JP2012255925A - Photosensitive resin composition, and photosensitive element and permanent resist using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition suppressing tackiness of a photosensitive layer and having excellent embedding property and surface flatness, and to provide a dry film type alkali-developable photosensitive element and a permanent resist.SOLUTION: A photosensitive resin composition comprises (a) a resin having at least one ethylenically unsaturated group and carboxyl group in a molecule, (b) a photopolymerizable monomer having at least one ethylenically unsaturated group and a tricyclodecane structure, (c) a photopolymerization initiator, and (d) an epoxy resin. The (a) component includes two or more compounds having different weight average molecular weights. The weight average molecular weights of the two or more compounds having different weight average molecular weights of the (a) component are preferably 3000 to 8000 and 9000 to 18000.

Description

  The present invention relates to a photosensitive solder resist for a printed wiring board, a semiconductor package substrate, and a flexible wiring board. The photosensitive solder resist is suitable for a photosensitive solder resist and particularly suppresses stickiness of a photosensitive layer and has excellent embedding property and surface flatness. The present invention relates to a photosensitive resin composition, a photosensitive element using the same, and a permanent resist.

  In recent years, with the reduction in size and weight of digital devices, miniaturization and higher density of circuits formed on a printed wiring board, a semiconductor package substrate, and a flexible wiring board are progressing. A solder resist having photosensitivity is used for the purpose of forming a fine opening pattern, and surface flatness, high resolution, insulation reliability, solder heat resistance, gold plating resistance, and the like are required.

  As the photosensitive resin composition for solder resist, a liquid photosensitive resin composition is usually used particularly in the field of printed wiring boards. Then, a solder resist is formed from a two-part type photosensitive resin composition obtained by separately dividing a thermosetting epoxy resin and a photosensitive prepolymer containing a carboxylic acid group for imparting alkali developability. Is common. As the photosensitive prepolymer, an alkali developable photosensitive prepolymer which is obtained by adding acrylic acid to a cresol novolak type epoxy resin and then acid-modifying with an acid anhydride or the like is widely used (for example, see Patent Document 1). .

  Since the reaction of the carboxylic acid group of the epoxy resin and the photosensitive prepolymer proceeds at room temperature, the storage stability (pot life) after mixing the two liquids is from a few hours. The usage conditions are limited, such as being short and short and having to be mixed immediately before use. In order to avoid such problems, in recent years, a one-component type photosensitive resin composition has been proposed in which storage stability is improved by using a blocked isocyanate compound instead of an epoxy resin as a thermosetting agent (for example, Patent Document 2).

  On the other hand, in recent years, a dry film type photosensitive resin composition for a solder resist has been strongly desired from the viewpoint of improving the film thickness uniformity, surface smoothness, thin film formability, and handleability of the solder resist. According to such a photosensitive resin composition, in addition to the above characteristics, effects such as simplification of a process for forming a solder resist and reduction of a solvent discharge amount at the time of forming the solder resist are obtained. So far, various photosensitive resin compositions for dry film type solder resists have been developed.

  For example, in Patent Document 3, a photosensitive film containing a polymer having a carboxyl group, a photopolymerizable compound, a photopolymerization initiator, and a bismaleimide compound is used as an anhydride group of a maleic anhydride copolymer in Patent Document 4. On the other hand, a photosensitive film containing a copolymer obtained by reacting 0.1 to 1.2 equivalents of a primary amine compound, a polymerizable compound and a photopolymerization initiator is disclosed.

  On the other hand, as the wiring pitch is narrowed, the solder resist embedding property between circuits has become a very important item. If this embedding property is insufficient, bubbles may enter between the circuits, leading to a decrease in various reliability such as insulation reliability and thermal shock reliability. As the semiconductor package becomes thinner, the pitch between the connection terminals is also narrowed, and the surface smoothness of the solder resist is required to reduce the thickness of the solder resist and ensure the connection reliability. In order to satisfy this surface smoothness and to embed a solder resist between fine wirings and through-hole portions without bubbles, the resin component must flow sufficiently during lamination. That is, it is important to control the molecular weight of the resin component and the lamination temperature.

JP-A 61-243869 JP 2001-305726 A JP 2004-287267 A JP 2005-316431 A

  It is an object of the present invention to provide a photosensitive resin composition that suppresses stickiness of a photosensitive layer and is excellent in embedding property and surface flatness, a dry film type photosensitive element capable of alkali development, and a permanent resist.

  As a result of intensive studies on a photosensitive resin composition that suppresses stickiness of the photosensitive layer and is excellent in embedding property and surface flatness, (a) one or more ethylenically unsaturated groups and carboxyl in the molecule. A resin having a group, (b) a photopolymerizable monomer having one or more ethylenically unsaturated groups and a tricyclodecane structure in the molecule, (c) a photopolymerization initiator, and (d) an epoxy resin. It has been found that a photosensitive resin composition containing the photosensitive resin composition, wherein the component (a) contains two or more kinds of compounds having different weight average molecular weights, can achieve the above-mentioned problems.

The present invention includes [1] (a) a resin having one or more ethylenically unsaturated groups and a carboxyl group in the molecule, and (b) one or more ethylenically unsaturated groups and a tricyclodecane structure in the molecule. A photopolymerizable monomer comprising: (c) a photopolymerization initiator; and (d) a photosensitive resin composition containing an epoxy resin, wherein the component (a) has two or more different weight average molecular weights. The present invention relates to a photosensitive resin composition containing the compound.
Moreover, this invention is [2] The photosensitivity as described in said [1] whose weight average molecular weights of 2 or more types of compounds from which the (a) component differs in the weight average molecular weight are 3000-8000 and 9000-18000. The present invention relates to a resin composition.
In the present invention, [3] the component (b) is selected from the group consisting of dimethylol tricyclodecane diacrylate, dimethylol tricyclodecane dimethacrylate, tricyclodecane diol diacrylate, and tricyclodecane diol dimethacrylate. It is related with the photosensitive resin composition as described in said [1] or [2] which is 1 or more types.
The present invention also provides: [4] The photosensitive composition according to any one of [1] to [3], wherein the component (b) has a partial structure represented by the following general formula (1) or general formula (2). The present invention relates to a functional resin composition.

［一般式（１）又は一般式（２）中、Ｒ^１、Ｒ^２は、直接結合、アルキレン、又はアリーレン基を示す。］

[In General Formula (1) or General Formula (2), R ¹ and R ² represent a direct bond, an alkylene, or an arylene group. ]

In the present invention, [5] the compound having the partial structure represented by the general formula (1) or the general formula (2) is a diol compound containing a tricyclodecane structure, a diisocyanate compound, and at least 1 in the molecule. It is related with the photosensitive resin composition as described in said [4] which is a urethane compound obtained by making the compound which has 1 or more ethylenically unsaturated group and one hydroxyl group react.
Furthermore, the present invention provides [6] a support and a photosensitive resin composition layer formed on the support and comprising the photosensitive resin composition according to any one of [1] to [5]. It is related with the photosensitive element provided.
In addition, the present invention is [7] a cured product of the photosensitive resin composition according to any one of [1] to [5] formed on a substrate for a printed wiring board, or the above [5]. The present invention relates to a permanent resist comprising a cured product of the photosensitive resin composition layer of the photosensitive element.

  According to the photosensitive resin composition of the present invention, a printed wiring board, a semiconductor package substrate, and a flexible wiring having excellent stickiness, resolution, plating resistance, surface smoothness, and embedding property of a photosensitive solder resist (permanent resist). The photosensitive element which can form the optimal soldering resist for a board, and the permanent resist using them can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail. In the present invention, (meth) acrylic acid means acrylic acid and methacrylic acid corresponding thereto, (meth) acrylate means acrylate and corresponding methacrylate, and (meth) acryloyl group means acryloyl group. And the corresponding methacryloyl group.

  The photosensitive resin composition of the present invention comprises (a) two or more kinds of resins having different weight average molecular weights, one or more ethylenically unsaturated groups and carboxyl groups in the molecule, and (b) one in the molecule. A photopolymerizable monomer having at least one ethylenically unsaturated group and a tricyclodecane structure; (c) a photopolymerization initiator; and (d) an epoxy resin.

  The main feature of the present invention is that the component (a) is mixed with resins having different weight average molecular weights to optimize the fluidity of the photosensitive layer and achieve the object.

<(A) component>
Examples of the resin having at least one ethylenically unsaturated group and a carboxyl group in the molecule as the component (a) of the present invention include, for example, esterified products of an epoxy compound (a1) and an unsaturated monocarboxylic acid (a2). An addition reaction product to which a saturated or unsaturated polybasic acid anhydride (a3) has been added can be used. These can be obtained, for example, by the following two-stage 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, bisphenol F type and epichlorohydrin are suitable. GY-260, GY-255, XB-2615 manufactured by Ciba-Geigy Corporation, Epicoat manufactured by Japan Epoxy Resin Co., Ltd. Epoxy compounds such as 828, 1007, 807 and the like bisphenol A type, bisphenol F type, hydrogenated bisphenol A type, amino group-containing, alicyclic or polybutadiene-modified are preferably used.

  As the novolak type epoxy compound, those obtained by reacting novolaks obtained by reacting phenol, cresol, halogenated phenol and alkylphenols with formaldehyde in the presence of an acidic catalyst and epichlorohydrin are suitable. YDCN-701, 704, YDPN-638, 602, DEN-431, 439 manufactured by Dow Chemical Co., EPN-1299 manufactured by Ciba Geigy Co., N-730, 770 manufactured by Dainippon Ink & Chemicals, Inc. (DIC Corporation), 865, 665, 673, VH-4150, 4240, Nippon Kayaku Co., Ltd. EOCN-120, BREN, etc. are mentioned.

  Moreover, as an epoxy compound of another structure, for example, salicylaldehyde-phenol or a cresol type epoxy compound (Nippon Kayaku Co., Ltd. EPPN502H, FAE2500, etc.), Dainippon Ink & Chemicals, Inc. (DIC Corporation) Epicron 840 860, 3050, DER-330, 337, 361 manufactured by Dow Chemical Co., Celoxide 2021, manufactured by Daicel Chemical Industries, Ltd., TETRAD-X, C manufactured by Mitsubishi Gas Chemical Co., Ltd., EPB-13, 27 manufactured by Nippon Soda Co., Ltd. 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 Hydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride, trimellitic anhydride and the like can be mentioned.

  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. Examples of the catalyst that can be used include triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, and triphenylphosphine. 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, in order to prevent polymerization between the epoxy compounds (a1) or between the unsaturated monocarboxylic acids (a2) or between the epoxy compound (a1) and the unsaturated monocarboxylic acid (a2), a polymerization inhibitor is used. It is preferable to use it. 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.

  Resins having one or more ethylenically unsaturated groups and carboxyl groups in the molecule include CCR-1218H, CCR-1159H, CCR-1222H, PCR-1050, TCR-1335H, ZAR-1035, ZAR-2001H, ZFR -1185 and ZCR-1569H (Nippon Kayaku Co., Ltd., trade name) are commercially available.

  Further, the resin having one or more ethylenically unsaturated groups and a carboxyl group in the molecule which is the component (a) of the present invention is an epoxy acrylate compound having two or more hydroxyl groups and ethylenically unsaturated groups in the molecule. It is also preferable to use a polyurethane compound obtained by reacting a diisocyanate compound with a diol compound having a carboxyl group.

  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. First, 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, and compounds obtained by reacting (meth) acrylic acid with epoxy compounds having a fluorene skeleton.

  As the raw material diisocyanate, any compound having two isocyanato groups can be used without particular limitation. 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-described 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 (3).

Here, in the general formula (3), R ⁷ is an epoxy acrylate residue, R ⁸ is a diisocyanate residue, R ⁹ is an alkyl group having 1 to 5 carbon atoms, and R ¹⁰ is a hydrogen atom or a methyl group. 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 described above, 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. Moreover, in each process mentioned above, you may use a catalyst etc. suitably.

  Moreover, you may make the polyurethane compound mentioned above and raw material epoxy react further. In this reaction, a so-called epoxycarboxylation reaction occurs mainly between the carboxyl group derived from the diol compound in the polyurethane compound and the epoxy group of the raw material epoxy. Thus, the compound obtained is equipped with the principal chain formed from the polyurethane compound mentioned above, and the side chain containing the ethylenically unsaturated group originating in raw material epoxy acrylate or raw material epoxy, for example.

As the polyurethane compound of the present embodiment, among the compounds represented by the general formula (3), the hard segment part of the raw material epoxy acrylate that is one of the main skeletons of the polyurethane, that is, R ⁷ having a bisphenol A type structure is preferable. . Such polyurethane compounds are commercially available as UXE-3011, UXE-3012, UXE-3024 (manufactured by Nippon Kayaku Co., Ltd.) and the like. These may be used alone or in combination of two or more.

  In addition, a photosensitive resin composition containing such a polyurethane compound can form a tough and stretched cured film, improving crack resistance and HAST resistance after curing (Highly Accelerated Stress Test). Can be made.

  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 the KOH aqueous solution, Wp represents the measurement resin solution mass (g), and I represents the nonvolatile content of the measurement resin solution. The ratio (mass%) is shown.

  Setting of the weight average molecular weight of the component (a) is an important point of the present invention. The optimum set value varies depending on the photosensitive layer thickness, the lamination condition, the remaining copper ratio of the substrate, etc., but from the viewpoint of fluidity, it is preferable that the weight average molecular weight is 3000 to 8000 and 9000 to 18000. Further, it is preferable that the ratio of the resin having a low weight average molecular weight is large.

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

<(B) component>
The component (b) of the present invention is a photopolymerizable monomer having at least one ethylenically unsaturated group and a tricyclodecane structure in the molecule.

  The component (b) is preferably at least one selected from the group consisting of dimethylol tricyclodecane diacrylate, dimethylol tricyclodecane dimethacrylate, tricyclodecanediol diacrylate, and tricyclodecanediol dimethacrylate. . These are commercially available as NK ester DCP and NK ester A-DCP (both manufactured by Shin-Nakamura Chemical Co., Ltd.).

  Furthermore, when using what has a urethane bond as said (b) component, it is also preferable to use (b) component which has the partial structure shown by the following general formula (1) or general formula (2).

“In General Formula (1) and General Formula (2), R ¹ and R ² represent a direct bond, an alkylene, or an arylene group”
The alkylene group is preferably an alkylene group having 2 to 20 carbon atoms, more preferably an alkylene group having 2 to 10 carbon atoms, and further preferably an alkylene group having 2 to 6 carbon atoms.

  Examples of the alkylene group having 2 to 6 carbon atoms include an ethylene group, a propylene group, an isopropylene group, a butylene group, a pentylene group, and a hexylene group. From the viewpoint of resolution and plating resistance, an ethylene group or an isopropylene group. It is preferred that it is ethylene group.

  The arylene group is preferably an arylene group having 6 to 14 carbon atoms, and more preferably an arylene group having 6 to 10 carbon atoms. Examples of such an arylene group include phenylene and naphthylene.

  When the compound having the partial structure represented by the general formula (1) or the general formula (2) is used as the component (b), (b1) a diol compound containing a tricyclodecane structure and (b2) diisocyanate A urethane compound obtained by reacting a compound with (b3) a compound having at least one ethylenically unsaturated group and one hydroxyl group in the molecule is preferable.

  Although there is no restriction | limiting in particular as said (b2) diisocyanate, The compound which has a ring structure is preferable. Among these, those having a rigid structure such as isophorone diisocyanate are more preferable from the viewpoint of crack resistance (heat resistance).

  In addition, the compound (b3) having at least one ethylenically unsaturated group and one hydroxyl group in the molecule has two ethylenically unsaturated groups from the viewpoint of crosslinking density. Those having three are particularly preferred.

  The compound having three ethylenically unsaturated groups preferably contains a compound represented by the following general formula (4).

[In General Formula (4), R ³ and R ⁴ may be the same or different, each R ³ represents an alkylene group or arylene group having 1 to 10 carbon atoms, and R ⁴ represents a hydrogen atom or 1 carbon atom. 10 represents an alkyl group or an aryl group, and l, m, and n represent an integer of 1 to 10. ]

  Among these, the diisocyanate is isophorone diisocyanate, and in addition, a compound having at least one ethylenically unsaturated group and one hydroxyl group in the molecule is represented by the general formula (4). Is more preferable. Examples of such a compound include UX-5002D-M20 (manufactured by Nippon Kayaku Co., Ltd.). These can be used alone or in combination of two or more.

<(C) Component: Photopolymerization initiator>
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, and 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, o-amino such as 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.

  From the viewpoint of making the resist shape better, it is preferable to use a phosphine oxide photopolymerization initiator. Examples of such compounds include monoacylphosphine oxides such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and bisacylphosphine oxides include bis (2,4,4). 6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide. These are commercially available as DAROCURE-TPO and IRGACURE-819 (both are trade names, manufactured by Ciba Japan).

  Moreover, it is preferable to further contain a compound having an oxime ester for the purpose of improving sensitivity. Examples of the compound having the oxime ester include (2- (acetyloxyiminomethyl) thioxanthen-9-one), (1,2-octanedione, 1- [4- (phenylthio)-, 2- (o -Benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (o-acetyloxime)). Examples of commercially available products include IRGACURE-OXE01 and IRGACURE-OXE02 (both manufactured by Ciba Specialty Chemicals).

  Further, (c) a thioxanthone compound may be included as a sensitizer for the photopolymerization initiator from the viewpoint of further improving the resist shape. Examples of the thioxanthone compounds include 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, and the like. Among them, it is more preferable that 2,4-diethylthioxanthone is included among them. 2,4-Diethylthioxanthone is commercially available as KAYACURE-DETX (manufactured by Nippon Kayaku Co., Ltd., product name).

<(D) component>
The (d) epoxy resin that can be used in the photosensitive resin composition of the present invention is not particularly limited, and examples thereof include bisphenol A type epoxy resins such as bisphenol A diglycidyl ether and bisphenols such as bisphenol F diglycidyl ether. F-type epoxy resins, bisphenol S-type epoxy resins such as bisphenol S diglycidyl ether, biphenol-type epoxy resins such as biphenol diglycidyl ether, bixylenol-type epoxy resins such as bixylenol diglycidyl ether, hydrogenated bisphenol A glycidyl ether, etc. Examples thereof include hydrogenated bisphenol A type epoxy resins and dibasic acid-modified diglycidyl ether type epoxy resins thereof. These can be used alone or in combination of two or more.

  Commercial products can be used as these compounds. For example, examples of bisphenol A diglycidyl ether include Epicoat 828, Epicoat 1001, and Epicoat 1002 (all are trade names manufactured by Japan Epoxy Resin Co., Ltd.). Examples of bisphenol F diglycidyl ether include Epicoat 807 (trade name, manufactured by Japan Epoxy Resin Co., Ltd.), and examples of bisphenol S diglycidyl ether include EBPS-200 (trade name, manufactured by Nippon Kayaku Co., Ltd.) and Epicron EXA-1514 (manufactured by Dainippon Ink & Chemicals, Inc. (DIC Corporation), trade name) and the like can be mentioned. Examples of the biphenol diglycidyl ether include YL-6121 (trade name, manufactured by Japan Epoxy Resin Co., Ltd.). Examples of the bixylenol diglycidyl ether include YX-4000 (trade name, manufactured by Japan Epoxy Resin Co., Ltd.). Etc. Furthermore, examples of the hydrogenated bisphenol A diglycidyl ether include ST-2004 and ST-2007 (both manufactured by Tohto Kasei Co., Ltd., trade names) and the like. As the above-mentioned dibasic acid-modified diglycidyl ether type epoxy resin Can include ST-5100 and ST-5080 (both manufactured by Tohto Kasei Co., Ltd., trade names).

  The photosensitive resin composition may further contain other components according to desired properties in addition to the components (a) to (d) described above.

  Examples of the other component include a photopolymerizable monomer having at least one ethylenically unsaturated group in the molecule, which is different from the component (b). Depending on the required properties, these photopolymerizable monomers can be appropriately selected and used in addition to the component (b).

  Specific examples of such compounds include bisphenol A (meth) acrylate compounds, compounds obtained by reacting polyhydric alcohols with α, β-unsaturated carboxylic acids, and glycidyl group-containing compounds with α, β- Examples thereof include a compound obtained by reacting an unsaturated carboxylic acid, a urethane monomer such as a (meth) acrylate compound having a urethane bond in the molecule, or a urethane oligomer. Besides these, nonylphenoxy polyoxyethylene acrylate, γ-chloro-β-hydroxypropyl-β '-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β'-(meth) acryloyloxy Examples thereof include phthalic acid compounds such as alkyl-o-phthalate, (meth) acrylic acid alkyl ester, and EO-modified nonylphenyl (meth) acrylate.

  In order to improve the alkali developability, it is preferable to use a bisphenol A-based (meth) acrylate compound in combination with the component (b). 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. One or more of these can be used in combination. Among these, in order to improve the sensitivity and resolution, among the above, 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane is used in combination with the component (b). It is preferable.

  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.). , And commercially available as trade name), and 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). Are available.

  In order to improve the balance of adhesion, resolution and electric corrosion resistance, it is preferable to use a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol in combination with the component (b). .

  Examples of the compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups. Polypropylene glycol di (meth) acrylate, polyethylene polypropylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di (meth) acrylate, tri Methylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO / PO-modified trimethylolpropane tri (meth) acrylate, tetramethylolmethanetri (meth) A Chlorate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, EO-modified glyceryl tri (meth) acrylate, PO-modified glyceryl tri (meth) acrylate, EO Examples thereof include PO-modified glyceryl tri (meth) acrylate.

“EO” refers to “ethylene oxide”, and “PO” refers to “propylene oxide”. Further, “EO modified” means having a block structure of ethylene oxide units (—CH ₂ —CH ₂ —O—), and “PO modified” means propylene oxide units (—CH ₂ —CH ₂ —CH _2). -O-) or isopropylene oxide units _{(-CH 2 -CH (CH 3)} -O -, - CH (CH 3) means having a block structure of -CH 2 -O-).

  Examples of the compound obtained by reacting the glycidyl group-containing compound with an α, β-unsaturated carboxylic acid include trimethylolpropane triglycidyl ether tri (meth) acrylate and 2,2-bis (4- (meta ) Acryloxy-2-hydroxy-propyloxy) phenyl and the like. Examples of the α, β-unsaturated carboxylic acid for obtaining the above compound include (meth) acrylic acid.

  Examples of urethane monomers or urethane oligomers such as (meth) acrylate compounds having a urethane bond in the molecule include (meth) acrylic monomers having an OH group at the β-position, isophorone diisocyanate, and 2,6-toluene. Addition reaction products with diisocyanate compounds such as diisocyanate, 2,4-toluene diisocyanate and 1,6-hexamethylene diisocyanate, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meta ) Acrylate, and EO or PO-modified urethane di (meth) acrylate.

  The photosensitive resin composition of the present invention, particularly when adhesion with a metal such as copper is required, as an adhesion improver, melamine, dicyandiamide, triazine compounds and derivatives thereof, imidazole, thiazole, triazole, Additives such as a silane coupling agent can be used. Examples include melamine, acetoguanamine, benzoguanamine, melamine-phenol-formalin resin, dicyandiamide, manufactured by Shikoku Kasei Kogyo Co., Ltd .; 2MZ-AZINE, 2E4MZ-AZINE, C11Z-AZINE, 2MA-OK and the like. 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% by mass based on 100 parts by mass of the total amount of component (a) and component (b).

  Moreover, in this invention, it is preferable to use an inorganic filler as needed in order to improve characteristics, such as adhesiveness and hardness. For example, inorganic fillers such as barium sulfate, barium titanate, powdered silicon oxide, amorphous silica, talc, clay, calcined kaolin, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, and mica powder can be used. The amount used is preferably 0 to 70% by mass.

  In the photosensitive resin composition of the present invention, it is effective to further add an elastomer that is not completely compatible with the photosensitive resin composition, if necessary. By including an elastomer in the photosensitive resin composition, it is possible to improve the adhesion to the conductor layer, and further improve the heat resistance, flexibility and toughness of the photosensitive resin composition after curing. It becomes possible to make it. Examples of the elastomer include styrene elastomers, olefin elastomers, urethane elastomers, polyester elastomers, polyamide elastomers, acrylic elastomers, and silicone elastomers. Examples of the styrene elastomer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, and styrene-ethylene-propylene-styrene block copolymer. As the styrene component in the styrene elastomer, styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene and the like can be used in addition to styrene.

  Styrenic elastomers are commercially available from Tufprene, Solprene T, Asaprene T, Tuftec (made by Asahi Kasei Co., Ltd.), Elastomer AR (made by Aron Kasei Co., Ltd.), Clayton G, Califlex (above, Shell Japan Co., Ltd.) Company), JSR-TR, TSR-SIS, Dynalon (above, manufactured by JSR Corporation), Denka STR (manufactured by Denki Kagaku Kogyo Co., Ltd.), Quintac (manufactured by Zeon Corporation), TPE-SB series (Sumitomo Chemical) Co., Ltd.), Lavalon (Mitsubishi Chemical Co., Ltd.), Septon, Hibler (above, Kuraray Co., Ltd.), Sumiflex (Sumitomo Bakelite Co., Ltd.), Reostoma, Actimer (above, Riken Vinyl Industry Co., Ltd.) Etc. are available.

  Examples of olefinic elastomers include homopolymers or copolymers of 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene and 4-methyl-pentene; ethylene-propylene copolymers (EPR) Ethylene-propylene-diene copolymer (EPDM); dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, butadiene, isoprene, and the like, and α-olefin A copolymer of methacrylic acid and a butadiene-acrylonitrile copolymer; an ethylene-α-olefin copolymer rubber; an ethylene-α-olefin-nonconjugated diene copolymer rubber; a propylene-α- Olefin copolymer rubber, butene-α-olefin copolymer Combined rubber and the like. Olefin-based elastomers are commercially available as MIRASTOMA (manufactured by Mitsui Petrochemical Co., Ltd.), EXACT (manufactured by ExxonMobil), ENGAGE (manufactured by Dow Chemical), DYNABON HSBR which is a hydrogenated styrene-butadiene copolymer, NBR series that is a butadiene-acrylonitrile copolymer, XER series that is a carboxyl group-modified butadiene-acrylonitrile copolymer having a crosslinking point (above, manufactured by JSR Corporation), and the like are available.

  The urethane elastomer is composed of a hard segment composed of a short-chain diol and diisocyanate and a soft segment composed of a long-chain diol and diisocyanate. As long chain diols, polypropylene glycol, polytetramethylene oxide, poly (1,4-butylene adipate), poly (ethylene-1,4-butylene adipate), polycaprolactone, poly (1,6-hexylene carbonate), Examples thereof include poly (1,6-hexylene-neopentylene adipate), and the number average molecular weight of the long-chain diol is preferably 500 to 10,000.

  Examples of the short chain diol include ethylene glycol, propylene glycol, 1,4-butanediol, bisphenol A and the like, and the number average molecular weight of the short chain diol is preferably 48 to 500. The urethane-based elastomer is commercially available as PANDEX T-2185, T-2983N (manufactured by Dainippon Ink & Chemicals, Inc. (DIC)). The polyester-based elastomer is an elastomer obtained by polycondensation of a dicarboxylic acid or a derivative thereof and a diol compound or a derivative thereof. Dicarboxylic acids include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid and aromatic dicarboxylic acids in which these aromatic rings are substituted with methyl, ethyl, phenyl, etc .; carbon such as adipic acid, sebacic acid, dodecanedicarboxylic acid, etc. Examples thereof include aliphatic dicarboxylic acids of 2 to 20; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and one or more of these compounds can be used.

  Examples of the diol compound include aliphatic or alicyclic compounds such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, and 1,4-cyclohexanediol. Diol; bisphenol A, bis- (4-hydroxyphenyl) -methane, bis- (4-hydroxy-3-methylphenyl) -propane, resorcin, etc. can be exemplified, and one or more of these compounds should be used Can do.

  Further, a multi-block copolymer having an aromatic polyester (for example, polybutylene terephthalate) as a hard segment component and an aliphatic polyester (for example, polytetramethylene glycol) as a soft segment component can be used. The polyester-based elastomer is commercially available as Hytrel (DuPont Toray Industries, Inc.), Perprene (Toyobo Co., Ltd.), Espel (Hitachi Chemical Industries, Ltd.), and the like. Polyamide elastomers are elastomers composed of a hard segment made of polyamide and a soft segment made of polyether or polyester, and are roughly divided into two types: polyether block amide type and polyether ester block amide type. The

  Examples of the polyamide include polyamide 6, polyamide 11, and polyamide 12, and examples of the polyether include polyoxyethylene, polyoxypropylene, and polytetramethylene glycol. The polyamide-based elastomer is commercially available from UBE polyamide elastomer (manufactured by Ube Industries, Ltd.), Daiamide (manufactured by Daicel Huls Co., Ltd. (Daicel Evonik Co., Ltd.)), PEBAX (manufactured by Toray Industries, Inc.), and Grilon ELY ( Moss Japan Co., Ltd.), Novamid (Mitsubishi Chemical Co., Ltd.), Glease (Dainippon Ink Chemical Co., Ltd. (DIC Co., Ltd.)), etc. are available. Acrylic elastomers are acrylic esters such as ethyl acrylate, butyl acrylate, methoxyethyl acrylate, and ethoxyethyl acrylate, and monomers having an epoxy group such as glycidyl methacrylate and allyl glycidyl ether, and / or vinyl such as acrylonitrile and ethylene. It is an elastomer obtained by copolymerizing with a monomer.

  Examples of the acrylic elastomer include acrylonitrile-butyl acrylate copolymer, acrylonitrile-butyl acrylate-ethyl acrylate copolymer, acrylonitrile-butyl acrylate-glycidyl methacrylate copolymer, and the like. The silicone elastomer is an elastomer mainly composed of organopolysiloxane, and examples thereof include polydimethylsiloxane, polymethylphenylsiloxane, and polydiphenylsiloxane silicone elastomers. An elastomer obtained by modifying organopolysiloxane with a vinyl group, an alkoxy group or the like may be used. Silicone elastomers are commercially available as KE series (manufactured by Shin-Etsu Chemical Co., Ltd.) SE series, CY series, SH series (above, manufactured by Toray Dow Corning Silicone Co., Ltd.) and the like. In addition to the above-described elastomers, rubber-modified epoxy resins, epoxy resins obtained by kneading the above-described elastomer particles, and the like can be used. The rubber-modified epoxy resin is obtained by modifying at least part of the epoxy group of the epoxy resin with a both-end carboxyl group-modified butadiene-acrylonitrile copolymer, a terminal amino-modified silicone rubber or the like. Furthermore, as an elastomer, the both-ends carboxyl group-modified butadiene-acrylonitrile copolymer and Espel (Espel 1108, Espel 1612, Espel 1620, manufactured by Hitachi Chemical Co., Ltd.) which is a polyester elastomer can also be used.

  In the present invention, it is desirable to use a diluting solvent as necessary. 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, methyl isobutyl ketone, methyl pentyl ketone, methyl hexyl ketone, ethyl butyl ketone, dibutyl ketone, ethylene glycol, diethylene glycol, tri Ethylene glycol, tetraethylene glycol, propylene glycol, ethylene glycol monoacetate, ethylene glycol diacetate, propylene glycol monoacetate, pro Ethylene glycol alkyl ethers such as lenglycol diacetate, propylene glycol monoethyl ether, methyl cellosolve, ethyl cellosolve, butyl cellosolve, phenyl cellosolve, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate And its acetate, diethylene glycol monoalkyl ether and its acetate, diethylene glycol dialkyl ether, triethylene glycol alkyl ether, propylene glycol alkyl ether and its acetate, dipropylene glycol alkyl ether, toluene, petroleum ether, petroleum naphtha , Hydrogenated oil naphtho Or petroleum solvents such as solvent naphtha, carboxylic acids such as ethyl formate, propyl formate, butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate Esters, amines, amides such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, dioxane, tetrahydrofuran, cyclohexanone, γ-butyrolactone, 3-hydroxy Solvents such as 2-butanone, 4-hydroxy-2-pentanone, and 6-hydroxy-2-hexanone can be used alone or in combination of two or more.

  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. it can. 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 agents such as silicone, fluorine and polymer Leveling agents can be used.

  When the diluent used in the present invention is applied to a support and used as a photosensitive element (photosensitive film), it is contained in an amount of 30 to 70% of the total mass in a varnish state before coating. Then, since it volatilizes in the drying process at the time of film preparation after setting it as a film, it will be 2% or less.

Next, the photosensitive element of the present invention will be described.
The photosensitive element of this invention is equipped with a 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.

  The photosensitive resin composition layer is obtained by dissolving and dispersing the photosensitive resin composition of the present invention in the above solvent or mixed solvent to obtain a solution having a solid content of about 30 to 80% by mass, and then applying the solution onto a support. Is preferably formed. Although the thickness of the photosensitive resin composition layer varies depending on the use, it is preferably 5 to 200 μm and more preferably 15 to 60 μm in thickness after drying after removing the solvent by heating and / or hot air blowing. . If this thickness is less than 5 μm, it tends to be difficult to apply industrially, and if it exceeds 200 μm, the above-mentioned effects produced by the present invention tend to be reduced, and in particular, physical properties and resolution tend to decrease.

  Examples of the support provided in the photosensitive element include a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester.

  The thickness of the support is preferably 5 to 100 μm, and more preferably 10 to 30 μm. If the thickness is less than 5 μm, the support tends to be broken when the support is peeled off before development, and if it exceeds 100 μm, the resolution and flexibility tend to decrease. In the present invention, since the photosensitive resin composition layer is formed using the modified epoxy resin as described above, when the thickness of the support is thicker than the conventional one, for example, when it is more than 25 μm and less than 100 μm Even so, its flexibility and resolution can be maintained.

  The photosensitive element consisting of two layers of the support and the photosensitive resin composition layer as described above or the photosensitive element consisting of three layers of the support, the photosensitive resin composition layer and the protective film is stored, for example, as it is. Alternatively, the protective film may be interposed and wound around the core in a roll shape and stored.

  The method for forming a resist pattern using the photosensitive resin composition or photosensitive element of the present invention is as follows. First, a known screen printing, a step of applying by a roll coater, or a step of applying by laminating or the like, Is laminated on the substrate to form Next, if necessary, a removal process for removing the protective film from the photosensitive element described above is performed, and an actinic ray is irradiated to a predetermined portion of the photosensitive resin composition layer through a mask pattern, so that the photosensitive resin of the irradiated portion is irradiated. An exposure step for photocuring the composition layer is performed. The photosensitive resin composition layer other than the irradiated part is removed by the next development step. In addition, the board | substrate which forms a resist points out a printed wiring board, a board | substrate for semiconductor packages, and a flexible wiring board.

As the light source of actinic light, a known light source such as a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, or a xenon lamp that emits ultraviolet rays effectively is used. Moreover, what emits visible light effectively, such as a photographic flood light bulb and a solar lamp, is also used.
Further, direct drawing direct laser exposure may be used. By using the component (c) corresponding to each laser light source and exposure method, it is possible to form an excellent pattern.

  In the development process, an alkaline developer such as a dilute solution of sodium carbonate (1 to 5% by mass aqueous solution) at 20 to 50 ° C. is used as the developer, and known spraying, rocking immersion, brushing, scraping, etc. Develop by the method of.

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, chemical resistance, and the like. In the case of irradiating ultraviolet rays, the irradiation amount can be adjusted as necessary. For example, the irradiation can be performed at an irradiation amount of about 0.2 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 100-170 degreeC. Furthermore, ultraviolet irradiation and heating can be performed at the same time, and after either one is performed, the other can be performed. When performing ultraviolet irradiation and heating simultaneously, it is more preferable to heat to 60 to 150 ° C. from the viewpoint of effectively imparting solder heat resistance, chemical resistance and the like.

  This photosensitive resin composition layer also serves as a protective film for wiring after soldering to the substrate, has good lamination temperature stability, excellent resolution, excellent flatness, crack resistance, HAST resistance, Since it has gold plating properties, it is effective as a solder resist (permanent resist) for printed wiring boards, semiconductor package substrates, and flexible wiring boards.

  The substrate provided with the resist pattern in this manner is then mounted with a semiconductor element or the like (for example, wire bonding or solder connection) and then mounted on an electronic device such as a personal computer.

  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 resin composition solution)
First, the photosensitive resin composition solution was obtained by mixing each component shown to Table 1-2 by the compounding quantity (mass part) shown to the same table. The following components were used for the components shown in Tables 1 and 2.

<(A) component>
“EXP-2810 (weight average molecular weight; 10,000)”: acid-modified cresol novolac epoxy acrylate (manufactured by DIC Corporation).
"EXP-2810 low molecular weight product (weight average molecular weight; 7000)": acid-modified cresol novolac epoxy acrylate (manufactured by DIC Corporation).
“EXP-2810 high molecular weight product (weight average molecular weight; 15000)”: acid-modified cresol novolac epoxy acrylate (manufactured by DIC Corporation).
“UXE-3024 (weight average molecular weight; 10,000)”: urethane-modified epoxy acrylate (manufactured by Nippon Kayaku Co., Ltd.).

<(B) component>
“NK Esper DCP”: Tricyclodecane dimethanol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
"UX-5002D-M20": Tricyclodecane structure-containing urethane acrylate (manufactured by Nippon Kayaku Co., Ltd.)

<(C) component (photopolymerization initiator)>
“DAROCURE-TPO”: bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by Ciba Specialty Chemicals).
“IRGACURE-OXE02”: Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) (Ciba Specialty Chemicals) ).
“IRGACURE-907”: 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one (manufactured by Ciba Specialty Chemicals).

<(D) component>
“NC-3000H”: biphenyl dimethylene type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.)
"BL-3175": Block type isocyanate (manufactured by Sumitomo Bayer Urethane Co., Ltd.)

<Other ingredients>
“FA-321M”: 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane (manufactured by Hitachi Chemical Co., Ltd.).
“Benzoguanamine”: 2,4-diamino-6-phenyl-1,3,5-triazine (trade name, manufactured by Nippon Shokubai Co., Ltd.).
“Dicyandiamide”: “Epicure DICY7” (trade name, manufactured by Japan Epoxy Resin Co., Ltd.).
“Esper 1108”: polyester elastomer (trade name, manufactured by Hitachi Chemical Co., Ltd.).
"Phthalocyanine blue" (trade name, manufactured by Toyo Ink Co., Ltd.)
“Variace B-30”: A barium sulfate dispersion prepared by the following method using barium sulfate “Variace B-30” (trade name, manufactured by Sakai Chemical Industry Co., Ltd.).

  (B) 20 parts by mass (solid content) of the component, 25 parts by mass of the barium sulfate, and 40 parts by mass of methyl ethyl ketone were mixed with Starmill LMZ (manufactured by Ashizawa Finetech Co., Ltd.) using zirconia beads having a diameter of 1.0 mm. Dispersion was carried out at 12 m / s for 3 hours to obtain a barium sulfate dispersion. Barium sulfate was added to the photosensitive resin composition by blending the dispersion prepared above.

  In the photosensitive resin composition solutions of Examples and Comparative Examples, a mixed solution of methyl ethyl ketone and N, N-dimethylformamide as a diluent at a mass ratio of 1: 1 is used, and the solid content of the resin composition solution is 60% by mass. It was added to become.

(Production of photosensitive element)
Next, the photosensitive resin composition solution obtained above is uniformly coated on a 16 μm-thick polyethylene terephthalate film (G2-16, trade name, manufactured by Teijin Ltd.) as a support, thereby forming the photosensitive resin composition. A material layer was formed and dried for about 10 minutes at 100 ° C. using a hot air convection dryer. The film thickness after drying of the photosensitive resin composition layer was 20 μm.

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

(Characteristic evaluation of photosensitive element)
Each of the following tests was performed using the photosensitive elements of Examples 1 to 5 and Comparative Examples 1 to 5, respectively, and when each photosensitive element was used, photosensitive layer stickiness, resolution, gold plating resistance, surface smoothness The sexuality and embeddability were evaluated. The obtained results are summarized in Table 2.

(Evaluation of stickiness of photosensitive layer)
The stickiness of the photosensitive resin composition layer of the obtained photosensitive element was determined according to the following criteria.
“A”: Sticking to a finger is not recognized or hardly recognized.
“B”: Applicable to the finger.
“C”: A sticking strong enough to adhere to a finger is recognized.

(Resolution evaluation)
The copper surface of a printed wiring board substrate (E-679, manufactured by Hitachi Chemical Co., Ltd., trade name) 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 press-type vacuum laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd., trade name), pressure bonding pressure 0.4 MPa, press hot plate temperature 80 ° C., evacuation time 20 seconds, Lamination was performed for 30 seconds at an atmospheric pressure of 4 kPa or less, and the polyethylene film of the photosensitive element was peeled off and laminated to obtain a laminate for evaluation.

  On the evaluation laminate, a photo tool having a via diameter pattern of 10 μm in a range of 30 to 100 μm in diameter as a negative is brought into close contact with an EXM-1201 type exposure machine manufactured by Oak Manufacturing Co., Ltd., 41 steps The exposure was performed with an energy amount such that the number of remaining steps after development of the tablet was 16.0. Next, after standing at room temperature (25 ° C.) for 1 hour, the polyethylene terephthalate on the laminate was peeled off, and spray development was performed for 60 seconds with a 1 mass% sodium carbonate aqueous solution at 30 ° C. to remove unexposed portions. A resist pattern was formed.

The formed resist pattern was observed with a stereomicroscope, and the resolution was determined according to the following criteria.
“A”: A via diameter of 50 μm can be resolved.
“B”: A via diameter of 50 μm was not resolved.
“C”: Resist residue can be observed in the via.

(Evaluation of electroless Ni / Au plating resistance)
The copper surface of a printed wiring board substrate (E-679, manufactured by Hitachi Chemical Co., Ltd., trade name) 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. Using a press-type vacuum laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd., trade name) on this printed wiring board substrate, press hot plate temperature 70 ° C., vacuuming time 20 seconds, laminating press time 30 seconds, Under the conditions of an atmospheric pressure of 4 kPa or less and a pressing pressure of 0.4 MPa, the polyethylene film of the photosensitive element was peeled and laminated to obtain a laminate for evaluation.

  A photo tool having a via pattern with a diameter of 200 μm as a negative is brought into close contact with the evaluation laminate, and the number of remaining steps after development of a 41-step tablet using an EXM-1201 type exposure machine manufactured by Oak Manufacturing Co., Ltd. Was exposed with an energy amount of 16.0. Subsequently, after leaving still at room temperature for 1 hour, the polyethylene terephthalate on this laminated body was peeled off, and spray development was carried out with a 1 mass% sodium carbonate aqueous solution at 30 ° C. for 60 seconds to form a pattern.

Subsequently, ultraviolet irradiation is performed with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd., and a heat treatment is performed at 160 ° C. for 60 minutes, thereby having a via opening with a diameter of 200 μm. A laminated substrate for evaluation in which a solder resist was formed was obtained.

  The laminated substrate for evaluation obtained above is subjected to electroless nickel plating (trade name Nimden NPR-4, manufactured by Uemura Kogyo Co., Ltd.) (15 minutes treatment), and further electroless gold plating (manufactured by Uemura Kogyo Co., Ltd.). The product name Orical TKK-511) was applied (15 minutes treatment).

For the evaluation laminated substrate thus plated, the plating solution soaked into the bottom of the solder resist, and the solder resist floating and peeling from the substrate were observed with a 100-fold metal microscope, and the following: The electroless Ni / Au plating resistance was evaluated according to the criterion.
“A”: No penetration into the solder resist bottom.
“B”: A penetration of 1 to 10 μm into the bottom of the solder resist.
“C”: other than above.

(Evaluation of surface smoothness (flatness))
A 100 × 100 mm square printed wiring board substrate (E-679, manufactured by Hitachi Chemical Co., Ltd., trade name) in which a 12 μm thick copper foil is laminated on a 0.06 mm thick glass epoxy base material has a radius of 0.2 mm. Through-holes were produced at 1 mm intervals and used as a surface flatness evaluation substrate. The copper surface of this substrate was polished with an abrasive brush, washed with water and dried. Using a press-type vacuum laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd., trade name) on both sides of this printed wiring board substrate, press hot plate temperature 70 ° C., evacuation time 20 seconds, laminating press time 30 seconds, Under the conditions of an atmospheric pressure of 4 kPa or less and a pressing pressure of 0.4 MPa, the polyethylene film of the photosensitive element was peeled and laminated to obtain a laminate for evaluation.

  Using an EXM-1201 type exposure machine manufactured by Oak Manufacturing Co., Ltd., the laminate for evaluation was exposed with an energy amount such that the number of remaining step stages after development of the 21-step tablet was 19.0. Next, after standing at room temperature (25 ° C.) for 1 hour, the polyethylene terephthalate on the laminate was peeled off, and a 1% by mass aqueous sodium carbonate solution at 30 ° C. was used for the minimum development time (minimum time for developing the unexposed area). ) Spray development was carried out in 1.5 times the time to form a pattern.

Subsequently, the surface flatness evaluation in which the solder resist was formed by performing ultraviolet irradiation with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd. and further performing heat treatment at 160 ° C. for 60 minutes. A laminated substrate was obtained.

Thus, the evaluation board | substrate obtained by measuring the dent in the through-hole part of a soldering resist using the ultra-deep shape measuring microscope (VK-8510, product made from Keyence Corporation) was evaluated by the following criteria.
“A”: a through hole having a dent of 0 to 3 μm.
“B”: The through hole has a dent of 4 to 7 μm.
“C”: 7 μm or more.

(Evaluation of embeddability)
A 100 × 100 mm square printed wiring board substrate (E-679, manufactured by Hitachi Chemical Co., Ltd., trade name) in which a 12 μm thick copper foil is laminated on a 0.40 mm thick glass epoxy substrate, has a radius of 0.3 mm. Through-holes were produced at intervals of 2 mm, and this was used as an embedded evaluation board. The copper surface of this substrate was polished with an abrasive brush, washed with water and dried. Using a press-type vacuum laminator (MVLP-500, manufactured by Meiki Seisakusho Co., Ltd., trade name) on both sides of this printed wiring board substrate, press hot plate temperature 70 ° C., evacuation time 20 seconds, laminating press time 30 seconds, Under the conditions of an atmospheric pressure of 4 kPa or less and a pressure pressure of 0.4 MPa, the polyethylene film of the photosensitive element was peeled off and laminated on both sides to obtain an evaluation laminate.

  Using an EXM-1201 type exposure machine manufactured by Oak Manufacturing Co., Ltd., the laminate for evaluation was exposed with an energy amount such that the number of remaining step stages after development of the 21-step tablet was 19.0. Next, after standing at room temperature for 1 hour, the polyethylene terephthalate on the laminate was peeled off, and 1% of the minimum development time (minimum time for developing the unexposed area) with a 1% by mass aqueous sodium carbonate solution at 30 ° C. Spray development was carried out in 5 times to form a pattern.

Subsequently, using an ultraviolet irradiation device manufactured by Oak Manufacturing Co., Ltd. for ultraviolet irradiation with an energy amount of 1 J / cm ² , and further heat treatment at 160 ° C. for 60 minutes, for evaluation of embedding property in which a solder resist is formed. A laminate substrate was obtained.

In the evaluation board thus obtained, 100 through-hole portions were observed using a metal microscope and evaluated according to the following criteria.
“A”: No bubbles or cracks are observed.
“B”: 1 to 10 bubbles / cracks are observed.
“C”: 11 or more bubbles / cracks are observed.

In Comparative Example 1 using one type of resin having one or more ethylenically unsaturated groups and a carboxyl group in the molecule of the component (a), the surface smoothness and embedding property are inferior. In Comparative Example 2 using a resin having a weight average molecular weight (Mw) lower than that of the resin used as the component (a) in Comparative Example 1, surface smoothness and embedding are improved, but stickiness and resolution are improved. It is inferior to sex. On the contrary, in Comparative Example 3 using a resin having a high Mw, the stickiness and resolution are good, but the surface smoothness and embedding are much worse.
On the other hand, in the embodiment containing two or more compounds having different weight average molecular weights as a resin having one or more ethylenically unsaturated groups and a carboxyl group in the molecule of component (a), A photosensitive resin composition capable of forming an optimal solder resist (permanent resist) for printed wiring boards, semiconductor package substrates, and flexible wiring boards, having excellent resolution, Ni / Au plating resistance, surface smoothness, and embedding properties. Can be provided.

Claims (7)

  (A) a resin having one or more ethylenically unsaturated groups and a carboxyl group in the molecule; and (b) a photopolymerizable monomer having one or more ethylenically unsaturated groups and a tricyclodecane structure in the molecule. A photosensitive resin composition containing (c) a photopolymerization initiator and (d) an epoxy resin, wherein the component (a) includes two or more compounds having different weight average molecular weights Composition.   The photosensitive resin composition according to claim 1, wherein the weight average molecular weights of two or more kinds of compounds having different weight average molecular weights of the component (a) are 3000 to 8000 and 9000 to 18000.   The component (b) is at least one selected from the group consisting of dimethylol tricyclodecane diacrylate, dimethylol tricyclodecane dimethacrylate, tricyclodecanediol diacrylate, and tricyclodecanediol dimethacrylate. The photosensitive resin composition of Claim 1 or Claim 2. The photosensitive resin composition according to any one of claims 1 to 3, wherein the component (b) has a partial structure represented by the following general formula (1) or general formula (2).

[In General Formula (1) or General Formula (2), R ¹ and R ² represent a direct bond, an alkylene, or an arylene group. ]   The compound having a partial structure represented by the general formula (1) or the general formula (2) is a diol compound containing a tricyclodecane structure, a diisocyanate compound, and at least one ethylenically unsaturated group in the molecule. The photosensitive resin composition of Claim 4 which is a urethane compound obtained by making it react with the compound which has one hydroxyl group.   A photosensitive element provided with a support body and the photosensitive resin composition layer which consists of the photosensitive resin composition in any one of Claims 1-5 formed on this support body.   Hardened | cured material of the photosensitive resin composition in any one of Claims 1-5 formed on the board | substrate for printed wiring boards, or hardening of the photosensitive resin composition layer of the photosensitive element of Claim 5. Permanent resist consisting of things.