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

Abstract

To provide a photosensitive resin composition which enables formation of a permanent resist having excellent resolution and crack resistance, a photosensitive element obtained by using the photosensitive resin composition, a printed wiring board, and a method for manufacturing a printed wiring board.SOLUTION: A photosensitive resin composition is provided, containing acid-modified vinyl group-containing resin (A), a photopolymerization initiator (B), and a photopolymerizable compound (C), wherein the photopolymerizable compound (C) has an ethylenic unsaturated group (C1).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] In the field of printed wiring board manufacturing, permanent resists are formed on printed wiring boards. The permanent resists have the role of preventing corrosion of the conductor layers and maintaining electrical insulation between the conductor layers when the printed wiring board is in use. In recent years, permanent resists have also come to function as solder resist films that prevent solder from adhering to unnecessary portions of the conductor layers of the printed wiring board in processes such as flip-chip mounting and wire bonding of semiconductor elements onto the printed wiring board via solder.

[0003] In semiconductor package substrates such as BGA (Ball Grid Array) and CSP (Chip Size Package) mounted on electronic components, it is necessary to remove the permanent resist from the bonding area in order to (1) flip-chip mount a semiconductor element onto the semiconductor package substrate via solder, (2) wire-bond the semiconductor element to the semiconductor package substrate, or (3) solder-bond the semiconductor package substrate to a motherboard. To achieve this, a photographic method is used to form the permanent resist. This method involves applying and drying a photosensitive resin composition, selectively irradiating it with actinic rays such as ultraviolet light to harden it, and then developing and removing only the unirradiated areas to form an image. Because of its ease of operation and its suitability for mass production, the photographic method is widely used in the electronic materials industry for forming images of photosensitive resin compositions (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-133851 [Patent Document 2] International Publication No. 2013 / 022068 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional photosensitive resin compositions often fail to provide sufficient resolution when forming fine patterns, and permanent resists can crack under harsh environments such as high temperatures. Therefore, there is a demand for photosensitive resin compositions capable of forming permanent resists with excellent crack resistance.

[0006] Therefore, an object of the present disclosure is to provide a photosensitive resin composition capable of forming a permanent resist having excellent resolution and crack resistance, a photosensitive element using the photosensitive resin composition, a printed wiring board, and a method for producing a printed wiring board. [Means for solving the problem]

[0007] In order to solve the above problems, the present disclosure provides the following photosensitive resin composition, photosensitive element, printed wiring board, and method for producing a printed wiring board.

[0008] [1] A photosensitive resin composition comprising (A) an acid-modified vinyl group-containing resin, (B) a photopolymerization initiator, and (C) a photopolymerizable compound, wherein the (C) photopolymerizable compound contains (C1) a polyrotaxane having an ethylenically unsaturated group. [2] The photosensitive resin composition according to [1] above, wherein the ethylenically unsaturated group includes at least one selected from the group consisting of an acryloyl group and a methacryloyl group. [3] The photosensitive resin composition according to [1] or [2] above, wherein the content of (C1) the polyrotaxane having an ethylenically unsaturated group is 1 mass % or more based on the total mass of (C) the photopolymerizable compound. [4] The photosensitive resin composition according to any one of the above [1] to [3], further comprising (D) a thermosetting resin. [5] The photosensitive resin composition according to any one of the above [1] to [4], further comprising (E) an inorganic filler. [6] The photosensitive resin composition according to any one of the above [1] to [5], further comprising (F) a pigment. [7] The photosensitive resin composition according to any one of the above [1] to [6], further comprising (G) a curing agent. [8] A photosensitive element comprising a support film and a photosensitive layer formed on the support film, wherein the photosensitive layer contains the photosensitive resin composition according to any one of [1] to [7] above. [9] A printed wiring board comprising a permanent resist containing a cured product of the photosensitive resin composition according to any one of [1] to [7] above.

[10] A method for producing a printed wiring board, comprising the steps of: forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of [1] to [7] above; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist.

[11] A method for manufacturing a printed wiring board, comprising the steps of: forming a photosensitive layer on a substrate using the photosensitive element described in [8] above; 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]

[0009] According to the present disclosure, it is possible to provide a photosensitive resin composition capable of forming a permanent resist having excellent resolution and crack resistance, 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]

[0010] [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

[0011] 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.

[0012] 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.

[0013] 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. 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 (25°C).

[0014] [Photosensitive resin composition] The photosensitive resin composition according to this embodiment contains (A) an acid-modified vinyl group-containing resin, (B) a photopolymerization initiator, and (C) a photopolymerizable compound, wherein the (C) photopolymerizable compound contains (C1) a polyrotaxane having an ethylenically unsaturated group. The photosensitive resin composition according to this embodiment, having the above-described configuration, can form a permanent resist having excellent resolution and crack resistance. The photosensitive resin composition according to this embodiment can be used to form a permanent resist. The photosensitive resin composition according to this embodiment is a negative-tone 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.

[0015] (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. From the viewpoint of resolution, the acidic group contained in the acid-modified vinyl group-containing resin may be a carboxy group.

[0016] Examples of the acid-modified vinyl group-containing resin include an acid-modified vinyl group-containing epoxy resin and an acid-modified vinyl group-containing phenolic resin.

[0017] Examples of acid-modified vinyl group-containing epoxy 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).

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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 1500 or more, 3000 or more, 4000 or more, or 5000 or more. From the viewpoint of further improving the resolution of the photosensitive layer, Mw of component (A) may be 30000 or less, 25000 or less, or 18000 or less. Mw can be measured by gel permeation chromatography (GPC).

[0025] The content of the component (A) in the photosensitive resin composition is not particularly limited, but from the viewpoint of improving the heat resistance, electrical properties, and chemical resistance of the cured film, it may be 20% by mass or more, 25% by mass or more, 30% by mass or more, 35% by mass or more, or 40% by mass or more, and may be 70% by mass or less, 60% by mass or less, 50% by mass or less, or 45% by mass or less, based on the total solid content of the photosensitive resin composition.

[0026] (Component (B): Photopolymerization initiator) The photosensitive resin composition according to this embodiment contains a photopolymerization initiator as component (B). There are no particular limitations on component (B) as long as it can polymerize component (A) and the like.

[0027] Examples of 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)-1-butanone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propane, N,N acetophenone compounds such as 2-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; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal. Compounds: 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) Imidazole compounds such as 4,5-diphenylimidazole dimer, 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.

[0028] Component (B) may be used singly or in combination of two or more. Component (B) may be at least one selected from the group consisting of acetophenone compounds, thioxanthone compounds, and oxime ester compounds. When component (B) contains an acetophenone compound, the content of the acetophenone compound may be 50% by mass or more, 70% by mass or more, or 90% by mass or more, and 100% by mass or less or 95% by mass or less, based on the total mass of component (B). When component (B) contains a thioxanthone compound, the content of the thioxanthone compound may be 1% by mass or more, 3% by mass or more, or 5% by mass or more, and 15% by mass or less or 10% by mass or less, based on the total mass of component (B). When component (B) contains an oxime ester compound, the content of the oxime ester compound may be 0.1% by mass or more, 0.5% by mass or more, or 1.0% by mass or more, and 10% by mass or less or 5% by mass or less, based on the total mass of component (B).

[0029] The content of component (B) in the photosensitive resin composition is not particularly limited, and may be 0.1 to 15 mass%, 0.5 to 5 mass%, 0.8 to 3 mass%, or 1 to 1.5 mass%, based on the total solid content of the photosensitive resin composition. When the content of component (B) is 0.1 mass% or more, elution of exposed areas during development when forming a resist pattern tends to be easily suppressed, and when the content of component (B) is 15 mass% or less, the heat resistance of the cured film tends to be easily improved.

[0030] ((C) component: photopolymerizable compound) The photosensitive resin composition according to this embodiment contains a photopolymerizable compound as component (C), which is a photopolymerizable compound having an ethylenically unsaturated group but no acidic group.

[0031] From the viewpoint of achieving excellent resolution and crack resistance, component (C) contains a polyrotaxane having an ethylenically unsaturated group (hereinafter also referred to as "component (C1)"). A rotaxane is a compound (inclusion compound) containing a cyclic molecule, a linear molecule that penetrates the molecular ring of the cyclic molecule, and terminal groups that are located at both ends of the linear molecule and prevent dissociation of the cyclic molecule. Polyrotaxane refers to a rotaxane formed from a large number of constituent molecules (particularly, cyclic molecules). Polyrotaxane has the property that the cyclic molecules can move along the linear molecules.

[0032] A cyclic molecule is a molecule that can encapsulate a linear molecule so that the molecule penetrates through the molecular ring. There are no particular limitations on the cyclic molecule, as long as it can move along the linear molecule. In this specification, the term "cyclic" in cyclic molecule means that the molecule is substantially "cyclic." In other words, the cyclic molecule does not need to be a completely closed ring as long as it can move along the linear molecule.

[0033] Examples of cyclic molecules include cyclodextrins such as α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, dimethylcyclodextrin, and glucosylcyclodextrin; crown ethers; and derivatives thereof. These may be used alone or in combination of two or more in the polyrotaxane. The cyclic molecule may be cyclodextrin because it is easily available and has a wide variety of terminal groups to choose from. The cyclic molecule may have a side chain. Examples of the side chain of the cyclic molecule include caprolactone chains.

[0034] The linear molecule is not particularly limited as long as it is a linear molecule that can be included in and integrated with a cyclic molecule. In this specification, the term "linear" in the linear molecule means that it is substantially "linear." In other words, as long as the cyclic molecule can move on the linear molecule, the linear molecule may have a branched chain.

[0035] Examples of linear molecules include polyalkylene glycols such as polyethylene glycol and polypropylene glycol; and polyolefins such as polyethylene, polypropylene, polyisoprene, polyisobutylene, and polybutadiene. These may be used alone or in combination of two or more. Among these, the linear molecule may be polyalkylene glycol.

[0036] The weight average molecular weight of the linear molecule may be 5,000 or more, 8,000 or more, or 10,000 or more, or may be 50,000 or less, 40,000 or less, 30,000 or less, or 25,000 or less.

[0037] The terminal group is not particularly limited as long as it can prevent dissociation of the cyclic molecule from the linear molecule. Examples of the terminal group include an adamantyl group, a dinitrophenyl group, a trityl group, a cyclodextrin group, a fluoresceinyl group, a pyrenyl group, and an anthracenyl group. These groups can be used alone or in combination of two or more. Among these, the terminal group may be an adamantyl group from the viewpoint of ease of introduction.

[0038] The ethylenically unsaturated group in component (C1) may be present in a cyclic molecule, a linear molecule, or a terminal group, or may be present mainly in the cyclic molecule. When the cyclic molecule has a side chain, the ethylenically unsaturated group may be present in the side chain of the cyclic molecule. When the cyclic molecule has an ethylenically unsaturated group, cross-linking the cyclic molecules allows the cross-linking points to move freely, and an air spring-like sliding effect occurs in which the uncross-linked cyclic molecules try to maintain a constant distance on the linear molecule, resulting in excellent compression set resistance and stress relaxation, and making it possible to form a permanent resist with excellent crack resistance.

[0039] The number of ethylenically unsaturated groups contained in the component (C1) is not particularly limited, as long as it is 1 or at least 2. Examples of ethylenically unsaturated groups include acryloyl groups and methacryloyl groups.

[0040] The component (C1) may be a commercially available product, such as CELMS Super Polymer SM2405P-20, SM1305P-20, SA2405P-20, or SA1305P-20, manufactured by ASM Corporation.

[0041] The weight average molecular weight of the (C1) component may be 30,000 or more, 50,000 or more, 100,000 or more, 150,000 or more, or 190,000 or more from the viewpoint of crack resistance, and may be 1,000,000 or less, 800,000 or less, 600,000 or less, 500,000 or less, or 450,000 or less from the viewpoint of resolution.

[0042] The content of the component (C1), based on the total mass of the component (C), may be 1 mass % or more, 3 mass % or more, 5 mass % or more, 7 mass % or more, 10 mass % or more, 12 mass % or more, or 14 mass % or more from the viewpoint of resolution and crack resistance, and may be 30 mass % or less, 25 mass % or less, or 20 mass % or less from the viewpoint of crosslinking reactivity.

[0043] The content of the component (C1), based on the total mass of the solid contents of the photosensitive resin composition, may be 0.1 mass % or more, 0.3 mass % or more, 0.5 mass % or more, 0.7 mass % or more, or 0.9 mass % or more from the viewpoint of resolution and crack resistance, and may be 10 mass % or less, 7 mass % or less, 5 mass % or less, 3 mass % or less, or 2 mass % or less from the viewpoint of crosslinking reactivity.

[0044] The photopolymerizable compound may further contain a photopolymerizable compound other than the component (C1) (hereinafter also referred to as "component (C2)"). Examples of the component (C2) include a photopolymerizable compound having one ethylenically unsaturated group, a photopolymerizable compound having two ethylenically unsaturated groups, and a photopolymerizable compound having three or more ethylenically unsaturated groups.

[0045] Examples of photopolymerizable compounds having one ethylenically unsaturated group include (meth)acrylic acid and (meth)acrylic acid alkyl esters. Examples of (meth)acrylic acid alkyl esters include (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid 2-ethylhexyl ester, and (meth)acrylic acid hydroxyethyl ester.

[0046] Examples of photopolymerizable compounds having two ethylenically unsaturated groups include polyethylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2-bis(4-(meth)acryloxypolyethoxypolypropoxyphenyl)propane, and bisphenol A diglycidyl ether di(meth)acrylate.

[0047] Examples of photopolymerizable compounds having three or more ethylenically unsaturated groups include (meth)acrylate compounds having a skeleton derived from trimethylolpropane, such as trimethylolpropane tri(meth)acrylate; (meth)acrylate compounds having a skeleton derived from tetramethylolmethane, such as tetramethylolmethane tri(meth)acrylate and tetramethylolmethane tetra(meth)acrylate; (meth)acrylate compounds having a skeleton derived from pentaerythritol, such as pentaerythritol tri(meth)acrylate and pentaerythritol tetra(meth)acrylate; (meth)acrylate compounds having a skeleton derived from dipentaerythritol, such as dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate; (meth)acrylate compounds having a skeleton derived from ditrimethylolpropane, such as ditrimethylolpropane tetra(meth)acrylate; and (meth)acrylate compounds having a skeleton derived from diglycerin.

[0048] Among these, from the viewpoints of crack resistance and resolution, a photopolymerizable compound having three or more ethylenically unsaturated groups may be used. Furthermore, from the viewpoints of improving chemical resistance after exposure and increasing the difference in developer resistance between exposed and unexposed areas, a (meth)acrylate compound having a skeleton derived from dipentaerythritol is preferred, and dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate are more preferred.

[0049] The content of the component (C) in the photosensitive resin composition according to this embodiment may be 1 mass % or more, 2 mass % or more, or 4 mass % or more, based on the total solid content of the photosensitive resin composition, and may be 20 mass % or less, 15 mass % or less, 12 mass % or less, 10 mass % or less, or 8 mass % or less.

[0050] ((D) component: thermosetting resin) The photosensitive resin composition according to this embodiment may further contain a thermosetting resin as component (D). By using component (D), it is possible to improve the heat resistance, adhesiveness, chemical resistance, etc. of a cured film formed from the photosensitive resin composition. The component (D) may be used alone or in combination of two or more.

[0051] Examples of component (D) 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.

[0052] 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.

[0053] When the photosensitive resin composition according to this embodiment contains component (D), the content thereof 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 (D) is within the above range, the heat resistance of the formed cured film can be further improved while maintaining good developability. (Component (E): inorganic filler) The photosensitive resin composition according to this embodiment may further contain an inorganic filler as component (E). By containing component (E), the adhesive strength, reliability, etc. of the permanent resist can be improved. The component (E) may be used alone or in combination of two or more.

[0054] 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.

[0055] Component (E) 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 in advance with alumina or an organosilane compound may be used.

[0056] 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.

[0057] When the photosensitive resin composition according to this embodiment contains component (E), the content thereof may be 5 mass % or more, 10 mass % or more, 15 mass % or more, or 20 mass % or more, based on the total solid content of the photosensitive resin composition, and may be 70 mass % or less, 60 mass % or less, 50 mass % or less, or 45 mass % or less. When the content of component (E) is within the above range, it is possible to further improve the low coefficient of thermal expansion, heat resistance, film strength, etc.

[0058] (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.

[0059] When the photosensitive resin composition according to this embodiment contains the component (F), the content thereof may be 0.05 to 10 mass %, 0.1 to 8 mass %, or 0.2 to 5 mass % based on the total amount of solids in the photosensitive resin composition, from the viewpoint of further concealing the wiring.

[0060] (Component (G): Hardener) The photosensitive resin composition according to this embodiment may further contain a curing agent as component (G). Examples of component (G) include a compound that cures by itself with heat, ultraviolet light, or the like, or a compound that cures by reacting with a carboxyl group or a hydroxyl group in component (A) with heat, ultraviolet light, or the like. The use of a curing agent can improve the heat resistance, adhesion, chemical resistance, and other properties of the permanent resist.

[0061] Examples of the component (G) include thermosetting compounds such as epoxy compounds, blocked isocyanates, melamine compounds, oxazoline compounds, etc. The component (G) can be used alone or in combination of two or more.

[0062] Examples of epoxy compounds that can be used include those listed as component (a). The epoxy compound may be liquid or solid at room temperature. Examples of epoxy compounds include bisphenol A epoxy resins, bisphenol F epoxy resins, hydrogenated bisphenol A epoxy resins, brominated bisphenol A epoxy resins, novolac epoxy resins, bisphenol S epoxy resins, biphenyl epoxy resins, naphthalene epoxy resins, dicyclo epoxy resins, hydantoin epoxy resins, triglycidyl isocyanurate, and bixylenol epoxy resins. Component (G) may contain at least one selected from the group consisting of bisphenol epoxy resins, such as bisphenol A epoxy resins and bisphenol F epoxy resins, and novolac epoxy resins.

[0063] The blocked isocyanate may be an addition reaction product of a polyisocyanate compound and an isocyanate blocking agent. The melamine compound may, for example, be triaminotriazine, hexamethoxymelamine, or hexabutoxylated melamine.

[0064] When the photosensitive resin composition according to this embodiment contains component (G), the content thereof may be 0.01 mass % or more, 0.03 mass % or more, or 0.05 mass % or more, and may be 20 mass % or less, 10 mass % or less, 1 mass % or less, or 0.5 mass % or less, based on the total solid content of the photosensitive resin composition. When the content of component (G) is within the above range, the heat resistance of the formed permanent resist can be further improved while maintaining better developability.

[0065] The photosensitive resin composition according to this embodiment may further contain various additives as needed, such as polymerization inhibitors, sensitizers, elastomers, 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.

[0066] (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.

[0067] 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.

[0068] 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 60 mass %, 20 to 50 mass %, or 25 to 40 mass %.

[0069] 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.

[0070] [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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] [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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] Next, a negative film is brought into contact with the photosensitive layer directly or via a support film, and the layer is exposed to actinic rays. Examples of actinic rays include electron beams, ultraviolet rays, and X-rays. The exposure dose is 10 to 2000 mJ / cm. 2 , 100-1500mJ / cm 2 , or 300 to 1000 mJ / cm 2 may be.

[0080] The light source for actinic rays is not particularly limited as long as it is a commonly used, well-known light source. For example, carbon arc lamps, mercury vapor arc lamps, ultra-high pressure mercury lamps, high-pressure mercury lamps, xenon lamps, gas lasers such as argon lasers, solid-state lasers such as YAG lasers, and semiconductor lasers such as gallium nitride blue-violet lasers can be used, which effectively emit ultraviolet rays. Among these, from the viewpoint of improving resolution and alignment in a well-balanced manner, light sources capable of emitting monochromatic i-line light with an exposure wavelength of 365 nm, light sources capable of emitting monochromatic h-line light with an exposure wavelength of 405 nm, or light sources capable of emitting actinic rays with exposure wavelengths that are a cross-over of i- and h-lines can be used. Examples of light sources capable of emitting monochromatic i-line light with an exposure wavelength of 365 nm include ultra-high pressure mercury lamps. Examples of light sources capable of emitting monochromatic h-line light with an exposure wavelength of 405 nm include blue-violet laser diodes with a wavelength of 405 nm.

[0081] 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.

[0082] 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.

[0083] The permanent resist according to this embodiment can be used as an interlayer insulating layer or a surface protective layer of a semiconductor element. By using the above-described photosensitive resin composition, a semiconductor element having an interlayer insulating layer or a surface protective layer containing a cured product 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 permanent resist formed from the photosensitive resin composition according to this embodiment, semiconductor elements and electronic devices with excellent reliability can be provided. [Example]

[0084] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0085] <(A) Synthesis of Acid-Modified Vinyl Group-Containing Resin> 350 parts by mass of dicyclopentadiene epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name "XD-1000", epoxy equivalent: 252 g / eq, softening point: 74.2°C, number of ring carbon atoms in alicyclic skeleton: 10), 70 parts by mass of acrylic acid, 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate were charged and reacted by heating to 90°C and stirring to dissolve the mixture. Next, the resulting solution was cooled to 60°C, 2 parts by mass of triphenylphosphine was added, and the mixture was heated to 100°C and reacted until the acid value of the solution reached 1 mgKOH / g. 98 parts by mass of tetrahydrophthalic anhydride and 85 parts by mass of carbitol acetate were added to the reacted solution, and the mixture was heated to 80°C and reacted for 6 hours. Thereafter, the solution was cooled to room temperature to obtain a solution of acid-modified dicyclopentadiene-type epoxy acrylate (A-1) (Mw: 1800) with a solid content concentration of 73 mass %.

[0086] <Preparation of components (B) to (G)> The following materials were prepared as components (B) to (G). (B) Photopolymerization initiator B-1: Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) (manufactured by BASF, trade name "Irgacure OXE02") B-2: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone B-3: 2,4-diethylthioxanthone (manufactured by Nippon Kayaku Co., Ltd., trade name "DETX-S") (C) Photopolymerizable compound C-1: Acryloyl group-containing polyrotaxane (manufactured by ASM Co., Ltd., product name "SA1305P-20", Mw: 200000) C-2: Methacryloyl group-containing polyrotaxane (manufactured by ASM Co., Ltd., product name "SM1305P-20", Mw: 200000) C-3: Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name "DPHA") C'-1: Polyrotaxane not containing an ethylenically unsaturated group (manufactured by ASM Co., Ltd., product name "SH1300P", Mw: 180000) (D) Thermosetting resin D-1: Biphenyl-type epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name "YX4000X") (E) Inorganic filler E-1: Silica particles (manufactured by Denka Co., Ltd., product name "SFP-20M", average particle size: 0.3 μm) (F) Pigment F-1: Phthalocyanine pigment (manufactured by Sanyo Pigment Co., Ltd.) (G) Hardener G-1: Melamine

[0087] [Examples 1-2 and Comparative Examples 1-2] <Preparation of Photosensitive Resin Composition> The components were blended according to the formulation shown in Table 1 (the units of values in the table are parts by mass, and in the case of a solution, the amounts are converted to solid content), and kneaded using a three-roll mill. Methyl ethyl ketone was then added so that the solid content concentration became 60% by mass, to obtain a photosensitive resin composition.

[0088] <Preparation of 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 would be 15 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.

[0089] [evaluation] <Crack resistance> A 0.6 mm thick copper-clad laminate (manufactured by Resonac Corporation, product name "MCL-E-67") was prepared, and the protective film was peeled off from the photosensitive element manufactured in each example. The exposed photosensitive layer was laminated onto the copper-clad laminate using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name "MVLP-500") to obtain a laminate for evaluation, in which the copper-clad laminate, photosensitive layer, and support film were laminated in this order. The lamination conditions were 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.

[0090] The support film was peeled off from the laminate for evaluation obtained above, and the exposed photosensitive layer was exposed to light at 50 to 1000 mJ / cm using an i-line exposure device (manufactured by Ushio Inc., product name "UX-2240SM-XJ-01") through a negative mask having a via pattern with openings of a predetermined size (a pattern with a hole diameter of 50 μm and a hole center distance of 50 μm). 2 in the range of 50 mJ / cm 2 After that, the film was exposed to light using a 1% by mass aqueous solution of sodium carbonate 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), for 1.765 × 10 5 The unexposed areas were then developed by spraying at a pressure of 2000 mJ / cm 2 using an ultraviolet exposure device. 2After exposure at this dose, the substrate was heated at 160°C for 1 hour to prepare a test specimen having a cured film (permanent resist) with a via pattern of a predetermined size on a copper-clad laminate substrate. The test specimen was subjected to 1,000 cycles of -65°C for 30 minutes / (room temperature: 25°C) / 150°C for 30 minutes, and then the appearance of the permanent resist was visually observed, and the crack resistance was evaluated according to the following criteria. (Evaluation criteria) A: There was no change in appearance within a 30cm x 30cm area of permanent resist. B: Within a 30 cm x 30 cm area of permanent resist, 1 to 5 lifts or blisters of the coating film occurred.

[0091] <Resolution> The support film was peeled off from the laminate for evaluation obtained above, and the exposed photosensitive layer was exposed to 50 to 1000 mJ / cm using an i-line exposure device (manufactured by Ushio Inc., product name "UX-2240SM-XJ-01") through a negative mask having a via pattern with a predetermined opening diameter (opening mask diameter size: 20 μmφ). 2 in the range of 50 mJ / cm 2 After that, the film was exposed to light using a 1% by mass aqueous solution of sodium carbonate 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), for 1.765 × 10 5 The unexposed areas were then developed by spraying at a pressure of 2000 mJ / cm 2 using an ultraviolet exposure device. 2 After exposure at an exposure dose of 1000 ppm, the substrate was heated at 160°C for 1 hour to prepare a test specimen having a cured film with a via pattern of a predetermined size provided on a copper-clad laminate substrate. The test specimen was observed using a metallurgical microscope, and the opening diameter at the top of the via (top opening diameter) was measured, and the resolution was evaluated according to the following criteria. (Evaluation criteria) A: The via was open and the top opening diameter was 17 μm or more. B: The via was open, and the top opening diameter was less than 17 μm.

[0092] [Table 1] [Explanation of symbols]

[0093] 1...photosensitive element, 10...support film, 20...photosensitive layer, 30...protective film.

Claims

1. A photosensitive resin composition comprising (A) an acid-modified vinyl group-containing resin, (B) a photopolymerization initiator, and (C) a photopolymerizable compound, wherein the (C) photopolymerizable compound contains (C1) a polyrotaxane having an ethylenically unsaturated group.

2. 2. The photosensitive resin composition according to claim 1, wherein the ethylenically unsaturated group comprises at least one selected from the group consisting of an acryloyl group and a methacryloyl group.

3. 2. The photosensitive resin composition according to claim 1, wherein the content of the polyrotaxane having an ethylenically unsaturated group (C1) is 1 mass% or more based on the total mass of the photopolymerizable compound (C).

4. The photosensitive resin composition according to claim 1 , further comprising (D) a thermosetting resin.

5. The photosensitive resin composition according to claim 1 , further comprising (E) an inorganic filler.

6. The photosensitive resin composition according to claim 1 , further comprising (F) a pigment.

7. The photosensitive resin composition according to claim 1 , further comprising (G) a curing agent.

8. 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 7.

9. 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 7.

10. forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of claims 1 to 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:

11. forming a photosensitive layer on a substrate using the photosensitive element of claim 8; a step of 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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