JP2024040191A - Photosensitive resin composition, photosensitive resin film, multilayer printed board and semiconductor package, and method for manufacturing multilayer printed board - Google Patents

Abstract

PROBLEM TO BE SOLVED: 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

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present disclosure relates to a photosensitive resin composition, a photosensitive resin film, a multilayer printed wiring board, a semiconductor package, and a method for manufacturing a multilayer printed wiring board.

BACKGROUND ART In recent years, electronic devices have become smaller and more sophisticated, and multilayer printed wiring boards have become 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 has increased significantly, and in addition to miniaturization of wiring, thinning of insulating films and There is a demand for further reduction in the diameter of vias (also called via holes).

As a conventional method for manufacturing printed wiring boards, there is a method for manufacturing multilayer printed wiring boards using a build-up method (for example, see Patent Document 1) in which an interlayer insulating layer and a conductor circuit layer are sequentially laminated. . With the miniaturization of circuits, semi-additive construction methods, in which circuits are formed by plating, have become mainstream for multilayer printed wiring boards.
In the conventional semi-additive construction method, for example, (1) a thermosetting resin film is laminated on a conductor circuit, and the thermosetting resin film is cured by heating to form an "interlayer insulation layer". (2) Next, vias for interlayer connection are formed by laser processing, and desmear treatment and roughening treatment are performed by alkaline permanganate treatment or the like. (3) Thereafter, the substrate is subjected to electroless copper plating treatment, a pattern is formed using a resist, and then electrolytic copper plating is performed to form a copper circuit layer. (4) Next, the resist was removed and the electroless layer was flash-etched to form a copper circuit.

As mentioned above, laser machining is the mainstream method for forming vias in interlayer insulation layers formed by curing thermosetting resin films, and it is possible to reduce the diameter of vias by laser irradiation using a laser processing machine. has reached its limit. Furthermore, when forming vias using a laser processing machine, it is necessary to form each via hole one by one, and when it is necessary to provide a large number of vias due to high density, it takes a lot of time to form the vias, and manufacturing The problem is that it is inefficient.

Under these circumstances, as a method that can form a large number of vias at once, (A) acid-modified vinyl group-containing epoxy resin, (B) photopolymerizable compound, (C) photopolymerization initiator, and (D) inorganic filler are used. A plurality of small-diameter vias are formed at once by a photolithography method using a photosensitive resin composition containing a material and (E) a silane compound, and the content of the (D) inorganic filler is 10 to 80% by mass. A method has been proposed (for example, see Patent Document 2).

Japanese Patent Application Publication No. 7-304931 JP 2017-116652 Publication

In Patent Document 2, the problem is to suppress the decrease in adhesive strength with plated copper caused by using a photosensitive resin composition instead of a conventional thermosetting resin composition as a material for an interlayer insulating layer or a surface protective layer. In addition, the company also addressed issues such as resolution of vias and adhesion to silicon substrates and chip components, which the company says has been resolved. However, there is still room for further improvement in terms of via resolution, adhesive strength with plated copper, and insulation reliability.
Similarly, it is conceivable to reuse photosensitive resin compositions, which are the materials of conventional solder resists, as materials for interlayer insulating layers, but the interlayer insulating layers have properties that are not necessary for solder resists (for example, As interlayer insulation reliability, adhesion strength with plated copper, high heat resistance that can withstand multiple heating, high dimensional accuracy of via shape, etc.) are required, it is difficult to see whether it can withstand practical use as an interlayer insulation layer. It is difficult to predict and cannot be easily diverted.

Therefore, the object of the present invention is to provide a photosensitive resin composition with excellent via resolution, adhesion strength with plated copper, and insulation reliability, a photosensitive resin composition for forming a photovia, and a photosensitive resin composition for an interlayer insulating layer. It's about providing things. The present invention also provides a photosensitive resin film and a photosensitive resin film for interlayer insulation layers made of the photosensitive resin composition, a multilayer printed wiring board and a semiconductor package, and a method for producing the multilayer printed wiring board. It is about providing.

As a result of extensive research in order to solve the above problems, the present inventors have developed a photosensitive resin composition containing components (A) to (D) described below, in which the content of component (D) is It has been found that the above problem can be solved by setting a specific amount.
That is, the present invention relates to the following [1] to [13].

[1] 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,
A photosensitive resin composition in which the content of the elastomer (D) is 2 to 30% by mass based on the total amount of resin components of the photosensitive resin composition.
[2] The elastomer (D) includes at least one selected from the group consisting of styrene elastomer, olefin elastomer, polyester elastomer, urethane elastomer, polyamide elastomer, acrylic elastomer, and silicone elastomer. The photosensitive resin composition described in [1] above.
[3] The elastomer (D) is polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyamideimide resin, polyimide resin, xylene resin, polyphenylene sulfide resin, polyetherimide resin, polyetheretherketone resin, polyetherimide resin, The photosensitive resin composition according to [1] above, which contains at least one selected from the group consisting of tetrafluoroethylene resin, polyacrylonitrile resin, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxy-modified polyacrylonitrile.
[4] The (A) photopolymerizable compound having an ethylenically unsaturated group is composed of (Ai) a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group, and (Aii) two polymerizable ethylenically unsaturated groups. The above-mentioned [1] to [3] containing at least one selected from the group consisting of a difunctional vinyl monomer having an unsaturated group and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups. ] The photosensitive resin composition according to any one of the above.
[5] The photopolymerizable compound having an ethylenically unsaturated group (A) includes (A1) a photopolymerizable compound having an acidic substituent as well as an ethylenically unsaturated group. The photosensitive resin composition according to any one of the above.
[6] A photosensitive resin composition for forming photovias, comprising the photosensitive resin composition according to any one of [1] to [5] above.
[7] A photosensitive resin composition for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of [1] to [5] above.
[8] A photosensitive resin film comprising the photosensitive resin composition according to any one of [1] to [5] above.
[9] A photosensitive resin film for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of [1] to [5] above.
[10] A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin composition according to any one of [1] to [5] above.
[11] A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin film according to [8] above.
[12] A semiconductor package comprising a semiconductor element mounted on the multilayer printed wiring board according to [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 step (1).
Step (3): A step of roughening the via and the interlayer insulating layer.
Step (4): A step of forming a circuit pattern on the interlayer insulating layer.

According to the present invention, a photosensitive resin composition, a photosensitive resin composition for forming a photovia, and a photosensitive resin composition for an interlayer insulating layer, which have excellent via resolution, adhesive strength with plated copper, and insulation reliability, are provided. can be provided. It also provides a photosensitive resin film and a photosensitive resin film for an interlayer insulating layer made of the photosensitive resin composition, and an interlayer insulating layer formed using the photosensitive resin composition or the photosensitive resin film. It is possible to provide a multilayer printed wiring board and a semiconductor package containing the same.
Furthermore, it is possible to provide a method for efficiently manufacturing a multilayer printed wiring board that has high-resolution vias, has high adhesive strength between an interlayer insulating layer and plated copper, and has excellent insulation reliability. The vias included in the multilayer printed wiring board obtained by the manufacturing method of the present invention can have a smaller diameter than the vias formed by laser processing.

FIG. 2 is a schematic diagram showing one aspect of the manufacturing process of the multilayer printed wiring board of the present embodiment.

In the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with the value shown in the Examples. Furthermore, in the present specification, the content of each component in the photosensitive resin composition is defined as the content of each component in the photosensitive resin composition, unless otherwise specified. It means the total content of the plurality of substances.
Furthermore, embodiments in which the items described in this specification are arbitrarily combined are also included in the present invention.

[Photosensitive resin composition, photosensitive resin composition for forming photovias, and photosensitive resin composition for interlayer insulation layer]
The photosensitive resin composition according to one embodiment of the present invention (hereinafter sometimes simply referred to as the present embodiment) comprises (A) a photopolymerizable compound having an ethylenically unsaturated group, and (B) a photopolymerizable compound having an ethylenically unsaturated group. A photosensitive resin composition containing an initiator, (C) an epoxy resin, and (D) an elastomer, wherein the content of the (D) elastomer is 2 to 30 mass based on the total amount of resin components of the photosensitive resin composition. % photosensitive resin composition.
In addition, in this specification, the above-mentioned components may be respectively referred to as (A) component, (B) component, (C) component, (D) component, etc., and other components may be abbreviated in the same manner. There is. In this specification, the "resin component" refers to the above-mentioned components (A) to (D), and other components that may be included as necessary (for example, (E) and (G) to (H ) components, etc.), but does not include (F) an inorganic filler, which may be included as required, which will be described later. In addition, "solid content" refers to the nonvolatile content excluding volatile substances such as water and solvent contained in the photosensitive resin composition, and when the resin composition is dried, it does not volatilize. It shows the remaining components, and also includes those that are liquid, starch syrup-like, and wax-like at room temperature around 25°C.

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, the photosensitive resin composition of this embodiment has excellent via resolution, adhesive strength with plated copper, and insulation reliability, and is useful as an interlayer insulation layer of a multilayer printed wiring board. A photosensitive resin composition for an interlayer insulation layer is also provided. In the present specification, the photosensitive resin composition includes a photosensitive resin composition for forming a photovia and a photosensitive resin composition for an interlayer insulating layer.
In addition, the photosensitive resin composition of this embodiment is useful as a negative photosensitive resin composition.
Each component that the photosensitive resin composition may contain will be described in detail below.

<(A) Photopolymerizable compound having an ethylenically unsaturated group>
The photosensitive resin composition of this embodiment contains a photopolymerizable compound having an ethylenically unsaturated group as the component (A). Component (A) contains photopolymerizable functional groups such as ethylene groups such as vinyl groups, allyl groups, propargyl groups, butenyl groups, ethynyl groups, phenylethynyl groups, maleimide groups, nadimide groups, and (meth)acryloyl groups. It is a compound that has a functional group that has a sexually unsaturated bond. As the functional group exhibiting photopolymerizability, a (meth)acryloyl group is preferable.

As a photopolymerizable compound having an ethylenically unsaturated group, (Ai) is used from the viewpoint of increasing the chemical resistance after curing (exposure) and increasing the difference in developer resistance between the exposed area and the unexposed area. a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group; (Aii) a difunctional vinyl monomer having two polymerizable ethylenically unsaturated groups; and (Aiii) at least three polymerizable ethylenically unsaturated groups. An embodiment containing at least one selected from the group consisting of polyfunctional vinyl monomers having groups is preferable, and an embodiment containing the component (Aiii) is more preferable. Components (Ai) to (Aiii) preferably have a molecular weight of 1,000 or less.

((Ai) monofunctional vinyl monomer)
Examples of the monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group include (meth)acrylic acid, (meth)acrylic acid alkyl ester, and the like. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and (meth)acrylate. Examples include acrylic acid hydroxylethyl ester. Component (Ai) may be used alone or in combination of two or more.

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

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

((A1) Photopolymerizable compound having an acidic substituent as well as an ethylenically unsaturated group)
In addition, a photopolymerizable compound having an ethylenically unsaturated group can be developed with an alkali, and from the viewpoint of via resolution and adhesive strength with plating copper, (A1) an acidic substituted compound with an ethylenically unsaturated group can be used. An embodiment containing a photopolymerizable compound having a group is also preferred. Here, examples of the acidic substituent include a carboxyl group, a sulfonic acid group, a phenolic hydroxyl group, and among these, a carboxyl group is preferable.
The component (A1) is a compound obtained by modifying (a1) an epoxy resin with (a2) a vinyl group-containing organic acid, which is capable of alkaline development and from the viewpoint of via resolution and adhesive strength with plated copper. [Hereinafter, it may be referred to as (A') component.] "(A1-1) Acid-modified vinyl group-containing epoxy derivative" which is obtained by reacting (a3) a polybasic acid anhydride containing a saturated group or an unsaturated group can be used.

-(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, and the like. Among these, glycidyl ether type epoxy resins are preferred.

Epoxy resins are also classified into various epoxy resins depending on their main skeletons, and each of the above-mentioned types of epoxy resins is further classified into the following types. 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 above-mentioned bisphenol novolac type epoxy resins, such as phenol novolac type epoxy resins, cresol novolac type epoxy resins, biphenyl novolac type epoxy resins; Phenol aralkyl type epoxy resins; Biphenyl aralkyl type epoxy resins; Stilbene type epoxy Resin; dicyclopentadiene type epoxy resin; naphthalene skeleton-containing type epoxy resin such as naphthalene type epoxy resin, naphthol novolac type epoxy resin, naphthol type epoxy resin, naphthol aralkyl type epoxy resin, naphthylene ether type epoxy resin; biphenyl type epoxy resin ; biphenylaralkyl type epoxy resin; xylylene type epoxy resin; dihydroanthracene type epoxy resin; dicyclopentadiene type epoxy resin; alicyclic epoxy resin; aliphatic chain epoxy resin; rubber-modified epoxy resin.
Among these, from the viewpoint of reliability during semiconductor chip mounting, bisphenol-based novolac type epoxy resin is preferred, and bisphenol F novolac type epoxy resin is more preferred. (a1) Epoxy resins may be used alone or in combination of two or more.

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

In general formula (I), R ¹ represents a hydrogen atom or a methyl group, and Y ¹ each independently represents a hydrogen atom or a glycidyl group. Two R ¹ 's may be the same or different. At least one of the two Y ¹ 's represents a glycidyl group.
R ¹ is preferably a hydrogen atom from the viewpoint of via resolution and adhesive strength with plated copper. Furthermore, from the same point of view, it is preferable that all Y ¹ 's are glycidyl groups.
The number of structural units in the epoxy resin (a1) having the structural unit represented by general formula (I) is 1 or more, preferably 10 to 100, more preferably 15 to 80, and even more preferably is 15-70. When the number of structural units is within the above range, adhesive strength with plated copper, heat resistance, and insulation reliability tend to improve.
In general formula (I ⁾ , those in which R ¹ is a hydrogen atom and both Y ¹ are glycidyl groups are referred to as EXA-7376 series (manufactured by DIC Corporation, trade name); Those in which Y 1 is a methyl group and both Y ¹ are glycidyl groups are commercially available as EPON SU8 series (manufactured by Mitsubishi Chemical Corporation, trade name).

-(a2) Vinyl group-containing organic acid-
The vinyl group-containing organic acid (a2) is not particularly limited, but vinyl group-containing monocarboxylic acids are preferred. Examples of the vinyl group-containing monocarboxylic acid include acrylic acid, acrylic acid dimer, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, α-cyanocinnamic acid, etc. acrylic acid derivatives; half-ester compounds that are the reaction products of hydroxyl group-containing acrylates and dibasic acid anhydrides; reaction products of vinyl group-containing monoglycidyl ethers or vinyl group-containing monoglycidyl esters and dibasic acid anhydrides; Certain half-ester compounds; and the like.

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

Examples of the hydroxyl group-containing acrylate, vinyl group-containing monoglycidyl ether, and vinyl group-containing monoglycidyl ester used in the synthesis of the half-ester compound, which is an example of component (a2), include hydroxyethyl acrylate, hydroxyethyl methacrylate, and 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.

The dibasic acid anhydride used in the synthesis of the half-ester compound may contain a saturated group or an unsaturated group. Examples of dibasic acid anhydrides include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride. , ethylhexahydrophthalic anhydride, itaconic anhydride, and the like.

In the reaction between the component (a1) and the component (a2), the reaction may be carried out at a ratio of 0.6 to 1.05 equivalents of the component (a2) to 1 equivalent of the epoxy group of the component (a1). Preferably, the reaction may be carried out at a ratio of 0.8 to 1.0 equivalents. Reaction at such a ratio tends to improve photopolymerizability, that is, increase photosensitivity and improve resolution of vias.

The component (a1) and the component (a2) can be dissolved in an organic solvent and reacted.
Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, and dipropylene. Glycol ethers such as 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 ; Examples include petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

Furthermore, it is preferable to use a catalyst to promote the reaction between the component (a1) and the component (a2). Examples of the catalyst include amine catalysts such as triethylamine and benzylmethylamine; quaternary ammonium salt catalysts such as methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide; and triphenylphosphine. Examples include phosphine catalysts such as. Among these, phosphine catalysts are preferred, and triphenylphosphine is more preferred.
The amount of the catalyst used is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably is 0.1 to 2 parts by mass. If the above usage amount is used, the reaction between the component (a1) and the component (a2) tends to be promoted.

Further, it is preferable to use a polymerization inhibitor for the purpose of preventing polymerization during the reaction. Examples of the polymerization inhibitor include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol.
When a polymerization inhibitor is used, from the viewpoint of improving the storage stability of the composition, the amount of the polymerization inhibitor used is preferably 0.00 parts based on a total of 100 parts by mass of the components (a1) and (a2). The amount is 0.01 to 1 part by weight, more preferably 0.02 to 0.8 part by weight, and even more preferably 0.05 to 0.5 part by weight.

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

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

-(a3) Polybasic acid anhydride-
The component (a3) may contain a saturated group or an unsaturated group. Component (a3) includes, for example, succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, Examples include ethylhexahydrophthalic anhydride and itaconic anhydride. Among these, from the viewpoint of via resolution, tetrahydrophthalic anhydride is preferred.

By further reacting the component (A') obtained above with the component (a3) containing a saturated or unsaturated group, the hydroxyl group of the component (A') (the hydroxyl group originally present in the component (a1)) can be removed. It is presumed that the acid-modified vinyl group-containing epoxy derivative (A1-1) is obtained by half-esterifying the acid anhydride group of the component (a3) and the acid anhydride group of the component (a3).

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

From the viewpoint of productivity, the reaction temperature between component (A') and component (a3) is preferably 50 to 150°C, more preferably 60 to 120°C, and still more preferably 70 to 100°C.

(A1-1) As the acid-modified vinyl group-containing epoxy derivative, commercially available products may be used, and commercially available products include, for example, CCR-1218H, CCR-1159H, CCR-1222H, PCR-1050, and 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., product name), UE-9000, Examples include UE-EXP-2810PM and UE-EXP-3045 (product names manufactured by DIC Corporation).

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

In addition, as the component (A1), an epoxy polyurethane obtained by reacting a compound obtained by modifying the epoxy resin (a1) with a vinyl group-containing organic acid (a2), that is, a component (A'), and an isocyanate compound. Resin (A1-3) can also be used. Component (A1-3) may be used alone or in combination of two or more.

((A1) Molecular weight of photopolymerizable compound having acidic substituent as well as 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 adhesive strength with plated copper, heat resistance, and insulation reliability will improve. In particular, the weight average molecular weight (Mw) of the acid-modified vinyl group-containing epoxy derivative (A1-1) is preferably within the above range. Here, in this specification, the weight average molecular weight is a value measured by gel permeation chromatography (GPC) (manufactured by Tosoh Corporation) using a standard polystyrene calibration curve. This is a value measured according to the method described.
<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 a standard polystyrene calibration curve was defined as the weight average molecular weight. In addition, to create a calibration curve, a set of 5 samples ("PStQuick MP-H" and "PStQuick B", manufactured by Tosoh Corporation) was used as standard polystyrene.
(GPC measurement device)
GPC device: High-speed GPC device “HCL-8320GPC”, detector is differential refractometer or UV, manufactured by Tosoh Corporation Column: Column TSKgel SuperMultipore HZ-H (column length: 15 cm, column inner diameter: 4.6 mm), Tosoh Corporation Manufactured by the company (measurement conditions)
Solvent: Tetrahydrofuran (THF)
Measurement temperature: 40℃
Flow rate: 0.35mL/min Sample concentration: 10mg/THF5mL
Injection volume: 20μL

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

Component (A) is not particularly limited, but from the viewpoint of photosensitivity, it is preferable to use the component (A1) and the component (Aiii) together. In this case, the content ratio [(A1)/(Aiii)] (mass ratio) of the component (A1) and the component (Aiii) is preferably 2 to 20, more preferably 3 to 15, even more preferably 4 to It is 12.

<(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.
Component (B) includes, for example, benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1 -dichloroacetophenone, 1-hydroxycyclohexylphenylketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2- Acetophenones such as morpholino-1-propanone and N,N-dimethylaminoacetophenone; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone, etc. anthraquinones; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone, methylbenzophenone , 4,4'-dichlorobenzophenone, 4,4'-bis(diethylamino)benzophenone, Michler's ketone, 4-benzoyl-4'-methyldiphenyl sulfide, and other benzophenones; 9-phenylacridine, 1,7-bis(9, Acridines such as 9'-acridinyl)heptane; Acylphosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-( O-benzoyloxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime), 1-phenyl-1,2-propanedione Examples include oxime esters such as -2-[O-(ethoxycarbonyl)oxime]. Among these, acetophenones and thioxanthone are preferred, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2,4-diethylthioxanthone are more preferred. Acetophenones have the advantage of being difficult to volatilize and are difficult to generate as outgas, and thioxanthones have the advantage of being photocurable even in the visible light range.
Component (B) may be used alone or in combination of two or more. When two or more types are used in combination, it is preferable to use acetophenones and thioxanthone in combination, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2,4-diethylthioxanthone are preferred. It is more preferable to use them together.

(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, based on the total amount of resin components in the photosensitive resin composition. , more preferably 0.5 to 1.5% by mass. If the content of the component (B) is 0.2% by mass or more, the risk of elution of exposed areas during development in the interlayer insulating layer formed using the photosensitive resin composition tends to be reduced. If the content is 15% by mass or less, the heat resistance tends to improve.

<(B') Photopolymerization initiation aid>
The photosensitive resin composition of this embodiment may contain (B') a photopolymerization initiation aid together with the above-mentioned (B) component. (B') Photopolymerization initiation aids include, for example, N,N-dimethylaminobenzoic acid ethyl ester, N,N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine, etc. Examples include tertiary amines. Component (B') may be used alone or in combination of two or more.
When the photosensitive resin composition of the present embodiment contains component (B'), the content is preferably 0.01 to 20% by mass, more preferably The amount is 0.2 to 5% by weight, more preferably 0.3 to 2% by weight. Note that the photosensitive resin composition of this embodiment does not need to contain the component (B').

<(C) Epoxy resin>
Component (C) does not contain anything corresponding to component (A), and in this respect it can be said that component (C) does not have an ethylenically unsaturated group. Further, a substance having an epoxy group while satisfying the above conditions is included in component (C).
The epoxy resin (C) 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, and the like. Among these, glycidyl ether type epoxy resins are preferred.

Epoxy resins are also classified into various epoxy resins depending on their main skeletons, and each of the above-mentioned types of epoxy resins is further classified into the following types. 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 above-mentioned bisphenol novolac type epoxy resins, such as phenol novolac type epoxy resins, cresol novolac type epoxy resins, biphenyl novolac type epoxy resins; Phenol aralkyl type epoxy resins; Biphenyl aralkyl type epoxy resins; Stilbene type epoxy Resin; dicyclopentadiene type epoxy resin; naphthalene skeleton-containing type epoxy resin such as naphthalene type epoxy resin, naphthol novolac type epoxy resin, naphthol type epoxy resin, naphthol aralkyl type epoxy resin, naphthylene ether type epoxy resin; biphenyl type epoxy resin ; Biphenylaralkyl type epoxy resin; It is classified into trimethylol type epoxy resin; aliphatic chain epoxy resin; rubber-modified epoxy resin; etc.
Component (C) may be used alone or in combination of two or more.

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 adhesive strength with plated copper. Preferably, bisphenol A type epoxy resin and bisphenol F type epoxy resin are more preferable, and bisphenol F type epoxy resin is even more preferable.
Commercially available products can be used for these, for example, bisphenol A epoxy resin ("jER828EL", "YL980" manufactured by Mitsubishi Chemical Corporation), bisphenol F epoxy resin ("jER806H", "YL983U" manufactured by Mitsubishi Chemical Corporation), ”), naphthalene type epoxy resin (DIC Corporation “HP4032D”, “HP4710”), naphthalene skeleton-containing polyfunctional epoxy resin (Nippon Kayaku Co., Ltd. “NC7000”), naphthol type epoxy resin (Nippon Steel & Sumitomo Metal Co., Ltd.) "ESN-475V" manufactured by Kagaku Co., Ltd.), epoxy resin with biphenyl structure ("NC3000H", "NC3500" manufactured by Nippon Kayaku Co., Ltd.), "YX4000HK", "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 & Sumikin Chemical Co., Ltd.), naphthylene ether type epoxy resin (“EXA7311-G4” manufactured by DIC Corporation), etc. It will be done.

(C) As the epoxy resin, epoxy-modified polybutadiene can be used in addition to the above-mentioned examples. In particular, as component (C), it is preferable to use an aromatic epoxy resin that is solid at room temperature and an epoxy resin that is liquid at room temperature in combination from the viewpoint of handling properties during printed wiring board production. From this point of view, It is preferable to use the above-mentioned epoxy resin (an aromatic epoxy resin that is solid at room temperature) and epoxy-modified polybutadiene (an epoxy resin that is liquid at room temperature) in combination. In this case, the content ratio of both used together (aromatic epoxy resin that is solid at room temperature/epoxy resin that is liquid at room temperature) is preferably 95/5 to 60/40, more preferably 90/10 in terms of mass ratio. ~70/30.

The epoxy-modified polybutadiene preferably has a hydroxyl group at the end of the molecule, more preferably has a hydroxyl group at both ends of the molecule, and even more preferably has a hydroxyl group only at both ends of the molecule. Further, the number of hydroxyl groups that the epoxy-modified polybutadiene has is not particularly limited as long as it is one or more, but it is preferably 1 to 5, more preferably 1 or 2, and still 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 adhesive strength with plated copper, heat resistance, thermal expansion coefficient, and flexibility.

(In the above formula (C-1), a, b, and c each represent the ratio of the structural units in parentheses, a is 0.05 to 0.40, and b is 0.02 to 0.30. , c is 0.30 to 0.80, and further satisfies a+b+c=1.00 and (a+c)>b.y represents the number of structural units in square brackets, and is an integer from 10 to 250. be.)

In the general formula (C-1), the bonding order of each structural unit within the square brackets is random. In other words, the structural unit shown on the left, the structural unit shown in the center, and the structural unit shown on the right may be interchanged, and they can be used as (a), (b), (c), respectively. Expressed as -[(a)-(b)-(c)]-[(a)-(b)-(c)-]-, -[(a)-(c)-(b)]- [(a)-(c)-(b)-]-,-[(b)-(a)-(c)]-[(b)-(a)-(c)-]-,-[( a)-(b)-(c)]-[(c)-(b)-(a)-]-, -[(a)-(b)-(a)]-[(c)-(b )-(c)-]-, -[(c)-(b)-(c)]-[(b)-(a)-(a)-]-, and various other bonding orders are possible.
From the viewpoint of adhesive 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. Further, from the same viewpoint, y is preferably an integer of 30 to 180.

In the general formula (C-1), a commercially available epoxidized polybutadiene in which a=0.20, b=0.20, c=0.60, and y=an integer from 10 to 250 includes “Epolead ( PB3600 (registered trademark) (manufactured by Daicel Corporation).

(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, based on the total amount of resin components in the photosensitive resin composition. , more preferably 7 to 30% by weight, particularly preferably 10 to 25% by weight. When the content of component (C) is 5% by mass or more, sufficient crosslinking of the photosensitive resin composition is obtained, and adhesive strength with plated copper and insulation reliability tend to improve. On the other hand, if it is 70% by mass or less, the resolution of vias tends to be good.

<(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, adhesive strength with plated copper, and insulation reliability. In addition, component (D) also has the effect of suppressing a decrease in flexibility and adhesive strength with plated copper due to distortion (internal stress) inside the cured product due to curing shrinkage of component (A).

Examples of the elastomer include styrene elastomer, olefin elastomer, polyester elastomer, urethane elastomer, polyamide elastomer, acrylic elastomer, silicone elastomer, etc., and at least one selected from these may be used. is preferred. These elastomers are comprised 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.
Among the above examples, component (D) is at least one selected from the group consisting of olefin elastomers, polyester elastomers, and urethane elastomers from the viewpoint of compatibility, solubility, and adhesive strength with plated copper. , and more preferably a urethane elastomer. Further, it is more preferable that component (D) is at least one selected from the group consisting of olefin elastomer, polyester elastomer, and urethane elastomer, and particularly preferably urethane elastomer.

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

Commercially available styrenic elastomers can be used, and commercially available products include Tuffprene, Solprene T, Asaprene T, and Tufftec (all of which are manufactured by Asahi Kasei Corporation; "Tuffprene", "Asaprene", and "Tufftec" are registered trademarks). , Elastomer AR (manufactured by Aron Kasei Co., Ltd.), Clayton G, Hyperreflex (manufactured by Shell Japan Co., Ltd.), JSR-TR, TSR-SIS, Dynalon (manufactured by JSR Corporation), Denka STR (Denka Stock Co., Ltd.) company), 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 (manufactured by Kuraray Co., Ltd., "Septon" and "Hyblar" are registered trademarks), Sumiflex (manufactured by Sumitomo Bakelite Co., Ltd.), Rheostomer, Actimer (manufactured by RIKEN TECHNOS Co., Ltd., "Rheostomer" and " Actimer" is a registered trademark).

(olefin elastomer)
The olefin elastomer is, for example, a polymer or copolymer of α-olefin having 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, and 4-methyl-pentene. The olefin elastomer may have a hydroxyl group at the end of the molecule, and preferably has a hydroxyl group at the end of the molecule.
Preferred examples of the olefin elastomer include polyethylene, polybutadiene, hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisopropylene, ethylene-propylene copolymer (EPR), ethylene-propylene-diene copolymer (EPDM), and the like. Further, the α-olefin having 2 to 20 carbon atoms and a non-conjugated diene having 2 to 20 carbon atoms such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidenenorbornene, butadiene, isoprene, etc. Also included are copolymers and the like. Further examples include carboxy-modified NBR, which is a butadiene-acnylonitrile copolymer copolymerized with methacrylic acid.
The olefin elastomer preferably has a number average molecular weight of 1,000 to 5,000, more preferably 1,500 to 3,500.

Commercially available olefin elastomers may be used, and examples of commercially available products include Milastomer (manufactured by Mitsui Chemicals, Inc., trade name), EXACT (manufactured by ExxonMobil, trade name), and ENGAGE (manufactured by The Dow Chemical Co., Ltd.).・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, trade name), "XER series" (manufactured by JSR Corporation, trade name) of butadiene-acrylonitrile copolymer modified with carboxyl groups on both ends, epoxidized polyester which is partially epoxidized polybutadiene. Examples include butadiene BF-1000 (manufactured by Nippon Soda Co., Ltd., trade name), PB-4700, PB-3600 (manufactured by Daicel Corporation, trade name).

(Polyester elastomer)
Examples of the polyester elastomer include those obtained by polycondensing dicarboxylic acids or derivatives thereof and diol compounds or derivatives thereof.
Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid; aromatic dicarboxylic acids in which the hydrogen atom of the aromatic ring of the aromatic dicarboxylic acid is substituted with a methyl group, ethyl group, phenyl group, etc. Examples include aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid and dodecanedicarboxylic acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; and the like. As the dicarboxylic acid, from the viewpoint of adhesion to the base material, it is also preferable to use a dimer acid derived from a natural product. One type of dicarboxylic acid may be used alone, or two or more types may be used in combination.
Examples of the derivative of the dicarboxylic acid include anhydrides of the dicarboxylic acid.
Examples of the diol compound include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decanediol; 1,4-cyclohexanediol Alicyclic diols such as; and the like can be mentioned. One type of diol compound may be used alone, or two or more types may be used in combination.
The polyester elastomer preferably has a number average molecular weight of 900 to 30,000, more preferably 1,000 to 25,000, even more preferably 5,000 to 20,000.

Commercially available polyester elastomers may be used, such as Hytrel (manufactured by DuPont-Toray Co., Ltd., "Hytrel" is a registered trademark) and Pelprene (manufactured by Toyobo Co., Ltd., "Pelprene" is a registered trademark). Trademark), Teslac 2505-63 (manufactured by Hitachi Chemical Co., Ltd., "Tesluck" is a registered trademark), Espel (manufactured by Hitachi Chemical Co., Ltd., "Espel" is a registered trademark), etc. are commercially available.

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

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

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

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

(acrylic elastomer)
Examples of the acrylic elastomer include polymers of raw material monomers containing acrylic ester as a main component. Preferred examples of the acrylic ester include ethyl acrylate, butyl acrylate, methoxyethyl acrylate, and ethoxyethyl acrylate. Further, the crosslinking point monomer may be a copolymer of glycidyl methacrylate, allyl glycidyl ether, etc., or may be a copolymer of acrylonitrile, ethylene, etc. Specific examples include acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer, and the like.
The acrylic elastomer preferably has a number average molecular weight of 1,000 to 50,000, more preferably 2,000 to 30,000.

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

Commercially available silicone elastomers may be used, and examples of commercially available products include KE series (manufactured by Shin-Etsu Chemical Co., Ltd.), SE series, CY series, and SH series (all manufactured by Dow Corning Toray Co., Ltd.). can be mentioned.

(Other elastomers)
In addition, as component (D), polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyamideimide resin, polyimide resin, xylene resin, polyphenylene sulfide resin, polyetherimide resin, polyetheretherketone resin, polyetherimide resin, tetra Also preferred is an embodiment containing at least one selected from the group consisting of fluoroethylene resin, polyacrylonitrile resin, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxy-modified polyacrylonitrile.

(Content of component (D))
The content of component (D) in the photosensitive resin composition of the present embodiment is 2 to 30% by mass, preferably 2 to 20% by mass, more preferably 3% by mass, based on the total amount of resin components in the photosensitive resin composition. ~15% by weight, more preferably 5-15% by weight, particularly preferably 8-13% by weight. If the content of component (D) is 0% by mass, the adhesive strength with plated copper will be insufficient, and even if component (D) is contained, if the content is less than 2% by mass, Not only is the effect of improving the adhesive strength with plated copper insufficient, but also the insulation reliability is reduced. If the content of component (D) exceeds 30% by mass, the via resolution, adhesive strength with plated copper, and insulation reliability will all be insufficient.

<(E) Thermal polymerization initiator>
The photosensitive resin composition of this embodiment may contain, and preferably contains, a thermal polymerization initiator as component (E).
Thermal polymerization initiators are not particularly limited, but include, for example, diisopropylbenzene hydroperoxide "Percumil P" (trade name, manufactured by NOF Corporation (the same applies hereinafter)), cumene hydroperoxide "Percumyl H" , hydroperoxides such as t-butyl hydroperoxide "Perbutyl H"; α,α-bis(t-butylperoxy-m-isopropyl)benzene "Perbutyl P", dicumyl peroxide "Percyl D", 2, 5-dimethyl-2,5-bis(t-butylperoxy)hexane "Perhexa 25B", t-butylcumyl peroxide "Perbutyl C", di-t-butyl peroxide "Perbutyl D", 2,5-dimethyl Dialkyl peroxides such as -2,5-bis(t-butylperoxy)hexine-3 "Perhexine 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; Examples include azo compounds such as 2,2'-azobisisobutylnitrile, 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile); . Among these, dialkyl peroxides are preferred from the viewpoint of not inhibiting photopolymerizability and are highly effective in improving the physical properties and characteristics of the photosensitive resin composition, and 2,5-dimethyl-2,5- More preferred is bis(t-butylperoxy)hexyne-3.
Thermal polymerization initiators may be used alone or in combination of two or more.

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

<(F) Inorganic filler>
The photosensitive resin composition of this embodiment may contain an inorganic filler as the component (F), and preferably contains an inorganic filler. By containing an inorganic filler, the thermal expansion can be lowered and the possibility of warping is reduced. In thermosetting resin compositions conventionally used as interlayer insulation layers of multilayer printed wiring boards, low thermal expansion has been achieved by incorporating inorganic fillers, but photosensitive resin compositions containing inorganic fillers have In this case, the inorganic filler causes light scattering and hinders development, so it is difficult to reduce thermal expansion by including a large amount of the inorganic filler. As described above, there are new challenges unique to photosensitive resin compositions when containing an inorganic filler, but the photosensitive resin composition of this embodiment does not contain a large amount of inorganic filler. Also, the resolution of the vias is high. Therefore, it is possible to achieve low thermal expansion and high resolution of the via.

As the component (F), for example, silica (SiO ₂ ), alumina (Al ₂ O ₃ ), titania (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), zirconia (ZrO ₂ ), silicon nitride (Si ₃ N ₄ ), barium titanate (BaO・TiO ₂ ), barium carbonate (BaCO ₃ ), magnesium carbonate (MgCO ₃ ), aluminum hydroxide (Al(OH) ₃ ), magnesium hydroxide (Mg(OH) ₂ ), titanium Lead acid (PbO・TiO ₂ ), lead zirconate titanate (PZT), lanthanum lead zirconate titanate (PLZT), gallium oxide (Ga ₂ O ₃ ), spinel (MgO・Al ₂ O ₃ ), mullite (3Al Contains _2O3.2SiO2 ), cordierite ( _{2MgO.2Al2O3 / 5SiO2} ), talc ( _{3MgO.4SiO2.H2O} ), _{aluminum titanate} ( _TiO2.Al2O3 ), _{and yttria .} 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.TiO ₂ ), hydrotalcite, mica, calcined kaolin, carbon (C), and the like. Component (F) may be used alone or in combination of two or more.

The average particle diameter 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 diameter of component (F) is the volume average particle diameter of the inorganic filler in a state dispersed in the photosensitive resin composition, and is a value obtained by measurement as follows. First, after diluting (or dissolving) the photosensitive resin composition 1,000 times with methyl ethyl ketone, it was measured using a submicron particle analyzer (manufactured by Beckman Coulter, Inc., trade name: N5) according to the international standard ISO13321. Accordingly, particles dispersed in a solvent with a refractive index of 1.38 are measured, and the particle diameter at an integrated value of 50% (volume basis) in the particle size distribution is defined as the average particle diameter (volume average particle diameter). In addition, the (F) component contained in the photosensitive resin film and interlayer insulation layer provided on the carrier film was also diluted (or dissolved) 1,000 times (volume ratio) using a solvent as described above. After that, the particles can be measured using the above-mentioned submicron particle analyzer.

Component (F) may include silica from the viewpoint of heat resistance and low thermal expansion, and barium sulfate from the viewpoint of heat resistance and adhesive strength with plated copper. may be included in combination. In addition, the component (F) may be surface-treated with alumina or an organic silane compound from the viewpoint of improving the dispersibility of the inorganic filler in the photosensitive resin composition due to the agglomeration prevention effect. .

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

<(G) Pigment>
The photosensitive resin composition of the present embodiment may contain a pigment as the component (G) depending on the desired color in order to adjust photosensitivity and the like. As component (G), a coloring agent that develops a desired color may be appropriately selected and used, such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black. Preferred examples include known colorants such as.

(Content of (G) component)
When the photosensitive resin composition of the present embodiment contains component (G), the content is preferably 0.01% based on the total solid content of the photosensitive resin composition from the viewpoint of adjusting photosensitivity. ~5% by weight, more preferably 0.03~3% by weight, even more preferably 0.05~2% by weight.

<(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, adhesive strength with plated copper, and chemical resistance.
Component (H) includes, for example, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole. imidazole derivatives such as; guanamines such as acetoguanamine and benzoguanamine; polyamines such as diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, and polybasic hydrazide; Organic acid salts and/or epoxy adducts; amine complexes of boron trifluoride; triazines such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xylyl-S-triazine, etc. Derivatives: trimethylamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa(N-methyl)melamine, 2,4,6-tris(dimethylaminophenol), tetramethylguanidine , m-aminophenol and other tertiary amines; polyvinylphenol, polyvinylphenol bromide, phenol novolak, alkylphenol novolak and other polyphenols; tributylphosphine, triphenylphosphine, tris-2-cyanoethylphosphine and other organic phosphines; 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 above-mentioned polybasic acid anhydrides Examples include diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and 2,4,6-triphenylthiopyrylium hexafluorophosphate.
Among these, polyamines are preferred, and melamine is more preferred, from the viewpoint of further improving various properties such as heat resistance, adhesive strength with plated copper, and chemical resistance.
When the photosensitive resin composition of the present embodiment contains component (H), its content is preferably 0.01 to 10% by mass, more preferably 0.01% by mass, based on the total amount of resin components in the photosensitive resin composition. 0.02 to 5% by weight, more preferably 0.03 to 3% by weight.

<Diluent>
A diluent can be used in the photosensitive resin composition of this embodiment, if necessary. As the diluent, for example, an organic solvent can be used. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, and dipropylene. Glycol ethers such as glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, propylene glycol monoethyl ether acetate, butyl cellosolve acetate, carbitol acetate; octane, decane and petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. One type of diluent may be used alone, or two or more types may be used in combination.

(Content of diluent)
The content of the diluent is determined as appropriate so that the concentration of the total solid content in the photosensitive resin composition is preferably 50 to 90% by mass, more preferably 60 to 80% by mass, and still more preferably 65 to 75% by mass. Just choose. By adjusting the amount of diluent used in this way, the coating properties of the photosensitive resin composition are improved, and it becomes possible to form a pattern with higher definition.

<Other additives>
The photosensitive resin composition of the present embodiment may optionally contain a polymerization inhibitor such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, or pyrogallol; a thickener such as bentone or montmorillonite; a silicone antifoaming agent; Various known and commonly used additives such as antifoaming agents such as fluorine-based antifoaming agents and vinyl resin antifoaming agents; silane coupling agents; and the like can be included. Furthermore, flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, phosphate compounds of antimony compounds and phosphorus compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters can be included.

The photosensitive resin composition of this embodiment can be obtained by kneading and mixing each component using a roll mill, bead mill, etc.
Here, the photosensitive resin composition of this embodiment may be used in a liquid form or in a film form.
When used in liquid form, there are no particular limitations on the method of applying the photosensitive resin composition of this embodiment, but examples include printing methods, spin coating methods, spray coating methods, jet dispensing methods, inkjet methods, dip coating methods, etc. Various coating methods can be mentioned. Among these, from the viewpoint of forming the photosensitive layer more easily, a printing method and a spin coating method may be selected as appropriate.
In addition, when used in the form of a film, it can be used, for example, in the form of a photosensitive resin film, which will be described later. In this case, a photosensitive layer of a desired thickness is formed by laminating it on a carrier film using a laminator or the like. be able to. Note that it is preferable to use it in the form of a film because it increases the production efficiency of multilayer printed wiring boards.

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

The photosensitive resin film of this embodiment can be produced by coating the photosensitive resin composition of this embodiment on a carrier film using a known coating method such as a comma coater, bar coater, kiss coater, roll coater, gravure coater, die coater, etc. It is obtained by coating and drying in an apparatus to form a photosensitive layer that will later become an interlayer insulating layer.
Examples of the carrier film include polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polyolefins such as polypropylene and polyethylene. The thickness of the carrier film may be appropriately selected from the range of 5 to 100 μm, preferably 5 to 60 μm, more preferably 15 to 45 μm.

Further, in the photosensitive resin film of this embodiment, a protective film can be provided on the surface of the photosensitive layer that is 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. Further, a polymer film similar to the carrier film described above may be used, or a different polymer film may be used.

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

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

[Multilayer printed wiring board and its manufacturing method]
The present invention also provides a multilayer printed wiring 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 wiring board, a method for manufacturing a multilayer printed wiring board using the photosensitive resin film (photosensitive resin film for interlayer insulation layer) of the present embodiment will be described as appropriate in FIG. This will be explained with reference to.
The multilayer printed wiring board 100A can be manufactured, for example, by a manufacturing method including the following steps (1) to (4).
Step (1): A step of laminating the photosensitive resin film of this embodiment on one or both sides of a circuit board [hereinafter referred to as laminating step (1)].
Step (2): Step of forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in Step (1) [hereinafter referred to as photovia forming step (2)].
Step (3): A step of roughening the via and the interlayer insulating layer [hereinafter referred to as roughening treatment step (3)].
Step (4): Step of forming a circuit pattern on the interlayer insulating layer [hereinafter referred to as circuit pattern forming step (4)].

(Lamination process (1))
In the laminating step (1), the photosensitive resin film of this embodiment (photosensitive resin film for interlayer insulation layer) is laminated on one or both sides of the circuit board (substrate 101 having the circuit pattern 102) using a vacuum laminator. It is a process. Examples of vacuum laminators include a vacuum applicator manufactured by Nichigo Morton Co., Ltd., a vacuum pressurized laminator manufactured by Meiki Seisakusho Co., Ltd., a roll-type dry coater manufactured by Hitachi, Ltd., and a vacuum laminator manufactured by Hitachi Chemical Electronics Co., Ltd. Can be mentioned.

If a protective film is provided on the photosensitive resin film, after peeling or removing the protective film, laminate the photosensitive resin film by pressing it onto the circuit board while applying pressure and heat so that it is in contact with the circuit board. can do.
The laminate is produced, for example, by preheating the photosensitive resin film and the circuit board as necessary, and then applying a pressure bonding temperature of 70 to 130°C, a pressure of 0.1 to 1.0 MPa, and an air pressure of 20 mmHg (26.7 hPa) or less. Although it can be carried out under reduced pressure, it is not particularly limited to this condition. Further, the lamination method may be a batch method or a continuous method using rolls.
Finally, the photosensitive resin film (hereinafter sometimes referred to as a photosensitive layer) laminated on the circuit board is cooled to around room temperature to form an interlayer insulating layer 103. The carrier film may be peeled off at this point, or may be peeled off after exposure as described below.

(Photovia formation process (2))
In the photovia forming step (2), at least a portion of the photosensitive resin film laminated on the circuit board is exposed, and then developed. By exposure, the portions irradiated with actinic rays are photocured to form a pattern. There are no particular restrictions on the exposure method; for example, a method of irradiating actinic rays imagewise through a negative or positive mask pattern called artwork (mask exposure method) may be adopted, or LDI (Laser Direct Imaging) may be used. A method of irradiating actinic rays imagewise by a direct drawing exposure method such as an exposure method or a DLP (Digital Light Processing) exposure method may be adopted.
A known light source can be used as the active light source. 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. Examples include things. The amount of exposure is appropriately selected depending on the light source used and the thickness of the photosensitive layer. For example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, when the thickness of the photosensitive layer is 1 to 100 μm, it is usually about 10 to 1,000 J/ ^m2 . is preferable, and 15 to 500 J/m ² is more preferable.

In development, the uncured portion of the photosensitive layer is removed from the substrate, thereby forming an interlayer insulating layer made of a photocured material on the substrate.
If a carrier film is present on the photosensitive layer, the carrier film is removed and then the unexposed portions are removed (developed). The development method includes wet development and dry development, and either of them may 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 performed by a known development method using a developer compatible with the photosensitive resin composition. Examples of the developing method include methods using a dipping method, a battle method, a spray method, brushing, slapping, scraping, rocking immersion, and the like. Among these, from the viewpoint of improving resolution, the spray method is preferred, and among the spray methods, the high-pressure spray method is more preferred. Development may be carried out by one type of method, but may be carried out by a combination of two or more types.
The composition of the developer is appropriately selected depending on the composition of the photosensitive resin composition. Examples include alkaline aqueous solutions, water-based developers, and organic solvent-based developers, and among these, alkaline aqueous solutions are preferred.

In the photovia forming step (2), after exposure and development, post-UV curing with an exposure amount of about 0.2 to 10 J/cm ² (preferably 0.5 to 5 J/cm ² ) and about 60 to 250 ° C. The interlayer insulating layer may, and is preferably, further cured by optionally performing post-thermal curing at a temperature of (preferably 120 to 200° C.).
In the manner described above, an interlayer insulating layer having vias 104 is formed. There are no particular restrictions on the shape of the via; examples of the cross-sectional shape include square, inverted trapezoid (the top side is longer than the bottom), and circular shape when viewed from the front (the direction from which the bottom of the via is visible). , rectangle, etc. By forming vias using the photolithography method in this embodiment, it is possible to form vias with an inverted trapezoidal cross-sectional shape (the upper side is longer than the lower side), and in this case, the ability of the plated copper to wrap around the via wall is increased. preferred.

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

(Roughening treatment step (3))
In the roughening treatment step (3), the surfaces of the via and the interlayer insulating layer are roughened using a roughening liquid. Note that if smear occurs in the photovia forming step (2), the smear may be removed by the roughening liquid. Roughening treatment and smear removal can be performed simultaneously.
Examples of the roughening liquid include a chromium/sulfuric acid roughening liquid, an alkaline permanganate roughening liquid (for example, a sodium permanganate roughening liquid, etc.), a sodium fluoride/chromium/sulfuric acid roughening liquid, and the like.
Due to the roughening treatment, uneven anchors are formed on the surfaces of the via and the interlayer insulating layer.

(Circuit pattern formation process (4))
The circuit pattern forming step (4) is a step of forming a circuit pattern on the interlayer insulating layer after the roughening treatment step (3).
Formation of the circuit pattern is preferably carried out by a semi-additive process from the viewpoint of forming fine wiring. A semi-additive process forms the circuit pattern and conducts the vias.
In the semi-additive process, first, after the roughening treatment step (3), the via bottom, the via wall surface, and the entire surface of the interlayer insulating layer are subjected to electroless copper plating using a palladium catalyst or the like to form the seed layer 105. form. The seed layer is for forming a power supply layer for electrolytic copper plating, and is preferably formed to have 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, the seed layer between wirings is flash-etched. There is no need to increase the amount of etching during etching, and damage to wiring during etching tends to be suppressed.

The electroless copper plating process is performed by depositing metallic copper on the surfaces of the via and the interlayer insulating layer through a reaction between copper ions and a reducing agent.
The electroless plating method and the electrolytic plating method may be known methods and are not particularly limited, but the catalyst in the electroless plating step is preferably a palladium-tin mixed catalyst. The primary particle diameter is preferably 10 nm or less. Furthermore, the plating composition in the electroless plating process preferably contains hypophosphorous acid as a reducing agent.
Commercial products can be used as the electroless copper plating solution, and examples of the commercial products include "MSK-DK" manufactured by Atotech Japan Co., Ltd. and "Surcup (registered trademark) PEA ver. 4 manufactured by Uemura Kogyo Co., Ltd." ” series, etc.

After performing the electroless copper plating treatment, a dry film resist is thermocompressed onto the electroless copper plating using a roll laminator. The thickness of the dry film resist must be higher than the wiring height after electrolytic copper plating, and from this point of view, a dry film resist with a thickness of 5 to 30 μm is preferable. As the dry film resist, "Fotech" series manufactured by Hitachi Chemical Co., Ltd., etc. are used.
After thermocompression bonding of the dry film resist, the dry film resist is exposed to light through a mask on which a desired wiring pattern is drawn, for example. Exposure can be performed using the same equipment and light source as those that can be used to form vias in 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 portions and form a resist pattern 106. Thereafter, the development residues of the dry film resist may be removed using plasma or the like, if necessary.
After development, electrolytic copper plating is performed to form a copper circuit layer 107 and to perform via filling.

After electrolytic copper plating, the dry film resist is removed using an alkaline aqueous solution or an amine remover. After removing the dry film resist, the seed layer between the wirings is removed (flash etching). Flash etching is performed using an acidic solution such as sulfuric acid and hydrogen peroxide, and an oxidizing solution. Specific examples include "SAC" manufactured by JCU Corporation and "CPE-800" manufactured by Mitsubishi Gas Chemical Corporation. After flash etching, palladium and the like attached to the areas between the wirings are removed if necessary. Palladium can be preferably removed using an acidic solution such as nitric acid or hydrochloric acid.

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

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

[Semiconductor package]
The present invention also provides a semiconductor package in which a semiconductor element is mounted on the multilayer printed wiring board of this embodiment. The semiconductor package of this embodiment can be manufactured by mounting a semiconductor element such as a semiconductor chip or a memory at a predetermined position on the multilayer printed wiring board of the present invention, and sealing the semiconductor element with a sealing resin or the like.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.
In addition, the characteristics of the photosensitive resin compositions obtained in each example were evaluated by the method shown below.

[1. Evaluation of via resolution]
(1) Preparation of laminate for evaluation The copper foil surface of a printed wiring board substrate (manufactured by Hitachi Chemical Co., Ltd., product name "MCL-E-679"), which is made by laminating a 12 μm thick copper foil on a glass epoxy base material, After being treated with a roughening pretreatment liquid (manufactured by MEC Co., Ltd., trade name "CZ-8100"), it was washed with water and dried to obtain a roughening pretreated printed wiring board substrate. Next, the protective film was peeled off and removed from the carrier film and the photosensitive resin film with protective film manufactured in each example and comparative example, and the exposed photosensitive resin film was used as the substrate for the printed wiring board that had undergone the roughening pretreatment. After placing it in contact with the copper foil, it was laminated using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., trade name "MVLP-500"). The laminating conditions were as follows: press hot plate temperature 70° C., evacuation time 20 seconds, lamination press time 30 seconds, air pressure 4 kPa or less, and pressure bonding pressure 0.4 MPa. After the lamination treatment, it was left at room temperature for 1 hour or more to obtain a laminate for evaluation in which a photosensitive resin film and a carrier film were laminated in this order on the copper foil surface of the printed wiring board substrate.
(2) Sensitivity measurement of photosensitive resin film After peeling and removing the carrier film of the evaluation laminate obtained above, a 41-step step tablet was placed, and a direct imaging exposure device "DXP" using an ultra-high pressure mercury lamp as a light source was used. -3512'' (manufactured by Oak Seisakusho Co., Ltd.). The exposure pattern used was a pattern in which dots were arranged in a grid pattern (dot diameter: distance between dot centers = 1:2). The diameter of the dots was varied in the range of φ30 to 100 μm in steps of 5 μm.
After exposure, the photosensitive resin composition was left to stand at room temperature for 30 minutes, and then the unexposed areas of the photosensitive resin composition were 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 remaining gloss step number of the 41 step tablet was 8.0 was defined as the sensitivity (unit: mJ/cm ² ) of the photosensitive resin film. Using the pattern exposed at this sensitivity, the resolution of vias provided in the photosensitive resin film was evaluated according to the following evaluation criteria.
(3) Evaluation of resolution The evaluation of resolution was performed by exposing the photosensitive resin film with an amount of exposure energy that would give the sensitivity of the photosensitive resin film measured in (2) above, that is, the number of steps was 8.0, and then spray developing it. The via pattern was observed using an optical microscope and evaluated according to the following criteria. The above-mentioned state of "opening" refers to a state in which the copper foil of the printed wiring board base material can be confirmed when the via portion of the dot pattern is observed using an optical microscope. A determination of "A" with a via opening indicates good characteristics.
A: The φ60 μm via portion of the dot pattern is open.
C: The φ60 μm via portion of the dot pattern was not opened.

[2. Evaluation of adhesive strength (peel strength) with plated copper]
(1) Preparation of laminate for evaluation and sensitivity measurement of photosensitive resin film [1. In steps (1) and (2) of [Evaluation of via resolution], the exposure machine used was a parallel light exposure machine (manufactured by Oak Seisakusho Co., Ltd., product name: EXM- 1201") above [1. Perform the same operations as steps (1) and (2) in [Evaluation of Via Resolution] to determine the amount of exposure energy that gives a gloss remaining step number of 8.0, and calculate this amount as the sensitivity of the photosensitive resin film ( Unit: mJ/cm ² ).
(2) Exposure process and development process Next, the carrier film of the evaluation laminate was peeled off, and the exposed surface of the photosensitive resin film was fully exposed with the exposure energy amount determined above. An insulating layer was formed by curing the film. After exposure, the film was allowed to stand at room temperature for 30 minutes, and then developed by spraying with a 1% by mass aqueous sodium carbonate solution at 30°C for 60 seconds.
(3) Post-cure treatment Next, post-UV cure was performed using a high-pressure mercury lamp irradiation type UV conveyor device (manufactured by Oak Seisakusho Co., Ltd.) at a conveyor speed that gave an exposure amount of 2 J/ ^cm2 , and then a hot air circulation type Post-heat curing was performed at 170° C. for 1 hour using a dryer (manufactured by Futaba Scientific Co., Ltd.).
(4) Roughening treatment The evaluation laminate after the above post-cure treatment was treated at 70°C for 5 minutes using the swelling liquid "Swelling Dip Securigant P", and then the roughening liquid "Dosing Securigant P500J" Roughening treatment was carried out by treating at 70° C. for 10 minutes using a neutralizing solution “Reduction Conditioner Securigant P500” and for 5 minutes at 40° C. Note that the swelling liquid, roughening liquid, and neutralizing liquid were all manufactured by Atotech Japan Co., Ltd.
(5) Plating treatment The evaluation laminate after the above roughening treatment was subjected to electroless plating treatment at 30°C for 20 minutes using electroless plating solution "Prigant MSK-DK" (manufactured by Atotech Japan Co., Ltd.). Then, electroplating was performed at 24° C. and 2 A/dm ² for 1 hour using electroplating solution "Kaparaside HL" (manufactured by Atotech Japan Co., Ltd.) to form a plated copper layer on the insulating layer. An evaluation board for measuring adhesive strength with plated copper was prepared. Note that the thickness of the plated copper formed by the plating process was 25 μm.
(6) Measurement of adhesive strength with plated copper (peel strength) The adhesive strength with plated copper was measured by measuring vertical peel strength at 23°C in accordance with JIS C6481 (1996). The adhesive strength with plated copper was determined to be good if it was 0.40 kN/m or more.

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

<Synthesis Example 1> (A1-1) Synthesis of acid-modified vinyl group-containing epoxy derivative Bisphenol F novolac type epoxy resin [In the general formula (I), a structural unit in which Y ¹ is a glycidyl group and R ¹ is a hydrogen atom] Bisphenol F novolac type epoxy resin containing, 350 parts by mass [corresponding to component (a1)], 70 parts by mass of acrylic acid [corresponding to component (a2)], 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate were charged, The mixture was reacted by heating to 0.degree. C. and stirring to completely dissolve the mixture.
Next, the obtained solution was cooled to 60°C, 2 parts by mass of triphenylphosphine was added, and the mixture was heated to 100°C and reacted until the acid value of the solution became 1 mgKOH/g. To the solution after the reaction, 98 parts by mass of tetrahydrophthalic anhydride [corresponding to component (a3)] and 85 parts by mass of carbitol acetate were added, heated to 80° C., and reacted for 6 hours.
Thereafter, it was cooled to room temperature to obtain acid-modified bisphenol F novolak type epoxy acrylate (corresponding to component (A1-1)) with a solid content concentration of 73% by mass.

<Examples 1 to 3, Comparative Examples 1 to 5>
(Preparation of photosensitive resin composition)
A composition was blended according to the formulation shown in Table 1 and kneaded in a three-roll mill to prepare a photosensitive resin composition. In each example, carbitol acetate was added as appropriate to adjust the concentration to obtain a photosensitive resin composition with a solid content concentration of 60% by mass.
(Preparation of photosensitive resin film)
A polyethylene terephthalate film (G2-16, manufactured by Teijin Ltd., trade name) with a thickness of 25 μm was used as a carrier film, and the photosensitive resin composition prepared in each example was applied onto the carrier film so that the film thickness after drying was 25 μm. The photosensitive resin film (photosensitive layer) was formed by coating the film and drying it for 10 minutes at 100° C. using a hot air convection dryer. Subsequently, a biaxially stretched polypropylene film (MA-411, manufactured by Oji F-Tex Co., Ltd., trade name) was placed on the surface of the photosensitive resin film (photosensitive layer) on the side opposite to the side in contact with the carrier film. A photosensitive resin film was produced by laminating the carrier film and the protective film together as a protective film.
Each evaluation was performed according to the method described above using the photosensitive resin film produced. The results are shown in Table 1.

The components used in each example are as follows.
(A) Component;
- Acid-modified bisphenol F novolak type epoxy acrylate: The acid-modified vinyl group-containing epoxy derivative obtained in Synthesis Example 1 [corresponding to component (A1-1)] was used.
・Dipentaerythritol pentaacrylate [equivalent to component (Aiii)]
(B) Component;
・Photoinitiator 1: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, acetophenones ・Photoinitiator 2: 2,4-diethylthioxanthone, thioxanthone (C )component;
・Bisphenol F type epoxy resin ・Epoxidized polybutadiene: "PB3600" (manufactured by Daicel Chemical Co., 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., trade 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)

From Table 1, it can be seen that in Examples, the results were excellent in via resolution, adhesive strength with plated copper, and insulation reliability. On the other hand, in Comparative Example 1 which did not contain component (D), the adhesive strength with plated copper was insufficient. In addition, in Comparative Examples 2 to 4 (compared to Examples 1 to 3, respectively), in which component (D) was contained but its content was insufficient, the effect of improving the adhesive strength with plated copper was small, and It was found that the addition of a small amount had the opposite effect, resulting in a decrease in insulation reliability. Furthermore, in Comparative Example 5, in which the content of component (D) was excessive, the resolution of the via, the adhesive strength with plated copper, and the insulation reliability all deteriorated, and excessive blending had the opposite effect. I understand.

100A Multilayer printed wiring board 102 Circuit pattern 103 Interlayer insulation layer 104 Via (via hole)
105 Seed layer 106 Resist pattern 107 Copper circuit layer 108 Solder resist layer

Claims (13)

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,
A photosensitive resin composition in which the content of the elastomer (D) is 2 to 30% by mass based on the total amount of resin components of the photosensitive resin composition. Claim 1, wherein the elastomer (D) includes at least one selected from the group consisting of styrene elastomer, olefin elastomer, polyester elastomer, urethane elastomer, polyamide elastomer, acrylic elastomer, and silicone elastomer. The photosensitive resin composition described in . The elastomer (D) is polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyamideimide resin, polyimide resin, xylene resin, polyphenylene sulfide resin, polyetherimide resin, polyetheretherketone resin, polyetherimide resin, tetrafluoroethylene. The photosensitive resin composition according to claim 1, comprising at least one selected from the group consisting of resin, polyacrylonitrile resin, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxy-modified polyacrylonitrile. The photopolymerizable compound having an ethylenically unsaturated group (A) includes (Ai) a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group, and (Aii) two polymerizable ethylenically unsaturated groups. and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups. The photosensitive resin composition described in . According to any one of claims 1 to 4, wherein the (A) photopolymerizable compound having an ethylenically unsaturated group includes (A1) a photopolymerizable compound having an acidic substituent together with an ethylenically unsaturated group. photosensitive resin composition. A photosensitive resin composition for forming photovias, comprising the photosensitive resin composition according to any one of claims 1 to 5. A photosensitive resin composition for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of claims 1 to 5. A photosensitive resin film comprising the photosensitive resin composition according to any one of claims 1 to 5. A photosensitive resin film for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of claims 1 to 5. A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin composition according to any one of claims 1 to 5. A multilayer printed wiring board comprising an interlayer insulating layer formed using the photosensitive resin film according to claim 8. A semiconductor package comprising a semiconductor element mounted on the multilayer printed wiring board according to claim 10 or 11. 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 according to claim 8 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 step (1).
Step (3): A step of roughening the via and the interlayer insulating layer.
Step (4): A step of forming a circuit pattern on the interlayer insulating layer.