Photosensitive resin composition, photosensitive element, printed wiring board, and method for manufacturing printed wiring board

Abstract

To provide a photosensitive resin composition having excellent resolution, a photosensitive element using the photosensitive resin composition, a printed wiring board, and a method for manufacturing a printed wiring board.SOLUTION: The present disclosure relates to a photosensitive resin composition for a permanent resist, which contains (A) an acid-modified vinyl group-containing resin, (B) a photopolymerization initiator, and (C) photopolymerizable compound. The photopolymerizable compounds include a photopolymerizable compound having four or more ethylenically unsaturated groups and a photopolymerizable compound having three or less ethylenically unsaturated groups.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a photosensitive resin composition for permanent resist, a photosensitive element, a printed wiring board, and a method for producing a printed wiring board. [Background technology]

[0002] As the performance of various electronic devices improves, semiconductor integration is becoming more and more advanced. Accordingly, various performance requirements are being placed on permanent resists (solder resists) formed on printed wiring boards, semiconductor package substrates, etc.

[0003] Known photosensitive resin compositions used to form permanent resists include, for example, photocurable resin compositions containing an acid-modified vinyl group-containing epoxy resin, an elastomer, a photopolymerization initiator, a diluent, and a curing agent as essential components (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-240930 Summary of the Invention [Problem to be solved by the invention]

[0005] As the pitch of wiring on semiconductor package substrates becomes narrower due to the high integration of semiconductor elements, photosensitive resin compositions used to form permanent resists are required to have higher resolution.

[0006] An object of the present disclosure is to provide a photosensitive resin composition having excellent resolution, a photosensitive element and a printed wiring board using the photosensitive resin composition, and a method for producing a printed wiring board. [Means for solving the problem]

[0007] One aspect of the present disclosure relates to a photosensitive resin composition for permanent resist, comprising (A) an acid-modified vinyl group-containing resin, (B) a photopolymerization initiator, and (C) a photopolymerizable compound, wherein the photopolymerizable compound includes a photopolymerizable compound having four or more ethylenically unsaturated groups and a photopolymerizable compound having three or less ethylenically unsaturated groups.

[0008] Another aspect of the present disclosure relates to a photosensitive element comprising a support film and a photosensitive layer formed on the support film, the photosensitive layer containing the above-described photosensitive resin composition.

[0009] Another aspect of the present disclosure relates to a printed wiring board comprising a permanent resist containing a cured product of the above-described photosensitive resin composition.

[0010] Another aspect of the present disclosure relates to a method for producing a printed wiring board, comprising the steps of: forming a photosensitive layer on a substrate using the above-described photosensitive resin composition or photosensitive element; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to provide a photosensitive resin composition having excellent resolution, a photosensitive element using the photosensitive resin composition, a printed wiring board, and a method for producing a printed wiring board. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional view schematically illustrating a photosensitive element according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present disclosure will be described in detail below. In this specification, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended function of the process is achieved. The term "layer" encompasses not only a structure that is formed over the entire surface when observed in a plan view, but also a structure that is formed only on a portion of the surface. A numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit of a numerical range of a certain stage may be replaced with the upper or lower limit of a numerical range of another stage. In numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples.

[0014] When referring to the amount of each component in a composition in this specification, if there are multiple substances corresponding to each component in the composition, the total amount of those multiple substances present in the composition is meant unless otherwise specified.

[0015] In this specification, "(meth)acrylate" means at least one of "acrylate" and its corresponding "methacrylate," and the same applies to other similar expressions such as (meth)acrylic acid and (meth)acryloyl. In this specification, "solid content" refers to the non-volatile content excluding volatile substances (water, solvent, etc.) contained in the photosensitive resin composition, and includes components that are liquid, syrup-like, or waxy at room temperature (around 25°C).

[0016] [Photosensitive resin composition] The photosensitive resin composition for permanent resist according to this embodiment contains (A) an acid-modified vinyl group-containing resin, (B) a photopolymerization initiator, and (C) a photopolymerizable compound, wherein the photopolymerizable compound includes a photopolymerizable compound having four or more ethylenically unsaturated groups and a photopolymerizable compound having three or less ethylenically unsaturated groups. The photosensitive resin composition according to this embodiment is a negative-type photosensitive resin composition, and a cured film of the photosensitive resin composition can be used as a permanent resist. Each component used in the photosensitive resin composition according to this embodiment will be described in more detail below.

[0017] (Component (A): Acid-modified vinyl group-containing resin) The photosensitive resin composition according to this embodiment contains an acid-modified vinyl group-containing resin as component (A). The acid-modified vinyl group-containing resin is not particularly limited as long as it has a vinyl group, which is a photopolymerizable ethylenically unsaturated bond, and an alkali-soluble acidic group. Examples of the acidic group contained in the acid-modified vinyl group-containing resin include a carboxy group, a sulfo group, and a phenolic hydroxyl group. Among these, a carboxy group is preferred from the viewpoint of resolution.

[0018] Examples of acid-modified vinyl group-containing resins include acid-modified epoxy(meth)acrylates. Acid-modified epoxy(meth)acrylates are resins obtained by acid-modifying epoxy(meth)acrylates, which are reaction products of epoxy resins and organic acids having vinyl groups. Examples of acid-modified epoxy(meth)acrylates include addition reaction products obtained by adding saturated or unsaturated polybasic acid anhydrides (c) to esterified products obtained by reacting epoxy resins (a) with vinyl group-containing monocarboxylic acids (b).

[0019] Examples of the epoxy resin (a) include bisphenol novolac type epoxy resins, novolac type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, triphenolmethane type epoxy resins, biphenyl type epoxy resins, naphthalene type epoxy resins, and dicyclopentadiene type epoxy resins.

[0020] Examples of the vinyl group-containing monocarboxylic acid (b) include acrylic acid, acrylic acid dimers, methacrylic acid, acrylic acid derivatives such as β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α-cyanocinnamic acid, half-ester compounds which are reaction products of hydroxyl group-containing (meth)acrylates and dibasic acid anhydrides, and half-ester compounds which are reaction products of vinyl group-containing monoglycidyl ethers or vinyl group-containing monoglycidyl esters and dibasic acid anhydrides.

[0021] Examples of hydroxyl group-containing (meth)acrylates, vinyl group-containing monoglycidyl ethers, and vinyl group-containing monoglycidyl esters include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol pentaacrylate, pentaerythritol pentamethacrylate, glycidyl acrylate, and glycidyl methacrylate.

[0022] 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.

[0023] Examples of the saturated or unsaturated polybasic acid anhydride (c) 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 may be used as the polybasic acid anhydride from the viewpoint of obtaining a photosensitive resin composition capable of forming a pattern with excellent resolution.

[0024] The acid value of component (A) is not particularly limited. From the viewpoint of improving the solubility of the unexposed area in an alkaline aqueous solution, the acid value of component (A) may be 30 mgKOH / g or more, 40 mgKOH / g or more, or 50 mgKOH / g or more. From the viewpoint of improving the electrical properties of the cured film, the acid value of component (A) may be 150 mgKOH / g or less, 120 mgKOH / g or less, or 100 mgKOH / g or less.

[0025] The weight average molecular weight (Mw) of component (A) is not particularly limited. From the viewpoint of improving the adhesion of the cured film, Mw of component (A) may be 3,000 or more, 4,000 or more, or 5,000 or more. From the viewpoint of improving the resolution of the photosensitive layer, Mw of component (A) may be 30,000 or less, 25,000 or less, or 18,000 or less. Mw can be measured by gel permeation chromatography (GPC).

[0026] The content of the component (A) in the photosensitive resin composition may be 20 to 70 mass%, 25 to 60 mass%, or 30 to 50 mass%, based on the total solid content of the photosensitive resin composition, from the viewpoint of improving the heat resistance, electrical properties, and chemical resistance of the permanent resist.

[0027] (Component (B): Photopolymerization initiator) The photopolymerization initiator as component (B) is not particularly limited as long as it can polymerize component (A). Component (B) may be used alone or in combination of two or more.

[0028] Examples of the component (B) 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-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propane, N, Acetophenone compounds such as N-dimethylaminoacetophenone; anthraquinone compounds such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, and 2-aminoanthraquinone; thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; 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, Michler's ketone, and 4-benzoyl-4'-methyldiphenyl sulfide; 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, and 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer. imidazole compounds such as 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer, 2,4-di(p-methoxyphenyl)-5-phenylimidazole dimer, and 2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazole dimer; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinyl)heptane; acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide;Examples of suitable oxime ester compounds include 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone-1-(O-acetyloxime), and 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl)oxime]; and tertiary amine compounds such as N,N-dimethylaminobenzoic acid ethyl ester, N,N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine.

[0029] The content of the component (B) in the photosensitive resin composition is not particularly limited, but may be 0.2 to 15 mass%, 0.5 to 10 mass%, or 1 to 5 mass%, based on the total solid content of the photosensitive resin composition.

[0030] ((C) component: photopolymerizable compound) The photosensitive resin composition according to this embodiment can improve the resolution of the photosensitive resin composition by using, as component (C), a photopolymerizable compound having four or more ethylenically unsaturated groups and a photopolymerizable compound having three or less ethylenically unsaturated groups in combination. The ethylenically unsaturated group is not particularly limited as long as it is a group that is photopolymerizable. Component (C) is a photopolymerizable compound that does not have an acidic group.

[0031] When component (C) contains a photopolymerizable compound having four or more ethylenically unsaturated groups, the crosslink density upon photocuring of the photosensitive resin composition can be increased, and the heat resistance and electrical insulating properties of the permanent resist can be improved. The photopolymerizable compound having four or more ethylenically unsaturated groups may have 4 to 10, 4 to 8, or 5 to 7 ethylenically unsaturated groups.

[0032] Examples of photopolymerizable compounds having four or more ethylenically unsaturated groups include dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, and tetramethylolmethane tetra(meth)acrylate. From the viewpoint of improving the sensitivity of the photosensitive resin composition, it is preferable that component (C) contains dipentaerythritol hexa(meth)acrylate.

[0033] When component (C) contains a photopolymerizable compound having three or less ethylenically unsaturated groups, the resolution of the photosensitive resin composition can be improved. The photopolymerizable compound having three or less ethylenically unsaturated groups can be at least one selected from the group consisting of a photopolymerizable compound having one ethylenically unsaturated group, a photopolymerizable compound having two ethylenically unsaturated groups, and a photopolymerizable compound having three ethylenically unsaturated groups. From the viewpoint of further improving the resolution of the photosensitive resin composition, component (C) preferably contains a photopolymerizable compound having one ethylenically unsaturated group. From the viewpoint of increasing the film strength of the permanent resist, component (C) preferably contains a photopolymerizable compound having two or three ethylenically unsaturated groups.

[0034] From the viewpoint of further improving resolution, the photopolymerizable compound having 3 or less ethylenically unsaturated groups may be at least one selected from the group consisting of photopolymerizable compounds having a dicyclopentadiene skeleton, photopolymerizable compounds having an isocyanate group, photopolymerizable compounds having a blocked isocyanate group, and photopolymerizable compounds having an oxyalkylene group.

[0035] Examples of photopolymerizable compounds having one ethylenically unsaturated group include (meth)acrylates having a dicyclopentadiene skeleton, such as dicyclopentanyl methacrylate and dicyclopentanyl acrylate; (meth)acrylates having an isocyanate group, such as 2-isocyanatoethyl methacrylate, 2-isocyanatoethyl acrylate, 2-(2-methacryloyloxyethyloxy)ethyl isocyanate and 2-(2-acryloyloxyethyloxy)ethyl isocyanate; and (meth)acrylates having a blocked isocyanate group, such as 2-[0-(1'-methylpropylideneamino)carboxyamino]ethyl methacrylate and 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate.

[0036] Examples of photopolymerizable compounds having two ethylenically unsaturated groups include alkylene di(meth)acrylates such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate; polyalkylene glycol di(meth)acrylates such as polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polyethylene-polypropylene glycol di(meth)acrylate; and alkylene oxide-modified di(meth)acrylates such as EO-modified bisphenol A di(meth)acrylate and PO-modified bisphenol A di(meth)acrylate. "EO modified" means that it has a block structure of ethylene oxide (EO) groups, and "PO modified" means that it has a block structure of propylene oxide (PO) groups.

[0037] Examples of photopolymerizable compounds having three ethylenically unsaturated groups include trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, and EO,PO-modified trimethylolpropane tri(meth)acrylate.

[0038] The content of component (C) may be 2 to 30 mass%, 3 to 20 mass%, or 3 to 15 mass% based on the total solid content of the photosensitive resin composition. When the content of component (C) is 2 mass% or more, the photosensitivity of the photosensitive resin composition is easily improved, and when it is 30 mass% or less, the heat resistance of the permanent resist is easily improved.

[0039] The content of the photopolymerizable compound having 3 or less ethylenically unsaturated groups may be 1% by mass or more, 2% by mass or more, or 3% by mass or more based on the total solid content of the photosensitive resin composition, from the viewpoint of further improving the resolution of the photosensitive resin composition. The content of the photopolymerizable compound having 3 or less ethylenically unsaturated groups may be 20% by mass or less, 15% by mass or less, or 10% by mass or less based on the total solid content of the photosensitive resin composition, from the viewpoint of further improving the film strength of the permanent resist.

[0040] (Component (D): inorganic filler) The photosensitive resin composition according to this embodiment may further contain an inorganic filler as component (D). By containing component (D), the adhesive strength, reliability, etc. of the permanent mask resist can be improved. The component (D) may be used alone or in combination of two or more.

[0041] Examples of inorganic fillers include silica, alumina, titania, tantalum oxide, zirconia, silicon nitride, barium titanate, barium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, lead titanate, lead zirconate titanate, lead lanthanum zirconate titanate, gallium oxide, spinel, mullite, cordierite, talc, aluminum titanate, yttria-containing zirconia, barium silicate, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, zinc oxide, magnesium titanate, hydrotalcite, mica, calcined kaolin, and carbon.

[0042] Component (D) may contain silica to improve the heat resistance of the permanent resist, or barium sulfate to improve the heat resistance and adhesive strength of the permanent resist. To improve the dispersibility of the inorganic filler, an inorganic filler that has been surface-treated with alumina or an organic silane compound may be used.

[0043] The average particle size of the inorganic filler may be 0.01 μm or more, 0.1 μm or more, 0.2 μm or more, or 0.3 μm or more, and may be 5.0 μm or less, 3.0 μm or less, 2.0 μm or less, or 1.5 μm or less.

[0044] The content of component (D) may be 5 to 70 mass%, 6 to 60 mass%, or 10 to 50 mass%, based on the total solid content of the photosensitive resin composition. When the content of component (D) is within the above range, it is possible to further improve the low thermal expansion coefficient, heat resistance, film strength, etc.

[0045] ((E) component: thermosetting resin) The photosensitive resin composition according to this embodiment may further contain a thermosetting resin as component (E). By using component (E), it is possible to improve the heat resistance, adhesiveness, chemical resistance, etc. of the cured film (permanent resist) formed from the photosensitive resin composition. The component (E) may be used alone or in combination of two or more.

[0046] Examples of component (E) 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.

[0047] Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, hydrogenated bisphenol A type epoxy resins, brominated bisphenol A type epoxy resins, bisphenol S type epoxy resins, novolac type epoxy resins, biphenyl type epoxy resins, naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, hydantoin type epoxy resins, triglycidyl isocyanurate, and bixylenol type epoxy resins.

[0048] The content of component (E) may be 2 to 30 mass%, 5 to 25 mass%, or 8 to 20 mass%, based on the total solid content of the photosensitive resin composition. When the content of component (E) is within the above range, good developability can be maintained while the heat resistance of the formed cured film can be further improved.

[0049] (Component (F): Pigment) The photosensitive resin composition of this embodiment may further contain a pigment as component (F) from the viewpoint of improving the distinguishability or appearance of the production equipment. As component (F), a colorant that develops a desired color when concealing wiring, etc., can be used. Examples of component (F) include phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black.

[0050] From the viewpoint of further concealing the wiring, the content of the component (F) may be 0.1 to 10 mass %, 0.5 to 8 mass %, or 1 to 5 mass % based on the total amount of solids in the photosensitive resin composition.

[0051] (Component (G): Elastomer) The photosensitive resin composition according to this embodiment may further contain an elastomer as component (G). By containing component (G), it is possible to suppress a decrease in flexibility and adhesive strength caused by strain (internal stress) inside the resin due to cure shrinkage of component (A).

[0052] Examples of component (G) include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers. These elastomers are composed of hard segment components that contribute to heat resistance and strength, and soft segment components that contribute to flexibility and toughness.

[0053] Examples of styrene-based elastomers include styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-ethylene-butylene-styrene block copolymers, and styrene-ethylene-propylene-styrene block copolymers. In addition to styrene, styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene can be used as components constituting styrene-based elastomers.

[0054] Examples of olefin-based elastomers include ethylene-propylene copolymers, ethylene-α-olefin copolymers, ethylene-α-olefin-non-conjugated diene copolymers, propylene-α-olefin copolymers, butene-α-olefin copolymers, ethylene-propylene-diene copolymers, copolymers of non-conjugated dienes such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylenenorbornene, ethylidenenorbornene, butadiene, and isoprene with α-olefins, and carboxylic acid-modified butadiene-acrylonitrile copolymers.

[0055] As the urethane-based elastomer, a compound composed of a hard segment made of a low molecular weight (short chain) diol and diisocyanate, and a soft segment made of a high molecular weight (long chain) diol and diisocyanate can be used.

[0056] 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 48-500.

[0057] Examples of 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 long-chain diol is preferably 500 to 10,000.

[0058] As the polyester elastomer, a compound obtained by polycondensation of a dicarboxylic acid or a derivative thereof with a diol compound or a derivative thereof can be used.

[0059] Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; 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. The dicarboxylic acids can be used alone or in combination of two or more.

[0060] Examples of diol compounds include aliphatic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,10-decanediol; alicyclic diols such as 1,4-cyclohexanediol; and aromatic diols such as bisphenol A, bis-(4-hydroxyphenyl)methane, bis-(4-hydroxy-3-methylphenyl)propane, and resorcinol.

[0061] Polyester elastomers can be multiblock copolymers that use aromatic polyesters (e.g., polybutylene terephthalate) as hard segment components and aliphatic polyesters (e.g., polytetramethylene glycol) as soft segment components. There are various grades of polyester elastomers that differ in the type, ratio, and molecular weight of the hard and soft segments.

[0062] Polyamide elastomers are broadly classified into two types: polyether block amides and polyether ester block amides, which use polyamides for the hard segments and polyethers or polyesters for the soft segments. Examples of polyamides include polyamide-6, polyamide-11, and polyamide-12. Examples of polyethers include polyoxyethylene glycol, polyoxypropylene glycol, and polytetramethylene glycol.

[0063] The acrylic elastomer may be a compound containing a structural unit based on a (meth)acrylic acid ester as a main component. Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, methoxyethyl (meth)acrylate, and ethoxyethyl (meth)acrylate. The acrylic elastomer may be a compound obtained by copolymerizing a (meth)acrylic acid ester with acrylonitrile, or may be a compound obtained by further copolymerizing a monomer having a functional group that serves as a crosslinking point. Examples of monomers having a functional group include glycidyl methacrylate and allyl glycidyl ether.

[0064] Examples of acrylic elastomers include acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, methyl methacrylate-butyl acrylate-methacrylic acid copolymer, and acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer. As the acrylic elastomer, acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer or methyl methacrylate-butyl acrylate-methacrylic acid copolymer is preferred, and methyl methacrylate-butyl acrylate-methacrylic acid copolymer is more preferred.

[0065] Silicone elastomers are compounds primarily composed of organopolysiloxane. Examples of organopolysiloxane include polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane. Silicone elastomers may be compounds in which a portion of an organopolysiloxane is modified with a vinyl group, an alkoxy group, or the like.

[0066] From the viewpoint of improving the adhesion of the cured film, the component (G) may contain a carboxylic acid-modified butadiene-acrylonitrile copolymer or a polyester-based elastomer having a hydroxyl group.

[0067] The amount of component (G) per 100 parts by mass of component (A) may be 2 to 50 parts by mass, 4 to 45 parts by mass, 6 to 40 parts by mass, or 10 to 35 parts by mass. When the amount of component (G) is within the above range, the elastic modulus of the cured film in the high temperature range decreases, and the unexposed areas become more easily eluted in a developer.

[0068] (Other ingredients) The photosensitive resin composition according to this embodiment may further contain various additives as needed, such as polymerization inhibitors such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; thickeners such as bentone and montmorillonite; silicone-based, fluorine-based, and vinyl resin-based antifoaming agents; silane coupling agents; and flame retardants such as brominated epoxy compounds, acid-modified brominated epoxy compounds, antimony compounds, phosphate compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters.

[0069] (solvent) The photosensitive resin composition according to this embodiment contains a solvent for dissolving and dispersing each component, which makes it easy to apply onto a substrate and allows the formation of a coating film of uniform thickness.

[0070] Examples of solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. These solvents may be used alone or in combination of two or more.

[0071] The amount of the solvent to be added is not particularly limited, but the ratio of the solvent in the photosensitive resin composition may be 10 to 50 mass %, 20 to 40 mass %, or 25 to 35 mass %.

[0072] The photosensitive resin composition of this embodiment can be prepared by uniformly mixing the above-mentioned components using a roll mill, a bead mill, or the like.

[0073] [Photosensitive element] The photosensitive element according to this embodiment includes a support film and a photosensitive layer containing the above-described photosensitive resin composition. Fig. 1 is a cross-sectional view schematically showing the photosensitive element according to this embodiment. As shown in Fig. 1, the photosensitive element 1 includes a support film 10 and a photosensitive layer 20 formed on the support film 10.

[0074] The photosensitive element 1 can be produced by applying the photosensitive resin composition according to this embodiment onto a support film 10 by a known method such as reverse roll coating, gravure roll coating, comma coating, or curtain coating, and then drying the coating to form a photosensitive layer 20.

[0075] Examples of the support film include polyester films such as polyethylene terephthalate and polybutylene terephthalate, and polyolefin films such as polypropylene and polyethylene. The thickness of the support film may be, for example, 5 to 100 μm. The thickness of the photosensitive layer may be, for example, 5 to 50 μm, 5 to 40 μm, or 10 to 30 μm. The surface roughness of the support film is not particularly limited, but the arithmetic mean roughness (Ra) may be 1000 nm or less, 500 nm or less, or 250 nm or less.

[0076] The coating film can be dried by hot air drying, far infrared drying, or near infrared drying. The drying temperature may be 60 to 120° C., 70 to 110° C., or 80 to 100° C. The drying time may be 1 to 60 minutes, 2 to 30 minutes, or 5 to 20 minutes.

[0077] The photosensitive element 1 may further include a protective film 30 on the photosensitive layer 20 to cover the photosensitive layer 20. The photosensitive element 1 may also have the protective film 30 laminated on the surface of the photosensitive layer 20 opposite to the surface that contacts the support film 10. The protective film 30 may be, for example, a polymer film such as polyethylene or polypropylene.

[0078] [Printed wiring board] The printed wiring board according to this embodiment is provided with a permanent resist containing a cured product of the photosensitive resin composition according to this embodiment.

[0079] The method for producing a printed wiring board according to this embodiment includes the steps of forming a photosensitive layer on a substrate using the above-described photosensitive resin composition or photosensitive element, exposing and developing the photosensitive layer to form a resist pattern, and curing the resist pattern to form a permanent resist. An example of each step will be described below.

[0080] First, a substrate such as a copper-clad laminate is prepared, and a photosensitive layer is formed on the substrate. The photosensitive layer may be formed by applying a photosensitive resin composition to the substrate and drying it. Examples of methods for applying the photosensitive resin composition include screen printing, spraying, roll coating, curtain coating, and electrostatic coating. The drying temperature may be 60 to 120°C, 70 to 110°C, or 80 to 100°C. The drying time may be 1 to 7 minutes, 1 to 6 minutes, or 2 to 5 minutes.

[0081] The photosensitive layer may be formed on the substrate by peeling off the protective film from the photosensitive element and laminating the photosensitive layer on the substrate. Examples of methods for laminating the photosensitive layer include thermal lamination using a laminator.

[0082] Next, a negative film is brought into contact with the photosensitive layer directly or via a support film, and exposed to actinic rays. Examples of actinic rays include electron beams, ultraviolet rays, and X-rays, with ultraviolet rays being preferred. Examples of light sources that can be used include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and halogen lamps. The exposure dose is 10 to 2000 mJ / cm. 2 , 100-1500mJ / cm 2 , or 300 to 1000 mJ / cm 2 may be.

[0083] After exposure, the unexposed areas are removed with a developer to form a resist pattern. Examples of the developing method include dipping and spraying. Examples of the developer that can be used include aqueous alkali solutions such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, and tetramethylammonium hydroxide.

[0084] A patterned cured film (permanent resist) can be formed by subjecting the resist pattern to at least one of post-exposure and post-heating. The exposure dose of the post-exposure is 100 to 5000 mJ / cm. 2 , 500~2000mJ / cm 2 , or 700 to 1500 J / cm 2 The heating temperature for post-heating may be 100 to 200° C., 120 to 180° C., or 135 to 165° C. The heating time for post-heating may be 5 minutes to 12 hours, 10 minutes to 6 hours, or 30 minutes to 2 hours.

[0085] The permanent resist according to this embodiment can be used as an interlayer insulating layer or a surface protective layer of a semiconductor element. A semiconductor element having an interlayer insulating layer or a surface protective layer formed from a cured film of the above-described photosensitive resin composition, and an electronic device including the semiconductor element, can be produced. The semiconductor element may be, for example, a memory, a package, or the like having a multilayer wiring structure, a rewiring structure, or the like. Examples of electronic devices include mobile phones, smartphones, tablet terminals, personal computers, and hard disk suspensions. By providing a patterned cured film formed from the photosensitive resin composition according to this embodiment, semiconductor elements and electronic devices with excellent reliability can be provided. [Example]

[0086] The present disclosure will be explained in more detail below using examples, but the present invention is not limited to these examples.

[0087] (Synthesis Example 1) 250 parts by mass of dicyclopentadiene-type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name "XD-1000"), 70 parts by mass of acrylic acid, 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate were mixed with stirring at 90°C. The mixed solution was cooled to 60°C, and 2 parts by mass of triphenylphosphine was added. The mixture was reacted at 100°C until the acid value of the solution reached 1 mgKOH / g. 98 parts by mass of tetrahydrophthalic anhydride and 850 parts by mass of carbitol acetate were added to the reaction solution, and the mixture was heated to 80°C and reacted for 6 hours. The reaction solution was then cooled to room temperature to obtain a solution of acid-modified epoxy acrylate resin (A-1) (solids concentration 65% by mass) as component (A).

[0088] (Synthesis Example 2) 350 parts by mass of bisphenol F novolac epoxy resin (manufactured by DIC Corporation, trade name "EXA-7376"), 70 parts by mass of acrylic acid, 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate were mixed with stirring at 90°C. The mixture was cooled to 60°C, and 2 parts by mass of triphenylphosphine was added. The mixture was reacted at 100°C until the acid value of the solution reached 1 mgKOH / g or less. 98 parts by mass of tetrahydrophthalic anhydride and 850 parts by mass of carbitol acetate were added to the reaction mixture, and the mixture was reacted at 80°C for 6 hours. The reaction mixture was then cooled to room temperature to obtain a solution of acid-modified epoxy acrylate (A-2) as component (A) (solids concentration: 73% by mass).

[0089] The following materials were prepared as components (B) to (G). B-1: 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propane (manufactured by IGM Resins BV, trade name "Omirad 907") B-2: 2,4-diethylthioxanthone (manufactured by Nippon Kayaku Co., Ltd., trade name "DETX-S") B-3: 4,4'-bis(diethylamino)benzophenone (EAB) C-1: Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name "DPHA") C-2: Dicyclopentanyl acrylate (manufactured by Showa Denko Materials Co., Ltd., product name "FA-513AS") C-3: Dicyclopentanyl methacrylate (manufactured by Showa Denko Materials Co., Ltd., product name "FA-513M") C-4: 2-Isocyanatoethyl methacrylate (manufactured by Showa Denko K.K., trade name "Karenz MOI") C-5: 2-[0-(1'-methylpropylideneamino)carboxyamino]ethyl methacrylate (manufactured by Showa Denko K.K., trade name "Karenz MOI-BM") C-6: (PO)(EO)(PO) modified dimethacrylate (manufactured by Showa Denko Materials Co., Ltd., product name "FA-024M") C-7: Trimethylolpropane trimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "TMPT") D-1: Silica (average particle size 0.5 μm) E-1: Bisphenol novolac epoxy resin (manufactured by Nippon Kayaku Co., Ltd., product name "RE-306") E-2: Biphenyl-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "YX4000") F-1: Phthalocyanine Green (manufactured by Sanyo Pigment Co., Ltd.)

[0090] [Photosensitive resin composition] The components were blended in the amounts (parts by mass, solid content equivalent) shown in Table 1 and kneaded using a three-roll mill. Then, carbitol acetate was added so that the solid content concentration became 60% by mass, thereby preparing a photosensitive resin composition.

[0091] [Photosensitive element] A 16 μm-thick polyethylene terephthalate film (manufactured by Teijin Limited, product name "G2-16") was prepared as a support film. A photosensitive resin composition was applied to the support film so that the thickness after drying was 10 μm, and the composition was dried at 75°C for 30 minutes using a hot air convection dryer to form a photosensitive layer. Next, a polyethylene film (manufactured by Tamapoly Corporation, product name "NF-15") was attached as a protective film to the surface of the photosensitive layer opposite the side in contact with the support film, thereby obtaining a photosensitive element.

[0092] (resolution) A 0.6 mm thick copper-clad laminate substrate (manufactured by Showa Denko Materials Co., Ltd., product name "MCL-E-67") was prepared. While peeling and removing the protective film from the photosensitive element, a photosensitive layer was laminated onto the copper-clad laminate substrate using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500") at a pressure of 0.4 MPa, a press hot plate temperature of 80°C, a vacuum time of 25 seconds, a lamination press time of 25 seconds, and an air pressure of 4 kPa or less, to obtain a laminate. Next, through a negative mask having a via pattern of a predetermined size, an i-line exposure apparatus (manufactured by Ushio Inc., product name "UX-2240SM-XJ-01") was used to expose the photosensitive layer to 100 to 1000 mJ / cm. 2 in the range of 50 mJ / cm 2 The photosensitive layer was exposed to light while changing the concentration by 1.765 × 10 for a time equivalent to twice the shortest development time at 30°C (the shortest time required to remove the unexposed portion of the photosensitive layer). 5 The unexposed areas were then developed by spraying at a pressure of 2000 mJ / cm 2 using an ultraviolet exposure device. 2 After heating at 160°C for 1 hour, a test specimen was prepared having a cured film with a via pattern of a predetermined size on a copper-clad laminate substrate. The test specimen was observed using a metallurgical microscope and evaluated according to the following criteria. A: The minimum opening diameter of the mask was 20 μm or less. B: The minimum diameter of the mask opening was greater than 20 μm and less than 25 μm. C: The minimum diameter of the mask opening exceeded 25 μm.

[0093] [Table 1] [Explanation of symbols]

[0094] 1...photosensitive element, 10...support film, 20...photosensitive layer, 30...protective film.

Claims

1. (A) an acid-modified vinyl group-containing resin, (B) a photopolymerization initiator, and (C) a photopolymerizable compound, The photosensitive resin composition for a permanent resist comprises a photopolymerizable compound having four or more ethylenically unsaturated groups and a photopolymerizable compound having three or less ethylenically unsaturated groups.

2. 2. The photosensitive resin composition according to claim 1, wherein the photopolymerizable compound having 3 or less ethylenically unsaturated groups has a dicyclopentadiene skeleton.

3. 2. The photosensitive resin composition according to claim 1, wherein the photopolymerizable compound having 3 or less ethylenically unsaturated groups has an isocyanate group, a blocked isocyanate group, or an oxyalkylene group.

4. The photosensitive resin composition according to any one of claims 1 to 3, further comprising (D) an inorganic filler.

5. The photosensitive resin composition according to any one of claims 1 to 4, further comprising (E) a thermosetting resin.

6. The photosensitive resin composition according to any one of claims 1 to 5, further comprising (F) a pigment.

7. A support film and a photosensitive layer formed on the support film, A photosensitive element, wherein the photosensitive layer comprises the photosensitive resin composition according to any one of claims 1 to 6.

8. A printed wiring board comprising a permanent resist comprising a cured product of the photosensitive resin composition according to any one of claims 1 to 6.

9. forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of claims 1 to 6 or the photosensitive element according to claim 7; exposing and developing the photosensitive layer to form a resist pattern; hardening the resist pattern to form a permanent resist; A method for manufacturing a printed wiring board, comprising:

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