JP4561560B2 - Photosensitive resin composition, photosensitive element using the same, and method for producing printed wiring board - Google Patents

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. For such mounting parts, a solder resist is formed on the entire surface of the circuit conductor of the printed wiring board excluding the mounting pads (solder pads), etc., and metal plating is applied to the mounting pad parts, etc. The mounted pads are engaged with solder balls and connected to the wiring board. 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 high density of printed wiring boards, the need for electrode lead wires, and uniform plating film thickness and smooth surface. This shift is particularly remarkable in the substrate for portable electronic devices.

  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.

A printed wiring board capable of performing surface mounting of electronic components such as CSP and BGA with higher reliability is manufactured as follows. First, a solder resist is formed in a predetermined pattern on a substrate on which a circuit is formed. Next, a photosensitive layer is laminated thereon, and the photosensitive layer is photocured and developed to obtain a resist patterned in a predetermined pattern. Furthermore, a printed wiring board is manufactured by performing electroless plating and peeling and removing the resist (see Patent Document 1).
JP 2004-12812 A

  However, in the lamination on the solder resist, unevenness on the surface of the circuit-formed substrate is remarkable, and the photosensitive layer may not completely follow the unevenness. Further, the resist on the solder resist is remarkably reduced in peelability, and a resist residue is generated on the surface of the printed wiring board.

  The present invention is a photosensitive resin composition for forming a cured resist on a surface resin layer of a circuit-formed substrate having a surface resin layer such as a patterned solder resist, and has excellent resolution, adhesion, It is another object of the present invention to provide a photosensitive resin composition having not only plating resistance but also improved followability and peelability on a solder resist. It is another object of the present invention to provide a method for producing a photosensitive element and a printed wiring board using the same.

式（１）中、Ｘ^１及びＹ^１は、それぞれ独立に炭素数２〜６のアルキレン基を示し、ｐ及びｑは、ｐ＋ｑ＝４〜４０を満たす正の整数である。 In order to solve the above problems, the photosensitive resin composition of the present invention comprises (A) a binder polymer, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated group, and (C) the following general formula. The compound represented by (1) and (D) a photopolymerization initiator are contained.

In formula (1), X ¹ and Y ¹ each independently represent an alkylene group having 2 to 6 carbon atoms, and p and q are positive integers satisfying p + q = 4 to 40.

  The present inventors have found that excellent followability and peelability can be obtained by using the compound represented by the general formula (1) as an essential component of the plasticizer in the photosensitive resin composition. . Since the component (C) has excellent flexibility, by using the component (C) as a plasticizer in the photosensitive resin composition, followability and releasability on a circuit-formed substrate with marked irregularities. Is thought to have improved. Moreover, the photosensitive resin composition of the present invention has an effect of sufficiently reducing the contamination of the plating bath in addition to the solution of the above problems.

式（２）中、Ｒ^１及びＲ^２は、それぞれ独立に水素原子又はメチル基を示し、Ｘ^２及びＹ^２は、それぞれ独立に炭素数２〜６のアルキレン基を示し、ｐ及びｑはｐ＋ｑ＝４〜４０を満たす正の整数である。 The photosensitive resin composition of the present invention preferably contains a compound represented by the following general formula (2) as the component (B), and 2,4,5-triarylimidazole as the component (D). It is preferable to contain a monomer. With such a composition, excellent resolution, adhesion, photosensitivity, plating resistance can be obtained, and contamination of the plating bath can be reduced.

In Formula (2), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, X ² and Y ² each independently represent an alkylene group having 2 to 6 carbon atoms, and p and q are p + q. = A positive integer satisfying 4 to 40.

  The photosensitive element of the present invention is a photosensitive element obtained by coating and drying a photosensitive layer on a support, and the photosensitive layer has a total amount of 100 parts by mass of the component (A) and the component (B). On the other hand, 40-80 mass parts of (A) component, 20-60 mass parts of (B) component, 0.1-40 mass parts of (C) component, and 0.1-20 mass of (D) component. It is preferable to contain a part. By adjusting the content of each component as described above, the followability and peelability when the photosensitive resin composition is used for a photosensitive element are both improved.

  The photosensitive layer preferably has a transmittance of 5 to 75% for ultraviolet rays having a wavelength of 365 nm. If the transmittance is less than 5%, the adhesion tends to be inferior, and if it exceeds 75%, the resolution tends to be inferior.

  The method for producing a printed wiring board according to the present invention is based on a cured product of a photosensitive resin composition on the surface resin layer of the first laminated substrate including a surface resin layer patterned on a circuit-formed substrate. A first step of forming a patterned cured product layer, and obtaining a second multilayer substrate comprising a surface resin layer and a cured product layer in this order on the circuit-formed substrate; and the second multilayer substrate. A second step of performing electroless plating on the substrate and a third step of removing the patterned cured product layer from the second laminated substrate on which the electroless plating has been performed.

  Further, in the printed circuit board manufacturing method, in the first step, a photosensitive resin composition is laminated on the surface resin layer, and a predetermined portion of the composition is irradiated with actinic rays to form a cured portion. Then, it is preferable to form a patterned cured product layer by removing portions other than the cured portion.

  Furthermore, in the method for manufacturing a printed wiring board according to the present invention, the photosensitive layer in the photosensitive element is formed on the surface resin layer of the first laminated substrate including the surface resin layer patterned on the circuit-formed substrate. Forming a cured product layer by irradiating a predetermined portion of the laminate with actinic rays, and then removing a portion other than the cured product layer to form a patterned cured product layer. A first step of obtaining a laminated substrate provided with a surface resin layer and a cured product layer in this order on a finished substrate, a second step of applying electroless plating to the laminated substrate, and electroless plating And a third step of removing the patterned cured product layer from the second laminated substrate.

  Since the photosensitive element is provided with the photosensitive layer of the present invention, it has not only excellent resolution, adhesion, and plating resistance, but also excellent followability and peelability, and is easy on the substrate. A film can be formed on the film. Therefore, the resist pattern forming method and the printed wiring board manufacturing method are excellent in workability and productivity.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the photosensitive element and printed wiring board using the photosensitive resin composition with good followable | trackability and peelability on a soldering resist can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. For the convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.

  The photosensitive resin composition of the present invention comprises (A) a binder polymer, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated group, and (C) a compound represented by the above general formula (1). And (D) a photopolymerization initiator. Hereinafter, the components (A) to (D) will be described in detail.

  (A) component of this invention should just be a polymer which can be photocured with the photopolymerizable compound mentioned later, and is not restrict | limited especially, For example, acrylic resin, styrene resin, epoxy resin, amide resin, Examples thereof include organic polymers such as 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 (A) binder polymer can be produced, for example, by radical polymerization of a polymerizable monomer. Examples of the polymerizable monomer include styrene; polymerizable styrene derivatives substituted at the α-position or aromatic ring such as vinyl toluene and α-methylstyrene; acrylamides such as diacetone acrylamide; acrylonitrile; vinyl- 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, (meta ) Acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acrylic acid , Α-Chlor (meta (Meth) acrylic monomers such as acrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic acid; maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, maleic acid Examples include maleic acid monoesters such as monoisopropyl; fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid and the like.

  In the present invention, (meth) acrylic acid means acrylic acid or methacrylic acid corresponding thereto, (meth) acrylate means acrylate or corresponding methacrylate, and (meth) acryloyl group means acryloyl group or The corresponding methacryloyl group is meant.

Examples of the (meth) acrylic acid alkyl ester include compounds represented by the following general formula (3) and compounds in which a hydroxyl group, an epoxy group, a halogen atom, or the like is substituted on the alkyl group R ⁴ of these compounds. .

^{_{CH 2 = C (R 3)}} -COOR 4 (3)
In formula (3), R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents an alkyl group having 1 to 12 carbon atoms.

Examples of the alkyl group having 1 to 12 carbon atoms represented by R ⁴ in the general formula (3) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. Group, nonyl group, decyl group, undecyl group, dodecyl group and structural isomers thereof. Examples of the compound represented by the general formula (3) 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 acid nonyl ester, (meth) Examples include acrylic acid decyl ester, (meth) acrylic acid undecyl ester, and (meth) acrylic acid dodecyl ester. These can be used alone or in combination of two or more.

  In addition, the binder polymer as the component (A) in the present invention preferably contains a carboxyl group from the viewpoint of alkali developability. For example, a polymerizable monomer having a carboxyl group and other polymerizable monomers. Can be produced by radical polymerization. Moreover, it is preferable that the binder polymer which is (A) component in this invention contains styrene or a styrene derivative as a polymerizable monomer from a chemical-resistant viewpoint.

  When the styrene or styrene derivative is used as a copolymerization component, it is preferable to contain 2 to 40% by mass with respect to the total amount of the polymerizable monomers, in order to improve both the adhesion and the release characteristics, and 3 to 28% by mass. %, More preferably 5 to 27% by mass. When the content is less than 2% by mass, the adhesion tends to be inferior. When the content exceeds 40% by mass, the peeled piece becomes large and the peeling time tends to be long.

  The weight average molecular weight of the (A) binder polymer is preferably 20000 to 300000, and more preferably 40000 to 150,000. When the weight average molecular weight is less than 20000, the developer resistance tends to decrease, and when it exceeds 300,000, the development time tends to be long.

  (A) It is preferable that the acid value of a binder polymer is 30-250 mgKOH / g, and it is more preferable that it is 50-200 mgKOH / g. When the acid value is less than 30 mg KOH / g, the development time tends to be delayed, and when it exceeds 250 mg KOH / 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. As a binder polymer in the case of using two or more types in combination, 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, two or more types of binder polymers having different degrees of dispersion are used. Examples thereof include a binder polymer.

  Next, a photopolymerizable compound (hereinafter referred to as “photopolymerizable compound”) having an ethylenically unsaturated bond polymerizable in the molecule as the component (B) will be described. (B) component of this invention should just be a photopolymerizable compound which has the ethylenically unsaturated bond which can superpose | polymerize in a molecule | numerator, Although it does not restrict | limit, For example, the following photopolymerizable compounds are mentioned, for example.

  That is, the component (B) of the present invention is obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid, and reacting a glycidyl group-containing compound with an α, β-unsaturated carboxylic acid. Compound, bisphenol A-based (meth) acrylate compound, nonylphenyldioxyalkylene (meth) acrylate, γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyethyl- β ′-(meth) acryloyloxyethyl-o-phthalate, (meth) acrylic acid alkyl ester and the like can be mentioned. These may be used alone or in combination of two or more.

  Examples of the compound obtained by reacting the polyhydric alcohol with α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups, and 2 to 2 propylene groups. 14 polypropylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethoxytri (meth) acrylate, trimethylolpropane diethoxytri (meth) acrylate, Trimethylolpropane triethoxytri (meth) acrylate, trimethylolpropanetetraethoxytri (meth) acrylate, trimethylolpropane pentaethoxytri (meth) acrylate, tetramethylolmethanetri (meta) ) Acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like.

  In addition, the photopolymerizable compound as the component (B) contains a bisphenol A-based (meth) acrylate compound and / or a (meth) acrylate compound having a urethane bond in the molecule from the viewpoint of plating resistance and adhesion. It is preferable to do.

In the present invention, the bisphenol A-based (meth) acrylate compound is a carbon-carbon unsaturated double bond derived from a (meth) acryloyl group or a (meth) acryloyl group, and -C ₆ H _4- derived from bisphenol A. _{C (CH 3) 2 -C 6} H 4 - refers to a compound having a group.

式（２）中、Ｒ^１及びＲ^２は、それぞれ独立に水素原子又はメチル基を示し、Ｘ^２及びＹ^２は、それぞれ独立に炭素数２〜６のアルキレン基を示し、ｐ及びｑはｐ＋ｑ＝４〜４０を満たす正の整数である。 Moreover, it is preferable that the said bisphenol A type (meth) acrylate compound is a compound represented by following General formula (2) from a viewpoint of improving adhesiveness more.

In Formula (2), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, X ² and Y ² each independently represent an alkylene group having 2 to 6 carbon atoms, and p and q are p + q. = A positive integer satisfying 4 to 40.

  Specific examples of the compound represented by the general formula (2) include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane, 2,2-bis (4-((meth)). Acryloxypolypropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl ) Propane and the like. Examples of the 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-((meta ) 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) acryloxynonane) Xyl) 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. These may 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 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) 2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.).

式（１）中、Ｘ^１及びＹ^１は、それぞれ独立に炭素数２〜６のアルキレン基を示し、ｐ及びｑは、ｐ＋ｑ＝４〜４０を満たす正の整数である。 Next, the compound represented by the following general formula (1) which is the component (C) will be described.

In formula (1), X ¹ and Y ¹ each independently represent an alkylene group having 2 to 6 carbon atoms, and p and q are positive integers satisfying p + q = 4 to 40.

That is, as component (C), for example, bisphenol A polyoxyethylene diacetate in which both X ¹ and Y ¹ are ethylene groups, bisphenol A polyoxypropylene diacetate in which both X ¹ and Y ¹ are propylene groups, X ¹ And bisphenol A polyoxyethylene / polyoxypropylene-modified diacetate in which Y ¹ is a block body of ethylene group and propylene group.

  Moreover, from the viewpoint of peeling time, p and q are each preferably 1 to 20, more preferably 2 to 15, and particularly preferably 4 to 10. p + q is 4 to 40, preferably 4 to 30, and particularly preferably 8 to 20.

  The component (C) also functions as a plasticizer, which is a single plasticizer or a combination of two or more plasticizers with other plasticizers such as paratoluenesulfonamide. May be used.

  The present inventors have found that excellent followability and peelability can be obtained by using the compound represented by the general formula (1) as an essential component of the plasticizer in the photosensitive resin composition. . Since the component (C) has excellent flexibility, the use of the component (C) as a plasticizer is considered to improve the followability and releasability on a circuit-formed substrate with marked unevenness.

  Examples of the photopolymerization initiator of component (D) in the present invention include benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4′-. Diaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl-1- [4- (methylthio) phenyl] Aromatic ketones such as 2-morpholino-propanone-1, 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenyl Anthraquinone, 2,3-diphenylanthraquinone, -Chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenantharaquinone, quinones such as 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, benzoin methyl ether, benzoin ethyl ether Benzoin ether compounds such as benzoin phenyl ether, benzoin compounds such as benzoin, methylbenzoin and ethylbenzoin, benzyl derivatives such as benzyldimethyl 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- (o-methoxyphenyl) -4, 5-diphenylimida Dimer, 2,4,5-triarylimidazole dimer such as 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 9-phenylacridine, 1,7-bis ( And acridine derivatives such as 9,9′-acridinyl) heptane, N-phenylglycine, N-phenylglycine derivatives, and coumarin compounds.

  Further, the substituents of the aryl groups of two 2,4,5-triarylimidazoles may be the same to give the target compound, or differently give an asymmetric compound. 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 blending amount of the (A) binder polymer is preferably 40 to 80 parts by mass and more preferably 45 to 70 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). preferable. 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 inferior, and if it exceeds 80 parts by mass, the photosensitivity tends to be insufficient. is there.

  The blending amount of the (B) photopolymerizable compound is preferably 20 to 60 parts by mass and preferably 30 to 55 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B). Is more preferable. If the blending amount is less than 20 parts by mass, the photosensitivity tends to be insufficient, and if it exceeds 60 parts by mass, the photocured product tends to become brittle.

  It is preferable that the compounding quantity of the compound represented by said (C) said General formula (1) shall be 0.1-40 mass parts with respect to 100 mass parts of total amounts of (A) component and (B) component. It is more preferable to set it as 0.5-30 mass parts, It is especially preferable to set it as 1-20 mass parts, It is most preferable to set it as 5-15 mass parts. If the blending amount is less than 0.1 parts by mass, the plastic effect tends to be insufficient, and if it exceeds 40 parts by mass, the photocured product tends to become brittle.

  The blending amount of the (D) photopolymerization initiator is preferably 0.1 to 20 parts by mass, and 0.2 to 10 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). More preferably, it is a part. If the blending amount is less than 0.1 parts by mass, the photosensitivity tends to be insufficient, and if it exceeds 20 parts by mass, the absorption at the surface of the composition increases during exposure and the internal photocuring is insufficient. It tends to be.

  In addition, the photosensitive resin composition of the present invention includes, if necessary, dyes such as malachite green, photochromic agents such as tribromophenyl sulfone and leuco crystal violet, thermochromic inhibitors, p-toluenesulfonamide and the like. Plasticizers, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion-imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal cross-linking agents, etc. (A) and ( B) About 0.01-20 mass parts can be contained with respect to 100 mass parts of the total amount of components. 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 can melt | dissolve in a mixed solvent and can apply | coat as a solution of solid content about 30-60 mass%.

  The photosensitive resin composition of the present invention is preferably applied as a liquid resist on a metal surface and dried, and then coated with a protective film as necessary, or used in the form of a photosensitive element described later. The metal is not particularly limited, and examples thereof include copper, copper-based alloys, iron-based alloys such as nickel, chromium, iron, and stainless steel, but from the standpoints of adhesion to resist and electronic conductivity, A copper-based alloy and an iron-based alloy are preferable.

  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.

  The photosensitive layer 20 is formed by dissolving the photosensitive resin composition of the present invention in the above solvent or mixed solvent to obtain a solution having a solid content of about 30 to 60% by mass, and then applying the solution onto the support 10. It is preferable.

  Moreover, although the thickness of the photosensitive layer 20 changes with uses, it is 1-100 micrometers in thickness after drying which removed the solvent by heating and / or hot air blowing, and it is more preferable that it is 1-50 micrometers. preferable. If this thickness is less than 1 μm, it tends to be difficult to apply industrially, and if it exceeds 100 μm, the above-described effect produced by the present invention tends to be small. In particular, the adhesive strength and resolution tend to decrease.

  Further, the transmittance of the photosensitive layer 20 with respect to ultraviolet rays having a wavelength of 365 nm is preferably 5 to 75%, more preferably 7 to 60%, and particularly preferably 10 to 40%. If the transmittance is less than 5%, the adhesion tends to be inferior, and if it exceeds 75%, the resolution tends to be inferior. The transmittance can be measured by a UV spectrometer, and examples of the UV spectrometer include a 228A type W beam spectrophotometer manufactured by Hitachi, Ltd.

  Examples of the support 10 included in the photosensitive element 1 include polymer films having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester.

  The thickness of the support 10 is preferably 5 to 25 μm, more preferably 8 to 20 μm, and particularly preferably 10 to 16 μm. When the thickness is less than 5 μm, the support 10 tends to be broken when the support 10 before development is peeled, and when it exceeds 25 μm, the resolution tends to be lowered.

  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. When this haze exceeds 5.0, 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.).

  The protective film 30 when used as the photosensitive element 1 preferably has a thickness of 5 to 30 μm, more preferably 10 to 28 μm, and particularly preferably 15 to 25 μm. When the thickness is less than 5 μm, the protective film 30 tends to be easily broken during lamination, 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, particularly preferably 14 to 100 MPa, and very preferably 15 to 100 MPa. 16 to 100 MPa is extremely preferable. If 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, particularly preferably 10 to 100 MPa, and most preferably 11 to 100 MPa. It is very preferably 12 to 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, a commercial tensile strength tester such as “Tensilon” manufactured by Toyo Baldwin Co., Ltd. Measurement is possible.

  The photosensitive element 1 which has the said structure can be manufactured by the method shown below, for example. For example, after applying a coating solution obtained by dissolving the above-described photosensitive resin composition in a predetermined solvent on the support 10, the solvent is removed to form the photosensitive layer 20, and then the photosensitive layer 20. The method of laminating | stacking protective films, such as the said polypropylene film, on the top is mentioned. As this coating liquid, the varnish of the photosensitive resin composition as described above is suitable.

Examples of the coating method include a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, and a bar coater. The solvent can be removed, for example, by heating. In this case, the heating temperature is preferably about 70 to 150 ° C., and the heating time is preferably about 5 to 30 minutes. The solvent remaining amount in the photosensitive layer 20 after removal of the solvent is preferably 2% by mass or less from the viewpoint of preventing solvent diffusion in the subsequent steps. Moreover, as a method of laminating a polypropylene film on the photosensitive layer 20, for example, a method of pressing with a roll while supplying the polypropylene film onto the photosensitive layer can be mentioned.

  The photosensitive element 1 thus obtained can be stored, for example, in the form of a flat plate as it is, or on a cylindrical core or the like, and stored in a roll form. Note that the photosensitive element 1 does not necessarily have the protective film 30 described above, and may have a two-layer structure of the support 10 and the photosensitive layer 20.

  In addition, since the support 10 and the protective film 30 must be removable from the photosensitive layer 20 later, it is preferable that the support 10 and the protective film 30 have not been subjected to a surface treatment that makes removal impossible. There is no particular limitation, and processing may be performed as necessary. Furthermore, the support 10 and the protective film 30 may be subjected to antistatic treatment as necessary.

  Next, a method for manufacturing a printed wiring board using the photosensitive element 1 described above will be described with reference to FIG. FIG. 2 is a diagram schematically showing a manufacturing process of the printed wiring board according to the embodiment of the present invention.

  In the printed wiring board manufacturing method of the present embodiment, first, a circuit-formed substrate 80 having a circuit pattern 50 on the substrate 40 and a surface resin layer 60 covering the circuit pattern surface of the circuit-formed substrate 80 are provided. A first laminated substrate 100 is prepared (FIG. 2A). In the first laminated substrate 100, an opening 70 is formed in a part of the surface resin layer 60. A part of the circuit pattern 50 is exposed through the opening 70 to form an exposed portion 50a. As the substrate 40, the circuit pattern 50, and the surface resin layer 60, a substrate, a wiring material, and a solder resist used in the conventional printed wiring board can be applied. Such a first laminated substrate 100 is a known circuit substrate. It can be manufactured by this manufacturing method.

  Next, the photosensitive element 1 according to the above-described embodiment is adhered on the surface resin layer 60 in the first multilayer substrate 100 so that the photosensitive layer 20 is in contact with the surface resin layer 60. The photosensitive layer 20 is laminated (FIG. 2B).

  Examples of the method for laminating the photosensitive layer 20 include a method in which when the protective film 30 is present on the photosensitive element 1, after removing the protective film 30, the photosensitive layer 20 is pressure-bonded to the first laminated substrate while being heated. In addition, it is preferable to perform this pressure bonding under reduced pressure from a viewpoint of improving adhesiveness and followable | trackability.

At this time, the heating temperature of the photosensitive layer 20 is preferably 70 to 130 ° C., and the pressure bonding pressure is preferably about 0.1 to 1.0 MPa (about 1 to 10 kgf / cm ² ). However, these conditions are not particularly limited. In addition, in order to further improve the stackability, the first stacked substrate 100 may be preheated. However, when the photosensitive layer 20 is heated to 70 to 130 ° C. as described above, this pre-heat treatment is not necessarily required.

  Next, the photosensitive layer 20 is irradiated with an actinic ray 92 through a mask 90 having a predetermined pattern, and the photosensitive resin composition constituting the photosensitive layer 20 of the portion irradiated with the actinic ray 92 is cured, An exposure part 22 is formed (FIG. 2C). In this exposure, exposure is performed on a region other than the region on the exposed portion 50 a of the circuit pattern 50 in the photosensitive layer 20. When the support 10 existing on the photosensitive layer 20 is transparent, it can be irradiated with actinic rays as it is. When the support 20 shows a light shielding property against the actinic rays, the support 20 is removed. After removal, the photosensitive layer 20 is irradiated with actinic rays.

  The mask 90 is, for example, a negative or positive mask pattern called an artwork, and includes a shielding portion 90a that shields the actinic ray 92 and a transparent portion 90b that transmits this. The actinic ray 92 passes through only the transparent portion 90b of the mask 90 and is irradiated onto the photosensitive layer 20 in an image form. Further, as the light source for the actinic ray 92, a conventionally known light source such as a carbon arc lamp, a mercury vapor arc lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, or the like that can effectively emit ultraviolet rays can be used. In addition, those that effectively emit visible light, such as photographic flood bulbs and solar lamps, can also be used.

  Next, if the support 10 remains on the photosensitive layer 20, it is removed, and then wet development, dry development, etc. are performed on the photosensitive layer 20 to remove portions other than the exposed portion 22 (unexposed portions). (FIG. 2D). Thereby, the second laminated substrate 200 in which the resist pattern 24 is further formed on the surface resin layer 60 in the first laminated substrate 100 is obtained (the first step). In this development, the exposed portion 50a is exposed again by removing the unexposed portion.

  In the case of wet development, a developer such as an alkaline aqueous solution, an aqueous developer, and an organic solvent can be used. In this case, as a developing method, methods such as spraying, rocking immersion, brushing, and scraping can be appropriately employed.

  In wet development, it is particularly preferable to use an alkaline aqueous solution because it is safe and stable and has good operability. Examples of the base of this 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, alkali metals such as calcium phosphate and sodium phosphate. Examples thereof include alkali metal pyrophosphates such as phosphate, sodium pyrophosphate and potassium pyrophosphate.

  More specifically, examples of the developer of the alkaline aqueous solution include a dilute solution of 0.1 to 5% by mass of sodium carbonate, a dilute solution of 0.1 to 5% by mass of potassium carbonate, and 0.1 to 5% by mass. % Dilute solution of sodium hydroxide, 0.1-5% by weight dilute solution of sodium tetraborate, and the like. Furthermore, the pH of the alkaline aqueous solution is preferably in the range of 9 to 11, and the temperature can be 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 added.

  Examples of the aqueous developer include a developer composed of water or an alkaline aqueous solution and one or more organic solvents. Here, as the base of the alkaline aqueous solution, in addition to the substances described above, for example, borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1, Examples include 3-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 And butyl ether. These can be used alone or in combination of two or more. The concentration of the organic solvent is preferably 2 to 90% by mass, and the temperature can be adjusted according to the developability. Further, a small amount of a surfactant, an antifoaming agent or the like can be mixed in the aqueous developer. 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. 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.

In addition, after the above-described development process, as a post-development process, heating at about 60 to 250 ° C. or exposure at about 0.2 to 10 J / cm ² may be performed as necessary to further cure the resist pattern 24. Good. Further, the metal surface may be etched after development, and for this, for example, a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, or the like can be used.

  Then, using the surface resin layer 60 and the resist pattern 24 as a mask, electroless plating is performed on the exposed portion 50a of the circuit pattern 50 on the circuit-formed substrate 80, and a plating layer 55 is formed on the surface of the exposed portion 50a (see FIG. FIG. 2 (e); second step).

  Electroless plating can be performed, for example, by immersing the second laminated substrate 200 in a plating bath. At this time, the temperature of the plating bath is preferably about 60 to 100 ° C. Examples of the electroless plating include electroless nickel plating. On the plating layer 55, metal plating such as gold, silver, palladium, platinum, rhodium, copper and tin may be further performed.

  Thereafter, the above-described resist pattern 24 is peeled and removed from the second laminated substrate 200, whereby the printed wiring board 300 in which the plating layer 55 is formed on the exposed portion 50a of the circuit pattern 50 is obtained (FIG. 2F). ).

  The removal of the resist pattern 24 can be performed by, for example, processing with an aqueous solution having alkalinity stronger than that used in the development described above. More specifically, 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 can be applied. Further, examples of the peeling method include dipping and spraying, and these can be performed in combination.

  In the printed wiring board 300 thus obtained, the exposed portion 50a functions as a mounting pad. And the printed wiring board 300 becomes a board | substrate mounted in a portable electronic device etc. by mounting mounting components via a solder ball etc. on this mounting pad. In the present embodiment, since the plating layer 55 is formed on the mounting pad (exposed portion 50a), it is very advantageous to join the mounting components via the solder pad.

  The present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the gist thereof. For example, a through hole or the like may be formed on the printed wiring board for multilayering.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples.
(Examples 1-5 and Comparative Examples 1-3)

(Synthesis example of component (C))
The compound represented by the above general formula (1) as the component (C) was synthesized as follows.

<Synthesis Example 1>
In a 1-liter flask equipped with a stirrer, a thermometer, and a rectifying tower (15 stages), 300 g (0.45 mol) of bisphenol A-10 mol ethylene oxide block alcohol (manufactured by Nippon Emulsifier Co., Ltd., trade name: BA-10 glycol) and 395 g (4.50 mol) of ethyl acetate were added, and the mixture was heated to reflux under normal pressure to remove moisture in the system. Next, 3.0 g of isopropyl orthotitanate (titanium tetraisopropoxide) was added as a catalyst to conduct a transesterification reaction. At first, the reaction mixture was heated to reflux, and the top temperature of the rectifying column was 77 ° C., which is the boiling point of ethyl acetate, but as the reaction progressed, the boiling point of the azeotropic mixture of ethanol and ethyl acetate approached the column. The reaction was carried out while distilling off ethanol as an azeotrope of ethyl acetate by adjusting the reflux ratio so that the top temperature was 72 ° C. A reaction solution 4 hours after the start of the reaction was collected and analyzed by HPLC. As a result, the ester conversion was 97.7%, so the reaction was completed. The reaction solution was cooled to 75 ° C., and 120 g of 17% by mass brine was added to hydrolyze and insolubilize the catalyst. After standing for 30 minutes, the organic layer was taken into a 1 liter eggplant flask by decantation, excess methyl methacrylate was distilled off under reduced pressure using a rotary evaporator, and the solution in the eggplant flask was filtered by suction filtration. Bisphenol A-10 mol ethylene oxide block diacetate (C-1) was obtained. The yield was 310 g (yield 92%).

When the product thus obtained was identified by IR and ¹ H-NMR, it was confirmed that the product was bisphenol A polyoxyethylene diacetate. The IR spectrum is shown in FIG. 3, and the ¹ H-NMR spectrum is shown in FIG.

<Synthesis Example 2>
In a 1 liter flask equipped with a stirrer, thermometer, and rectification tower (15 stages), 200 g (0.5 mol) of bisphenol A-4 mol ethylene oxide block alcohol (trade name: BA manufactured by Nippon Emulsifier Co., Ltd.) -4 glycol) and 395 g (4.50 mol) of ethyl acetate were reacted under the same conditions as in Synthesis Example 1 to obtain a pale yellow transparent bisphenol A-4 mol ethylene oxide block diacetate (C-2). Got. At this time, the yield was 220 g (yield 90%).

<Synthesis Example 3>
To a 1 liter flask equipped with a stirrer, thermometer, and rectification tower (15 stages), 230 g (0.5 mol) of bisphenol A-4 mol propylene oxide block alcohol (trade name: BA, manufactured by Nippon Emulsifier Co., Ltd.) -P4 glycol) and 395 g (4.50 mol) of ethyl acetate were reacted under the same conditions as in Synthesis Example 1 to obtain a pale yellow transparent bisphenol A-4 mol propylene oxide block diacetate (C-3). Got. At this time, the yield was 230 g (yield 94%).

<Synthesis Example 4>
To a 1 liter flask equipped with a stirrer, thermometer, and rectification tower (15 stages), 300 g (0.43 mol) of bisphenol A-8 mol propylene oxide block alcohol (trade name: BA, manufactured by Nippon Emulsifier Co., Ltd.) -P8 glycol) and 395 g (4.50 mol) of ethyl acetate were reacted under the same conditions as in Synthesis Example 1 to obtain a pale yellow transparent bisphenol A-8 mol propylene oxide block diacetate (C-4). Got. At this time, the yield was 310 g (93% yield).

(Preparation of photosensitive resin composition)
(A) component and additive component shown in Table 1 are mixed at a mixing ratio (parts by mass) shown in the same table, and (B) component, (C) component, (D) component and other components are dissolved in this mixture. Thus, a solution of the photosensitive resin composition was obtained.

＊１…固形分としての質量部
＊２…ＢＰＥ−５００：ビスフェノールＡポリオキシエチレンジメタクリレート、新中村化学工業（株）製商品名
＊３…ＵＡ−１３：ポリプロピレングリコール／ポリエチレングリコール変性ウレタンアクリレート、新中村化学工業（株）製商品名

* 1 Mass parts as solid content * 2 ... BPE-500: Bisphenol A polyoxyethylene dimethacrylate, trade name * 3 from shin-Nakamura Chemical Co., Ltd. * UA-13: Polypropylene glycol / polyethylene glycol modified urethane acrylate, Product name manufactured by Shin-Nakamura Chemical Co., Ltd.

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

(Formation of circuit-formed board)
On the other hand, a peripheral part on the copper foil surface of one side of a copper clad laminate (made by Hitachi Chemical Co., Ltd., trade name: MCL-E-679), which is a glass epoxy material laminated with copper foil (thickness 35 μm) on both sides Etch resist is formed leaving 1 cm, unnecessary copper foil is removed by etching, metal terminals (mounting pads) and wiring circuits are formed, and the remaining etching resist is peeled off to obtain a circuit-formed substrate. It was.

(Formation of the first laminated substrate)
A photoresist (manufactured by Taiyo Ink Co., Ltd., trade name: PSR-4000) was applied to the entire surface of the circuit surface of the obtained circuit-formed substrate, 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 (Corporation | KK Oak Manufacturing, HMW-590) through the photo tool. The unexposed portion is spray-developed with a 1% by mass aqueous sodium carbonate solution (30 ° C.), the photoresist on the mounting pad portion is removed to form a resist pattern, and then heated at 150 ° C. for 1 hour. It was cured and a surface resin layer (solder resist: thickness = about 20 μm) was formed on the circuit-formed substrate to obtain a first laminated substrate.

(Formation of second laminated substrate and follow-up test)
On the first laminated substrate provided with the surface resin layer on the circuit-formed substrate, the photosensitive layers in the photosensitive elements of Examples 1 to 5 and Comparative Examples 1 to 3 previously obtained were subjected to a pressure of 0.4 MPa, Lamination was performed at a temperature of 100 ° C. and a laminating speed of 1.5 m / min. Here, the presence or absence of a gap between the photosensitive layer and the substrate was confirmed by visual observation as to whether or not the resin followed the recesses on the substrate. The results are shown in Table 2. The entire surface of the laminated photosensitive layer except for the mounting pad portion was exposed and further developed to form a resist pattern on the surface to obtain a second laminated substrate.

(Peel test)
A plating layer was formed on the circuit pattern by performing electroless plating on the obtained second laminated substrate. Then, the beaker was immersed in 3 mass% sodium hydroxide aqueous solution (50 degreeC), and the peeling time (unit: second) of the resist pattern and the peeling remainder were evaluated. The results are shown in Table 2 for the peeling time and the remaining peeling state.

＊４…○：空隙なし △：若干の空隙あり ×：空隙多発
＊５…目視による確認

* 4… ○: No void Δ: Some void ×: Many voids
* 5: Visual confirmation

It is a figure which shows typically the cross-sectional structure of the photosensitive element which concerns on embodiment. It is a figure which shows typically the manufacturing process of the printed wiring board which concerns on embodiment. It is a figure which shows the infrared absorption spectrum of the bisphenol A-10 mol ethylene oxide block diacetate obtained by the synthesis example 1. 1 is a diagram showing a ¹ H-NMR spectrum of bisphenol A-10 mol ethylene oxide block diacetate obtained in Synthesis Example 1. FIG.

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, 50 ... Circuit pattern, 50a ... Exposed part, 55 ... Plating layer, 60 ... surface resin layer, 70 ... opening, 80 ... circuit-formed substrate, 90 ... mask, 90a ... shielding part, 90b ... transparent part, 92 ... actinic ray, 100 ... first laminated substrate, 200 ... second Laminated substrate, 300 ... printed wiring board.

Claims (9)

(A) a binder polymer, (B) a photopolymerizable compound having a polymerizable ethylenically unsaturated group, (C) a compound represented by the following general formula (1), and (D) a photopolymerization initiator, And a photosensitive resin composition.

[In ^the formula (1), ^{X 1} and ^{Y 1} each independently represent an alkylene group having 2 to 6 carbon atoms, p and q are positive integers satisfying p + q = 4 to 40. ]   The photosensitive resin composition of Claim 1 containing a 2,4,5-triaryl imidazole dimer as said (D) component. The photosensitive resin composition of Claim 1 or 2 containing the compound represented by following General formula (2) as said (B) component.

[In Formula (2), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, X ² and Y ² each independently represent an alkylene group having 2 to 6 carbon atoms, and p and q are It is a positive integer satisfying p + q = 4-40. ]   (A) Component is 40-80 mass parts, (B) Component is 20-60 mass parts, (C) Component is 0.1-40 with respect to 100 mass parts of total amounts of (A) component and (B) component. The photosensitive resin composition as described in any one of Claims 1-3 which contains 0.1-20 mass parts of mass parts and (D) component.   The photosensitive element formed by apply | coating and drying the photosensitive layer which consists of the photosensitive resin composition as described in any one of Claims 1-4 on a support body.   The photosensitive element according to claim 5, wherein the photosensitive layer has a transmittance of 5 to 75% for ultraviolet rays having a wavelength of 365 nm. A patterned cured product layer made of a cured product of the photosensitive resin composition is formed on the surface resin layer of the first laminated substrate having a patterned surface resin layer on a circuit-formed substrate. A first step of obtaining a second laminated substrate comprising the surface resin layer and the cured product layer in this order on a circuit-formed substrate;
A second step of applying electroless plating to the second laminated substrate;
A third step of removing the patterned cured product layer from the second laminated substrate subjected to the electroless plating, and a method of manufacturing a printed wiring board comprising:
The manufacturing method of the printed wiring board whose said photosensitive resin composition is the photosensitive resin composition as described in any one of Claims 1-4.   In the first step, the photosensitive resin composition is laminated on the surface resin layer, and a predetermined portion of the composition is irradiated with actinic rays to form a cured portion, and then a portion other than the cured portion The manufacturing method of the printed wiring board of Claim 7 which forms the said hardened | cured material layer patterned by removing the. A photosensitive layer in the photosensitive element according to claim 5 or 6 is laminated on the surface resin layer of the first laminated substrate comprising a surface resin layer patterned on a circuit-formed substrate, A predetermined portion is irradiated with actinic rays to form a cured product layer, and then a patterned cured product layer is formed by removing portions other than the cured product layer, and the surface resin is formed on the circuit-formed substrate. A first step of obtaining a second laminated substrate comprising a layer and the cured product layer in this order;
A second step of applying electroless plating to the second laminated substrate;
And a third step of removing the patterned cured product layer from the second laminated substrate on which the electroless plating has been performed.

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