JP2010072425A - Photosensitive resin composition, and photosensitive element and method for manufacturing printed wiring board using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which is excellent in photosensitivity and capable of obtaining a cured material excellent in both of electroless plating resistance and peeling property, and a photosensitive element and a method for manufacturing a printed wiring board using the same. <P>SOLUTION: The photosensitive resin composition includes (A) a binder polymer, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated group, and (C) a photopolymerization initiator, wherein the component (B) includes a bisphenol A-based (meth)acrylate compound, an alkoxylated trimethylolpropane tri(meth)acrylate compound, and a nonylphenylpolyalkylene glycol (meth)acrylate compound, and the component (C) includes an acridine compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition, a photosensitive element using the same, and a method for producing a printed wiring board.

  Conventionally, in the printed wiring board manufacturing field, metal plating is performed on a circuit for the purpose of protecting the circuit and reducing contact resistance. In addition, with the spread of portable electronic devices, the form of mounted components used is rapidly increasing in the chip scale package (CSP) and the ball grid array (BGA), which are advantageous for downsizing. Such mounting parts are formed by forming a solder resist on the entire surface of the circuit conductor of the printed wiring board excluding the mounting pads (solder pads), etc., and performing metal plating on the pads, etc. The wiring board is connected by solder balls. In many cases, gold plating is used for metal plating in order to ensure a good metal bond.

  And the gold plating method in the said field | area is changing rapidly from the electroplating method to the electroless-plating method. This is based on the progress of miniaturization and higher density of printed wiring boards, the need for electrode lead wires and the uniform plating film thickness and smooth surface. The transition is particularly noticeable in portable electronic device substrates.

  By the way, in a substrate used for a portable electronic device such as a cellular phone whose market has been rapidly expanding in recent years, a mounting component such as CSP or BGA is likely to fall off the surface of the substrate due to a drop impact or bending due to a force of pressing an input key. However, it is considered that the printed wiring board by the electroless plating method has lower solder ball connection reliability than that by the electrolytic plating method. In order to solve this problem, a method has been proposed in which the portion (copper circuit) on which the mounting component is mounted is not subjected to electroless plating and the other portion is subjected to electroless plating (see, for example, Patent Document 1). .

  A printed wiring board that can perform surface mounting of electronic components such as CSP and BGA with higher reliability is a surface resin layer (solder) in a predetermined pattern on a circuit-formed substrate (substrate on which a circuit pattern is formed). After the layer of the photosensitive resin composition (resist pattern) is formed on the laminated substrate on which the resist is formed so that the circuit pattern is exposed and electroless plating is performed on the circuit pattern, It can manufacture by the method of removing the hardened | cured material layer (resist pattern).

  In addition, in order to provide a photosensitive resin composition that not only has excellent resolution, adhesion, photosensitivity and plating resistance, but can sufficiently reduce the contamination of the plating bath, the binder polymer and at least one in the molecule Photosensitive resin composition containing a photopolymerizable compound having a polymerizable ethylenically unsaturated bond, a photopolymerization initiator, and a colorant, and having a total light transmittance of 60% or more in an uncured state The thing is disclosed (for example, refer patent document 2).

  On the other hand, in recent years, a direct drawing method in which actinic rays are directly irradiated in an image form using digital data without passing through a mask film has been put into practical use. As a light source used in the direct drawing method, a YAG laser and a semiconductor laser are used from the viewpoint of safety and handleability, and recently, a technology using a gallium nitride blue laser having a long life and a high output is used. Proposed.

Furthermore, in recent years, a direct drawing method called a DLP (Digital Light Processing) exposure method capable of forming a fine pattern has been introduced. In general, in the DLP exposure method, active light having a wavelength of 390 to 430 nm using a blue-violet semiconductor laser as a light source is used. In addition, an exposure method using a polygon multi-beam having a wavelength of 355 nm using a YAG laser as a light source, which can deal with a small variety of products in general-purpose printed wiring boards, is also used. Therefore, various sensitizers are used in the photosensitive resin composition in order to correspond to each wavelength (for example, see Patent Documents 3 and 4).
International Publication No. 02/079877 Pamphlet JP 2004-12812 A JP 2004-301996 A JP-A-2005-107191

  However, the direct drawing method in which exposure is performed by moving the laser at a high speed is a conventional exposure method that uses a light source that effectively emits ultraviolet rays, such as a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, and a xenon lamp. Compared with the exposure method, the amount of exposure energy per spot is small and the production efficiency is low. Therefore, in the direct drawing method, a photosensitive resin composition with higher sensitivity is required.

  Therefore, in order to improve photosensitivity, when the photoinitiator or sensitizer contained in the photosensitive resin composition is increased, the photoreaction proceeds locally at the top of the photosensitive resin composition layer, and the bottom is cured. Since the property decreases, the electroless plating resistance tends to deteriorate.

  Further, when the photosensitivity of the photosensitive resin composition is increased using a sensitizer having a maximum absorption at each wavelength, and a resist pattern of a cured product of the photosensitive resin composition is formed on the solder resist, there is no effect. There have been problems such as a long peeling time when the resist pattern is peeled and removed after the electrolytic plating treatment, or a residual peel of the cured product on the solder resist.

  The present invention has been made in view of the above problems, and is a photosensitive resin composition capable of obtaining a cured product excellent in photosensitivity and excellent in both electroless plating resistance and peeling characteristics, and uses the same. It is an object of the present invention to provide a method for manufacturing a photosensitive element and a printed wiring board.

  The present invention is a photosensitive resin composition comprising (A) a binder polymer, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated group, and (C) a photopolymerization initiator, ) Component is a bisphenol A-based (meth) acrylate compound represented by the following general formula (1), an alkoxylated trimethylolpropane tri (meth) acrylate compound represented by the following general formula (2), and the following general formula ( A photosensitive resin composition comprising a nonylphenyl polyalkylene glycol (meth) acrylate compound represented by 3), wherein the component (C) comprises an acridine compound represented by the following general formula (4).

In General Formula (1), X ¹ and X ² each independently represent an alkylene group having 2 to 6 carbon atoms, R ¹ and R ² each independently represent a hydrogen atom or a methyl group, and p and q are p + q = A positive integer of 4 to 40, and in general formula (2), X ³ , X ⁴ and X ⁵ each independently represent an alkylene group having 2 to 6 carbon atoms, and R ³ , R ⁴ and R 5 ⁵ independently represents a hydrogen atom or a methyl group, k, m, and n represent a positive integer such that k + m + n = 3 to 30, and in general formula (3), X ⁶ represents an alkylene having 2 to ⁶ carbon atoms. R ⁶ represents a hydrogen atom or a methyl group, and r represents a positive integer of 1 to 20.

In General Formula (4), R ⁷ represents an alkylene group having 2 to 20 carbon atoms, an oxadialkylene group, or a thiodialkylene group.

  Since the photosensitive resin composition of the present invention has the above-described configuration, a cured product excellent in photosensitivity and excellent in both electroless plating resistance and peeling characteristics can be obtained. Further, the photosensitive resin composition of the present invention can be applied to a laser direct drawing method, and can be peeled off when a photocured product is formed on a solder resist.

  Moreover, in the photosensitive resin composition of this invention, when the total amount of (A) component and (B) component is 100 mass parts, the quantity of (A) component is 40-80 mass parts, (B ) The amount of component is preferably 20 to 60 parts by mass, and the amount of component (C) is preferably 0.1 to 20 parts by mass. Thereby, the effect of the present invention can be further improved.

  In the photosensitive resin composition of the present invention, the component (C) preferably further contains N, N-tetraalkyl-4,4′-diaminobenzophenone. Thereby, the photosensitivity of the photosensitive resin composition becomes more excellent.

  Moreover, this invention provides a photosensitive element provided with a support body and the photosensitive layer which consists of the said photosensitive resin composition of this invention provided on this support body.

  The photosensitive element of the present invention is provided with the photosensitive layer composed of the photosensitive resin composition of the present invention, so that a cured product excellent in photosensitivity and excellent in both electroless plating resistance and peeling characteristics can be obtained. it can. In addition, the photosensitive element of the present invention can be applied to a laser direct drawing method, and can be peeled off when a photocured material is formed on a solder resist.

  In the photosensitive element of the present invention, the photosensitive layer preferably has a transmittance of 5 to 75% for ultraviolet rays having a wavelength of 405 nm. This makes it possible to further improve the effects of the present invention when applied to a laser direct writing method having a wavelength of 405 nm.

  Further, the present invention provides a circuit forming substrate, a circuit formed substrate having a circuit pattern formed on the circuit forming substrate, and a solder formed so that the circuit pattern is exposed on the circuit formed substrate. A first step of laminating a pre-formed photosensitive layer made of the photosensitive resin composition on a surface of the first laminated substrate having a resist on the solder resist side; and a predetermined portion of the photosensitive layer A second step of obtaining a second laminated substrate having the solder resist and the resist pattern provided in this order on the circuit-formed substrate; And a third step of forming a plating layer on the circuit pattern by performing electroless plating on the two laminated substrates.

  In the printed wiring board manufacturing method of the present invention, the resist pattern is formed so that a part of the circuit pattern is exposed, and the plating layer is formed on the entire exposed part of the circuit pattern. It is preferable.

  Moreover, it is preferable that the electroless plating in the said 3rd process of the manufacturing method of the printed wiring board of this invention is Ni electroless plating and substituted Au plating.

  In the second step of the method for producing a printed wiring board of the present invention, it is preferable to irradiate a predetermined portion of the photosensitive layer with an actinic ray having a wavelength of 390 to 410 nm. Thereby, the effect of the present invention can be further improved.

  Moreover, this invention provides the manufacturing method of a printed wiring board further provided with the process of peeling the said resist pattern from the laminated substrate in which the plating layer was formed at the said 3rd process.

  ADVANTAGE OF THE INVENTION According to this invention, the photosensitive resin composition which can obtain the hardened | cured material which was excellent in photosensitivity, and was excellent in both the electroless-plating tolerance and peeling characteristics, and the photosensitive element and printed wiring board using the same A manufacturing method can be provided.

  Further, according to the present invention, a photosensitive resin composition that can be applied to a laser direct writing method and that does not cause peeling residue even when a photocured product is formed on a solder resist, and the same are used. It is possible to provide a photosensitive element and a method for manufacturing a printed wiring board.

  Hereinafter, preferred embodiments of the present invention will be described in detail. In this specification, (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.

  As the binder polymer of the component (A) in the present invention, any polymer that functions as a binder for the photosensitive resin composition can be used without particular limitation. Specific examples include acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, and phenol resins. From the viewpoint of alkali developability, an acrylic resin is preferable. These are used alone or in combination of two or more.

  The binder polymer can be produced, for example, by radical polymerization of a polymerizable monomer. Examples of the polymerizable monomer include polymerizable styrene derivatives substituted at the α-position or aromatic ring such as styrene, vinyl toluene, α-methylstyrene, acrylamide such as diacetone acrylamide, acrylonitrile, vinyl, and the like. -Esters of vinyl alcohol such as n-butyl ether, (meth) acrylic acid alkyl ester, (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, ( (Meth) acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acryl Acid, α-chloro ( T) Acrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate and the like, Examples include fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid.

The (meth) acrylic acid alkyl ester is represented by, for example, the following general formula (5). In General Formula (5), R ⁸ represents a hydrogen atom or a methyl group, and R ⁹ represents an alkyl group having 1 to 12 carbon atoms that may have a substituent. Examples of the substituent that R ⁹ has include a hydroxyl group, an epoxy group, and a halogen group.

Examples of the alkyl group in R ⁹ include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, and their structures. Isomers.

  Specific examples of the (meth) acrylic acid alkyl ester represented by the general formula (5) include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic. Acid butyl ester, (meth) acrylic acid pentyl ester, (meth) acrylic acid hexyl ester, (meth) acrylic acid heptyl ester, (meth) acrylic acid octyl ester, (meth) acrylic acid 2-ethylhexyl ester, (meth) acrylic Examples include acid nonyl ester, (meth) acrylic acid decyl ester, (meth) acrylic acid undecyl ester, and (meth) acrylic acid dodecyl ester. These are used alone or in combination of two or more.

  The binder polymer preferably has a carboxyl group from the viewpoint of alkali developability. The binder polymer having a carboxyl group can be produced, for example, by radical polymerization of a polymerizable monomer having a carboxyl group and another polymerizable monomer. Among the polymerizable monomers having a carboxyl group, (meth) acrylic acid is preferable.

  The binder polymer preferably contains styrene or a styrene derivative as a monomer unit from the viewpoint of chemical resistance. In order to improve both adhesiveness and release properties using styrene or a styrene derivative as a copolymerization component, the binder polymer preferably contains 2 to 40% by mass, more preferably 3 to 28% by mass, It is particularly preferable to contain 27% by mass. If this content is less than 2% by mass, the adhesion tends to decrease, and if it exceeds 40% by mass, the peeled piece tends to be large and the peeling time tends to be long.

  The weight average molecular weight of the binder polymer is preferably 20,000 to 300,000, and more preferably 40000 to 150,000. When the weight average molecular weight is less than 20,000, the developer resistance tends to decrease, and when it exceeds 300,000, the development time tends to be long.

  The acid value of the binder polymer is preferably 30 to 250 mgKOH / g, more preferably 40 to 200 mgKOH / g, and more preferably 50 to 150 mgKOH / g. When the acid value is less than 30 mgKOH / g, the development time tends to be long, and when it exceeds 250 mgKOH / g, the developer resistance of the photocured resist tends to be lowered.

  These binder polymers are used alone or in combination of two or more. Examples of combinations of binder polymers when two or more types are used in combination include, for example, two or more types of binder polymers comprising different copolymerization components, two or more types of binder polymers having different weight average molecular weights, and two types having different dispersities. The above binder polymers are mentioned.

  The photopolymerizable compound having a polymerizable ethylenically unsaturated group as the component (B) is represented by the bisphenol A-based (meth) acrylate compound represented by the general formula (1) and the general formula (2). An alkoxylated trimethylolpropane tri (meth) acrylate compound and a nonylphenyl polyalkylene glycol (meth) acrylate compound represented by the general formula (3).

In General Formula (1), X ¹ and X ² each independently represent an alkylene group having 2 to 6 carbon atoms, R ¹ and R ² each independently represent a hydrogen atom or a methyl group, and p and q are p + q = A positive integer of 4 to 40. Either X ¹ or the carbon number of X ² is not within the range of 2 to 6, or if p + q is not within the range of 4 to 40, or adhesion is hardly obtained sufficiently, stripping time of the resist is delayed Tend. From the viewpoints of adhesion and releasability of the resist, X ¹ and X ² are preferably ethylene groups, and p + q is preferably 10-30.

A preferred specific example of the compound of the general formula (1) is bisphenol A polyoxyethylene dimethacrylate (2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane). 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 the like.
2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is commercially available as BPE-500 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.), and 2,2-bis (4 -(Methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300N (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.). These may be used alone or in combination of two or more.

In the general formula (2), X ³ , X ⁴ and X ⁵ each independently represent an alkylene group having 2 to 6 carbon atoms, R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group, k, m, and n represent positive integers such that k + m + n = 3-30. When the carbon number of X ³ , X ⁴ or X ⁵ is not within the range of 2 to 6 or is not within the range of k + m + n = 3 to 30, the toughness of the resist and the peelability of the resist tend to decrease. . From the viewpoint of improving both the toughness of the resist and the releasability of the resist, X ³ , X ⁴ and X ⁵ are preferably ethylene groups. Moreover, it is preferable to exist in the range of k + m + n = 6-27, and it is more preferable to exist in the range of 9-27. A preferred specific example of the compound of the general formula (2) is ethoxylated trimethylolpropane triacrylate.

In General Formula (3), X ⁶ represents an alkylene group having 2 to ⁶ carbon atoms, R ⁶ represents a hydrogen atom or a methyl group, and r represents a positive integer of 1 to 20. When the number of carbon atoms of X ⁶ is not within the range of 2 to 6 or when r is not within the range of 1 to 20, there is a tendency that the resist peeling residue occurs or the peeling time is delayed. From the viewpoint of improving both the resist peeling residue and the resist peeling property, X ⁶ is preferably an ethylene group. Further, r is preferably in the range of 1 to 8, and more preferably in the range of 1 to 4. Preferable specific examples of the compound of the general formula (3) include nonylphenyl polyethylene glycol acrylate.

  The component (B) may further contain a photopolymerizable compound other than the above. Other photopolymerizable compounds include compounds obtained by reacting polyhydric alcohols with α, β-unsaturated carboxylic acids, compounds obtained by reacting glycidyl group-containing compounds with α, β-unsaturated carboxylic acids, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, (meth) acrylic acid alkyl ester, etc. Is mentioned.

(C) The photoinitiator of a component contains the acridine compound represented by the said General formula (4). In the general formula (4), R ⁷ represents an alkylene group having 2 to 20 carbon atoms, an oxadialkylene group or a thiodialkylene group. From the standpoint of improving the balance of photosensitivity, electroless plating resistance and peeling properties, it is preferably an alkyl group having 2 to 20 carbon atoms, more preferably an alkyl group having 4 to 14 carbon atoms, It is particularly preferable that the alkyl group has a number of 6 to 12.

  Examples of the acridine compound represented by the general formula (4) include 1,2-bis (9-acridinyl) ethane, 1,3-bis (9-acridinyl) propane, and 1,4-bis (9-acridinyl). Butane, 1,5-bis (9-acridinyl) pentane, 1,6-bis (9-acridinyl) hexane, 1,7-bis (9-acridinyl) heptane, 1,8-bis (9-acridinyl) octane, 1,9-bis (9-acridinyl) nonane, 1,10-bis (9-acridinyl) decane, 1,11-bis (9-acridinyl) undecane, 1,12-bis (9-acridinyl) dodecane, 14-bis (9-acridinyl) tetradecane, 1,16-bis (9-acridinyl) hexadecane, 1,18-bis (9-acridinyl) octadecane, Bis (9-acridinyl) alkanes such as 0-bis (9-acridinyl) eicosane, 1,3-bis (9-acridinyl) -2-oxapropane, 1,3-bis (9-acridinyl) -2-thiapropane, 1,5-bis (9-acridinyl) -3-thiapentane and the like can be mentioned. These are used alone or in combination of two or more.

Among the compounds represented by the general formula (4), R ⁷ is an alkylene group having 7 carbon atoms in the general formula (4) from the viewpoint of further improving the balance of photosensitivity, electroless plating resistance and peeling properties. 1,7-bis (9-acridinyl) heptane (for example, product name “N-1717” manufactured by Asahi Denka Kogyo Co., Ltd.) is more preferable.

  The photopolymerization initiator of component (C) preferably further contains N, N-tetraalkyl-4,4′-diaminobenzophenone from the viewpoint of further improving the photosensitivity of the photosensitive resin composition. Examples of N, N-tetraalkyl-4,4′-diaminobenzophenone include N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler's ketone), N, N′-tetraethyl-4,4′-. And diaminobenzophenone. Among these, N, N′-tetraethyl-4,4′-diaminobenzophenone is preferable.

  (C) The component may contain photoinitiators other than the said General formula (4). Examples of other photopolymerization initiators include benzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl- Aromatic ketones such as 1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenantharaquinone, 2-methyl 1,4- Naphthoquinone, 2,3-dimethylan Quinones such as traquinone, benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether, benzoin compounds such as benzoin, methyl benzoin, and ethyl benzoin, benzyl derivatives such as benzyl dimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer 2,4,5-triarylimidazole such as 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer Dimer, 9-phenylacridine, etc. Lysine derivative, N- phenylglycine, N- phenylglycine derivatives, coumarin-based compounds. The 2,4,5-triarylimidazole dimer may be a symmetrical compound in which the substituents of the aryl groups of two 2,4,5-triarylimidazoles are the same, or the substituents are different. An asymmetric compound may be used. Moreover, you may combine a thioxanthone type compound and a tertiary amine compound like the combination of diethyl thioxanthone and dimethylaminobenzoic acid. These are used alone or in combination of two or more.

  The amount of the binder polymer is preferably 40 to 80 parts by mass, more preferably 45 to 75 parts by mass, and more preferably 50 to 70 parts by mass in 100 parts by mass of the total amount of the component (A) and the component (B). It is particularly preferable to use parts. If this blending amount is less than 40 parts by mass, the photocured product tends to be brittle, and when used as a photosensitive element, the coating properties tend to be reduced, and if it exceeds 80 parts by mass, the photosensitivity tends to decrease.

  The amount of the (B) component photopolymerizable compound is preferably 20 to 60 parts by mass and preferably 25 to 55 parts by mass in 100 parts by mass of the total amount of the (A) component and the (B) component. More preferably, it is especially preferable to set it as 30-50 mass parts. If this amount is less than 20 parts by mass, the photosensitivity tends to decrease, and if it exceeds 60 parts by mass, the photocured product tends to be brittle.

  In the total amount of component (B), the content of the bisphenol A-based (meth) acrylate compound represented by the general formula (1) is preferably 10 to 60% by mass, and preferably 15 to 55% by mass. More preferably, it is 20-50 mass%, and it is especially preferable. If it is less than 10% by mass, the peeling property tends to be lowered, and if it exceeds 60% by mass, plating tends to occur due to insufficient adhesion.

  Moreover, it is preferable that the content rate of the alkoxylation trimethylol propane tri (meth) acrylate compound represented by General formula (2) in the total amount of (B) component is 10-60 mass%, 15-55 mass. % Is more preferable, and 20 to 50% by mass is particularly preferable. If it is less than 10% by mass, the plating tends to be stripped due to insufficient adhesion, and if it exceeds 60% by mass, the peeling property tends to deteriorate and the resist tends to become brittle.

  Furthermore, the content ratio of the nonylphenyl polyalkylene glycol (meth) acrylate compound represented by the general formula (3) in the total amount of the component (B) is preferably 3 to 40% by mass, More preferably, it is 10 mass%, and it is especially preferable that it is 10-30 mass%. If it is less than 3% by mass, the peeling property tends to deteriorate, and if it exceeds 40% by mass, the adhesion tends to be insufficient.

  The amount of the photopolymerization initiator of the component (C) is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B), and 0.2 to 10 It is more preferable that it is a mass part, and it is especially preferable that it is 0.5-5 mass parts. If this amount is less than 0.1 parts by mass, the photosensitivity tends to decrease, and if it exceeds 20 parts by mass, absorption at the surface of the composition increases during exposure, and internal photocuring tends to be insufficient. Tend.

  In addition to the components described above, the photosensitive resin composition may include, if necessary, a dye such as malachite green, a photochromic agent such as tribromophenyl sulfone or leuco crystal violet, a thermochromic inhibitor, p-toluenesulfonamide. Contains plasticizers, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion-imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, etc. Also good. It is preferable that the quantity of these components is about 0.01-20 mass parts, respectively with respect to 100 mass parts of total amounts of (A) component and (B) component. These are used alone or in combination of two or more.

  The photosensitive resin composition of the present invention is, for example, a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether, or the like as necessary. It is preferably used in the state of a solution (liquid resist) having a solid content of about 30 to 60% by mass dissolved in a mixed solvent.

  For example, the liquid resist is applied on a metal surface and dried to form a photosensitive layer, and a protective film is coated as necessary to form a resist pattern. The metal in this case is not particularly limited, but examples include iron-based alloys such as copper, copper-based alloys, nickel, chromium, iron, and stainless steel, but from the standpoint of adhesion to resists and electronic conductivity. Copper, a copper-based alloy, and an iron-based alloy are preferable.

  Or the photosensitive resin composition of this invention is used suitably in the state of the photosensitive element. FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the photosensitive element of the present invention. The photosensitive element 1 shown in FIG. 1 includes a support 10, a photosensitive layer 20 provided on the support 10, and a protective film 30 provided on the photosensitive layer 20.

  The photosensitive layer 20 is made of the above-described photosensitive resin composition of the present invention. Although the thickness of the photosensitive layer 20 changes with uses, it is preferable that it is 1-100 micrometers, and it is more preferable that it is 1-50 micrometers. If the thickness is less than 1 μm, it tends to be difficult to apply industrially, and if it exceeds 100 μm, the effect of the present invention is reduced, and the adhesive force and resolution tend to decrease.

  The photosensitive layer 20 preferably has a transmittance for ultraviolet rays having a wavelength of 405 nm of 5 to 75%, more preferably 7 to 60%, and particularly preferably 10 to 40%. If this transmittance is less than 5%, the adhesion tends to decrease, and if it exceeds 75%, the resolution tends to decrease. This transmittance can be measured by a UV spectrometer. Examples of the UV spectrometer include a 228A type W beam spectrophotometer manufactured by Hitachi, Ltd.

  The photosensitive layer 20 is preferably formed by preparing a solution of the photosensitive resin composition of the present invention and coating it on the support 10. The coating can be performed by a known method such as a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, or a bar coater. Moreover, drying can be performed at 70-150 degreeC and about 5 to 30 minutes.

  The support 10 preferably has a thickness of 5 to 25 μm, more preferably 8 to 20 μm, and particularly preferably 10 to 16 μm. If the thickness is less than 5 μm, the substrate tends to be easily broken when it is peeled off, and if it exceeds 25 μm, the resolution tends to decrease.

  The haze of the support 10 is preferably 0.001 to 5.0%, more preferably 0.001 to 2.0%, and particularly preferably 0.01 to 1.8%. If this haze exceeds 2.0%, the resolution tends to decrease. The haze is measured according to JIS K 7105, and can be measured with a commercially available turbidimeter such as NDH-1001DP (trade name, manufactured by Nippon Denshoku Industries Co., Ltd.).

  As the support 10 and the protective film 30, polymer films such as polyethylene terephthalate, polypropylene, polyethylene, and polyester are preferably used because they are excellent in heat resistance and solvent resistance.

  The protective film 30 preferably has a thickness of 5 to 30 μm, more preferably 10 to 28 μm, and particularly preferably 15 to 25 μm. When this thickness is less than 5 μm, the protective film tends to be easily broken at the time of being minated, and when it exceeds 30 μm, the cost tends to be inferior.

  The tensile strength in the longitudinal direction of the protective film 30 is preferably 13 MPa or more, more preferably 13 to 100 MPa, still more preferably 14 to 100 MPa, and still more preferably 15 to 100 MPa, It is still more preferable that it is 16-100 MPa. When the tensile strength is less than 13 MPa, the protective film 30 tends to be easily broken during lamination.

  The tensile strength in the width direction of the protective film 30 is preferably 9 MPa or more, more preferably 9 to 100 MPa, still more preferably 10 to 100 MPa, still more preferably 11 to 100 MPa, Even more preferably, it is 12-100 MPa. If the tensile strength is less than 9 MPa, the protective film 30 tends to be easily broken during lamination.

  The tensile strength can be measured according to JIS C 2318-1997 (5.3.3). For example, the tensile strength can be measured with a commercially available tensile strength tester such as Toyo Baldwin's trade name Tensilon. Is possible.

  Since the support 10 and the protective film 30 must be removable from the photosensitive layer 20 later, the support 10 and the protective film 30 should not have been subjected to a surface treatment that makes removal impossible, but are not particularly limited and necessary. Processing may be performed according to the above. The support 10 and the protective film 30 may be subjected to antistatic treatment as necessary.

  The photosensitive element of the present invention is not limited to the above embodiment, and has an intermediate layer and a protective layer such as a cushion layer, an adhesive layer, a light absorption layer, and a gas barrier layer in addition to the photosensitive layer, the support and the protective film. May be.

  The photosensitive element is stored, for example, as it is or by further stacking a protective film 30 on the other surface of the photosensitive layer 20 and winding it around a cylindrical core.

  Next, an embodiment of a method for producing a printed wiring board using the photosensitive resin composition of the present invention will be described. In the printed wiring board manufacturing method of this embodiment, the circuit-formed board is included in the printed wiring board and includes a circuit forming board and a circuit pattern (circuit conductor). The circuit formed substrate may have a through hole or the like, or may have a multilayer structure.

  In this embodiment, a resist is used. The resist is a coating material that masks or protects a specific area of the printed wiring board in order to selectively perform etching, soldering, or film formation, and also functions as a plating protective film. Usually, a photoresist is used, and a fine and accurate pattern is coated on a predetermined region with high accuracy by utilizing its photosensitivity to protect an object to be protected. In the method for producing a printed wiring board of the present invention, the resist is classified into two types depending on the purpose.

  One of them is a solder resist, which is formed so as to have a desired coating (protection) pattern by, for example, applying and exposing so as to expose only a region where a joint portion is formed by soldering. That is, the solder resist is formed so as to cover the entire surface of the circuit-formed substrate excluding a part or all of the circuit pattern.

  The other is a plating resist. The plating resist is a resist pattern formed so as to have a coating (protection) pattern that exposes only a region where electroless plating is performed by laminating a photosensitive layer using a photosensitive element. That is, the resist pattern is formed so as to cover the entire surface of the circuit-formed substrate where metal adhesion by plating such as a mounting pad portion is not desirable.

  Hereinafter, the present embodiment will be described in more detail with reference to the drawings. FIG. 2 is a process diagram showing an embodiment of a method for producing a printed wiring board of the present invention. In the embodiment shown in FIG. 2, first, a first stack having a circuit-formed substrate 80 on which a circuit pattern 50 is formed on a circuit-forming substrate 40 and a solder resist 60 formed on the circuit-formed substrate 80. A substrate 100 is prepared (FIG. 2A). The solder resist 60 has an opening 70 through which the exposed portion 50a of the circuit pattern 50 is exposed. Then, the photosensitive element 1 is laminated on the surface of the first laminated substrate 100 on the solder resist 60 side so that the photosensitive layer 20 is in close contact with the solder resist 60 ((b) of FIG. 2).

  Next, an actinic ray 92 is irradiated in an image form to the photosensitive layer 20 laminated on the circuit-formed substrate 80 ((c) in FIG. 2). Thereby, a part (exposure part 22) of the photosensitive layer 20 is exposed, and the hardened | cured material of the photosensitive resin composition is formed. After the exposure, the support 10 is removed and developed, and the unexposed portion is removed to form a resist pattern 24 ((d) in FIG. 2). In this way, the second laminated substrate 200 provided with the solder resist 60 and the resist pattern 24 in this order on the circuit-formed substrate 80 is obtained. The resist pattern 24 is formed for the purpose of plating resist so that the exposed portion 50a of the circuit pattern 50 is exposed. The resist pattern 24 can be optionally post-cured thereafter.

  Using the solder resist 60 and the resist pattern 24 as a mask, Ni electroless plating is performed on the second laminated substrate 200 to form a plating layer 55 on the circuit pattern 50 ((e) of FIG. 2). Subsequently, the resist pattern 24 is removed from the second laminated substrate 200 that has been subjected to electroless plating to obtain a printed wiring board 300 ((f) in FIG. 2).

  3 and 4 are process diagrams showing another embodiment of the printed wiring board of the present invention. FIG. 3 is a process chart showing the second process, and FIG. 4 is a process chart showing the third process. . In the first step shown in FIG. 3, first, a circuit-formed substrate 80 on which circuit patterns 50 and 51 are formed on a circuit-forming substrate 40 and a solder resist 60 formed on the circuit-formed substrate 80 are provided. 1 laminated substrate 100 is prepared (FIG. 3A). The solder resist 60 is formed with an opening 70 through which the exposed portions 50a and 51a of the circuit patterns 50 and 51 are exposed. Then, the photosensitive element 1 is laminated on the surface of the first laminated substrate 100 on the solder resist 60 side so that the photosensitive layer 20 is in close contact with the solder resist 60 ((b) of FIG. 3).

  In the second step, the photosensitive layer 20 laminated on the circuit-formed substrate 80 is irradiated with actinic rays 92 in the form of an image ((c) in FIG. 3). Thereby, a part (exposure part 22) of the photosensitive layer 20 is exposed, and the hardened | cured material of the photosensitive resin composition is formed. After the exposure, the support 10 is removed and developed, and the unexposed portion is removed to form a resist pattern 24 ((d) in FIG. 3). In this way, the second laminated substrate 200 provided with the solder resist 60 and the resist pattern 24 in this order on the circuit-formed substrate 80 is obtained. The resist pattern 24 functions as a plating resist that covers a region such as the circuit pattern 51 where only the circuit pattern 50 for performing electroless plating is exposed and metal adhesion by plating is not preferable. The resist pattern 24 can be optionally post-cured thereafter.

  In the third step shown in FIG. 4, Ni electroless plating is performed on the second laminated substrate 200 using the solder resist 60 and the resist pattern 24 as a mask, and a plating layer 55a is formed on the surface of the unmasked circuit pattern 50. Is formed ((e) of FIG. 4). Subsequently, substitution Au plating is performed to form an Au plating layer 55b on the Ni plating layer ((f) in FIG. 4). In this way, metal plating is applied only to the required portion, and the resist pattern 24 is peeled off to obtain a printed wiring board 300 with excellent reliability of the mounted component ((g) in FIG. 4).

  2 and 3, for example, the photosensitive element 1 is laminated on a circuit forming substrate 40 so that the photosensitive layer 20 is in close contact with the circuit forming substrate 40, and the active light beam. In this method, the patterned solder resist 60 is formed and the circuit pattern 50 is formed by etching or plating using the solder resist 60 as a mask.

In the first step, after the protective film 30 is removed, the photosensitive element 1 is laminated by pressure bonding onto the solder resist 60 while heating the photosensitive layer 20. At this time, it is preferable to laminate under reduced pressure from the viewpoint of adhesion and followability. More specifically, during lamination, the photosensitive layer 20 is preferably heated to 70 to 130 ° C., and the pressure is preferably about 0.1 to 1 MPa (about 1 to 10 kgf / cm ² ). If the photosensitive layer 20 is heated to 70 to 130 ° C. in this way, it is not necessary to pre-heat the circuit-formed substrate in advance, but in order to further improve the stackability, the circuit-formed substrate is pre-heated. May be.

  As a method of irradiating the active light ray 92 in an image form, for example, a direct drawing method in which digital data of a pattern is directly applied to the photosensitive layer, a shielding part for shielding the active light ray 92, and a transparent part for transmitting the active light ray 92 A batch exposure method of irradiating through a mask pattern is exemplified. From the viewpoint of obtaining the effect of the present invention more efficiently, it is preferable to use a direct drawing method.

  As the light source of the actinic ray 92, a known light source, for example, a carbon arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, a xenon lamp, a YAG laser, a semiconductor laser, or the like that effectively emits ultraviolet light, visible light, or the like is used. . As a light source of the actinic ray 92 in the case of using the direct drawing method, it is preferable to use a YAG laser or a semiconductor laser as a light source from the viewpoint of obtaining the effect of the present invention more efficiently.

  Further, the wavelength of the actinic ray 92 is preferably ultraviolet light having a wavelength of 350 to 420 nm, more preferably 390 to 420 nm, and particularly preferably 405 nm.

  Development after exposure is performed by removing unexposed portions by wet development, dry development or the like with a developer corresponding to a photosensitive resin composition such as an alkaline aqueous solution, an aqueous developer, or an organic solvent. Development methods include a dip method, a battle method, a spray method, brushing, and slapping, and the high pressure spray method is most suitable for improving the resolution.

  As the developer, an alkaline aqueous solution or the like is preferably used in terms of safety and stability and good operability. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium or potassium hydroxide, alkali carbonates such as lithium, sodium, potassium or ammonium carbonate or bicarbonate, potassium phosphate, sodium phosphate And alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate.

  More specifically, the alkaline aqueous solution is a dilute solution of 0.1 to 5% by mass sodium carbonate, a dilute solution of 0.1 to 5% by mass potassium carbonate, a dilute solution of 0.1 to 5% by mass sodium hydroxide, A dilute solution of 0.1 to 5% by mass sodium tetraborate is preferred. The pH of the alkaline aqueous solution is preferably in the range of 9 to 11, and the temperature is adjusted according to the developability of the photosensitive layer.

  In the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for promoting development, and the like may be mixed. Examples of the alkaline substance used in this case include, in addition to the above substances, borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1, 3- Examples include propanediol, 1,3-diaminopropanol-2, morpholine and the like. The pH of the developer is preferably as low as possible within a range where the resist can be sufficiently developed, preferably pH 8-12, more preferably pH 9-10.

  Examples of the organic solvent include triacetone alcohol, acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono Butyl ether is mentioned. These are used alone or in combination of two or more. The concentration of the organic solvent is usually preferably 2 to 90% by mass, and the temperature can be adjusted according to the developability. A small amount of a surfactant, an antifoaming agent, or the like can be added to the aqueous developer mixed with an organic solvent.

  Examples of the organic solvent-based developer used alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. These organic solvents preferably add water in the range of 1 to 20% by mass in order to prevent ignition. Moreover, you may use together 2 or more types of image development methods as needed.

As the treatment after development, the resist pattern may be further cured by performing heating at about 60 to 250 ° C. or exposure at about 0.2 to 10 mJ / cm ² as necessary.

  Examples of the electroless plating include electroless Ni plating. Metal plating such as gold, silver, palladium, platinum, rhodium, copper, and tin may be performed on the electroless Ni plating.

  The removal of the resist pattern after the electroless nickel plating can be performed, for example, by peeling off with a strongly alkaline aqueous solution from the alkaline aqueous solution used for development. As the strong alkaline aqueous solution, for example, a 1 to 10% by mass sodium hydroxide aqueous solution, a 1 to 10% by mass potassium hydroxide aqueous solution and the like are used. Examples of the peeling method include an immersion method and a spray method.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.
Examples 1-4 and Comparative Examples 1-3
(Synthesis of binder polymer 1)
A copolymer having a weight average molecular weight of 60,000, a glass transition temperature of 124 ° C., and an acid value of 68 mgKOH / g (copolymer) (binder polymer 1) by copolymerizing methacrylic acid / methyl methacrylate / styrene at a mass ratio of 28/60/12. Got. The binder polymer 1 was dissolved in methyl cellosolve / toluene (6/4, mass ratio) so as to be 50% by mass of a non-volatile component (solid content) to obtain a solution of the binder polymer 1.

The weight average molecular weight was measured by a gel permeation chromatography (GPC) method and was derived by conversion using a standard polystyrene calibration curve. The measurement conditions for GPC are shown below.
(GPC measurement conditions)
・ Pump: Hitachi L-6000 type [manufactured by Hitachi, Ltd.]
Column: Gelpack GL-R420 + Gelpack GL-R430 + Gelpack GL-R440 (3 in total) [above, manufactured by Hitachi Chemical Co., Ltd., product name]
・ Eluent: Tetrahydrofuran ・ Measurement temperature: 25 ° C.
-Flow rate: 2.05 mL / min-Detector: Hitachi L-3300 type RI [manufactured by Hitachi, Ltd., product name]

  The component (A) shown in Table 1 and other additive components are mixed at the mixing ratio shown in the table, and the component (B) and the component (C) are dissolved in this mixture to prepare a solution of the photosensitive resin composition. Obtained.

* 1: Mass as solid content * 2: Bisphenol A polyoxyethylene dimethacrylate: trade name of Shin-Nakamura Chemical Co., Ltd. (in the general formula (1), R ¹ and R ² are methyl groups, X ¹ and X ² Is ethylene group, the average value of p + q is about 10)
* 3: Bisphenol A polyoxyethylene dimethacrylate: trade name manufactured by Shin-Nakamura Chemical Co., Ltd. (in general formula (1), R ¹ and R ² are methyl groups, X ¹ and X ² are ethylene groups, and average value of p + q) About 30)
* 4: Ethoxylated trimethylolpropane triacrylate: Nippon Kayaku Co., Ltd. product name (in general formula (2), R ³ , R ⁴ and R ⁵ are hydrogen atoms, X ³ , X ⁴ and X ⁵ are ethylene groups, The average value of k + m + n is about 9)
* 5: Nonylphenyl polyethylene glycol acrylate: Product name of Toa Gosei Co., Ltd. (In general formula (3), R ⁶ is a hydrogen atom, X ⁶ is an ethylene group, and the average value of r is about 4)
* 6: Nonylphenyl polyethylene glycol acrylate: Product name of Shin-Nakamura Chemical Co., Ltd. (In general formula (3), R ⁶ is a hydrogen atom, X ⁶ is an ethylene group, and the average value of r is about 8)

  Subsequently, the obtained photosensitive resin composition solution was uniformly applied onto a 16 μm thick polyethylene terephthalate film (haze: 1.7%, trade name: GS-16, manufactured by Teijin Ltd.), and hot air at 100 ° C. After drying with a convection dryer for 10 minutes, a photosensitive element was obtained by protection with a polyethylene protective film. The film thickness after drying of the photosensitive resin composition layer was 50 μm.

(Production of circuit-formed board)
12.5cm in length, 20cm in width, 1.6mm thickness of double-sided copper-clad epoxy laminate (manufactured by Hitachi Chemical Co., Ltd., trade name: MCL-E-61) on one side of the copper foil surface, leaving a 1cm rim Thus, an etching resist having a predetermined pattern was formed. A portion of the copper foil not covered with the etching resist was removed by etching to form a circuit pattern having metal terminals (pads) and wiring. The remaining etching resist was peeled off to obtain a circuit-formed substrate. The entire back surface was etched so that the glass epoxy surface was exposed.

(Formation of solder resist)
Photoresist (trade name: PSR-4000, manufactured by Taiyo Ink Co., Ltd.) was applied to the entire surface of the circuit-formed substrate obtained, leaving a peripheral edge of 1 cm, and dried at 80 ° C. for 30 minutes. Then, the whole surface except the mounting pad part to plate was exposed using the exposure machine (Oak Manufacturing Co., Ltd. brand name: HMW-590) through the photo tool. The unexposed area is spray-developed with a 1% by weight aqueous sodium carbonate solution (30 ° C) for 60 seconds, the photoresist on the pad is removed to form a pattern, and then heated at 150 ° C for 1 hour to thermally cure. A solder resist was formed on the circuit-formed substrate.

(Formation of resist pattern)
The photosensitive layer (photosensitive resin composition layer) of the photosensitive element obtained in Examples 1 to 4 and Comparative Examples 1 and 2 was applied to both sides of a circuit-formed substrate provided with a solder resist, with a pressure of 0.4 MPa and a temperature. Lamination was performed at 110 ° C. and a laminating speed of 1.5 m / min. Of the laminated photosensitive layer, the entire surface excluding the circuit pattern to be subjected to electroless plating is subjected to a 405 nm DLP exposure machine (DE-1AH, manufactured by Hitachi Via Mechanics Co., Ltd.) after development on a stove 21-step tablet. Exposure was performed with an energy exposure amount such that the number of remaining steps was 8.0, and a resist pattern was formed by spray development with a 1% by mass aqueous sodium carbonate solution (30 ° C.) for 80 seconds.

  Thereafter, the resist pattern was further thermally cured by heating at 150 ° C. for 1 hour, and a laminated substrate in which the solder resist and the resist pattern were formed in this order on the circuit-formed substrate was obtained.

  About the photosensitive element and laminated substrate which were obtained by the above, characteristic evaluation was performed with the following method. Table 2 shows the evaluation results.

(Electroless plating resistance)
The laminated substrates obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were immersed in Pro Select SF (Atotech Japan Co., Ltd., trade name) for 5 minutes at 50 ° C. to perform a degreasing treatment. After washing with running water for 1 minute at room temperature (25 ° C.), it was immersed in Micro Etch SF (Atotech Japan Co., Ltd., product name) for 1 minute at 30 ° C. to perform a soft etching treatment. After washing with running water for 1 minute at room temperature, it was immersed in a 5% by mass sulfuric acid solution for 1 minute at room temperature to perform pickling.

  Thereafter, the multilayer substrate was immersed in electroless plating catalyst solution Aurotech 1000 (Atotech Japan Co., Ltd., trade name) for 90 seconds at room temperature to activate. After washing with running water for 2 minutes at room temperature, it was immersed in Aurotech HP (Atotech Japan Co., Ltd., product name), which is a Ni-P plating solution, for 40 minutes at 83 ° C. to perform electroless Ni plating.

  After washing with running water for 2 minutes at room temperature, it was added to Aurotech CS4000 (Atotech Co., Ltd., Aurotech CS4000: 150 mL / L, potassium gold cyanide: 1.47 g / L, Aurotech SF: 1 mL / L) at 85 ° C. Was immersed for 10 minutes, and substitution type electroless Au plating was performed.

With respect to the laminated substrate on which the plating layer was formed in this manner, the presence or absence of resist pattern tearing and swelling (particularly around the pad portion) was visually judged according to the following criteria to evaluate electroless plating resistance. The evaluation of electroless plating resistance means that it is better that there is no tearing or swelling.
“○”: No torn or swollen “△”: Some torn or swollen “×”: All torn or swollen
(Peeling time)
On one side of a double-sided copper-clad epoxy laminate (Hitachi Chemical Industry Co., Ltd., trade name: MCL-E-61) having a length of 4 cm, a width of 5 cm, and a thickness of 1.6 mm, a photoresist (made by Taiyo Ink Co., Ltd., trade name) : PSR-4000) was coated on the entire surface and dried at 80 ° C. for 30 minutes.

  The entire surface of the laminate coated with the photoresist was exposed through a grid-like phototool (mask pattern) 90 shown in FIG. The lattice-like phototool (mask pattern) 90 has a plurality of shielding portions 90a that shield active light rays and a transparent portion 90b that transmits active light rays. The shielding portions 90a are 2.6 mm in width (A in FIG. 5) and 0.8 mm in length (B in FIG. 5), and are arranged with a sense of 0.45 mm (C in FIG. 5). An exposure machine (trade name: HMW-590, manufactured by Oak Manufacturing Co., Ltd.) was used for the exposure.

  After the exposure, the unexposed part was spray-developed with a 1% by mass aqueous sodium carbonate solution (30 ° C.) for 60 seconds. Then, it heated at 150 degreeC for 1 hour, was hardened, and the soldering resist was formed on the said laminated board. The solder resist is formed with an opening through which a part of the copper of the laminated plate is exposed.

  Laminate the photosensitive layers of the photosensitive elements of Examples 1 to 4 and Comparative Examples 1 and 2 on both surfaces of the laminate plate provided with the solder resist at a pressure of 0.4 MPa, a temperature of 110 ° C., and a laminating speed of 1.5 m / min. And laminated. Exposure energy for the number of remaining steps after development in a stove 21 step tablet using a 405 nm DLP exposure machine (DE-1AH, manufactured by Hitachi Via Mechanics Co., Ltd.) for the laminated photosensitive layer The entire surface was exposed in an amount to form a cured product layer (resist). In this way, the evaluation laminated board which a hardened | cured material layer (resist) covers the upper and lower surfaces of the laminated board provided with the said soldering resist was obtained.

  The laminate for evaluation was spray-developed with a 1% by mass aqueous sodium carbonate solution (30 ° C.) for 80 seconds, and plated by the same method as in the electroless plating resistance evaluation. Then, it immersed in 3 mass% sodium hydroxide aqueous solution heated at 50 degreeC, and time until a hardened | cured material layer peeled from the laminated board provided with the said soldering resist was measured. The evaluation of the peeling time means that the shorter the time, the better.

(Peeling residue on solder resist)
Using the evaluation laminate after measuring the peeling time, visually observe the presence or absence of resist residues adhering to the solder resist without being completely peeled off, and evaluate the remaining peeling on the solder resist according to the following criteria did. The evaluation of the remaining peeling on the solder resist means that the smaller the resist residue, the better.
“◯”: Resist residue is less than 10% “△”: Resist residue is 10 to 50%
“×”: Resist residue is 50% or more

(Light sensitivity)
The photosensitive layers in the photosensitive elements obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were laminated to the above copper-clad laminate under the conditions of pressure 0.4 MPa, temperature 110 ° C., and lamination speed 1.5 m / min. And laminated. On the obtained laminate, a Hitachi 41-step tablet was placed as a negative, and a DLP exposure machine (DE-1AH, manufactured by Hitachi Via Mechanics Co., Ltd.) capable of 405 nm was used with 30, 60, 120 mJ / cm ² . It exposed with the amount of exposure energy. Subsequently, it developed on the same conditions as the above and the unexposed part was removed. The number of steps of the step tablet of the cured product layer (resist) formed on the copper-clad laminate at each exposure amount is measured, and the amount of exposure energy (mJ / cm ²⁾ required to cure 14 steps of the 41-step step tablet. ) And calculated as photosensitivity. In addition, it means that the photosensitivity of the photosensitive resin composition is so high that this exposure energy amount is low.

  From Table 2, Examples 1-4 using the photosensitive resin composition of the present invention have excellent photosensitivity even when exposed with a 405 nm laser direct drawing exposure machine, and form a cured product on the solder resist. In this case, it is clear that both the electroless plating resistance and the peeling characteristics are excellent. On the other hand, Comparative Example 1 is inferior in photosensitivity, Comparative Example 2 is inferior in electroless plating resistance, and a peeling residue is generated on the solder resist.

  In other words, Examples 1 to 4 using the photosensitive resin composition of the present invention are applicable to the laser direct drawing method, and also cause peeling residue when a photocured product is formed on the solder resist. In addition, a printed wiring board with high workability and high reliability can be manufactured.

It is a schematic cross section which shows one Embodiment of the photosensitive element of this invention. It is process drawing which shows one Embodiment of the manufacturing method of the printed wiring board of this invention. It is process drawing which shows other embodiment (until a 2nd process) of the manufacturing method of the printed wiring board of this invention. It is process drawing which shows other embodiment (3rd process) of the manufacturing method of the printed wiring board of this invention. It is a top view which shows a grid | lattice-like phototool (mask pattern).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Photosensitive element, 10 ... Support body, 20 ... Photosensitive layer, 22 ... Exposure part, 24 ... Resist pattern, 30 ... Protective film, 40 ... Substrate for circuit formation, 50, 51 ... Circuit pattern, 50a, 51a ... Exposure 55, plating layer, 55a ... Ni plating layer, 55b ... Au plating layer, 60 ... solder resist, 70 ... opening, 80 ... circuit-formed substrate, 90 ... mask pattern, 90a ... light shielding part, 90b ... transparent part , 92 ... actinic rays, 100 ... first laminated substrate, 200 ... second laminated substrate, 300 ... printed wiring board

Claims (10)

A photosensitive resin composition comprising (A) a binder polymer, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated group, and (C) a photopolymerization initiator,
The component (B) is
Bisphenol A (meth) acrylate compound represented by the following general formula (1),
An alkoxylated trimethylolpropane tri (meth) acrylate compound represented by the following general formula (2), and a nonylphenyl polyalkylene glycol (meth) acrylate compound represented by the following general formula (3):
The photosensitive resin composition in which the said (C) component contains the acridine compound represented by following General formula (4).

[In General Formula (1), X ¹ and X ² each independently represent an alkylene group having 2 to 6 carbon atoms, R ¹ and R ² each independently represent a hydrogen atom or a methyl group, and p and q are p + q. = Indicates a positive integer such that 4 to 40,
In the general formula (2), X ³ , X ⁴ and X ⁵ each independently represent an alkylene group having 2 to 6 carbon atoms, R ³ , R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group, k, m and n represent positive integers such that k + m + n = 3 to 30,
In General Formula (3), X ⁶ represents an alkylene group having 2 to ⁶ carbon atoms, R ⁶ represents a hydrogen atom or a methyl group, and r represents a positive integer of 1 to 20. ]

[In General Formula (4), R ⁷ represents an alkylene group having 2 to 20 carbon atoms, an oxadialkylene group or a thiodialkylene group. ] When the total amount of component (A) and component (B) is 100 parts by mass,
(A) The quantity of a component is 40-80 mass parts,
(B) The quantity of a component is 20-60 mass parts,
The photosensitive resin composition of Claim 1 whose quantity of (C) component is 0.1-20 mass parts.   The photosensitive resin composition according to claim 1, wherein the component (C) further contains N, N-tetraalkyl-4,4′-diaminobenzophenone.   A photosensitive element provided with a support body and the photosensitive layer which consists of a photosensitive resin composition in any one of Claims 1-3 provided on this support body.   The photosensitive element according to claim 4, wherein the photosensitive layer has a transmittance of 5 to 75% for ultraviolet rays having a wavelength of 405 nm. A circuit forming substrate, a circuit formed substrate having a circuit pattern formed on the circuit forming substrate, and a solder resist formed so that the circuit pattern is exposed on the circuit formed substrate. A first step of laminating a preformed photosensitive layer made of the photosensitive resin composition according to any one of claims 1 to 3 on a surface of the laminated substrate of the solder resist side;
First, a predetermined portion of the photosensitive layer is irradiated with actinic rays and then developed to form a resist pattern, and a second laminated substrate having the solder resist and the resist pattern in this order on the circuit-formed substrate is obtained. Two steps;
A third step of performing electroless plating on the second laminated substrate to form a plating layer on the circuit pattern;
A method of manufacturing a printed wiring board comprising:   The method of manufacturing a printed wiring board according to claim 6, wherein the resist pattern is formed so that a part of the circuit pattern is exposed, and the plating layer is formed on the entire exposed portion of the circuit pattern.   The method for manufacturing a printed wiring board according to claim 6 or 7, wherein the electroless plating in the third step is Ni electroless plating and displacement Au plating.   9. The method for producing a printed wiring board according to claim 6, wherein in the second step, a predetermined portion of the photosensitive layer is irradiated with an actinic ray having a wavelength of 390 to 420 nm.   The method for manufacturing a printed wiring board according to claim 6, further comprising a step of peeling the resist pattern from the laminated substrate on which the plating layer is formed in the third step.

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