to 3.

[0052] In the case of the vinylbenzyl compound oligomer or prepolymer, the number of vinylbenzyl groups in the molecule may be one or more, but it is preferable that the monomeric structural unit contains one or two or more vinylbenzyl groups, and the monomeric structural unit may contain two to four or two to three vinylbenzyl groups.

[0053] In vinylbenzyl compounds, the vinylbenzyl group may be any of o-vinylbenzyl, m-vinylbenzyl, or p-vinylbenzyl groups. If a single molecule of a vinylbenzyl compound contains two or more vinylbenzyl groups, these two or more vinylbenzyl groups may be the same isomer or different from each other. From the viewpoint of dielectric properties, it is preferable that a single molecule of a vinylbenzyl compound contains at least one p-vinylbenzyl group.

[0054] The proportion of p-vinylbenzyl groups in the total vinylbenzyl groups of a vinylbenzyl compound may be 10 mol% or more, 20 mol% or more, or 30 mol% or more. It may also be 100 mol% or less, 80 mol% or less, or 70 mol% or less. The proportion of p-vinylbenzyl groups in the total vinylbenzyl groups of compound (A) may be in the range of, for example, 10 to 100 mol%, 20 to 80 mol%, or 30 to 70 mol%. If the proportion of p-vinylbenzyl groups is less than 100 mol%, the remaining vinylbenzyl groups may be m-vinylbenzyl groups.

[0055] In vinylbenzyl compounds, the vinylbenzyl group may be unsubstituted or substituted. If substituted, the substituent may be, for example, an aliphatic hydrocarbon group having 1 to 20, 1 to 8, or 1 to 4 carbon atoms, or an alkyl group having these carbon atoms. Alternatively, the substituent may be a halogen atom, such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. In the vinylbenzyl group, at least one of the 1 to 4 hydrogen atoms bonded to the benzene ring may be substituted, and if there are two or more substituents, they may be the same or different. When a vinylbenzyl compound has two or more vinylbenzyl groups, the presence, number, and type of substituents among the two or more vinylbenzyl groups may be the same or different. From the viewpoint of dielectric properties, it is preferable that the vinylbenzyl compound has at least one unsubstituted vinylbenzyl group, and all vinylbenzyl groups may be unsubstituted.

[0056] The vinylbenzyl compound is preferably a hydrocarbon compound, and the structure other than the vinylbenzyl group may be a chain-like hydrocarbon structure, an alicyclic hydrocarbon structure or other non-aromatic hydrocarbon structure, or an aromatic hydrocarbon structure, but it is preferably an aromatic hydrocarbon structure. The aromatic hydrocarbon structure may be a monocyclic or polycyclic aromatic ring, a fused ring of two or more aromatic rings, a fused ring of an aromatic ring and a non-aromatic ring, etc.

[0057] Examples of aromatic hydrocarbon structures include indene rings, indan rings, phenanthrene rings, acenaphthylene rings, and fluorene rings. From the viewpoint of dielectric properties, indene rings and fluorene rings are preferred. More preferably, the vinylbenzyl compound is a compound having an indene ring. Furthermore, it is preferable that the vinylbenzyl group is directly bonded to a carbon atom on the ring of the aromatic hydrocarbon structure. When the vinylbenzyl compound contains an aromatic hydrocarbon structure, the indene ring, indan ring, phenanthrene ring, acenaphthylene ring, fluorene ring, etc., may be unsubstituted or may have substituents. However, this excludes the bonding site with the vinylbenzyl group. Examples of substituents include those described above for the vinylbenzyl group. For example, when the vinylbenzyl compound contains an indene ring, at least one of the multiple hydrogen atoms bonded to the indene ring may be substituted, and if there are two or more substituents, they may be the same or different. When a vinylbenzyl compound contains an aromatic hydrocarbon structure, from the viewpoint of dielectric properties, the indene ring, indan ring, phenanthrene ring, acenaphthylene ring, fluorene ring, etc., may be unsubstituted except for the bond site with the vinylbenzyl group.

[0058] The monomers of vinylbenzyl compounds will be described below. The monomer of a vinylbenzyl compound is preferably a hydrocarbon compound, and among hydrocarbon compounds, it is preferably a compound having an indene ring, indan ring, phenanthrene ring, acenaphthylene ring, fluorene ring, etc., or a combination thereof, more preferably a compound having an indene ring, a fluorene ring, or a combination thereof, and even more preferably a compound having an indene ring. For example, a vinylbenzyl compound may be a monomer having one or more vinylbenzyl groups and one indene ring in one molecule.

[0059] One example of a vinylbenzyl compound is a monomer having an indene ring and one or more vinylbenzyl groups bonded to any of the 1st, 2nd, or 3rd positions of the indene ring.

[0060] Specific examples of vinylbenzyl compounds include monomers represented by the following formula (4).

[0061]

[0062] In formula (4), n is 1, 2, or 3, but n may be 2 or 3. Furthermore, a mixture of monomers represented by formula (4) may contain multiple monomers with different values ​​of n. In this case, n is preferably 2 to 3 on average, and more preferably 2.0 to 2.5.

[0063] In formula (4), the vinylbenzyl group may be directly bonded to any carbon atom at position 1, 2, or 3 of the indene ring, but it is preferable that it be bonded to position 1, or a combination of position 1 and position 3. At each position, one or two vinylbenzyl groups may be bonded. For example, the vinylbenzyl group may be bonded to a combination of position 1, 1', and 3 of the indene ring, or to a combination of position 1 and 1' of the indene ring.

[0064] In formula (4), the methylene group of the vinylbenzyl group may be in any of the o, m, and p positions, but the m or p position is preferred. In formula (4), if one molecule contains two or three vinylbenzyl groups, the two or three vinylbenzyl groups may be any of the o, m, and p forms, or a combination thereof, but it is preferable to include the p form, and it may be only the p form, or a combination of the m and p forms. In a resin composition, if two or more monomers represented by formula (4) are included, the positions of the methylene groups of the vinylbenzyl groups among the two or more monomers may be the same or different. In a resin composition, if two or more monomers represented by formula (4) are included, in a mixture of the two or more monomers, the vinylbenzyl group may be one or a combination of two or more of the o, m, and p forms, and it is preferable to include the p form, and it may be only the p form, or a combination of the m and p forms. In this case, the mass ratio of the m-isomer to the p-isomer in the resin composition or its cured product is preferably 40:60 to 60:40.

[0065] One example of a vinylbenzyl compound is compound (XA), which includes an indene ring, a vinylbenzyl group, and an arylalkyl group other than the vinylbenzyl group. In compound (XA), the total number of vinylbenzyl groups and arylalkyl groups other than the vinylbenzyl group in one molecule may be, for example, 2 or 3.

[0066] Compound (XA) can be any compound, regardless of its specific structure, molecular weight, etc., as long as it contains an indene ring, a vinylbenzyl group, and an arylalkyl group other than a vinylbenzyl group in its molecular structure.

[0067] The vinylbenzyl groups in compound (XA) may be o-vinylbenzyl groups, m-vinylbenzyl groups, or p-vinylbenzyl groups. Among these, p-vinylbenzyl groups are preferred because they result in a compound with excellent dielectric properties in the cured product. The proportion of p-vinylbenzyl groups in the total vinylbenzyl groups of compound (XA) may be 10 mol% or more, 20 mol% or more, or 30 mol% or more. It may also be 100 mol% or less, 80 mol% or less, or 70 mol% or less. For example, the proportion of p-vinylbenzyl groups in the total vinylbenzyl groups of compound (XA) may be in the range of 10 to 100 mol%, 20 to 80 mol%, or 30 to 70 mol%. If the proportion of p-vinylbenzyl groups is less than 100 mol%, the remaining vinylbenzyl groups may be m-vinylbenzyl groups.

[0068] Regarding the arylalkyl group other than the vinylbenzyl group in compound (XA) (hereinafter sometimes referred to as "arylalkyl group"), the number of carbon atoms in the alkyl group within the arylalkyl group is not particularly limited, but may be in the range of 1 to 6, for example. Furthermore, the alkyl group may be linear or have a branched structure. Specific examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, t-pentyl group, n-hexyl group, isohexyl group, etc. Among these, it is preferable that the alkyl group in the arylalkyl group has a relatively small number of carbon atoms, as this results in a compound with excellent dielectric properties. For example, the alkyl group in the arylalkyl group may be a methyl group or an ethyl group, or it may be a methyl group.

[0069] The aryl group in the arylalkyl group is not particularly limited as long as it is not a styryl group, and examples include a phenyl group, a naphthyl group, and structural parts having one or more substituents on their aromatic rings. Substituents on the aromatic ring include, for example, halogen atoms such as fluorine, chlorine, bromine, or iodine; alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-pentyl, n-hexyl, and isohexyl groups; alkoxy groups represented as RO- where R is one of the aforementioned alkyl groups; polymerizable unsaturated bond-containing groups such as vinyl, vinyloxy, allyl, allyloxy, (meth)acryloyl, and (meth)acryloyloxy groups; aryl groups such as phenyl, tolyl, xylyl, mesityl, and naphthyl groups; and aryloxy groups such as phenyloxy, tolyloxy, xylyloxy, mesityloxy, and naphthyloxy groups.

[0070] The arylalkyl group may not have polymerizable unsaturated bonds. The aryl group in the arylalkyl group may be a phenyl group, a naphthyl group, and have one to three alkyl groups with 1 to 3 carbon atoms on their aromatic rings.

[0071] An example of compound (XA) is a compound having one indene ring in one molecule (hereinafter sometimes referred to as "compound (XA1)"). Compound (XA1) may have one indene ring, one or more vinylbenzyl groups, and one or more arylalkyl groups. In compound (XA1), the vinylbenzyl group and the arylalkyl group may be directly bonded to the indene ring. In this case, the substitution positions of the vinylbenzyl group and the arylalkyl group on the indene ring are not particularly limited.

[0072] Examples of compounds (XA1) include those represented by the following formula (5).

[0073]

[0074] [In formula (5), R １ ~R４ each independently represents a hydrogen atom or a monovalent organic group. R １ , R ２ and R ３ at least one of which is a vinylbenzyl group and at least one is an arylalkyl group other than a vinylbenzyl group. All four Rs ４ may be different from each other, and two or more of the four Rs ４ may be identical to each other. ]

[0075] In formula (5), R １ to R ４ each independently represents a hydrogen atom or a monovalent organic group. Examples of the monovalent organic group include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom; alkyl groups having 1 to 6 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a t-pentyl group, an n-hexyl group, an isohexyl group; an alkoxy group represented by RO—, where R is the aforementioned alkyl group; polymerizable unsaturated bond-containing groups such as a vinyl group, a vinyloxy group, an allyl group, an allyloxy group, a (meth)acryloyl group, a (meth)acryloyloxy group; aryl groups such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group; aryloxy groups such as a phenyloxy group, a tolyloxy group, a xylyloxy group, a mesityloxy group, a naphthyloxy group, etc.

[0076] In formula (5), at least one of R １ , R ２ and R ３ is a vinylbenzyl group, and at least one is an arylalkyl group other than a vinylbenzyl group. One of R １ , R ２ and R ３ may be a vinylbenzyl group, one may be an arylalkyl group, and one may be a hydrogen atom. Two of R １ , R ２ and R ３ may be vinylbenzyl groups and one may be an arylalkyl group. Two of R １ , R ２ and R３ One of the groups may be a vinylbenzyl group, and the other two may be arylalkyl groups. The two arylalkyl groups in a single molecule may be the same or different.

[0077] R in equation (5) ４ All of them may be hydrogen atoms.

[0078] The following describes the synthesis method for monomers of vinylbenzyl compounds. Note that vinylbenzyl compounds are identified by their molecular structure, regardless of the synthesis method described below.

[0079] One method for synthesizing monomers among vinylbenzyl compounds is to react a base compound having a desired structure, such as indene or fluorene, with styrene having a methyl halide group, and other compounds as needed, in the presence of a basic compound. Examples of styrene having a methyl halide group include o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene, which may be used individually or in combination of two or more.

[0080] In the case of compound (XA1), for example, other compounds can be used, such as aromatic compounds having a halogenated alkyl group corresponding to an arylalkyl group. Examples of aromatic compounds having a halogenated alkyl group include α-chlorotoluene, α-chloroxylene, and 1-(chloromethyl)naphthalene. These may be used individually or in combination of two or more.

[0081] In the case of compound (XA1), the ratio of styrene having a methyl halide group to the total number of moles of styrene having a methyl halide group and aromatic compound having an alkyl halide group may be 30 mol% or more, 50 mol% or more, or 60 mol% or more. It may also be 90 mol% or less, 85 mol% or less, or 80 mol% or less. The ratio of styrene having a methyl halide group to the total number of moles of styrene having a methyl halide group and aromatic compound having an alkyl halide group may be in the range of 30 to 90 mol%.

[0082] In the case of compound (XA1), the total number of moles of styrene having a methyl halide group and the aromatic compound having an alkyl halide per mole of indene may be 1.5 moles or more, 1.8 moles or more, or 2.0 moles or more. It may also be 3.0 moles or less, 2.8 moles or less, or 2.5 moles or less. The total number of moles of styrene having a methyl halide group and the aromatic compound having an alkyl halide per mole of indene may be in the range of 1.5 to 3.0 moles.

[0083] Examples of basic compounds include alkali metal hydroxides and alkali metal alkoxides. These may be used individually or in combination of two or more.

[0084] A phase-transfer catalyst may be used in the above reaction. Examples of phase transfer catalysts include quaternary ammonium salts such as tetra-n-butylammonium bromide, tetra-n-butylammonium bromide (tetra-n-butylammonium bromide), tetraethylammonium chloride, tetraethylammonium bromide, tetrapropylammonium chloride, tetrapropylammonium bromide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltributylammonium chloride, benzyltributylammonium bromide, benzyldimethyltetradecylammonium chloride, tricaprylmethylammonium chloride, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, trioctylmethylammonium chloride, and tetra-n-butylammonium bisulfate; and quaternary phosphonium salts such as tetra-n-butylphosphonium chloride, tetra-n-butylphosphonium bromide, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, benzyltriphenylphosphonium chloride, and benzyltriphenylphosphonium bromide. These may be used individually or in combination of two or more types.

[0085] The reaction can be carried out by solution polymerization. The reaction may be carried out, for example, under heating and stirring. The heating temperature may be, for example, 40 to 100°C or 50 to 100°C.

[0086] Polymerization inhibitors may be added to the reaction system. Examples of polymerization inhibitors include hydroquinone, methylhydroquinone, t-butylhydroquinone, 2,6-di-t-butylhydroquinone, 2,5-di-t-butylhydroquinone, hydroquinone monomethyl ether, 1,4-benzoquinone, 2-t-butyl-1,4-benzoquinone, 2-t-butylphenol, 2,4-di-t-butylphenol, 2,6-di-t-butylphenol, cresol, catechol, 4-t-butylcatechol, pyrogallol, 4 Examples include methoxyphenol, thiodiphenylamine, phenothiazine, 3,7-dioctylphenothiazine, 3,7-dicumylphenothiazine, 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and bis(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl) sebacate. These may be used individually or in combination of two or more.

[0087] The obtained product may be purified by known methods such as concentration, reprecipitation, and washing, if necessary.

[0088] The resulting product may be a single compound or a mixture of two or more compounds. For example, when indene is used as the base compound, a compound is synthesized in which a vinylbenzyl group is directly bonded to at least one carbon atom at positions 1, 2, and 3 of the indene ring. However, the mixture may contain two or more isomers of vinylbenzyl compounds with different bonding sites. Furthermore, depending on the synthesis conditions, a compound can be obtained in which a vinylbenzyl group is directly bonded to at least two carbon atoms at positions 1, 2, and 3 of the indene ring. In this case, the mixture may contain two or more vinylbenzyl compounds with different numbers and bonding sites of vinylbenzyl groups to the indene ring. For example, in the synthesis of compound (XA1), if a mixture of two or more compounds is obtained, the mixture may contain, in addition to the compound corresponding to compound (XA1), a compound that does not contain a vinylbenzyl group in its molecule, or a compound that does not contain an arylalkyl group other than a vinylbenzyl group in its molecule, or part of both. Each compound may be isolated and purified from the resulting mixture before use, or the mixture may be used as is.

[0089] When the vinylbenzyl compound is a monomer, the molecular weight is not particularly limited, but from the viewpoint of moldability and handling, for example, 200 to 800 is preferred, 250 to 750 is more preferred, and 300 to 700 is even more preferred. When the vinylbenzyl compound is a monomer, the molecular weight is the weight-average molecular weight (Mw) in the case of a mixture of multiple compounds.

[0090] The following describes vinylbenzyl compounds as prepolymers. The vinylbenzyl compound used as a prepolymer is preferably a hydrocarbon compound, and among hydrocarbon compounds, it is preferably a compound having an indene ring, indan ring, phenanthrene ring, acenaphthylene ring, fluorene ring, etc., or a combination thereof, more preferably a compound having an indene ring, a fluorene ring, or a combination thereof, and even more preferably a compound having an indene ring. For example, the vinylbenzyl compound may be a prepolymer containing a structural unit having one or more vinylbenzyl groups and one indene ring.

[0091] Prepolymers can be obtained by polymerizing monomers. Vinylbenzyl groups are preferably introduced from the monomer. For example, monomers having one or more vinylbenzyl groups are often used, and monomers having two or more vinylbenzyl groups are preferable. Polymerization should be stopped before it is completely finished, leaving a certain amount of monomer-derived vinylbenzyl groups. For example, to obtain a curable prepolymer in liquid form, polymerization should be stopped when the viscosity of the polymerization reaction system for the curable prepolymer reaches a certain level. In the polymerization of prepolymers, oligomers may be used together with the monomer, or in place of the monomer. For example, in the polymerization of prepolymers, the monomer of the vinylbenzyl compound described above may be used, or an oligomer of this monomer may be used.

[0092] When the vinylbenzyl compound is a prepolymer, the weight-average molecular weight (Mw) may be 1,000 or more, 2,000 or more, 3,000 or more, or 5,000 or more, for example, from the viewpoint of ease of manufacture and ease of handling of the curable resin material. When the vinylbenzyl compound is a prepolymer, the weight-average molecular weight (Mw) may be 50,000 or less, 30,000 or less, 15,000 or less, 10,000 or less, or 8,000 or less. When the vinylbenzyl compound is a prepolymer, the weight-average molecular weight (Mw) may be 1,000 to 50,000, 1,000 to 30,000, 2,000 to 15,000, 3,000 to 10,000, or 5,000 to 8,000. When a vinylbenzyl compound is used as a prepolymer, the weight-average molecular weight (Mw) may be, for example, 5,000 to 50,000 or 10,000 to 30,000, from the viewpoint of the fluidity of the resin composition.

[0093] An example of a prepolymer in which a vinylbenzyl compound is used is a prepolymer (XA2) in which compound (XA1) is the monomer component.

[0094] The prepolymer (XA2) may also contain compound (XA1) along with other monomers other than compound (XA1). The proportion of compound (XA1) in the total monomers constituting the prepolymer (XA2) may be 50 mol% or more, 80 mol% or more, or 100 mol%.

[0095] The weight-average molecular weight (Mw) of the prepolymer (XA2) is not particularly limited, but may be 1,000 or more, 2,000 or more, or 3,000 or more, for example, from the viewpoint of ease of manufacture and ease of handling of the curable resin material. The weight-average molecular weight (Mw) of the prepolymer (XA2) may be 15,000 or less, 10,000 or less, or 8,000 or less. The weight-average molecular weight (Mw) of the prepolymer (XA2) may be in the range of 1,000 to 15,000, 2,000 to 10,000, or 3,000 to 8,000.

[0096] Next, a method for polymerizing a vinylbenzyl compound to obtain a vinylbenzyl compound as a prepolymer will be described. Polymerization of the vinylbenzyl compound is preferably carried out by radical polymerization so as not to generate polar components in the reaction product. Radical polymerization can be carried out using a radical polymerization initiator. Polymerization can be carried out by solution polymerization, and the polymerization solvent is not particularly limited. Examples of solvents that can be used include toluene and xylene. These may be used individually or in combination of two or more. For example, one or more organic solvents used in the resin composition described later may be used as polymerization solvents.

[0097] The radical polymerization initiator may be a thermal radical polymerization initiator or a photoradical polymerization initiator, but a thermal radical polymerization initiator is preferred. The radical polymerization initiator is not particularly limited and examples include azo polymerization initiators and organic peroxide polymerization initiators. Specifically, for example, azo polymerization initiators and organic peroxide polymerization initiators, which are exemplified as curing accelerators later, may be appropriately selected and used.

[0098] The radical polymerization initiator may be used alone or in combination of two or more. The amount of radical polymerization initiator used may be appropriately selected according to the desired degree of polymerization of the prepolymer. For example, the amount of radical polymerization initiator used may be 0.05 to 5 parts by mass, 0.1 to 4 parts by mass, or 0.5 to 2 parts by mass per 100 parts by mass of the vinylbenzyl compound of the polymerization system.

[0099] The vinylbenzyl compound used as the prepolymer may be a homopolymer or copolymer of vinylbenzyl compounds. The copolymer may be a copolymer of two or more vinylbenzyl compounds, or a copolymer of a vinylbenzyl compound with another monomer. In the case of a copolymer, it may be a random copolymer, a block copolymer, or the like.

[0100] The oligomer among the vinylbenzyl compounds may be a low-molecular-weight polymer of the monomer described above.

[0101] From the viewpoint of fluidity, component (A) may be 1% by mass or more, 10% by mass or more, or 20% by mass or more, relative to the solid content of the resin composition. On the other hand, from the viewpoint of moldability, component (A) may be 60% by mass or less, 50% by mass or less, or 40% by mass or less, relative to the solid content of the resin composition. For example, component (A) may be 1 to 60% by mass, 10 to 50% by mass, or 20 to 40% by mass, relative to the solid content of the resin composition.

[0102] In this disclosure, "solids" in a resin composition refers to components in the resin composition other than the solvent described later. The solids are components that remain without volatilizing when the resin composition is dried, and include components that are liquid at room temperature around 25°C, and do not necessarily mean that they are solid.

[0103] Component (A) may be 1% by mass or more, 10% by mass or more, or 20% by mass or more, relative to the total amount of component (A), component (B) described later (phosphorus compound (B) having a phosphazene structure and a biphenyl structure), and component (C) described later (filler (C)). On the other hand, component (A) may be 60% by mass or less, 50% by mass or less, or 40% by mass or less, relative to the total amount of component (A), component (B), and component (C). For example, component (A) may be 1 to 60% by mass, 10 to 50% by mass, or 20 to 40% by mass, relative to the total amount of component (A), component (B), and component (C).

[0104] <Phosphorus compound (B) having a phosphazene structure and a biphenyl structure> Component (B) is a phosphorus compound that may have a phosphazene structure and a biphenyl structure. Component (B) is preferably a compound that can act as a flame retardant.

[0105] In designing resin compositions for producing products with a desired coefficient of thermal expansion, it is desirable that the coefficient of thermal expansion is not easily affected by the addition of additives to the resin composition and that the change in the coefficient of thermal expansion is small. When phosphorus compounds are added to a resin composition, there may be a large difference between the coefficient of thermal expansion of the resulting product and the coefficient of thermal expansion of a product obtained using a composition without phosphorus compounds. When component (B), a phosphorus compound having a phosphazene structure and a biphenyl structure, is added to a resin composition, the change in the coefficient of thermal expansion tends to be small compared to a resin composition without this component.

[0106] In phosphorus-based compound (B), the phosphazene structure has a structure in which a phosphorus atom and a nitrogen atom are bonded by a double bond. It is presumed that the presence of an -N=P- bond in phosphorus-based compound (B) enhances the thermal stability in the cured product and contributes to suppressing changes in the coefficient of thermal expansion caused by the addition of phosphorus-based compound (B). One or more -N=P- bonds may be present in one molecule of the phosphorus-based compound, for example, 1 to 20, 2 to 10, or 3 to 8. For example, the structure may be represented by the following formula (B1). The phosphorus-based compound may be, for example, a compound containing the structure represented by the following formula (B1).

[0107]

[0108] In equation (B1), R Ｂ１ and R Ｂ２ Each of these may independently be a hydrogen atom, a halogen atom, or a monovalent organic group. Ｂ１ R may be an integer between 1 and 20, 2 and 10, or 3 and 8. Ｂ１ and R Ｂ２ Preferably, at least one of them is a group having a biphenyl structure, R Ｂ１ and R Ｂ２ This may form a cyclic structure having a biphenyl structure.

[0109] R Ｂ１ and R Ｂ２ Examples of monovalent organic groups represented by include substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, substituted or unsubstituted aryloxy groups having 6 to 30 carbon atoms, substituted or unsubstituted aralkyl groups having 6 to 30 carbon atoms, substituted or unsubstituted aralkyloxy groups having 6 to 30 carbon atoms, or groups having a biphenyl structure. If these monovalent organic groups have substituents, the substituents are preferably aliphatic hydrocarbon groups or aromatic hydrocarbon groups. Groups having a biphenyl structure may have 12 to 30 carbon atoms, 12 to 20 carbon atoms, or 12 to 16 carbon atoms.

[0110] The phosphazene structure may be either a linear phosphazene structure or a cyclic phosphazene structure. From the viewpoint of the thermal stability of the cured product, it is preferable that the phosphorus compound (B) has a cyclic phosphazene structure. That is, it is preferable that the phosphazene structure of the phosphorus compound (B) is a cyclic phosphazene structure. An example of a cyclic phosphazene structure is the structure represented by the following formula (B2).

[0111]

[0112] In equation (B2), R Ｂ３ and R Ｂ４ Each of these may independently be a hydrogen atom, a halogen atom, or a monovalent organic group. Ｂ２R may be an integer between 3 and 20, 3 and 10, or 3 and 8. Ｂ３ and R Ｂ４ Preferably, at least one of them is a group having a biphenyl structure, R Ｂ３ and R Ｂ４ R may form a cyclic structure having a biphenyl structure. Ｂ３ and R Ｂ４ Each of them is R independently Ｂ１ and R Ｂ２ The explanation above is sufficient. For details, please refer to the explanation in formula (B1) above.

[0113] In phosphorus-based compound (B), the biphenyl structure may be included in phosphorus-based compound (B) as a biphenyl group or a biphenylene group (biphenyldiyl group). The biphenylene group and the biphenylene group may each be unsubstituted or substituted. The substituent is preferably an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and the number of carbon atoms of the substituent may be 1 to 30, 1 to 12, 1 to 8, or 1 to 4. For example, the substituent is R, which will be described later. Ｂ５ and R Ｂ６ The following may be listed. One or more biphenyl structures may be included in one molecule of the phosphorus compound (B).

[0114] The phosphorus compound (B) may be a compound in which the phosphorus atom of the phosphazene structure and the carbon atom of the biphenyl structure are directly bonded, or bonded via a C1-C4 alkylene group, a C1-C4 alkylene oxy group, or an oxygen atom. In one example, in the phosphorus compound (B), it is preferable that the phosphorus atom of the phosphazene structure and the carbon atom of the biphenyl structure are directly bonded. In another example, in the phosphorus compound (B), it is preferable that the phosphorus atom of the phosphazene structure and the carbon atom of the biphenyl structure are bonded via a methylene group or an oxygen atom, preferably via an oxygen atom. Examples include a biphenyl group, a biphenylene group, a biphenyl oxy group, and a biphenylene oxy group.

[0115] The phosphorus compound (B) may have one biphenyl group directly or via a linking group bonded to one phosphorus atom in a -N=P- bond of the phosphazene structure. Alternatively, the phosphorus compound (B) may have one biphenylene group forming a cyclic structure and bonded directly or via a linking group to one phosphorus atom in a -N=P- bond of the phosphazene structure. The phosphorus compound (B) may have, for example, a structure represented by the following formula (B3).

[0116]

[0117] In equation (B3), R Ｂ５ and R Ｂ６ Each of these may independently be a halogen atom, a C1-C20 alkyl group, a C1-C20 alkoxy group, a C6-C20 aryl group, a C6-C20 aryloxy group, a C6-C20 aralkyl group, or a C6-C20 aralkyloxy group. For example, R Ｂ５ and R Ｂ６ This may be an alkyl group, alkoxy group, aryl group, aryloxy group, aralkyl group, or aralkyloxy group having 20 or fewer carbon atoms, 12 or fewer carbon atoms, or 4 or fewer carbon atoms, and may be a methyl group or an ethyl group. Ｂ４ and n Ｂ５ Each of these can be an integer between 0 and 4, independently of the others. Preferably, n Ｂ４ and n Ｂ５ At least one of these values ​​may be 0, and both may be 0. In other words, it is preferable that the biphenyl structure is unsubstituted. The bonding position between the biphenyl structure and the phosphazene structure is not particularly limited, but may be any of the 2-4 position and 2'-4' position of the biphenyl structure, or it may be the 2 position and the 2' position.

[0118] Specifically, the phosphorus compound (B) may have a structure represented by the following formula (B4).

[0119]

[0120] The phosphorus compound (B) is preferably a cyclic phosphazene represented by the following formula (B5), and more preferably a cyclic phosphazene represented by the following formula (B6).

[0121]

[0122]

[0123] In equation (B5), R Ｂ５ and R Ｂ６ and n Ｂ４ and n Ｂ５ This is as explained in formula (B3) above. The binding position of the biphenyl structure and the phosphazene structure is not particularly limited, but it may be any of the 2-4 position and 2'-4' position of the biphenyl structure, or it may be the 2 position and the 2' position. Ｂ３ n may be an integer between 3 and 20, 3 and 10, or 3 and 8. In formula (B6), n Ｂ６ This can be an integer between 3 and 20, 3 and 10, or 3 and 8.

[0124] In the example described above, the structure consists of one -P=N- bond and one group having a biphenyl structure repeated; however, phosphorus compound (B) may also contain -P=N- bonds that do not have a group having a biphenyl structure.

[0125] The phosphorus compound (B) may be, for example, the compound represented by (B7) below.

[0126]

[0127] In equation (B7), R Ｂ Each is independently a hydrogen atom, a halogen atom, or a monovalent organic group, and multiple R Ｂ At least one of the groups is a biphenyl structure, and two adjacent R groups Ｂ This may form a cyclic structure having a biphenyl structure. For example, two R atoms bonded to one phosphorus atom Ｂ This may form a cyclic structure having a biphenyl structure. For example, two R atoms bonded to three phosphorus atoms in one molecule Ｂ Each of these may form a cyclic structure having a biphenyl structure. Furthermore, two R atoms bonded to one phosphorus atom ＢThe structure that forms a cyclic structure having a biphenyl structure may be the structure represented by formula (B3) or formula (B4) above. Ｂ If it is a monovalent organic group, it may be the one described in formula (B1) above.

[0128] From the viewpoint of thermal stability and / or moldability, component (B) may be 0.1% by mass or more, 1% by mass or more, or 5% by mass or more, relative to the solid content of the resin composition. On the other hand, from the viewpoint of fluidity, component (B) may be 40% by mass or less, 30% by mass or less, or 20% by mass or less, relative to the solid content of the resin composition. For example, component (B) may be 0.1 to 40% by mass, 1 to 30% by mass, or 5 to 20% by mass, relative to the solid content of the resin composition.

[0129] Component (B) may be 0.1% by mass or more, 1% by mass or more, or 5% by mass or more, relative to the total amount of component (A), component (B), and component (C) described later. On the other hand, component (B) may be 40% by mass or less, 30% by mass or less, or 20% by mass or less, relative to the total amount of component (A), component (B), and component (C). Component (B) may be, for example, 0.1 to 40% by mass, 1 to 30% by mass, or 5 to 20% by mass, relative to the total amount of component (A), component (B), and component (C).

[0130] <Filler (C)> As the filler (C), an inorganic filler is preferred, for example, silica (SiO ２ ), alumina (Al ２ O ３ Examples include titanium dioxide, barium titanate, strontium titanate, potassium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, aluminum borate, silicon carbide, mica, beryllia, clay, and talc. From the viewpoint of dielectric properties, silica is preferred.

[0131] The shape and size of the filler (C) are not particularly limited. The average particle diameter of the filler may be, for example, 0.01 to 20 μm, or 0.1 to 10 μm. Here, the average particle diameter of the filler is the particle diameter at the point corresponding to 50% of the cumulative value in the volume-based particle distribution obtained by laser diffraction scattering.

[0132] The filler (C) may be used alone or in combination of two or more types.

[0133] From the viewpoint of thermal stability, moldability, and / or dielectric loss tangent, component (C) is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 45% by mass or more, based on the solid content of the resin composition. On the other hand, from the viewpoint of fluidity and / or relative dielectric constant, component (C) is preferably 75% by mass or less, more preferably 65% ​​by mass or less, or even more preferably 60% by mass or less, based on the solid content of the resin composition. Component (C) may be, for example, 30 to 75% by mass, 40 to 65% by mass, or 45 to 60% by mass, based on the solid content of the resin composition.

[0134] Component (C) may be 30% by mass or more, 40% by mass or more, or 45% by mass or more, relative to the total amount of components (A), (B), and (C). On the other hand, component (C) may be 75% by mass or less, 65% by mass or less, or 60% by mass or less, relative to the total amount of components (A), (B), and (C). Component (C) may be, for example, 30 to 75% by mass, 40 to 65% by mass, or 45 to 60% by mass, relative to the total amount of components (A), (B), and (C).

[0135] <Other Components> The resin composition may contain other components besides those listed above, as needed. Examples of other components include elastomers, curing accelerators, coupling agents, solvents, resins other than those listed above, flame retardants, antioxidants, heat stabilizers, antistatic agents, UV absorbers, pigments, colorants, lubricants, etc.

[0136] Examples of elastomers include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers.

[0137] As a curing accelerator, for example, a radical polymerization initiator can be used. The radical polymerization initiator may be a thermal radical polymerization initiator or a photoradical polymerization initiator, but a thermal radical polymerization initiator is preferred. The radical polymerization initiator is not particularly limited, and examples include azo polymerization initiators and organic peroxide polymerization initiators. Examples of azo polymerization initiators include 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylpropanenitrile), 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylpropionic acid)dimethyl, 1,1'-azobis(methyl cyclohexylcarboxylate), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), 4,4'-azobis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl4-cyanopentanoate), and 1,1'-azobis(cyclohexane-1-carbonitride). Examples of organic peroxide polymerization initiators include dicumyl peroxide, dibenzoyl peroxide, 2-butanone peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, bis(tert-butylperoxyisopropyl)benzene, and tert-butyl hydroperoxide.

[0138] Among radical polymerization initiators, it is preferable to use compounds with a low oxygen atom content. Azo polymerization initiators are preferred as such compounds. In particular, azo polymerization initiators that do not contain heteroatoms other than the two nitrogen atoms (N) of the azo group are preferred. For example, a compound represented by the following formula (2) can be cited.

[0139] As an azo polymerization initiator, a compound represented by the following formula (PI-1) can be used. Ｘ -N = N - R Ｙ (PI-1)

[0140] In equation (PI-1), R Ｘ and R Ｙ Each is independently a hydrogen atom or a monovalent group, R Ｘ and R ２ At least one of them is a monovalent group. Ｘ and R Ｙ These may be the same or different from each other. The monovalent group is preferably a hydrocarbon group, and may be a saturated hydrocarbon group or an unsaturated hydrocarbon group, and may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The monovalent group is preferably a saturated or unsaturated aliphatic hydrocarbon group, and is preferably an alkyl group.

[0141] The alkyl group may be either a linear alkyl group or a cyclic alkyl group. The linear alkyl group may be a linear alkyl group or a branched alkyl group. The cyclic alkyl group may have substituents bonded to carbon atoms on the ring.

[0142] The alkyl group may be, for example, an alkyl group having 1 to 10 carbon atoms, 3 to 8 carbon atoms, or 4 to 8 carbon atoms. Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, n-hexyl group, isohexyl group, cyclohexyl group, methylcyclohexyl group, cyclohexylmethyl group, heptyl group, octyl group, isooctyl group, 2-ethylhexyl group, nonyl group, decyl group, 1,1',3,3'-tetramethylbutyl group, 2,2',4,4'-tetramethylbutyl group, and the like.

[0143] Specific examples of compounds represented by formula (PI-1) include 2,2'-azobis(2,4,4-trimethylpentane) and 2,2'-azobis(2,4-dimethylvaleronitrile).

[0144] The curing accelerator may be used alone or in combination of two or more types.

[0145] The curing accelerator may be 0.01% by mass or 0.1% by mass or more relative to the solid content of the resin composition. On the other hand, the curing accelerator may be 10% by mass or 1% by mass or less relative to the solid content of the resin composition. The curing accelerator may be, for example, 0.01 to 10% by mass or 0.1 to 1% by mass relative to the solid content of the resin composition. The curing accelerator may be 0.01% by mass or 0.1% by mass or more relative to the total amount of component (A), component (B), and component (C). On the other hand, the curing accelerator may be 10% by mass or 1% by mass or less relative to the total amount of component (A), component (B), and component (C). The curing accelerator may be, for example, 0.01 to 10% by mass or 0.1 to 1% by mass relative to the total amount of component (A), component (B), and component (C).

[0146] Examples of coupling agents that can be used include silane coupling agents. Examples of silane coupling agents include (meth)acrylicsilane coupling agents, epoxysilane coupling agents, aminosilane coupling agents, vinylsilane coupling agents, phenylsilane coupling agents, alkylsilane coupling agents, alkenylsilane coupling agents, alkynylsilane coupling agents, haloalkylsilane coupling agents, siloxane coupling agents, hydrosilane coupling agents, silazane coupling agents, alkoxysilane coupling agents, chlorosilane coupling agents, isocyanuratesilane coupling agents, ureidosilane coupling agents, mercaptosilane coupling agents, sulfidosilane coupling agents, isocyanatesilane coupling agents, and the like. A single coupling agent may be used, or two or more may be used in combination.

[0147] The coupling agent may be 0.01% by mass or 0.1% by mass or more relative to the solid content of the resin composition. On the other hand, the coupling agent may be 10% by mass or less or 5% by mass or less relative to the solid content of the resin composition. The curing accelerator may be, for example, 0.01 to 10% by mass or 0.1 to 5% by mass relative to the solid content of the resin composition. The coupling agent may be 0.01% by mass or 0.1% by mass or more relative to the total amount of component (A), component (B), and component (C). On the other hand, the coupling agent may be 10% by mass or less or 5% by mass or less relative to the total amount of component (A), component (B), and component (C). The coupling agent may be, for example, 0.01 to 10% by mass or 0.1 to 5% by mass relative to the total amount of component (A), component (B), and component (C).

[0148] The resin composition may be a solvent-free resin composition or may contain a solvent. For example, the resin composition may contain a liquid compound as a thermosetting resin and may be a solvent-free resin composition, or it may contain a thermosetting resin and a solvent. The solvent can adjust the viscosity of the resin composition and further improve its coating properties. Organic solvents are preferred as the solvent.

[0149] Examples of organic solvents include alcohol-based solvents such as ethanol, propanol, butanol, methyl cellosolve, ethylene glycol monobutyl ether, and propylene glycol monomethyl ether; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based solvents such as tetrahydrofuran; aromatic hydrocarbon-based solvents such as toluene, xylene, and mesitylene; nitrogen-containing solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfur-containing solvents such as dimethyl sulfoxide; and ester-based solvents such as γ-butyrolactone. Organic solvents may be used individually or in combination of two or more.

[0150] If the resin composition contains a solvent, the solid content of the resin composition may be, for example, 30 to 95% by mass, 40 to 90% by mass, or 50 to 80% by mass, based on the total mass of the resin composition.

[0151] <Method for Manufacturing Resin Compositions> The method for manufacturing resin compositions is not particularly limited. Resin compositions according to one embodiment are not limited by the manufacturing method, and their characteristics are as described in this disclosure. As an example of a method for manufacturing resin compositions, a resin composition can be obtained by mixing component (A), component (B), component (C), and any optional component as needed. More specifically, for example, a resin composition can be obtained by dissolving or dispersing component (A), component (B), and component (C) in a solvent, and mixing other components as needed. The mixing order of each component, temperature, time, and other conditions are not particularly limited and can be appropriately adjusted according to the type of raw materials, manufacturing scale, manufacturing equipment, etc.

[0152] [Prepreg] According to one embodiment, a prepreg comprising a resin composition or a semi-cured product of the resin composition can be provided. This prepreg can be formed, for example, using a resin composition and a fibrous substrate. As the resin composition, the above-described resin composition can be used. Details of the resin composition are as described above.

[0153] The prepreg includes the resin composition described above or a semi-cured product of the resin composition described above. In this disclosure, one indicator of a semi-cured product is the B-stage state as defined in JIS K 6800 (1985). The prepreg may include, for example, a resin composition or a semi-cured product of the resin composition and a fibrous substrate such as a sheet-like fibrous substrate. In the prepreg, the resin composition may be in an uncured state, or it may be partially or entirely in a semi-cured state. For example, a cured product can be obtained by assembling a molded product such as a laminate using this prepreg and curing it by heat treatment or the like.

[0154] A prepreg can be obtained, for example, by coating a fibrous substrate with a resin composition and drying it. For example, a prepreg can be obtained by impregnating a fibrous substrate with a resin composition and drying the fibrous substrate impregnated with the resin composition. Drying is preferably carried out at a temperature above which volatile components such as solvents that may be contained in the resin composition are removed, and may also be carried out at a temperature above which the thermosetting resin contained in the resin composition is semi-cured, depending on the application. Furthermore, it is preferable that the drying is adjusted so that the thermosetting resin contained in the resin composition is not completely cured. From this viewpoint, the drying temperature may be, for example, 80 to 200°C, and the drying time may be, for example, 1 to 30 minutes, depending on the drying temperature, drying equipment, and its scale.

[0155] The fibrous base material may be woven, knitted, or nonwoven fabric. The fibrous base material may be provided in the form of chopped strand mat, roving, etc. The fiber material may be either inorganic or organic fiber. Examples of inorganic fibers include glass fiber and carbon fiber. Examples of glass fiber include E glass, NE glass, D glass, S glass, and Q glass. Examples of organic fibers include polyimide, polyester, and tetrafluoroethylene. The fibrous base material may use one type of fiber alone, or two or more types in combination. From the viewpoint of dielectric properties and heat resistance, inorganic fibers are preferred for the fibrous base material, and glass fibers are more preferred.

[0156] The fibrous substrate can be appropriately selected depending on the application of the prepreg, but a sheet-like fibrous substrate is preferred. The sheet-like fibrous substrate may be, for example, various sheet-like fibrous substrates used in known laminates for electrical insulation materials. The thickness of the sheet-like fibrous substrate is not particularly limited, but for example, 0.02 to 0.5 mm is preferred. Here, the thickness is determined by measuring the thickness at five points at equal distances across the entire surface of the sheet-like fibrous substrate and taking the arithmetic mean of the five points.

[0157] [Resin Film] According to one embodiment, a resin film containing a resin composition or a semi-cured product of the resin composition can be provided. Details of the resin composition are as described above.

[0158] The resin film includes the resin composition described above or a semi-cured product of the resin composition described above. In the resin film, the resin composition may be in an uncured state, or it may be partially or entirely in a semi-cured state. For example, a cured product can be obtained by curing the resin film by heat treatment or the like. The resin film can be obtained, for example, by coating a material to be coated with the resin composition and drying it. Drying may be carried out, for example, in the same manner as the method for manufacturing the prepreg described above. After drying the resin film on the material to be coated, the product may be provided as a combination of the resin film and the material to be coated. For example, this method can provide a resin film for forming an insulating layer on a material to be coated in electronic equipment, etc. Alternatively, after drying the resin film on the material to be coated, the resin film may be peeled off the material to provide the resin film as a product.

[0159] The material to be coated may be either an inorganic or organic substrate, and examples include glass substrates, metal foils, metal plates and other metal substrates, plastic plates, plastic films and other plastic substrates, paper substrates, and even fibrous substrates as described in the prepreg section above. In order to peel the resin film from the material to be coated and provide it, a material to be coated that has a release layer formed on its surface may be used.

[0160] [Metal-clad laminate] According to one embodiment, a metal-clad laminate comprising a cured resin composition and a metal foil can be provided. This metal-clad laminate may, for example, be a metal-clad laminate comprising a cured prepreg and a metal foil. According to another embodiment, a metal-clad laminate formed using a prepreg and a metal foil can also be provided. This metal-clad laminate may, for example, be a metal-clad laminate comprising a cured prepreg and a metal foil.

[0161] Details of the resin composition and prepreg are as described above. In this disclosure, one indicator of the cured product is the state of the C-stage as defined in JIS K 6800 (1985).

[0162] The metal-clad laminate preferably includes a resin-cured layer containing a resin curing product and a metal foil disposed on at least one surface of the resin-cured layer. The resin-cured layer contains a cured product of the resin composition described above, but may be a cured product of the prepreg described above. For example, in the metal-clad laminate, the metal foil is disposed on at least one surface of the cured prepreg, and more preferably, the metal foil is disposed on both surfaces of the cured prepreg. The metal-clad laminate may be manufactured by disposing the metal foil on at least one surface of a single sheet-like prepreg, or by laminating two or more sheet-like prepregs and disposing the metal foil on at least one surface of the outermost surface of the laminate. For example, the metal-clad laminate may be manufactured by laminating two or more sheet-like prepregs and disposing the metal foil on both surfaces of this laminate.

[0163] The following describes a specific method for manufacturing metal-clad laminates, which involves arranging metal foil on a laminate of two or more sheet-like prepregs.

[0164] First, two or more sheet-like prepregs are laminated to obtain a laminate. In this laminate, the two or more sheet-like prepregs may be identical, or they may be partially or completely different. In the laminate, it is sufficient that at least one of the two or more sheet-like prepregs is obtained using the resin composition according to one embodiment.

[0165] Next, a metal foil is placed on at least one surface of the laminate. The laminate with the metal foil is then heated and pressurized. This causes the sheet-like prepreg to harden, and a hardened prepreg product can be obtained. Adjacent sheet-like prepregs can also be bonded together. The heating and pressurizing conditions are not particularly limited, but for example, the temperature can be 100 to 300°C, the time 10 to 300 minutes, and the pressure 1.5 to 5 MPa. After heating and pressurizing, reheating may be performed to further harden the prepreg. In this case, the reheating temperature can be 100 to 300°C. As for the pressurizing method, for example, an autoclave molding machine, a multi-stage press machine, a multi-stage vacuum press machine, a continuous molding machine, etc., can be used.

[0166] The metal used for the metal foil is not particularly limited and can include, for example, copper, nickel, aluminum, gold, silver, platinum, molybdenum, ruthenium, tungsten, iron, titanium, chromium, and alloys containing two or more of these metal elements. Industrially, it is preferable to use elemental copper, nickel, or aluminum. By using copper as the metal foil, a copper-clad laminate can be provided.

[0167] The dielectric properties of an evaluation substrate obtained by removing the metal foil from a metal-clad laminate (hereinafter also referred to as the "metal foil-removed evaluation substrate") are preferably as follows.

[0168] The relative permittivity (Dk) of the metal foil removal evaluation substrate at 25°C and 10GHz may be 4.0 or less, 3.5 or less, or 3.4 or less. A smaller relative permittivity (Dk) of the metal foil removal evaluation substrate at 25°C and 10GHz is preferable, and there is no particular limit to its lower limit, but considering the balance with other physical properties, it may be, for example, 2.3 or more, or 2.4 or more. For example, the relative permittivity (Dk) of the metal foil removal evaluation substrate at 25°C and 10GHz may be, for example, 2.3 to 4.0, 2.3 to 3.5, or 2.4 to 3.4.

[0169] The dielectric loss tangent (Df) of the metal foil removal evaluation substrate at 25°C and 10GHz is preferably 0.0040 or less, and more preferably 0.0025 or less. A smaller dielectric loss tangent (Df) at 25°C and 10GHz is preferable, and there is no particular limit to its lower limit, but considering the balance with other physical properties, it may be, for example, 0.0001 or more, or 0.00050 or more. For example, the dielectric loss tangent (Df) of the metal foil removal evaluation substrate at 25°C and 10GHz may be 0.0001 to 0.0040, or 0.00050 to 0.0025.

[0170] In this disclosure, the relative permittivity (Dk) and dielectric loss tangent (Df) at 25°C and 10 GHz are measured at 25°C in the 10 GHz band in accordance with the SPDR method (split-post dielectric resonator). The measuring device can be the "PNA Network Analyzer N5227A" (product name) from agilent technologies. The sample used to measure the relative permittivity (Dk) and dielectric loss tangent (Df) of the metal foil removal evaluation substrate can be prepared by removing the metal foil by immersing the metal-clad laminate in an etching solution, and then cutting out a test piece measuring 40 mm wide x 100 mm long from the material from which the metal foil has been removed. In the case of a copper-clad laminate, a 10% by mass solution of ammonium persulfate is used as the etching solution.

[0171] [Printed Wiring Board] According to one embodiment, a printed wiring board having a cured product of a resin composition can be provided. Details of the resin composition are as described above.

[0172] In printed circuit boards, the cured resin composition can be manufactured using a resin composition, a prepreg, a resin film, a metal-clad laminate, or a combination thereof. For example, a printed circuit board can be provided by forming wiring on a cured prepreg using a known method. In another example, a printed circuit board can be provided by forming wiring on a metal-clad laminate using a known method. A printed circuit board may also be a combination of these examples. Details of the prepreg, resin film, and metal-clad laminate are as described above.

[0173] The printed circuit board may be either a single-layer printed circuit board or a multi-layer printed circuit board.

[0174] [Semiconductor Package] According to one embodiment, a semiconductor package including a printed circuit board and a semiconductor element can be provided. More specifically, a semiconductor package including a printed circuit board containing a cured resin composition and a semiconductor element can be provided. Details of the resin composition are as described above. Details of the cured resin composition and the printed circuit board are also as described above. The semiconductor package can be manufactured, for example, by mounting a semiconductor element, memory, etc., on a printed circuit board by a known method. The cured resin composition may be used as an insulating material, sealing material, etc., for the semiconductor package.

[0175] [Examples of Embodiments] Examples of embodiments of the present invention are listed below. Embodiments of the present invention are not limited to the following examples. <1> A resin composition comprising a thermosetting resin (A), a phosphorus-based compound (B) having a phosphazene structure and a biphenyl structure, and a filler (C) in an amount of 30% by mass or more relative to the solid content of the resin composition. <2> The resin composition according to <1>, wherein the phosphazene structure is a cyclic phosphazene structure. <3> The resin composition according to <1> or <2>, wherein the phosphorus-based compound (B) comprises a compound in which the phosphorus atom of the phosphazene structure and the carbon atom of the biphenyl structure are directly bonded, or bonded via an alkylene group having 1 to 4 carbon atoms, an alkylene oxy group having 1 to 4 carbon atoms, or an oxygen atom. <4> The resin composition according to any one of <1> to <3>, wherein the thermosetting resin (A) comprises a compound having a vinylbenzyl group. <5> The resin composition according to any one of <1> to <5>, wherein the filler (C) comprises silica. A prepreg comprising the resin composition described in any one of items <6> <1> to <5> or a semi-cured product of the said resin composition. A resin film comprising the resin composition described in any one of items <7> <1> to <5> or a semi-cured product of the said resin composition. A metal-clad laminate comprising a cured product of the resin composition described in any one of items <8> <1> to <5> and a metal foil. A printed circuit board comprising a cured product of the resin composition described in any one of items <9> to <5>. A semiconductor package comprising the printed circuit board described in <9> and a semiconductor element.

[0176] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0177] "Preparation of Composition 1 Containing a Vinylbenzyl Compound" In a 500 ml reaction vessel equipped with a stirrer, thermometer, reflux tubing, and nitrogen inlet, 116.16 parts by mass (1.00 mol) of indene, 335.76 parts by mass (2.20 mol) of chloromethylstyrene, 16.12 parts by mass of tetra-n-butylammonium bromide (manufactured by Kanto Chemical Co., Ltd.) as a phase transfer catalyst, 0.80 parts by mass of phenothiazine as a polymerization inhibitor, and 305.45 parts by mass of toluene as a solvent were charged, and the mixture was heated and stirred at 40°C while blowing in nitrogen at a flow rate of 50 ml / min. Next, 435.00 parts by mass of an aqueous sodium hydroxide solution (concentration 48% by mass) was added. The reaction was carried out at 70°C. １ After confirming the disappearance of chloromethylstyrene by H-NMR, 98.43 parts by mass (0.70 moles) of α-chloro-p-xylene were added. The reaction was then carried out at 70°C. １ The reaction was terminated after confirming the disappearance of α-chloro-p-xylene by 1H-NMR. Nitrogen was continuously blown into the mixture during the reaction. The reaction mixture was cooled to room temperature (25°C), neutralized with a 10% hydrochloric acid aqueous solution, and then washed twice with pure water. After removing toluene under reduced pressure, the resulting viscous liquid was washed with methanol and vacuum-dried to obtain composition 1 containing compound (XA1).

[0178] Chloromethylstyrene: AGC Seimi Chemical Co., Ltd. "CMS-P", a mixture of m-isomer and p-isomer, m-isomer content 50% by mass, p-isomer content 50% by mass.

[0179] Composition 1 was prepared using "ECX400II" manufactured by JEOL RESONANCE Co., Ltd. １ H-NMR spectrum (400 MHz, CDCl) ３ When the following was measured, a shift or disappearance of the peak of the raw material was observed, indicating that a reaction was occurring in which a vinylbenzyl group was bonded to one of the 1st to 3rd positions of the indene ring, and a methylbenzyl group was bonded to one of the 1st to 3rd positions of the indene ring.

[0180] The peak area ratio of each compound was calculated from the area ratio of the GPC chart measured under the following conditions. The GPC chart of composition 1 is shown in Figure 1. The results of calculating the peak area ratio of each compound are shown in Table 1.

[0181] Instrument: High-speed GPC instrument "HLC-8420GPC" (Tosoh Corporation, product name) Detector: Ultraviolet absorption detector "UV-8420" (Tosoh Corporation, product name) Columns: Guard column; TSKgel guard column SuperHZ-L, Columns; TSKgel SuperHZ4000 + TSKgel SuperHZ2500 + TSKgel SuperHZ1000 (3 tubes), Reference column; None (resistance tube) (all Tosoh Corporation, product names) Column size: 4.6 × 20 mm (guard column), 4.6 × 150 mm (column) Eluent: Tetrahydrofuran Sample concentration: 1 mg / 1 mL Injection volume: 2 μL Flow rate: 0.35 mL / min Measurement temperature: 40°C

[0182]

[0183] "Preparation of Composition 2 containing a vinylbenzyl compound" In a 500 mL reaction vessel equipped with a stirrer, thermometer, reflux tubing, and nitrogen inlet, 35.6 parts by mass of indene, 101.2 parts by mass of chloromethylstyrene (as described below), 7.1 parts by mass of tetra-n-butylammonium bromide (manufactured by Kanto Chemical Co., Ltd.) as a phase transfer catalyst, 0.1 parts by mass of phenothiazine as a polymerization inhibitor, and 77.6 parts by mass of toluene as a solvent were charged, and the mixture was heated and stirred at 40°C while blowing in nitrogen at a flow rate of 50 ml / min.

[0184] Chloromethylstyrene: AGC Seimi Chemical Co., Ltd. "CMS-P", a mixture of m-isomer and p-isomer, m-isomer content 50% by mass, p-isomer content 50% by mass.

[0185] Next, 46.5 parts by mass of an aqueous solution of the basic compound listed below was added dropwise over 20 minutes, and the mixture was stirred at 60°C for 9 hours. Nitrogen was continuously blown in during the reaction. After cooling to room temperature (25°C) and neutralizing with a 10% hydrochloric acid aqueous solution, the mixture was washed twice with pure water, toluene was removed by reduced-pressure distillation, the resulting viscous liquid was washed with methanol, and then vacuum-dried to obtain a vinylbenzyl compound. As described later, a mixture of a compound with two vinylbenzyl groups and a compound with three vinylbenzyl groups was obtained. This is referred to as composition 2.

[0186] Aqueous solution of basic compound: 48% by mass aqueous solution of sodium hydroxide, Kanto Chemical Co., Ltd.

[0187] The resulting vinylbenzyl compound is １ ¹H-NMR analysis confirmed that the structure has vinylbenzyl groups directly bonded to the carbon atoms at positions 1, 3, or combinations thereof of the indene ring, as shown in formula (A-1) below. Furthermore, GPC analysis revealed that the vinylbenzyl compound was a mixture of compounds with two vinylbenzyl groups and compounds with three vinylbenzyl groups. In the case of the vinylbenzyl compound with three vinylbenzyl groups, it was confirmed that there were two vinylbenzyl groups directly bonded to the carbon atom at position 1 of the indene ring and one vinylbenzyl group directly bonded to the carbon atom at position 3. The weight-average molecular weight (Mw) of the vinylbenzyl compound was 500. The weight-average molecular weight was measured by the following method.

[0188]

[0189] "Method for Measuring Weight-Average Molecular Weight (Mw)" The weight-average molecular weight was calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The calibration curve was approximated by a cubic equation using standard polystyrene: TSK standard POLYSTYRENE (Type; A-2500, A-5000, F-20, F-80) (manufactured by Tosoh Corporation, trade name). The GPC measurement conditions are shown below.

[0190] Instrument: High-speed GPC instrument HLC-8320GPC (Tosoh Corporation, product name) Detector: Ultraviolet absorption detector UV-8320 (Tosoh Corporation, product name) Columns: Guard column; TSKgel guardcolumn Super(HZ)-M+, Column; TSKgel SuperMultipore HZ-M (2), Reference column; TSKgel SuperH-RC (2) (all Tosoh Corporation, product names) Column size: 4.6 × 20 mm (guard column), 4.6 × 150 mm (column), 6.0 × 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 1 mL Injection volume: 20 μL or 2 μL Flow rate: 0.35 mL / min Measurement temperature: 40°C

[0191] [Preparation of Resin Compositions] Each component listed in Tables 2 and 3 was combined with toluene according to the proportions listed in Tables 2 and 3, and stirred and mixed at 25°C to prepare the resin compositions (varnishes) of Examples 1 to 11. The solid content concentration of the resin compositions of Examples 1 to 11 is approximately 65% ​​by mass. In Tables 2 and 3, the unit of the proportion of each component is parts by mass, and in the case of a solution, it means parts by mass on a solid content basis.

[0192] Details of each material listed in Tables 2 and 3 are as follows: Composition 1: Manufactured as described above Composition 2: Manufactured as described above Maleimide compound: Aromatic bismaleimide compound containing an indan ring having the structure represented by formula (1) above Vinyl group compound: LF-310 (trade name) (manufactured by Nippon Steel Chemical & Material Co., Ltd.) (Tg ≥ 150°C, vinyl group equivalent: 265 g / eq, weight-average molecular weight (Mw): 36,000, number-average molecular weight (Mn): 3,300) Phosphorus compound 1: Compound represented by the following formula (X) Phosphorus compound 2: Compound represented by the above formula (B6) (wherein n Ｂ６ (3-8) Filler: Silica (average particle size: 2.4 μm) Curing accelerator: 2,2'-Azobis(2,4,4-trimethylpentane) ("VR-110" (product name) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Coupling agent: 3-Methacryloxypropyltrimethoxysilane ("KBM-503" (product name) manufactured by Shin-Etsu Chemical Co., Ltd.)

[0193]

[0194] [Preparation of Prepreg] The resin composition (varnish) obtained as described above was impregnated and coated onto a glass cloth (manufactured by Nitto Boseki Co., Ltd.) with a thickness of 0.046 mm, and heated and dried at 135°C for 10 minutes to obtain a prepreg with a solid content of 89% by mass of the resin composition.

[0195] [Preparation of Double-Sided Copper-Clad Laminates] Double-sided copper-clad laminates were prepared using the obtained prepreg. Multiple layers of prepreg were prepared according to the thickness of the double-sided copper-clad laminate to be prepared and the test specimens to be used in each evaluation described later. More specifically, for Examples 1 to 8, a number of prepreg layers was prepared so that the thickness of the test specimen described later would be 0.2 mm, and for Examples 9 to 11, a number of prepreg layers was prepared so that the thickness of the test specimen described later would be 0.6 mm. On both sides of these, 18 μm thick electrolytic copper foil (Mitsui Mining & Smelting Co., Ltd. "3EC-M3-VLP-18" (product name)) was placed so that the matte side (roughened side) was aligned with the prepreg, and the double-sided copper-clad laminate was prepared by heating and pressurizing at 230°C for 90 minutes under vacuum press conditions of 2 MPa.

[0196] [Evaluation methods and measurement methods]

[0197] <Evaluation of the rate of change of the thermal expansion coefficient> (Examples 1-8) The copper foil was removed from the double-sided copper-clad laminate obtained above by immersion in a copper etching solution to prepare a test specimen with dimensions of 20 mm in length, 5 mm in width (bias), and 0.2 mm in thickness (Z direction). Thermomechanical analysis was performed on this test specimen using the tensile method with a TMA test apparatus (TMA450EM1, manufactured by TA Instruments). After mounting the test specimen in the longitudinal direction of the apparatus, the temperature was raised from 30°C to 265°C under measurement conditions of a load of 0.4 N, a span distance of 16 mm, and a heating rate of 10°C / min, then cooled to 30°C, and measured up to 320°C under measurement conditions of a heating rate of 10°C / min. The average thermal expansion coefficient in the temperature range of 30 to 120°C was taken as the value of the thermal expansion coefficient. The thermal expansion coefficient referred to here is the thermal expansion coefficient in the plane direction of the test specimen.

[0198] (Examples 9-11) The copper foil was removed from the double-sided copper-clad laminate obtained above by immersion in a copper etching solution to prepare a test specimen measuring 5 mm in length (X direction), 5 mm in width (Y direction), and 0.6 mm in thickness (Z direction). Thermomechanical analysis was performed on this test specimen using a TMA test apparatus (TA Instruments, Q400) by compression. After mounting the test specimen in the X direction, measurements were taken twice consecutively from 30°C to 260°C under measurement conditions of a load of 5 g and a heating rate of 10°C / min. The average coefficient of thermal expansion in the temperature range of 30 to 120°C was calculated from the results of the second measurement and was taken as the value of the coefficient of thermal expansion. Note that the coefficient of thermal expansion referred to here is the coefficient of thermal expansion in the plane direction of the test specimen.

[0199] (Rate of change of average thermal expansion coefficient ΔCTE) Using the average thermal expansion coefficient (CTE(30-120°C)) obtained above for the temperature range of 30-120°C, the rate of change of the average thermal expansion coefficient (CTE(30-120°C)) ΔCTE was calculated for Examples 2, 3, 5, 6, 8, 10, and 11, which contain phosphorus compounds, compared to Examples 1, 4, 7, and 9, which do not contain phosphorus compounds, based on the following formula. The results are shown in Tables 2 and 3 below.

[0200] ΔCTE for Example 2 = (CTE for Example 2 (30-120°C) / CTE for Example 1 (30-120°C)) - 1 ΔCTE for Example 3 = (CTE for Example 3 (30-120°C) / CTE for Example 1 (30-120°C)) - 1 ΔCTE for Example 5 = (CTE for Example 5 (30-120°C) / CTE for Example 4 (30-120°C)) - 1 ΔCTE for Example 6 = (CTE for Example 6 (30-120°C) / CTE for Example 4 (30-120°C)) - 1 ΔCTE for Example 8 = (CTE for Example 8 (30-120°C) / CTE for Example 7 (30-120°C)) - 1 ΔCTE for Example 10 = (CTE for Example 10 (30-120°C) / CTE for Example 9 (30-120°C)) - 1 ΔCTE for Example 11 = (CTE for Example 11 (30-120°C) / CTE for Example 9 (30-120°C)) - 1

[0201] <Evaluation of the rate of change of dielectric loss tangent (Df) of double-sided copper-clad laminates> The copper foil was removed from the double-sided copper-clad laminates obtained above by immersion in a copper etching solution, and pieces measuring 100 mm in length and 40 mm in width were cut out to be used as test specimens for dielectric property measurement. The thickness of the test specimens was 0.2 mm for Examples 1 to 8 and 0.6 mm for Examples 9 to 11. The dielectric loss tangent (Df) was measured using the SPDR method with these test specimens. The measurement instrument used was the Agilent Technologies vector network analyzer "PNA Network Analyzer N5227A". The measurements were performed under conditions of a frequency of 10 GHz and a measurement temperature of 25°C. For Examples 3, 6, 8, and 11, which contain phosphorus compounds, the rate of change ΔDf of the Df value was calculated based on the following formula, compared to Examples 1, 4, 7, and 9, which do not contain phosphorus compounds. The results are shown in Table 4.

[0202] ΔDf for Example 3 = (Df value for Example 3 / Df value for Example 1) - 1 ΔDf for Example 6 = (Df value for Example 6 / Df value for Example 4) - 1 ΔDf for Example 8 = (Df value for Example 8 / Df value for Example 7) - 1 ΔDf for Example 11 = (Df value for Example 11 / Df value for Example 9) - 1

[0203]

[0204]

[0205]

[0206] As shown in Tables 2 and 3, it was confirmed that laminates using a resin composition containing a thermosetting resin, a phosphorus-based compound having a phosphazene structure and a biphenyl structure, and a filler at a concentration of 30% by mass or more relative to the solid content of the resin composition showed a smaller change in the coefficient of thermal expansion compared to those using a resin composition without a phosphorus-based compound.

Claims

1. A resin composition comprising a thermosetting resin (A), a phosphorus-based compound (B) having a phosphazene structure and a biphenyl structure, and a filler (C) in an amount of 30% by mass or more relative to the solid content of the resin composition.

2. The resin composition according to claim 1, wherein the phosphazene structure is a cyclic phosphazene structure.

3. The resin composition according to claim 1 or 2, wherein the phosphorus compound (B) comprises a compound in which the phosphorus atom of the phosphazene structure and the carbon atom of the biphenyl structure are directly bonded, or bonded via an alkylene group having 1 to 4 carbon atoms, an alkylene oxy group having 1 to 4 carbon atoms, or an oxygen atom.

4. The resin composition according to any one of claims 1 to 3, wherein the thermosetting resin (A) comprises a compound having a vinylbenzyl group.

5. The resin composition according to any one of claims 1 to 4, wherein the filler (C) contains silica.

6. A prepreg comprising the resin composition described in any one of claims 1 to 5 or a semi-cured product of the resin composition.

7. A resin film comprising the resin composition described in any one of claims 1 to 5 or a semi-cured product of the resin composition.

8. A metal-clad laminate comprising a cured resin composition according to any one of claims 1 to 5 and a metal foil.

9. A printed circuit board comprising a cured product of the resin composition according to any one of claims 1 to 5.

10. A semiconductor package comprising a printed circuit board according to claim 9 and a semiconductor element.

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