Photosensitive resin composition, photosensitive resin film, multilayer printed circuit board and semiconductor package, and method for manufacturing a multilayer printed circuit 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] This disclosure relates to a photosensitive resin composition, a photosensitive resin film, a multilayer printed circuit board and a semiconductor package, and a method for manufacturing a multilayer printed circuit board. [Background technology]

[0002] In recent years, electronic devices have become smaller and more high-performance, and multilayer printed circuit boards are becoming denser due to an increase in the number of circuit layers and miniaturization of 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 remarkably. In addition to miniaturization of wiring, there is a demand for thinner insulating films and further reduction in the diameter of vias (also called via holes) used for interlayer connections.

[0003] A conventional method for manufacturing printed circuit boards is the build-up method (see, for example, Patent Document 1), in which interlayer insulating layers and conductive circuit layers are sequentially laminated to form a multilayer printed circuit board. In multilayer printed circuit boards, with the miniaturization of circuits, the semi-additive method, in which circuits are formed by plating, has become the mainstream. In conventional semi-additive manufacturing methods, for example, (1) a thermosetting resin film is laminated onto a conductor circuit, and the thermosetting resin film is cured by heating to form an "interlayer insulating layer." (2) Next, vias for interlayer connection are formed by laser processing, and desmear treatment and roughening treatment are performed by alkaline permanganate treatment, etc. (3) After that, electroless copper plating is applied to the substrate, a pattern is formed using a resist, and then electrolytic copper plating is performed to form a copper circuit layer. (4) Subsequently, the resist is peeled off, and the copper circuit is formed by flash etching of the electroless layer.

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

[0005] Under these circumstances, a method has been proposed for forming multiple small-diameter vias simultaneously by photolithography using 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, wherein the content of the inorganic filler (D) is 10 to 80% by mass (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] Japanese Patent Publication No. 2017-116652 [Overview of the project] [Problems that the invention aims to solve]

[0007] Patent Document 2 addresses the issue of suppressing the decrease in adhesion strength with plated copper caused by using a photosensitive resin composition instead of a conventional thermosetting resin composition as the material for the interlayer insulating layer or surface protective layer. It also addresses the issues of via resolution and adhesion to silicon substrates and chip components, and claims to have solved these problems. However, there is still room for further improvement in terms of via resolution, adhesion strength with plated copper, and insulation reliability. Similarly, it is conceivable to repurpose conventional solder resist materials such as photosensitive resin compositions as interlayer insulating layers. However, interlayer insulating layers require properties that are not necessary for solder resists (for example, interlayer insulation reliability, adhesion strength to plated copper, high heat resistance to withstand multiple heating cycles, and high dimensional accuracy of via shapes). Therefore, it is difficult to predict whether they will be suitable for practical use as interlayer insulating layers, and they cannot be easily repurposed.

[0008] Therefore, the object of the present invention is to provide a photosensitive resin composition, a photosensitive resin composition for forming photovias, and a photosensitive resin composition for interlayer insulating layers that are excellent in via resolution, adhesion strength to plated copper, and insulation reliability. Furthermore, the object of the present invention is to provide a photosensitive resin film and a photosensitive resin film for interlayer insulating layers made from the photosensitive resin composition, to provide a multilayer printed circuit board and a semiconductor package, and to provide a method for manufacturing the multilayer printed circuit board. [Means for solving the problem]

[0009] As a result of diligent research to solve the aforementioned problems, the present inventors have found that the aforementioned problems can be solved by providing a photosensitive resin composition containing components (A) to (D) described below, wherein the content of component (D) is set to a specific amount. In other words, 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 in which the content of the (D) elastomer is 2 to 30% by mass based on the total amount of resin components of the photosensitive resin composition. [2] The photosensitive resin composition according to [1] above, wherein the (D) elastomer comprises at least one selected from the group consisting of styrene elastomers, olefin elastomers, polyester elastomers, urethane elastomers, polyamide elastomers, acrylic elastomers, and silicone elastomers. [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, polyamide-imide 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 carboxylate-modified polyacrylonitrile. [4] The photosensitive resin composition according to any one of [1] to [3] above, wherein the (A) photopolymerizable compound 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, (Aii) a difunctional 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 [1] to [4] above, wherein the (A) photopolymerizable compound having an ethylenically unsaturated group comprises (A1) a photopolymerizable compound having an acidic substituent together with an ethylenically unsaturated group. [6] A photosensitive resin composition for photovia formation, comprising the photosensitive resin composition described in any of [1] to [5] above. [7] A photosensitive resin composition for an interlayer insulating layer, comprising the photosensitive resin composition described in any of [1] to [5] above. [8] A photosensitive resin film comprising the photosensitive resin composition described in any of [1] to [5] above. [9] A photosensitive resin film for interlayer insulating layer, comprising the photosensitive resin composition described in any of [1] to [5] above.

[10] A multilayer printed circuit board comprising an interlayer insulating layer formed using any of the photosensitive resin compositions described in [1] to [5] above.

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

[12] A semiconductor package obtained by mounting a semiconductor element on the multilayer printed wiring board described in

[10] or

[11] above.

[13] A method for manufacturing a multilayer printed wiring board, comprising the following steps (1) to (4). Step (1): A step of laminating the photosensitive resin film described in [8] above on 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 vias and the interlayer insulating layer. Step (4): A step of forming a circuit pattern on the interlayer insulating layer.

Advantages 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 interlayer insulating layers, which are excellent in the resolution of vias, the adhesive strength with plated copper, and the insulation reliability. Further, it is possible to provide a photosensitive resin film made of the photosensitive resin composition and a photosensitive resin film for interlayer insulating layers, and a multilayer printed wiring board and a semiconductor package containing 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 vias with high resolution, high adhesive strength between the interlayer insulating layer and plated copper, and excellent insulation reliability. The vias of the multilayer printed wiring board obtained by the manufacturing method of the present invention can be vias having a smaller diameter than the vias formed by laser processing.

Brief Description of the Drawings

[0012] [Figure 1] It is a schematic diagram showing one aspect of the manufacturing process of the multilayer printed wiring board of the present embodiment.

Embodiments for Carrying Out the Invention

[0013] In the numerical ranges described herein, the upper or lower limits of the numerical range may be replaced with the values ​​shown in the examples. Furthermore, in this specification, 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, if there are multiple substances corresponding to each component. Furthermore, embodiments that combine any combination of the matters described herein are also included in the present invention.

[0014] [Photosensitive resin composition, photosensitive resin composition for photovia formation, and photosensitive resin composition for interlayer insulating layer] A photosensitive resin composition according to one embodiment of the present invention (hereinafter sometimes 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 (D) the elastomer is 2 to 30% by mass based on the total amount of resin components of the photosensitive resin composition. In this specification, the aforementioned components may be referred to as component (A), component (B), component (C), component (D), etc., and other components may be abbreviated in the same way. In this specification, "resin component" refers to the aforementioned components (A) to (D), etc., and also includes other components that may be included as needed (for example, components (E) and (G) to (H), etc.), but does not include the inorganic filler (F) which may be included as needed as described later. Furthermore, "solid content" refers to the non-volatile content of the photosensitive resin composition excluding volatile substances such as water and solvents, and indicates the components that remain without volatilization when the resin composition is dried, and also includes liquid, syrup-like, 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, adhesion strength to plated copper, and insulation reliability, and is useful as an interlayer insulating layer for multilayer printed circuit boards, the present invention also provides a photosensitive resin composition for interlayer insulating layers. In this specification, the term "photosensitive resin composition" includes both the photosensitive resin composition for photovia formation and the photosensitive resin composition for interlayer insulating layers. Furthermore, the photosensitive resin composition of this embodiment is useful as a negative-type photosensitive resin composition. The following details each component that may be contained in the photosensitive resin composition.

[0016] <(A) Photopolymerizable compounds having ethylenically unsaturated groups> The photosensitive resin composition of this embodiment includes a photopolymerizable compound having an ethylenically unsaturated group as component (A). Component (A) is a compound having a functional group with an ethylenically unsaturated bond, such as a vinyl group, allyl group, propargyl group, butenyl group, ethynyl group, phenylethynyl group, maleimide group, nadiimide group, or (meth)acryloyl group, as the functional group exhibiting photopolymerization. A (meth)acryloyl group is preferred as the functional group exhibiting photopolymerization.

[0017] As a photopolymerizable compound having an ethylenically unsaturated group, from the viewpoint of improving chemical resistance after curing (exposure) and increasing the difference in developer resistance between the exposed and unexposed areas, it is preferable to have an embodiment that includes at least one selected from the group consisting of (Ai) a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group, (Aii) a difunctional vinyl monomer having two polymerizable ethylenically unsaturated groups, and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups, and more preferably an embodiment that includes component (Aiii). Components (Ai) to (Aiii) 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 and alkyl (meth)acrylate. Examples of alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and hydroxyethyl (meth)acrylate. Component (Ai) may be used alone or in combination of two or more.

[0019] ((Aii) Difunctional vinyl monomer) Examples of the two polymerizable ethylenically unsaturated difunctional vinyl monomers include polyethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2-bis(4-(meth)acryloxypolyethoxypolypropoxyphenyl)propane, and bisphenol A diglycidyl ether di(meth)acrylate. Component (Aii) may be used alone or in combination of two or more.

[0020] ((Aiii) Polyfunctional vinyl monomer) Examples of polyfunctional vinyl monomers having at least three polymerizable ethylenically unsaturated groups include (meth)acrylate compounds having a trimethylolpropane-derived skeleton such as trimethylolpropane tri(meth)acrylate; (meth)acrylate compounds having a tetramethylolmethane-derived skeleton such as tetramethylolmethane tri(meth)acrylate and tetramethylolmethane tetra(meth)acrylate; (meth)acrylate compounds having a pentaerythritol-derived skeleton such as pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate; (meth)acrylate compounds having a dipentaerythritol-derived skeleton such as dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate; (meth)acrylate compounds having a ditrimethylolpropane-derived skeleton such as ditrimethylolpropane tetra(meth)acrylate; and (meth)acrylate compounds having a diglycerin-derived skeleton. Among these, (meth)acrylate compounds having a dipentaerythritol-derived skeleton are preferred, and dipentaerythritol penta(meth)acrylate is more preferred, from the viewpoint of improving chemical resistance after curing (exposure) and increasing the difference in developer resistance between the exposed and unexposed areas. Component (Aiii) may be used alone or in combination of two or more. Here, the "(meth)acrylate compound having a skeleton derived from XXX" (where XXX is a compound name) refers to an esterified product of XXX and (meth)acrylic acid, and this esterified product also includes compounds modified with alkylene oxy groups.

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

[0022] -(a1) Epoxy resin- The epoxy resin (a1) 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] Furthermore, epoxy resins are classified into various types based on differences in their 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 resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin; bisphenol-based novolac type epoxy resins such as bisphenol A novolac type epoxy resin and bisphenol F novolac type epoxy resin; novolac type epoxy resins other than the bisphenol-based novolac type epoxy resins, such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, and biphenyl novolac type epoxy resin; phenol aralkyl type epoxy resin; biphenyl aralkyl These are classified into types such as: sterlenide epoxy resins; dicyclopentadiene epoxy resins; naphthalene-type epoxy resins, naphthol novolac epoxy resins, naphthol epoxy resins, naphthol aralkyl epoxy resins, naphthylene ether epoxy resins, and other naphthalene skeleton-containing epoxy resins; biphenyl epoxy resins; biphenyl aralkyl epoxy resins; xylylene epoxy resins; dihydroanthracene epoxy resins; dicyclopentadiene epoxy resins; alicyclic epoxy resins; aliphatic chain epoxy resins; and rubber-modified epoxy resins. Among these, bisphenol-based novolac type epoxy resin is preferred from the viewpoint of reliability when mounting semiconductor chips, and bisphenol F novolac type epoxy resin is more preferred. (a1) One type of epoxy resin may be used alone, or two or more types may be used in combination.

[0024] (a1) The epoxy resin may also be an epoxy resin having structural units represented by the following general formula (I). [ka]

[0025] In general formula (I), R 1 Y represents a hydrogen atom or a methyl group. 1 Each of these independently represents a hydrogen atom or a glycidyl group. The two R1 may be the same or different from each other. At least one of the two Ys 1 represents a glycidyl group. R 1 is preferably a hydrogen atom from the viewpoints of via resolution and adhesion strength to electrodeposited copper. Also, from the same viewpoints, Y 1 is preferably a glycidyl group. The number of structural units of the structural unit having the structural unit represented by the general formula (I) in the (a1) epoxy resin is a number of 1 or more, preferably 10 to 100, more preferably 15 to 80, and still more preferably 15 to 70. When the number of structural units is within the above range, the adhesion strength to electrodeposited copper, heat resistance, and insulation reliability tend to be improved. In the general formula (I), R 1 are all hydrogen atoms, and Y 1 are all glycidyl groups are available commercially as the EXA-7376 series (trade name, manufactured by DIC Corporation), and R 1 are all methyl groups, and Y 1 are all glycidyl groups are available commercially as the EPON SU8 series (trade name, manufactured by Mitsubishi Chemical Corporation). [[ID=URL]] [[ID=URL]]

[0026] [[ID=URL]] -(a2) Vinyl group-containing organic acid-<00001Z8>The (a2) vinyl group-containing organic acid is not particularly limited, but a vinyl group-containing monocarboxylic acid is preferred. Examples of the vinyl group-containing monocarboxylic acid include acrylic acid derivatives such as acrylic acid, a dimer of acrylic acid, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α-cyanocinnamic acid; a half ester compound which is a reaction product of a hydroxyl group-containing acrylate and a dibasic acid anhydride; a half ester compound which is a reaction product of a vinyl group-containing monoglycidyl ether or a vinyl group-containing monoglycidyl ester and a dibasic acid anhydride; and the like.

[0027] The aforementioned semi-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 equimolar ratios. Component (a2) may be used alone or in combination of two or more.

[0028] (a2) Examples of hydroxyl group-containing acrylates, vinyl group-containing monoglycidyl ethers, and vinyl group-containing monoglycidyl esters used in the synthesis of the aforementioned semi-ester compound, which is an example of 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, glycidyl methacrylate, and the like.

[0029] The dibasic acid anhydride used in the synthesis of the aforementioned semi-ester compound may contain saturated groups or unsaturated groups. Examples of dibasic acid anhydrides 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 component (a1) and component (a2), it is preferable to react them in a ratio of 0.6 to 1.05 equivalents of component (a2) per 1 equivalent of epoxy group of component (a1), although a ratio of 0.8 to 1.0 equivalents is also acceptable. Reacting in such a ratio tends to improve photopolymerization, that is, increase photosensitivity and improve the resolution of the via.

[0031] The components (a1) and (a2) can be dissolved in an organic solvent and reacted together. 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-based 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 component (a1) and component (a2). Examples of such catalysts include amine-based catalysts such as triethylamine and benzylmethylamine; quaternary ammonium salt catalysts such as methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, and benzyltrimethylammonium iodide; and phosphine-based catalysts such as triphenylphosphine. Among these, phosphine-based catalysts are preferred, and triphenylphosphine is more preferred. The amount of 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, based on 100 parts by mass of the total of components (a1) and (a2). With the above amount, the reaction between components (a1) and (a2) tends to be promoted.

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

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

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

[0036] -(a3) Polybasic anhydrides- The aforementioned component (a3) ​​may contain a saturated group or an unsaturated group. Examples of component (a3) ​​include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride. Among these, tetrahydrophthalic anhydride is preferred from the viewpoint of via resolution.

[0037] It is presumed that by further reacting the (A') component obtained above with a saturated or unsaturated group-containing (a3) ​​component, the hydroxyl groups of component (A') (including the hydroxyl groups originally present in component (a1)) and the acid anhydride groups of component (a3) ​​are semi-esterified to form (A1-1) acid-modified vinyl group-containing epoxy derivative.

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

[0039] The reaction temperature between component (A') and component (a3) ​​is preferably 50 to 150°C, more preferably 60 to 120°C, and even more preferably 70 to 100°C, from the viewpoint of productivity.

[0040] (A1-1) As the acid-modified vinyl group-containing epoxy derivative, commercially available products may be used. Examples of commercially available products 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 manufactured by Nippon Kayaku Co., Ltd., trade names), UE-9000, UE-EXP-2810PM, UE-EXP-3045 (all manufactured by DIC Corporation, trade names), etc.

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

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

[0043] ((A1) Molecular weight of a photopolymerizable compound having an acidic substituent along with an ethylenically unsaturated group) The weight-average molecular weight (Mw) of 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 adhesion strength to plated copper, heat resistance, and insulation reliability are improved. In particular, it is preferable that the weight-average molecular weight (Mw) of the acid-modified vinyl group-containing epoxy derivative (A1-1) is within the above range. Hereinafter, the weight-average molecular weight is the value measured using a calibration curve for standard polystyrene by gel permeation chromatography (GPC) (manufactured by Tosoh Corporation), and more specifically, the value measured according to the method described below. <Method for measuring weight-average molecular weight> The weight-average molecular weight was measured using the GPC measuring device and measurement conditions described below, and the value converted using the calibration curve for standard polystyrene was defined as the weight-average molecular weight. The calibration curve was created using five sample sets of standard polystyrene ("PStQuick MP-H" and "PStQuick B," manufactured by Tosoh Corporation). (GPC measurement device) GPC system: High-speed GPC system "HCL-8320GPC", detector is differential refractometer or UV, manufactured by Tosoh Corporation. Column: TSKgel SuperMultipore HZ-H column (column length: 15cm, column inner diameter: 4.6mm), manufactured by Tosoh Corporation. (Measurement conditions) Solvent: Tetrahydrofuran (THF) Measurement temperature: 40℃ Flow rate: 0.35mL / min Sample concentration: 10 mg / THF 5 mL Injection volume: 20μL

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

[0045] Component (A) is not particularly limited, but from the viewpoint of photosensitive properties, it is preferable to use component (A1) and component (Aiii) in combination. In this case, the content ratio of component (A1) to 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 this embodiment is not particularly limited as long as it can polymerize the component (A), and can be appropriately selected from commonly used photopolymerization initiators. (B) Components include, for example, benzoin compounds 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-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, and 2-methyl-1-[4-(methyl Acetophenones such as thio)phenyl]-2-morpholino-1-propanone and N,N-dimethylaminoacetophenone; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone. Thioxanthones such as santon; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis(diethylamino)benzophenone, Michla'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 include acylphosphine oxides such as trimethylbenzoyldiphenylphosphine oxide; oxime esters such as 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyl oxime), and 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl)oxime]. Among these, acetophenones and thioxanthones are preferred, with 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2,4-diethylthioxanthone being more preferred. Acetophenones have the advantage of being less volatile and less likely to generate outgassing, while thioxanthones have the advantage of being photocurable even in the visible light range. (B) Component may be used alone or in combination of two or more. When two or more are used in combination, it is preferable to use acetophenones and thioxanthones, and more preferable to use 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2,4-diethylthioxanthone.

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

[0048] <(B') Photopolymerization initiator> The photosensitive resin composition of this embodiment may contain a photopolymerization initiator (B') along with the above-mentioned component (B). Examples of the photopolymerization initiator (B') include ethyl N,N-dimethylaminobenzoate, isoamyl N,N-dimethylaminobenzoate, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine, and other tertiary amines. Component (B') may be used alone or in combination of two or more. If the photosensitive resin composition of this embodiment contains component (B'), its content is preferably 0.01 to 20% by mass, more preferably 0.2 to 5% by mass, and even more preferably 0.3 to 2% by mass, based on the total amount of resin components in the photosensitive resin composition. The photosensitive resin composition of this embodiment does not necessarily have to contain component (B').

[0049] <(C) Epoxy resin> Component (C) does not contain anything equivalent to component (A), and in that respect, component (C) can be said to be one that does not have an ethylenically unsaturated group. Furthermore, any substance that satisfies this condition and has an epoxy group is included in component (C). (C) The 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] Furthermore, epoxy resins are classified into various types based on differences in their 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 resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin; bisphenol-based novolac type epoxy resins such as bisphenol A novolac type epoxy resin and bisphenol F novolac type epoxy resin; novolac type epoxy resins other than the bisphenol-based novolac type epoxy resins, such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, and biphenyl novolac type epoxy resin; phenol aralkyl type epoxy resin; biphenyl aralkyl type epoxy resin; stilbene type epoxy resin; dicyclopentadiene These are classified into various types of epoxy resins, including: naphthalene-type epoxy resins, naphthol novolac-type epoxy resins, naphthol-type epoxy resins, naphthol aralkyl-type epoxy resins, naphthylene ether-type epoxy resins, and other naphthalene skeleton-containing 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; cyclohexanedimethanol-type epoxy resins; trimethylol-type epoxy resins; aliphatic chain-like epoxy resins; rubber-modified epoxy resins, and others. (C) Component may be used alone or in combination of two or more components.

[0051] Among these, bisphenol-based epoxy resins, naphthol-type epoxy resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, and naphthylene ether-type epoxy resins are particularly preferred from the viewpoint of heat resistance, insulation reliability, and adhesion strength to plated copper, 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 can also be commercially available products, such as bisphenol A type epoxy resin (Mitsubishi Chemical Corporation's "jER828EL" and "YL980"), bisphenol F type epoxy resin (Mitsubishi Chemical Corporation's "jER806H" and "YL983U"), naphthalene type epoxy resin (DIC Corporation's "HP4032D" and "HP4710"), naphthalene skeleton-containing polyfunctional epoxy resin (Nippon Kayaku Co., Ltd.'s "NC7000"), and naphthol type epoxy resin (Nippon Steel & Sumitomo Metal Corporation). Examples include "ESN-475V" manufactured by Chemical Co., Ltd., biphenyl structure epoxy resins ("NC3000H" and "NC3500" manufactured by Nippon Kayaku Co., Ltd., "YX4000HK" and "YL6121" manufactured by Mitsubishi Chemical Corporation), anthracene type epoxy resin ("YX8800" manufactured by Mitsubishi Chemical Corporation), glycerol type epoxy resin ("ZX1542" manufactured by Nippon Steel & Sumitomo Metal Chemical Corporation), naphthylene ether type epoxy resin ("EXA7311-G4" manufactured by DIC Corporation), etc.

[0052] (C) As the epoxy resin, epoxy-modified polybutadiene can be used in addition to the examples given above. In particular, as component (C), from the viewpoint of handling during the manufacture of printed circuit 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. From this viewpoint, it is preferable to use in combination the epoxy resin exemplified as a preferred example (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 resins 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 by mass ratio, and more preferably 90 / 10 to 70 / 30.

[0053] The epoxy-modified polybutadiene is preferably one having hydroxyl groups at its molecular ends, more preferably one having hydroxyl groups at both molecular ends, and even more preferably one having hydroxyl groups only at both molecular ends. The number of hydroxyl groups in the epoxy-modified polybutadiene is not particularly limited as long as it is one or more, but is preferably 1 to 5, more preferably 1 or 2, and even more preferably 2. The epoxy-modified polybutadiene is preferably an epoxy-modified polybutadiene represented by the following general formula (C-1) from the viewpoint of adhesion strength with plated copper, heat resistance, coefficient of thermal expansion, and flexibility.

[0054] [ka] (In equation (C-1) above, a, b, and c represent the ratios of the structural units enclosed in parentheses, respectively: a is between 0.05 and 0.40, b is between 0.02 and 0.30, and c is between 0.30 and 0.80. Furthermore, a + b + c = 1.00 and (a + c) > b. y represents the number of structural units enclosed in square brackets and is an integer between 10 and 250.)

[0055] In the general formula (C-1) above, the order in which the structural units within the square brackets are combined is not limited to any particular order. In other words, the structural units shown on the left, the structural units shown in the center, and the structural units shown on the right may be swapped, and if we represent them as (a), (b), and (c), then there are various possible combinations, such as -[(a)-(b)-(c)]-[(a)-(b)-(c)-]-, -[(a)-(c)-(b)]-[(a)-(c)-(b)-, ​​-[(b)-(a)-(c)]-[(b)-(a)-(c)-, -[(a)-(b)-(a)]-[(c)-(b)-(c)-, and -[(c)-(b)-(c)]-[(b)-(a)-(a)-]-. From the viewpoint of adhesion strength with plated copper, heat resistance, coefficient of thermal expansion, 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. Also, from a similar viewpoint, y is preferably an integer between 30 and 180.

[0056] Examples of commercially available epoxidized polybutadienes in the general formula (C-1) above, where a=0.20, b=0.20, c=0.60, and y=an integer between 10 and 250, include "Epollead (registered trademark) PB3600" (manufactured by Daicel Corporation).

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

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

[0059] Examples of elastomers include styrene-based elastomers, olefin-based elastomers, polyester-based elastomers, urethane-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers, and it is preferable to use at least one selected from these. These elastomers consist of hard segment components and soft segment components, with the former tending to contribute to heat resistance and strength, and the latter tending to contribute to flexibility and toughness. As for component (D), from among the examples above, it is preferable that it includes at least one selected from the group consisting of olefin-based elastomers, polyester-based elastomers, and urethane-based elastomers, and more preferably a urethane-based elastomer, from the viewpoint of compatibility, solubility, and adhesive strength with plated copper. Furthermore, it is even more preferable that component (D) is at least one selected from the group consisting of olefin-based elastomers, polyester-based elastomers, and urethane-based elastomers, and particularly preferable that it is a urethane-based elastomer.

[0060] (CE-based elastomer) Examples of the styrene-based elastomers include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-ethylene-propylene-styrene block copolymer. As for the styrene-based elastomer, those with a number average molecular weight of 1,000 to 50,000 are preferred, and those with a number average molecular weight of 3,000 to 20,000 are more preferred. In this specification, the number-average molecular weight is the value obtained on a standard polystyrene basis by gel permeation chromatography (GPC) using tetrahydrofuran as the solvent.

[0061] Styrene-based elastomers can also be commercially available. Examples of commercially available products include Toughprene, Solprene T, Asaprene T, Toughtech (all manufactured by Asahi Kasei Corporation; "Toughprene," "Asaprene," and "Toughtech" are registered trademarks), Elastomer AR (manufactured by Aron Kasei Co., Ltd.), Kraton G, Kareflex (all manufactured by Shell Japan Co., Ltd.), JSR-TR, TSR-SIS, Dynalon (all manufactured by JSR Corporation), Denka STR (manufactured by Denka Co., Ltd.), and Quintah. Examples include Quintac (manufactured by Zeon Corporation, "Quintac" is a registered trademark), TPE-SB series (manufactured by Sumitomo Chemical Co., Ltd.), Lavalon (manufactured by Mitsubishi Chemical Corporation, "Lavalon" is a registered trademark), Septon, Hybler (both manufactured by Kuraray Co., Ltd., "Septon" and "Hybler" are registered trademarks), Sumiflex (manufactured by Sumitomo Bakelite Co., Ltd.), Rheostomer, Actimar (both manufactured by Riken Technos Corporation, "Rheostomer" and "Actimer" are registered trademarks), etc.

[0062] (Olefin-based elastomer) The olefin-based elastomer is, for example, a polymer or copolymer of α-olefins having 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, and 4-methylpentene. The olefin-based elastomer may have hydroxyl groups at its molecular ends, and it is preferable that it has hydroxyl groups at its molecular ends. Suitable olefin-based elastomers include, for example, polyethylene, polybutadiene, hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisopropylene, ethylene-propylene copolymer (EPR), and ethylene-propylene-diene copolymer (EPDM). Also suitable 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, and isoprene. Furthermore, carboxylated NBR obtained by copolymerizing butadiene-acyllonitrile copolymer with methacrylic acid is also a suitable example. As for the olefin-based elastomer, those with a number average molecular weight of 1,000 to 5,000 are preferred, and those with a number average molecular weight of 1,500 to 3,500 are more preferred.

[0063] Olefin-based elastomers may be commercially available products, such as Milastoma (manufactured by Mitsui Chemicals, Inc., product name), EXACT (manufactured by ExxonMobil, Inc., product name), ENGAGE (manufactured by The Dow Chemical Company, product name), Poly ip, Poly bd (manufactured by 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 with carboxyl groups at both ends "XER series" (manufactured by JSR Corporation, product name), and epoxidized polybutadiene such as BF-1000 (manufactured by Nippon Soda Co., Ltd., product name), PB-4700, and PB-3600 (manufactured by Daicel Corporation, product name), in which polybutadiene is partially epoxidized.

[0064] (Polyester elastomer) Examples of the polyester elastomers mentioned above include those obtained by polycondensation of a dicarboxylic acid or its derivative and a diol compound or its derivative. Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; aromatic dicarboxylic acids in which the hydrogen atoms of the aromatic ring of the aromatic dicarboxylic acid are substituted with methyl groups, ethyl groups, phenyl groups, etc.; 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. From the viewpoint of adhesion to the substrate, it is also preferable to use dimer acids derived from natural products as the dicarboxylic acid. One type of dicarboxylic acid may be used alone, or two or more types may be used in combination. Examples of derivatives of the dicarboxylic acid include the anhydride of the dicarboxylic acid. Examples of the diol compounds include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decanediol; and alicyclic diols such as 1,4-cyclohexanediol. The diol compounds may be used individually or in combination of two or more. As for the polyester elastomer, those with a number average molecular weight of 900 to 30,000 are preferred, those with a number average molecular weight of 1,000 to 25,000 are more preferred, and those with a number average molecular weight of 5,000 to 20,000 are even more preferred.

[0065] Polyester elastomers may be commercially available products, such as Hytrel (manufactured by Toray DuPont Ltd., "Hytrel" is a registered trademark), Perprene (manufactured by Toyobo Co., Ltd., "Perprene" is a registered trademark), Teslac 2505-63 (manufactured by Hitachi Chemical Co., Ltd., "Teslac" is a registered trademark), and Esper (manufactured by Hitachi Chemical Co., Ltd., "Esper" is a registered trademark), which are commercially available.

[0066] (Urethane elastomer) Examples of suitable urethane elastomers include those containing a hard segment composed of a short-chain diol and a diisocyanate, and a soft segment composed of a polymer (long-chain) diol and a diisocyanate. Examples of polymeric (long-chain) diols include polypropylene glycol, polytetramethylene oxide, poly(1,4-butylene adipate), poly(ethylene-1,4-butylene adipate), polycaprolactone, poly(1,6-hexylene carbonate), and poly(1,6-hexylene-neopentylene adipate). The number-average molecular weight of the polymeric (long-chain) diol is preferably 500 to 10,000. Examples of short-chain diols 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. As for the urethane elastomer, those with a number average molecular weight of 1,000 to 25,000 are preferred, those with a number average molecular weight of 1,500 to 20,000 are more preferred, and those with a number average molecular weight of 2,000 to 15,000 are even more preferred.

[0067] Commercially available urethane elastomers may be used, and examples of such commercially available products include Nipponran 3116 (manufactured by Tosoh Corporation, "Nipporan" is a registered trademark), PANDEX T-2185, T-2983N (both manufactured by DIC Corporation), the Miractran series (manufactured by Nippon Miractran Co., Ltd., "Miractran" is a registered trademark), and the Hitaloid series (manufactured by Hitachi Chemical Co., Ltd., "Hitaloid" is a registered trademark).

[0068] (Polyamide elastomer) Examples of the polyamide-based elastomer include block copolymers in which polyamide is the hard segment component and polybutadiene, butadiene-acrylonitrile copolymer, styrene-butadiene copolymer, polyisoprene, ethylene propylene copolymer, polyether, polyester, polybutadiene, polycarbonate, polyacrylate, polymethacrylate, polyurethane, silicone rubber, etc., are used as the soft segment component. As for the polyamide elastomer, those with a number average molecular weight of 1,000 to 50,000 are preferred, and those with a number average molecular weight of 2,000 to 30,000 are more preferred.

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

[0070] (Acrylic elastomer) Examples of the acrylic elastomer include polymers of raw material monomers mainly composed of acrylic acid esters. Suitable acrylic acid esters include ethyl acrylate, butyl acrylate, methoxyethyl acrylate, and ethoxyethyl acrylate. Furthermore, the crosslinking monomer may be a copolymer of glycidyl methacrylate, allyl glycidyl ether, etc., or a copolymer of acrylonitrile, ethylene, etc. Specifically, examples include acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, and acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer. As for the acrylic elastomer, those with a number average molecular weight of 1,000 to 50,000 are preferred, and those with a number average molecular weight of 2,000 to 30,000 are more preferred.

[0071] (Silicone-based elastomer) The aforementioned silicone-based elastomers are elastomers whose main component is organopolysiloxane, and are classified, for example, into polydimethylsiloxane-based elastomers, polymethylphenylsiloxane-based elastomers, polydiphenylsiloxane-based elastomers, etc. As for the silicone elastomer, those with a number average molecular weight of 1,000 to 50,000 are preferred, and those with a number average molecular weight of 2,000 to 30,000 are more preferred.

[0072] Commercially available silicone elastomers may be used, such as the KE series (manufactured by Shin-Etsu Chemical Co., Ltd.), SE series, CY series, and SH series (all manufactured by Toray Dow Corning Co., Ltd.).

[0073] (Other elastomers) Furthermore, an embodiment in which component (D) includes at least one selected from the group consisting of polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyamide-imide 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 is also preferred.

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

[0075] <(E) Thermal polymerization initiator> The photosensitive resin composition of this embodiment may contain a thermal polymerization initiator as component (E), and it is preferable that it does. While there are no particular limitations on the thermal polymerization initiators, examples include hydroperoxides such as diisopropylbenzene hydroperoxide "Permil P" (trade name, manufactured by NOF Corporation (hereinafter the same)), cumene hydroperoxide "Permil H", and t-butyl hydroperoxide "Perbutyl H"; α,α-bis(t-butylperoxy-m-isopropyl)benzene "Perbutyl P", dicumyl peroxide "Permil D", 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane "Perhexa 25B", t-butylcumyl peroxide "Perbutyl C", and di-t-butyl peroxide "Perbutyl D". Examples include dialkyl peroxasides such as 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyn-3 "Perhexyn 25B" and t-butylperoxy-2-ethylhexanoate "Perbutyl O"; ketone peroxides; peroxyketals such as n-butyl 4,4-di-(t-butylperoxy)valerate "Perhexa V"; diacyl peroxides; peroxydicarbonates; organic peroxides such as peroxyesters; and azo compounds such as 2,2'-azobisisobutylnitrile, 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). Among these, dialkylperoxides are preferred, and 2,5-dimethyl-2,5-bis(t-bitylperoxy)hexyn-3 is more preferred, from the viewpoint of not inhibiting photopolymerization and having a significant effect in improving the physical properties and characteristics of the photosensitive resin composition. A single thermal polymerization initiator may be used alone, or two or more may be used in combination.

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

[0077] <(F) Inorganic filler> The photosensitive resin composition of this embodiment may contain an inorganic filler as component (F), and it is preferable that it contains an inorganic filler. By including an inorganic filler, thermal expansion can be reduced, and the risk of warping is minimized. In thermosetting resin compositions conventionally used as interlayer insulating layers in multilayer printed circuit boards, thermal expansion has been reduced by including an inorganic filler. However, when an inorganic filler is included in a photosensitive resin composition, it is difficult to include a large amount of the inorganic filler to reduce thermal expansion because the inorganic filler causes light scattering and hinders development. Thus, there are new challenges unique to photosensitive resin compositions when including an inorganic filler. However, the photosensitive resin composition of this embodiment maintains high via resolution even when a large amount of inorganic filler is included. Therefore, high via resolution can be achieved along with low thermal expansion.

[0078] (F) Component examples include silica (SiO2), alumina (Al2O3), titania (TiO2), tantalum oxide (Ta2O5), zirconia (ZrO2), silicon nitride (Si3N4), barium titanate (BaO·TiO2), barium carbonate (BaCO3), magnesium carbonate (MgCO3), aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), lead titanate (PbO·TiO2), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide (Ga2O3), and spinel (MgO·Al2O3). Examples include ), mullite (3Al2O3·2SiO2), cordierite (2MgO·2Al2O3 / 5SiO2), talc (3MgO·4SiO2·H2O), aluminum titanate (TiO2·Al2O3), yttria-containing zirconia (Y2O3·ZrO2), barium silicate (BaO·8SiO2), boron nitride (BN), calcium carbonate (CaCO3), barium sulfate (BaSO4), calcium sulfate (CaSO4), zinc oxide (ZnO), magnesium titanate (MgO·TiO2), hydrotalcite, mica, calcined kaolin, and carbon (C). Component (F) may be used alone or in combination of two or more.

[0079] The average particle size of component (F) is preferably 0.01 to 5 μm, more preferably 0.05 to 3 μm, and even more preferably 0.05 to 2 μm, from the viewpoint of via resolution. Here, the average particle size of component (F) is the volume-average particle size of the inorganic filler dispersed in the photosensitive resin composition, and is the value obtained by measurement 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 using a submicron particle analyzer (manufactured by Beckman Coulter, Inc., product name: N5) in accordance with the international standard ISO 13321, with a refractive index of 1.38, and the particle size at 50% of the cumulative value (volume basis) in the particle size distribution is taken as the average particle size (volume-average particle size). Furthermore, the (F) component contained in the photosensitive resin film and interlayer insulating layer provided on the carrier film can also be measured using the submicron particle analyzer described above after diluting (or dissolving) it 1,000 times (by volume) using a solvent as described above.

[0080] Component (F) may contain silica from the viewpoint of heat resistance and low thermal expansion, may contain barium sulfate from the viewpoint of heat resistance and adhesion strength with plated copper, or may contain a combination of silica and barium sulfate. Furthermore, component (F) may be surface-treated with alumina or an organosilane compound from the viewpoint of improving the dispersibility of inorganic fillers in the photosensitive resin composition by an anti-aggregation effect.

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

[0082] <(G) Pigment> The photosensitive resin composition of this embodiment may contain a pigment as component (G) depending on the desired color for adjusting the photosensitivity. As component (G), any coloring agent that produces the desired color can be appropriately selected and used. For example, known coloring agents such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, carbon black, and naphthalene black are preferred.

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

[0084] <(H) Epoxy resin curing agent> The photosensitive resin composition of this embodiment may contain an epoxy resin curing agent from the viewpoint of further improving various properties such as heat resistance, adhesion strength to plated copper, and chemical resistance. (H) components include, for example, 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-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, and polybasic hydrazides; organic 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, and hexa(N-methyl) Examples include tertiary amines such as melamine, 2,4,6-tris(dimethylaminophenol), tetramethylguanidine, and m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol brominated, phenol novolac, and alkylphenol novolac; organophosphines such as tributylphosphine, triphenylphosphine, and tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl(2,5-dihydroxyphenyl)phosphonium bromide and hexadecyltributylphosnium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; the aforementioned polybasic acid anhydrides; diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and 2,4,6-triphenylthiopyrillium hexafluorophosphate. Among these, polyamines are preferred, and melamine is more preferred, from the viewpoint of further improving various properties such as heat resistance, adhesion strength to plated copper, and chemical resistance. If the photosensitive resin composition of this embodiment contains component (H), its content is preferably 0.01 to 10% by mass, more preferably 0.02 to 5% by mass, and even more preferably 0.03 to 3% by mass, based on the total amount of resin components in the photosensitive resin composition.

[0085] <Diluent> A diluent may be used in the photosensitive resin composition of this embodiment as needed. Examples of diluents include organic solvents. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol 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; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. One diluent may be used alone, or two or more may be used in combination.

[0086] (Diluent content) The amount of diluent can be appropriately selected so that the total solid content concentration in the photosensitive resin composition is preferably 50-90% by mass, more preferably 60-80% by mass, and even more preferably 65-75% by mass. By adjusting the amount of diluent used in this way, the coatability of the photosensitive resin composition is improved, and it becomes possible to form finer patterns.

[0087] <Other additives> The photosensitive resin composition of this embodiment may optionally contain various known and conventional additives such as polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; thickeners such as bentonite and montmorillonite; defoamers such as silicone-based defoamers, fluorine-based defoamers, and vinyl resin-based defoamers; and silane coupling agents. Furthermore, it may contain flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, phosphate compounds of phosphorus compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters.

[0088] The photosensitive resin composition of this embodiment can be obtained by kneading and mixing each component in a roll mill, bead mill, or the like. Here, the photosensitive resin composition of this embodiment may be used in liquid form or in film form. When used in liquid form, there are no particular restrictions on the application method of the photosensitive resin composition of this embodiment, but various application methods such as printing, spin coating, spray coating, jet dispensing, inkjet, and immersion coating can be used. Among these, printing and spin coating can be appropriately selected from the viewpoint of forming the photosensitive layer more easily. Furthermore, when used in film form, it can be used, for example, in the form of a photosensitive resin film as described later. In this case, a photosensitive layer of the desired thickness can be formed by laminating it onto a carrier film using a laminator or the like. It is preferable to use it in film form because it increases the manufacturing efficiency of multilayer printed circuit boards.

[0089] [Photosensitive resin film, photosensitive resin film for interlayer insulation layer] The photosensitive resin film of this embodiment is a photosensitive layer that later becomes an interlayer insulating layer, and is made of the photosensitive resin composition of this embodiment. The photosensitive resin film may also 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 thinning the multilayer printed circuit board, 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 this embodiment can be obtained, for example, by applying and drying the photosensitive resin composition of this embodiment onto a carrier film using a known coating apparatus such as a comma coater, bar coater, kiss coater, roll coater, gravure coater, or die coater to form a photosensitive layer that will later become an interlayer insulating layer. Examples of carrier films include polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyolefins such as polypropylene and polyethylene. The thickness of the carrier film can be appropriately selected from the range of 5 to 100 μm, but is preferably 5 to 60 μm, and more preferably 15 to 45 μm.

[0091] Furthermore, in this embodiment, a protective film may be provided on the surface of the photosensitive resin film opposite to the surface in contact with the carrier film. As the protective film, for example, a polymer film such as polyethylene or polypropylene can be used. Alternatively, a polymer film similar to 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 hot air dryer, a far-infrared dryer, or a near-infrared dryer. 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 residual 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 avoiding the diffusion of the diluent during the manufacturing process of the multilayer printed circuit board.

[0093] The photosensitive resin film of this embodiment is suitable as an interlayer insulating layer for multilayer printed circuit boards because it has excellent via resolution, adhesion strength to plated copper, and insulation reliability. In other words, the present invention also provides a photosensitive resin film for interlayer insulating layers. The photosensitive resin film for interlayer insulating layers may also be called an interlayer insulating photosensitive film.

[0094] [Multilayer printed circuit board and method for manufacturing the same] The present invention also provides a multilayer printed circuit board containing an interlayer insulating layer formed using the photosensitive resin composition or photosensitive resin film of this embodiment. Hereinafter, as an example of a preferred embodiment of the method for manufacturing a multilayer printed circuit board, a method for manufacturing a multilayer printed circuit board using the photosensitive resin film (photosensitive resin film for interlayer insulating layer) of this embodiment will be described with reference to Figure 1 as appropriate. The multilayer printed circuit 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 this embodiment onto one or both sides of a circuit board [hereinafter referred to as lamination step (1)]. Step (2): A step to form an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in step (1) [hereinafter referred to as the photovia formation 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 the circuit pattern formation step (4)].

[0095] (Lamination process (1)) Lamination step (1) is a step of laminating the photosensitive resin film of this embodiment (photosensitive resin film for interlayer insulating layer) to one or both sides of a circuit board (substrate 101 having a circuit pattern 102) using a vacuum laminator. Examples of vacuum laminators include vacuum applicators manufactured by Nichigo Morton Co., Ltd., vacuum pressure laminators manufactured by Meiki Seisakusho Co., Ltd., roll-type dry coaters manufactured by Hitachi, Ltd., and vacuum laminators manufactured by Hitachi Chemical Electronics Co., Ltd.

[0096] If a protective film is provided on the photosensitive resin film, the protective film can be peeled off or removed, and then the photosensitive resin film can be laminated to the circuit board by applying pressure and heating so that it comes into contact with the circuit board. The lamination can be carried out, for example, by preheating the photosensitive resin film and circuit board as needed, at a pressure temperature of 70-130°C, a pressure of 0.1-1.0 MPa, and under reduced pressure of 20 mmHg (26.7 hPa) or less, but is not limited to these conditions. Furthermore, the lamination method may be batch-type or continuous-type using rolls. Finally, the photosensitive resin film laminated to the circuit board (hereinafter sometimes referred to as the photosensitive layer) is cooled to near room temperature to form the interlayer insulating layer 103. The carrier film may be peeled off at this point, or it may be peeled off after exposure as described later.

[0097] (Photovia formation process (2)) In the photovia formation step (2), at least a portion of the photosensitive resin film laminated to the circuit board is exposed to light, and then developed. The exposure causes the portion irradiated with active light to photocur, forming a pattern. There are no particular restrictions on the exposure method; for example, a method in which active light is irradiated in an image-like manner through a negative or positive mask pattern called artwork (mask exposure method) may be employed, or a method in which active light is irradiated in an image-like manner using direct drawing exposure methods such as LDI (Laser Direct Imaging) exposure method or DLP (Digital Light Processing) exposure method may be employed. Known light sources can be used as the light source for the active light. Specifically, 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 semiconductor lasers that effectively emit ultraviolet or visible light. The exposure dose is appropriately selected depending on the light source used and the thickness of the photosensitive layer, but for example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, for a photosensitive layer thickness of 1 to 100 μm, it is usually 10 to 1,000 J / m 2 A suitable degree is 15-500 J / m³. 2 This is preferable.

[0098] During development, the uncured portion of the photosensitive layer is removed from the substrate, thereby forming an interlayer insulating layer on the substrate consisting of the photocured material. If a carrier film is present on the photosensitive layer, the carrier film is removed before removing the unexposed areas (development). There are two development methods: wet development and dry development. Either can be used, but wet development is widely used, and wet development can also be used in this embodiment. In the case of wet development, development is carried out using a developer solution corresponding to the photosensitive resin composition and a known development method. Development methods include the dip method, battle method, spray method, brushing, slapping, scraping, and agitation immersion. Among these, the spray method is preferred from the viewpoint of improving resolution, and among spray methods, the high-pressure spray method is more preferred. Development may be carried out using one method, or two or more methods may be combined. The composition of the developer is appropriately selected according to the composition of the photosensitive resin composition. Examples include alkaline aqueous solutions, aqueous developers, and organic solvent-based developers, with alkaline aqueous solutions being preferred among these.

[0099] In the photovia formation process (2), after exposure and development, 0.2~10 J / cm 2 Degree (preferably 0.5~5J / cm) 2 The interlayer insulating layer may be further cured, and is preferable, by performing post-UV curing with an exposure dose of ) and post-thermal curing at a temperature of approximately 60 to 250°C (preferably 120 to 200°C) as needed. As described above, an interlayer insulating layer having vias 104 is formed. There are no particular restrictions on the shape of the vias. In terms of cross-sectional shape, examples include a square or an inverted trapezoid (where the top side is longer than the bottom side). In terms of shape as viewed from the front (the direction in which the bottom of the via is visible), examples include a circular or square shape. In the photolithography method for forming vias in this embodiment, it is possible to form vias with an inverted trapezoidal cross-sectional shape (where the top side is longer than the bottom side), which is preferable because it improves the adhesion of the plated copper to the via wall surface.

[0100] The size (diameter) of the vias formed by this process can be less than 40 μm, and can even be 35 μm or less, or 30 μm or less, making them smaller in diameter than vias produced by laser processing. There is no particular lower limit to the size (diameter) of the vias 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 by this process is not necessarily limited to less than 40 μm; for example, it can be arbitrarily selected within the range of 15 to 300 μm.

[0101] (Roughening process (3)) In the roughening process (3), the surfaces of the vias and interlayer insulating layers are roughened with a roughening solution. If smearing occurs in the photovia formation process (2), the smearing may be removed with the roughening solution. The roughening process and smearing can be performed simultaneously. Examples of the aforementioned roughening solutions include chromium / sulfuric acid roughening solution, alkaline permanganate roughening solution (for example, sodium permanganate roughening solution, etc.), and sodium fluoride / chromium / sulfuric acid roughening solution. The roughening treatment creates uneven anchors on the surface of the vias and interlayer insulating layers.

[0102] (Circuit pattern formation process (4)) The circuit pattern formation step (4) is a step in which a circuit pattern is formed on the interlayer insulating layer after the roughening treatment step (3). From the viewpoint of forming fine wiring, it is preferable to perform the formation of the circuit pattern by a semi-additive process. The semi-additive process forms the circuit pattern and simultaneously conducts the vias. In the semi-additive process, first, a seed layer 105 is formed by electroless copper plating using a palladium catalyst or the like on the entire surface of the via bottom, via wall, and interlayer insulating layer after the roughening process (3). This 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 thickness of the seed layer is 0.1 μm or more, it tends to suppress a decrease in connection reliability during electrolytic copper plating, and if it is 2.0 μm or less, it does not need to increase the amount of etching when flash etching the seed layer between wirings, and tends to suppress damage to the wiring during etching.

[0103] The electroless copper plating process is carried out by the reaction of copper ions with a reducing agent, which causes metallic copper to be deposited on the surface of the vias and interlayer insulating layers. The electroless plating method and the electrolytic plating method may be known methods and are not particularly limited, but the catalyst for the electroless plating process is preferably a palladium-tin mixed catalyst, and the primary particle size of the catalyst is preferably 10 nm or less. Furthermore, the plating composition of the electroless plating process preferably contains hypophosphorous acid as a reducing agent. Commercially available electroless copper plating solutions can be used, such as "MSK-DK" from Attec Japan Co., Ltd. and the "Surupap (registered trademark) PEA ver.4" series from Uemura Kogyo Co., Ltd.

[0104] After the electroless copper plating process described above, 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 height of the wiring after the electroplated copper plating, and from this viewpoint, a dry film resist with a thickness of 5 to 30 μm is preferred. As the dry film resist, products such as the "Photec" series manufactured by Hitachi Chemical Co., Ltd. are used. After the dry film resist is thermocompressed, for example, the dry film resist is exposed through a mask on which the desired wiring pattern is drawn. Exposure can be performed using the same apparatus and light source as those used when forming vias on the photosensitive resin film. After exposure, the carrier film on the dry film resist is peeled off, and development is performed using an alkaline aqueous solution to remove unexposed areas and form the resist pattern 106. After this, if necessary, the development residue of the dry film resist may be removed using plasma or the like. After development, electroplating is performed to form a copper circuit layer 107 and to perform via filling.

[0105] After electroplating copper, the dry film resist is removed using an alkaline aqueous solution or an amine-based stripping agent. After removing the dry film resist, the seed layer between the wiring is removed (flash etching). Flash etching is performed using an acidic solution such as sulfuric acid and hydrogen peroxide, and an oxidizing solution. Specifically, examples include "SAC" from JCU Corporation and "CPE-800" from Mitsubishi Gas Chemical Company, Inc. After flash etching, palladium and other materials adhering to the areas between the wiring are removed as needed. Palladium removal can preferably be performed using an acidic solution such as nitric acid or hydrochloric acid.

[0106] After peeling off the dry film resist or after the flash etching process, a post-bake treatment is preferably performed. The post-bake treatment thoroughly heat-cures any unreacted thermosetting components, thereby improving insulation reliability, curing characteristics, and adhesion strength to the plated copper. Although the heat curing conditions vary depending on the type of resin composition, a curing temperature of 150 to 240°C and a curing time of 15 to 100 minutes are preferred. The post-bake treatment completes one step of the photovia method for manufacturing printed circuit boards, and this process is repeated to manufacture substrates according to the required number of interlayer insulating layers. Then, a solder resist layer 108 is preferably formed on the outermost layer.

[0107] The above describes a method for manufacturing a multilayer printed circuit board using the photosensitive resin composition of this embodiment to form vias. However, since the photosensitive resin composition of this embodiment has excellent pattern resolution, it is also suitable for forming cavities for embedding chips or passive elements, for example. The cavities can be suitably formed, for example, in the description of the multilayer printed circuit board above, by making the drawing pattern when exposing the photosensitive resin film to form a pattern such that the desired cavity can be formed.

[0108] [Semiconductor Packages] The present invention also provides a semiconductor package comprising semiconductor elements mounted on a multilayer printed circuit board according to this embodiment. The semiconductor package according to this embodiment can be manufactured by mounting semiconductor elements such as semiconductor chips and memory at predetermined positions on the multilayer printed circuit board of the present invention and sealing the semiconductor elements 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 photosensitive resin compositions obtained in each example were evaluated for their properties using the method described below.

[0110] [1. Evaluation of via resolution] (1) Preparation of evaluation laminate A printed circuit board substrate (manufactured by Hitachi Chemical Co., Ltd., product name "MCL-E-679"), in which 12 μm thick copper foil was laminated on a glass epoxy substrate, was treated with a roughening pretreatment solution (manufactured by MEC Corporation, product name "CZ-8100") on the copper foil surface, then washed with water and dried to obtain a roughened pretreatment printed circuit board substrate. Next, the protective film was peeled off from the carrier film and photosensitive resin film with protective film manufactured in each example and comparative example, and the exposed photosensitive resin film was placed in contact with the copper foil of the roughened pretreatment printed circuit board substrate. Then, lamination was performed using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500"). The lamination conditions were: press hot plate temperature 70°C, vacuum evacuation time 20 seconds, lamination press time 30 seconds, atmospheric pressure 4 kPa or less, and compression pressure 0.4 MPa. After lamination, the substrate was left at room temperature for more than one hour to obtain an evaluation laminate in which a photosensitive resin film and a carrier film were laminated in that order on the copper foil surface of a printed circuit board substrate. (2) Sensitivity measurement of photosensitive resin film After peeling and removing the carrier film from the evaluation laminate obtained above, a 41-step tablet was placed, and exposure was performed using a direct imaging exposure system "DXP-3512" (manufactured by Oak Manufacturing Co., Ltd.) with an ultra-high pressure mercury lamp as the light source. The exposure pattern used was a grid pattern of dots (dot diameter:distance between dot centers = 1:2). The dot diameter was varied in 5 μm increments within the range of φ30 to 100 μm. After exposure, the unexposed areas of the photosensitive resin composition were left at room temperature for 30 minutes, and then spray-developed for 60 seconds using a 1% by mass aqueous sodium carbonate solution at 30°C. After development, the exposure energy amount at which the gloss retention step count of the 41-step tablet reached 8.0 was determined by the sensitivity (unit: mJ / cm²) of the photosensitive resin film. 2 The sensitivity was set to ). Using the pattern exposed at this sensitivity, the resolution of vias provided on the photosensitive resin film was evaluated according to the evaluation criteria below. (3) Evaluation of resolution The resolution was evaluated by exposing the photosensitive resin film to the exposure energy amount that corresponds to the sensitivity of the film measured in (2) above, i.e., the step number of 8.0, followed by spray development, and then observing the via pattern using an optical microscope and evaluating it according to the following criteria. The above-mentioned "aperture" refers to the state in which the copper foil of the substrate for the printed circuit board can be seen when observing the via portion of the dot pattern using an optical microscope. A judgment of "A" indicating via aperture indicates good characteristics. A: The φ60μm via portion of the dot pattern is open. C: The φ60μm via portion of the dot pattern is not open.

[0111] [2. Evaluation of adhesion strength (peel strength) with plated copper] (1) Preparation of evaluation laminates and measurement of the sensitivity of photosensitive resin films In the procedures of (1) and (2) in [1. Evaluation of Via Resolution] above, the exposure machine used was changed to a parallel light exposure machine using an ultra-high pressure mercury lamp as the light source (manufactured by Oak Manufacturing Co., Ltd., product name "EXM-1201"), but the operation was carried out in the same manner as in the procedures of (1) and (2) in [1. Evaluation of Via Resolution] above, and the amount of exposure energy at which the gloss retention step number becomes 8.0 was determined, and this was used to determine the sensitivity (unit: mJ / cm) of the photosensitive resin film. 2 ) (2) Emission and development processes Next, the carrier film of the evaluation laminate was peeled off, and the entire surface of the exposed photosensitive resin film was exposed to light using the exposure energy amount determined above to form an insulating layer formed by the curing of the photosensitive resin film. After exposure, the film was left at room temperature for 30 minutes, and then spray-developed with a 1% by mass sodium carbonate aqueous solution at 30°C for 60 seconds. (3) Post-curing treatment Next, using a high-pressure mercury lamp-type UV conveyor system (manufactured by Oak Manufacturing Co., Ltd.), the exposure amount was 2 J / cm². 2 Post-UV curing was performed at the conveyor speed, and then post-thermal curing was carried out at 170°C for 1 hour using a hot air circulation dryer (manufactured by Futaba Kagaku Co., Ltd.). (4) Roughening treatment The evaluation laminate, after the above post-curing treatment, was treated with the swelling solution "Swelling Dip Securigant P" at 70°C for 5 minutes, then with the roughening solution "Dosing Securigant P500J" at 70°C for 10 minutes, and finally with the neutralizing solution "Reduction Conditioner Securigant P500" at 40°C for 5 minutes to perform roughening treatment. The swelling solution, roughening solution, and neutralizing solution were all manufactured by Atotech Japan Co., Ltd. (5) Plating treatment The evaluation laminate, after the roughening treatment described above, was subjected to electroless plating using the electroless plating solution "Prigant MSK-DK" (manufactured by Atotec Japan Co., Ltd.) at 30°C for 20 minutes, followed by electroplating using the electroplating solution "Caparaside HL" (manufactured by Atotec Japan Co., Ltd.) at 24°C and 2 A / dm². 2The process was carried out for one hour to form a plated copper layer on the insulating layer, and an evaluation substrate for measuring the adhesion strength with the plated copper was fabricated. The thickness of the plated copper formed by the plating process was set to 25 μm. (6) Measurement of adhesion strength (peel strength) with plated copper The adhesion strength to plated copper was measured by vertical peel strength at 23°C, in accordance with JIS C6481 (1996). Adhesion strength to plated copper was judged to be good if it was 0.40 kN / m or higher.

[0112] [3. Evaluation of insulation reliability (HAST resistance)] Using a printed circuit board substrate (manufactured by Hitachi Chemical Co., Ltd., product name: MCL-E-700G(R)) in which 3 μm thick copper foil was laminated on a glass epoxy substrate, comb-shaped electrodes with a line / space of 12 μm / 12 μm were fabricated using the MSAP (Modified Semi-Additive Process) method, and these were used as evaluation substrates. On this evaluation substrate, an interlayer insulating layer was formed using a photosensitive resin film in the same manner as in [1. Evaluation of via resolution], and then plated copper was formed in the same manner as in [2. Evaluation of adhesion strength (peel strength) with plated copper]. Subsequently, electrodes with a diameter of 6 mm were formed by etching. Then, the substrate was exposed to 130°C, 85% RH, and 6 V conditions for 200 hours. The resistance between the electrodes was measured, and if the resistance value was 10 -6 The time at which the resistance fell below Ω was defined as the time of copper migration, and the interlayer insulation reliability (HAST resistance) was evaluated according to the evaluation criteria below. A: No copper migration occurred even after 200 hours. B: Copper migration occurred between 100 hours and 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 Derivatives Bisphenol F novolac type epoxy resin [In the above general formula (I), Y 1 is a glycidyl group, R 1350 parts by mass of bisphenol F novolac type epoxy resin containing a structural unit of a hydrogen atom, [equivalent to component (a1)], 70 parts by mass of acrylic acid [equivalent to component (a2)], 0.5 parts by mass of methyl hydroquinone, and 120 parts by mass of carbitol acetate were charged, and the mixture was reacted by heating to 90°C and stirring until the mixture was completely dissolved. Next, the resulting solution was cooled to 60°C, 2 parts by mass of triphenylphosphine were added, and the mixture was heated to 100°C until the acid value of the solution reached 1 mg KOH / g. To the reaction solution, 98 parts by mass of tetrahydrophthalic anhydride [equivalent to component (a3)] and 85 parts by mass of carbitol acetate were added, and the mixture was heated to 80°C and reacted for 6 hours. Subsequently, the mixture was cooled to room temperature to obtain an acid-modified bisphenol F novolac-type epoxy acrylate (equivalent to component (A1-1)) with a solid content of 73% by mass.

[0114] <Examples 1-3, Comparative Examples 1-5> (Preparation of photosensitive resin composition) A photosensitive resin composition was prepared by compounding the compositions according to the formulations shown in Table 1 and kneading them in a three-roll mill. In each example, carbitol acetate was added as appropriate 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, manufactured by Teijin Limited, trade name) with a thickness of 25 μm was used as a carrier film. The photosensitive resin composition prepared in each example was applied to the carrier film so that the film thickness after drying was 25 μm. The film was dried at 100°C for 10 minutes using a hot air convection dryer to form a photosensitive resin film (photosensitive layer). Subsequently, a biaxially oriented polypropylene film (MA-411, manufactured by Oji F-Tex Co., Ltd., trade name) was laminated as a protective film onto the surface of the photosensitive resin film (photosensitive layer) opposite to the side in contact with the carrier film, thereby producing a photosensitive resin film with the carrier film and protective film laminated together. The prepared photosensitive resin film was used to perform each evaluation according to the method described above. 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 [equivalent to component (A1-1)] was used. • Dipentaerythritol pentaacrylate [(Aiii) equivalent ingredient] (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 type epoxy resin • Epoxy-modified polybutadiene: "PB3600" (manufactured by Daicel Chemicals, Ltd., product name) (D) Component; • Polyurethane: "Nipporan (registered trademark) 3116" (manufactured by Tosoh Corporation, product name) • Hydroxyl group-containing polyisopropylene: "poly ip" (manufactured by Idemitsu Kosan Co., Ltd., product name) • Polyester: "Teslac (registered trademark) 2505-63" (manufactured by Hitachi Chemical Co., Ltd., product name) (F) component; • Silica: Silica slurry with a solid content concentration of 70% by mass (manufactured by Admatex, average particle size 0.5 μm, dispersion medium: methyl ethyl ketone)

[0117] Table 1 shows that the examples demonstrated excellent via resolution, adhesion strength to plated copper, and insulation reliability. On the other hand, Comparative Example 1, which did not contain component (D), showed insufficient adhesion strength to plated copper. Furthermore, Comparative Examples 2-4 (compared to Examples 1-3, respectively), which contained component (D) but insufficient amounts, showed little improvement in adhesion strength to plated copper and decreased insulation reliability, indicating that small amounts of component (D) have a counterproductive effect. In addition, Comparative Example 5, which contained an excessive amount of component (D), showed deterioration in via resolution, adhesion strength to plated copper, and insulation reliability, indicating that excessive amounts have a counterproductive effect. [Explanation of symbols]

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

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 acidic substituent along with an ethylenically unsaturated group and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups, and the content ratio of component (A1) to component (Aiii) [(A1) / (Aiii)] (mass ratio) is 4 to 20. The aforementioned component (A1) is an acid-modified vinyl group-containing epoxy derivative (A1-1) obtained by reacting a compound obtained by modifying (a1) epoxy resin with (a2) an organic acid containing vinyl groups with (a3) ​​a polybasic acid anhydride containing saturated or unsaturated groups, The (D) elastomer comprises hydroxyl group-containing polyisopropylene, A photosensitive resin composition in which the content of the (D) elastomer is 10.8 to 30% by mass based on the total amount of resin components of the photosensitive resin composition.

2. The photosensitive resin composition according to claim 1, wherein the content of the (D) elastomer is 2 to 30% by mass on a basis of the total amount of resin components of the photosensitive resin composition.

3. The photosensitive resin composition according to claim 1 or 2, wherein the (A) photopolymerizable compound 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 difunctional vinyl monomer having two polymerizable ethylenically unsaturated groups.

4. A photosensitive resin composition for forming photovias, 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 circuit board comprising an interlayer insulating layer formed using the photosensitive resin composition described in any one of claims 1 to 3.

9. A multilayer printed circuit board comprising an interlayer insulating layer formed using the photosensitive resin film described in claim 6.

10. A semiconductor package comprising a semiconductor element mounted on a multilayer printed circuit board according to claim 8 or 9.

11. A method for manufacturing a multilayer printed circuit board, comprising the following steps (1) to (4). Step (1): A step of laminating the photosensitive resin film described in claim 6 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 step (1). Step (3): A step of roughening the vias and the interlayer insulating layer. Step (4): Step of forming a circuit pattern on the interlayer insulating layer.

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