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

Abstract

Provided is a resin composition with which it is possible to form a cured product that has excellent high-frequency characteristics and in which the size of surface pitting after desmearing is kept small. Also provided are a resin film, a prepreg, a laminate, a printed wiring board, and a semiconductor package, all of which use the resin composition. The resin composition contains a maleic anhydride-modified styrene elastomer (A) having a modification rate of 1.0 mass% or more and a thermosetting resin (B).

Description

Resin compositions, resin films, prepregs, laminates, printed wiring boards, and semiconductor packages

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

[0002] Mobile communication devices such as mobile phones, their base station equipment, servers, routers, and other network infrastructure devices, and large-scale computers are increasingly using faster and larger-capacity signals. Accordingly, printed wiring boards used in these electronic devices must be compatible with higher frequencies, and substrate materials with excellent dielectric properties (low dielectric constant and low dielectric loss tangent; hereinafter, sometimes referred to as "high-frequency properties") in high-frequency bands (e.g., 10 GHz or higher) that enable reduced transmission loss are in demand. In recent years, in addition to the electronic devices mentioned above, new systems using high-frequency wireless signals have been planned and put into practical use in the fields of ITS (automotive and transportation systems) and indoor short-range communications. Therefore, it is expected that low-transmission-loss substrate materials will also be required for printed wiring boards used in these devices in the future.

[0003] Under these circumstances, a resin composition containing a specific polyphenylene ether derivative, a specific thermosetting resin, and a styrene-based thermoplastic elastomer has been proposed, with the objective of providing a resin composition that has particularly good compatibility and also has high-frequency characteristics, high adhesion to conductors, excellent heat resistance, a high glass transition temperature, a low thermal expansion coefficient, and high flame retardancy (see Patent Document 1).

[0004] International Publication No. 2016 / 175326

[0005]

[0003] In the manufacturing process of printed wiring boards, a desmear treatment is performed on an insulating layer with an aqueous oxidizing solution to remove residual components after drilling holes in the insulating layer or to roughen the surface to improve adhesion between the insulating layer and the conductor layer. The inventors' investigations have revealed that copper-clad laminates using a resin composition containing a styrene-based elastomer may develop pits with a diameter exceeding 1.0 μm on the surface of the insulating layer after the desmear treatment. The inventors believe that these pits may result in a decrease in copper foil peel strength.

[0006] In view of the current situation, an object of the present invention is to provide a resin composition that is excellent in high-frequency characteristics and capable of forming a cured product in which the size of depressions on the surface after desmearing is suppressed to be small, and to provide a resin film, a prepreg, a laminate, a printed wiring board, and a semiconductor package using the resin composition.

[0007] As a result of extensive research, the present inventors have found that the resin composition of the present disclosure can achieve the above-mentioned object. The present disclosure includes the following embodiments [1] to

[11] . [1] A resin composition containing a maleic anhydride-modified styrene-based elastomer (A) having a modification rate of 1.0 mass% or more and a thermosetting resin (B). [2] The resin composition according to [1] above, wherein the thermosetting resin (B) contains one or more resins selected from the group consisting of epoxy resins, maleimide compounds, phenolic resins, polyimide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, and silicone resins. [3] The resin composition according to [1] or [2] above, wherein the content of the component (A) is 1 to 50 parts by mass per 100 parts by mass of the solid content of the resin composition. [4] The resin composition according to any one of [1] to [3] above, further containing an inorganic filler (C). [5] The resin composition according to any one of [1] to [4] above, further comprising a polyphenylene ether derivative (D) having an ethylenically unsaturated bond-containing group. [6] The resin composition according to any one of [1] to [5] above, further comprising a curing accelerator (E). [7] A resin film containing the resin composition according to any one of [1] to [6] above or a semi-cured product of the resin composition. [8] A prepreg containing the resin composition according to any one of [1] to [6] above or a semi-cured product of the resin composition. [9] A laminate having a cured product of the resin composition according to any one of [1] to [6] above or a cured product of the prepreg according to [8] above, and a metal foil.

[10] A printed wiring board having a cured product of the resin composition according to any one of [1] to [6] above.

[11] A semiconductor package having the printed wiring board according to

[10] above and a semiconductor element.

[0008] According to the present invention, it is possible to provide a resin composition capable of forming a cured product which has excellent high-frequency characteristics and in which the size of depressions on the resin layer surface after desmearing is suppressed to be small, and to provide a resin film, a prepreg, a laminate, a printed wiring board, and a semiconductor package using the resin composition.

[0009] In the numerical ranges described in this disclosure, the upper or lower limit of the numerical range may be replaced with the values ​​shown in the examples. Furthermore, the lower and upper limits of a numerical range can be arbitrarily combined with the lower or upper limit of another numerical range. In the expression "AA to BB," the numerical values ​​AA and BB at both ends are included as the lower and upper limits, respectively, of the numerical range. In this disclosure, for example, the expression "10 or more" means 10 and a numerical value greater than 10, and this also applies when the numerical values ​​differ. Furthermore, for example, the expression "10 or less" means a numerical value less than 10 and a numerical value less than 10, and this also applies when the numerical values ​​differ. Furthermore, unless otherwise specified, each component and material exemplified in this disclosure may be used alone or in combination of two or more types. In this disclosure, when multiple substances corresponding to each component are present in the resin composition, the content of each component in the resin composition refers to the total amount of the multiple substances present in the resin composition, unless otherwise specified.

[0010] In the present disclosure, the term "resin component" refers to all components of the solid content constituting the resin composition, excluding inorganic compounds such as inorganic fillers, which will be described later. In the present disclosure, the term "solid content" refers to components other than the solvent, and components that are liquid at 25°C are also considered to be solid content. The expression "containing XX" described in the present disclosure may mean that XX is contained in a reacted state if XX is reactive, or may simply mean that XX is contained as is, or may include both of these aspects. Any combination of the items described in the present disclosure is also included in the present disclosure and the present embodiment.

[0011] [Resin Composition] The resin composition of this embodiment is a resin composition containing a maleic anhydride-modified styrene-based elastomer (A) [hereinafter, also referred to as component (A)] having a modification rate of 1.0 mass% or more, and a thermosetting resin (B) [hereinafter, also referred to as component (B)]. Each component contained in the resin composition of this embodiment will be described below.

[0012] <Maleic anhydride-modified styrene-based elastomer (A) with a modification rate of 1.0% by mass or more> The resin composition of this embodiment contains a maleic anhydride-modified styrene-based elastomer with a modification rate of 1.0% by mass or more as component (A), which is presumably responsible for improved compatibility with the thermosetting resin (B) compared to when the resin composition contains a maleic anhydride-modified styrene-based elastomer with a modification rate of less than 1.0% by mass. As a result, it is presumed that the depressions on the surface of the resin layer after desmearing are smaller (specifically, have a diameter of 1.0 μm or less). However, even if this presumption is incorrect, it does not adversely affect the scope of the present disclosure. Here, the size and diameter of the depression refer to the length of the longest straight line that can be drawn within the depression area in a planar view of the resin plate.

[0013] Component (A) is preferably a thermoplastic elastomer, that is, component (A) is preferably a maleic anhydride-modified styrene-based thermoplastic elastomer having a modification rate of 1.0% by mass or more.

[0014] Component (A) can be prepared by reacting a predetermined amount of maleic anhydride with a styrene-based elastomer. Component (A) has an acid anhydride group based on maleic anhydride in its side chain. The styrene-based elastomer may be a copolymer having structural units derived from a styrene-based compound and structural units derived from a conjugated diene compound. In the styrene-based elastomer, the content of structural units derived from a styrene-based compound (hereinafter sometimes referred to as the "styrene content") is not particularly limited, but is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 20 to 40% by mass. The styrene content of component (A) itself is also not particularly limited, but is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and even more preferably 20 to 40% by mass. Here, the styrene content is １ This value was determined by quantifying the styrene group by H NMR measurement.

[0015] Examples of the styrene-based compound include styrene, α-methylstyrene, p-methylstyrene, p-tert-butylstyrene, etc. Among these, from the viewpoints of availability and productivity, styrene, α-methylstyrene, and 4-methylstyrene are preferred, and styrene is more preferred.

[0016] Examples of the conjugated diene compound include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 1,3-pentadiene (piperylene), 1-phenyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3,4-dimethyl-1,3-hexadiene, 4,5-diethyl-1,3-octadiene, etc. Among these, from the viewpoints of availability and productivity, 1,3-butadiene and isoprene are preferred, and 1,3-butadiene is more preferred.

[0017] The styrene-based elastomer may be a hydrogenated styrene-based elastomer in which at least a portion of the structural units derived from a conjugated diene compound are hydrogenated. Examples of hydrogenated styrene-butadiene-styrene block copolymers include hydrogenated styrene-isoprene-styrene block copolymers (SEPS). The styrene-based elastomer may be produced by a known method, or a commercially available product may be used. Examples of commercially available styrene-based elastomers include the Tuftec (registered trademark) H series and M series manufactured by Asahi Kasei Corporation, the Septon (registered trademark) series manufactured by Kuraray Co., Ltd., and the Kraton (registered trademark) G Polymer series manufactured by Kraton Polymer Japan Co., Ltd.

[0018] The weight average molecular weight (Mw) of the styrene-based elastomer is preferably 20,000 to 120,000, more preferably 30,000 to 110,000, even more preferably 40,000 to 100,000, and particularly preferably 50,000 to 80,000. In the present disclosure, the weight average molecular weight is a value calculated by gel permeation chromatography (GPC) from a calibration curve using standard polystyrene, and more specifically, a value determined by the measurement method described in the examples.

[0019] The styrene elastomer may be a hydrogenated styrene elastomer or a non-hydrogenated styrene elastomer. In the case of a hydrogenated styrene elastomer, the hydrogenation rate is preferably 80% or more, more preferably 90% or more, from the viewpoint of maleic anhydride modification. Here, the hydrogenation rate is determined by the content of carbon-carbon double bonds derived from conjugated diene monomers in the styrene elastomer before and after hydrogenation. １ The values ​​were determined by H NMR.

[0020] More specifically, examples of the method for producing component (A) include a method in which a radical generator is added to a mixed solution obtained by dissolving a styrene-based elastomer and maleic anhydride in a solvent under a nitrogen atmosphere, and maleic anhydride is reacted with the styrene-based elastomer. The reaction temperature may be 20 to 150°C. After the reaction, it is preferable to remove unreacted maleic anhydride by extraction, from the viewpoint of suppressing side reactions.

[0021] The radical generator may be an organic peroxide, an azo compound, or the like. Examples of organic peroxides include dicumyl peroxide, benzoyl peroxide (benzoyl 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. Examples of azo compounds include 2,2'-azobis(2-methylpropanenitrile), 2,2'-azobis(2-methylbutanenitrile), and 1,1'-azobis(cyclohexanecarbonitrile).

[0022] Examples of the solvent include butyl cellosolve, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, toluene, xylene, mesitylene, methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, and ethyl acetate. These may be used alone or in combination of two or more. Among these, toluene, xylene, and propylene glycol monomethyl ether are preferred from the viewpoint of solubility.

[0023] The modification rate (maleic anhydride modification rate) of component (A) is 1.0% by mass or more, and from the viewpoint of reducing the size of depressions on the surface after desmearing, it is preferably 1.8% by mass or more, more preferably 1.9% by mass or more, even more preferably 2.0% by mass or more, particularly preferably 2.5% by mass or more, and most preferably 3.0% by mass or more. From the viewpoint of high-frequency characteristics, the modification rate may be 7.0% by mass or less, 6.5% by mass or less, 6.3% by mass or less, or 6.0% by mass or less. That is, the modification rate may be 1.0 to 7.0% by mass, 1.8 to 6.5% by mass, 1.9 to 6.3% by mass, 2.0 to 6.0% by mass, 2.5 to 6.0% by mass, or 3.0 to 6.0% by mass. The modification rate of component (A) can be adjusted by increasing or decreasing the amount of maleic anhydride used to react with the styrene-based elastomer and, if necessary, the amount of radical generator used. The modification rate of the component (A) can be calculated using the acid value of the maleic anhydride-modified styrene elastomer, and more specifically, can be calculated by the method described in the examples.

[0024] From the viewpoint of reducing the size of depressions on the surface after desmearing, the acid value of the component (A) is preferably 15 to 110 mgKOH / g, more preferably 20 to 100 mgKOH / g, even more preferably 30 to 90 mgKOH / g, and particularly preferably 35 to 80 mgKOH / g.

[0025] From the standpoint of compatibility, the weight average molecular weight (Mw) of component (A) is preferably 20,000 to 120,000, more preferably 30,000 to 110,000, even more preferably 40,000 to 100,000, and particularly preferably 50,000 to 80,000.

[0026] (Content of Component (A)) The content of the component (A) in the resin composition of the present embodiment is not particularly limited, but from the viewpoint of high-frequency characteristics and reducing the size of depressions on the surface of the resin layer after desmearing, the content is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, even more preferably 3 to 35 parts by mass, particularly preferably 3 to 25 parts by mass, and most preferably 3 to 15 parts by mass, relative to 100 parts by mass of the solid content in the resin composition.

[0027] <Thermosetting Resin (B)> The resin composition of this embodiment contains a thermosetting resin as component (B). The thermosetting resin preferably contains at least one selected from the group consisting of epoxy resins, maleimide compounds, phenolic resins, polyimide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins (such as melamine resins), unsaturated polyester resins, allyl resins, dicyclopentadiene resins, and silicone resins. From the viewpoints of high-frequency characteristics, adhesion to conductors, flame retardancy, and the like, the thermosetting resin more preferably contains at least one selected from the group consisting of epoxy resins, maleimide compounds, phenolic resins, polyimide resins, cyanate resins, and isocyanate resins, even more preferably contains at least one selected from epoxy resins, maleimide compounds, and cyanate resins, and particularly preferably contains a maleimide compound.

[0028] (Maleimide Compound) The maleimide compound is preferably at least one selected from the group consisting of maleimide compounds having two or more N-substituted maleimide groups [hereinafter, sometimes simply referred to as "maleimide compound (b1)" or "component (b1)"] and derivatives thereof. Examples of the "derivatives thereof" include addition reaction products of maleimide compounds having two or more N-substituted maleimide groups with amine compounds such as diamine compounds described below.

[0029] Specific examples of the maleimide compound (b1) are not particularly limited as long as they are maleimide compounds having two or more N-substituted maleimide groups, and include aromatic maleimide compounds such as bis(4-maleimidophenyl)methane, polyphenylmethane maleimide, bis(4-maleimidophenyl)ether, bis(4-maleimidophenyl)sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, m-phenylene bismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, and indane ring-containing aromatic bismaleimide; and aliphatic maleimide compounds such as 1,6-bismaleimido-(2,2,4-trimethyl)hexane and pyrophosphate binder-type long-chain alkyl bismaleimide. Among these, from the viewpoints of adhesion to the conductor and mechanical properties, aromatic maleimide compounds are preferred, aromatic bismaleimide compounds are more preferred, and 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane and 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide are even more preferred.

[0030] From the viewpoints of solubility in organic solvents, compatibility, adhesion to conductors, and high-frequency characteristics, the maleimide compound is preferably a derivative of maleimide compound (b1). The derivative of maleimide compound (b1) is preferably a modified maleimide compound (hereinafter sometimes abbreviated as "modified maleimide compound (X)" or "component (X)") having a structural unit derived from maleimide compound (b1) and a structural unit derived from an amine compound having a primary amino group (hereinafter sometimes abbreviated as "component (b2)"). The structural unit derived from component (b1) and the structural unit derived from component (b2) contained in modified maleimide compound (X) may each be one type, or a combination of two or more types.

[0031] The modified maleimide compound (X) is preferably a compound having a structure represented by the following formula (B-1), which is formed by an addition reaction between a maleimide group in the component (b1) and a primary amino group in the component (b2): (* indicates the bond position to other structures.)

[0032] The amine compound (b2) is preferably a compound having two or more amino groups, and more preferably a diamine compound having two amino groups. Examples of the amine compound (b2) include 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ketone, 4,4'-diaminobiphenyl, and 3,3'-dimethyl-4,4'-diaminodiphenyl. Aminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis(3-aminophenoxy)benzene, 1 ,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, 1,3-bis[1-[4-(4-aminophenoxy)phenyl]-1-methylethyl]benzene, 1,4-bis[1-[4-(4-aminophenoxy)phenyl]-1-methylethyl]benzene, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, Examples of the aromatic diamine compounds include 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 3,3'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, and 9,9-bis(4-aminophenyl)fluorene; and amine-modified siloxane compounds having a primary amino group.

[0033] Among these, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, and 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline are preferred as component (b2) from the viewpoints of excellent solubility in organic solvents, reactivity with component (b1), and heat resistance. Furthermore, 3,3'-dimethyl-5,5'-diethyl-4,4'-diaminodiphenylmethane is preferred from the viewpoints of excellent high-frequency characteristics and low water absorption. Furthermore, 2,2-bis[4-(4-aminophenoxy)phenyl]propane is preferred from the viewpoints of excellent mechanical properties such as high adhesion to conductors, elongation, and breaking strength. Furthermore, from the viewpoints of excellent solubility in organic solvents, reactivity during synthesis, heat resistance, high adhesion to conductors, as well as excellent high-frequency characteristics and low moisture absorption, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline and 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline are preferred. Furthermore, from the viewpoint of low thermal expansion, amine-modified siloxane compounds are preferred.

[0034] The functional group equivalent weight of the amine-modified siloxane compound is not particularly limited, but is preferably 300 to 3,000 g / mol, more preferably 400 to 2,000 g / mol, and even more preferably 600 to 1,000 g / mol.

[0035] From the viewpoints of heat resistance and low thermal expansion, it is preferable to use a combination of an aromatic diamine compound and an amine-modified siloxane compound as component (b2). The ratio of the aromatic diamine compound and the amine-modified siloxane compound used [aromatic diamine compound / amine-modified siloxane compound] is not particularly limited, but is preferably 20 / 80 to 80 / 20, more preferably 40 / 60 to 70 / 30, and even more preferably 50 / 50 to 65 / 35 by mass ratio.

[0036] The content of the structural units derived from component (b2) in the modified maleimide compound (X) is not particularly limited, but is preferably 5 to 50 mass%, more preferably 8 to 30 mass%, and even more preferably 10 to 15 mass%. When the content of the structural units derived from component (b2) is within this range, excellent high-frequency characteristics, as well as better heat resistance, flame retardancy, and glass transition temperature, tend to be obtained.

[0037] The total content of the structural units derived from the component (b1) and the structural units derived from the component (b2) in the modified maleimide compound (X) is not particularly limited, but is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 100% by mass (i.e., consisting solely of structural units derived from the component (b1) and structural units derived from the component (b2)).

[0038] The content ratio of the structural unit derived from the component (b1) and the structural unit derived from the component (b2) in the modified maleimide compound (X) is not particularly limited. ２ Group derived from the group (-NH ２ The content ratio is such that the equivalent ratio (Ta1 / Ta2) of the total equivalent (Ta1) of groups (including maleimide groups) derived from component (b1) to the total equivalent (Ta2) of groups (including maleimide groups) derived from maleimide groups is preferably 0.05 to 10, more preferably 1 to 5. When the equivalent ratio (Ta1 / Ta2) is within the above range, excellent high-frequency characteristics, and better heat resistance, flame retardancy, and glass transition temperature tend to be obtained.

[0039] (Method for Producing Modified Maleimide Compound (X)) Component (X) can be obtained as a reaction product between component (b1) and component (b2), and can be produced, for example, by reacting component (b1) with component (b2) in an organic solvent. Specifically, a reactor is charged with predetermined amounts of components (b1), (b2), and, if necessary, other components, and the components (b1) and (b2) are subjected to a Michael addition reaction (hereinafter, sometimes abbreviated as "pre-reaction") to obtain modified maleimide compound (X). The reaction conditions for the pre-reaction are not particularly limited, but from the viewpoint of obtaining good reactivity and workability while suppressing gelation, a reaction temperature of 50 to 160°C and a reaction time of 1 to 10 hours are preferred.

[0040] In the pre-reaction, a reaction catalyst may be used as necessary. Examples of the reaction catalyst include acidic catalysts such as p-toluenesulfonic acid; amines such as triethylamine, pyridine, and tributylamine; imidazole compounds such as methylimidazole and phenylimidazole; and phosphorus-based catalysts such as triphenylphosphine. These may be used alone or in combination of two or more. There are no particular restrictions on the amount of the reaction catalyst used, but it is, for example, 0.01 to 5 parts by mass per 100 parts by mass of the total amount of component (b1) and component (b2).

[0041] The weight average molecular weight (Mw) of the modified maleimide compound (X) is not particularly limited, but is preferably 400 to 10,000, more preferably 1,000 to 5,000, even more preferably 1,500 to 4,000, and particularly preferably 2,000 to 3,000.

[0042] (Content of Component (B)) The content of the thermosetting resin (B) in the resin composition of the present embodiment is not particularly limited, but from the viewpoints of high-frequency characteristics, heat resistance, and moldability, it is preferably 10 to 70 parts by mass, more preferably 15 to 60 parts by mass, even more preferably 20 to 50 parts by mass, and particularly preferably 25 to 45 parts by mass, relative to 100 parts by mass of the solid content in the resin composition.

[0043] <Inorganic Filler (C)> The resin composition of this embodiment may contain an inorganic filler as component (C). By including component (C) in the resin composition of this embodiment, the thermal expansion coefficient, heat resistance, and flame retardancy tend to be improved. Examples of component (C) include, but are not limited to, silica, alumina, titanium oxide, mica, beryllia, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay (e.g., calcined clay), molybdenum compounds (e.g., zinc molybdate), talc, aluminum borate, and silicon carbide. One type of component (C) may be used alone, or two or more types may be used in combination. Among these, silica, alumina, mica, and talc are preferred from the viewpoints of thermal expansion coefficient, heat resistance, and flame retardancy, with silica and alumina being more preferred, and silica being even more preferred. Examples of silica include crushed silica, fumed silica, and fused silica (fused spherical silica).

[0044] The shape and particle size of component (C) are not particularly limited, but the particle size is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm, even more preferably 0.2 to 3 μm, particularly preferably 0.2 to 1 μm, and most preferably 0.3 to 0.8 μm. Here, particle size refers to the average particle size, and is the particle size at the point corresponding to 50% volume when a cumulative frequency distribution curve of particle sizes is calculated, assuming the total volume of particles to be 100%. The particle size of component (C) can be measured using a particle size distribution analyzer using a laser diffraction scattering method, for example.

[0045] (Content of Component (C)) When the resin composition of the present embodiment contains the component (C), the content of the component (C) is not particularly limited, but from the viewpoints of the thermal expansion coefficient, heat resistance, and flame retardancy, it is preferably 5 to 70 parts by mass, more preferably 15 to 65 parts by mass, even more preferably 20 to 60 parts by mass, and particularly preferably 30 to 55 parts by mass, per 100 parts by mass of the solid content in the resin composition.

[0046] Furthermore, when component (C) is used, a coupling agent may be used in combination, if necessary, to improve the dispersibility of component (C) and the adhesion between component (C) and the organic components in the resin composition. The coupling agent is not particularly limited, and, for example, a silane coupling agent or a titanate coupling agent can be appropriately selected and used. One coupling agent may be used alone, or two or more coupling agents may be used in combination. The amount of coupling agent used is also not particularly limited. When a coupling agent is used, a so-called integral blending method may be used in which the coupling agent is added after blending component (C) into the resin composition. However, a method in which an inorganic filler is previously surface-treated with a coupling agent by dry or wet processing is preferred. By adopting this method, the characteristics of component (C) can be more effectively expressed.

[0047] When the component (C) is used in this embodiment, in order to improve the dispersibility of the component (C) in the resin composition, the component (C) may be used as a slurry in which the component (C) is dispersed in an organic solvent in advance, as necessary. Examples of the organic solvent include the same organic solvents as those described below.

[0048] <Polyphenylene Ether Derivative (D) Having an Ethylenically Unsaturated Bond-Containing Group> The resin composition of this embodiment may contain a polyphenylene ether derivative having an ethylenically unsaturated bond-containing group as component (D) (hereinafter, simply referred to as "polyphenylene ether derivative (D)"). When the resin composition of this embodiment contains component (D), the high-frequency characteristics are further improved, and the compatibility between components (A) and (B) tends to be improved. Component (D) is preferably a polyphenylene ether derivative having an ethylenically unsaturated bond-containing group at its terminal, and more preferably a polyphenylene ether derivative having ethylenically unsaturated bond-containing groups at both terminals. In the present disclosure, the term "ethylenically unsaturated bond-containing group" refers to a substituent containing a carbon-carbon double bond capable of addition reaction, and does not include a double bond in an aromatic ring. The polyphenylene ether derivative (D) may be used singly or in combination of two or more types.

[0049] Examples of the ethylenically unsaturated bond-containing group include unsaturated aliphatic hydrocarbon groups such as vinyl, allyl, 1-methylallyl, isopropenyl, 2-butenyl, 3-butenyl, and styryl groups; maleimide groups; and groups containing a heteroatom and an ethylenically unsaturated bond, such as groups represented by the following general formula (D-1). Among these, from the viewpoints of high-frequency characteristics, adhesion to conductors, and compatibility between components (A) and (B), the ethylenically unsaturated bond-containing group is preferably a group represented by the following general formula (D-1).

[0050] (In the formula, R ｄ１ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

[0051] R ｄ１ The alkyl group having 1 to 20 carbon atoms represented by may be any of a linear alkyl group, a branched alkyl group, or a cyclic alkyl group, and is preferably a linear alkyl group. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, and particularly preferably 1. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a pentadecyl group, a hexadecyl group, and a heptadecyl group, and among these, a methyl group is preferred. From the viewpoints of high-frequency characteristics, adhesion to a conductor, and compatibility between component (A) and component (B), the group represented by general formula (D-1) is preferably a (meth)acryloyl group (i.e., R ｄ１ is a hydrogen atom or a methyl group), and more preferably a methacryloyl group.

[0052] In the present disclosure, groups that partially contain an unsaturated aliphatic hydrocarbon group, such as a maleimide group and a group represented by the general formula (D-1), but cannot be considered to be an unsaturated aliphatic hydrocarbon group when viewed as a whole, are not included in the "unsaturated aliphatic hydrocarbon group".

[0053] The polyphenylene ether derivative (D) preferably has a group represented by the general formula (D-1) at one end or both ends. When the polyphenylene ether derivative (D) has an ethylenically unsaturated bond-containing group at one end or both ends, it may further have an ethylenically unsaturated bond-containing group at an end other than one end or both ends, but it is preferable that the polyphenylene ether derivative (D) has an ethylenically unsaturated bond-containing group only at both ends. The polyphenylene ether derivative (D) is preferably a polyphenylene ether having methacryloyl groups at both ends.

[0054] The number of ethylenically unsaturated bond-containing groups that the polyphenylene ether derivative (D) has in one molecule is not particularly limited, but is preferably 2 to 5, more preferably 2 to 3, and even more preferably 2. When the number of ethylenically unsaturated bond-containing groups is at least the above-mentioned lower limit, excellent heat resistance and compatibility between the (A) and (B) components tend to be obtained, while when the number is at most the above-mentioned upper limit, excellent flowability and moldability tend to be obtained.

[0055] The polyphenylene ether derivative (D) has a phenylene ether bond and preferably has a structural unit represented by the following general formula (D-2).

[0056] (In the formula, R ｄ２ represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. ｄ１ represents an integer from 0 to 4.)

[0057] R in the general formula (D-2) ｄ２ Examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by n include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, etc. As the aliphatic hydrocarbon group, an aliphatic hydrocarbon group having 1 to 3 carbon atoms is preferred, an alkyl group having 1 to 3 carbon atoms is more preferred, and a methyl group is even more preferred. ｄ１ represents an integer of 0 to 4, preferably 1 or 2, and more preferably 2. ｄ１ When R is 1 or 2, ｄ２is preferably substituted at the ortho position on the benzene ring (based on the substitution position of the oxygen atom). ｄ１ is an integer of 2 or more, a plurality of R ｄ２ The structural unit represented by the general formula (D-2) is preferably a structural unit represented by the following general formula (D-2'):

[0058]

[0059] From the viewpoints of high-frequency characteristics, adhesion to a conductor, and compatibility between components (A) and (B), the polyphenylene ether derivative (D) is preferably a compound represented by the following general formula (D-3):

[0060] (In the formula, R ｄ２ and n ｄ１ is as explained in the general formula (D-2). ｄ３ and R ｄ４ Each of n independently represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. ｄ２ and n ｄ３ Each independently represents an integer of 0 to 4. ｄ４ and n ｄ５ each independently represents an integer of 0 to 20, ｄ４ and n ｄ５ The sum of X is an integer from 1 to 30. ｄ１ represents an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, or a single bond. ｄ１ and Y ｄ２ each independently represents the ethylenically unsaturated bond-containing group.

[0061] R in the general formula (D-3) ｄ３ and R ｄ４ The aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by R in the general formula (D-2) is explained below. ｄ２ The same applies to the aliphatic hydrocarbon group having 1 to 5 carbon atoms as shown by n ｄ２ and n ｄ３ represents an integer of 0 to 4, preferably an integer of 0 to 3, and more preferably 2 or 3.ｄ２ or n ｄ３ is an integer of 2 or more, a plurality of R ｄ３ R ｄ４ may be the same or different. ｄ４ and n ｄ５ represents an integer of 0 to 20, preferably an integer of 1 to 20, more preferably an integer of 2 to 15, and even more preferably an integer of 3 to 10. ｄ４ or n ｄ５ is an integer of 2 or more, ｄ１ They may be the same or different. ｄ４ and n ｄ５ The sum of these is an integer of 1 to 30, preferably an integer of 2 to 25, more preferably an integer of 5 to 20, and even more preferably an integer of 7 to 15.

[0062] X in the general formula (D-3) ｄ１ Examples of the alkylene group having 1 to 5 carbon atoms represented by X include a methylene group, a 1,2-dimethylene group, a 1,3-trimethylene group, a 1,4-tetramethylene group, and a 1,5-pentamethylene group. ｄ１ Examples of the alkylidene group having 2 to 5 carbon atoms represented by X include an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group, and an isopentylidene group. ｄ１ Among the groups represented by the formula (I), an isopropylidene group is preferred from the viewpoints of high frequency characteristics, adhesion to a conductor, and compatibility between the components (A) and (B). ｄ１ and Y ｄ２ The preferred embodiment of the ethylenically unsaturated bond-containing group represented by formula (D-3) is as described above. From the viewpoints of high-frequency characteristics, adhesion to a conductor, and compatibility between components (A) and (B), the compound represented by formula (D-3) is preferably a compound represented by formula (D-4) below.

[0063] (In the formula, n ｄ４ and n ｄ５ is as explained in the general formula (D-3). ｄ５ and R ｄ６ Each of X independently represents a hydrogen atom or a methyl group.ｄ２ represents a methylene group or an isopropylidene group.

[0064] [Weight-average molecular weight (Mw) of polyphenylene ether derivative (D)] The weight-average molecular weight (Mw) of the polyphenylene ether derivative (D) is not particularly limited, but is preferably 500 to 7,000, more preferably 800 to 5,000, even more preferably 1,000 to 3,000, and particularly preferably 1,200 to 2,500. When the weight-average molecular weight (Mw) of the (D) component is at least the above-mentioned lower limit, a cured product having the excellent dielectric properties of polyphenylene ether and excellent heat resistance tends to be obtained, while when it is at most the above-mentioned upper limit, excellent moldability tends to be obtained.

[0065] The method for synthesizing the polyphenylene ether derivative (D) is not particularly limited, and known methods for synthesizing and modifying polyphenylene ethers can be applied.

[0066] (Content of Component (D)) The content of component (D) in the resin composition of this embodiment is not particularly limited, but is preferably 0.1 to 40 parts by mass, more preferably 0.5 to 20 parts by mass, even more preferably 1 to 15 parts by mass, and particularly preferably 2 to 10 parts by mass, per 100 parts by mass of the solid content in the resin composition. When the content of component (D) is equal to or greater than the lower limit, better high-frequency characteristics and compatibility tend to be obtained, and when it is equal to or less than the upper limit, better heat resistance, moldability, and processability tend to be obtained.

[0067] <Curing Accelerator (E)> The resin composition of this embodiment further contains a curing accelerator as component (E), which tends to improve curability and provide better high-frequency characteristics, heat resistance, adhesion to conductors, elastic modulus, and glass transition temperature. When the resin composition of this embodiment contains a curing accelerator (E), a suitable curing accelerator (E) may be appropriately selected depending on the type of thermosetting resin (B) component used. The curing accelerator (E) may be used alone or in combination of two or more types.

[0068] Examples of component (E) include amine-based curing accelerators, imidazole-based curing accelerators, phosphorus-based curing accelerators, organometallic salts, acidic catalysts, and organic peroxides. In this embodiment, imidazole-based curing accelerators are not classified as amine-based curing accelerators. Examples of amine-based curing accelerators include amine compounds having primary to tertiary amines, such as triethylamine, pyridine, tributylamine, dicyandiamide, and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane; and quaternary ammonium compounds. Examples of imidazole-based curing accelerators include imidazole compounds such as methylimidazole, phenylimidazole, 2-undecylimidazole, and isocyanate-masked imidazole (e.g., an addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole). Examples of phosphorus-based curing accelerators include tertiary phosphines such as triphenylphosphine; and quaternary phosphonium compounds such as the addition product of p-benzoquinone and tri-n-butylphosphine. Examples of organic metal salts include carboxylates of manganese, cobalt, zinc, etc. Examples of acidic catalysts include p-toluenesulfonic acid. Examples of organic peroxides include dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3,2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, and α,α'-di(t-butylperoxy)diisopropylbenzene. Among these, from the viewpoint of obtaining better high frequency characteristics, heat resistance, adhesion to conductors, elastic modulus, and glass transition temperature, amine-based curing accelerators, imidazole-based curing accelerators, and phosphorus-based curing accelerators are preferred, and dicyandiamide, imidazole-based curing accelerators, and quaternary phosphonium compounds are more preferred, and it is even more preferred to use these in combination. In this case, an organic peroxide may also be used in combination, but from the viewpoint of the physical properties of the cured product, it is preferable not to contain an organic peroxide.

[0069] (Content of Component (E)) When the resin composition of the present embodiment contains the component (E), the content of the component (E) is not particularly limited, but is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, still more preferably 0.1 to 4 parts by mass, and particularly preferably 0.5 to 3 parts by mass, per 100 parts by mass of the resin component. When the content of the curing accelerator (E) is within the above range, better high-frequency characteristics, heat resistance, storage stability, and moldability tend to be obtained.

[0070] <Other Components> The resin composition of this embodiment may further contain, as necessary, one or more optional components other than the above-mentioned components, such as resin materials, flame retardants, flame retardant assistants, antioxidants, heat stabilizers, antistatic agents, UV absorbers, pigments, colorants, lubricants, and silane coupling agents. Each of the optional components may be used alone, or two or more may be used in combination. When the resin composition of this embodiment contains the optional components, the content thereof is not particularly limited, but may be 0.01 parts by mass or more, 0.1 parts by mass or more, 0.5 parts by mass or more, or 10 parts by mass or less, 5 parts by mass or less, or 1 part by mass or less, per 100 parts by mass of the total resin components. Furthermore, the resin composition of this embodiment may not contain the optional components, depending on the desired performance.

[0071] The total content of components (A) to (E) in the resin components contained in the resin composition of the present embodiment is not particularly limited, but is preferably 80 parts by mass or more, more preferably 90 parts by mass or more, and even more preferably 95 parts by mass or more, per 100 parts by mass of the solid content in the resin composition, and may be 100 parts by mass.

[0072] (Organic Solvent) The resin composition of this embodiment may be a varnish-like resin composition containing an organic solvent, from the viewpoint of ease of handling and ease of production of the prepreg described below. Examples of the organic solvent include alcohol-based solvents such as ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, 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 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. These organic solvents may be used alone or in combination of two or more.

[0073] When the resin composition of this embodiment contains an organic solvent, its content is not particularly limited, but is preferably an amount such that the solids concentration of the resin composition of this embodiment is 30 to 90 mass%, more preferably 40 to 80 mass%, and even more preferably 50 to 70 mass%. When the organic solvent content is within the above range, the resin composition is easy to handle, and the impregnation into the substrate and the appearance of the produced prepreg are good. Furthermore, this makes it easy to adjust the solids concentration of the resin in the prepreg, as described below, and tends to make it easier to produce a prepreg with a desired thickness.

[0074] <Dielectric Properties> When a test specimen is prepared from the resin composition of this embodiment by the method described in the Examples below, the dielectric constant (Dk) at 10 GHz is not particularly limited, but is preferably 4.0 or less, more preferably 3.7 or less, even more preferably 3.3 or less, and can even be 3.1 or less. The smaller the dielectric constant (Dk), the better. There is no particular restriction on the lower limit of the dielectric constant (Dk). However, taking into account the balance with other physical properties, it may be, for example, 2.5 or more, or even 2.8 or more. That is, the dielectric constant (Dk) may be 2.5 to 4.0. When a test specimen is prepared from the resin composition of this embodiment by the method described in the Examples below, the dielectric loss tangent (Df) at 10 GHz is not particularly limited, but is preferably 0.0040 or less, more preferably 0.0038 or less, even more preferably 0.0035 or less, even more preferably 0.0033 or less, and can even be 0.0031 or less. The smaller the dielectric loss tangent (Df), the better. There is no particular restriction on the lower limit of the dielectric loss tangent (Df). However, taking into consideration the balance with other physical properties, the dielectric loss tangent (Df) may be, for example, 0.0020 or more, 0.0025 or more, or 0.0028 or more. That is, the dielectric loss tangent (Df) may be 0.0020 to 0.0040. The dielectric constant (Dk) and the dielectric loss tangent (Df) are values ​​measured in accordance with the cavity resonator perturbation method, and more specifically, are values ​​measured by the method described in the examples. In addition, in the present disclosure, when simply referring to dielectric constant, it means relative dielectric constant.

[0075] The resin composition of this embodiment can be produced by mixing component (A), component (B), and other components as needed using a known method. In this process, each component may be dissolved or dispersed in the organic solvent while stirring. The mixing order, temperature, time, and other conditions are not particularly limited and can be set as desired.

[0076] [Resin Film] The resin film of this embodiment is a resin film containing the resin composition of this embodiment or a semi-cured product of the resin composition. The resin film of this embodiment can be produced, for example, by applying a resin composition containing an organic solvent, i.e., a varnish, to a support, drying it by heating, and semi-curing (B-staging) as needed. The thickness of the resin film is not particularly limited, but is preferably 1 to 100 μm, more preferably 3 to 70 μm, and even more preferably 5 to 35 μm. Examples of the support include plastic film, metal foil, and release paper. The drying temperature and drying time can be determined appropriately depending on the amount of organic solvent used, the boiling point of the organic solvent, and the like. However, a resin film can be suitably formed by drying at 50 to 200°C for about 1 to 10 minutes.

[0077] [Prepreg] The prepreg of this embodiment is a prepreg containing the resin composition of this embodiment or a semi-cured product of the resin composition. The prepreg of this embodiment contains, for example, the resin composition of this embodiment or a semi-cured product of the resin composition and a sheet-like fiber substrate. The prepreg is formed using the resin composition of this embodiment or the resin film and a sheet-like fiber substrate. For example, the prepreg can be obtained by impregnating a sheet-like fiber substrate with the resin composition of this embodiment or the resin film, followed by heating and drying to semi-cure (B-staging) as needed. More specifically, the prepreg of this embodiment can be produced by, for example, heating and drying in a drying oven, typically at 80 to 200°C for 1 to 30 minutes to semi-cure (B-staging). Here, in this disclosure, B-staging refers to achieving a B-stage state as defined in JIS K6900 (1994). The amount of resin composition used can be determined appropriately so that the solids concentration derived from the resin composition in the prepreg after drying is 30 to 90% by mass. By setting the solid content concentration within the above range, better moldability tends to be obtained when the laminate is formed.

[0078] As the sheet-like fiber substrate for the prepreg, known materials used in various laminates for electrical insulating materials are used. Examples of materials for the sheet-like fiber substrate include inorganic fibers such as E-glass, D-glass, S-glass, and Q-glass; organic fibers such as polyimide, polyester, and tetrafluoroethylene; and mixtures thereof. These sheet-like fiber substrates have shapes such as woven fabric, nonwoven fabric, roving, chopped strand mat, and surfacing mat. The thickness of the sheet-like fiber substrate is not particularly limited, but may be 1 to 100 μm, 3 to 70 μm, 5 to 55 μm, 15 to 55 μm, or 25 to 55 μm.

[0079] [Laminate] The laminate of this embodiment is a laminate having a cured product of the resin composition of this embodiment or a cured product of the prepreg of this embodiment and a metal foil. An embodiment of the laminate of this embodiment can be produced, for example, by placing a metal foil on one or both sides of a resin film of this embodiment, or by placing a metal foil on one or both sides of a laminate obtained by stacking two or more resin films of this embodiment, followed by hot-press molding. In the laminate obtained by this production method, the resin film of this embodiment is C-staged. Another embodiment of the laminate of this embodiment can be produced, for example, by placing a metal foil on one or both sides of a prepreg of this embodiment, or by placing a metal foil on one or both sides of a laminate obtained by stacking two or more prepregs of this embodiment, followed by hot-press molding. In the laminate obtained by this production method, the prepreg of this embodiment is C-staged. In the present disclosure, C-staging refers to achieving the C-stage state defined in JIS K6900 (1994). A laminate having a metal foil is sometimes referred to as a metal-clad laminate. The metal of the metal foil is not particularly limited, but from the viewpoint of electrical conductivity, it may be copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing one or more of these metal elements. Copper and aluminum are preferred, and copper is more preferred. The method for carrying out the hot-press molding is not particularly limited, but can be carried out, for example, under conditions of a temperature of 100 to 300°C, a pressure of 0.2 to 10 MPa, and a time of 0.1 to 5 hours. Furthermore, the hot-press molding can be carried out using a vacuum press or the like to maintain a vacuum state for 0.5 to 5 hours.

[0080] [Printed Wiring Board] The printed wiring board of this embodiment has a cured product of the resin composition of this embodiment. It can also be said that the printed wiring board of this embodiment is a printed wiring board having one or more materials selected from the group consisting of a cured product of the thermosetting resin composition of this embodiment, a cured product of the resin film of this embodiment, a cured product of the prepreg of this embodiment, and a laminate of this embodiment. The printed wiring board of this embodiment can be manufactured by performing circuit formation processing such as drilling, metal plating, and etching of metal foil using one or more materials selected from the group consisting of the prepreg of this embodiment, the resin film of this embodiment, and the laminate of this embodiment, using a known method. Furthermore, a multilayer printed wiring board can also be manufactured by further performing multilayer adhesive processing as necessary. In the printed wiring board of this embodiment, the prepreg of this embodiment and the resin film of this embodiment are C-staged.

[0081] [Semiconductor Package] The semiconductor package of this embodiment is a semiconductor package including the printed wiring board of this embodiment and a semiconductor element. The semiconductor package of this embodiment can be manufactured by mounting semiconductor elements such as semiconductor chips and memories at predetermined positions on the printed wiring board of this embodiment.

[0082] The resin composition, resin film, prepreg, laminate, printed wiring board, and semiconductor package of this embodiment can be suitably used in electronic devices that handle high-frequency signals of 10 GHz or more. In particular, the printed wiring board is useful as a printed wiring board for millimeter-wave radar.

[0083] Although preferred embodiments have been described above, these are merely examples for the purpose of explaining the present disclosure, and the scope of the present disclosure is not intended to be limited to these embodiments. The present disclosure also includes various aspects that differ from the above-described embodiments without departing from the gist of the present disclosure.

[0084] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the following examples. In each example, the weight average molecular weight (Mw), acid value, and modification rate were measured by the following methods.

[0085] (Measurement of weight average molecular weight (Mw)) The weight average molecular weight (Mw) was measured by gel permeation chromatography (GPC) using a calibration curve prepared using standard polystyrene. The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Types: A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Corporation, trade name]. The GPC measurement conditions are shown below. Apparatus: Pump: L-6200 type [manufactured by Hitachi High-Technologies Corporation] Detector: L-3300 type RI [manufactured by Hitachi High-Technologies Corporation] Column oven: L-655A-52 [manufactured by Hitachi High-Technologies Corporation] Column: Guard column; TSK Guard column HHR-L + column; TSKgel G4000HHR + TSKgel G2000HHR (all manufactured by Tosoh Corporation, trade names) Column size: 6.0 x 40 mm (guard column), 7.8 x 300 mm (column) Eluent: tetrahydrofuran Sample concentration: 30 mg / 5 mL Injection volume: 20 μL Flow rate: 1.00 mL / min Measurement temperature: 40°C

[0086] (Acid Value Measurement) Approximately 1 g of maleic anhydride-modified styrene-based elastomer and 200 g of xylene were mixed at 80°C, and 0.5 mL of distilled water was added. The mixture was then stirred at reflux for 1 hour to hydrolyze the succinic anhydride groups. The temperature of the mixture was lowered to 80°C, a small amount of phenolphthalein was added, and then a 0.1 M potassium hydroxide (KOH)-containing ethanol solution was added dropwise for 30 seconds until the color did not disappear. The acid value (mg KOH / g) was measured from the amount of maleic anhydride-modified styrene-based elastomer and the amount of KOH added dropwise. The acid value of the maleic anhydride-modified styrene-based elastomer is a value derived from the two carboxy groups generated by hydrolysis of the succinic anhydride groups.

[0087] (Method of Calculating Modification Ratio) The modification ratio of the maleic anhydride-modified styrene-based elastomer was calculated by incorporating the acid value, the molecular weight of KOH, and the molecular weight of maleic anhydride into the following formula: Modification ratio (mass%) = [acid value (mg KOH / g) / molecular weight of KOH (mg / mol)] x 0.5 x molecular weight of maleic anhydride (g / mol) x 100 (%)

[0088] [Production Example 1: Production of maleic anhydride-modified styrene-based elastomer 2 (component (A′))] Into a 2-L flask equipped with a condenser, a nitrogen inlet tube, a thermocouple, and a stirrer, 950 g of xylene, 100 g of a hydrogenated styrene-based thermoplastic elastomer (manufactured by Asahi Kasei Corporation, trade name “Tuftec (registered trademark) H1041”, weight average molecular weight (Mw) = 73,300, styrene content = 30% by mass), and 4 g of maleic anhydride (Fujifilm Wako Pure Chemical Industries, Ltd.) were placed and stirred at 80°C for 0.5 hours. ３ Nitrogen bubbling was performed for 1.0 hour at a flow rate of 1.5 g / L. Next, 1.5 g of benzoyl peroxide (FUJIFILM Wako Pure Chemical Industries, Ltd.) was added, and the reaction was carried out by stirring for 6.0 hours while bubbling nitrogen at 80°C. Unreacted maleic anhydride was extracted from the reaction solution three times with isopropyl alcohol and concentrated. The concentrate was vacuum dried at 70°C to obtain maleic anhydride-modified styrene-based elastomer 2 (acid value = 9.3 mgKOH / g) with a modification rate of 0.8 mass%.

[0089] [Production Example 2: Production of maleic anhydride-modified styrene-based elastomer 3 (component (A))] The same operations as in Production Example 1 were carried out, except that the amount of maleic anhydride used was changed to 8 g and the amount of benzoyl peroxide used was changed to 3 g, to obtain maleic anhydride-modified styrene-based elastomer 3 (acid value = 18.4 mgKOH / g) with a modification rate of 1.6 mass%.

[0090] [Production Example 3: Production of maleic anhydride-modified styrene-based elastomer 4 (component (A))] The same operations as in Production Example 1 were carried out, except that the amount of maleic anhydride used was changed to 17 g and the amount of benzoyl peroxide used was changed to 6.5 g, to obtain maleic anhydride-modified styrene-based elastomer 4 (acid value = 37.4 mgKOH / g) with a modification rate of 3.3 mass%.

[0091] [Production Example 4: Production of maleic anhydride-modified styrene-based elastomer 5 (component (A))] The same operations as in Production Example 1 were carried out, except that the amount of maleic anhydride used was changed to 25.5 g and the amount of benzoyl peroxide used was changed to 9.75 g, to obtain maleic anhydride-modified styrene-based elastomer 5 (acid value = 52.5 mg KOH / g) with a modification rate of 4.6 mass%.

[0092] [Production Example 5: Production of maleic anhydride-modified styrene-based elastomer 6 (component (A))] The same operations as in Production Example 1 were carried out, except that the amount of maleic anhydride used was changed to 34 g and the amount of benzoyl peroxide used was changed to 13 g, to obtain maleic anhydride-modified styrene-based elastomer 6 (acid value = 72.1 mgKOH / g) with a modification rate of 6.3 mass%.

[0093] [Production Example 6: Production of Modified Maleimide Compound (X-1) (Component (B))] 100 parts by mass of 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 5.6 parts by mass of a siloxane compound (functional group equivalent: 750 g / mol) having amino groups at both ends, 7.9 parts by mass of 3,3'-diethyl-4,4'-diaminodiphenylmethane, and 171 parts by mass of propylene glycol monomethyl ether were added to a 5 L reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser and moisture content monitor, and the mixture was allowed to react under reflux for 2 hours. The mixture was concentrated at reflux temperature for 3 hours to produce a modified maleimide compound (X-1) solution with a solids concentration of 65% by mass. The weight-average molecular weight (Mw) of the resulting modified maleimide compound (X-1) was approximately 2,700.

[0094] Examples 1-4, Comparative Examples 1-2 (Preparation of Resin Compositions) The components listed in Table 1 were mixed with 58 parts by weight of toluene and 10 parts by weight of methyl isobutyl ketone at room temperature, stirring to prepare resin compositions with solids concentrations of 55-65% by weight. (Production of Resin Films) The resin compositions were applied to a 0.050 mm-thick PET film using a coating machine and then dried by heating at 120°C for 3 minutes to produce resin-coated PET films with a resin thickness of 25 μm. (Production of Double-Sided Copper-Clad Laminates) The resin surfaces of the resin-coated PET films were bonded together using vacuum pressure lamination (temperature 110°C, pressure 0.5 MPa). The PET film on one side was then peeled off, and the resin surface of another resin-coated PET film was bonded to the exposed resin surface. This process was repeated until the resin thickness reached 325 μm. The double-sided PET film of this 325 μm thick resin-coated PET film was peeled off, and 18 μm thick low-profile copper foil (BF-ANP18, M-side Rz: 1.5 μm, manufactured by CIRCUIT FOIL) was laminated on top and bottom of the resin so that the M-side was in contact with the resin, and this laminate was placed in a 300 μm thick mold. Next, it was heated and press-molded at a temperature of 230°C, a pressure of 3.0 MPa, and a time of 90 minutes to produce a double-sided copper-clad laminate.

[0095] [Evaluation Method] The double-sided copper-clad laminate obtained in each example was evaluated according to the following methods. The results are shown in Table 1.

[0096] (1. Measurement of recess size) The double-sided copper-clad laminate obtained in each example was immersed in a copper etching solution to remove the copper foil, and a desmear treatment was carried out by carrying out the following steps (1) to (4) in this order to produce a resin board. (1) Immersed in a swelling solution (manufactured by Atotech Japan Co., Ltd., product name "Swelling Dip Securigant P", glycol ethers, aqueous solution of sodium hydroxide) at 60°C for 10 minutes, followed by rinsing with water. (2) Roughening solution (manufactured by Atotech Japan Co., Ltd., product name "Concentrate Compact P", KMnO ４(3) Immerse in a neutralizing solution (an aqueous solution of sulfuric acid, "Reduction Showreusin Securigant P" manufactured by Atotech Japan Co., Ltd.) at 40°C for 5 minutes, then rinse with water. (4) Dry at 80°C for 10 minutes.

[0097] The surface of the resin plate (resin layer) after the desmear treatment obtained above was observed using a scanning electron microscope (SEM) (manufactured by Hitachi High-Technologies Corporation, product name: SV-4700) under conditions of secondary electron mode, accelerating voltage of 10 kV, and observation magnification of 5,000 times. In the obtained surface SEM image, the sizes of any five depressions present within a 30 × 20 μm area on the surface of the resin plate (resin layer) were measured, and the average value was calculated. Note that the size of the depression here means the length of the longest straight line that can be drawn within the depression area in a planar view of the resin plate.

[0098] (2. Evaluation of High-Frequency Characteristics) A resin plate was prepared under the same conditions as in the "Measurement of Cavity Size" above, and cut into a piece 60 mm long and 2 mm wide to serve as a test piece. The dielectric constant and dielectric loss tangent were measured by the cavity resonator perturbation method. The measuring instrument used was an Agilent Technologies vector network analyzer "N5227A," the cavity resonator used was a "CP129" (10 GHz band resonator) manufactured by Kanto Electronics Application Development Co., Ltd., and the measurement program was "CPMA-V2." The measurements were performed at a frequency of 10 GHz and a measurement temperature of 25°C.

[0099]

[0100] The abbreviations for each material in Table 1 are as follows: [Component (A'): Styrenic elastomer other than component (A) (for comparative examples)] Styrene-based elastomer 1: "Tuftec (registered trademark) H1041", manufactured by Asahi Kasei Corporation, weight average molecular weight (Mw) = 73,300, styrene content = 30 mass%, unmodified Maleic anhydride-modified styrene-based elastomer 2: Maleic anhydride-modified styrene-based elastomer 2 with a modification rate of 0.8 mass%, obtained in Production Example 1

[0101] [Component (A): Maleic anhydride-modified styrene-based elastomer with a modification rate of 1.0% by mass or more] Maleic anhydride-modified styrene-based elastomer 3: Maleic anhydride-modified styrene-based elastomer 3 with a modification rate of 1.6% by mass obtained in Production Example 2 Maleic anhydride-modified styrene-based elastomer 4: Maleic anhydride-modified styrene-based elastomer 4 with a modification rate of 3.3% by mass obtained in Production Example 3 Maleic anhydride-modified styrene-based elastomer 5: Maleic anhydride-modified styrene-based elastomer 5 with a modification rate of 4.6% by mass obtained in Production Example 4 Maleic anhydride-modified styrene-based elastomer 6: Maleic anhydride-modified styrene-based elastomer 6 with a modification rate of 6.3% by mass obtained in Production Example 5

[0102] [Component (B): Thermosetting Resin] Modified maleimide compound: Modified maleimide compound (X-1) prepared in Production Example 6 [Component (C): Inorganic Filler] Silica: Spherical fused silica, average particle size: 0.5 μm, 70% by mass slurry of methyl isobutyl ketone

[0103] [Component (D): Polyphenylene ether derivative having an ethylenically unsaturated bond-containing group] Polyphenylene ether derivative having a methacryloyl group: Polyphenylene ether having methacryloyl groups at both ends (weight average molecular weight (Mw): 1,700) [Component (E): Curing accelerator] Curing accelerator 1: p-benzoquinone and tri-n-butylphosphine addition product Curing accelerator 2: 2-undecylimidazole Curing accelerator 3: N-2-(aminoethyl)-3-aminopropyltrimethoxysilane

[0104] As is clear from the results shown in Table 1, the copper-clad laminates of Examples 1 to 4, which were produced using the resin composition of this embodiment, had excellent high-frequency characteristics, while the depressions on the resin layer that occurred in the copper-clad laminates of Comparative Examples 1 and 2 were reduced in size, i.e., were reduced to a diameter of 1 μm or less.

Claims

1. A resin composition containing maleic anhydride-modified styrene-based elastomer (A) with a modification rate of 1.0 mass% or more and a thermosetting resin (B).

2. The resin composition according to claim 1, wherein the thermosetting resin (B) contains one or more selected from the group consisting of epoxy resins, maleimide compounds, phenol resins, polyimide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, and silicone resins.

3. The resin composition according to claim 1, wherein the content of the component (A) is 1 to 50 parts by mass with respect to 100 parts by mass of the solid content in the resin composition.

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

5. The resin composition according to claim 1, further containing a polyphenylene ether derivative (D) having an ethylenically unsaturated bond-containing group.

6. The resin composition according to claim 1, further containing a curing accelerator (E).

7. A resin film containing the resin composition according to claim 1 or a semi-cured product of the resin composition.

8. A prepreg containing the resin composition according to claim 1 or a semi-cured product of the resin composition.

9. A laminate having a cured product of the resin composition according to claim 1 or a cured product of the prepreg according to claim 8 and a metal foil.

10. A printed wiring board having a cured product of the resin composition according to claim 1.

11. A semiconductor package having the printed wiring board according to claim 10 and a semiconductor element.

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