Thermosetting resin composition and use thereof

Abstract

To provide a thermosetting resin composition which gives a cured product having a low dielectric loss tangent, excellent adhesiveness, and especially excellent desmear resistance.SOLUTION: A thermosetting resin composition comprising (A) an aromatic cyclic imide compound having a weight average molecular weight of 5,000 to 100,000, (B) an aliphatic cyclic imide compound having a weight average molecular weight of 100 to 2,000, (C) an epoxy resin having two or more epoxy groups in one molecule, (D) a curing agent for epoxy resins, (E) a curing catalyst, and (F) an inorganic filler, wherein the total content of the components (A) to (E) is 5 to 99% by mass of the entire composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermosetting resin composition, a bonding film, a prepreg, a copper foil, a build-up film, and a printed wiring board. [Background technology]

[0002] In recent years, the next-generation communication system known as 5G (millimeter-wave band, 26 GHz to 80 GHz) has become popular, and development of the next-generation communication system known as 6G has also begun. To realize communication systems with higher speeds, larger capacities, and lower latency than current systems, materials for the high-frequency band between 3 and 80 GHz are required, and reducing transmission loss is essential as a noise countermeasure. Transmission loss is the sum of conductor loss and dielectric loss. Reducing conductor loss requires reducing the surface roughness of the metal foil used, especially copper foil. Dielectric loss is proportional to the square root of the dielectric constant and the dielectric loss tangent. Therefore, insulating materials with excellent dielectric properties (low dielectric constant and low dielectric loss tangent) are required. Circuit board applications, in particular, require insulating materials with such excellent dielectric properties. A material known as reactive polyphenylene ether resin (PPE) has been used in rigid circuit boards. Furthermore, materials known as liquid crystal polymers (LCPs) and modified polyimides (MPIs) have been used in flexible printed circuit boards (FPCs).

[0003] Furthermore, in the manufacturing method of circuit boards known as semi-additive process (SAP) and its improved method (M-SAP), a thermosetting film for forming an insulating layer called build-up film (interlayer laminate) and an adhesive film (bonding film) for improving adhesion between the thermosetting film, the substrate, and metal are used. These materials use epoxy resin, and in recent years, those using active ester curing agents to improve dielectric properties have been widely used (Patent Document 1).

[0004] In response to this, thermosetting resin compositions for substrates that use maleimide compounds that essentially have a dimer diamine skeleton (hereinafter referred to as special maleimide compounds) have been reported (Patent Documents 2 and 3). Contrary to the properties of typical maleimide resins, special maleimide compounds have a low glass transition temperature (Tg) and a high coefficient of thermal expansion (CTE). However, compared to conventional thermosetting resins, they also have excellent dielectric properties and flexibility. Furthermore, they have many advantages, such as superior adhesion to metals and other materials compared to epoxy resins, and because they are thermosetting resins, they can be highly multilayered, and are therefore the subject of extensive research and development.

[0005] New build-up films and bonding films are also being developed by taking advantage of the properties of special maleimide compounds (Patent Document 4). Special maleimide compounds are primarily used to reduce the dielectric loss tangent of the cured product and improve adhesion to metals, especially copper. In particular, adding special maleimide compounds to existing epoxy resin compositions has improved dielectric loss tangent and adhesion. It has also been found that special maleimide compounds are effective in removing smears (desmearing) in the wet desmearing process after via formation, making the vias cleaner.

[0006] However, as we have studied the special maleimide compound in more detail, we have also found other issues. Generally, as the surface roughness of copper foil decreases, the adhesive strength of the material decreases. However, the special maleimide compound has a sufficiently high adhesive strength even to such copper foil. However, if the surface roughness of the copper foil is reduced too much, the resin dissolves too much during the desmear process. As a result, we have found that the etching solution penetrates deeper into the interface between the resin and copper foil, making it more likely to peel off from the copper foil. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2024-37078 [Patent Document 2] International Publication No. 2016 / 114287 [Patent Document 3] Japanese Patent Application Publication No. 2018-201024 [Patent Document 4] Japanese Patent Application Publication No. 2020-83898 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, an object of the present invention is to provide a thermosetting resin composition that gives a cured product that has a low dielectric tangent and excellent adhesiveness, and that is particularly excellent in desmear resistance (etchant resistance), and further to provide a bonding film, a prepreg, a copper foil, a build-up film, and a printed wiring board that contain the composition. [Means for solving the problem]

[0009] As a result of extensive research to solve the above problems, the present inventors have found that the following thermosetting resin composition can achieve the above object, and have completed the present invention.

[0010] [1] A thermosetting resin composition comprising the following components (A) to (F), wherein the total content of the following components (A) to (E) is 5 to 99 mass % of the entire composition. (A) Aromatic cyclic imide compound having a weight average molecular weight of 5,000 to 100,000 (B) an aliphatic cyclic imide compound having a weight average molecular weight of 100 to 2,000 (C) Epoxy resin having two or more epoxy groups in one molecule (D) Epoxy resin curing agent (E) Curing catalyst (F) Inorganic filler [2] The thermosetting resin composition according to [1], wherein the cyclic imide resin compound of the component (A) is one or more aromatic cyclic imides selected from the following formulae (1) and (2): [ka] (In formula (1), P and Q are independently represented by the following formula: [ka] In the above formula, X is a divalent group represented by 1 are independently expressed by the following formula: [ka] In addition, in formula (1), a is a number of 1 to 40, and X is a hydrogen atom or a methyl group. [ka] (In formula (2), Q 1 are independently expressed by the following formula: [ka] In the above formula, X is a divalent group represented by 2 are independently expressed by the following formula: [ka] In formula (2), b is a number from 1 to 50, c is a number from 1 to 50, and A 1 and A 2 are each independently represented by the following formula (3) or the following formula (4): [ka] (In formula (3) and formula (4), X 3 is expressed as follows: [ka] In formula (3), R 1 are independently a hydrogen atom, a chlorine atom, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms. X is a hydrogen atom or a methyl group. [3] The thermosetting resin composition according to [1] or [2], wherein the cyclic imide resin compound of the component (B) is an aliphatic cyclic imide compound represented by the following formula (5): [ka] (In formula (5), A's are independently tetravalent organic groups containing an aliphatic cyclic structure, X's are hydrogen atoms or methyl groups, W's are independently divalent aliphatic hydrocarbon groups having 5 to 25 carbon atoms which may contain a heteroatom, and s is 0 to 10.) [4] The thermosetting resin composition according to [3], wherein W in formula (5) is a linear or branched alkylene group having 5 to 25 carbon atoms, or a divalent aliphatic hydrocarbon group represented by any of the following structural formulas: [ka] (p 5 and p 6 are numbers from 0 to 4, and may be the same or different. 2 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 20 carbon atoms. Z is an oxygen atom, a sulfur atom, or a methylene group. In the above structural formula, the bond to which no substituent is bonded is the one that bonds to the nitrogen atom that forms the cyclic imide structure in formula (5). [5] The thermosetting resin composition according to any one of [1] to [4], wherein the blending amount of the component (B) is 5 to 150 parts by mass per 100 parts by mass of the component (A). [6] The thermosetting resin composition according to any one of [1] to [5], wherein the epoxy resin curing agent of component (D) is an amine curing agent. [7] A bonding film comprising the thermosetting resin composition according to any one of [1] to [6]. [8] A prepreg comprising a cured product of the thermosetting resin composition according to any one of [1] to [6]. [9] A resin-coated copper foil comprising a cured product of the thermosetting resin composition according to any one of [1] to [6].

[10] A build-up film comprising the thermosetting resin composition according to any one of [1] to [6].

[11] A printed wiring board using the material according to any one of [7] to

[10] . [Effects of the Invention]

[0011] The thermosetting resin composition of the present invention can provide a cured product having a low dielectric loss tangent and excellent adhesion, and particularly excellent desmear resistance (etchant resistance). Furthermore, the composition of the present invention is useful for bonding films, prepregs, copper foils, build-up films, and printed wiring boards, particularly bonding films and build-up films for high-speed communication. In the present invention, the bonding film is also called an adhesive film and is used, for example, to bond the core material of a flexible substrate to a coverlay film, to bond the core material of a rigid substrate to a copper foil or a build-up film, and to bond the core materials of flexible or rigid substrates together. The build-up film is also called an interlayer insulating material and is used as a fine wiring formation layer on a substrate. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention is a thermosetting resin composition comprising (A) an aromatic cyclic imide compound having a weight-average molecular weight of 5,000 to 100,000, (B) an aliphatic cyclic imide compound having a weight-average molecular weight of 100 to 2,000, (C) an epoxy resin having two or more epoxy groups per molecule, (D) an epoxy resin curing agent, (E) a curing catalyst, and (F) an inorganic filler, wherein the total content of components (A) to (E) is 5 to 99 mass% of the total composition. The present invention will be described in more detail below.

[0013] (A) Aromatic cyclic imide compound having a weight average molecular weight of 5,000 to 100,000 Component (A) is an aromatic cyclic imide compound having a weight-average molecular weight of 5,000 to 100,000. Here, the aromatic cyclic imide compound refers to a compound in which a cyclic imide group is directly bonded to an aromatic ring. By using an aromatic cyclic imide compound, it is possible to obtain a cured product that has excellent handleability of the uncured resin film and excellent heat resistance and desmear resistance.

[0014] The aromatic cyclic imide resin of component (A) is preferably one or more aromatic cyclic imides selected from the following formulae (1) and (2). [ka] (In formula (1), P and Q are independently represented by the following formula: [ka] In the above formula, X is a divalent group represented by 1 are independently expressed by the following formula: [ka] In addition, in formula (1), a is a number of 1 to 40, and X is a hydrogen atom or a methyl group.

[0015] X in formula (1) 1 As the alkyl group, -CH2- and -C(CH3)2- are preferred from the viewpoint of easy availability of raw materials. In formula (1), a is a number from 1 to 40, and preferably a number from 5 to 30. In formula (1), X is a hydrogen atom or a methyl group, and is preferably a hydrogen atom.

[0016] [ka] (In formula (2), Q 1 are independently expressed by the following formula: [ka] In the above formula, X is a divalent group represented by 2 are independently expressed by the following formula: [ka] In formula (2), b is a number from 1 to 50, c is a number from 1 to 50, and A 1 and A 2 are each independently represented by the following formula (3) or the following formula (4): [ka] (In formula (3) and formula (4), X 3 is expressed as follows: [ka] In formula (3), R 1 are independently a hydrogen atom, a chlorine atom, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms. X is a hydrogen atom or a methyl group.

[0017] X in equation (2) 2 As the alkyl group, -CH2- and -C(CH3)2- are preferred from the viewpoint of easy availability of raw materials. In formula (2), b is a number from 1 to 50, and preferably a number from 1 to 40. In formula (2), c is a number from 1 to 50, and preferably a number from 1 to 40. In formula (2), A 1 and A 2 are each independently a group represented by the above formula (3) or (4).

[0018] X in formula (3) and formula (4) 3 As the alkyl group, -CH2- and -C(CH3)2- are preferred from the viewpoint of easy availability of raw materials. In formula (3), R 1 are independently a hydrogen atom, a chlorine atom, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms. R in equation (3) 1Examples of the aliphatic hydrocarbon group having 1 to 6 carbon atoms represented by the formula (R) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, and a cyclohexyl group. In addition, groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms such as F, Cl, or Br, for example, groups having a trifluoromethyl group, may also be used. 1 From the viewpoint of availability of raw materials, X is preferably a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms. As in formula (1), X is a hydrogen atom or a methyl group, and is preferably a hydrogen atom.

[0019] In the aromatic cyclic imide compound represented by formula (2), A 1 and A 2 For example, in formula (2), A 1 When A is a group represented by the formula (3), 2 is a group represented by the formula (4), and for example, A 1 When A is a group represented by the formula (4), 2 is preferably a group represented by the formula (3). Furthermore, the bonding pattern of the units having the repeating unit number b and the units having the repeating unit number c in the cyclic imide compound represented by formula (2) may be either random or block, but is preferably block from the viewpoint of the mechanical strength and dielectric properties (particularly low dielectric tangent) of the cured product.

[0020] The aromatic cyclic imide compound represented by formula (1) and the aromatic cyclic imide compound represented by formula (2) have a bisphenol structure in the molecule, so they can be produced without using N-methylpyrrolidone (NMP). Furthermore, they have excellent solvent solubility, being soluble in solvents other than NMP. Cyclic imide compounds having a bisphenol structure are also suitable from the standpoint of ease of raw material availability. Examples of the bisphenol structure contained in the aromatic cyclic imide compound represented by formula (1) and the aromatic cyclic imide compound represented by formula (2) include bisphenol A, bisphenol F, bisphenol E, and bisphenol AF, and are not particularly limited, but bisphenol A and bisphenol F are preferred. Furthermore, when a, b, and c are each within the above ranges, the aromatic cyclic imide compound represented by formula (1) and the aromatic cyclic imide compound represented by formula (2) exhibit a good balance between solubility in solvents and film formation when uncured, and the toughness and heat resistance of the resulting cured product.

[0021] The weight-average molecular weight of the aromatic cyclic imide compound of component (A) is 5,000 to 100,000, preferably 7,000 to 80,000, and more preferably 8,000 to 60,000. When the weight-average molecular weight is within this range, the aromatic cyclic imide compound of component (A) dissolves stably in a solvent and ensures wettability to the substrate. Furthermore, the coating film before curing is less likely to crack and is of good quality. The weight average molecular weight referred to in this specification refers to the weight average molecular weight measured by gel permeation chromatography (GPC) under the following conditions using polystyrene as a standard substance. [GPC measurement conditions] Developing solvent: tetrahydrofuran Flow rate: 0.35mL / min Detector: Refractive index detector (RI) Column: TSK-GEL H type (manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 5 μL (0.2% by mass THF solution)

[0022] The aromatic cyclic imide compound represented by formula (1) or (2) of component (A) can be produced, for example, by the method described in JP-A-2021-017485. The aromatic cyclic imide compound of the component (A) may be used alone or in combination of two or more types. The blend amount of component (A) in the composition of the present invention is preferably from 5 to 70 mass %, more preferably from 5 to 60 mass %, and particularly preferably from 6 to 50 mass %.

[0023] (B) an aliphatic cyclic imide compound having a weight average molecular weight of 100 to 2,000 Component (B) is an aliphatic cyclic imide compound having a weight-average molecular weight of 100 to 2,000. Here, the aliphatic cyclic imide compound refers to one in which the linker moieties between the two cyclic imide groups are all aliphatic chains and do not contain an aromatic ring. However, the compound may contain heteroatoms. Examples of heteroatoms include oxygen atoms, nitrogen atoms, and sulfur atoms. The use of an aliphatic cyclic imide compound provides excellent handleability for uncured resin films and reduces the melt viscosity of the resin composition, thereby improving lamination and moldability. It also has the effect of improving adhesion to metals such as copper.

[0024] The aliphatic cyclic imide compound of the component (B) is preferably an aliphatic cyclic imide compound represented by the following formula (5). [ka] (In formula (5), A's are independently tetravalent organic groups containing an aliphatic cyclic structure, X's are hydrogen atoms or methyl groups, W's are independently divalent aliphatic hydrocarbon groups having 5 to 25 carbon atoms which may contain a heteroatom, and s is 0 to 10.)

[0025] In formula (5), A is independently a tetravalent organic group containing an aliphatic cyclic structure, and X is a hydrogen atom or a methyl group, preferably a methyl group from the viewpoint of reducing viscosity.

[0026] In formula (5), W is a linear or branched alkylene group having 5 to 25 carbon atoms, or a divalent aliphatic hydrocarbon group represented by any of the following structural formulas, preferably a linear or branched alkylene group having 6 to 20 carbon atoms, and more preferably a branched alkylene group having 6 to 20 carbon atoms. [ka] (p 5 and p 6 are numbers from 0 to 4, and may be the same or different. 2 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 20 carbon atoms. Z is an oxygen atom, a sulfur atom, or a methylene group. In the above structural formula, the bond to which no substituent is bonded is the one that bonds to the nitrogen atom that forms the cyclic imide structure in formula (5).

[0027] In the above formula, p 5 and p 6 are each a number from 0 to 4, preferably a number from 0 to 2, and may be the same or different. 2 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 20 carbon atoms, preferably a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a hydrogen atom or a linear alkyl group having 1 to 10 carbon atoms. Z is an oxygen atom, a sulfur atom or a methylene group.

[0028] In the formula (5), s is 0 to 10, preferably 0 to 5, more preferably 0 to 3, and further preferably s=0.

[0029] The weight-average molecular weight (Mw) of the aliphatic cyclic imide compound represented by formula (5) is 100 to 2,000, preferably 250 to 1,500, and more preferably 300 to 1,000. If the weight-average molecular weight is more than 2,000, the melt viscosity of the resin composition at high temperatures does not decrease, which may result in poor moldability and adhesiveness of the resin composition.

[0030] The aliphatic cyclic imide compound of the component (B) may be used alone or in combination of two or more. The blend amount of component (B) is preferably 5 to 150 parts by mass, more preferably 12 to 90 parts by mass, and particularly preferably 15 to 80 parts by mass, per 100 parts by mass of component (A).

[0031] (C) Epoxy resin having two or more epoxy groups in one molecule The thermosetting resin composition of the present invention uses an epoxy resin having two or more epoxy groups per molecule as component (C). By blending the epoxy resin, the adhesive strength of the resin composition can be increased and other mechanical properties can be improved.

[0032] In consideration of reactivity and storage stability, the component (C) is preferably an epoxy resin having a glycidyl group.

[0033] Examples of component (C) include phenol novolac type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, biphenol type epoxy resins, naphthalene type epoxy resins, anthracene type epoxy resins, naphthol type epoxy resins, xylylene type epoxy resins, biphenyl type epoxy resins, biphenyl aralkyl type epoxy resins, triphenylmethane type epoxy resins, alicyclic type epoxy resins, glycidylamine type epoxy resins, dicyclopentadiene type epoxy resins, stilbene type epoxy resins, sulfur atom-containing epoxy resins, and phosphorus atom-containing epoxy resins. It is preferable to use component (C) that is liquid at room temperature (25°C) from the viewpoints of compatibility and wettability with the substrate.

[0034] The amount of component (C) blended is preferably 0.05 to 25 parts by mass, and more preferably 0.1 to 20 parts by mass, per 100 parts by mass of components (A) and (B) combined. Within the above range, the curing speed during molding is appropriate, which is preferable. Furthermore, the resulting cured product has a good balance between heat resistance and moisture resistance, and the desired low dielectric properties are easily achieved.

[0035] The epoxy resin of component (C) may be used alone or in combination of two or more different types.

[0036] (D) Epoxy resin curing agent The thermosetting resin composition of the present invention uses an epoxy resin curing agent as component (D). The incorporation of an epoxy resin curing agent can improve mechanical properties, adjust curing properties, and reduce the effects of moisture absorption. Examples of epoxy resin curing agents include phenolic curing agents, amine curing agents, acid anhydride curing agents, and active ester curing agents.

[0037] Considering reactivity and storage stability, an amine curing agent is preferred as component (D). The amine curing agent is preferably an amine compound, and more preferably an aromatic amine compound. If an aliphatic amine compound is used, its nucleophilicity may be too high, resulting in a significant decrease in storage stability or an increase in the hygroscopicity of the cured product.

[0038] The amount of component (D) blended is preferably 0.05 to 25 parts by mass, and more preferably 0.1 to 20 parts by mass, per 100 parts by mass of components (A) and (B) combined.

[0039] The epoxy resin curing agent (D) may be used alone or in combination of two or more.

[0040] (E) Curing catalyst Component (E) is a catalyst that accelerates the curing reaction of the thermosetting resin composition of the present invention. It is added to initiate and accelerate the crosslinking reaction of the cyclic imide compounds (components (A) and (B)), the epoxy resin (component (C)), and the curing agent (component (D)). Examples of catalysts include thermal radical polymerization initiators, anionic polymerization initiators, and quaternary onium salts.

[0041] Among cyclic imide compounds, the thermal radical polymerization initiator preferentially promotes crosslinking of maleimide compounds (X=H in formulas (1) and (2)), while the quaternary onium salt preferentially promotes crosslinking of epoxy resins and epoxy resin curing agents. Basic compounds such as imidazoles and tertiary amines, and anionic polymerization catalysts such as organic phosphorus compounds are preferred because crosslinking of each component proceeds evenly, and imidazoles are particularly preferred.

[0042] The amount of component (E) is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of components (A) to (D). When other thermosetting resins, as described below, are incorporated into the composition, the amount is preferably 0.05 to 10 parts by mass, particularly 0.1 to 5 parts by mass, per 100 parts by mass of the total of components (A) to (D) and the other thermosetting resin components. A content within the above range is preferred because the curing properties of the thermosetting resin composition of the present invention are stable during molding. Furthermore, the resulting cured product has a good balance of heat resistance and moisture resistance, which is also preferred. The catalyst of component (E) may use either a single type alone, or two or more types in combination.

[0043] In the thermosetting resin composition of the present invention, the above components (A) to (E) account for 5 to 99% by mass, preferably 10 to 90% by mass, and more preferably 20 to 80% by mass of the entire composition.

[0044] (F) Inorganic filler The thermosetting resin composition of the present invention further contains (F) an inorganic filler. The inorganic filler is blended for the purposes of increasing the strength and rigidity of the cured product of the thermosetting resin composition of the present invention, and adjusting the thermal expansion coefficient and dimensional stability of the cured product. As the inorganic filler, those typically blended in epoxy resin compositions and silicone resin compositions can be used, but silica particles such as spherical silica, fused silica, and crystalline silica, and boron nitride are preferred in order to reduce the dielectric loss tangent of the entire composition.

[0045] The average particle size and shape of the inorganic filler are not particularly limited, but from the viewpoint of the processability of the substrate, spherical silica having an average particle size of 0.1 to 5 μm is preferably used. The average particle size is the mass average particle size D 50 (or median diameter).

[0046] Furthermore, to improve the properties of the inorganic filler, it is preferable that the inorganic filler be surface-treated with a silane coupling agent having an organic group capable of reacting with the functional groups of components (A) to (D). Examples of such silane coupling agents include epoxy-containing alkoxysilanes, amino-containing alkoxysilanes, (meth)acrylic-containing alkoxysilanes, and alkenyl-containing alkoxysilanes.

[0047] As the silane coupling agent, a (meth)acrylic group- and / or amino group-containing alkoxysilane is preferably used, and specific examples thereof include 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, and 3-aminopropyltrimethoxysilane.

[0048] In the thermosetting resin composition of the present invention, the component (F) accounts for 1 to 95% by mass, preferably 10 to 90% by mass, and more preferably 20 to 80% by mass of the entire composition.

[0049] Other additives The thermosetting resin composition of the present invention may further contain various additives as required. Examples of other additives are listed below.

[0050] Thermosetting resin having a reactive group capable of reacting with a maleimide group In the present invention, a thermosetting resin having reactive groups capable of reacting with components (A) to (D) may also be added, and the type of the thermosetting resin is not limited, and examples thereof include melamine resins, silicone resins, cyclic imide resins other than components (A) and (B), urea resins, thermosetting polyimide resins, modified polyphenylene ether resins, thermosetting acrylic resins, and epoxy-silicone hybrid resins.

[0051] Furthermore, reactive groups that can react with cyclic imide groups include cyclic imide groups, hydroxyl groups, acid anhydride groups, alkenyl groups such as allyl groups and vinyl groups, (meth)acrylic groups, and thiol groups. From the viewpoint of reactivity, the reactive group is preferably selected from among cyclic imide groups, hydroxyl groups, and alkenyl groups, and furthermore, from the viewpoint of dielectric properties, an alkenyl group or a (meth)acrylic group is more preferred.

[0052] However, the blending amount is preferably 0 to 40 mass % of the total amount of the thermosetting resin composition of the present invention.

[0053] others In addition to the above, non-functional silicone oil, reactive diluent, thermoplastic resin, thermoplastic elastomer, organic synthetic rubber, photosensitizer, light stabilizer, polymerization inhibitor, flame retardant, pigment, dye, adhesion aid such as silane coupling agent, ion trapping material, etc. may be blended.

[0054] In addition, a silane coupling agent such as an epoxy group-containing alkoxysilane, an amino group-containing alkoxysilane, a (meth)acrylic group-containing alkoxysilane, or an alkenyl group-containing alkoxysilane, which is used to surface treat the inorganic filler, may be separately blended into the thermosetting resin composition of the present invention. Specific examples of the silane coupling agent include those similar to those mentioned above.

[0055] The thermosetting resin composition of the present invention can also be dissolved in an organic solvent and used as a varnish or slurry. Forming the composition into a varnish facilitates film formation and facilitates coating and impregnation of glass cloth made of E-glass, low-dielectric glass, quartz glass, and other materials. Any organic solvent can be used as long as it dissolves the thermosetting resins containing reactive groups in components (A) to (D) and / or other additives. Examples include anisole, tetralin, mesitylene, xylene, toluene, tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and acetonitrile. Among these, aromatic organic solvents such as anisole, tetralin, mesitylene, xylene, and toluene are preferred. Ketone-based solvents with low boiling points below 100°C, such as methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK), are often used to prepare varnishes and slurries. However, the cyclic imide compound (A) used in the present invention has low solubility in these ketone-based solvents, making their use undesirable. These organic solvents may be used alone or in combination of two or more.

[0056] The thermosetting resin composition of the present invention can be produced by mixing the components (A), (B), (C), (D), (E), and (F), as well as other additives that may be added as needed, using, for example, a planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.) or a THINKY CONDITIONING MIXER (manufactured by THINKY CORPORATION).

[0057] This thermosetting resin composition can be formed into an uncured resin sheet or film by applying the varnish to a substrate and then volatilizing the organic solvent, and then curing the uncured resin sheet or film. Examples of methods for producing the sheet and film are given below, but the present invention is not limited to these.

[0058] For example, a thermosetting resin composition (varnish) dissolved in an organic solvent is applied to a substrate, typically heated at 80°C or higher, preferably 100°C or higher, for 0.5 to 20 minutes to remove the organic solvent, followed by further heating at 130°C or higher, preferably 150°C or higher, for 0.5 to 10 hours, resulting in the formation of a flat, strong cured resin coating. The temperatures in the drying step to remove the organic solvent and the subsequent heat-curing step may each be constant, but it is preferable to increase the temperature stepwise. This allows the organic solvent to be efficiently removed from the composition and the resin curing reaction to proceed efficiently. Methods for applying the varnish include, but are not limited to, a spin coater, slit coater, spray, dip coater, bar coater, and the like.

[0059] The substrate can be a general resin substrate, such as polyolefin resins such as polyethylene (PE) resin, polypropylene (PP) resin, and polystyrene (PS) resin, and polyester resins such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, and polycarbonate (PC) resin. The surface of the substrate may be subjected to a release treatment. The thickness of the coating layer is not particularly limited, but the thickness after solvent removal is in the range of 1 to 200 μm, preferably 3 to 150 μm. A cover film may also be used on the coating layer. Alternatively, the components may be premixed and extruded into a sheet or film using a melt kneader, and then used as is.

[0060] The film obtained in this way can be used as a bonding film or build-up film. As a bonding film, it can be used between the core material and coverlay film to produce flexible printed wiring boards, or between an organic substrate and build-up film. Build-up films are used in the semi-additive process (SAP) and its improved method (M-SAP) to produce laminates and printed wiring boards.

[0061] Here, copper foil is used as the substrate, and an uncured or semi-cured film can be formed on the copper foil in the same manner as above to produce a resin-coated copper foil. Alternatively, as described above, a thermosetting resin can be dissolved in an organic solvent to form a varnish, which is then applied to a release-treated polyethylene terephthalate (PET) film, the solvent is dried to produce a film, and the film is then attached to the copper foil, after which the PET film is peeled off to obtain a resin-coated copper foil. The lamination conditions are not particularly limited, but lamination is preferably performed at a heating temperature of 80 to 130°C, under 0.1 to 1.0 MPa, and for 0.5 to 5 minutes.

[0062] The copper foil used is not particularly limited in terms of roughness, but from the perspective of reducing conductor loss, it is preferable to use a copper foil with a ten-point average roughness (Rz) of 1.5 μm or less on the surface of the copper foil that is in contact with the uncured or semi-cured thermosetting resin. To reduce conductor loss, a small Rz is preferred, preferably 1.3 μm or less, and more preferably 1.0 μm or less. On the other hand, in terms of adhesive strength, materials with a small Rz tend to have a low anchoring effect and a low adhesive strength. However, the thermosetting resin composition of the present invention has high adhesive strength and can be used with copper foils with such low roughness.

[0063] The copper foil to be used may be produced by any method, but is generally produced by electrolysis or rolling, and electrolytic copper foil produced by electrolysis is often used. The copper foil to be used may be surface-treated to improve adhesive strength, heat resistance, chemical resistance, etc.

[0064] There are no particular restrictions on the thickness of the copper foil, but foils in the range of 6 to 50 μm are commonly used. Thinner foils can be used in a form called carrier-attached copper foil. This is a method in which a carrier is attached to thin copper foil to improve handling, and the foil is thickened and the carrier is then peeled off in a subsequent process.

[0065] Alternatively, the thermosetting resin composition of the present invention in the form of a varnish can be impregnated into a fiber substrate such as glass cloth made of E-glass, low-dielectric glass, quartz glass, etc., and the organic solvent can be removed to semi-cure the substrate, which can then be used as a prepreg. Furthermore, laminates, including multi-layer laminates, and printed wiring boards can be produced by laminating the prepreg with copper foil, etc.

[0066] This prepreg comprises a thermosetting resin and a fiber substrate. The thermosetting resin is the thermosetting resin composition or a semi-cured product of the resin composition. A semi-cured product is a resin composition that has been partially cured to the extent that it can be further cured. That is, a semi-cured product is a resin composition that has been semi-cured, or in other words, a B-staged resin composition. On the other hand, an uncured state is sometimes referred to as an A-stage. That is, the thermosetting resin may be the thermosetting resin composition in an A-stage state or the thermosetting resin composition in a B-stage state. As mentioned above, examples of the fiber substrate include E-glass, low-dielectric glass, quartz glass, S-glass, and T-glass. While the type of glass used is not critical, quartz glass cloth, which has low dielectric properties, is preferred in order to take advantage of the properties of the thermosetting resin composition. The thickness of a commonly used fiber substrate is, for example, 0.01 mm or more and 0.3 mm or less.

[0067] When producing a prepreg, the thermosetting resin is preferably in the form of a varnish, as described above, for impregnation into a fiber substrate, which is the base material for forming the prepreg. Examples of methods for producing a prepreg include impregnating a fiber substrate with a thermosetting resin composition prepared in a varnish form and then drying the resulting mixture. The thermosetting resin is impregnated into the fiber substrate by immersion, coating, or the like. Impregnation can be repeated multiple times as needed. Furthermore, by repeating the impregnation process using multiple resin compositions with different compositions and concentrations, it is possible to adjust the final composition and impregnation amount to the desired level. The fiber substrate impregnated with the resin composition (resin varnish) is heated under the desired heating conditions, for example, at 80°C to 180°C for 1 minute to 20 minutes. Heating produces a prepreg containing an A-stage or B-stage thermosetting resin. The heating can volatilize the organic solvent from the varnish, thereby reducing or eliminating the organic solvent.

[0068] A laminate according to one embodiment of the present invention is a laminate comprising an insulating layer containing a cured product of the thermosetting resin composition or an insulating layer consisting of a cured product of the thermosetting resin composition, and a layer other than the insulating layer. A commonly known laminate is a metal-clad laminate, particularly a copper-clad laminate. A metal-clad laminate comprises an insulating layer containing or consisting of a cured product of the thermosetting resin composition, and metal foil on both sides of the insulating layer. A single-sided metal-clad laminate may also be provided with metal foil on only one side of the insulating layer. The insulating layer may also be a cured product of the thermosetting resin composition, a cured product of the prepreg described above, or a laminate of multiple cured prepregs. A copper-clad laminate may also be prepared using resin-coated copper foil, or a metal-clad laminate may be prepared by first preparing a cured prepreg and then laminating a metal foil between the cured prepregs via a bonding film consisting of the thermosetting resin composition.

[0069] The method for producing such a laminate is not particularly limited as long as it is a common method, and examples thereof include a method in which, when prepreg is used, one or more prepreg sheets are stacked, and then a metal foil such as a copper foil is placed on either or both of the upper and lower surfaces of the prepreg sheets, and the stacked sheets are molded under heat and pressure to form an integrated laminate.

[0070] A printed wiring board according to one embodiment of the present invention comprises a cured product of the thermosetting resin composition. The insulating layer of a metal-clad laminate used in the manufacture of the printed wiring board may be manufactured using the prepreg described above. The printed wiring board can be manufactured by subjecting the metal-clad laminate to circuit formation processing such as drilling, metal plating, and metal foil etching, and multi-layer adhesive processing, using known methods.

[0071] When manufacturing a printed wiring board, the following steps may be further carried out: (1) drilling holes in the insulating layer, (2) roughening the insulating layer, and (3) forming a conductor layer. These steps (1) and (3) may be carried out according to various known methods used in manufacturing printed wiring boards.

[0072] Step (1) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (1) can be performed using, for example, a drill, a laser, plasma, or the like, depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes depend on the design of the printed wiring board.

[0073] Step (2) is a step of roughening the insulating layer. The insulating layer is roughened while removing (desmearing) the remaining resin, called smear, generated in step (1). The roughening procedure and conditions are not particularly limited, and known procedures and conditions used for forming insulating layers of printed wiring boards can be used. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order.

[0074] As mentioned above, in recent years, the roughness of metal foils, especially copper foils, has tended to decrease in order to reduce conductor loss. As the roughness decreases, the anchoring effect weakens, and the adhesive strength of the resin layer tends to decrease. Furthermore, peeling can occur during the roughening process, which will be discussed in more detail later.

[0075] The swelling liquid used in the roughening treatment is not particularly limited, but examples thereof include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. These may be commercially available solutions, and examples of commercially available swelling liquids include "Swelling Dip Securigans P," "Swelling Dip Securigans SBU," and "Swelling Dip Securigant P" manufactured by Atotech Japan. The swelling treatment using the swelling liquid is not particularly limited, but can be performed by, for example, immersing the insulating layer in a swelling liquid at 30 to 90°C for 1 to 20 minutes. From the viewpoint of suppressing swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40 to 80°C for 5 to 15 minutes.

[0076] The oxidizing agent used in the roughening treatment is not particularly limited, but examples include alkaline permanganate aqueous solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as alkaline permanganate aqueous solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60 to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate aqueous solution is preferably 5 to 10% by mass. These solutions can be commercially available, and examples of commercially available oxidizing agents include alkaline permanganate aqueous solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0077] This oxidizing agent dissolves the smear, but it also dissolves the resin layer itself, which is not smeared. As mentioned above, if the metal surface has a low roughness, when the oxidizing agent begins to dissolve the resin layer, the solution penetrates into the interface between the metal and resin layer, tending to easily peel off, so resistance to these oxidizing agents is necessary. On the other hand, if the resistance to these oxidizing agents is too high, problems occur in which desmearing is not possible, so simply having high resistance is not enough. The resin needs to have moderate oxidizing agent resistance, adhesive strength to prevent the solution from penetrating the interface, and wettability to the metal.

[0078] The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan can be cited. Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30 to 80°C for 1 to 30 minutes. From the standpoint of workability, a preferred method is to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40 to 70°C for 5 to 20 minutes.

[0079] Step (3) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer may be a single metal layer or an alloy layer. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among these, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

[0080] The conductor layer may have a single layer structure or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy. The thickness of the conductor layer depends on the desired design of the printed wiring board, but is generally 3 to 35 μm, preferably 5 to 30 μm. The conductor layer may also be formed by plating. [Example]

[0081] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the examples and comparative examples, "room temperature" means 25°C.

[0082] The components used in the examples and comparative examples are shown below. In the following, the weight average molecular weight (Mw) is a value obtained by gel permeation chromatography (GPC) using polystyrene as a standard substance, measured under the following measurement conditions. [GPC measurement conditions] Developing solvent: tetrahydrofuran Flow rate: 0.35mL / min Detector: Refractive index detector (RI) Column: TSK-GEL H type (manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 5 μL (0.2% by mass THF solution)

[0083] (A) Aromatic cyclic imide compound having a weight average molecular weight of 5,000 to 100,000 [Synthesis Example 1] A 1 L glass four-neck flask equipped with a stirrer, Dean-Stark tube, cooling condenser, and thermometer was charged with 65.06 g (0.125 mol) of 2,2-bis[4-(2,3-dicarboxyphenoxy)phenyl]propane dianhydride, 61.59 g (0.150 mol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 250 g of anisole, and the amic acid was synthesized by stirring at 80°C for 3 hours. The temperature was then raised to 150°C and the mixture was stirred for 2 hours while distilling off the by-product water, producing a diamine-terminated product. The flask containing the resulting solution of the diamine-terminated compound was cooled to room temperature, and then 5.39 g (0.055 mol) of maleic anhydride was added. The mixture was stirred at 80°C for 3 hours to synthesize maleamic acid. The temperature was then raised to 150°C and the mixture was stirred for 2 hours while distilling off the by-product water, yielding a varnish of an aromatic bismaleimide compound represented by the following formula (A-1). The weight-average molecular weight (Mw) of the aromatic bismaleimide compound was 25,300. Anisole was added so that the nonvolatile components of the varnish became 25% by mass. [ka] (In formula (A-1), P and Q are independently a divalent group represented by the following formula.) [ka]

[0084] [Synthesis Example 2] A 1 L glass four-neck flask equipped with a stirrer, Dean-Stark tube, cooling condenser, and thermometer was charged with 65.06 g (0.125 mol) of 2,2-bis[4-(2,3-dicarboxyphenoxy)phenyl]propane dianhydride, 35.26 g (0.115 mol) of 4,4-methylenebis(2,6-diethylaniline), and 250 g of anisole, and the mixture was stirred at 80°C for 3 hours to synthesize an amic acid. The mixture was then heated to 150°C and stirred for 2 hours while distilling off the by-product water to synthesize a copolymer. After that, 7.05 g (0.015 mol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane was added to the flask containing the copolymer solution, which had been cooled to room temperature, and the mixture was stirred at 80°C for 3 hours to synthesize an amic acid.The mixture was then heated to 150°C and stirred for 2 hours while distilling off the by-product water, synthesizing a diamine-terminated product. The flask containing the resulting solution of diamine compounds at both ends was cooled to room temperature, and then 1.47 g (0.015 mol) of maleic anhydride was added. The mixture was stirred at 80°C for 3 hours to synthesize maleamic acid. The temperature was then raised to 150°C and the mixture was stirred for 2 hours while distilling off the by-product water, yielding a varnish of an aromatic bismaleimide compound represented by the following formula (A-2). The weight-average molecular weight (Mw) of the aromatic bismaleimide compound was 30,800. Anisole was added so that the nonvolatile components of the varnish reached 25% by mass. [ka]

[0085] [Synthesis Example 3] A 1 L glass four-neck flask equipped with a stirrer, Dean-Stark tube, cooling condenser, and thermometer was charged with 65.06 g (0.125 mol) of 2,2-bis[4-(2,3-dicarboxyphenoxy)phenyl]propane dianhydride, 61.59 g (0.150 mol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 250 g of anisole, and the amic acid was synthesized by stirring at 80°C for 3 hours. The temperature was then raised to 150°C and the mixture was stirred for 2 hours while distilling off the by-product water, producing a diamine-terminated product. The flask containing the resulting solution of the diamine-terminated compound was cooled to room temperature, and then 6.16 g (0.055 mol) of citraconic anhydride was added. The mixture was stirred at 80°C for 3 hours to synthesize maleamic acid. The temperature was then raised to 150°C and the mixture was stirred for 2 hours while distilling off the by-product water, yielding a varnish of an aromatic biscitraconimide compound represented by the following formula (A-3). The weight-average molecular weight (Mw) of the aromatic biscitraconimide compound was 25,300. Anisole was added so that the nonvolatile components of the varnish reached 25% by mass. [ka] (In formula (A-3), P and Q are independently a divalent group represented by the following formula.) [ka]

[0086] Other cyclic imide compounds (A-4): A bismaleimide compound represented by the following formula (trade name: BMI-5000, Mw: 18,000, manufactured by Designer Molecules Inc., for comparative purposes) [ka]

[0087] (A-5): Biscitraconimide compound represented by the following formula (Mw: 18,000, for comparative example) [ka]

[0088] (A-6): 4,4'-diphenylmethane bismaleimide (BMI-1000, Mw: 520, manufactured by Daiwa Chemical Industry Co., Ltd., for comparative example)

[0089] (A-7): Bisphenol A diphenyl ether bismaleimide (BMI-4000, Mw: 670, manufactured by Daiwa Chemical Industry Co., Ltd., for comparative example)

[0090] [Synthesis Example 4] A 1 L glass four-neck flask equipped with a stirrer, Dean-Stark tube, cooling condenser, and thermometer was charged with 77.55 g (0.149 mol) of 2,2-bis[4-(2,3-dicarboxyphenoxy)phenyl]propane dianhydride, 61.59 g (0.150 mol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 250 g of anisole. The mixture was stirred at 80 °C for 3 hours to synthesize amic acid. The mixture was then heated to 150 °C and stirred for 2 hours while distilling off the by-product water, producing a diamine-terminated product. The flask containing the resulting diamine-terminated product solution was then cooled to room temperature, and 0.79 g (0.010 mol) of maleic anhydride was added. The mixture was stirred at 80 °C for 3 hours to synthesize maleamic acid. The mixture was then heated to 150°C and stirred for 2 hours while distilling off the by-product water in an attempt to obtain a varnish of the aromatic bismaleimide compound represented by the following formula (A-8), but the viscosity was too high at room temperature to stir. The weight-average molecular weight (Mw) of the aromatic bismaleimide compound was 162,000, making it very difficult to handle, so evaluation of this bismaleimide was not performed. [ka] (In formula (A-8), P and Q are independently a divalent group represented by the following formula.) [ka]

[0091] (B) an aliphatic cyclic imide compound having a weight average molecular weight of 100 to 2,000 [Synthesis Example 5] To 250g of N-methylpyrrolidone, 202g (1.0mol) of 1,12-diaminododecane, 245g (2.5mol) of maleic anhydride, 82g (1.0mol) of sodium acetate, and 204g (2.0mol) of acetic anhydride were added and stirred at 100°C for 5 hours. 500g of toluene was then added, and the mixture was washed with water and dehydrated. The solvent was then distilled off under reduced pressure to obtain an aliphatic bismaleimide compound represented by the following formula (B-1). The weight-average molecular weight (Mw) of the aliphatic bismaleimide compound was 500. [ka]

[0092] (B-2) Aliphatic bismaleimide compound represented by the following formula (trade name: BMI-TMH, manufactured by Daiwa Chemical Industry Co., Ltd.) (weight average molecular weight: 450) [ka]

[0093] (B-3) Aliphatic biscitraconimide compound (weight average molecular weight 470) represented by the following formula: [ka]

[0094] (C) Epoxy resin having two or more epoxy groups in one molecule (C-1): Bisphenol A liquid epoxy resin (trade name: jER-828, manufactured by Mitsubishi Chemical Corporation) (C-2): Multifunctional epoxy resin (product name: EPPN-501, manufactured by Nippon Kayaku Co., Ltd.)

[0095] (D) Epoxy resin curing agent (D-1): Amine curing agent (4,4'-diaminodiphenylmethane, manufactured by TCI Corporation) (D-2): Phenol novolac resin (product name: TD-2131, manufactured by DIC Corporation)

[0096] (E) Curing catalyst (E-1): 2-ethyl-4-methylimidazole (trade name: 2E4MZ, manufactured by Shikoku Kasei Holdings Co., Ltd.) (E-2): Triphenylphosphine (trade name: TPP, manufactured by Hokko Chemical Industry Co., Ltd.) (E-3): Dicumyl peroxide (trade name: Percumyl D, manufactured by NOF Corporation)

[0097] (F) Inorganic filler (F-1): A slurry containing spherical silica particles having an average particle size of 0.5 μm and a solid concentration of 75% by mass, dispersed in toluene (product name: 5SV-CT1, manufactured by Admattex Co., Ltd.)

[0098] Preparation and compatibility of resin varnish The components shown in Tables 1 to 3, except for component (E), were added to a 500 mL four-neck flask equipped with a Dimroth condenser and a stirrer, and stirred at 80°C for 4 hours. After cooling to room temperature, component (E) was added and stirred at room temperature for 1 hour, followed by filtration through a 100-mesh wire screen to obtain a varnish-like resin composition. If the varnish did not separate and remained integrated, it was marked with an O; if it separated or remained undissolved, it was marked with an X. Those marked with an X were not further evaluated.

[0099] <Production and handling of uncured resin film> For those resin varnishes that could be produced without any problems using the above procedure, the resin varnish was applied to a 50 μm thick release-treated PET film (TN-010, manufactured by Toyobo STC) using a roller coater and dried for 10 minutes at 100° C. to obtain an uncured resin film with a thickness of 50 μm. When evaluating the handleability of the obtained uncured resin film, when the uncured resin film was cut with a cutter knife, a rating of ◯ was given for films that did not spill from the uncured resin, a rating of △ was given for films that spilled from the uncured resin, and an rating of × was given for films that had cracks when they were produced in the first place.

[0100] <Relative permittivity, dielectric loss tangent> The uncured resin film was fixed directly onto a flat plate together with a release-treated PET film, and heated and cured at 200°C for 60 minutes to obtain a cured resin film. A network analyzer (Keysight, product name: E5063-2D5) was connected to a strip line (Keycom Corporation) to measure the relative permittivity and dielectric loss tangent of the cured resin film at a frequency of 10 GHz.

[0101] <Glass transition temperature> The glass transition temperatures of the test samples (cured products) prepared as described above in the section <Dielectric constant, dielectric loss tangent> were measured and calculated using a DMA Q800 (manufactured by TA Instruments, Inc.) The measurement conditions were a 20 mm × 5 mm × 50 μm thick cured product, a heating rate of 5°C / min, a multi-frequency mode, a tensile mode, and an amplitude of 15 μm.

[0102] <Peel strength> A 75mm long, 25mm wide, and 1.0mm thick SUS304 board was prepared. The uncured resin film with the PET film was placed on one surface of the board, with the resin film facing the board. Lamination was performed at 100°C, 0.3 MPa, and 60 seconds. After lamination, the PET film was peeled off, and an 18μm thick copper foil (Ra: 0.17μm, Rz: 0.6μm) was placed on the resin film facing the board. Lamination was performed at 100°C, 0.3 MPa, and 60 seconds. After lamination, the board was heated at 200°C for 60 minutes and cured to prepare adhesive test specimens. To evaluate adhesion, the 90° peel strength (kN / m) of each adhesive test specimen was measured at 23°C and a tensile speed of 50mm / min according to JIS-C-6481 "Test Methods for Copper-Clad Laminates for Printed Wiring Boards."

[0103] <Desmear Resistance> A double-sided copper foil glass epoxy substrate (FR-4, product name: R-1075, Panasonic Industries Co., Ltd.) measuring 100 mm in length, 25 mm in width, and 1.0 mm in thickness was prepared and pretreated by reducing the copper in a formic acid reflow oven. The uncured resin film with the PET film was placed on one surface of the substrate, with the resin film facing the substrate, and laminated at 100°C, 0.3 MPa pressure, and 60 seconds. After lamination, the PET film was peeled off and the substrate was cured by heating at 200°C for 60 minutes. Slits were made according to JIS K5600-5-6:1999 (Adhesion (cross-cut method)). The cured substrate was immersed in a swelling solution (product name: Swelling Dip, Atotech Japan) at 60°C for 10 minutes. Next, the cured substrate was immersed in a roughening solution (product name: Concentrate Compact P, Atotech Japan) at 80°C for 60 minutes. Finally, the substrate with the cured product was immersed in a neutralizing solution (product name: Reduction Solution Securigant P, manufactured by Atotech Japan) at 40°C for 5 minutes. After rinsing with water, it was dried at 120°C for 20 minutes and visually inspected for peeling. Those that showed no peeling were marked with an ◯, and those that showed peeling were marked with an ×.

[0104] [Table 1]

[0105] [Table 2]

[0106] [Table 3]

Claims

1. A thermosetting resin composition comprising the following components (A) to (F), wherein the total content of the following components (A) to (E) is 5 to 99 mass% of the total composition: (A) Aromatic cyclic imide compound having a weight average molecular weight of 5,000 to 100,000 (B) Aliphatic cyclic imide compound having a weight average molecular weight of 100 to 2,000 (C) Epoxy resin having two or more epoxy groups in one molecule (D) Epoxy resin curing agent (E) Curing catalyst (F) Inorganic filler

2. 2. The thermosetting resin composition according to claim 1, wherein the cyclic imide resin compound of component (A) is at least one aromatic cyclic imide selected from the following formulae (1) and (2): 【Chemistry 1】 (In formula (1), P and Q are independently represented by the following formula: 【Chemistry 2】 In the above formula, X is a divalent group represented by 1 are independently expressed by the following formula: 【Transformation 3】 In addition, in formula (1), a is a number from 1 to 40, and X is a hydrogen atom or a methyl group. 【Chemistry 4】 (In formula (2), Q 1 are independently expressed by the following formula: 【Transformation 5】 In the above formula, X is a divalent group represented by 2 are independently expressed by the following formula: 【Transformation 6】 In formula (2), b is a number from 1 to 50, c is a number from 1 to 50, and A 1 and A 2 are each independently represented by the following formula (3) or the following formula (4): 【Transformation 7】 (In formula (3) and formula (4), X 3 is expressed as follows: 【Transformation 8】 In formula (3), R 1 are independently a hydrogen atom, a chlorine atom, or an aliphatic hydrocarbon group having 1 to 6 carbon atoms. X is a hydrogen atom or a methyl group.

3. 2. The thermosetting resin composition according to claim 1, wherein the cyclic imide resin compound of component (B) is an aliphatic cyclic imide compound represented by the following formula (5): 【Chemistry 9】 (In formula (5), A's are independently tetravalent organic groups containing an aliphatic cyclic structure, X's are hydrogen atoms or methyl groups, W's are independently divalent aliphatic hydrocarbon groups having 5 to 25 carbon atoms which may contain a heteroatom, and s is 0 to 10.)

4. 4. The thermosetting resin composition according to claim 3, wherein W in formula (5) is a linear or branched alkylene group having 5 to 25 carbon atoms, or a divalent aliphatic hydrocarbon group represented by any of the following structural formulas: 【Chemistry 10】 (p 5 and p 6 are each a number from 0 to 4, and may be the same or different. 2 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 20 carbon atoms. Z is an oxygen atom, a sulfur atom, or a methylene group. The bond not bonded to a substituent in the above structural formula is bonded to the nitrogen atom that forms the cyclic imide structure in formula (5).

5. 2. The thermosetting resin composition according to claim 1, wherein the blending amount of component (B) is 5 to 150 parts by mass per 100 parts by mass of component (A).

6. 2. The thermosetting resin composition according to claim 1, wherein the epoxy resin curing agent of component (D) is an amine curing agent.

7. A bonding film comprising the thermosetting resin composition of claim 1.

8. A prepreg comprising a cured product of the thermosetting resin composition according to claim 1.

9. A resin-coated copper foil comprising a cured product of the thermosetting resin composition according to claim 1.

10. A build-up film comprising the thermosetting resin composition according to claim 1.

11. A printed wiring board using the material according to any one of claims 7 to 10.