Curable resin composition

Abstract

To provide a resin composition that yields a cured product with a low dielectric constant, a low dielectric dissipation factor, reduced warpage, and superior resistance to chemicals.SOLUTION: A curable resin composition comprises (A-1) a cyclic imide resin represented by formula (1) (in formula (1), A independently represents a tetravalent organic group containing a cyclic structure, B independently represents a divalent aliphatic hydrocarbon group having 6 or more carbon atoms and optionally containing a hetero atom, X represents a hydrogen atom or a methyl group, and n represents 1 to 200, with the repeating units bracketed by n being identical or different and their sequence not being limited), and (B) a curing catalyst, wherein the total molar number of curable functional groups per 100 g of resin component is 2 to 20 mol.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition. [Background technology]

[0002] In recent years, the speed and capacity of signals used in electronic devices such as mobile phones, their base station equipment, servers, routers, and other network infrastructure equipment, as well as large-scale computers, have been increasing year by year. As a result, the printed wiring boards used in these electronic devices use high frequencies in the 20 GHz range, and insulating materials for printed wiring boards are required to have properties such as a low dielectric constant and a low dielectric loss tangent.

[0003] Materials that may satisfy these properties include epoxy resins, modified polyphenylene ether resins, aromatic maleimide resins, and aliphatic maleimide resins (Patent Documents 1 to 4). Among printed wiring boards, build-up boards are formed by stacking insulating and conductor layers alternately. Fine copper wiring is spread across the top and bottom of build-up boards, but the density of the copper wiring and insulating resin varies depending on the location, causing slight warping across the entire board. As copper wiring becomes finer, even slight warping affects the yield of build-up boards. Highly elastic resins such as epoxy resins, modified polyphenylene ether resins, and aromatic maleimide resins are excellent in processability for printed wiring boards, but are prone to warping due to their high elasticity.On the other hand, low-elasticity resins such as aliphatic maleimide resins are less likely to warp, but have the disadvantage of poor processability due to their high expansion coefficient and low chemical resistance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-1965 A [Patent Document 2] Japanese Patent Application Publication No. 2018-28044 [Patent Document 3] Japanese Patent Application Publication No. 2020-176190 [Patent Document 4] Japanese Patent Publication No. 2020-12026 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a curable resin composition that gives a cured product that has a low relative dielectric constant and a low dielectric loss tangent, but also exhibits little warpage and excellent chemical resistance (desmear resistance). [Means for solving the problem]

[0006] As a result of extensive research to solve the above problems, the present inventors have found that the following curable resin composition can achieve the above object, and have completed the present invention. That is, the present invention provides the following curable resin composition and the like.

[0007] [1] (A-1) A cyclic imide resin represented by the following formula (1): [ka] (In formula (1), A's independently represent tetravalent organic groups containing a cyclic structure. B's independently represent divalent aliphatic hydrocarbon groups having 6 or more carbon atoms which may contain a heteroatom, and at least half of the B's are groups represented by formula (2) below. X represents a hydrogen atom or a methyl group, and n is 1 to 200. The repeating units bracketed by n may be the same or different, and the order in which they occur is not limited.) [ka] (In formula (2), R is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x is independently a number from 0 to 4.) and (B) Curing catalyst and wherein the total number of moles of curable functional groups per 100 g of the resin component is 2 to 20 mol. [2] The curable resin composition according to [1], further comprising an inorganic filler as component (C). [3] The curable resin composition according to [1] or [2], further comprising a cyclic imide compound represented by the following formula (3) as a component (A-2): [ka] (In formula (3), A independently represents a tetravalent organic group containing a cyclic structure. B independently represents a divalent aliphatic hydrocarbon group having 6 or more carbon atoms which may contain a heteroatom and does not contain a group represented by formula (2) above. X represents a hydrogen atom or a methyl group, and s is 0 to 200.) [Effects of the Invention]

[0008] The curable resin composition of the present invention forms a cured product having a low dielectric constant, a low dielectric loss tangent, little warpage, and excellent chemical resistance (desmear resistance). Therefore, the curable resin composition of the present invention is useful for applications such as copper-clad laminates, printed wiring boards, base films for flexible printed wiring boards, coverlay films, and semiconductor encapsulants. DETAILED DESCRIPTION OF THE INVENTION

[0009] The curable resin composition of the present invention will be described in detail below.

[0010] [(A-1) Cyclic imide compound represented by the following formula (1)] The cyclic imide compound of component (A-1) is the main component of the curable resin composition of the present invention and is represented by the following formula (1): By including component (A-1) in the curable resin composition of the present invention, a cured product of the curable resin composition will have a low relative dielectric constant, a low dielectric loss tangent, low warpage, and high chemical resistance. [ka] (In formula (1), A's independently represent tetravalent organic groups containing a cyclic structure. B's independently represent divalent aliphatic hydrocarbon groups having 6 or more carbon atoms which may contain a heteroatom, and at least half of the B's are groups represented by formula (2) below. X represents a hydrogen atom or a methyl group, and n is 1 to 200. The repeating units bracketed by n may be the same or different, and the order in which they occur is not limited.) [ka] (In formula (2), R is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x is independently a number from 0 to 4.)

[0011] Here, the organic groups represented by A in formula (1) are independently tetravalent organic groups containing a cyclic structure, and are particularly preferably any of the tetravalent organic groups represented by the following structural formulas. [ka] (The bond not bonded to a substituent in the above structural formula is bonded to the carbonyl carbon that forms the cyclic imide structure in formula (1).)

[0012] In formula (1), each B is independently a divalent aliphatic hydrocarbon group having 6 or more carbon atoms which may contain a heteroatom (including a group represented by formula (2) below), and is preferably a divalent hydrocarbon group represented by any of the following structural formulas or a divalent hydrocarbon group derived from a dimer acid skeleton. [ka]

[0013] In the above formula, R 1 R are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 20 carbon atoms. 1 is preferably a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, and more preferably a hydrogen atom or a linear alkyl group having 1 to 10 carbon atoms. In the above formula, p1 and p 2 are each a number of 5 or more, preferably a number of 5 to 12, more preferably a number of 6 to 10, and may be the same or different. In the above formula, p 3 and p 4 are each a number of 0 or more, preferably a number of 0 to 4, more preferably a number of 0 to 3, and may be the same or different. In the above formula, p 5 and p 6 are each a number of 0 or more, preferably a number of 0 to 4, more preferably a number of 0 to 2, and may be the same or different.

[0014] The divalent hydrocarbon group derived from a dimer acid skeleton is a group derived from dimer acid, a liquid fatty acid primarily composed of a 36-carbon dicarboxylic acid, produced by dimerization of an 18-carbon unsaturated fatty acid derived from natural sources such as vegetable oils. Dimer acids do not have a single skeleton but have multiple structures, resulting in several isomers. The dimer acid skeleton refers to a group derived from a dimer diamine, which has a structure in which the carboxyl group of such a dimer acid is substituted with a primary aminomethyl group. From the standpoint of heat resistance and reliability of the cured product, it is more preferable for the divalent hydrocarbon group derived from the dimer acid skeleton to have a structure in which the carbon-carbon double bond in the hydrocarbon group derived from the dimer acid skeleton is reduced by a hydrogenation reaction. Generally, dimer acids may contain trimers (trimer acids) due to the use of natural products such as vegetable oils and fats as raw materials. However, it is preferable that the proportion of hydrocarbon groups derived from dimer acids among the hydrocarbon groups derived from dimer acids and trimer acids is high, for example, 95 mass % or more, because this tends to result in excellent dielectric properties, excellent moldability due to a tendency for the viscosity to decrease when heated, and reduced effects of moisture absorption. As described above, the dimer acid skeleton has a plurality of structures, and therefore, in this specification, the divalent hydrocarbon group derived from the dimer acid skeleton is referred to as the average structure, i.e., -C 36 H 70 It may be written as -.

[0015] At least half of the B's in formula (1) are groups represented by the following formula (2): In formula (2), R's are independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group. [ka]

[0016] In formula (2), x is independently a number of 0 to 4, and preferably a number of 0 to 2. The x's may be the same or different.

[0017] Specific examples of formula (2) include the following structures: [ka]

[0018] The bond to which no substituent is bonded in the above formula is bonded to the nitrogen atom that forms the cyclic imide structure in formula (1).

[0019] A higher content of the group represented by the above formula (2) than other groups in B (that is, groups other than the above formula (2)) is preferred for improving chemical resistance (desmear resistance). Here, the content of the group represented by formula (2) in B is preferably from 50 to 100%, more preferably from 50 to 90%, and particularly preferably from 50 to 80%.

[0020] In formula (1), X is a hydrogen atom or a methyl group, and is preferably a hydrogen atom. In formula (1), n ​​is 1 to 200, preferably 2 to 100, and more preferably 2 to 50. The repeating units enclosed by n may be the same or different, and the order of these repeating units is not limited.

[0021] The weight-average molecular weight (Mw) of the cyclic imide compound of component (A-1) is not particularly limited, but is preferably 500 to 1,000,000, more preferably 1,000 to 100,000, and even more preferably 3,000 to 50,000. If the weight-average molecular weight (Mw) is within this range, the curable resin composition will have sufficient strength and the terminal cyclic imide groups can be reacted efficiently. The weight average molecular weight (Mw) referred to in this specification refers to the weight average molecular weight measured by GPC under the following conditions using polystyrene as the standard. [GPC measurement conditions] Developing solvent: tetrahydrofuran Flow rate: 0.6mL / min Column: TSK Guardcolumn SuperH-L TSKgel SuperH4000(6.0mmI.D.×15cm×1) TSKgel SuperH3000(6.0mmI.D.×15cm×1) TSKgel SuperH2000(6.0mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 20 μL (sample concentration: 0.5% by mass in tetrahydrofuran solution) Detector: Differential refractometer (RI)

[0022] The method for producing the cyclic imide compound of component (A-1) is not particularly limited. For example, it may be produced by reacting an amine compound with an excess of maleic anhydride or citraconic anhydride, or it may be produced by reacting an acid anhydride with a diamine to synthesize an amine-terminated compound, and then reacting the amine-terminated compound with an excess of maleic anhydride or citraconic anhydride.

[0023] Examples of acid anhydrides include pyromellitic anhydride, maleic anhydride, succinic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-diphthalic anhydride, 4,4'-sulfonyldiphthalic anhydride, 4,4'-oxydiphthalic anhydride, and 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride. These acid anhydrides may be used alone or in combination depending on the purpose, application, etc. From the viewpoint of the electrical properties of the cyclic imide compound, pyromellitic anhydride, 4,4'-oxydiphthalic anhydride, and 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride are preferred.

[0024] Examples of diamines include tetramethyl-1,3-bis(3-aminopropyl)disiloxane, 1,12-diaminododecane, 1,10-diaminodecane, dimer diamine, octyldiamine, 1,3-di(aminomethyl)cyclohexane, isophoronediamine, 2,4,4-trimethylhexane-1,6-diamine, 2-methylpentane-1,5-diamine, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0(2,6)]decane, etc. These diamines may be used alone or in combination of two or more depending on the purpose, application, etc. From the viewpoint of the electrical properties of the cyclic imide compound, the diamine is preferably an aliphatic diamine such as tetramethyl-1,3-bis(3-aminopropyl)disiloxane, 1,12-diaminododecane, 1,10-diaminodecane, dimerdiamine, octyldiamine, 1,3-di(aminomethyl)cyclohexane, 1-amino-4-(aminomethyl)cyclohexane, 1,3-diaminoadamantane, isophoronediamine, 2,4,4-trimethylhexane-1,6-diamine, or 2-methylpentane-1,5-diamine, with dimerdiamine and isophoronediamine being particularly preferred.

[0025] The equivalent weight of the cyclic imide group in the component (A-1) is preferably 0.001 to 0.5 mol / 100 g, more preferably 0.003 to 0.4 mol / 100 g, even more preferably 0.01 to 0.3 mol / 100 g, and even more preferably 0.02 to 0.2 mol / 100 g. This range is preferable because the cured product of the curable resin composition has a low dielectric constant and a low dielectric loss tangent.

[0026] The component (A) may be used alone or in combination of two or more types. The content of the component (A-1) in the curable resin composition of the present invention is preferably 50 to 90 mass %, more preferably 60 to 80 mass %.

[0027] [(B) Curing catalyst] The curing catalyst of component (B) is not particularly limited, but examples thereof include thermal radical polymerization initiators and thermal anionic polymerization initiators. Examples of the thermal radical polymerization initiator include methyl ethyl ketone peroxide, methylcyclohexanone peroxide, methylacetoacetate peroxide, acetylacetone peroxide, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-hexylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(4,4-di-t -butylperoxycyclohexyl)propane, 1,1-bis(t-butylperoxy)cyclododecane, n-butyl-4,4-bis(t-butylperoxy)valerate, 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, t-butyl hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-hexyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl 2,5-Dimethyl-2,5-bis(t-butylperoxy)hexane, α,α'-bis(t-butylperoxy)diisopropylbenzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, cinnamic acid peroxide, m-toluoyl peroxide, benzoyl peroxide, diisopropyl Pyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di(3-methyl-3-methoxybutyl) peroxydicarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, α,α'-bis(neodecanoylperoxy)diisopropylbenzene, cumyl peroxyneodecanoate, 1,1,3,3-Tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy Peroxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxy Organic peroxides such as 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis[N-(2-methylpropyl)-2-methylpropionamide], 2,2'-azobis[N-(2-methylethyl ... ethyl)-2-methylpropionamide], 2,2'-azobis(N-hexyl-2-methylpropionamide), 2,2'-azobis(N-propyl-2-methylpropionamide), 2,2'-azobis(N-ethyl-2-methylpropionamide), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,Examples of the azo compounds include 2'-azobis[N-(2-propenyl)-2-methylpropionamide] and dimethyl-1,1'-azobis(1-cyclohexanecarboxylate).

[0028] Examples of the thermal anionic polymerization initiator include amine compounds such as triethylamine, triethylenediamine, 2-(dimethylaminomethyl)phenol, 1,8-diaza-bicyclo[5.4.0]undecene-7, tris(dimethylaminomethyl)phenol, and benzyldimethylamine; and imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine, and 2-phenyl-4-hydroxy-5-methylimidazole. midazole compounds; and organic phosphorus compounds such as triphenylphosphine, tributylphosphine, trioctylphosphine, tetrabutylphosphonium hexafluorophosphate, tetrabutylphosphonium tetraphenylborate, tetrabutylphosphonium acetate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium bromide, tetrabutylphosphonium bromide, tetrabutylphosphonium laurate, tetraphenylphosphonium hydrogen phthalate, bis(tetraphenylphosphonium)dihydrogenpyromellitate, and bis(tetrabutylphosphonium)dihydrogenpyromellitate.

[0029] Among these, thermal anionic polymerization initiators are preferred, and among these, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine, and 2-phenyl-4-hydroxy-5-methylimidazole are particularly preferred. These polymerization initiators may be used alone or in combination of two or more.

[0030] The amount of component (B) blended is not particularly limited, but is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.3 to 3 parts by mass, per 100 parts by mass of component (A-1). Within this range, the curable resin composition can be sufficiently cured without adversely affecting the physical properties.

[0031] The curable resin composition of the present invention satisfies the following condition (α), and thus a cured product of the curable resin composition satisfies the following conditions (β) and / or (γ). Each of the conditions will be described in detail below.

[0032] [(α) The total number of moles of curable functional groups per 100 g of resin component is 2 to 20 mol] One of the causes of warping of substrates is the curing shrinkage of resins, which occurs when the functional groups of molecules that had been maintaining distance through interaction react and form covalent bonds, shortening the distance between molecules. Therefore, in the curable resin composition of the present invention, the total number of moles of curable functional groups (e.g., maleimide group, citraconic group, epoxy group, acrylic group, silanol group, etc.) per 100 g of resin component is 2 to 20 mol, preferably 3 to 15 mol, and more preferably 4 to 10 mol. If the total number of moles is less than 2 mol, the crosslinking density of the resin may be low, and the heat resistance and chemical resistance may be poor. If the total number of moles is more than 20 mol, the cure shrinkage may be large, resulting in significant warpage. Here, the resin component refers to component (A-1), optional component (A-2), component (B), and optional components such as adhesion promoters, antioxidants, and flame retardants. Note that optional fillers such as inorganic fillers and organic fillers are not included in the resin component.

[0033] The curable functional group was calculated according to the following procedure. First, the 400 MHz of a mixture of 0.1 g of a compound having a curable functional group and 0.078 g of dimethyl sulfoxide as an internal standard was measured. 1The H-NMR spectrum was measured, and the integral value of the hydrogen atoms of dimethyl sulfoxide was set to 0.06 mol, and the number of moles of curable functional groups per 1 g of compound was calculated from the integral value of the hydrogen atoms of the functional group. Next, the amount of compound containing curable functional groups per 100 g of resin component was determined. Finally, the number of moles of curable functional groups per 100 g of resin component was calculated from the number of moles of curable functional groups per 1 g of compound and the amount of compound.

[0034] [(β) The storage modulus of the cured resin composition at 25°C is 1 to 6 GPa] One way to reduce warpage of a board is to reduce the elastic modulus of the resin. The stress applied to the resin at temperature T, which causes warpage, can be approximated by multiplying the strain applied to the resin at temperature T by the storage elastic modulus at temperature T. Therefore, the storage modulus of the curable resin composition of the present invention at 25°C is 1 to 6 GPa, preferably 2 to 5 GPa, and more preferably 3 to 5 GPa. If the storage modulus is less than 1 GPa, dimensional stability may be impaired. If the storage modulus is more than 6 GPa, warpage may increase.

[0035] [(γ) The linear expansion coefficient of the cured resin composition at 20 to 200°C is 140 ppm / K or less] One of the causes of warping in substrates is thermal shrinkage of resin, which occurs when the resin gels or hardens at high temperatures and then shrinks when cooled to room temperature. For this reason, the linear expansion coefficient of the curable resin composition of the present invention at 20 to 200° C. is 140 ppm / K or less, preferably 10 to 130 ppm / K, and more preferably 10 to 120 ppm / K. If the linear expansion coefficient is greater than 140 ppm / K, thermal shrinkage becomes large, which may result in significant warpage.

[0036] [(C) Inorganic filler] The curable resin composition of the present invention may contain an inorganic filler as component (C). The inorganic filler is not particularly limited, and examples thereof include metal oxides such as silica, titanium dioxide, yttrium oxide, aluminum oxide, magnesium oxide, zinc oxide, and beryllium oxide; metal nitrides such as boron nitride, aluminum nitride, and silicon nitride; carbon-containing particles such as silicon carbide, diamond, and graphene; hollow particles such as silica balloons (hollow silica), carbon balloons, alumina balloons, and aluminosilicate balloons; elemental metals such as gold, silver, copper, palladium, aluminum, nickel, iron, cobalt, titanium, manganese, zinc, tungsten, platinum, lead, and tin; and alloys such as solder, steel, and stainless steel. Examples of such materials include magnetic metal alloys such as stainless steel, Fe-Cr-Al-Si alloys, Fe-Si-Al alloys, Fe-Ni alloys, Fe-Cu-Si alloys, Fe-Si alloys, Fe-Si-B(-Cu-Nb) alloys, Fe-Si-Cr-Ni alloys, Fe-Si-Cr alloys, and Fe-Si-Al-Ni-Cr alloys; and ferrites such as hematite (Fe2O3), magnetite (Fe3O4), Mn-Zn ferrites, Ni-Zn ferrites, Mg-Mn ferrites, Zr-Mn ferrites, Ti-Mn ferrites, Mn-Zn-Cu ferrites, barium ferrites, and strontium ferrites. These may be used alone or in combination of two or more.

[0037] By adding metal oxides, metal nitrides, or carbon-containing particles, the linear expansion coefficient of the cured product of the curable resin composition can be reduced and the thermal conductivity can be increased; by adding hollow particles, the relative dielectric constant, dielectric loss tangent, density, etc. of the cured product of the curable resin composition can be reduced; by adding metals or alloys, the electrical conductivity, thermal conductivity, etc. of the cured product of the resin composition can be increased; and by adding ferrites, electromagnetic wave absorption ability can be imparted to the cured product of the curable resin composition.

[0038] The shape of the inorganic filler is not particularly limited, and examples thereof include spherical, scale-like, flake-like, needle-like, rod-like, and elliptical shapes. Among these, spherical, scale-like, flake-like, elliptical, and rod-like shapes are preferred, and spherical, scale-like, flake-like, and elliptical shapes are more preferred.

[0039] The primary particle size of the inorganic filler is not particularly limited, but is preferably 0.05 to 500 μm, more preferably 0.1 to 300 μm, and even more preferably 1 to 100 μm, as a median diameter measured with a laser diffraction particle size distribution analyzer. Within this range, the inorganic filler can be easily uniformly dispersed in the curable resin composition, and the inorganic filler does not settle, separate, or become unevenly distributed over time, which is preferable.

[0040] The amount of the inorganic filler is not particularly limited, but is preferably 5 to 300 parts by mass, more preferably 10 to 250 parts by mass, and even more preferably 50 to 200 parts by mass, per 100 parts by mass of component (A-1) in the curable resin composition of the present invention. Within this range, the inorganic filler can fully exhibit its function while maintaining the storage modulus of condition (β).

[0041] [(A-2) Cyclic imide compound represented by the following formula (3)] The curable resin composition of the present invention may contain, as the component (A-2), a cyclic imide compound represented by the following formula (3): [ka] (In formula (3), A independently represents a tetravalent organic group containing a cyclic structure. B independently represents a divalent aliphatic hydrocarbon group having 6 or more carbon atoms which may contain a heteroatom and does not contain a group represented by formula (2) above. X represents a hydrogen atom or a methyl group, and s is 0 to 200.)

[0042] In formula (3), A and X are the same as those in formula (1), and B is the same as those in formula (1) (but does not include the group represented by formula (2)). In formula (3), s is 0 to 200, preferably 0 to 100, more preferably 0 to 50, and particularly preferably 0 to 25. Furthermore, the repeating units bracketed by S may be the same or different, and the order thereof is not limited.

[0043] The weight-average molecular weight (Mw) of the cyclic imide compound of component (A-2) is not particularly limited, but is preferably 500 to 1,000,000, more preferably 1,000 to 100,000, and even more preferably 3,000 to 50,000. If the weight-average molecular weight (Mw) is within this range, the curable resin composition will have sufficient strength and the terminal cyclic imide groups can be reacted efficiently.

[0044] The method for producing the cyclic imide compound of component (A-2) is not particularly limited. For example, it may be produced by reacting an amine compound with an excess of maleic anhydride or citraconic anhydride, or it may be produced by reacting an acid anhydride with a diamine to synthesize an amine-terminated compound, and then reacting the amine-terminated compound with an excess of maleic anhydride or citraconic anhydride.

[0045] Examples of acid anhydrides include pyromellitic anhydride, maleic anhydride, succinic anhydride, 4,4'-carbonyldiphthalic anhydride, 4,4'-diphthalic anhydride, 4,4'-sulfonyldiphthalic anhydride, 4,4'-oxydiphthalic anhydride, and 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride. These acid anhydrides may be used alone or in combination depending on the purpose, application, etc. From the viewpoint of the electrical properties of the cyclic imide compound, pyromellitic anhydride, 4,4'-oxydiphthalic anhydride, and 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride are preferred.

[0046] Examples of diamines include tetramethyl-1,3-bis(3-aminopropyl)disiloxane, 1,12-diaminododecane, 1,10-diaminodecane, dimer diamine, octyldiamine, 1,3-di(aminomethyl)cyclohexane, isophoronediamine, 2,4,4-trimethylhexane-1,6-diamine, 2-methylpentane-1,5-diamine, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0(2,6)]decane, etc. These diamines may be used alone or in combination of two or more depending on the purpose, application, etc. From the viewpoint of the electrical properties of the cyclic imide compound, the diamine is preferably an aliphatic diamine such as tetramethyl-1,3-bis(3-aminopropyl)disiloxane, 1,12-diaminododecane, 1,10-diaminodecane, dimerdiamine, octyldiamine, 1,3-di(aminomethyl)cyclohexane, 1-amino-4-(aminomethyl)cyclohexane, 1,3-diaminoadamantane, isophoronediamine, 2,4,4-trimethylhexane-1,6-diamine, or 2-methylpentane-1,5-diamine, with dimerdiamine and isophoronediamine being particularly preferred.

[0047] The equivalent weight of the cyclic imide group in component (A-2) is preferably 0.001 to 0.5 mol / 100 g, more preferably 0.003 to 0.4 mol / 100 g, even more preferably 0.01 to 0.3 mol / 100 g, and even more preferably 0.02 to 0.2 mol / 100 g. This range is preferable because the cured product of the curable resin composition has a low dielectric constant, a low dielectric loss tangent, and high adhesion.

[0048] The amount of component (A-2) to be blended is an amount that satisfies the above-mentioned condition (α), and is preferably 5 to 50 parts by mass, and more preferably 10 to 30 parts by mass, per 100 parts by mass of component (A-1) in the curable resin composition of the present invention. Within this range, the curable resin composition of the present invention forms a cured product that has a low relative dielectric constant, a low dielectric loss tangent, little warpage, and excellent chemical resistance (desmear resistance).

[0049] [Organic filler] The curable resin composition of the present invention may further contain an organic filler. The organic filler is not particularly limited, and examples thereof include thermoplastic resin particles such as acrylic-butadiene copolymer, styrene-butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, and acrylic block copolymer, carbon fiber, cellulose fiber, silicone powder, acrylic powder, polytetrafluoroethylene powder, polyethylene powder, and polypropylene powder. These may be used alone or in combination of two or more.

[0050] The shape of the organic filler is not particularly limited, and examples thereof include spherical, fibrous, flake-like, needle-like, rod-like, and elliptical shapes. Among these, spherical, fibrous, flake-like, elliptical, and rod-like shapes are preferred, and spherical, fibrous, flake-like, and elliptical shapes are more preferred.

[0051] The primary particle size of the organic filler is not particularly limited, but is preferably 0.05 to 500 μm, more preferably 0.1 to 300 μm, and even more preferably 1 to 100 μm, as a median diameter measured with a laser diffraction particle size distribution analyzer. Within this range, the organic particles can be easily dispersed uniformly in the curable resin composition, and the organic particles do not settle, separate, or become unevenly distributed over time, which is preferable.

[0052] The amount of the organic filler to be added is not particularly limited, but is preferably 1 to 400 parts by mass, more preferably 5 to 200 parts by mass, and even more preferably 10 to 100 parts by mass, per 100 parts by mass of component (A) in the curable resin composition of the present invention. Within this range, it is possible to increase the strength of the curable resin composition.

[0053] [Adhesion promoter] The curable resin composition of the present invention may contain an adhesion-imparting agent (component (D)) as needed to impart adhesiveness or tackiness (pressure-sensitive adhesiveness). Examples of adhesion-imparting agents include epoxy resins, acrylic resins, urethane resins, phenolic resins, terpene resins, and silane coupling agents. Of these, epoxy resins, acrylic resins, and silane coupling agents are preferred for imparting adhesiveness, and terpene resins are preferred for imparting tackiness (pressure-sensitive adhesiveness).

[0054] The epoxy resin is not particularly limited, and examples thereof include known epoxy resins that are liquid or solid at room temperature, such as biphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, 3,3',5,5'-tetramethyl-4,4'-biphenol-type epoxy resins and 4,4'-biphenol-type epoxy resins, biphenylaralkyl-type epoxy resins, phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, bisphenol A novolac-type epoxy resins, naphthalenediol-type epoxy resins, trisphenylolmethane-type epoxy resins, tetrakisphenylolethane-type epoxy resins and phenoldicyclopentadiene novolac-type epoxy resins in which the aromatic rings are hydrogenated, and alicyclic epoxy resins.

[0055] The acrylic resin is not particularly limited, and examples thereof include lauryl acrylate, stearyl acrylate, isostearyl acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl acid phosphate, polyethylene glycol diacrylate, dimethyloltricyclodecane diacrylate, trimethylolpropane triacrylate, and dipentaerythritol hexaacrylate. acrylate, dioxane glycol diacrylate, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene diacrylate, lauryl methacrylate, phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, tetrahydrofurfuryl methacrylate, isobornyl methacrylate, 2-methacryloyloxyethyl phthalate, 2-methacryloyloxyethyl acid phosphate, polyethylene glycol dimethacrylate, dimethyloltricyclodecane dimethacrylate, and the like.

[0056] The terpene resin is not particularly limited, and examples thereof include homopolymers of terpenes such as monoterpenes such as α-pinene, β-pinene, dipentene, and limonene, sesquiterpenes such as cedrene and farnesene, and diterpenes such as abietic acid, aromatic modified terpene resins which are copolymers of the above-mentioned terpenes with aromatic vinyl compounds such as styrene and α-methylstyrene, and terpene phenol resins which are copolymers of the above-mentioned terpenes with phenols such as phenol, cresol, hydroquinone, naphthol, and bisphenol A. Hydrogenated terpene resins obtained by hydrogenating these terpene resins can also be used.

[0057] The silane coupling agent is not particularly limited, and examples thereof include silane coupling agents such as n-propyltrimethoxysilane, n-propyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, 2-[methoxy(polyethyleneoxy)propyl]-trimethoxysilane, methoxytri(ethyleneoxy)propyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-isocyanatopropyltrimethoxysilane.

[0058] The amount of the adhesion promoter is not particularly limited, but is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and even more preferably 1 to 5 parts by mass, per 100 parts by mass of component (A-1). This range can further improve the adhesive strength or cohesive strength of the curable resin composition without changing the mechanical properties of the resin composition. Furthermore, when the adhesion promoter has a curable functional group such as an epoxy group, an acrylic group, or a silanol group, condition (α) may be satisfied if the total number of moles of the maleimide groups of components (A-1) and (A-2) and the curable functional groups of the adhesion promoter per 100 g of the resin component is 2 to 20 mol.

[0059] [Antioxidants] The resin composition of the present invention may contain an antioxidant, if necessary. The antioxidant is not particularly limited, and examples thereof include n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)acetate, neododecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, dodecyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, ethyl Octadecyl-α-(4-hydroxy-3,5-di-t-butylphenyl)isobutyrate, Octadecyl-α-(4-hydroxy-3,5-di-t-butylphenyl)isobutyrate, Octadecyl-α-(4-hydroxy-3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2-(n-octylthio)ethyl-3,5-di-t-butyl-4-hydroxyphenylacetate, 2-(n-octadecylthio)ethyl-3, 5-Di-t-butyl-4-hydroxyphenyl acetate, 2-(n-octadecylthio)ethyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2-(2-stearoyloxyethylthio)ethyl-7-(3-methyl-5-t-butyl-4-hydroxyphenyl)heptanoate, 2-hydroxyethyl-7-(3-methyl-5-t-butyl-4-hydroxyphenyl)propionate, Pentaerythritol Phenolic antioxidants such as rhythritol tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]; sulfur-based antioxidants such as dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, ditridecyl-3,3'-thiodipropionate, and pentaerythrityl tetrakis(3-laurylthiopropionate);Examples of phosphorus-based antioxidants include tridecyl phosphite, triphenyl phosphite, tris(2,4-di-t-butylphenyl)phosphite, 2-ethylhexyl diphenyl phosphite, diphenyl tridecyl phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octyl phosphite, distearyl pentaerythritol diphosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, and 2-[[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl]oxy]-N,N-bis[2-[[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphepin-6-yl]oxy]-ethyl]ethanamine;

[0060] The amount of the antioxidant to be added is not particularly limited, but is preferably 0.00001 to 5 parts by mass, more preferably 0.0001 to 4 parts by mass, and even more preferably 0.001 to 3 parts by mass, per 100 parts by mass of component (A-1).Within this range, oxidation of the curable resin composition can be prevented without changing the mechanical properties of the resin composition.

[0061] [Flame retardant] The curable resin composition of the present invention may contain a flame retardant as needed to impart flame retardancy. The flame retardant is not particularly limited, and examples thereof include phosphorus-based flame retardants, metal hydrates, halogen-based flame retardants, guanidine-based flame retardants, etc. Examples of phosphorus-based flame retardants include red phosphorus, ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and ammonium polyphosphate, inorganic nitrogen-containing phosphorus compounds such as guanidine phosphate and phosphoric acid amide, phosphoric acid, phosphine oxide, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl di-2,6-xylenyl phosphate, resorcinol bis(diphenyl phosphate), 1,3-phenylene bis(di-2,6-xylenyl phosphate), bisphenol A bis(diphenyl phosphate), 1,3-phenylene bis( Examples of suitable phosphazene compounds include bis(1-butenyl)phenylphosphonate, bis(2-allylphenoxy)phosphazene (diphenyl phosphate), divinyl phenylphosphonate, diallyl phenylphosphonate, bis(1-butenyl)phenylphosphonate, phenyl diphenylphosphinate, methyl diphenylphosphinate, bis(2-allylphenoxy)phosphazene, and dicresylphosphazene; melamine phosphate, melamine pyrophosphate, melamine polyphosphate, melam polyphosphate, melem polyphosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; and 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. Examples of suitable metal hydrates include aluminum hydroxide hydrate and magnesium hydroxide hydrate. Examples of halogen-based flame retardants include hexabromobenzene, pentabromotoluene, ethylenebis(pentabromophenyl), ethylenebistetrabromophthalimide, 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane, tetrabromocyclooctane, hexabromocyclododecane, bis(tribromophenoxy)ethane, brominated polyphenylene ether, brominated polystyrene, 2,4,6-tris(tribromophenoxy)-1,3,5-triazine, etc. Examples of guanidine-based flame retardants include guanidine sulfamate, guanidine phosphate, etc.

[0062] The amount of the flame retardant to be added is not particularly limited, but is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, and even more preferably 0.1 to 3 parts by mass, per 100 parts by mass of component (A-1).Within this range, flame retardancy can be imparted to the curable resin composition without changing the mechanical properties of the resin composition.

[0063] [Manufacturing method] The curable resin composition of the present invention can be produced by mixing component (A-1), component (B), and other additives, as needed, using, for example, a planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.) or a THINKY CONDITIONING MIXER (manufactured by THINKY Corporation). Preferably, an organic solvent (e.g., cyclopentanone, cyclopentanone, cyclohexanone, mesitylene, anisole, dibutyl ether, diphenyl ether, 1,4-dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, etc.) is further added and mixed. The addition of an organic solvent reduces the viscosity of the curable resin composition, allowing for more uniform mixing. The curable resin composition can be obtained by distilling off the organic solvent under reduced pressure after mixing. However, when used as a film, the organic solvent may be used as is without distilling off, or may be adjusted to a desired concentration before use. [Example]

[0064] EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0065] The molecular weights shown in the following examples are weight-average molecular weights (Mw) measured by gel permeation chromatography (GPC) using polystyrene as a standard substance. The measurement conditions are as follows: [GPC measurement conditions] Developing solvent: tetrahydrofuran Flow rate: 0.6mL / min Column: TSK Guardcolumn SuperH-L TSKgel SuperH4000(6.0mmI.D.×15cm×1) TSKgel SuperH3000(6.0mmI.D.×15cm×1) TSKgel SuperH2000(6.0mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 20 μL (sample concentration: 0.5% by mass in tetrahydrofuran solution) Detector: Differential refractometer (RI)

[0066] (A-1) Cyclic imide compound (A-1-1) To 263 g of N-methylpyrrolidone, 114 g (1.0 mol) of 1,4-cyclohexanediamine and 499 g (0.96 mol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride were added, and the mixture was stirred at 25°C for 3 hours, followed by further stirring at 150°C for 5 hours. To the resulting solution, 196 g (2.0 mol) of maleic anhydride, 82 g (1.0 mol) of sodium acetate, and 204 g (2.0 mol) of acetic anhydride were added, and the mixture was stirred at 80°C for 1 hour. Then, 500 g of toluene was added, and the mixture was washed with water and dehydrated. The solvent was then distilled off under reduced pressure to obtain bismaleimide (A-1-1) represented by the following formula: (weight average molecular weight 5,000, maleimide equivalent 0.040 mol / 100 g) [ka]

[0067] (A-1-2) To 263 g of N-methylpyrrolidone, 113 g (0.67 mol) of isophoronediamine, 174 g (0.33 mol) of dimer diamine, and 209 g (0.96 mol) of pyromellitic anhydride were added, and the mixture was stirred at 25°C for 3 hours, followed by stirring at 150°C for an additional 5 hours. To the resulting solution, 196 g (2.0 mol) of maleic anhydride, 82 g (1.0 mol) of sodium acetate, and 204 g (2.0 mol) of acetic anhydride were added, and the mixture was stirred at 80°C for 1 hour. Then, 500 g of toluene was added, and the mixture was washed with water and dehydrated. The solvent was then removed by distillation under reduced pressure to obtain bismaleimide (A-1-2) represented by the following formula: (weight average molecular weight 5,700, maleimide equivalent 0.035 mol / 100 g) [ka]

[0068] (A-1-3) To 263 g of N-methylpyrrolidone, 136 g (0.80 mol) of isophoronediamine, 104 g (0.20 mol) of dimer diamine, and 298 g (0.96 mol) of 4,4'-diphthalic anhydride were added and stirred at 25°C for 3 hours, followed by stirring at 150°C for an additional 5 hours. To the resulting solution, 196 g (2.0 mol) of maleic anhydride, 82 g (1.0 mol) of sodium acetate, and 204 g (2.0 mol) of acetic anhydride were added and stirred at 80°C for 1 hour. 500 g of toluene was then added, and the mixture was washed with water and dehydrated. The solvent was then removed by distillation under reduced pressure to obtain bismaleimide (A-1-3) represented by the following formula: (weight average molecular weight 10,000, maleimide equivalent 0.019 mol / 100 g) [ka]

[0069] (A'-1) (for comparative example) To 263 g of N-methylpyrrolidone, 100 g (0.5 mol) of dodecanediamine, 264 g (0.5 mol) of dimer diamine, and 298 g (0.96 mol) of 4,4'-oxydiphthalic anhydride were added and stirred at 25°C for 3 hours, followed by stirring at 150°C for an additional 5 hours. To the resulting solution, 196 g (2.0 mol) of maleic anhydride, 82 g (1.0 mol) of sodium acetate, and 204 g (2.0 mol) of acetic anhydride were added and stirred at 80°C for 1 hour. 500 g of toluene was then added, and the mixture was washed with water and dehydrated. The solvent was then removed by distillation under reduced pressure to obtain bismaleimide (A'-2) represented by the following formula: (weight average molecular weight 5,000, maleimide equivalent 0.040 mol / 100 g) [ka]

[0070] (A'-2) (for comparative example) To 263 g of N-methylpyrrolidone, 310 g (1.0 mol) of 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane and 298 g (0.96 mol) of 4,4'-oxydiphthalic anhydride were added, and the mixture was stirred at 25°C for 3 hours, followed by stirring at 150°C for an additional 5 hours. To the resulting solution, 196 g (2.0 mol) of maleic anhydride, 82 g (1.0 mol) of sodium acetate, and 204 g (2.0 mol) of acetic anhydride were added, and the mixture was stirred at 80°C for 1 hour. 500 g of toluene was then added, and the mixture was washed with water and dehydrated. The solvent was then removed by distillation under reduced pressure to obtain bismaleimide (A'-2) represented by the following formula: (weight average molecular weight 5,000, maleimide equivalent 0.040 mol / 100 g) [ka]

[0071] (A-2) Cyclic imide compound (A-2-1) Maleimide compound (BMI-1500, manufactured by Designer Molecules Inc.) represented by the following formula (weight average molecular weight: 3,000, maleimide equivalent: 0.067 mol / 100 g) [ka]

[0072] (A-2-2) Maleimide compound (BMI-689, manufactured by Designer Molecules Inc.) represented by the following formula (weight average molecular weight: 700, maleimide equivalent: 0.29 mol / 100 g) [ka]

[0073] (B) Curing catalyst (B-1) 2-Ethyl-4-methylimidazole

[0074] (C) Inorganic filler (C-1) Silica "SFP-130MC" (median primary particle size: 0.6 μm) (manufactured by Denka Co., Ltd.)

[0075] (D) Adhesion promoter (D-1) Bisphenol A epoxy resin (trade name "jER-828EL" (manufactured by Mitsubishi Chemical Corporation), epoxy equivalent 0.55 mol / 100 g (183 g / eq))

[0076] [Method for preparing curable resin composition] For Examples 1 to 7 and Comparative Examples 1 to 3, in addition to the formulation (parts by mass) shown in Table 1, 100 parts by mass of cyclopentanone was added to a total of 100 parts by mass of each component, and the mixture was kneaded at 80° C. for 30 minutes using a planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.), and then cooled to 25° C. The resulting solution was transferred to a flask, and the solvent was distilled off under reduced pressure to prepare a curable resin composition.

[0077] [Number of moles of curable functional groups] The number of moles of curable functional groups was calculated from the functional group equivalents and blend amounts of components (A) to (D). The results are shown in Table 1.

[0078] [Storage modulus] The prepared curable resin composition was sandwiched between a 30 mm x 40 mm x 100 μm thick mold frame and press-cured at 180°C and 3 MPa for 1 hour to prepare a test sample. The prepared sample was cut into a 20 mm x 5 mm x 100 μm thick piece and measured using a DMA Q800 (manufactured by TA Instruments) at a temperature range of -50°C to 300°C, a heating rate of 5°C / min, multi-frequency mode, tensile mode, and an amplitude of 15 μm, and the storage modulus at 25°C was read. The results are shown in Table 1.

[0079] [Linear expansion coefficient] The linear expansion of the test sample (cured product) prepared as described above in the section "Storage Modulus" was measured using a TMA Q400 (manufactured by TA Instruments) over the temperature range of -50°C to 300°C, and the linear expansion coefficient from 20 to 200°C was calculated from the graph. The measurement conditions were a test sample (cured product) of 20 mm x 3 mm x 100 μm thick, a heating rate of 5°C / min, and testing in tensile mode. The results are shown in Table 1.

[0080] [Dielectric constant and dielectric loss tangent] The prepared curable resin composition was sandwiched between a 30 mm x 40 mm x 100 μm thick mold frame and press-cured at 180°C and 3 MPa for 1 hour to prepare a test sample. A network analyzer (Keysight E5063-2D5) and a stripline (Keycom Corporation) were connected to the prepared test sample to measure the relative permittivity and dielectric loss tangent at a frequency of 10 GHz. The results are shown in Table 1.

[0081] [Warp test] The resin composition prepared by the above method was compression molded onto a 775 μm thick, 300 mm diameter silicon wafer at 180°C and 3 MPa to a thickness of 200 μm. After molding, the sample was post-cured at 180°C for 1 hour to prepare a test sample. The molded sample was cooled to 25°C and placed on a desk. One edge was pressed down, and the distance between the other edge and the desk was measured. The results are shown in Table 1.

[0082] [Desmear resistance] The prepared curable resin composition was sandwiched between a mold frame measuring 30 mm x 40 mm x 100 μm thick and press-cured at 180°C and 3 MPa for 1 hour to prepare a test sample. The weight loss rate of the prepared test sample before and after desmearing was calculated (mass loss (g) / test piece surface area (dm2)). The desmearing treatment was carried out in the following order: swelling (70°C, 5 minutes), roughening (80°C, 10 minutes), neutralization (40°C, 5 minutes), and water rinsing (room temperature, 5 minutes). The test solutions used were swelling solution, desmear solution, and neutralization solution manufactured by Atotech, adjusted to the specified concentrations. The results are shown in Table 1.

[0083] [Table 1]

[0084] In Examples 1 to 7, the silicon wafers on which the curable resin compositions were molded had little warpage and excellent desmear resistance. In Comparative Example 1, the linear expansion coefficient was large, which resulted in large warpage and low desmear resistance. In Comparative Example 2, the storage modulus of the curable resin composition at 25° C. was large, and therefore the warpage was large. In Comparative Example 3, the number of moles of the curable functional group was small, and therefore the desmear resistance was low.

Claims

1. (A-1) A cyclic imide resin represented by the following formula (1): 【Chemical 1】 (In formula (1), A's independently represent tetravalent organic groups containing a cyclic structure. B's independently represent divalent aliphatic hydrocarbon groups having 6 or more carbon atoms which may contain a heteroatom, and at least half of the B's are groups represented by the following formula (2). X represents a hydrogen atom or a methyl group, and n is 1 to 200. The repeating units bracketed by n may be the same or different, and the order in which they occur is not limited.) 【Chemistry 2】 (In formula (2), R is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x is independently a number from 0 to 4.) and (B) Curing catalyst and the total number of moles of curable functional groups per 100 g of resin components is 2 to 20 mol.

2. The curable resin composition according to claim 1 , further comprising an inorganic filler as component (C).

3. The curable resin composition according to claim 1 or 2, further comprising a cyclic imide compound represented by the following formula (3) as a component (A-2): 【Chemistry 3】 (In formula (3), A's independently represent tetravalent organic groups containing a cyclic structure. B's independently represent divalent aliphatic hydrocarbon groups having 6 or more carbon atoms which may contain a heteroatom and do not contain the group represented by formula (2). X represents a hydrogen atom or a methyl group, and s is 0 to 200.)

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