Metal-clad laminated sheet prepreg, metal-clad laminated sheet, printed wiring board, and semiconductor package

Abstract

A metal-clad laminated sheet prepreg according to the present invention contains a curable resin material and a glass fiber base material, the value of Tanδ at 260°C measured in a cured product of said prepreg being 0.08 or greater.

Description

Prepregs for metal-clad laminates, metal-clad laminates, printed circuit boards, and semiconductor packages 【0001】 This disclosure relates to prepregs for metal-clad laminates, metal-clad laminates, printed circuit boards, and semiconductor packages. 【0002】 Metal-clad laminates, such as copper-clad laminates, are used as semiconductor packaging materials in a wide variety of electronic devices, including mobile communication devices such as smartphones, their base station equipment, network infrastructure equipment such as servers, routers, and large servers, as well as large computers, personal computers, and industrial computers. They are also used in electronic devices installed in home appliances, automobiles, and other similar devices. 【0003】 Metal-clad laminates generally consist of a prepreg, which is made by impregnating a glass fiber substrate with resin, and metal foil laminated to both sides thereof. One of the basic required characteristics of the prepreg is that the dielectric constant and dielectric loss tangent are small, and that the transmission loss in the high-frequency range is small. 【0004】 Patent Document 1 discloses a curable vinylbenzyl compound having an indene ring structure into which vinylbenzyl groups are introduced, which can be used as a curable vinylbenzyl compound that has excellent low dielectric constant, low dielectric loss tangent, high heat resistance, and low water absorption. 【0005】 Japanese Patent Publication No. 2003-277440 【0006】 In recent years, in order to cope with the further increase in speed and capacity of information processing, miniaturization of circuits and expansion of substrate sizes in semiconductor packages have been progressing. This disclosure aims to solve the problem of poor connection between chips and semiconductor package substrates that occur as a result of narrowing the bump pitch and expanding the substrate size. Specifically, one of the objectives is to provide a prepreg for metal-clad laminates, a metal-clad laminate, a printed wiring board, and a semiconductor package that have excellent dimensional stability. 【0007】This disclosure includes, but is not limited to, the following embodiments. One embodiment relates to a metal-clad prepreg comprising a curable resin material and a glass fiber substrate, wherein the value of Tanδ measured in the cured product at 260°C is 0.08 or higher. 【0008】 This disclosure makes it possible to provide metal-clad laminate prepregs, metal-clad laminates, printed circuit boards, and semiconductor packages with excellent dimensional stability. 【0009】 The embodiments of the present invention will be described in detail below. The present invention is not limited to the embodiments described below. 【0010】 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 curable resin material means the total amount of the multiple substances present in the curable resin material if there are multiple substances corresponding to each component in the curable resin material, unless otherwise specified. 【0011】 In this disclosure, unless otherwise specified, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) are values ​​measured by the following procedure. The weight-average molecular weight and number-average molecular weight are converted 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) (manufactured by Tosoh Corporation, trade name). The GPC conditions are shown below. 【0012】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 【0013】 One embodiment of the present disclosure is a metal-clad prepreg comprising a curable resin material and a glass fiber substrate, wherein the value of Tanδ measured in the cured product at 260°C is 0.08 or higher. 【0014】In this disclosure, the value of Tanδ measured at 260°C in the cured product of a metal-clad laminate prepreg (hereinafter sometimes referred to as "prepreg") is specifically the value measured by the following procedure and conditions. [Manufacturing of the cured product of the prepreg] 1. A curable resin material is impregnated and coated onto glass cloth, and heated and dried at 120±5°C for 10 minutes to obtain a prepreg with a curable resin material content of 50 to 80% by mass. 2. Multiple prepregs are stacked and adjusted to a thickness in the range of 0.5 to 1 mm, and electrolytic copper foil is placed on both sides so that the matte side faces the prepreg. This is heated and pressurized at 240±5°C for 85±5 minutes under a vacuum press condition of 3.0 MPa to obtain a double-sided copper-clad laminate. 3. The double-sided copper-clad laminate is immersed in a 10% by mass aqueous solution of ammonium persulfate to remove the copper foil from both sides. 4. After drying in a constant temperature oven at 105±5℃ for 1 hour, the material is left to stand for 24 hours in an ambient temperature of 24.2±5℃ and humidity of 54±5%RH to obtain the cured prepreg for Tanδ measurement. [Measurement of Tanδ] Dynamic viscoelasticity measurement is performed on the cured prepreg for Tanδ measurement obtained above under the following conditions to determine the Tanδ value at 260℃. Equipment: UBM "Reogel-E4000" Heating rate: 10℃ / min Frequency: 10.0Hz Specimen dimensions: 5.0mm × 20.0mm 【0015】The dimensional stability addressed in this disclosure specifically refers to dimensional stability when exposed to high-temperature conditions for extended periods. In one embodiment, the prepreg exhibits particularly excellent dimensional stability when exposed to high-temperature conditions for extended periods because the Tanδ value measured in the cured product at 260°C is 0.08 or higher. Conventionally known prepregs are often designed to satisfy a desired value in the coefficient of thermal expansion, which is widely used as an indicator of dimensional stability. However, the Tanδ value measured in the cured product at 260°C is not controlled and does not meet the requirement of 0.08 or higher. This is because the coefficient of thermal expansion is the degree to which an object expands with increasing temperature, and evaluates dimensional stability in short-term thermal history, not dimensional stability when exposed to high-temperature conditions for extended periods. Generally, prepregs containing a curable resin material and a glass fiber substrate tend to expand initially due to short-term thermal history, but then contract. This disclosure is the result of repeated studies on prepreg characteristics that affect this contraction, which had not been previously considered. 【0016】 The Tanδ value measured in the cured prepreg at 260°C is preferably 0.09 or higher. While there is no particular upper limit, it may be 0.2 or lower, 0.18 or lower, or 0.15 or lower. The Tanδ value measured in the cured prepreg at 260°C may be in the range of 0.08 to 0.2. 【0017】 The curable resin material included in the prepreg is not particularly limited in terms of its specific structure, as long as it can be heat-cured, and a wide variety of materials can be used. Examples of components that the curable resin material may include are (A) to (C) below. The curable resin material may include at least one selected from the group consisting of (A) to (C) below. Compound having a maleimide group (A) Compound having a vinylbenzyl group (B) Compound having an epoxy group (C) 【0018】Further, as an example of the theoretical structure of the compound that the curable resin material may contain, the following general formula (1) and the following general formula (2) can be mentioned. The curable resin material may contain at least one selected from the group consisting of a resin having a theoretical structure represented by the following general formula (1) (hereinafter sometimes referred to as "resin (1)") and a resin having a theoretical structure represented by the following general formula (2) (hereinafter sometimes referred to as "resin (2)"). 【0019】 【0020】 [In general formula (1), Ar １ represents an aromatic ring structure which may have a substituent. Ar ２ represents a structural part containing 1 to 3 aromatic rings. m is an integer of 1 or more. A plurality of Ar in the formula １ may all be different or some or all of them may be the same. When m is 2 or more, a plurality of Ar in the formula ２ may all be different or some or all of them may be the same. R １ is a maleimide group, a vinylbenzyloxy group, or a glycidyloxy group. ] 【0021】 【0022】 [In general formula (2), Ar ３ represents an aromatic ring structure which may have a substituent. n is an integer of 1 or more. A plurality of Ar in the formula ３ may all be different or some or all of them may be the same. R ２ is a maleimide group, a vinylbenzyloxy group, or a glycidyloxy group. ] 【0023】 Regarding resin (1), general formula (1) is a theoretical structure, and the resin may partly contain components not corresponding to general formula (1). Components not corresponding to general formula (1) are, for example, components having a branched structure in the molecule. 【0024】 Ar in general formula (1) １represents an aromatic ring structure which may have substituents. Specific examples of aromatic ring structures include, for example, benzene and naphthalene. 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; aryl groups such as phenyl, tolyl, xylyl, mesityl, and naphthyl groups; aryloxy groups such as phenyloxy, tolyloxy, xylyloxy, mesityloxy, and naphthyloxy groups; and aralkyl groups such as benzyl, phenethyl, phenylpropyl, tolylmethyl, and naphthylmethyl groups. 【0025】 Ar in general formula (1) ２ Ar represents a structural region containing 1 to 4 aromatic rings. ２ Specific examples include, for instance, phenylene groups, naphthylene groups, biphenyl structures, and structures having one or more substituents on their aromatic rings. The substituents on the aromatic ring are Ar １ Examples include those shown in [reference]. ２ This may be a phenylene group or a biphenyl structure. 【0026】 In general formula (1), m is an integer greater than or equal to 1. The average value of m may be in the range of 3 to 5. Furthermore, the resin having the theoretical structure represented by general formula (1) may have a weight-average molecular weight (Mw) in the range of 1,000 to 5,000. 【0027】 Resin (2) is sometimes commonly referred to as a novolac-type resin. General formula (2) is a theoretical structure, and the resin may contain some components that do not correspond to general formula (2). Components that do not correspond to general formula (2) are, for example, components that have a branched structure in their molecule. 【0028】 Ar in general formula (2) ３This represents an aromatic ring structure which may have substituents. Specific examples of aromatic ring structures include benzene and naphthalene. Substituents on the aromatic ring include Ar １ Examples include those shown in [reference]. 【0029】 In general formula (2), n is an integer greater than or equal to 1. The average value of n may be in the range of 3 to 5. Furthermore, the resin having the theoretical structure represented by general formula (2) may have a weight-average molecular weight (Mw) in the range of 1,000 to 5,000. 【0030】 R in general formula (1) １ and R in general formula (2) ２ In the case where is a vinylbenzyloxy group, the vinylbenzyloxy group may be any of o-vinylbenzyloxy, m-vinylbenzyloxy, or p-vinylbenzyloxy groups. Among these, the p-vinylbenzyloxy group is preferred because it results in a compound with excellent dielectric properties in the cured product. The proportion of p-vinylbenzyloxy groups among the total vinylbenzyloxy groups present in the resin 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-vinylbenzyloxy groups among the total vinylbenzyloxy groups present in the resin may be in the range of 10 to 100 mol%. If the proportion of p-vinylbenzyloxy groups is less than 100 mol%, the remaining vinylbenzyloxy groups may be m-vinylbenzyl groups. 【0031】 Among the components that the curable resin material may contain, the compound (A) having a maleimide group is, for example, a bismaleimide compound having two maleimide groups, an amine-modified bismaleimide compound, and R in the above general formula (1). １ A resin in which R is a maleimide group, in the above general formula (2) ２ Examples include resins in which the maleimide group is located, and other maleimide resins. 【0032】Specific examples of bismaleimide compounds 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, and 3,3'-dimethyl-5,5'-die Tyl-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-dimethicone Rubenzyl]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 having an indane skeleton. 【0033】 Amine-modified bismaleimide compounds are obtained by reacting one or more bismaleimide compounds with one or more amine compounds. Examples of amine compounds include monoamine compounds having one amino group in one molecule, and polyamine compounds having two or more amino groups in one molecule. 【0034】Examples of monoamine compounds include aniline and compounds having one or more substituents on the aromatic ring of aniline. Examples of substituents include aliphatic hydrocarbon groups having 1 to 5 carbon atoms, halogen atoms, hydroxyl groups, carboxyl groups, sulfonic acid groups, etc. Specific examples of monoamine compounds include m-aminophenol, p-aminophenol, o-aminophenol, p-aminobenzoic acid, m-aminobenzoic acid, o-aminobenzoic acid, o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid, 3,5-dihydroxyaniline, and 3,5-dicarboxyaniline. The monoamine compound may be one or more selected from m-aminophenol, p-aminophenol, o-aminophenol, p-aminobenzoic acid, m-aminobenzoic acid, and 3,5-dihydroxyaniline. Alternatively, it may be one or more selected from m-aminophenol and p-aminophenol, or it may be p-aminophenol. 【0035】Examples of polyamine compounds include bisaniline, 4,4'-diamino-3,3'-dihydroxybiphenyl, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylthioether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylpropane, 2,2'-bis(4,4'-diaminodiphenyl)propane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylethane, 3,3'-diethyl-4,4'-diaminodiphenylethane, 3,3'-dihydroxy-4,4'-diaminodiphenylmethane, and 2,2',6,6'- Examples include tetramethyl-4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 3,3'-dibromo-4,4'-diaminodiphenylmethane, 2,2',6,6'-tetrachloro-4,4'-diaminodiphenylmethane, 2,2',6,6'-tetrabromo-4,4'-diaminodiphenylmethane, 1,3'-bis(4-aminophenoxy)benzene, 1,4'-bis(4-aminophenoxy)benzene, 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, diamine compounds such as amino group-containing silicone resins represented by the following general formula (3); and polyamine compounds represented by the following general formula (4). 【0036】 【0037】 [R in general formula (3)] ３ R represents an alkyl group or aryl group. Multiple R in the formula ３ They may all be different, or some or all of them may be the same. ４ R represents an aliphatic hydrocarbon group with 1 to 12 carbon atoms. The two R's in the formula ４ The elements may be different from each other or the same. p is an integer greater than or equal to 1. 【0038】 [R in general formula (4)] ５R represents an aliphatic hydrocarbon group with 1 to 4 carbon atoms. q is an integer of 1 or more. If q is 2 or more, multiple R in the formula ５ They may all be different, or some or all of them may be the same. 【0039】 R in general formula (3) ３ R represents an alkyl group or an aryl group. Examples of alkyl groups include alkyl groups having 1 to 4 carbon atoms, such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and t-butyl group. Examples of aryl groups include phenyl group, tolyl group, xylyl group, mesityl group, and naphthyl group. ３ This may be an alkyl group having 1 to 4 carbon atoms, or it may be a methyl group. 【0040】 R in general formula (3) ４ R represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms. The aliphatic hydrocarbon group may be linear or have a branched structure. ４ This may be an alkylene group having 1 to 12 carbon atoms, or an alkylene group having 1 to 6 carbon atoms. 【0041】 In general formula (3), p is an integer of 1 or more. The amino group equivalent of the amino group-containing silicone resin represented by general formula (3) is not particularly limited, but may be, for example, 300 g / mol or more, 400 g / mol or more, or 500 g / mol or more. It may also be 2,000 g / mol or less, 1,500 g / mol or less, or 1,000 g / mol or less. The amino group equivalent of the amino group-containing silicone resin may be in the range of 300 to 2,000 g / mol. 【0042】 R in general formula (4) ５ The symbol represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. The aliphatic hydrocarbon group may be linear or have a branched structure. The aliphatic hydrocarbon group having 1 to 4 carbon atoms may be, for example, a methylene group or an isopropylidene group, and may be a methylene group. 【0043】In general formula (4), q is an integer greater than or equal to 1. q may be 100 or greater, 200 or greater, or 250 or greater. It may also be 400 or less, or 350 or less. q may be in the range of 100 to 400. 【0044】 Bismaleimide compounds and amine compounds can be reacted, for example, by a Michael addition reaction. The reaction conditions are not particularly limited, but one example is a reaction carried out at a temperature range of 50 to 160°C for 0.5 to 10 hours. A reaction catalyst may be used if necessary. 【0045】 The reaction ratio between the bismaleimide compound and the amine compound is adjusted as appropriate according to the desired resin properties, etc. For example, the total amount of amino groups contained in the amine compound may be 0.05 moles or more, 1 mole or more, or 3 moles or more, per 1 mole of maleimide groups contained in the bismaleimide compound. Alternatively, it may be 10 moles or less, 8 moles or less, or 7 moles or less. The total number of moles of amino groups contained in the amine compound per 1 mole of maleimide groups contained in the bismaleimide compound may be in the range of 0.05 to 10 moles. 【0046】 The amine-modified bismaleimide compound may contain amino groups in addition to maleimide groups. The maleimide group equivalents and amino group equivalents of the amine-modified bismaleimide compound are not particularly limited and can be adjusted as appropriate according to the desired resin properties. 【0047】 The molecular weight of the amine-modified bismaleimide compound is appropriately adjusted according to the desired resin properties, etc. For example, the weight-average molecular weight (Mw) may be 400 or more, 1,000 or more, 1,500 or more, or 2,000 or more. It may also be 10,000 or less, 5,000 or less, 4,000 or less, or 3,000 or less. The weight-average molecular weight (Mw) of the amine-modified bismaleimide compound may be in the range of 400 to 10,000. 【0048】Other specific examples of maleimide resins include, for example, maleimide resins having an indane skeleton. Maleimide resins having an indane skeleton include, for example, those represented by the following general formula (3). 【0049】 [R in general formula (5)] ６ is a hydrogen atom or a methyl group, and r is an integer of 1 or more. 【0050】 Compound (B) having a vinylbenzyl group is, for example, a compound having an indene ring and a vinylbenzyl group in its molecular structure (hereinafter sometimes referred to as "compound (B1)"), in the above general formula (1) R １ A resin in which R is a vinylbenzyloxy group, in the above general formula (2) ２ Examples include resins in which the group is a vinylbenzyloxy group. 【0051】 Regarding the vinylbenzyl groups in compound (B1), the vinylbenzyl groups 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 (B1) 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 (B1) may be in the range of 10 to 100 mol%. If the proportion of p-vinylbenzyl groups is less than 100 mol%, the remaining vinylbenzyl groups may be m-vinylbenzyl groups. 【0052】 Compound (B1) is a resin containing, for example, two or more compounds with different structures from among the compounds represented by the following general formula (6) (hereinafter sometimes referred to as "compound (B1-1)"), a prepolymer obtained using compound (B1-1) (hereinafter sometimes referred to as "prepolymer (B1-2)"), and the compound represented by the following general formula (7), wherein R is present in the resin. １１ , R １２ and R１３ At least one of them is a vinylbenzyl group, and R present in the resin １１ , R １２ and R １３ Examples include resins in which at least one of the elements is an arylalkyl group other than a vinylbenzyl group (hereinafter sometimes referred to as "resin (B1-3)"). 【0053】 【0054】 [In general formula (6), R ７ , R ８ and R ９ R is a hydrogen atom or a vinylbenzyl group, ７ , R ８ and R ９ At least one of them is a vinylbenzyl group. １０ It is a monovalent organic group, and has four R １０ All of them may be different from each other, and there are four R １０ Two or more of them may be identical. 【0055】 【0056】 [In general formula (7), R １１ , R １２ and R １３ These are, independently, a hydrogen atom, a vinylbenzyl group, and an arylalkyl group other than a vinylbenzyl group. R present in the resin １１ , R １２ and R １３ At least one of them is a vinylbenzyl group, and R present in the resin １１ , R １２ and R １３ At least one of them is an arylalkyl group other than a vinylbenzyl group. １４ It is a monovalent organic group, and has four R １４ All of them may be different from each other, and there are four R １４ Two or more of them may be identical. 【0057】 Regarding compound (B1-1), R in general formula (6) ７ , R ８ and R ９ R is a hydrogen atom or a vinylbenzyl group,７ , R ８ and R ９ At least one of the groups is a vinylbenzyl group. Compound (B1-1) may be one of the compounds represented by general formula (6) used alone, or it may be a mixture of multiple compounds with different numbers of vinylbenzyl groups in one molecule. In compound (B1-1), the average number of vinylbenzyl groups in one molecule is preferably 1 or more, more preferably 1.6 or more, and particularly preferably 2 or more, as this results in excellent curability. It may also be 3 or less, 2.8 or less, or 2.5 or less. 【0058】 R in general formula (6) １０ R is a monovalent organic group. Examples of monovalent organic groups include hydrogen atoms; halogen atoms such as fluorine, chlorine, bromine, or iodine atoms; alkyl groups with 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; unsaturated bond-containing groups such as vinyl and allyl groups; aryl groups such as phenyl, tolyl, xylyl, mesityl, and naphthyl groups; aryloxy groups such as phenyloxy, tolyloxy, xyloxy, mesityloxy, and naphthyloxy groups; and aralkyl groups such as benzyl, phenethyl, phenylpropyl, tolylmethyl, and naphthylmethyl groups. １０ All of them may be hydrogen atoms. 【0059】 Compound (B1-1) is a compound identified by its molecular structure, and its preparation method is not particularly limited. One example of a method for producing compound (B1-1) is to react an indene compound with styrene having a methyl halide group in the presence of a basic compound. 【0060】Examples of styrenes having methyl halogenated groups include o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene. Styrenees having methyl halogenated groups may be used individually or in combination of two or more types. Examples of basic compounds include alkali metal hydroxides and alkali metal alkoxides. Basic compounds may be used individually or in combination of two or more types. 【0061】 The number of moles of styrene having a methyl halide group per mole of indene compound is preferably 1 mole or more, more preferably 1.6 moles or more, and particularly preferably 2 moles or more, as this results in excellent curability. It may also be 3 moles or less, 2.8 moles or less, or 2.5 moles or less. 【0062】 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 chloride, 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. 【0063】The reaction between indene compounds and styrene having methyl halogenated groups can be carried out by solution polymerization. Examples of solvents include toluene and xylene. The reaction may also be carried out under heating and stirring conditions. If necessary, polymerization inhibitors may be added to the reaction system. Examples of polymerization inhibitors include hydroquinone, methyl hydroquinone, tert-butylhydroquinone, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, hydronoquinone monomethyl ether, 1,4-benzoquinone, 2-tert-butyl-1,4-benzoquinone, 2-tert-butylphenol, 2,4-di-tert-butylphenol, 2,6-di-tert-butylphenol, cresol, catechol, 4-tert-butylcatechol, and pyrogallol. Examples include phenol or benzoquinone compounds such as 4-methoxyphenol; phenothiazine compounds such as phenothiazine, 3,7-dioctylphenothiazine, and 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. The amount of polymerization inhibitor added may be, for example, in the range of 0.05 to 5% by mass per 100 parts by mass of the total of the indene compound and the styrene having a methyl halogenated group. 【0064】 The obtained product may be purified by known methods such as concentration, reprecipitation, and washing, as needed. The obtained product may be a single compound or a mixture of two or more compounds. If it is a mixture of two or more compounds, R in the general formula (6) above is omitted. ７ , R ８ and R ９The mixture may contain a compound in which all atoms are hydrogen atoms, and the mixture may be used as is in the curable resin material. The average number of vinylbenzyl groups per molecule in the mixture is preferably 1 or more, more preferably 1.6 or more, and particularly preferably 2 or more, as this results in excellent curability. It may also be 3 or less, 2.8 or less, or 2.5 or less. 【0065】 In this disclosure, a prepolymer (B1-2) using compound (B1-1) is defined as a polymer in which some of the polymerizable reactive groups of the monomer, which is the raw material for the polymer, remain. Therefore, prepolymer (B1-2) has unreacted vinylbenzyl groups derived from compound (B1-1) and exhibits radical polymerizability. 【0066】 The prepolymer (B1-2) may also contain compound (B1-1) along with other monomers other than compound (B1-1). The proportion of compound (B1-1) in the total monomers constituting the prepolymer (B1-2) is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, and particularly preferably 90 to 100% by mass. 【0067】 The method for producing the prepolymer (B1-2) is not particularly limited and can be produced by polymerizing a monomer containing compound (B1-1) using a general method. One example of such a method is radical polymerization. 【0068】Polymerization initiators used in radical polymerization are not particularly limited, and examples include azo polymerization initiators and organic peroxide polymerization initiators. Examples of azo polymerization initiators include 2,2'-azobis(2,4,4-trimethylpentane), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 1,1'-azobis(cyclohexane-1-carbonitride), and dimethyl-1 Examples include 1'-azobis(1-cyclohexanecarboxylate), 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(2,4-dimethylvaleronitrile), 4,4'-azobis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl4-cyanopentanoate), etc. 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. 【0069】 A single radical polymerization initiator may be used alone, or two or more may be used in combination. The amount of radical polymerization initiator used can be adjusted as appropriate according to the desired degree of polymerization, but from the standpoint of facilitating reaction control, a range of 0.01 to 5 parts by mass per 100 parts by mass of the total amount of monomers used as reaction raw materials is preferred. 【0070】 The polymerization reaction of the prepolymer (B1-2) may be carried out in a solvent. Examples of solvents that can be used include toluene and xylene. These may be used individually or as a mixture of two or more solvents. The amount of solvent used is not particularly limited, but from the standpoint of facilitating reaction control, it is preferable to use 30 to 500 parts by mass per 100 parts by mass of the total amount of monomer reactants. 【0071】 The weight-average molecular weight (Mw) of the prepolymer (B1-2) is not particularly limited, but for example, from the viewpoint of ease of manufacture and ease of handling of the curable resin material, it may be 1,000 or more, 2,000 or more, or 3,000 or more. It may also be 15,000 or less, 10,000 or less, or 8,000 or less. The weight-average molecular weight (Mw) of the prepolymer (B1-2) may be in the range of 1,000 to 15,000. 【0072】 Regarding resin (B1-3), R in general formula (7) １１ , R １２ and R １３ These are, independently, a hydrogen atom, a vinylbenzyl group, and an arylalkyl group other than a vinylbenzyl group. 【0073】 Regarding arylalkyl groups other than vinylbenzyl groups (hereinafter sometimes referred to as "arylalkyl groups"), 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. 【0074】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. 【0075】 The arylalkyl group may not have polymerizable unsaturated bonds. The arylalkyl group may have a benzyl group, a naphthylmethyl group, and one to three alkyl groups having 1 to 3 carbon atoms on these aromatic rings. 【0076】 In resin (B1-3), R present in the resin １１ , R １２ and R １３ At least one of them is a vinylbenzyl group, and at least one is an arylalkyl group other than a vinylbenzyl group. The resin (B1-3) is R １１ , R １２ and R １３ A compound in which one of the atoms is a vinylbenzyl group, one is an arylalkyl group, and one is a hydrogen atom, R １１ , R １２ and R １３ A compound in which two of the groups are vinylbenzyl groups and one is an arylalkyl group, R １１ , R １２ and R １３ A compound in which one of the groups is a vinylbenzyl group and the other two are arylalkyl groups, R１１ , R １２ and R １３ where 1 to 3 of them are vinylbenzyl groups and the others are hydrogen atoms, R １１ , R １２ and R １３ where 1 to 3 of them are arylalkyl groups and the others are hydrogen atoms, R １１ , R １２ and R １３ may contain at least one of the compounds in which all of R 【0077】 In the resin (B1-3), since the total average of vinylbenzyl groups and arylalkyl groups in one molecule is excellent in curability, it is preferably 1.5 or more, more preferably 1.8 or more, and particularly preferably 2.0 or more. Also, it may be 3.0 or less, may be 2.8 or less, or may be 2.5 or less. The total average of vinylbenzyl groups and arylalkyl groups in one molecule may be in the range of 1.5 to 3.0. 【0078】 Also, the ratio of vinylbenzyl groups to the total number of vinylbenzyl groups and arylalkyl groups present in the resin (B-3) may be 30 mol% or more, may be 60 mol% or more, or may be 85 mol% or more. Also, it may be 99 mol% or less, may be 95 mol% or less, or may be 80 mol% or less. The ratio of vinylbenzyl groups to the total number of vinylbenzyl groups and arylalkyl groups may be in the range of 30 to 99 mol%. 【0079】 R in the general formula (7) １４is a monovalent organic group. Examples of the monovalent organic group include a hydrogen atom; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom; an alkyl group 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, or an isohexyl group; an alkoxy group represented by RO—, where R is the aforementioned alkyl group; an unsaturated bond-containing group such as a vinyl group or an allyl group; an aryl group such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, or a naphthyl group; an aryloxy group such as a phenyloxy group, a tolyloxy group, a xylyloxy group, a mesityloxy group, or a naphthyloxy group; an aralkyl group such as a benzyl group, a phenethyl group, a phenylpropyl group, a trimethylphenyl group, or a naphthylmethyl group, etc. R １４ may all be hydrogen atoms. 【0080】 Resin (B1-3) is a compound specified by its molecular structure, and its production method is not particularly limited. As an example of a method for producing resin (B1-3), it can be produced by reacting an indene compound, a styrene having a methyl halide group, and an aromatic compound having an alkyl halide group corresponding to an arylalkyl group in the presence of a basic compound. The reaction conditions of this reaction are the same as those described in the production method of compound (B1-1). 【0081】 The total number of moles of styrene having a methyl halide group and an aromatic compound having an alkyl halide group with respect to 1 mole of the indene compound may be 1.5 moles or more, may be 1.8 moles or more, or may be 2.0 moles or more. Also, it may be 3.0 moles or less, may be 2.8 moles or less, or may be 2.5 moles or less. The total number of moles of styrene having a methyl halide group and an aromatic compound having an alkyl halide group with respect to 1 mole of the indene compound may be in the range of 1.5 to 3.0 moles. 【0082】The ratio of styrene having a methyl halide group to the total number of moles of styrene having a methyl halide group and aromatic compounds having an alkyl halide group may be 30 mol% or more, 60 mol% or more, or 85 mol% or more. It may also be 99 mol% or less, 95 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 compounds having an alkyl halide group may be in the range of 30 to 99 mol%. 【0083】 The reaction product may be purified by known methods such as concentration, reprecipitation, and washing, if necessary. 【0084】 Compound (C) having an epoxy group is, for example, R in the general formula (1) above. １ A resin in which is a glycidyloxy group and in the above general formula (2), R ２ In addition to resins in which the glycidyloxy group is present, other examples include bisphenol-type epoxy resins such as bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and bisphenol S-type epoxy resin, biphenyl-type epoxy resin, naphthylene ether-type epoxy resin, dihydroanthracene-type epoxy resin, epoxy resin containing a saturated dicyclopentadiene skeleton, cyclohexanedimethanol-type epoxy resin, spiro-ring-containing epoxy resin, heterocyclic epoxy resin, alicyclic epoxy resin, aliphatic chain-type epoxy resin, and rubber-modified epoxy resin. 【0085】 The curable resin material may contain other resin components in addition to the compound (A) having a maleimide group, the compound (B) having a vinylbenzyl group, and the compound (C) having an epoxy group. Examples of other resin components include curable compounds other than compounds (A) to (C) (hereinafter sometimes referred to as "compound (D)"), elastomers (E), etc. Each of these may be used individually or in combination of two or more. 【0086】Specific examples of compound (D) include, for example, polyarylene ether compounds having polymerizable groups, aromatic compounds having vinyl groups, triallyl isocyanurate, phenol resins, cyanate resins, benzoxazine resins, oxetane resins, amino resins, silicone resins, triazine resins, melamine resins, and the like. 【0087】 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. Examples of polymerizable groups include vinyl groups, vinyloxy groups, allyl groups, allyloxy groups, (meth)acryloyl groups, (meth)acryloyloxy groups, vinylbenzyl groups, vinylbenzyloxy groups, etc. Polyarylene ether compounds having polymerizable groups may have structural parts other than the polyarylene ether structure. Specifically, they may have acrylic polymerization sites, (poly)urethane sites, (poly)ester sites, etc., in the molecular chain. The number of polymerizable groups in one molecule of a polyarylene ether compound is not particularly limited, nor is the substitution position of the polymerizable groups particularly limited. For example, a polyarylene ether compound may have polymerizable groups at the molecular end, or it may have polymerizable groups at both ends. 【0088】 Specific examples of polyarylene ether compounds having polymerizable groups include, for example, the compound represented by the following general formula (6). 【0089】 【0090】 [In general formula (8), R １５ and R １６ Each of these is independently either a hydrogen atom or a methyl group. s and t are integers greater than or equal to 1. X is a divalent organic group. 【0091】 In general formula (6), 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. 【0092】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. 【0093】 Aromatic compounds having a vinyl group include, for example, styrene, divinylbenzene, 1,2-bis(4-vinylphenyl)ethane, and compounds represented by the following general formula (9). 【0094】 【0095】 [In general formula (9), u is an integer greater than or equal to 1.] 【0096】 Examples of elastomers (E) include polyether-based elastomers, styrene-based elastomers, conjugated diene-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers. 【0097】 In one embodiment, there are no limitations on the composition of the curable resin material as long as the Tanδ value measured in the cured prepreg at 260°C is 0.08 or higher; however, several design concepts are exemplified below. 【0098】 In terms of providing an excellent balance between the dimensional stability and heat resistance of the prepreg, the curable resin material may contain a compound (A) having a maleimide group. The amount of compound (A) having a maleimide group in the curable resin material is not particularly limited, but the proportion to the total resin components of the curable resin material may be 10% by mass or more, 15% by mass or more, or 20% by mass or more. It may also be 70% by mass or less, 65% by mass or less, or 60% by mass or less. The proportion of compound (A) having a maleimide group to the total resin components of the curable resin material may be in the range of 10 to 70% by mass. The resin components of the curable resin material refer to components other than fillers, various additives, and organic solvents contained in the curable resin material, and specifically refer to compound (A) having a maleimide group, compound (B) having a vinylbenzyl group, compound (C) having an epoxy group, compound (D), and elastomer (E). 【0099】The content of compound (B) having a vinylbenzyl group in the curable resin material is not particularly limited, but the proportion of compound (B) to the total resin components of the curable resin material may be 15% by mass or more, 25% by mass or more, or 35% by mass or more. It may also be 70% by mass or less, 60% by mass or less, or 55% by mass or less. The proportion of compound (B) having a vinylbenzyl group to the total resin components of the curable resin material may be in the range of 15 to 70% by mass. 【0100】 The amount of compound (C) having an epoxy group in the curable resin material is not particularly limited, but the proportion of the epoxy group to the total resin components of the curable resin material may be 15% by mass or more, 25% by mass or more, or 35% by mass or more. It may also be 70% by mass or less, 65% by mass or less, or 60% by mass or less. The proportion of compound (C) having an epoxy group to the total resin components of the curable resin material may be in the range of 15 to 70% by mass. 【0101】 The total mass ratio of the maleimide group compound (A), the vinylbenzyl group compound (B), and the epoxy group compound (C) to the total curable components of the curable resin material is not particularly limited, but may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass. Specifically, the curable components of the curable resin material refer to the maleimide group compound (A), the vinylbenzyl group compound (B), the epoxy group compound (C), and compound (D). 【0102】 The amount of elastomer (E) in a curable resin material is not particularly limited, but its proportion to the total resin components of the curable resin material may be 10% by mass or more, 15% by mass or more, or 20% by mass or more. It may also be 50% by mass or less, 40% by mass or less, or 35% by mass or less. The proportion of elastomer (E) to the total resin components of the curable resin material may be in the range of 10 to 50% by mass. 【0103】According to one embodiment, the curable resin material includes at least one selected from the group consisting of resin (1) and resin (2). Resin (1) and resin (2) may be any of a compound having a maleimide group (A), a compound having a vinylbenzyl group (B), and a compound having an epoxy group (C). 【0104】 As an example of the design, if compound (B) having a vinylbenzyl group contains at least one selected from the group consisting of resin (1) and resin (2), the curable resin material may contain a bifunctional maleimide compound in addition to the compound (B) having a vinylbenzyl group, which contains at least one selected from the group consisting of resin (1) and resin (2). Examples of bifunctional maleimide compounds include the bismaleimide compound described above and the maleimide resin represented by the general formula (3) described above. In this case, the ratio of the total mass of resin (1) and resin (2) to the total mass of compound (B) having a vinylbenzyl group may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass. Furthermore, the ratio of the bifunctional maleimide compound to the total mass of compound (A) having a maleimide group may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass. Furthermore, if the compound (B) having a vinylbenzyl group includes at least one selected from the group consisting of resin (1) and resin (2), it may also include an elastomer. 【0105】As another example of the design, if compound (C) having an epoxy group contains at least one selected from the group consisting of resin (1) and resin (2), the curable resin material may contain compound (A) having a maleimide group in addition to compound (C) having an epoxy group, which contains at least one selected from the group consisting of resin (1) and resin (2). In this case, compound (A) having a maleimide group may include an amine modified bismaleimide compound. The ratio of the total mass of resin (1) and resin (2) to the total mass of compound (C) having an epoxy group may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass. Also, the ratio of amine modified bismaleimide compounds to the total mass of compound (A) having a maleimide group may be 70% by mass or more, 80% by mass or more, 90% by mass or more, or 100% by mass. 【0106】 The curable resin material may contain fillers, various additives, and organic solutions in addition to the resin components mentioned above. Examples of additives include curing accelerators, flame retardants, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, and colorants. Each of these may be used individually or in combination of two or more. 【0107】 Both organic and inorganic fillers can be used as fillers, but inorganic fillers are preferred. Examples of inorganic fillers include silica (SiO₂). ２ ), alumina (Al ２ O ３Examples 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. Among these, silica is preferred from the viewpoint of dielectric properties. The type of silica is not particularly limited and may be crystalline silica or amorphous silica, and may be natural silica or synthetic silica. The method of producing synthetic silica is also not particularly limited and may be any of the following: wet silica such as colloidal silica, fumed silica (dry silica), fused silica, etc. The shape of silica is also not particularly limited and may be any of the following: spherical silica, crushed silica, etc. Among these, spherical silica is preferred in that it becomes a curable resin material with excellent fluidity. 【0108】 The shape and size of the filler 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. 【0109】 If the curable resin material contains a filler, the amount of filler added may be in the range of 50 to 500 parts by mass per 100 parts by mass of the total resin components of the curable resin material. 【0110】As curing accelerators, for example, anionic polymerization initiators, radical polymerization initiators, etc., can be used. Examples of anionic polymerization initiators include acidic catalysts such as p-toluenesulfonic acid; amine compounds such as triethylamine, tributylamine, pyridine, and dicyandiamide; imidazole compounds such as methylimidazole, phenylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate; isocyanate-mask imidazole compounds such as the addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole; quaternary ammonium compounds; phosphorus compounds such as triphenylphosphine; organic peroxides such as dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyn-3, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, and α,α'-bis(t-butylperoxy)diisopropylbenzene; and carboxylates of manganese, cobalt, zinc, etc. 【0111】The radical polymerization initiator may be a thermal radical polymerization initiator or a photoradical polymerization initiator, but a thermal radical polymerization initiator is preferred. Specific examples of polymerization initiators include azo polymerization initiators and organic peroxide polymerization initiators. Examples of azo polymerization initiators include 2,2'-azobis(2,4,4-trimethylpentane), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 1,1'-azobis(cyclohexane-1-carbonitride), and dimethyl-1,1'-azobis(1-cyclohexanecarboxylate). Examples 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(2,4-dimethylvaleronitrile), and 4,4'-azobis(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl4-cyanopentanoate). Examples of organic peroxide polymerization initiators include dicumyl peroxide, dibenzoyl peroxide, 2-butanone peroxide, t-butyl perbenzoate, di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyn-3, α,α'-di(t-butylperoxy)diisopropylbenzene, and t-butyl hydroperoxide. 【0112】 The content of the curing accelerator in the curable resin material is not particularly limited, but may be in the range of 0.05 to 5 parts by mass per 100 parts by mass of the total resin components of the curable resin material. 【0113】 Examples of flame retardants include phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, and inorganic flame retardants. The amount of flame retardant added is adjusted as appropriate depending on the type of flame retardant, the intended use of the curable composition, and the desired physical properties. 【0114】Examples of antioxidants include benzophenone-based antioxidants, benzoate-based antioxidants, hindered amine-based antioxidants, benzotriazole-based antioxidants, and phenol-based antioxidants. The content of antioxidants in the curable resin material is not particularly limited, but may be in the range of 0.05 to 5 parts by mass per 100 parts by mass of the total resin components of the curable resin material. 【0115】 The curable resin material may be solvent-free or may contain an organic solvent. The organic solvent is used to adjust the viscosity of the curable resin material and further improve its coating properties. 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 atom-containing solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfur atom-containing solvents such as dimethyl sulfoxide; and ester-based solvents such as γ-butyrolactone. When the curable resin material contains a solvent, the solid content of the curable resin material may be in the range of, for example, 30 to 95% by mass. 【0116】 The method for manufacturing curable resin materials is not particularly limited. One example of a method for manufacturing curable resin materials is a method of mixing each component of the curable resin material all at once or in separate steps. The mixing order of each component, temperature, time, mixing method, and other conditions are not particularly limited and can be appropriately adjusted according to the type of raw materials, production scale, production equipment, etc. 【0117】The glass fiber base material included in the prepreg can be of any type, and a wide range of materials commonly used in metal-clad laminate applications can be used. Examples of glass fiber types include E-glass, D-glass, T-glass, S-glass, etc. The glass fiber base material may also be glass cloth. The weave density of the glass cloth is not particularly limited, but for example, the warp threads may be in the range of 55 to 75 threads / 25 mm, and the weft threads may be in the range of 50 to 72 threads / 25 mm. The thickness of the task loss is not particularly limited, but for example, it may be in the range of 50 to 150 μm. 【0118】 In one embodiment of a prepreg for a metal-clad laminate, the curable resin material may be in an uncured or semi-cured state. Regarding the semi-cured product of the curable resin material, in this disclosure, the B-stage state in JIS K 6800 (1985) can be cited as one indicator of the semi-cured state. 【0119】 The method for manufacturing a prepreg is not particularly limited, but for example, it can be manufactured by impregnating a glass fiber substrate with a curable resin material and drying the fiber substrate impregnated with the curable resin material. Drying is preferably carried out at a temperature above which volatile components such as organic solvents that may be contained in the curable resin material are removed, and may be carried out at a temperature above which the curable components contained in the curable resin material are partially cured, if necessary. Furthermore, drying should be adjusted so that the thermosetting resin contained in the curable resin material 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. 【0120】 [Metal-clad laminate] According to one embodiment, a metal-clad laminate including a prepreg for metal-clad laminates can be provided. The prepreg included in the metal-clad laminate may be in a cured state. With respect to the cured state, in this disclosure, the state of the C-stage in JIS K 6800 (1985) can be cited as one indicator of the cured state. 【0121】A metal-clad laminate may include a prepreg layer and a metal foil disposed on at least one side of the prepreg layer. The prepreg layer may consist of a single prepreg or multiple prepregs laminated together. Furthermore, the metal-clad laminate may have the metal foil disposed on one side of the prepreg layer, or on both sides of the prepreg layer. The metal-clad laminate may also consist of multiple prepregs laminated together with metal foil disposed on both sides of the prepreg layer. 【0122】 The following describes a specific method for manufacturing metal-clad laminates, which involves placing metal foil on a prepreg layer formed by stacking multiple prepregs. 【0123】 First, multiple prepregs are laminated. The multiple prepregs may all be different from each other, or some or all of them may be identical. At least one of the multiple prepregs must be a prepreg according to one embodiment. 【0124】 Next, a metal foil is placed on at least one surface of a prepreg layer formed by laminating multiple prepregs. By heating and pressurizing the laminate on which the metal foil is placed, the curing reaction of the curable resin material contained in the prepreg proceeds, and a cured prepreg product can be obtained. At the same time, adjacent prepregs can be fixed together. The heating and pressurizing conditions are not particularly limited, but for example, the temperature can be 100 to 300°C, the time can be 10 to 300 minutes, and the pressure can be 0.5 to 50 MPa. In addition, reheating may be performed after heating and pressurizing to further advance the curing of 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. 【0125】 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. 【0126】 [Printed Wiring Board] According to one embodiment, a printed wiring board using a metal-clad laminate can be provided. The wiring pattern on the printed wiring board can be formed by known methods. The printed wiring board may be either a single-layer printed wiring board or a multi-layer printed wiring board. 【0127】 [Semiconductor Package] According to one embodiment, a semiconductor package using a metal-clad laminate can be provided. The semiconductor package may include, for example, a printed circuit board using a metal-clad laminate and a semiconductor element. The semiconductor package can be manufactured, for example, by mounting a semiconductor element, memory, etc., on a printed circuit board using a metal-clad laminate by a known method. 【0128】 Examples of embodiments of the present disclosure are given below. The present invention is not limited to the following embodiments. <1> A prepreg for metal-clad laminate comprising a curable resin material and a glass fiber substrate, wherein the value of Tanδ measured in the cured product at 260°C is 0.08 or more. 【0129】 <2> The metal-clad laminate prepreg according to <1>, wherein the value of Tanδ measured in the cured product at 260°C is in the range of 0.08 to 0.2. 【0130】 <3> A prepreg for metal-clad laminates, wherein the curable resin material comprises at least one selected from the group consisting of (A) to (C) below, in addition to <1> or <2>: A compound having a maleimide group (A) A compound having a vinylbenzyl group (B) A compound having an epoxy group (C) 【0131】 <4> The prepreg for metal-clad laminate according to any one of <1> to <3> above, wherein the curable resin material includes at least one selected from the group consisting of a resin having a theoretical structure represented by the following general formula (1) and a resin having a theoretical structure represented by the following general formula (2). 【0132】 【0133】 [Ar in general formula (1)] １Ar represents an aromatic ring structure which may have substituents. ２ The symbol represents a structural region containing 1 to 3 aromatic rings. m is an integer greater than or equal to 1. Multiple Ars in the formula １ They may all be different, or some or all of them may be the same. If m is 2 or more, multiple Ar in the formula ２ They may all be different, or some or all of them may be the same. １ This is a maleimide group, a vinylbenzyloxy group, or a glycidyloxy group. 【0134】 【0135】 [Ar in general formula (2)] ３ represents an aromatic ring structure which may have substituents. n is an integer of 1 or more. Multiple Ar in the formula ３ They may all be different, or some or all of them may be the same. ２ This is a maleimide group, a vinylbenzyloxy group, or a glycidyloxy group. 【0136】 <5> A metal-clad laminate comprising a prepreg for metal-clad laminates described in any one of <1> to <4> above. 【0137】 <6> A printed circuit board using the metal-clad laminate described in <5> above. 【0138】 <7> A semiconductor package using the metal-clad laminate described in <5> above. 【0139】 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. 【0140】 Measurement Method for Weight-Average Molecular Weight (Mw) and Number-Average Molecular Weight (Mn) The weight-average molecular weight and number-average molecular weight were 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. 【0141】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 【0142】 [Production of Compound (A-1) Having a Maleimide Group] In a 500 mL reaction vessel equipped with a stirrer, thermometer, reflux tubing, and nitrogen inlet, 76.3 parts by mass of 4,4'-diphenylmethanebismaleimide, 12.2 parts by mass of amino group-containing silicone resin (amino group equivalent 800 g / mol), 8.2 parts by mass of polyamine compound (amino group equivalent 150 g / mol), 2.9 parts by mass of p-aminophenol, and propylene glycol monomethyl ether and cyclohexanone as solvents were charged. The mixture was heated and stirred at reflux temperature while blowing in nitrogen to obtain Compound (A-1), which is an amine-modified product of the bismaleimide compound and has a maleimide group. 【0143】[Production of resin (B-1) containing vinylbenzyl groups] A flask equipped with a stirrer, thermometer, cooling condenser, dropping funnel, and nitrogen inlet was purged with nitrogen, and 46.5 parts by mass of indene, 200 parts by mass of toluene, 7.75 parts by mass of tetra-n-butylammonium bromide, 0.08 parts by mass of phenothiazine, and 128.0 parts by mass of a 50% by mass sodium hydroxide aqueous solution were charged. The mixture was heated to 50°C while stirring to make a homogeneous solution. 134.1 parts by mass of vinylbenzyl chloride (CMS-AM, manufactured by Seimi Chemical Co., Ltd., a mixture with an m / p isomer ratio of 50 / 50% by weight, purity 91% by mass) was added dropwise over 15 minutes, and the mixture was then reacted at 50-52°C for 10 hours. The contents of the flask were neutralized with 2N hydrochloric acid and then washed twice with distilled water. After removing toluene under reduced pressure, the resulting orange viscous liquid was washed with methanol and vacuum-dried to obtain a liquid vinylbenzyl group-containing resin (B-1). 【0144】 [Examples 1-4 and Comparative Example 1] Each component was blended in the proportions shown in Table 1, and the solid content was adjusted to approximately 65% ​​by mass with toluene to produce a curable resin material. For the components that are solutions in Table 1, the amounts are calculated on a solid content basis. Details of each component listed in Table 1 are as follows: Compound (A-1): Compound (A-1) having a maleimide group, which is an amine modified product of the bismaleimide compound obtained above. Resin (A-2): Maleimide resin having the structure represented by the above general formula (3). Resin (B-1): Having the theoretical structure represented by the general formula (1) obtained above, with R in general formula (1) １ Resin (B-1) having a vinylbenzyl group, where is a maleimide group. Resin (C-1): has a theoretical structure represented by general formula (2), and R in general formula (2) ２ The group is a glycidyloxy group, and Ar ３ A part of it is a benzene ring, Ar ３ Epoxy resin in which the other part is a naphthalene ring, manufactured by Nippon Kayaku Co., Ltd. "NC-7000L" Elastomer (E-1): Styrene-ethylene-butylene-styrene copolymer (SEBS), styrene ratio 30%, manufactured by Asahi Kasei Corporation "ToughTec H1041" Filler (1): Molten spherical silica, average particle size (D ５０) 0.5 μm Filler (2): Spherical zinc molybdate Antioxidant: 4,4'-Butylidenebis-(6-t-butyl-3-methylphenol), manufactured by Mitsubishi Chemical Corporation "Yoshinox BB" Curing accelerator: Isocyanate maskimidazole, manufactured by Daiichi Kogyo Seiyaku Co., Ltd. "G-8009L" 【0145】 [Manufacturing of Cured Prepreg] The cured prepreg was manufactured using the following procedure: 1. A curable resin material was impregnated and coated onto glass cloth, and heated and dried at 120°C for 10 minutes to obtain a prepreg with a curable resin material content of 50% by mass. 2. Eight sheets of prepreg were stacked to adjust the thickness to 0.8 mm, and electrolytic copper foil was placed on both sides with the matte side facing the prepreg. This was heated and pressurized at 240°C for 85 minutes under a vacuum press condition of 3.0 MPa to obtain a double-sided copper-clad laminate. 3. The double-sided copper-clad laminate was immersed in a 10% by mass aqueous solution of ammonium persulfate to remove the copper foil from both sides. 4. After drying in a constant temperature oven at 105°C for 1 hour, it was left to stand for 24 hours in an ambient temperature of 24.2°C and humidity of 54% RH to obtain a cured prepreg. 【0146】 [Measurement of Tanδ and Glass Transition Temperature (Tg)] Dynamic viscoelasticity measurements were performed on the cured prepreg obtained above under the following conditions to obtain the Tanδ value at 260°C and the glass transition temperature (Tg) value. Apparatus: UBM "Reogel-E4000" Heating rate: 10°C / min Frequency: 10.0 Hz Specimen dimensions: 5.0 mm × 20.0 mm 【0147】 [Evaluation of dimensional stability] A 5.0 mm x 5.0 mm test specimen was cut from the cured prepreg obtained earlier. This was kept in a constant temperature oven at 260°C for 1 hour. The size of the test specimen after heat treatment was measured, and the dimensional change rate along the long axis of the test specimen was calculated as [(Length of the long side before heat treatment (XX mm)) - (Length of the long side after heat treatment)] / (Length of the long side before heat treatment) × 100 [%]. 【0148】 【0149】As shown in Table 1, Examples 1 to 4, in which the Tanδ value measured at 260°C in the cured prepreg was 0.08 or higher, showed little dimensional change and excellent dimensional stability even when exposed to high-temperature conditions for a long period of time. On the other hand, Comparative Example 1, in which the Tanδ value measured at 260°C in the cured prepreg was less than 0.08, showed large dimensional changes when exposed to high-temperature conditions for a long period of time.

Claims

1. A prepreg for metal-clad laminates comprising a curable resin material and a glass fiber substrate, wherein the value of Tanδ measured in the cured product at 260°C is 0.08 or higher.

2. The prepreg for metal-clad laminates according to claim 1, wherein the value of Tanδ measured in the cured product at 260°C is in the range of 0.08 to 0.

2.

3. The metal-clad laminate prepreg according to claim 1, wherein the curable resin material comprises at least one selected from the group consisting of (A) to (C) below: A compound having a maleimide group (A) A compound having a vinylbenzyl group (B) A compound having an epoxy group (C) 4. The prepreg for metal-clad laminate according to claim 1, wherein the curable resin material includes at least one selected from the group consisting of a resin having a theoretical structure represented by the following general formula (1) and a resin having a theoretical structure represented by the following general formula (2). [Ar in general formula (1)] １ Ar represents an aromatic ring structure which may have substituents. ２ The symbol represents a structural region containing 1 to 3 aromatic rings. m is an integer greater than or equal to 1. Multiple Ars in the formula １ They may all be different, or some or all of them may be the same. If m is 2 or more, multiple Ar in the formula ２ They may all be different, or some or all of them may be the same. １ This is a maleimide group, a vinylbenzyloxy group, or a glycidyloxy group. [Ar in general formula (2)] ３ represents an aromatic ring structure which may have substituents. n is an integer of 1 or more. Multiple Ar in the formula ３ They may all be different, or some or all of them may be the same. ２ This is a maleimide group, a vinylbenzyloxy group, or a glycidyloxy group.

5. A metal-clad laminate comprising a prepreg for metal-clad laminates according to any one of claims 1 to 4.

6. A printed circuit board using the metal-clad laminate described in claim 5.

7. A semiconductor package using the metal-clad laminate described in claim 5.

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