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

Abstract

The present disclosure relates to a photosensitive resin composition for a permanent resist, the composition containing: (A) acid-modified vinyl group-containing resin; (B) epoxy compound; (C) photopolymerization initiator; (D) photopolymerizable compound; and (F) inorganic filler, wherein the equivalent ratio of epoxy groups in (B) epoxy compound to carboxy groups in (A) acid-modified vinyl group-containing resin is 1.25-7.5, and (F) inorganic filler includes silica filler with vinyl groups derived from a vinylsilane compound.

Description

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

[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.

[0002] In the field of printed wiring boards, 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 mounting of semiconductor elements on the printed wiring board via solder.

[0003] Conventionally, permanent resists have been produced by screen printing using a thermosetting resin composition or by a photographic method using a photosensitive resin composition. For example, in flexible wiring boards using mounting methods such as FC (Flip Chip), TAB (Tape Automated Bonding), and COF (Chip On Film), a thermosetting resin paste is screen-printed and thermally cured to form a permanent resist, except for IC chips, electronic components, or LCD (Liquid Crystal Display) panels and connection wiring pattern portions (see, for example, Patent Document 1).

[0004] 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, and (3) solder-bond the semiconductor package substrate to a motherboard. A photographic method is used to form an image on the permanent resist, in which a photosensitive resin composition is applied and dried, and then selectively irradiated with actinic rays such as ultraviolet light to harden it, and only the unirradiated areas are removed by development 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 on photosensitive materials (see, for example, Patent Document 2).

[0005] JP 2003-198105 JP 11-240930

[0006] On the other hand, permanent resists formed from conventional photosensitive resin compositions may crack under harsh environments such as high temperatures, and therefore a photosensitive resin composition capable of forming a permanent resist with excellent crack resistance is desired. Furthermore, when a permanent resist is formed using a conventional photosensitive resin composition, resist residue is generated after development, which may cause fatal defects when connecting bumps to a chip, and therefore a photosensitive resin composition with excellent developability is desired.

[0007] Therefore, an object of the present disclosure is to provide a photosensitive resin composition for a permanent resist that can form a permanent resist having excellent crack resistance and excellent developability, and a photosensitive element, a printed wiring board, and a method for manufacturing a printed wiring board that use the photosensitive resin composition.

[0008] Some aspects of the present disclosure provide the following [1] to [9]. [1] A photosensitive resin composition for a permanent resist, comprising (A) an acid-modified vinyl group-containing resin, (B) an epoxy compound, (C) a photopolymerization initiator, (D) a photopolymerizable compound, and (F) an inorganic filler, wherein the equivalent ratio of the epoxy groups contained in the (B) epoxy compound to the carboxy groups contained in the (A) acid-modified vinyl group-containing resin is 1.25 to 7.50, and the (F) inorganic filler comprises a silica filler having a vinyl group derived from a vinylsilane compound. [2] The photosensitive resin composition according to [1] above, wherein the equivalent ratio is 2.00 to 7.50. [3] The photosensitive resin composition according to [1] above, wherein the equivalent ratio is 2.50 to 7.50. [4] The photosensitive resin composition according to any one of [1] to [3] above, further comprising (E) a pigment. [5] A photosensitive element comprising a support film and a photosensitive layer formed on the support film, the photosensitive layer comprising the photosensitive resin composition described in any one of [1] to [4] above. [6] A printed wiring board comprising a permanent resist comprising a cured product of the photosensitive resin composition described in any one of [1] to [4] above. [7] The printed wiring board described in [6] above, wherein the permanent resist has a thickness of 10 to 50 μm. [8] A method for manufacturing a printed wiring board, comprising the steps of: forming a photosensitive layer on a substrate using the photosensitive resin composition described in any one of [1] to [4] above; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist. [9] 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 [5] above; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist.

[0009] According to the present disclosure, it is possible to provide a photosensitive resin composition for a permanent resist that can form a permanent resist having excellent crack resistance and excellent developability, as well as a photosensitive element, a printed wiring board, and a method for manufacturing a printed wiring board that use the photosensitive resin composition.

[0010] FIG. 1 is a cross-sectional view that schematically illustrates a photosensitive element according to this embodiment.

[0011] Hereinafter, one embodiment of the present disclosure will be specifically described, but the present disclosure is not limited thereto. In the following embodiments, the components (including element steps, etc.) are not essential unless otherwise specified, or unless they are considered to be clearly essential in principle. The same applies to numerical values ​​and their ranges, and they do not unduly limit the present disclosure.

[0012] In this disclosure, the term "layer" encompasses not only a structure with a shape formed over the entire surface when observed in a plan view, but also a structure with a shape formed on a portion of the surface. In this disclosure, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved. In this disclosure, 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 disclosure, 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. Furthermore, in numerical ranges described in this disclosure, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. In this disclosure, "A or B" may include either A or B, or may include both. Unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0013] In the present disclosure, the term "solid content" refers to the non-volatile content excluding volatile substances such as water and diluents contained in the photosensitive resin composition, and refers to components that remain without evaporating or vaporizing when the resin composition is dried, and also includes components that are liquid, syrup-like, or waxy at room temperature (25°C; the same applies hereinafter).

[0014] [Photosensitive Resin Composition] The photosensitive resin composition according to this embodiment contains (A) an acid-modified vinyl group-containing resin, (B) an epoxy compound, (C) a photopolymerization initiator, (D) a photopolymerizable compound, and (F) an inorganic filler, wherein the equivalent ratio (epoxy group / carboxy group equivalent ratio, molar ratio) of the epoxy groups contained in the (B) epoxy compound to the carboxy groups contained in the (A) acid-modified vinyl group-containing resin is 1.25 to 7.50, and the (F) inorganic filler contains a silica filler having a vinyl group derived from a vinylsilane compound. The photosensitive resin composition according to this embodiment is a negative-tone photosensitive resin composition, and a cured product of the photosensitive resin composition can be used as a permanent resist. The present inventors have discovered that when the epoxy group / carboxy group equivalent ratio is 1.25 or higher, there will be more epoxy groups derived from the epoxy compound than carboxy groups derived from the acid-modified vinyl group-containing resin, and as a result, the elasticity of the permanent resist formed is likely to be improved and the crack resistance of the permanent resist can be improved. However, as the epoxy group / carboxy group equivalent ratio increases, the solubility of the cured product formed in a developer tends to decrease, resulting in poor developability. They have also discovered that by using a silica filler having a vinyl group derived from a vinylsilane compound in combination as the inorganic filler, the silica filler having a vinyl group derived from a vinylsilane compound is more likely to bond with functional groups such as vinyl groups contained in the acid-modified vinyl group-containing resin, photopolymerizable compound, etc. in the photosensitive resin composition and be developed compared to other silica fillers, and therefore it is possible to prevent the solubility of the cured product formed in a developer from decreasing even when the epoxy group / carboxy group equivalent ratio is high and improve developability, thereby completing the present invention.

[0015] The photosensitive resin composition according to this embodiment can form a permanent resist having excellent crack resistance and can reduce the generation of residues after development, and therefore has excellent developability. Furthermore, the photosensitive resin composition according to this embodiment can form a permanent resist having excellent flowability and excellent adhesion to copper substrates. Furthermore, the photosensitive resin composition according to this embodiment also has excellent performance required of a photosensitive resin composition used in the manufacture of printed wiring boards, such as resolution, electrical insulation, soldering heat resistance, solvent resistance, acid resistance, and alkali resistance. Hereinafter, each component contained in the photosensitive resin composition according to this embodiment will be described in detail.

[0016] <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 bond that is a photopolymerizable ethylenically unsaturated bond and an alkali-soluble acidic group.

[0017] Examples of the group having an ethylenically unsaturated bond contained in component (A) include a vinyl group, an allyl group, a propargyl group, a butenyl group, an ethynyl group, a phenylethynyl group, a maleimide group, a nadimide group, and a (meth)acryloyl group. Among these, a (meth)acryloyl group is preferred from the viewpoint of reactivity and resolution. Examples of the acidic group contained in component (A) 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] The component (A) may be an acid-modified vinyl group-containing epoxy derivative obtained by reacting a resin (A') (hereinafter sometimes referred to as "component (A')") obtained by reacting (a) an epoxy resin (hereinafter sometimes referred to as "component (a)") with (b) an ethylenically unsaturated group-containing organic acid (hereinafter sometimes referred to as "component (b)"), with (c) a saturated group- or unsaturated group-containing polybasic acid anhydride (hereinafter sometimes referred to as "component (c)").

[0019] Examples of acid-modified vinyl group-containing epoxy derivatives include acid-modified epoxy(meth)acrylates. Acid-modified epoxy(meth)acrylates are resins obtained by acid-modifying epoxy(meth)acrylate, which is a reaction product of components (a) and (b), with component (c). Examples of acid-modified epoxy(meth)acrylates include addition reaction products obtained by adding saturated or unsaturated polybasic acid anhydrides to esters obtained by reacting epoxy resins with vinyl group-containing monocarboxylic acids.

[0020] Examples of the component (A) include an acid-modified vinyl group-containing resin (A1) (hereinafter, sometimes referred to as "component (A1)") obtained by using a bisphenol novolac epoxy resin (a1) (hereinafter, sometimes referred to as "epoxy resin (a1)") as the component (a), and an acid-modified vinyl group-containing resin (A2) (hereinafter, sometimes referred to as "component (A2)") obtained by using an epoxy resin (a2) (hereinafter, sometimes referred to as "epoxy resin (a2)") other than the epoxy resin (a1) as the component (a). These can be used alone or in combination of two or more.

[0021] (Epoxy Resin (a1)) Examples of the epoxy resin (a1) include epoxy resins having a structural unit represented by the following formula (I) or (II): The epoxy resin (a1) may be an epoxy resin having a structural unit represented by formula (I).

[0022]

[0023] In formula (I), R １１ represents a hydrogen atom or a methyl group, and a plurality of R １１ may be the same or different. １ and Y ２ each independently represents a hydrogen atom or a glycidyl group, and Y １ and Y ２ At least one of the groups is a glycidyl group.

[0024] From the viewpoint of improving resolution, R １１ may be a hydrogen atom, and Y １ and Y ２may be a glycidyl group.

[0025] The number of structural units represented by formula (I) in the epoxy resin (a1) is 1 or more, and may be 10 to 100, 15 to 80, or 15 to 70. When the number of structural units is within the above range, heat resistance and electrical insulation properties are easily improved. Here, the number of structural units represents an integer value in a single molecule, and represents a rational number that is an average value in an aggregate of multiple types of molecules (the same applies hereinafter).

[0026]

[0027] In formula (II), R １２ represents a hydrogen atom or a methyl group, and a plurality of R １２ may be the same or different. ３ and Y ４ each independently represents a hydrogen atom or a glycidyl group, and Y ３ and Y ４ At least one of the groups is a glycidyl group.

[0028] From the viewpoint of improving resolution, R １２ may be a hydrogen atom, and Y ３ and Y ４ may be a glycidyl group.

[0029] The number of structural units represented by formula (II) in the epoxy resin (a1) is 1 or more, and may be 10 to 100, 15 to 80, or 15 to 70. When the number of structural units is within the above range, heat resistance and electrical insulation properties are easily improved.

[0030] In formula (II), R １２ is a hydrogen atom, and Y ３ and Y ４ The epoxy resin in which R is a glycidyl group is commercially available as the EXA-7376 series (trade name, manufactured by DIC Corporation). １２ is a methyl group, and Y ３ and Y ４ Epoxy resins in which the carboxyl group is a glycidyl group are commercially available as EPON SU8 series (trade name, manufactured by Mitsubishi Chemical Corporation).

[0031] (Epoxy Resin (a2)) The epoxy resin (a2) is not particularly limited as long as it is an epoxy resin different from the epoxy resin (a1), and may be at least one selected from the group consisting of novolac type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, triphenolmethane type epoxy resins, and biphenyl type epoxy resins.

[0032] Examples of the epoxy resin (a2) include bisphenol A type epoxy resins or bisphenol F type epoxy resins having a structural unit represented by the following formula (III): Epoxy resins having such a structural unit include bisphenol A type epoxy resins or bisphenol F type epoxy resins represented by the following formula (III'):

[0033]

[0034] In formulas (III) and (III′), R １３ represents a hydrogen atom or a methyl group, and there are multiple R １３ may be the same or different, and Y ５ represents a hydrogen atom or a glycidyl group. ２ represents a number of 1 or more, and n ２ If there are two or more Y ５ may be the same or different, and at least one Y ５ is a glycidyl group.

[0035] From the viewpoint of improving resolution, R １３ may be a hydrogen atom. From the viewpoint of further improving crack resistance, Y ５ may be a glycidyl group. ２ represents 1 or more, but may be 10 to 100, 10 to 80, or 15 to 60. ２ When the amount of the carboxylic acid is within the above range, the linearity and heat resistance of the resist pattern contour can be easily improved.

[0036] Y in formula (III) ５ The bisphenol A type epoxy resin or bisphenol F type epoxy resin in which Y is a glycidyl group can be, for example, ５is a hydrogen atom, ５ ) with epichlorohydrin.

[0037] To promote the reaction between hydroxyl groups and epichlorohydrin, the reaction may be carried out in a polar organic solvent such as dimethylformamide, dimethylacetamide, or dimethylsulfoxide in the presence of an alkali metal hydroxide at a reaction temperature of 50 to 120° C. When the reaction temperature is within the above range, the reaction does not become too slow, and side reactions can be suppressed.

[0038] As the bisphenol A type epoxy resin or bisphenol F type epoxy resin represented by formula (III'), for example, jER807, jER815, jER825, jER827, jER828, jER834, jER1001, jER1004, jER1007 and jER1009 (all manufactured by Mitsubishi Chemical Corporation, trade names), DER-330, DER-301 and DER-361 (all manufactured by Dow Chemical Company, trade names), YD-8125, YDF-170, YDF-175S, YDF-2001, YDF-2004 and YDF-8170 (all manufactured by Nippon Steel Chemical & Material Co., Ltd., trade names) are commercially available.

[0039] (Ethylenically Unsaturated Group-Containing Organic Acid (b)) Examples of the component (b) include acrylic acid; acrylic acid derivatives such as acrylic acid dimers, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α-cyanocinnamic acid; half-ester compounds which are reaction products of hydroxyl group-containing 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. The component (b) can be used alone or in combination of two or more.

[0040] The half-ester compound can be obtained, for example, by reacting a hydroxyl group-containing acrylate, a vinyl group-containing monoglycidyl ether or a vinyl group-containing monoglycidyl ester with a dibasic acid anhydride in an equimolar ratio.

[0041] Examples of hydroxyl group-containing 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.

[0042] 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.

[0043] In the reaction between component (a) and component (b), the ratio may be such that 0.6 to 1.05 equivalents of component (b) are used per 1 equivalent of the epoxy group in component (a), or 0.8 to 1.0 equivalents of component (b). By using such a ratio, photopolymerization is improved, i.e., photosensitivity is increased, making it easier to improve resolution.

[0044] The components (a) and (b) can be dissolved in an organic solvent and reacted. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, and carbitol acetate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. The organic solvents may be used alone or in combination of two or more.

[0045] A catalyst may be used to promote the reaction between component (a) and component (b). Examples of the catalyst include triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, and triphenylphosphine. The catalyst may be used alone or in combination of two or more.

[0046] From the viewpoint of promoting the reaction between the component (a) and the component (b), the amount of the catalyst used may be 0.01 to 10 parts by mass, 0.05 to 2 parts by mass, or 0.1 to 1 part by mass, relative to 100 parts by mass of the total of the component (a) and the component (b).

[0047] A polymerization inhibitor may be used to prevent polymerization during the reaction. Examples of polymerization inhibitors include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol. One polymerization inhibitor may be used alone, or two or more polymerization inhibitors may be used in combination. From the viewpoint of storage stability, the amount of the polymerization inhibitor used may be 0.01 to 1 part by mass, 0.02 to 0.8 parts by mass, or 0.04 to 0.5 parts by mass per 100 parts by mass of the total of component (a) and component (b).

[0048] The reaction temperature between the components (a) and (b) may be 60 to 150°C, 80 to 120°C, or 90 to 110°C from the viewpoint of productivity.

[0049] Component (A'), obtained by reacting components (a) and (b), is presumed to have hydroxyl groups formed by a ring-opening addition reaction between the epoxy groups in component (a) and the carboxyl groups in component (b). It is presumed that further reaction of component (A') with component (c) produces an acid-modified vinyl-group-containing epoxy resin in which the hydroxyl groups in component (A') (including the hydroxyl groups originally present in component (a)) and the acid anhydride groups in component (c) are semi-esterified.

[0050] (Polybasic Acid Anhydride (c)) Examples of the component (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 is preferred from the viewpoint of resolution. The component (c) may be used alone or in combination of two or more.

[0051] The reaction temperature between the component (A') and the component (c) may be 50 to 150°C, 60 to 120°C, or 70 to 100°C from the viewpoint of productivity.

[0052] If necessary, as component (a), for example, a hydrogenated bisphenol A type epoxy resin may be used in combination, or a styrene-maleic acid resin such as a hydroxyethyl (meth)acrylate modified product of a styrene-maleic anhydride copolymer may be used in combination.

[0053] In the reaction of component (A') with component (c), for example, the acid value of component (A) can be adjusted by reacting 0.1 to 1.0 equivalents of component (c) with one equivalent of hydroxyl groups in component (A').

[0054] The acid value of component (A) may be 30 to 150 mgKOH / g or 40 to 120 mgKOH / g. When the acid value of component (A) is 30 mgKOH / g or more, the photosensitive resin composition tends to have excellent solubility in a dilute alkaline solution. From the same viewpoint, the acid value of component (A) may be 35 mgKOH / g or more or 40 mgKOH / g or more. When the acid value of component (A) is 150 mgKOH / g or less, the electrical properties of the permanent resist are easily improved. From the same viewpoint, the acid value of component (A) may be 120 mgKOH / g or less, 100 mgKOH / g or less, 90 mgKOH / g or less, 80 mgKOH / g or less, 70 mgKOH / g or less, 60 mgKOH / g or less, or 50 mgKOH / g or less.

[0055] The acid value can be measured by the following method. First, approximately 1 g of the solution of component (A) is weighed out. Then, 30 g of acetone is added to this solution and mixed uniformly. An appropriate amount of phenolphthalein, which serves as an indicator, is added to the mixed solution. Titration is carried out using a 0.1 N aqueous KOH solution. The titration amount of the aqueous KOH solution is determined, and the acid value is calculated using the following formula: Acid value = 10 x Vf x 56.1 / (Wp x I)

[0056] In the formula, Vf represents the titration volume (mL) of the 0.1 N KOH aqueous solution, Wp represents the measured mass (g) of the solution of component (A), and I represents the proportion (mass%) of nonvolatile matter in the measured solution of component (A).

[0057] The weight average molecular weight (Mw) of the component (A) may be 3,000 to 30,000, 4,000 to 25,000, or 5,000 to 18,000 from the viewpoints of resolution, heat resistance, and electrical insulation. Here, Mw can be measured by gel permeation chromatography (GPC). Mw can be measured, for example, under the GPC conditions below, and the value converted using a calibration curve of standard polystyrene can be used as Mw. To create the calibration curve, a five-sample set ("PStQuick MP-H" and "PStQuick B", manufactured by Tosoh Corporation) can be used as standard polystyrene.

[0058] (GPC conditions) GPC device: High-speed GPC device "HCL-8320GPC" (manufactured by Tosoh Corporation) Detector: Differential refractometer or UV detector (manufactured by Tosoh Corporation) Column: Column TSKgel SuperMultipore HZ-H (column length: 15 cm, column inner diameter: 4.6 mm) (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran (THF) Measurement temperature: 40°C Flow rate: 0.35 mL / min Sample concentration: 10 mg / 5 mL THF Injection amount: 20 μL

[0059] From the viewpoint of improving the heat resistance, electrical properties, and chemical resistance of the permanent resist, the content of the component (A) in the photosensitive resin composition may be 10% by mass or more, 15% by mass or more, or 20% by mass or more, and may be 80% by mass or less, 70% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total solid content of the photosensitive resin composition. From the same viewpoint, the content of the component (A) may be 10% by mass to 80% by mass, 15% by mass to 70% by mass, 20% by mass to 50% by mass, or 20% by mass to 40% by mass.

[0060] When component (A1) and component (A2) are used in combination as component (A), the total content of components (A1) and (A2) in component (A) may be 80 to 100 mass%, 90 to 100 mass%, 95 to 100 mass%, or 100 mass%, based on the total amount of component (A), from the viewpoint of improving solder heat resistance. When component (A1) or component (A2) is used alone, the amount can be appropriately selected from the above ranges.

[0061] When the component (A1) and the component (A2) are used in combination as the component (A), the mass ratio (A1 / A2) thereof may be 20 / 80 to 90 / 10, 20 / 80 to 80 / 20, or 30 / 70 to 70 / 30, from the viewpoint of improving solder heat resistance.

[0062] <Component (B): Epoxy Compound> The photosensitive resin composition according to this embodiment contains an epoxy compound as component (B). As component (B), a compound having two or more epoxy groups can be used, and examples thereof include a carboxy group contained in component (A) and an epoxy compound that is cured by heat or ultraviolet light. By using component (B), the photosensitive resin composition according to this embodiment can form a permanent resist that is excellent in heat resistance, adhesion, and chemical resistance. The component (B) may be used alone or in combination of two or more.

[0063] Examples of the component (B) include bisphenol A type epoxy resins, bisphenol F type epoxy resins, hydrogenated bisphenol A type epoxy resins, brominated bisphenol A type epoxy resins, novolac type epoxy resins, bisphenol S type epoxy resins, biphenyl type epoxy resins, heterocyclic epoxy resins such as triglycidyl isocyanurate, and bixylenol type epoxy resins.

[0064] From the viewpoint of crack resistance, the epoxy equivalent of component (B) may be 100 g / eq or more, 130 g / eq or more, or 150 g / eq or more. The epoxy equivalent of component (B) may be 450 g / eq or less, 400 g / eq or less, or 380 g / eq or less. The epoxy equivalent of component (B) may be 100 g / eq to 450 g / eq, 130 g / eq to 400 g / eq, or 150 g / eq to 380 g / eq. The epoxy equivalent can be measured in accordance with JIS K 7236.

[0065] From the viewpoint of crack resistance, the content of component (B) in the photosensitive resin composition may be 2% by mass or more, 4% by mass or more, or 6% by mass or more, based on the total solid content of the photosensitive resin composition. The content of component (B) may be 40% by mass or less, or 35% by mass or less. The content of component (B) may be 2 to 40% by mass, 4 to 40% by mass, or 6 to 35% by mass.

[0066] From the viewpoint of excellent crack resistance and developability, the equivalent ratio of the epoxy groups in component (B) to the carboxy groups in component (A) is 1.25 to 7.50. From the viewpoint of even better crack resistance and developability, the equivalent ratio may be 1.50 or more, 1.75 or more, 1.95 or more, 2.00 or more, 2.20 or more, 2.40 or more, 2.50 or more, 3.00 or more, 3.50 or more, or 4.00 or more, and may be 7.40 or less, 7.30 or less, 7.20 or less, 7.10 or less, 7.00 or less, 6.75 or less, 6.50 or less, or 6.00 or less. From the same viewpoint, the equivalent ratio may be 2.00 to 7.50, 2.00 to 7.00, 2.50 to 7.00, or 4.00 to 7.00. When the equivalent ratio is 1.25 or more and 7.50 or less, in addition to crack resistance and developability, the resolution, solder heat resistance, solvent resistance, acid resistance, alkali resistance and electrical insulation also tend to be excellent. That is, the content of component (B) in the photosensitive resin composition is such that the amount of epoxy groups contained in component (B) per equivalent of carboxy groups contained in component (A) is 1.25 to 7.50 equivalents, but may be 1.50 equivalents or more, 1.75 equivalents or more, 1.95 equivalents or more, 2.00 equivalents or more, 2.20 equivalents or more, 2.40 equivalents or more, 2.50 equivalents or more, 3.00 equivalents or more, 3.50 equivalents or more, or 4.00 equivalents or more, or may be 7.40 equivalents or less, 7.30 equivalents or less, 7.20 equivalents or less, 7.10 equivalents or less, 7.00 equivalents or less, 6.75 equivalents or less, 6.50 equivalents or less, or 6.00 equivalents or less.

[0067] The equivalent ratio of epoxy groups to carboxy groups can be calculated using the following formulas: Amount of carboxy groups (mmol) = Number of parts of component (A) × Acid value of component (A) (mg KOH / g) / KOH molecular weight Amount of epoxy groups (mmol) = Number of parts of component (B) / Epoxy equivalent of component (B) (g / eq) × 1000 Equivalent ratio (molar ratio) of epoxy groups to carboxy groups = Amount of epoxy groups (mmol) / Amount of carboxy groups (mmol)

[0068] <Component (C): Photopolymerization Initiator> The photosensitive resin composition according to this embodiment contains a photopolymerization initiator as component (C). The component (C) is not particularly limited as long as it can polymerize the photopolymerizable compound (component (D)). Examples of component (C) include alkylphenone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, compounds having a thioxanthone skeleton, and titanocene-based photopolymerization initiators. Among these, alkylphenone-based photopolymerization initiators, compounds having a thioxanthone skeleton, or acylphosphine oxide-based photopolymerization initiators may be used from the viewpoint of improving solder heat resistance. The component (C) may be used alone or in combination of two or more.

[0069] Examples of alkylphenone photopolymerization initiators include benzophenone, N,N,N',N'-tetraalkyl-4,4'-diaminobenzophenone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 4,4'-bis(dimethylamino)benzophenone (Michler's ketone), 4,4'-bis(diethylamino)benzophenone, and 4-methoxy-4'-dimethylaminobenzophenone.

[0070] Examples of the acylphosphine oxide photopolymerization initiator include (2,6-dimethoxybenzoyl)-2,4,4-pentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl-2,4,6-trimethylbenzoylphenylphosphinate, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, (2,5-dihydroxyphenyl)diphenylphosphine oxide, (p-hydroxyphenyl)diphenylphosphine oxide, bis(p-hydroxyphenyl)phenylphosphine oxide, tris(p-hydroxyphenyl)phosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide.

[0071] Examples of compounds having a thioxanthone skeleton include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[0072] The content of component (C) in the photosensitive resin composition is not particularly limited, and may be 0.2 to 15 mass%, 0.4 to 5 mass%, or 0.6 to 1 mass%, based on the total solid content of the photosensitive resin composition. When the content of component (C) is 0.2 mass% or more, the exposed area is less likely to dissolve during development, and when it is 15 mass% or less, it is easier to suppress a decrease in heat resistance.

[0073] <Component (D): Photopolymerizable Compound> The photosensitive resin composition according to this embodiment contains a photopolymerizable compound as component (D). Component (D) is not particularly limited as long as it is a compound having a functional group exhibiting photopolymerizability. Examples of the functional group exhibiting photopolymerizability include ethylenically unsaturated groups such as a vinyl group, an allyl group, a propargyl group, a butenyl group, an ethynyl group, a phenylethynyl group, a maleimide group, a nadimide group, and a (meth)acryloyl group. From the viewpoint of reactivity, component (D) may contain a compound having a (meth)acryloyl group.

[0074] Examples of the component (D) include hydroxyalkyl (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; mono- or di(meth)acrylate compounds of glycols such as ethylene glycol, methoxytetraethylene glycol, and polyethylene glycol; (meth)acrylamide compounds such as N,N-dimethyl(meth)acrylamide and N-methylol(meth)acrylamide; aminoalkyl (meth)acrylate compounds such as N,N-dimethylaminoethyl (meth)acrylate; hexanediol, trimethylolpropane, pentaerythritol, and ditrimethylolpropane. Examples of the (D) component include polyhydric (meth)acrylate compounds of polyhydric alcohols such as polypropylene glycol, dipentaerythritol, and tris-hydroxyethyl isocyanurate, or polyhydric (meth)acrylate compounds of ethylene oxide or propylene oxide adducts thereof; (meth)acrylate compounds of ethylene oxide or propylene oxide adducts of phenolic compounds such as phenoxyethyl (meth)acrylate and polyethoxydi(meth)acrylate of bisphenol A; (meth)acrylate compounds of glycidyl ethers such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and melamine (meth)acrylate. Component (D) can be used singly or in combination of two or more.

[0075] The content of the component (D) in the photosensitive resin composition may be 0.1 to 10 mass%, 0.5 to 8 mass%, or 2 to 7 mass%, based on the total solid content of the photosensitive resin composition. When the content of the component (D) is 0.1 mass% or more, the exposed area is less likely to dissolve during development, and when it is 10 mass% or less, heat resistance is more likely to be improved.

[0076] <Component (E): Pigment> The photosensitive resin composition according to this embodiment may further contain a pigment as component (E). As component (E), a colorant that develops a desired color when concealing wiring or the like can be used. Examples of component (E) include known colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black. The component (E) can be used alone or in combination of two or more.

[0077] From the viewpoint of further concealing the wiring, the content of the component (E) may be 2 to 30 mass%, 2.5 to 20 mass%, or 2.5 to 10 mass%, based on the total amount of solids in the photosensitive resin composition.

[0078] <Component (F): Inorganic Filler> The photosensitive resin composition according to this embodiment contains an inorganic filler as component (F) for the purpose of improving the adhesion, hardness, and other properties of the permanent resist. Examples of component (F) include silica, alumina, zirconia, talc, aluminum hydroxide, calcium carbonate, barium sulfate, calcium sulfate, zinc oxide, magnesium titanate, and carbon. The component (F) can be used alone or in combination of two or more.

[0079] From the viewpoints of crack resistance, developability, and resolution, component (F) contains a silica filler having a vinyl group derived from a vinylsilane compound (hereinafter, sometimes referred to as a "vinyl group-containing silica filler"). The vinyl group-containing silica filler can be obtained by surface-treating silica particles with a vinylsilane compound. The surface treatment can be carried out, for example, by adding a solution of the vinylsilane compound to the silica particles and stirring them.

[0080] The vinylsilane compound is not particularly limited as long as it is a silane compound having one or more vinyl groups bonded to a silicon atom. In the vinylsilane compound, the number of vinyl groups bonded to a silicon atom may be two or three. The vinylsilane compound may have an alkoxy group, an acetoxy group, an alkyl group, or the like as a group other than the vinyl group bonded to the silicon atom. Examples of the vinylsilane compound include vinylalkoxysilane and acetoxysilane in which the alkoxy group in the vinylalkoxysilane is substituted with an acetoxy group.

[0081] The vinylalkoxysilane is not particularly limited as long as it is a silane compound having a vinyl group bonded to a silicon atom and an alkoxy group bonded to a silicon atom. In a vinylalkoxysilane, the number of alkoxy groups bonded to a silicon atom may be two or three. In a vinylalkoxysilane where the number of alkoxy groups bonded to a silicon atom is two or more, these alkoxy groups may be the same or different. The number of carbon atoms in the alkoxy group bonded to the silicon atom may be 1 to 10, 1 to 6, 1 to 5, 1 to 4, or 1 to 3. The vinylalkoxysilane may have an alkyl group bonded to the silicon atom. When the vinylalkoxysilane has an alkyl group bonded to a silicon atom, the number of carbon atoms in the alkyl group may be 1 to 10, 1 to 6, 1 to 5, 1 to 4, or 1 to 3.

[0082] Examples of vinylalkoxysilane include vinyltrialkoxysilanes having three alkoxy groups bonded to silicon atoms, such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyldimethoxysilane, vinyldiethoxysilane, vinyldiisopropoxysilane, vinyldialkoxysilanes having two alkoxy groups bonded to silicon atoms, and vinylalkoxysilanes having one alkoxy group bonded to silicon atoms, such as vinylmonomethoxysilane, vinylmonoethoxysilane, vinylmonoisopropoxysilane, vinylalkoxysilane.These vinylalkoxysilanes may be used alone or in combination of two or more.

[0083] Vinylacetoxysilanes include, for example, vinyltriacetoxysilane, vinyldiacetoxysilane, and vinylmonoacetoxysilane.

[0084] The component (F) may contain barium sulfate from the viewpoints of solder heat resistance, crack resistance, and pressure cooker resistance (PCT resistance).The component (F) may contain alumina from the viewpoint of improving the aggregation prevention effect.

[0085] The average particle size of component (F) may be 0.1 to 20 μm, 0.1 to 10 μm, 0.1 to 5 μm, or 0.1 to 1 μm. When the average particle size is 20 μm or less, deterioration in the insulating reliability of the permanent resist can be further suppressed.

[0086] The content of component (F) may be 10 to 80% by mass, 15 to 70% by mass, 20 to 60% by mass, 25 to 50% by mass, or 30 to 45% by mass, based on the total solids content of the photosensitive resin composition. When the content of component (F) is within the above range, the resolution of the photosensitive resin composition can be further improved, and the strength, heat resistance, insulation reliability, and crack resistance of the permanent resist can be further improved. From the same viewpoint, the content of component (F) may be 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, and may be 80% by mass or less, 70% by mass or less, 60% by mass or less, 50% by mass or less, or 45% by mass or less.

[0087] The content of the vinyl group-containing silica filler may be 5 to 60 mass%, 15 to 55 mass%, 20 to 50 mass%, or 25 to 45 mass%, based on the total solids content of the photosensitive resin composition. When the content of the vinyl group-containing silica filler is within the above range, the developability and resolution of the photosensitive resin composition and the crack resistance of the permanent resist can be further improved. From the same perspective, the content of the vinyl group-containing silica filler may be 5 mass% or more, 15 mass% or more, 20 mass% or more, or 25 mass% or more, and may be 60 mass% or less, 55 mass% or less, 50 mass% or less, or 45 mass% or less.

[0088] From the viewpoints of developability, resolution, and crack resistance, the content of the vinyl group-containing silica filler in component (F) may be 50% by mass to 100% by mass, 55% by mass to 100% by mass, 60% by mass to 100% by mass, or 65% by mass to 100% by mass, based on the total amount of component (F).

[0089] When barium sulfate is used as component (F), the content of barium sulfate may be 5 to 30 mass%, 5 to 25 mass%, or 5 to 20 mass%, based on the total solid content of the photosensitive resin composition. When the content of barium sulfate is within the above range, solder heat resistance and PCT resistance can be further improved.

[0090] <Component (G): Curing Agent> 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 of component (A) with heat, ultraviolet light, or the like. Use of a curing agent can improve the heat resistance, adhesion, chemical resistance, and the like of the permanent resist.

[0091] Examples of the component (G) include thermosetting compounds such as melamine compounds and oxazoline compounds. Examples of the melamine compound include triaminotriazine, hexamethoxymelamine, and hexabutoxylated melamine. The component (G) can be used alone or in combination of two or more.

[0092] When the component (G) is used, its content may be 2 to 40 mass %, 3 to 30 mass %, or 5 to 20 mass %, based on the total solid content of the photosensitive resin composition. When the content of the component (G) is within the above range, the heat resistance of the formed permanent resist can be further improved while maintaining better developability.

[0093] The photosensitive resin composition according to this embodiment may contain a curing accelerator for accelerating the curing of the component (D) in order to further improve the properties of the permanent resist, such as heat resistance, adhesion, and chemical resistance.

[0094] Examples of the curing accelerator include imidazole derivatives such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; guanamines such as acetoguanamine and benzoguanamine; polyamines such as diaminodiphenylmethane, m-phenylenediamine, m-xylylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, and polybasic hydrazides; organic acid salts or epoxy adducts thereof; amine complexes of boron trifluoride; and triazine derivatives such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, and 2,4-diamino-6-xylyl-S-triazine. The curing accelerator can be used alone or in combination of two or more.

[0095] When a curing accelerator is used, the content thereof may be 0.01 to 20 mass % or 0.1 to 10 mass % based on the total solid content of the photosensitive resin composition, from the viewpoint of improving reliability.

[0096] <Component (H): Elastomer> The photosensitive resin composition according to this embodiment may further contain an elastomer as component (H). Component (H) may be used when the photosensitive resin composition according to this embodiment is used for a semiconductor package substrate. By adding component (H) to the photosensitive resin composition, 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). In other words, it is possible to improve the flexibility and adhesive strength of a permanent resist formed from the photosensitive resin composition.

[0097] Examples of the component (H) include thermoplastic elastomers such as styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic elastomers, and silicone-based elastomers. Thermoplastic elastomers are composed of a hard segment component that contributes to heat resistance and strength, and a soft segment component that contributes to flexibility and toughness. The component (H) can be used alone or in combination of two or more.

[0098] The urethane-based elastomer may be a compound composed of a hard segment formed from a low-molecular-weight (short-chain) diol and a diisocyanate, and a soft segment formed from a high-molecular-weight (long-chain) diol and a diisocyanate. Examples of low-molecular-weight diols include ethylene glycol, propylene glycol, 1,4-butanediol, and bisphenol A. Examples of high-molecular-weight 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).

[0099] The number average molecular weight (Mn) of the low molecular weight diol may be 48 to 500. The Mn of the high molecular weight diol may be 500 to 10,000. As the urethane elastomer, for example, PANDEX T-2185, T-2983N (manufactured by DIC Corporation), and Miractoran E790 (manufactured by Nippon Miractoran Co., Ltd.) are commercially available.

[0100] The polyester elastomer may be a compound obtained by polycondensation of a dicarboxylic acid or a derivative thereof with a diol compound or a derivative thereof. Examples of the dicarboxylic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and aromatic dicarboxylic acids in which the hydrogen atoms of the aromatic nuclei are substituted with methyl groups, ethyl groups, phenyl groups, etc.; aliphatic dicarboxylic acids having 2 to 20 carbon atoms such as adipic acid, sebacic acid, and dodecanedicarboxylic acid; and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid.

[0101] Examples of the diol compound include aliphatic diols or alicyclic diols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, and 1,4-cyclohexanediol, and dihydric phenols represented by the following formula (IV):

[0102]

[0103] In formula (IV), Y represents an alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 4 to 8 carbon atoms, an ether group, a thioether group, a sulfonyl group, or a single bond; R １ and R ２ each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 12 carbon atoms, l and m each independently represents an integer of 0 to 4, and p is 0 or 1. The alkylene group and cycloalkylene group may be linear or branched, and may be substituted with a halogen atom, an alkyl group, an aryl group, an aralkyl group, an amino group, an amido group, an alkoxy group, or the like.

[0104] Examples of the dihydric phenol represented by formula (IV) include bisphenol A, bis-(4-hydroxyphenyl)methane, bis-(4-hydroxy-3-methylphenyl)propane, and resorcinol. These compounds can be used alone or in combination of two or more.

[0105] As the polyester-based elastomer, a multiblock copolymer can be used in which an aromatic polyester (e.g., polybutylene terephthalate) portion serves as the hard segment component and an aliphatic polyester (e.g., polytetramethylene glycol) portion serves as the soft segment component. There are various grades of polyester-based elastomers, depending on the type, ratio, and molecular weight of the hard and soft segments. Commercially available polyester-based elastomers include, for example, Hytrel (manufactured by DuPont-Toray Industries, Inc., "Hytrel" is a registered trademark), Pelprene (manufactured by Toyobo Co., Ltd., "Pelprene" is a registered trademark), and Espel (manufactured by Showa Denko Materials K.K., "Espel" is a registered trademark).

[0106] The acrylic elastomer may be a compound containing a structural unit based on an acrylic ester as a main component. Examples of acrylic esters include ethyl acrylate, butyl acrylate, methoxyethyl acrylate, and ethoxyethyl acrylate. The acrylic elastomer may be a compound obtained by copolymerizing an acrylic 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. Examples of acrylic elastomers include acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, and acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer.

[0107] As an elastomer other than the thermoplastic elastomer, a rubber-modified epoxy resin may be used. The rubber-modified epoxy resin can be obtained, for example, by modifying some or all of the epoxy groups of the above-mentioned bisphenol F epoxy resin, bisphenol A epoxy resin, salicylaldehyde epoxy resin, phenol novolac epoxy resin, or cresol novolac epoxy resin with a butadiene-acrylonitrile rubber modified at both ends with carboxylic acid, an amino-modified silicone rubber, or the like. Among these elastomers, from the viewpoint of shear adhesion, a butadiene-acrylonitrile copolymer modified at both ends with carboxy groups, or Espel (manufactured by Showa Denko Materials Co., Ltd., Espel 1612, 1620), a polyester-based elastomer having hydroxyl groups, may be used.

[0108] The content of component (H) may be 2 to 40 parts by mass, 4 to 30 parts by mass, 10 to 25 parts by mass, or 15 to 22 parts by mass, relative to 100 parts by mass of component (A). By ensuring that the content of component (H) is within the above range, the unexposed areas of the photosensitive layer tend to be more easily eluted in a developer, and the elastic modulus of the permanent resist at high temperatures tends to be lower.

[0109] <Other Components> The photosensitive resin composition according to this embodiment may be mixed with a diluent such as an organic solvent to adjust the viscosity, as necessary. Examples of the organic solvent 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.

[0110] When a diluent is used, the content of the diluent in the photosensitive resin composition may be 10 to 50 mass %, 20 to 40 mass %, or 25 to 35 mass %. By setting the content of the diluent within the above range, the coatability of the photosensitive resin composition is improved, and it becomes possible to form a more precise pattern.

[0111] The photosensitive resin composition according to this embodiment may further contain various additives as needed. Examples of the additives include 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 of phosphorus compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters.

[0112] The photosensitive resin composition according to this embodiment can be prepared by uniformly mixing the above-mentioned components using a roll mill, a bead mill, or the like.

[0113] [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.

[0114] The photosensitive element 1 can be produced, for example, 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 the photosensitive layer 20.

[0115] 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, 10 to 50 μm, 15 to 40 μm, or 20 to 30 μm.

[0116] 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.

[0117] 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. The protective film may be the same film as the support film or a different film.

[0118] [Printed Wiring Board] The printed wiring board according to this embodiment includes a permanent resist containing a cured product of the photosensitive resin composition according to this embodiment. Because the printed wiring board according to this embodiment includes a permanent resist containing a cured product of the photosensitive resin composition according to this embodiment, the occurrence of cracks in the permanent resist can be reduced.

[0119] 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 the above-described 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.

[0120] First, a metal-clad laminate such as a copper-clad laminate is prepared as a substrate, and a photosensitive layer is formed on the substrate. When a photosensitive resin composition is used, the photosensitive resin composition may be applied to the substrate by a method such as screen printing, spraying, roll coating, curtain coating, or electrostatic coating, and the resulting coating film may be dried at 60 to 110°C to form the photosensitive layer. The thickness of the coating film may be 10 to 200 μm, 15 to 150 μm, 20 to 100 μm, or 23 to 50 μm. When a photosensitive element is used, the photosensitive layer may be formed by thermally laminating the photosensitive layer of the photosensitive element onto the substrate using a laminator.

[0121] Next, a negative mask is brought into contact with the photosensitive layer directly or through a transparent film such as a support film, and the layer is exposed to actinic rays. The unexposed areas are then dissolved and removed with a developer to form a resist pattern. 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 The developing method may be, for example, a dipping method or a spraying method. As the developer, for example, an aqueous alkali solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, or tetramethylammonium hydroxide may be used.

[0122] Next, the formed resist pattern is subjected to at least one of post-exposure and post-heating treatment to sufficiently harden it, thereby forming a permanent resist. The exposure dose of the post-exposure is 100 to 5000 mJ / cm ２ , 500-2000mJ / cm ２ or 700 to 1500 mJ / cm ２The 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. The thickness of the permanent resist may be 10 to 50 μm, 15 to 40 μm, or 20 to 30 μm. Thereafter, wiring is formed by etching, and a printed wiring board is produced.

[0123] 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.

[0124] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0125] Synthesis Example 1 A flask equipped with a stirrer, a reflux condenser, and a thermometer was charged with bisphenol F novolac epoxy resin (trade name: EXA-7376, manufactured by DIC Corporation; in formula (I), Y １ and Y ２ is a glycidyl group, R １１350 parts by weight of bisphenol F novolac epoxy resin (having a structure in which ≡1≡1 is a hydrogen atom; epoxy equivalent: 186 g / eq), 70 parts by weight of acrylic acid, 0.5 parts by weight of methylhydroquinone, and 120 parts by weight of carbitol acetate were charged and stirred at 90°C to completely dissolve the mixture. The resulting solution was then cooled to 60°C, 2 parts by weight of triphenylphosphine was added, and the mixture was heated to 100°C and allowed to react until the acid value of the solution reached 1 mgKOH / g or less. To the reacted solution, 98 parts by weight of tetrahydrophthalic anhydride (THPAC) and 85 parts by weight of carbitol acetate were added and allowed to react at 80°C for 6 hours. The mixture was then cooled to room temperature to obtain a solution of THPAC-modified bisphenol F novolac epoxy acrylate, component (A) (solid acid value: 50.0 mgKOH / g; solid concentration: 73% by weight).

[0126] [Photosensitive Resin Composition] The components were blended according to the blending amounts shown in Tables 1 and 2 and kneaded using a three-roll mill. Carbitol acetate was then added so that the solids concentration was 70% by mass to obtain a photosensitive resin composition. Tables 1 and 2 show the parts by mass of the solids of components (A) to (F) based on the total solids content of the photosensitive resin composition.

[0127] Details of each component in Tables 1 and 2 are as follows: A-1: ​​Acid-modified vinyl group-containing resin obtained in Synthesis Example 1 A-2: In formula (III′), R １３ is a hydrogen atom, Y ５is a glycidyl group), and the hydroxyl groups are modified with tetrahydrophthalic anhydride. B-1: Bisphenol A epoxy resin (trade name: YD-8125; manufactured by Nippon Steel Chemical & Material Co., Ltd.; epoxy equivalent: 173 g / eq). B-2: Novolac multifunctional epoxy resin (trade name: RE-306; manufactured by Nippon Kayaku Co., Ltd.; epoxy equivalent: 270 g / eq). B-3: Bisphenol A novolac epoxy resin (trade name: jER157S70; manufactured by Mitsubishi Chemical Corporation; epoxy equivalent: 210 g / eq). B-4: Bisphenol F type epoxy resin (trade name: EXA-9580; manufactured by DIC Corporation; epoxy equivalent: 360 g / eq) B-5: Tetrafunctional epoxy resin (trade name: jER1031S; manufactured by Mitsubishi Chemical Corporation; epoxy equivalent: 200 g / eq) C-1: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone (trade name: Irgacure 907; manufactured by BASF) C-2: 2,4-diethylthioxanthone (trade name: DETX-S; manufactured by Nippon Kayaku Co., Ltd.) D-1: Dipentaerythritol hexaacrylate (trade name: DPHA; manufactured by Nippon Kayaku Co., Ltd.) E-1: Phthalocyanine pigment (trade name: C.I. Pigment Blue 15; manufactured by Sanyo Dye Co., Ltd.) F-1: Barium sulfate particles (trade name: B34; manufactured by Sakai Chemical Industry Co., Ltd.; average particle size: 0.3 μm) F-2: Silica filler having a vinyl group derived from a vinylsilane compound, obtained by adding 1 g of 1 mass % vinyltrimethoxysilane (trade name: KBM-1003; manufactured by Shin-Etsu Silicones Co., Ltd.) to 100 g of untreated silica particles (trade name: SO-C2; manufactured by Admattex Co., Ltd.; average particle size: 0.5 μm) and stirring at 80°C for 30 minutes F-3: Silica filler having an epoxy group, obtained in the same manner as F-2, except that vinyltrimethoxysilane was changed to 3-glycidoxypropyltrimethoxysilane (trade name: KBM-403; manufactured by Shin-Etsu Silicones Co., Ltd.) F-4: Silica filler having an epoxy group obtained in the same manner as F-2, except that vinyltrimethoxysilane was changed to 3-methacryloxypropylmethyldimethoxysilane (trade name: KBM-502;F-5: A silica filler having a phenylamino group, obtained in the same manner as F-2, except that vinyltrimethoxysilane was changed to N-phenyl-3-aminopropyltrimethoxysilane (trade name: KBM-573; manufactured by Shin-Etsu Silicones Co., Ltd.); F-6: Untreated silica particles (trade name: SO-C2; manufactured by Admattex Co., Ltd., average particle size: 0.5 μm);

[0128] The equivalent ratios shown in Tables 1 and 2, i.e., the equivalent ratio of epoxy groups in component (B) to carboxy groups in component (A), were calculated by calculating the amount of carboxy groups in component (A) and the amount of epoxy in component (B) as follows: Amount of carboxy groups (mmol) = parts by mass (g) of component (A) × acid value of component (A) (mg KOH / g) / molecular weight of KOH Amount of epoxy groups (mmol) = parts by mass (g) of component (B) / epoxy equivalent of component (B) (g / eq) × 1000

[0129] In Example 1, the parts by mass (solid content) of component (A) was 26.9 (g), the acid value (solid content) of component (A) was 50 (mg KOH / g), and the molecular weight of KOH was 56.11. Therefore, the amount of carboxy groups in component (A) was 26.9 × 50 / 56.11 = 23.97 (mmol). The parts by mass (solid content) of component (B) was 6.2 g, and the epoxy equivalent of component (B) was 173 g / eq. Therefore, the amount of epoxy groups in component (B) was 6.2 / 173 × 1000 = 35.84 (mmol). Therefore, in Example 1, the equivalent ratio of epoxy groups in component (B) to carboxy groups in component (A) was 1.50.

[0130] The photosensitive resin composition was used to carry out various evaluations under the conditions shown below. The results are shown in Tables 1 and 2.

[0131] (Preparation of Test Piece 1) The photosensitive resin compositions of the Examples and Comparative Examples were applied by screen printing to a 0.6 mm thick copper-clad laminate substrate (a copper-clad laminate substrate having copper foil disposed on a glass epoxy material, manufactured by Showa Denko Materials Co., Ltd., product name: MCL-E-67) so that the thickness after drying would be 35 μm, and then dried at 80° C. for 20 minutes using a hot air circulation dryer to form a photosensitive layer. Next, a negative mask having a predetermined pattern was brought into close contact with the obtained photosensitive layer, and the photosensitive layer was exposed to 600 mJ / cm using an ultraviolet exposure device. ２ Thereafter, the film was exposed to a 1% by mass aqueous solution of sodium carbonate for 60 seconds at an exposure dose of 1.765 × 10 ５ The unexposed area was then developed by spraying at a pressure of 1000 mJ / cm using an ultraviolet exposure device. ２ and heated at 150° C. for 1 hour to prepare a test piece 1 having a permanent resist.

[0132] (Crack Resistance) Test piece 1 was subjected to a temperature cycle test consisting of 30 minutes at -65°C and 30 minutes at 150°C, and the permanent resist was observed visually and with an optical microscope at the time points of 1000 cycles, 2000 cycles, and 3000 cycles, and the crack resistance was evaluated according to the following criteria. S: No cracks were observed at 3000 cycles. A: No cracks were observed at 2000 cycles, but cracks were observed at 3000 cycles. B: No cracks were observed at 1000 cycles, but cracks were observed at 2000 cycles. C: Cracks were observed at 1000 cycles.

[0133] (Developability) The photosensitive resin compositions of the Examples and Comparative Examples were applied to a copper-clad laminate substrate (manufactured by Showa Denko Materials Co., Ltd., product name: MCL-E-67) by screen printing so as to have a thickness of 15 μm after drying, and then dried at 75° C. for 30 minutes using a hot air circulation dryer to form a photosensitive layer. Next, the resulting photosensitive layer was exposed to an integrated exposure dose of 100 mJ / cm through a negative mask having a 1×1 cm square area dotted with light-non-transmitting portions of 80 μm in diameter. ２ Then, the film was irradiated with ultraviolet light of 1.8 kgf / cm for 60 seconds using a 1% by mass aqueous solution of sodium carbonate. ２The resist was spray-developed at a pressure of 10,000, and the unexposed areas were dissolved and developed to prepare test piece 2. Thereafter, the opening of test piece 2 was observed at 10,000 magnification using an SEM (High Technologies Corporation, Model No. S4200, field emission scanning electron microscope), and the developability was evaluated based on the amount of remaining resist residue according to the following criteria: S: There were 0 residues in one visual field. A: There were 1 or more but less than 5 residues in one visual field. B: There were 5 or more but less than 10 residues in one visual field. C: There were 10 or more residues in one visual field.

[0134] (Resolution) Test piece 3 having a cured film on which an opening pattern of a predetermined size was formed was prepared in the same manner as Test piece 1 above, except that a negative mask having an opening pattern of a predetermined size (opening diameter size: 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 150, 200 μm) was used as the negative mask. Test piece 3 was observed using an optical microscope, and the resolution was evaluated according to the following criteria. A: The minimum opening mask diameter was 35 μm or less. B: The minimum opening mask diameter was more than 35 μm and less than 55 μm. C: The minimum opening mask diameter was more than 55 μm.

[0135] (Soldering heat resistance) Test piece 1 was coated with water-soluble flux and immersed in a solder bath at 265°C for 10 seconds. This constituted one cycle, and after six cycles were repeated, the appearance of the permanent resist was visually observed and the soldering heat resistance was evaluated according to the following criteria: A: No change in appearance occurred within a 30 cm x 30 cm area of ​​the permanent resist. B: One to five lifts or blisters occurred in the coating film within a 30 cm x 30 cm area of ​​the permanent resist. C: Six or more lifts or blisters occurred in the coating film within a 30 cm x 30 cm area of ​​the permanent resist.

[0136] (Solvent Resistance) Test piece 1 was immersed in isopropyl alcohol at room temperature for 30 minutes, and after checking whether there were any abnormalities in the appearance of the permanent resist, a peeling test was performed using cellophane tape. Solvent resistance was evaluated according to the following criteria: A: There was no abnormality in the appearance of the permanent resist and no peeling occurred. B: There was only a slight change in the appearance of the permanent resist. C: There was an abnormality in the appearance of the permanent resist or peeling occurred.

[0137] (Acid Resistance) Test piece 1 was immersed in a 10% by mass aqueous solution of hydrochloric acid at room temperature for 30 minutes, and after checking whether there were any abnormalities in the appearance of the permanent resist, a peeling test was performed using cellophane tape. Acid resistance was evaluated according to the following criteria: A: There was no abnormality in the appearance of the permanent resist and no peeling occurred. B: There was only a slight change in the appearance of the permanent resist. C: There was an abnormality in the appearance of the permanent resist or peeling occurred.

[0138] (Alkali Resistance) Test piece 1 was immersed in a 5% by mass aqueous solution of sodium hydroxide at room temperature for 30 minutes, and after checking whether there were any abnormalities in the appearance of the permanent resist, a peeling test was performed using cellophane tape. The alkali resistance was evaluated according to the following criteria: A: There was no abnormality in the appearance of the permanent resist and no peeling occurred. B: There was only a slight change in the appearance of the permanent resist. C: There was an abnormality in the appearance of the permanent resist or peeling occurred.

[0139] (Electrical Insulation) Test piece 4 was prepared in the same manner as test piece 1, except that a bismaleimide triazine substrate on which interdigital electrodes (line / space = 10 μm / 10 μm) were formed was used instead of the copper-clad laminate substrate. Test piece 4 was then exposed to conditions of 135°C, 85%, and 5 V. Thereafter, the extent of migration in the permanent resist was observed using a metallurgical microscope at 100x magnification, and the electrical insulation was evaluated according to the following criteria. A: No migration occurred in the permanent resist even after 200 hours, and the resistance value was 10 －６ B: For 100 hours or more and less than 200 hours, the resistance value did not decrease to 10 Ω or less without migration occurring in the permanent resist. －６ C: Migration occurred in the permanent resist within 100 hours, and the resistance value did not decrease below 10 Ω. －６ It dropped below Ω.

[0140]

[0141]

[0142] From Tables 1 and 2, it was confirmed that the photosensitive resin compositions of the examples were capable of forming permanent resists with excellent crack resistance and also had excellent developability.

[0143] [Photosensitive element] Each photosensitive resin composition was diluted with methyl ethyl ketone, coated on a polyethylene terephthalate (PET) film, and dried for 10 minutes at 90° C. to form a photosensitive layer with a thickness of 25 μm. A PET film was laminated on the photosensitive layer as a protective film to prepare a photosensitive element.

[0144] The photosensitive layer of the photosensitive element was used to evaluate crack resistance, developability, resolution, soldering heat resistance, solvent resistance, acid resistance, alkali resistance, and electrical insulation, and the results obtained were similar to those obtained when the photosensitive resin compositions shown in Tables 1 and 2 were used. Test specimens using the photosensitive layer were prepared in the same manner as Test Specimens 1 to 4 above, except that the protective film was peeled off from the photosensitive element, the photosensitive layer of the photosensitive element was thermally laminated onto a substrate, and then the support film was peeled off to form the photosensitive layer on the substrate.

[0145] 1...photosensitive element, 10...support film, 20...photosensitive layer, 30...protective film

Claims

1. (A) an acid-modified vinyl group-containing resin, (B) an epoxy compound, (C) a photopolymerization initiator, (D) a photopolymerizable compound, and (F) an inorganic filler, an equivalent ratio of an epoxy group contained in the epoxy compound (B) to a carboxy group contained in the acid-modified vinyl group-containing resin (A) is 1.25 to 7.50; (F) A photosensitive resin composition for a permanent resist, wherein the inorganic filler comprises a silica filler having a vinyl group derived from a vinylsilane compound.

2. 2. The photosensitive resin composition according to claim 1, wherein the equivalent ratio is from 2.00 to 7.

50.

3. 2. The photosensitive resin composition according to claim 1, wherein the equivalent ratio is from 2.50 to 7.

50.

4. A photosensitive resin composition as described in claim 1, wherein the content of silica filler having a vinyl group derived from the vinyl silane compound is 20 mass% or more based on the total solid content of the photosensitive resin composition.

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

6. 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 5.

7. 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 5.

8. 8. The printed wiring board according to claim 7, wherein the permanent resist has a thickness of 10 to 50 μm.

9. forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of claims 1 to 5; 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 the steps of:

10. forming a photosensitive layer on a substrate using the photosensitive element according to claim 6; 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 the steps of: