Photosensitive resin composition, photosensitive resin film, multilayer printed wiring board and semiconductor package, and method for manufacturing multilayer printed wiring board

Abstract

To provide a photosensitive resin composition that expresses excellent dielectric loss tangent, a photosensitive resin film using the photosensitive resin composition, a multilayer printed wiring board and a method for producing the same, and a semiconductor package.SOLUTION: A photosensitive resin composition comprises (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, (B) epoxy resin, and (C) a crosslinker having two or more ethylenically unsaturated groups represented by the general formula (C-1) (where RC1 is a fluorine atom, a C1-4 alkyl group, a C1-4 fluoroalkyl group, a phenyl group or a benzyl group. * is a binding site to another structure).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a photosensitive resin composition, a photosensitive resin film, a multilayer printed wiring board and a semiconductor package, and a method for producing a multilayer printed wiring board. [Background technology]

[0002] In recent years, electronic devices have become smaller and more powerful, and multilayer printed wiring boards have become increasingly dense due to an increase in the number of circuit layers and finer wiring. In particular, the density of semiconductor package substrates, such as BGA (ball grid array) and CSP (chip size package), on which semiconductor chips are mounted, has increased significantly, and in addition to finer wiring, thinner insulating layers and smaller diameter vias (also called via holes) for interlayer connection are required.

[0003] A conventional method for manufacturing a printed wiring board is a build-up method (see, for example, Patent Document 1) in which an interlayer insulating layer and a conductor circuit layer are sequentially laminated to form a multilayer printed wiring board. As circuits become finer, the semi-additive method in which circuits are formed by plating has become mainstream for multilayer printed wiring boards. In conventional semi-additive processes, for example, (1) a thermosetting resin film is laminated onto a conductor circuit, and the thermosetting resin film is hardened by heating to form an "interlayer insulating layer." (2) Next, vias for interlayer connection are formed by laser processing, and desmearing and roughening treatments are performed using alkaline permanganate or similar. (3) After that, electroless copper plating is performed on the substrate, and a pattern is formed using a resist, followed by electrolytic copper plating to form a copper circuit layer. (4) Next, the resist is peeled off, and the electroless layer is flash-etched to form the copper circuit.

[0004] As mentioned above, laser processing is the mainstream method for forming vias in an interlayer insulating layer formed by curing a thermosetting resin film, but the reduction in the diameter of vias by laser irradiation using a laser processing machine is reaching its limit. Furthermore, when forming vias using a laser processing machine, each via hole must be formed one by one, and when a large number of vias are required for high density, forming the vias takes a long time, resulting in poor manufacturing efficiency.

[0005] Under these circumstances, a method has been proposed as a method capable of forming a large number of vias at once, in which a photosensitive resin composition containing an acid-modified vinyl group-containing epoxy resin, a photopolymerizable compound, a photopolymerization initiator, an inorganic filler, and a silane compound, and in which the inorganic filler content is 10 to 80 mass %, is used to form a plurality of small diameter vias at once by photolithography (see, for example, Patent Document 2). In Patent Document 2, one of the problems is to suppress the decrease in adhesion with copper plating that occurs when a photosensitive resin composition is used instead of a conventional thermosetting resin composition as the material for the interlayer insulating layer or surface protective layer, and further problems are also identified, such as via resolution and adhesion with silicon substrates and chip components, and these are claimed to have been solved. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 7-304931 [Patent Document 2] Japanese Patent Application Publication No. 2017-116652 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, there has been a demand for circuit board materials to be used in fifth-generation mobile communication system (5G) antennas, which use radio waves in high frequency bands, and millimeter-wave radars, which use radio waves in even higher frequency bands. To achieve this, it is necessary to develop a resin composition with a further improved dielectric loss tangent in the 10 GHz band or higher. However, the technology in Patent Document 2 leaves room for improvement in the dielectric loss tangent.

[0008] Therefore, an object of the present disclosure is to provide a photosensitive resin composition that exhibits an excellent dielectric loss tangent, a photosensitive resin film using the photosensitive resin composition, a multilayer printed wiring board and a method for producing the same, and a semiconductor package. [Means for solving the problem]

[0009] As a result of extensive research, the present inventors have found that the above object can be achieved by the present disclosure. The present disclosure includes the following embodiments [1] to

[16] . [1] (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, (B) an epoxy resin, and (C) a crosslinking agent having two or more ethylenically unsaturated groups represented by the following general formula (C-1): [ka] (In the formula, R C1 is a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, a phenyl group, or a benzyl group. * is a bonding site to another structure. A photosensitive resin composition comprising: [2] The photosensitive resin composition according to the above [1], wherein the component (C) has 2 to 6 ethylenically unsaturated groups represented by the general formula (C-1). [3] The photosensitive resin composition according to the above [1] or [2], wherein the component (C) is dicyclopentadiene dimethacrylate or trimethylolpropane trimethacrylate. [4] The photosensitive resin composition according to any one of the above [1] to [3], wherein the component (A) contains an alicyclic structure represented by the following general formula (A-1): [ka] (In the formula, R A1 represents an alkyl group having 1 to 12 carbon atoms, and may be substituted anywhere in the alicyclic structure. 1 is an integer between 0 and 6. * is a binding site to another structure. [5] The photosensitive resin composition according to any one of the above [1] to [4], wherein the equivalent ratio of the acidic substituent of the component (A) to the epoxy group of the component (B) [epoxy group / acidic substituent] is 0.5 to 6.0. [6] The photosensitive resin composition according to any one of the above [1] to [5], further comprising an elastomer (D), wherein the elastomer (D) comprises an elastomer having an ethylenically unsaturated group and an acidic substituent. [7] The photosensitive resin composition according to any one of the above [1] to [6], further comprising (E) an inorganic filler in an amount of 10 to 80 mass % based on the total solid content of the photosensitive resin composition. [8] The photosensitive resin composition according to any one of the above [1] to [7], further comprising (H) a photopolymerization initiator. [9] The photosensitive resin composition according to [8] above, which contains two or more types of the component (H).

[10] The photosensitive resin composition according to any one of the above [1] to [9], further comprising (I) a photosensitizer.

[11] The photosensitive resin composition according to

[10] above, which contains two or more types of component (I).

[12] The photosensitive resin composition according to any one of the above [1] to

[11] , which is used for forming one or more selected from the group consisting of a photovia and an interlayer insulating layer.

[13] A photosensitive resin film comprising the photosensitive resin composition according to any one of the above [1] to

[12] .

[14] A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin composition according to any one of [1] to

[12] above or the photosensitive resin film according to

[13] above.

[15] A semiconductor package comprising the multilayer printed wiring board according to

[14] above and a semiconductor element.

[16] A method for producing a multilayer printed wiring board, comprising the following steps (1) to (4): (1): The photosensitive resin film described in

[13] above is laminated on one or both sides of a circuit board. (2) Forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in (1) above. (3) Roughening the via and the interlayer insulating layer. (4): Forming a circuit pattern on the interlayer insulating layer. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a photosensitive resin composition that exhibits an excellent dielectric loss tangent. It is also possible to provide a photosensitive resin film formed using the photosensitive resin composition. It is also possible to provide a multilayer printed wiring board containing an interlayer insulating layer formed using the photosensitive resin composition or the photosensitive resin film, and it is also possible to provide a method for manufacturing the multilayer printed wiring board. It is also possible to provide a semiconductor package including the multilayer printed wiring board and a semiconductor element. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing one embodiment of a manufacturing process for a multilayer printed wiring board using the photosensitive resin film of the present embodiment as a material for at least one of a surface protective layer and an interlayer insulating layer. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with the values ​​shown in the examples. Furthermore, the lower and upper limits of a numerical range can be arbitrarily combined with the lower or upper limit of another numerical range. In the expression "AA to BB," the numerical values ​​AA and BB at the ends are included as the lower and upper limits, respectively, of the numerical range. In this specification, for example, the expression "10 or more" means 10 or a numerical value exceeding 10, and this also applies when the numerical values ​​are different. Furthermore, for example, the expression "10 or less" means 10 or a numerical value less than 10, and this also applies when the numerical values ​​are different. In this specification, when there are multiple substances corresponding to each component in the photosensitive resin composition, the content of each component means the total content of the multiple substances present in the photosensitive resin composition, unless otherwise specified. As used herein, the term "number of ring carbon atoms" refers to the number of carbon atoms necessary to form a ring, and does not include the number of carbon atoms of substituents on the ring. For example, both a cyclohexane skeleton and a methylcyclohexane skeleton have 6 ring carbon atoms. The expression "(meth)acrylic XX" means either or both of acrylic XX and the corresponding methacrylic XX. Also, the expression "(meth)acryloyl group" means either or both of an acryloyl group and a methacryloyl group. In this specification, the term "dielectric loss tangent" refers to the dielectric loss tangent in the 10 GHz band unless otherwise specified. Additionally, any combination of the features described in this specification is also included in this embodiment.

[0013] [Photosensitive resin composition] The photosensitive resin composition according to one embodiment of the present disclosure (hereinafter may be simply referred to as the present embodiment) comprises: (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, (B) an epoxy resin, and (C) a crosslinking agent having two or more ethylenically unsaturated groups represented by the following general formula (C-1): [ka] (In the formula, R C1 is a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, a phenyl group, or a benzyl group. * is a bonding site to another structure. The photosensitive resin composition comprises: In this specification, the above components may be abbreviated as component (A), component (B), component (C), etc., and similar abbreviations may be used for other components. In this specification, the term "resin component" refers to the aforementioned components (A) and (B), as well as other components that may be contained as needed (e.g., components (C), (D), (F), (G), (H), and (I)), but does not include inorganic compounds such as inorganic fillers and pigments (E). Furthermore, the term "solid content" refers to the nonvolatile content excluding volatile substances such as water and solvents contained in the photosensitive resin composition, and refers to components that remain without volatilization when the resin composition is dried, and also includes liquid, starch syrup-like, and wax-like substances at room temperature around 25°C.

[0014] The photosensitive resin composition of this embodiment has an excellent dielectric loss tangent and is suitable for via formation by photolithography (also referred to as photovia formation), making it suitable for forming one or more layers selected from the group consisting of photovias and interlayer insulating layers. Therefore, the present disclosure also provides a photosensitive resin composition for photovia formation comprising the photosensitive resin composition of this embodiment, and a photosensitive resin composition for interlayer insulating layers comprising the photosensitive resin composition of this embodiment. Herein, when the term "layer" is used in this disclosure, such as an interlayer insulating layer, the term "layer" includes not only solid layers, but also layers that are not solid but have at least some island-like structures, have holes, and have unclear interfaces with adjacent layers. The photosensitive resin composition of this embodiment is suitable as a negative photosensitive resin composition. Each component that the photosensitive resin composition may contain will be described in detail below.

[0015] <(A) Photopolymerizable Compound Having an Ethylenically Unsaturated Group and an Acidic Substituent> The photosensitive resin composition of this embodiment contains, as component (A), a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent. The component (A) may be used alone or in combination of two or more types.

[0016] The component (A) is a compound that exhibits radical polymerizability due to the presence of an ethylenically unsaturated group. Examples of the ethylenically unsaturated group contained in component (A) include photopolymerizable functional groups such as vinyl, allyl, propargyl, butenyl, ethynyl, phenylethynyl, maleimide, nadimide, and (meth)acryloyl groups. Of these, (meth)acryloyl groups are preferred from the viewpoints of reactivity and via resolution.

[0017] The component (A) has an acidic substituent group so as to enable alkaline development. Examples of the acidic substituent contained in component (A) include a carboxy group, a sulfonic acid group, a phenolic hydroxyl group, etc. Of these, from the viewpoint of via resolution, a carboxy group is preferred. The acid value of component (A) is preferably 20 to 200 mgKOH / g, more preferably 40 to 180 mgKOH / g, even more preferably 70 to 150 mgKOH / g, and particularly preferably 90 to 120 mgKOH / g. When the acid value of component (A) is at least the above-mentioned lower limit, the solubility of the photosensitive resin film in a dilute alkaline solution tends to be excellent, and when it is at most the above-mentioned upper limit, the dielectric loss tangent tends to be excellent. The acid value of component (A) can be measured by the method described in the examples. Two or more (A) components with different acid values ​​may be used in combination. In this case, it is preferable that the weighted average acid value of the two or more (A) components falls within one of the above ranges.

[0018] The weight-average molecular weight (Mw) of component (A) is preferably 600 to 30,000, more preferably 800 to 25,000, even more preferably 1,000 to 18,000, still more preferably 1,000 to 8,000, particularly preferably 1,200 to 5,000, and most preferably 1,200 to 3,500. When the weight-average molecular weight (Mw) of component (A) is within the above range, the adhesive strength to copper plating, heat resistance, and insulation reliability tend to be excellent. Herein, the weight-average molecular weight is a value determined in terms of standard polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and more specifically, a value measured according to the method described in the Examples.

[0019] From the viewpoint of dielectric loss tangent, the component (A) preferably contains an alicyclic skeleton. From the viewpoints of via resolution, adhesive strength with copper plating, and electrical insulation reliability, the alicyclic skeleton of component (A) is preferably an alicyclic skeleton having 5 to 20 ring carbon atoms, more preferably an alicyclic skeleton having 5 to 18 ring carbon atoms, even more preferably an alicyclic skeleton having 6 to 18 ring carbon atoms, particularly preferably an alicyclic skeleton having 8 to 14 ring carbon atoms, and most preferably an alicyclic skeleton having 8 to 12 ring carbon atoms. Furthermore, from the viewpoints of via resolution, adhesive strength with copper plating, and electrical insulation reliability, the alicyclic skeleton preferably consists of two or more rings, more preferably two to four rings, and even more preferably three rings. Examples of alicyclic skeletons having two or more rings include a norbornane skeleton, a decalin skeleton, a bicycloundecane skeleton, and a saturated dicyclopentadiene skeleton. Among these, from the viewpoints of via resolution, adhesive strength with copper plating, and electrical insulation reliability, a saturated dicyclopentadiene skeleton is preferred. From the same viewpoint, the component (A) preferably contains an alicyclic structure represented by the following general formula (A-1).

[0020] [ka] (In the formula, R A1represents an alkyl group having 1 to 12 carbon atoms, and may be substituted anywhere in the alicyclic structure. 1 is an integer between 0 and 6. * is a binding site to another structure.

[0021] In the above general formula (A-1), R A1 Examples of the alkyl group having 1 to 12 carbon atoms represented by include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, etc. The alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group. m 1 is an integer of 0 to 6, preferably an integer of 0 to 2, and more preferably 0. m 1 is an integer between 2 and 6, multiple R A1 may be the same or different. A1 may be substituted on the same carbon atom or on different carbon atoms, to the extent possible. * denotes a bonding site to another structure, and may be bonded to any carbon atom on the alicyclic skeleton, but is preferably bonded to either the carbon atom represented by 1 or 2 and the carbon atom represented by 3 or 4 in the following general formula (A-1').

[0022] [ka] (In the formula, R A1 , m 1 and * are the same as those in general formula (A-1).

[0023] From the viewpoints of via resolution and adhesive strength with copper plating, component (A) is preferably an acid-modified vinyl group-containing epoxy resin obtained by reacting (a1) a compound obtained by modifying an epoxy resin with (a2) an ethylenically unsaturated group-containing organic acid [hereinafter sometimes referred to as component (A')] with (a3) ​​a saturated or unsaturated group-containing polybasic acid anhydride. Here, the term "acid-modified" in the acid-modified vinyl group-containing epoxy resin refers to the presence of an acidic substituent, "vinyl group" refers to an ethylenically unsaturated group, and "epoxy resin" refers to the use of an epoxy resin as a raw material. The acid-modified vinyl group-containing epoxy resin does not necessarily have to contain epoxy groups, and may not necessarily have epoxy groups. Hereinafter, preferred embodiments of the component (A) obtained from (a1) an epoxy resin, (a2) an ethylenically unsaturated group-containing organic acid, and (a3) ​​a saturated or unsaturated group-containing polybasic acid anhydride will be described.

[0024] ((a1) Epoxy resin) The (a1) epoxy resin is preferably an epoxy resin having two or more epoxy groups. The (a1) epoxy resin may be used alone or in combination of two or more kinds. (a1) Epoxy resins are classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, etc. Among these, glycidyl ether type epoxy resins are preferred.

[0025] (a1) Epoxy resins can be classified into various epoxy resins depending on the difference in the main skeleton, and can be classified into epoxy resins having an alicyclic skeleton, novolac epoxy resins, bisphenol epoxy resins, aralkyl epoxy resins, other epoxy resins, etc. Among these, epoxy resins having an alicyclic skeleton and novolac epoxy resins are preferred.

[0026] -Epoxy resin with alicyclic skeleton- The alicyclic skeleton of the epoxy resin having an alicyclic skeleton is explained in the same manner as the alicyclic skeleton of the component (A) described above, and preferred embodiments are also the same. The epoxy resin having an alicyclic skeleton is preferably an epoxy resin represented by the following general formula (A-2).

[0027] [ka] (In the formula, R A1 represents an alkyl group having 1 to 12 carbon atoms, and may be substituted anywhere in the alicyclic skeleton. A2 represents an alkyl group having 1 to 12 carbon atoms. 1 is an integer between 0 and 6, m 2 is an integer between 0 and 3. n is a number between 0 and 50.

[0028] In general formula (A-2), R A1 represents R in general formula (A-1). A1 The preferred embodiments are also the same. R in general formula (A-2) A2 Examples of the alkyl group having 1 to 12 carbon atoms represented by include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, etc. The alkyl group is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group. m in general formula (A-2) 1 is m in general formula (A-1) 1 The preferred embodiments are also the same. m in general formula (A-2) 2 is an integer of 0 to 3, preferably 0 or 1, and more preferably 0. In general formula (A-2), n represents the repeating number of the structural unit in the parentheses and is a number from 0 to 50. Usually, epoxy resins are mixtures of structural units in the parentheses with different repeating numbers, and in that case, n represents the average value of the mixture. Preferably, n is a number from 0 to 30.

[0029] As the epoxy resin having an alicyclic skeleton, commercially available products may be used, and examples of commercially available products include XD-1000 (trade name, manufactured by Nippon Kayaku Co., Ltd.) and EPICLON (registered trademark) HP-7200 (trade name, manufactured by DIC Corporation).

[0030] -Novolac epoxy resin- Examples of novolac epoxy resins include bisphenol novolac epoxy resins such as bisphenol A novolac epoxy resins, bisphenol F novolac epoxy resins, and bisphenol S novolac epoxy resins; phenol novolac epoxy resins, cresol novolac epoxy resins, biphenyl novolac epoxy resins, and naphthol novolac epoxy resins. The novolac type epoxy resin is preferably an epoxy resin having a structural unit represented by the following general formula (A-3).

[0031] [ka] (In the formula, R A3 represents a hydrogen atom or a methyl group, and Y A1 Each of R independently represents a hydrogen atom or a glycidyl group. A3 may be the same or different. A1 At least one of the groups represents a glycidyl group.

[0032] R A3 From the viewpoints of via resolution and adhesive strength with copper plating, it is preferable that Y be a hydrogen atom. A1 are preferably all glycidyl groups. The number of structural units in the epoxy resin (a1) having the structural unit represented by general formula (A-3) is 1 or more, preferably 10 to 100, more preferably 15 to 80, and even more preferably 15 to 70. When the number of structural units is within the above range, adhesive strength with copper plating, heat resistance, and insulation reliability tend to be improved. In general formula (A-3), R A3 are all hydrogen atoms, and Y A1 The ones in which all of these groups are glycidyl groups are available as the EXA-7376 series (manufactured by DIC Corporation, trade name), and R A3 are all methyl groups, and Y A1 However, those having a glycidyl group are commercially available as the EPON SU8 series (trade name, manufactured by Mitsubishi Chemical Corporation).

[0033] Examples of bisphenol type epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, and 3,3',5,5'-tetramethyl-4,4'-diglycidyloxydiphenylmethane. Examples of the aralkyl type epoxy resin include phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, and naphthol aralkyl type epoxy resin. Other epoxy resins include stilbene-type epoxy resins, naphthalene skeleton-containing epoxy resins, biphenyl-type epoxy resins, dihydroanthracene-type epoxy resins, cyclohexanedimethanol-type epoxy resins, trimethylol-type epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, and rubber-modified epoxy resins.

[0034] ((a2) Ethylenically unsaturated group-containing organic acid) The (a2) ethylenically unsaturated group-containing organic acid is preferably an ethylenically unsaturated group-containing monocarboxylic acid. Examples of the ethylenically unsaturated group contained in the component (a2) include the same groups as those exemplified as the ethylenically unsaturated group contained in the component (A). Examples of the component (a2) include acrylic acid, acrylic acid dimers, methacrylic acid, acrylic acid derivatives such as β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α-cyanocinnamic acid; half-ester compounds which are reaction products of hydroxyl group-containing acrylates and dibasic acid anhydrides; and half-ester compounds which are reaction products of vinyl group-containing monoglycidyl ethers or vinyl group-containing monoglycidyl esters and dibasic acid anhydrides. The component (a2) may be used alone or in combination of two or more.

[0035] The half-ester compound can be obtained by reacting one or more ethylenically unsaturated group-containing compounds selected from the group consisting of hydroxyl group-containing acrylates, vinyl group-containing monoglycidyl ethers, and vinyl group-containing monoglycidyl esters with a dibasic acid anhydride. The reaction is preferably carried out by reacting equimolar amounts of the ethylenically unsaturated group-containing compound and the dibasic acid anhydride.

[0036] Examples of the hydroxyl group-containing acrylate used in the synthesis of the semi-ester compound include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. Examples of vinyl group-containing monoglycidyl ethers include glycidyl (meth)acrylate.

[0037] The dibasic acid anhydride used in the synthesis of the half ester compound may contain either a saturated group or an unsaturated group, and examples of the dibasic acid anhydride include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride.

[0038] In the reaction between component (a1) and component (a2), the amount of component (a2) used is preferably 0.6 to 1.05 equivalents, more preferably 0.7 to 1.02 equivalents, and even more preferably 0.8 to 1.0 equivalents per equivalent of epoxy groups in component (a1). Reacting components (a1) and (a2) in the above ratio improves the photopolymerizability of component (A), and tends to improve the via resolution of the resulting photosensitive resin composition.

[0039] The components (a1) and (a2) are preferably dissolved in an organic solvent and reacted. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ether compounds such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. One organic solvent may be used alone, or two or more organic solvents may be used in combination.

[0040] The reaction between component (a1) and component (a2) preferably uses a catalyst to promote the reaction. Examples of such catalysts include amine-based catalysts such as triethylamine and benzylmethylamine; quaternary ammonium salt catalysts such as methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide and benzyltrimethylammonium iodide; and phosphine-based catalysts such as triphenylphosphine. Among these, phosphine-based catalysts are preferred, with triphenylphosphine being more preferred. One catalyst may be used alone, or two or more catalysts may be used in combination. When a catalyst is used, the amount used is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 2 parts by mass, per 100 parts by mass of the total of the components (a1) and (a2), in order to obtain an appropriate reaction rate.

[0041] In the reaction between component (a1) and component (a2), it is preferable to use a polymerization inhibitor to prevent polymerization during the reaction. Examples of polymerization inhibitors include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol. One type of polymerization inhibitor may be used alone, or two or more types may be used in combination. When a polymerization inhibitor is used, the amount used is preferably 0.01 to 1 part by mass, more preferably 0.02 to 0.8 parts by mass, and even more preferably 0.1 to 0.5 parts by mass, per 100 parts by mass of the total of the (a1) component and the (a2) component.

[0042] The reaction temperature between component (a1) and component (a2) is preferably 60 to 150°C, more preferably 80 to 120°C, and even more preferably 90 to 110°C, from the viewpoint of ensuring sufficient reactivity and allowing the reaction to proceed homogeneously.

[0043] Thus, when an ethylenically unsaturated group-containing monocarboxylic acid is used as component (a2), component (A') obtained by reacting components (a1) and (a2) has hydroxyl groups formed by a ring-opening addition reaction between the epoxy groups of component (a1) and the carboxyl groups of component (a2). Next, by further reacting component (A') with component (a3), an acid-modified vinyl-containing epoxy resin can be obtained in which the hydroxyl groups of component (A') (including the hydroxyl groups originally present in component (a1)) and the acid anhydride groups of component (a3) ​​are half-esterified.

[0044] ((a3) Polybasic acid anhydride) The component (a3) ​​may contain a saturated group or an unsaturated group. Examples of the component (a3) ​​include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride. Among these, tetrahydrophthalic anhydride is preferred from the viewpoint of via resolution. The component (a3) ​​may be used alone or in combination of two or more.

[0045] In the reaction between component (A') and component (a3), for example, the acid value of the acid-modified vinyl group-containing epoxy resin can be adjusted by reacting 0.1 to 1.0 equivalents of component (a3) ​​with 1 equivalent of hydroxyl groups in component (A').

[0046] The reaction temperature between component (A') and component (a3) ​​is preferably 50 to 150°C, more preferably 60 to 120°C, and even more preferably 70 to 100°C, from the viewpoint of ensuring sufficient reactivity and allowing the reaction to proceed homogeneously.

[0047] The content of component (A) in the photosensitive resin composition of the present embodiment is not particularly limited, but from the viewpoints of heat resistance, dielectric loss tangent, and chemical resistance, it is preferably 10 to 80 mass%, more preferably 10 to 60 mass%, even more preferably 15 to 45 mass%, and particularly preferably 15 to 35 mass%, and may alternatively be 15 to 30 mass%, or even 20 to 30 mass%, based on the total amount of resin components in the photosensitive resin composition.

[0048] <(B) Epoxy resin> The photosensitive resin composition of this embodiment contains an epoxy resin as component (B). The photosensitive resin composition of this embodiment contains the epoxy resin (B), which improves the adhesive strength with copper plating and the insulation reliability, as well as providing excellent heat resistance. The (B) epoxy resin may be used alone or in combination of two or more kinds.

[0049] The (B) epoxy resin is preferably an epoxy resin having two or more epoxy groups. Epoxy resins are classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, etc. Among these, glycidyl ether type epoxy resins are preferred.

[0050] Epoxy resins are also classified into various epoxy resins depending on the main skeleton, and each of the above types of epoxy resins is further classified as follows: Specifically, bisphenol-based epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and bisphenol S-type epoxy resins; bisphenol-based novolac-type epoxy resins such as bisphenol A-type novolac-type epoxy resins and bisphenol F-type novolac-type epoxy resins; novolac-type epoxy resins other than the above bisphenol-based novolac-type epoxy resins, such as phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, and biphenyl novolac-type epoxy resins; phenol aralkyl-type epoxy resins; stilbene-type epoxy resins; and naphthol They are classified into naphthalene skeleton-containing epoxy resins such as novolac type epoxy resins, naphthol type epoxy resins, naphthol aralkyl type epoxy resins, and naphthylene ether type epoxy resins; biphenyl type epoxy resins; biphenyl aralkyl type epoxy resins; xylylene type epoxy resins; dihydroanthracene type epoxy resins; alicyclic epoxy resins such as saturated dicyclopentadiene type epoxy resins; heterocyclic epoxy resins; spiro ring-containing epoxy resins; cyclohexane dimethanol type epoxy resins; trimethylol type epoxy resins; aliphatic linear epoxy resins; and rubber-modified epoxy resins.

[0051] Among these, (B) epoxy resin is preferably at least one selected from the group consisting of bisphenol-based epoxy resins, naphthalene skeleton-containing epoxy resins, alicyclic epoxy resins, and saturated dicyclopentadiene epoxy resins, particularly from the viewpoints of heat resistance, electrical insulation reliability, developability, and adhesive strength with copper plating, and more preferably contains a bisphenol-based epoxy resin, a naphthalene skeleton-containing epoxy resin, an alicyclic epoxy resin, or a saturated dicyclopentadiene epoxy resin. From the viewpoints of developability and ease of handling during printed wiring board production, it is preferable to use a combination of an epoxy resin having an epoxy equivalent of more than 220 g / eq and an epoxy resin having an epoxy equivalent of 220 g / eq or less as component (B). In this case, the ratio of the two components (epoxy resin having an epoxy equivalent of more than 220 g / eq / epoxy resin having an epoxy equivalent of 220 g / eq or less) is preferably 95 / 5 to 40 / 60 by mass, or alternatively 85 / 15 to 50 / 50, 75 / 25 to 50 / 50, or even 65 / 35 to 50 / 50, from the viewpoints of developability and ease of handling during printed wiring board production. The epoxy equivalent of the epoxy resin having an epoxy equivalent of more than 220 g / eq is preferably 240 g / eq or more, more preferably 250 g / eq or more, with the upper limit being preferably 600 g / eq or less, more preferably 500 g / eq or less, even more preferably 400 g / eq or less, and particularly preferably 350 g / eq or less. The epoxy equivalent of the epoxy resin having an epoxy equivalent of 220 g / eq or less is preferably 210 g / eq or less, more preferably 200 g / eq or less, and the lower limit is preferably 50 g / eq or more, more preferably 80 g / eq or more, even more preferably 120 g / eq or more, and particularly preferably 150 g / eq or more.

[0052] The equivalent ratio of the acidic substituents in component (A) to the epoxy groups in component (B) [epoxy groups / acidic substituents] in the photosensitive resin composition of this embodiment is not particularly limited, but from the viewpoints of insulation reliability, dielectric dissipation factor, heat resistance, and adhesive strength with copper plating, it is preferably 0.5 to 6.0, more preferably 0.7 to 4.0, even more preferably 0.8 to 2.0, and particularly preferably 0.9 to 1.2.

[0053] The content of component (B) in the photosensitive resin composition of the present embodiment is not particularly limited, but from the viewpoints of insulation reliability, dielectric loss tangent, heat resistance, and adhesive strength with copper plating, it is preferably 1 to 50 mass %, more preferably 5 to 30 mass %, and even more preferably 10 to 20 mass %, based on the total amount of resin components in the photosensitive resin composition.

[0054] <(C) Crosslinking agent having two or more ethylenically unsaturated groups represented by general formula (C-1)> The photosensitive resin composition of this embodiment contains, as component (C), a crosslinking agent having two or more ethylenically unsaturated groups represented by the following general formula (C-1) (hereinafter, sometimes simply referred to as "crosslinking agent (C)"). One type of crosslinking agent (C) may be used alone, or two or more types may be used in combination. [ka] (In the formula, R C1 is a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, a phenyl group, or a benzyl group. * is a bonding site to another structure.

[0055] The crosslinking agent (C) reacts with the ethylenically unsaturated groups in the component (A) to increase the crosslink density of the cured product. Therefore, by including the crosslinking agent (C), the photosensitive resin composition of this embodiment tends to have improved heat resistance and dielectric loss tangent. The exact reason why the dielectric loss tangent is lowered when the crosslinking agent (C) has an ethylenically unsaturated group represented by the general formula (C-1) is unclear, but it is thought that the substituent R C1It is presumed that the presence of the cross-linking agent makes the main chain rigid, thereby suppressing the vibration of the dipole. Furthermore, the photosensitive resin composition of the present embodiment tends to have improved desmear resistance due to the inclusion of the component (C), which is expected to improve the dimensional accuracy of the fine wiring in the film thickness direction and the dimensional accuracy of the via opening diameter.

[0056] In the general formula (C-1), R C1 Examples of the alkyl group having 1 to 4 carbon atoms represented by include linear alkyl groups having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, and an n-butyl group; and branched alkyl groups having 3 or 4 carbon atoms, such as an isopropyl group, an isobutyl group, an s-butyl group, and a t-butyl group. From the viewpoints of dielectric loss tangent and desmear resistance, the alkyl group having 1 to 4 carbon atoms is preferably a linear alkyl group having 1 to 4 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, further preferably a methyl group or an ethyl group, and particularly preferably a methyl group. R C1 Examples of the fluoroalkyl group having 1 to 4 carbon atoms represented by the formula (I) include groups in which one or more fluorine atoms are substituted on the alkyl group having 1 to 4 carbon atoms. Specific examples include a monofluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and a pentafluoroethyl group. In the fluoroalkyl group having 1 to 4 carbon atoms, one to three fluorine atoms are preferably substituted. Although not particularly limited, R C1 From the viewpoints of dielectric loss tangent, desmear resistance, and crosslinking reactivity, the alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

[0057] From the viewpoints of heat resistance, dielectric loss tangent, and desmear resistance, the (C) crosslinking agent preferably has 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3 ethylenically unsaturated groups represented by the general formula (C-1).

[0058] Specific examples of the (C) crosslinking agent include aliphatic dimethacrylates such as trimethylolpropane dimethacrylate, polypropylene glycol dimethacrylate, and polyethylene glycol dimethacrylate; dimethacrylates having an alicyclic skeleton such as dicyclopentadiene dimethacrylate and tricyclodecane dimethanol dimethacrylate; aromatic dimethacrylates such as 2,2-bis(4-methacryloxypolyethoxypolypropoxyphenyl)propane and bisphenol A diglycidyl ether dimethacrylate; methacrylate compounds having a skeleton derived from trimethylolpropane such as trimethylolpropane trimethacrylate; and tetramethylolmethane trimethacrylate. acrylate, methacrylate compounds having a skeleton derived from tetramethylolmethane such as tetramethylolmethane tetramethacrylate; methacrylate compounds having a skeleton derived from pentaerythritol such as pentaerythritol trimethacrylate and pentaerythritol tetramethacrylate; methacrylate compounds having a skeleton derived from dipentaerythritol such as dipentaerythritol pentamethacrylate and dipentaerythritol hexamethacrylate; methacrylate compounds having a skeleton derived from ditrimethylolpropane such as ditrimethylolpropane tetramethacrylate; and methacrylate compounds having a skeleton derived from diglycerin. Further examples include compounds having a structure in which the methyl group of the methacrylate group of these exemplary compounds is replaced with a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, a phenyl group, or a benzyl group. Among these, from the viewpoints of dielectric loss tangent and desmear resistance, dimethacrylates having an alicyclic skeleton, methacrylate compounds having a skeleton derived from trimethylolpropane, and methacrylate compounds having a skeleton derived from dipentaerythritol are preferred, dicyclopentadiene dimethacrylate, trimethylolpropane trimethacrylate, and dipentaerythritol hexamethacrylate are more preferred, and dicyclopentadiene dimethacrylate and trimethylolpropane trimethacrylate are even more preferred. Here, the above-mentioned "methacrylate compound having a skeleton derived from XXX" (where XXX is the name of the compound) means an esterification product of XXX and methacrylic acid, and the esterification product also includes a compound modified with an alkyleneoxy group.

[0059] The photosensitive resin composition of the present embodiment may or may not contain a crosslinking agent other than the component (C') (hereinafter, sometimes referred to as "crosslinking agent (C')") as the component (C'). As long as the component (C) is not contained, the crosslinking agent (C') may be a bifunctional monomer having two ethylenically unsaturated groups or a polyfunctional monomer having three or more ethylenically unsaturated groups. The ethylenically unsaturated groups contained in the crosslinking agent (C') include the same ethylenically unsaturated groups as those contained in the component (A), and the preferred groups are also the same.

[0060] Examples of the bifunctional monomer as the (C') crosslinking agent include aliphatic diacrylates such as trimethylolpropane diacrylate, polypropylene glycol diacrylate, and polyethylene glycol diacrylate; diacrylates having an alicyclic skeleton such as dicyclopentadiene dimethacrylate and tricyclodecane dimethanol diacrylate; and aromatic diacrylates such as 2,2-bis(4-acryloxypolyethoxypolypropoxyphenyl)propane and bisphenol A diglycidyl ether diacrylate.

[0061] Examples of the polyfunctional monomer as the (C') crosslinking agent include acrylate compounds having a skeleton derived from trimethylolpropane, such as trimethylolpropane triacrylate; acrylate compounds having a skeleton derived from tetramethylolmethane, such as tetramethylolmethane triacrylate and tetramethylolmethane tetraacrylate; acrylate compounds having a skeleton derived from pentaerythritol, such as pentaerythritol triacrylate and pentaerythritol tetraacrylate; acrylate compounds having a skeleton derived from dipentaerythritol, such as dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate; acrylate compounds having a skeleton derived from ditrimethylolpropane, such as ditrimethylolpropane tetraacrylate; and acrylate compounds having a skeleton derived from diglycerin. Here, the above-mentioned "acrylate compound having a skeleton derived from XXX" (where XXX is the name of the compound) means an esterification product of XXX and acrylic acid, and the esterification product also includes a compound modified with an alkyleneoxy group.

[0062] The content of the (C) crosslinking agent in the photosensitive resin composition of the present embodiment is not particularly limited, but from the viewpoints of heat resistance, dielectric loss tangent, and desmear resistance, it is preferably 5 to 70 parts by mass, more preferably 10 to 60 parts by mass, even more preferably 25 to 55 parts by mass, particularly preferably 35 to 55 parts by mass, and most preferably 40 to 55 parts by mass per 100 parts by mass of the (A) component.

[0063] <(D) Elastomer> The photosensitive resin composition of this embodiment preferably further contains an elastomer as component (D). By including the elastomer (D), the photosensitive resin composition of this embodiment tends to have improved adhesive strength with copper plating. Furthermore, by including the elastomer (D), the photosensitive resin composition of this embodiment tends to have the effect of suppressing "a decrease in flexibility and adhesive strength with copper plating" caused by strain (internal stress) inside the cured product that may occur due to cure shrinkage of the component (A). The (D) elastomer may be used alone or in combination of two or more kinds.

[0064] The (D) elastomer may have a reactive functional group at the molecular end or in the molecular chain. Examples of the reactive functional group include an acid anhydride group, an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an amide group, an isocyanato group, an acrylic group, a methacrylic group, a vinyl group, etc. Among these, from the viewpoints of via resolution and adhesive strength with copper plating, an acid anhydride group, an epoxy group, a hydroxyl group, a carboxyl group, an amino group, and an amide group are preferred, an acid anhydride group and an epoxy group are more preferred, and an acid anhydride group is even more preferred. The acid anhydride group is preferably an acid anhydride group derived from phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, glutaric anhydride, dimethylglutaric anhydride, diethylglutaric anhydride, succinic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, or the like, and more preferably an acid anhydride group derived from maleic anhydride. When the (D) elastomer has acid anhydride groups, the number of acid anhydride groups in one molecule is preferably 1 to 10, more preferably 1 to 6, and even more preferably 2 to 5, from the viewpoints of via resolution and dielectric loss tangent.

[0065] The photosensitive resin composition of this embodiment preferably contains, as the elastomer (D), an elastomer having an ethylenically unsaturated group and an acidic substituent. Examples of the acidic substituent and the ethylenically unsaturated group include the same as those contained in component (A). Among these, the elastomer (D) preferably has an acid anhydride group as the acidic substituent, as described above, and a 1,2-vinyl group as the ethylenically unsaturated group, as described below.

[0066] Examples of the (D) elastomer include polybutadiene-based elastomers, polyester-based elastomers, styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyamide-based elastomers, acrylic-based elastomers, silicone-based elastomers, derivatives of these elastomers, etc. Among these, polybutadiene-based elastomers are preferred from the viewpoints of improving adhesive strength with copper plating and further improving compatibility and solubility with resin components.

[0067] Suitable examples of polybutadiene elastomers include those containing 1,2-vinyl groups and having 1,4-trans and 1,4-cis structures. As described above, from the viewpoint of via resolution, the polybutadiene elastomer is preferably a polybutadiene elastomer having an acid anhydride group that has been modified with an acid anhydride, and more preferably a polybutadiene elastomer having an acid anhydride group derived from maleic anhydride. Polybutadiene-based elastomers are commercially available, and specific examples thereof include "POLYVEST (registered trademark) MA75" and "POLYVEST (registered trademark) EP MA120" (all of which are product names manufactured by Evonik), "Ricon (registered trademark) 130MA8", "Ricon (registered trademark) 131MA5", and "Ricon (registered trademark) 184MA6" (all of which are product names manufactured by Cray Valley).

[0068] From the viewpoint of adhesive strength with copper plating, the polybutadiene elastomer may be polybutadiene having epoxy groups (hereinafter, may be referred to as epoxidized polybutadiene), and is preferably polybutadiene having epoxy groups. From the viewpoints of adhesive strength to copper plating and flexibility, the epoxidized polybutadiene is preferably an epoxidized polybutadiene represented by the following general formula (D-1).

[0069] [ka] (In the formula, a, b, and c each represent the ratio of the structural units in the parentheses, where a is 0.05 to 0.40, b is 0.02 to 0.30, and c is 0.30 to 0.80, and further, a+b+c=1.00 and (a+c)>b are satisfied. y represents the number of structural units in the square brackets and is an integer of 10 to 250.)

[0070] In the general formula (D-1), the structural units in the square brackets may be bonded in any order. In other words, the structural unit shown on the left, the structural unit shown in the center, and the structural unit shown on the right may be interchanged, and if they are represented as (a), (b), and (c), respectively, various bonding orders are possible, such as -[(a)-(b)-(c)]-[(a)-(b)-(c)-]-, -[(a)-(c)-(b)]-[(a)-(c)-(b)-]-, -[(b)-(a)-(c)]-[(b)-(a)-(c)-]-, -[(a)-(b)-(c)]-[(c)-(b)-(a)-]-, -[(a)-(b)-(a)]-[(c)-(b)-(c)-]-, and -[(c)-(b)-(c)]-[(b)-(a)-(a)-]-. From the viewpoints of adhesive strength to copper plating and flexibility, a is preferably 0.10 to 0.30, b is preferably 0.10 to 0.30, and c is preferably 0.40 to 0.80. From the same viewpoints, y is preferably an integer of 30 to 180. In the above general formula (D-1), examples of commercially available epoxidized polybutadiene in which a=0.20, b=0.20, c=0.60, and y=an integer of 10 to 250 include "Epolead (registered trademark) PB3600" (manufactured by Daicel Corporation).

[0071] Examples of polyester elastomers include those obtained by polycondensation of dicarboxylic acid or a derivative thereof and diol compound or a derivative thereof. Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and aromatic dicarboxylic acids in which the hydrogen atoms of the aromatic nuclei are substituted with methyl groups, ethyl groups, phenyl groups, or the like; aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid, and dodecanedicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. Examples of diol compounds include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decanediol; alicyclic diols such as 1,4-cyclohexanediol; and aromatic diols such as bisphenol A, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3-methylphenyl)propane, and resorcinol. Another suitable polyester elastomer is a multiblock copolymer in which an aromatic polyester (e.g., polybutylene terephthalate) portion serves as the hard segment component and an aliphatic polyester (e.g., polytetramethylene glycol) portion serves as the soft segment component. Multiblock copolymers are available in various grades depending on the type, ratio, and molecular weight of the hard and soft segments.

[0072] When the photosensitive resin composition of the present embodiment contains the elastomer (D), the content of the elastomer (D) is not particularly limited, but from the viewpoints of heat resistance and adhesive strength with copper plating, it is preferably 0.5 to 15 mass %, more preferably 1.0 to 10 mass %, even more preferably 1.0 to 7 mass %, and particularly preferably 1.0 to 5 mass %, based on the total amount of resin components in the photosensitive resin composition.

[0073] <(E) Inorganic filler> The photosensitive resin composition of the present embodiment preferably further contains an inorganic filler as component (E). By containing the inorganic filler (E), the photosensitive resin composition of the present embodiment tends to have a lower dielectric tangent and excellent low thermal expansion. The (E) inorganic filler may be used alone or in combination of two or more kinds.

[0074] (E) Inorganic fillers include silica (SiO2), alumina (Al2O3), titania (TiO2), tantalum oxide (Ta2O5), zirconia (ZrO2), silicon nitride (Si3N4), barium titanate (BaO·TiO2), barium carbonate (BaCO3), magnesium carbonate (MgCO3), aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), lead titanate (PbO·TiO2), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide (Ga2O3), and spinel (MgO·Al2O3). Examples of suitable silica include mullite (3Al2O3·2SiO2), cordierite (2MgO·2Al2O3 / 5SiO2), talc (3MgO·4SiO2·H2O), aluminum titanate (TiO2·Al2O3), yttria-containing zirconia (Y2O3·ZrO2), barium silicate (BaO·8SiO2), boron nitride (BN), calcium carbonate (CaCO3), barium sulfate (BaSO4), calcium sulfate (CaSO4), zinc oxide (ZnO), magnesium titanate (MgO·TiO2), hydrotalcite, mica, calcined kaolin, and carbon (C). Among these, silica is preferred from the viewpoints of heat resistance, low thermal expansion, and dielectric loss tangent.

[0075] The (E) inorganic filler may be surface-treated with a coupling agent such as a silane coupling agent to improve dispersibility in the photosensitive resin composition. Examples of silane coupling agents include aminosilane coupling agents, epoxysilane coupling agents, phenylsilane coupling agents, alkylsilane coupling agents, alkenylsilane coupling agents, alkynylsilane coupling agents, haloalkylsilane coupling agents, siloxane coupling agents, hydrosilane coupling agents, silazane coupling agents, alkoxysilane coupling agents, chlorosilane coupling agents, (meth)acrylicsilane coupling agents, isocyanuratesilane coupling agents, ureidosilane coupling agents, mercaptosilane coupling agents, sulfidesilane coupling agents, and isocyanatesilane coupling agents. Among these, from the viewpoints of dispersibility of the inorganic filler, pot life of the photosensitive resin composition, and reliability of the coating film, alkenylsilane coupling agents are preferred, and it is more preferred to use a vinylsilane coupling agent as the alkenylsilane coupling agent.

[0076] The (E) inorganic filler may be an inorganic filler whose surface has been treated with one type of coupling agent, or two or more types of inorganic fillers whose surface has been treated with different coupling agents may be used in combination. When a coupling agent is used, the addition method may be a so-called integral blending method in which the coupling agent is added after blending the inorganic filler (E) into the photosensitive resin composition, or a method in which the inorganic filler (E) before blending is previously surface-treated with the coupling agent by a dry or wet method.

[0077] From the viewpoint of via resolution, the average particle size of (E) the inorganic filler is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, even more preferably 0.1 to 1 μm, and particularly preferably 0.15 to 0.7 μm. (E) The inorganic filler may be a mixture of two or more inorganic fillers with different average particle sizes, from the viewpoints of improving adhesion to copper plating and via resolution. (E) The average particle size of the inorganic filler means the volume-average particle size, and can be determined as the particle size corresponding to an integrated value of 50% (volume basis) in the particle size distribution by measuring particles dispersed in a solvent at a refractive index of 1.38 using a submicron particle analyzer (manufactured by Beckman Coulter, Inc., product name: N5) in accordance with the international standard ISO 13321.

[0078] When the photosensitive resin composition of this embodiment contains an inorganic filler (E), its content is not particularly limited, but is preferably 10 to 80 mass %, more preferably 20 to 65 mass %, even more preferably 30 to 55 mass %, and particularly preferably 35 to 50 mass %, based on the total solid content of the photosensitive resin composition. When the content of the inorganic filler (E) is equal to or greater than the above lower limit, a lower dielectric loss tangent and thermal expansion coefficient tend to be obtained, while when it is equal to or less than the above upper limit, better adhesion strength to copper plating and via resolution tend to be obtained.

[0079] <(F) Epoxy resin hardener> The photosensitive resin composition of the present embodiment preferably further contains an epoxy resin curing agent as component (F). By containing the epoxy resin curing agent (F), the photosensitive resin composition of the present embodiment tends to be able to further improve heat resistance, dielectric loss tangent, and the like. The (F) epoxy resin curing agent may be used alone or in combination of two or more kinds.

[0080] (F) Epoxy resin curing agents include guanamines such as acetoguanamine and benzoguanamine; polyamines such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, and polybasic hydrazides; organic acid salts and / or epoxy adducts thereof; amine complexes of boron trifluoride; triazine derivatives such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, and 2,4-diamino-6-xylyl-S-triazine; and polyphenols such as polyvinylphenol, brominated polyvinylphenol, phenol novolac, alkylphenol novolac, and triazine ring-containing phenol novolac resin. The polyphenol may be a modified polyphenol modified with, for example, melamine or benzoguanamine. The hydroxyl equivalent of the polyphenol is not particularly limited, but is preferably 40 to 300 g / eq, and may be 40 to 250 g / eq, 60 to 200 g / eq, 80 to 160 g / eq, or 100 to 140 g / eq. Here, the hydroxyl equivalent (g / eq) can be determined by titration using an acetylation method with acetic anhydride.

[0081] When the photosensitive resin composition of the present embodiment contains an epoxy resin curing agent (F), its content is not particularly limited, but from the viewpoint of further improving the heat resistance and dielectric loss tangent, it is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.1 to 1 mass %, based on the total amount of the resin components of the photosensitive resin composition.

[0082] <(G) Curing accelerator> The photosensitive resin composition of the present embodiment preferably further contains a curing accelerator as component (G). By containing the curing accelerator (G), the photosensitive resin composition of the present embodiment tends to be able to further improve the heat resistance, dielectric loss tangent, and the like. The (G) curing accelerator may be used alone or in combination of two or more kinds.

[0083] (G) Examples of curing accelerators include imidazole compounds such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, 2-phenyl-1-benzyl-1H-imidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and isocyanate-masked imidazole (an addition reaction product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole); trimethylamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa(N-methyl)melamine, 2,4,6-tris(dimethylaminophenol), and tetramethylamine. Examples of suitable amines include tertiary amines such as methylguanidine and m-aminophenol; organic phosphines such as tributylphosphine, triphenylphosphine and tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl(2,5-dihydroxyphenyl)phosphonium bromide and hexadecyltributylphosphonium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; the above-mentioned polybasic acid anhydrides; and diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate and 2,4,6-triphenylthiopyrylium hexafluorophosphate. Among these, imidazole and imidazole derivatives are preferred from the viewpoint of obtaining an excellent curing effect.

[0084] When the photosensitive resin composition of the present embodiment contains the curing accelerator (G), its content is not particularly limited, but from the viewpoint of further improving the heat resistance and dielectric loss tangent, it is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.1 to 2 mass %, based on the total amount of the resin components of the photosensitive resin composition.

[0085] <(H) Photopolymerization initiator> The photosensitive resin composition of the present embodiment preferably further contains a photopolymerization initiator as component (H). By containing the photopolymerization initiator (H), the photosensitive resin composition of the present embodiment tends to further improve the resolution of vias. The (H) photopolymerization initiator may be used alone or in combination of two or more. From the viewpoint of via resolution, the photosensitive resin composition of the present embodiment preferably contains two or more types of (H) component.

[0086] The (H) photopolymerization initiator is not particularly limited as long as it can photopolymerize an ethylenically unsaturated group, and can be appropriately selected from commonly used photopolymerization initiators. (H) Photopolymerization initiators include benzoin-based compounds such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone-based compounds such as acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane, and N,N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2 ketal compounds such as acetophenone dimethyl ketal and benzil dimethyl ketal; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; acylphosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; and oxime ester compounds such as 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone-1-(O-acetyloxime), and 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl)oxime].

[0087] Among these, acetophenone-based compounds and acylphosphine oxide-based compounds are preferred, with 2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide being more preferred. Acetophenone-based compounds have the advantage of being less volatile and less prone to outgassing, while acylphosphine oxide-based compounds have the advantage of reducing the absorption of actinic rays such as ultraviolet light, thereby allowing the actinic rays to reach the bottom of the photosensitive resin film, resulting in enhanced curing of the bottom of the exposed area. The combined use of an acetophenone-based compound and an acylphosphine oxide-based compound tends to further improve via resolution.

[0088] When the photosensitive resin composition of this embodiment contains a (H) photopolymerization initiator, its content is not particularly limited, but is preferably 0.01 to 20 mass%, more preferably 0.1 to 10 mass%, even more preferably 0.2 to 5 mass%, and particularly preferably 0.3 to 2 mass%, based on the total amount of resin components in the photosensitive resin composition. When the content of (H) photopolymerization initiator is equal to or greater than the above lower limit, elution of exposed areas during development tends to be reduced, and when it is equal to or less than the above upper limit, heat resistance tends to be improved.

[0089] <(I) Photosensitizer> The photosensitive resin composition of this embodiment may contain a photosensitizer as component (I) as needed. The (I) photosensitizer may be used alone or in combination of two or more. From the viewpoint of via resolution, the photosensitive resin composition of the present embodiment preferably contains two or more types of component (I). (I) Examples of photosensitizers include thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; tertiary amines such as trialkylamines and triethanolamine; dialkylaminobenzoic acid alkyl esters such as ethyl N,N-dimethylaminobenzoate and amyl N,N-dimethylaminobenzoate; bis(dialkylamino)benzophenones such as 4,4'-bis(dimethylamino)benzophenone and 4,4'-bis(diethylamino)benzophenone; phosphine compounds such as triphenylphosphine; toluidine compounds such as N,N-dimethyltoluidine; anthracene compounds such as 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, and 2-ethyl-9,10-diethoxyanthracene; perylene compounds; and coumarin compounds. (I) As the photosensitizer, from the viewpoints of via resolution and sensitivity to actinic rays, bis(dialkylamino)benzophenone and thioxanthone compounds are preferred, and 4,4'-bis(diethylamino)benzophenone and 2,4-diethylthioxanthone are more preferred.

[0090] When the photosensitive resin composition of this embodiment contains (I) a photosensitizer, its content is not particularly limited, but is preferably 0.01 to 5 mass%, more preferably 0.05 to 3 mass%, even more preferably 0.1 to 1.5 mass%, and particularly preferably 0.1 to 1.0 mass%, based on the total amount of resin components in the photosensitive resin composition. If the content of (I) a photosensitizer is above the above-mentioned lower limit, the unexposed portions of the photosensitive resin film are also likely to cure, which can lead to tapered exposed portions and footing. If the content is below the above-mentioned upper limit, the degree of cure at the bottom of the exposed portions is reduced, which can lead to the formation of an undercut shape. Here, footing refers to the phenomenon in which the width of the bottom of a non-resist portion is narrower than the width of the top (the side irradiated with actinic radiation).

[0091] <(J) Additives> The photosensitive resin composition of the present embodiment may contain, as necessary, various known and commonly used additives, such as pigments such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black; adhesion aids such as melamine; foam stabilizers such as silicone compounds; polymerization inhibitors; thickeners; and flame retardants. The content of these (J) additives may be adjusted appropriately depending on each purpose, but for each, it is preferably 0.01 to 5 mass%, alternatively 0.05 to 3 mass%, or alternatively 0.1 to 1 mass%, based on the total amount of resin components in the photosensitive resin composition.

[0092] <Diluent> The photosensitive resin composition of this embodiment may contain a diluent as needed. Examples of the diluent include organic solvents. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ether compounds such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, propylene glycol monoethyl ether acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. These diluents may be used alone or in combination.

[0093] When the photosensitive resin composition of this embodiment contains a diluent, the content thereof may be appropriately selected for the purpose of adjusting the concentration of the total solid content in the photosensitive resin composition to preferably 40 to 90 mass %, more preferably 50 to 85 mass %, and even more preferably 60 to 80 mass %. By adjusting the amount of diluent used to within the above range, the coatability of the photosensitive resin composition is improved, and it becomes possible to form a more highly precise pattern.

[0094] The photosensitive resin composition of this embodiment can be obtained by kneading and mixing the components using a roll mill, a bead mill, or the like. Here, the photosensitive resin composition of the present embodiment may be used in the form of a liquid or a film. When used in a liquid form, the method for applying the photosensitive resin composition of the present embodiment is not particularly limited, and examples thereof include various application methods such as printing, spin coating, spray coating, jet dispensing, inkjet coating, dip coating, etc. Among these, printing and spin coating are preferred from the viewpoint of more easily forming a photosensitive layer. When used in the form of a film, it can be used, for example, in the form of a photosensitive resin film described later, and in this case, a photosensitive layer of a desired thickness can be formed by laminating it on a carrier film using a laminator, etc. Note that use in the form of a film is preferred because it increases the production efficiency of multilayer printed wiring boards.

[0095] [Photosensitive resin film] The photosensitive resin film of the present embodiment is formed using the photosensitive resin composition of the present embodiment, and is useful as a photosensitive layer for forming an interlayer insulating layer. The photosensitive resin film of the present embodiment may be provided on a carrier film.

[0096] The photosensitive resin film of the present embodiment can be formed, for example, by applying the photosensitive resin composition of the present embodiment onto a carrier film using a known coating device such as a comma coater, a bar coater, a kiss coater, a roll coater, a gravure coater, or a die coater, and then drying the applied composition. Examples of the carrier film include polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyolefins such as polypropylene and polyethylene. The thickness of the carrier film is preferably 5 to 100 μm, more preferably 10 to 60 μm, and even more preferably 15 to 45 μm.

[0097] The photosensitive resin film of this embodiment may also have a protective film on the surface opposite to the surface in contact with the carrier film. Polymer films such as polyethylene and polypropylene may be used as the protective film. The same polymer film as the carrier film described above may be used, or a different polymer film may be used.

[0098] The coating film formed by applying the photosensitive resin composition can be dried using hot air drying or a dryer using far-infrared or near-infrared rays. The drying temperature is preferably 60 to 150°C, more preferably 70 to 120°C, and even more preferably 80 to 100°C. The drying time is preferably 1 to 60 minutes, more preferably 2 to 30 minutes, and even more preferably 5 to 20 minutes. The content of the remaining diluent in the photosensitive resin film after drying is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, from the viewpoint of preventing the diluent from diffusing during the manufacturing process of a multilayer printed wiring board.

[0099] The thickness (thickness after drying) of the photosensitive resin film (photosensitive layer) is not particularly limited, but from the viewpoint of thinning the multilayer printed wiring board, it is preferably 1 to 100 μm, more preferably 3 to 50 μm, and even more preferably 5 to 40 μm.

[0100] The photosensitive resin film of this embodiment is suitable as an interlayer insulating layer for a multilayer printed wiring board because it has excellent via resolution, adhesive strength with copper plating, and insulation reliability.

[0101] [Multilayer printed wiring board and its manufacturing method] The multilayer printed wiring board of this embodiment contains an interlayer insulating layer formed using the photosensitive resin composition of this embodiment or the photosensitive resin film of this embodiment. Here, the expression "containing an interlayer insulating layer" includes a case where the interlayer insulating layer is contained as is, and a case where the interlayer insulating layer is contained after being subjected to processing such as via formation, various treatments such as roughening treatment, wiring formation, etc. The multilayer printed wiring board of this embodiment can be easily produced by any method, as long as it includes a step of forming an interlayer insulating layer using the photosensitive resin composition or photosensitive resin film of this embodiment, and can be easily produced, for example, by the following method for producing a multilayer printed wiring board of this embodiment.

[0102] A method for producing a multilayer printed wiring board using the photosensitive resin film of this embodiment will be described with reference to FIG. 1 as needed. Multilayer printed wiring board 100A can be manufactured by, for example, a manufacturing method including the following steps (1) to (4). (1): Laminating the photosensitive resin film of the present embodiment onto one or both sides of a circuit board (hereinafter referred to as "laminating step (1)"). (2): Forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in step (1) (hereinafter referred to as "photovia forming step (2)"). (3) Roughening the via and the interlayer insulating layer (hereinafter referred to as "roughening treatment step (3)"). (4): Forming a circuit pattern on the interlayer insulating layer (hereinafter referred to as "circuit pattern forming step (4)"). Herein, as described above, for convenience, a given operation may be referred to as "XX step" in this specification, but the XX step is not limited to only the embodiments specifically described in this specification.

[0103] (Lamination process (1)) The laminating step (1) is a step of laminating the photosensitive resin film of this embodiment (photosensitive resin film for interlayer insulating layer) onto one or both sides of a circuit board (substrate 101 having circuit pattern 102) using a vacuum laminator. Examples of vacuum laminators include a vacuum applicator manufactured by Nichigo-Morton Co., Ltd., a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a roll-type dry coater manufactured by Hitachi, Ltd., and a vacuum laminator manufactured by Showa Denko Materials Electronics K.K.

[0104] When a protective film is provided on the photosensitive resin film, the protective film can be peeled off or removed, and then the photosensitive resin film can be laminated by being pressed against the circuit board while applying pressure and heat, with the photosensitive resin film in contact with the circuit board. The lamination can be carried out, for example, after preheating the photosensitive resin film and the circuit board as necessary, at a pressure of 70 to 130°C, a pressure of 0.1 to 1.0 MPa, and a reduced pressure of 20 mmHg (26.7 hPa) or less, but is not particularly limited to these conditions. The lamination method may be a batch method or a continuous method using a roll. Finally, the photosensitive resin film laminated to the circuit board is cooled to about room temperature to form the interlayer insulating layer 103. If the photosensitive resin film has a carrier film, the carrier film may be peeled off at this stage, or may be peeled off after exposure, as described below.

[0105] (Photovia formation process (2)) In the photovia forming step (2), at least a portion of the photosensitive resin film laminated to the circuit board is exposed to light and then developed. The exposed portion is photocured to form a pattern. The exposure method is not particularly limited, and may be, for example, a method of irradiating the active light imagewise through a negative or positive mask pattern known as artwork (mask exposure method), or a method of irradiating the active light imagewise by a direct imaging exposure method such as LDI (Laser Direct Imaging) exposure or DLP (Digital Light Processing) exposure. Known light sources can be used as the light source for actinic rays. Specific examples of light sources include carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, gas lasers such as argon lasers, solid-state lasers such as YAG lasers, and semiconductor lasers that effectively emit ultraviolet or visible light. The exposure dose is appropriately selected depending on the light source used and the thickness of the photosensitive layer. For example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, the exposure dose is usually 10 to 1,000 mJ / cm for a photosensitive layer with a thickness of 1 to 100 μm. 2 The preferred range is 50 to 700 mJ / cm 2 More preferably, 150 to 550 mJ / cm 2 is more preferably 250 to 500 mJ / cm 2 is particularly preferred.

[0106] In the development, the uncured portions of the photosensitive layer are removed from the substrate, and the photocured portions are formed on the substrate as an interlayer insulating layer. When a carrier film is present on the photosensitive layer, the carrier film is removed before removing (developing) the unexposed portion. The development method includes wet development and dry development, either of which may be used, but wet development is widely used, and can also be used in this embodiment. In the case of wet development, development is carried out by a known development method using a developer suitable for the photosensitive resin composition. Examples of development methods include dipping, bathing, spraying, brushing, slapping, scraping, and swinging immersion. Among these, from the viewpoint of improving via resolution, the spraying method is preferred, and among spraying methods, the high-pressure spraying method is more preferred. Development may be carried out by one method, or by combining two or more methods. The composition of the developer is appropriately selected depending on the composition of the photosensitive resin composition. Examples include an alkaline aqueous solution, a water-based developer, and an organic solvent-based developer, and among these, an alkaline aqueous solution is preferred.

[0107] In the photovia forming process (2), after exposure and development, 0.2 to 10 J / cm 2 (preferably 0.5 to 5 J / cm 2 The interlayer insulating layer may be further cured, and it is preferable to perform post-UV curing with an exposure amount of 1000 ppm or more, and post-thermal curing at a temperature of about 60 to 250°C (preferably 120 to 200°C) as needed. In this manner, an interlayer insulating layer having vias 104 is formed. There are no particular limitations on the shape of the vias, and examples of cross-sectional shapes include a rectangle and an inverted trapezoid (the upper side is longer than the lower side), and examples of shapes viewed from the front (the direction from which the via bottom is visible) include a circle and a rectangle. In the formation of vias by photolithography in this embodiment, it is possible to form vias having a cross-sectional shape of an inverted trapezoid (the upper side is longer than the lower side), which is preferable because it improves the adhesion of copper plating to the via wall surface.

[0108] The size (diameter) of the via formed by this process can be less than 40 μm, and can even be 35 μm or less or 30 μm or less, which is smaller than the size of vias formed by laser processing. There is no particular lower limit to the size (diameter) of the via formed by this process, but it may be 15 μm or more, or 20 μm or more. However, the size (diameter) of the vias formed in this step is not limited to less than 40 μm, and may be selected arbitrarily within the range of, for example, 15 to 300 μm.

[0109] (Roughening treatment step (3)) In the roughening treatment step (3), the surfaces of the vias and the interlayer insulating layer are roughened with a roughening liquid. If smears occur in the photovia forming step (2), the smears may be removed with the roughening liquid. The roughening treatment and smear removal (desmearing) can be performed simultaneously. Examples of the roughening solution include a chromium / sulfuric acid roughening solution, an alkaline permanganate roughening solution (for example, a sodium permanganate roughening solution), and a sodium fluoride / chromium / sulfuric acid roughening solution. The roughening treatment forms uneven anchors on the surface of the via and the interlayer insulating layer.

[0110] (Circuit pattern formation process (4)) The circuit pattern forming step (4) is a step of forming a circuit pattern on the interlayer insulating layer after the roughening treatment step (3). From the viewpoint of forming fine wiring, the circuit pattern is preferably formed by a semi-additive process, which forms the circuit pattern and also establishes via conduction. In the semi-additive process, first, the via bottom, via wall, and entire surface of the interlayer insulating layer after the roughening treatment step (3) are subjected to electroless copper plating using a palladium catalyst or the like to form a seed layer 105. The seed layer serves to form a power supply layer for electrolytic copper plating, and is preferably formed to a thickness of approximately 0.1 to 2.0 μm. If the seed layer is 0.1 μm or thicker, it tends to be possible to suppress a decrease in connection reliability during electrolytic copper plating, while if it is 2.0 μm or thinner, it is not necessary to increase the etching depth when flash etching the seed layer between wirings, and damage to the wiring during etching tends to be suppressed.

[0111] The electroless copper plating process is carried out by depositing metallic copper on the surface of the via and interlayer insulating layer through a reaction between copper ions and a reducing agent. The electroless plating method and the electrolytic plating method may be any known method and are not particularly limited. Commercially available electroless copper plating solutions can be used, including "MSK-DK" manufactured by Atotech Japan Co., Ltd. and "Sulcup (registered trademark) PEA series" manufactured by Uemura Kogyo Co., Ltd.

[0112] After the electroless copper plating process, a dry film resist is thermocompressed onto the electroless copper plating using a roll laminator. The thickness of the dry film resist must be greater than the wiring height after electrolytic copper plating, and from this perspective, a dry film resist with a thickness of 5 to 30 μm is preferred. As the dry film resist, the "Photec (registered trademark)" series manufactured by Showa Denko Materials Co., Ltd., or the like is used. After thermocompression bonding of the dry film resist, the dry film resist is exposed, for example, through a mask on which a desired wiring pattern is drawn. The exposure can be performed using the same equipment and light source as those used to form vias in the photosensitive resin film. After exposure, the dry film resist is developed using an alkaline aqueous solution, and the unexposed portions are removed to form a resist pattern 106. Thereafter, if necessary, a process of removing development residues of the dry film resist using plasma or the like may be performed. After development, copper electroplating is carried out to form a copper circuit layer 107 and fill vias.

[0113] After electrolytic copper plating, the dry film resist is stripped using an alkaline aqueous solution or an amine-based stripper. After the dry film resist is stripped, the seed layer between the wirings is removed (flash etching). Flash etching is performed using an acidic solution such as sulfuric acid and hydrogen peroxide, and an oxidizing solution. After flash etching, palladium and other materials adhering to the portions between the wirings are removed as necessary. Palladium removal is preferably performed using an acidic solution such as nitric acid or hydrochloric acid.

[0114] After the dry film resist is removed or after the flash etching step, a post-baking process is preferably performed. The post-baking process sufficiently heat-cures any unreacted thermosetting components, thereby improving insulation reliability, curing characteristics, and adhesive strength with copper plating. While the thermosetting conditions vary depending on the type of resin composition, a curing temperature of 150 to 240°C and a curing time of 15 to 100 minutes are preferred. The post-baking process completes the entire process for manufacturing a multilayer printed wiring board using the photovia method. This process is repeated to manufacture the board depending on the number of interlayer insulating layers required. A solder resist layer 108 is then preferably formed as the outermost layer.

[0115] The method for manufacturing a multilayer printed wiring board in which vias are formed using the photosensitive resin composition of this embodiment has been described above, but the photosensitive resin composition of this embodiment has excellent pattern resolution, so it is also suitable for forming cavities for incorporating chips, passive elements, etc. The cavities can be suitably formed, for example, by using a drawing pattern that can form the desired cavities when forming a pattern by exposing the photosensitive resin film in the above description of the multilayer printed wiring board.

[0116] [Semiconductor Package] The present disclosure also provides a semiconductor package including the multilayer printed wiring board of the present embodiment and a semiconductor element. The semiconductor package of the present embodiment can be manufactured by mounting a semiconductor element such as a semiconductor chip or memory at a predetermined position on the multilayer printed wiring board of the present embodiment and encapsulating the semiconductor element with an encapsulating resin or the like. [Example]

[0117] The present embodiment will be described in more detail below using examples, but the present disclosure is not limited to these examples. The weight-average molecular weight of component (A) was measured according to the following method. The photosensitive resin compositions obtained in each example were evaluated for their properties according to the following methods.

[0118] <Method for measuring weight average molecular weight> The weight-average molecular weight was measured using the GPC measurement device and measurement conditions described below, and the value converted using a calibration curve of standard polystyrene was used as the weight-average molecular weight. The calibration curve was created using a set of five standard polystyrene samples ("PStQuick MP-H" and "PStQuick B", manufactured by Tosoh Corporation). (GPC measurement device) GPC equipment: High-speed GPC equipment "HCL-8320GPC", detector is differential refractometer or UV, manufactured by Tosoh Corporation Column: TSKgel SuperMultipore HZ-H column (column length: 15 cm, column inner diameter: 4.6 mm), manufactured by Tosoh Corporation (Measurement conditions) Solvent: tetrahydrofuran (THF) Measurement temperature: 40℃ Flow rate: 0.35ml / min Sample concentration: 10mg / THF5ml Injection volume: 20μl

[0119] [1. Evaluation of dielectric constant (Dk) and dielectric loss tangent (Df)] The protective film was removed and two sheets of photosensitive resin film were bonded together. With the carrier film on both sides still attached, the film was exposed to 400 mJ / cm using a flatbed exposure machine. 2(wavelength 365nm), 2J / cm using a UV conveyor exposure machine 2 This was heat-treated in a hot air circulation dryer at 170°C for 1 hour, and then cut into a size of 7 cm x 10 cm to prepare an evaluation sample. The obtained evaluation sample was dried at 105° C. for 10 minutes in a hot air circulation dryer, and the dielectric constant (Dk) and dielectric loss tangent (Df) were measured in the 10 GHz band by the split post dielectric resonator method (SPDR method).

[0120] [2. Evaluation of desmear resistance] While peeling off the protective film from the "photosensitive resin film having a carrier film and a protective film bonded thereto" produced in the examples and comparative examples, the film was laminated onto a 1.0 mm thick copper-clad laminate substrate using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500") at a pressure of 0.4 MPa, a press hot plate temperature of 75°C, a vacuum time of 20 seconds, a lamination press time of 20 seconds, and an air pressure of 4 kPa or less, to obtain a laminate. The resulting laminate was exposed to 400 mJ / cm 2 using a parallel light exposure machine (manufactured by Oak Manufacturing Co., Ltd., product name "EXM-1201") using an ultra-high pressure mercury lamp as a light source. 2 The entire surface was exposed to UV light (wavelength 365 nm). Then, a UV exposure device was used to expose the entire surface to UV light at 2,000 mJ / cm. 2 The copper-clad laminate was exposed to light (wavelength 365 nm) and heated at 170° C. for 1 hour to obtain a cured product on the copper-clad laminate, thereby obtaining a laminate for evaluation.

[0121] Next, for the resulting evaluation laminate, a swelling solution of 500 ml / L of diethylene glycol monobutyl ether aqueous solution and 3 g / L of sodium hydroxide was prepared, and the swelling solution was heated to 70°C, after which the evaluation laminate was immersed for 5 minutes. Next, a roughening solution of 115 g / L of sodium permanganate and 40 g / L of sodium hydroxide was prepared, and the solution was heated to 70°C, after which the evaluation laminate was immersed for 15 minutes. Subsequently, a neutralizing solution (100 mL / L of hydroxylamine sulfate aqueous solution, 47 ml / L of sulfuric acid) was prepared, and the solution was heated to 50°C, after which the evaluation laminate was immersed for 5 minutes to reduce the sodium permanganate. In this manner, a desmear treatment was performed. Desmear resistance is the weight loss per unit area after desmearing compared to the dry weight before desmearing (g / m 2 The smaller the weight loss, the better the desmear resistance.

[0122] [Preparation of Photosensitive Resin Composition] Examples 1-2, Comparative Examples 1-3 (1) Production of photosensitive resin composition Compositions were compounded according to the formulations shown in Table 1 (the units of values ​​in the table are parts by mass, and in the case of solutions or dispersions, they are amounts converted to solid content), and kneaded using a three-roll mill. Methyl ethyl ketone was then added so that the solid content concentration became 65% by mass, to obtain photosensitive resin compositions. (2) Manufacture of photosensitive resin films A 16 μm thick polyethylene terephthalate film (manufactured by Teijin Limited, trade name "G2-16") was used as a carrier film, and the photosensitive resin composition prepared in each example was applied to the carrier film so that the film thickness after drying would be 25 μm, and dried at 75°C for 30 minutes using a hot air convection dryer to form a photosensitive resin film (photosensitive layer). Subsequently, a polyethylene film (manufactured by Tamapoly Corporation, trade name "NF-15") was laminated as a protective film to the surface of the photosensitive resin film (photosensitive layer) opposite the side in contact with the carrier film, and a photosensitive resin film with the carrier film and protective film laminated together was produced.

[0123] The photosensitive resin film thus prepared was evaluated according to the above-mentioned methods. The results are shown in Table 1.

[0124] [Table 1]

[0125] The components used in Table 1 are as follows: [(A) Photopolymerizable Compound Having an Ethylenically Unsaturated Group and an Acidic Substituent] "ZXR-1807H" (Nippon Kayaku Co., Ltd., weight average molecular weight: 1,500)

[0126] [(B) Epoxy resin] "YSLV-80XY" (Nippon Steel Chemical & Material Co., Ltd., bisphenol-based epoxy resin, epoxy equivalent: 192g / eq) "Epotohto (registered trademark) ESN-475V" (manufactured by Nippon Steel Chemical & Material Co., Ltd., naphthol-type epoxy resin, epoxy equivalent: 325g / eq) "EPICLON® HP-7200" (DIC Corporation, alicyclic epoxy resin, epoxy equivalent: 259 g / eq) "EP4088L" (ADEKA Corporation, dicyclopentadiene dimethanol diglycidyl ether, epoxy equivalent: 165g / eq)

[0127] [(C) Crosslinking agent having two or more ethylenically unsaturated groups represented by general formula (C-1)] <Methacrylate compounds> "DCP": Dicyclopentadiene dimethacrylate "TMPT": Trimethylolpropane trimethacrylate [(C') Crosslinking agent other than component (C)] <Acrylate compounds> "DPHA": Dipentaerythritol hexaacrylate "A-CDP": Dicyclopentadiene diacrylate "TMPTA"; Trimethylolpropane triacrylate

[0128] [(D) Elastomer] "Epolead (registered trademark) PB3600" (epoxidized polybutadiene, manufactured by Daicel Chemical Industries, Ltd.)

[0129] [(E) Inorganic filler] E1: Fused spherical silica with an average particle size of 0.5 μm (treated with a vinylsilane coupling agent)

[0130] [(F) Epoxy resin hardener] "Phenolite (registered trademark) LA7052" (DIC Corporation, novolac-type phenolic resin modified with melamine, benzoguanamine, etc., hydroxyl group equivalent: 120 g / eq)

[0131] [(G) Curing accelerator] G1: 2-phenyl-1-benzyl-1H-imidazole (imidazole compounds)

[0132] [(H) Photopolymerization initiator] ·H1;2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane (acetophenone-based compound) ·H2;Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (acylphosphine oxide compounds)

[0133] [(I) Photosensitizer] 2,4-Diethylthioxanthone (thioxanthone compounds) ·I2;4,4'-Bis(diethylamino)benzophenone

[0134] [(J) Additives] 4-t-butylcatechol; polymerization inhibitor "SH-193" (silicone foam stabilizer, manufactured by Dow Toray Industries, Inc.)

[0135] From Table 1, it can be seen that the photosensitive resin compositions of Examples 1 and 2 of this embodiment have reduced dielectric tangents compared to the photosensitive resin compositions of Comparative Examples 1 to 3 which used crosslinking agents other than component (C). Furthermore, it can be seen that the photosensitive resin compositions of Examples 1 and 2 of this embodiment also had improved desmear resistance compared to the photosensitive resin compositions of Comparative Examples 1 to 3, which used a crosslinking agent other than component (C). This improved desmear resistance is expected to improve the dimensional accuracy of the fine wiring in the film thickness direction and the dimensional accuracy of the via opening diameter. [Explanation of symbols]

[0136] 100A multilayer printed wiring board 101 Substrate 102 Circuit Pattern 103 Interlayer insulating layer 104 Beer (Beer Hall) 105 seed layer 106 Resist Pattern 107 Copper circuit layers 108 Solder resist layer

Claims

1. (A) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent, (B) an epoxy resin; (C) a crosslinking agent having two or more ethylenically unsaturated groups represented by the following general formula (C-1), and (H) a photopolymerization initiator, 【Chemistry 1】 (In the formula, R Ｃ１ is a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, a phenyl group, or a benzyl group. * is a bonding site to another structure.) A photosensitive resin composition comprising: The component (A) contains an alicyclic structure represented by the following general formula (A-1), and the content of the component (A) is 10 to 80 mass% based on the total amount of resin components of the photosensitive resin composition. 【Chemistry 2】 (In the formula, R A1 represents an alkyl group having 1 to 12 carbon atoms and may be substituted anywhere in the alicyclic structure. m 1 is an integer of 0 to 6. * represents a bonding site to another structure.)

2. 2. The photosensitive resin composition according to claim 1, wherein the component (C) has 2 to 6 ethylenically unsaturated groups represented by the general formula (C-1).

3. 3. The photosensitive resin composition according to claim 1, wherein the component (C) is dicyclopentadiene dimethacrylate or trimethylolpropane trimethacrylate.

4. 4. The photosensitive resin composition according to claim 1, wherein an equivalent ratio of the acidic substituent of the component (A) to the epoxy group of the component (B) [epoxy group / acidic substituent] is 0.5 to 6.

0.

5. The photosensitive resin composition according to any one of claims 1 to 4, further comprising an elastomer (D), wherein the elastomer (D) comprises an elastomer having an ethylenically unsaturated group and an acidic substituent.

6. The photosensitive resin composition according to any one of claims 1 to 5, further comprising (E) an inorganic filler in an amount of 10 to 80 mass% based on the total solid content of the photosensitive resin composition.

7. A photosensitive resin composition described in any one of claims 1 to 6, wherein the (H) photopolymerization initiator comprises one or more compounds selected from the group consisting of benzoin-based compounds, acetophenone-based compounds, anthraquinone-based compounds, ketal-based compounds, acridine-based compounds, acylphosphine oxide-based compounds, and oxime ester-based compounds.

8. The photosensitive resin composition according to any one of claims 1 to 7, comprising two or more types of the component (H).

9. The photosensitive resin composition according to any one of claims 1 to 8, further comprising (I) a photosensitizer.

10. The photosensitive resin composition according to claim 9 , comprising two or more types of the component (I).

11. The photosensitive resin composition according to any one of claims 1 to 10, which is used to form one or more selected from the group consisting of a photovia and an interlayer insulating layer.

12. A photosensitive resin film comprising the photosensitive resin composition according to any one of claims 1 to 11.

13. A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin composition according to any one of claims 1 to 11 or the photosensitive resin film according to claim 12.

14. A semiconductor package comprising the multilayer printed wiring board according to claim 13 and a semiconductor element.

15. A method for producing a multilayer printed wiring board, comprising the following steps (1) to (4): (1): The photosensitive resin film according to claim 12 is laminated on one or both sides of a circuit board. (2) Forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in (1) above. (3) Roughening the via and the interlayer insulating layer. (4): Forming a circuit pattern on the interlayer insulating layer.

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