JP2010217903A - Photosensitive resin composition and method for manufacturing printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for forming a cured product layer on a surface resin layer of a substrate where a circuit has been formed and the surface resin layer has a predetermined pattern, the photosensitive resin composition having excellent resolution, adhesion property, photosensitivity and plating durability as well as excellent peel properties. <P>SOLUTION: The following photosensitive resin composition is used to form the cured product layer on the surface resin layer of the substrate where the circuit has been formed and the surface resin layer has the predetermined pattern. The photosensitive resin composition contains (A) a binder polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond in the molecule, and (C) a photopolymerization initiator, wherein the total molar number of ethylenically unsaturated groups included in the component (B) per 1 kg of the solid content in the photosensitive resin composition is from 1.5 to 3.5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition 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, chip scale packages (CSPs) and ball grid arrays (BGAs), which are advantageous for downsizing, are rapidly increasing in the form of mounted components used. Such mounting components are plated with mounting components 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 subjecting the pads to metal plating. The pad is engaged with the solder ball 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 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.

  When an electroless plating method is used for a substrate used in a portable electronic device such as a mobile phone whose market has been rapidly expanding in recent years, mounting parts such as CSP and BGA are caused by bending due to a drop impact or pressing force of an input key. Problems such as easy removal from the substrate surface have occurred. One reason for this is believed to be 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 improve the solder ball connection reliability, surface mounting of electronic components such as CSP and BGA onto a printed wiring board is performed by forming a solder resist with a predetermined pattern on a circuit board. It is conceivable that the photosensitive resin composition layer is formed in a predetermined pattern and electroless plating is performed, and then the photosensitive resin composition layer is peeled and removed using an alkaline aqueous solution or the like.

As such a photosensitive resin composition, the liquid resist ink composition of the following patent document 1, and the photosensitive thermosetting resin composition of the following patent document 2 are proposed.
JP-A 61-243869 JP-A-1-141904

  However, as a result of detailed investigations on the photosensitive resin compositions described in Patent Documents 1 and 2, the present inventors have found that the photosensitive resin composition is flat without conventional circuit formation. It was found that the composition of the conventional photosensitive resin composition for obtaining good photosensitivity and resolution cannot be applied as it is because it is applied directly on the substrate. That is, the present inventors have applied the photosensitive resin composition on the surface of the wiring board having a solder resist already formed and uneven on the surface in the above-described method for mounting an electronic component on a printed wiring board. It has been found that characteristics such as resolution, adhesion, photosensitivity and plating resistance tend to decrease.

  As a result of further detailed investigation, when the adhesiveness with the solder resist is improved in order to maintain the above-mentioned properties such as the adhesiveness of the photosensitive resin composition, the photosensitive resin can be used even when an alkaline aqueous solution is used. It was also confirmed that the composition could not be peeled off from the solder resist.

  Then, this invention is made | formed in view of the said situation, The photosensitive resin composition for forming a hardened | cured material layer on the said surface resin layer of the circuit-formed board | substrate provided with the surface resin layer which has a fixed pattern. An object of the present invention is to provide a photosensitive resin composition having not only excellent resolution, adhesion, photosensitivity and plating resistance but also excellent peelability and a method for producing a printed wiring board using the same. To do.

  As a result of intensive studies to achieve the above object, the present inventors have determined that the specific group in the specific compound contained in the photosensitive resin composition has the adhesiveness of the photosensitive resin composition. It has been found that it has an influence, and the present invention has been completed.

  That is, the photosensitive resin composition of the present invention is for forming a cured product layer on the surface resin layer of a circuit-formed substrate having a surface resin layer having a certain pattern, and (A) a binder A polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond in the molecule, and (C) a photopolymerization initiator, in the photosensitive resin composition The total number of moles of ethylenically unsaturated groups contained in the component (B) per 1 kg of the solid content is 1.5 to 3.5.

  In addition to the presence of irregularities on the surface of the circuit-formed substrate having a surface resin layer having a certain pattern, the photosensitive resin composition is in contact with the surface resin layer. Therefore, the conventional photosensitive resin composition layer laminated | stacked on the conductor layer of the circuit formation board | substrate in the state in which circuit formation is not made cannot be applied directly to a circuit formation board | substrate. However, the inventors have provided a surface resin layer by adjusting the number of ethylenically unsaturated groups in the photopolymerizable compound contained in the photosensitive resin composition as described above, and the surface It is possible to improve all of resolution, adhesion, photosensitivity, and plating resistance even when using a circuit-formed substrate having irregularities, and it has a new excellent peelability. It is what I found in.

  Furthermore, the photosensitive resin composition of the present invention comprises, as component (B), bisphenol A-based polyoxyethylene di (meth) acrylate, ethylene oxide, propylene oxide-modified urethane di (meth) acrylate, and ethylene oxide-modified trimethylolpropane triacrylate. It is preferable to contain at least one selected from the group. Thereby, the adhesiveness etc. of the photosensitive resin composition can be improved further.

で表される化合物を含有することが好ましい。なお、式中Ｒ¹、Ｒ²、Ｒ³及びＲ⁴は、それぞれ独立に炭素数１〜１８のアルキル基、炭素数２〜１８のアルケニル基、炭素数２〜１８のアルキニル基、アリール基、炭素数１〜１８のカルボキシレート基、炭素数１〜１８のアルコキシル基、炭素数２〜１８のアルケニルオキシ基、炭素数２〜１８のアルキニルオキシ基、炭素数２〜１８のアリルオキシ基、炭素数２〜１８のアルコキシカルボニル基、炭素数１〜１８のアルキルチオ基、炭素数１〜１８のアルキルスルホニル基又は炭素数１〜１８のアルキルスルフィニル基を示す。これにより、該感光性樹脂組成物はめっき浴の汚染を抑制することもできる。 The photosensitive resin composition of the present invention also contains (D) a colorant, and as the component (D), the following general formula (1);

It is preferable to contain the compound represented by these. In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, an aryl group, C1-C18 carboxylate group, C1-C18 alkoxyl group, C2-C18 alkenyloxy group, C2-C18 alkynyloxy group, C2-C18 allyloxy group, carbon number A C1-C18 alkylthio group, a C1-C18 alkylsulfonyl group, or a C1-C18 alkylsulfinyl group is shown. Thereby, this photosensitive resin composition can also suppress the contamination of a plating bath.

  The present invention also provides a circuit wherein a cured product layer made of a cured product of a photosensitive resin composition and having a certain pattern is formed on a surface resin layer of a circuit-formed substrate having a surface resin layer having a certain pattern, A first step of obtaining a laminated substrate having a surface resin layer and a cured product layer in this order on a formed substrate; a second step of performing electroless plating on the laminated substrate; and performing the electroless plating. And a third step of removing the cured product layer having a certain pattern from the laminated substrate, wherein the photosensitive resin composition is the photosensitive resin composition of the present invention. It is a thing.

  Furthermore, it is preferable to include a fourth step of curing the surface resin layer after performing the second step, and the second step is a step of performing electroless nickel-gold plating on the multilayer substrate. And more preferred.

  As described above, according to the present invention, a photosensitive resin composition for forming a cured product layer on the surface resin layer of a circuit-formed substrate having a surface resin layer having a certain pattern, A photosensitive resin composition having not only excellent resolution, adhesion, photosensitivity and plating resistance but also excellent peelability can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  The photosensitive resin composition of the present invention is for forming a cured product layer on the surface resin layer of a circuit-formed substrate having a surface resin layer having a certain pattern as described above, A) contains a binder polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond in the molecule, and (C) a photopolymerization initiator. The total number of moles of ethylenically unsaturated groups per kg of solid content in the photosensitive resin composition to be contained is 1.5 to 3.5.

  Here, the “circuit-formed substrate” is a substrate including an insulator layer and a conductor layer formed thereon, and the conductor layer forms a circuit having a predetermined shape. In addition, “a circuit-formed substrate having a surface resin layer having a certain pattern” means that a surface resin layer is provided on the surface of the circuit-formed substrate on which a circuit is formed, and the layer has a certain pattern. Say. Furthermore, the “surface resin layer” is a resin layer formed on a circuit-formed substrate, and is typically made of a tough curable resin such as an epoxy resin.

((A) component)
Examples of the component (A) include polyester resins, acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, phenol resins, and urethane resins. These binder polymers can be used alone or in combination of two or more.

  The binder polymer is preferably obtained by polymerizing a monomer having an ethylenically unsaturated double bond (such as radical polymerization). Examples of the monomer having an ethylenically unsaturated double bond include styrene; styrene derivatives such as vinyltoluene, α-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-chlorostyrene; diacetone acrylamide Acrylamide such as acrylonitrile; esters of vinyl alcohol such as vinyl-n-butyl ether; alkyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dimethylaminoethyl ester (meth) acrylate, (meth) Glycidyl acrylate, 2,2,2-trifluoroethyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic (Meth) acrylic acid monomers such as acids Maleic acid monomers such as maleic acid, maleic anhydride, monomethyl maleate and the like are listed. Besides these, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid Can be exemplified.

  In addition, (meth) acrylic acid refers to acrylic acid or methacrylic acid corresponding thereto, and (meth) acrylate refers to acrylate or methacrylate corresponding thereto.

  The binder polymer is preferably composed of one or more kinds of polymers having a carboxyl group from the viewpoint of developability when alkali development is performed using an alkaline solution.

  From the viewpoint of flexibility, the polymer having a carboxyl group is a copolymer of (meth) acrylic acid, (meth) acrylic acid alkyl ester, and a monomer copolymerizable therewith (hereinafter referred to as “copolymerization monomer”). A polymer is preferred. As the copolymerization monomer, styrene and / or a styrene derivative are preferable to further improve flexibility, and styrene is more preferable.

  In the copolymer of (meth) acrylic acid, (meth) acrylic acid alkyl ester and styrene and / or styrene derivative, the total weight ratio of styrene and / or styrene derivative is the total weight of the polymerizable monomer. As a reference, it is preferably 3 to 30% by weight, more preferably 4 to 28% by weight, and particularly preferably 5 to 27% by weight. If the total content of styrene and / or styrene derivative is less than 3% by weight, the adhesion tends to be insufficient, and if it exceeds 30% by weight, the peel piece tends to be large and the peel time tends to be long. . Note that “% by weight” here is equivalent to the mass standard (the same applies hereinafter).

  Moreover, it is preferable that the acid value of (A) component is 30-200 mgKOH / g, and it is more preferable that it is 45-150 mgKOH / g. When the acid value is less than 30 mgKOH / g, the development time tends to be long, and when it exceeds 200 mgKOH / g, the developer resistance of the photocured photosensitive resin composition tends to be lowered.

  The weight average molecular weight (Mw) and number average molecular weight (Mn) of the component (A) can be measured by gel permeation chromatography (GPC) (converted by a calibration curve using standard polystyrene). According to this measurement method, the Mw of the binder polymer is preferably 20,000 to 300,000, more preferably 25,000 to 150,000. When the Mw is less than 20,000, the developer resistance tends to decrease, and when it exceeds 300,000, the development time tends to be long. Further, the degree of dispersion (Mw / Mn) of the binder polymer is preferably 1.0 to 3.0, and more preferably 1.0 to 2.5. When the degree of dispersion exceeds 3.0, the adhesiveness and resolution tend to decrease.

  The binder polymer demonstrated above can be used individually by 1 type or in combination of 2 or more types. 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, and two or more types of binder polymers having different degrees of dispersion are used. Examples thereof include a binder polymer.

((B) component)
The component (B) is a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond in the molecule, as described above, in the photosensitive resin composition contained in the component (B). The total number of moles of ethylenically unsaturated groups per kg of solid content is 1.5 to 3.5.

  Here, the “solid content in the photosensitive resin composition” means a solid state dissolved in a solvent in order to apply the photosensitive resin composition to a circuit-formed substrate having a surface resin layer on which a certain pattern is formed. It refers to the solute.

  In addition, the ethylenically unsaturated group contained in the component (B) is involved in bonding with another photopolymerizable compound during photopolymerization. Therefore, for example, when the photopolymerizable compound is a bisphenol A (meth) acrylate compound, the number of “ethylenically unsaturated groups” per molecule of the compound is 2.

  By using a photopolymerizable compound in which the total number of moles of ethylenically unsaturated groups is in the above numerical range, the resolution is obtained even when a circuit-formed substrate having a surface resin layer and having surface irregularities is used. It becomes possible to improve all of adhesiveness, photosensitivity, and plating resistance, and also to have excellent peelability (alkali peelability).

  When the total number of moles of ethylenically unsaturated groups is less than 1.5, a part of the plating layer tends not to adsorb to the underlying layer, and when it exceeds 3.5, peeling with an alkaline aqueous solution tends to be difficult. Therefore, productivity is lowered. In addition, peeling residue is likely to occur, which causes defective printed wiring boards. From such a viewpoint and the viewpoint of further exerting the effect of the present invention, the total number of moles of the ethylenically unsaturated group is preferably 1.5 to 2.5, and more preferably 1.6 to 2.0. .

  Examples of the photopolymerizable compound as component (B) include compounds obtained by reacting polyhydric alcohols with α, β-unsaturated carboxylic acids; bisphenol A-based (meth) acrylate compounds; glycidyl group-containing compounds with α, Compounds obtained by reacting β-unsaturated carboxylic acids; urethane monomers such as (meth) acrylate compounds having a urethane bond in the molecule; nonylphenoxypolyoxyethylene acrylate; γ-chloro- Phthalic acid compounds such as β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloyloxyalkyl-o-phthalate; alkyl (meth) acrylate Examples include esters. These can be used alone or in combination of two or more.

Examples of the compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups. Polypropylene glycol di (meth) acrylate which is a polyethylene polypropylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di (meth) acrylate, Trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO, PO-modified trimethylolpropane tri (meth) acrylate, tetramethylolmethanetri (meta) ) Examples include acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. These can be used alone or in combination of two or more. Here, “EO” refers to “ethylene oxide”, and “PO” refers to “propylene oxide”. “EO modified” means having a block structure of ethylene oxide units (—CH ₂ —CH ₂ —O—), and “PO modified” means propylene oxide units (—CH ₂ —CH ₂ —CH ₂ —). O-) having a block structure.

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

  Examples of the nonylphenoxypolyethyleneoxy (meth) acrylate include nonylphenoxytetraethyleneoxy (meth) acrylate, nonylphenoxypentaethyleneoxy (meth) acrylate, nonylphenoxyhexaethyleneoxy (meth) acrylate, and nonylphenoxyhepta. Examples include ethyleneoxy (meth) acrylate, nonylphenoxyoctaethyleneoxy (meth) acrylate, nonylphenoxynonaethyleneoxy (meth) acrylate, nonylphenoxydecaethyleneoxy (meth) acrylate, nonylphenoxyundecaethyleneoxy (meth) acrylate, etc. It is done. These can be used alone or in combination of two or more.

で表される化合物であることが好ましい。なお、式中、Ｒ¹¹及びＲ¹²はそれぞれ独立に水素原子又はメチル基を示し、Ｘ及びＹ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となるように選ばれる正の整数を示す。さらに、Ｒ¹¹及びＲ¹²はいずれもメチル基であることが好ましく、Ｘ及びＹはいずれもエチレン基であることが好ましく、ｐ及びｑはｐ＋ｑ＝１０〜４０となるように選ばれる正の整数であることが好ましい。 Among these, the component (B) preferably contains a bisphenol A (meth) acrylate compound, and the bisphenol A (meth) acrylate compound is represented by the following general formula (2);

It is preferable that it is a compound represented by these. In the formula, R ¹¹ and R ¹² each independently represent a hydrogen atom or a methyl group, X and Y each independently represent an alkylene group having 2 to 6 carbon atoms, and p and q are p + q = 4 to 40 A positive integer chosen to be Further, R ¹¹ and R ¹² are preferably both methyl groups, X and Y are preferably both ethylene groups, and p and q are positive integers selected such that p + q = 10-40. It is preferable that

  Examples of bisphenol A-based (meth) acrylate compounds include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl. ) Propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane and the like. . These can be used alone or in combination of two or more.

  Further, the Mw of the component (B) is preferably 1000 or more, more preferably 1500 or more, still more preferably 2000 or more, and particularly preferably 2500 or more based on GPC. Moreover, it is preferable that the upper limit of Mw is 5000. If Mw is less than 1000, the peelability tends to decrease, and if it exceeds 5000, the viscosity of the photosensitive resin composition increases and the workability tends to decrease.

((C) component)
Examples of the component (C) include benzophenone; N, N′-tetraalkyl-4,4′-diaminobenzophenone; 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2. -Aromatic ketones such as methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1; quinones such as alkylanthraquinones; benzoin ether compounds such as benzoin alkyl ethers; benzoins such as benzoin and alkylbenzoins Compound; benzyl derivative such as benzyldimethyl ketal; 2,4,5-triarylimidazole dimer; acridine derivative such as 9-phenylacridine, 1,7-bis (9,9′-acridinyl) heptane; N-phenyl Glycine, N-phenylglycine derivative, coumarin compound And the like. These can be used alone or in combination of two or more.

  Among these, 2,4,5-triarylimidazole dimer and N, N′-tetraalkyl-4,4′-diaminobenzophenone are more preferable.

で表される化合物である。なお、式中、Ｒ²¹、Ｒ²²及びＲ²³は、それぞれ独立に、フェニル基又は置換フェニル基を示す。 The 2,4,5-triarylimidazole dimer is, for example, the following general formula (3);

It is a compound represented by these. In the formula, R ²¹ , R ²² and R ²³ each independently represent a phenyl group or a substituted phenyl group.

  Suitable triarylimidazole dimers include, for example, 2,2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole, 2- (o -Chlorophenyl) -4,5-diphenylimidazole dimer, 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetra (p-chlorophenyl) imidazole dimer, 2- ( o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra (p-fluorophenyl) Imidazole dimer, 2,2′-bis (o-bromophenyl) -4,4 ′, 5,5′-tetra (p-chloro-p-methoxyphenyl) imidazole dimer, 2,2′-bis (O-Chlorophe ) -4,4 ′, 5,5′-tetra (o, p-dichlorophenyl) imidazole dimer, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra ( o, p-dibromophenyl) imidazole dimer, 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra (p-chloronaphthyl) imidazole dimer, 2,2 ′ -Bis (m, p-dichlorophenyl) -4,4 ', 5,5'-tetraphenylimidazole dimer, 2,2'-bis (o, p-dichlorophenyl) -4,4', 5,5 ' -Tetraphenylimidazole dimer, 2,2'-bis (o, p-dichlorophenyl) -4,4 ', 5,5'-tetra (o, p-dichlorophenyl) imidazole dimer, 2- (o- Fluorophenyl) -4,5-diphenylimi Zole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p -Methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methylmercaptophenyl) -4,5-diphenylimidazole Dimer, 2,2′-bis (p-bromophenyl) -4,4 ′, 5,5′-tetraphenylimidazole dimer, 2,2′-bis (o-bromophenyl) -4,4 ', 5,5'-tetra (o, p-dichlorophenyl) imidazole dimer, 2,2'-bis (o-bromophenyl) -4,4', 5,5'-tetra (p-iodophenyl) Imidazo Dimer, 2,2′-bis (m-bromophenyl) -4,4 ′, 5,5′-tetraphenylimidazole dimer, 2,2′-bis (m, p-dibromophenyl) And -4,4 ', 5,5'-tetraphenylimidazole dimer. These can be used alone or in combination of two or more.

で表される化合物である。ここで、式中、Ｒ³¹、Ｒ³²、Ｒ³³及びＲ³⁴は、それぞれ独立にアルキル基（好ましくは炭素数１〜４のアルキル基）を示す。 N, N′-tetraalkyl-4,4′-diaminobenzophenone is, for example, the following general formula (4);

It is a compound represented by these. Here, in the formula, R ³¹ , R ³² , R ³³ and R ³⁴ each independently represent an alkyl group (preferably an alkyl group having 1 to 4 carbon atoms).

  Suitable N, N′-tetraalkyl-4,4′-diaminobenzophenones include N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), N, N′-tetraethyl-4,4 ′. -Diaminobenzophenone etc. are mentioned.

((D) component)
The photosensitive resin composition of the present invention may contain a colorant as the component (D). The colorant as component (D) is added to the photosensitive resin composition in order to stabilize the hue in order to sufficiently prevent halation during exposure.

  As the component (D), N- [4-[[4- (diethylamino) phenyl] phenylmethylene] -2,5-cyclohexadiene-1-ylidene] -N-ethyl-ethanaminium sulfate (diamond green), N -[4-[[4- (dimethylamino) phenylmethylene] -2,5-cyclohexadiene-1-ylidene] -N-ethyl-ethanaminium sulfate, malachite green, ethyl violet, acid magenta, and other triphenylmethane series And dyes, styryl dyes, methocyanine dyes, and oxonol dyes. These can be used alone or in combination of two or more.

で表される化合物を含有することが好ましい。なお、式中Ｒ¹、Ｒ²、Ｒ³及びＲ⁴はそれぞれ独立に炭素数１〜１８のアルキル基，炭素数２〜１８のアルケニル基、炭素数２〜１８のアルキニル基、アリール基、炭素数１〜１８のカルボキシレート基、炭素数１〜１８のアルコキシ基、炭素数２〜１８のアルケニルオキシ基、炭素数２〜１８のアルキニルオキシ基、炭素数２〜１８のアリルオキシ基、炭素数２〜１８のアルコキシカルボニル基、炭素数１〜１８のアルキルチオ基、炭素数１〜１８のアルキルスルホニル基又は炭素数１〜１８のアルキルスルフィニル基を示す。 Among these, from the viewpoint of excellent electroless plating contamination, the following general formula (1);

It is preferable to contain the compound represented by these. In the formula, R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, an aryl group, carbon C1-C18 carboxylate group, C1-C18 alkoxy group, C2-C18 alkenyloxy group, C2-C18 alkynyloxy group, C2-C18 allyloxy group, C2-C2 -18 alkoxy carbonyl group, a C1-C18 alkylthio group, a C1-C18 alkylsulfonyl group, or a C1-C18 alkylsulfinyl group is shown.

R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group having 1 to 18 carbon atoms, an alkoxyl group having 1 to 18 carbon atoms, carbon, from the viewpoint of being industrially available as a general dye. It is preferably an alkylsulfonyl group having 1 to 18 carbon atoms or a carboxylate group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 18 carbon atoms, or an alkoxyl group having 1 to 18 carbon atoms. More preferably, they are different alkyl groups having 1 to 18 carbon atoms, particularly preferably the same or different alkyl groups having 1 to 8 carbon atoms, and even more preferably the same alkyl groups having 1 to 8 carbon atoms. preferable.

Examples of the compound represented by the general formula (2) include 4- (p- (diethylamino) -α-phenylbenzylidene) -2,5 in which R ¹ , R ² , R ³ and R ⁴ are all ethyl groups. -Cyclohexadiene-1-ylidene sulfate (N- [4-[[4- (diethylamino) phenyl] phenylmethylene] -2,5-cyclohexadien-1-ylidene] -N-ethyl-ethanaminium sulfate), 4- (p- (dimethylamino) -α-phenylbenzylidene) -2,5-cyclohexadiene-1-ylidene sulfate (N- [4-[[4- (dimethylamino) phenyl] phenylmethylene] -2, 5-cyclohexadiene-1-ylidene] -N-ethyl-ethanaminium sulfate). These can be used alone or in combination of two or more. Among these, 4- (p- (diethylamino) -α-phenylbenzylidene) -2,5-cyclohexadiene-1-ylidene sulfate is known as Basic Green 1 or Brilliant Green and has low plating contamination. It is very preferable because it is easily available.

  In the photosensitive resin composition of this invention, the compounding quantity of (C) component and (D) component with respect to a total of 100 weight part of (A) component 40-80 weight part and (B) component 20-60 weight part. Are preferably 0.01 to 20 parts by weight and 0.001 to 0.5 parts by weight, respectively, and 0.05 to 10 parts by weight and 0.005 to 0.2 parts by weight, respectively. More preferred. Moreover, it is preferable that the compounding quantity of the bisphenol A type | system | group (meth) acrylate compound on the basis of the total weight of (B) component is 3-90 weight%.

  The content of component (D) is preferably 0.001 to 0.5% by weight, more preferably 0.005 to 0.2% by weight, based on the total weight of the photosensitive resin composition. . By keeping the content of the component (D) within the above range, the plating bath contamination by the photosensitive resin composition during plating can be significantly reduced while maintaining high resolution, adhesion and photosensitivity. It becomes possible.

  Further, as component (C), 4,4′-bis (diethylamino) benzophenone and 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer are included, and after these are included, diamond is added to component (D) It preferably contains at least one of green, malachite green and Victoria pure blue.

  In the photosensitive resin composition, as components other than the components (A) to (D), a photochromic agent such as tribromophenylsulfone or leucocrystal violet, a thermochromic inhibitor, p-toluene, if necessary. Further contains plasticizers such as sulfonamides, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion-imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, etc. can do.

  The photosensitive resin composition of the present invention is soluble in a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether, or a mixed solvent thereof. . In that case, it can also be set as the solution of solid content about 30-60%.

  The photosensitive resin composition of this invention can also be comprised in the photosensitive element. A photosensitive element is equipped with a support body and the photosensitive resin composition layer which consists of a photosensitive resin composition of the said this invention formed on the support body. In addition, you may further provide the protective film which coat | covers a layer on the photosensitive resin composition layer.

  The photosensitive resin composition layer is prepared by dissolving the photosensitive resin composition of the present invention in a solvent as described above to obtain a solution having a solid content of about 30 to 60% by weight, and then applying the solution on a support. It is preferable to form by drying. The application can be performed by a known method such as a roll coater, comma coater, gravure coater, air knife coater, die coater, bar coater, etc., and drying can be performed at 70 to 150 ° C. for about 5 to 30 minutes. Further, the amount of the remaining organic solvent in the photosensitive resin composition is preferably 2% by weight or less from the viewpoint of preventing the organic solvent from diffusing in the subsequent step.

  The thickness of the photosensitive resin composition layer is the thickness after drying, preferably 1 to 100 μm, and more preferably 1 to 50 μm. If the thickness is less than 1 μm, it is difficult to apply industrially, and if it exceeds 100 μm, the adhesive strength and the resolution tend to decrease.

  As the support, for example, a polymer film having heat resistance and solvent resistance, such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used. The thickness is preferably 5 to 25 μm, more preferably 8 to 20 μm, and particularly preferably 10 to 20 μm. When the thickness is less than 5 μm, the support tends to be broken when the support is peeled off before development, and when it exceeds 25 μm, the resolution tends to decrease.

  As the protective film, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used. The thickness is preferably 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 tends to be easily broken during lamination, and when it exceeds 30 μm, the cost tends to be inferior.

  The photosensitive element of the present invention may further include an intermediate layer such as a cushion layer, an adhesive layer, a light absorption layer, and a gas barrier layer, a protective layer, and the like. Moreover, the obtained photosensitive element can be wound up and stored in the form of a sheet or a roll around a core.

  Next, the manufacturing method of the printed wiring board of this invention is demonstrated.

  The method for producing a printed wiring board of the present invention comprises a cured product of the above-described photosensitive resin composition of the present invention on a surface resin layer of a circuit-formed substrate provided with a surface resin layer having a certain pattern. A first step of forming a cured product layer having a pattern and obtaining a laminated substrate having a surface resin layer and a cured product layer in this order on a circuit-formed substrate, and a second step of performing electroless plating on the laminated substrate And the third step of removing the cured product layer having a certain pattern from the laminated substrate subjected to electroless plating.

  In the above 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, and then a portion other than the cured portion. By removing, a cured product layer having a certain pattern can be formed.

In the first step, the photosensitive resin composition layer in the photosensitive element of the present invention described above is laminated on the surface resin layer of the circuit-formed substrate having a surface resin layer having a certain pattern. Then, a predetermined portion of the layer is irradiated with actinic rays to form a cured product layer, and then a portion other than the cured product layer is removed to form a cured product layer having a certain pattern. A laminated substrate having a surface resin layer and a cured product layer in this order may be obtained. In such a case, the photosensitive resin composition layer in the photosensitive element is heated and pressure-bonded at a pressure of about 0.1 to 1 MPa (about 1 to 10 kgf / cm ² ) while being heated to about 70 to 150 ° C., and laminated. Preferably, such lamination may be performed under reduced pressure.

In the above manufacturing method, both the surface resin layer and the photosensitive resin composition layer are patterned, but patterning of both layers is performed by irradiating with actinic rays (such as ultraviolet rays) through a negative mask or a positive mask and then removing after irradiation. Preferably, the portion to be formed is removed by a known method. For the photosensitive resin composition, after forming a cured layer with ultraviolet rays using the mask, an uncured portion is, for example, a dilute solution of 0.1 to 5 wt% sodium carbonate, 0.1 to 5 wt% potassium carbonate. Alkaline solutions such as dilute solutions of 0.1 to 5 wt% sodium hydroxide (pH is preferably 9 to 11, and surfactants, antifoaming agents, organic solvents, etc. may be added). Can be removed (developed). After development, the photosensitive resin composition layer (cured product layer) having a certain pattern may be post-cured by heating at about 60 to 250 ° C. and / or exposure at about 0.2 to 10 J / cm ^2. preferable. Thereby, the cured product layer is further stabilized.

  As a result of patterning, at least a part of the circuit (conductor layer) on the circuit-formed substrate is exposed, and a plating layer is formed on the circuit (conductor layer) by electroless plating. Examples of the electroless plating include electroless nickel plating, and metal plating such as gold, silver, palladium, platinum, rhodium, copper, and tin may be performed on the electroless nickel plating. Among these, electroless nickel-gold plating in which gold plating is performed on electroless nickel is preferable from the viewpoint of the reliability of plating.

  After the electroless plating, the photosensitive resin composition layer (cured product layer) having a certain pattern is removed. For removal, for example, it is preferable to use a stronger alkaline aqueous solution than the alkaline aqueous solution used for development. Examples of the strongly alkaline aqueous solution include 1 to 10% by weight sodium hydroxide aqueous solution, 1 to 10% by weight potassium hydroxide aqueous solution, 1 to 50% by weight monoethanolamine aqueous solution, and 1 to 50% by weight triethanolamine aqueous solution. Examples of the removal method include a method of dipping or spraying in the range of room temperature to 70 ° C.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

  First, the materials shown in Table 1 were mixed to obtain a photosensitive resin composition solution.

  In Table 1, * 1 represents 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane (manufactured by Shin-Nakamura Chemical Co., Ltd.), and * 2 represents 2,2-bis (4- ( Methacryloxypentadecaethoxy) phenyl) propane (made by Shin-Nakamura Chemical Co., Ltd.), * 3 is PO / EO-modified urethane acrylate (made by Shin-Nakamura Chemical Co., Ltd.), * 4 is EO-modified trimethylolpropane triacrylate (Manufactured by Sanyo Chemical Industries, Ltd.), * 5 is γ-chloro-β-hydroxypropyl-β′-methacryloyloxyethyl-o-phthalate (manufactured by Hitachi Chemical Co., Ltd.), * 6 is polypropylene glycol diacrylate ( The repeating unit of propylene glycol chain is 6-7, manufactured by Shin-Nakamura Chemical Co., Ltd.), * 7 is isocyanurate-modified triac Rate (made by Shin-Nakamura Chemical Co., Ltd.), * 8 is 4- (p- (diethylamino) -α-phenylbenzylidene) -2,5-cyclohexadiene-1-ylidene sulfate (made by Fuji Kasei Trading Co., Ltd.) , * 9 is N- (4- (dimethylamino) phenyl) phenylmethylene-2,5-cyclohexadiene-1-ylidene) -N-methylmetaminium succinate (manufactured by Hodogaya Chemical Co., Ltd.), * 10 Indicates Eizen Victoria Pure Blue BOH (trade name, manufactured by Hodogaya Chemical Co., Ltd.). Furthermore, the unit of numerical values in Table 1 is parts by weight.

  Next, the obtained photosensitive resin composition solution is dried on a polyethylene terephthalate film (hereinafter referred to as “PET film”) having dimensions (width 380 mm × thickness 20 μm) so that the thickness after drying becomes 50 μm. Then, it was dried at 100 ° C. using a hot air convection dryer to form a photosensitive resin composition layer. After drying, the photosensitive resin composition layer was coated with a polyethylene film having a thickness of 35 μm and pressed with a roll to obtain a photosensitive element.

(Production of circuit-formed board)
Etching resist leaving 1 cm peripheral edge on the copper foil surface of one side of double-sided copper-clad epoxy laminate (HCL, Hitachi Chemical Co., Ltd., MCL-E-61) measuring 12.5 cm long × 20 cm wide × 1.6 mm thick Then, unnecessary copper foil was removed by etching to form metal terminals (pads) and wiring circuits, and then the remaining etching resist was removed to obtain a circuit-formed substrate. The entire back surface was etched so that the glass epoxy surface was exposed.

(Formation of surface resin layer)
Photoresist (manufactured by Taiyo Ink Co., Ltd., PSR-4000) was applied to the entire peripheral surface of 1 cm on the circuit surface of the obtained circuit-formed substrate, 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 area is spray-developed with a 1% by weight aqueous sodium carbonate solution (30 ° C), the photoresist on the pad is removed to form a resist pattern, and then heat-cured by heating at 150 ° C for 1 hour. A surface resin layer (solder resist) was formed on the circuit-formed substrate.

(Formation of photosensitive resin composition layer)
The photosensitive resin composition layers in the photosensitive elements according to Examples 1 to 6 and Comparative Examples 1 and 2 previously obtained on both surfaces of the circuit-formed substrate provided with the surface resin layer were pressure 0.4 MPa, temperature. Lamination was performed at 100 ° C. and a lamination speed of 1.5 m / min. The entire surface of the laminated photosensitive resin composition layer excluding the mounting pad was exposed and developed to form a resist pattern. Then, the photosensitive resin composition layer is thermally cured by heating at 150 ° C. for 1 hour, and a surface resin layer and a cured product layer (cured photosensitive resin composition layer) are formed in this order on the circuit-formed substrate. A patterned laminated substrate was obtained.

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

(Plating resistance)
With respect to the obtained multilayer substrate, the following treatment was continuously performed.
(a) Immersion treatment was performed at 50 ° C. for 1 minute in degreasing treatment Z-200 (trade name, manufactured by World Metal Co., Ltd.).
(b) Washing with water Washing with running water at room temperature for 2 minutes.
(c) Soft etching The substrate was immersed in a 100 g / L ammonium persulfate bath at room temperature for 1 minute.
(d) Washing with water Washing with running water at room temperature for 2 minutes.
(e) Pickling treatment It was immersed in a 10% sulfuric acid solution for 1 minute at room temperature.
(f) Washing with water Washing with running water at room temperature for 2 minutes.
(g) The activated electroless plating catalyst solution SA-100 (trade name, manufactured by Hitachi Chemical Co., Ltd.) was immersed for 5 minutes at room temperature.
(h) Washing with water Washing with running water at room temperature for 2 minutes.
(i) An immersion treatment was performed at 95 ° C. for 20 minutes in NIPS-100 (trade name, manufactured by Hitachi Chemical Co., Ltd.) which is an electroless nickel plating Ni—P plating (P content: 7%) solution.
(j) Washing with water Washing with running water at room temperature for 2 minutes.
(k) Substitution type electroless gold plating Substitution type electroless gold plating solution Aurotec SF (Atotech Co., Ltd., trade name) was immersed for 10 minutes at 85 ° C.
(l) Post-treatment After completion of plating, the plate was washed with water and dried at 85 ° C. for 15 minutes.

  The plated laminated substrate thus obtained was visually examined for the presence or absence of tearing of the cured product layer (cured photosensitive resin composition layer), particularly around the pad portion.

(Peeling characteristics)
The laminated substrate obtained was immersed in a 3% aqueous sodium hydroxide solution preheated to 50 ° C., and the time required for the cured product layer (cured photosensitive resin composition layer) to peel and the remaining peeling The presence or absence of was observed.

  The results obtained by the above test method are shown in Table 2 below.

  In Table 2, “number of moles of ethylenically unsaturated groups” refers to the total number of moles of ethylenically unsaturated groups contained in component (B) per kg of solid content in the photosensitive resin composition. . Regarding plating resistance, “◯” means that the cured product layer was not torn, and “x” means that the cured product layer was torn. Furthermore, regarding the peeling characteristics, “◯” means that no peeling residue was observed, and “X” means that peeling residue was recognized.

Claims (6)

A photosensitive resin composition for forming a cured product layer on the surface resin layer of a circuit-formed substrate having a surface resin layer having a certain pattern,
(A) a binder polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond in the molecule, and (C) a photopolymerization initiator,
The component (B) has a total number of moles of ethylenically unsaturated groups per kg of solid content in the photosensitive resin composition contained in the component (B) of 1.5 to 3.5. A photosensitive resin composition characterized by the above. The component (B) contains at least one selected from the group consisting of bisphenol A-based polyoxyethylene di (meth) acrylate, ethylene oxide, propylene oxide-modified urethane di (meth) acrylate and ethylene oxide-modified trimethylolpropane triacrylate. The photosensitive resin composition of Claim 1 characterized by the above-mentioned. (D) contains a colorant, and as the component (D), the following general formula (1);

Wherein R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an alkynyl group having 2 to 18 carbon atoms, an aryl group, carbon C1-C18 carboxylate group, C1-C18 alkoxyl group, C2-C18 alkenyloxy group, C2-C18 alkynyloxy group, C2-C18 allyloxy group, C2-C2 An alkoxycarbonyl group having 18 to 18 carbon atoms, an alkylthio group having 1 to 18 carbon atoms, an alkylsulfonyl group having 1 to 18 carbon atoms, or an alkylsulfinyl group having 1 to 18 carbon atoms.)
The photosensitive resin composition of Claim 1 or 2 containing the compound represented by these. A cured product layer comprising a cured product of a photosensitive resin composition and having a certain pattern is formed on the surface resin layer of a circuit-formed substrate having a surface resin layer having a certain pattern, and the circuit-formed substrate is formed. A first step of obtaining a laminated substrate comprising the surface resin layer and the cured product layer in this order;
A second step of performing electroless plating on the laminated substrate;
A third step of removing the cured product layer having the certain pattern from the laminated substrate subjected to the electroless plating, and a method for producing a printed wiring board,
The manufacturing method of the printed wiring board characterized by using the photosensitive resin composition as described in any one of Claims 1-3 as the said photosensitive resin composition. The method for manufacturing a printed wiring board according to claim 4, further comprising a fourth step of curing the surface resin layer after performing the second step. 6. The method for manufacturing a printed wiring board according to claim 4, wherein the second step is a step of performing electroless nickel-gold plating on the multilayer substrate.