JP2008180992A - Photosensitive resin composition, photosensitive film for permanent resist, resist pattern forming method, printed wiring board and semiconductor package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which enables a permanent resist to be formed, the permanent resist having thermal shock resistance and electric corrosion resistance of sufficiently high levels, and which exhibits sufficiently excellent storage stability in the state of a dry film. <P>SOLUTION: The photosensitive resin composition comprises (A) a polymer including a structure represented by formula (1) (wherein Z denotes -OH, -NH-R<SP>5</SP>or -O-R<SP>6</SP>, and R<SP>5</SP>and R<SP>6</SP>are each a group having an ethylenically unsaturated bond, an alkyl group which may have a substituent or a phenyl group which may have a substituent), (B) a photopolymerizable compound having an ethylenically unsaturated group, and (C) a photopolymerization initiator. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition, a photosensitive film for permanent resist, a method for forming a resist pattern, a printed wiring board, and a semiconductor package.

  In a printed circuit board and a package substrate for mounting a semiconductor chip, a solder resist formed of a photosensitive resin composition is used for the purpose of forming a circuit pattern.

  As a method for forming the solder resist, there is a method using a liquid photoresist, but from the viewpoint of production efficiency and uniformity of the resist film thickness, a method using a so-called dry film resist as disclosed in Patent Document 1. Is becoming mainstream. As a dry film resist material, for example, in Patent Document 2, a cured film having excellent heat resistance, heat and humidity resistance, adhesion, and mechanical properties can be obtained, and production of printed wiring boards, high-density multilayer boards, semiconductor packages, and the like. It is obtained by reacting an esterified product of an epoxy compound (a) and an unsaturated monocarboxylic acid with a saturated or unsaturated polybasic acid anhydride for the purpose of providing a photosensitive resin composition suitably used for At least one photosensitive resin (B) selected from a photosensitive resin having a carboxyl group (A), a photosensitive polyamide resin having a carboxyl group, and a photosensitive polyamideimide resin having a carboxyl group, an elastomer (C), an epoxy A photosensitive resin composition containing a curing agent (D) and a photopolymerization initiator (E) has been proposed. According to Patent Document 2, it is described that the solder resist formed from this photosensitive resin composition is excellent in solvent resistance.

  In Patent Document 3, a solder resist film having excellent printability, heat resistance, adhesion to the coated surface, chemical resistance, solvent resistance, electrical properties, and mechanical properties on the coated surface can be formed. A mixture of a novolak epoxy resin having a specific structure and a rubber-modified bisphenol A type epoxy resin having a specific structure and 0.2 to 1.2 mol per epoxy equivalent of the mixture is intended to provide a photosensitive resin composition Photosensitive product having a carboxyl group, which is a reaction product of a reaction product with an ethylenically unsaturated carboxylic acid and 0.2 to 1.0 mole of a polybasic acid and / or an anhydride thereof per epoxy equivalent of the above mixture. A photosensitive resin composition containing an adhesive prepolymer, a photopolymerizable reactive diluent, a photopolymerization initiator, and a thermosetting component has been proposed.

Furthermore, Patent Document 4 intends to provide a permanent resist exhibiting high moisture resistance insulation without deteriorating flexibility, solder heat resistance and chemical resistance as a permanent resist, and in a water washing step after alkali development. Means for containing divalent inorganic ions such as divalent calcium ions in water for washing is disclosed.
Japanese Patent Laid-Open No. 54-1018 Japanese Patent Laid-Open No. 11-288087 Japanese Patent Laid-Open No. 9-5997 JP 2004-252485 A

  However, the present inventors have examined the photosensitive resin compositions described in Patent Documents 2 and 3 in detail. As a result, the solder resist (permanent resist) obtained from these photosensitive resin compositions has a thermal shock resistance. It became clear that the level of sex was not yet satisfactory. Moreover, it became clear that the dry film formed using these photosensitive resin compositions does not have sufficient storage stability. If the storage stability is insufficient, it is difficult to sufficiently maintain various properties such as coating properties, resolution, and thermal shock resistance when stored for a long time in a dry film state.

  Furthermore, when the means disclosed in the above-mentioned Patent Document 4 is used, it has been clarified as a result of the examination by the present inventors that although there is a certain effect with respect to electric corrosion resistance, the thermal shock resistance is still insufficient.

  Therefore, the present invention is capable of forming a permanent resist that achieves a sufficiently high level in terms of thermal shock resistance and electric corrosion resistance, and is a photosensitive film that exhibits sufficiently excellent storage stability in a dry film state. It aims at providing a conductive resin composition.

  In one aspect, the present invention relates to a photosensitive resin composition. The photosensitive resin composition according to the present invention includes (A) a polymer containing a structure represented by the following general formula (1), (B) a photopolymerizable compound having an ethylenically unsaturated group, and (C) light. A polymerization initiator.

In formula (1), R ¹ and R ³ each independently represent an isobutylene unit, a styrene unit, a methyl vinyl ether unit or a (meth) acrylate unit, and R ² may have a hydrogen atom or a substituent. alkyl group, a phenyl group which may have a even better cyclohexyl group or a substituent substituted, Z is -OH, indicates ^{-NH-R 5} or ^{-O-R 6, R 5} And R ⁶ is a group having an ethylenically unsaturated bond, an alkyl group which may have a substituent or a phenyl group which may have a substituent, and n and m are each independently an integer of 1 or more Indicates.

  The photosensitive resin composition according to the present invention has a sufficiently high level in terms of thermal shock resistance and electric corrosion resistance by using the polymer having the specific structure in combination with the components (B) to (C). It was possible to form a permanent resist that achieves the above, and exhibited sufficiently excellent storage stability in the dry film state.

  In order to make the above effect particularly remarkable, n / (n + m) is preferably 0.1 to 0.7 in the formula (1).

  The polymer is preferably one that reacts alone by light or heating to produce a crosslinked product having a glass transition temperature of 120 ° C to 200 ° C. Thereby, more excellent heat resistance, chemical resistance, thermal shock resistance and electric corrosion resistance can be obtained.

  The polymer preferably has an acid value of 100 to 350 mgKOH / g. Thereby, the developability by the dilute alkaline aqueous solution of the photosensitive resin composition and the electrical insulation after curing are further improved.

  The polymer preferably has a weight average molecular weight of 10,000 to 200,000. Thereby, the developability of the photosensitive resin composition with a dilute alkali aqueous solution and the mechanical properties such as the tensile strength and elongation of the cured product are further improved.

  The photosensitive resin composition of the present invention may further contain (D) a thermosetting compound that is cured by heating. This thermosetting compound is preferably a compound having a (meth) acrylate group and a blocked isocyanate group. Thereby, reaction with the carboxyl group in the polymer of (A) component and a thermosetting compound is suppressed at normal temperature. As a result, the effect of improving the storage stability in the dry film state becomes even more remarkable. Further, in this case, when the photosensitive resin composition is irradiated with light, the (meth) acrylate group in the thermosetting compound (D) is polymerized together with the photopolymerizable compound (B). And the blocked isocyanate group of a thermosetting compound and the carboxyl group of (A) component react by the heating after light irradiation, and a three-dimensional crosslinked structure is formed. As a result, the heat resistance and thermal shock resistance of the permanent resist are further improved.

  In another aspect, the present invention relates to a photosensitive film for permanent resist used for forming a permanent resist. The photosensitive film for permanent resist according to the present invention includes a photosensitive layer made of the photosensitive resin composition according to the present invention. The photosensitive film for permanent resist according to the present invention can form a solder resist that achieves a sufficiently high level in terms of thermal shock resistance and electric corrosion resistance, and exhibits sufficiently excellent storage stability. .

  In still another aspect, the present invention relates to a method for forming a resist pattern. The forming method according to the present invention includes a step of forming a photosensitive layer covering the conductor layer on a surface of the laminated substrate having the insulating substrate and the conductor layer provided on the insulating substrate and having a circuit pattern formed thereon. And a step of irradiating a predetermined part of the photosensitive layer with actinic rays and then removing a part of the photosensitive layer to form a resist pattern in which an opening exposing a part of the conductor layer is formed. The photosensitive layer is composed of the photosensitive resin composition according to the invention.

  In still another aspect, the present invention relates to a printed wiring board. A printed wiring board according to the present invention includes an insulating substrate, a laminated substrate having a conductor layer provided on the insulating substrate and having a circuit pattern formed thereon, and a conductor layer provided on the surface of the laminated substrate on the conductor layer side. And a permanent resist layer in which an opening partly exposed is formed. The permanent resist layer is made of a cured product of the photosensitive resin composition according to the present invention.

  In yet another aspect, the present invention relates to a semiconductor package. A semiconductor package according to the present invention includes a laminated substrate having an insulating substrate and a conductor layer provided on the insulating substrate and having a circuit pattern formed thereon, and a part of the conductor layer provided on the surface of the laminated substrate on the conductor layer side. And a semiconductor chip mounted on the package substrate. The package substrate includes a permanent resist layer in which an opening exposing the substrate is formed. The permanent resist layer is made of a cured product of the photosensitive resin composition according to the present invention.

  According to the present invention, it is possible to form a permanent resist that achieves a sufficiently high level in terms of thermal shock resistance and electric corrosion resistance, and a photosensitivity exhibiting sufficiently excellent storage stability in a dry film state. A functional resin composition is provided. The permanent resist formed by the photosensitive resin composition according to the present invention is excellent in terms of photosensitivity, resolution, solder heat resistance, and mechanical strength.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. In the present specification, “(meth) acrylic acid” means “acrylic acid” and “methacrylic acid” corresponding thereto, and “(meth) acrylate” means “acrylate” and “methacrylate” corresponding thereto. means.

  The photosensitive resin composition according to the present embodiment includes (A) a polymer substantially composed of a structure represented by the general formula (1), and (B) a photopolymerizable compound having an ethylenically unsaturated group. And (C) a photopolymerization initiator.

The polymer of the component (A) (hereinafter sometimes referred to as “maleic anhydride copolymer”) includes a structure represented by the formula (1). In other words, the polymer of the component (A) has a structural unit represented by the following formula (11) and a structural unit represented by the following formula (12). Each structural unit may form a block, or may be bonded to each other at random. A plurality of structural units contained in the maleic acid-based copolymer is may be addressed by those same R ¹ to R ³ and Z together also R ¹ to R ³ and Z are different from each other structural units a mix Good. In the formula (11) and ^(12), R 1 to R ³ and Z have the same meanings as ^R 1 to R ³ and Z in formula (1). The maleic anhydride-based copolymer is usually composed of the structure of the formula (1) except for its terminal portion.

  The ratio of the formula (11) in the formula (1), that is, n / (n + m) independently represents an integer of 1 or more. In the formula (1), n / (n + m) (hereinafter sometimes referred to as “imidation rate”) is preferably 0.1 to 0.7. When the imidation ratio is not within the range of 0.1 to 0.7, the degree of the effect according to the present invention tends to be small. From the same viewpoint, the imidation rate is more preferably 0.3 to 0.5.

In the formula (1), Z represents —OH, —NH—R ⁵ or —O—R ⁶ . R ⁵ and R ⁶ are a group having an ethylenically unsaturated bond, an alkyl group which may have a substituent, or a phenyl group which may have a substituent. R ⁵ and R ⁶ are typically groups having a (meth) acryloyloxy group (such as a (meth) acryloyloxyalkyl group).

R ¹ and R ³ each independently represent an isobutylene unit, a styrene unit, a methyl vinyl ether unit or a (meth) acrylic acid ester unit. Among these, an isobutylene unit is particularly preferable. R ² represents a hydrogen atom, an alkyl group that may have a substituent, a cyclohexyl group that may have a substituent, or a phenyl group that may have a substituent. R ² is preferably a hydrogen atom or a carboxyphenyl group.

Z represents —OH, —NH—R ⁵ or —O—R ⁶ , and R ⁵ and R ⁶ each have a group having an ethylenically unsaturated bond, an alkyl group which may have a substituent, or a substituent. And n and m each independently represents an integer of 1 or more.

For example, when Z is —NH—R ⁵ or —O—R ⁶ , and R ⁵ and R ⁶ are groups having an ethylenically unsaturated bond, the maleic acid-based copolymer can be obtained by light or heating alone. Reacts to form a crosslinked product. The glass transition temperature of this crosslinked product is preferably 120 to 200 ° C, more preferably 130 to 180 ° C.

  The weight average molecular weight (Mw) of the maleic acid copolymer is preferably 10,000 to 200,000, more preferably 15,000 to 150,000, and particularly preferably 30,000 to 100,000. When the Mw of the maleic anhydride copolymer is within the above range, the developability of the photosensitive resin composition with a dilute alkaline aqueous solution and the mechanical properties such as tensile strength and elongation of the cured product are further improved. It will be a thing.

Thus, even when a relatively high molecular weight maleic anhydride copolymer is used, the photosensitive resin composition has a sufficiently high solubility in a dilute alkali developer. In particular, when the maleic anhydride-based copolymer contains a methyl vinyl ether unit as R ¹ or R ³ , or when Z contains a constituent unit that is a group containing an ethylene oxide group, the solubility is improved. There is a tendency.

The said weight average molecular weight is the conversion value by a standard polystyrene measured by gel permeation chromatography (GPC). GPC for determining the weight average molecular weight is measured, for example, under the following conditions.
Pump: L-7100 type (manufactured by Hitachi, Ltd.)
Detector: UV L-4000 type UV (manufactured by Hitachi, Ltd.)
RI L-7490 (manufactured by Hitachi, Ltd.)
Column: Gelpack GL-S300MDT-5 (two in total) (trade name, manufactured by Hitachi Chemical Co., Ltd.)
Column size: 8mmφ × 300mm
Eluent: DMF / THF = 1/1 + 0.06M phosphoric acid + 0.06M lithium bromide
Sample concentration: 5 mg / 1 mL
Injection volume: 5 μL
Pressure: 343 Pa (35 kgf / cm ² )
Flow rate: 1.0 mL / min

  The acid value of the maleic anhydride-based copolymer is preferably 100 to 350 mgKOH / g from the viewpoints of developability with a dilute aqueous alkali solution and electrical insulation of the resulting cured film (solder resist).

  The acid value of the maleic anhydride copolymer can be measured by the following method. First, about 1 g of a maleic anhydride copolymer solution is precisely weighed, and 30 g of N-methylpyrrolidone is added to the 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. From the titration result the following formula:

A = 10 × Vf × 56.1 / (Wp × I)
Is used to calculate the acid value. In the formula, A represents the acid value (mgKOH / g), Vf represents the titration amount (mL) of phenolphthalein, Wp represents the maleic anhydride copolymer solution mass (g), and I represents maleic anhydride. The ratio (mass%) of the non volatile matter in a system copolymer solution is shown.

  The maleic acid-based copolymer includes, for example, a step of partially imidating an acid anhydride group in a copolymer of maleic anhydride and isobutylene, styrene, or methyl vinyl ether, and an acid anhydride remaining in the copolymer. And reacting an amine compound, an alcohol, an epoxy compound or water with a physical group. The imidization of the acid anhydride group is carried out, for example, by a method in which amide oxidation is performed by reaction with ammonia or an amine compound, and this is thermally or chemically closed to imidize. Alternatively, a step of copolymerizing maleic anhydride, maleimide, and isobutylene, styrene, or methyl vinyl ether, and a step of reacting an acid anhydride group in the produced copolymer with an amine compound, an alcohol, an epoxy compound, or water. A maleic acid copolymer can also be obtained by a method comprising

Reaction of an acid anhydride group with an amine compound produces an amic acid in which Z in Formula (1) is —NH—R ⁵ . A half ester in which Z in formula (1) is —O—R ⁶ is produced by the reaction of an acid anhydride group with an alcohol or an epoxy compound. The reaction of the acid anhydride group with water produces a dicarboxylic acid in which Z in Formula (1) is —OH. Examples of the alcohol to be reacted with the acid anhydride group include 2-hydroxyethyl (meth) acrylate and ethylene glycol monomethyl ether. Examples of the epoxy compound to be reacted with the acid anhydride group include glycidyl methacrylate.

  In synthesizing the maleic anhydride copolymer, an appropriate amount of solvent is usually used. Specifically, for example, ketone compounds such as methyl isobutyl ketone, cyclohexanone and methylcyclohexanone, aromatic hydrocarbon compounds such as toluene, xylene and tetramethylbenzene, cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methylcarbitol, butyl Carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, glycol ether compounds such as dipropylene glycol diethyl ether and triethylene glycol monoethyl ether, ester compounds such as acetate compounds of the glycol ether compounds, ethylene glycol and propylene glycol Petroleum such as alcohol compounds such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha Solvent, dimethylformamide, N- methylpyrrolidone, and γ- butyrolactone. These are used singly or in combination of two or more.

  The photopolymerizable compound having an ethylenically unsaturated bond in the molecule as the component (B) most typically has a (meth) acrylate group. In addition, when (A) component has an ethylenically unsaturated bond, the photopolymerizable compound different from (A) component is used as (B) component. Photopolymerizable compounds include bisphenol A-based (meth) acrylate compounds, compounds obtained by reacting polyhydric alcohols with α, β-unsaturated carboxylic acids, and glycidyl group-containing compounds with α, β-unsaturated carboxylic acids. Examples include compounds obtained by reaction, urethane monomers or urethane oligomers having a urethane bond and a (meth) acrylate group, and α, β-unsaturated carboxylic acids such as (meth) acrylic acid. Besides these, nonylphenoxy polyoxyethylene acrylate, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate and β-hydroxyalkyl-β ′-(meth) acryloyloxyalkyl- Illustrative are phthalic acid compounds such as o-phthalate, (meth) acrylic acid alkyl esters, and EO-modified nonylphenyl (meth) acrylate. These may be used alone or in combination of two or more.

  Specific examples of bisphenol A-based (meth) acrylate compounds include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypoly). Propoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane Can be mentioned. These can be used alone or in combination of two or more.

  Examples of 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2- Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) propane 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy nonaethoxy) ) Phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, 2, 2-bis (4-((meth) acryloxydodecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4- ( (Meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxyhexa) Decaethoxy) phenyl) propane. These can be used alone or in combination of two or more.

  Of these, 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is commercially available as BPE-500 (product name, manufactured by Shin-Nakamura Chemical Co., Ltd.). -Bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.).

  Examples of 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydipropoxy) phenyl) propane, 2,2- Bis (4-((meth) acryloxytripropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetrapropoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxypentapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptapropoxy) phenyl) propane 2,2-bis (4-((meth) acryloxyoctapropoxy) phenyl) propane, 2,2-bis (4-((meth) acrylic) Xinonapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxydecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecapropoxy) phenyl) propane 2,2-bis (4-((meth) acryloxydodecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecapropoxy) phenyl) propane, 2,2-bis ( 4-((meth) acryloxytetradecapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecapropoxy) phenyl) propane and 2,2-bis (4-((meth)) Acryloxyhexadecapropoxy) phenyl) propane. These may be used alone or in combination of two or more.

  Examples of 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxyoctapropoxy) phenyl) propane, Examples include 2,2-bis (4-((meth) acryloxytetraethoxytetrapropoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxyhexaethoxyhexapropoxy) phenyl) propane. These can be used alone or in combination of two or more.

  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 Examples include acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. These may be used alone or in combination of two or more.

“EO” means “ethylene oxide” and “PO” means “propylene oxide”. In addition, “EO modification” means that a block structure of an ethylene oxide unit (—CH ₂ —CH ₂ —O—) is included, and “PO modification” means a propylene oxide unit (—CH ₂ —CH (CH ₃ ) — It means that a block structure of O-) is included.

  Examples of the compound obtained by reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid include trimethylolpropane triglycidyl ether tri (meth) acrylate, 2,2-bis (4- (meth) acryloxy- 2-hydroxy-propyloxy) phenyl and the like are fisted. These can be used alone or in combination of two or more.

  Examples of urethane monomers include (meth) acrylic monomers having an OH group at the β-position and diisocyanate compounds such as isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate. Examples include addition reaction products, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, EO or PO-modified urethane di (meth) acrylate. These can be used alone or in combination of two or more.

  Examples of the (meth) acrylic acid alkyl ester include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid butyl ester, and (meth) acrylic acid-2-ethylhexyl ester. These can be used alone or in combination of two or more.

  Examples of the (C) component photopolymerization initiator include benzophenone, N, N′-tetraalkyl-4,4′-diaminobenzophenone, and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl)-. Aromatic ketones such as butanone-1,2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, quinones such as alkylanthraquinones, benzoin ether compounds such as benzoin alkyl ether, benzoin and Benzoin compounds such as alkylbenzoin, benzyl derivatives such as benzyldimethyl ketal, 2,4,5-triarylimidazole dimer, 9-phenylacridine, acridine such as 1,7-bis (9,9′-acridinyl) heptane Derivatives, N-phenylglycine, N-phenylglycine derivatives Body, and coumarin compounds. These can be used singly or in combination of two or more.

  The photosensitive resin composition may contain the thermosetting compound which hardens | cures by (D) 120-200 degreeC heating. This thermosetting compound has a plurality of crosslinkable functional groups that react by heating to form a crosslinked structure. From the viewpoint of solder heat resistance, electroless Ni / Au plating resistance, electric corrosion resistance and thermal shock resistance, the thermosetting compound is a group consisting of a blocked isocyanate compound, an epoxy compound, a bismaleimide compound, an oxetane compound and a melamine compound. It is preferable that it is 1 or more types selected from more. From the viewpoint of storage stability, the thermosetting compound is preferably at least one selected from the group consisting of a blocked isocyanate compound, a bismaleimide compound and an oxetane compound. In particular, a compound having a (meth) acrylate group and a blocked isocyanate group is preferable.

  The blocked isocyanate group contained in the blocked isocyanate compound is a group in which the isocyanate group is protected by reaction with a blocking agent and temporarily deactivated. When heated to a predetermined temperature, the blocking agent is dissociated to produce isocyanate groups.

  As the isocyanate compound to be reacted with the blocking agent, aromatic polyisocyanate, aliphatic polyisocyanate, or alicyclic polyisocyanate is used. Specific examples of the aromatic polyisocyanate include 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m- Examples include xylylene diisocyanate and 2,4-tolylene dimer. Specific examples of the aliphatic polyisocyanate include hexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate. Specific examples of the alicyclic polyisocyanate include bicycloheptane triisocyanate.

  The blocking agent preferably has active hydrogen. Examples of the blocking agent include active methylene compounds, diketone compounds, oxime compounds, phenol compounds, alkanol compounds, and caprolactam compounds. Specifically, methyl ethyl ketone oxime, ε-caprolactam or the like can be used as a blocking agent.

  The blocked isocyanate compound is available as a commercial product. For example, Sumidur BL-3175, BL-4165, BL-1100, BL-1265, Death Module TPLS-2957, TPLS-2062, TPLS-2957, TPLS-2078, TPLS-2117, Desmotherm 2170, Desmotherm 2265 (above, Sumitomo Bayer Urethane Co., Ltd., trade name), Coronate 2512, Coronate 2513, Coronate 2520 (above, Nippon Polyurethane Industry Co., Ltd., trade name).

  Examples of the blocked isocyanate compound having a (meth) acrylate group and a blocked isocyanate group include methacrylic acid-2- [0- (1′-methylpropylideneamino) carboxyamino] ethyl, acrylic acid-2- [0- ( 1'-methylpropylideneamino) carboxyamino] ethyl and the like. For example, Karenz MOI-BM (manufactured by Showa Denko KK, trade name) is available as a commercial product.

  A bismaleimide compound is a compound having two or more maleimide groups in the molecule. Specific examples of the bismaleimide compound include 1-methyl-2,4-bismaleimide benzene, N, N′-m-phenylene bismaleimide, N, N′-p-phenylene bismaleimide, N, N′-m- Toluylene bismaleimide, N, N′-4,4′-biphenylenebismaleimide, N, N′-4,4 ′-[3,3′-dimethyl-biphenylene] bismaleimide, N, N′-4,4 '-[3,3'-dimethyldiphenylmethane] bismaleimide, N, N'-4,4'-[3,3'-diethyldiphenylmethane] bismaleimide, N, N'-4,4'-diphenylmethane bismaleimide, N, N′-4,4′-diphenylpropane bismaleimide, N, N′-4,4′-diphenyl ether bismaleimide, N, N′-3,3′-diphenylsulfone Bismaleimide, N, N′-4,4′-diphenylsulfone bismaleimide, 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-tert-butyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-s-butyl-4- (4-maleimidophenoxy) phenyl] propane, 1,1-bis [4- (4-maleimidophenoxy) phenyl] Decane, 1,1-bis [2-methyl-4- (4-maleimidophenoxy) -5-tert-butylphenyl] -2-methylpropane, 4,4′-cyclohexylidene-bis [1- (4- Maleimidophenoxy) -2- (1,1-dimethylethyl) benzene], 4,4′-methylene-bis [1- (4-maleimidophenoxy) -2,6-bis (1,1- Methylethyl) benzene], 4,4′-methylene-bis [1- (4-maleimidophenoxy) -2,6-di-s-butylbenzene], 4,4′-cyclohexylidene-bis [1- ( 4-maleimidophenoxy) -2-cyclohexylbenzene, 4,4′-methylenebis [1- (maleimidophenoxy) -2-nonylbenzene], 4,4 ′-(1-methylethylidene) -bis [1- (maleimidophenoxy) ) -2,6-bis (1,1-dimethylethyl) benzene], 4,4 ′-(2-ethylhexylidene) -bis [1- (maleimidophenoxy) -benzene], 4,4 ′-( 1-methylheptylidene) -bis [1- (maleimidophenoxy) -benzene], 4,4′-cyclohexylidene-bis [1- (maleimidophenoxy) -3-methylbenzene , 2,2-bis [4- (4-maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3-methyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-Methyl-4- (4-maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3,5-dimethyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3 , 5-Dimethyl-4- (4-maleimidophenoxy) phenyl] hexafluoropropane, 2,2-bis [3-ethyl-4- (4-maleimidophenoxy) phenyl] propane, 2,2-bis [3-ethyl -4- (4-maleimidophenoxy) phenyl] hexafluoropropane, bis [3-methyl- (4-maleimidophenoxy) phenyl Methane, bis [3,5-dimethyl- (4-maleimidophenoxy) phenyl] methane, bis [3-ethyl- (4-maleimidophenoxy) phenyl] methane, 3,8-bis [4- (4-maleimidophenoxy) Phenyl] -tricyclo [5.2.1.02,6] decane, 4,8-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo [5.2.1.02,6] decane, 3, 9-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo [5.2.1.02,6] decane, 4,9-bis [4- (4-maleimidophenoxy) phenyl] -tricyclo [5. 2.1.02,6] decane, 1,8-bis [4- (4-maleimidophenoxy) phenyl] menthane, 1,8-bis [3-methyl-4- (4-maleimidophenoxy) Phenyl] menthane and 1,8-bis [3,5-dimethyl-4- (4-maleimide phenoxy) phenyl] menthane and the like. These bismaleimide compounds can be synthesized by conventional methods, or commercially available products can be obtained.

  Among these bismaleimide compounds, those having no halogen atom in the molecule are preferable from the viewpoint of further suppressing the generation of harmful substances.

As the melamine compound, alkoxymethylated melamine is preferable. The alkoxymethylated melamine has a structure in which part or all of the hydrogen atoms of the amino group of melamine are substituted with an alkoxymethyl group (preferably a C _1-10 alkoxymethyl group, more preferably a C _1-4 alkoxymethyl group). Have. The degree of alkoxymethylation is not particularly limited, but preferably 30% or more, more preferably 70% or more of hydrogen atoms are substituted with alkoxymethyl groups. In this case, the hydrogen atom may be substituted by an alkoxymethyl group having a different carbon number. Alkoxymethylated melamine is usually obtained by reacting melamine and aldehyde under acidic conditions, but a low polymer having a polymerization degree of 2 to 5 can be obtained simultaneously with the monomer. In this embodiment, the monomer ratio of alkoxymethylated melamine is preferably 60% or more, and more preferably 80% or more.

  Specific examples of the alkoxymethylated melamine include methoxymethylated melamine, ethoxymethylated melamine, propoxymethylated melamine and butoxymethylated melamine.

  Commercially available alkoxymethylated melamine can also be used. For example, Cymel (registered trademark) 300 (manufactured by Mitsui Cyanamid, methoxymethylated melamine, monomer ratio 85%), 303 (manufactured by Mitsui Cyanamid, methoxymethylated melamine, monomer ratio 60%), Nicalak MW-30HM (Sanwa Chemical) And Mikaru MW-40 (manufactured by Sanwa Chemical Co., Ltd., methoxy and butoxy mixed methylated melamine).

  These melamines can be used alone or in combination.

  The content ratio of the component (A) is from the viewpoint of preventing exudation from the end face of a photosensitive film provided with a photosensitive layer made of a photosensitive resin composition, and from the viewpoint of obtaining better solder heat resistance and photosensitivity. It is preferable that it is 30-70 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, and it is more preferable that it is 45-55 mass parts.

  The content ratio of the component (B) is preferably 10 to 70 parts by mass and more preferably 35 to 55 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). . If this content is less than 10 parts by mass, the photosensitivity tends to decrease, and if it exceeds 70 parts by mass, the cured product formed after curing tends to become brittle.

  The content ratio of the component (C) is 0.1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B) from the viewpoint of obtaining more excellent photosensitivity and solder heat resistance. It is preferable that it is 0.2 to 10 parts by mass.

  The content ratio of the component (D) is the total amount of the component (A) and the component (B) from the viewpoint of improving the photosensitivity such as photosensitivity and resolution, and from the viewpoint of further improving the thermal shock resistance, electric corrosion resistance, and storage stability. It is preferable that it is 5-40 mass parts with respect to 100 mass parts, and it is more preferable that it is 10-30 mass parts.

  When using the photosensitive resin composition in a liquid state, the photosensitive resin composition preferably further contains a diluent as the component (E). In this case, it is preferable that the content rate of (E) component is 5-40 mass% with respect to the whole quantity of the photosensitive resin composition. Moreover, also in the case of the photosensitive film which has the photosensitive layer which shape | molded the photosensitive resin composition in the film form, the diluent used in order to form a photosensitive layer may be contained in the photosensitive resin composition. In this case, the content ratio of the diluent is usually 3% by mass or less with respect to the total amount of the photosensitive layer.

  The diluent is not particularly limited as long as it is a solvent capable of dissolving or dispersing other components. Examples of the diluent include aliphatic alcohols, cyclic hydrocarbons, ketones, keto alcohols, alkylene glycols, alkylene glycol alkyl ethers, acetate compounds and carboxylic acid esters thereof. These can be used alone or in combination of two or more.

  Examples of the aliphatic alcohol include methanol, ethanol, n-propanol, iso-propanol, n-butanol, n-pentanol, and n-hexanol. Examples of the cyclic hydrocarbon include benzyl alcohol, cyclohexane, and toluene. These can be used alone or in combination of two or more.

  Examples of the ketone include acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, methyl isobutyl ketone, methyl pentyl ketone, methyl hexyl ketone, ethyl butyl ketone, dibutyl ketone, cyclopentanone and cyclohexanone. Examples of keto alcohols include diacetone alcohol, 3-hydroxy-2-butanone, 4-hydroxy-2-pentanone, and 6-hydroxy-2-hexanone. These can be used alone or in combination of two or more.

  Examples of the alkylene glycol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and propylene glycol. Examples of the alkylene glycol alkyl ether include diethylene glycol monoalkyl ether, diethylene glycol dialkyl ether, triethylene glycol alkyl ether, propylene glycol alkyl ether and dipropylene glycol alkyl ether. More specifically, for example, 3-methoxy- Examples include 1-butanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, methyl cellosolve, ethyl cellosolve, and butyl cellosolve. The acetate compound of alkylene glycol or alkylene glycol alkyl ether may be any of the above-mentioned alkylene glycol or alkylene glycol alkyl ether acetate compounds, such as ethylene glycol monoacetate, ethylene glycol diacetate, propylene glycol monoacetate, propylene glycol diacetate. Examples include acetate, methyl cellosolve acetate, and ethyl cellosolve acetate. These can be used alone or in combination of two or more.

  Examples of the carboxylic acid ester include ethyl formate, propyl formate, butyl formate, amyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate and ethyl butyrate. These can be used alone or in combination of two or more.

  As the diluent, for example, γ-butyrolactone, phenyl cellosolve, dimethylformamide, dimethyl sulfoxide, dioxane, tetrahydrofuran, methyl lactate, ethyl lactate, methyl benzoate, ethyl benzoate, or propylene carbonate may be used. .

  The photosensitive resin composition may further contain other components as necessary. For example, dyes such as malachite green, photochromic agents such as tribromophenylsulfone and leucocrystal violet, thermochromic inhibitors, plasticizers such as p-toluenesulfonamide, organic pigments or inorganic pigments, silica, alumina, talc, carbonic acid Fillers such as calcium and barium sulfate, antifoaming agents, flame retardants, stabilizers, adhesion-imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, and imaging agents can be added to the photosensitive resin composition. . Organic pigments include phthalocyanine pigments such as phthalocyanine green and phthalocyanine blue, and azo pigments. Inorganic pigments include titanium dioxide. A polymer other than the component (A) such as an acrylic copolymer or an acid-modified vinyl group-containing epoxy resin may be used in combination with the component (A). These can be used alone or in combination of two or more. It is preferable that the content rate of these additional components is about 0.01-20 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component, respectively.

  By forming a resist pattern using the photosensitive resin composition according to the present embodiment, a solder resist (permanent resist layer) having sufficiently high thermal shock resistance can be obtained. In addition, a dry film (photosensitive film) exhibiting sufficiently excellent storage stability can be formed. Furthermore, it has excellent photosensitive properties such as good developability and high resolution, and can form a good coating film with reduced stickiness.

  The cured film formed by the photosensitive resin composition according to the present embodiment is particularly useful as a printed wiring board such as a rigid wiring board and a flexible wiring board, or as a solder resist for a package substrate, an interlayer insulating film, or a semiconductor protective film. It is a thing. According to the photosensitive resin composition according to the present embodiment, a high level can be achieved with respect to various properties and reliability required for these applications. Furthermore, the solder resist formed from the photosensitive resin composition according to the present embodiment is sufficiently excellent in thermal shock resistance, in addition to alkali resistance, solder heat resistance, electrolytic Ni / Au plating resistance, elongation. It is also excellent in terms of mechanical properties such as rate and tensile strength, and electric corrosion resistance.

  FIG. 1 is an end view showing an embodiment of a photosensitive film. A photosensitive film 1 shown in FIG. 1 includes a support 11, a photosensitive layer 12 provided on the support 11 and made of a photosensitive resin composition, and a protective film 13 laminated on the photosensitive layer 12.

  As the support 11, for example, a polymer film having heat resistance and solvent resistance, such as polyethylene terephthalate, polypropylene, polyethylene, and polyester, is preferably used.

  The thickness of the support 11 is preferably 5 to 100 μm, and more preferably 10 to 30 μm. If the thickness is less than 5 μm, the support 11 tends to be broken when the support 11 is peeled off from the photosensitive film 1 before development, and if it exceeds 100 μm, the resolution and flexibility tend to decrease. .

  The photosensitive layer 12 is comprised from the photosensitive resin composition which concerns on the above-mentioned embodiment. The photosensitive layer 12 is formed on the support 11 by a method including, for example, a step of applying a photosensitive resin composition diluted with the above-described diluent to the support and a step of drying the applied photosensitive resin composition. Formed. The photosensitive resin composition applied to the support preferably contains 30 to 70% by mass of the diluent. As a result, even when the thermosetting compound of component (D) is a poorly soluble compound such as an epoxy compound, component (D) is well dispersed in the form of fine solid particles, and in component (A) The reaction between the carboxyl group and the component (D) tends to be further suppressed, and as a result, the storage stability of the photosensitive film is further improved. Drying of the photosensitive resin composition is performed by, for example, heating and / or hot air blowing.

  Although the thickness of the photosensitive layer 12 changes with uses, it is preferable that it is 10-100 micrometers after drying, and it is more preferable that it is 20-60 micrometers. If this thickness is less than 10 μm, coating tends to be difficult industrially, and if it exceeds 100 μm, the above-described effects produced by the present invention tend to be small. In particular, physical properties such as mechanical properties and resolution tend to decrease.

  As the protective film 13, a polyethylene film, a polypropylene film, a Teflon (registered trademark) film, a surface-treated paper, or the like is preferably used. The protective film 13 preferably has an adhesive force between the photosensitive layer 12 and a smaller adhesive force than the photosensitive layer 12 and the support 11.

  The photosensitive film which concerns on this invention is not limited to a structure like the said embodiment. For example, the photosensitive film may be composed of only the photosensitive layer 12 and the support 11 without using the protective film 13.

  The photosensitive film which concerns on this embodiment shows sufficient storage stability which can maintain various characteristics, such as a coating film property, the resolution of a cured film, and a thermal shock resistance, even after preserve | saving for a long time. Further, since the surface of the photosensitive layer is less sticky, it is possible to efficiently produce a high-resolution and high-density printed wiring board.

  A resist pattern can be formed using the photosensitive resin composition or photosensitive film according to the present embodiment. The resist pattern includes, for example, a step of forming a photosensitive layer covering the conductor layer on a surface of the laminated substrate having an insulating substrate and a conductive layer provided on the insulating substrate and having a circuit pattern formed thereon; Irradiating a predetermined part of the photosensitive layer with actinic rays and then removing a part of the photosensitive layer to form a resist pattern in which an opening exposing a part of the conductor layer is formed. The

  As a method for forming the photosensitive layer, there are a method in which a photosensitive resin composition is directly applied, and a method in which a photosensitive film is prepared in advance, and the photosensitive layer is heated and pressure-bonded to a laminated substrate and laminated. When the photosensitive resin composition contains a volatile component such as a diluent, most of it is removed. Moreover, when a photosensitive film has a protective film, a protective film is peeled from the photosensitive film before lamination | stacking of a photosensitive layer.

  When pressure-bonding to the laminated substrate while heating the photosensitive layer of the photosensitive film, the heating temperature is preferably 70 to 110 ° C., the pressing pressure is preferably about 0.1 to 1.0 MPa, and the ambient atmospheric pressure is preferable. Is 4 kPa or less. In order to further improve the lamination property, the laminated substrate may be preheated.

  Actinic rays are applied to a predetermined portion of the formed photosensitive layer. An exposed portion is formed in the irradiated portion. For example, it is possible to irradiate a predetermined portion of the photosensitive layer with actinic rays by a method of irradiating actinic rays in an image form through a negative or positive mask pattern called an artwork. At the time of irradiation, a support may be laminated on the photosensitive layer.

  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.

After the exposure, if a support is present on the photosensitive layer, the support is removed. Thereafter, a portion other than the exposed portion of the photosensitive layer is removed by wet development, dry development, or the like to form a resist pattern made of a cured product of the photosensitive resin composition. In the case of wet development, development is performed by a known method such as spraying, rocking immersion, brushing, and scraping using a developer such as an alkaline aqueous solution, an aqueous developer, and an organic solvent. Note that after the resist pattern is formed, post-curing may be further performed by exposure at 1 to 5 J / cm ² or / and heating at 100 to 200 ° C. for 30 minutes to 12 hours (post-heating step).

  As the developer, a developer that is safe and stable and has good operability is preferably used. For example, a dilute solution (1 to 5% by weight aqueous solution) of sodium carbonate at 20 to 50 ° C. is used. The developer used in the development process is not particularly limited as long as it selectively elutes the unexposed part without damaging the exposed part, and is determined by the development type of the resin composition, Common ones such as a semi-aqueous developer and a solvent developer can be used. For example, an emulsion developer containing water and an organic solvent as described in JP-A-7-234524 can be used. Particularly useful emulsion developers include, for example, propylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, 2,2-butoxyethoxyethanol, butyl lactate, cyclohexyl lactate, ethyl benzoate, and 3-methyl-3 as organic solvent components. An emulsion developer containing 10 to 40% by mass of an organic solvent such as methoxybutyl acetate can be mentioned. When an alkaline developer is used, an alkaline aqueous solution such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, 4-sodium borate, ammonia, amines and the above organic solvent are used. It is also possible to use an emulsion developer. The formed resist pattern functions as, for example, a solder resist or a permanent resist. This resist pattern exhibits sufficiently high thermal shock resistance, mechanical properties such as tensile strength and elongation, electrical insulation, wet heat resistance, alkali resistance, solvent resistance, solder heat resistance, and electrolytic Ni / Au plating resistance Also excellent. Therefore, it is useful as a permanent mask (solder resist) for semiconductor packages. In this case, the substrate provided with the resist pattern is used as a package substrate. A semiconductor chip is mounted on the package substrate by a method such as wire bonding or solder connection. The semiconductor package is attached to an electronic device such as a personal computer.

  FIG. 2 is an end view showing an embodiment of the printed wiring board. The printed wiring board 2 shown in FIG. 2 has an insulating substrate 22, a conductor layer 23 provided on one surface of the insulating substrate 22, and a circuit pattern formed on the other surface of the insulating substrate 22. A multilayer substrate 20 including the conductor layer 21 that is not provided, and a permanent resist layer 24 provided on the surface of the multilayer substrate 20 on the conductor layer 23 side. The permanent resist layer 24 is made of a cured product of the photosensitive resin composition according to the above embodiment. The permanent resist layer 24 is a resist pattern having a pattern in which an opening 26 from which a part of the conductor layer 23 is exposed is formed.

  Since the printed wiring board 2 has the opening 26, a mounting component such as CSP or BGA can be joined to the conductor layer 23 with solder or the like. That is, surface mounting is possible. The permanent resist layer 24 has a role as a solder resist for preventing solder from adhering to unnecessary portions of the conductor layer 23 during soldering for bonding. The permanent resist layer 24 also functions as a permanent mask for protecting the conductor layer 23 after mounting.

  The permanent resist layer 24 exhibits sufficiently high thermal shock resistance, mechanical properties such as tensile strength and elongation, electrical insulation, wet heat resistance, alkali resistance, solvent resistance, solder heat resistance, and electrolytic Ni / Au resistance. Excellent plating ability. When the permanent resist layer 24 is formed by both light irradiation and heating treatments, the above-described effects are more remarkably exhibited.

  The printed wiring board according to the present invention is not limited to the configuration of the above embodiment. For example, the printed wiring board according to the present invention may be a multilayer printed wiring board in which a plurality of conductive layers and insulating layers are alternately laminated on one side or both sides of an insulating substrate. In this case, the cured film formed from the photosensitive resin composition of the present invention functions as an interlayer insulating film for reliably insulating the conductive layers.

  FIG. 3 is a process diagram showing an embodiment of a method for manufacturing a printed wiring board as an end view. In the manufacturing method according to the present embodiment, the insulating substrate 22, the conductor layer 23 provided on one surface of the insulating substrate 22, and the circuit pattern is formed on the other surface of the insulating substrate 22. A step (FIG. 3A) of preparing a laminated substrate 20 having no conductive layer 21, and forming a photosensitive layer 24 a made of an uncured photosensitive resin composition on the surface of the laminated substrate 20 on the conductive layer 23 side. A step (FIG. 3B), a step of irradiating a predetermined portion of the photosensitive layer 24a with actinic rays (FIG. 3C), a predetermined portion of the photosensitive layer 24a is removed, and the photosensitive resin composition Forming a resist pattern made of a cured product as a permanent resist layer 24 (FIG. 3D).

  The laminated substrate 20 is obtained by, for example, a method of etching one side of a double-sided metal-clad laminate (for example, a double-sided copper-clad laminate). The steps from the formation of the photosensitive layer 24a (FIG. 3B) to the formation of the resist pattern (permanent resist layer 24) (FIG. 3D) are performed in the same manner as the resist pattern forming method described above. it can.

In order to further improve the solder heat resistance, chemical resistance, etc. of the permanent resist layer 24, it is preferable to irradiate the resist pattern after development with ultraviolet rays or heat. Ultraviolet irradiation is performed, for example, at an irradiation dose of about 0.2 to 10 J / cm ² . Moreover, when heating a resist pattern, it is preferable to heat for about 15 to 90 minutes in the range of about 100-170 degreeC. Ultraviolet irradiation and heating can be performed simultaneously or sequentially. 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.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

Synthesis Example 1 (P1)
A flask equipped with a stirrer, reflux condenser, thermometer, and dry nitrogen gas inlet tube was prepared. Then, 40 g of 2-hydroxyethyl, a partially imidized isobutylene-maleic anhydride copolymer (manufactured by Kuraray, imidation ratio of maleic anhydride portion: 40 mol%, “Isoban 304” (trade name)) 20 g of methacrylate and 60 g of dehydrated dimethylformamide (DMF) were charged. Isoban 340 was sufficiently dried in advance. Then, the mixture was stirred while heating at 60 ° C. for 4 hours, and further stirred while heating at 90 ° C. for 2 hours, and a maleic anhydride copolymer having a methacryloyloxyethyloxy group introduced as a side chain (hereinafter “anhydrous”). A DMF solution of maleic acid copolymer P1 ”) was obtained. The obtained maleic anhydride copolymer P1 had a weight average molecular weight of 65,000 and an acid value of 220 mgKOH / g. Moreover, solid content in a solution was 50 mass%.

Synthesis example 2 (P2)
A flask equipped with a stirrer, reflux condenser, thermometer, and dry nitrogen gas inlet tube was prepared. Then, a partially imidized isobutylene-maleic anhydride copolymer (manufactured by Kuraray, imidation ratio of maleic anhydride part: 40 mol%, 40 g of “Isoban 304” (trade name), ethylene glycol monomethyl ether 60 g of isoban 340 was used, which had been sufficiently dried in advance, and stirred with heating at 60 ° C. for 4 hours and then with heating at 90 ° C. for 2 hours, and methoxyethyloxy as a side chain. A solution of a maleic anhydride copolymer into which groups were introduced (hereinafter referred to as “maleic anhydride copolymer P2”) was obtained.The weight average molecular weight of the obtained maleic anhydride copolymer P2 was The acid value was 250 mg KOH / g, and the solid content in the solution was 40% by mass.

Synthesis example 3 (P3)
A flask equipped with a stirrer, reflux condenser, thermometer, and dry nitrogen gas inlet tube was prepared. Thereto, 50 g of a copolymer of methyl vinyl ether and maleic anhydride (manufactured by IPS, “GANTREZ AN-119” (trade name)), 20 g of p-aminobenzoic acid, and 100 g of DMF were charged. Gantrez AN-119 was sufficiently dried in advance. Then, the mixture was stirred while heating at 60 ° C. for 4 hours, and then 20 g of glycidyl methacrylate was added, and further stirred while heating at 90 ° C. for 2 hours to obtain a maleic anhydride copolymer into which a methacryl group was introduced (hereinafter referred to as “ A DMF solution of maleic anhydride copolymer P3 ”) was obtained. The obtained maleic anhydride copolymer P3 had a weight average molecular weight of 98,000 and an acid value of 200 mgKOH / g. Moreover, solid content in a solution was 49 mass%.

Preparation of photosensitive resin composition The components and blending ratio (mass ratio) shown in Table 1 were mixed to obtain photosensitive resin composition solutions of Examples 1 to 5.

The contents of each component in Table 1 are shown below.
FA321M: EO-modified bisphenol A dimethacrylate (manufactured by Hitachi Chemical Co., Ltd.)
NK-DCP: Tricyclodecane dimethanol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)
I-369: (Ciba Specialty Chemicals)
EGME: Ethylene glycol monomethyl ether
MOI-BM: Methacrylic acid-2- [0- (1′-methylpropylideneamino) carboxyamino] ethyl
MW30HM: Hexamethoxymethylolmelamine (manufactured by Sanwa Chemical)

Comparative Example 1
A photosensitive resin composition solution having the same composition as in Example 1 was prepared except that the maleic anhydride copolymer P1 was replaced with “ZFR-1158” (manufactured by Nippon Kayaku Co., Ltd.), which is an acid-modified epoxy acrylate.

Comparative Example 2
The same composition as in Example 1 except that “Epicoat 1004” (manufactured by Japan Epoxy Resin), which is a bisphenol A type epoxy resin, was used in place of the maleic anhydride copolymer P1, and MOI-IBM was not blended. A photosensitive resin composition solution was prepared.

Production of Photosensitive Film Each photosensitive resin composition solution prepared above was uniformly coated on a 16 μm-thick polyethylene terephthalate (PET) film (G2-16, trade name, manufactured by Teijin Limited) as a support. The applied solution was dried by heating at 100 ° C. for about 10 minutes in a hot air convection dryer to form a photosensitive layer (film thickness: 25 μm) made of an uncured photosensitive resin composition.

  Subsequently, on the surface of the photosensitive layer opposite to the side in contact with the support, a polyethylene film (NF-13, product name, manufactured by Tamapoly Co., Ltd.) was bonded as a protective film to obtain a photosensitive film.

Preparation of Evaluation Laminate 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. After washing with water, it was dried. A continuous vacuum laminator (HLM-V570, Hitachi Chemical Co., Ltd.) is placed on the polished copper foil of the printed wiring board substrate so that the photosensitive layer and the copper foil are in close contact with each other while peeling the polyethylene film. The laminate for evaluation was obtained by stacking using a product name of the company. Lamination was performed under the conditions of heat shoe temperature: 100 ° C., laminating speed: 0.5 m / min, atmospheric pressure: 4 kPa or less, and pressure bonding pressure: 0.3 MPa.

Evaluation of Photosensitivity A phototool having a 21-step Stofer step tablet is adhered as a negative on the PET film of the obtained laminate for evaluation, and the number of remaining step steps after development of the 21-step Stepper tablet is 8. Exposure was performed using an HMW-201GX type exposure machine manufactured by Oak Manufacturing Co., Ltd. with an energy amount of zero. Thereafter, the evaluation laminate was allowed to stand at room temperature for 1 hour. Then, the PET film was peeled off, developed by spraying a 1 mass% sodium carbonate aqueous solution at 30 ° C. for 60 seconds, and further dried by heating at 80 ° C. for 10 minutes. The energy amount was used as an index of photosensitivity. A lower value indicates higher photosensitivity. The results are shown in Table 2.

Evaluation of resolution Stacking for evaluation with a photo tool having a stove 21-step tablet and a photo tool having a wiring pattern with a line width / space width of 30/30 to 200/200 (unit: μm) as a negative for resolution evaluation The film was brought into close contact with the body PET film and exposed using the above-described exposure apparatus with an energy amount such that the number of remaining steps after development of the stove 21-step tablet was 8.0. After the exposure, the evaluation laminate was allowed to stand at room temperature for 1 hour. Thereafter, the PET film was peeled off, developed by spraying a 1% by mass aqueous sodium carbonate solution at 30 ° C. for 60 seconds, and further dried by heating at 80 ° C. for 10 minutes. The resolution was evaluated using the smallest value (unit: μm) of the space width between the line widths in the portion where the resist shape having a rectangular cross section was formed by the development process. The smaller this value, the better the resolution. The results are shown in Table 2.

Evaluation of coating properties Peel off the PET film of the unexposed evaluation laminate, lightly press the finger against the exposed photosensitive layer surface, and evaluate the coating properties according to the following criteria based on the degree of sticking to the finger at that time did. The results are shown in Table 2.
“A”: Sticking to the finger is not or hardly recognized “B”: Sticking to the finger is recognized

Evaluation of soldering heat resistance A phototool having a 21-step tablet with a stopher and a phototool having a rectangular pattern of 2 mm square as a negative are brought into close contact with the PET film of the evaluation laminate, and the above-described exposure apparatus is used. Then, the exposure was performed with an energy amount such that the number of remaining step steps after development of the stove 21-step tablet was 8.0. After exposure, it was allowed to stand at room temperature for 1 hour. Thereafter, the PET film was peeled from the laminate, spray development was performed under the same developer and development conditions as in the photosensitivity evaluation, and drying was performed by heating at 80 ° C. for 10 minutes. Subsequently, the photosensitive layer was irradiated with ultraviolet rays with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Seisakusho. After the irradiation, the photosensitive layer was further heated at 160 ° C. for 60 minutes to obtain an evaluation package substrate having a solder resist in which a rectangular opening of 2 mm square was formed.

  Next, rosin-based flux (MH-820V, manufactured by Tamura Kaken Co., Ltd., trade name) was applied to the package substrate, and then immersed in a solder bath at 260 ° C. for 30 seconds to perform solder plating.

The state of crack generation in the solder resist on the package substrate after the solder plating treatment, and the degree of floating and peeling of the solder resist from the substrate were visually observed. Based on the observation results, the solder heat resistance was evaluated according to the following criteria. The results are shown in Table 2.
“A”: No cracking, floating and peeling of the solder resist “B”: No cracking, floating and peeling of the solder resist

Evaluation of thermal shock resistance The evaluation package substrate subjected to solder plating in the evaluation of solder heat resistance was heated in the atmosphere of −55 ° C. for 15 minutes at a temperature increase rate of 180 ° C./min, and 125 ° C. The treatment by the thermal cycle composed of the temperature decrease for 15 minutes in the air and the temperature decrease rate of 180 ° C./min was repeated 1500 times. The crack and peeling degree in the solder resist of the evaluation package substrate after the thermal cycle test were observed with a 100-fold metal microscope. Based on the observation results, the thermal shock resistance was evaluated according to the following criteria. The results are shown in Table 2.
"A": No cracking or peeling of solder resist was observed "B": No cracking or peeling of solder resist was observed

Evaluation of electric corrosion resistance Line width / space by etching copper foil of printed wiring board substrate (E-679, manufactured by Hitachi Chemical Co., Ltd., product name) in which 12μm thick copper foil is laminated on glass epoxy substrate The width was 50 μm / 50 μm, the lines were not in contact with each other, and comb electrodes on the same surface opposed to each other were formed. On this comb-shaped electrode, using a continuous vacuum laminator (HLM-V570, manufactured by Hitachi Chemical Co., Ltd., trade name), a heat shoe temperature of 100 ° C., a laminating speed of 0.5 m / min, an atmospheric pressure of 4 kPa or less, a pressure of pressure bonding of 0.3 MPa Under the above conditions, the photosensitive film was laminated while peeling the polyethylene film so that the photosensitive layer and the comb electrode were in close contact with each other, and a laminate for evaluation of electric corrosion resistance was obtained under the same conditions as described above.

A phototool having a stove 21-step tablet as a negative is brought into close contact with the PET film of the obtained laminate for evaluation of electric corrosion resistance, and the stove 21 is used using an HMW-201GX type exposure machine manufactured by Oak Manufacturing Co., Ltd. The exposure was performed with an energy amount such that the number of steps remaining after development of the stepped tablet was 8.0. After the exposure, the evaluation laminate was allowed to stand at room temperature for 1 hour. Thereafter, the PET film was peeled off, developed by spraying a 1% by mass aqueous sodium carbonate solution at 30 ° C. for 60 seconds, and further dried by heating at 80 ° C. for 10 minutes. Subsequently, the photosensitive layer was irradiated with ultraviolet rays with an energy amount of 1 J / cm ² using an ultraviolet irradiation device manufactured by Oak Seisakusho. After the irradiation, a solder resist was formed by further heat treatment at 160 ° C. for 60 minutes.

A shield wire made of polytetrafluoroethylene was connected by Sn / Pb solder to the comb-shaped electrode of the laminate for evaluation of electric corrosion resistance on which the solder resist was formed, and a voltage of 5 V was applied between the comb-shaped electrodes. In this state, the laminate for evaluation was allowed to stand for 200 hours in a super accelerated high temperature high humidity life test (HAST) bath at 130 ° C. and 85% RH. The degree of migration in the solder resist of the evaluation laminate after standing was observed with a 100-fold metal microscope and evaluated according to the following criteria. The results are shown in Table 2.
“A”: The occurrence of migration in the solder resist could not be confirmed. “B”: The occurrence of migration in the solder resist could be confirmed.

Evaluation of Storage Stability The photosensitive film obtained as described above was allowed to stand in the atmosphere at 5 ° C. for 1 month. Using the photosensitive film after standing, a laminate for evaluation was obtained in the same manner as described above. Then, in the same manner as in the evaluation of solder heat resistance, an evaluation package substrate having a solder resist in which a rectangular opening of 2 mm square was formed was obtained. The storage resist pattern was evaluated by observing the solder resist pattern formed on the evaluation package substrate with a stereomicroscope. “A” indicates that no resin remains in the unexposed area, and “B” indicates that resin remains. The results are shown in Table 2.

Evaluation of Glass Transition Temperature Each photosensitive film was exposed and heated under the same conditions as described above, and the photosensitive layer was cured to form a cured film on the support. The glass transition temperature of the cured film was measured with TMA (manufactured by Seiko Instruments). The results are shown in Table 2.

Evaluation of physical properties of cured film Each photosensitive film was exposed and heated under the same conditions as described above to cure the photosensitive layer to form a cured film on the support. The tensile strength and elongation of the cured film were measured according to JIS K 7127 “Plastic Film and Sheet Tensile Test Method”. The results are shown in Table 2.

以上の実験結果から明らかなように、本実施形態に係る感光性樹脂組成物によれば、耐熱衝撃性及び耐電食性の点で十分に高いレベルを達成するソルダーレジスト（永久レジスト層）を形成することが可能である。また、ドライフィルムである感光性フィルムの状態で十分に優れた貯蔵安定性を得ることも可能である。更には、本実施形態に係る感光性樹脂組成物は、光感度、解像度、塗膜性及び機械的強度の点でも高いレベルを達成可能である。

As is clear from the above experimental results, according to the photosensitive resin composition according to the present embodiment, a solder resist (permanent resist layer) that achieves a sufficiently high level in terms of thermal shock resistance and electric corrosion resistance is formed. It is possible. It is also possible to obtain sufficiently excellent storage stability in the state of a photosensitive film that is a dry film. Furthermore, the photosensitive resin composition according to the present embodiment can achieve a high level in terms of photosensitivity, resolution, coating properties, and mechanical strength.

It is an end view which shows one Embodiment of a photosensitive film. It is an end view which shows one Embodiment of a printed wiring board. It is process drawing which shows one Embodiment of the manufacturing method of a printed wiring board.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Photosensitive film, 2 ... Printed wiring board, 11 ... Support body, 12 ... Photosensitive layer, 13 ... Protective film, 20 ... Laminated substrate, 21 ... Conductive layer, 22 ... Insulating substrate, 23 ... Conductive layer, 24 ... Permanent Resist layer, 24a ... photosensitive layer, 26 ... opening.

Claims (11)

(A) The following general formula (1):

[Where:
R ¹ and R ³ each independently represent an isobutylene unit, a styrene unit, a methyl vinyl ether unit or a (meth) acrylic acid ester unit;
R ² represents a hydrogen atom, an alkyl group which may have a substituent, a cyclohexyl group which may have a substituent or a phenyl group which may have a substituent,
Z represents —OH, —NH—R ⁵ or —O—R ⁶ , and R ⁵ and R ⁶ each have a group having an ethylenically unsaturated bond, an alkyl group which may have a substituent, or a substituent. An optionally substituted phenyl group,
n and m each independently represent an integer of 1 or more. ]
A polymer comprising a structure represented by:
(B) a photopolymerizable compound having an ethylenically unsaturated bond;
(C) a photopolymerization initiator;
Containing a photosensitive resin composition.   The photosensitive resin composition of Claim 1 which is n / (n + m) = 0.1-0.7.   The photosensitive resin composition of Claim 1 or 2 with which the said polymer reacts by light or a heating independently, and produces | generates the crosslinked body whose glass transition temperature is 120-200 degreeC.   The photosensitive resin composition as described in any one of Claims 1-3 in which the said polymer has an acid value of 100-350 mgKOH / g.   The photosensitive resin composition as described in any one of Claims 1-4 whose said polymer has a weight average molecular weight of 10,000-200000.   (D) The photosensitive resin composition as described in any one of Claims 1-5 which further contains the thermosetting compound hardened | cured by heating.   The photosensitive resin composition of Claim 6 in which the said thermosetting compound has a (meth) acrylate group and a blocked isocyanate group.   The photosensitive film for permanent resist provided with the photosensitive layer which consists of the photosensitive resin composition as described in any one of Claims 1-7. Forming a photosensitive layer covering the conductor layer on a surface of the laminated substrate having an insulating substrate and a conductive layer provided on the insulating substrate and having a circuit pattern formed thereon; and
Irradiating a predetermined part of the photosensitive layer with actinic rays and then removing a part of the photosensitive layer to form a resist pattern in which an opening exposing a part of the conductor layer is formed. ,
A method for forming a resist pattern, wherein the photosensitive layer comprises the photosensitive resin composition according to claim 1. A laminated substrate having an insulating substrate and a conductor layer provided on the insulating substrate and having a circuit pattern formed thereon;
A permanent resist layer provided on the surface of the laminated substrate on the conductor layer side and having an opening in which a part of the conductor layer is exposed; and
The printed wiring board in which the said permanent resist layer consists of the hardened | cured material of the photosensitive resin composition as described in any one of Claims 1-7. A laminated substrate having an insulating substrate and a conductive layer provided on the insulating substrate, on which a circuit pattern is formed, and an opening provided on the surface of the laminated substrate on the side of the conductive layer are exposed. A package substrate comprising a permanent resist layer formed;
A semiconductor chip mounted on the package substrate,
The semiconductor package in which the said permanent resist layer consists of the hardened | cured material of the photosensitive resin composition as described in any one of Claims 1-7.

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