JP4496845B2 - Photosensitive resin composition, photosensitive element using the same, resist pattern forming method, and printed wiring board manufacturing method - Google Patents

Description

  The present invention relates to a photosensitive resin composition, a photosensitive element using the same, a resist pattern forming method, and a printed wiring board manufacturing method.

  Conventionally, in the field of manufacturing printed wiring boards, it is common to ensure adhesion between an insulating layer and a wiring layer in a semi-additive package substrate by using a roughened roughness formed on the insulating layer. However, since irregularities on the substrate surface can be an obstacle to fine wiring and low dielectric loss, in recent years, substrates with very few irregularities are becoming mainstream.

  On the other hand, as a resist material used for forming a wiring, various photosensitive resin compositions are known, and a wide range of photosensitive elements in which a photosensitive resin composition layer composed of such a composition is formed on a support. It is used (see, for example, Patent Documents 1 to 4).

When using such a photosensitive element, the photosensitive element is laminated on the substrate so that the surface on the photosensitive resin composition layer side faces the circuit-forming substrate, pattern exposure is performed, and then the cured portion is developed with a developer. Then, a resist pattern is formed by removing the resist pattern, and the substrate on which the resist pattern is formed is etched or plated to form a pattern. And the wiring formation on a board | substrate can be performed by peeling and removing a hardened part on a board | substrate.
JP-A-10-207057 JP 2000-39709 A JP 2000-250208 A JP 2002-258479 A

  However, in the case of using a substrate with very few surface irregularities as described above, it is very difficult to ensure adhesion by an anchor effect using the irregularities of the base substrate as in the prior art. Therefore, when such wiring formation on the substrate is performed using the above-described conventional resist material, the resist is partially peeled off during development after resist patterning, etching, or plating, resulting in disconnection or short-circuiting of the wiring. Is likely to occur, resulting in a decrease in yield.

  Note that, as a method for preventing the resist from peeling off, improvement of the adhesive strength of the resist material to the substrate can be considered. However, since the resist material is required to have peeling characteristics as well as adhesion to the substrate, it cannot be a fundamental solution simply by increasing the adhesive strength of the resist material.

  The present invention has been made in view of the above-described problems of the prior art, and even when a circuit forming substrate with less surface irregularities is used, both the adhesion to the substrate and the peeling characteristics are at a high level. A photosensitive resin composition capable of sufficiently preventing the occurrence of disconnection and short-circuiting when forming a wiring, a photosensitive element using the same, and a method for forming a resist pattern And it aims at providing the manufacturing method of a printed wiring board.

In order to achieve the above object, the present invention forms a resist pattern by laminating as a photosensitive resin composition layer on a circuit forming substrate and peels it from the circuit forming substrate after etching or plating treatment. , A photosensitive resin composition for forming a resist pattern, comprising (A) a binder polymer, (B) a photopolymerizable compound having a fluorene skeleton in the molecule, and (C) a photopolymerization initiator. characterized in that, to provide a sensitive light-sensitive resin composition. Here, the circuit forming substrate preferably has a metal surface .

  According to such a photosensitive resin composition, by having the above-described configuration, it is possible to ensure sufficient adhesion even to a circuit forming substrate with few surface irregularities while sufficiently maintaining the peeling characteristics, Plating resistance, etching resistance and resolution can be achieved at a high level. Such an effect is achieved particularly when the fluorene skeleton portion has a high polarity, exhibits good adhesion to a substrate having a metal surface such as copper, and improves the refractive index of the photosensitive resin composition layer. The present inventors presume that this is achieved by effectively capturing actinic rays irradiated during exposure and promoting the photocrosslinking reaction. Therefore, the photosensitive resin composition of the present invention can realize fine wiring and low dielectric loss when performing wiring formation on a circuit-formed substrate with less surface irregularities, and can also be used during etching or plating. It is possible to sufficiently prevent the peeling of the wiring, the disconnection of the wiring, and the occurrence of a short circuit.

［式中、Ｒ^１は水素原子又はメチル基を示し、ｎは１〜１０の整数を示す。］ Moreover, in the photosensitive resin composition of this invention, it is preferable that the said photopolymerizable compound which is (B) component has a structure represented by the following general formula (I).

[Wherein, R ¹ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10. ]

  By using the photopolymerizable compound having the above configuration as the component (B), the photosensitive resin composition tends to have improved adhesion to a metal surface such as copper.

  The present invention also provides a photosensitive element comprising: a support; and a photosensitive resin composition layer comprising the photosensitive resin composition of the present invention formed on the support. .

  According to such a photosensitive element, by having the above-described configuration, the photosensitive resin composition layer can be sufficiently adhered to the substrate, and the peeling characteristics can be sufficiently maintained. Such an effect is achieved particularly when the fluorene skeleton portion has a high polarity, exhibits good adhesion to a substrate having a metal surface such as copper, and improves the refractive index of the photosensitive resin composition layer. The present inventors presume that this is achieved by effectively capturing actinic rays irradiated during exposure and promoting the photocrosslinking reaction. Therefore, the photosensitive element of the present invention can realize fine wiring and low dielectric loss when performing wiring formation on a circuit-formed substrate with less surface irregularities, and can be peeled off during etching or plating. It is possible to sufficiently prevent disconnection of wiring and occurrence of short circuit.

  In the present invention, a photosensitive resin composition layer comprising the above-described photosensitive resin composition of the present invention is laminated on a circuit forming substrate, and a predetermined portion of the photosensitive resin composition layer is irradiated with actinic rays. Thus, a method for forming a resist pattern is provided, in which an exposed portion is photocured and then a portion other than the exposed portion is removed.

  Further, in the present invention, the photosensitive resin composition layer in the photosensitive element of the present invention is laminated on a circuit forming substrate, and exposure is performed by irradiating a predetermined portion of the photosensitive resin composition layer with an actinic ray. A method for forming a resist pattern is provided, in which a portion is photocured and then a portion other than the exposed portion is removed.

  Furthermore, the present invention provides a method for manufacturing a printed wiring board, characterized by etching or plating a circuit forming substrate on which a resist pattern is formed by the resist pattern forming method of the present invention.

  Since both the method for forming a resist pattern and the method for producing a printed wiring board according to the present invention use the photosensitive resin composition or the photosensitive element according to the present invention, the circuit forming substrate has few surface irregularities. Even if it is a thing, these can fully adhere to a substrate, maintaining sufficiently the peeling characteristic of a photosensitive resin composition or a photosensitive resin composition layer, and peeling at the time of subsequent etching or plating, The yield can be improved by sufficiently preventing the disconnection and short-circuit of the wiring. In particular, when the ten-point average roughness (Rz) of the circuit forming substrate surface is 2 μm or less, the above-described effect according to the present invention is very excellent.

  In addition, the ten-point average roughness (Rz) of the circuit forming substrate surface in the present invention can be measured based on JIS B0601.

  According to the present invention, even when a circuit-forming substrate with less surface irregularities is used, both the adhesion to the substrate and the peeling property can be maintained at a high level. It is possible to provide a photosensitive resin composition capable of sufficiently preventing the occurrence of wiring disconnection and short circuit, and a photosensitive element, a resist pattern forming method and a printed wiring board manufacturing method using the same. It becomes.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof. In the following description, “(meth) acrylic acid” means “acrylic acid” and its corresponding “methacrylic acid”, and “(meth) acrylate” means “acrylate” and its corresponding “methacrylate”. Means. In the following description, “EO” and “PO” represent “ethylene oxide” and “propylene oxide”, respectively, and “EO-modified” compound and “PO-modified” compound have a block structure of “ethylene oxide group”. And a compound having a block structure of a propylene oxide group.

  The photosensitive resin composition of the present invention comprises (A) a binder polymer, (B) a photopolymerizable compound having a hydroxyurethane skeleton in the molecule, and (C) a photopolymerization initiator.

  Examples of the (A) binder polymer include acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, and phenol resins. From the viewpoint of alkali developability, an acrylic resin is preferable. These can be used alone or in combination of two or more.

  (A) The binder polymer can be produced, for example, by radical polymerization of a polymerizable monomer. Examples of the polymerizable monomer include polymerizable styrene derivatives such as styrene, vinyl toluene, α-methyl styrene, p-methyl styrene, and p-ethyl styrene, vinyl such as acrylamide, acrylonitrile, and vinyl-n-butyl ether. Esters of alcohol, (meth) acrylic acid alkyl ester, (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, (meth) acrylic acid glycidyl ester, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acrylic acid, α-chloro (meth) ) Acrylic acid, β-furyl (meth) ) Acrylic acid, β-styryl (meth) acrylic acid, maleic acid, maleic anhydride, maleic acid monoesters such as monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanosilicic acid Cinnamic acid, itaconic acid, crotonic acid, propiolic acid and the like. These may be used alone or in combination of two or more.

  Examples of the (meth) acrylic acid alkyl ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, (meth ) Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and structural isomers thereof. These can be used alone or in combination of two or more.

  (A) The binder polymer preferably contains a carboxyl group from the viewpoint of alkali developability, and is produced, for example, by radical polymerization of a polymerizable monomer having a carboxyl group and another polymerizable monomer. be able to. As the polymerizable monomer having a carboxyl group, methacrylic acid is preferable. The (A) binder polymer preferably contains styrene or a styrene derivative as a polymerizable monomer from the viewpoint of flexibility.

  When the styrene or styrene derivative is used as a copolymerization component, the content of styrene or styrene derivative is preferably 3 to 30% by weight in order to improve both the adhesion and release properties. More preferably, it is 5 to 27% by weight. If this content is less than 3% by weight, the adhesion tends to be inferior, and if it exceeds 30% by weight, the peel piece tends to be large and the peel time tends to be long.

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

  (A) The weight average molecular weight of the binder polymer (measured by gel permeation chromatography (GPC) and converted by a calibration curve using standard polystyrene) is preferably 20,000 to 300,000, preferably 30,000. More preferably, it is ˜150,000. When the weight average molecular weight is less than 20,000, the developer resistance tends to decrease, and when it exceeds 300,000, the development time tends to be long.

  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, and two or more types of binder polymers having different degrees of dispersion are used. Examples thereof include a binder polymer. A polymer having a multimode molecular weight distribution described in JP-A No. 11-327137 can also be used.

［式中、Ｒ^１は水素原子又はメチル基を示し、ｎは１〜１０の整数を示す。］ (B) The photopolymerizable compound having a fluorene skeleton in the molecule is preferably a compound having a structure represented by the following general formula (I).

[Wherein, R ¹ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10. ]

  As such a photopolymerizable compound (B) having a fluorene skeleton in the molecule, there is a product provided by Osaka Gas Chemical Co., Ltd., for example, bisphenoxyethanol fluorene acrylate (trade name: BPEF-A, And compounds of the general formula (I) where n = 1 to 5).

  Moreover, the photosensitive resin composition of this invention can be made to contain photopolymerizable compounds other than (B) component. For example, the photopolymerizable compound contained in the photosensitive resin composition of the present invention is a compound having at least one ethylenically unsaturated bond in the molecule, and is particularly limited as long as it has an ethylenically unsaturated bond. There is no. For example, a fumaric acid type compound etc. are mentioned as what has one ethylenically unsaturated bond in a molecule | numerator. Examples of those having two ethylenically unsaturated bonds in the molecule include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and polybutylene glycol di (meth) acrylate. Further, those having three ethylenically unsaturated bonds in the molecule include trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO , PO-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, EO-modified pentaerythritol tri (meth) acrylate, PO-modified pentaerythritol tri (meth) acrylate, EO, PO-modified pentaerythritol tri (meth) Acrylate, tetramethylol methane tri (meth) acrylate, EO modified tetramethylol methane tri (meth) acrylate, PO modified tetramethylol methane tri (meth) acrylate, EO, P Modified tetramethylolmethane tri (meth) acrylate. As what can be obtained, for example, A-TMM-3 (trade name, tetramethylol methane triacrylate manufactured by Shin-Nakamura Chemical Co., Ltd.), TMPT21E, TMPT30E (sample name, EO-modified trioxide manufactured by Hitachi Chemical Co., Ltd.) Methylolpropane trimethacrylate), FA-321M (sample name, EO-modified bisphenol A dimethacrylate manufactured by Hitachi Chemical Co., Ltd.) and the like.

  In this invention, the above photopolymerizable compounds can be used individually or in combination of 2 or more types.

  In addition, as a photopolymerizable compound other than the component (B), 2,2-bis (4-((meth) acryloxypolyalkoxy) phenyl) propane having two ethylenically unsaturated bonds can be used. When used in combination with the above-mentioned compounds as one of a plurality of photopolymerizable compounds, it is effective in terms of resolution and peelability.

  The polyalkoxy groups of the 2,2-bis (4-((meth) acryloxypolyalkoxy) phenyl) propane may be the same or different. The plurality of alkoxy groups constituting the polyalkoxy group may be the same or different. When the polyalkoxy group is composed of two or more types of alkoxy groups, the various alkoxy groups may be present at random or may form a block. Specific examples of the compounds are shown below.

  Examples of 2,2-bis (4-((meth) acryloxypolyalkoxy) phenyl) propane in which the polyalkoxy group is composed of one kind of alkoxy group 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.

  The 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane in which the polyalkoxy group is a polyethoxy group includes different compounds depending on the number of ethoxy groups. (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acrylic) Loxytetraethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyocta Toxi) phenyl) propane, 2,2-bis (4-((meth) acryloxynonaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2, 2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxide decaethoxy) phenyl) propane, 2,2-bis (4- ( (Meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypenta) Examples include decaethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxyhexadecaethoxy) phenyl) propane. Commercially available 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane product includes, for example, BPE-500 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) As for -bis (4- (methacryloxypentadecaethoxy) phenyl) propane product, BPE-1300 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like are commercially available.

  Examples of the compound in which the polyalkoxy group is composed of a plurality of types of alkoxy groups include 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane.

  The 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane includes compounds having different numbers of ethoxy groups and propoxy groups. For example, 2,2-bis (4- ((Meth) acryloxydiethoxyoctapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxytetrapropoxy) phenyl) propane, 2,2-bis (4-((meth)) Acryloxyhexaethoxyhexapropoxy) phenyl) propane and the like.

  The compounds exemplified above can be used alone or in combination of two or more as the photopolymerizable compound of the present invention.

  (C) As a photopolymerization initiator, for example, N, N′-tetraalkyl-4,4′-diaminobenzophenone such as benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone (Michler ketone), Aromatic ketones such as 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, Quinones such as alkyl anthraquinone, benzoin ether compounds such as benzoin alkyl ether, benzoin compounds such as benzoin and alkylbenzoin, benzyl derivatives such as benzyldimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer 2- (o-chlorophenyl) -4,5-di (meth) Ciphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p- Acridine such as 2,4,5-triarylimidazole dimer such as methoxyphenyl) -4,5-diphenylimidazole dimer, 9-phenylacridine, 1,7-bis (9,9′-acridinyl) heptane Derivatives, N-phenylglycine, N-phenylglycine derivatives, coumarin compounds and the like can be mentioned.

  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. From the viewpoint of adhesion and sensitivity, 2,4,5-triarylimidazole dimer is more preferable. These are used alone or in combination of two or more.

  The blending amount of the component (A) is preferably 40 to 80 parts by weight with respect to 100 parts by weight of the total amount of the components (A) and (B). If the blending amount is less than 40 parts by weight, the photocured product tends to be brittle, and when used as a photosensitive element, the coating property tends to be inferior, and if it exceeds 80 parts by weight, the sensitivity tends to be insufficient.

  The blending amount of the component (B) is preferably 20 to 60 parts by weight with respect to 100 parts by weight of the total amount of the components (A) and (B). If the blending amount is less than 20 parts by weight, the sensitivity tends to be insufficient, and if it exceeds 60 parts by weight, the photocured product tends to become brittle.

  The blending amount of the component (C) is preferably 0.1 to 10.0 parts by weight, and 0.5 to 6.0 parts per 100 parts by weight of the total amount of the components (A) and (B). More preferred are parts by weight. If the blending amount is less than 0.1 parts by weight, the sensitivity tends to be insufficient, and if it exceeds 10.0 parts by weight, the curability at the bottom of the resist is lowered and scum tends to be generated.

  The photosensitive resin composition of the present invention preferably contains a photopolymerizable compound having at least one cationically polymerizable cyclic ether group in the molecule from the viewpoint of sensitivity and peeling properties. Preferred examples of the photopolymerizable compound having at least one cationically polymerizable cyclic ether group in the molecule include oxetane compounds and epoxy compounds. Examples of the available compounds include oxetane compounds such as OXT-101 (trade name, manufactured by Toa Gosei Co., Ltd.), and epoxy compounds such as OXT-121 (trade name, manufactured by Toa Gosei Co., Ltd.). . These may be used alone or in combination of two or more.

  In addition, the photosensitive resin composition of the present invention includes a cationic polymerization initiator, a dye such as malachite green, a photochromic agent such as tribromophenylsulfone or leucocrystal violet, a thermochromic inhibitor, p- if necessary. Plasticizers such as toluenesulfonamide, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion-imparting agents, leveling agents, peeling accelerators, antioxidants, fragrances, imaging agents, thermal crosslinking agents, etc. About 0.01 to 20 parts by weight can be added to 100 parts by weight of the total amount of component A) and component (B), respectively. These may be used alone or in combination of two or more.

  The photosensitive resin composition of the present invention is optionally mixed with a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether, or a mixture thereof. It can melt | dissolve in a solvent and can apply | coat as a solution of solid content about 30 to 60 weight%.

  The photosensitive resin composition of the present invention having the above configuration is not particularly limited, but is applied as a liquid resist on a metal surface such as copper, a copper-based alloy, iron, or an iron-based alloy, dried, and if necessary. The protective film is preferably used after being coated or in the form of a photosensitive element described later.

  Moreover, although the thickness of the photosensitive resin composition layer which consists of photosensitive resin compositions changes with uses, it is preferable that it is about 1-100 micrometers by the thickness after drying. In the case of using a liquid resist coated with a protective film, a polymer film such as polyethylene or polypropylene is used as the protective film.

  The photosensitive element of this invention is equipped with a support body and the photosensitive resin composition layer which consists of the said photosensitive resin composition of this invention formed on this support body.

  Examples of the support include polymer films such as polyethylene terephthalate, polypropylene, polyethylene, and polyester. The thickness of these polymer films is preferably 1 to 100 μm.

  The photosensitive resin composition layer can be obtained by applying the photosensitive resin composition of the present invention on a support and drying it. The application can be performed by a known method such as a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, or a bar coater. Moreover, drying can be performed at 70-150 degreeC and about 5 to 30 minutes. In addition, the amount of the remaining organic solvent in the photosensitive resin composition layer is preferably 2% by weight or less from the viewpoint of preventing diffusion of the organic solvent in the subsequent step.

  The photosensitive element of this invention may be equipped with the protective film on the surface on the opposite side to the support body of the photosensitive resin composition layer. As the protective film, the polymer film exemplified in the description of the support can be used, but the adhesive strength between the photosensitive resin composition layer and the protective film is higher than the adhesive strength between the photosensitive resin composition layer and the support. It is preferable to use one having a smaller value. Also, a low fisheye film is preferred.

  In addition to the photosensitive resin composition layer, the support and the protective film, the photosensitive element of the present invention has an intermediate layer and a protective layer such as a cushion layer, an adhesive layer, a light absorption layer, and a gas barrier layer. Also good.

  The photosensitive element of the present invention is stored, for example, as it is or by further laminating a protective film on the other surface of the photosensitive resin composition layer and winding it around a cylindrical core. In addition, it is preferable to wind up so that a support body may become the outermost part in this case. An end face separator is preferably installed on the end face of the roll-shaped photosensitive element roll from the viewpoint of end face protection, and a moisture-proof end face separator is preferably installed from the viewpoint of edge fusion resistance. Moreover, as a packing method, it is preferable to wrap and package in a black sheet with low moisture permeability. Examples of the winding core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

  Next, the case where the photosensitive element of the present invention is used as an example of the resist pattern forming method of the present invention will be described.

When forming a resist pattern using the photosensitive element of the present invention, first, when the above protective film is present on the photosensitive element, the protective film is removed. Subsequently, it arrange | positions so that the surface by the side of the photosensitive resin composition layer may face a board | substrate for circuit formation, and it crimps | bonds to the board | substrate direction, heating the photosensitive resin composition layer to about 70-130 degreeC. The pressure at this time is preferably about 0.1 to 1 MPa (about 1 to 10 kgf / cm ² ). It is also possible to perform pressure bonding under reduced pressure. Although the surface of the board | substrate with which the photosensitive resin composition layer is laminated | stacked is a metal surface normally, there is no restriction | limiting in particular.

  In this way, the photosensitive resin composition layer laminated on the substrate is irradiated with actinic rays in an image form through a negative or positive mask pattern. As the light source of the actinic light, a known light source, for example, a light source that effectively emits ultraviolet light, visible light, or the like, such as a carbon arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, or a xenon lamp is used. In addition, when the support body of a photosensitive element is transparent, irradiation of actinic light can be performed to the photosensitive resin composition layer through a support body. On the other hand, when the support is not transparent, it is necessary to peel and remove the support before irradiation with actinic rays. The same applies when the photosensitive element includes an intermediate layer (such as a cushion layer) between the support and the photosensitive resin composition layer.

  After the exposure, if a support is present on the photosensitive resin composition layer, the support is removed, and the substrate is not subjected to wet development, dry development, or the like with a developer such as an alkaline aqueous solution, an aqueous developer, or an organic solvent. The exposed portion can be removed and developed to form a resist pattern.

Examples of the alkaline aqueous solution include a dilute solution of 0.1 to 5 wt% sodium carbonate, a dilute solution of 0.1 to 5 wt% potassium carbonate, a dilute solution of 0.1 to 5 wt% sodium hydroxide, and the like. It is done. The pH of the alkaline aqueous solution is preferably in the range of 9 to 11, and the temperature is adjusted according to the developability of the photosensitive resin composition layer. Further, a surfactant, an antifoaming agent, an organic solvent, or the like may be mixed in the alkaline aqueous solution. Examples of the development method include a dip method, a spray method, brushing, and slapping. As processing after development, the resist pattern may be further cured and used by heating at about 60 to 250 ° C. or exposure at about 0.2 to 10 J / cm ² as necessary.

  When a printed wiring board is produced using the photosensitive element of the present invention, the surface of the circuit forming substrate is treated by a known method such as etching or plating using the developed resist pattern as a mask. Examples of the plating method include copper plating, solder plating, nickel plating, and gold plating. Next, the resist pattern can be peeled with a stronger alkaline aqueous solution than the alkaline aqueous solution used for development, for example. As said strong alkaline aqueous solution, 1-10 weight% sodium hydroxide aqueous solution, 1-10 weight% potassium hydroxide aqueous solution, etc. are used, for example. Examples of the peeling method include an immersion method and a spray method. Further, the printed wiring board on which the resist pattern is formed may be a multilayer printed wiring board or may have a small diameter through hole.

  Moreover, when etching a metal surface after development, for example, a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, or the like can be used.

  Moreover, as a circuit formation board | substrate used in the formation method of the resist pattern of this invention mentioned above, and the manufacturing method of the printed wiring board of this invention, the board | substrate which consists of metals, such as copper, a copper-type alloy, iron, an iron-type alloy, is mentioned. Can be mentioned. Such a circuit forming substrate preferably has a 10-point average roughness (Rz) of a surface on which a resist pattern is to be formed of 2 μm or less. As a result, fine wiring and low dielectric loss can be realized, and since the photosensitive resin composition or photosensitive element of the present invention is used, peeling during etching or plating, disconnection of wiring, and short circuit Can be sufficiently prevented.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

[Example 1]
The following materials were blended to obtain a solution.
(Binder polymer)
Binder polymer solution (solid component (weight ratio): methacrylic acid / methyl methacrylate / styrene (25/50/25), solvent (weight ratio): methyl cellosolve / toluene (3/2), polymer weight average molecular weight: 50000, Solid content acid value: 163 mg KOH / g): 113 g (solid content 52 g)
(Photopolymerizable compound)
EO-modified bisphenol A dimethacrylate (FA-321M, manufactured by Hitachi Chemical Co., Ltd.): 24 g
Bisphenoxyethanol full orange acrylate (BPEF-A, compound of general formula (I) where n = 1, manufactured by Osaka Gas Chemical Company): 24 g
(Photopolymerization initiator)
2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbisimidazole: 3.2 g
4,4′-bis (diethylamino) benzophenone: 0.1 g
(Coloring agent)
Leuco Crystal Violet: 0.3g
(Thermal polymerization inhibitor)
4-tert-butylcatechol (TBC): 0.025 g
(dye)
Malachite green: 0.05g
(solvent)
Acetone: 10g
Toluene: 4g
N, N-dimethylformamide: 3.2 g

  A photosensitive resin composition solution obtained by blending the above materials was uniformly applied onto a 16 μm thick polyethylene terephthalate film, and dried with a hot air convection dryer at 70 ° C. and 110 ° C. to obtain a photosensitive element. Obtained. At this time, the film thickness of the photosensitive resin composition layer was 20 μm.

  Next, a Mitsui Chemicals sputtered copper substrate (Etcher Flex, thickness: 0.25 μm, ten-point average roughness (Rz): 0.08 μm) was prepared. The surface of the sputtered copper substrate is acid-treated, washed with water, and then dried with an air stream. The obtained substrate is heated to 80 ° C., and the photosensitive resin composition layer of the photosensitive element is formed on the copper surface. Was laminated while heating to 110 ° C.

Next, with reference to EXM1201 exposing machine (manufactured by Oak Co.) with a high-pressure mercury lamp, 30 mJ ^/ cm ² a Stouffer 41-step tablet as a mask placed on the test ^{piece, 60mJ} / cm ^{2, 120mJ} / It was exposed in cm ^2. Thereafter, the polyethylene terephthalate film was peeled off, and a 1% by weight sodium carbonate aqueous solution was sprayed at 30 ° C. for 30 seconds to remove unexposed portions. The sensitivity of the photosensitive resin composition is evaluated by measuring the number of steps of the step tablet of the photocured film formed on the substrate, and 12 steps of the 41 step tablet (OD = 0.05) are cured. The exposure amount (mJ / cm ² ) necessary for the exposure was determined.

  Next, the photosensitive resin composition layer is exposed through a quartz hard chrome mask manufactured by Tokyo Process Co., Ltd. with an exposure amount equivalent to 12 steps of step tablet obtained by the above method, and 30 wt. Development was performed by removing the unexposed portion by spraying for 2 seconds to form a resist pattern.

  Here, the resolution and adhesion were evaluated as follows. That is, the minimum resist line formed without developing meandering or chipping after the development of the resist pattern was visually confirmed using a projector or the like. The adhesion evaluation pattern was a pattern formed continuously at an interval of 10 times the line width of the resist line, and it was confirmed that the resist line remained. The resolution evaluation pattern was a reverse pattern of the adhesion evaluation pattern, and it was confirmed that the resist lines were not filled with resist. As a result, good characteristics of 10 μm resolution and 8 μm adhesion were shown.

  Further, electrolytic copper plating (copper sulfate / sulfuric acid, 0.5 A / dm 2, 30 minutes, 15 μm thickness) was performed using this resist pattern, and then 3% caustic soda was sprayed at 50 ° C. to remove the resist. At this time, the resist showed good peeling characteristics. Subsequently, the underlying copper was etched with sulfuric acid / hydrogen peroxide solution to form a copper wiring to produce a printed wiring board. When the formed copper wiring was observed with a scanning electron microscope (SEM), there was no disconnection or short circuit.

[Comparative Example 1]
A printed wiring board was produced in the same manner as in Example 1 except that 48 g of EO-modified bisphenol A dimethacrylate (FA-321M, manufactured by Hitachi Chemical Co., Ltd.) was used alone as a photopolymerizable compound. At this time, the resist pattern had a resolution of 10 μm and an adhesiveness of 12 μm, and showed particularly poor adhesiveness compared to Example 1. Moreover, the favorable peeling characteristic was shown. In addition, due to insufficient adhesion of the resist to the formed copper wiring due to insufficient adhesion of the resist, the plating solution sunk into the bottom of the resist, resulting in frequent short errors in the obtained copper wiring.

Claims (8)

A photosensitive resin composition for forming a resist pattern, which is laminated as a photosensitive resin composition layer on a circuit forming substrate to form a resist pattern, and is peeled off from the circuit forming substrate after etching or plating. A thing,
(A) a binder polymer, a photopolymerizable compound having a fluorene skeleton in the (B) molecule, and, (C), characterized in that it contains a photopolymerization initiator sensitive photosensitive resin composition. The photosensitive resin composition according to claim 1, wherein the circuit forming substrate has a metal surface. The photosensitive resin composition according to claim 1, wherein the photopolymerizable compound has a structure represented by the following general formula (I).

[Wherein, R ¹ represents a hydrogen atom or a methyl group, and n represents an integer of 1 to 10. ]   A photosensitive material comprising: a support; and a photosensitive resin composition layer comprising the photosensitive resin composition according to any one of claims 1 to 3 formed on the support. Sex element.   A photosensitive resin composition layer comprising the photosensitive resin composition according to any one of claims 1 to 3 is laminated on a circuit-forming substrate, and a predetermined portion of the photosensitive resin composition layer is laminated. A method for forming a resist pattern, comprising irradiating actinic rays to photocure an exposed portion and then removing portions other than the exposed portion.   The photosensitive resin composition layer in the photosensitive element according to claim 4 is laminated on a circuit forming substrate, and a predetermined portion of the photosensitive resin composition layer is irradiated with actinic rays to photocure the exposed portion. Then, a method for forming a resist pattern, wherein a portion other than the exposed portion is removed.   The method for forming a resist pattern according to claim 5 or 6, wherein the ten-point average roughness (Rz) of the circuit forming substrate surface is 2 µm or less.   A method for manufacturing a printed wiring board, comprising etching or plating a circuit forming substrate on which a resist pattern is formed by the method for forming a resist pattern according to claim 5.