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

Abstract

To provide a photosensitive resin composition, a photovia-forming photosensitive resin composition and a photosensitive resin composition for an interlayer insulation layer being excellent in via resolution, adhesive strength to plated copper and insulation reliability; provide a photosensitive resin film and a photosensitive resin film for an interlayer insulation layer comprising the photosensitive resin composition; provide a multilayer printed board and a semiconductor package; and provide a method for manufacturing the multilayer printed board.SOLUTION: A photosensitive resin composition contains (A) a photopolymerizable compound having an ethylenically unsaturated group, (B) a photopolymerization initiator, (C) an epoxy resin and (D) an elastomer, the content of the (D) elastomer being 2-30 mass% relative to the total amount of resin components of the photosensitive resin composition.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 are becoming denser 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 is increasing significantly, and in addition to finer wiring, there is a demand for thinner insulating films and smaller diameters of vias (also called via holes) for interlayer connection.

[0003] A conventional method for manufacturing a printed wiring board is a build-up method (see, for example, Patent Document 1) for sequentially laminating an interlayer insulating layer and a conductor circuit layer. As circuits become finer, the semi-additive method for forming circuits 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 are performed by alkaline permanganate treatment or the like. (3) After that, electroless copper plating is performed on the board, and after a pattern is formed using a resist, electrolytic copper plating is performed to form a copper circuit layer. (4) Next, the resist is stripped, 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, and the reduction in the diameter of vias by laser irradiation using a laser processing machine has reached 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 must be provided for high density, it takes a long time to form the vias, 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 (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable compound, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a silane compound is used, in which the content of the inorganic filler (D) is 10 to 80 mass %, and a plurality of small vias are formed at once by a photolithography method (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

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

[0007] In Patent Document 2, one of the problems is to suppress the decrease in adhesive strength with plated copper caused by using a photosensitive resin composition instead of a conventional thermosetting resin composition as a material for an interlayer insulating layer or a surface protective layer, and further problems are also identified as via resolution and adhesion to silicon substrates and chip components, and these are said to have been solved. However, there is room for further improvement in terms of via resolution, adhesive strength with plated copper, and insulation reliability. Similarly, it is conceivable that photosensitive resin compositions, which are materials for conventional solder resists, could be used as materials for the interlayer insulating layer. However, since interlayer insulating layers require properties that were not necessary for solder resists (e.g., interlayer insulating reliability, adhesive strength with plated copper, high heat resistance capable of withstanding multiple heating processes, high dimensional accuracy of the via shapes, etc.), it is difficult to predict whether such layers will be practical for use as interlayer insulating layers, and they cannot be easily repurposed.

[0008] The present invention aims to provide a photosensitive resin composition, a photosensitive resin composition for forming photovias, and a photosensitive resin composition for an interlayer insulating layer, which are excellent in via resolution, adhesive strength with plated copper, and insulation reliability. It is also an object of the present invention to provide a photosensitive resin film and a photosensitive resin film for an interlayer insulating layer, each of which is made of the photosensitive resin composition, to provide a multilayer printed wiring board and a semiconductor package, and to provide a method for producing the multilayer printed wiring board. [Means for solving the problem]

[0009] Means for Solving the Problems The present inventors have conducted intensive research to solve the above problems and have found that the above problems can be solved by using a photosensitive resin composition containing the below-described components (A) to (D), in which the content of component (D) is a specific amount. That is, the present invention relates to the following [1] to

[13] .

[0010] [1] A photosensitive resin composition comprising (A) a photopolymerizable compound having an ethylenically unsaturated group, (B) a photopolymerization initiator, (C) an epoxy resin, and (D) an elastomer, A photosensitive resin composition, wherein the content of the (D) elastomer is 2 to 30 mass % based on the total amount of resin components in the photosensitive resin composition. [2] The photosensitive resin composition according to the above [1], wherein the (D) elastomer comprises at least one selected from the group consisting of a styrene-based elastomer, an olefin-based elastomer, a polyester-based elastomer, a urethane-based elastomer, a polyamide-based elastomer, an acrylic-based elastomer, and a silicone-based elastomer. [3] The photosensitive resin composition according to [1] above, wherein the (D) elastomer comprises at least one selected from the group consisting of polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyamideimide resin, polyimide resin, xylene resin, polyphenylene sulfide resin, polyetherimide resin, polyetheretherketone resin, polyetherimide resin, tetrafluoroethylene resin, polyacrylonitrile resin, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxy-modified polyacrylonitrile. [4] The photosensitive resin composition according to any one of the above [1] to [3], wherein the (A) photopolymerizable compound having an ethylenically unsaturated group comprises at least one member selected from the group consisting of (Ai) a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group, (Aii) a bifunctional vinyl monomer having two polymerizable ethylenically unsaturated groups, and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups. [5] The photosensitive resin composition according to any one of the above [1] to [4], wherein the (A) photopolymerizable compound having an ethylenically unsaturated group includes (A1) a photopolymerizable compound having an acidic substituent together with an ethylenically unsaturated group. [6] A photosensitive resin composition for forming a photovia, comprising the photosensitive resin composition according to any one of the above [1] to [5]. [7] A photosensitive resin composition for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of the above [1] to [5]. [8] A photosensitive resin film comprising the photosensitive resin composition according to any one of [1] to [5] above. [9] A photosensitive resin film for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of the above [1] to [5].

[10] A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin composition according to any one of the above [1] to [5].

[11] A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin film described in [8] above.

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

[10] or

[11] above and a semiconductor element mounted thereon.

[13] A method for producing a multilayer printed wiring board, comprising the following steps (1) to (4): Step (1): A step of laminating the photosensitive resin film described in the above item [8] onto one or both sides of a circuit board. Step (2): A step of forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in the step (1). Step (3): A step of roughening the via and the interlayer insulating layer. Step (4): forming a circuit pattern on the interlayer insulating layer. Effect of the Invention

[0011] According to the present invention, it is possible to provide a photosensitive resin composition, a photosensitive resin composition for forming photovias, and a photosensitive resin composition for an interlayer insulating layer, which are excellent in via resolution, adhesive strength with plated copper, and insulation reliability. It is also possible to provide a photosensitive resin film and a photosensitive resin film for an interlayer insulating layer, which are made of the photosensitive resin composition, and a multilayer printed wiring board and a semiconductor package, which include an interlayer insulating layer formed using the photosensitive resin composition or the photosensitive resin film. Furthermore, it is possible to provide a method for efficiently manufacturing a multilayer printed wiring board having high-resolution vias, high adhesive strength between an interlayer insulating layer and plated copper, and excellent insulation reliability. The vias in the multilayer printed wiring board obtained by the manufacturing method of the present invention can be smaller in diameter than vias formed by laser processing. [Brief description of the drawings]

[0012] [Figure 1] 2A to 2C are schematic diagrams illustrating one aspect of a manufacturing process for a multilayer printed wiring board according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 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, in this specification, when there are multiple substances corresponding to each component, the content of each component in the photosensitive resin composition means the total content of the multiple substances present in the photosensitive resin composition, unless otherwise specified. Additionally, any combination of the descriptions in this specification is also included in the present invention.

[0014] [Photosensitive resin composition, photosensitive resin composition for forming photovias, and photosensitive resin composition for interlayer insulating layer] A photosensitive resin composition according to one embodiment of the present invention (hereinafter may be simply referred to as this embodiment) is a photosensitive resin composition containing (A) a photopolymerizable compound having an ethylenically unsaturated group, (B) a photopolymerization initiator, (C) an epoxy resin, and (D) an elastomer, wherein the content of the (D) elastomer is 2 to 30 mass % based on the total amount of resin components in the photosensitive resin composition. In this specification, the above components may be referred to as component (A), component (B), component (C), component (D), etc., and other components may be abbreviated in the same manner. In this specification, the "resin component" refers to the above components (A) to (D), etc., and also includes other components that may be contained as necessary (e.g., components (E) and (G) to (H), etc.), but does not include the inorganic filler (F) that may be contained as necessary, which will be described later. In addition, the "solid content" refers to the non-volatile content excluding volatile substances such as water and solvent contained in the photosensitive resin composition, and indicates the components that remain without volatilization when the resin composition is dried, and also includes liquid, starch syrup, and wax-like substances at room temperature around 25°C.

[0015] Since the photosensitive resin composition of this embodiment is suitable for via formation by photolithography (also referred to as photovia formation), the present invention also provides a photosensitive resin composition for photovia formation. Furthermore, since the photosensitive resin composition of this embodiment is excellent in via resolution, adhesive strength with plated copper, and insulation reliability, and is useful as an interlayer insulating layer of a multilayer printed wiring board, the present invention also provides a photosensitive resin composition for an interlayer insulating layer. In this specification, the term "photosensitive resin composition" includes photosensitive resin compositions for photovia formation and photosensitive resin compositions for an interlayer insulating layer. The photosensitive resin composition of the present embodiment is useful as a negative photosensitive resin composition. Each component that the photosensitive resin composition may contain will be described in detail below.

[0016] <(A) Photopolymerizable compound having an ethylenically unsaturated group> The photosensitive resin composition of the present embodiment contains a photopolymerizable compound having an ethylenically unsaturated group as component (A). Component (A) is a compound having a functional group having an ethylenically unsaturated bond, such as a vinyl group, an allyl group, a propargyl group, a butenyl group, an ethynyl group, a phenylethynyl group, a maleimide group, a nadimide group, or a (meth)acryloyl group, as a functional group exhibiting photopolymerizability. As the functional group exhibiting photopolymerizability, a (meth)acryloyl group is preferred.

[0017] From the viewpoint of increasing the chemical resistance after curing (exposure) and increasing the difference in developer resistance between exposed and unexposed areas, the photopolymerizable compound having an ethylenically unsaturated group preferably contains at least one selected from the group consisting of (Ai) a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group, (Aii) a bifunctional vinyl monomer having two polymerizable ethylenically unsaturated groups, and (Aiii) a multifunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups, and more preferably contains the component (Aiii). The components (Ai) to (Aiii) preferably have a molecular weight of 1,000 or less.

[0018] ((Ai) Monofunctional vinyl monomer) Examples of the monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group include (meth)acrylic acid, (meth)acrylic acid alkyl esters, etc. Examples of the (meth)acrylic acid alkyl esters include (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid 2-ethylhexyl ester, (meth)acrylic acid hydroxyl ethyl ester, etc. The (Ai) component may be used alone or in combination of two or more.

[0019] ((Aii) Bifunctional vinyl monomer) Examples of the bifunctional vinyl monomer having two polymerizable ethylenically unsaturated groups include polyethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2-bis(4-(meth)acryloxypolyethoxypolypropoxyphenyl)propane, bisphenol A diglycidyl ether di(meth)acrylate, etc. The component (Aii) may be used alone or in combination of two or more.

[0020] ((Aiii) Multifunctional vinyl monomer) Examples of the polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups include (meth)acrylate compounds having a skeleton derived from trimethylolpropane, such as trimethylolpropane tri(meth)acrylate; (meth)acrylate compounds having a skeleton derived from tetramethylolmethane, such as tetramethylolmethane tri(meth)acrylate and tetramethylolmethane tetra(meth)acrylate; (meth)acrylate compounds having a skeleton derived from pentaerythritol, such as pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate; (meth)acrylate compounds having a skeleton derived from dipentaerythritol, such as dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate; (meth)acrylate compounds having a skeleton derived from ditrimethylolpropane, such as ditrimethylolpropane tetra(meth)acrylate; and (meth)acrylate compounds having a skeleton derived from diglycerin. Among these, from the viewpoint of increasing the chemical resistance after curing (exposure) and increasing the difference in developer resistance between the exposed and unexposed areas, a (meth)acrylate compound having a skeleton derived from dipentaerythritol is preferred, and dipentaerythritol penta(meth)acrylate is more preferred. The component (Aiii) may be used alone or in combination of two or more. Here, the "(meth)acrylate compound having a skeleton derived from XXX" (wherein XXX is the name of the compound) means an esterification product of XXX and (meth)acrylic acid, and the esterification product also includes a compound modified with an alkyleneoxy group.

[0021] ((A1) Photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent) In addition, the photopolymerizable compound having an ethylenically unsaturated group is preferably capable of alkaline development, and from the viewpoints of via resolution and adhesive strength with plated copper, the photopolymerizable compound (A1) also preferably contains an ethylenically unsaturated group and an acidic substituent. Examples of the acidic substituent include a carboxyl group, a sulfonic acid group, and a phenolic hydroxyl group, and among these, a carboxyl group is preferred. As the component (A1), an "(A1-1) acid-modified vinyl-group-containing epoxy derivative" can be used, which is obtained by reacting (a1) an epoxy resin modified with (a2) a vinyl-group-containing organic acid [hereinafter sometimes referred to as component (A')] with (a3) ​​a saturated or unsaturated group-containing polybasic acid anhydride, which is capable of alkaline development and, from the viewpoints of via resolution and adhesive strength with plated copper, is used.

[0022] -(a1) Epoxy resin- The (a1) 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.

[0023] Epoxy resins are also classified into various epoxy resins according to the difference in 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 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; biphenyl aralkyl type epoxy resins; stilbene type epoxy resins; dicyclopentadiene type epoxy resins; naphthalene skeleton-containing epoxy resins such as naphthalene type epoxy resins, naphthol 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; dicyclopentadiene type epoxy resins; alicyclic epoxy resins; aliphatic chain epoxy resins; and rubber-modified epoxy resins. Among these, from the viewpoint of reliability during semiconductor chip mounting, bisphenol-based novolac type epoxy resins are preferred, and bisphenol F novolac type epoxy resins are more preferred. (a1) The epoxy resins may be used alone or in combination of two or more.

[0024] The (a1) epoxy resin is also preferably an epoxy resin having a structural unit represented by the following general formula (I). [ka]

[0025] In general formula (I), R 1 represents a hydrogen atom or a methyl group, and Y 1 Each of R independently represents a hydrogen atom or a glycidyl group.1 may be the same or different. 1 At least one of these represents a glycidyl group. R 1 From the viewpoints of via resolution and adhesive strength with plated copper, it is preferable that Y 1 is preferably a glycidyl group. The number of structural units in the epoxy resin (a1) having a structural unit represented by general formula (I) is 1 or more, and is 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, the adhesive strength with plated copper, heat resistance, and insulation reliability tend to be improved. In the general formula (I), R 1 are all hydrogen atoms, and Y 1 The glycidyl group is available as EXA-7376 series (manufactured by DIC Corporation), and R 1 are all methyl groups, and Y 1 However, those having glycidyl groups are commercially available as the EPON SU8 series (product name, manufactured by Mitsubishi Chemical Corporation).

[0026] -(a2) Vinyl group-containing organic acid- The vinyl group-containing organic acid (a2) is not particularly limited, but is preferably a vinyl group-containing monocarboxylic acid. Examples of the vinyl group-containing monocarboxylic acid include acrylic acid, acrylic acid dimer, methacrylic acid, β-furfuryl acrylic acid, β-styryl acrylic acid, cinnamic acid, crotonic acid, α-cyano cinnamic acid and other acrylic acid derivatives; half ester compounds which are reaction products of hydroxyl group-containing acrylates and dibasic acid anhydrides; half ester compounds which are reaction products of vinyl group-containing monoglycidyl ethers or vinyl group-containing monoglycidyl esters and dibasic acid anhydrides; and the like.

[0027] The half ester compound can be obtained, for example, by reacting a hydroxyl group-containing acrylate, a vinyl group-containing monoglycidyl ether, or a vinyl group-containing monoglycidyl ester with a dibasic acid anhydride in an equimolar ratio. The component (a2) may be used alone or in combination of two or more kinds.

[0028] Examples of the hydroxyl group-containing acrylate, vinyl group-containing monoglycidyl ether, and vinyl group-containing monoglycidyl ester used in the synthesis of the half-ester compound, which is an example of the component (a2), include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol pentaacrylate, pentaerythritol pentamethacrylate, glycidyl acrylate, and glycidyl methacrylate.

[0029] The dibasic acid anhydride used in the synthesis of the half ester compound may contain a saturated group or an unsaturated group. 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.

[0030] In the reaction between the (a1) component and the (a2) component, the (a2) component is preferably reacted at a ratio of 0.6 to 1.05 equivalents per equivalent of the epoxy group of the (a1) component, or may be reacted at a ratio of 0.8 to 1.0 equivalents. By reacting at such a ratio, the photopolymerization property is improved, that is, the photosensitivity is increased, and the resolution of the via tends to be improved.

[0031] The component (a1) and the component (a2) can be reacted by dissolving them in an organic solvent. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers 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.

[0032] Furthermore, it is preferable to use a catalyst to promote the reaction between the (a1) component and the (a2) component. Examples of the catalyst include amine catalysts such as triethylamine and benzylmethylamine; quaternary ammonium salt catalysts such as methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide and benzyltrimethylammonium iodide; and phosphine catalysts such as triphenylphosphine. Among these, phosphine catalysts are preferred, and triphenylphosphine is more preferred. The amount of the catalyst 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, relative to 100 parts by mass of the total of the (a1) component and the (a2) component. The amount used above tends to promote the reaction between the (a1) component and the (a2) component.

[0033] In order to prevent polymerization during the reaction, it is preferable to use a polymerization inhibitor, such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol, etc. When a polymerization inhibitor is used, the amount thereof is preferably 0.01 to 1 part by mass, more preferably 0.02 to 0.8 parts by mass, and even more preferably 0.05 to 0.5 parts by mass, relative to 100 parts by mass of the total of the (a1) component and the (a2) component, from the viewpoint of improving the storage stability of the composition.

[0034] The reaction temperature between the component (a1) and the component (a2) is preferably 60 to 150°C, more preferably 80 to 120°C, and further preferably 90 to 110°C, from the viewpoint of productivity.

[0035] In this way, it is presumed that the (A') component obtained by reacting the (a1) component with the (a2) component has a hydroxyl group formed by a ring-opening addition reaction between the epoxy group of the (a1) component and the carboxyl group of the (a2) component.

[0036] -(a3) Polybasic acid anhydride- The (a3) ​​component may contain a saturated group or an unsaturated group. Examples of the (a3) ​​component 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.

[0037] It is presumed that by further reacting the above-obtained component (A') with the saturated or unsaturated group-containing component (a3), 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 to form an acid-modified vinyl group-containing epoxy derivative (A1-1).

[0038] In the reaction between the component (A') and the component (a3), for example, the acid value of the acid-modified vinyl group-containing epoxy derivative (A1-1) can be adjusted by reacting 0.1 to 1.0 equivalent of the component (a3) ​​with one equivalent of the hydroxyl group in the component (A'). The acid value of the acid-modified vinyl group-containing epoxy derivative (A1-1) is preferably 20 to 150 mgKOH / g, more preferably 30 to 120 mgKOH / g, and even more preferably 40 to 100 mgKOH / g. If the acid value is 20 mgKOH / g or more, the photosensitive resin composition tends to have excellent solubility in a dilute alkaline solution, and if it is 150 mgKOH / g or less, the electrical properties of the cured film tend to be improved.

[0039] The reaction temperature between the component (A') and the 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 productivity.

[0040] As the acid-modified vinyl group-containing epoxy derivative (A1-1), a commercially available product may be used. Examples of the commercially available product include CCR-1218H, CCR-1159H, CCR-1222H, PCR-1050, TCR-1335H, ZAR-1035, ZAR-2001H, UXE-3024, ZFR-1185, ZCR-1569H, ZXR-1807, ZCR-6000, ZCR-8000 (all of which are product names manufactured by Nippon Kayaku Co., Ltd.), UE-9000, UE-EXP-2810PM, and UE-EXP-3045 (all of which are product names manufactured by DIC Corporation).

[0041] As the (A1) component, a styrene-maleic acid resin (A1-2) such as a hydroxyethyl (meth)acrylate modified product of a styrene-maleic anhydride copolymer can be used. The (A1-2) can also be used in combination with the (A1-1) component. The (A1-2) component can be used alone or in combination of two or more.

[0042] As the component (A1), an epoxy polyurethane resin (A1-3) obtained by reacting the compound (A') obtained by modifying the epoxy resin (a1) with an organic acid containing a vinyl group (a2) with an isocyanate compound can also be used. The component (A1-3) may be used alone or in combination of two or more kinds.

[0043] ((A1) Molecular weight of photopolymerizable compound having an acidic substituent together with an ethylenically unsaturated group) The weight average molecular weight (Mw) of the component (A1) is preferably 1,000 to 30,000, more preferably 2,000 to 25,000, and even more preferably 3,000 to 18,000. Within this range, the adhesive strength with plated copper, heat resistance, and insulation reliability are improved. In particular, the weight average molecular weight (Mw) of the acid-modified vinyl group-containing epoxy derivative (A1-1) is preferably within the above range. Here, in this specification, the weight average molecular weight is a value measured by gel permeation chromatography (GPC) (manufactured by Tosoh Corporation) using a calibration curve of standard polystyrene, and more specifically, a value measured according to the method described below. <Method for measuring weight average molecular weight> The weight average molecular weight was measured using the following GPC measuring device and measuring conditions, and the value converted using the calibration curve of standard polystyrene was used as the weight average molecular weight. The calibration curve was created using a 5-sample set ("PStQuick MP-H" and "PStQuick B", manufactured by Tosoh Corporation) as standard polystyrene. (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 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

[0044] (Content of component (A)) The content of the component (A) is not particularly limited, but from the viewpoints of heat resistance, electrical properties, and chemical resistance, it is preferably 5 to 85 mass %, more preferably 20 to 80 mass %, and even more preferably 50 to 75 mass %, based on the total amount of the resin components in the photosensitive resin composition.

[0045] Although there is no particular limitation on the component (A), it is preferable to use the component (A1) and the component (Aiii) in combination from the viewpoint of photosensitive properties. In this case, the content ratio of the component (A1) to the component (Aiii) [(A1) / (Aiii)] (mass ratio) is preferably 2 to 20, more preferably 3 to 15, and even more preferably 4 to 12.

[0046] <(B) Photopolymerization initiator> The component (B) used in the present embodiment is not particularly limited as long as it can polymerize the component (A), and can be appropriately selected from commonly used photopolymerization initiators. Examples of the component (B) include benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; 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-methyl-1-[4-(methyl acetophenones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone; anthraquinones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, Thioxanthones such as xanthones; ketals such as acetophenone dimethyl ketal and benzil dimethyl ketal; benzophenones such as benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis(diethylamino)benzophenone, Michler's ketone, and 4-benzoyl-4'-methyldiphenyl sulfide; acridines such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; 2,4,6- Examples of the acylphosphine oxides include trimethylbenzoyldiphenylphosphine oxide; oxime esters 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]. Among these, acetophenones and thioxanthones are preferred, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2,4-diethylthioxanthones are more preferred. Acetophenones have the advantage of being less volatile and less likely to be generated as outgassing, and thioxanthones have the advantage of being photocurable even in the visible light range. The component (B) may be used alone or in combination of two or more. When using two or more in combination, it is preferable to use acetophenones and thioxanthones in combination, and it is more preferable to use 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone in combination with 2,4-diethylthioxanthone.

[0047] (B) Component Content The content of component (B) is not particularly limited, but is preferably 0.2 to 15 mass%, more preferably 0.4 to 5 mass%, and even more preferably 0.5 to 1.5 mass%, based on the total amount of resin components in the photosensitive resin composition. If the content of component (B) is 0.2 mass% or more, the risk of elution of exposed parts during development in the interlayer insulating layer formed using the photosensitive resin composition tends to be reduced, and if it is 15 mass% or less, heat resistance tends to be improved.

[0048] <(B') Photopolymerization initiator aid> The photosensitive resin composition of the present embodiment may contain a photopolymerization initiation aid (B') together with the above-mentioned component (B). Examples of the photopolymerization initiation aid (B') include tertiary amines such as N,N-dimethylaminobenzoic acid ethyl ester, N,N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine. The component (B') may be used alone or in combination of two or more. When the photosensitive resin composition of the present embodiment contains the component (B'), the content thereof is preferably 0.01 to 20 mass%, more preferably 0.2 to 5 mass%, and further preferably 0.3 to 2 mass%, based on the total amount of the resin components of the photosensitive resin composition. The photosensitive resin composition of the present embodiment does not necessarily need to contain the component (B').

[0049] <(C) Epoxy resin> Component (C) does not include anything that corresponds to component (A), and in that respect, it can be said that component (C) does not have an ethylenically unsaturated group. Furthermore, any substance that meets the above conditions and has an epoxy group is included in component (C). The (C) 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 according to the difference in 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 epoxy resins and bisphenol F-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; biphenyl aralkyl-type epoxy resins; stilbene-type epoxy resins; dicyclopentadiene-type epoxy resins; type epoxy resins; naphthalene skeleton-containing epoxy resins such as naphthalene type epoxy resins, naphthol 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; dicyclopentadiene type epoxy resins; alicyclic 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. The component (C) may be used alone or in combination of two or more types.

[0051] Among these, particularly from the viewpoints of heat resistance, insulation reliability, and adhesive strength with plated copper, bisphenol-based epoxy resins, naphthol-type epoxy resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, and naphthylene ether-type epoxy resins are preferred, bisphenol A-type epoxy resins and bisphenol F-type epoxy resins are more preferred, and bisphenol F-type epoxy resins are even more preferred. These may be commercially available products, and examples thereof include bisphenol A type epoxy resins ("jER828EL" and "YL980" manufactured by Mitsubishi Chemical Corporation), bisphenol F type epoxy resins ("jER806H" and "YL983U" manufactured by Mitsubishi Chemical Corporation), naphthalene type epoxy resins ("HP4032D" and "HP4710" manufactured by DIC Corporation), naphthalene skeleton-containing multifunctional epoxy resins ("NC7000" manufactured by Nippon Kayaku Co., Ltd.), naphthol type epoxy resins (Nippon Steel & Sumitomo Metal Corporation), and the like. Examples of epoxy resins that can be used include epoxy resins having a biphenyl structure ("NC3000H" and "NC3500" manufactured by Nippon Kayaku Co., Ltd.), "YX4000HK" and "YL6121" manufactured by Mitsubishi Chemical Corporation), anthracene-type epoxy resins ("YX8800" manufactured by Mitsubishi Chemical Corporation), glycerol-type epoxy resins ("ZX1542" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and naphthylene ether-type epoxy resins ("EXA7311-G4" manufactured by DIC Corporation).

[0052] As the epoxy resin (C), in addition to the above examples, epoxy-modified polybutadiene can be used. In particular, as the component (C), from the viewpoint of handling during the manufacture of printed wiring boards, it is preferable to use in combination an aromatic epoxy resin that is solid at room temperature and an epoxy resin that is liquid at room temperature, and from this viewpoint, it is preferable to use in combination the epoxy resin exemplified as a preferred one (aromatic epoxy resin that is solid at room temperature) and epoxy-modified polybutadiene (epoxy resin that is liquid at room temperature). In this case, the content ratio of the two used in combination (aromatic epoxy resin that is solid at room temperature / epoxy resin that is liquid at room temperature) is preferably 95 / 5 to 60 / 40, more preferably 90 / 10 to 70 / 30, by mass ratio.

[0053] The epoxy-modified polybutadiene preferably has hydroxyl groups at the molecular terminals, more preferably has hydroxyl groups at both molecular terminals, and even more preferably has hydroxyl groups only at both molecular terminals. The number of hydroxyl groups that the epoxy-modified polybutadiene has is not particularly limited as long as it is 1 or more, but is preferably 1 to 5, more preferably 1 or 2, and even more preferably 2. From the viewpoints of adhesive strength with plated copper, heat resistance, thermal expansion coefficient and flexibility, the epoxy-modified polybutadiene is preferably an epoxy-modified polybutadiene represented by the following general formula (C-1).

[0054] [ka] (In the above formula (C-1), a, b, and c each represent a ratio of the structural unit in 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 square brackets and is an integer of 10 to 250.)

[0055] In the general formula (C-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 with plated copper, heat resistance, thermal expansion coefficient, 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.

[0056] In the general formula (C-1), a=0.20, b=0.20, c=0.60, and y=an integer of 10 to 250, examples of commercially available epoxidized polybutadiene include "Epolead (registered trademark) PB3600" (manufactured by Daicel Corporation).

[0057] ((C) Component Content) The content of component (C) is not particularly limited, but is preferably 5 to 70 mass%, more preferably 5 to 40 mass%, further preferably 7 to 30 mass%, and particularly preferably 10 to 25 mass%, based on the total amount of resin components in the photosensitive resin composition. If the content of component (C) is 5 mass% or more, sufficient crosslinking of the photosensitive resin composition is obtained, and the adhesive strength with plated copper and the insulation reliability tend to be improved. On the other hand, if it is 70 mass% or less, the resolution of vias tends to be good.

[0058] <(D) Elastomer> The photosensitive resin composition of the present embodiment contains a predetermined amount of elastomer as component (D). This results in a photosensitive resin composition with excellent via resolution, adhesive strength with plated copper, and insulation reliability. In addition, component (D) has the effect of suppressing a decrease in flexibility and adhesive strength with plated copper caused by distortion (internal stress) inside the cured product due to cure shrinkage of component (A).

[0059] Examples of the elastomer include styrene-based elastomers, olefin-based elastomers, polyester-based elastomers, urethane-based elastomers, polyamide-based elastomers, acrylic-based elastomers, silicone-based elastomers, etc., and it is preferable to use at least one selected from these. These elastomers are composed of a hard segment component and a soft segment component, the former of which tends to contribute to heat resistance and strength, and the latter of which tends to contribute to flexibility and toughness. Among the above-listed components, component (D) preferably contains at least one selected from the group consisting of olefin-based elastomers, polyester-based elastomers, and urethane-based elastomers, more preferably contains a urethane-based elastomer, from the viewpoints of compatibility, solubility, and adhesive strength with plated copper. Also, component (D) is more preferably at least one selected from the group consisting of olefin-based elastomers, polyester-based elastomers, and urethane-based elastomers, and is particularly preferably a urethane-based elastomer.

[0060] (styrene elastomer) Examples of the styrene-based elastomer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-ethylene-propylene-styrene block copolymer. The styrene-based elastomer preferably has a number average molecular weight of 1,000 to 50,000, and more preferably 3,000 to 20,000. In this specification, the number average molecular weight is a value determined in terms of standard polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent.

[0061] Commercially available styrene-based elastomers may also be used. Examples of commercially available products include Tufprene, Solprene T, Asaprene T, and Tuftec (all manufactured by Asahi Kasei Corporation; "Tufprene", "Asaprene" and "Tuftec" are registered trademarks), Elastomer AR (manufactured by Aronkasei Co., Ltd.), Kraton G, and Kareflex (all manufactured by Shell Japan Co., Ltd.), JSR-TR, TSR-SIS, and Dynaron (all manufactured by JSR Corporation), Denka STR (manufactured by Denka Co., Ltd.), and Quinta. Examples of such rubbers include Quintac (manufactured by Zeon Corporation, "Quintac" is a registered trademark), TPE-SB series (manufactured by Sumitomo Chemical Co., Ltd.), Labaron (manufactured by Mitsubishi Chemical Corporation, "Labaron" is a registered trademark), Septon, Hybra (all manufactured by Kuraray Co., Ltd., "Septon" and "Hybra" are registered trademarks), Sumiflex (manufactured by Sumitomo Bakelite Co., Ltd.), Leostomer, and Actimer (all manufactured by RIKEN TECHNOS CORPORATION, "Leostomer" and "Actimer" are registered trademarks).

[0062] (Olefin elastomer) The olefin elastomer is, for example, a polymer or copolymer of an α-olefin having 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-pentene, etc. The olefin elastomer may have a hydroxyl group at the molecular end, and preferably has a hydroxyl group at the molecular end. Suitable examples of olefin elastomers include polyethylene, polybutadiene, hydroxyl-containing polybutadiene, hydroxyl-containing polyisopropylene, ethylene-propylene copolymer (EPR), ethylene-propylene-diene copolymer (EPDM), etc. Also included are copolymers of the above-mentioned α-olefins having 2 to 20 carbon atoms with non-conjugated dienes having 2 to 20 carbon atoms, such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylenenorbornene, ethylidenenorbornene, butadiene, isoprene, etc. Furthermore, carboxy-modified NBR obtained by copolymerizing butadiene-acrylonitrile copolymer with methacrylic acid, etc., can also be mentioned. The olefin-based elastomer preferably has a number average molecular weight of 1,000 to 5,000, and more preferably has a number average molecular weight of 1,500 to 3,500.

[0063] The olefin-based elastomer may be a commercially available product. Examples of commercially available products include Milastomer (manufactured by Mitsui Chemicals, Inc., product name), EXACT (manufactured by Exxon Mobil Corporation, product name), ENGAGE (manufactured by The Dow Chemical Company, product name), Poly ip, Poly bd (Idemitsu Kosan Co., Ltd., product name), hydrogenated styrene-butadiene rubber "DYNABON HSBR" (manufactured by JSR Corporation, product name), butadiene-acrylonitrile copolymer "NBR series" (manufactured by JSR Corporation, product name), butadiene-acrylonitrile copolymer modified with carboxyl groups at both ends "XER series" (manufactured by JSR Corporation, product name), and epoxylated polybutadiene BF-1000 (manufactured by Nippon Soda Co., Ltd., product name), PB-4700, and PB-3600 (manufactured by Daicel Corporation, product names) obtained by partially epoxy-modifying polybutadiene.

[0064] (Polyester elastomer) The polyester elastomer may be one obtained by polycondensing a dicarboxylic acid or a derivative thereof and a diol compound or a derivative thereof. Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; aromatic dicarboxylic acids in which hydrogen atoms in the aromatic ring of the aromatic dicarboxylic acid are substituted with methyl groups, ethyl groups, phenyl groups, and 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. As the dicarboxylic acid, it is also preferable to use a dimer acid derived from a natural product from the viewpoint of adhesion to a substrate. The dicarboxylic acid may be used alone or in combination of two or more kinds. Examples of the derivatives of the dicarboxylic acids include anhydrides of the dicarboxylic acids. Examples of the diol compound 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; etc. The diol compound may be used alone or in combination of two or more kinds. The polyester elastomer preferably has a number average molecular weight of 900 to 30,000, more preferably 1,000 to 25,000, and even more preferably 5,000 to 20,000.

[0065] As the polyester-based elastomer, commercially available products may be used, and examples of commercially available products include Hytrel (manufactured by Toray-DuPont Co., Ltd., "Hytrel" is a registered trademark), Pelprene (manufactured by Toyobo Co., Ltd., "Pelprene" is a registered trademark), Teslac 2505-63 (manufactured by Hitachi Chemical Co., Ltd., "Teslac" is a registered trademark), and Espel (manufactured by Hitachi Chemical Co., Ltd., "Espel" is a registered trademark).

[0066] (Urethane elastomer) Suitable examples of the urethane-based elastomer include those containing a hard segment made of a short-chain diol and a diisocyanate, and a soft segment made of a polymeric (long-chain) diol and a diisocyanate. Examples of the polymeric (long-chain) diol include polypropylene glycol, polytetramethylene oxide, poly(1,4-butylene adipate), poly(ethylene-1,4-butylene adipate), polycaprolactone, poly(1,6-hexylene carbonate), poly(1,6-hexylene-neopentylene adipate), etc. The number average molecular weight of the polymeric (long-chain) diol is preferably 500 to 10,000. Examples of the short-chain diol include ethylene glycol, propylene glycol, 1,4-butanediol, and bisphenol A. The number average molecular weight of the short-chain diol is preferably 48 to 500. The urethane-based elastomer preferably has a number average molecular weight of 1,000 to 25,000, more preferably 1,500 to 20,000, and even more preferably 2,000 to 15,000.

[0067] The urethane-based elastomer may be a commercially available product, and examples of commercially available products include Nipporan 3116 (manufactured by Tosoh Corporation, "Nipporan" is a registered trademark), PANDEX T-2185, T-2983N (all manufactured by DIC Corporation), the Miractoran series (manufactured by Nippon Miractoran Co., Ltd., "Miractran" is a registered trademark), and the Hitaloid series (manufactured by Hitachi Chemical Co., Ltd., "Hitaroid" is a registered trademark).

[0068] (Polyamide elastomer) Examples of the polyamide-based elastomer include block copolymers having polyamide as a hard segment component and polybutadiene, butadiene-acrylonitrile copolymer, styrene-butadiene copolymer, polyisoprene, ethylene propylene copolymer, polyether, polyester, polybutadiene, polycarbonate, polyacrylate, polymethacrylate, polyurethane, silicone rubber, or the like as a soft segment component. The polyamide elastomer preferably has a number average molecular weight of 1,000 to 50,000, and more preferably 2,000 to 30,000.

[0069] Commercially available polyamide elastomers may be used, and examples of commercially available products include UBE polyamide elastomers (manufactured by Ube Industries, Ltd.), DIAMID (manufactured by Daicel-Evonik Ltd., "DIAMID" is a registered trademark), PEBAX (manufactured by Toray Industries, Inc.), Grillon ELY (manufactured by MS-Chemie Japan, Inc., "Grillon" is a registered trademark), Novamid (manufactured by Mitsubishi Chemical Corporation), and Glylux (manufactured by Toyobo Co., Ltd., "Glylux" is a registered trademark).

[0070] (Acrylic elastomer) The acrylic elastomer may be, for example, a polymer of a raw material monomer mainly composed of an acrylic acid ester. Suitable examples of the acrylic acid ester include ethyl acrylate, butyl acrylate, methoxyethyl acrylate, and ethoxyethyl acrylate. The crosslinking point monomer may be a copolymer of glycidyl methacrylate, allyl glycidyl ether, or acrylonitrile, ethylene, or the like. Specific examples include acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, and acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer. The acrylic elastomer preferably has a number average molecular weight of 1,000 to 50,000, and more preferably 2,000 to 30,000.

[0071] (Silicone elastomer) The silicone elastomer is an elastomer containing organopolysiloxane as a main component, and is classified into, for example, polydimethylsiloxane elastomers, polymethylphenylsiloxane elastomers, polydiphenylsiloxane elastomers, and the like. The silicone elastomer preferably has a number average molecular weight of 1,000 to 50,000, and more preferably 2,000 to 30,000.

[0072] As the silicone elastomer, commercially available products may be used, and examples of commercially available products include the KE series (manufactured by Shin-Etsu Chemical Co., Ltd.), the SE series, the CY series, and the SH series (all manufactured by Dow Corning Toray Co., Ltd.).

[0073] (Other elastomers) Also preferred is an embodiment in which the component (D) contains at least one selected from the group consisting of polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyamideimide resin, polyimide resin, xylene resin, polyphenylene sulfide resin, polyetherimide resin, polyetheretherketone resin, polyetherimide resin, tetrafluoroethylene resin, polyacrylonitrile resin, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxy-modified polyacrylonitrile.

[0074] ((D) Component Content) The content of the (D) component in the photosensitive resin composition of this embodiment is 2 to 30 mass% based on the total amount of the resin components of the photosensitive resin composition, preferably 2 to 20 mass%, more preferably 3 to 15 mass%, further preferably 5 to 15 mass%, and particularly preferably 8 to 13 mass%. If the content of the (D) component is 0 mass%, the adhesive strength with plated copper is insufficient, and even if the (D) component is contained, if the content is less than 2 mass%, the effect of improving the adhesive strength with plated copper is insufficient and the insulation reliability is reduced. If the content of the (D) component exceeds 30 mass%, the resolution of the via, the adhesive strength with plated copper, and the insulation reliability are all insufficient.

[0075] <(E) Thermal polymerization initiator> The photosensitive resin composition of the present embodiment may contain, and preferably contains, a thermal polymerization initiator as the component (E). The thermal polymerization initiator is not particularly limited, and examples thereof include hydroperoxides such as diisopropylbenzene hydroperoxide "Percumyl P" (trade name, manufactured by NOF Corporation (hereinafter the same)), cumene hydroperoxide "Percumyl H", and t-butyl hydroperoxide "Perbutyl H"; α,α-bis(t-butylperoxy-m-isopropyl)benzene "Perbutyl P", dicumyl peroxide "Percumyl D", 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane "Perhexa 25B", t-butylcumyl peroxide "Perbutyl C", and di-t-butyl peroxide "Perbutyl D". peroxyketals such as n-butyl 4,4-di-(t-butylperoxy)valerate (Perhexa V); diacyl peroxides; peroxydicarbonates; organic peroxides such as peroxyesters; azo compounds such as 2,2'-azobisisobutylnitrile, 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile); and the like. Among these, from the viewpoint of not inhibiting photopolymerization and having a large effect of improving the physical properties and characteristics of the photosensitive resin composition, dialkyl peroxoside is preferred, and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3 is more preferred. The thermal polymerization initiator may be used alone or in combination of two or more kinds.

[0076] ((E) Component Content) When the photosensitive resin composition of the present embodiment contains the component (E), its content is not particularly limited, but is preferably 0.01 to 5 mass%, more preferably 0.02 to 3 mass%, and even more preferably 0.03 to 2 mass%, based on the total amount of the resin components of the photosensitive resin composition. If it is 0.01 mass% or more, the photosensitive properties tend to decrease, and if it is 5 mass% or less, the photosensitive properties and heat resistance tend to be good.

[0077] <(F) Inorganic filler> The photosensitive resin composition of the present embodiment may contain an inorganic filler as the component (F), and preferably contains an inorganic filler. By containing an inorganic filler, the thermal expansion can be reduced, and the risk of warping is reduced. In the thermosetting resin composition that has been conventionally used as an interlayer insulating layer of a multilayer printed wiring board, the thermal expansion has been reduced by containing an inorganic filler, but when an inorganic filler is contained in a photosensitive resin composition, the inorganic filler causes light scattering and becomes an obstacle to development, so it was difficult to contain a large amount of inorganic filler to achieve low thermal expansion. Thus, there is a new problem unique to photosensitive resin compositions when an inorganic filler is contained, but the photosensitive resin composition of the present embodiment has high via resolution even if a large amount of inorganic filler is contained. Therefore, it is possible to achieve high via resolution together with low thermal expansion.

[0078] Examples of the (F) component 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), spinel (MgO·Al2O3 ), 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, carbon (C), etc. (F) component may be used alone or in combination of two or more types.

[0079] From the viewpoint of via resolution, the average particle diameter of the (F) component is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, and even more preferably 0.05 to 2 μm. Here, the average particle diameter of the (F) component is the volume average particle diameter of the inorganic filler in a state dispersed in the photosensitive resin composition, and is a value obtained by measuring as follows. First, the photosensitive resin composition is diluted (or dissolved) 1,000 times with methyl ethyl ketone, and then the particles dispersed in the solvent are measured 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 ISO13321, and the particle diameter at an integrated value of 50% (volume basis) in the particle size distribution is taken as the average particle diameter (volume average particle diameter). In addition, the (F) component contained in the photosensitive resin film and the interlayer insulating layer provided on the carrier film can also be measured by diluting (or dissolving) it 1,000 times (volume ratio) using a solvent as described above, and then using the submicron particle analyzer.

[0080] The component (F) may contain silica from the viewpoints of heat resistance and low thermal expansion, barium sulfate from the viewpoints of heat resistance and adhesive strength with plated copper, or a combination of silica and barium sulfate. The component (F) may be surface-treated with alumina or an organic silane compound from the viewpoint of improving the dispersibility of the inorganic filler in the photosensitive resin composition by the aggregation prevention effect.

[0081] ((F) Component Content) When the photosensitive resin composition of the present embodiment contains the component (F), its content is not particularly limited, but is preferably 10 to 80 mass%, more preferably 12 to 70 mass%, further preferably 15 to 60 mass%, and particularly preferably 25 to 55 mass%, based on the total solid content of the photosensitive resin composition. If the content of the component (F) is within the above range, the mechanical strength, heat resistance, via resolution, etc. can be improved.

[0082] <(G) Pigment> The photosensitive resin composition of the present embodiment may contain a pigment as component (G) according to the desired color in order to adjust photosensitivity, etc. As the component (G), a colorant that develops the desired color may be appropriately selected and used, and preferred examples thereof include known colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black.

[0083] ((G) Component Content) When the photosensitive resin composition of the present embodiment contains the component (G), the content thereof is preferably 0.01 to 5 mass %, more preferably 0.03 to 3 mass %, and even more preferably 0.05 to 2 mass %, based on the total solid content of the photosensitive resin composition, from the viewpoint of adjusting photosensitivity, etc.

[0084] <(H) Epoxy resin hardener> The photosensitive resin composition of the present embodiment may contain an epoxy resin curing agent from the viewpoint of further improving various properties such as heat resistance, adhesive strength with plated copper, and chemical resistance. Examples of the component (H) include imidazole derivatives such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; guanamines such as acetoguanamine and benzoguanamine; polyamines such as diaminodiphenylmethane, m-phenylenediamine, m-xylylenediamine, 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; trimethylamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa(N-methyl) tertiary amines such as m-aminophenol, 2,4,6-tris(dimethylaminophenol), tetramethylguanidine, and m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolac, and alkylphenol novolac; 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; diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and 2,4,6-triphenylthiopyrylium hexafluorophosphate. Among these, from the viewpoint of further improving various properties such as heat resistance, adhesive strength to plated copper, and chemical resistance, polyamines are preferred, and melamine is more preferred. When the photosensitive resin composition of the present embodiment contains the component (H), the content thereof is preferably 0.01 to 10 mass %, more preferably 0.02 to 5 mass %, and even more preferably 0.03 to 3 mass %, based on the total amount of the resin components in the photosensitive resin composition.

[0085] <Diluent> A diluent can be used in the photosensitive resin composition of the present embodiment as necessary. As the diluent, for example, an organic solvent can be used. As the organic solvent, for example, ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers 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; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha can be used. The diluent may be used alone or in combination of two or more.

[0086] (Diluent content) The content of the diluent may be appropriately selected so that the concentration of the total solid content in the photosensitive resin composition is preferably 50 to 90 mass%, more preferably 60 to 80 mass%, and further preferably 65 to 75 mass%. By adjusting the amount of the diluent used in this manner, the coatability of the photosensitive resin composition is improved, and a more precise pattern can be formed.

[0087] <Other additives> The photosensitive resin composition of the present embodiment may contain various known and commonly used additives, such as polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol, thickeners such as bentone and montmorillonite, antifoaming agents such as silicone-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents, and silane coupling agents, as required.Furthermore, flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, phosphate compounds of antimony compounds and phosphorus-based compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters may be contained.

[0088] The photosensitive resin composition of the present 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, dip coating, etc. Among these, from the viewpoint of more easily forming the photosensitive layer, the printing method or spin coating method may be appropriately selected. When used in the form of a film, it can be used in the form of a photosensitive resin film described later, for example, 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 using it in the form of a film is preferable because it increases the production efficiency of multilayer printed wiring boards.

[0089] [Photosensitive resin film, photosensitive resin film for interlayer insulation layer] The photosensitive resin film of the present embodiment is a photosensitive layer that will later become an interlayer insulating layer, and is made of the photosensitive resin composition of the present embodiment. The photosensitive resin film may be provided on a carrier film. The thickness (thickness after drying) of the photosensitive resin film (photosensitive layer) is not particularly limited, but from the viewpoint of making the multilayer printed wiring board thinner, it is preferably 1 to 100 μm, more preferably 1 to 50 μm, and even more preferably 5 to 40 μm.

[0090] The photosensitive resin film of the present embodiment can be obtained, 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 drying the composition to form a photosensitive layer that will later become an interlayer insulating layer. Examples of the carrier film include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyolefins such as polypropylene and polyethylene, etc. The thickness of the carrier film may be appropriately selected from the range of 5 to 100 μm, preferably 5 to 60 μm, and more preferably 15 to 45 μm.

[0091] In addition, the photosensitive resin film of this embodiment may have a protective film on the surface of the photosensitive layer opposite to the surface in contact with the carrier film. As the protective film, for example, a polymer film such as polyethylene or polypropylene may be used. In addition, the same polymer film as the carrier film described above may be used, or a different polymer film may be used.

[0092] The coating film formed by applying the photosensitive resin composition can be dried using a dryer using hot air drying, far infrared rays, 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 in the manufacturing process of a multilayer printed wiring board.

[0093] The photosensitive resin film of the present embodiment is suitable as an interlayer insulating layer of a multilayer printed wiring board because it has excellent via resolution, adhesive strength with plated copper, and insulation reliability. That is, the present invention also provides a photosensitive resin film for an interlayer insulating layer. The photosensitive resin film for an interlayer insulating layer can also be called an interlayer insulating photosensitive film.

[0094] [Multilayer printed wiring board and its manufacturing method] The present invention also provides a multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin composition or photosensitive resin film of the present embodiment. Hereinafter, as an example of a preferred embodiment of a method for manufacturing a multilayer printed wiring board, a method for manufacturing a multilayer printed wiring board using the photosensitive resin film of this embodiment (photosensitive resin film for interlayer insulating layer) will be described with reference to FIG. 1 as appropriate. Multilayer printed wiring board 100A can be manufactured, for example, by a manufacturing method including the following steps (1) to (4). Step (1): A step of laminating the photosensitive resin film of the present embodiment onto one or both sides of a circuit board (hereinafter referred to as lamination step (1)). Step (2): A step of 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)). Step (3): A step of roughening the vias and the interlayer insulating layer (hereinafter referred to as roughening step (3)). Step (4): A step of forming a circuit pattern on the interlayer insulating layer (hereinafter referred to as circuit pattern forming step (4)).

[0095] (Lamination process (1)) The lamination 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 a circuit pattern 102) using a vacuum laminator. Examples of the vacuum laminator include a vacuum applicator manufactured by Nichigo-Morton Co., Ltd., a vacuum pressure laminator manufactured by Meiki Co., Ltd., a roll-type dry coater manufactured by Hitachi, Ltd., and a vacuum laminator manufactured by Hitachi Chemical Electronics Co., Ltd.

[0096] When a protective film is provided on the photosensitive resin film, after peeling or removing the protective film, the photosensitive resin film can be laminated by being pressed and heated onto the circuit board so that the photosensitive resin film is 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, under reduced pressure at a pressure bonding temperature of 70 to 130°C, a pressure bonding pressure of 0.1 to 1.0 MPa, and an air 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 (hereinafter sometimes referred to as the photosensitive layer) laminated to the circuit board is cooled to about room temperature to form the interlayer insulating layer 103. The carrier film may be peeled off at this point, or may be peeled off after exposure as described below.

[0097] (Photovia formation process (2)) In the photovia forming process (2), at least a part of the photosensitive resin film laminated to the circuit board is exposed to light, and then developed. The exposed part is photocured to form a pattern. There is no particular limitation on the exposure method, and for example, a method of irradiating an image-wise pattern of active light through a negative or positive mask pattern called artwork (mask exposure method) may be adopted, or a method of irradiating an image-wise pattern of active light by a direct writing exposure method such as LDI (Laser Direct Imaging) exposure method or DLP (Digital Light Processing) exposure method may be adopted. Known light sources can be used as the light source of the actinic rays. Specific examples of light sources include gas lasers such as carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, and argon lasers; solid-state lasers such as YAG lasers; and those that effectively emit ultraviolet or visible light such as semiconductor lasers. The exposure dose is appropriately selected depending on the light source used and the thickness of the photosensitive layer, and for example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, the exposure dose is usually 10 to 1,000 J / m for a photosensitive layer with a thickness of 1 to 100 μm. 2 The preferred range is 15 to 500 J / m 2 is more preferred.

[0098] In the development, the uncured portions of the photosensitive layer are removed from the substrate, and an interlayer insulating layer made of a photocured product is formed on the substrate. When a carrier film is present on the photosensitive layer, the carrier film is removed before removing (developing) the unexposed portion. The developing method includes wet development and dry development, either of which may be adopted, but wet development is widely used and can be adopted in this embodiment as well. In the case of wet development, a developer corresponding to the photosensitive resin composition is used to develop the photosensitive resin composition by a known development method. Examples of the development method include a dip method, a bath method, a spray method, a brushing method, a slapping method, a scraping method, a swing immersion method, and the like. Among these, from the viewpoint of improving the resolution, the spray method is preferred, and among the spray methods, the high pressure spray method is more preferred. The development may be performed by one method, or may be performed by combining two or more methods. The composition of the developer is appropriately selected depending on the composition of the photosensitive resin composition. For example, an alkaline aqueous solution, a water-based developer, or an organic solvent-based developer may be used, and among these, an alkaline aqueous solution is preferred.

[0099] 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 ) and post-thermal cure at a temperature of about 60 to 250°C (preferably 120 to 200°C) as necessary to further harden the interlayer insulating layer, and this is also preferable. 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 the cross-sectional shape include a rectangle and an inverted trapezoid (where the upper side is longer than the lower side), and examples of the shape as viewed from the front (the direction in which the via bottom is visible) include a circle and a rectangle. In the formation of vias by photolithography in this embodiment, a via having a cross-sectional shape of an inverted trapezoid (where the upper side is longer than the lower side) can be formed, which is preferable because it increases the adhesion of plated copper to the via wall surface.

[0100] The size (diameter) of the via formed by this process can be less than 40 μm, and can also be 35 μm or less or 30 μm or less, which is smaller than the size of the via produced 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 necessarily limited to less than 40 μm, and can be selected arbitrarily within the range of, for example, 15 to 300 μm.

[0101] (Roughening treatment step (3)) In the roughening process (3), the surface of the via and the interlayer insulating layer is roughened with a roughening liquid. If a smear occurs in the photovia forming process (2), the smear may be removed with the roughening liquid. The roughening process and the removal of the smear 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.

[0102] (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, it is preferable to form the circuit pattern by a semi-additive process, which forms the circuit pattern and also provides electrical continuity of the vias. In the semi-additive process, first, the via bottom, via wall surface, and the entire surface of the interlayer insulating layer after the roughening treatment step (3) are subjected to electroless copper plating treatment using a palladium catalyst or the like to form a seed layer 105. The seed layer is for forming a power supply layer for electrolytic copper plating, and is preferably formed to a thickness of about 0.1 to 2.0 μm. If the seed layer is 0.1 μm or more thick, there is a tendency to suppress a decrease in connection reliability during electrolytic copper plating, and if it is 2.0 μm or less, there is no need to increase the amount of etching when flash etching the seed layer between wirings, and damage to wiring during etching tends to be suppressed.

[0103] The electroless copper plating process is carried out by reacting copper ions with a reducing agent to deposit metallic copper on the surface of the vias and the interlayer insulating layer. The electroless plating method and the electrolytic plating method may be known methods and are not particularly limited, but the catalyst in the electroless plating step is preferably a palladium-tin mixed catalyst, and the primary particle size of the catalyst is preferably 10 nm or less. In addition, the plating composition in the electroless plating step preferably contains hypophosphorous acid as a reducing agent. Commercially available electroless copper plating solutions can be used, and examples of such commercially available solutions include "MSK-DK" manufactured by Atotech Japan Co., Ltd. and "ThruCup (registered trademark) PEA ver. 4" series manufactured by Uemura Kogyo Co., Ltd.

[0104] After the electroless copper plating process, a dry film resist is heat-pressed 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 viewpoint, a dry film resist having a thickness of 5 to 30 μm is preferred. As the dry film resist, the "Photec" series manufactured by Hitachi Chemical Co., Ltd., or the like is used. After the dry film resist is thermocompression bonded, the dry film resist is exposed to light, for example, through a mask on which a desired wiring pattern is drawn. The exposure can be performed using the same device and light source as those that can be used when forming vias in the photosensitive resin film. After the exposure, the carrier film on the dry film resist is peeled off, and development is performed using an alkaline aqueous solution to remove the unexposed parts, forming 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 performed to form a copper circuit layer 107 and fill vias.

[0105] After the copper electroplating, the dry film resist is stripped off using an alkaline aqueous solution or an amine-based stripper. After the dry film resist is stripped off, 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. Specific examples include "SAC" manufactured by JCU Corporation and "CPE-800" manufactured by Mitsubishi Gas Chemical Company, Inc. After flash etching, palladium and the like attached to the portions between the wirings is removed as necessary. Palladium can be removed preferably using an acidic solution such as nitric acid or hydrochloric acid.

[0106] After the dry film resist is peeled off or after the flash etching step, a post-baking process is preferably performed. The post-baking process sufficiently heat-cures unreacted thermosetting components, thereby improving the insulation reliability, curing characteristics, and adhesive strength with plated copper. Although the heat-curing conditions vary depending on the type of resin composition, etc., it is preferable that the curing temperature is 150 to 240°C and the curing time is 15 to 100 minutes. The post-baking process completes a series of steps for manufacturing a printed wiring board using the photovia method, but this process is repeated depending on the number of interlayer insulating layers required to manufacture a board. Then, a solder resist layer 108 is preferably formed on the outermost layer.

[0107] The method for producing a multilayer printed wiring board in which vias are formed using the photosensitive resin composition of this embodiment has been described above, but since the photosensitive resin composition of this embodiment has excellent pattern resolution, it is also suitable for forming cavities for incorporating chips, passive elements, etc. The cavities can be suitably formed, for example, by selecting a drawing pattern that can form a desired cavity when forming a pattern by exposing the photosensitive resin film in the above description of the multilayer printed wiring board.

[0108] [Semiconductor package] The present invention also provides a semiconductor package comprising a semiconductor element mounted on the multilayer printed wiring board of the present embodiment. 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 invention and sealing the semiconductor element with a sealing resin or the like. EXAMPLES

[0109] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The properties of the photosensitive resin compositions obtained in the respective examples were evaluated by the methods described below.

[0110] [1. Evaluation of via resolution] (1) Preparation of laminate for evaluation The copper foil surface of a printed wiring board substrate (manufactured by Hitachi Chemical Co., Ltd., product name "MCL-E-679") in which a 12 μm thick copper foil was laminated on a glass epoxy base material was treated with a roughening pretreatment liquid (manufactured by MEC Co., Ltd., product name "CZ-8100"), and then washed with water and dried to obtain a roughening pretreated printed wiring board substrate. Next, the protective film was peeled off and removed from the carrier film and the photosensitive resin film with the protective film produced in each Example and Comparative Example, and the exposed photosensitive resin film was placed so as to abut against the copper foil of the roughening pretreated printed wiring board substrate, and then a lamination process was performed using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500"). The lamination conditions were a press hot plate temperature of 70° C., a vacuum drawing time of 20 seconds, a lamination press time of 30 seconds, an atmospheric pressure of 4 kPa or less, and a pressure of 0.4 MPa. After lamination, the product was left to stand at room temperature for at least 1 hour to obtain a laminate for evaluation in which a photosensitive resin film and a carrier film were laminated in this order on the copper foil surface of the substrate for printed wiring board. (2) Sensitivity measurement of photosensitive resin film After peeling and removing the carrier film from the laminate for evaluation obtained above, a 41-step tablet was placed on it and exposed using a direct imaging exposure device "DXP-3512" (Oak Manufacturing Co., Ltd.) with an ultra-high pressure mercury lamp as the light source. The exposure pattern used was a pattern in which dots were arranged in a lattice (dot diameter: distance between dot centers = 1:2). The dot diameter was changed in 5 μm increments within the range of φ30 to 100 μm. After exposure, the film was left to stand at room temperature for 30 minutes, and then the unexposed portion of the photosensitive resin composition was spray-developed for 60 seconds using a 1% by mass aqueous solution of sodium carbonate at 30° C. After development, the amount of exposure energy at which the gloss remaining step number of the 41-step tablet was 8.0 was determined as the sensitivity of the photosensitive resin film (unit: mJ / cm 2 Using the pattern exposed at this sensitivity, the resolution of the vias provided in the photosensitive resin film was evaluated according to the following evaluation criteria. (3) Evaluation of resolution Resolution was evaluated by exposing the photosensitive resin film to an exposure energy amount that gave a sensitivity of 8.0 steps, measured in (2) above, and then spray developing. The via pattern was observed using an optical microscope and evaluated according to the following criteria. The "open" state above refers to the state in which the copper foil of the printed wiring board substrate can be confirmed when observing the via portion of the dot pattern using an optical microscope. A rating of "A", where the via is open, indicates good characteristics. A: The φ60 μm via part of the dot pattern is open. C: The φ60 μm via part of the dot pattern is not open.

[0111] [2. Evaluation of adhesive strength (peel strength) with plated copper] (1) Preparation of laminate for evaluation and measurement of sensitivity of photosensitive resin film The same procedures as in (1) and (2) of [1. Evaluation of via resolution] above were carried out, except that the exposure machine used in the procedures (1) and (2) was changed to a parallel light exposure machine using an ultra-high pressure mercury lamp as the light source (manufactured by ORC Manufacturing Co., Ltd., product name "EXM-1201"). The amount of exposure energy at which the gloss remaining step number was 8.0 was determined, and this was used as the sensitivity of the photosensitive resin film (unit: mJ / cm 2 ) was decided. (2) Exposure process and development process Next, the carrier film of the evaluation laminate was peeled off and the surface of the exposed photosensitive resin film was exposed to light with the amount of exposure energy determined above, and the photosensitive resin film was cured to form an insulating layer. After leaving the film at room temperature for 30 minutes after exposure, the film was spray-developed with a 1% by mass aqueous solution of sodium carbonate at 30°C for 60 seconds. (3) Post-cure treatment Next, a UV conveyor device with high-pressure mercury lamp irradiation type (manufactured by Oak Manufacturing Co., Ltd.) was used, with an exposure dose of 2 J / cm 2 Then, a post-UV cure was performed at a conveyor speed of 1000 rpm, and a post-thermal cure was performed at 170° C. for 1 hour using a hot air circulation dryer (manufactured by Futaba Scientific Co., Ltd.). (4) Roughening treatment The evaluation laminate after the post-cure treatment was treated with a swelling liquid "Swelling Dip Securigant P" at 70° C. for 5 minutes, then with a roughening liquid "Dosing Securigant P500J" at 70° C. for 10 minutes, and further with a neutralizing liquid "Reduction Conditioner Securigant P500" at 40° C. for 5 minutes to perform a roughening treatment. The swelling liquid, roughening liquid, and neutralizing liquid used were all manufactured by Atotech Japan Co., Ltd. (5) Plating The evaluation laminate after the roughening treatment was subjected to electroless plating treatment at 30° C. for 20 minutes using an electroless plating solution "Prigant MSK-DK" (manufactured by Atotech Japan Co., Ltd.), and then electroplating treatment was performed at 24° C. and 2 A / dm using an electroplating solution "Cupracid HL" (manufactured by Atotech Japan Co., Ltd.). 2The plating was performed for 1 hour at 40° C. to form a plated copper layer on the insulating layer, and an evaluation board for measuring the adhesive strength with the plated copper was prepared. The thickness of the plated copper formed by the plating process was 25 μm. (6) Measurement of adhesive strength (peel strength) with plated copper The adhesive strength to plated copper was measured in accordance with JIS C6481 (1996) by measuring the vertical peel strength at 23° C. Adhesive strength to plated copper of 0.40 kN / m or more was judged to be good.

[0112] [3. Evaluation of insulation reliability (HAST resistance)] A printed wiring board substrate (Hitachi Chemical Co., Ltd., product name: MCL-E-700G(R)) consisting of 3 μm-thick copper foil laminated onto a glass epoxy base material was used to fabricate a comb-shaped electrode with a line / space of 12 μm / 12 μm using the MSAP (Modified Semi-Additive Process) method, and this was used as the evaluation substrate. An interlayer insulating layer was formed on the comb-shaped electrodes of this evaluation board using a photosensitive resin film in the same manner as in [1. Evaluation of via resolution] above, and then plated copper was formed in the same manner as in [2. Evaluation of adhesive strength (peel strength) with plated copper] above. Then, an electrode with a diameter of 6 mm was formed by etching. Next, it was exposed to conditions of 130°C, 85% RH, and 6 V for 200 hours. The resistance value between the electrodes was measured, and it was found that the resistance value was 10 -6 The time when the resistance became Ω or less was defined as the occurrence time of copper migration, and the insulation reliability (HAST resistance) between layers was evaluated according to the following evaluation criteria. A: No copper migration occurred even after 200 hours. B: The time for which copper migration occurred was 100 hours or more but less than 200 hours. C: Copper migration occurred for less than 100 hours.

[0113] <Synthesis Example 1> (A1-1) Synthesis of acid-modified vinyl group-containing epoxy derivative Bisphenol F novolac epoxy resin [wherein, in the above general formula (I), Y 1 is a glycidyl group, R 1A bisphenol F novolac epoxy resin containing a structural unit in which R is a hydrogen atom, 350 parts by mass of [corresponding to component (a1)], 70 parts by mass of acrylic acid [corresponding to component (a2)], 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate were charged and reacted by heating to 90°C and stirring, until the mixture was completely dissolved. Next, the obtained solution was cooled to 60° C., 2 parts by mass of triphenylphosphine was added, and the solution was heated to 100° C. and reacted until the acid value of the solution reached 1 mgKOH / g. To the solution after the reaction, 98 parts by mass of tetrahydrophthalic anhydride [corresponding to component (a3)] and 85 parts by mass of carbitol acetate were added, and the solution was heated to 80° C. and reacted for 6 hours. Thereafter, the mixture was cooled to room temperature to obtain an acid-modified bisphenol F novolac epoxy acrylate (corresponding to component (A1-1)) having a solid content of 73 mass %.

[0114] <Examples 1 to 3 and Comparative Examples 1 to 5> (Preparation of Photosensitive Resin Composition) Photosensitive resin compositions were prepared by mixing the components according to the composition shown in Table 1 using a three-roll mill. In each example, carbitol acetate was added as needed to adjust the concentration, and a photosensitive resin composition with a solid content of 60% by mass was obtained. (Preparation of photosensitive resin film) A polyethylene terephthalate film (G2-16, Teijin Limited, product name) having a thickness of 25 μm was used as a carrier film, and the photosensitive resin composition prepared in each example was applied onto the carrier film so that the film thickness after drying was 25 μm, and dried at 100° C. for 10 minutes using a hot air convection dryer to form a photosensitive resin film (photosensitive layer). Next, a biaxially oriented polypropylene film (MA-411, Oji F-Tex Co., Ltd., product name) was laminated as a protective film on the surface of the photosensitive resin film (photosensitive layer) opposite to the side in contact with the carrier film, to produce a photosensitive resin film in which the carrier film and the protective film were laminated together. The photosensitive resin film thus produced was subjected to the evaluations according to the above-mentioned methods. The results are shown in Table 1.

[0115] [Table 1]

[0116] The components used in each example are as follows: (A) component; Acid-modified bisphenol F novolac type epoxy acrylate: The acid-modified vinyl group-containing epoxy derivative obtained in Synthesis Example 1 [corresponding to component (A1-1)] was used. Dipentaerythritol pentaacrylate [equivalent to component (Aiii)] (B) Ingredients; Photopolymerization initiator 1: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, acetophenones Photopolymerization initiator 2: 2,4-diethylthioxanthone, thioxanthones (C) Component; Bisphenol F epoxy resin Epoxidized polybutadiene: "PB3600" (product name, manufactured by Daicel Chemical Industries, Ltd.) (D) Component; Polyurethane: "Nippolan (registered trademark) 3116" (product name, manufactured by Tosoh Corporation) Hydroxyl-containing polyisopropylene: "Poly IP" (product name, manufactured by Idemitsu Kosan Co., Ltd.) Polyester: "Teslac (registered trademark) 2505-63" (product name, manufactured by Hitachi Chemical Co., Ltd.) (F) component; Silica: Silica slurry with a solid content of 70% by mass (manufactured by Admatechs, average particle size 0.5 μm, dispersion medium: methyl ethyl ketone)

[0117] From Table 1, it can be seen that the examples had excellent via resolution, adhesive strength with plated copper, and insulation reliability. On the other hand, in Comparative Example 1, in which component (D) was not included, adhesive strength with plated copper was insufficient. Moreover, in Comparative Examples 2 to 4 (compared to Examples 1 to 3, respectively), in which component (D) was included but its content was insufficient, the effect of improving adhesive strength with plated copper was small and the insulation reliability was reduced, and it was found that the incorporation of a small amount was counterproductive. Furthermore, in Comparative Example 5, in which the content of component (D) was excessive, all of the via resolution, adhesive strength with plated copper, and insulation reliability were deteriorated, and it was found that the incorporation of an excessive amount was counterproductive. [Explanation of symbols]

[0118] 100A Multilayer Printed Wiring Board 102 Circuit Pattern 103 Interlayer insulation layer 104 Beer (Beer Hall) 105 Seed Layer 106 Resist Pattern 107 Copper circuit layer 108 Solder resist layer

Claims

1. A photosensitive resin composition comprising (A) a photopolymerizable compound having an ethylenically unsaturated group, (B) a photopolymerization initiator, (C) an epoxy resin, and (D) an elastomer, the (A) photopolymerizable compound having an ethylenically unsaturated group comprises (A1) a photopolymerizable compound having an ethylenically unsaturated group and an acidic substituent and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups, and the content ratio of the component (A1) to the component (Aiii) [(A1) / (Aiii)] (mass ratio) is 4 to 20; The component (A1) is (A1-1) an acid-modified vinyl group-containing epoxy derivative obtained by reacting (a1) an epoxy resin modified with (a2) a vinyl group-containing organic acid with (a3) a saturated or unsaturated group-containing polybasic acid anhydride, the (D) elastomer includes at least one selected from the group consisting of polyester-based elastomers, urethane-based elastomers, and hydroxyl group-containing polyisopropylene; A photosensitive resin composition, wherein the content of the (D) elastomer is 10.8 to 30 mass% based on the total amount of resin components of the photosensitive resin composition.

2. 2. The photosensitive resin composition according to claim 1, wherein the elastomer (D) comprises at least one selected from the group consisting of urethane elastomers and hydroxyl group-containing polyisopropylenes.

3. 3. The photosensitive resin composition according to claim 1, wherein the photopolymerizable compound (A) having an ethylenically unsaturated group comprises at least one selected from the group consisting of (Ai) a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group and (Aii) a bifunctional vinyl monomer having two polymerizable ethylenically unsaturated groups.

4. A photosensitive resin composition for forming a photovia hole, comprising the photosensitive resin composition according to any one of claims 1 to 3.

5. A photosensitive resin composition for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of claims 1 to 3.

6. A photosensitive resin film comprising the photosensitive resin composition according to any one of claims 1 to 3.

7. A photosensitive resin film for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of claims 1 to 3.

8. A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin composition according to any one of claims 1 to 3.

9. A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin film according to claim 6.

10. A semiconductor package comprising the multilayer printed wiring board according to claim 8 or 9 mounted with a semiconductor element.

11. A method for producing a multilayer printed wiring board, comprising the following steps (1) to (4): Step (1): A step of laminating the photosensitive resin film according to claim 6 onto one or both surfaces of a circuit board. Step (2): A step of forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in step (1). Step (3): A step of roughening the via and the interlayer insulating layer. Step (4): forming a circuit pattern on the interlayer insulating layer.

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