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

Abstract

Provided is a photosensitive resin composition which comprises (A) one or more photopolymerizable compounds each having an ethylenically unsaturated group, (X) organic particles, and (B) a photopolymerization initiator, wherein the photopolymerizable compounds each having an ethylenically unsaturated group include (A1) a photopolymerizable compound having an acidic substituent and an alicyclic skeleton besides the ethylenically unsaturated group. Also provided are: a photosensitive resin film and a photosensitive resin film for dielectric interlayers, the photosensitive resin films being obtained from the photosensitive resin composition; a multilayered printed wiring board; a semiconductor package; and a method for producing the multilayered printed wiring board.

Description

[Technical Field]

[0001] This disclosure relates to a photosensitive resin composition, a photosensitive resin film, a multilayer printed circuit board and a semiconductor package, and a method for manufacturing a multilayer printed circuit board. [Background technology]

[0002] In recent years, as electronic devices have become smaller and more high-performance, multilayer printed circuit boards (PCBs) have seen increased density due to an increase in the number of circuit layers and miniaturization of wiring. In particular, the density of semiconductor package substrates such as BGAs (Ball Grid Arrays) and CSPs (Chip Size Packages) on which semiconductor chips are mounted has increased significantly, requiring not only miniaturization of wiring but also thinning of insulating films and further reduction in the diameter of vias (also called "via holes") for interlayer connections. In addition, with the thinning of insulating films in PCBs, excellent electrical insulation reliability between layers, especially electrical insulation reliability after moisture absorption [HAST (High Accelerated Stress Test) resistance], is also required.

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

[0004] As described above, laser processing is the mainstream method for forming vias in an interlayer insulating layer formed by curing a thermosetting resin film. However, the miniaturization of via diameters by laser irradiation using a laser processing machine has reached its limit. Furthermore, in the formation of vias by a laser processing machine, it is necessary to form each via hole one by one. When a large number of vias need to be provided due to high density, it takes a long time to form the vias, resulting in poor manufacturing efficiency.

[0005] Under such circumstances, as a method capable of forming a large number of vias at once, a photosensitive resin composition containing (A) an acid-modified vinyl group-containing epoxy resin, (B) a photopolymerizable compound, (C) a photopolymerization initiator, (D) an inorganic filler, and (E) a silane compound, and having a content of the (D) inorganic filler of 10 to 80% by mass, is proposed to form a plurality of small-diameter vias at once by a photolithography method (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] Patent Document 2 addresses the issue of suppressing the decrease in adhesive strength with plated copper caused by using a photosensitive resin composition instead of a conventional thermosetting resin composition as the material for the interlayer insulating layer or surface protective layer. It also addresses the issues of via resolution and adhesion to silicon substrates and chip components, and claims to have solved these problems. However, with the further miniaturization of wiring, the thinning of insulating films, and the reduction in diameter of via holes for interlayer connections, there is a growing demand for improvements in adhesive strength with plated copper and electrical insulation reliability. In these respects, there is room for further improvement in the photosensitive resin composition of Patent Document 2. Furthermore, conventional photosensitive resin compositions did not possess sufficient crack resistance to withstand reflow soldering.

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

[0009] As a result of diligent research, the present inventors have found that the above-mentioned objectives can be achieved by this disclosure. This disclosure includes the following [1] to

[19] .

[0010] [1] A photosensitive resin composition comprising (A) a photopolymerizable compound having an ethylenically unsaturated group, (X) organic particles, and (B) a photopolymerization initiator, A photosensitive resin composition comprising (A) a photopolymerizable compound having an ethylenically unsaturated group, and (A1) a photopolymerizable compound having an acidic substituent and an alicyclic skeleton together with an ethylenically unsaturated group. [2](X) The photosensitive resin composition according to [1] above, wherein the components constituting the organic particles (organic matter) contain at least one selected from the group consisting of polyethylene, polybutadiene, polystyrene, acrylonitrile-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-butadiene copolymer, styrene-divinylbenzene copolymer, (meth)acrylic acid ester copolymer, silicone rubber, polyvinyl alcohol, epoxy resin, polyester, polyamide, polyimide, polyamideimide, polyurethane, polyphenylene ether, and melamine resin. [3] The photosensitive resin composition according to [1] or [2] above, wherein the (X) organic particles contain core-shell particles. [4] The photosensitive resin composition according to [3] above, wherein the combination of the core component and the shell component of the core-shell particle (core / shell) is styrene-butadiene copolymer / (meth)acrylic acid copolymer, (meth)acrylic acid copolymer / epoxy resin, epoxy resin / silicone rubber, acrylonitrile-butadiene copolymer / (meth)acrylic acid copolymer, polyethylene / (meth)acrylic acid copolymer, polybutadiene / (meth)acrylic acid copolymer, or polyester / (meth)acrylic acid copolymer. [5] The photosensitive resin composition according to any one of [1] to [4] above, wherein the (A) photopolymerizable compound having an ethylenically unsaturated group further comprises at least one selected from the group consisting of (Ai) a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group, (Aii) a difunctional vinyl monomer having two polymerizable ethylenically unsaturated groups, and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups. [6] The photopolymerizable compound according to any one of [1] to [5] above, wherein the (A1) ethylenically unsaturated group is accompanied by an acidic substituent and an alicyclic skeleton, and the alicyclic skeleton is an alicyclic skeleton having 5 to 20 ring-forming carbon atoms. [7] The photopolymerizable compound having an acidic substituent and an alicyclic skeleton together with the (A1) ethylenically unsaturated group, wherein the alicyclic skeleton consists of two or more rings, the photosensitive resin composition according to any one of [1] to [6] above. [8] A photosensitive resin composition according to any one of [1] to [7] above, further comprising (C) a thermosetting resin. [9] A photosensitive resin composition according to any one of [1] to [8] above, further comprising (D) an elastomer.

[10] The photosensitive resin composition according to [9] above, wherein the (D) elastomer comprises at least one selected from the group consisting of styrene elastomers, olefin elastomers, polyester elastomers, urethane elastomers, polyamide elastomers, acrylic elastomers, and silicone elastomers.

[11] A photosensitive resin composition according to any one of [1] to

[10] above, further comprising (F) an inorganic filler.

[12] A photosensitive resin composition for photovia formation, comprising the photosensitive resin composition described in any of [1] to

[11] above.

[13] A photosensitive resin composition for interlayer insulating layers, comprising the photosensitive resin composition described in any of [1] to

[11] above.

[14] A photosensitive resin film comprising the photosensitive resin composition described in any of [1] to

[11] above.

[15] A photosensitive resin film for interlayer insulating layer, comprising the photosensitive resin composition described in any of [1] to

[11] above.

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

[11] above.

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

[14] above.

[18] A semiconductor package comprising a multilayer printed circuit board as described in

[16] or

[17] above and a semiconductor element.

[19] A method for manufacturing a multilayer printed circuit board, including (1) to (4) below. (1) Laminating the photosensitive resin film described in

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

[0011] According to this disclosure, it is possible to provide a photosensitive resin composition, a photosensitive resin composition for forming photovias, and a photosensitive resin composition for interlayer insulating layers that are excellent in via resolution, adhesion strength to plated copper, electrical insulation reliability, and crack resistance. Furthermore, it is possible to provide a photosensitive resin film and a photosensitive resin film for interlayer insulating layers made from the photosensitive resin composition, and to provide a multilayer printed circuit board and a semiconductor package containing an interlayer insulating layer formed using the photosensitive resin composition or the photosensitive resin film. Furthermore, this invention provides a method for efficiently manufacturing multilayer printed circuit boards that have high-resolution vias, high adhesive strength between the interlayer insulating layer and the plated copper, and excellent electrical insulation reliability. The vias in the multilayer printed circuit boards obtained by the manufacturing method of this disclosure can be smaller in diameter than vias formed by laser processing. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram illustrating one aspect of the manufacturing process for the multilayer printed circuit board of this embodiment. [Modes for carrying out the invention]

[0013] Within the numerical ranges described herein, the upper or lower limits of those ranges may be replaced with the values ​​shown in the examples. Furthermore, the lower and upper limits of the numerical ranges may be arbitrarily combined with the lower or upper limits of other numerical ranges. Furthermore, in this specification, the content of each component in the photosensitive resin composition refers to the total content of multiple substances present in the photosensitive resin composition, unless otherwise specified, if there are multiple substances corresponding to each component. In this specification, "ring-forming carbon number" refers to the number of carbon atoms required to form a ring, and does not include the number of carbon atoms in substituents on the ring. For example, both the cyclohexane skeleton and the methylcyclohexane skeleton have a ring-forming carbon number of 6. The notation "(meth)acrylic XX" refers to either or both acrylic XX and its corresponding methacrylic XX. Similarly, "(meth)acryloyl group" refers to either or both an acryloyl group and a methacryloyl group. In this specification, for example, the phrase "10 or more" means 10 and numbers greater than 10, and the same applies when the numbers are different. Similarly, for example, the phrase "10 or less" means 10 and numbers less than 10, and the same applies when the numbers are different. In this specification, "interlayer insulating layer" refers to a layer located between two conductive layers and intended to insulate the conductive layers. Examples of "interlayer insulating layers" in this specification include cured photosensitive resin films. In this specification, "layer" also includes layers that are partially missing, or that have vias or patterns formed on them. Furthermore, embodiments that combine any combination of the information described herein are also included in this disclosure.

[0014] [Photosensitive resin composition, photosensitive resin composition for photovia formation, and photosensitive resin composition for interlayer insulating layer] A photosensitive resin composition according to one embodiment of the present disclosure (hereinafter sometimes simply referred to as this embodiment) is a photosensitive resin composition comprising (A) a photopolymerizable compound having an ethylenically unsaturated group, (X) organic particles, and (B) a photopolymerization initiator, wherein the (A) photopolymerizable compound having an ethylenically unsaturated group comprises (A1) a photopolymerizable compound having an acidic substituent and an alicyclic skeleton together with the ethylenically unsaturated group. In this specification, the aforementioned components may be referred to as component (A), component (X), component (B), component (A1), etc., and other components may be abbreviated in the same way. In this specification, "resin component" refers to component (A), component (X), and component (B), etc., and also includes other components that may be included as needed (for example, components (C), (D), (E), and (H), etc.), but does not include inorganic compounds such as (F) inorganic fillers and (G) pigments that may be included as needed as described later. Furthermore, "solid content" refers to the non-volatile content of the photosensitive resin composition excluding volatile substances such as water and solvents, and indicates the components that remain without volatilization when the resin composition is dried, and also includes liquid, syrup-like, and wax-like substances at room temperature around 25°C.

[0015] Since the photosensitive resin composition of this embodiment is suitable for via formation by photolithography (also referred to as photovia formation), this disclosure also provides a photosensitive resin composition for photovia formation. Furthermore, since the photosensitive resin composition of this embodiment is excellent in via resolution, adhesion strength to plated copper, electrical insulation reliability, and crack resistance, and is useful as an interlayer insulating layer for multilayer printed circuit boards, this disclosure also provides a photosensitive resin composition for interlayer insulating layers. In this specification, when referring to a photosensitive resin composition, it includes both a photosensitive resin composition for photovia formation and a photosensitive resin composition for interlayer insulating layers. Furthermore, the photosensitive resin composition of this embodiment is useful as a negative-type photosensitive resin composition. The following details each component that may be contained in the photosensitive resin composition.

[0016] <(A) Photopolymerizable compounds having ethylenically unsaturated groups> The photosensitive resin composition of this embodiment includes a photopolymerizable compound having an ethylenically unsaturated group as component (A) from the viewpoint of adhesion strength to plated copper. Examples of ethylenically unsaturated groups in component (A) include vinyl group, allyl group, propargyl group, butenyl group, ethynyl group, phenylethynyl group, maleimide group, nadiimide group, and (meth)acryloyl group. A (meth)acryloyl group is preferred as the ethylenically unsaturated group. In this embodiment, component (A) includes "(A1) a photopolymerizable compound having an ethylenically unsaturated group along with an acidic substituent and an alicyclic skeleton," which will be described later. By including component (A1) in component (A), a photosensitive resin composition is obtained that exhibits excellent via resolution, adhesion strength to plated copper, electrical insulation reliability, and crack resistance. The following details component (A1).

[0017] ((A1) Photopolymerizable compounds having an ethylenically unsaturated group along with an acidic substituent and an alicyclic skeleton) (A1) The ethylenically unsaturated groups that component (A1) possesses are the same as those described above. Among these, at least one selected from the group consisting of vinyl group, allyl group, propargyl group, butenyl group, ethynyl group, phenylethynyl group, maleimide group, nadiimide group and (meth)acryloyl group is preferred, vinyl group, allyl group and (meth)acryloyl group are more preferred, and (meth)acryloyl group is even more preferred. The acidic substituent of component (A1) is preferably at least one selected from the group consisting of, for example, a carboxyl group, a sulfonic acid group, a phenolic hydroxyl group, and the like, with a carboxyl group being more preferred.

[0018] As for the alicyclic skeleton of component (A1), from the viewpoint of via resolution, adhesion strength with plated copper, electrical insulation reliability and crack resistance, an alicyclic skeleton with 5 to 20 ring-forming carbon atoms is preferred, an alicyclic skeleton with 5 to 18 ring-forming carbon atoms is more preferred, an alicyclic skeleton with 6 to 18 ring-forming carbon atoms is even more preferred, an alicyclic skeleton with 8 to 14 ring-forming carbon atoms is particularly preferred, and an alicyclic skeleton with 8 to 12 ring-forming carbon atoms is most preferred. Furthermore, the alicyclic skeleton is preferably composed of two or more rings, more preferably of two to four rings, and even more preferably of three rings, from the viewpoint of via resolution, adhesion strength with plated copper, electrical insulation reliability, and crack resistance. Examples of a single-ring alicyclic skeleton include the cyclohexane skeleton and the cyclohexene skeleton. Examples of alicyclic skeletons with two or more rings include the norbornane skeleton, the decalin skeleton, the bicycloundecane skeleton, and the saturated dicyclopentadiene skeleton. As the alicyclic skeleton, a saturated dicyclopentadiene skeleton is preferred from the viewpoint of via resolution, adhesion strength with plated copper, electrical insulation reliability, and crack resistance, and a alicyclic skeleton represented by the following general formula (a) (saturated dicyclopentadiene skeleton) is more preferred. [ka] (In general formula (a), R A1 represents an alkyl group having 1 to 12 carbon atoms, and may be substituted anywhere in the above alicyclic skeleton. 1 (This is an integer between 0 and 6. * indicates a binding site to another structure.)

[0019] In general formula (a), R A1 Examples of C1-C12 alkyl groups represented by include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups. C1-C6 alkyl groups are preferred, C1-C3 alkyl groups are more preferred, and methyl groups are even more preferred. m 1 is an integer between 0 and 6, preferably between 0 and 2, and more preferably 0. m 1 If is an integer between 2 and 6, multiple R A1 These may be the same or different. Furthermore, multiple R A1 The substitutions may be made on the same carbon atom as much as possible, or on different carbon atoms. * is a bonding site to other structures and may be bonded to any carbon atom on the alicyclic skeleton, but is preferably bonded to the carbon atom represented by 1 or 2 in the following general formula (a') and the carbon atom represented by any of 3 to 5.

Chemical formula

[0020] Examples of the component (A1) include · A compound obtained by modifying (a1) an alicyclic skeleton-containing epoxy resin with (a2) an ethylenically unsaturated group-containing organic acid [hereinafter sometimes referred to as the (A') component]. Reacting (a3) a saturated group or unsaturated group-containing polybasic acid anhydride to obtain an "(A1-1) acid-modified ethylenically unsaturated group and alicyclic skeleton-containing epoxy derivative", · A modified novolak-type epoxy resin obtained by addition-polymerizing at least one selected from the group consisting of ethylene oxide and propylene oxide to a phenol novolak resin or a cresol novolak resin, and reacting (a2) an ethylenically unsaturated group-containing organic acid and (a4) an alicyclic skeleton-containing and saturated group or unsaturated group-containing polybasic acid anhydride to obtain an "(A1-2) acid-modified ethylenically unsaturated group and alicyclic skeleton-containing phenol novolak or cresol novolak resin", and the like. From the viewpoints that the component (A1) can be alkali-developed and is excellent in via resolution, adhesion strength to plated copper, electrical insulation reliability, and crack resistance, the above-mentioned "(A1-1) acid-modified ethylenically unsaturated group and alicyclic skeleton-containing epoxy derivative" is preferable. First, the raw materials that can be used for the production of the "(A1-1) acid-modified ethylenically unsaturated group and alicyclic skeleton-containing epoxy derivative" will be described in detail.

[0021] -(a1) Alicyclic skeleton-containing epoxy resin- The (a1) alicyclic skeleton-containing epoxy resin is preferably an epoxy resin having two or more epoxy groups. Epoxy resins are classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, etc. Among these, glycidyl ether type epoxy resins are preferred.

[0022] In this embodiment, at least an epoxy resin having an alicyclic skeleton is used as the epoxy resin. The alicyclic skeleton is described in the same way as the alicyclic skeleton of component (A1) described above, and the preferred embodiments are also the same. (a1) As the alicyclic skeleton-containing epoxy resin, epoxy resin represented by the following general formula (a1-1) is preferred. Epoxy resins having structural units represented by the following general formula (a1-2) are also preferred. [ka] (In general formula (a1-1), R A1 R represents an alkyl group having 1 to 12 carbon atoms and may be substituted anywhere in the above alicyclic skeleton. A2 m represents an alkyl group with 1 to 12 carbon atoms. 1 is an integer from 0 to 6, m 2 n is an integer between 0 and 3. n is between 0 and 10. [ka] (In general formula (a1-2), R A1 represents an alkyl group having 1 to 12 carbon atoms, and may be substituted anywhere in the above alicyclic skeleton. 1 (This is an integer between 0 and 6.)

[0023] In general formulas (a1-1) and (a1-2), R A1 R in general formula (a) A1 It is the same as, and the preferred form is also the same. R in general formula (a1-1) A2Examples of C1-C12 alkyl groups represented by include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups. C1-C6 alkyl groups are preferred, C1-C3 alkyl groups are more preferred, and methyl groups are even more preferred. m in general formula (a1-1) and general formula (a1-2) 1 m in general formula (a) 1 It is the same as, and the preferred form is also the same. m in general formula (a1-1) 2 is an integer between 0 and 3, preferably 0 or 1, and more preferably 0. In general formula (a1-1), n ​​represents the number of repetitions of the structural unit in parentheses, and is between 0 and 10. Typically, epoxy resins are mixtures of structural units with different numbers of repetitions, in which case n is represented by the average value of the mixture. A value of 2 to 10 is preferred for n.

[0024] (a1) Commercially available epoxy resins containing an alicyclic skeleton may be used, and examples of such commercial products include XD-1000 (manufactured by Nippon Kayaku Co., Ltd., trade name), EPICLON HP-7200L, EPICLON HP-7200, EPICLON HP-7200HH, and EPICLON HP-7200HHH (manufactured by DIC Corporation, trade name; "EPICLON" is a registered trademark).

[0025] (a1) Other epoxy resins besides the epoxy resin having an alicyclic skeleton (hereinafter sometimes referred to as "other epoxy resins") may be used in combination as the epoxy resin. Other epoxy resins include 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 aforementioned bisphenol-based novolac type epoxy resins, such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, and biphenyl novolac type epoxy resin; phenol aralkyl type epoxy resin; biphenyl aralkyl type epoxy resin; stilbene type epoxy resin; naphthalene skeleton-containing epoxy resins such as naphthalene type epoxy resin, naphthol novolac type epoxy resin, naphthol type epoxy resin, naphthol aralkyl type epoxy resin, and naphthylene ether type epoxy resin; biphenyl type epoxy resin; xylylene type epoxy resin; dihydroanthracene type epoxy resin; aliphatic chain epoxy resin; and rubber-modified epoxy resin.

[0026] -(a2) Ethylenically unsaturated group-containing organic acid- The ethylenically unsaturated group-containing organic acid (a2) is not particularly limited, but a monocarboxylic acid containing an ethylenically unsaturated group is preferred. The ethylenically unsaturated group is as described in the explanation of the ethylenically unsaturated group in component (A1) above. Examples of monocarboxylic acids containing an ethylenically unsaturated group include acrylic acid; acrylic acid derivatives such as acrylic acid dimers, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α-cyanocinnamic acid; semi-ester compounds obtained as reaction products of hydroxyl group-containing acrylates and dibasic acid anhydrides; and semi-ester compounds obtained as reaction products of ethylenically unsaturated group-containing monoglycidyl ethers or ethylenically unsaturated group-containing monoglycidyl esters and dibasic acid anhydrides. Among these, acrylic acid is preferred. (a2) One component may be used alone, or two or more components may be used in combination.

[0027] The aforementioned semi-ester compound can be obtained, for example, by reacting a hydroxyl group-containing acrylate, an ethylenically unsaturated group-containing monoglycidyl ether, or an ethylenically unsaturated group-containing monoglycidyl ester with a dibasic acid anhydride in equimolar ratios.

[0028] (a2) Examples of hydroxyl group-containing acrylates, ethylenically unsaturated group-containing monoglycidyl ethers, and ethylenically unsaturated group-containing monoglycidyl esters used in the synthesis of the aforementioned semi-ester compounds, which are components of (a2), include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, glycidyl acrylate, glycidyl methacrylate, and the like.

[0029] The dibasic acid anhydride used in the synthesis of the aforementioned semi-ester compound may contain 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, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride.

[0030] While not particularly limited, in the reaction between component (a1) and component (a2), it is preferable to react them in a ratio of 0.6 to 1.05 equivalents of component (a2) per 1 equivalent of epoxy group of component (a1), although a ratio of 0.8 to 1.0 equivalents is also acceptable. Reacting in such a ratio tends to improve photopolymerization, that is, increase photosensitivity and improve the resolution of the via.

[0031] The components (a1) and (a2) can be reacted while dissolved in an organic solvent. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha.

[0032] Furthermore, it is preferable to use a catalyst to promote the reaction between component (a1) and component (a2). Examples of such catalysts include amine-based catalysts such as triethylamine and benzylmethylamine; quaternary ammonium salt catalysts such as methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, and benzyltrimethylammonium iodide; and phosphine-based catalysts such as triphenylphosphine. Among these, phosphine-based catalysts are preferred, and triphenylphosphine is more preferred. The amount of catalyst used is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.1 to 2 parts by mass, based on 100 parts by mass of the total of components (a1) and (a2). With the above amount, the reaction between components (a1) and (a2) tends to be promoted.

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

[0034] From the viewpoint of productivity, the reaction temperature between component (a1) and component (a2) is preferably 60 to 150°C, more preferably 70 to 120°C, and even more preferably 80 to 110°C.

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

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

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

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

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

[0040] Based on the above, the photopolymerizable compound having an acidic substituent and an alicyclic skeleton together with the ethylenically unsaturated group (A1) is not particularly limited, but it is preferably represented by the following general formula (A-1). [ka] (In general formula (A-1), R A1 R represents an alkyl group having 1 to 12 carbon atoms and may be substituted anywhere in the above alicyclic skeleton. A2 R represents an alkyl group with 1 to 12 carbon atoms. A3is an organic group having an ethylenically unsaturated group, an organic group having an ethylenically unsaturated group and an acidic substituent, or a glycidyl group, and has at least one R A3 m is an organic group having an ethylenically unsaturated group and an acidic substituent. 1 is an integer from 0 to 6, m 2 n is an integer between 0 and 3. n is between 0 and 10.

[0041] In the above general formula (A-1), R A1 , R A2 , m 1 , m 2 And n are the same as those in the general formula (a1-1) above, and the preferred values ​​are also the same. R A3 As defined above, R corresponds to the site formed by the reaction of the glycidyl group in the general formula (a1-1) with component (a2) and component (a3), and the definition also takes into account that some of the glycidyl group may remain unreacted. A3 The option "organic group having an ethylenically unsaturated group" is a group derived from component (a2), and "organic group having an ethylenically unsaturated group and an acidic substituent" is a group derived from components (a2) and (a3), and if components (a2) and (a3) ​​react with all the glycidyl groups in the general formula (a1-1), then R A3 The result is an "organic group having an ethylenically unsaturated group and an acidic substituent," but the part that has reacted only with component (a2) becomes an "organic group having an ethylenically unsaturated group," and the part that has not reacted with either component (a2) or (a3) ​​becomes a "glycidyl group."

[0042] Next, we will briefly explain the raw materials that can be used in the production of the aforementioned "(A1-2) Acid-modified ethylenically unsaturated group and alicyclic skeleton-containing phenol novolac or cresol novolac resin". One of the raw materials is a modified novolac-type epoxy resin obtained by addition polymerization of a phenol novolac resin or a cresol novolac resin with at least one selected from the group consisting of ethylene oxide and propylene oxide. It is preferable to use a catalyst for this addition polymerization, and examples of catalysts include metallic sodium, sodium methoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium phenolate, and various Lewis acids. There are no particular restrictions on the weight-average molecular weight of the phenol novolac resin and the cresol novolac resin, but they are preferably 500 to 30,000 and more preferably 1,000 to 10,000, respectively. In this specification, the weight-average molecular weight (and number-average molecular weight) is the value obtained on a standard polystyrene basis by gel permeation chromatography (GPC) using tetrahydrofuran as the solvent, and more specifically, the value measured according to the method described later. There are no particular restrictions on the reaction temperature, but it can be carried out in the range of 60 to 230°C. The addition polymerization described above can be carried out using or by applying known methods, and is not limited in any way to the above-mentioned methods. The above addition polymerization yields a modified novolac-type epoxy resin.

[0043] The "(a2) ethylenically unsaturated group-containing organic acid" to be reacted with the modified novolac-type epoxy resin obtained above will be explained in the same way as the explanation for (a2) ethylenically unsaturated group-containing organic acid described above. Furthermore, the alicyclic skeleton contained in "(a4) polybasic acid anhydride containing an alicyclic skeleton and a saturated or unsaturated group" that is reacted with the modified novolac-type epoxy resin obtained above is preferably an alicyclic skeleton with 5 to 20 ring-forming carbon atoms, more preferably an alicyclic skeleton with 5 to 15 ring-forming carbon atoms, even more preferably an alicyclic skeleton with 5 to 10 ring-forming carbon atoms, and particularly preferably an alicyclic skeleton with 5 to 8 ring-forming carbon atoms. The alicyclic skeleton may consist of one ring or two or more rings, but it is preferably one ring. The alicyclic skeleton is preferably a cyclohexane skeleton, a cyclohexene skeleton, and the like, and more preferably a cyclohexene skeleton. Examples of the aforementioned "(a4) polybasic acid anhydride containing an alicyclic skeleton and a saturated or unsaturated group" include tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and ethylhexahydrophthalic anhydride. Among these, tetrahydrophthalic anhydride and phthalic anhydride are preferred, and tetrahydrophthalic anhydride is more preferred. There are no particular restrictions on the conditions for reacting a modified novolac-type epoxy resin with (a2) an organic acid containing an ethylenically unsaturated group and (a4) a polybasic acid anhydride containing an alicyclic skeleton and either a saturated or unsaturated group. For example, one method involves reacting component (a2) at 20-100°C, followed by reacting component (a4) at 20-100°C, if necessary, in the presence of a catalyst.

[0044] ((A1) Molecular weight of photopolymerizable compounds having an ethylenically unsaturated group along with an acidic substituent and an alicyclic skeleton) The weight-average molecular weight (Mw) of component (A1) is preferably 1,000 to 30,000, more preferably 2,000 to 25,000, and even more preferably 3,000 to 18,000. Within this range, the adhesion strength to plated copper, heat resistance, and electrical insulation reliability are improved. In particular, it is preferable that the weight-average molecular weight (Mw) of the (A1-1) acid-modified ethylenically unsaturated group and alicyclic skeleton-containing epoxy derivative is within the above range. Here, the weight-average molecular weight (and number-average molecular weight) is the value measured using a calibration curve for standard polystyrene by gel permeation chromatography (GPC) (manufactured by Tosoh Corporation), and more specifically, the value measured according to the method described below. <Method for measuring weight-average molecular weight and number-average molecular weight> The weight-average molecular weight and number-average molecular weight were measured using the GPC measuring device and measurement conditions described below, and the values ​​converted using the calibration curve for standard polystyrene were used as the weight-average molecular weight or number-average molecular weight. For the creation of the calibration curve, five sample sets ("PStQuick MP-H" and "PStQuick B," manufactured by Tosoh Corporation) were used as standard polystyrene. (GPC measurement device) GPC system: High-speed GPC system "HCL-8320GPC", detector is a differential refractive index detector or UV detector, manufactured by Tosoh Corporation. Column: TSKgel SuperMultipore HZ-H column (column length: 15cm, column inner diameter: 4.6mm), manufactured by Tosoh Corporation. (Measurement conditions) Solvent: Tetrahydrofuran (THF) Measurement temperature: 40℃ Flow rate: 0.35mL / min Sample concentration: 10 mg / THF 5 mL Injection volume: 20μL

[0045] ((A2-1) Acid-modified ethylenically unsaturated group-containing epoxy derivative that does not contain an alicyclic skeleton) (A) The photopolymerizable compound having an ethylenically unsaturated group may further include (A2-1) an acid-modified ethylenically unsaturated group-containing epoxy derivative that does not contain an alicyclic skeleton, obtained by reacting (a23) a polybasic acid anhydride containing a saturated or unsaturated group with (a21) an epoxy resin (however, without an alicyclic skeleton) modified with (a22) an organic acid containing an ethylenically unsaturated group.

[0046] The epoxy resin (a21) is not particularly limited as long as it does not contain an alicyclic skeleton, and examples include glycidyl ether type epoxy resins, glycidylamine type epoxy resins, and glycidyl ester type epoxy resins. Among these, glycidyl ether type epoxy resins are preferred. Furthermore, the epoxy resins (a21) described above can be classified into various types of epoxy resins depending on the differences in their main skeletons, and each of the above types of epoxy resins can be further classified as follows. Specifically, epoxy resins are classified into 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 aforementioned bisphenol-based novolac type epoxy resins, such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, and biphenyl novolac type epoxy resin; phenol aralkyl type epoxy resin; stilbene type epoxy resin; naphthalene skeleton-containing epoxy resins such as naphthalene type epoxy resin, naphthol novolac type epoxy resin, naphthol type epoxy resin, naphthol aralkyl type epoxy resin, and naphthylene ether type epoxy resin; biphenyl type epoxy resin; biphenyl aralkyl type epoxy resin; xylylene type epoxy resin; dihydroanthracene type epoxy resin; aliphatic chain epoxy resin; and rubber-modified epoxy resin. Among these, bisphenol-based novolac type epoxy resins are preferred, and bisphenol F novolac type epoxy resins are even more preferred.

[0047] The (a22) ethylenically unsaturated group-containing organic acid and the (a23) saturated or unsaturated group-containing polybasic acid anhydride are described in the same manner as the (a2) ethylenically unsaturated group-containing organic acid and the (a3) ​​saturated or unsaturated group-containing polybasic acid anhydride, and the preferred embodiments are also the same. Furthermore, as a method for reacting component (a23) with a compound modified with component (a22) in which component (a21) has been modified, one can refer to a method for reacting component (a3) ​​with a compound modified with component (a1) in which component (a2) has been modified.

[0048] (A2-1) As an acid-modified ethylenically unsaturated group-containing epoxy derivative that does not contain an alicyclic skeleton, commercially available products may be used. Examples of commercially available products include CCR-1218H, CCR-1159H, CCR-1222H, PCR-1050, TCR-1335H, ZAR-1035, ZAR-2001H, UXE-3024, ZFR-1185, ZCR-1569H, ZXR-1807, ZCR-6000, ZCR-8000 (all manufactured by Nippon Kayaku Co., Ltd., trade names), UE-9000, UE-EXP-2810PM, UE-EXP-3045 (all manufactured by DIC Corporation, trade names), etc.

[0049] When component (A) contains both component (A1) (or component (A1-1)) and component (A2-1), from the viewpoint of balancing properties such as via resolution, adhesion strength to plated copper, electrical insulation reliability and crack resistance, the content ratio of component (A1) (or component (A1-1)) to component (A2-1) [(A1) or (A1-1) / (A2-1)] is preferably 20 / 80~99 / 1 by mass ratio, more preferably 50 / 50~99 / 1, even more preferably 60 / 40~99 / 1, particularly preferably 60 / 40~85 / 15, and most preferably 65 / 35~80 / 20.

[0050] ((A2-2) Styrene-maleic acid resin) (A) As a photopolymerizable compound having an ethylenically unsaturated group, "(A2-2) styrene-maleic acid resins" such as hydroxyethyl (meth)acrylate modified products of styrene-maleic anhydride copolymers can also be used in combination. The (A2-2) component does not contain an alicyclic skeleton. The (A2-2) component may be used alone or two or more may be used in combination.

[0051] ((A2-3) Epoxy polyurethane resin) Furthermore, as the (A) photopolymerizable compound having an ethylenically unsaturated group, a "(A2-3) epoxy polyurethane resin" obtained by reacting the (a21) epoxy resin modified with (a22) an ethylenically unsaturated group-containing organic acid with an isocyanate compound can also be used in combination. Examples of the (a21) epoxy resin modified with (a22) an ethylenically unsaturated group-containing organic acid include the (A') component, which is the (a1) alicyclic skeleton-containing epoxy resin modified with the (a2) ethylenically unsaturated group-containing organic acid. The (A2-3) components do not contain an alicyclic skeleton. The (A2-3) components may be used individually or in combination of two or more.

[0052] (Other components (A)) (A) As a photopolymerizable compound having an ethylenically unsaturated group, from the viewpoint of improving chemical resistance after curing (exposure) and increasing the difference in developer resistance between the exposed and unexposed areas, it is preferable that the (A) photopolymerizable compound having an ethylenically unsaturated group further includes at least one selected from the group consisting of (Ai) a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group, (Aii) a difunctional vinyl monomer having two polymerizable ethylenically unsaturated groups, and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups, and more preferably the embodiment including component (Aiii). Components (Ai) to (Aiii) each preferably have a molecular weight of 1,000 or less. However, in this embodiment, components (Ai) to (Aiii) do not include component (A1).

[0053] ((Ai) Monofunctional vinyl monomer) Examples of monofunctional vinyl monomers having one polymerizable ethylenically unsaturated group include (meth)acrylic acid and alkyl (meth)acrylates. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and hydroxyethyl (meth)acrylate. Component (Ai) may be used alone or in combination of two or more.

[0054] ((Aii) Difunctional vinyl monomer) Examples of the two polymerizable ethylenically unsaturated difunctional vinyl monomers include polyethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2-bis(4-(meth)acryloxypolyethoxypolypropoxyphenyl)propane, and bisphenol A diglycidyl ether di(meth)acrylate. Component (Aii) may be used alone or in combination of two or more.

[0055] ((Aiii) Polyfunctional vinyl monomer) Examples of polyfunctional vinyl monomers having at least three polymerizable ethylenically unsaturated groups include (meth)acrylate compounds having a trimethylolpropane-derived skeleton such as trimethylolpropane tri(meth)acrylate; (meth)acrylate compounds having a tetramethylolmethane-derived skeleton such as tetramethylolmethane tri(meth)acrylate and tetramethylolmethane tetra(meth)acrylate; (meth)acrylate compounds having a pentaerythritol-derived skeleton such as pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate; (meth)acrylate compounds having a dipentaerythritol-derived skeleton such as dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate; (meth)acrylate compounds having a ditrimethylolpropane-derived skeleton such as ditrimethylolpropane tetra(meth)acrylate; and (meth)acrylate compounds having a diglycerin-derived skeleton. Among these, (meth)acrylate compounds having a dipentaerythritol-derived skeleton are preferred, and dipentaerythritol penta(meth)acrylate is more preferred, from the viewpoint of improving chemical resistance after curing (exposure) and increasing the difference in developer resistance between the exposed and unexposed areas. Component (Aiii) may be used alone or in combination of two or more. Here, the "(meth)acrylate compound having a skeleton derived from XXX" (where XXX is a compound name) means an esterified product of XXX and (meth)acrylic acid, and this esterified product also includes compounds modified with alkylene oxy groups.

[0056] (Content of component (A)) The content of component (A) is not particularly limited, but from the viewpoint of heat resistance, electrical properties and chemical resistance, it is preferably 60% by mass or less, more preferably 0.1 to 55% by mass, even more preferably 1 to 50% by mass, particularly preferably 2 to 40% by mass, most preferably 3 to 37% by mass, and may also be 5 to 37% by mass, 15 to 37% by mass, or 20 to 37% by mass.

[0057] Component (A) is not particularly limited, but from the viewpoint of photosensitive properties, it is preferable to use component (A1) and component (Aiii) in combination. In this case, the content ratio of component (A1) to component (Aiii) [(A1) / (Aiii)] (mass ratio) is preferably 2 to 20, more preferably 2 to 15, even more preferably 2.5 to 10, and particularly preferably 3 to 6. Furthermore, the ratio of component (A1) to the total amount of component (A) is preferably 20 to 95% by mass, more preferably 40 to 95% by mass, even more preferably 65 to 95% by mass, and particularly preferably 80 to 95% by mass, from the viewpoint of via resolution, adhesion strength to plated copper, electrical insulation reliability, and crack resistance.

[0058] <(X)Organic particles> The photosensitive resin composition of this embodiment, by containing (X) organic particles, can improve adhesion to plated copper, electrical insulation reliability, and crack resistance while maintaining high resolution of vias. In particular, the electrical insulation reliability after moisture absorption (HAST resistance) is improved. (X) The organic particles exist in particulate form in the photosensitive resin composition. (X) The ratio of the major axis r2 to the minor axis r1 (r2 / r1) of the organic particles is preferably 1.4 or less, more preferably 1.2 or less, and even more preferably 1.1 or less. This ratio (r2 / r1) is the average value of 10 arbitrary particles. Note that the minor axis r1 and major axis r2 of the organic particles (X) were measured using a laser diffraction scattering particle size distribution analyzer (for example, the LS13320 manufactured by Beckman Coulter, Inc.). Alternatively, the minor axis r1 and major axis r2 of the organic particles can be measured by observation using a scanning electron microscope (SEM).

[0059] (X) The organic particles are not particularly limited as long as they are mainly composed of organic matter. Here, "mainly composed of organic matter" means that the proportion of organic matter in the total mass of the particles is 50% by mass or more, and preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably substantially 100% by mass. (X) The components (organic matter) constituting the organic particles preferably contain at least one selected from the group consisting of polyethylene, polybutadiene, polystyrene, acrylonitrile-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-butadiene copolymer, styrene-divinylbenzene copolymer, (meth)acrylic acid ester copolymer, silicone rubber, polyvinyl alcohol, epoxy resin, polyester, polyamide, polyimide, polyamideimide, polyurethane, polyphenylene ether, and melamine resin. (X) The organic particles may or may not have a cross-linked structure.

[0060] The (X) organic particles used in this embodiment are preferably easily detached or dissolved during desmear treatment, and from this viewpoint, it is preferable that the (X) organic particles contain core-shell particles. Here, core-shell particles are polymer particles in which the core and shell of the particle have different properties, and in this embodiment, it is preferable that the core and shell of the particle consist of different components. When the (X) organic particles contain core-shell particles, there is no particular limit to the amount, but from the viewpoint of ease of detachment or dissolution during desmear treatment, it is preferably 5% by mass or more, more preferably 20% by mass or more, even more preferably 50% by mass or more, particularly preferably 80% by mass or more, most preferably 95% by mass or more, and may be substantially 100% by mass.

[0061] While not particularly limited, the core-shell particles are preferably formed from the components constituting the (X) organic particles described above. However, the components constituting each part of the core and shell are more preferably resins that have low desmear resistance, excellent flexibility, and excellent compatibility and dispersibility. Examples of such resins include epoxy resins, butadiene rubber, styrene-butadiene copolymers, polyamide resins, and (meth)acrylic acid ester copolymers. Among these, epoxy resins, styrene-butadiene copolymers, and (meth)acrylic acid ester copolymers are preferred as the resins. Furthermore, if the core components are styrene-butadiene copolymers, the adhesion strength to plated copper is further improved, which is preferable. Examples of core / shell combinations include styrene-butadiene copolymer / (meth)acrylic acid copolymer, (meth)acrylic acid copolymer / epoxy resin, epoxy resin / silicone rubber, acrylonitrile-butadiene copolymer / (meth)acrylic acid copolymer, polyethylene / (meth)acrylic acid copolymer, polybutadiene / (meth)acrylic acid copolymer, and polyester / (meth)acrylic acid copolymer. Among these, styrene-butadiene copolymer / (meth)acrylic acid copolymer and (meth)acrylic acid copolymer / epoxy resin are preferred.

[0062] In the components constituting the (X) organic particles, the core components, or the shell components, examples of (meth)acrylic acid ester copolymers include acrylic acid ester-methacrylic acid ester copolymers, methacrylic acid ester-styrene copolymers, and acrylic acid ester copolymers. Examples of the ester moiety of the (meth)acrylic acid ester include alkyl esters having 1 to 12 carbon atoms such as alkyl groups, cycloalkyl esters having 3 to 12 ring-forming carbon atoms such as cycloalkyl groups, aryl esters having 6 to 18 ring-forming carbon atoms such as phenyl groups, and aralkyl groups such as benzyl groups, as well as heterogroups in which some of these groups are substituted with heteroatoms. Examples of the above acrylic acid esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, s-butyl acrylate, t-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-lauryl acrylate, 2-hydroxyethylhexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, tetrahydrofuryl acrylate, benzyl acrylate, and phenyl acrylate. Among these, methyl acrylate, ethyl acrylate, n-propyl acrylate, and isopropyl acrylate are preferred, with methyl acrylate and ethyl acrylate being more preferred. Examples of the above methacrylic acid esters include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, pentadecyl methacrylate, dodecyl methacrylate, isobornyl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate, 2-methoxyethyl methacrylate, glycidyl methacrylate, and allyl methacrylate. Among these, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and isopropyl methacrylate are preferred, and methyl methacrylate and ethyl methacrylate are more preferred.

[0063] Similarly, in the components constituting the (X) organic particles, the components constituting the core, or the components constituting the shell, the epoxy resin is preferably a glycidyl ether type or a glycidylamine type epoxy resin, and either may be used, but a glycidyl ether type epoxy resin is more preferred. The epoxy resins include bisphenol-based epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin; bisphenol-based novolac type epoxy resins such as bisphenol A novolac type epoxy resin and bisphenol F novolac type epoxy resin; novolac type epoxy resins other than the bisphenol-based novolac type epoxy resins, such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, and biphenyl novolac type epoxy resin; phenol aralkyl type epoxy resin; stilbene type epoxy resin; and naphthalene type epoxy resin. Preferred epoxy resins include naphthalene skeleton-containing epoxy resins such as xylylene resin, naphthol novolac type epoxy resin, naphthol type epoxy resin, naphthol aralkyl type epoxy resin, and naphthylene ether type epoxy resin; biphenyl type epoxy resin; biphenyl aralkyl type epoxy resin; xylylene type epoxy resin; dihydroanthracene type epoxy resin; dicyclopentadiene type epoxy resin; alicyclic epoxy resins such as dicyclopentadiene type epoxy resin; heterocyclic epoxy resin; spiro ring-containing epoxy resin; cyclohexanedimethanol type epoxy resin; trimethylol type epoxy resin; aliphatic chain epoxy resin; and rubber-modified epoxy resin. Among these, bisphenol-based novolac type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol A novolac type epoxy resin, and bisphenol F novolac type epoxy resin; and novolac type epoxy resins other than the bisphenol-based novolac type epoxy resins, such as phenol novolac type epoxy resin and cresol novolac type epoxy resin, are preferred.

[0064] Core-shell particles may be prepared by conventional methods, such as emulsion polymerization, seed polymerization, micro-suspension polymerization, or suspension polymerization, or commercially available products may be used. Commercially available core-shell particles include the Paraloid® series, such as EXL2620, EXL2650, EXL2655, TMS-2670, BTA-717, and BTA-731 (all manufactured by Toray Dow Corning Co., Ltd.), and the Kaneka® MX series, such as MX-153, MX-128, MX-139, MX-257, MX-136, and MX-217 (all manufactured by Kaneka Corporation).

[0065] (X) As for the average particle diameter of organic particles, from the viewpoint of via resolution and surface shape after desmear treatment, the average primary particle diameter (volume average particle diameter) is preferably 0.5 μm or less, more preferably 0.01 to 0.5 μm, even more preferably 0.01 to 0.2 μm, and may be 0.01 to 0.15 μm or 0.01 to 0.10 μm. The same applies to the average particle diameter of core-shell particles. In this specification, the average primary particle diameter (volume average particle diameter) is the particle diameter at 50% of the cumulative value (volume basis) of the particle size distribution obtained by measuring particles dispersed in a solvent with a refractive index of 1.38 using a zeta potential / particle size distribution analyzer (Beckman Coulter) in accordance with the international standard ISO 13321.

[0066] (Content of component (X)) (X) The content of organic particles is not particularly limited, but from the viewpoint of via resolution, adhesion strength to plated copper, electrical insulation reliability and crack resistance, it is preferably 1 to 60% by mass, more preferably 3 to 50% by mass, based on the total solid content of the photosensitive resin composition, and from the viewpoint of providing more sufficient crack resistance, it is even more preferably 5 to 40% by mass, particularly preferably 7 to 35% by mass, and from the viewpoint of providing more sufficient via resolution, it is most preferably 8 to 20% by mass.

[0067] <(B) Photopolymerization initiator> The component (B) used in this embodiment is not particularly limited as long as it can polymerize the component (A), and can be appropriately selected from commonly used photopolymerization initiators.(B) Components include benzoin compounds such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, and 2-methyl-1-[4-(methylthio)phenate Acetophenone compounds such as [nyl]-2-morpholino-1-propanone and N,N-dimethylaminoacetophenone; anthraquinone compounds such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; and 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone. Thioxanthone compounds; ketal compounds such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone compounds such as benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis(diethylamino)benzophenone, Michla's ketone, and 4-benzoyl-4'-methyldiphenyl sulfide; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; 2,4,6- Examples include acylphosphine oxide compounds such as methylbenzoyldiphenylphosphine oxide; oxime ester compounds such as 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]ethanone 1-(O-acetyl oxime), and 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl)oxime]. Among these, acetophenone compounds and thioxanthone compounds are preferred, with 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2,4-diethylthioxanthone being more preferred.Acetophenone compounds have the advantage of being less volatile and less likely to produce outgassing, while thioxanthone compounds have the advantage of being photocurable even in the visible light range. (B) Component may be used alone or in combination of two or more. When two or more are used in combination, it is preferable to use an acetophenone compound and a thioxanthone compound, and more preferably to use 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone and 2,4-diethylthioxanthone.

[0068] (Content of component (B)) The content of component (B) is not particularly limited, but is preferably 0.1 to 15% by mass, more preferably 0.15 to 5% by mass, even more preferably 0.15 to 1.5% by mass, and particularly preferably 0.20 to 0.8% by mass, based on the total solid content of the photosensitive resin composition. If the content of component (B) is 0.1% by mass or more, the risk of the exposed area eluting during development in the interlayer insulating layer formed using the photosensitive resin composition tends to be reduced, and if it is 15% by mass or less, the heat resistance tends to be improved.

[0069] <(B') Photopolymerization initiator> The photosensitive resin composition of this embodiment may contain a photopolymerization initiator (B') along with the above-mentioned component (B). Examples of the photopolymerization initiator (B') include ethyl N,N-dimethylaminobenzoate, isoamyl N,N-dimethylaminobenzoate, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine, and other tertiary amine compounds. Component (B') may be used alone or in combination of two or more. If the photosensitive resin composition of this embodiment contains component (B'), its content is preferably 0.01 to 20% by mass, more preferably 0.2 to 5% by mass, and even more preferably 0.3 to 2% by mass, based on the total amount of resin components in the photosensitive resin composition. The photosensitive resin composition of this embodiment does not necessarily have to contain component (B').

[0070] <(C) Thermosetting resin> The photosensitive resin composition of this embodiment may further contain a thermosetting resin as component (C), and it is preferable that it does. Component (C) does not contain anything equivalent to component (A), and in that respect, component (C) can be said to be one that does not have ethylenically unsaturated groups. Furthermore, substances that have epoxy groups while satisfying the condition of not having ethylenically unsaturated groups (such as epoxy-modified polybutadiene) are included in this component (C). Moreover, since component (C) is not in particulate form, it does not contain the aforementioned (X) organic particles. The photosensitive resin composition of this embodiment, by containing (C) a thermosetting resin, tends to improve heat resistance in addition to improving adhesion strength and insulation reliability with plated copper. Examples of thermosetting resins include epoxy resins, phenolic resins, unsaturated imide resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, and melamine resins. Furthermore, the use of known thermosetting resins is not limited to these. Among these, epoxy resins are preferred. (C) Component may be used alone or in combination of two or more components.

[0071] The epoxy resin is preferably one having two or more epoxy groups. Epoxy resins are classified into glycidyl ether type epoxy resins, glycidyl amine type epoxy resins, glycidyl ester type epoxy resins, etc. Among these, glycidyl ether type epoxy resins are preferred.

[0072] Furthermore, epoxy resins are classified into various types based on differences in their main skeleton, and each of the above types of epoxy resins is further classified as follows: Specifically, bisphenol-based epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin; bisphenol-based novolac type epoxy resins such as bisphenol A novolac type epoxy resin and bisphenol F novolac type epoxy resin; novolac type epoxy resins other than the aforementioned bisphenol-based novolac type epoxy resins, such as phenol novolac type epoxy resin, cresol novolac type epoxy resin, and biphenyl novolac type epoxy resin; phenol aralkyl type epoxy resin; stilbene type epoxy resin; naphthalene type epoxy Epoxy resins are classified into categories such as: naphthalene skeleton-containing epoxy resins (e.g., naphthol novolac type epoxy resin, naphthol type epoxy resin, naphthol aralkyl type epoxy resin, naphthylene ether type epoxy resin); biphenyl type epoxy resin; biphenyl aralkyl type epoxy resin; xylylene type epoxy resin; dihydroanthracene type epoxy resin; dicyclopentadiene type epoxy resin; alicyclic epoxy resins; heterocyclic epoxy resins; spiroring-containing epoxy resins; cyclohexanedimethanol type epoxy resin; trimethylol type epoxy resin; aliphatic chain epoxy resin; rubber-modified epoxy resin; and others. (C) Component may be used alone or in combination of two or more components.

[0073] Among these, bisphenol epoxy resins, naphthol-type epoxy resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, and cresol novolac-type epoxy resins are particularly preferred from the viewpoint of heat resistance, electrical insulation reliability, and adhesive strength with plated copper. Bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and biphenyl-type epoxy resins are more preferred, bisphenol F-type epoxy resins and biphenyl-type epoxy resins are even more preferred, and biphenyl-type epoxy resins are particularly preferred. These can also be commercially available, including bisphenol A epoxy resin (Mitsubishi Chemical Corporation's "jER828EL" and "YL980"), bisphenol F epoxy resin (Mitsubishi Chemical Corporation's "jER806H" and "YL983U"), naphthalene epoxy resin (DIC Corporation's "HP4032D" and "HP4710"), naphthalene skeleton-containing polyfunctional epoxy resin (Nippon Kayaku Co., Ltd.'s "NC7000"), and naphthol epoxy resin (Nippon Steel Chemical & Material Co., Ltd.'s "ESN-475V"). Examples include epoxy resins having a biphenyl structure ("NC3000H" and "NC3500" from Nippon Kayaku Co., Ltd.), "YX4000HK" and "YL6121" from Mitsubishi Chemical Corporation, anthracene-type epoxy resin ("YX8800" from Mitsubishi Chemical Corporation), glycerol-type epoxy resin ("ZX1542" from Nippon Steel Chemical & Material Co., Ltd.), naphthylene ether-type epoxy resin ("EXA7311-G4" from DIC Corporation), and cresol novolac-type epoxy resin ("EPICLON N-680" from DIC Corporation).

[0074] As the epoxy resin for component (C), epoxy-modified polybutadiene can be used in addition to the examples given above. In particular, as component (C), from the viewpoint of handling during the manufacture of printed circuit boards, it is preferable to use in combination an aromatic epoxy resin that is solid at room temperature and an epoxy resin that is liquid at room temperature. From this viewpoint, it is preferable to use in combination the epoxy resin exemplified as a preference (aromatic epoxy resin that is solid at room temperature) and epoxy-modified polybutadiene (a epoxy resin that is liquid at room temperature). In this case, the content ratio of the two resins used in combination (aromatic epoxy resin that is solid at room temperature / epoxy resin that is liquid at room temperature) is preferably 95 / 5 to 60 / 40 by mass ratio, more preferably 95 / 5 to 70 / 30, and even more preferably 95 / 5 to 80 / 20.

[0075] The epoxy-modified polybutadiene is preferably one having hydroxyl groups at the molecular ends, more preferably one having hydroxyl groups at both molecular ends, even more preferably one having hydroxyl groups only at the molecular ends, and particularly preferably one having hydroxyl groups only at both molecular ends. Furthermore, there is no particular limit to the number of hydroxyl groups that the epoxy-modified polybutadiene has, as long as it is one or more, but it is preferably 1 to 5, more preferably 1 or 2, and even more preferably 2. The epoxy-modified polybutadiene is preferably an epoxy-modified polybutadiene represented by the following general formula (C-1) from the viewpoint of adhesion strength with plated copper, heat resistance, coefficient of thermal expansion, and flexibility.

[0076] [ka] (In equation (C-1) above, a, b, and c represent the ratios of the structural units enclosed in parentheses, respectively: a is between 0.05 and 0.40, b is between 0.02 and 0.30, and c is between 0.30 and 0.80. Furthermore, a + b + c = 1.00 and (a + c) > b. y represents the number of structural units enclosed in square brackets and is an integer between 10 and 250.)

[0077] In the general formula (C-1) above, the order in which the structural units within the square brackets are combined is not limited to any particular order. In other words, the structural units shown on the left, the structural units shown in the center, and the structural units shown on the right may be swapped, and if we represent them as (a), (b), and (c), then various combination orders are possible, such as -[(a)-(b)-(c)]-[(a)-(b)-(c)-]-, -[(a)-(c)-(b)]-[(a)-(c)-(b)-, ​​-[(b)-(a)-(c)]-[(b)-(a)-(c)-, -[(a)-(b)-(a)]-[(c)-(b)-(c)-, -[(c)-(b)-(c)]-[(b)-(a)-(a)-]-, etc. From the viewpoint of adhesion strength with plated copper, heat resistance, coefficient of thermal expansion, and flexibility, a is preferably 0.10 to 0.30, b is preferably 0.10 to 0.30, and c is preferably 0.40 to 0.80. Also, from a similar viewpoint, y is preferably an integer between 30 and 180.

[0078] Examples of commercially available epoxidized polybutadienes in the general formula (C-1) above, where a=0.20, b=0.20, c=0.60, and y=an integer between 10 and 250, include "Epollead (registered trademark) PB3600" (manufactured by Daicel Corporation).

[0079] (Content of component (C)) If the photosensitive resin composition of this embodiment contains component (C), its content is not particularly limited, but is preferably 5 to 70% by mass, more preferably 5 to 40% by mass, even more preferably 7 to 30% by mass, and particularly preferably 10 to 20% by mass, based on the total solid content of the photosensitive resin composition. If the content of component (C) is 5% by mass or more, sufficient crosslinking of the photosensitive resin composition is obtained, and the adhesion strength to plated copper and electrical insulation reliability tend to improve. On the other hand, if it is 70% by mass or less, the resolution of the vias tends to be good.

[0080] <(D) Elastomer> The photosensitive resin composition of this embodiment may contain an elastomer as component (D), and it is preferable that it does. The inclusion of component (D) tends to result in a photosensitive resin composition with excellent via resolution, adhesion strength to plated copper, and electrical insulation reliability. Furthermore, component (D) also has the effect of suppressing the decrease in flexibility and adhesion strength to plated copper caused by internal stress (strain) inside the cured product due to curing shrinkage of component (A). (D) Component is preferably an elastomer that is liquid at 25°C. (D) Component (D) may be used alone or in combination of two or more components.

[0081] Examples of elastomers include styrene-based elastomers, olefin-based elastomers, polyester-based elastomers, urethane-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers. It is preferable to use at least one of these elastomers. These elastomers consist of hard segment components and soft segment components, with the former tending to contribute to heat resistance and strength, and the latter tending to contribute to flexibility and toughness. As for component (D), from the above examples, it is preferable that it includes at least one selected from the group consisting of olefin-based elastomers, polyester-based elastomers, and urethane-based elastomers, and more preferably a polyester-based elastomer, from the viewpoint of compatibility, solubility, and adhesive strength with plated copper. Furthermore, it is even more preferable that component (D) is at least one selected from the group consisting of olefin-based elastomers, polyester-based elastomers, and urethane-based elastomers, and particularly preferable that it is a polyester-based elastomer.

[0082] (CE-based elastomer) Examples of the aforementioned styrene-based elastomers include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-ethylene-propylene-styrene block copolymer. One type of styrene-based elastomer may be used alone, or two or more types may be used in combination. Components that make up styrene-based elastomers include styrene; and styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene. As for the styrene-based elastomer, those with a number average molecular weight of 1,000 to 50,000 are preferred, and those with a number average molecular weight of 3,000 to 20,000 are more preferred. In this specification, the number-average molecular weight is the value obtained on a standard polystyrene basis by gel permeation chromatography (GPC) using tetrahydrofuran as the solvent. Styrene elastomers can also be commercially available.

[0083] (Olefin-based elastomer) The olefin-based elastomer is a polymer or copolymer of α-olefins having 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, and 4-methylpentene. The olefin-based elastomer may have hydroxyl groups at its molecular ends, and it is preferable that it has hydroxyl groups at its molecular ends. One type of olefin-based elastomer may be used alone, or two or more types may be used in combination. Suitable olefin-based elastomers include polyethylene, polybutadiene, hydroxyl group-containing polybutadiene, hydroxyl group-containing polyisopropylene, ethylene-propylene copolymer (EPR), and ethylene-propylene-diene copolymer (EPDM). Also suitable are copolymers of the above-mentioned α-olefins having 2 to 20 carbon atoms with non-conjugated dienes having 2 to 20 carbon atoms, such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylenenorbornene, ethylidenenorbornene, butadiene, and isoprene. Furthermore, carboxylated NBR obtained by copolymerizing butadiene-acyllonitrile copolymer with methacrylic acid is also a suitable example. As for the olefin-based elastomer, those with a number average molecular weight of 1,000 to 8,000 are preferred, and those with a number average molecular weight of 1,500 to 6,500 are more preferred. Commercially available olefin-based elastomers may be used.

[0084] (Polyester elastomer) Examples of the polyester elastomers mentioned above include those obtained by polycondensation of a dicarboxylic acid or its derivative and a diol compound or its derivative. One type of polyester elastomer may be used alone, or two or more types may be used in combination. Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; aromatic dicarboxylic acids in which the hydrogen atoms of the aromatic ring of the aromatic dicarboxylic acid are substituted with methyl groups, ethyl groups, phenyl groups, etc.; aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid, and dodecanedicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. From the viewpoint of adhesion to the substrate, it is also preferable to use dimer acids derived from natural products as the dicarboxylic acid. One type of dicarboxylic acid may be used alone, or two or more types may be used in combination. Examples of derivatives of the dicarboxylic acid include the anhydride of the dicarboxylic acid.

[0085] Examples of the aforementioned diol compounds include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decanediol; alicyclic diols such as 1,4-cyclohexanediol; and aromatic diols represented by the following general formula (D-1). The diol compounds may be used individually or in combination of two or more.

[0086] [ka] (In general formula (D-1), X D1 R represents alkylene groups with 1 to 10 carbon atoms, alkylidene groups with 2 to 10 carbon atoms, cycloalkylene groups with 4 to 8 carbon atoms, and -O-, -S-, and -SO2-. D1 and R D2 Each of these independently represents a halogen atom or an alkyl group having 1 to 12 carbon atoms. p and q are each independently integers from 0 to 4, and r is either 0 or 1.

[0087] In general formula (D-1), X D1Examples of alkylene groups having 1 to 10 carbon atoms represented by include methylene groups, 1,2-dimethylene groups, 1,3-trimethylene groups, 1,4-tetramethylene groups, and 1,5-pentamethylene groups. From the viewpoint of via resolution, adhesion strength to plated copper, and electrical insulation reliability, alkylene groups having 1 to 3 carbon atoms are preferred, and methylene groups are more preferred. X D1 Examples of alkylidene groups having 2 to 10 carbon atoms represented by include ethylidene, propyridene, isopropylidene, butyridene, isobutylidene, pentyridene, and isopentyridene. From the viewpoint of via resolution, adhesion strength to plated copper, and electrical insulation reliability, isopropylidene is preferred as the alkylidene group. X D1 Examples of cycloalkylene groups with 4 to 8 carbon atoms represented by this symbol include cyclopentylene, cyclohexylene, and cyclooctylene groups. X D1 Of the above, alkylene groups having 1 to 10 carbon atoms and alkylidene groups having 2 to 10 carbon atoms are preferred, and methylene groups and isopropylidene groups are more preferred.

[0088] In general formula (D-1), R D1 and R D2 Examples of halogen atoms represented by this symbol include fluorine, chlorine, bromine, and iodine atoms. R D1 and R D2 Examples of C1-C12 alkyl groups represented by include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups. C1-C6 alkyl groups are preferred, C1-C3 alkyl groups are more preferred, and methyl groups are even more preferred. p and q are each independent integers between 0 and 4, preferably 0 or 1. r can be either 0 or 1, but when r is 0, the structure is represented by the following general formula (D-1'). [ka] (In general formula (D-1'), X D1 , R D1 (Both p and p are the same as those in general formula (D-1), and the preferred embodiment is also the same.)

[0089] Examples of aromatic diols represented by the general formula (D-1) include bisphenol A, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3-methylphenyl)propane, and resorcinol.

[0090] Furthermore, as a polyester elastomer, a multi-block copolymer can be used in which the aromatic polyester (e.g., polybutylene terephthalate) portion is the hard segment component and the aliphatic polyester (e.g., polytetramethylene glycol) portion is the soft segment component, and it is preferable to use such a multi-block copolymer. As such multi-block copolymers, there are commercially available products in various grades depending on the type, ratio, and molecular weight of the hard and soft segments. Specifically, examples include "Hytrel®" (manufactured by Toray DuPont Co., Ltd.), "Perprene®" (manufactured by Toyobo Co., Ltd.), "Esper®" and "Teslac®" (manufactured by Showa Denko Materials K.K.).

[0091] As for the polyester elastomer, those with a number average molecular weight of 900 to 30,000 are preferred, those with a number average molecular weight of 1,000 to 25,000 are more preferred, and those with a number average molecular weight of 5,000 to 20,000 are even more preferred.

[0092] (Urethane elastomer) Examples of suitable urethane elastomers include those containing a hard segment composed of a short-chain diol and a diisocyanate, and a soft segment composed of a polymer (long-chain) diol and a diisocyanate. One type of urethane elastomer may be used alone, or two or more types may be used in combination. Examples of polymeric (long-chain) diols include polypropylene glycol, polytetramethylene oxide, poly(1,4-butylene adipate), poly(ethylene-1,4-butylene adipate), polycaprolactone, poly(1,6-hexylene carbonate), and poly(1,6-hexylene-neopentylene adipate). The number-average molecular weight of the polymeric (long-chain) diol is preferably 500 to 10,000. Examples of short-chain diols include ethylene glycol, propylene glycol, 1,4-butanediol, and bisphenol A. The number-average molecular weight of the short-chain diol is preferably 48 to 500. As for the urethane elastomer, those with a number average molecular weight of 1,000 to 25,000 are preferred, those with a number average molecular weight of 1,500 to 20,000 are more preferred, and those with a number average molecular weight of 2,000 to 15,000 are even more preferred. Commercially available urethane elastomers may be used.

[0093] (Polyamide elastomer) Polyamide elastomers are broadly classified into two types: polyether block amide type, which uses polyamide for the hard segment and polyether for the soft segment; and polyether ester block amide type, which uses polyamide for the hard segment and polyester for the soft segment. Specific examples of the polyamide-based elastomer include block copolymers in which polyamide is used as the hard segment component and polybutadiene, butadiene-acrylonitrile copolymer, styrene-butadiene copolymer, polyisoprene, ethylene propylene copolymer, polyether, polyester, polybutadiene, polycarbonate, polyacrylate, polymethacrylate, polyurethane, silicone rubber, etc., are used as the soft segment component. The polyamide-based elastomer may be used alone or in combination of two or more types. As for the polyamide elastomer, those with a number average molecular weight of 1,000 to 50,000 are preferred, and those with a number average molecular weight of 2,000 to 30,000 are more preferred. Commercially available polyamide elastomers may be used.

[0094] (Acrylic elastomer) Examples of the acrylic elastomer include polymers of raw material monomers mainly composed of acrylic acid esters. Suitable acrylic acid esters include ethyl acrylate, butyl acrylate, methoxyethyl acrylate, and ethoxyethyl acrylate. The crosslinking monomer may be a copolymer of glycidyl methacrylate, allyl glycidyl ether, etc., with the acrylic acid ester, or a copolymer of acrylonitrile, ethylene, etc., with the acrylic acid ester, or with the acrylic acid ester and the crosslinking monomer. Specifically, examples include acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, and acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer. One type of acrylic elastomer may be used alone, or two or more types may be used in combination. As for the acrylic elastomer, those with a number average molecular weight of 1,000 to 50,000 are preferred, and those with a number average molecular weight of 2,000 to 30,000 are more preferred. You may use commercially available acrylic elastomers.

[0095] (Silicone-based elastomer) The aforementioned silicone elastomers are elastomers mainly composed of organopolysiloxanes, and are classified, for example, into polydimethylsiloxane elastomers, polymethylphenylsiloxane elastomers, polydiphenylsiloxane elastomers, etc. One type of silicone elastomer may be used alone, or two or more types may be used in combination. As for the silicone elastomer, those with a number average molecular weight of 1,000 to 50,000 are preferred, and those with a number average molecular weight of 2,000 to 30,000 are more preferred. You may use commercially available silicone elastomers.

[0096] (Other elastomers) Furthermore, component (D) may include at least one selected from the group consisting of polyphenylene ether resin, phenoxy resin, polycarbonate resin, polyamide-imide resin, polyimide resin, xylene resin, polyphenylene sulfide resin, polyetherimide resin, polyetheretherketone resin, tetrafluoroethylene resin, polyacrylonitrile resin, maleic anhydride-modified polybutadiene, phenol-modified polybutadiene, and carboxy-modified polyacrylonitrile.

[0097] (Content of component (D)) If the photosensitive resin composition of this embodiment contains component (D), its content is preferably 0.5 to 20% by mass, more preferably 0.5 to 15% by mass, even more preferably 0.5 to 10% by mass, particularly preferably 1.0 to 6% by mass, and most preferably 1.0 to 4.0% by mass, based on the total solid content of the photosensitive resin composition. If the content of component (D) is 0.5% by mass or more, the effect of improving the adhesion strength with plated copper is sufficient, and the electrical insulation reliability tends to be even better. If the content of component (D) is 20% by mass or less, the resolution of the vias, the adhesion strength with plated copper, and the electrical insulation reliability tend to all be sufficient.

[0098] <(E) Thermal polymerization initiator> The photosensitive resin composition of this embodiment may contain a thermal polymerization initiator as component (E). While there are no particular restrictions on the thermal polymerization initiator, hydroperoxide compounds such as diisopropylbenzene hydroperoxide "Permil P", cumene hydroperoxide "Permil H", and t-butyl hydroperoxide "Perbutyl H" (all manufactured by NOF Corporation); α,α-bis(t-butylperoxy-m-isopropyl)benzene "Perbutyl P", dicumyl peroxide "Permil D", 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane "Perhexa 25B", t-butylcumyl peroxide "Perbutyl C", di-t-butyl peroxide "Perbutyl D", and 2,5-dimethyl-2,5-bis(t-butyl Examples include dialkyl peroxaside compounds such as peroxy)hexyn-3 "Perhexyn 25B" and t-butyl peroxy-2-ethylhexanoate "Perbutyl O" (both manufactured by NOF Corporation); ketone peroxide compounds; peroxyketal compounds such as n-butyl 4,4-di-(t-butylperoxy)valerate "Perhexa V" (manufactured by NOF Corporation); diacyl peroxide compounds; peroxydicarbonate compounds; organic peroxides such as peroxyester compounds; and azo compounds such as 2,2'-azobisisobutylnitrile, 2,2'-azobis(2-cyclopropylpropionitrile), and 2,2'-azobis(2,4-dimethylvaleronitrile). Among these, dialkylperoxaside compounds are preferred, and 2,5-dimethyl-2,5-bis(t-bitylperoxy)hexyn-3 is more preferred, from the viewpoint of not inhibiting photopolymerization and having a significant effect in improving the physical properties and characteristics of the photosensitive resin composition. A single thermal polymerization initiator may be used alone, or two or more may be used in combination.

[0099] (Content of component (E)) If the photosensitive resin composition of this embodiment contains component (E), its content is not particularly limited, but is preferably 0.01 to 5% by mass, more preferably 0.02 to 3% by mass, and even more preferably 0.03 to 2% by mass, based on the total amount of resin components in the photosensitive resin composition. If it is 0.01% by mass or more, sufficient thermal curing tends to be possible, and if it is 5% by mass or less, good photosensitive properties and heat resistance tend to be obtained.

[0100] <(F) Inorganic filler> The photosensitive resin composition of this embodiment may contain an inorganic filler as component (F), and it is preferable that it contains an inorganic filler. By including an inorganic filler, thermal expansion can be reduced, and the risk of warping is minimized. In thermosetting resin compositions that have been conventionally used as interlayer insulating layers in multilayer printed circuit boards, thermal expansion has been reduced by including an inorganic filler. However, when an inorganic filler is included in a photosensitive resin composition, it is difficult to include a large amount of the inorganic filler to reduce thermal expansion because the inorganic filler causes light scattering and hinders development. Thus, there are new challenges unique to photosensitive resin compositions when including an inorganic filler. However, the photosensitive resin composition of this embodiment tends to maintain high via resolution even when an inorganic filler is included. Therefore, with the photosensitive resin composition of this embodiment, it is possible to achieve both low thermal expansion and high via resolution.

[0101] (F) Components include silica (SiO2), alumina (Al2O3), titania (TiO2), tantalum oxide (Ta2O5), zirconia (ZrO2), silicon nitride (Si3N4), barium titanate (BaO·TiO2), barium carbonate (BaCO3), magnesium carbonate (MgCO3), aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), lead titanate (PbO·TiO2), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide (Ga2O3), and spinel (MgO·Al2O3). Examples include mullite (3Al2O3·2SiO2), cordierite (2MgO·2Al2O3 / 5SiO2), talc (3MgO·4SiO2·H2O), aluminum titanate (TiO2·Al2O3), yttria-containing zirconia (Y2O3·ZrO2), barium silicate (BaO·8SiO2), boron nitride (BN), calcium carbonate (CaCO3), barium sulfate (BaSO4), calcium sulfate (CaSO4), zinc oxide (ZnO), magnesium titanate (MgO·TiO2), hydrotalcite, mica, calcined kaolin, and carbon. Component (F) may be used alone or in combination of two or more.

[0102] Component (F) is preferably silica, and more preferably silica, from the viewpoint of heat resistance and low thermal expansion. Furthermore, from the viewpoint of improving the dispersibility of inorganic fillers in the photosensitive resin composition by preventing aggregation, component (F) may be surface-treated with alumina or an organosilane compound.

[0103] The average particle size of component (F) is preferably 0.01 to 5 μm, more preferably 0.1 to 3 μm, even more preferably 0.1 to 2 μm, and particularly preferably 0.1 to 1 μm, from the viewpoint of via resolution. Here, the average particle size of component (F) is the volume-average particle size of the inorganic filler dispersed in the photosensitive resin composition, and is the value obtained by measurement as follows. First, the photosensitive resin composition is diluted (or dissolved) 1,000 times with methyl ethyl ketone, and then the particles dispersed in the solvent are measured at a refractive index of 1.38 using a submicron particle analyzer (manufactured by Beckman Coulter, Inc., product name: N5) in accordance with the international standard ISO 13321, and the particle size at 50% of the cumulative value (volume basis) in the particle size distribution is taken as the average particle size (volume-average particle size). Furthermore, the (F) component contained in the photosensitive resin film and interlayer insulating layer provided on the carrier film can also be measured using the submicron particle analyzer described above after diluting (or dissolving) it 1,000 times (by volume) using a solvent as described above.

[0104] (Content of component (F)) If the photosensitive resin composition of this embodiment contains component (F), its content is not particularly limited, but is preferably 5 to 80% by mass, more preferably 15 to 60% by mass, even more preferably 15 to 50% by mass, particularly preferably 20 to 35% by mass, and most preferably 23 to 27.5% by mass, based on the total solid content of the photosensitive resin composition. If the content of component (F) is within the above range, mechanical strength, heat resistance, and via resolution can be improved.

[0105] <(G) Pigment> The photosensitive resin composition of this embodiment may contain a pigment as component (G) depending on the desired color for adjusting the photosensitivity, etc. As component (G), any coloring agent that produces the desired color can be appropriately selected and used, and known coloring agents such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, carbon black, and naphthalene black are preferred.

[0106] (Content of component (G)) If the photosensitive resin composition of this embodiment contains component (G), its content is preferably 0.01 to 5% by mass, more preferably 0.03 to 3% by mass, and even more preferably 0.05 to 2% by mass, based on the total solid content of the photosensitive resin composition, from the viewpoint of adjusting photosensitivity, etc.

[0107] <(H) Hardener or curing accelerator> The photosensitive resin composition of this embodiment may contain a curing agent or a curing accelerator from the viewpoint of further improving various properties such as heat resistance, adhesion strength to plated copper, and chemical resistance. In particular, if the (C) thermosetting resin contains an epoxy resin, it is preferable to include an epoxy resin curing agent as the curing agent. (H) components include active ester curing agents; imidazole derivatives such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; guanamine compounds such as acetoguanamine and benzoguanamine; diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, and urea derivatives. Polyamine compounds such as melamine and polybasic hydrazides; the imidazole derivatives, guanamine compounds, organic salts or epoxy adducts of the polyamine compounds; the imidazole derivatives, guanamine compounds, organic salts and epoxy adducts of the polyamine compounds; amine complexes of boron trifluoride; triazine derivatives such as ethyldiamino-s-triazine, 2,4-diamino-s-triazine, and 2,4-diamino-6-xylyl-s-triazine; trimethylamine, N,N-dimethyloctylamine, N Examples include tertiary amine compounds such as benzyldimethylamine, pyridine, N-methylmorpholine, hexa(N-methyl)melamine, 2,4,6-tris(dimethylaminophenol), tetramethylguanidine, and m-aminophenol; polyphenol compounds such as polyvinylphenol, polyvinylphenol brominated, phenol novolac, and alkylphenol novolac; organic phosphine compounds such as tributylphosphine, triphenylphosphine, and tris-2-cyanoethylphosphine; phosphonium salts such as tri-n-butyl(2,5-dihydroxyphenyl)phosphonium bromide and hexadecyltributylphosphonium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride; the aforementioned polybasic acid anhydrides; and diphenyliodonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and 2,4,6-triphenylthiopyrillium hexafluorophosphate. Among these, polyamine compounds are preferred, and melamine is more preferred, from the viewpoint of further improving various properties such as heat resistance, adhesion strength to plated copper, and chemical resistance. If the photosensitive resin composition of this embodiment contains component (H), its content is preferably 0.01 to 20% by mass, more preferably 0.02 to 10% by mass, and even more preferably 0.03 to 3% by mass, based on the total amount of resin components in the photosensitive resin composition.

[0108] <Diluent> The photosensitive resin composition of this embodiment may be used with a diluent as needed. Examples of diluents include organic solvents. Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, propylene glycol monoethyl ether acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. One diluent may be used alone, or two or more may be used in combination. Ketones and esters are preferred as diluents, and esters are more preferred.

[0109] (Diluent content) The amount of diluent can be appropriately adjusted to ensure that the total solid content concentration in the photosensitive resin composition is preferably 40-90% by mass, more preferably 50-80% by mass, and even more preferably 55-70% by mass. By adjusting the amount of diluent used in this way, the coatability of the photosensitive resin composition is improved, and it becomes possible to form finer patterns.

[0110] <Other additives> The photosensitive resin composition of this embodiment may optionally contain various known and conventional additives such as polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; thickeners such as bentonite and montmorillonite; foam stabilizers such as silicone-based foam stabilizers, fluorine-based foam stabilizers, and vinyl resin-based foam stabilizers; and silane coupling agents. Furthermore, it may also contain flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, and phosphorus-based phosphate compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters; and thermoplastic resins such as polyester polyurethane resins.

[0111] The photosensitive resin composition of this embodiment can be obtained by kneading and mixing each component in a roll mill, bead mill, or the like. In this embodiment, the photosensitive resin composition may be in liquid form or in film form. When using a liquid photosensitive resin composition, there are no particular limitations on the application method of the photosensitive resin composition of this embodiment, but various application methods such as printing, spin coating, spray coating, jet dispensing, inkjet, and immersion coating can be used. Among these, printing and spin coating can be appropriately selected from the viewpoint of more easily forming the photosensitive layer. Furthermore, when using a film-like photosensitive resin composition, it can be used, for example, in the form of a photosensitive resin film as described later. In this case, a photosensitive layer of the desired thickness can be formed by laminating it onto a carrier film using a laminator or the like. It is preferable to use a film-like photosensitive resin composition because it increases the manufacturing efficiency of multilayer printed circuit boards.

[0112] [Photosensitive resin film, photosensitive resin film for interlayer insulation layer] The photosensitive resin film of this embodiment is a photosensitive layer that later becomes an interlayer insulating layer, and is made of the photosensitive resin composition of this embodiment. The photosensitive resin film of this embodiment may also be configured such that the 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 thinning the multilayer printed circuit board, it is preferably 1 to 100 μm, more preferably 1 to 50 μm, and even more preferably 5 to 40 μm.

[0113] The photosensitive resin film of this embodiment can be obtained, for example, by applying and drying the photosensitive resin composition of this embodiment onto a carrier film using a known coating apparatus such as a comma coater, bar coater, kiss coater, roll coater, gravure coater, or die coater to form a photosensitive layer that will later become an interlayer insulating layer. Examples of carrier films include polyester films such as polyethylene terephthalate film and polybutylene terephthalate film; and polyolefin films such as polypropylene film and polyethylene film. The thickness of the carrier film can be appropriately selected from the range of 5 to 100 μm, but is preferably 5 to 60 μm, and more preferably 15 to 45 μm.

[0114] Furthermore, in this embodiment, a protective film may be provided on the side of the photosensitive resin film opposite to the side in contact with the carrier film. A polymer film such as polyethylene or polypropylene can be used as the protective film. Alternatively, a polymer film similar to the carrier film described above may be used, or a different polymer film may be used.

[0115] For drying the coating film formed by applying the photosensitive resin composition, a dryer using hot air, far-infrared rays, or near-infrared rays can be used. The drying temperature is preferably 60 to 150°C, more preferably 70 to 120°C, and even more preferably 80 to 100°C. The drying time is preferably 1 to 60 minutes, more preferably 2 to 30 minutes, and even more preferably 5 to 20 minutes. The content of residual diluent in the photosensitive resin film after drying is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less, from the viewpoint of avoiding the diffusion of diluent during the manufacturing process of multilayer printed circuit boards.

[0116] The photosensitive resin film of this embodiment is suitable for use as an interlayer insulating layer in multilayer printed circuit boards because it exhibits excellent via resolution, adhesion strength to plated copper, electrical insulation reliability, and crack resistance. In other words, this disclosure also provides a photosensitive resin film for interlayer insulating layers. The photosensitive resin film for interlayer insulating layers may also be referred to as an interlayer insulating photosensitive film.

[0117] [Multilayer printed circuit board and method for manufacturing the same] This disclosure also provides a multilayer printed circuit board containing an interlayer insulating layer formed using the photosensitive resin composition or photosensitive resin film of this embodiment. The multilayer printed circuit board of this embodiment is not particularly limited in its manufacturing method, as long as it includes forming an interlayer insulating layer using the photosensitive resin composition of this embodiment, and can be easily manufactured, for example, by the manufacturing method of the multilayer printed circuit board of this embodiment described below.

[0118] Hereinafter, as an example of a preferred embodiment of the method for manufacturing a multilayer printed circuit board, a method for manufacturing a multilayer printed circuit board using the photosensitive resin film (photosensitive resin film for interlayer insulating layer) of this embodiment will be described with reference to Figure 1 as appropriate. The multilayer printed circuit board 100A can be manufactured, for example, by a manufacturing method including (1) to (4) below. (1): Laminating the photosensitive resin film of this embodiment to one or both sides of a circuit board (hereinafter referred to as "laminating process (1)"). (2) Forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in (1) above (hereinafter referred to as "photovia formation process (2)"). (3) Roughening the vias and the interlayer insulating layer (hereinafter referred to as "roughening process (3)"). (4) Forming a circuit pattern on the interlayer insulating layer (hereinafter referred to as "circuit pattern formation process (4)").

[0119] (Laminating process (1)) In the lamination process (1), the photosensitive resin film of this embodiment (photosensitive resin film for interlayer insulating layer) is laminated to one or both sides of the circuit board (substrate 101 having a circuit pattern 102) using a vacuum laminator. Examples of vacuum laminators include a vacuum applicator manufactured by Nichigo Morton Co., Ltd., a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a roll-type dry coater manufactured by Hitachi, Ltd., and a vacuum laminator manufactured by Showa Denko Materials Electronics Co., Ltd.

[0120] If a protective film is provided on the photosensitive resin film, the protective film can be peeled off or removed, and then the photosensitive resin film can be laminated to the circuit board by applying pressure and heating while the film is in contact with the circuit board. The lamination can be carried out, for example, by preheating the photosensitive resin film and circuit board as needed, at a pressure temperature of 70-130°C, a pressure of 0.1-1.0 MPa, and under reduced pressure of 20 mmHg (26.7 hPa) or less, but is not limited to these conditions. Furthermore, the lamination method may be batch-type or continuous-type using rolls. Finally, the photosensitive resin film laminated to the circuit board (hereinafter sometimes referred to as the photosensitive layer) is cooled to near room temperature to form the interlayer insulating layer 103. The carrier film may be peeled off at this point, or, as described later, it may be peeled off after exposure.

[0121] (Photovia formation process (2)) In the photovia formation process (2), at least a portion of the photosensitive resin film laminated to the circuit board is exposed, and then developed. The exposure causes the portion irradiated with active light to photocur, forming a pattern. There are no particular restrictions on the exposure method; for example, a method may be employed in which a negative or positive mask pattern called artwork is placed between the exposure device and the photosensitive resin film, and active light is irradiated onto the photosensitive resin film in an image-like manner from the exposure device (mask exposure method). Alternatively, a method may be employed in which active light is irradiated onto the photosensitive resin film in an image-like manner using a direct drawing exposure method such as LDI (Laser Direct Imaging) exposure or DLP (Digital Light Processing) exposure. Known light sources can be used as the light source for the active light. Specifically, examples of light sources include gas lasers such as carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, and argon lasers; solid-state lasers such as YAG lasers; and semiconductor lasers that effectively emit ultraviolet or visible light. The exposure dose is appropriately selected depending on the light source used and the thickness of the photosensitive layer, but for example, in the case of ultraviolet irradiation from a high-pressure mercury lamp, for a photosensitive layer thickness of 1 to 100 μm, it is usually 10 to 1,000 mJ / cm². 2 A suitable level is 15-500 mJ / cm². 2 This is preferable.

[0122] During development, the uncured portion of the photosensitive layer is removed from the substrate, thereby forming an interlayer insulating layer on the substrate consisting of the photocured material. If a carrier film is present on the photosensitive layer, the carrier film is removed before removing the unexposed areas (development). There are two development methods: wet development and dry development. Either can be used, but wet development is widely used, and wet development can also be used in this embodiment. In the case of wet development, development is carried out using a developer solution corresponding to the photosensitive resin composition and a known development method. Development methods include the dip method, paddle method, spray method, brushing, slapping, scraping, and agitation immersion. Among these, the spray method is preferred from the viewpoint of improving via resolution, and among spray methods, the high-pressure spray method is more preferred. Development may be carried out using one method, or two or more methods may be combined. The composition of the developer is appropriately selected according to the composition of the photosensitive resin composition. Examples of developers include alkaline aqueous solutions, aqueous developers, and organic solvent-based developers. Among these, alkaline aqueous solutions are preferred as the developer.

[0123] In the photovia formation process (2), after exposure and development, 0.2~10 J / cm 2 Degree (preferably 0.5~5J / cm) 2 The interlayer insulating layer may be further cured, and is preferable, by performing post-UV curing with an exposure dose of ) and post-thermal curing at a temperature of approximately 60 to 250°C (preferably 120 to 200°C) as needed. By the above method, an interlayer insulating layer having vias 104 is formed. There are no particular restrictions on the shape of the vias; in terms of cross-sectional shape, examples include squares and inverted trapezoids (where the top side is longer than the bottom side), and in terms of shape when viewed from the front (the direction in which the bottom of the via is visible), examples include circular and square shapes. In the photolithography method for forming vias in this embodiment, it is possible to form vias with an inverted trapezoidal cross-sectional shape (where the top side is longer than the bottom side), which is preferable because it improves the adhesion of the plated copper to the via wall surface.

[0124] The size (diameter) of the vias formed by this process can be 60 μm or less, and can even be less than 40 μm or 30 μm or less, making them smaller in diameter than vias produced by laser processing. There is no particular lower limit to the size (diameter) of the vias formed by this process, but it may be 15 μm or more, or 20 μm or more. However, the size (diameter) of the vias formed by this process is not necessarily limited to 60 μm or less; for example, it may be around 200 μm or less, and can be arbitrarily selected within the range of 15 to 300 μm.

[0125] (Roughening process (3)) In the roughening process (3), the surfaces of the vias and interlayer insulating layers are roughened with a roughening solution. If smearing occurs in the photovia formation process (2), the smearing may be removed with the roughening solution. The roughening process and smearing can be performed together. Examples of the aforementioned roughening solutions include chromium / sulfuric acid roughening solution, alkaline permanganate roughening solution (for example, sodium permanganate roughening solution, etc.), and sodium fluoride / chromium / sulfuric acid roughening solution. The roughening treatment creates uneven anchors on the surface of the vias and interlayer insulating layers.

[0126] (Circuit pattern formation process (4)) The circuit pattern formation process (4) is a process in which a circuit pattern is formed on the interlayer insulating layer after the roughening process (3). From the viewpoint of forming fine wiring, it is preferable to perform the formation of the circuit pattern by a semi-additive process. The semi-additive process forms the circuit pattern and simultaneously conducts the vias. In the semi-additive process, first, a seed layer 105 is formed by electroless copper plating using a palladium catalyst or the like on the entire surface of the via bottom, via wall, and interlayer insulating layer after the roughening process (3). This seed layer is for forming a power supply layer for electrolytic copper plating and is preferably formed to a thickness of about 0.1 to 2.0 μm. If the thickness of the seed layer is 0.1 μm or more, it tends to suppress a decrease in connection reliability during electrolytic copper plating, and if it is 2.0 μm or less, it tends to reduce the amount of etching required when flash etching the seed layer between wirings, thereby reducing damage to the wiring during etching.

[0127] The electroless copper plating process is carried out by the reaction of copper ions with a reducing agent, which causes metallic copper to be deposited on the surface of the vias and interlayer insulating layers. The electroless plating method and the electrolytic plating method may be known methods and are not particularly limited, but the catalyst for the electroless plating process is preferably a palladium-tin mixed catalyst, and the primary particle size of the catalyst is preferably 10 nm or less. Furthermore, the plating composition of the electroless plating process preferably contains hypophosphorous acid. The hypophosphorous acid functions as a reducing agent. Commercially available electroless copper plating solutions can be used, including "MSK-DK" from Attec Japan Co., Ltd. and the "Surupap (registered trademark) PEA ver.4" series from Uemura Kogyo Co., Ltd.

[0128] After the electroless copper plating process described above, a dry film resist is heat-pressed onto the electroless copper plating using a roll laminator. The thickness of the dry film resist must be greater than the height of the wiring after the electroplated copper, and from this viewpoint, a dry film resist with a thickness of 5 to 30 μm is preferred. As the dry film resist, the "Photec" series manufactured by Showa Denko Materials Co., Ltd. is used. After the dry film resist is thermocompressed, the dry film resist is exposed, for example, through a mask on which the desired wiring pattern is drawn. Exposure can be performed using the same apparatus and light source as those used when forming vias on the photosensitive resin film. After exposure, the carrier film on the dry film resist is peeled off, and development is performed using an alkaline aqueous solution to remove unexposed areas and form the resist pattern 106. After this, if necessary, the development residue of the dry film resist may be removed using plasma or the like. After development, electroplating is performed to form a copper circuit layer 107 and to perform via filling.

[0129] After electroplating copper, the dry film resist is removed using an alkaline aqueous solution or an amine-based stripping agent. After removing the dry film resist, the seed layer between the wiring is removed (flash etching). Flash etching is performed using an acidic solution such as sulfuric acid and hydrogen peroxide, and an oxidizing solution. Specifically, examples include "SAC" from JCU Corporation and "CPE-800" from Mitsubishi Gas Chemical Company, Inc. After flash etching, palladium and other materials adhering to the areas between the wiring are removed as needed. Palladium removal can preferably be performed using an acidic solution such as nitric acid or hydrochloric acid.

[0130] After peeling off the dry film resist or after flash etching, a post-bake treatment is preferably performed. The post-bake treatment thoroughly heat-cures any unreacted thermosetting components, thereby improving electrical insulation reliability, curing characteristics, and adhesion strength to plated copper. Although the heat curing conditions vary depending on the type of resin composition, a curing temperature of 150 to 240°C and a curing time of 15 to 100 minutes are preferable. The post-bake treatment completes a complete photovia method for manufacturing printed circuit boards, and this process is repeated to manufacture substrates according to the required number of interlayer insulating layers. Then, a solder resist layer 108 is preferably formed on the outermost layer.

[0131] The above describes a method for manufacturing a multilayer printed circuit 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 embedding chips or passive elements, for example. Cavities can be suitably formed, for example, in the description of the multilayer printed circuit board above, by making the drawing pattern when forming a pattern by exposure to the photosensitive resin film such that it can form the desired cavity. Furthermore, the photosensitive resin composition of this embodiment is also useful as a surface protective film for solder resists and the like.

[0132] [Semiconductor Packages] This disclosure also provides a semiconductor package containing the multilayer printed circuit board of this embodiment and semiconductor elements. The semiconductor package of this embodiment can be manufactured by mounting semiconductor elements such as semiconductor chips and memory at predetermined positions on the multilayer printed circuit board of this embodiment and sealing the semiconductor elements with a sealing resin or the like. [Examples]

[0133] The embodiment will be described in more detail below with reference to examples, but this embodiment is not limited to these examples. The properties of the photosensitive resin compositions obtained in each example were evaluated using the method described below.

[0134] [1. Evaluation of via resolution] (1-1) Preparation of evaluation laminate A printed circuit board substrate (manufactured by Showa Denko Materials Co., Ltd., product name "MCL-E-679"), in which 12 μm thick copper foil was laminated on a glass epoxy substrate, was treated with a roughening solution (manufactured by MEC Corporation, product name "CZ-8100"), then washed with water and dried to obtain a roughened printed circuit board substrate. Next, the protective film was peeled off from the "photosensitive resin film with carrier film and protective film laminated together" manufactured in each example and comparative example. The exposed photosensitive resin film was then placed in contact with the copper foil of the roughened printed circuit board substrate, and laminated using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500"). The lamination conditions were: press hot plate temperature 70°C, vacuum evacuation time 20 seconds, lamination press time 30 seconds, atmospheric pressure 4kPa or less, and bonding pressure 0.4MPa. After lamination, the laminate was left at room temperature for at least one hour to obtain an evaluation laminate in which the photosensitive resin film and carrier film were laminated in that order on the copper foil surface of the printed circuit board substrate. (1-2) Sensitivity measurement of photosensitive resin film After peeling and removing the carrier film from the evaluation laminate obtained in (1-1) above, a 41-step tablet was placed, and exposure was performed using a direct imaging exposure system "DXP-3512" (manufactured by Oak Manufacturing Co., Ltd.) with an ultra-high pressure mercury lamp as the light source. The exposure pattern used was a grid pattern of squares (side length:distance between the centers of the squares = 1:2). After exposure, the unexposed areas of the photosensitive resin composition were left at room temperature for 30 minutes, and then spray-developed for 60 seconds using a 1% by mass aqueous sodium carbonate solution at 30°C. After development, the exposure energy amount at which the gloss retention step count of the 41-step tablet reached 8.0 was determined by the sensitivity (unit: mJ / cm²) of the photosensitive resin film. 2 The sensitivity was set to ). Using the pattern exposed at this sensitivity, the resolution of vias provided on the photosensitive resin film was evaluated according to the evaluation criteria below. (1-3) Evaluation of via resolution The resolution of the vias was evaluated by exposing the photosensitive resin film to an exposure energy level that corresponds to a step count of 8.0, as measured in (1-2) above, followed by spray development. The via pattern was then observed using an optical microscope and evaluated according to the following criteria. The above-mentioned "aperture" refers to a state in which the copper foil of the printed circuit board substrate can be seen when observing the via portion of the dot pattern using an optical microscope. A rating of "A" indicates good characteristics. A: The φ60μm via portion of the dot pattern is open. B: The φ60μm via portion of the dot pattern is not open. C: Did not harden with light.

[0135] [2. Evaluation of adhesion strength (peel strength) with plated copper] In each example and comparative example, the protective film was peeled off from the "photosensitive resin film formed by laminating a carrier film and a protective film," and the laminate was obtained by laminating it onto a 1.0 mm thick copper-clad laminate substrate using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500") at a pressing pressure of 0.4 MPa, a press hot plate temperature of 80°C, a vacuum evacuation time of 25 seconds, a lamination press time of 25 seconds, and an atmospheric pressure of 4 kPa or less. The resulting laminate was subjected to 500 mJ / cm² exposure using a parallel light exposure machine (manufactured by Oak Manufacturing Co., Ltd., product name "EXM-1201") with an ultra-high pressure mercury lamp as the light source. 2 The entire surface was exposed. Next, a UV lithography apparatus was used to expose it at 2,000 mJ / cm². 2 An evaluation laminate was obtained by exposing it to a certain exposure level, heating it at 170°C for 1 hour, and forming a cured material (cured film) on a copper-clad laminate substrate.

[0136] Next, an aqueous solution containing 200 ml / L of diethylene glycol monobutyl ether and 5 g / L of sodium hydroxide was prepared as a swelling solution, and the evaluation laminate was immersed in this swelling solution, which was heated to 70°C, for 10 minutes. Then, an aqueous solution containing 60 g / L of potassium permanganate and 40 g / L of sodium hydroxide was prepared as a roughening solution, and the evaluation laminate was immersed in this roughening solution, which was heated to 70°C, for 15 minutes. Subsequently, a neutralizing solution (an aqueous solution of 30 g / L of tin chloride (SnCl2) and 300 ml / L of hydrogen chloride) was prepared, and the evaluation laminate was immersed in this neutralizing solution, which was heated to 40°C, for 5 minutes to reduce the potassium permanganate. In this manner, the surface of the cured evaluation laminate was desmeared. Next, the surface of the desmeared evaluation laminate cured material was degreased and cleaned by treating it with the 60°C alkaline cleaner "Cleaner Securigant 902" (manufactured by Atotec Japan Co., Ltd., product name) for 5 minutes. After cleaning, the desmeared cured material was treated with the 23°C pre-dip solution "Pre-dip Neogant B" (manufactured by Atotec Japan Co., Ltd., product name) for 1 minute. Subsequently, the cured material was treated with the 35°C activator solution "Activator Neogant 834" (manufactured by Atotec Japan Co., Ltd., product name) for 5 minutes, and then treated with the 30°C reducing solution "Reducer Neogant WA" (manufactured by Atotec Japan Co., Ltd., product name) for 5 minutes. The resulting evaluation laminate was placed in a chemical copper solution ("Basic Print Gant MSK-DK", "Copper Print Gant MSK", "Stabilizer Print Gant MSK" (all manufactured by Atotec Japan Co., Ltd., product names)) and electroless plating was performed until the plating thickness reached approximately 0.5 μm. After the electroless plating, an annealing treatment was performed at 120°C for 30 minutes to remove any remaining hydrogen gas. Subsequently, copper sulfate electroplating was performed, followed by an annealing treatment at 180°C for 60 minutes to form a conductive layer with a thickness of 25 μm.

[0137] The evaluation laminates, in which the conductive layer was formed by the method described above, were subjected to vertical peel strength measurements at 23°C in accordance with JIS C6481 (1996), and then evaluated according to the following evaluation criteria. A: The adhesive strength with plated copper was 0.40 kN / m or higher. B: The adhesive strength with plated copper was between 0.30 kN / m and less than 0.40 kN / m. C: The adhesive strength with plated copper was less than 0.30 kN / m.

[0138] [3. Measurement of surface roughness (arithmetic mean roughness; Ra)] An evaluation substrate for surface roughness measurement was prepared by fabricating a substrate in the same manner as the substrate for measuring peel strength described in [2. Evaluation of adhesion strength (peel strength) with plated copper] above, and by performing desmear treatment in the same manner. The surface roughness (arithmetic mean roughness; Ra) of the insulating layer was measured using a non-contact surface roughness meter "Contour GT-K" (manufactured by Bruker) with an external lens at 50x magnification and an internal lens at 1x magnification. The average of five points was used as Ra, and the results were evaluated according to the evaluation criteria below. A: Ra was less than 150 nm. B:Ra was between 150nm and 300nm. C:Ra was 300nm or higher.

[0139] [4. Evaluation of HAST resistance (electrical insulation reliability after moisture absorption)] In the above [2. Evaluation of adhesion strength (peel strength) with plated copper], the procedure was carried out in the same manner except that a conductive layer with a thickness of 35 μm was formed instead of a conductive layer with a thickness of 25 μm, and a laminate with a conductive layer was obtained. The formed conductive layer was etched to create a circular electrode with a diameter (φ) of 6 mm. Subsequently, a photosensitive solder resist film "FZ-2700GA" (manufactured by Showa Denko Materials Co., Ltd., product name) was laminated onto the electrode and the cured film using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500") under the following conditions: pressure of 0.4 MPa, press hot plate temperature of 80°C, vacuum evacuation time of 25 seconds, lamination press time of 40 seconds, and atmospheric pressure of 4 kPa or less, to obtain an evaluation laminate. The thickness of the photosensitive solder resist film layer in the evaluation laminate was 25 μm.

[0140] The evaluation laminate obtained by the above method was subjected to 500 mJ / cm² exposure using a parallel light exposure machine (manufactured by Oak Manufacturing Co., Ltd., product name "EXM-1201") with an ultra-high pressure mercury lamp as the light source. 2 The entire surface was exposed. Next, a UV lithography apparatus was used to expose it at 2,000 mJ / cm². 2 After exposure with the specified exposure dose, the film was heated at 160°C for 1 hour to obtain a cured film. Next, the circuit was wired so that the circular electrode was the positive electrode and the copper foil on the side of the copper-clad laminate where the circular electrode was formed was the negative electrode. The circuit was then exposed to a pressure cooker (model name "Unsaturated Ultra-Accelerated Life Testing Device PC-422RP", manufactured by Hirayama Seisakusho Co., Ltd.) at 135°C, 85%, and 5.5V for 200 hours. The resistance between the electrodes was measured and then evaluated according to the evaluation criteria below. A: The resistance value after 200 hours is 10 × 10 7 It was Ω or higher. B: The resistance value after 200 hours is 10 × 10 6 Greater than Ω, and 10 × 10 7 It was less than Ω. C: Resistance value after 200 hours is 10 × 10 6 It was less than Ω.

[0141] [5. Evaluation of crack resistance] (5-1) Preparation of evaluation laminates A printed circuit board substrate (manufactured by Showa Denko Materials Co., Ltd., product name "MCL-E-679"), in which 12 μm thick copper foil was laminated onto a glass epoxy substrate, had its copper foil surface polished with an abrasive brush, washed with water, and dried to obtain a roughened printed circuit board substrate. Next, the protective film was peeled off from the "photosensitive resin film with carrier film and protective film laminated together" manufactured in each example and comparative example. The exposed photosensitive resin film was placed in contact with the copper foil of the roughened printed circuit board substrate, and then laminated using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500"). The lamination conditions were: press hot plate temperature 70°C, vacuuming time 20 seconds, lamination press time 30 seconds, atmospheric pressure 4 kPa or less, and compression pressure 0.4 MPa. After lamination, the substrate was left at room temperature for more than one hour to obtain an evaluation laminate in which a photosensitive resin film and a carrier film were laminated in that order on the copper foil surface of a printed circuit board substrate. (5-2) Sensitivity measurement of photosensitive resin film Using the carrier film of the evaluation laminate obtained above, the test specimens obtained by subjecting them to the same treatment as in (1-2) above were exposed to air at -65°C for 15 minutes, then heated at a heating rate of 180°C / min, and then exposed to air at 150°C for 15 minutes, followed by cooling at a cooling rate of 180°C / min. This thermal cycle was repeated 1,000 times. Subsequently, the evaluation laminate was observed using a metallurgical microscope at 100x magnification at 10 arbitrary locations within the openings of 2mm square vias, and the degree of cracking and delamination was evaluated according to the evaluation criteria below. A: No cracks or delamination were observed. B: Cracks and delamination were observed in 1 or 2 out of 10 locations. C: Cracks and delamination were observed in 3 out of 10 locations. D: Cracks and delamination were observed in 4 or more out of 10 locations.

[0142] <Synthesis Example 1> Synthesis of Acid-Modified Ethylene-Unsaturated Group and Alicyclic Skeleton-Containing Epoxy Derivative 1 [Component (A1)] Dicyclopentadiene type epoxy resin (XD-1000, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 252 g / eq, softening point 74.2°C, corresponding to component (a1), represented by the general formula (a1-1), number of ring-forming carbon atoms in the alicyclic skeleton: 10) 350 parts by mass, acrylic acid (corresponding to component (a2)) 70 parts by mass, methyl hydroquinone 0.5 parts by mass, and carbitol acetate 120 parts by mass were charged and reacted by heating to 90°C and stirring to dissolve the mixture. Next, the obtained solution was cooled to 60°C, 2 parts by mass of triphenylphosphine were added, and the mixture was heated to 100°C and reacted until the acid value of the solution reached 1 mg KOH / g. To the reacted solution, 98 parts by mass of tetrahydrophthalic anhydride (corresponding to component (a3)) and 85 parts by mass of carbitol acetate were added, and the mixture was heated to 80°C and reacted for 6 hours. Subsequently, the mixture was cooled to room temperature to obtain an acid-modified dicyclopentadiene type epoxy acrylate with a solid content of 73% by mass (corresponding to components (A1) and (A1-1). Hereinafter referred to as "acid-modified ethylenically unsaturated group and alicyclic skeleton-containing epoxy derivative 1").

[0143] <Examples 1-5, Comparative Example 1> (Preparation of photosensitive resin composition) A photosensitive resin composition was prepared by mixing the compositions according to the formulations and amounts shown in Table 1, and then kneading them in a three-roll mill. In each example, a photosensitive resin composition with a solid content of 60% by mass was obtained by adjusting the concentration by adding carbitol acetate as appropriate. (Preparation of photosensitive resin film) A polyethylene terephthalate film with a thickness of 25 μm (G2-25, manufactured by Teijin Limited, trade name) was used as a carrier film. After applying the photosensitive resin composition prepared in each example onto the carrier film, a photosensitive resin film (photosensitive layer) with a thickness of 25 μm was formed by drying it at 100°C for 10 minutes using a hot air convection dryer. Subsequently, a biaxially oriented polypropylene film (MA-411, manufactured by Oji F-Tex Co., Ltd., trade name) was laminated as a protective film onto the surface of the photosensitive resin film (photosensitive layer) opposite to the side in contact with the carrier film, thereby producing a photosensitive resin film with the carrier film and protective film laminated together. The prepared photosensitive resin film was used to perform each evaluation according to the method described above. The results are shown in Table 1.

[0144] [Table 1]

[0145] The components used in each example are as follows: (A) Component; • Acid-modified ethylenically unsaturated group and alicyclic skeleton-containing epoxy derivative 1 [(A1) component]: The one obtained in Synthesis Example 1 was used. • Dipentaerythritol pentaacrylate [(Aiii) ingredient] (X) Ingredient: • Core-shell particle 1: (Core: Styrene-butadiene copolymer, Shell: Acrylic acid ester copolymer) (Average primary particle size: 0.1 μm) • Core-shell particle 2: (Core: acrylic ester copolymer, Shell: epoxy resin) (Average primary particle diameter: 0.1 μm) Here, the average primary particle diameter (volume-average particle diameter) of core-shell particles 1 and 2 was defined as the particle diameter at 50% (volume basis) of the integrated particle size distribution obtained by measuring particles dispersed in a solvent with a refractive index of 1.38 using a zeta potential / particle size distribution analyzer (Beckman Coulter), in accordance with the international standard ISO 13321. (B) Ingredients; • Photopolymerization initiator 1: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, acetophenone compound • Photopolymerization initiator 2: 2,4-diethylthioxanthone, thioxanthone compound (C) Component; • Biphenyl-type epoxy resin: "YX-4000" (manufactured by Mitsubishi Chemical Corporation, product name) • Epoxy-modified polybutadiene: "Epolleed (registered trademark) PB3600" (manufactured by Daicel Corporation, product name) (D) Component; • Polyester elastomer: "Esper (registered trademark) 1108" (manufactured by Showa Denko Materials Co., Ltd., product name) (E) Ingredients; • Silica: "SFP-20M" (manufactured by Denka Co., Ltd., average particle size 0.3 μm, product name)

[0146] Table 1 shows that Examples 1-5 exhibited excellent via resolution, adhesion strength to plated copper, electrical insulation reliability, and crack resistance, while also exhibiting a reduced surface roughness (Ra). Furthermore, the low surface roughness (Ra) of the interlayer insulating layer, made of a photosensitive resin composition, allowed for the formation of fine surface features, facilitating the formation of fine wiring. The high adhesion strength to plated copper despite the low surface roughness (Ra) is particularly noteworthy. On the other hand, in Comparative Example 1, which did not contain component (X), although the via resolution was good, the adhesion strength to the plated copper, electrical insulation reliability, and crack resistance were insufficient, resulting in a large surface roughness Ra. [Explanation of Symbols]

[0147] 100A Multilayer Printed Circuit Board 102 Circuit Patterns 103 Interlayer insulating layer 104 Beer (Beer Hall) 105 Seed Layer 106 Resist Patterns 107 Copper circuit layer 108 Solder Resist Layers

Claims

1. A photosensitive resin composition comprising (A) a photopolymerizable compound having an ethylenically unsaturated group, (X) organic particles, and (B) a photopolymerization initiator, (X) The organic particles contain a (meth)acrylic acid ester copolymer, and the (X) organic particles contain core-shell particles. The content of the (X) organic particles is 7 to 20% by mass based on the total solid content of the photosensitive resin composition. A photosensitive resin composition wherein the (A) photopolymerizable compound having an ethylenically unsaturated group comprises (A1) a photopolymerizable compound having an acidic substituent and an alicyclic skeleton together with an ethylenically unsaturated group, and the (A1) component is (A1-1) an acid-modified epoxy derivative containing an ethylenically unsaturated group and an alicyclic skeleton, obtained by reacting (a3) ​​a polybasic acid anhydride containing a saturated group or an unsaturated group with (a1) an alicyclic skeleton-containing epoxy resin modified with (a2) an ethylenically unsaturated group-containing organic acid.

2. (X) The photosensitive resin composition according to claim 1, wherein the ratio of the major axis r2 to the minor axis r1 (r2 / r1) of the organic particles is 1.4 or less.

3. The photosensitive resin composition according to claim 1 or 2, wherein the combination of the core component and the shell component of the core-shell particle (core / shell) is a styrene-butadiene copolymer / (meth)acrylic acid ester copolymer or a (meth)acrylic acid ester copolymer / epoxy resin.

4. (X) The photosensitive resin composition according to any one of claims 1 to 3, wherein the average primary particle diameter (volume average particle diameter) of the organic particles is 0.5 μm or less.

5. The photosensitive resin composition according to any one of claims 1 to 4, wherein the (A) photopolymerizable compound having an ethylenically unsaturated group further comprises at least one selected from the group consisting of (Ai) a monofunctional vinyl monomer having one polymerizable ethylenically unsaturated group, (Aii) a difunctional vinyl monomer having two polymerizable ethylenically unsaturated groups, and (Aiii) a polyfunctional vinyl monomer having at least three polymerizable ethylenically unsaturated groups.

6. The photopolymerizable compound according to any one of claims 1 to 5, wherein the (A1) ethylenically unsaturated group is accompanied by an acidic substituent and an alicyclic skeleton, and the alicyclic skeleton is an alicyclic skeleton having 5 to 20 ring-forming carbon atoms.

7. The photopolymerizable compound according to any one of claims 1 to 6, wherein the (A1) ethylenically unsaturated group is accompanied by an acidic substituent and an alicyclic skeleton, and the alicyclic skeleton consists of two or more rings.

8. The photosensitive resin composition according to any one of claims 1 to 7, further comprising (C) a thermosetting resin.

9. The photosensitive resin composition according to any one of claims 1 to 8, further comprising (D) an elastomer.

10. The photosensitive resin composition according to claim 9, wherein the (D) elastomer comprises at least one selected from the group consisting of styrene elastomers, olefin elastomers, polyester elastomers, urethane elastomers, polyamide elastomers, acrylic elastomers, and silicone elastomers.

11. The photosensitive resin composition according to any one of claims 1 to 10, further comprising (F) an inorganic filler.

12. A photosensitive resin composition for forming photovias, comprising the photosensitive resin composition according to any one of claims 1 to 11.

13. A photosensitive resin composition for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of claims 1 to 11.

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

15. A photosensitive resin film for an interlayer insulating layer, comprising the photosensitive resin composition according to any one of claims 1 to 11.

16. A multilayer printed circuit board comprising an interlayer insulating layer formed using the photosensitive resin composition described in any one of claims 1 to 11.

17. A multilayer printed circuit board comprising an interlayer insulating layer formed using the photosensitive resin film described in claim 14.

18. A semiconductor package comprising a multilayer printed circuit board according to claim 16 or 17 and a semiconductor element.

19. A method for manufacturing a multilayer printed circuit board, including (1) to (4) below. (1) Laminating the photosensitive resin film described in claim 14 to one or both sides of a circuit board. (2) Forming an interlayer insulating layer having vias by exposing and developing the photosensitive resin film laminated in (1) above. (3) Roughen the vias and the interlayer insulating layer. (4) Forming a circuit pattern on the interlayer insulating layer.