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

Abstract

A photosensitive resin composition comprising (A) a resin having olefinic unsaturated bonds and acidic groups, (B) a thermosetting resin, (C) a photopolymerizable compound, (D) a photopolymerization initiator, and (E) an inorganic filler, wherein the (E) inorganic filler comprises a first inorganic filler having an average particle size of 0.5 μm or more and a second inorganic filler having an average particle size of 0.3 μm or less, and the solid component mass ratio of the content of the first inorganic filler to the content of the second inorganic filler is 6:4 to 8:2.

Description

Technical Field

[0001] This invention relates to a photosensitive resin composition, a photosensitive element, a printed circuit board, and a method for manufacturing the printed circuit board. Background Technology

[0002] In the field of printed circuit boards (PCBs), the formation of permanent resists on PCBs is underway. Permanent resists serve to prevent corrosion of conductor layers or maintain electrical insulation between conductor layers during PCB use. In recent years, permanent resists have also been used in processes such as flip-chip mounting of semiconductor components onto PCBs via soldering and wire bonding, acting as a solder resist film to prevent solder from adhering to unwanted portions of the conductor layers on the PCB.

[0003] Conventionally, permanent resists have been manufactured by screen printing using thermosetting resin compositions or by photographic methods using photosensitive resin compositions. For example, in flexible circuit boards using mounting methods such as FC (Flip Chip), TAB (Tape Automated Bonding), and COF (Chip On Film), permanent resists are formed by screen printing thermosetting resin paste and then thermally curing it, except for IC chips, electronic components, or LCD (Liquid Crystal Display) panels and connecting wiring patterns (see, for example, Patent Document 1).

[0004] In semiconductor packaging substrates such as BGA (Ball Grid Array) and CSP (Chip Scale Package) mounted on electronic components, (1) in order to mount the semiconductor element flip chip onto the semiconductor packaging substrate via solder, (2) in order to perform wire bonding between the semiconductor element and the semiconductor packaging substrate, and (3) in order to bond the semiconductor packaging substrate to the main substrate with solder, it is necessary to remove the permanent resist at the bonding portion. In the image formation of the permanent resist, the following photographic method is used: after coating and drying a photosensitive resin composition, it is selectively irradiated with active light such as ultraviolet light to cure it, and only the unirradiated portion is removed by development to form an image. The photographic method is suitable for mass production due to its good operability, and therefore it is widely used in the electronics materials industry for image formation of photosensitive materials (for example, see Patent Document 2).

[0005] Previous technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2003-198105 Patent Document 2: Japanese Patent Application Publication No. 2011-133851 Summary of the Invention

[0006] The technical problem to be solved by the invention To cope with the increasing density of printed circuit boards, there is a growing demand for higher performance permanent resists (solder resists). In particular, the requirements for resolution and insulation reliability are increasing year by year, making it crucial to achieve a high degree of balance between these characteristics. However, permanent resists formed from conventional photosensitive resin compositions have the following problems: for example, while they can form large-diameter via patterns at a film thickness of 18 μm, at a film thickness of 25 μm, forming large-diameter via patterns with the same exposure as at 18 μm results in undercutting and poor thickness margin. Furthermore, regarding permanent resists formed from conventional photosensitive resin compositions, in the HAST (Highly Accelerated Stress Test), which is part of the insulation reliability evaluation, short circuits due to migration sometimes occur within less than 200 hours of testing, even with a line width / blank width of 10 μm / 10 μm.

[0007] The purpose of this invention is to provide a photosensitive resin composition capable of forming a permanent resist with good resolution and excellent insulation reliability for both 18μm and 25μm film thicknesses under the same exposure conditions, a photosensitive element using the photosensitive resin composition, a printed circuit board, and a method for manufacturing the printed circuit board.

[0008] means for solving technical problems To address the aforementioned issues, the present invention provides the following photosensitive resin composition, photosensitive element, printed circuit board, and method for manufacturing the printed circuit board.

[0009] [1] A photosensitive resin composition comprising (A) a resin having olefinic unsaturated bonds and acidic groups, (B) a thermosetting resin, (C) a photopolymerizable compound, (D) a photopolymerization initiator and (E) an inorganic filler, wherein the (E) inorganic filler comprises a first inorganic filler having an average particle size of 0.5 μm or more and a second inorganic filler having an average particle size of 0.3 μm or less, wherein the mass ratio of the content of the first inorganic filler to the content of the second inorganic filler is 6:4 to 8:2.

[0010] [2] According to the photosensitive resin composition described in [1] above, the content of the above (E) component is 10 to 80 by mass, based on the total amount of solid components in the photosensitive resin composition.

[0011] [3] According to the photosensitive resin composition described in [1] or [2] above, wherein the first inorganic filler and the second inorganic filler are both inorganic oxide fillers.

[0012] [4] The photosensitive resin composition according to any one of [1] to [3] above, wherein the first inorganic filler and the second inorganic filler are both spherical silica fillers.

[0013] [5] The photosensitive resin composition according to any one of [1] to [4] above further contains (F) a photosensitizer.

[0014] [6] The photosensitive resin composition according to any one of [1] to [5] above further contains (H) ultraviolet absorber.

[0015] [7] The photosensitive resin composition according to any one of [1] to [6] above, wherein the above (C) photopolymerizable compound comprises a difunctional (meth)acrylic acid monomer having two (meth)acryloyl groups and a polyfunctional (meth)acrylic acid monomer having at least three (meth)acryloyl groups.

[0016] [8] A photosensitive element comprising a support film and a photosensitive layer formed on the support film, the photosensitive layer comprising any one of the photosensitive resin compositions described in [1] to [7].

[0017] [9] A printed circuit board comprising a permanent resist comprising a cured product of the photosensitive resin composition described in any one of [1] to [7] above.

[0018]

[10] A method for manufacturing a printed circuit board includes: a step of forming a photosensitive layer on a substrate using the photosensitive resin composition described in any one of [1] to [7] above; a step of exposing and developing the photosensitive layer to form a resist pattern; and a step of curing the resist pattern to form a permanent resist.

[0019]

[11] A method for manufacturing a printed circuit board includes: a step of forming a photosensitive layer on a substrate using the photosensitive element described above [8]; a step of exposing and developing the photosensitive layer to form a resist pattern; and a step of curing the resist pattern to form a permanent resist.

[0020] Invention Effects According to the present invention, a photosensitive resin composition capable of forming a permanent resist with good resolution and excellent insulation reliability at film thicknesses of 18 μm and 25 μm under the same exposure conditions, a photosensitive element using the photosensitive resin composition, a printed circuit board, and a method for manufacturing the printed circuit board are provided. Attached Figure Description

[0021] Figure 1 This is a schematic cross-sectional view showing the photosensitive element of this embodiment. Detailed Implementation

[0022] The present invention will now be described in detail. In this specification, the term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from other processes, provided that the intended function of the process is achieved. When viewed as a top view, the term "layer" includes not only structures forming a shape across the entire surface, but also structures forming a shape locally. The numerical range indicated by "~" represents a range encompassed by the values ​​before and after "~", respectively, as the minimum and maximum values. Within the numerical ranges described in stages in this specification, the upper or lower limit of the numerical range for a certain stage can be replaced with the upper or lower limit of the numerical range for other stages. Within the numerical ranges described in this specification, the upper or lower limit of the numerical range can also be replaced with the values ​​shown in the embodiments.

[0023] In this specification, references to the amount of each component in the composition, or the presence of multiple substances in the composition equivalent to each component, refer to the total amount of those multiple substances present in the composition, unless otherwise specified.

[0024] In this specification, "(meth)acrylate" refers to at least one of "acrylate" and its corresponding "methacrylate," and the same applies to other similar expressions such as (meth)acrylic acid and (meth)acryloyl. In this specification, "solid component" refers to non-volatile components other than volatile substances (water, solvents, etc.) contained in the photosensitive resin composition, including components that are liquid, syrupy, or waxy at room temperature (around 25°C).

[0025] [Photosensitive Resin Composition] The photosensitive resin composition of this embodiment contains (A) a resin having olefinic unsaturated bonds and acidic groups, (B) a thermosetting resin, (C) a photopolymerizable compound, (D) a photopolymerization initiator, and (E) an inorganic filler. The inorganic filler comprises a first inorganic filler with an average particle size of 0.5 μm or more and a second inorganic filler with an average particle size of 0.3 μm or less. In the above photosensitive resin composition, the solid component mass ratio (first inorganic filler: second inorganic filler) of the content of the first inorganic filler to the content of the second inorganic filler is 6:4 to 8:2. The photosensitive resin composition of this embodiment is a negative photosensitive resin composition, and the cured film of the photosensitive resin composition is suitable for use as a permanent photoresist. Hereinafter, each component used in the photosensitive resin composition of this embodiment will be described in more detail.

[0026] (A) Component: Resin containing olefinic unsaturated bonds and acidic groups) The photosensitive resin composition of this embodiment contains a resin having olefinic unsaturated bonds and acidic groups as component (A). The resin having olefinic unsaturated bonds and acidic groups is not particularly limited as long as it has photopolymerizable olefinic unsaturated bonds and alkali-soluble acidic groups.

[0027] Groups having olefinic unsaturated bonds as part of component (A) include, for example, vinyl, allyl, propargyl, butenyl, ethynyl, phenylethynyl, maleimide, nadiimide, and (meth)acryloyl. Of these, (meth)acryloyl is preferred from the viewpoint of reactivity and resolution. Acidic groups as part of component (A) include, for example, carboxyl, sulfonyl, and phenolic hydroxyl groups. Of these, carboxyl is preferred from the viewpoint of resolution.

[0028] (A) is preferably an epoxy derivative having olefinic unsaturated bonds and acidic groups, formed by reacting (c) a polybasic acid anhydride containing saturated or unsaturated groups (hereinafter, sometimes referred to as "(c) component") with a resin (A') formed by reacting (a) an epoxy resin (hereinafter, sometimes referred to as "(a) component") with (b) an organic acid containing olefinic unsaturated groups (hereinafter, sometimes referred to as "(b) component").).

[0029] Examples of epoxy derivatives having olefinic unsaturated bonds and acidic groups include acid-modified epoxy (meth)acrylates. Acid-modified epoxy (meth)acrylates are resins obtained by acid modification of an epoxy (meth)acrylate, which is a reactant of components (a) and (b), with component (c). For example, an addition reaction product obtained by reacting an epoxy resin with a monocarboxylic acid having olefinic unsaturated bonds to an ester can be used as an acid-modified epoxy (meth)acrylate.

[0030] Examples of components (A) include resins (A1) having olefinic unsaturated bonds and acidic groups made from bisphenol phenolic varnish-type epoxy resin (a1) (hereinafter sometimes referred to as "epoxy resin (a1)"), which is used as component (a), and resins (A2) having olefinic unsaturated bonds and acidic groups made from epoxy resins (a2) other than epoxy resin (a1) (hereinafter sometimes referred to as "epoxy resin (a2)").

[0031] As an epoxy resin (a1), examples of epoxy resins having structural units represented by the following formulas (I) or (II) can be cited.

[0032] In equation (I), R 11Represents a hydrogen atom or a methyl group, multiple R 11 They can be the same or different. Y 1 and Y 2 Each can be independently represented by a hydrogen atom or a glycidyl group, but Y 1 and Y 2 At least one of them is a glycidyl group. From the viewpoint of suppressing undercutting and improving the straightness and resolution of the resist pattern outline, R 11 Preferably, hydrogen atoms are preferred, and from the viewpoint of further improving thermal shock resistance, Y 1 and Y 2 Glycidyl group is preferred.

[0033] The number of structural units in the epoxy resin (a1), represented by formula (I), is 1 or more, but can also be 10 to 100, 15 to 80, or 15 to 70. When the number of structural units is within the above range, it is easy to improve the linearity of the resist pattern outline, the adhesion to the copper substrate, the heat resistance, and the electrical insulation. Here, the number of structural units in a single molecule is represented as an integer value, and in an aggregate of multiple molecules, it is represented as a rational number as an average value. The same applies to the number of structural units in the following text.

[0034] In equation (II), R 12 Represents a hydrogen atom or a methyl group, multiple R 12 They can be the same or different. Y 3 and Y 4 Each can be independently represented by a hydrogen atom or a glycidyl group, but Y 3 and Y 4 At least one of them is a glycidyl group. From the viewpoint of suppressing undercutting and improving the straightness and resolution of the resist pattern outline, R 12 Preferably, hydrogen atoms are preferred, and from the viewpoint of further improving thermal shock resistance, Y 3 and Y 4 Glycidyl group is preferred.

[0035] The number of structural units represented by formula (II) in epoxy resin (a1) is 1 or more, or it can be 10 to 100, 15 to 80, or 15 to 70. When the number of structural units is within the above range, it is easy to improve the straightness of the resist pattern outline, the adhesion to the copper substrate, and the heat resistance.

[0036] In equation (II), R 12 It is a hydrogen atom and Y 3 and Y 4 Glycidyl ether-based epoxy resins are commercially available as the EXA-7376 series (manufactured by DIC Corporation, trade name). 12It is methyl and Y 3 and Y 4 Glycidyl ester-based epoxy resins are commercially available as part of the EPON SU8 series (manufactured by Westlake Corporation, trade name).

[0037] There are no particular restrictions on the epoxy resin (a2) as long as it is a different epoxy resin from epoxy resin (a1). However, from the viewpoint of suppressing undercutting and improving the straightness of the resist pattern outline, adhesion to the copper substrate and resolution, it is preferred to be selected from at least one of the group consisting of phenolic varnish type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, triphenol methane type epoxy resin and biphenyl type epoxy resin.

[0038] Examples of phenolic varnish-type epoxy resins include epoxy resins having structural units represented by formula (III) below. Examples of bisphenol A type epoxy resins or bisphenol F type epoxy resins include epoxy resins having structural units represented by formula (IV) below. Examples of triphenol methane type epoxy resins include epoxy resins having structural units represented by formula (V) below. Examples of biphenyl type epoxy resins include epoxy resins having structural units represented by formula (VI) below.

[0039] As the epoxy resin (a2), a phenolic varnish-type epoxy resin having a structural unit represented by the following formula (III) is preferred. As a phenolic varnish-type epoxy resin having such a structural unit, an example can be listed as a phenolic varnish-type epoxy resin represented by the following formula (III').

[0040] In equations (III) and (III'), R 13 Y represents a hydrogen atom or a methyl group. 5 It represents a hydrogen atom or a glycidyl group, but Y 5 At least one of them is a glycidyl group. In formula (III'), n1 is a number greater than or equal to 1, and multiple R... 13 and Y 5 They can be the same or different. From the perspective of suppressing undercutting and improving the straightness and resolution of the resist pattern outline, R... 13 Hydrogen atoms are preferred.

[0041] In equation (III'), from the viewpoint of suppressing undercutting and improving the straightness and resolution of the resist pattern outline, Y, as a hydrogen atom 5 With Y as a glycidyl group 5The molar ratio can also be 0 / 100 to 30 / 70 or 0 / 100 to 10 / 90. n1 is 1 or more, but can also be 10 to 200, 30 to 150 or 30 to 100. When n1 is within the above range, it is easy to improve the straightness of the resist pattern outline, the adhesion to the copper substrate and the heat resistance.

[0042] Examples of phenolic varnish-type epoxy resins represented by formula (III') include phenolic varnish-type epoxy resins and cresol varnish-type epoxy resins. These phenolic varnish-type epoxy resins can be obtained, for example, by reacting phenolic varnish-type resins or cresol varnish-type resins with epichlorohydrin using known methods.

[0043] As phenolic varnish-type epoxy resins or cresol varnish-type epoxy resins represented by formula (III'), commercially available varieties include YDCN-700-7, YDCN-700-10, YDCN-704, YDCN-704A, YDPN-638 (manufactured by NIPPONSTEEL Chemical & Material Co., Ltd., trade name), EOCN-102S, EOCN-103S, EOCN-104S, EOCN-1012, EOCN-1027, BREN-S (manufactured by Nippon Kayaku Co., Ltd., trade name), N-740, N-770, N-665, N-673 (manufactured by DIC Corporation, trade name), etc.

[0044] As epoxy resin (a2), bisphenol A type epoxy resin or bisphenol F type epoxy resin having structural units represented by the following formula (IV) can be preferably listed. As epoxy resin having such structural units, bisphenol A type epoxy resin or bisphenol F type epoxy resin represented by the following formula (IV') can be listed for example.

[0045] In equations (IV) and (IV'), R 14 Representing a hydrogen atom or a methyl group, with multiple R atoms present. 14 They can be the same or different, Y 6 This represents a hydrogen atom or a glycidyl group. In formula (IV'), n2 represents a number greater than or equal to 1. When n2 is greater than or equal to 2, multiple Y atoms... 6 They can be the same or different, but at least one Y 6 It is a glycidyl group.

[0046] From the perspective of suppressing undercutting and improving the straightness and resolution of the resist pattern outline, R 14 Preferably, hydrogen atoms are preferred, and from the viewpoint of further improving thermal shock resistance, Y6 Glycidyl groups are preferred. n2 indicates 1 or more, but can also be 10-100, 10-80, or 15-60. When n2 is within the above range, it is easy to improve the straightness of the resist pattern outline, the adhesion to the copper substrate, and the heat resistance.

[0047] Regarding Y in equation (IV) 6 Bisphenol A type epoxy resin or bisphenol F type epoxy resin with glycidyl groups, for example, capable of being produced by making Y in formula (IV) 6 The hydroxyl group (-OY) of bisphenol A type epoxy resin or bisphenol F type epoxy resin containing hydrogen atoms 6 It is obtained by reacting it with epichlorohydrin.

[0048] Bisphenol A type epoxy resin or bisphenol F type epoxy resin represented by formula (IV') are commercially available, for example, jER807, jER825, jER827, jER828, jER834, jER1004F, jER1007FS and jER1009F (manufactured by Mitsubishi Chemical Corporation, trade name), YD-8125, YDF-170, YDF-2001, YDF-2004, YDF-8170C (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name), etc.

[0049] As an epoxy resin (a2), a pyrrolidone-methane type epoxy resin having a structural unit represented by the following formula (V) can be preferably cited. As a pyrrolidone-methane type epoxy resin having such a structural unit, a pyrrolidone-methane type epoxy resin represented by the following formula (V') can be cited as an example.

[0050] In equations (V) and (V'), Y 7 Represents a hydrogen atom or a glycidyl group, multiple Y atoms 7 They can be the same or different, but at least one Y 7 It is a glycidyl group. In formula (V'), n3 represents a number greater than 1.

[0051] From the perspective of suppressing undercut and top defects and improving the straightness and resolution of the resist pattern outline, Y 7 Y as a hydrogen atom 7 With Y as a glycidyl group 7 The molar ratio between them can be from 0 / 100 to 30 / 70. From this molar ratio, it can be seen that Y 7At least one of them is a glycidyl group. n3 is 1 or more, but can also be 10-100, 15-80 or 15-70. When n3 is in the above range, it is easy to improve the straightness of the resist pattern outline, the adhesion to the copper substrate and the heat resistance.

[0052] Triphenol-methane type epoxy resins represented by formula (V') are commercially available, such as FAE-2500, EPPN-501H, and EPPN-502H (all manufactured by Nippon Kayaku Co., Ltd., trade names).

[0053] As an epoxy resin (a2), a biphenyl-type epoxy resin having a structural unit represented by the following formula (VI) can be preferably listed. As a biphenyl-type epoxy resin having such a structural unit, a biphenyl-type epoxy resin represented by the following formula (VI') can be listed for example.

[0054] In equations (VI) and (VI'), Y 8 Represents a hydrogen atom or a glycidyl group, multiple Y atoms 8 They can be the same or different, but at least one Y 8 It is a glycidyl group. In formula (V'), n4 represents a number greater than 1.

[0055] As biphenyl-type epoxy resins represented by formula (VI'), commercially available examples include NC-3000, NC-3000-L, NC-3000-H, and NC-3000-FH-75M (all manufactured by Nippon Kayaku Co., Ltd., trade names).

[0056] As the epoxy resin (a2), it is preferably selected from at least one of the following groups: phenolic varnish type epoxy resin having a structural unit represented by formula (III), bisphenol A type epoxy resin having a structural unit represented by formula (IV), and bisphenol F type epoxy resin having a structural unit represented by formula (IV), and more preferably bisphenol F type epoxy resin having a structural unit represented by formula (IV).

[0057] From the viewpoint of further improving thermal shock resistance, warpage reduction and resolution, the component (A1) of a bisphenol varnish-type epoxy resin having a structural unit represented by formula (II) as epoxy resin (a1) can be used in combination with the component (A2) of a bisphenol A type epoxy resin or a bisphenol F type epoxy resin having a structural unit represented by formula (IV) as epoxy resin (a2).

[0058] Examples of components (b) include acrylic acid, acrylic acid dimers, methacrylic acid, β-furfurylic acid, β-styrylic acid, cinnamic acid, crotonic acid, α-cyanocinonic acid, and other acrylic acid derivatives; half-ester compounds that are the reaction products of hydroxyl-containing (meth)acrylates and diacid anhydrides; and half-ester compounds that are the reaction products of monoglycidyl ethers or monoglycidyl esters with olefinic unsaturated bonds and diacid anhydrides. Component (b) may be used alone or in combination of two or more.

[0059] Half-ester compounds are obtained, for example, by reacting a hydroxyl-containing (meth)acrylate, a monoglycidyl ether having an olefinic unsaturated bond, or a monoglycidyl ester having an olefinic unsaturated bond with a dicarboxylic anhydride.

[0060] Examples of hydroxyl-containing (meth)acrylates, monoglycidyl ethers having olefinic unsaturated bonds, and monoglycidyl esters having olefinic unsaturated bonds 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.

[0061] Examples of dicarboxylic anhydrides include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride.

[0062] In the reaction between component (a) and component (b), the reaction is preferably carried out at a ratio of 0.6 to 1.05 equivalents of component (b) relative to the epoxy group of component (a), and more preferably at a ratio of 0.8 to 1.0 equivalents. By carrying out the reaction at this ratio, the photosensitivity increases, and there is a tendency for excellent linearity in the resist pattern profile.

[0063] In the reaction between component (a) and component (b), polymerization inhibitors may be used to prevent polymerization during the reaction. Examples of polymerization inhibitors include hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol. Polymerization inhibitors may be used alone or in combination of two or more.

[0064] From the perspective of improving stability, the amount of polymerization inhibitor used relative to the total 100 parts by mass of components (a) and (b) can 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.

[0065] Component (A'), formed by reacting component (a) with component (b), has hydroxyl groups formed through a ring-opening addition reaction between the epoxy group of component (a) and the carboxyl group of component (b). By further reacting component (A') with component (c), a resin is obtained in which the hydroxyl groups of component (A') (including those originally present in component (a)) and the anhydride groups of component (c) are half-esterified, resulting in an olefinic unsaturated bond and an acidic group.

[0066] Examples of components (c) include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, and itaconic anhydride. Of these, tetrahydrophthalic anhydride is preferred from the viewpoint of resolution. Component (c) may be used alone or in combination of two or more.

[0067] In the reaction between component (A') and component (c), for example, component (c) is reacted in an amount of 0.1 to 1.0 equivalent relative to 1 equivalent of the hydroxyl group in component (A'), thereby adjusting the acid value of component (A).

[0068] As required, as component (a), a portion of hydrogenated bisphenol A type epoxy resin may be used simultaneously, as well as a portion of styrene-maleic acid resins such as hydroxyethyl (meth) acrylate modified from styrene-maleic anhydride copolymer.

[0069] Regarding component (A), from the viewpoint of suppressing undercut and further improving adhesion to the copper substrate, thermal shock resistance and resolution, it is preferable to include component (A1), and more preferably from the viewpoint of improving adhesion strength, it includes components (A1) and (A2).

[0070] When components (A1) and (A2) are used as a combination of components (A), the mass ratio of (A1) / (A2) is not particularly limited. From the viewpoint of improving the straightness of the resist pattern outline, resistance to electroless plating, and heat resistance, it can be 20 / 80 to 90 / 10, 30 / 70 to 80 / 20, 40 / 60 to 75 / 25, or 50 / 50 to 70 / 30.

[0071] The acid value of component (A) is not particularly limited. From the viewpoint of improving the solubility of the unexposed portion in alkaline aqueous solution, the acid value of component (A) may be 30 mg KOH / g or more, 40 mg KOH / g or more, or 50 mg KOH / g or more. From the viewpoint of improving the electrical properties of the cured film, the acid value of component (A) may be 150 mg KOH / g or less, 120 mg KOH / g or less, or 100 mg KOH / g or less.

[0072] (A) The weight average molecular weight (Mw) of component (A) is not particularly limited. From the viewpoint of improving the adhesion of the cured film, the Mw of component (A) can be 3000 or more, 4000 or more, or 5000 or more. From the viewpoint of improving the resolution of the photosensitive layer, the Mw of component (A) can also be 30000 or less, 25000 or less, or 18000 or less.

[0073] Mw can be determined by gel permeation chromatography (GPC). For example, Mw can be defined as the value obtained by measuring under the following GPC conditions and converting it using a calibration curve of standard polystyrene. Regarding the preparation of the calibration curve, five sample kits (“PStQuick MP-H” and “PStQuick B”, manufactured by TOSOH CORPORATION) can be used as standard polystyrene.

[0074] GPC Unit: High-speed GPC unit "HCL-8320GPC" (manufactured by TOSOH CORPORATION) Detector: Differential refractometer or UV detector (manufactured by TOSOH CORPORATION) Tube String: TSKgel SuperMultipore HZ-H (Tube String Length: 15cm, Tube String Inner Diameter: 4.6mm) (Manufactured by TOSOH CORPORATION) Eluent: Tetrahydrofuran (THF) Measurement temperature: 40℃ Flow rate: 0.35 mL / min Sample concentration: 10 mg / THF 5 mL Injection volume: 20μL From the perspective of improving the heat resistance, electrical properties and chemical resistance of permanent photoresist, based on the total amount of solid components in the photosensitive resin composition, the content of component (A) in the photosensitive resin composition can be 20-70% by mass, 25-60% by mass or 30-50% by mass.

[0075] (B) Component: Thermosetting resin) The photosensitive resin composition of this embodiment uses a thermosetting resin as component (B), thereby improving the heat resistance, adhesion, and chemical resistance of the cured film (permanent resist) formed from the photosensitive resin composition. Component (B) can be used alone or in combination of two or more.

[0076] As a component (B), examples include epoxy resin, phenolic resin, unsaturated imide resin, cyanate ester resin, isocyanate ester resin, benzoxazine resin, oxetane resin, amino resin, unsaturated polyester resin, allyl resin, dicyclopentadiene resin, silicone resin, triazine resin, and melamine resin.

[0077] Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, phenolic varnish type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, hydantoin type epoxy resin, triglycidyl isocyanate, and bixylenol type epoxy resin.

[0078] Based on the total solid content of the photosensitive resin composition, the content of component (B) can also be 2-30% by mass, 5-25% by mass, or 8-20% by mass. When the content of component (B) is within the above range, good developability can be maintained, and the heat resistance of the formed cured film can be further improved.

[0079] (C) Component: Photopolymerizable compound) (C) is not particularly limited as long as it is a compound with a functional group exhibiting photopolymerizability. (C) can be a photopolymerizable compound having an olefinic unsaturated group that does not have an acidic group. (C) is preferably composed of at least one of the following: (Ci) a monofunctional monomer having one polymerizable olefinic unsaturated group, (Cii) a difunctional monomer having two polymerizable olefinic unsaturated groups, and (Ciii) a polyfunctional monomer having at least three polymerizable olefinic unsaturated groups. More preferably, it is composed of at least (Ciii). From the viewpoint of improving the micro-aperture properties, it is further preferred to include both (Cii) and (Ciii). Furthermore, the polymerizable olefinic unsaturated group is preferably (meth)acryloyl. That is, from the viewpoint of improving the micro-aperture properties, component (C) preferably includes a difunctional (meth)acrylic acid monomer having two (meth)acryloyl groups as component (Cii) above and a polyfunctional (meth)acrylic acid monomer having at least three (meth)acryloyl groups as component (Ciii) above. As components (Ci) to (Ciii), components with a molecular weight of 1000 or less are preferred.

[0080] ((Ci) monofunctional monomer) As a monofunctional monomer having one polymerizable olefinic unsaturated group, examples include monofunctional (meth)acryloyl monomers having one (meth)acryloyl group. Examples of monofunctional (meth)acrylic monomers include (meth)acrylic acid and alkyl (meth)acrylic acid esters. Examples of alkyl (meth)acrylic acid esters include methyl (meth)acrylic acid, ethyl (meth)acrylic acid, butyl (meth)acrylic acid, 2-ethylhexyl (meth)acrylic acid, and hydroxyethyl (meth)acrylic acid ester. The (Ci) component can be used alone or in combination with two or more components.

[0081] ((Cii) difunctional monomer) Examples of difunctional monomers having two polymerizable olefinic unsaturated groups include difunctional (meth)acryloyl monomers having two (meth)acryloyl groups. Examples of difunctional (meth)acrylic monomers include ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane dimethacrylate, polypropylene glycol dimethacrylate, 2,2-bis(4-(meth)acryloyloxypolyethoxypolypropoxyphenyl)propane, bisphenol A diglycidyl ether dimethacrylate, 1,4-butanediol dimethacrylate, neopentyl glycol dimethacrylate, bisphenol A ethylene oxide modified dimethacrylate, and EO modified bisphenol A dimethacrylate. The (Cii) component can be used alone or in combination with two or more components.

[0082] ((Ciii) multifunctional monomer) As examples of polyfunctional monomers having at least three polymerizable olefinic unsaturated groups, polyfunctional (meth)acrylic acid monomers having at least three (meth)acryloyl groups can be listed. Examples of polyfunctional (meth)acrylic acid monomers include, for example, trimethylolpropane tri(meth)acrylate and other (meth)acrylate compounds having a backbone derived from trimethylolpropane; tetramethylolmethane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate and other (meth)acrylate compounds having a backbone derived from tetramethylolmethane; pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate and other (meth)acrylate compounds having a backbone derived from pentaerythritol; dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate and other (meth)acrylate compounds having a backbone derived from dipentaerythritol; bis(trimethylolpropane tetra(meth)acrylate and other (meth)acrylate compounds having a backbone derived from bis(trimethylolpropane); and (meth)acrylate compounds having a backbone derived from dipropylene glycol. From the viewpoint of improving the chemical resistance after curing (exposure) and increasing the difference in developer resistance between the exposed and unexposed areas, a (meth)acrylate compound having a backbone derived from dipentaerythritol is preferred, and dipentaerythritol hexa(meth)acrylate is more preferred. Component (Ciii) can be used alone or in combination with two or more components.

[0083] The content of component (C) in the photosensitive resin composition is not particularly limited. Based on the total amount of solid components in the photosensitive resin composition, it can be 0.2 to 15% by mass, 0.5 to 10% by mass, or 1 to 5% by mass.

[0084] (D) Component: Photopolymerization initiator) As for component (D), i.e., the photopolymerization initiator, there are no particular limitations as long as it can polymerize components (A) and (C). Component (D) can be used alone or in combination of two or more.

[0085] Examples of acetophenone compounds that can be listed as component (D) include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, 2-methyl-[4-(methylthio)phenyl]-2-morpholinyl-1-propane, N,N-dimethylaminoacetophenone, etc.; anthraquinone compounds such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-pentylanthraquinone, 2-aminoanthraquinone, etc.; benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, etc. Benzophenone compounds such as 4,4'-bis(diethylamino)benzophenone, milchnerone, and 4-benzoyl-4'-methyldiphenyl sulfide; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridyl)heptane; acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide; and oxime ester compounds such as 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(O-benzoyl oxime), 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl] acetone-1-(O-acetyl oxime), and 1-phenyl-1,2-propanedione-2-[O-(ethoxycarbonyl)oxime].

[0086] The content of component (D) in the photosensitive resin composition is not particularly limited. Based on the total amount of solid components in the photosensitive resin composition, it can be 0.2 to 15% by mass, 0.5 to 10% by mass, or 1 to 5% by mass.

[0087] (E) Composition: Inorganic filler) Regarding the photosensitive resin composition of this embodiment, by simultaneously using inorganic fillers with different average particle sizes as component (E) in a specific mass ratio, resolution and thickness margin can be improved. Under the same exposure conditions, good resolution can be obtained for both 18 μm and 25 μm film thicknesses, and a permanent resist with excellent insulation reliability can be formed. Component (E) contains a first inorganic filler with an average particle size of 0.5 μm or more and a second inorganic filler with an average particle size of 0.3 μm or less in a solid component mass ratio (first inorganic filler: second inorganic filler) in the range of 6:4 to 8:2.

[0088] Materials used as inorganic fillers include, for example, silicon dioxide, aluminum oxide, titanium dioxide, tantalum oxide, zirconium oxide, silicon nitride, barium titanate, barium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, lead titanate, lead zirconium titanate, lanthanum lead zirconium titanate, gallium oxide, spinel, mullite, cordierite, talc, aluminum titanate, yttrium-containing zirconium oxide, barium silicate, boron nitride, calcium carbonate, barium sulfate, calcium sulfate, zinc oxide, magnesium titanate, hydrotalcite, mica, calcined kaolin, and carbon.

[0089] Regarding component (E), from the viewpoint of improving the heat resistance of the permanent resist, it may contain silica filler; from the viewpoint of improving the heat resistance and adhesion strength of the permanent resist, it may contain barium sulfate filler, or it may contain both silica filler and barium sulfate filler. Furthermore, from the viewpoint of improving heat dissipation, component (E) may contain inorganic oxide filler, or it may contain silica filler. From the viewpoint of improving the dispersibility of inorganic fillers, inorganic fillers that have been surface-treated with alumina or organosilane compounds may also be used.

[0090] Regarding the first inorganic filler and the aforementioned second inorganic filler, from the viewpoint of improving heat dissipation, both can be inorganic oxide fillers; from the viewpoint of improving the heat resistance of permanent corrosion inhibitors, both can be silica fillers.

[0091] (E) The shape of the component is not particularly limited, but from the point of view of improving crack resistance, it can be spherical.

[0092] The average particle size of the first inorganic packing is 0.5 μm or larger. From the viewpoint of improving the dispersibility of the packing, it can be 0.5–5.0 μm, 0.5–3.0 μm, 0.5–2.0 μm, or 0.5–1.0 μm. The first inorganic packing can be used alone or two or more at the same time.

[0093] The average particle size of the second inorganic filler is less than 0.3 μm. From the viewpoint of improving light transmittance, it can be 0.001–0.3 μm, 0.005–0.3 μm, 0.01–0.3 μm, or 0.1–0.3 μm. The second inorganic filler can be used alone or two or more at the same time.

[0094] (E) Component may further include, but is not limited to, the third inorganic filler with an average particle size greater than 0.3 μm and less than 0.5 μm, in addition to the first and second inorganic fillers. Based on the total amount of (E) component, the content of the third inorganic filler may be less than 10% by mass or may be 0% by mass.

[0095] (E) The average particle size of the component is the average particle size of the inorganic filler dispersed in the photosensitive resin composition, and is obtained by determination as follows: First, the photosensitive resin composition was diluted 1000 times with methyl ethyl ketone, and then the particles dispersed in the solvent were measured using a submicron particle analyzer (Beckman Coulter, Inc., trade name "N5") according to the international standard ISO 13321 with a refractive index of 1.38. The particle size at 50% (volume basis) of the cumulative value in the particle size distribution was taken as the average particle size.

[0096] Based on the total solid content of the photosensitive resin composition, the content of component (E) can be 5-80% by mass, 5-70% by mass, 6-60% by mass, or 10-50% by mass. Moreover, in component (E), the solid content mass ratio (first inorganic filler: second inorganic filler) of the first inorganic filler content to the second inorganic filler content is 6:4 to 8:2, and can be 6.5:3.5 to 7.5:2.5.

[0097] (F) Ingredient: Photosensitizer The photosensitive resin composition of this embodiment may further contain a photosensitizer as component (F). By containing component (F) in the photosensitive resin composition, the absorption wavelength of the active light used in the exposure can be effectively utilized.

[0098] Examples of photosensitizers as components (F) include thioxanthone compounds such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; phosphine compounds such as triphenylphosphine; toluidine compounds such as N,N-dimethyltoluidine; anthracene compounds such as 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, and 2-ethyl-9,10-diethoxyanthracene; perylene compounds; coumarin compounds; pyrazoline compounds; oxazole compounds; benzoxazole compounds; thiazole compounds; triazole compounds; stilbene compounds; triazine compounds; thiophene compounds; naphthalenedicarboximide compounds; and triarylamine compounds.

[0099] From the viewpoint of maintaining the shape of the via well, 2,4-dimethylthioxanthone or 2,4-diethylthioxanthone are preferred as photosensitizers, and 2,4-diethylthioxanthone is more preferred. When 2,4-diethylthioxanthone is used, it tends to reduce the scattered light to the unexposed portion, and as a result, the shape of the via well is maintained.

[0100] The content of component (F) is based on the total amount of solid components in the photosensitive resin composition, preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, even more preferably 0.1 to 2% by mass, and especially preferably 0.3 to 1.5% by mass.

[0101] ((G) Ingredient: Pigment) From the viewpoint of improving the recognizability or appearance of the manufacturing apparatus, the photosensitive resin composition of this embodiment may further contain pigment as component (G). As component (G), a colorant that displays a desired color when masking wiring (conductor patterns), etc., can be used. Component (G) can be used alone or in combination of two or more.

[0102] Examples of components (G) include phthalocyanine blue, phthalocyanine green, iodine green, azo yellow, titanium dioxide, carbon black, and naphthalene black.

[0103] From the viewpoint of easily identifying the manufacturing device and further shielding the wiring, the content of component (G) can be 0.01 to 5.0% by mass, 0.03 to 3.0% by mass, or 0.05 to 2.0% by mass, based on the total amount of solid components in the photosensitive resin composition.

[0104] (H) Component: Ultraviolet absorber) From the viewpoint of improving the micro-aperture properties, the photosensitive resin composition of this embodiment may further contain an ultraviolet absorber as component (H). Component (H) may be a compound that absorbs light in the wavelength range of 340 to 430 nm, or a compound that effectively absorbs light in the wavelength range of 365 nm. The molar absorptivity of component (H) for light in the wavelength range of 365 nm may be in the range of 500 to 50,000 L / (mol·cm). The molar absorptivity is an indicator of the ease with which light is absorbed. Component (H) may be used alone or in combination of two or more.

[0105] Examples of UV absorbers that are (H) components include salicylates, cyanoacrylates, benzotriazoles, benzophenones, triazines, benzoxazinones, and benzoates.

[0106] From the viewpoint of improving micro-opening properties and increasing thickness margin, the content of component (H) can be 0.01 to 5.0% by mass, 0.01 to 3.0% by mass, or 0.01 to 1.0% by mass, based on the total amount of solid components in the photosensitive resin composition.

[0107] (Other ingredients) As needed, the photosensitive resin composition of this embodiment may further contain various additives. Examples of additives include curing accelerators such as melamine; polymerization inhibitors such as hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; defoamers of silicone, fluorine, and vinyl resins; silane coupling agents; and flame retardants such as phosphate compounds, aromatic condensed phosphates, and halogenated condensed phosphates.

[0108] (solvent) The photosensitive resin composition of this embodiment contains a solvent for dissolving / dispersing the components, which enables it to be easily coated onto a substrate to form a coating film of uniform thickness.

[0109] Examples of solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; ethylene 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. One solvent can be used alone or in combination of two or more.

[0110] There is no particular limitation on the amount of solvent used, but the proportion of solvent in the photosensitive resin composition can be 10-50% by mass, 20-40% by mass, or 25-35% by mass.

[0111] The photosensitive resin composition of this embodiment can be prepared by uniformly mixing the above-mentioned components using a roller mill, a bead mill, or the like.

[0112] [Photosensitive element] The photosensitive element of this embodiment includes a support film and a photosensitive layer comprising the above-described photosensitive resin composition. Figure 1 This is a schematic cross-sectional view illustrating the photosensitive element of this embodiment. (e.g.) Figure 1 As shown, the photosensitive element 1 includes a support film 10 and a photosensitive layer 20 formed on the support film 10.

[0113] Regarding the photosensitive element 1, it can be manufactured by coating the photosensitive resin composition of this embodiment onto the support film 10 using known methods such as reverse roller coating, gravure roller coating, corner roller coating, and curtain coating, and then drying the coating to form a photosensitive layer 20.

[0114] Examples of support films include polyester films such as polyethylene terephthalate and polybutylene terephthalate, and polyolefin films such as polypropylene and polyethylene. The thickness of the support film can be, for example, 5–100 μm. The thickness of the photosensitive layer can be, for example, 5–50 μm, 5–40 μm, 10–30 μm, 15–30 μm, 20–30 μm, or 25–30 μm. The surface roughness of the support film is not particularly limited, but the arithmetic mean roughness (Ra) can be less than 1000 nm, less than 500 nm, or less than 250 nm.

[0115] Regarding the drying of the coating, hot air drying, or drying using far-infrared or near-infrared rays can be used. The drying temperature can also be 60–120℃, 70–110℃, or 80–100℃. The drying time can also be 1–60 minutes, 2–30 minutes, or 5–20 minutes.

[0116] A protective film 30 covering the photosensitive layer 20 may also be further provided on the photosensitive layer 20. The photosensitive element 1 may also have the protective film 30 laminated on the side opposite to the side of the photosensitive layer 20 that is in contact with the support film 10. As the protective film 30, a polymer film such as polyethylene or polypropylene may be used, for example.

[0117] The range of solid content of each component ((A) to (G) and other components) in the photosensitive layer 20, other than the volatile substances, can be the same as the range of solid content of each component in the photosensitive resin composition.

[0118] Printed Circuit Board The printed circuit board of this embodiment includes a permanent resist comprising a cured product of the photosensitive resin composition of this embodiment.

[0119] The method for manufacturing a printed circuit board according to this embodiment includes: a step of forming a photosensitive layer on a substrate using the above-described photosensitive resin composition or photosensitive element; a step of exposing and developing the photosensitive layer to form a resist pattern; and a step of curing the resist pattern to form a permanent resist. An example of each step will be described below.

[0120] First, a substrate such as a copper-clad laminate is prepared, and a photosensitive layer is formed on this substrate. The photosensitive layer can also be formed by coating a photosensitive resin composition onto the substrate and then drying it. Methods for coating the photosensitive resin composition include, for example, screen printing, spraying, roller coating, curtain coating, and electrostatic coating. The drying temperature can also be 60–120°C, 70–110°C, or 80–100°C. The drying time can also be 1–60 minutes, 2–30 minutes, or 3–20 minutes.

[0121] Regarding the photosensitive layer, it can also be formed by peeling off the protective film from the photosensitive element and laminating the photosensitive layer onto the substrate. As a method for laminating the photosensitive layer, for example, thermal lamination using a laminator can be cited.

[0122] Next, the negative film is brought into direct contact with the photosensitive layer or through a supporting film, and exposed to active light. Examples of active light include electron beams, ultraviolet light, and X-rays, with ultraviolet light being preferred. As the light source, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, halogen lamps, etc., can be used. The exposure dose can also be 10–2000 mJ / cm². 2 100~1500mJ / cm 2 Or 300~1000mJ / cm 2 .

[0123] After exposure, the unexposed areas are removed using a developer to form a resist pattern. Examples of developing methods include immersion and spraying. Examples of developers include alkaline aqueous solutions such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, and tetramethylammonium hydroxide.

[0124] A pattern-cured film (permanent resist) can be formed by at least one of post-exposure and post-heating treatments on the resist pattern. The exposure amount for post-exposure can be 100–5000 mJ / cm². 2 500~2000mJ / cm 2 Or 700~1500mJ / cm 2 The post-heating temperature can also be 100–200℃, 120–180℃, or 135–165℃. The post-heating time can also be 5 minutes to 6 hours, 10 minutes to 3 hours, or 30 minutes to 2 hours.

[0125] The permanent photoresist can have through-holes with a diameter of 25 to 200 μm, or through-holes with a diameter of 25 to 100 μm. Even when such through-holes are formed in the permanent photoresist, through-holes with suppressed undercut can be formed by using the photosensitive resin composition of this embodiment. Furthermore, the permanent photoresist can have both large-diameter through-holes with a diameter of 70 μm or more and small-diameter through-holes with a diameter of 35 μm or less. Even when such through-holes with different diameters are formed in the permanent photoresist, through-holes with suppressed undercut can be formed at any diameter by using the photosensitive resin composition of this embodiment.

[0126] The permanent photoresist of this embodiment can be used as an interlayer insulating layer or a surface protective layer for semiconductor devices. Semiconductor devices having an interlayer insulating layer or a surface protective layer formed from a cured film of the above-described photosensitive resin composition, and electronic devices containing such semiconductor devices, can be manufactured. Semiconductor devices can be, for example, memory devices or packages having multilayer wiring structures, rewiring structures, etc. Examples of electronic devices include mobile phones, smartphones, tablet terminals, personal computers, and hard disk drives. By having a patterned cured film formed from the photosensitive resin composition of this embodiment, semiconductor devices and electronic devices with excellent reliability can be provided.

[0127] Example The present invention will be further described in detail below through embodiments, but the present invention is not limited to these embodiments.

[0128] (Synthesis example 1) At 90°C, bisphenol F phenolic varnish-type epoxy resin (manufactured by DIC Corporation, trade name "EXA-7376"), in formula (II), has Y 3 and Y4 glycidyl group, R 12 Bisphenol F phenolic varnish-type epoxy resin with hydrogen atom structural units, epoxy equivalent: 186) 350 parts by mass, acrylic acid 70 parts by mass, methyl hydroquinone 0.5 parts by mass, and carbitol acetate 120 parts by mass were mixed while stirring. The mixture was cooled to 60°C, 2 parts by mass of triphenylphosphine were added, and the mixture was reacted at 100°C until the acid value of the solution was below 1 mg KOH / g. Tetrahydrophthalic anhydride (THPAC) 98 parts by mass and carbitol acetate 85 parts by mass were added to the reaction solution, and the reaction was carried out at 80°C for 6 hours. Afterwards, the reaction solution was cooled to room temperature to obtain a solution of acid-modified epoxy acrylate (A-1) as component (A) (solid component concentration: 73% by mass).

[0129] The following materials were prepared as components (B) to (G).

[0130] B-1: Tetramethylbisphenol F type epoxy resin (manufactured by NIPPON STEEL Chemical & Material Co., Ltd., trade name "YSLV-80XY") C-1: A mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name "KAYARAD DPHA") C-2: Polyethylene glycol #200 dimethacrylate (manufactured by Resonac Holdings Corporation, trade name "FA-220M") D-1: 2-Methyl-[4-(methylthio)phenyl]morpholino-1-propanone (manufactured by IGM Resins BV, trade name "Omnirad 907") D-2: 4,4'-bis(diethylamino)benzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) E-1: Spherical silica filler (manufactured by Admatechs Company Limited, trade name "SC2050", methacryloxysilane surface-treated product, average particle size: 0.5μm) E-2: Spherical silica filler (manufactured by Admatechs Company Limited, trade name "SO-C1", methacryloxysilane surface-treated product, average particle size: 0.3μm) E-3: Spherical silica filler (manufactured by Admatechs Company Limited, trade name "YC100C", methacryloyloxysilane surface-treated product, average particle size: 0.1μm) F-1: 2,4-Diethylthioxanthone (manufactured by IGM Resins BV, trade name "Omnirad DETX") G-1: Phthalocyanine pigments (manufactured by Sanyo Color Works, LTD.) H-1: Benzophenone-based ultraviolet absorbing material (manufactured by Chemipro Kasei Kaisha, Ltd., trade name "KEMISORB 111") [Examples 1-19 and Comparative Examples 1-14] <Photosensitive Resin Composition> The components were formulated according to the proportions (parts by mass, converted solids content) shown in Tables 1 to 3, and then mixed using a three-roll mill. Carbitol acetate was then added to bring the solids content to 70% by mass, thus preparing the photosensitive resin composition.

[0131] <Photosensitive element> A polyethylene terephthalate film (manufactured by TOYOBO CO., LTD., trade name "G2-25") with a thickness of 25 μm was prepared as the support film. A solution diluted with methyl ethyl ketone to the photosensitive resin composition was coated onto the support film to achieve a thickness of 18 μm or 25 μm after drying, and then 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., trade name "NF-15") was laminated onto the surface of the photosensitive layer, with the side in contact with the support film being the opposite side, as a protective film, thereby obtaining a photosensitive element.

[0132] [Resolution Evaluation] After treating the surface of the copper foil of a copper-clad laminate substrate (manufactured by Resonac Holdings Corporation, trade name "MCL-E-679") with a 12μm thick copper foil laminated on a glass epoxy substrate using a roughening pretreatment solution (manufactured by MEC COMPANY LTD., trade name "CZ-8100"), the substrate was washed and dried to obtain a roughened copper-clad laminate substrate. Next, the protective film was peeled off from the photosensitive element, and the exposed photosensitive layer was placed in contact with the copper foil of the roughened copper-clad laminate substrate. Lamination was then performed using a vacuum laminator (manufactured by MEIKI CO., LTD., trade name "MVLP-500") to obtain a laminate. The lamination conditions were set as follows: air pressure below 4 kPa, vacuum time 25 seconds, pressing pressure 0.4 MPa, hot plate temperature 80°C, and lamination pressing time 25 seconds. After the above-described laminate was left at room temperature for more than one hour, the photosensitive layer was exposed using an i-ray exposure apparatus (manufactured by Ushio Inc., trade name "UX-2240SM") with an exposure dose equal to 10 of the fully cured segments in a 41-segment staged exposure table. A negative mask with an opening pattern of a specified size (aperture diameter: 70 μm) was used for the exposure pattern. Subsequently, the support film was peeled off from the photosensitive layer using a 1% (w / w) sodium carbonate aqueous solution at an exposure dose of 1.765 × 10⁻⁶. 5 Pressure spray development was performed for 40 seconds, and the unexposed areas were dissolved and developed. Next, ultraviolet exposure was conducted at 2000 mJ / cm². 2 After exposing the developed photosensitive layer to the specified exposure amount, the film is heated at 170°C for 1 hour to produce a test piece with a cured film (film thickness 18μm or 25μm) having an opening pattern of a specified size on a copper-clad laminate substrate.

[0133] The test pieces were molded with embedding resin (using Mitsubishi Chemical Corporation's trade name "jER828" as the epoxy resin and triethylenetetramine as the curing agent) and allowed to fully cure. Then, they were ground using a polisher (Refinetech Co., Ltd., trade name "Refine Polisher") to create a cross-section of the cured film's opening pattern. The obtained opening pattern cross-section was observed using a metal microscope and evaluated according to the following criteria. The results are shown in Tables 1 to 3. An evaluation result of S, A, or B indicates good resolution.

[0134] S: No bottom cut, and the through hole is a straight line shape. A: No bottom cut, and the through hole is conical. B: It has an undercut, and the diameter of the undercut portion is smaller than the top diameter of the through hole + 5μm. C: It has an undercut, and the diameter of the undercut portion is at least 5 μm larger than the top diameter of the through hole. [Evaluation of minimum aperture] A laminate consisting of a copper-clad laminate substrate / photosensitive layer / support film was obtained in the same manner as described above for [resolution evaluation]. After the laminate was left at room temperature for more than 1 hour, the photosensitive layer was exposed using an i-ray exposure apparatus (manufactured by Ushio Inc., trade name "UX-2240SM") with an exposure dose equal to 10 fully cured segments in a 41-segment staged exposure table. The exposure pattern used a grid pattern of dots (dot diameter: distance between dot centers = 1:2). Regarding the dot diameter (... The micrometers were varied in increments of 1 μm within the range of 15–50 μm and in increments of 5 μm within the range of 50–200 μm. Afterward, the support film was peeled off from the photosensitive layer using a 1% (w / w) sodium carbonate aqueous solution at a magnification of 1.765 × 10⁻⁶. 5 Pressure spray development was performed for 40 seconds, and the unexposed areas were dissolved and developed. Next, ultraviolet exposure was conducted at 2000 mJ / cm². 2 After exposing the developed photosensitive layer to the specified exposure amount, the film is heated at 170°C for 1 hour to produce a test piece with a cured film (film thickness 18μm) having an opening pattern of a specified size on a copper-clad laminate substrate.

[0135] The opening pattern of the test pieces was observed using a scanning electron microscope (manufactured by Hitachi High-Tech Corporation, trade name "SU8010"). Test pieces with no resin residue at the bottom of the opening and where the copper foil of the copper-clad laminate could be clearly seen were considered to have an opening. The minimum masking size (diameter of the dot) of the opening was then determined. The minimum aperture is used as the minimum opening diameter. The results of the minimum aperture measurement are shown in Tables 1 to 3.

[0136] [Evaluation of Insulation Reliability] An evaluation substrate with comb-shaped electrodes (line / blank = 10 μm / 10 μm) was used instead of a copper-clad laminate substrate, and full-area exposure was performed without a negative mask. Otherwise, test pieces were fabricated in the same manner as described above for [resolution evaluation]. The test pieces were then exposed at 130°C, 85%RH, and 6V for 250 hours. The resistance between the electrodes was measured, and the resistance value was recorded as 10⁻⁶. -6 The time below Ω was defined as the copper migration occurrence time. The copper migration occurrence time was measured, and the interlayer insulation reliability (HAST withstand) was evaluated according to the following criteria. The results are shown in Tables 1 to 3. An evaluation result of A or B indicates excellent insulation reliability.

[0137] A: The migration occurred more than 250 hours ago. B: The migration occurred more than 200 hours but less than 250 hours ago. C: The migration occurred less than 200 hours ago. Symbol Explanation 1-Photosensitive element, 10-Supporting film, 20-Photosensitive layer, 30-Protective film.

Claims

1. A photosensitive resin composition comprising (A) a resin having olefinic unsaturated bonds and acidic groups, (B) a thermosetting resin, (C) a photopolymerizable compound, (D) a photopolymerization initiator, and (E) an inorganic filler. The inorganic filler (E) comprises a first inorganic filler with an average particle size of 0.5 μm or more and a second inorganic filler with an average particle size of 0.3 μm or less. The solid component mass ratio of the content of the first inorganic filler to the content of the second inorganic filler is 6:4 to 8:

2.

2. The photosensitive resin composition according to claim 1, wherein, Based on the total amount of solid components in the photosensitive resin composition, the content of component (E) is 10 to 80% by mass.

3. The photosensitive resin composition according to claim 1, wherein, Both the first inorganic packing and the second inorganic packing are inorganic oxide packings.

4. The photosensitive resin composition according to claim 1, wherein, Both the first inorganic filler and the second inorganic filler are spherical silica fillers.

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

6. The photosensitive resin composition according to claim 1, further comprising (H) an ultraviolet absorber.

7. The photosensitive resin composition according to claim 1, wherein, The (C) photopolymerizable compound comprises a difunctional (meth)acrylic acid monomer having two (meth)acryloyl groups and a polyfunctional (meth)acrylic acid monomer having at least three (meth)acryloyl groups.

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

9. A printed circuit board comprising a permanent resist comprising a cured photosensitive resin composition according to any one of claims 1 to 7.

10. A method for manufacturing a printed circuit board, comprising: The process of forming a photosensitive layer on a substrate using the photosensitive resin composition according to any one of claims 1 to 7; The process of exposing and developing the photosensitive layer to form a resist pattern; and The process of curing the resist pattern to form a permanent resist.

11. A method for manufacturing a printed circuit board, comprising: The process of forming a photosensitive layer on a substrate using the photosensitive element as described in claim 8; The process of exposing and developing the photosensitive layer to form a resist pattern; and The process of curing the resist pattern to form a permanent resist.

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