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

Abstract

A photosensitive resin composition according to the present disclosure contains an acid-modified vinyl group-containing resin, a photopolymerizable compound, a photopolymerization initiator, and a thermosetting resin. The photopolymerization initiator includes a photopolymerization initiator having a fluorene skeleton. The thermosetting resin includes at least one selected from the group consisting of bisphenol F epoxy resins and novolac epoxy resins.

Description

Photosensitive resin composition, photosensitive element, printed wiring board, and method for producing 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] Permanent resists are prepared, for example, by screen printing using a thermosetting resin composition or by a photographic method using a photosensitive resin composition. 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 substrate. 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. Due to 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 1).

[0004] Japanese Patent Application Publication No. 11-240930

[0005] In response to the increasing density of printed wiring boards, even higher performance is being demanded of permanent resists. In particular, the demand for forming fine patterns is increasing year by year. Permanent resists formed from conventional photosensitive resin compositions do not have sufficient resolution when forming fine patterns, and may cause footing at openings, resulting in closure.

[0006] An object of the present disclosure is to provide a photosensitive resin composition capable of forming a permanent resist with excellent resolution, a photosensitive element and a printed wiring board using the photosensitive resin composition, and a method for producing a printed wiring board.

[0007] One aspect of the present disclosure relates to the following photosensitive resin composition, photosensitive element, printed wiring board, and method for producing a printed wiring board. [1] A photosensitive resin composition for permanent resist, comprising an acid-modified vinyl group-containing resin, a photopolymerizable compound, a photopolymerization initiator, and a thermosetting resin, wherein the photopolymerization initiator comprises a photopolymerization initiator having a fluorene skeleton, and the thermosetting resin comprises at least one selected from the group consisting of bisphenol F epoxy resins and novolac epoxy resins. [2] The photosensitive resin composition according to [1] above, wherein the photopolymerization initiator having a fluorene skeleton comprises an α-aminoketone compound having a fluorene skeleton. [3] The photosensitive resin composition according to [1] or [2] above, wherein the thermosetting resin comprises a bisphenol F epoxy resin and a novolac epoxy resin. [4] The photosensitive resin composition according to any one of [1] to [3] above, wherein the novolac epoxy resin comprises a phenol novolac epoxy resin. [5] The photosensitive resin composition according to any one of [1] to [4] above, wherein the photopolymerization initiator further comprises a thioxanthone-based photopolymerization initiator. [6] A photosensitive element comprising a support film and a photosensitive layer formed on the support film, wherein the photosensitive layer comprises the photosensitive resin composition according to any one of [1] to [5] above. [7] A printed wiring board comprising a permanent resist containing a cured product of the photosensitive resin composition according to any one of [1] to [5] above. [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 according to any one of [1] to [5] 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 according to [6] above; exposing and developing the photosensitive layer to form a resist pattern; and curing the resist pattern to form a permanent resist.

[0008] According to the present disclosure, it is possible to provide a photosensitive resin composition capable of forming a permanent resist with excellent resolution, a photosensitive element using the photosensitive resin composition, a printed wiring board, and a method for producing a printed wiring board.

[0009] FIG. 1 is a cross-sectional view that schematically illustrates a photosensitive element according to this embodiment.

[0010] 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.

[0011] 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 thereof. In this disclosure, 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 purpose of the process is achieved.

[0012] In the present 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 the present 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 the present disclosure, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. In the present 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 multiple substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the multiple 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) a photopolymerizable compound, (C) a photopolymerization initiator, and (D) a thermosetting resin, wherein the (C) photopolymerization initiator contains a photopolymerization initiator having a fluorene skeleton, and the (D) thermosetting resin contains at least one selected from the group consisting of bisphenol F epoxy resins and novolac epoxy resins. The photosensitive resin composition according to this embodiment is a negative-type photosensitive resin composition. By using such a specific photopolymerization initiator and a specific thermosetting resin in combination, the photosensitive resin composition according to this embodiment can form a permanent resist with excellent resolution. Below, each component contained in the photosensitive resin composition according to this embodiment will be described in detail.

[0015] <Component (A): Acid-Modified Vinyl Group-Containing Resin> The photosensitive resin composition according to this embodiment includes 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.

[0016] 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, from the viewpoint of reactivity and resolution, the group having an ethylenically unsaturated bond may be a (meth)acryloyl group. Examples of the acidic group contained in component (A) include a carboxy group, a sulfo group, and a phenolic hydroxyl group. Among these, from the viewpoint of resolution, the acidic group may be a carboxy group.

[0017] The component (A) may be an acid-modified vinyl group-containing epoxy derivative obtained by reacting a resin (A') (hereinafter referred to as "component (A')") obtained by reacting (a) an epoxy resin (hereinafter referred to as "component (a)") with (b) an ethylenically unsaturated group-containing organic acid (hereinafter referred to as "component (b)"), with (c) a saturated group- or unsaturated group-containing polybasic acid anhydride (hereinafter referred to as "component (c)").

[0018] 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.

[0019] Examples of component (A) include an acid-modified vinyl group-containing resin (A1) (hereinafter referred to as "component (A1)") obtained by using a bisphenol novolac epoxy resin (a1) (hereinafter referred to as "epoxy resin (a1)") as component (a), and an acid-modified vinyl group-containing resin (A2) (hereinafter referred to as "component (A2)") obtained by using an epoxy resin (a2) (hereinafter referred to as "epoxy resin (a2)") other than epoxy resin (a1) as component (a). These can be used alone or in combination of two or more.

[0020] (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).

[0021]

[0022] 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 R is a glycidyl group. From the viewpoint of suppressing the occurrence of undercut and improving the linearity and resolution of the resist pattern contour, １１ may be a hydrogen atom, and from the viewpoint of further improving thermal shock resistance, Y １ and Y ２may be a glycidyl group.

[0023] 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, the linearity of the resist pattern contour, adhesion to the copper substrate, heat resistance, and electrical insulation 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 to the number of structural units in structural units.

[0024]

[0025] 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 R is a glycidyl group. From the viewpoint of suppressing the occurrence of undercut and improving the linearity and resolution of the resist pattern contour, １２ may be a hydrogen atom, and from the viewpoint of further improving thermal shock resistance, Y ３ and Y ４ may be a glycidyl group.

[0026] 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, it becomes easier to improve the linearity of the resist pattern contour, adhesion to a copper substrate, and heat resistance.

[0027] 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 ４Epoxy resins in which .alpha. is a glycidyl group are commercially available as EPON SU8 series (trade name, manufactured by Westlake).

[0028] (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), but from the viewpoints of suppressing the occurrence of undercut and improving the linearity of the resist pattern contour, adhesion to the copper substrate, and resolution, it may be at least one type 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.

[0029] Examples of novolac-type epoxy resins include epoxy resins having a structural unit represented by the following formula (III): Bisphenol A-type epoxy resins or bisphenol F-type epoxy resins include epoxy resins having a structural unit represented by the following formula (IV): Triphenolmethane-type epoxy resins include epoxy resins having a structural unit represented by the following formula (V): Biphenyl-type epoxy resins include epoxy resins having a structural unit represented by the following formula (VI):

[0030] As the epoxy resin (a2), a novolac epoxy resin having a structural unit represented by the following formula (III) may be used. An example of a novolac epoxy resin having such a structural unit is a novolac epoxy resin represented by the following formula (III').

[0031]

[0032] In formulas (III) and (III′), R １３ represents a hydrogen atom or a methyl group, and Y ５ represents a hydrogen atom or a glycidyl group, and Y ５ At least one of n is a glycidyl group. １ is a number equal to or greater than 1, and a plurality of R １３ and Y ５and may be the same or different. From the viewpoint of suppressing the occurrence of undercut and improving the linearity and resolution of the resist pattern contour, R １３ may be a hydrogen atom.

[0033] In formula (III′), Y is a hydrogen atom. ５ and Y, a glycidyl group ５ From the viewpoint of suppressing the occurrence of undercut and improving the linearity and resolution of the resist pattern contour, the molar ratio of n to n may be 0 / 100 to 30 / 70 or 0 / 100 to 10 / 90. １ is 1 or more, but may be 10 to 200, 30 to 150, or 30 to 100. １ When the amount of the resist film falls within the above range, the linearity of the resist pattern contour, adhesion to the copper substrate, and heat resistance are likely to be improved.

[0034] Examples of the novolac epoxy resin represented by formula (III') include phenol novolac epoxy resin and cresol novolac epoxy resin. These novolac epoxy resins can be obtained, for example, by reacting a phenol novolac resin or a cresol novolac resin with epichlorohydrin using a known method.

[0035] Examples of commercially available phenol novolac epoxy resins or cresol novolac epoxy resins represented by formula (III') include YDCN-700-7, YDCN-700-10, YDCN-704, YDCN-704A, and YDPN-638 (all of which are trade names manufactured by Nippon Steel Chemical & Material Co., Ltd.), EOCN-102S, EOCN-103S, EOCN-104S, and BREN-S (all of which are trade names manufactured by Nippon Kayaku Co., Ltd.), and N-740, N-770, N-665, and N-673 (all of which are trade names manufactured by DIC Corporation).

[0036] 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 (IV): Epoxy resins having such a structural unit include bisphenol A type epoxy resins or bisphenol F type epoxy resins represented by the following formula (IV'):

[0037]

[0038] In formulas (IV) and (IV′), R １４ represents a hydrogen atom or a methyl group, and there are multiple R １４ may be the same or different, and Y ６ represents a hydrogen atom or a glycidyl group, and Y ６ At least one of n is a glycidyl group. ２ represents a number of 1 or more, and n ２ If there are two or more Y ６ may be the same or different.

[0039] From the viewpoint of suppressing the occurrence of undercut and improving the linearity and resolution of the resist pattern contour, R １４ may be a hydrogen atom, and from the viewpoint of further improving thermal shock resistance, Y ６ 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 resist film falls within the above range, the linearity of the resist pattern contour, adhesion to the copper substrate, and heat resistance are likely to be improved.

[0040] Y in formula (IV) ６ The bisphenol A type epoxy resin or bisphenol F type epoxy resin in which Y is a glycidyl group can be, for example, ６ is a hydrogen atom, ６ ) with epichlorohydrin.

[0041] 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.

[0042] Commercially available examples of the bisphenol A type epoxy resin or bisphenol F type epoxy resin represented by formula (IV') include jER807, jER825, jER827, jER828, jER834, jER1004F, jER1007FS, and jER1009F (all of which are product names manufactured by Mitsubishi Chemical Corporation), and YD-8125, YDF-170, YDF-2001, YDF-2004, and YDF-8170C (all of which are product names manufactured by Nippon Steel Chemical & Material Co., Ltd.).

[0043] Examples of the epoxy resin (a2) include triphenolmethane-type epoxy resins having a structural unit represented by the following formula (V): Examples of the triphenolmethane-type epoxy resins having such a structural unit include triphenolmethane-type epoxy resins represented by the following formula (V'):

[0044]

[0045] In formulas (V) and (V′), Y ７ represents a hydrogen atom or a glycidyl group, and a plurality of Y ７ may be the same or different, and at least one Y ７ is a glycidyl group. ３ indicates a number of 1 or more.

[0046] From the viewpoint of suppressing the occurrence of undercut and upper portion loss and improving the linearity and resolution of the resist pattern contour, Y ７ Y is a hydrogen atom in ７ and Y, a glycidyl group ７ The molar ratio of Y to Y may be 0 / 100 to 30 / 70. ７ At least one of the groups is a glycidyl group. ３is 1 or more, but may be 10 to 100, 15 to 80, or 15 to 70. ３ When the amount of the resist film falls within the above range, the linearity of the resist pattern contour, adhesion to the copper substrate, and heat resistance are likely to be improved.

[0047] As the triphenolmethane type epoxy resin represented by formula (V'), for example, FAE-2500, EPPN-501H, EPPN-502H (all of which are trade names manufactured by Nippon Kayaku Co., Ltd.) and the like are commercially available.

[0048] Examples of the epoxy resin (a2) include biphenyl-type epoxy resins having a structural unit represented by the following formula (VI): Examples of the biphenyl-type epoxy resins having such a structural unit include biphenyl-type epoxy resins represented by the following formula (VI'):

[0049]

[0050] In formulas (VI) and (VI′), Y ８ represents a hydrogen atom or a glycidyl group, and a plurality of Y ８ may be the same or different, and at least one Y ８ is a glycidyl group. ４ indicates a number of 1 or more.

[0051] As the biphenyl type epoxy resin represented by formula (VI'), for example, NC-3000, NC-3000-L, NC-3000-H, NC-3000-FH-75M (all of which are trade names manufactured by Nippon Kayaku Co., Ltd.) and the like are commercially available.

[0052] The epoxy resin (a2) may contain at least one selected from the group consisting of novolac epoxy resins having a structural unit represented by formula (III), bisphenol A epoxy resins having a structural unit represented by formula (IV), and bisphenol F epoxy resins having a structural unit represented by formula (IV), or may contain a bisphenol F epoxy resin having a structural unit represented by formula (IV).

[0053] From the viewpoints of thermal shock resistance, warpage reduction, and resolution, a combination of a component (A1) using a bisphenol novolac epoxy resin having a structural unit represented by the above formula (I) as the component (a1) and a component (A2) using a bisphenol A epoxy resin or bisphenol F epoxy resin having a structural unit represented by the formula (IV) as the component (a2) may be used.

[0054] (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 (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. The component (b) can be used alone or in combination of two or more.

[0055] The half-ester compound can be obtained, for example, by reacting a hydroxyl group-containing (meth)acrylate, a vinyl group-containing monoglycidyl ether, or a vinyl group-containing monoglycidyl ester with a dibasic acid anhydride.

[0056] Examples of hydroxyl group-containing (meth)acrylates, vinyl group-containing monoglycidyl ethers, and vinyl group-containing monoglycidyl esters include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and glycidyl (meth)acrylate.

[0057] 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.

[0058] In the reaction between component (a) and component (b), the reaction may be carried out in a ratio such that 0.6 to 1.05 equivalents of component (b) are used per equivalent of the epoxy groups in component (a), or in a ratio such that 0.8 to 1.0 equivalents of component (b) are used per equivalent of the epoxy groups in component (a). By carrying out the reaction in such a ratio, photosensitivity increases and the linearity of the resist pattern contour tends to be excellent.

[0059] A polymerization inhibitor may be used in the reaction between component (a) and component (b) 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 improving stability, the amount of 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).

[0060] Component (A'), obtained by reacting components (a) and (b), has hydroxyl groups formed by a ring-opening addition reaction between the epoxy groups of component (a) and the carboxyl groups of component (b). By further reacting component (A') with component (c), an acid-modified vinyl group-containing epoxy resin is obtained in which the hydroxyl groups of component (A') (including the hydroxyl groups originally present in component (a)) and the acid anhydride groups of component (c) are half-esterified.

[0061] (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, from the viewpoint of resolution, the component (c) may be tetrahydrophthalic anhydride. The component (c) may be used alone or in combination of two or more.

[0062] 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.

[0063] In the reaction between component (A') and component (c), for example, the acid value of the acid-modified vinyl group-containing resin can be adjusted by reacting 0.1 to 1.0 equivalents of component (c) with 1 equivalent of hydroxyl groups in component (A').

[0064] The acid value of component (A) may be 30 to 150 mgKOH / g, 40 to 120 mgKOH / g, or 50 to 100 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. When the acid value of component (A) is 150 mgKOH / g or less, the electrical properties of the permanent resist are easily improved.

[0065] The weight average molecular weight (Mw) of the component (A) is not particularly limited, but may be 3,000 to 30,000, 4,000 to 25,000, or 5,000 to 18,000 from the viewpoints of resolution, adhesion, heat resistance, and insulation reliability.

[0066] Mw can be measured by gel permeation chromatography (GPC). Mw can be measured, for example, under the following GPC conditions, and the value converted using a calibration curve of standard polystyrene can be used as Mw. The calibration curve can be created using a five-sample set ("PStQuick MP-H" and "PStQuick B", manufactured by Tosoh Corporation) as standard polystyrene. GPC apparatus: High-speed GPC apparatus "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

[0067] From the viewpoint of the heat resistance, electrical properties, and chemical resistance of the permanent resist, the content of the component (A) 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 60% by mass or less, 50% by mass or less, 45% by mass or less, or 40% by mass or less, based on the total solid content of the photosensitive resin composition.

[0068] <Component (B): Photopolymerizable Compound> The photosensitive resin composition according to this embodiment includes a photopolymerizable compound (excluding the above-described component (A)) as component (B). Component (B) 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 groups having an ethylenically unsaturated bond, 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.

[0069] Examples of the component (B) include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; mono- or di(meth)acrylates 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)acrylates such as N,N-dimethylaminoethyl (meth)acrylate; hexanediol, trimethylolpropane, pentaerythritol, and ditrimethylolpropane. , dipentaerythritol, tris-hydroxyethyl isocyanurate, and other polyhydric alcohols, or polyhydric (meth)acrylates of these ethylene oxide or propylene oxide adducts; (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)acrylates of glycidyl ethers, such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and melamine (meth)acrylate. Component (B) can be used singly or in combination of two or more.

[0070] From the viewpoint of insulation reliability, the (B) component may contain a (meth)acrylic compound having a (meth)acryloyl group. The (meth)acrylic compound may be a monofunctional (meth)acrylic compound or a polyfunctional (meth)acrylic compound. A "monofunctional (meth)acrylic compound" refers to a compound in which the total number of acryloyl groups and methacryloyl groups in one molecule is 1, and a "polyfunctional (meth)acrylic compound" refers to a compound in which the total number of acryloyl groups and methacryloyl groups in one molecule is 2 or more. From the viewpoint of more excellent insulation reliability, the (meth)acrylic compound may contain a tetrafunctional or higher (meth)acrylic compound. Examples of tetrafunctional or higher (meth)acrylic compounds include pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, propoxylated pentaerythritol tetra(meth)acrylate, ethoxylated propoxylated pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, and propoxylated dipentaerythritol hexa(meth)acrylate.

[0071] The content of the component (B) may be 1.0 mass% or more, 2.0 mass% or more, 3.0 mass% or more, or 4.0 mass% or more, and may be 7.0 mass% or less, 6.0 mass% or less, or 5.0 mass% or less, based on the total amount of solids in the photosensitive resin composition.

[0072] <Component (C): Photopolymerization Initiator> The photosensitive resin composition according to this embodiment contains one or more components (C). The component (C) contains a photopolymerization initiator having a fluorene skeleton (hereinafter also referred to as "component (C1)"). Examples of the component (C1) include a compound represented by the following formula (1):

[0073]

[0074] In formula (1), R １a and R １b R each independently represents a hydrogen atom or a monovalent organic group. １a and R１b Examples of the monovalent organic group represented by R include a halogen atom, a linear or branched alkyl group having 1 to 20 carbon atoms, a chain alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, and an alkyl group having 1 to 10 carbon atoms substituted with a cycloalkyl group having 3 to 8 carbon atoms. １a and R １b may be the same or different. １a and R １b may be bonded to form a cycloalkyl group having 3 to 8 carbon atoms. １a and R １b may each independently be a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms (for example, a linear alkyl group having 1 to 10 carbon atoms, a linear alkyl group having 1 to 5 carbon atoms, or a linear alkyl group having 1 to 4 carbon atoms), or a linear alkenyl group having 2 to 20 carbon atoms (for example, a linear alkenyl group having 2 to 10 carbon atoms or a linear alkenyl group having 2 to 4 carbon atoms), and may combine to form a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclohexyl group).

[0075] R ２a and R ３a R each independently represents a monovalent organic group. ２a and R ３a Examples of the monovalent organic group represented by R include a linear or branched alkyl group having 1 to 20 carbon atoms, a chain alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with a cycloalkyl group having 3 to 8 carbon atoms, or an aryl group having 6 to 20 carbon atoms. ２a and R ３a may be the same or different. ２a and R ３a may be bonded to form a cycloalkyl group having 3 to 8 carbon atoms. ２a and R ３a may each independently be a linear alkyl group having 1 to 20 carbon atoms (for example, a linear alkyl group having 1 to 10 carbon atoms, a linear alkyl group having 1 to 5 carbon atoms, or a linear alkyl group having 1 to 3 carbon atoms).

[0076] R ４arepresents a hydroxy group or a monovalent organic group containing a nitrogen atom. Examples of the monovalent organic group containing a nitrogen atom include a morpholinyl group, a piperidinyl group, a pyrrolidinyl group, and —NR ９a R ９b Examples include: R ９a and R ９b each independently represents a linear or branched alkyl group having 1 to 5 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, or a butyl group). ４a may be a monovalent organic group containing a nitrogen atom.

[0077] X represents a hydrogen atom or a monovalent organic group. Examples of the monovalent organic group represented by X include a linear or branched alkyl group having 1 to 20 carbon atoms, a chain alkenyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an alkyl group having 1 to 10 carbon atoms substituted with a cycloalkyl group having 3 to 8 carbon atoms, and -X １ -(X ２ ) ｎ X １ represents a heteroatom selected from the group consisting of O, N, and S; X ２ represents a linear or branched alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, or an alkyl group having 1 to 10 carbon atoms substituted with a cycloalkyl group having 3 to 8 carbon atoms; X ２ One or more of the carbon atoms in may be substituted with the heteroatom, and n is 1 or 2.

[0078] From the viewpoint of achieving superior resolution, the component (C1) may be an α-aminoketone compound having a fluorene skeleton. Examples of the α-aminoketone compound having a fluorene skeleton include R ４a is a morpholinyl group, a piperidinyl group, a pyrrolidinyl group, or —NR ９ａ R ９ｂ Examples of the compound include compounds represented by the above formula (1):

[0079] The upper limit of the molecular weight of the compound represented by formula (1) is not particularly limited, but may be 3,000 or less, 2,000 or less, 1,000 or less, or 500 or less. The compound represented by formula (1) can be produced, for example, based on the method described in JP-A-2019-528331. Examples of commercially available products of the compound represented by formula (1) include TR-NPI-20400 (trade name, manufactured by TRONLY).

[0080] The component (C) may contain a photopolymerization initiator other than the component (C1) as long as the effects of the present disclosure are not impaired. Examples of such photopolymerization initiators include thioxanthone-based photopolymerization initiators such as 2,4-diethylthioxanthone.

[0081] The content of component (C) may be 0.1 mass% or more, 0.5 mass% or more, 0.8 mass% or more, or 0.9 mass% or more, and may be 10.0 mass% or less, 5.0 mass% or less, 3.0 mass% or less, 2.5 mass% or less, 2.0 mass% or less, or 1.5 mass% or less, based on the total solid content of the photosensitive resin composition. The mass ratio of components (A) and (B) to component (C) (component (A) and (B) / component (C)) may be 15 or more, 20 or more, 25 or more, 30 or more, or 31 or more, and may be 49 or less, 47 or less, 45 or less, or 43 or less.

[0082] <Component (D): Thermosetting Resin> The photosensitive resin composition according to this embodiment contains one or more components (D). The component (D) contains at least one selected from the group consisting of a bisphenol F epoxy resin (hereinafter also referred to as "component (d1)") and a novolac epoxy resin (hereinafter also referred to as "component (d2)"). The component (D) may contain a bisphenol F epoxy resin and a novolac epoxy resin.

[0083] The component (d1) is not particularly limited as long as it is an epoxy resin having a bisphenol F skeleton. Examples of the component (d1) include bisphenol F-type epoxy resins represented by the following formula (2):

[0084]

[0085] In formula (2), R５ ~R ８ each independently represents a linear or branched alkyl group having 1 to 5 carbon atoms; Y ９ represents a hydrogen atom or a glycidyl group, n ５ represents an integer of 0 or more, and n ５ If there are two or more Y ９ may be the same or different, and n ６ ~n ９ each independently represents an integer of 0 to 4. From the viewpoint of achieving superior resolution, R ５ ~R ８ may each independently be a linear alkyl group having 1 to 3 carbon atoms (e.g., a methyl group), and n ５ may be 0, and n ６ ~n ９ may each independently be 1 or 2.

[0086] As the component (d1), for example, YSLV-80XY (trade name, manufactured by Nippon Steel Chemical & Material Co., Ltd.) and jER807 (trade name, manufactured by Mitsubishi Chemical Corporation) are commercially available.

[0087] Examples of the component (d2) include phenol novolac epoxy resins and cresol novolac epoxy resins. From the viewpoint of achieving superior resolution, the component (d2) may be a phenol novolac epoxy resin. As the component (d2), for example, a novolac epoxy resin represented by the above formula (III') may be used. From the viewpoint of achieving superior resolution, the component (d2) may be a resin having the formula R １３ is a hydrogen atom.

[0088] Examples of commercially available components (d2) include YDCN-700-7, YDCN-700-10, YDCN-704, YDCN-704A, and YDPN-638 (all of which are trade names manufactured by Nippon Steel Chemical & Material Co., Ltd.), EOCN-102S, EOCN-103S, EOCN-104S, BREN-S, and RE-306 (all of which are trade names manufactured by Nippon Kayaku Co., Ltd.), and N-740, N-770, N-665, and N-673 (all of which are trade names manufactured by DIC Corporation).

[0089] The component (D) may further contain a thermosetting resin other than the components (d1) and (d2), as long as the effects of the present disclosure are not impaired.

[0090] From the viewpoint of achieving better resolution, the content of the (D) component may be 1.0 mass% or more, 5.0 mass% or more, 8.0 mass% or more, 10.0 mass% or more, or 10.5 mass% or more, and may be 20 mass% or less, 18 mass% or less, 15 mass% or less, 13 mass% or less, or 12 mass% or less, based on the total solid content of the photosensitive resin composition. From the viewpoint of achieving better resolution, the mass ratio of the (D) component to the (C) component ((D) component / (C) component) may be 4 or more, 6 or more, or 8 or more, and may be 20 or less, 18 or less, 16 or less, 14 or less, or 12 or less.

[0091] <Component (E): Inorganic Filler> The photosensitive resin composition according to this embodiment may further contain an inorganic filler as component (E). Component (E) may be a filler that has not been surface-treated, or may be a surface-treated filler. The surface-treated filler can be obtained by treating the surface of the inorganic filler with a surface treatment agent. Treating the surface of the inorganic filler improves the adhesion between the (A), (B), and (D) components at the filler interface, thereby improving the heat resistance and thermal shock resistance of the permanent resist. One type of surface-treated filler may be used alone, or two or more types may be used in combination.

[0092] Examples of inorganic fillers include silica (SiO ２ ), alumina (Al ２ O ３ ), titania (TiO ２ ), tantalum oxide (Ta ２ O ５ ), zirconia (ZrO ２ ), silicon nitride (Si ３ N ４ ), barium titanate (BaO.TiO ２ ), barium carbonate (BaCO ３ ), magnesium carbonate (MgCO ３ ), aluminum hydroxide (Al(OH) ３ ), magnesium hydroxide (Mg(OH)２ ), lead titanate (PbO.TiO ２ ), lead zirconate titanate (PZT), lead lanthanum zirconate titanate (PLZT), gallium oxide (Ga ２ O ３ ), spinel (MgO.Al ２ O ３ ), mullite (3Al ２ O ３ 2SiO ２ ), cordierite (2MgO 2Al ２ O ３ / 5SiO ２ ), talc (3MgO.4SiO ２ ・H ２ O), aluminum titanate (TiO ２ ・Al ２ O ３ ), yttria-containing zirconia (Y ２ O ３ ZrO ２ ), barium silicate (BaO.8SiO ２ ), boron nitride (BN), calcium carbonate (CaCO ３ ), barium sulfate (BaSO ４ ), calcium sulfate (CaSO ４ ), zinc oxide (ZnO), magnesium titanate (MgO.TiO ２ ), hydrotalcite, mica, calcined kaolin, and carbon (C). The inorganic filler may contain silica from the viewpoint of improving heat resistance, and may contain barium sulfate or a combination of silica and barium sulfate from the viewpoint of improving heat resistance and adhesive strength.

[0093] Examples of surface treatment agents include organic zirconium compounds, organic titanium compounds, organic aluminum compounds, and organic silane compounds. The method for surface treatment of the inorganic filler is not particularly limited. Surface-treated fillers can also be purchased commercially.

[0094] From the viewpoint of resolution, the average particle size of component (E) may be 0.01 to 5 μm, 0.05 to 3 μm, 0.1 to 2 μm, or 0.15 to 1 μm. The average particle size of component (E) is the average particle size in a state where it is dispersed in the photosensitive resin composition, and is a value obtained by measurement according to the following procedure.

[0095] The photosensitive resin composition is diluted 1000 times with a solvent (methyl ethyl ketone), and the particle size distribution of the particles dispersed in the solvent is measured using a submicron particle analyzer (manufactured by Beckman Coulter, Inc., product name: N5) at a refractive index of 1.38 in accordance with international standard ISO 13321. The particle size at an integrated value of 50% (volume basis) in the particle size distribution is defined as the average particle size. The component (E) contained in the photosensitive layer formed using the photosensitive resin composition can also be measured using the same procedure.

[0096] The content of the component (E) may be 10% by mass or more, 20% by mass or more, 30% by mass or more, 35% by mass or more, or 40% by mass or more, based on the total solid content of the photosensitive resin composition, and may be 70% by mass or less, 60% by mass or less, or 50% by mass or less.

[0097] <Component (F): Elastomer> The photosensitive resin composition according to this embodiment may further contain an elastomer as component (F). By adding component (F) to the photosensitive resin composition, it is possible to suppress a decrease in flexibility and adhesion 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 adhesion strength of a permanent resist formed from the photosensitive resin composition.

[0098] Examples of the (F) component include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic elastomers, and silicone-based elastomers. The (F) component may also contain a thermoplastic elastomer. The thermoplastic elastomer is composed of a hard segment component that contributes to heat resistance and strength, and a soft segment component that contributes to flexibility and toughness. Among these, olefin-based elastomers, polyester-based elastomers, and acrylic elastomers are preferred, and from the viewpoint of resolution, olefin-based elastomers are more preferred. The (F) component can be used alone or in combination of two or more.

[0099] The content of the component (F) may be 0.10 mass% or more, 0.50 mass% or more, 1.0 mass% or more, or 1.5 mass% or more, based on the total solid content of the photosensitive resin composition, and may be 10 mass% or less, 8 mass% or less, 5 mass% or less, or 3 mass% or less.

[0100] <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. 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; and esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, and carbitol acetate.

[0101] 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 can be improved.

[0102] The photosensitive resin composition according to this embodiment may further contain various additives as needed. Examples of additives include curing accelerators such as melamine; 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 defoamers; silane coupling agents; flame retardants such as phosphorus-based phosphate compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters; and pigments such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, titanium oxide, carbon black, and naphthalene black. These may be used alone or in combination of two or more.

[0103] 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.

[0104] [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. The solid content of each component other than the volatile substance in the photosensitive layer 20 may be within the numerical range of the solid content of each component in the above-described photosensitive resin composition.

[0105] 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.

[0106] 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.

[0107] 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 3 to 20 minutes.

[0108] 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.

[0109] [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.

[0110] 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.

[0111] 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.

[0112] Next, by irradiating at least a part of the photosensitive layer with actinic rays, the part irradiated with actinic rays is photocured to form a latent image. In this case, if a support is present on the photosensitive layer, and the support is transparent to actinic rays, the actinic rays can be irradiated through the support, but if the support is light-shielding, the support is removed before irradiating the photosensitive layer with actinic rays.

[0113] Examples of exposure methods include direct imaging exposure methods such as LDI (Laser Direct Imaging) exposure and DLP (Digital Light Processing) exposure, in which actinic rays are irradiated in an imagewise manner; mask exposure methods in which actinic rays are irradiated in an imagewise manner through a negative mask pattern; and projection exposure methods in which actinic rays are irradiated in an imagewise manner. Examples of actinic rays include electron beams, ultraviolet rays, and X-rays. 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 or 100 to 1500 mJ / cm ２ may be.

[0114] After exposure, the unexposed areas are dissolved and 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.

[0115] 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 ２ The heating temperature of the post-heating may be 100 to 200°C, 120 to 180°C, or 135 to 165°C. The heating time of the post-heating may be 5 minutes to 6 hours, 10 minutes to 3 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.

[0116] 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.

[0117] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples.

[0118] (Synthesis of Component (A1)) A flask equipped with a stirrer, reflux condenser, and thermometer was charged with 350 parts by mass of bisphenol F novolac epoxy resin (manufactured by DIC Corporation, product name: EXA-7376), 70 parts by mass of acrylic acid, 0.5 parts by mass of methylhydroquinone, and 120 parts by mass of carbitol acetate. The mixture was reacted at 90°C with stirring to completely dissolve the mixture. Next, the resulting solution was cooled to 60°C, and 2 parts by mass of triphenylphosphine was added. The mixture was reacted at 100°C until the acid value of the solution reached 1 mgKOH / g or less. To the reacted solution, 98 parts by mass of tetrahydrophthalic anhydride (THPAC) and 85 parts by mass of carbitol acetate were added, and the mixture was reacted at 80°C for 6 hours. The reaction solution was then cooled to room temperature to obtain a solution of THPAC-modified bisphenol F novolac epoxy acrylate (solids concentration: 73% by mass) as component (A1).

[0119] [Photosensitive Resin Composition] The components were blended in the amounts (parts by mass, solid content equivalent) shown in Table 1 below and kneaded using a three-roll mill. Carbitol acetate was then added to give a solid content concentration of 70% by mass to obtain a photosensitive resin composition. Details of each component shown in Table 1 are as follows.

[0120] (Acid-modified vinyl group-containing resin) A-1: ​​Component (A1) synthesized above (Photopolymerizable compound) B-1: KAYARAD DPHA (a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate, product name, manufactured by Nippon Kayaku Co., Ltd.) (Photopolymerization initiator) C-1: TR-NPI-20400 (X represents a hydrogen atom, R １a and R １b each represents a butyl group, and R ２a and R ３a each represents a methyl group, and R ４arepresents a morpholinyl group, manufactured by TRONLY Co., Ltd.) C-2: Omnipol 910 (manufactured by IGM Resins B.V., trade name) C-3: Omnirad 819 (manufactured by IGM Resins B.V., trade name) C-4: Irgacure OXE02 (1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone 1-(O-acetyloxime), manufactured by BASF Japan Ltd., trade name) C-5: Omnirad DETX (2,4-diethylthioxanthone, manufactured by IGM Resins B.V., trade name) C-6: 4,4'-bis(diethylamino)benzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) (thermosetting resin) D-1: YSLV-80XY (bisphenol F type epoxy resin, product name, manufactured by Nippon Steel Chemical & Material Co., Ltd.) D-2: RE-306 (phenol novolac type epoxy resin, product name, manufactured by Nippon Kayaku Co., Ltd.) D-3: NC-7000L (naphthalene type epoxy resin, product name, manufactured by Nippon Kayaku Co., Ltd.) D-4: NC-3000H (biphenyl type epoxy resin, product name, manufactured by Nippon Kayaku Co., Ltd.) (inorganic filler) E-1: SO-C2 (silica, product name, manufactured by Admatechs Co., Ltd.) E-2: B-34 (barium sulfate, product name, manufactured by Sakai Chemical Industry Co., Ltd.) (elastomer) F-1: PB-3600 (epoxidized polybutadiene, product name, manufactured by Daicel Corporation) (pigment) G-1: phthalocyanine pigment

[0121] [Photosensitive element] A 25 μm thick polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: G2-25) was prepared as a support film. A solution obtained by diluting the photosensitive resin composition with methyl ethyl ketone was applied to the support film so that the thickness after drying was 25 μm, and the coating was dried at 75° C. for 15 minutes using a hot air convection dryer to form a photosensitive layer. Next, a polyethylene film (manufactured by Tamapoly Co., Ltd., 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.

[0122] [Evaluation] The copper foil surface of a printed wiring board substrate (manufactured by Resonac Corporation, product name: MCL-E-679) in which 18 μm thick copper foil was laminated on a glass epoxy base material was treated with a roughening pretreatment solution (manufactured by MEC Co., Ltd., product name: CZ-8101), followed by rinsing with water and drying to obtain a roughening pretreated printed wiring board substrate. The protective film was peeled off and removed from the photosensitive element, and the exposed photosensitive layer was placed so as to abut against the copper foil of the roughening pretreated printed wiring board substrate, followed by lamination using a press-type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., product name: MVLP-500). The lamination conditions were a press hot plate temperature of 75°C, a vacuuming time of 20 seconds, a lamination press time of 20 seconds, an atmospheric pressure of 4 kPa or less, and a pressure of 0.4 MPa. After lamination, the laminate was left at room temperature for at least 1 hour to obtain a laminate for evaluation in which the photosensitive layer and the support film were laminated in this order on the copper foil surface of the substrate for printed wiring board.

[0123] (Sensitivity) A 41-step tablet was placed on the support film of the photosensitive layer of the evaluation laminate, and the entire surface was exposed using a direct imaging exposure device (manufactured by Oak Manufacturing Co., Ltd., product name: Mms508D) with an ultra-high pressure mercury lamp as a light source. After exposure, the tablet was left at room temperature for 30 minutes, and then the support film was peeled off. The photosensitive layer was spray-developed for 40 seconds using a 1% by mass aqueous solution of sodium carbonate at 30°C. After development, the exposure amount at which the number of remaining gloss steps of the 41-step tablet was 10 was determined as the sensitivity of the photosensitive layer (unit: mJ / cm). ２ The smaller the exposure dose, the higher the sensitivity. The sensitivity was evaluated according to the following criteria: A: Exposure dose of 150 mJ / cm ２ B: The exposure amount was 150 mJ / cm or less. ２ Super, 200mJ / cm ２ C: The exposure amount was 200 mJ / cm or less. ２ It was super.

[0124] (Resolution) For the evaluation of resolution, the resist was exposed at an exposure dose such that the number of remaining gloss steps measured above was 10, and the exposure pattern used was a pattern in which dots were arranged in a grid pattern (dot diameter: distance between dot centers = 1:2). The dot diameter (φ) was varied in 10 μm increments within the range of 30 μm to 100 μm. After exposure, the resist was left at room temperature for 30 minutes, and then the support film was peeled off. After spray development, the resist pattern was observed using an optical microscope to confirm a dot pattern with a diameter of 80 μm. The resolution was evaluated by assigning a bottom opening diameter of more than 58 μm to "A," a bottom opening diameter of more than 54 μm to 58 μm to "B," and a bottom opening diameter of 54 μm or less to "C."

[0125]

[0126] 1...photosensitive element, 10...support film, 20...photosensitive layer, 30...protective film

Claims

1. A photosensitive resin composition for permanent resist, comprising an acid-modified vinyl group-containing resin, a photopolymerizable compound, a photopolymerization initiator, and a thermosetting resin, wherein the photopolymerization initiator comprises a photopolymerization initiator having a fluorene skeleton, and the thermosetting resin comprises at least one resin selected from the group consisting of bisphenol F type epoxy resins and novolac type epoxy resins.

2. The photosensitive resin composition according to claim 1, wherein the photopolymerization initiator having a fluorene skeleton comprises an α-aminoketone compound having a fluorene skeleton.

3. The photosensitive resin composition according to claim 1, wherein the thermosetting resin comprises a bisphenol F type epoxy resin and a novolac type epoxy resin.

4. The photosensitive resin composition according to claim 1, wherein the novolac epoxy resin comprises a phenol novolac epoxy resin.

5. The photosensitive resin composition according to claim 1, wherein the photopolymerization initiator further comprises a thioxanthone-based photopolymerization initiator.

6. A photosensitive element comprising a support film and a photosensitive layer formed on the support film, 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 containing a cured product of the photosensitive resin composition according to any one of claims 1 to 5.

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 according to any one of claims 1 to 5; 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 according to claim 6; exposing and developing the photosensitive layer to form a resist pattern; and hardening the resist pattern to form a permanent resist.

Images