Photosensitive resin composition, liquid material, photosensitive resin sheet, and electric wiring board

Abstract

The present disclosure addresses the problem of providing a photosensitive resin composition capable of improving adhesion and electrical characteristics of a cured product. This photosensitive resin composition contains a cation-polymerizable compound (A) and a photocationic polymerization initiator (B). The cation-polymerizable compound (A) contains: at least one selected from the group consisting of an epoxy compound (a1) and an episulfide compound (a2); and a polycyclic aromatic compound (a3). The polycyclic aromatic compound (a3) has: at least one selected from the group consisting of polyphenylene ether skeletons and polystyrene skeletons; and a vinylbenzyl group.

Description

Photosensitive resin composition, liquid material, photosensitive resin sheet, and electrical wiring board

[0001] The present disclosure relates to a photosensitive resin composition, a liquid material, a photosensitive resin sheet, and an electrical wiring board, and more particularly to a photocurable photosensitive resin composition, a liquid material containing the photosensitive resin composition, a photosensitive resin sheet containing the photosensitive resin composition, and an electrical wiring board made from the photosensitive resin composition.

[0002] Patent Document 1 discloses that a photosensitive resin composition for forming an optical waveguide contains an alicyclic epoxy monomer having two or more functional groups and / or an oxetane monomer having two or more functional groups, and an acid generator, and that this photosensitive resin composition is used to produce optical wiring and an optoelectronic hybrid board equipped with an optical waveguide.

[0003] JP 2011-209664 A

[0004] An object of the present disclosure is to provide a photosensitive resin composition that can improve the adhesion and electrical properties of a cured product, a liquid material containing this photosensitive resin composition, a photosensitive resin sheet containing this photosensitive resin composition, and an electrical wiring board made from this photosensitive resin composition.

[0005] A photosensitive resin composition according to one embodiment of the present disclosure contains a cationically polymerizable compound (A) and a photocationic polymerization initiator (B). The cationically polymerizable compound (A) contains at least one compound selected from the group consisting of an epoxy compound (a1) and an episulfide compound (a2), and a polycyclic aromatic compound (a3). The polycyclic aromatic compound (a3) ​​has at least one compound selected from the group consisting of a polyphenylene ether skeleton and a polystyrene skeleton, and a vinylbenzyl group.

[0006] The liquid material according to one embodiment of the present disclosure includes a photosensitive resin composition.

[0007] A photosensitive resin sheet according to one embodiment of the present disclosure includes a photosensitive resin composition.

[0008] An electric wiring board according to one aspect of the present disclosure includes an insulating layer and conductor wiring, wherein the insulating layer contains a cured product of the photosensitive resin composition.

[0009] FIG. 1 is a cross-sectional view showing a manufacturing process for an electric wiring board according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view showing a manufacturing process for an electric wiring board according to an embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing a manufacturing process for an electric wiring board according to an embodiment of the present disclosure. FIG. 4 is a cross-sectional view showing a manufacturing process for an electric wiring board according to an embodiment of the present disclosure. FIG. 5 is a cross-sectional view showing a manufacturing process for an electric wiring board according to an embodiment of the present disclosure. FIG. 6 is a cross-sectional view showing a manufacturing process for an electric wiring board according to an embodiment of the present disclosure. FIG. 7 is a cross-sectional view showing a manufacturing process for an electric wiring board according to an embodiment of the present disclosure. FIG. 8 is a cross-sectional view showing a manufacturing process for an electric wiring board according to an embodiment of the present disclosure. FIG. 9 is a cross-sectional view of an electric wiring board according to an embodiment of the present disclosure. FIG. 10 is a plan view showing an application example of an electric wiring board according to an embodiment of the present disclosure.

[0010] Embodiments of the present disclosure will be described. Note that the following embodiments are merely a portion of various embodiments of the present disclosure. Furthermore, the following embodiments can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. The figures referred to below are schematic diagrams, and the dimensional ratios of the components in the figures do not necessarily reflect the actual dimensional ratios. The mechanism of action described below is a conjecture, and the present disclosure is not bound by the explanation of the mechanism of action below.

[0011] 1. Overview A photosensitive resin composition (X) according to one embodiment of the present disclosure contains a cationically polymerizable compound (A) and a photocationic polymerization initiator (B). The cationically polymerizable compound (A) contains at least one compound selected from the group consisting of an epoxy compound (a1) and an episulfide compound (a2), and a polycyclic aromatic compound (a3). The polycyclic aromatic compound (a3) ​​contains at least one compound selected from the group consisting of a polyphenylene ether skeleton and a polystyrene skeleton, and a vinylbenzyl group.

[0012] The photosensitive resin composition (X) contains a cationically polymerizable compound (A) and a photocationic polymerization initiator (B), and thus has photocurability. That is, a cured product can be produced by irradiating the photosensitive resin composition (X) with light. Furthermore, a cured product having an appropriate pattern can also be produced from the photosensitive resin composition (X) by photolithography.

[0013] The cured product of the photosensitive resin composition (X) can have excellent adhesion. This is presumably because the photosensitive resin composition (X) contains at least one compound selected from the group consisting of an epoxy compound (a1) and an episulfide compound (a2). For this reason, for example, when a film-like cured product of the photosensitive resin composition (X) is prepared on a substrate 1 such as a silicon wafer or glass, the cured product is less likely to peel off from the substrate 1. For this reason, for example, when this film-like cured product is subjected to a polishing treatment such as chemical mechanical polishing (CMP), the cured product is less likely to be damaged.

[0014] A cured product of the photosensitive resin composition (X) can have excellent electrical properties. Specifically, the relative dielectric constant and dielectric loss tangent of the cured product can be reduced. Therefore, for example, when the photosensitive resin composition (X) is used to prepare an insulating layer 2 (interlayer insulating layer) in an electrical wiring board 102, the electrical wiring board 102 can have excellent high-frequency properties. An insulating layer 2 having an appropriate pattern can also be prepared by photolithography or the like.

[0015] As long as the photosensitive resin composition (X) does not contain a substance that excessively inhibits light transmission, the photosensitive resin composition (X) can have good optical transparency. In this case, the photosensitive resin composition (X) can also be used to produce an electrical wiring board 102 including an optical waveguide (see FIG. 9 ). In this case, at least one of the core 5 and the clad in the optical waveguide is a cured product of the photosensitive resin composition (X). When the core 5 and the clad in the optical waveguide are each a cured product of the photosensitive resin composition (X), at least one of the specific components and the blending ratios of the components contained in the photosensitive resin composition (X) for producing the core 5 (hereinafter also referred to as core composition (X1)) and the photosensitive resin composition (X) for producing the insulating layer 2 that also serves as the clad (hereinafter also referred to as insulating layer composition (X2)) are made different from each other, so that the refractive index of the cured product of the core composition (X1) is greater than that of the insulating layer composition (X2). At least one of the core 5 and the cladding can be fabricated by photolithography.

[0016] 2. Photosensitive Resin Composition The components of the photosensitive resin composition (X) will be explained.

[0017] The cationically polymerizable compound (A) is a compound having a cationically polymerizable functional group, such as at least one selected from the group consisting of an epoxy group, an episulfide group, an oxetanyl group, a vinylbenzyl group, and a vinyl ether group.

[0018] In an embodiment, the cationically polymerizable compound (A) contains at least one compound selected from the group consisting of an epoxy compound (a1) and an episulfide compound (a2), and a polycyclic aromatic compound (a3). The polycyclic aromatic compound (a3) ​​has at least one compound selected from the group consisting of a polyphenylene ether skeleton and a polystyrene skeleton, and a vinylbenzyl group.

[0019] The epoxy compound (a1) is a compound having an epoxy group. The epoxy compound (a1) may include any of a monomer, an oligomer, and a polymer (prepolymer). The epoxy compound (a1) may be liquid or solid at room temperature. The epoxy compound (a1) can improve the adhesion of the cured product.

[0020] The epoxy compound (a1) preferably contains at least one selected from the group consisting of a glycidyl-type epoxy compound (a11) which is an epoxy compound having a glycidyl group and is different from the alicyclic epoxy compound (a12), and the alicyclic epoxy compound (a12). In this case, the cured product of the photosensitive resin composition (X) can have particularly good adhesion.

[0021] The glycidyl epoxy compound (a11) preferably contains a compound having a glycidyl ether group (glycidyl ether epoxy compound), which can further improve the adhesion of the cured product.

[0022] The glycidyl epoxy compound (a11) contains at least one selected from the group consisting of, for example, bisphenol A epoxy resins (e.g., product name 1006FS manufactured by Mitsubishi Chemical Corporation), hydrogenated bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol AP epoxy resins, bisphenol AF epoxy resins, bisphenol B epoxy resins, bisphenol BP epoxy resins, bisphenol C epoxy resins, bisphenol E epoxy resins, bisphenol G epoxy resins, bisphenol M epoxy resins, bisphenol S epoxy resins, bisphenol P epoxy resins, bisphenol PH epoxy resins, bisphenol TMC epoxy resins, phenol novolac epoxy resins, cresol novolac epoxy resins, and epoxidation reaction products of 2,2'-diallyl bisphenol A diallyl ether with hydrogen peroxide (CAS No. 1799411-80-5, for example, Showfree BATG manufactured by Resonac Corporation).

[0023] The alicyclic epoxy compound (a12) is, for example, at least one compound selected from the group consisting of compounds (a121) having an alicyclic ring in the molecule and an epoxy group composed of two adjacent carbon atoms and an oxygen atom that constitute the alicyclic ring, and compounds (a122) having an alicyclic ring in the molecule and an epoxy group bonded to the alicyclic ring by a single bond.

[0024] The compound (a121) contains, for example, at least one selected from the group consisting of a compound represented by the following formula (E1), a compound represented by the following formula (E20), and a compound represented by the following formula (E10).

[0025]

[0026] In formula (E1), R 1 ~R 18 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group. The number of carbon atoms in the hydrocarbon group is preferably within the range of 1 to 20. Examples of the hydrocarbon group include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, and propyl groups; alkenyl groups having 2 to 20 carbon atoms, such as vinyl and allyl groups; and alkylidene groups having 2 to 20 carbon atoms, such as ethylidene and propylidene groups. The hydrocarbon group may contain an oxygen atom or a halogen atom. 1 ~R 18 are each independently preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, more preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

[0027] In formula (E1), X is a single bond or a divalent organic group, and the organic group is, for example, —CO—O—CH 2 —.

[0028] Examples of the compound represented by formula (E1) include a compound represented by formula (E1a) below and a compound represented by formula (E1b) below.

[0029]

[0030]

[0031]

[0032] In formula (E20), R 1 ~R 12 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. The halogen atom is, for example, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. The hydrocarbon group having 1 to 20 carbon atoms is, for example, an alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, or a propyl group; an alkenyl group having 2 to 20 carbon atoms such as a vinyl group or an allyl group; or an alkylidene group having 2 to 20 carbon atoms such as an ethylidene group or a propylidene group. The hydrocarbon group having 1 to 20 carbon atoms may contain an oxygen atom or a halogen atom.

[0033] R 1 ~R 12 are each independently preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, more preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

[0034] Examples of compounds represented by formula (E20) include tetrahydroindene diepoxides represented by formula (E20a) below.

[0035]

[0036]

[0037] In formula (E10), R is a single bond or a divalent organic group, and is preferably an alkylene group. Y is a siloxane skeleton, which may be linear, branched, or cyclic, and the number of Si atoms is preferably 2 to 14, more preferably 2 to 10, even more preferably 2 to 7, and particularly preferably 3 to 6. n is an integer of 2 or more, and is preferably in the range of 2 to 4.

[0038] The compound represented by formula (E10) includes, for example, a compound represented by the following formula (E10a):

[0039]

[0040] In formula (E10a), R represents a single bond or a divalent organic group, and is preferably an alkylene group having 1 to 4 carbon atoms. In formula (E10a), n represents an integer of 0 or greater. n is preferably within the range of 0 to 12, more preferably within the range of 0 to 8, even more preferably within the range of 0 to 5, and particularly preferably within the range of 1 to 4.

[0041] The compound represented by formula (E10) contains at least one component selected from the group consisting of product numbers KR470, X-40-2669, X-40-2678, X-40-2670, X-40-2715, X-40-2732, X-22-169AS, X-22-169B, X-22-2046, X-22-343, X-22-163, and X-22-163B, manufactured by Shin-Etsu Chemical Co., Ltd., for example.

[0042] The compound (a122) may contain, for example, a 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (for example, EHPE3150 manufactured by Daicel Corporation).

[0043] The epoxy compound (a1) may contain only at least one selected from the group consisting of a glycidyl-type epoxy compound (a11) and an alicyclic epoxy compound (a12). Alternatively, the epoxy compound (a1) may contain only a compound (a13) that is neither a glycidyl-type epoxy compound (a11) nor an alicyclic epoxy compound (a12). The epoxy compound (a1) may contain at least one selected from the group consisting of a glycidyl-type epoxy compound (a11) and an alicyclic epoxy compound (a12) and the compound (a13).

[0044] The compound (a13) contains at least one selected from the group consisting of, for example, a polyfunctional epoxy resin that is neither a glycidyl-type epoxy compound (a11) nor an alicyclic epoxy compound (a12), a brominated epoxy resin, a fluorine-containing epoxy resin, an aromatic epoxy resin, a biphenyl skeleton-type epoxy resin, an aliphatic epoxy resin, and an epoxy resin having a silicone (siloxane) skeleton.

[0045] It is also preferred that the epoxy compound (a1) contains a compound having three or more epoxy groups, such as the above-mentioned epoxidation reaction product of 2,2'-diallyl bisphenol A diallyl ether with hydrogen peroxide, which can increase the glass transition temperature of the cured product and improve the heat resistance of the cured product.

[0046] When the cationic polymerizable compound (A) contains at least one selected from the group consisting of a glycidyl-type epoxy compound (a11) and an alicyclic epoxy compound (a12), the total ratio of the glycidyl-type epoxy compound (a11) and the alicyclic epoxy compound (a12) to the cationic polymerizable compound (A) is preferably 5% by mass or more and 80% by mass or less. When this ratio is 5% by mass or more, the adhesion of the cured product can be further improved. This ratio is more preferably 10% by mass or more, even more preferably 13% by mass or more, and particularly preferably 18% by mass or more. When this ratio is 80% by mass or less, there is an advantage that the dielectric tangent of the cured product is low. This ratio is more preferably 70% by mass or less, even more preferably 66% by mass or less, and particularly preferably 63% by mass or less.

[0047] The episulfide compound (a2) is a compound having an episulfide group. The episulfide compound (a2) may include any of a monomer, an oligomer, and a polymer (prepolymer). The episulfide compound (a2) may be liquid or solid at room temperature.

[0048] The episulfide compound (a2) can also improve the adhesion of the cured product. Furthermore, the episulfide compound (a2) tends to have a higher refractive index than the epoxy compound (a1). Therefore, by using the epoxy compound (a1) and the episulfide compound (a2) in combination and appropriately selecting the ratio of the epoxy compound (a1) to the episulfide compound (a2), the refractive index of the cured product can be set to an appropriate value while maintaining good adhesion of the cured product. Furthermore, the episulfide compound (a2) can enhance the photocurability of the photosensitive resin composition (X) and increase the flexibility of the cured product.

[0049] The episulfide compound (a2) contains, for example, hydrogenated bisphenol A diepisulfide (for example, TBIS-AHS manufactured by Taoka Chemical Co., Ltd.) The hydrogenated bisphenol A diepisulfide can improve the photocurability of the cured product and can also improve the flexibility of the cured product.

[0050] The cationically polymerizable compound (A) may contain an epoxy compound (a1) but not an episulfide compound (a2), may contain an episulfide compound (a2) without containing an epoxy compound (a1), or may contain both an epoxy compound (a1) and an episulfide compound (a2).

[0051] When the cationically polymerizable compound (A) contains an epoxy compound (a1), the proportion of the epoxy compound (a1) is preferably 10% by mass or more relative to the cationically polymerizable compound (A). In this case, the cured product can have better adhesion. This proportion is more preferably 13% by mass or more, and even more preferably 15% by mass or more. Furthermore, the proportion of the epoxy compound (a1) is preferably 70% by mass or less. In this case, there is an advantage that the dielectric tangent of the cured product is low. This proportion is more preferably 66% by mass or less, and even more preferably 63% by mass or less.

[0052] When the cationically polymerizable compound (A) contains an episulfide compound (a2), the proportion of the episulfide compound (a2) is preferably 10% by mass or more relative to the cationically polymerizable compound (A). In this case, the cured product can have better adhesion. This proportion is more preferably 15% by mass or more. Furthermore, the proportion of the episulfide compound (a2) is preferably 70% by mass or less. In this case, there is an advantage that the photosensitivity of the photosensitive resin composition (X) is excellent. This proportion is more preferably 60% by mass or less, and even more preferably 40% by mass or less.

[0053] When the cationically polymerizable compound (A) contains both an epoxy compound (a1) and an episulfide compound (a2), the total proportion of the epoxy compound (a1) and the episulfide compound (a2) is preferably 10% by mass or more relative to the total mass of the cationically polymerizable compound (A). In this case, the cured product can have better adhesion. This proportion is more preferably 13% by mass or more, and even more preferably 15% by mass or more. Furthermore, this proportion is preferably 70% by mass or less. In this case, there is an advantage that the dielectric tangent of the cured product is low. This proportion is more preferably 65% ​​by mass or less.

[0054] When the cationically polymerizable compound (A) contains both an epoxy compound (a1) and an episulfide compound (a2), the ratio of the episulfide compound (a2) to the total of the epoxy compound (a1) and the episulfide compound (a2) is selected depending on the properties required of the cured product, such as the refractive index, and is, for example, 10% by mass or more and 80% by mass or less. This ratio is more preferably 20% by mass or more, and even more preferably 30% by mass or more. This ratio is more preferably 70% by mass or less, and even more preferably 60% by mass or less.

[0055] As described above, the polycyclic aromatic compound (a3) ​​has at least one selected from the group consisting of a polyphenylene ether skeleton and a polystyrene skeleton, and a vinylbenzyl group. The polycyclic aromatic compound (a3) ​​can improve the electrical properties of the cured product, i.e., can reduce the dielectric constant and dielectric loss tangent of the cured product. Furthermore, while the epoxy compound (a1), particularly a glycidyl ether-type epoxy compound, tends to reduce the electrical properties of the cured product, the photosensitive resin composition (X) containing the epoxy compound (a1) and the polycyclic aromatic compound (a3) ​​can achieve both good adhesion and good electrical properties.

[0056] The polycyclic aromatic compound (a3) ​​preferably has two or more vinylbenzyl groups per molecule, and the vinylbenzyl groups are preferably 4-vinylbenzyl groups.

[0057] The polycyclic aromatic compound (a3) ​​includes, for example, a vinylbenzyl-modified polyphenylene ether (a31) having a vinylbenzyl group and a polyphenylene ether skeleton. The vinylbenzyl-modified polyphenylene ether (a31) preferably contains a vinylbenzyl-modified polyphenylene ether having a repeating unit represented by the following formula (1) and a vinylbenzyl group. In this case, the number of repeating units represented by formula (1) is preferably 2 or more and 300 or less, more preferably 2 or more and 100. In formula (1), R １ , R ２ , R ３ and R ４ Each of the groups is a hydrogen atom or a substituent. The substituent is preferably an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. The substituent is preferably an alkyl group. The alkyl group is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, the alkyl group is, for example, a methyl group, an ethyl group, a propyl group, a hexyl group, or a decyl group, and is particularly preferably a methyl group.

[0058]

[0059] More preferably, the vinylbenzyl-modified polyphenylene ether (a31) contains a polyphenylene ether modified with vinylbenzyl groups at both ends, in which the hydrogen atoms of the hydroxyl groups at both ends of the polyphenylene ether are replaced with vinylbenzyl groups. The vinylbenzyl-modified polyphenylene ether (a31) contains, for example, a compound represented by the following formula:

[0060]

[0061] In formula (2), Y is an alkylene group having 1 to 3 carbon atoms or a single bond. Y is, for example, a dimethylmethylene group. In formula (2), s is a number of 0 or more, t is a number of 0 or more, and the sum of s and t is a number of 1 or more. s is preferably a number of 0 or more and 20 or less, t is preferably a number of 0 or more and 20 or less, and the sum of s and t is preferably a number of 1 or more and 30 or less.

[0062] When the polycyclic aromatic compound (a3) ​​contains a compound having a polystyrene skeleton (hereinafter also referred to as polycyclic aromatic compound (a32)), the polycyclic aromatic compound (a32) has, for example, a repeating unit (u1) derived from a divinyl aromatic compound and a repeating unit (u2) derived from a monovinyl aromatic compound.

[0063] The repeating unit (u1) derived from a divinyl aromatic compound includes, for example, a repeating unit (u1-1) represented by the following formula (3):

[0064]

[0065] In formula (3), R ９ is an aromatic hydrocarbon group having 6 to 30 carbon atoms.

[0066] In the polycyclic aromatic compound (a32), the proportion of the repeating unit (u1) relative to the total of the repeating unit (u1) and the repeating unit (u2) is preferably 2 mol% or more and less than 95 mol%. The proportion of the repeating unit (u2) relative to the total of the repeating unit (u1) and the repeating unit (u2) is preferably 5 mol% or more and less than 98 mol%. Furthermore, when the repeating unit (u2) contains the repeating unit (u1-1), the proportion of the repeating unit (u1-1) relative to the total of the repeating unit (u1) and the repeating unit (u2) is preferably 2 mol% or more and 80 mol% or less.

[0067] The polycyclic aromatic compound (a32) preferably has a number-average molecular weight Mn of 300 or more and 100,000 or less. The polycyclic aromatic compound (a32) preferably has a molecular weight distribution, expressed as the ratio of the weight-average molecular weight Mw to the number-average molecular weight, of 100.0 or less. The polycyclic aromatic compound (a32) is preferably soluble in at least one of toluene, xylene, tetrahydrofuran, dichloroethane, and chloroform.

[0068] The polycyclic aromatic compound (a32) is not limited to, but examples thereof include copolymers having a repeating unit (u1) derived from a divinyl aromatic compound and a repeating unit (u2) derived from a monovinyl aromatic compound, as shown in the following formula (4): The repeating units shown in formula (4) may be arranged regularly or randomly.

[0069]

[0070] In formula (4), R １０ is an aromatic hydrocarbon group having 6 to 30 carbon atoms derived from a monovinyl aromatic compound, and R １１ is an aromatic hydrocarbon group having 6 to 30 carbon atoms derived from a divinyl aromatic compound, and h to k are each independently an integer of 0 to 200, provided that the sum of their numbers is 2 to 20,000.

[0071] Preferably, in the above formula (4), R １０ and R １１ is an aromatic hydrocarbon group selected from the group consisting of an optionally substituted phenyl group, an optionally substituted biphenyl group, an optionally substituted naphthalene group, and an optionally substituted terphenyl group.

[0072] The polycyclic aromatic compound (a32) is preferably soluble in a solvent. The repeating unit referred to in this specification is derived from a monomer and includes a unit that is present in the main chain of the copolymer and appears repeatedly, as well as a unit or terminal group that is present at the end or in the side chain. The repeating unit is also referred to as a structural unit or a constitutional unit.

[0073] The repeating unit (u1) derived from the divinylaromatic compound is contained in an amount of 2 mol% or more but less than 95 mol% of the total of the repeating units (u2) derived from the divinylaromatic compound and the monovinyl aromatic compound. The repeating unit (u1) derived from the divinylaromatic compound can have a variety of structures, such as one in which only one of two vinyl groups has reacted, or two in which two have reacted. Of these, the repeating unit represented by the above formula (3) in which only one vinyl group has reacted is preferably contained in an amount of 2 mol% or more but less than 80 mol%, more preferably 5 mol% or more but less than 70 mol%, even more preferably 10 mol% or more but less than 60 mol%, and particularly preferably 15 mol% or more but less than 50 mol%. By containing 2 mol% or more but less than 80 mol%, it is believed that the dielectric loss tangent is low, heat resistance is excellent, and compatibility with other resins is excellent. If it is less than 2 mol%, heat resistance tends to decrease, and if it exceeds 80 mol%, adhesion strength tends to decrease.

[0074] The polycyclic aromatic compound (a32) contains repeating units (u2) derived from a monovinyl aromatic compound in an amount of 5 mol% or more and less than 98 mol% based on the total amount. More preferably, it contains 10 mol% or more and less than 90 mol%. Even more preferably, it contains 15 mol% or more and less than 85 mol%. If it is less than 5 mol%, moldability may be insufficient, and if it exceeds 98 mol%, the heat resistance of the cured product may be insufficient.

[0075] The vinyl group present in the above formula (3) acts as a cross-linking component and contributes to the development of heat resistance of the polycyclic aromatic compound (a32). On the other hand, the repeating unit (u2) derived from a monovinyl aromatic compound does not have a vinyl group because it is believed that polymerization usually proceeds through a 1,2-addition reaction of the vinyl group. In other words, the repeating unit (u2) derived from a monovinyl aromatic compound does not act as a cross-linking component but contributes to the development of moldability.

[0076] The number average molecular weight (number average molecular weight in terms of standard polystyrene measured using GPC) of the polycyclic aromatic compound (a32) is preferably 300 to 100,000, more preferably 400 to 50,000, and even more preferably 500 to 10,000. If Mn is less than 300, the amount of monofunctional copolymer component contained in the polycyclic aromatic compound (a32) increases, tending to reduce the heat resistance of the cured product. If Mn exceeds 100,000, gel tends to be formed more easily and the viscosity increases, tending to reduce moldability. In addition, the molecular weight distribution (Mw / Mn), expressed as the ratio of the weight average molecular weight (weight average molecular weight in terms of standard polystyrene measured using GPC) to Mn, is preferably 100.0 or less, more preferably 50.0 or less, even more preferably 1.5 to 30.0, and most preferably 2.0 to 20.0. If Mw / Mn exceeds 100.0, the processing characteristics of the polycyclic aromatic compound (a32) tend to deteriorate, and gel tends to occur.

[0077] When the polycyclic aromatic compound (a32) has a repeating unit (u1) derived from a divinyl aromatic compound, i.e., when the polycyclic aromatic compound (a32) is a copolymer containing a divinyl aromatic compound, the divinyl aromatic compound serves to form a branched structure in the polycyclic aromatic compound (a32) to make it multifunctional, and also serves as a cross-linking component to impart heat resistance when the polycyclic aromatic compound (a32) is thermally cured. Examples of divinyl aromatic compounds are not limited as long as they are aromatic compounds having two vinyl groups, but preferred are divinylbenzene (including each positional isomer or a mixture thereof), divinylnaphthalene (including each positional isomer or a mixture thereof), and divinylbiphenyl (including each positional isomer or a mixture thereof). These compounds may be used alone or in combination of two or more. From the viewpoint of moldability, divinylbenzene (m-isomer, p-isomer, or a mixture of these positional isomers) is more preferred.

[0078] Regarding the repeating unit (u2) derived from a monovinyl aromatic compound, the monovinyl aromatic compound contains styrene. That is, the repeating unit (u2) derived from a monovinyl aromatic compound contains a repeating unit (u2-1) derived from styrene. The monovinyl aromatic compound may contain a monovinyl aromatic compound other than styrene together with styrene. Styrene serves to impart low dielectric properties and thermal oxidative degradation resistance to the polycyclic aromatic compound (a32), and also serves as a chain transfer agent to control the molecular weight of the polycyclic aromatic compound (a32). Furthermore, the monovinyl aromatic compound other than styrene improves the solvent solubility and processability of the polycyclic aromatic compound (a32).

[0079] Examples of monovinyl aromatic compounds other than styrene are not limited as long as they are aromatic compounds other than styrene having one vinyl group, but include vinyl aromatic compounds such as vinylnaphthalene and vinylbiphenyl; and nuclear alkyl-substituted vinyl aromatic compounds such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, and p-ethylvinylbenzene. Ethylvinylbenzene (including each positional isomer or a mixture thereof), ethylvinylbiphenyl (including each positional isomer or a mixture thereof), or ethylvinylnaphthalene (including each positional isomer or a mixture thereof) are preferred because they prevent gelation of the polycyclic aromatic compound (a32), are highly effective in improving solvent solubility and processability, are low cost, and are easily available. More preferred is ethylvinylbenzene (m-isomer, p-isomer, or a mixture of these positional isomers) from the viewpoints of dielectric properties and cost.

[0080] In the repeating units (u2) derived from a monovinyl aromatic compound, the proportion of the repeating units (u2-1) derived from styrene relative to the sum of the repeating units (u2-1) derived from styrene and the repeating units (u2-2) derived from a monovinyl aromatic compound other than styrene is preferably 20 mol% or more and 99 mol% or less. More preferably, it is 30 mol% or more and 98 mol% or less. If the proportion of (a2-1) is within the above range, it is preferable because it combines thermal oxidative degradation resistance and moldability. If the proportion of the repeating units (u2-1) is more than 99 mol%, heat resistance tends to decrease, and if the proportion of the repeating units (u2-2) is more than 80 mol%, moldability tends to decrease.

[0081] Furthermore, one or more monomer components other than the divinyl aromatic compound and the monovinyl aromatic compound may be used as long as the effects of the present disclosure are not impaired. That is, the polycyclic aromatic compound (a3) ​​may further have a repeating unit (u3) derived from a monomer component other than the divinyl aromatic compound and the monovinyl aromatic compound. Examples of the monomer component other than the divinyl aromatic compound and the monovinyl aromatic compound include a trivinyl aromatic compound, a trivinyl aliphatic compound, a divinyl aliphatic compound, and a monovinyl aliphatic compound.

[0082] With regard to the repeating unit (u3), examples of monomer components other than divinyl aromatic compounds and monovinyl aromatic compounds include 1,3,5-trivinylbenzene, 1,3,5-trivinylnaphthalene, 1,2,4-trivinylcyclohexane, ethylene glycol diacrylate, butadiene, 1,4-butanediol divinyl ether, cyclohexanedimethanol divinyl ether, diethylene glycol divinyl ether, triallyl isocyanurate, etc. These can be used alone or in combination of two or more.

[0083] The molar fraction of the monomer components other than the divinyl aromatic compound and the monovinyl aromatic compound relative to the sum of all the monomer components is preferably less than 30 mol %. In other words, the molar fraction of the repeating unit (u3) derived from the monomer components other than the divinyl aromatic compound and the monovinyl aromatic compound relative to the sum of the repeating units (u1), (u2), and (u3) derived from all the monomer components constituting the copolymer is preferably less than 30 mol %.

[0084] As described above, the polycyclic aromatic compound (a3) ​​may contain at least one selected from the group consisting of vinylbenzyl-modified polyphenylene ether (a31) having a vinylbenzyl group and a polyphenylene ether skeleton, and polycyclic aromatic compounds (a32) having a polystyrene skeleton, such as divinylbenzene polymer oligomer. Commercially available products may be used as these compounds.

[0085] The proportion of the polycyclic aromatic compound (a3) ​​relative to the cationically polymerizable compound (A) is preferably 30% by mass or more. In this case, the electrical properties of the cured product can be further improved. This proportion is more preferably 35% by mass or more, and even more preferably 45% by mass or more. This proportion is preferably 90% by mass or less. In this case, there is an advantage that the brittleness of the cured product is eliminated and the abrasion resistance is improved. This proportion is more preferably 80% by mass or less.

[0086] The total ratio of the epoxy compound (a1), the episulfide compound (a2), and the polycyclic aromatic compound (a3) ​​to the cationically polymerizable compound (A) is preferably 60 mass% or more, more preferably 70 mass% or more. The cationically polymerizable compound (A) may contain only at least one selected from the group consisting of the epoxy compound (a1) and the episulfide compound (a2), and the polycyclic aromatic compound (a3).

[0087] The cationically polymerizable compound (A) may further contain a compound that is not an epoxy compound (a1), an episulfide compound (a2), or a polycyclic aromatic compound (a3).

[0088] For example, the cationically polymerizable compound (A) may further contain an oxetane compound (a4). The oxetane compound (a4) is a compound having an oxetanyl group. The oxetane compound (a4) may be any of a monomer, an oligomer, and a polymer (prepolymer).

[0089] The oxetane compound (a4) can increase the reaction rate when the photosensitive resin composition (X) is cured, thereby increasing the molecular weight of the molecules in the cured product. This can increase the strength of the cured product. Therefore, for example, when a film-like cured product is subjected to a polishing treatment such as chemical mechanical polishing (CMP), damage to the cured product can be further suppressed. Furthermore, the oxetane compound (a4) can increase the glass transition temperature of the cured product of the photosensitive resin composition (X), thereby improving the heat resistance of the cured product.

[0090] Examples of the oxetane compound (a4) include 3-ethyl-3-hydroxymethyloxetane (e.g., product name OXT-101 manufactured by Toagosei Co., Ltd., and product name EXO manufactured by UBE Inc.), 1,4-bis[(3-ethyloxetan-3-yl)methoxy]methyl]benzene (e.g., product name OXT-121 manufactured by Toagosei Co., Ltd.), 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (e.g., product name OXT-221 manufactured by Toagosei Co., Ltd.), 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane (e.g., product name OXT212 manufactured by Toagosei Co., Ltd.), 4,4′-bis[(3-ethyloxetan-3-yl)methoxy]methyl]benzene, and the like.

[0033] The copolymer contains at least one member selected from the group consisting of [3-(4-hydroxybutyloxymethyl)-3-oxetanyl]biphenyl (for example, the product name OXBP manufactured by UBE Corporation), [3-ethyl-3-oxetanyl]methyl methacrylate (for example, the product name OXMA manufactured by UBE Corporation), 3-ethyl-3-(4-hydroxybutyloxymethyl)oxetane (for example, the product name HBOX manufactured by UBE Corporation), 3-allyloxyoxetane (for example, the product name AL-OX manufactured by Shikoku Chemical Industry Co., Ltd.), 3-allyloxymethyl-3-ethyloxetane (for example, the product name AL-EOX manufactured by Shikoku Chemical Industry Co., Ltd.), and the product name TOIC manufactured by Shikoku Chemical Industry Co., Ltd.

[0091] When the cationically polymerizable compound (A) contains an oxetane compound (a4), the proportion of the oxetane compound (a4) is preferably 5% by mass or more relative to the cationically polymerizable compound (A). In this case, the strength and heat resistance of the cured product can be further improved. This proportion is preferably 10% by mass or more, and more preferably 15% by mass or more. The proportion of the oxetane compound (a4) is preferably 40% by mass or less. In this case, there is an advantage that the dielectric constant and dielectric loss tangent of the cured product are less likely to deteriorate. This proportion is more preferably 35% by mass or less, and even more preferably 30% by mass or less.

[0092] The cationically polymerizable compound (A) may further contain a vinyl sulfide compound (a5). The vinyl sulfide compound (a5) is a compound represented by the formula "CH ２ The vinyl sulfide compound (a5) is a compound having a group represented by the formula "=CH-S-*". Here, "-*" represents a single bond. The vinyl sulfide compound (a5) may be any of a monomer, an oligomer, and a polymer (prepolymer).

[0093] The vinyl sulfide compound (a5) can increase the glass transition temperature of the cured product of the photosensitive resin composition (X), thereby improving the heat resistance of the cured product. In addition, since the vinyl sulfide compound (a5) has a relatively high refractive index, the refractive index of the cured product of the photosensitive resin composition (X) can be appropriately set by appropriately selecting the content of the vinyl sulfide compound (a5).

[0094] The vinyl sulfide compound (a5) contains, for example, at least one selected from the group consisting of bis(4-vinylthiophenyl) sulfide (e.g., MPV manufactured by Sumitomo Seika Chemicals Co., Ltd.), 1-(vinylsulfanyl)-4-{[4-(vinylsulfanyl)phenyl]sulfanyl}benzene, bis(4-methacryloylthiophenyl) sulfide, and phenyl vinyl sulfide.

[0095] When the cationically polymerizable compound (A) contains a vinyl sulfide compound (a5), the proportion of the vinyl sulfide compound (a5) is preferably 10% by mass or more relative to the cationically polymerizable compound (A). In this case, the heat resistance of the cured product can be further improved. This proportion is preferably 15% by mass or more, and more preferably 20% by mass or more. The proportion of the vinyl sulfide compound (a5) is preferably 40% by mass or less. In this case, there is an advantage that the storage stability of the photosensitive resin composition (X) is improved. This proportion is more preferably 35% by mass or less, and even more preferably 30% by mass or less.

[0096] The cationically polymerizable compound (A) may contain a compound (hereinafter referred to as compound (a6)) that is not an epoxy compound (a1), an episulfide compound (a2), a polycyclic aromatic compound (a3), an oxetane compound (a4), or a vinyl sulfide compound (a5), as long as the compound (A) does not excessively impair the performance of the photosensitive resin composition (X). When the cationically polymerizable compound (A) contains compound (a6), the proportion of compound (a6) is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, relative to the cationically polymerizable compound (A). The cationically polymerizable compound (A) does not necessarily contain compound (a6).

[0097] The cationic photopolymerization initiator (B) is a compound that generates a protonic acid or a Lewis acid upon irradiation with light such as ultraviolet light. The cationic photopolymerization initiator (B) contains, for example, at least one selected from the group consisting of an ionic photoacid-generating cationic curing catalyst and a nonionic photoacid-generating cationic curing catalyst.

[0098] The ionic photoacid-generating cationic curing catalyst contains, for example, at least one selected from the group consisting of onium salts and organometallic complexes. The onium salts include, for example, at least one selected from the group consisting of aromatic diazonium salts, aromatic halonium salts, and aromatic sulfonium salts. The organometallic complexes include, for example, at least one selected from the group consisting of iron-allene complexes, titanocene complexes, and arylsilanol-aluminum complexes.

[0099] The nonionic photoacid-generating cationic curing catalyst contains at least one selected from the group consisting of, for example, nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, phenolsulfonic acid esters, diazonaphthoquinones, and N-hydroxyimide phosphonates, etc. However, the components that can be contained in the nonionic photoacid-generating cationic curing catalyst are not limited to those listed above.

[0100] More specific examples of compounds that can contain the photocationic polymerization initiator (B) include Midori Chemical's DPI series (105, 106, 109, 201, etc.), BI-105, MPI series (103, 105, 106, 109, etc.), BBI series (101, 102, 103, 105, 106, 109, 110, 200, 210, 300, 301, etc.), and TSP series. Series (102, 103, 105, 106, 109, 200, 300, 1000, etc.), HDS-109, MDS series (103, 105, 109, 203, 205, 209, etc.), BDS-109, MNPS-109, DTS series (102, 103, 105, 200, etc.), NDS series (103, 105, 155, 165, etc.), DAM series (1 01, 102, 103, 105, 201, etc.), SI series (105, 106, etc.), PI-106, NDI series (105, 106, 109, 1001, 1004, etc.), PAI series (01, 101, 106, 1001, 1002, 1003, 1004, etc.), MBZ-101, PYR-100, NB series (101, 201, etc.), NAI series Series (100, 1002, 1003, 1004, 101, 105, 106, 109, etc.), TAZ series (100, 101, 102, 103, 104, 107, 108, 109, 110, 113, 114, 118, 122, 123, 203, 204, etc.), NBC-101, ANC-101, TPS-Acetate, DTS-Acetate, Di-Boc Bisphinolic acid, tert-butyl lithocholate, tert-butyl deoxycholate, tert-butyl cholate, BX, BC-2, MPI-103, BDS-105, TPS-103, NAT-103, BMS-105, and TMS-105; Cyracure UVI-6970, Cyracure UVI-6974, Cyracure UVI-6990, and Cyracure UVI-950 manufactured by Union Carbide Corporation, USA; Irgacure 250, Irgacure 261, and Irgacure 264 manufactured by BASF Corporation; CG-24-61 manufactured by Ciba-Geigy Corporation; ADEKA Optomer SP-150, ADEKA Optomer SP-151, ADEKA Optomer SP-170, and ADEKA Optomer SP-171 manufactured by ADEKA Corporation;DAICAT II manufactured by Daicel Corporation; UVAC1590 and UVAC1591 manufactured by Daicel-Cytec Co., Ltd.; CI-2064, CI-2639, CI-2624, CI-2481, CI-2734, CI-2855, CI-2823, CI-2758, and CIT-1682 manufactured by Nippon Soda Co., Ltd.; PI-2074, which is tetrakis(pentafluorophenyl)borate toluylcumyl iodonium salt manufactured by Rhodia; FFC509 manufactured by 3M; CD-1010, CD-1011, and CD-1012 manufactured by Sartomer Corporation, USA; CPI-100P, CPI-101A, CPI-110P, CPI-110A, and CPI-210S manufactured by San-Apro Ltd., and UVI-6992 and UVI-6976 manufactured by The Dow Chemical Company. The photocationic polymerization initiator (B) can contain at least one compound selected from the group consisting of these compounds.

[0101] The cationic photopolymerization initiator (B) preferably contains multiple ionic photoacid generators having different anionic conjugate acid strengths. In this case, patterning can be improved when preparing a cured product having an appropriate pattern from the photosensitive resin composition (X) by photolithography or the like. Therefore, the photosensitive resin composition (X) can be used to prepare a cured product having a fine pattern with a large aspect ratio of height to width. Therefore, for example, preparing the insulating layer 2 of an electrical wiring board 102 from the photosensitive resin composition (X) can contribute to the miniaturization and high density of the conductor wiring 4 in the electrical wiring board 102. Furthermore, when the cationic photopolymerization initiator (B) contains multiple ionic photoacid generators having different anionic conjugate acid strengths, the storage stability of the photosensitive resin composition (X) is less likely to be impaired. Furthermore, when the photosensitive resin composition (X) is irradiated with light such as ultraviolet light, the photosensitive resin composition (X) is less likely to be cured too rapidly, and therefore the cured product is less likely to suffer from deterioration in transparency due to white turbidity, etc.

[0102] The cationic photopolymerization initiator (B) preferably contains a first agent (b1) containing an ionic photoacid generator having an anion species whose conjugate acid strength is higher, and a second agent (b2) containing an ionic photoacid generator having an anion species whose conjugate acid strength is lower.

[0103] The first agent (b1) preferably contains an ionic photoacid generator having an anion species whose conjugate acid strength is equal to or greater than that of HSbF. The second agent (b2) preferably contains an ionic photoacid generator having an anion species whose conjugate acid strength is lower than that of HSbF, and more preferably contains an ionic photoacid generator having an anion species whose conjugate acid strength is equal to or less than that of HPF.

[0104] The first agent (b1) is, for example, (Rf) n PF 6-n - an ionic photoacid generator (Rx) having n BX 4-n - and (Rx) n GaX 4-n - The second agent (b2) contains at least one ionic photoacid generator selected from the group consisting of ionic photoacid generators having, for example, PF6 - an ionic photoacid generator having BF - an ionic photoacid generator having (Rf)SO - The photoacid generator contains at least one ionic photoacid generator selected from the group consisting of ionic photoacid generators having a structure of the formula (I) and ionic photoacid generators having a sulfite ion.

[0105] In addition, (Rf) n PF 6-n - and (Rf) SO - In the formula (Rf), Rf is a perfluoroalkyl group. n PF 6-n - In the formula, n is any number from 1 to 5. (Rf) n PF 6-n - In the formula (Rf), the number of carbon atoms in Rf is, for example, 1 or more and 3 or less, and when there are multiple Rfs, the Rfs may be the same or different from one another. - The number of carbon atoms in Rf is, for example, 1 or more and 8 or less.

[0106] (Rx) n BX 4-n- and (Rx) n GaX 4-n - In each of the above, Rx is a phenyl group in which some of the hydrogen atoms are substituted with halogen atoms or electron-withdrawing substituents. The halogen atoms are fluorine atoms, chlorine atoms, bromine atoms, etc. The electron-withdrawing substituents are, for example, trifluoromethyl groups, nitro groups, cyano groups, etc. (Rx) n BX 4-n - and (Rx) n GaX 4-n - In each of the formulas (Rx), X is a halogen atom, and preferably a fluorine atom. n BX 4-n - and (Rx) n GaX 4-n - In each of the formulas, n is any number from 1 to 4. When there are multiple Rx, the Rx may be the same or different. Rx is, for example, C6F5, (CF3)2C6H3, CF3C6H4, or C6H3F2. (Rx) n BX 4-n - For example, (C6F5)4B - , ((CF3)2C6H3)4B - , (CF3C6H4)4B - , (C6F5)2BF2 - , C6F5BF3 - or (C6H3F2)4B - etc.

[0107] Photocationic polymerization initiator (B) is PF6 - When an ionic photoacid generator having the formula (I) is contained, the amount of PF6 relative to the total amount of the photocationic polymerization initiator (B) is - The amount of the ionic photoacid generator having PF6 is preferably 50% by mass or less. - may generate a small amount of hydrofluoric acid, which may corrode the silicon wafer or the like that is the substrate 1. - When the amount of the ionic photoacid generator having PF6 is 50 mass % or less as described above, the risk of hydrofluoric acid corroding the substrate 1 and the like can be reduced.- It is more preferable that the amount of the ionic photoacid generator having the formula (I) is 25% by mass or less.

[0108] The photocationic polymerization initiator (B) is (Rf) n PF 6-n - When the photopolymerization initiator (B) contains an ionic photoacid generator having the formula (Rf), the ratio of the total amount of the photocationic polymerization initiator (B) to the total amount of the photoacid generator (B) is 1: n PF 6-n - The amount of the ionic photoacid generator having the formula (Rf) is preferably 75% by mass or less. n PF 6-n - Also PF6 - Although it is not as strong as the fluorine-containing compound, it may generate a small amount of hydrofluoric acid. n PF 6-n - When the amount of the ionic photoacid generator having the formula (I) is 75 mass % or less as described above, the risk of hydrofluoric acid corroding the substrate 1 and the like can be reduced.

[0109] In addition, the photocationic polymerization initiator (B) is PF6 - an ionic photoacid generator having (Rf) n PF 6-n - When both an ionic photoacid generator having the formula (B) and an ionic photoacid generator having the formula (B), the amount of PF6 relative to the total amount of the cationic photopolymerization initiator (B) is - Preferably, the amount of the ionic photoacid generator having PF6 is 25% by mass or less. - an ionic photoacid generator having (Rf) n PF 6-n - It is particularly preferable that the total amount of the ionic photoacid generator having the formula (I) is 80% by mass or less based on the total amount of the cationic photopolymerization initiator (B).

[0110] On the other hand, (Rx) n BX 4-n - and (Rx) n GaX 4-n - An ionic photoacid generator having the formula (I) is preferred in that it is less likely to generate hydrofluoric acid.

[0111] There are no particular restrictions on the cationic species in the ionic photoacid generator contained in the first agent (b1) and the cationic species in the ionic photoacid generator contained in the second agent (b2), and they may be, for example, at least one selected from the group consisting of various aromatic oniums, more specifically, various aromatic diazoniums, aromatic haloniums, aromatic sulfoniums, and the like.

[0112] As described above, when the photocationic polymerization initiator (B) contains the first agent (b1) and the second agent (b2), the patterning properties of the cured product produced from the photosensitive resin composition (X) by a photolithography method or the like become good, and the cured product of the photosensitive resin composition (X) is particularly unlikely to become cloudy, and further the storage stability of the photosensitive resin composition (X) can be improved.

[0113] The ratio of the first agent to the total amount of the first agent (b1) and the second agent (b2) is preferably 50% by mass or more. In this case, the photosensitive resin composition (X) can have good curability, and the patterning properties of the cured product can be particularly good. Furthermore, this ratio is preferably 90% by mass or less. In this case, the cured product is particularly unlikely to become cloudy, and the storage stability of the photosensitive resin composition (X) can be particularly high. This ratio is more preferably 60% by mass or more and 90% by mass or less, and even more preferably 70% by mass or more and 85% by mass or less.

[0114] The amount of the photocationic polymerization initiator (B) is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, relative to 100 parts by mass of the cationically polymerizable compound (A), and is preferably 10 parts by mass or less, more preferably 4 parts by mass or less, and even more preferably 3 parts by mass or less.

[0115] The photosensitive resin composition (X) may contain additives other than the above components within a range that does not excessively impair the properties of the photosensitive resin composition (X). The additives may include at least one selected from the group consisting of, for example, an antioxidant, a leveling agent, a coupling agent such as a silane coupling agent, a flame retardant, and an inorganic filler.

[0116] The elastic modulus of the photosensitive resin composition (X) is preferably 2 GPa or less, and more preferably 1 GPa or less. In this case, warping of the electric wiring board 102 is mitigated, and physical damage such as cracking of the electric wiring board 102 during reliability tests and the like can be suppressed. By using the above components, the elastic modulus of the cured product can be within the above range. In particular, the episulfide compound (a2) can reduce the elastic modulus of the cured product. Therefore, by incorporating the episulfide compound (a2) into the photosensitive resin composition (X) and appropriately setting the content of the episulfide compound (a2), the elastic modulus of the cured product can be effectively reduced. The method for measuring the elastic modulus will be explained in the Examples section below.

[0117] The glass transition point of the cured product of the photosensitive resin composition (X) is preferably 150°C or higher. In this case, the cured product can have better heat resistance. A glass transition point of 170°C or higher is more preferable, and a glass transition point of 185°C or higher is even more preferable. By using the above components, the glass transition point of the cured product can be within the above range. The method for measuring the glass transition point will be explained in the Examples section below.

[0118] The relative dielectric constant of the cured product of the photosensitive resin composition (X) is preferably 3.1 or less. Furthermore, the dielectric loss tangent of this cured product is preferably 0.01 or less. In these cases, the cured product has better electrical properties, and an electric wiring board 102 having an insulating layer 2 containing this cured product can have better high-frequency properties. By using the above components, the relative dielectric constant and dielectric loss tangent of the cured product can be within the above ranges. The method for measuring the relative dielectric constant and dielectric loss tangent will be explained in the Examples section below.

[0119] In particular, when at least one of the core 5 and the cladding of the optical waveguide is produced from the photosensitive resin composition (X), the cured product of the photosensitive resin composition (X) is preferably transparent. In an embodiment, the use of the above components can make the cured product of the photosensitive resin composition (X) transparent. Furthermore, the refractive index of the cured product of the photosensitive resin composition (X) at a wavelength of 589.3 nm is preferably 1.45 or more and 1.60 or less. The use of the above components can make the refractive index of the cured product of the photosensitive resin composition (X) fall within the above range. Furthermore, the difference in refractive index between the cured product of the core composition (X1) and the cured product of the insulating layer composition (X2) is, for example, 0.003 or more and 0.05 or less.

[0120] 3. Liquid Material The liquid material of the embodiment contains the photosensitive resin composition (X) and is in a liquid state. The term "liquid" means that the material has fluidity at 25°C. The liquid material is, for example, a resin varnish containing the photosensitive resin composition (X) and a solvent. For example, the liquid material can be formed into an appropriate shape, such as a sheet, while being allowed to flow at room temperature.

[0121] 4. Photosensitive Resin Sheet The photosensitive resin sheet of the embodiment contains a photosensitive resin composition (X). The photosensitive resin sheet is produced, for example, by forming the photosensitive resin composition (X) into a sheet. For example, the photosensitive resin sheet may be produced by applying a liquid material to form a coating film, and then heating and drying the coating film.

[0122] When the entire photosensitive resin sheet is exposed to light and cured, a sheet-like cured film containing a cured product of the photosensitive resin composition (X) can be produced. Furthermore, by patterning the photosensitive resin sheet by photolithography and curing it, a cured film having an appropriate pattern shape can be produced. The cured film can be used, for example, as an insulating layer in an electrical wiring board or a clad in an optical waveguide.

[0123] 5. Electrical Wiring Board The electrical wiring board 102 includes an insulating layer 2 (interlayer insulating layer) containing a cured product of the photosensitive resin composition (X), and conductor wiring 4. Because the cured product of the photosensitive resin composition (X) has excellent electrical properties, the electrical wiring board 102 can have excellent high-frequency properties.

[0124] Electrical wiring board 102 of the embodiment also includes an optical waveguide. The optical waveguide includes core 5 and clad. Insulating layer 2 also serves as the clad of the optical waveguide, and core 5 is embedded in this clad.

[0125] Hereinafter, the photosensitive resin composition (X) for producing the core 5 will be referred to as a core composition (X1), and the photosensitive resin composition (X) for producing the insulating layer 2 that also serves as a clad will be referred to as an insulating layer composition (X2). The core 5 is made of a cured product of the core composition (X1), and the insulating layer 2 that also serves as a clad is made of a cured product of the insulating layer composition (X2).

[0126] The specific compositions of the core composition (X1) and the insulating layer composition (X2) are set so that the refractive index of the core 5 is greater than the refractive index of the clad, and the difference between the refractive index of the clad and the refractive index of the core 5 is a desired appropriate value.

[0127] The refractive index of the episulfide compound (a2) tends to be higher than the refractive index of the epoxy compound (a1). Therefore, by containing the episulfide compound (a2) in the core composition (X1) and not containing the episulfide compound (a2) in the insulating layer composition (X2), the refractive index of the core 5 can be made higher than the refractive index of the clad. Also, by containing the epoxy compound (a1) and the episulfide compound (a2) in each of the core composition (X1) and the insulating layer composition (X2), and by making the ratio of the episulfide compound (a2) in the core composition (X1) higher than the total of the epoxy compound (a1) and the episulfide compound (a2) in the core composition (X1), the refractive index of the core 5 can be made higher than the refractive index of the clad.

[0128] Furthermore, the vinyl sulfide compound (a5) has a relatively high refractive index. Therefore, by including the vinyl sulfide compound (a5) in the core composition (X1) and not including the vinyl sulfide compound (a5) in the insulating layer composition (X2), the refractive index of the core 5 can be made higher than the refractive index of the clad. Furthermore, by including the vinyl sulfide compound (a5) in each of the core composition (X1) and the insulating layer composition (X2) and by making the content of the vinyl sulfide compound (a5) higher in the core composition (X1), the refractive index of the core 5 can be made higher than the refractive index of the clad.

[0129] In addition to the above, the composition of the core composition (X1) and the composition of the insulating layer composition (X2) can be set by various methods.

[0130] Of the core 5 and the clad in the optical waveguide, the core 5 may be made of a cured product of the photosensitive resin composition (X), and the clad may be made of a material different from the cured product of the photosensitive resin composition (X). Also, of the core 5 and the clad in the optical waveguide, the clad may be made of a cured product of the photosensitive resin composition (X), and the core 5 may be made of a material different from the cured product of the photosensitive resin composition (X).

[0131] An example of a manufacturing process for the electric wiring board 102 according to the embodiment will be described.

[0132] A substrate 1 such as a silicon wafer, a core composition (X1) and an insulating layer composition (X2) having different compositions are prepared.

[0133] The core composition (X1) or a liquid material (resin varnish) containing the core composition (X1) is formed into a sheet and dried as needed to produce a photosensitive resin sheet, the core film 50. The insulating layer composition (X2) or a liquid material (resin varnish) containing the insulating layer composition (X2) is also formed into a sheet and dried as needed to produce an insulating film 20, which is a photosensitive resin sheet.

[0134] As shown in Fig. 1, an insulating film 20 is disposed on one main surface of a substrate 1. This insulating film 20 is patterned and cured by photolithography. As a result, an insulating layer 2 (first insulating layer 21) made of a cured product of the insulating layer composition (X2) is produced, as shown in Fig. 2. The first insulating layer 21 has a shape with a plurality of grooves 3 that extend from the surface opposite the substrate 1 side to the substrate 1.

[0135] A seed layer is formed on the surface of the first insulating layer 21 opposite to the substrate 1 side, on the inner surface of the groove 3, and on the surface of the substrate 1 exposed at the bottom of the groove 3. The seed layer is a layer made of a metal thin film. The seed layer is made of, for example, copper or a copper-nickel alloy. The seed layer is formed by a vapor deposition method such as sputtering.

[0136] Next, as shown in Fig. 3, a plating layer 40 is grown from the seed layer by electrolytic plating. The plating layer 40 is made of, for example, copper. The plating layer 40 is formed so as to cover the surface of the first insulating layer 21 opposite to the substrate 1 side and to fill the grooves 3.

[0137] Next, the surface portion of the plating layer 40 opposite the substrate 1 side is polished until the surface of the first insulating layer 21 opposite the substrate 1 side is exposed. One polishing method is chemical mechanical polishing (CMP). As a result, as shown in FIG. 4 , the portion of the plating layer 40 that filled the grooves 3 remains, and this portion becomes the conductor wiring 4.

[0138] Next, as shown in Fig. 5, a core film 50 is disposed on the surface of the first insulating layer 21 opposite the substrate 1. This core film 50 is patterned by photolithography and cured, thereby producing a plurality of cores 5 made of the cured product of the core composition (X1), as shown in Fig. 6.

[0139] 7, an insulating film 20 is placed on the surface of the first insulating layer 21 opposite the substrate 1 so as to cover the conductor wiring 4 and the core 5. The insulating film 20 is thermocompression bonded to the first insulating layer 21.

[0140] This insulating film 20 is patterned and cured by photolithography, thereby producing an insulating layer 2 (second insulating layer 22) made of a cured product of the insulating layer composition (X2), as shown in Fig. 8. The second insulating layer 22 has a shape with a plurality of grooves 3 that extend from the surface opposite to the first insulating layer 21 side to the first insulating layer 21.

[0141] Next, the fabrication of the conductor wiring 4, the fabrication of the core 5, and the fabrication of the insulating layer 2 are repeated in the same manner as above. As a result, as shown in FIG. 9 , the conductor wiring 4 is fabricated in the groove 3 of the second insulating layer 22, a plurality of cores 5 are fabricated on the surface of the second insulating layer 22 opposite the first insulating layer 21, and a third insulating layer 23 is fabricated to cover the conductor wiring 4 and cores 5. The third insulating layer 23 has a shape with a plurality of grooves 3 that reach from the surface opposite the second insulating layer 22 side to the second insulating layer 22. Next, the fabrication of the conductor wiring 4 is repeated in the same manner as above. As a result, the conductor wiring 4 is fabricated in the groove 3 of the third insulating layer 23.

[0142] Furthermore, the steps of forming the core 5, the insulating layer 2 and the conductor wiring 4 may be repeated any number of times.

[0143] As a result of the above, an electric wiring board 102 is obtained, which has a plurality of insulating layers 2, which also serve as cladding, stacked on the substrate 1, and has conductor wiring 4 and cores 5 embedded in each insulating layer 2.

[0144] In this embodiment, the thickness of each of the multiple insulating layers 2 is, for example, 5 μm or more and 50 μm or less. Furthermore, in this embodiment, the core 5 and the insulating layers 2 can be formed finely by photolithography. Therefore, for example, the cross-sectional width of the core 5 can be formed to minute dimensions of 3 μm or more and 10 μm or less, and the height can be formed to minute dimensions of 3 μm or more and 10 μm or less. Furthermore, the width of the conductor wiring 4 can be formed to 0.3 μm or more and 20 μm or less, and the distance between adjacent conductor wirings 4 can be formed to 0.3 μm or more and 20 μm or less. This can achieve high density electrical wiring and optical waveguides in the optoelectronic hybrid board.

[0145] The dimensions of the insulating layer 2, the core 5, and the conductor wiring 4 are not limited to those described above, and for example, the insulating layer 2, the core 5, and the conductor wiring 4 may each have dimensions larger than those described above.

[0146] Furthermore, in this embodiment, the adhesion between the substrate 1 and the insulating layer 2 (first insulating layer 21) overlapping the substrate 1 can be improved. Therefore, in the above-described manufacturing process, even if a load is applied to the insulating layer 2 when polishing the plating layer 40 by chemical mechanical polishing or the like during the production of the conductor wiring 4, damage such as peeling of the insulating layer 2 from the substrate 1 can be suppressed.

[0147] Furthermore, in this embodiment, the insulating layer 2 can have high strength, which can prevent the insulating layer 2 from being excessively worn away by polishing such as the chemical mechanical polishing described above.

[0148] The optical-electrical hybrid board of this embodiment is applied to, for example, a package substrate 6. FIG. 10 shows an example in which the optical-electrical hybrid board is applied to the package substrate 6. In FIG. 10 , a package substrate 6 including an optical-electrical hybrid board is mounted on a main substrate 7 made of a printed wiring board or the like. An integrated circuit 8 is mounted on the package substrate 6. An optical fiber 9 is connected to a core 5 of the package substrate 6 via a connector 10. Within the package substrate 6, the core 5 is connected to the conductor wiring 4 via a transceiver 11. The transceiver 11 converts an optical signal to an electrical signal, or converts an electrical signal to an optical signal. The conductor wiring 4 is connected to the integrated circuit 8. In this case, an optical signal transmitted from the optical fiber 9 is transmitted to the core 5 of the optical-electrical hybrid board 103 via the connector 10, and the optical signal transmitted through the core 5 is converted to an electrical signal by the transceiver 11 and transmitted to the integrated circuit 8 via the conductor wiring 4. The integrated circuit 8 processes the electrical signal and outputs the corresponding result as an electrical signal. The electrical signal output from the integrated circuit 8 is transmitted through the conductor wiring 4 and converted into an optical signal by the transceiver 11. This optical signal is transmitted through the core 5 and further through the connector 10 to the optical fiber 9 .

[0149] This allows the transmission of electrical signals only between the transceiver 11 and the integrated circuit 8 within the package substrate 6, thereby shortening the transmission distance of the electrical signals, thereby achieving faster signal transmission and reduced power consumption.

[0150] In the embodiment, the core 5 is embedded in the same insulating layer 2 as the insulating layer 2 in which the conductor wiring 4 is embedded, but the core 5 may be embedded in an insulating layer 2 different from the insulating layer 2 in which the conductor wiring 4 is embedded. For example, the electrical wiring board 102 may have a structure in which a plurality of insulating layers 2 (clad layers) in which cores 5 are embedded are layered on top of a plurality of insulating layers 2 in which conductor wiring 4 are embedded, respectively.

[0151] In addition, in the embodiment, the electrical wiring board 102 is an optical / electrical hybrid board including an optical waveguide, but the electrical wiring board 102 does not have to include an optical waveguide.

[0152] 6. An optical waveguide not including conductor wiring 4 may be produced from the optical waveguide photosensitive resin composition (X). In this case, at least one of the core 5 and the clad of the optical waveguide can be produced from the photosensitive resin composition (X). The photosensitive resin composition (X) for producing the core 5 is referred to as a core composition (X1), and the photosensitive resin composition (X) for producing the clad is referred to as a clad composition (X3). The core 5 of the optical waveguide is made of a cured product of the core composition (X1), and the clad of the optical waveguide is made of a cured product of the clad composition (X3).

[0153] The specific compositions of the core composition (X1) and the clad composition (X3) are set so that the refractive index of the core 5 is greater than that of the clad, and the difference between the refractive index of the clad and the refractive index of the core 5 is a desired appropriate value.

[0154] The refractive index of the episulfide compound (a2) tends to be higher than the refractive index of the epoxy compound (a1). Therefore, by containing the episulfide compound (a2) in the core composition (X1) and not containing the episulfide compound (a2) in the clad composition (X3), the refractive index of the core 5 can be made higher than the refractive index of the clad. Also, by containing the epoxy compound (a1) and the episulfide compound (a2) in each of the core composition (X1) and the clad composition (X3), and by making the ratio of the episulfide compound (a2) in the core composition (X1) higher than the total of the epoxy compound (a1) and the episulfide compound (a2) in the core composition (X1), the refractive index of the core 5 can be made higher than the refractive index of the clad.

[0155] Furthermore, the vinyl sulfide compound (a5) has a relatively high refractive index. Therefore, by including the vinyl sulfide compound (a5) in the core composition (X1) and not including the vinyl sulfide compound (a5) in the clad composition (X3), the refractive index of the core 5 can be made higher than that of the clad. Furthermore, by including the vinyl sulfide compound (a5) in each of the core composition (X1) and the clad composition (X3) and by making the content of the vinyl sulfide compound (a5) higher in the core composition (X1), the refractive index of the core 5 can be made higher than that of the clad.

[0156] In addition to the above, the composition of the core composition (X1) and the composition of the clad composition (X3) can be set by various methods.

[0157] Of the core 5 and the clad in the optical waveguide, the core 5 may be made of a cured product of the photosensitive resin composition (X), and the clad may be made of a material different from the cured product of the photosensitive resin composition (X). Also, of the core 5 and the clad in the optical waveguide, the clad may be made of a cured product of the photosensitive resin composition (X), and the core 5 may be made of a material different from the cured product of the photosensitive resin composition (X).

[0158] [Aspects] As is clear from the above embodiments, the present disclosure includes the following aspects.

[0159] The photosensitive resin composition of the first embodiment contains a cationically polymerizable compound (A) and a photocationic polymerization initiator (B). The cationically polymerizable compound (A) contains at least one compound selected from the group consisting of an epoxy compound (a1) and an episulfide compound (a2), and a polycyclic aromatic compound (a3). The polycyclic aromatic compound (a3) ​​has at least one compound selected from the group consisting of a polyphenylene ether skeleton and a polystyrene skeleton, and a vinylbenzyl group.

[0160] According to this embodiment, the adhesiveness and electrical properties of the cured product of the photosensitive resin composition can be improved.

[0161] In a second aspect, the cationically polymerizable compound (A) in the first aspect contains an epoxy compound (a1). The epoxy compound (a1) contains at least one selected from the group consisting of an alicyclic epoxy compound (a12) and a glycidyl-type epoxy compound (a11) different from the alicyclic epoxy compound (a12).

[0162] In a third embodiment, the cationically polymerizable compound (A) in the first or second embodiment further contains an oxetane compound (a4).

[0163] According to this embodiment, the strength and heat resistance of the cured product of the photosensitive resin composition can be increased.

[0164] In a fourth aspect, in any one of the first to third aspects, the cationically polymerizable compound further contains a vinyl sulfide compound (a5).

[0165] According to this embodiment, the heat resistance of the cured product of the photosensitive resin composition can be improved.

[0166] In a fifth aspect, in any one of the first to fourth aspects, the cationically polymerizable compound (A) contains an epoxy compound (a1). The proportion of the epoxy compound (a1) relative to the cationically polymerizable compound (A) is 10% by mass or more and 70% by mass or less.

[0167] In a sixth aspect, in any one of the first to fifth aspects, the cationically polymerizable compound (A) contains an episulfide compound (a2). The proportion of the episulfide compound (a2) relative to the cationically polymerizable compound (A) is 10% by mass or more and 70% by mass or less.

[0168] In a seventh aspect, in any one of the first to sixth aspects, the proportion of the polycyclic aromatic compound (a3) ​​is 30% by mass or more and 90% by mass or less with respect to the cationically polymerizable compound (A).

[0169] In an eighth aspect, in any one of the first to seventh aspects, the photosensitive resin composition is for producing an insulating layer.

[0170] A liquid material according to a ninth aspect includes the photosensitive resin composition according to any one of the first to eighth aspects.

[0171] A photosensitive resin sheet according to a tenth aspect includes the photosensitive resin composition according to any one of the first to ninth aspects.

[0172] An electric wiring board (102) according to an eleventh aspect includes an insulating layer (2) and conductor wiring (4). The insulating layer (2) contains a cured product of the photosensitive resin composition according to any one of the first to tenth aspects.

[0173] In a twelfth aspect, the optical waveguide of the eleventh aspect further comprises an optical waveguide having a core (5) and a clad. The core (5) is embedded in an insulating layer (2), and the insulating layer (2) also serves as the clad.

[0174] Specific examples of the present disclosure are presented below, but the aspects of the present disclosure are not limited to the following examples.

[0175] 1. Preparation of Composition The components shown in Table 1 were mixed, and then 50 parts by mass of a mixed solvent of methyl ethyl ketone and toluene was added to 100 parts by mass of the cationically polymerizable compound, followed by mixing while heating at 50° C. to 60° C. The resulting mixture was filtered through a membrane filter with a pore size of 1.0 μm and then degassed to prepare a varnish-like composition.

[0176] The details of the components shown in Table 1 are as follows: - Epoxy compound #1: Bisphenol A type epoxy resin. Solid (melting point 50°C). Manufactured by Mitsubishi Chemical Corporation. Product name: 1006FS. Epoxy equivalent: 1000 g / eq. - Epoxy compound #2: Epoxidation reaction product of 2,2'-diallyl bisphenol A diallyl ether with hydrogen peroxide. Liquid (viscous liquid). Manufactured by Resonac Inc. Product name: Showfree BATG. - Epoxy compound #3: 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol shown in the formula below. Solid. Manufactured by Daicel Chemical Industries, Ltd. Product name: EHPE3150. Epoxy equivalent: 180 g / eq.

[0177]

[0178] Episulfide compound: A compound represented by the following formula. Liquid (viscous liquid). Manufactured by Taoka Chemical Co., Ltd. Product name: TBIS-AHS.

[0179]

[0180] - Polycyclic aromatic compound #1: Modified oligophenylene ether styrene. A compound having a number average molecular weight of 1,000 and having the structure shown in formula (2). Melting point: 150°C. Manufactured by Mitsubishi Gas Chemical Company, Inc. Product name: OPE-2st 1200. - Polycyclic aromatic compound #2: Divinylbenzene. Manufactured by Tokyo Chemical Industry Co., Ltd. - Oxetane compound: A compound having the structure shown in the following formula, the main component of which is 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, where n = 1. Melting point: 42°C. Manufactured by UBE Inc. Product name: TTERNACOLL OXBP.

[0181]

[0182] - Vinyl sulfide compound: bis(4-vinylthiophenyl) sulfide. Manufactured by Sumitomo Seika Chemicals Co., Ltd. Product name: MPV. - Photocationic initiator #1: Sulfonium salt type photoacid generator. Triarylsulfonium-tetrakispentafluorophenylgallate. Anion species: Special anion with a conjugate acid strength higher than that of HSbF6. Manufactured by San-Apro Co., Ltd. Product name: CPI-310FG. - Photocationic initiator #2: Triarylsulfonium salt type photoacid generator. Anion species: PF6 - Manufactured by San-Apro Co., Ltd. Product name: CPI-110P.

[0183] 2. Method for producing dried film and cured film A coating film was produced by applying the composition of each example and comparative example to a PET film (product number A4100) manufactured by Toyobo Co., Ltd. using a multi-coater with a comma coater head manufactured by Hirano Tecseed Co., Ltd. The coating film was then dried at 130°C for 10 minutes to a predetermined thickness, and a dried film was produced.

[0184] After drying, the film was irradiated with 10 mW / cm using an electrodeless H bulb manufactured by Heraeus. ２ at an illuminance of 2000 mJ / cm ２ The film was then irradiated with ultraviolet light of 1000 kJ / 2 ..., and then heat-treated at 150° C. for 15 minutes to obtain a cured film.

[0185] 3. Evaluation Test (1) A first mask having ten negative patterns with a photosensitive line width / space width of 2 μm / 2 μm, a second mask having ten negative patterns with a line width / space width of 3 μm / 3 μm, and a third mask having ten negative patterns with a line width / space width of 5 μm / 5 μm were prepared.

[0186] After drying, the film obtained by the above method was exposed to a mask and irradiated with 2 J / cm 2 of an ultra-high pressure mercury lamp. ２The sample was exposed to light at a light intensity of 100°C and further heat-treated at 100°C for 15 minutes. The unexposed portions were then developed using cyclopentanone as the developer to dissolve and remove the unexposed portions. The remaining portions were then finished washed with water, air-blown, and dried at 120°C for 15 minutes to form a cured product having a line pattern. The cured product was observed under a microscope. Results were evaluated as "good" when no post-development residue was observed between the lines and no waviness or peeling was observed in the lines, and "bad" when otherwise. A rating of "A" was given for a sample judged as "good" when all of the first to third masks were used; a rating of "B" was given for a sample judged as "good" when the second and third masks were used but "bad" when the first mask was used; a rating of "C" was given for a sample judged as "good" when the third mask was used but "bad" when the first and second masks were used; and a rating of "D" was given for a sample judged as "bad" when any of the masks was used.

[0187] (2) Elastic Modulus A sample cut out from the cured film (20 μm) obtained by the above method was measured for storage modulus at 25° C. using a viscoelasticity measuring device (manufactured by Hitachi High-Tech Science Corporation, model number DMA7100).

[0188] (3) Glass Transition Point The glass transition point of a sample cut out from the cured film (20 μm) obtained by the above method was measured using a viscoelasticity measuring device (manufactured by Hitachi High-Tech Science Corporation, Model No. DMA7100).

[0189] (4) Dielectric Constant and Dielectric Loss Tangent The dielectric constant and dielectric loss tangent at 10 GHz of the cured film (20 μm) obtained by the above method were measured by a cavity resonator perturbation method. Specifically, the dielectric constant and dielectric loss tangent at 10 GHz were measured using a network analyzer (N5230A manufactured by Keysight Technologies, Inc.).

[0190] (5) Polishing Resistance The composition was applied by spin coating to a silicon wafer having a diameter of 3 inches (7.62 cm), dried at 130°C for 10 minutes, and then heated to 10 mW / cm using an electrodeless H bulb manufactured by Heraeus Corporation. ２ at an illuminance of 2000 mJ / cm ２The coated silicon wafer was then irradiated with ultraviolet light of 1000 kJ / cm, and then heat-treated at 150° C. for 15 minutes, thereby forming a cured film having a thickness of 2 μm on the silicon wafer.

[0191] The cured film was subjected to CMP polishing under the following conditions. After polishing, the surface of the cured film was observed, and the result was evaluated as "A" when no peeling of the cured film from the silicon wafer was observed, and "B" when peeling occurred.

[0192] Polishing conditions Polishing device: Tabletop single-sided polishing device manufactured by Maruto Co., Ltd. Product name: DIA LAP ACE ML-160A. Polishing pad: Manufactured by Anchor Techno Co., Ltd. Product name: SUBA 600. Polishing pressure: 45.9 kPa (6.6 psi). Platen rotation speed: 60 rpm. Head rotation speed: 60 rpm. Polishing time: 1 minute. Polishing liquid (polishing slurry) supply rate: 0.3 mL / min (flowing). Polishing liquid temperature: 25°C. Polishing liquid (CMP slurry): Ultrapure water to which Fuso Chemical Co., Ltd.'s PL7 (primary particle size 75 nm) was added to give a concentration of 5 wt%, and hydrogen peroxide was also added to give a concentration of 5 wt%.

[0193] (6) Refractive Index The refractive index of the cured film obtained by the above method was measured using an Abbe refractometer DR-M2 manufactured by Atago Co., Ltd.

[0194]

[0195]

[0196]

[0197]

Claims

1. A photosensitive resin composition comprising: a cationically polymerizable compound (A); and a photocationic polymerization initiator (B), wherein the cationically polymerizable compound (A) comprises at least one compound selected from the group consisting of an epoxy compound (a1) and an episulfide compound (a2), and a polycyclic aromatic compound (a3), wherein the polycyclic aromatic compound (a3) ​​has at least one compound selected from the group consisting of a polyphenylene ether skeleton and a polystyrene skeleton, and a vinylbenzyl group.

2. The photosensitive resin composition according to claim 1, wherein the cationically polymerizable compound (A) contains the epoxy compound (a1), and the epoxy compound (a1) contains at least one selected from the group consisting of an alicyclic epoxy compound (a12) and a glycidyl-type epoxy compound (a11) different from the alicyclic epoxy compound (a12).

3. The photosensitive resin composition according to claim 1, wherein the cationically polymerizable compound (A) further contains an oxetane compound (a4).

4. The photosensitive resin composition according to claim 1, wherein the cationically polymerizable compound further contains a vinyl sulfide compound (a5).

5. The photosensitive resin composition according to claim 1, wherein the cationically polymerizable compound (A) contains the epoxy compound (a1), and the proportion of the epoxy compound (a1) relative to the cationically polymerizable compound (A) is 10% by mass or more and 70% by mass or less.

6. The photosensitive resin composition according to claim 1, wherein the cationically polymerizable compound (A) contains the episulfide compound (a2), and the proportion of the episulfide compound (a2) is 10% by mass or more and 70% by mass or less relative to the cationically polymerizable compound (A).

7. The photosensitive resin composition according to claim 1, wherein the proportion of the polycyclic aromatic compound (a3) ​​is 30% by mass or more and 90% by mass or less relative to the cationically polymerizable compound (A).

8. The photosensitive resin composition according to any one of claims 1 to 7, which is used to prepare an insulating layer.

9. A liquid material comprising the photosensitive resin composition according to any one of claims 1 to 7.

10. A photosensitive resin sheet comprising the photosensitive resin composition according to any one of claims 1 to 7.

11. An electrical wiring board comprising an insulating layer and conductor wiring, wherein the insulating layer comprises a cured product of the photosensitive resin composition according to any one of claims 1 to 7.

12. The electrical wiring board according to claim 11, further comprising an optical waveguide having a core and a clad, the core being embedded in the insulating layer, and the insulating layer also serving as the clad.

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