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

Abstract

Provided is a resin composition capable of forming a cured product in which the size of a recess generated on a surface after a desmear treatment is kept to be small or generation of a recess is suppressed, the cured product having a high glass transition temperature (Tg). Specifically, provided is a resin composition containing (A) a maleic anhydride-modified styrene-based elastomer with a modification rate of 2.5% by mass or more, (B) a thermosetting resin, and (Z) an organic peroxide, wherein the content of the organic peroxide (Z) is 0.10 parts by mass or more with respect to 100 parts by mass of the thermosetting resin (B). Also provided are a resin film, a prepreg, a laminated plate, a printed wiring board, and a semiconductor package, all of which use said resin composition.

Description

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

[0001] The present invention relates to resin compositions, resin films, prepregs, laminates, printed circuit boards, and semiconductor packages.

[0002] Mobile communication devices such as mobile phones, their base station equipment, servers, routers and other network infrastructure equipment, and large computers are all experiencing increasing signal speeds and capacities year after year. Consequently, printed circuit boards (PCBs) used in these electronic devices require high-frequency compatibility, demanding substrate materials with superior 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 and above) to reduce transmission loss. In recent years, in addition to the aforementioned electronic devices, new systems handling high-frequency wireless signals are being planned and implemented in the ITS (Intelligent Transport Systems) field (automobiles, transportation systems) and in short-range indoor communication fields. Therefore, it is anticipated that low-transmission-loss substrate materials will be increasingly required for printed circuit boards used in these devices in the future.

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

[0004] International Publication No. 2016 / 175326

[0005] Incidentally, in the manufacturing process of printed circuit boards, desmear treatment is performed on the insulating layer with an oxidizing agent aqueous solution for the purpose of removing residual components after drilling the insulating layer or for surface roughening to improve the adhesion between the insulating layer and the conductor layer. According to the inventors' research, it was found that in copper-clad laminates using a resin composition containing a styrene-based elastomer, depressions with a diameter of 0.5 μm or more may occur on the surface of the insulating layer after the desmear treatment. Therefore, the inventors conducted further research and found that by adding a predetermined amount of organic peroxide to the resin composition, the depressions could be reduced or their occurrence could be suppressed. However, although the depressions could be reduced or their occurrence could be suppressed by adding organic peroxide, it was found that the glass transition temperature (Tg) of the cured resin composition decreased. Thus, it was found that in resin compositions containing a styrene-based elastomer to improve high-frequency characteristics, it is difficult to achieve both the suppression of depression occurrence and a high glass transition temperature (Tg).

[0006] In view of the current situation, the present invention aims to provide a resin composition that can form a cured product with a high glass transition temperature (Tg) and in which the size of depressions that occur on the surface after desmearing is suppressed or the occurrence of depressions themselves is suppressed, and in which a resin composition that can form a cured product with a high glass transition temperature (Tg), and to provide a resin film, prepreg, laminate, printed circuit board, and semiconductor package using the resin composition.

[0007] As a result of diligent research, the present inventors have found that the above objective can be achieved with the resin composition of the present disclosure. The present disclosure includes the following embodiments [1] to

[11] . [1] A resin composition comprising a maleic anhydride-modified styrene elastomer (A) with a modification rate of 2.5% by mass or more, a thermosetting resin (B), and an organic peroxide (Z), wherein the content of the organic peroxide (Z) is 0.10 parts by mass or more per 100 parts by mass of component (B). [2] The resin composition according to [1] above, wherein the thermosetting resin (B) comprises one or more selected from the group consisting of epoxy resin, maleimide compound, phenol resin, polyimide resin, cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, amino resin, unsaturated polyester resin, allyl resin, dicyclopentadiene resin, silicone resin, triazine resin, and melamine resin. [3] The resin composition according to [1] or [2] above, wherein the content of component (A) is 1 to 50 parts by mass per 100 parts by mass of solids in 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 containing 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 containing a curing accelerator (E) (except for component (Z) above). [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 circuit board having a cured product of any of the resin compositions described in [1] to [6] above.

[11] A semiconductor package having the printed circuit board described in

[10] above and a semiconductor element.

[0008] According to the present invention, it is possible to provide a resin composition that can form a cured product in which the size of depressions that occur on the surface after desmearing is suppressed to a small degree or the occurrence of depressions themselves is suppressed, and a glass transition temperature (Tg) is high, and to provide a resin film, prepreg, laminate, printed circuit board, and semiconductor package using the resin composition.

[0009] In the numerical ranges described in this disclosure, the upper or lower limits of the numerical range may be replaced with the values ​​shown in the examples. Furthermore, the lower and upper limits of a numerical range may be arbitrarily combined with the lower or upper limits of other numerical ranges. In the notation "AA to BB" for a numerical range, the numbers AA and BB at both ends are included in the range as the lower and upper limits, respectively. In this disclosure, for example, "10 or more" means 10 and numbers greater than 10, and this applies even if the numbers are different. Similarly, for example, "10 or less" means 10 and numbers less than 10, and this applies even if the numbers are different. Furthermore, unless otherwise specified, each component and material exemplified in this disclosure may be used alone or in combination of two or more. In this disclosure, if there are multiple substances corresponding to each component in the resin composition, unless otherwise specified, the content of each component in the resin composition means the total amount of such multiple substances present in the resin composition.

[0010] In this disclosure, “resin components” refers to all components of the resin composition that constitute the solid content, excluding inorganic compounds such as inorganic fillers described later. In this disclosure, “solid content” means components other than the solvent, and components that are liquid at 25°C are also considered to be solid content. The expression “contains XX” as described in this disclosure may mean that XX is contained in a reacted state if XX is reactable, or that XX is simply contained as is, or that both of these forms are included. Forms that combine any combination of the matters described in this disclosure are also included in this disclosure and these embodiments.

[0011] [Resin Composition] The resin composition of this embodiment is as follows: A resin composition containing a maleic anhydride-modified styrene elastomer (A) with a modification rate of 2.5% by mass or more [hereinafter sometimes referred to as component (A)], a thermosetting resin (B) [hereinafter sometimes referred to as component (B)], and an organic peroxide (Z) [hereinafter sometimes referred to as component (Z)], wherein the content of the organic peroxide (Z) is 0.10 parts by mass or more per 100 parts by mass of component (B). The components contained in the resin composition of this embodiment will be described below.

[0012] <Maleic acid-modified styrene elastomer (A) with a modification rate of 2.5% by mass or more> The resin composition of this embodiment contains a maleic acid-modified styrene elastomer with a modification rate of 2.5% by mass or more as component (A), which makes it possible to maintain a high glass transition temperature (Tg) of the cured product of the resin composition. If the modification rate of component (A) is less than 2.5% by mass, it becomes difficult to maintain a high Tg. It is presumed that by having a modification rate of 2.5% by mass or more in component (A), the compatibility with the thermosetting resin (B) is improved, and components (A) and (B) can react before phase separation occurs due to the blending of organic peroxides, thus maintaining a high Tg. Furthermore, it is presumed that by having a modification rate of 2.5% by mass or more in component (A), the compatibility with the thermosetting resin (B) is improved, making it easier to reduce the size of depressions that occur on the surface of the resin layer after desmear treatment (specifically, the diameter becomes less than 0.5 μm). However, even if the above inferences are incorrect, it will not adversely affect the scope of this disclosure. Here, the size and diameter of the recess refer to the length of the longest straight line that can be drawn within the recess area in a plan view of the resin plate.

[0013] Component (A) is preferably a thermoplastic elastomer. Specifically, component (A) is preferably a maleic anhydride-modified styrene-based thermoplastic elastomer with a modification rate of 2.5% by mass or more.

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

[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 preferable, and 1,3-butadiene is more preferable.

[0017] The styrene-based elastomer may be a hydrogenated styrene-based elastomer in which at least a portion of the structural units derived from the conjugated diene compound are hydrogenated. Examples of hydrogenated styrene-based elastomers include hydrogenated styrene-butadiene-styrene block copolymers (SEBS) and hydrogenated styrene-isoprene-styrene block copolymers (SEPS). The styrene-based elastomer may be manufactured by known methods or a commercially available product may be used. Examples of commercially available styrene-based elastomers include the ToughTec H series and M series from Asahi Kasei Corporation, the Septon series from Kuraray Co., Ltd., and the Kraton G polymer series from 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 this disclosure, the weight-average molecular weight is a value calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC), and more specifically, a value obtained by the measurement method described in the examples.

[0019] The styrene elastomer may be a hydrogenated styrene elastomer or an unhydrogenated styrene elastomer. In the case of a hydrogenated styrene elastomer, the hydrogenation rate is preferably 80% or more, and more preferably 90% or more, from the viewpoint of performing maleic anhydride modification. Here, the hydrogenation rate is the content of carbon-carbon double bonds derived from conjugated diene monomers in the styrene elastomer before and after hydrogenation. １ This value was obtained from measurements taken using 1H NMR.

[0020] As a method for producing the component (A), more specifically, for example, a method of adding a radical generator to a mixed solution of a styrene-based elastomer and maleic anhydride dissolved in a solvent and reacting maleic anhydride with the styrene-based elastomer under a nitrogen atmosphere can be mentioned. The reaction temperature may be 20 to 150 °C. After the reaction, from the viewpoint of suppressing side reactions, it is preferable to remove unreacted maleic anhydride by extraction.

[0021] As the radical generator, organic peroxides, azo compounds, etc. can be used. Examples of organic peroxides include dicumyl 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, tert-butyl hydroperoxide, etc. Examples of azo compounds include 2,2'-azobis(2-methylpropanenitrile), 2,2'-azobis(2-methylbutanenitrile), 1,1'-azobis(cyclohexanecarbonitrile), etc.

[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, ethyl acetate, etc. These may be used alone or in combination of two or more. Among these, from the viewpoint of solubility, toluene, xylene, and propylene glycol monomethyl ether are preferable.

[0023] The modification rate in component (A) (maleic anhydride modification rate) is 2.5% by mass or more, but from the viewpoint of suppressing the size of depressions that occur on the surface after desmear treatment, it is preferably 2.8% by mass or more, more preferably 3.0% by mass or more, even more preferably 3.2% by mass or more, and particularly preferably 3.3% 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. In other words, the modification rate may be 2.5 to 7.0% by mass, 2.8 to 6.5% by mass, 3.0 to 6.3% by mass, 3.2 to 6.0% by mass, 3.3 to 6.0% by mass, or 2.8 to 5.0% by mass, 2.8 to 4.5% by mass, 3.0 to 4.0% by mass, or 3.2 to 3.8% by mass. The rate of modification in 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 rate of modification in component (A) can be calculated using the acid value of the maleic anhydride-modified styrene-based elastomer, and more specifically, by the method described in the examples.

[0024] (A) The acid value of component (A) is preferably 15 to 110 mg KOH / g, more preferably 20 to 100 mg KOH / g, even more preferably 30 to 90 mg KOH / g, and particularly preferably 35 to 80 mg KOH / g, from the viewpoint of suppressing the size of depressions that occur on the insulating layer surface after desmear treatment.

[0025] (A) 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, from the viewpoint of compatibility.

[0026] (Content of component (A)) The content of component (A) in the resin composition of this embodiment is not particularly limited, but from the viewpoint of high-frequency characteristics, suppressing the size of depressions that occur on the surface of the resin layer after desmearing or suppressing the occurrence of depressions themselves, and glass transition temperature, it 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 per 100 parts by mass of 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 one or more selected from the group consisting of epoxy resin, maleimide compound, phenol resin, polyimide resin, cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, amino resin, unsaturated polyester resin, allyl resin, dicyclopentadiene resin, silicone resin, triazine resin, and melamine resin. From the viewpoint of high-frequency characteristics, adhesion to conductors, and flame retardancy, the thermosetting resin more preferably contains one or more selected from the group consisting of epoxy resin, maleimide compound, phenol resin, polyimide resin, cyanate resin, and isocyanate resin, even more preferably contains one or more selected from epoxy resin, maleimide compound, and cyanate resin, and particularly preferably contains a maleimide compound.

[0028] (Maleimide Compound) The maleimide compound is preferably one or more 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 its derivatives. Examples of the "derivative" include addition reaction products of a maleimide compound having two or more N-substituted maleimide groups and an amine compound such as a diamine compound described later.

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

[0030] As the maleimide compound, a derivative of maleimide compound (b1) is preferred from the viewpoint of solubility in organic solvents, compatibility, adhesion to conductors, and high-frequency characteristics. As the derivative of maleimide compound (b1), it is preferable that it is a modified maleimide compound 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 simply referred to as "component (b2)"] [hereinafter sometimes abbreviated as "modified maleimide compound (X)" or "component (X)"]. Note that the structural unit derived from component (b1) and the structural unit derived from component (b2) contained in the modified maleimide compound (X) may be one type each, or a combination of two or more types.

[0031] The modified maleimide compound (X) is preferably a compound containing a structure represented by the following formula (B-1), which is formed by an addition reaction between the maleimide group of component (b1) and the primary amino group of component (b2). (* indicates the location of attachment 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 amine compounds (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'-di 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 include aromatic diamine compounds such as 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, as component (b2), 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 from the viewpoint 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 viewpoint of excellent high-frequency characteristics and low water absorption. Furthermore, 2,2-bis[4-(4-aminophenoxy)phenyl]propane is preferred from the viewpoint of excellent mechanical properties such as high adhesion to conductors, elongation, and tensile strength. Furthermore, in addition to excellent solubility in organic solvents, reactivity during synthesis, heat resistance, and high adhesion to conductors, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline and 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline are preferred from the viewpoint of excellent high-frequency characteristics and low hygroscopicity. Also, from the viewpoint of low thermal expansion, amine-modified siloxane compounds are preferred.

[0034] The functional group equivalent 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] (b2) As for the component, from the viewpoint of heat resistance and low thermal expansion, it is preferable to use an aromatic diamine compound and an amine-modified siloxane compound in combination. The ratio of aromatic diamine compound and amine-modified siloxane compound used [aromatic diamine compound / amine-modified siloxane compound] is not particularly limited, but is preferably 20 / 80 to 80 / 20 by mass ratio, more preferably 40 / 60 to 70 / 30, and even more preferably 50 / 50 to 65 / 35.

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

[0037] The total content of structural units derived from component (b1) and 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 only of structural units derived from component (b1) and component (b2)).

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

[0039] (Method for producing modified maleimide compound (X)) Component (X) can be obtained as a reaction product of component (b1) and component (b2), for example, by reacting component (b1) and component (b2) in an organic solvent. Specifically, component (b1), component (b2), and other components as needed are charged in predetermined amounts into a reactor, and component (b1) and component (b2) are subjected to a Michael addition reaction [hereinafter sometimes abbreviated as "pre-reaction"] to obtain modified maleimide compound (X). The reaction conditions in the pre-reaction are not particularly limited, but from the viewpoint of suppressing gelation while obtaining good reactivity and workability, 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 needed. Examples of reaction catalysts 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 individually or in combination of two or more. There are no particular restrictions on the amount of reaction catalyst used, but for example, it is 0.01 to 5 parts by mass per 100 parts by mass of the total amount of components (b1) and (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 most preferably 2,000 to 3,000.

[0042] (Content of component (B)) The content of thermosetting resin (B) in the resin composition of this embodiment is not particularly limited, but from the viewpoint 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, per 100 parts by mass of solid content in the resin composition.

[0043] <Organic Peroxide (Z)> The resin composition of this embodiment contains 0.10 parts by mass or more of organic peroxide (Z) per 100 parts by mass of component (B), thereby reducing the size of depressions that occur on the surface of the insulating layer after desmear treatment, or suppressing the occurrence of depressions altogether. The organic peroxide (Z) is not particularly limited as long as it is an organic compound containing a peroxide bond (-O-O-). Component (Z) may be used alone or in combination of two or more types.

[0044] (Z) Component includes peroxyketal compounds such as 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(t-butylperoxy)butane, 2,2-di(4,4-di-t-butylperoxycyclohexyl)propane, and 1,1-di(t-amylperoxy)cyclohexane; hydroperoxide compounds such as cumene hydroperoxide and t-butyl hydroperoxide; alkyl peroxide compounds such as t-butylperoxyacetate and t-amylperoxyisononanoate; t-butylcumylperoxide and di-t-butylperoxy Examples include dialkyl peroxide compounds such as dihydrate, dicumyl peroxide, di-t-hexyl peroxide, and α,α'-di(t-butylperoxy)diisopropylbenzene; peroxyester compounds such as t-butyl peroxyacetate, t-butyl peroxybenzoate, and t-butyl peroxyisopropyl monocarbonate; peroxycarbonate compounds such as t-butyl peroxyisopropyl carbonate and polyethertetrakis(t-butyl peroxycarbonate); and diacyl peroxide compounds such as dibenzoyl peroxide. Among these, α,α'-di(t-butylperoxy)diisopropylbenzene is preferred from the viewpoint of excellent handling properties and the fact that the size of depressions that occur after desmearing is reduced or the occurrence of depressions themselves is suppressed.

[0045] (Content of organic peroxide (Z)) The content of organic peroxide (Z) in the resin composition of this embodiment is 0.10 parts by mass or more per 100 parts by mass of component (B), preferably 0.10 to 2.0 parts by mass, more preferably 0.15 to 1.5 parts by mass, even more preferably 0.20 to 1.0 parts by mass, and particularly preferably 0.25 to 0.80 parts by mass. However, if the resin composition of this embodiment contains a polyphenylene ether derivative (D) having an ethylenically unsaturated bond-containing group as described later, it is preferable that the content of organic peroxide (Z) is within the above numerical range per 100 parts by mass of the total amount of components (B) and (D). If the content of organic peroxide (Z) is less than 0.10 parts by mass per 100 parts by mass of component (B), depressions are likely to occur after desmearing, and the size of the depressions is likely to be large. Furthermore, when the content of organic peroxides (Z) is below the above upper limit, it tends to be easier to suppress the decrease in the glass transition temperature.

[0046] <Inorganic Filler (C)> The resin composition of this embodiment may contain an inorganic filler as component (C). The resin composition of this embodiment tends to have improved low thermal expansion coefficient, heat resistance and flame retardancy when it contains component (C). Component (C) is not particularly limited, but examples include silica, alumina, titanium oxide, mica, beryllium, 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 (such as calcined clay), molybdate compounds (such as zinc molybdate), talc, aluminum borate, silicon carbide, etc. Component (C) may be used alone or in combination of two or more. Among these, silica, alumina, mica, and talc are preferred from the viewpoint of thermal expansion coefficient, heat resistance and flame retardancy, silica and alumina are more preferred, and silica is even more preferred. Examples of silica include crushed silica, fumed silica, and fused silica (fused spherical silica).

[0047] 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 0.1 to 5 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 diameter, which is the particle diameter at the point corresponding to 50% of the volume when the cumulative frequency distribution curve by particle diameter is determined with the total volume of the particles set to 100%. The particle size of component (C) can be measured using a particle size distribution analyzer that uses laser diffraction scattering or the like.

[0048] (Content of component (C)) When the resin composition of this embodiment contains component (C), the content of component (C) is not particularly limited, but from the viewpoint of 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 solid content in the resin composition.

[0049] Furthermore, when using component (C), a coupling agent may be used in combination as needed 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 may be appropriately selected and used. One type of coupling agent may be used alone, or two or more types may be used in combination. The amount of coupling agent used is also not particularly limited. When using a coupling agent, a so-called integral blending method may be used, in which the coupling agent is added after the component (C) has been blended into the resin composition, but it is preferable to use an inorganic filler in which the inorganic filler has been surface-treated with the coupling agent in a dry or wet manner beforehand. By adopting this method, the characteristics of component (C) can be expressed more effectively.

[0050] In this embodiment, when component (C) is used, in order to improve the dispersibility of component (C) in the resin composition, it may be used as a slurry in which component (C) is pre-dispersed in an organic solvent, if necessary. Examples of organic solvents include those described later.

[0051] <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 (hereinafter sometimes simply referred to as "polyphenylene ether derivative (D)") as component (D). The resin composition of this embodiment tends to have improved high-frequency characteristics and improved compatibility between component (A) and component (B) when component (D) is included. Component (D) is preferably a polyphenylene ether derivative having an ethylenically unsaturated bond-containing group at one end, and more preferably a polyphenylene ether derivative having ethylenically unsaturated bond-containing groups at both ends. In this disclosure, "ethylenically unsaturated bond-containing group" means a substituent containing a carbon-carbon double bond that can undergo addition reactions, and does not include double bonds of aromatic rings. One type of polyphenylene ether derivative (D) may be used alone, or two or more types may be used in combination.

[0052] Examples of ethylenically unsaturated bond-containing groups include unsaturated aliphatic hydrocarbon groups such as vinyl groups, allyl groups, 1-methylallyl groups, isopropenyl groups, 2-butenyl groups, 3-butenyl groups, and styryl groups; and groups containing heteroatoms and ethylenically unsaturated bonds, such as maleimide groups and groups represented by the following general formula (D-1). Among these, from the viewpoint of high-frequency characteristics, adhesion to conductors, and compatibility between component (A) and component (B), the ethylenically unsaturated bond-containing group is preferably the group represented by the following general formula (D-1).

[0053] (In the formula, R ｄ１ (This represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

[0054] R ｄ１The alkyl group having 1 to 20 carbon atoms represented by may be 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 of 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 alkyl groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, pentadecyl group, hexadecyl group, heptadecyl group, etc., and among these, the methyl group is preferred. The group represented by the general formula (D-1) is, from the viewpoint of high-frequency characteristics, adhesion to conductors, and compatibility between component (A) and component (B), a (meth)acryloyl group (i.e., R in the general formula (D-1)). ｄ１ However, it is preferable that the group is a hydrogen atom or a methyl group, and more preferably a methacryloyl group.

[0055] In this disclosure, groups that have a portion of an unsaturated aliphatic hydrocarbon group, such as a maleimide group or the group represented by the general formula (D-1), but cannot be considered an unsaturated aliphatic hydrocarbon group when viewed as a whole, are not included in the term "unsaturated aliphatic hydrocarbon group."

[0056] The polyphenylene ether derivative (D) preferably has the group represented by the general formula (D-1) at one or both ends. If the polyphenylene ether derivative (D) has an ethylenically unsaturated bond-containing group at one or both ends, it may also have ethylenically unsaturated bond-containing groups in addition to the groups at one or both ends, but it is preferable that it has ethylenically unsaturated bond-containing groups only at both ends. The polyphenylene ether derivative (D) is preferably a polyphenylene ether having methacryloyl groups at both ends.

[0057] The number of ethylenically unsaturated bond-containing groups in one molecule of the polyphenylene ether derivative (D) 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 lower limit value, excellent heat resistance and compatibility between the component (A) and the component (B) tend to be obtained. When it is at most the upper limit value, excellent fluidity and moldability tend to be obtained.

[0058] The polyphenylene ether derivative (D) has a phenylene ether bond and preferably has a structural unit represented by the following general formula (D-2).

[0059] (In the formula, R ｄ２ represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. n ｄ１ represents an integer of 0 to 4.)

[0060] As the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by R ｄ２ in the general formula (D-2), examples 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, and the like. As the aliphatic hydrocarbon group, an aliphatic hydrocarbon group having 1 to 3 carbon atoms is preferable, an alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group is even more preferable. n ｄ１ represents an integer of 0 to 4, preferably 1 or 2, and more preferably 2. When n ｄ１ is 1 or 2, R ｄ２ is preferably substituted at the ortho position on the benzene ring (however, based on the substitution position of the oxygen atom). When n ｄ１ is an integer of 2 or more, the plurality of R ｄ２ may be the same or different from each other. The structural unit represented by the general formula (D-2) is preferably a structural unit represented by the following general formula (D-2').

[0061]

[0062] The polyphenylene ether derivative (D) is preferably a compound represented by the following general formula (D-3) from the viewpoint of high-frequency characteristics, adhesion to conductors, and compatibility between component (A) and component (B).

[0063] (In the formula, R ｄ２ and n ｄ１ This is as explained in the general formula (D-2) above. ｄ３ and R ｄ４ Each of these independently represents an aliphatic hydrocarbon group or halogen atom having 1 to 5 carbon atoms. ｄ２ and n ｄ３ Each of these independently represents an integer between 0 and 4. ｄ４ and n ｄ５ Each of these independently represents an integer from 0 to 20, and n ｄ４ and n ｄ５ The sum is an integer between 1 and 30. ｄ１ This 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 of these independently represents the ethylenically unsaturated bond-containing group.

[0064] R in the above general formula (D-3) ｄ３ and R ｄ４ The explanation for the aliphatic hydrocarbon group having 1 to 5 carbon atoms shown is as follows: ｄ２ This is the same as the explanation for aliphatic hydrocarbon groups with 1 to 5 carbon atoms shown. ｄ２ and n ｄ３ n represents an integer between 0 and 4, preferably between 0 and 3, and preferably 2 or 3. ｄ２ or n ｄ３ If is an integer greater than or equal to 2, then multiple R ｄ３ R with other R or multiple R ｄ４ The elements may be identical or different. ｄ４ and n ｄ５ n represents an integer between 0 and 20, preferably between 1 and 20, more preferably between 2 and 15, and even more preferably between 3 and 10. ｄ４ or n ｄ５If n is an integer greater than or equal to 2, then multiple n ｄ１ They may be the same or they may be different. ｄ４ and n ｄ５ The sum of the integers is an integer between 1 and 30, preferably between 2 and 25, more preferably between 5 and 20, and even more preferably between 7 and 15.

[0065] X in the above general formula (D-3) ｄ１ Examples of alkylene groups having 1 to 5 carbon atoms include methylene group, 1,2-dimethylene group, 1,3-trimethylene group, 1,4-tetramethylene group, and 1,5-pentamethylene group. ｄ１ Examples of alkylidene groups with 2 to 5 carbon atoms shown include ethylidene, propyridene, isopropylidene, butylidene, isobutylidene, pentylidene, and isopentylidene. ｄ１ Among the groups shown, the isopropylidene group is preferred from the viewpoint of high-frequency characteristics, adhesion to conductors, and compatibility between component (A) and component (B). ｄ１ and Y ｄ２ The preferred embodiment of the ethylenically unsaturated bond-containing group shown is as described above. The compound represented by the general formula (D-3) is preferably the compound represented by the following general formula (D-4) from the viewpoint of high-frequency characteristics, adhesion to conductors, and compatibility between component (A) and component (B).

[0066] (In the formula, n ｄ４ and n ｄ５ This is as explained in the general formula (D-3) above. R ｄ５ and R ｄ６ Each of these independently represents either a hydrogen atom or a methyl group. ｄ２ (This indicates a methylene group or an isopropylidene group.)

[0067] [Weight-average molecular weight (Mw) of polyphenylene ether derivative (D)] The weight-average molecular weight (Mw) of 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 component (D) is above the lower limit, a cured product with excellent dielectric properties and heat resistance of polyphenylene ether tends to be obtained, and when it is below the upper limit, excellent moldability tends to be obtained.

[0068] The method for synthesizing polyphenylene ether derivative (D) is not particularly limited and can be any known method for synthesizing or modifying polyphenylene ethers.

[0069] (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 solids in the resin composition. When the content of component (D) is above the lower limit, excellent high-frequency characteristics and compatibility tend to be obtained, and when it is below the upper limit, excellent heat resistance, moldability and processability tend to be obtained.

[0070] <Curing Accelerator (E)> The resin composition of this embodiment, by further containing a curing accelerator as component (E), tends to have improved curability, resulting in better high-frequency characteristics, heat resistance, adhesion to conductors, elastic modulus, and glass transition temperature. However, component (E) does not contain the organic peroxide (Z). When the resin composition of this embodiment contains a curing accelerator (E), a suitable curing accelerator (E) should be appropriately selected according to the type of thermosetting resin (B) component used. One type of curing accelerator (E) may be used alone, or two or more types may be used in combination.

[0071] (E) Component may include amine-based curing accelerators, imidazole-based curing accelerators, phosphorus-based curing accelerators, organometallic salts, acidic catalysts, etc. 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-masquimidazole (for example, 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 tri-n-butylphosphine addition reaction product of p-benzoquinone. Examples of organometallic salts include carboxylates of manganese, cobalt, zinc, etc. Examples of acidic catalysts include p-toluenesulfonic acid. Among these, amine-based curing accelerators, imidazole-based curing accelerators, and phosphorus-based curing accelerators are preferred from the viewpoint of obtaining better high-frequency characteristics, heat resistance, adhesion to conductors, elastic modulus, and glass transition temperature, and dicyandiamide, imidazole-based curing accelerators, and quaternary phosphonium compounds are more preferred, and using them in combination is even more preferable.

[0072] (Content of component (E)) When the resin composition of this embodiment contains component (E), the content of 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, even 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.

[0073] <Other Components> The resin composition of this embodiment may further contain one or more optional components other than the above-mentioned components, such as resin materials, flame retardants, flame retardant aids, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, colorants, lubricants, and silane coupling agents, as needed. Each of the above optional components may be used individually or in combination of two or more. When the resin composition of this embodiment contains the above optional components, the amount 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, 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 amount of resin components. Furthermore, the resin composition of this embodiment may not contain the above optional components, depending on the desired performance.

[0074] The total content of components (A) to (E) in the resin components contained in the resin composition of this embodiment is not particularly limited, but is preferably 80 parts by mass or more, more preferably 90 parts by mass or more, even more preferably 95 parts by mass or more, and may be 100 parts by mass, based on 100 parts by mass of solids in the resin composition.

[0075] (Organic solvent) The resin composition of this embodiment may be a varnish-like resin composition containing an organic solvent, from the viewpoint of facilitating handling and facilitating the production of the prepreg described later. Examples of organic solvents 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 individually or in combination of two or more.

[0076] When the resin composition of this embodiment contains an organic solvent, the amount is not particularly limited, but it is preferable that the solid content concentration of the resin composition of this embodiment be 30 to 90% by mass, more preferably 40 to 80% by mass, and even more preferably 50 to 70% by mass. When the organic solvent content is within the above range, the resin composition becomes easier to handle, and the impregnation into the substrate and the appearance of the manufactured prepreg become good. Furthermore, it becomes easier to adjust the solid content concentration of the resin in the prepreg, as described later, and it tends to become easier to manufacture a prepreg with the desired thickness.

[0077] <Glass Transition Temperature (Tg)> The glass transition temperature (Tg) when the resin composition of this embodiment is used to prepare a test specimen by the method described in the examples below is not particularly limited, but is preferably 260 to 350°C, more preferably 265 to 340°C, even more preferably 270 to 330°C, particularly preferably 275 to 320°C, and most preferably 280 to 310°C. The glass transition temperature (Tg) is measured using a dynamic viscoelasticity analyzer (DMA) in tensile mode, with a temperature range of 30 to 350°C and a heating rate of 5°C / min, and is determined from the obtained storage modulus and loss modulus. More specifically, it is the value measured by the method described in the examples.

[0078] The resin composition of this embodiment can be produced by mixing component (A), component (B), and component (Z), and other components as needed, in a known manner. In this case, 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 arbitrarily.

[0079] [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 manufactured, for example, by applying a resin composition containing an organic solvent, i.e., a varnish, to a support, heating and drying it, and semi-curing it (B-stage) 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 support materials include plastic films, metal foils, and release paper. The drying temperature and drying time can be appropriately determined according to the amount of organic solvent used and the boiling point of the organic solvent used, but the resin film can be suitably formed by drying at 50 to 200°C for about 1 to 10 minutes.

[0080] [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 fibrous substrate. The prepreg is formed using the resin composition of this embodiment or the resin film and a sheet-like fibrous substrate. For example, it can be obtained by impregnating the resin composition of this embodiment or the resin film into a sheet-like fibrous substrate, then heating and drying it to partially cure (B-stage) it as needed. More specifically, for example, the prepreg of this embodiment can be manufactured by heating and drying it in a drying oven at a temperature of 80 to 200°C for 1 to 30 minutes to partially cure (B-stage) it. Here, in this disclosure, B-stage means reaching the B-stage state as defined in JIS K6900 (1994). The amount of resin composition used can be appropriately determined for the purpose of making the solid content concentration derived from the resin composition in the prepreg after drying 30 to 90% by mass. By setting the solid content concentration within the aforementioned range, better moldability tends to be obtained when the laminate is formed.

[0081] As the sheet-like fiber base material for the prepreg, known materials used in laminates for various electrical insulating materials are used. Examples of materials for the sheet-like fiber base material 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 base materials have the form of woven fabric, nonwoven fabric, rawhide, chopped strand mat, or surfacing mat. The thickness of the sheet-like fiber base material 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.

[0082] [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 a prepreg, and a metal foil. Embodiments of the laminate of this embodiment can be manufactured, for example, by arranging a metal foil on one or both sides of a single resin film of this embodiment, or by arranging a metal foil on one or both sides of a laminate obtained by stacking two or more resin films of this embodiment, and then by heating and pressing. In the laminate obtained by this manufacturing method, the resin film of this embodiment is C-staged. Another embodiment of the laminate of this embodiment can be manufactured, for example, by arranging a metal foil on one or both sides of a single prepreg of this embodiment, or by arranging a metal foil on one or both sides of a laminate obtained by stacking two or more prepregs of this embodiment, and then by heating and pressing. In the laminate obtained by this manufacturing method, the prepreg of this embodiment is C-staged. In this disclosure, C-staged means being in the state of C-stage as defined in JIS K6900 (1994). Laminates having metal foil are sometimes called metal-clad laminates. The metal of the metal foil is not particularly limited, but from the viewpoint of 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, with copper and aluminum being preferred, and copper being more preferred. The method of carrying out the heat-pressure molding is not particularly limited, but for example, it can be carried out 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 heat-pressure molding can be carried out by using a vacuum press or the like to maintain a vacuum state for 0.5 to 5 hours.

[0083] [Printed Wiring Board] The printed wiring board of this embodiment has a cured product of the resin composition of this embodiment. Alternatively, the printed wiring board of this embodiment can be said to have one or more 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 using one or more selected from the group consisting of the prepreg of this embodiment, the resin film of this embodiment, and the laminate of this embodiment, and performing circuit formation processing by known methods such as drilling, metal plating, and etching of metal foil. Furthermore, a multilayer printed wiring board can also be manufactured by performing multilayer bonding processing as needed. In the printed wiring board of this embodiment, the prepreg of this embodiment and the resin film of this embodiment are C-staged.

[0084] [Semiconductor Package] The semiconductor package of this embodiment is a semiconductor package having the printed circuit board of this embodiment and semiconductor elements. The semiconductor package of this embodiment can be manufactured by mounting semiconductor elements such as semiconductor chips and memory at predetermined positions on the printed circuit board of this embodiment.

[0085] The resin composition, resin film, prepreg, laminate, printed circuit board, and semiconductor package of this embodiment can be suitably used in electronic equipment that handles high-frequency signals of 10 GHz or higher. In particular, the printed circuit board is useful as a printed circuit board for millimeter-wave radar.

[0086] While preferred embodiments have been described above, these are illustrative examples for the purpose of explaining the Disclosure and are not intended to limit the scope of the Disclosure to these embodiments only. The Disclosure also includes various other embodiments without departing from its essence.

[0087] 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 denaturation rate were measured by the following methods.

[0088] (Measurement of weight-average molecular weight (Mw)) The weight-average molecular weight (Mw) was calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The calibration curve was approximated by a cubic equation using standard polystyrene: TSK standard POLYSTYRENE (Type; A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Corporation, trade name]. The GPC measurement conditions are shown below. Equipment: Pump: L-6200 [Hitachi High-Technologies Corporation] Detector: L-3300 RI [Hitachi High-Technologies Corporation] Column Oven: L-655A-52 [Hitachi High-Technologies Corporation] Column: Guard column; TSK Guardcolumn HHR-L + Column; TSKgel G4000HHR + TSKgel G2000HHR (all manufactured by Tosoh Corporation, product names) Column size: 6.0 × 40 mm (Guard column), 7.8 × 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

[0089] (Measurement of Acid Value) Approximately 1 g of maleic anhydride-modified styrene elastomer and 200 g of xylene were mixed at 80°C. 0.5 mL of distilled water was added to the mixture, and the mixture was stirred at reflux temperature for 1 hour to hydrolyze the succinic anhydride groups. The mixture was cooled 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 disappeared. The acid value (mgKOH / g) was measured from the amount of maleic anhydride-modified styrene elastomer and the amount of KOH added. Note that the acid value of the maleic anhydride-modified styrene elastomer is derived from the two carboxyl groups produced by the hydrolysis of the succinic anhydride groups.

[0090] (Method for calculating the denaturation rate) The denaturation rate of maleic anhydride-modified styrene elastomer was calculated by introducing the acid value, the molecular weight of KOH, and the molecular weight of maleic anhydride into the following formula: Denaturation rate (mass%) = [Acid value (mg KOH / g) / Molecular weight of KOH (mg / mol)] × 0.5 × Molecular weight of maleic anhydride (g / mol) × 100 (%)

[0091] [Manufacturing Example 1: Manufacturing of Maleic Anhydride Modified Styrene Elastomer 1 (Component (A))] In a 2 L flask equipped with a condenser, nitrogen inlet tube, thermocouple and stirrer, 950 g of xylene, 100 g of hydrogenated styrene thermoplastic elastomer (manufactured by Asahi Kasei Corporation, trade name "ToughTec H1041", weight-average molecular weight (Mw) = 73,300, styrene content = 30% by mass), and 17 g of maleic anhydride (Fujifilm Wako Pure Chemical Industries, Ltd.) were added and stirred at 80°C for 0.5 hours, then 0.5 cm ３ Nitrogen bubbling was carried out at a flow rate of 1 / L for 1.0 hour. Next, 6.5 g of benzoyl peroxide (Fujifilm Wako Pure Chemical Corporation) was added, and the reaction was carried out by stirring at 80°C with nitrogen bubbling for 6.0 hours. 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 elastomer 1 (acid value = 37.4 mg KOH / g) with a modification rate of 3.3% by mass.

[0092] [Production Example 2: Production of Maleic Anhydride Modified Styrene Elastomer 2 (Component (A')] The same procedure as in Production Example 1 was followed except that the amount of maleic anhydride used was changed to 4 g and the amount of benzoyl peroxide used was changed to 1.5 g to obtain Maleic Anhydride Modified Styrene Elastomer 2 (acid value = 9.3 mg KOH / g) with a modification rate of 0.8% by mass.

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

[0094] [Examples 1-3, Comparative Examples 1-4] (Preparation of Resin Composition) Each component listed in Table 1 was mixed with 58 parts by mass of toluene and 10 parts by mass of methyl isobutyl ketone at room temperature according to the blending composition listed in Table 1 to prepare a resin composition with a solid content of 55-65% by mass. (Production of Resin Film) The resin composition was applied to a PET film with a thickness of 0.050 mm using a coating machine, and heated and dried at 120°C for 3 minutes to produce a resin-coated PET film with a resin thickness of 25 μm. (Production of Double-Sided Copper-Clad Laminate) The resin sides of the resin-coated PET films were bonded together by vacuum pressure lamination (temperature 110°C, pressure 0.5 MPa). Furthermore, the process of peeling off one side of the PET film and bonding the resin side of another resin-coated PET film to the exposed resin surface was repeated until the resin thickness reached 325 μm. The PET film on both sides of a 325 μm thick resin-coated PET film was peeled off, and an 18 μm thick low-profile copper foil (BF-ANP18, M-side Rz: 1.5 μm, manufactured by CIRCUIT FOIL Co., Ltd.) was laminated on the top and bottom of the resin so that the M-side was in contact with the resin. This laminate was then placed in a 300 μm thick mold. Next, a double-sided copper-clad laminate was produced by heating and pressurizing under the conditions of 230°C, 3.0 MPa, and 90 minutes.

[0095] [Evaluation Method] Each evaluation was performed using the double-sided copper-clad laminates obtained in each example, according to the method described below. The results are shown in Table 1.

[0096] (1. Measurement of the size of the depressions) The copper foil was removed from the double-sided copper-clad laminates obtained in each example by immersing them in a copper etching solution, and then desmear treatment was performed by carrying out the following steps (1) to (4) in this order to produce resin plates. (1) Immerse in swelling solution (Atotec Japan Co., Ltd., product name "Swelling Dip Securigant P", aqueous solution of glycol ethers and sodium hydroxide) at 60°C for 10 minutes, then rinse with water. (2) Roughening solution (Atotec Japan Co., Ltd., product name "Concentrate Compact P", KMnO ４ (3) Immerse in an aqueous solution of 60 g / L of sodium sulfate and 40 g / L of NaOH at 80°C for 20 minutes, then rinse with water. (4) Immerse in a neutralizing solution (Atotec Japan Co., Ltd., "Reduction Sulfuric Acid Securigant P", an aqueous solution of sulfuric acid) at 40°C for 5 minutes, then rinse with water. (5) Dry at 80°C for 10 minutes.

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

[0098] (2. Measurement of Glass Transition Temperature (Tg)) A resin plate was prepared under the same conditions as in "Measurement of the Size of the Indentation" above. The obtained resin plate was cut to a width of 0.4 mm and a length of 40 mm, and then dried at 105°C for 1 hour to be used as a test specimen. The test specimen was held by both ends of its long side with upper and lower grips, with a gap of 20 mm between the grips. Then, a dynamic viscoelasticity analyzer (DMA) (manufactured by T.A. Instruments, trade name "DMA850") was used to measure the glass transition temperature in tensile mode, with a temperature range of 30 to 350°C and a heating rate of 5°C / min. The temperature corresponding to the highest value of tanδ (loss modulus / storage modulus) was defined as the glass transition temperature.

[0099]

[0100] The abbreviations for each material in Table 1 are as follows:

[0101] [Component (A): Maleic anhydride-modified styrene elastomer with a modification rate of 2.5% by mass or more] - Maleic anhydride-modified styrene elastomer 1: Maleic anhydride-modified styrene elastomer 1 with a modification rate of 3.3% by mass obtained in Production Example 1

[0102] [Component (A'): Styrene-based elastomer other than component (A) (for comparative example)] - Maleic anhydride-modified styrene-based elastomer 2: Maleic anhydride-modified styrene-based elastomer 2 obtained in Production Example 2 with a modification rate of 0.8% by mass

[0103] [Component (B): Thermosetting resin] Modified maleimide compound: Modified maleimide compound (X-1) prepared in Production Example 3

[0104] [(Z) Component: Organic Peroxide] • Organic Peroxide 1: α,α'-di(t-butylperoxy)diisopropylbenzene

[0105] [(C) Component: Inorganic filler] Silica: Spherical fused silica, average particle size: 0.5 μm, 70% by mass of methyl isobutyl ketone slurry

[0106] [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: Tri-n-butylphosphine addition reaction product of p-benzoquinone - Curing accelerator 2: 2-undecylimidazole - Curing accelerator 3: N-2-(aminoethyl)-3-aminopropyltrimethoxysilane

[0107] As is clear from the results shown in Table 1, the copper-clad laminates of Examples 1 to 3, prepared using the resin composition of this embodiment, contained a styrene-based elastomer, yet they were able to suppress the depressions on the insulating layer that occurred in the copper-clad laminates of Comparative Examples 1, 3, and 4, reducing them to less than 0.5 μm in diameter or suppressing the occurrence of depressions altogether. Furthermore, in Comparative Example 2, which contained an organic peroxide in the resin composition compared to Comparative Example 1, the Tg of the resin plate in the copper-clad laminate decreased significantly. However, in the copper-clad laminates of Examples 1 to 3, although the resin composition used contained an organic peroxide, the decrease in the Tg of the resin plate was suppressed, and it can be seen that they had a high Tg. Comparing Example 3 with Comparative Example 2, the effect is clearly remarkable.

Claims

A resin composition comprising a maleic anhydride-modified styrene elastomer (A) with a modification rate of 2.5% by mass or more, a thermosetting resin (B), and an organic peroxide (Z), A resin composition in which the content of the organic peroxide (Z) is 0.10 parts by mass or more per 100 parts by mass of component (B). 　 The resin composition according to claim 1, wherein the thermosetting resin (B) comprises one or more selected from the group consisting of epoxy resin, maleimide compound, phenol resin, polyimide resin, cyanate resin, isocyanate resin, benzoxazine resin, oxetane resin, amino resin, unsaturated polyester resin, allyl resin, dicyclopentadiene resin, silicone resin, triazine resin, and melamine resin. 　 The resin composition according to claim 1, wherein the content of component (A) is 1 to 50 parts by mass per 100 parts by mass of solids in the resin composition. 　 Furthermore, the resin composition according to claim 1, further containing an inorganic filler (C). 　 The resin composition according to claim 1, further comprising a polyphenylene ether derivative (D) having an ethylenically unsaturated bond-containing group. Furthermore, the resin composition according to claim 1 contains a curing accelerator (E) (excluding component (Z)). 　 A resin film containing the resin composition described in claim 1 or a semi-cured product of the resin composition. 　 A prepreg containing the resin composition described in claim 1 or a semi-cured product of the resin composition. 　 A laminate having a cured product of the resin composition described in claim 1 or a cured product of the prepreg described in claim 8, and a metal foil. 　 A printed circuit board having a cured product of the resin composition described in claim 1. 　 A semiconductor package having a printed circuit board according to claim 10 and a semiconductor element.

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