JP2012242592A - Photosensitive resin composition, photosensitive element and permanent resist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alkali developable photosensitive resin composition, from which a fine aperture pattern can be formed without degrading developability and which shows excellent HAST (high accelerated stress test) durability between fine wiring lines and has high heat resistance, and to provide a photosensitive film using the composition.SOLUTION: The photosensitive resin composition includes components of: (a) a resin having an ethylenically unsaturated group and a carboxyl group; (b) a photopolymerizable monomer having an ethylenically unsaturated group; (c) a photopolymerization initiator; (d) an epoxy resin and (e) silica filler. In the resin composition, the component (e) has an average particle diameter of less than 50 nm in the measurement of particle size distribution by a dynamic light scattering method and is dispersed in the photosensitive resin composition with the maximum particle diameter of 1 μm or less.

Description

  The present invention relates to a photosensitive resin composition, a photosensitive element using the same, and a permanent resist. In particular, the present invention relates to a photosensitive resin composition suitable as a solder resist used for printed wiring boards, semiconductor package substrates, and flexible wiring boards.

  With the reduction in size and weight of various electronic devices, photosensitive solder resist is used for printed wiring boards, semiconductor package boards, and flexible wiring boards for the purpose of forming fine opening patterns. In particular, the solder resist used for semiconductor package substrates is shifting to a flip-chip method for chip-to-substrate connection, and the connection pitch is becoming narrower. It is required that a simple opening pattern can be formed.

  In addition, the solder resist generally requires developability, resolution, solder heat resistance, gold plating resistance, etc., but the solder resist used for the semiconductor package substrate has a high reliability in view of TCT. High crack resistance against (temperature cycle test), PCT resistance (pressure cooker test resistance), and HAST resistance (high acceleration stress test resistance) between fine wirings are required. Further, with the demand for lead-free due to consideration for environmental problems, high heat resistance (high Tg (glass transition temperature), crack resistance) is also required.

  A general solder resist currently used is mainly a liquid two-component type in which an epoxy resin as a curing agent and a carboxylic acid-containing photosensitive resin for imparting alkali developability are separately divided.

  As the carboxylic acid-containing photosensitive resin, since it has high temperature and humidity resistance, an acrylic resin that can be developed with an acid after adding acrylic acid to a cresol novolac type epoxy resin and then acid-modified is widely used (for example, Patent Document 1). Recently, photosensitive resins further containing an elastomer have been used for the purpose of improving resistance to TCT (see, for example, Patent Documents 2 and 3).

  In the photosensitive resin composition used for the solder resist, an inorganic filler such as silica or barium sulfate is kneaded and dispersed with a three roll or the like. For this reason, the resolution is lowered due to the inorganic filler, and it has become difficult to form a fine opening pattern required in the future.

  By the way, a negative photosensitive resin composition is cured by exposure and developed. However, in order to improve developability (high resolution), it is effective to increase the solubility of the unexposed portion in the developer. In order to increase the solubility of the unexposed area, there is a method of introducing a hydrophilic group into the photosensitive resin composition. When a carboxyl group is used as such a hydrophilic group, the high hydrophilicity has an acid value. The higher the acid value resin, the higher the solubility.

  However, in the case of a permanent resist such as a solder resist, the higher the acid value of the polymer, the higher the water absorption. Therefore, the insulation resistance (HAST resistance) and heat resistance under high temperature and high humidity conditions are likely to decrease. As described above, it is difficult to develop a photosensitive resin composition that simultaneously satisfies developability, heat resistance, and HAST resistance.

JP-A 61-243869 JP 2002-162738 A JP 2004-28726 A

  The present invention is capable of forming a fine opening pattern without impairing developability, is excellent in HAST resistance between fine wires, and has a high heat resistance, and an alkali developable photosensitive resin composition, and It aims at providing the photosensitive film using this.

  A highly reliable photosensitive resin composition having high crack resistance against TCT (temperature cycle test) by greatly reducing the thermal expansion coefficient of the resin, and a photosensitive film using the same The purpose is to provide.

The inventors have
(A) component: resin having an ethylenically unsaturated group and a carboxyl group,
(B) component: a photopolymerizable monomer having an ethylenically unsaturated group,
(C) component: photopolymerization initiator,
(D) component: epoxy resin, and (e) component: a photosensitive resin composition containing a silica filler,
The photosensitive resin in which the average particle size of the component (e) is less than 50 nm in the particle size distribution measurement by a dynamic light scattering method, and the maximum particle size is dispersed in the photosensitive resin composition with a maximum particle size of 1 μm or less. The composition can form a fine opening pattern, has excellent HAST resistance between fine wires, has a low thermal expansion coefficient, and has high crack resistance against TCT (temperature cycle test). The present invention has been completed.

  The present invention also relates to the above photosensitive resin composition, wherein the component (e) has been subjected to at least one silane coupling treatment selected from epoxy silane, mercaptosilane, isocyanate silane, acrylic silane, and methacryl silane. .

  Another aspect of the present invention relates to a photosensitive element comprising a support and a photosensitive layer made of the photosensitive resin composition formed on the support.

  Furthermore, another aspect of the present invention relates to a permanent resist made of a cured product of the photosensitive resin composition, which is formed on a substrate for a printed wiring board.

  According to the present invention, an alkali developable photosensitive resin composition having excellent developability, capable of forming a fine opening pattern with good pattern formation, having sufficient HAST resistance, and obtaining high heat resistance. And a dry film type photosensitive film can be provided. Furthermore, the photosensitive resin composition of the present invention can greatly reduce the thermal expansion coefficient of the resin due to the effect of the silica filler, and has a high crack resistance against TCT (temperature cycle test). Highly sensitive photosensitive resin composition can be obtained.

Hereinafter, preferred embodiments of the present invention will be described in detail.
[Photosensitive resin composition]
Hereinafter, each component used by the photosensitive resin composition of this invention is demonstrated in detail.

  Examples of the (a) photo-radical reactive resin having an ethylenically unsaturated group and a carboxyl group that can be used in the present invention are saturated with an esterified product of an epoxy compound (a1) and an unsaturated monocarboxylic acid (a2). Alternatively, an addition reaction product obtained by adding an unsaturated polybasic acid anhydride (a3) or the like can be used. These can be obtained by the following two-step reaction. In the first reaction (hereinafter referred to as “first reaction” for convenience), the epoxy compound (a1) and the unsaturated monocarboxylic acid (a2) react. In the next reaction (hereinafter referred to as “second reaction” for convenience), the esterified product produced in the first reaction reacts with the saturated or unsaturated polybasic acid anhydride (a3).

  Although there is no restriction | limiting in particular as said epoxy compound (a1), For example, a bisphenol type epoxy compound, a novolak type epoxy compound, a biphenyl type epoxy compound, a polyfunctional epoxy compound etc. are mentioned. As the bisphenol type epoxy compound, those obtained by reacting bisphenol A type or bisphenol F type with epichlorohydrin are suitable. A bisphenol A type, a bisphenol F type, a hydrogenated bisphenol A type, an amino group-containing, alicyclic or polybutadiene-modified epoxy compound such as a company-made product name: jER828, 1007, or 807 is suitable.

  As a novolak type epoxy compound, it can be obtained by reacting at least one kind selected from phenols such as phenol, cresol, halogenated phenol and alkylphenol with formaldehyde and an novolak and epichlorohydrin. Goods, manufactured by Nippon Kayaku Epoxy Manufacturing Co., Ltd., trade names: YDCN-701, 704, YDPN-638, 602, manufactured by Dow Chemical Co., Ltd., trade names: DEN-431, 439, manufactured by BASF Corporation, commercial products Name: EPN-1299, manufactured by DIC Corporation, trade names: N-730, 770, 865, 665, 673, VH-4150, 4240, manufactured by Nippon Kayaku Co., Ltd., trade names: EOCN-120, BREN, etc. It is done.

  Examples of epoxy compounds having other structures include salicylaldehyde-phenol or salicylaldehyde-cresol type epoxy compounds (manufactured by Nippon Kayaku Co., Ltd., trade names: EPPN502H, FAE2500, etc.), manufactured by Dow Chemical Company, trade name: DER -330, 337, 361, Daicel Chemical Industries, Ltd., trade name: Celoxide 2021, Mitsubishi Gas Chemical Co., Ltd., trade name: TETRAD-X, C, Nippon Soda Co., Ltd., trade name: EPB-13, 27 Etc. can also be used. These may be used alone or in combination of two or more, and a mixture or a block copolymer may be used.

  Examples of the unsaturated monocarboxylic acid (a2) include (meth) acrylic acid, crotonic acid, cinnamic acid, and saturated or unsaturated polybasic acid anhydrides and (meth) acrylates having one hydroxyl group in one molecule. Or the reaction material of the half-ester compound of a saturated or unsaturated dibasic acid and an unsaturated monoglycidyl compound is mentioned. Examples of the reactant include phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, succinic acid, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and tris (hydroxyethyl) isocyanurate. Examples thereof include reactants obtained by reacting di (meth) acrylate, glycidyl (meth) acrylate and the like in an equimolar ratio by a conventional method. These unsaturated monocarboxylic acids can be used alone or in combination. Among these, acrylic acid is preferable.

  Examples of the saturated or unsaturated polybasic acid anhydride include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexa Examples thereof include hydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride, trimellitic anhydride and the like.

  In the first reaction, a hydroxyl group is generated by an addition reaction between the epoxy group of the epoxy compound (a1) and the carboxyl group of the unsaturated monocarboxylic acid (a2). In the first reaction, the ratio of the epoxy compound (a1) to the unsaturated monocarboxylic acid (a2) is such that the unsaturated monocarboxylic acid (a2) is 0.001 equivalent to 1 equivalent of the epoxy group of the epoxy compound (a1). The ratio is preferably 7 to 1.05 equivalent, and more preferably 0.8 to 1.0 equivalent.

  The epoxy compound (a1) and the unsaturated monocarboxylic acid (a2) can be reacted by dissolving in an organic solvent. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, aliphatic carbonization such as octane and decane Petroleum solvents such as hydrogen, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha can be used.

  In the first reaction, it is preferable to use a catalyst in order to accelerate the reaction. As the catalyst, for example, triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, triphenylphosphine, and the like can be used. It is preferable that the usage-amount of a catalyst shall be 0.1-10 mass parts with respect to a total of 100 mass parts of an epoxy compound (a1) and unsaturated monocarboxylic acid (a2).

In the first reaction, the epoxy compounds (a1) or unsaturated monocarboxylic acids (a2)
In order to prevent polymerization of each other or the epoxy compound (a1) and the unsaturated monocarboxylic acid (a2), it is preferable to use a polymerization inhibitor. As the polymerization inhibitor, for example, hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol and the like can be used. It is preferable that the usage-amount of a polymerization inhibitor shall be 0.01-1 mass part with respect to a total of 100 mass parts of an epoxy compound (a1) and unsaturated monocarboxylic acid (a2). 60-150 degreeC is preferable and, as for the reaction temperature of a 1st reaction, 80-120 degreeC is more preferable.

  In the first reaction, an unsaturated monocarboxylic acid (a2) and a polybasic acid anhydride such as trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, biphenyltetracarboxylic anhydride, etc., if necessary Can be used in combination.

  In the second reaction, when the hydroxyl group formed in the first reaction and the hydroxyl group originally present in the epoxy compound (a1) undergo a half-ester reaction with the acid anhydride group of the saturated or unsaturated polybasic acid anhydride (a3). Inferred. Here, 0.1 to 1.0 equivalent of polybasic acid anhydride (a3) can be reacted with 1 equivalent of hydroxyl group in the resin obtained by the first reaction. By adjusting the amount of the polybasic acid anhydride (a3) within this range, the acid value of the component (a) can be adjusted.

  Examples of the resin having a carboxyl group include CCR-1218H, CCR-1159H, CCR-1222H, PCR-1050, TCR-1335H, ZAR-1035, ZAR-2001H, ZFR-1185, and ZCR-1569H (above, Nippon Kayaku). (Trade name, manufactured by Yakuhin Co., Ltd.) is commercially available.

  When a compound having a urethane bond is used as the component (a), an epoxy acrylate compound having two or more hydroxyl groups and an ethylenically unsaturated group in the molecule, a diisocyanate compound, and a diol compound having a carboxyl group are reacted. It is preferable to use the polyurethane compound obtained by making it.

  As described above, the polyurethane compound includes an epoxy acrylate compound having two or more hydroxyl groups and an ethylenically unsaturated group (hereinafter referred to as “raw material epoxy acrylate”), a diisocyanate compound (hereinafter referred to as “raw material diisocyanate”), and a carboxyl. It is a compound obtained using a diol compound having a group (hereinafter referred to as “raw diol”) as a raw material component. These raw material components will be described.

  Examples of the raw material epoxy acrylate include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, novolac type epoxy compounds, compounds obtained by reacting (meth) acrylic acid with epoxy compounds having a fluorene skeleton, and the like.

  As said raw material diisocyanate, if it is a compound which has two isocyanate groups, it can apply without a restriction | limiting in particular. For example, phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, tolden diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, arylene sulfone ether diisocyanate, allyl cyanide diisocyanate, N-acyl diisocyanate, trimethylhexamethylene diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, norbornane-diisocyanate methyl and the like can be mentioned. These may be used alone or in combination of two or more.

  The raw material diol is a compound having two hydroxyl groups such as an alcoholic hydroxyl group and / or a phenolic hydroxyl group in the molecule and a carboxyl group. The hydroxyl group preferably has an alcoholic hydroxyl group from the viewpoint of improving the developability of the photosensitive resin composition with an alkaline aqueous solution. Examples of such diol compounds include dimethylolpropionic acid and dimethylolbutanoic acid.

  Next, an example of a process for producing a polyurethane compound using the above raw material components will be described. In the production process of the polyurethane compound, first, the raw material epoxy acrylate and the raw material diol are reacted with the raw material diisocyanate. In such a reaction, a so-called urethanization reaction occurs mainly between the hydroxyl group in the raw material epoxy acrylate and the isocyanate group in the raw material diisocyanate and between the hydroxyl group in the raw material diol and the isocyanate group in the raw material diisocyanate. By this reaction, for example, a polyurethane compound in which a structural unit derived from a raw material epoxy acrylate and a structural unit derived from a raw material diol are polymerized alternately or in a block manner via a structural unit derived from a raw material diisocyanate is generated. An example of such a polyurethane compound is a compound represented by the following general formula (1).

Here, in the general formula (1), R ⁷ is a residue of raw material epoxy acrylate, R ⁸ is a residue of raw material diisocyanate, R ⁹ is an alkyl group having 1 to 5 carbon atoms, and R ¹⁰ is a hydrogen atom or a methyl group. Show. In addition, a residue means the structure of the part remove | excluding the functional group used for the coupling | bonding from the raw material component. In addition, a plurality of groups in the formula may be the same or different. The terminal hydroxyl group of the polyurethane compound may be treated with a saturated or unsaturated polybasic acid anhydride.

  In the production process of the polyurethane compound, a diol compound different from these may be further added in addition to the raw material epoxy acrylate, the raw material diol, and the raw material diisocyanate. Thereby, it becomes possible to change the main chain structure of the obtained polyurethane compound, and the characteristics such as the acid value described later can be adjusted to a desired range. In each of the above steps, a catalyst or the like may be used as appropriate.

  Moreover, you may make the said polyurethane compound and raw material epoxy acrylate react further. In this reaction, a so-called epoxycarboxylation reaction occurs mainly between the carboxyl group derived from the raw material diol compound in the polyurethane compound and the epoxy group of the raw material epoxy acrylate. The compound thus obtained has, for example, a main chain formed from the above polyurethane compound and a side chain containing an ethylenically unsaturated group derived from the raw material epoxy acrylate.

As the polyurethane compound of the present embodiment, among the compounds represented by the general formula (1), the hard segment part of the raw material epoxy acrylate that becomes one of the main skeletons of polyurethane, that is, R ⁷ has a bisphenol A structure. preferable. Such a polyurethane compound is commercially available as UXE-3011, UXE-3012, UXE-3024 (all manufactured by Nippon Kayaku Co., Ltd., trade names) and the like. These may be used alone or in combination of two or more. Moreover, the photosensitive resin composition containing this polyurethane compound can improve HAST tolerance more.

  The resin having a carboxyl group as the component (a) exemplified above has an acid value of preferably 20 to 180 mgKOH / g, more preferably 30 to 150 mgKOH / g, and 40 to 120 mgKOH / g. It is particularly preferred that Thereby, the developability with the alkaline aqueous solution of the photosensitive resin composition becomes good, and an excellent resolution can be obtained.

Here, the acid value can be measured by the following method. First, after precisely weighing about 1 g of the measurement resin solution, 30 g of acetone is added to the resin solution to uniformly dissolve the resin solution. Next, an appropriate amount of phenolphthalein as an indicator is added to the solution, and titration is performed using a 0.1N aqueous KOH solution. And an acid value is computed by following Formula.
A = 10 × Vf × 56.1 / (Wp × I)
In the formula, A represents the acid value (mgKOH / g), Vf represents the titration amount (mL) of KOH, Wp represents the measurement resin solution mass (g), and I represents the nonvolatile content of the measurement resin solution. A ratio (mass%) is shown.

  The weight average molecular weight of the resin having a carboxyl group as component (a) is preferably 3000 to 30000, more preferably 5000 to 20000, and more preferably 7000 to 15000 from the viewpoint of coating properties. Is particularly preferred. These can also be used in combination of two or more resins having different molecular weights.

  In addition, a weight average molecular weight (Mw) can be calculated | required from the standard polystyrene conversion value by a gel permeation chromatography (GPC).

  The photopolymerizable monomer (b) having an ethylenically unsaturated group used in the present invention preferably contains a bisphenol A (meth) acrylate compound from the viewpoint of improving alkali developability. Examples of bisphenol A-based (meth) acrylate compounds include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolypropoxy). ) Phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane, etc. Is mentioned. You may use these individually or in combination of 2 or more types.

  Among the above compounds, 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is FA-321M (manufactured by Hitachi Chemical Co., Ltd., trade name) or BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd.). , Commercially available as BPE-1300 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.), and 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) is commercially available as Is available.

  The (c) photopolymerization initiator used in the present invention is not particularly limited as long as it matches the light wavelength of the exposure machine to be used, and known ones can be used. Specifically, for example, benzophenone, N, N′-tetraalkyl-4,4′-diaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl- 1- [4- (methylthio) phenyl] -2-morpholino-propanone-1,4,4′-bis (dimethylamino) benzophenone (Michler ketone), 4,4′-bis (diethylamino) benzophenone, 4-methoxy-4 Aromatic ketones such as' -dimethylaminobenzophenone; quinones such as alkylanthraquinone and phenanthrenequinone; benzoin compounds such as benzoin and alkylbenzoin; benzoin ether compounds such as benzoin alkyl ether and benzoin phenyl ether; benzyl such as benzyldimethyl ketal Conductor: 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluoro Phenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer , 2,4,5-triarylimidazole dimer such as 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer; N-phenylglycine, N-phenylglycine derivative, 9- Acridine derivatives such as phenylacridine; 1,2-octanedione, 1- [4- (phenylthio)-, 2- (o-benzoyloxime)] Simesters; coumarin compounds such as 7-diethylamino-4-methylcoumarin, thioxanthone compounds such as 2,4-diethylthioxanthone; acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide These can be used, and these can be used alone or in combination of two or more.

  Among these, aromatic ketones or thioxanthone compounds are preferably used from the viewpoint of excellent resolution (resist shape).

  (D) Examples of the epoxy resin include bisphenol A type epoxy resins such as bisphenol A diglycidyl ether, bisphenol F type epoxy resins such as bisphenol F diglycidyl ether, bisphenol S type epoxy resins such as bisphenol S diglycidyl ether, and biphenol. Biphenol type epoxy resins such as diglycidyl ether, bixylenol type epoxy resins such as bixylenol diglycidyl ether, hydrogenated bisphenol A type epoxy resins such as hydrogenated bisphenol A glycidyl ether, and dibasic acid-modified diglycidyl ethers thereof Type epoxy resin.

These may be used alone or in combination of two or more. As these compounds, commercially available compounds can be used.
For example, examples of the bisphenol A type epoxy resin include jER828, jER1001 and jER1002 (all are trade names, manufactured by Mitsubishi Chemical Corporation).
Examples of bisphenol F type epoxy resins include jER807 (trade name, manufactured by Mitsubishi Chemical Corporation), YSLV-80 (trade name, manufactured by Nippon Steel Chemical Co., Ltd.), and the like. , EBPS-200 (trade name, manufactured by Nippon Kayaku Co., Ltd.) and Epicron EXA-1514 (trade name, manufactured by DIC Corporation).
Examples of the biphenol type epoxy resin include YL-6121 (trade name, manufactured by Mitsubishi Chemical Corporation). Examples of the bixylenol type epoxy resin include YX-4000 (trade name, manufactured by Mitsubishi Chemical Corporation). Etc. Furthermore, examples of the hydrogenated bisphenol A type epoxy resin include ST-2004 and ST-2007 (both manufactured by Nippon Kasei Epoxy Manufacturing Co., Ltd., trade names) and the like, and the dibasic acid-modified diglycidyl ether described above. Examples of the type epoxy resin include ST-5100 and ST-5080 (both manufactured by Nippon Kayaku Epoxy Manufacturing Co., Ltd., trade names).

  Among the above, it is preferable to include at least one selected from bisphenol F type epoxy resin, biphenol type epoxy resin, and bixylenol type epoxy resin.

  (D) As a compounding quantity of an epoxy resin, the total amount of (a) resin which has an ethylenically unsaturated group and a carboxyl group, and (b) photopolymerizable monomer which has an ethylenically unsaturated group is 100 mass parts. On the other hand, it is preferably 2 to 40 parts by mass, and more preferably 5 to 30 parts by mass.

  Next, in the particle size distribution measurement by the dynamic light scattering method, the average particle size, which is a feature of the present invention, is less than 50 nm, and the maximum particle size is dispersed in the photosensitive resin composition at 1 μm or less (e). The silica filler will be described.

  The silica filler used in the present invention uses a silane coupling agent in order to disperse it in the resin without agglomeration while maintaining the primary particle size. As the silane coupling agent, generally available ones can be used, for example, alkyl silane, alkoxy silane, vinyl silane, epoxy silane, amino silane, acrylic silane, methacryl silane, mercapto silane, sulfide silane, isocyanate silane, Sulfur silane, styryl silane, alkylchlorosilane, and the like can be used. Specific compound names include methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, methyltriphenoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, diisopropyldimethoxysilane, isobutyltrimethoxy. Silane, diisobutyldimethoxysilane, isobutyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, cyclohexylmethyldimethoxysilane, n-octyltriethoxysilane, n-dodecylmethoxysilane, phenyltrimethoxysilane, diphenyldimethoxy Silane, triphenylsilanol, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, n-octyldi Tylchlorosilane, tetraethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane 3-phenylaminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldixysilane Bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, vinyltriacetoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl Lyisopropoxysilane, allyltrimethoxysilane, diallyldimethylsilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3 -Mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, N- (1,3-dimethylbutylden) -3-aminopropyltriethoxysilane, aminosilane and the like.

  A preferable silane coupling agent to be used is preferably a kind that reacts with a carboxyl group of a resin having a carboxyl group and an ethylenically unsaturated group contained in the photosensitive resin composition, for example, epoxy silane, Mercaptosilane and isocyanate silane are preferred. These silane coupling agents enhance the bond between silica and resin, so that when used as a permanent mask resist, the strength of the film can be increased, and at the same time the thermal expansion coefficient can be greatly reduced. Contributes to cracking and the like.

  Acrylic silane or methacrylic silane may also be used. (B) It is thought that it reacts with the ethylenically unsaturated group of the photopolymerizable monomer having an ethylenically unsaturated group and exhibits the same effect as when the previous silane coupling agent is used.

  The amount of silica filler used is preferably 25 to 70 parts by mass, more preferably 25 to 60 parts by mass, and even more preferably 30 to 40 parts by mass with respect to 100 parts by mass of the total mass part. . From the viewpoint of reducing the thermal expansion coefficient, 25 parts by mass or more is preferable, and from the viewpoint of coating properties, 70 parts by mass or less is preferable.

  In addition to the above-described components (a) to (e), the photosensitive resin composition preferably further contains an antioxidant as the component (f). Moreover, it is more preferable that the antioxidant of the component (f) is a phenolic antioxidant.

  The photosensitive resin composition of the present invention may further contain other components according to desired properties. Examples of other components include a diluent. Examples of the diluent include aliphatic alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, n-pentanol and hexanol; hydrocarbons such as benzyl alcohol and cyclohexane; diacetone alcohol; Aliphatic ketones such as 3-methoxy-1-butanol, acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone; ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, ethylene glycol monoacetate, ethylene glycol diacetate , Propylene glycol monoacetate, propylene glycol diacetate, propylene glycol monoethyl ether, methyl cellosolve, ethyl cellosolve Ethylene glycol alkyl ethers and acetates thereof; diethylene glycol monoalkyl ethers and acetate diethylene glycol dialkyl ethers; petroleum solvents such as toluene, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha or solvent naphtha; ethyl formate, propyl formate; Carboxylic acid esters such as butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate and ethyl butyrate; solvents such as amines and amides alone or in combination More than one type can be used in combination.

  Furthermore, the photosensitive resin composition of the present invention is a melamine, dicyandiamide, triazine compound and derivatives thereof, imidazole, thiazole, and triazole as adhesion improvers, particularly when adhesion with a metal such as copper is required. Additives such as systems and silane coupling agents can be used. Examples include melamine, acetoguanamine, benzoguanamine, melamine-phenol-formalin resin, dicyandiamide, imidazole additive manufactured by Shikoku Kasei Kogyo Co., Ltd., trade names: 2MZ-AZINE, 2E4MZ-AZINE, C11Z-AZINE, 2MA-OK, etc. It is done. Alternatively, triazine derivatives such as ethyldiamino-s-triazine, 2,4-diamino-s-triazine, and 2,4-diamino-6-xylyl-s-triazine are exemplified. These compounds increase adhesion with a copper circuit and improve PCT resistance, and are also effective in HAST resistance. These are preferably used in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of components (a) to (c). Among these, it is preferable to contain dicyandiamide.

  If necessary, use colorants such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, malachite green, crystal violet, titanium oxide, carbon black, naphthalene black, azo organic pigments, dyes, etc. Can do. Furthermore, polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol, pyrogallol and phenothiazine, thixotropic agents such as benton, montmorillonite, aerosil and amide wax, antifoaming such as silicone, fluorine and polymer Agents and leveling agents can be used.

  The content of each component in the photosensitive resin composition is preferably 30 to 80 parts by mass with respect to 100 parts by mass of the total amount of the component (a) and the component (a). It is more preferable to set it as 40-75 mass parts, and it is especially preferable to set it as 50-70 mass parts. When the content of the component (a) is within this range, the coating property of the photosensitive resin composition and the strength of the photocured product become better, and characteristics such as developability, resolution, solder heat resistance and gold plating resistance are obtained. Without impairing the resistance, the HAST resistance between fine wirings is excellent and the heat resistance is high.

  The content of the component (b) is preferably 20 to 70 parts by mass and more preferably 25 to 50 parts by mass with respect to 100 parts by mass of the total amount of the components (a) and (b). 30 to 40 parts by mass is particularly preferable. When the content of the component (b) is within this range, the photosensitivity and coating property of the photosensitive resin composition become better.

  The content of each component (c) in the photosensitive resin composition is 0.1 to 10 parts by mass of component (c) with respect to 100 parts by mass in total of components (a) and (b). It is preferable that it is 0.2 to 5 parts by mass.

[Photosensitive film]
Next, the photosensitive film of suitable embodiment is demonstrated. The photosensitive film which concerns on this invention consists of a photosensitive laminated body provided with the support body and the photosensitive resin composition layer which consists of the photosensitive resin composition of this invention formed on this support body. . On the photosensitive resin composition layer, you may further provide the protective film which coat | covers this photosensitive resin composition layer.

  As the support, for example, a polymer film having heat resistance and solvent resistance such as polyester such as polyethylene terephthalate, polypropylene, and polyethylene can be used. The thickness of the support (polymer film) is preferably 5 to 25 μm. If the thickness is less than 5 μm, the support film tends to be broken when the support film is peeled off before development. If it exceeds, the resolution tends to decrease. In addition, you may use the said polymer film laminated | stacked on both surfaces of the photosensitive resin composition layer as a support body and a protective film.

  As the protective film, for example, a polymer film having heat resistance and solvent resistance such as polyester such as polyethylene terephthalate, polypropylene, and polyethylene can be used. Examples of commercially available products include, for example, trade names made by Oji Paper Co., Ltd .: Alphan MA-410, E-200C, polypropylene films made by Shin-Etsu Film Co., Ltd., trade names made by Teijin Limited: PS-25, etc. Examples thereof include polyethylene terephthalate films such as PS series, but are not limited thereto.

  The thickness of the protective film is preferably 1 to 100 μm, more preferably 5 to 50 μm, further preferably 5 to 30 μm, and particularly preferably 15 to 30 μm. If this thickness is less than 1 μm, the protective film tends to be broken during lamination, and if it exceeds 100 μm, the cost tends to be inferior. The protective film preferably has a smaller adhesive strength between the photosensitive resin composition layer and the protective film than the adhesive strength between the photosensitive resin composition layer and the support, and is preferably a low fisheye film. . Fisheye is a material in which foreign materials, undissolved materials, oxidatively deteriorated materials, etc. are incorporated into the film when the material is melted and kneaded, extruded, biaxially stretched, or casted to produce a film. It is.

  The photosensitive resin composition layer is prepared by dissolving the photosensitive resin composition of the present invention in a diluent (solvent) as described above to obtain a solution (coating liquid) having a solid content of about 30 to 70% by mass. Such a solution (coating solution) is preferably formed by coating on a support and drying. The application can be performed by a known method using, for example, a roll coater, comma coater, gravure coater, air knife coater, die coater, bar coater or the like. Moreover, the said drying can be performed at 70-150 degreeC and about 5 to 30 minutes. The amount of the remaining organic solvent in the photosensitive resin composition is preferably 3% by mass or less with respect to the total amount of the photosensitive resin composition from the viewpoint of preventing diffusion of the organic solvent in the subsequent step.

  Although the thickness of the said photosensitive layer changes with uses, it is preferable that it is 5-200 micrometers by the thickness after drying, It is more preferable that it is 15-60 micrometers, It is especially preferable that it is 20-50 micrometers. If the thickness is less than 5 μm, it tends to be difficult to apply industrially, and if it exceeds 200 μm, the sensitivity and resolution inside the photosensitive resin composition layer tend to be lowered.

  The photosensitive film may further have an intermediate layer such as a cushion layer, an adhesive layer, a light absorption layer, and a gas barrier layer. Moreover, the obtained photosensitive film can be wound up and stored in a sheet form or a roll around a core. In addition, it is preferable to wind up so that a support body may become the outermost part in this case. From the viewpoint of end face protection, it is preferable to install an end face separator on the end face of the roll-shaped photosensitive film roll, and it is preferable to install a moisture-proof end face separator from the viewpoint of edge fusion resistance. Moreover, as a packing method, it is preferable to wrap and package in a black sheet with low moisture permeability. Examples of the winding core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

[Method of forming resist pattern]
Next, a method for forming a resist pattern using the photosensitive film of the present invention will be described.

  A photosensitive layer made of the above-described photosensitive resin composition is formed on a substrate on which a resist is to be formed. The protective film of the photosensitive film is peeled from the photosensitive resin composition layer, and the exposed surface is adhered by a laminate or the like so as to cover the conductor layer having a circuit pattern formed on the substrate. A method of laminating under reduced pressure is also preferable from the viewpoint of improving adhesion and followability. In addition, the photosensitive resin composition can also be apply | coated on a board | substrate by well-known methods, such as the method of apply | coating the varnish of the photosensitive resin composition with a screen printing method or a roll coater.

  Next, an exposure process is performed through which a predetermined portion of the photosensitive resin composition layer is irradiated with actinic rays through the mask pattern, and the photosensitive resin composition layer in the irradiated portion is photocured.

  Further, when a support is present on the photosensitive layer, after removing the support, by removing a portion that has not been photocured by wet development or dry development (unexposed portion) and developing, A resist pattern can be formed.

  In the case of the above-described wet development, as the developer, an alkaline aqueous solution, an aqueous developer, an organic solvent, or the like that is safe and stable and has good operability is used according to the type of the photosensitive resin composition. Further, as a developing method, a known method such as spraying, rocking dipping, brushing, scraping or the like is appropriately employed.

  Examples of the base of the alkaline aqueous solution include alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide which are hydroxides of lithium, sodium and potassium, carbonates or bicarbonates such as alkali metals and ammonium. Alkaline carbonate or bicarbonate, alkali metal phosphate sodium phosphate, potassium phosphate, etc., alkali metal pyrophosphate sodium pyrophosphate, potassium pyrophosphate etc., safe and stable, operability The one with good is used.

  Examples of the alkaline aqueous solution include a dilute solution of 0.1 to 5% by mass of sodium carbonate, a dilute solution of 0.1 to 5% by mass of potassium carbonate, and a dilute solution of 0.1 to 5% by mass of sodium hydroxide. A solution, a dilute solution of 0.1 to 5% by mass sodium tetraborate is preferred, and the pH is preferably in the range of 9 to 11. The temperature of the alkaline aqueous solution is adjusted according to the developability of the photosensitive layer, and is preferably 20 to 50 ° C. Furthermore, a small amount of an organic solvent such as a surfactant or an antifoaming agent may be mixed in the alkaline aqueous solution in order to promote development.

  As the aqueous developer, one comprising water and an alkaline aqueous solution or one or more organic solvents is used. Here, as the base of the alkaline aqueous solution, in addition to those described above, for example, borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3- Examples include propanediol, 1,3-diaminopropanol-2, and morpholine. The pH of such an aqueous developer is preferably as small as possible within a range where development processing can be sufficiently performed, preferably pH 8 to 12, and more preferably pH 9 to 10.

  Examples of the organic solvent include acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether. . The concentration of such an organic solvent is usually preferably 2 to 90% by mass. Moreover, the temperature of such an organic solvent can be adjusted according to developability. Furthermore, such organic solvents can be used alone or in combination of two or more. Examples of the organic solvent-based developer used alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. Furthermore, a small amount of an organic solvent such as a surfactant or an antifoaming agent may be mixed in the alkaline aqueous solution in order to promote development.

  In the method for forming a resist pattern of the present invention, two or more kinds of development methods described above may be used in combination as necessary. Development methods include a dip method, a battle method, a spray method, a high-pressure spray method, brushing, and slapping, and the high-pressure spray method is most suitable for improving resolution. For the etching of the metal surface performed after development, for example, a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, or the like can be used.

[Preferred embodiment of photosensitive permanent resist]
A preferred embodiment of a photosensitive permanent resist using the photosensitive film of the present invention will be described.

After the development step, it is preferable to perform ultraviolet irradiation or heating with a high-pressure mercury lamp for the purpose of improving solder heat resistance and chemical resistance. In the case of irradiating ultraviolet rays, the irradiation amount can be adjusted as necessary, and for example, irradiation can be performed at an irradiation amount of about 0.05 to 10 J / cm ² . Moreover, when heating a resist pattern, it is preferable to carry out for about 15 to 90 minutes in the range of about 130-200 degreeC.

  Both ultraviolet irradiation and heating may be performed. In this case, both may be performed at the same time, and after either one is performed, the other may be performed. When performing ultraviolet irradiation and heating simultaneously, it is preferable to heat to 60-150 degreeC from a viewpoint of providing solder heat resistance and chemical resistance more favorably.

  The photosensitive permanent resist formed in this way also serves as a protective film for the wiring after soldering the substrate, and has various characteristics of a solder resist, for printed wiring boards, for semiconductor package boards, flexible wiring boards It can be used as a solder resist.

  The solder resist, for example, is used as a plating resist or an etching resist when plating or etching is performed on a substrate, and is also left on the substrate as it is to protect a wiring or the like (photosensitive permanent). Resist).

  Further, in the above exposure step, when exposure is performed using a mask or drawing data having a pattern in which a predetermined portion of the conductor layer is unexposed, the unexposed portion is removed by developing this, and the substrate A resist having an opening pattern in which a part of the conductor layer formed thereon is exposed is obtained. Thereafter, it is preferable to perform a treatment necessary for forming the photosensitive permanent resist.

  Thereafter, the substrate provided with the photosensitive permanent resist is mounted with a semiconductor element or the like (for example, wire bonding, C4 solder connection), and is mounted on an electronic device such as a personal computer.

  The present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.
(Preparation of photosensitive film)
The photosensitive resin composition solutions of Examples 1 to 6 and Comparative Examples 1 to 6 were obtained by mixing the components shown in Table 1 and Table 2 at the mixing ratio (mass basis) shown therein. Note that methyl ethyl ketone was used as the diluent.

  Next, a photosensitive resin composition layer is formed by uniformly coating the prepared photosensitive resin composition solution on a 16 μm-thick polyethylene terephthalate film (trade name: G2-16, manufactured by Teijin Limited) as a support layer. It was dried at 100 ° C. for about 10 minutes using a hot air convection dryer. The film thickness after drying of the photosensitive resin composition layer was 15 μm.

  Subsequently, a polyethylene film (manufactured by Tamapoly Co., Ltd., trade name: NF-15) is bonded as a protective film on the surface of the photosensitive resin composition layer opposite to the side in contact with the support layer, and the support layer / Photosensitive resin composition layer / A photosensitive film having a protective film was obtained.

The details of each component shown in Tables 1 and 2 are as follows.
<(A) Resin having an ethylenically unsaturated group and a carboxyl group>
EXP-2810: Acid-modified cresol novolac type epoxy acrylate (manufactured by DIC Corporation, trade name)
ZFR-1158: Bisphenol F type epoxy acrylate (Nippon Kayaku Co., Ltd., trade name)
CCR-1219H: Cresol novolac type epoxy acrylate (Nippon Kayaku Co., Ltd., trade name)
UXE-3024: Polyurethane compound (weight average molecular weight: 10,000, acid value: 60 mg KOH / g, manufactured by Nippon Kayaku Co., Ltd., trade name)

<(B) Photopolymerizable monomer having an ethylenically unsaturated group>
DCP: Tricyclodecane dimethanol dimethacrylate (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.)
DPHA: Dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd., trade name)
FA-321M: 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane (trade name, manufactured by Hitachi Chemical Co., Ltd.)

<(C) Photopolymerization initiator>
I-907: 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one (trade name: IRGACURE-907, manufactured by BASF)
DETX-S: 2,4-diethylthioxanthone (Nippon Kayaku Co., Ltd., trade name)
TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (manufactured by BASF, trade name: LUCIRIN-TPO)
OXE-02: Ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) (manufactured by BASF, trade name: IRGACURE- OXE02)

<(D) Epoxy resin>
YX4000H: Biphenol type epoxy resin (epoxy equivalent 190, manufactured by Mitsubishi Chemical Corporation, trade name)
YSLV-80: Bisphenol F type epoxy resin (trade name, manufactured by Nippon Steel Chemical Co., Ltd.)
NC-3000H: biphenyl aralkyl type epoxy resin (product name) manufactured by Nippon Kayaku Co., Ltd.

<(E) Silica filler>
Silica A: The silica filler has an average particle size of 10 nm, and is subjected to a coupling treatment with 3-methacryloxypropyltrimethoxysilane, which is methacrylic silane, as the silane coupling agent, and the above (a) carboxyl group and ethylenically unsaturated group Was dispersed in a resin having at least one in the molecule. The dispersion state was measured using a dynamic light scattering nanotrack particle size distribution analyzer (manufactured by Nikkiso Co., Ltd., trade name: UPA-EX150), and it was confirmed that the maximum particle size was 1 μm or less.
Silica B: The silica filler has an average particle size of 50 nm, and is coupled with 3-methacryloxypropyltrimethoxysilane, which is methacrylic silane, as the silane coupling agent. The above (a) carboxyl group and ethylenically unsaturated group Was dispersed in a resin having at least one in the molecule. The dispersion state was measured using a dynamic light scattering nanotrack particle size distribution analyzer (manufactured by Nikkiso Co., Ltd., trade name: UPA-EX150), and it was confirmed that the maximum particle size was 1 μm or less.
Silica C: A silica filler dispersion (manufactured by Admatechs Co., Ltd., trade name: SC2050) having an average particle diameter of 1 μm and dispersed in a slurry in methyl ethyl ketone was used. The dispersion state was measured using a laser diffraction / scattering microtrack particle size distribution meter (trade name: MT-3100, manufactured by Nikkiso Co., Ltd.). It was confirmed that the maximum particle size was about 3 μm.

(Characteristic evaluation)
[Evaluation of coating properties]
Without exposing to the obtained photosensitive film, the polyethylene terephthalate on a photosensitive film was peeled off, the finger | toe was lightly pressed on the coating-film surface, and the sticking degree with respect to the finger was evaluated on the following references | standards. In other words, “3” means that sticking to the finger is not or hardly recognized, “2” means that sticking to the finger is allowed, and “2” means that the resin sticks to the finger. It was set to “1”. The results are shown in Tables 3 and 4.

[Evaluation of resolution (resist shape)]
The copper surface of a printed wiring board substrate (trade name: E-679, manufactured by Hitachi Chemical Co., Ltd.) obtained by laminating a 12 μm thick copper foil on a glass epoxy substrate was polished with an abrasive brush, washed with water, and dried. On this printed wiring board substrate, using a continuous press type vacuum laminator (manufactured by Meiki Seisakusho Co., Ltd., trade name: MVLP-500), press hot plate temperature 70 ° C., evacuation time 20 seconds, laminating press time 30 The above-mentioned photosensitive film from which the polyethylene film was peeled was laminated under the conditions of second, atmospheric pressure of 4 kPa or less, and pressure bonding pressure of 0.4 MPa to obtain a laminate for evaluation.

On the evaluation laminate, a photo tool having a 2 mm square pattern is adhered as a negative,
Using an exposure machine manufactured by Oak Manufacturing Co., Ltd., trade name: EXM-1201, exposure was performed with an energy amount such that the number of remaining step stages after development of the stove 21-step step tablet was 8.0. Next, after standing at room temperature (25 ° C.) for 1 hour, the polyethylene terephthalate on the laminate was peeled off, and a minimum development time (minimum time for developing an unexposed portion) with a 1% by mass aqueous sodium carbonate solution at 30 ° C. ) Spray development was carried out in 2.0 times as long as the above, to form a pattern.

  At this time, the resolution was evaluated as “3” when an unexposed portion having a diameter of 30 μm was developed and an opening pattern was obtained as a good resist shape, and the resist shape was an overhang, but an opening pattern was obtained. The case where the aperture pattern was not obtained was “1”. The results are shown in Tables 3 and 4.

[Evaluation of gold plating resistance]
The evaluation laminate substrate on which the solder resist having a 2 mm square opening is formed is plated using a commercially available electroless nickel / gold plating solution so that the nickel plating thickness is 5 μm and the gold plating thickness is 0.1 μm. The appearance of the solder resist was observed with a stereomicroscope and evaluated according to the following criteria. That is, “3” indicates that the solder resist is not whitened around the opening, “2” indicates that whitening or peeling occurs at 10 μm or less, and “1” indicates that whitening or peeling greatly occurs. It was. The results are shown in Tables 3 and 4.

[Evaluation of HAST resistance]
A comb-shaped electrode having a line / space of 50 μm / 50 μm by etching the copper surface of a printed wiring board substrate (Hitachi Kasei Kogyo Co., Ltd., trade name: E-679) in which a 12 μm thick copper foil is laminated on a glass epoxy substrate. This was used as an evaluation substrate.

A solder resist made of a cured resist is formed on the comb-shaped electrode on the evaluation substrate in the same manner as in the above “evaluation of developability and solder heat resistance” (exposure is performed so that the solder resist remains on the comb-shaped electrode portion). The film was exposed to 130 ° C., 85% RH, and 20 V for 100 hours. Thereafter, the resistance value was measured and the degree of migration was observed with a 100-fold metal microscope, and evaluated according to the following criteria. That is, a resistance value of 1.0 × 10 ¹⁰ Ω or more is maintained, and “3” is given when no migration occurs in the solder resist film, and a resistance value of 1.0 × 10 ¹⁰ Ω or more is maintained. However, it was “2” when a slight migration occurred, and “1” when a migration value was 1.0 × 10 ¹⁰ Ω or less and a large migration occurred. The results are shown in Tables 3 and 4.

[Evaluation of crack resistance]
Similar to the above “evaluation of developability and solder heat resistance”, the evaluation laminate substrate on which the solder resist was formed was exposed to the air at −65 ° C. for 15 minutes, and then heated at a temperature increase rate of 180 ° C./min. Then, after being exposed to an atmosphere of 150 ° C. for 15 minutes, a thermal cycle in which the temperature was decreased at a temperature decrease rate of 180 ° C./min was repeated 1000 times. After being exposed to such an environment, cracks and peeling of the permanent resist film of the evaluation laminate substrate were observed with a 100-fold metal microscope and evaluated according to the following criteria. In other words, “3” means that the cracks and peeling of the permanent resist film were not observed at all after confirming 10 places of the 2 mm square openings, and those where cracks and peeling were observed in 2 or less of the 10 places. “2” and those in which cracking and peeling were observed at 3 or more of 10 locations were designated as “1”. The results are shown in Tables 3 and 4.

  From the above evaluation results, the photosensitive resin composition of the present invention is excellent in developability, can form a fine opening pattern, has sufficient HAST resistance, and can be alkali-developed to obtain high heat resistance. It was confirmed that a dry film type photosensitive film using the photosensitive resin composition can be provided. Furthermore, the photosensitive resin composition of the present invention is a highly reliable photosensitive resin composition having a small coefficient of thermal expansion of the resin and having a high crack resistance against TCT (temperature cycle test). It was confirmed that the present photosensitive film could be provided.

Claims (4)

(A) component: resin having an ethylenically unsaturated group and a carboxyl group,
(B) component: a photopolymerizable monomer having an ethylenically unsaturated group,
(C) component: photopolymerization initiator,
(D) component: epoxy resin, and (e) component: a photosensitive resin composition containing a silica filler,
The photosensitive resin in which the average particle size of the component (e) is less than 50 nm in the particle size distribution measurement by a dynamic light scattering method, and the maximum particle size is dispersed in the photosensitive resin composition with a maximum particle size of 1 μm or less. Composition.   The photosensitive resin composition according to claim 1, wherein the component (e) has been subjected to at least one silane coupling treatment selected from epoxy silane, mercaptosilane, isocyanate silane, acrylic silane, and methacryl silane.   A photosensitive element provided with a support body and the photosensitive layer which consists of a photosensitive resin composition of Claim 1 or 2 formed on this support body.   The permanent resist formed with the hardened | cured material of the photosensitive resin composition of Claim 1 or 2 formed on the board | substrate for printed wiring boards.