JP6022749B2 - Photosensitive resin composition, photosensitive element, method for producing resist pattern, method for producing lead frame, and method for producing printed wiring board - Google Patents

Description

The present invention relates to a photosensitive resin composition, a photosensitive element, a resist pattern manufacturing method of the concerns in the manufacture how the manufacturing method and printed wiring board of the lead frame.

  Conventionally, in the field of manufacturing printed wiring boards, a photosensitive resin composition as a resist material used for etching and plating, and a layer containing the photosensitive resin composition (hereinafter referred to as “photosensitive resin layer”). A photosensitive element (laminate) having a structure in which is formed on a support film and a protective film is disposed on a photosensitive resin layer is widely used.

  Conventionally, a printed wiring board is manufactured by the following procedure, for example, using the photosensitive element. That is, first, the photosensitive resin layer of the photosensitive element is laminated on a circuit forming substrate such as a copper-clad laminate. At this time, the surface (hereinafter referred to as the “upper surface” of the photosensitive resin layer) opposite to the surface in contact with the support film of the photosensitive resin layer (hereinafter referred to as the “lower surface” of the photosensitive resin layer) The circuit forming substrate is brought into close contact with the surface on which the circuit is formed. Therefore, when the protective film is arrange | positioned on the upper surface of the photosensitive resin layer, the operation | work of this lamination is performed, peeling off a protective film. Lamination is performed by thermocompression bonding the photosensitive resin layer to an underlying circuit forming substrate (normal pressure laminating method).

  Next, the photosensitive resin layer is subjected to pattern exposure through a mask film or the like. At this time, the support film is peeled off at any timing before or after exposure. Thereafter, the unexposed portion of the photosensitive resin layer is dissolved or dispersed and removed with a developer. Next, an etching process or a plating process is performed to form a pattern, and finally the cured portion is peeled and removed.

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

  Further, in recent years, along with higher definition and higher density in printed wiring boards, a direct drawing method called a DLP (Digital Light Processing) exposure method capable of forming a fine pattern has been introduced. In general, in the DLP exposure method, active light having a wavelength of 390 to 430 nm using a blue-violet semiconductor laser as a light source is used.

  In addition, an exposure method using a polygon multi-beam having a wavelength of 355 nm using a YAG laser as a light source, which can deal with a small variety of products in general-purpose printed wiring boards, is also used.

  With the development of such various pattern exposure methods, application of various sensitizers to the photosensitive resin composition has been studied in order to cope with each exposure wavelength (see, for example, Patent Documents 1 to 5). ).

JP 2004-301996 A JP-A-2005-107191 JP-A-2005-215142 JP 2007-101941 A JP 2007-101940 A

As the resist pattern is increasingly miniaturized in recent years, it has a sufficient tent reliability particularly in an etching process and is a pattern formation with L / S (line width / space width) = 20/20 (unit: μm) or less. It is required to satisfy high resolution at the same time.
Here, tent reliability refers to the performance of resist films that are difficult to break when a through hole is covered with a resist film and before a resist stripping process such as development processing.

  Moreover, the adhesiveness is also requested | required about the photosensitive resin layer for forming a resist pattern. In order to improve the adhesion, it is effective to soften the photosensitive resin layer, whereby the followability to the unevenness of the substrate is improved. However, as a result, it takes a long time to remove the resist in the peeling step, which may reduce the production efficiency. In addition, the softening of the photosensitive resin layer may cause a phenomenon (edge fusion) that the photosensitive resin layer oozes out from the end of the product roll around which the photosensitive element is wound, and there is a concern about contamination of the laminate roll. Is done.

  In order to improve the resolution of the photosensitive resin layer, it is effective to reduce the thickness of the photosensitive resin layer. However, if a certain amount of circuit thickness (copper thickness, etc.) is required when forming a printed wiring board, the etching method tends to be insufficient in tent reliability at the time of etching. Is likely to be missing. Therefore, there is a limit to the method of increasing the resolution by narrowing the width of the resist pattern by thinning the photosensitive resin layer.

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

  Therefore, in order to improve the photosensitivity, when the amount of the photoinitiator or sensitizer contained in the photosensitive resin composition is increased, the photoreaction proceeds locally in the surface layer portion of the photosensitive resin layer, and the layer bottom portion is increased. Since curability decreases, the resolution and resist shape obtained after photocuring tend to deteriorate.

  The present invention has been made in view of the above problems, and is a photosensitive resin composition that has excellent photosensitivity and can improve the tent reliability and adhesion of the formed resist film and the resolution of the formed resist pattern. It is an object of the present invention to provide a photosensitive element, a resist pattern manufacturing method, a lead frame manufacturing method, and a printed wiring board manufacturing method using the same.

  The present inventors include a binder polymer as the component (A), a photopolymerizable compound having at least one ethylenically unsaturated bond as the component (B), a photopolymerization initiator as the component (C), and an increase as the component (D). By using a photosensitive resin composition that contains a dye, the component (B) includes a (meth) acrylate compound having a skeleton derived from dipentaerythritol, and the component (D) includes a pyrazoline compound, the photosensitivity is improved. The present inventors have found that it is possible to improve the tent reliability and adhesion of the formed resist film and the resolution of the formed resist pattern, and have reached the present invention.

  Moreover, this invention relates to the photosensitive element which has a support body and the photosensitive resin layer originating in the said photosensitive resin composition formed on the said support body. Thereby, the photosensitive element excellent in the said characteristic can be provided.

  Furthermore, the present invention is a photosensitive resin layer forming step of forming a photosensitive resin layer derived from the photosensitive resin composition on a substrate, and irradiating at least a part of the photosensitive resin layer with actinic rays, The present invention relates to a method for producing a resist pattern having an exposure step of photocuring an exposed portion and a development step of removing an uncured portion of the photosensitive resin layer from a substrate by development. Thereby, the resist pattern excellent in the said characteristic can be formed.

  Further, the present invention provides a method for manufacturing a printed wiring board including a step of forming a conductor pattern by etching or plating a substrate on which a resist pattern is formed by the method for manufacturing a resist pattern, and a printed wiring board obtained thereby About. Since the photosensitive resin composition to be used is excellent in the above characteristics, a production method suitable for increasing the density of the printed wiring board can be provided.

  Furthermore, this invention relates to the manufacturing method of a lead frame including the process of plating the board | substrate with which the resist pattern was formed by the said resist pattern formation method, and forming a conductor pattern. Since the photosensitive resin composition to be used is excellent in the above characteristics, a production method suitable for increasing the density of the lead frame can be provided.

According to the present invention, a photosensitive resin composition having excellent photosensitivity, excellent tent reliability and adhesion of the formed resist film and excellent resolution of the formed resist pattern, a photosensitive element using the same, and a resist pattern forming method, it is possible to provide a manufacturing how the manufacturing method and printed wiring board of the lead frame.

It is a schematic cross section which shows one Embodiment of the photosensitive element of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail. In the present invention, (meth) acrylic acid means acrylic acid and methacrylic acid corresponding thereto, (meth) acrylate means acrylate and corresponding methacrylate, (meth) acryloyl group means acryloyl group and The corresponding methacryloyl group is meant.

Further, in the present invention, the term “process” is not limited to an independent process, and is included in this term if the intended action of the process is achieved even when it cannot be clearly distinguished from other processes. .
Furthermore, the numerical range indicated using “to” in this specification indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.

<Photosensitive resin composition>
The photosensitive resin composition of the present invention contains (A) a binder polymer, (B) a photopolymerizable compound having at least one ethylenically unsaturated bond, (C) a photopolymerization initiator, and (D) a sensitizing dye. Do it.
Hereinafter, each component used by the photosensitive resin composition of this invention is demonstrated in detail.

[(A) component: binder polymer]
Component (A) that can be used in the present invention: Examples of the binder polymer include acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, and phenol resins. It is done. From the viewpoint of alkali developability, an acrylic resin is preferable. These can be 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 polymerizable styrene derivatives substituted at the α-position or aromatic ring such as styrene, vinyltoluene, and α-methylstyrene, acrylamide such as diacetone acrylamide, acrylonitrile, and the like. Esters of vinyl alcohol such as vinyl-n-butyl ether, (meth) acrylic acid alkyl ester, (meth) acrylic acid benzyl 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-bromoacrylic acid, α-chloroacrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic acid, maleic acid, maleic anhydride, monomethyl maleate, monoethyl maleate, monoisopropyl maleate maleic acid monoester and the like, full circle acid, cinnamic acid, alpha-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid. These can be used alone or in combination of two or more.
Examples of the (meth) acrylic acid alkyl ester include, for example, the following general formula (IV):

^{_{H 2 C = C (R 6}} ) -COOR 7 (IV)

[In the formula (IV), R ⁶ represents a hydrogen atom or a methyl group, R ⁷ represents an alkyl group having 1 to 12 carbon atoms], and the alkyl group of these compounds is a hydroxyl group or an epoxy group And a compound substituted with a halogen group or the like.
Examples of the alkyl group having 1 to 12 carbon atoms represented by R ⁷ in the general formula (IV) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, Nonyl group, decyl group, undecyl group, dodecyl group, benzyl group and structural isomers thereof can be mentioned.

  Examples of the monomer represented by the general formula (IV) 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, Examples include (meth) acrylic acid decyl ester, (meth) acrylic acid undecyl ester, (meth) acrylic acid dodecyl ester, and (meth) acrylic acid benzyl ester. These can be used alone or in combination of two or more.

  In addition, the binder polymer as 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. As the polymerizable monomer having a carboxyl group, (meth) acrylic acid is preferable, and methacrylic acid is more preferable.

  The carboxyl group content of the (A) binder polymer (the blending ratio of the polymerizable monomer having a carboxyl group with respect to the total polymerizable monomer used) is 12 to 12 in terms of the balance between alkali developability and alkali resistance. It is preferably 50% by mass, more preferably 12 to 40% by mass, still more preferably 15 to 35% by mass, and particularly preferably 15 to 30% by mass. When the carboxyl group content is 12% by mass or more, alkali developability is improved, and when it is 50% by mass or less, alkali resistance tends to be excellent.

  In addition, the content rate of the structural unit derived from the polymerizable monomer which has a carboxyl group in the said (A) binder polymer correlates with the compounding rate of the said monomer containing a carboxyl group, Therefore 12-50 mass% It is preferable that it is 12-40 mass%, It is more preferable that it is 15-35 mass%, It is especially preferable that it is 15-30 mass%.

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 the viewpoint of adhesiveness and chemical resistance.
The content when the above styrene or styrene derivative is used as a copolymerization component (the blending ratio of styrene or styrene derivative with respect to the total polymerizable monomer used) is from the viewpoint of improving adhesion and chemical resistance. A) It is preferable to contain 10 mass%-60 mass% with respect to solid content of the whole component, and it is more preferable to contain 15 mass%-50 mass%. When the content is 10% by mass or more, the adhesion tends to be improved, and when the content is 50% by mass or less, a long time required for peeling due to an increase in the peeling piece is suppressed.

  In addition, it is preferable that the content rate of the structural unit derived from styrene or a styrene derivative in said (A) binder polymer correlates with the said mixture ratio of styrene or a styrene derivative, and is 10 mass%-60 mass%, 15 It is more preferable that it is 50 mass%-50 mass%.

  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 composed of different copolymerization components, two or more types of binder polymers having different weight average molecular weights, and two or more types of different dispersities The binder polymer is mentioned.

  Said (A) binder polymer can be manufactured by a normal method. Specifically, for example, it can be produced by radical polymerization of (meth) acrylic acid alkyl ester, (meth) acrylic acid, styrene and the like.

  The weight average molecular weight of the (A) binder polymer is preferably 20,000 to 300,000, more preferably 40,000 to 150,000, from the viewpoint of the balance between mechanical strength and alkali developability. 40,000 to 120,000 is more preferable, and 50,000 to 80,000 is particularly preferable. When the weight average molecular weight is 20,000 or more, the developer resistance tends to be excellent, and when it is 300,000 or less, the development time tends to be suppressed. In addition, the weight average molecular weight in this invention is the value measured by the gel permeation chromatography method, and converted with the analytical curve created using standard polystyrene.

  The content of the (A) binder polymer is preferably 30 parts by mass to 80 parts by mass, and 40 parts by mass to 75 parts by mass with respect to 100 parts by mass of the total amount of the component (A) and the component (B) described later. More preferably, it is more preferably 50 parts by mass to 70 parts by mass. When the content of the component (A) is within this range, the coating property of the photosensitive resin composition and the strength of the photocured product become better.

[Component (B): Photopolymerizable compound having at least one ethylenically unsaturated bond]
The photopolymerizable compound having at least one ethylenically unsaturated bond as the component (B) used in the present invention has at least a skeleton derived from dipentaerythritol from the viewpoint of improving the resolution and tent reliability in a balanced manner ( Contains a meth) acrylate compound. Here, the (meth) acrylate having a skeleton derived from dipentaerythritol means an esterified product of dipentaerythritol and (meth) acrylic acid, and the esterified product is modified with an alkyleneoxy group. It is defined as containing the compound. Further, the number of ester bonds in one molecule is preferably 6, but a compound having 1 to 5 ester bonds may be mixed.

More specifically, examples of the (meth) acrylate having a skeleton derived from dipentaerythritol include compounds represented by the following general formula (I).

In general formula (I), each R ⁴ independently represents a hydrogen atom or a methyl group, A represents an alkylene group having 2 to 6 carbon atoms, and a plurality of A's may be the same or different from each other. May be. n is an integer of 0-20.

In general formula (I), each R ⁴ independently represents a hydrogen atom or a methyl group, and is preferably a methyl group from the viewpoint of further improving sensitivity, adhesion, and resolution.

  In the general formula (I), A represents an alkylene group having 2 to 6 carbon atoms, preferably an alkylene group having 2 to 5 carbon atoms, and more preferably an alkylene group having 2 to 4 carbon atoms.

  In general formula (I), n is an integer of 0-20, it is preferable that it is 0-15, it is more preferable that it is 0-10, and it is more preferable that it is 0-5.

  In addition, the content of the (meth) acrylate compound having a skeleton derived from dipentaerythritol is based on a balance of tent reliability and resolution, with respect to 100 parts by mass of the total amount of the component (A) and the component (B). It is preferably 3 to 25 parts by mass, and more preferably 5 to 20 parts by mass.

As the component (B), in addition to the (meth) acrylate compound having a skeleton derived from dipentaerythritol, other photopolymerizable compounds can be used.
Other photopolymerizable compounds include, for example, compounds obtained by reacting polyhydric alcohols with α, β-unsaturated carboxylic acids, bisphenol A (meth) acrylate compounds, (meth) acrylate compounds having a urethane bond, etc. Urethane monomer, nonylphenoxybutaethyleneoxy (meth) acrylate, nonylphenoxyoctaethyleneoxy (meth) acrylate, γ-chloro-β-hydroxypropyl-β '-(meth) acryloyloxyethyl-o-phthalate, β-hydroxy Examples include ethyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, and (meth) acrylic acid alkyl esters. These may be used alone or in combination of two or more.

  Among the above, it is preferable to contain a bisphenol A (meth) acrylate compound in terms of improving the tent reliability and resolution in a balanced manner. Examples of the bisphenol A-based (meth) acrylate compound 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 It is done. These may be used alone or in combination of two or more.

  As the bisphenol A-based (meth) acrylate compound, for example, 2,2-bis (4-((meth) acryloxydipropoxy) phenyl) propane is BPE-200 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name). ) Is commercially available, and 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name) or FA-321M It is commercially available as a product name (manufactured by Hitachi Chemical Co., Ltd.). Furthermore, 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name).

  The content of the bisphenol A-based (meth) acrylate compound is preferably 5% by mass to 25% by mass, and preferably 7% by mass to 15% by mass with respect to the total amount of the component (A) and the component (B). Is more preferable.

  Examples of the compound obtained by reacting the 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 2 propylene groups. Polypropylene glycol di (meth) acrylate which is 14, the number of ethylene groups is 2 to 14, the number of propylene groups is 2 to 14, and the number of ethylene groups is 1 to 21 Certain trimethylolpropane polyethylene tri (meth) acrylates, tetramethylol methane polyethylene tri (meth) acrylates having 1 to 21 ethylene groups, and tetramethylol methane polyethylene tetra (meth) having 1 to 30 ethylene groups An acrylate is mentioned. These may be used alone or in combination of two or more.

  Among the above, it is preferable to include trimethylolpropane polyethylene tri (meth) acrylate having 1 to 21 ethylene groups in terms of excellent tent reliability and resolution.

  The content of the compound obtained by reacting the polyhydric alcohol with the α, β-unsaturated carboxylic acid is preferably 5% by mass to 25% by mass with respect to the total amount of the component (A) and the component (B). 7 mass% to 15 mass% is more preferable.

Examples of the urethane monomer include a (meth) acrylic monomer having a hydroxyl group at the β-position and a diisocyanate compound such as isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate. Addition reaction product, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, and EO, PO-modified urethane di (meth) acrylate.
Note that EO represents ethylene oxide, and the EO-modified compound has a block structure of an ethylene oxide group. PO represents propylene oxide, and the PO-modified compound has a block structure of propylene oxide groups.

  Examples of the EO-modified urethane di (meth) acrylate include product name UA-11 manufactured by Shin-Nakamura Chemical Co., Ltd. Examples of EO and PO-modified urethane di (meth) acrylate include product name UA-13 manufactured by Shin-Nakamura Chemical Co., Ltd. In addition, examples of tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate include a product name UA-21 manufactured by Shin-Nakamura Chemical Co., Ltd. Among them, from the viewpoint of further improving the tent reliability, a urethane monomer having an isocyanuric ring skeleton is preferable, and UA-21 (made by Shin-Nakamura Chemical Co., Ltd.), which is tris (methacryloyloxytetraethylene glycol isocyanate hexamethylene) isocyanurate, Product name) is more preferred.

  Although the content rate of the urethane monomer which has an isocyanuric ring skeleton is 5 mass%-25 mass% with respect to the total amount of (A) component and (B) component, it is preferable that it is 7 mass%-15 mass%. More preferred.

  The said other photopolymerizable compound is used individually or in combination of 2 or more types.

  The content of the component (B) is preferably 20 parts by mass to 60 parts by mass, and preferably 30 parts by mass to 55 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). It is more preferable, and it is especially preferable to set it as 35 mass parts-50 mass parts. When the content of the component (B) is within this range, the photosensitivity and coating properties of the photosensitive resin composition become better.

[(C) component: photopolymerization initiator]
Examples of the photopolymerization initiator (C) include benzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 , 2-methyl-1- [4- (methylthio) phenyl ] Aromatic ketones such as 2-morpholino-propanone-1, quinones such as alkylanthraquinones, benzoin ether compounds such as benzoin alkyl ether, benzoin compounds such as benzoin and alkylbenzoin, benzyl derivatives such as benzyldimethyl ketal, 2- 2,4,5-triarylimidazole dimers such as (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 9 -Phenylacridine, 1,7- (9,9'-acridinyl Including acridine derivatives heptane, and the like. These can be used alone or in combination of two or more.

Among these, it is preferable to contain a 2,4,5-triarylimidazole dimer. Examples of the 2,4,5-triarylimidazole dimer include 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-bis- Examples include (m-methoxyphenyl) imidazole dimer and 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer. Among these, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer is preferable.
Examples of the 2,4,5-triarylimidazole dimer include 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbisimidazole and B-CIM (Hodogaya). It is commercially available as a chemical product and product name).

  The content of component (C) is preferably 0.01 to 30 parts by mass, and 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of components (A) and (B). It is preferable that it is 1 mass part-7 mass parts, It is more preferable that it is 0.1 mass part-20 mass parts, It is more preferable that it is 2 mass parts-6 mass parts, It is particularly preferably 3 to 5 parts by mass. If the blending amount is 0.1 parts by mass or more, the photosensitivity, resolution, or adhesion tends to be improved, and if it is 10 parts by mass or less, the resist shape tends to be excellent.

[(D) component: sensitizing dye]
The sensitizing dye as component (D) contains a pyrazoline compound. Used in combination with a (meth) acrylate compound having a skeleton derived from dipentaerythritol as a photopolymerizable compound, it has excellent photosensitivity, tent reliability and adhesion of the formed resist film, and resolution of the formed resist pattern A photosensitive resin composition having excellent resistance is obtained.

As the pyrazoline compound, those used as sensitizing dyes can be applied. Examples thereof include compounds having a group containing a styryl group, thienyl group, furyl group, biphenyl group, or naphthyl group in the pyrazoline ring, and a group containing at least one selected from a styryl group, a thienyl group, and a furyl group It is preferable to have.
The position to which the styryl group, thienyl group or furyl group-containing group on the pyrazoline ring is bonded may be any of 1-position to 5-position, and it is more preferable that the position is bonded to at least one of 3-position and 5-position. .

  The pyrazoline compound preferably further has a phenyl group. The substitution position of the phenyl group on the pyrazoline ring may be any of the 1st to 5th positions, and is more preferably the 1st position.

  The pyrazoline compound preferably includes a compound represented by the following general formula (II).

In the general formula (II), R ¹ and R ² each independently represent a substituted or unsubstituted phenyl group, a thienyl group, or a furyl group, and are substituted or unsubstituted phenyl groups from the viewpoint of further improving resolution. It is preferable.

Examples of the substituent of the phenyl group, thienyl group or furyl group represented by R ¹ and R ² include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an ester group having 1 to 10 carbon atoms. It is preferable that it is a C1-C10 alkyl group or a C1-C10 alkoxy group, and it is more preferable that they are a C3-C8 alkyl group or a C1-C5 alkoxy group.

When the phenyl group, thienyl group or furyl group represented by R ¹ and R ² is an alkyl group, the alkyl group may be linear, branched or cyclic, and It is preferably a chain or branched chain, and more preferably a branched alkyl group.
When the phenyl group, thienyl group or furyl group represented by R ¹ and R ² is an alkoxy group, the alkoxy group may be linear, branched, or cyclic. It is preferably a chain or branched.

When R ¹ or R ² is a substituted phenyl group, the bonding position of the substituent in the phenyl group is preferably the para position (4 position).

R ³ in the general formula (II) represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or an ester group having 1 to 10 carbon atoms, and an alkyl group having 1 to 10 carbon atoms or 1 carbon atom. It is preferable that it is a C-10 alkoxy group, and it is more preferable that it is a C3-C8 alkyl group or a C1-C5 alkoxy group.

The alkyl group having 1 to 10 carbon atoms or the alkoxy group having 1 to 10 carbon atoms represented by R ³ may be linear or branched. Examples of the alkyl group having 1 to 10 carbon atoms include, but are not limited to, a methyl group, an ethyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an isopentyl group, and a tert-octyl group.

M in the general formula (II) represents an integer of 0 to 5, preferably 0 to 4, more preferably 0 to 3, and still more preferably 0.
Incidentally, when m is 2 to 5, a plurality of R ³ may be the same or different from each other.

A in general formula (II) represents the integer of 0-2, and it is more preferable that it is 1.
B in the general formula (II) represents an integer of 0 to 2, is preferably 0 or 1, and more preferably 0.

  Moreover, the sum of a and b in the general formula (II) is 1 to 4, preferably 1 to 3, more preferably 1 or 2, and still more preferably 1.

  Examples of the compound represented by the general formula (II) include 1-phenyl-3- (4-methoxystyryl) -5- (4-methoxyphenyl) -pyrazoline, 1-phenyl-3- (4-isopropyl). Styryl) -5- (4-isopropylphenyl) -pyrazoline, 1-phenyl-3- (3,5-dimethoxystyryl) -5- (3,5-dimethoxyphenyl) -pyrazoline, 1-phenyl-3- (3 , 4-Dimethoxystyryl) -5- (3,4-dimethoxyphenyl) -pyrazoline, 1-phenyl-3- (2,6-dimethoxystyryl) -5- (2,6-dimethoxyphenyl) -pyrazoline, 1- Phenyl-3- (2,5-dimethoxystyryl) -5- (2,5-dimethoxyphenyl) -pyrazoline, 1-phenyl-3- (2,3-dimethoxystyri) L) -5- (2,3-dimethoxyphenyl) -pyrazoline, 1-phenyl-3- (2,4-dimethoxystyryl) -5- (2,4-dimethoxyphenyl) -pyrazoline, 1- (4-tert -Butyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1-phenyl-3- (4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline, 1,5- Bis- (4-tert-butyl-phenyl) -3- (4-tert-butyl-styryl) -pyrazoline, 1- (4-tert-octyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1- Phenyl-3- (4-tert-octyl-styryl) -5- (4-tert-octyl-phenyl) -pyrazoline, 1,5-bis- (4-tert-o Til-phenyl) -3- (4-tert-octyl-styryl) -pyrazoline, 1- (4-dodecyl-phenyl) -3-styryl-5-phenyl-pyrazoline, 1-phenyl-3- (4-dodecyl- Styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1- (4-dodecyl-phenyl) -3- (4-dodecyl-stynyl) -5- (4-dodecyl-phenyl) -pyrazoline, 1- ( 4-tert-octyl-phenyl) -3- (4-tert-butyl-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline, 1- (4-tert-butyl-phenyl) -3- ( 4-tert-octyl-styryl) -5- (4-tert-octyl-phenyl) -pyrazoline, 1- (4-dodecyl-phenyl) -3- (4-tert-butyl) Til-styryl) -5- (4-tert-butyl-phenyl) -pyrazoline, 1- (4-tert-butyl-phenyl) -3- (4-dodecyl-styryl) -5- (4-dodecyl-phenyl) -Pyrazolin, 1- (4-dodecyl-phenyl) -3- (4-tert-octyl-styryl) -5- (4-tert-octyl-phenyl) -pyrazoline, 1- (4-tert-octyl-phenyl) -3- (4-dodecyl-styryl) -5- (4-dodecyl-phenyl) -pyrazoline, 1-phenyl-3- (4-methoxyphenyl) -5- (4-tert-butylphenyl) pyrazoline, 1- Phenyl-3- (2-thienyl) -5- (4-tert-butylphenyl) -pyrazoline, 1-phenyl-3- (2-thienyl) ethenyl-5- (2-thi Nyl) -pyrazoline, 1-phenyl-3- (2-thienyl) -5- (2-thienyl) -pyrazoline, 1-phenyl-3- (2-thienyl) -5-styrylpyrazoline, 1-phenyl-3 -(4-biphenyl) -5- (4-tert-butyl-phenyl) -pyrazoline and 1-phenyl-3- (4-biphenyl) -5- (4-tert-octyl-phenyl) -pyrazoline. . These are used alone or in combination of two or more.

  Among the compounds represented by the general formula (II), 1-phenyl-3- (4-methoxystyryl) -5- (4-methoxyphenyl) is preferable from the viewpoint of improving the ease of synthesis and photosensitivity. -Pyrazoline is particularly preferred, and 1-phenyl-3- (4-isopropylstyryl) -5- (4-isopropylphenyl) pyrazoline is particularly preferred from the viewpoint of improving ease of synthesis and solubility in a solvent.

  In addition, the photosensitive resin composition of the present invention can be mixed with a sensitizing dye other than the compound represented by the general formula (II) to the extent that the effects of the present invention are not impaired.

  Examples of the sensitizing dye other than the compound represented by the general formula (IV) include dialkylaminobenzophenones, anthracenes, coumarins, xanthones, oxazoles, benzoxazoles, thiazoles, benzothiazoles, and triazoles. , Stilbenes, triazines, thiophenes, naphthalimides, and triarylamines. These are used alone or in combination of two or more.

  The content ratio of the compound represented by the general formula (II) in the sensitizing dye as the component (D) is preferably 10% by mass to 100% by mass in the total amount of the component (D). It is more preferable that it is mass%-100 mass%, and it is especially preferable that it is 50-100 mass%. When the blending amount is 10% by mass or more, high sensitivity and high resolution tend to be obtained.

  The content of the component (D) is preferably 0.01% by mass to 10% by mass, and 0.05% by mass to 5% by mass with respect to 100 parts by mass of the total amount of the components (A) and (B) It is more preferable to set it as 0.1 mass%-3 mass parts. When the content is 0.01 parts by mass or more, photosensitivity and resolution tend to be easily obtained. When the content is 10 parts by mass or less, a sufficiently good resist shape tends to be easily obtained.

[Other ingredients]
In addition, the photosensitive resin composition of the present invention includes, if necessary, dyes such as malachite green, Victoria pure blue, brilliant green, and methyl violet, tribromophenyl sulfone, leuco crystal violet, diphenylamine, benzylamine, Photochromic agents such as phenylamine, diethylaniline, o-chloroaniline and tertiary butylcatechol, plasticizers such as thermochromic inhibitor, p-toluenesulfonamide, pigments, fillers, antifoaming agents, flame retardants, adhesion An imparting agent, a leveling agent, a peeling accelerator, an antioxidant, a fragrance, an imaging agent, a thermal crosslinking agent, a polymerization inhibitor and the like are each 0.01 mass with respect to 100 mass parts of the total amount of the component (A) and the component (B). About 20 parts by mass can be contained. These are used alone or in combination of two or more.

The photosensitive resin composition of this invention can contain at least 1 sort (s) of the organic solvent as needed. As the organic solvent, a commonly used organic solvent is not particularly limited and can be used. Specifically, solvents 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 can be used.
For example, the (A) binder polymer, (B) polymerizable compound, (C) photopolymerization initiator, and (D) sensitizing dye are dissolved in the organic solvent to obtain a solid content of 30% by mass to 60% by mass. % Solution (hereinafter referred to as “coating solution”).
In addition, solid content means the remaining component remove | excluding the volatile component from the said solution (photosensitive resin composition).

The said coating liquid can be used for formation of the photosensitive resin layer as follows, for example. A photosensitive resin layer derived from the photosensitive resin composition can be formed on the support by applying the coating solution on the surface of a support such as a support film or a metal plate described later and drying the support. .
Examples of the metal plate include iron alloys such as copper, copper alloys, nickel, chromium, iron, and stainless steel, preferably copper, copper alloys, and iron alloys.

  Although the thickness of the photosensitive resin layer to be formed varies depending on the application, the thickness after drying is preferably about 1 μm to 100 μm. You may coat | cover the surface (surface) on the opposite side to the surface which opposes the support body of the photosensitive resin layer with a protective film. Examples of the protective film include polymer films such as polyethylene and polypropylene.

<Photosensitive element>
The photosensitive element 10 of the present invention has a support 2 and a photosensitive resin layer 4 derived from the photosensitive resin composition formed on the support, as shown in FIG. And includes other layers such as a protective film 6 provided as necessary.

[Support]
As said support body, the polymer film which has heat resistance and solvent resistance, such as a polyethylene terephthalate, a polypropylene, polyethylene, and polyester, can be used, for example.
The thickness of the support (hereinafter sometimes referred to as “support film”) is preferably 1 μm to 100 μm, more preferably 1 μm to 50 μm, and still more preferably 1 μm to 30 μm. When the thickness of the support is 1 μm or more, the support film can be prevented from being broken when the support film is peeled off. Moreover, the fall of the resolution is suppressed because it is 100 micrometers or less.

[Protective film]
The photosensitive element 10 may further include a protective film 6 that covers the surface (surface) opposite to the surface facing the support 2 of the photosensitive resin layer 4 as necessary.

The protective film preferably has a lower adhesive force to the photosensitive resin layer than that of the support film to the photosensitive resin layer, and is preferably a low fisheye film.
Here, “fish eye” means that a material constituting a protective film is melted by heat, kneaded, extruded, biaxially stretched, a film is produced by a casting method, etc., and foreign materials, undissolved materials, oxidative deterioration of the material. This means that an object or the like is taken into the film. That is, “low fish eye” means that the above-mentioned foreign matter or the like in the film is small.

  Specifically, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used as the protective film. Examples of commercially available products include polypropylene films such as Alphan MA-410 and E-200C manufactured by Oji Paper Co., Ltd., Shin-Etsu Film Co., Ltd., and polyethylene terephthalate films such as PS series such as PS-25 manufactured by Teijin Limited. The protective film may be the same as the above support.

  The thickness of the protective film is preferably 1 μm to 100 μm, more preferably 5 μm to 50 μm, still more preferably 5 μm to 30 μm, and particularly preferably 15 μm to 30 μm. When the thickness of the protective film is 1 μm or more, the protective film can be prevented from being broken when the photosensitive resin layer and the support film are laminated on the substrate while peeling off the protective film. Moreover, productivity improves by being 100 micrometers or less.

[Production method]
The photosensitive element of this invention can be manufactured as follows, for example. A step of preparing a coating solution in which (A) a binder polymer, (B) a polymerizable compound, (C) a photopolymerization initiator, and (D) a sensitizing dye are dissolved in the organic solvent; It can be manufactured by a manufacturing method including a step of coating on a support to form a coating layer and a step of drying the coating layer to form a photosensitive resin layer.

  Application of the coating solution onto the support can be performed by a known method such as a roll coater, comma coater, gravure coater, air knife coater, die coater, bar coater, spray coater or the like.

  The drying of the coating layer is not particularly limited as long as at least a part of the organic solvent can be removed from the coating layer. For example, it can be performed at 70 ° C. to 150 ° C. for about 5 minutes to 30 minutes. After drying, the amount of the remaining organic solvent in the photosensitive resin layer is preferably 2% by mass or less from the viewpoint of preventing the organic solvent from diffusing in the subsequent step.

  The thickness of the photosensitive resin layer in the photosensitive element can be appropriately selected depending on the use, but it is preferably 1 μm to 200 μm, more preferably 5 μm to 100 μm, and more preferably 10 μm to 50 μm after drying. It is particularly preferred. When this thickness is 1 μm or more, industrial coating becomes easy and productivity is improved. In the case of 200 μm or less, the effects of the present invention are sufficiently obtained, the photosensitivity is high, and the photocurability at the bottom of the resist tends to be excellent.

  The photosensitive element of the present invention may further have an intermediate layer such as a cushion layer, an adhesive layer, a light absorption layer, or a gas barrier layer, if necessary.

The form of the photosensitive element of the present invention is not particularly limited. For example, it may be in the form of a sheet, or may be in the form of a roll wound around a core.
When it winds up in roll shape, it is preferable to wind up so that a support film may become an outer side.
Examples of the winding core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, or ABS (acrylonitrile-butadiene-styrene copolymer).

  From the viewpoint of end face protection, it is preferable to install an end face separator on the end face of the roll-shaped photosensitive element roll thus obtained, and it is preferable to install a moisture-proof end face separator from the standpoint of edge fusion resistance. Moreover, as a packaging method, it is preferable to wrap and package in a black sheet with low moisture permeability.

  The photosensitive element of this invention can be used suitably for the manufacturing method of the resist pattern mentioned later, for example.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises: (i) a photosensitive resin layer forming step for forming a photosensitive resin layer derived from the photosensitive resin composition on a substrate; and (ii) at least one of the photosensitive resin layers. An exposure step of irradiating a part with actinic rays and photocuring the exposed portion; and (iii) a development step of removing the uncured portion of the photosensitive resin layer from the substrate by development. Other steps may be included accordingly.

(I) Photosensitive resin layer formation process In the photosensitive resin layer formation process, the photosensitive resin layer originating in the said photosensitive resin composition is formed on a board | substrate. Although it does not restrict | limit especially as said board | substrate, Usually, die pads (base material for lead frames), such as a circuit formation board | substrate provided with the insulating layer and the conductor layer formed on the insulating layer, or an alloy base material are used.

  As a method for forming the photosensitive resin layer on the substrate, for example, when the photosensitive element has a protective film, the protective film is removed and then the photosensitive resin layer of the photosensitive element is heated. However, it can be performed by pressure bonding to the circuit forming substrate. Thereby, the laminated body provided with the board | substrate for circuit formation, the photosensitive resin layer, and a support body in this order is obtained.

This photosensitive resin layer forming step is preferably performed under reduced pressure from the viewpoint of adhesion and followability. Heating at the time of pressure bonding is preferably performed at a temperature of 70 ° C to 130 ° C. The pressure bonding is preferably performed at a pressure of about 0.1 MPa to 1.0 MPa (about 1 to 10 kgf / cm ² ), but these conditions are appropriately selected as necessary. In addition, if the photosensitive resin layer is heated to 70 ° C. to 130 ° C., it is not necessary to pre-heat the circuit forming substrate in advance, but in order to further improve the adhesion and followability, Pre-heat treatment can also be performed.

(Ii) Exposure process In the exposure process, at least a part of the photosensitive resin layer formed on the substrate is irradiated with actinic rays, so that the exposed portion irradiated with the actinic rays is photocured and a latent image is formed. It is formed.
At this time, when the support (support film) present on the photosensitive resin layer is transparent to actinic rays, it can be irradiated with actinic rays through the support film, but the support film is light-shielding. In some cases, the photosensitive resin layer is irradiated with actinic rays after removing the support film.

  Examples of the exposure method include a method of irradiating an actinic ray in an image form through a negative or positive mask pattern called an artwork (mask exposure method). Alternatively, a method of irradiating actinic rays in the form of an image by a direct drawing exposure method such as an LDI (Laser Direct Imaging) exposure method or a DLP (Digital Light Processing) exposure method may be employed.

  Examples of active light sources include known light sources such as carbon arc lamps, mercury vapor arc lamps, ultrahigh pressure mercury lamps, high pressure mercury lamps, xenon lamps, argon lasers and other solid state lasers such as YAG lasers, semiconductor lasers, and gallium nitride. A laser that effectively emits ultraviolet rays such as a blue-violet laser is used. Moreover, you may use what radiates | emits visible light effectively, such as a flood bulb for photography, a solar lamp.

  Although the photosensitive resin composition of this invention can be used without restrict | limiting especially the light source of actinic light, it is preferable to apply to a direct drawing exposure use.

(Iii) Development Step In the development step, the uncured portion of the photosensitive resin layer is removed from the substrate by development, whereby a resist pattern made of a cured product obtained by photocuring the photosensitive resin layer is formed on the substrate. It is formed.
When the support film exists on the photosensitive resin layer, the support film is removed, and then the unexposed portions other than the exposed portions are removed (developed). Development methods include wet development and dry development.

In the case of wet development, development is performed by a known development method using a developer corresponding to the photosensitive resin composition. As a developing method, dipping method, a paddle method, a spray method, brushing, slapping, scratcher bi ranging method may be mentioned using the oscillating dipping, in terms of resolution improvement, the high pressure spray system is most suitable . You may develop by combining these 2 or more types of methods.

  The configuration of the developer is appropriately selected according to the configuration of the photosensitive resin composition. Examples thereof include an alkaline aqueous solution, an aqueous developer, and an organic solvent developer.

  The alkaline aqueous solution is safe and stable when used as a developer, and has good operability. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium or potassium hydroxide, alkali carbonates such as lithium, sodium, potassium or ammonium carbonate or bicarbonate, potassium phosphate, sodium phosphate And alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate.

  Examples of the alkaline aqueous solution used for development include a dilute solution of 0.1% by mass to 5% by mass of sodium carbonate, a dilute solution of 0.1% by mass to 5% by mass of potassium carbonate, and 0.1% by mass to 5% by mass of sodium hydroxide. A dilute solution of 0.1 mass% to 5 mass% of sodium tetraborate is preferred. Moreover, it is preferable to make pH of the alkaline aqueous solution used for image development into the range of 9-11, and the temperature is adjusted according to the developability of the photosensitive resin layer. In the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like may be mixed.

  The aqueous developer is, for example, 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, and morpholine. The pH of the aqueous developer is preferably as low as possible within a range where development is sufficiently performed, preferably 8 to 12, and more preferably 9 to 10.

  Examples of the organic solvent used in the aqueous developer include 3-acetone 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 mono Examples include ethyl ether and diethylene glycol monobutyl ether. These are used alone or in combination of two or more. In general, the concentration of the organic solvent in the aqueous developer is preferably 2% by mass to 90% by mass, and the temperature can be adjusted according to the developability. A small amount of a surfactant, an antifoaming agent or the like can be mixed in the aqueous developer.

  Examples of the organic solvent developer 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% by mass to 20% by mass in order to prevent ignition.

In the present invention, after the removal of the unexposed portions in the development step, the resist pattern by performing about 60 ° C. to 250 DEG ° C. heating or 0.2J ^/ cm ² ~10J ^/ cm 2 about exposure optionally further It may be used after being cured.

<Method for manufacturing printed wiring board>
The printed wiring board manufacturing method of the present invention includes a step of forming a conductor pattern by etching or plating a circuit forming substrate on which a resist pattern is formed by the above-described resist pattern manufacturing method. It includes other processes such as a removal process. Although the photosensitive resin composition of this invention can be used conveniently for manufacture of a resist pattern, the application to the manufacturing method which forms a conductor pattern by plating process is more suitable especially.

  In the etching process, using the resist pattern formed on the substrate as a mask, the conductor layer of the circuit forming substrate not covered with the resist is removed by etching to form a conductor pattern.

  The etching method is appropriately selected according to the conductor layer to be removed. For example, as an etching solution, a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, and a hydrogen peroxide-based etching solution can be mentioned. It is desirable to use a ferric chloride solution from the viewpoint of good etch factor. .

  On the other hand, in the plating process, copper, solder, or the like is plated on the conductor layer of the circuit forming substrate that is not covered with the resist, using the resist pattern formed on the substrate as a mask. After the plating process, the cured resist is removed, and the conductor layer covered with the resist is etched to form a conductor pattern.

  The plating treatment method may be electrolytic plating treatment or electroless plating treatment, but electroless plating treatment is preferable. Examples of the electroless plating treatment include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-throw solder plating, nickel plating such as watt bath (nickel sulfate-nickel chloride) plating and nickel sulfamate plating, Gold plating such as hard gold plating and soft gold plating can be used.

  After the etching process or the plating process, the resist pattern on the substrate is removed. The resist pattern can be removed by, for example, a stronger alkaline aqueous solution than the alkaline aqueous solution used in the development step. As this strongly alkaline aqueous solution, for example, a 1% by mass to 10% by mass sodium hydroxide aqueous solution and a 1% by mass to 10% by mass potassium hydroxide aqueous solution are used. Especially, it is preferable to use 1 mass%-10 mass% sodium hydroxide aqueous solution or potassium hydroxide aqueous solution, and it is more preferable to use 1 mass%-5 mass% sodium hydroxide aqueous solution or potassium hydroxide aqueous solution.

  Examples of the resist pattern peeling method include an immersion method and a spray method, and these may be used alone or in combination.

  When the resist pattern is removed after the plating treatment, a desired printed wiring board can be manufactured by further etching the conductor layer covered with the resist by the etching treatment to form a conductor pattern. The etching method at this time is appropriately selected according to the conductor layer to be removed. For example, the above-described etching solution can be applied.

  The printed wiring board manufactured by the printed wiring board manufacturing method of the present invention can be applied not only to a single-layer printed wiring board but also to a multilayer printed wiring board, and also to a printed wiring board having a small-diameter through hole. It can also be applied to manufacturing.

<Lead frame manufacturing method>
The lead frame manufacturing method of the present invention includes a step of forming a conductor pattern by plating a substrate on which a resist pattern is formed by the resist pattern forming method, and if necessary, a resist removing step and an etching step. It is comprised including other processes, such as.

  As the substrate, for example, a die pad (base material for lead frame) such as an alloy base material is used as the substrate. In the present invention, the support is plated using the resist pattern formed on the support as a mask.

  Examples of the plating method include those described in the above-described printed wiring board manufacturing method. After the plating process, the resist pattern on the support is removed. The resist pattern can be removed by, for example, a stronger alkaline aqueous solution than the alkaline aqueous solution used in the development step. Examples of the strong alkaline aqueous solution include those described in the method for producing a printed wiring board described above.

  Examples of the resist pattern peeling method include an immersion method and a spray method, which may be used alone or in combination. After removing the resist pattern, the lead frame can be manufactured by further performing an etching process to remove an unnecessary metal layer.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “part” and “%” are based on mass.

[Examples 1-4, Comparative Examples 1-4]
First, the binder polymer (A-1) shown in Table 1 was synthesized according to Synthesis Example 1 and (A-2) according to Synthesis Example 2.

<Synthesis Example 1>
As a comonomer, 125 g of methacrylic acid, 275 g of methyl methacrylate and 100 g of styrene were mixed with 1.0 g of azobisisobutyronitrile to prepare a solution a.
Further, 1.0 g of azobisisobutyronitrile was dissolved in 100 g of a mixed solution (mass ratio 6: 4) of 60 g of methyl cellosolve and 40 g of toluene to prepare a solution b.

  On the other hand, to a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen gas introduction tube, 400 g of a mixture of methyl cellosolve and toluene having a mass ratio of 6: 4 is added and stirred while blowing nitrogen gas. And heated to 80 ° C.

  The solution a was added dropwise over 4 hours, and then kept at 80 ° C. for 2 hours with stirring. Next, the solution b was added dropwise to the solution in the flask over 10 minutes, and then the solution in the flask was kept at 80 ° C. for 3 hours while stirring. Further, the solution in the flask was heated to 90 ° C. over 30 minutes, kept at 90 ° C. for 2 hours, and then cooled to obtain a binder polymer (A-1) solution. Acetone was added to the binder polymer (A-1) solution to prepare a nonvolatile component (solid content) of 50% by mass.

<Synthesis Example 2>
As a comonomer, 125 g of methacrylic acid, 25 g of methyl methacrylate, 125 g of benzyl methacrylate and 225 g of styrene and 1.5 g of azobisisobutyronitrile were mixed to prepare a solution c.
Further, 1.2 g of azobisisobutyronitrile was dissolved in 100 g of a mixed solution (mass ratio 6: 4) of 60 g of methyl cellosolve and 40 g of toluene to prepare a solution d.

  On the other hand, to a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen gas introduction tube, 400 g of a mixture of methyl cellosolve and toluene having a mass ratio of 6: 4 is added and stirred while blowing nitrogen gas. And heated to 80 ° C.

  The solution c was added dropwise over 4 hours, and then kept at 80 ° C. for 2 hours with stirring. Next, after the solution d was dropped into the solution in the flask over 10 minutes, the solution in the flask was kept at 80 ° C. for 3 hours while stirring. Further, the solution in the flask was heated to 90 ° C. over 30 minutes, kept at 90 ° C. for 2 hours, and then cooled to obtain a binder polymer (A-2) solution. Acetone was added to the binder polymer (A-2) solution to prepare a non-volatile component (solid content) of 50% by mass.

  The weight average molecular weight of the binder polymer (A-1) was 60,000, and the acid value was 163 mgKOH / g. Moreover, the weight average molecular weight of binder polymer (A-2) was 50,000, and the acid value was 163 mgKOH / g. The weight average molecular weight was measured by a gel permeation chromatography method and was derived by conversion using a standard polystyrene calibration curve. The GPC conditions are shown below.

-GPC conditions-
Pump: Hitachi L-6000 type [manufactured by Hitachi, Ltd.]
Column: Gelpack GL-R420 + Gelpack GL-R430 + Gelpack GL-R440 (3 in total) [above, product name, manufactured by Hitachi Chemical Co., Ltd.]
Eluent: Tetrahydrofuran Measurement temperature: 25 ° C
Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI [manufactured by Hitachi, Ltd., product name]

<Preparation of photosensitive resin composition>
Next, the materials shown in Table 1 were blended to obtain a photosensitive resin composition. In addition, the numerical value in a table | surface shows a compounding part number (mass basis). Moreover, (A) component and (B) component represent the mass in solid content.

  Each component in the above table represents the following.

-(A) component: Binder polymer-
* 1: (A-1) methacrylic acid / methyl methacrylate / styrene = 25/55/20 (weight ratio), weight average molecular weight = 60,000, 50 mass% methyl cellosolve / toluene = 6/4 (weight ratio) ) Solution * 2: (A-2) methacrylic acid / methyl methacrylate / benzyl methacrylate / styrene = 25/5/25/45 (weight ratio), weight average molecular weight = 50,000, 50 mass% methyl cellosolve / toluene = 6/4 (weight ratio) solution

-Component (B): Photopolymerizable compound-
* 3: (B-1)
A compound represented by the formula (I), wherein n = 0 and R ⁴ is a methyl group.
* 4: TMPT [Product name, manufactured by Shin-Nakamura Chemical Co., Ltd.]
Trimethylolpropane triacrylate * 5: FA-321M [manufactured by Hitachi Chemical Co., Ltd., product name]
2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane * 6: TMPT-21 [manufactured by Hitachi Chemical Co., Ltd., product name]
Ethoxylated trimethylolpropane triacrylate * 7: UA-21 [manufactured by Shin-Nakamura Chemical Co., Ltd., product name]
Tris (methacryloyloxytetraethylene glycol isocyanate hexamethylene) isocyanurate

-Component (C): Photopolymerization initiator-
* 8: B-CIM [Product name, manufactured by Hodogaya Chemical]
2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbisimidazole

-Component (D): Sensitizing dye-
* 9: (D-1)
1-phenyl-3- (4-methoxystyryl) -5- (4-methoxyphenyl) pyrazoline * 10: (D-2)
1-phenyl-3- (4-isopropylstyryl) -5- (4-isopropylphenyl) pyrazoline * 11: (D-3)
1-phenyl-3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) pyrazoline * 12: EAB [product name, manufactured by Hodogaya Chemical]
4,4'-bis (diethylamino) benzophenone

<Preparation of photosensitive element>
The photosensitive resin composition obtained above was uniformly applied onto a polyethylene terephthalate film (product name “HTF01”, manufactured by Teijin Ltd.) having a thickness of 16 μm, and 10% by a hot air convection dryer at 100 ° C. A photosensitive resin layer having a thickness of 10 μm after drying was formed.
A protective film made of polypropylene (manufactured by Oji Paper Co., Ltd., product name “E200C”) is bonded onto the photosensitive resin layer, and a polyethylene terephthalate film (support film), the photosensitive resin layer, and the protective film are bonded. A photosensitive element laminated in this order was obtained.

<Production of laminate>
Brush of # 600 Was polished using a polishing machine (manufactured by Sankei Co., Ltd.), washed with water, and then dried with an air stream. The polished copper-clad laminate was heated to 80 ° C., and the photosensitive element obtained above was laminated so that the photosensitive resin layer was in contact with the copper surface while peeling off the protective film. Lamination was performed using a heat roll at 110 ° C. with a pressure of 0.40 MPa and a roll speed of 1.5 m / min.
In this way, the laminated body laminated | stacked in order of the copper clad laminated board, the photosensitive resin layer, and the support film was obtained, respectively. The obtained laminate was used as a test piece in the following tests.

<Evaluation>
(Photosensitivity measurement test)
On the support film of the test piece obtained above, a Hitachi 41-step tablet is placed, and a direct drawing exposure apparatus (trade name Paragon-9000m, manufactured by Nippon Orbotech Co., Ltd.) using a semiconductor laser with a wavelength of 355 nm as a light source. And exposed with a predetermined amount of energy.

Next, the support film was peeled off, and a 1.0% by mass sodium carbonate aqueous solution at 30 ° C. was sprayed for 45 seconds to remove the unexposed portion, and development processing was performed.
After the development treatment, the number of steps of the step tablet of the photocured film formed on the copper clad laminate was measured, and the amount of energy (mJ / cm ² ) at which the number of remaining step steps after development was 17.0 was determined. The photosensitivity of the photosensitive resin composition indicates that the smaller the energy amount (mJ / cm ² ), the higher the photosensitivity. The results are shown in Table 2.

(Evaluation of adhesion and resolution)
On the support film of the test piece obtained above, drawing data having a wiring pattern with a line width / space width of 5/5 to 47/47 (unit: μm) is used as a resolution evaluation pattern. The exposure was performed with an energy amount such that the number of steps remaining after development of the stepped tablet was 17.0. After the exposure, the same development treatment as in the photosensitivity measurement test was performed.

  After the development process, the resist pattern was observed using an optical microscope. Of the resist pattern in which the space portion (unexposed portion) of the resist pattern is completely removed and the line portion (exposed portion) is formed without meandering or chipping, the space width between the line widths is minimized. Was determined and evaluated as adhesion (μm) and resolution (μm). A smaller value indicates better adhesion and resolution. The results are shown in Table 2.

(Evaluation of tent reliability)
Laminate the photosensitive element obtained above on both sides of a copper clad laminate with a 1mm diameter round hole 7mm apart on a 0.4mm thick copper clad laminate, and develop Hitachi 41-step tablet The exposure was performed with an energy amount so that the remaining number of remaining steps was 17.0. After the exposure, the same developing solution as in the photosensitivity measurement test was used, and development was performed by spraying for 30 seconds.
After development, the number of photosensitive element tears (pieces) in a total of 320 round holes was measured, and the tent tear rate was calculated according to the following formula, which was defined as tent reliability. The results are shown in Table 2.

    Tent tear rate = (number of hole tears (pieces) /) x 100

As shown in Table 2, the photosensitive elements prepared from the photosensitive resin compositions of Examples 1 to 4 were superior in light sensitivity, tent reliability, adhesion, and resolution as compared with Comparative Examples 1 to 4. showed that. In particular, Comparative Example 2 uses a (meth) acrylate compound having a skeleton derived from dipentaerythritol as the photopolymerizable compound of component (B), but uses a pyrazoline compound as the sensitizing dye of component (D). In this case, not only the photosensitivity was inferior to those of Examples 1 and 2, but also the tent reliability was inferior.
From the above, the photosensitive resin compositions of Examples 1 to 4 can form a printed wiring board excellent in photosensitivity, tent reliability, adhesion, and resolution in the etching method by the direct drawing exposure method. found.

[Examples 5 to 9]
A photosensitive resin composition and a photosensitive element were prepared in the same manner as in Example 1 except that the type of the sensitizing dye of component (D) was changed as shown in Table 3 below in Example 1, and this was prepared. And evaluated by the above method. The results are shown in Table 3. Table 3 also shows the evaluation results of Comparative Example 2 for comparison.

Each component in the above table represents the following.
(D-4): 1-phenyl-3- (4-methoxyphenyl) -5- (4-tert-butylphenyl) pyrazoline (D-5): 1-phenyl-3- (2-thienyl) -5 (4-tert-butylphenyl) pyrazoline (D-6): 1-phenyl-3- (2-thienyl) ethenyl-5- (2-thienyl) pyrazoline (D-7): 1-phenyl-3- (2 -Thienyl) -5- (2-thienyl) pyrazoline (D-8): 1-phenyl-3- (2-thienyl) -5-styrylpyrazoline

  As shown in Table 3, even when the type of the sensitizing dye of component (D) is changed, in the case of a pyrazoline compound (particularly a compound corresponding to the general formula (II)), photosensitivity, tent reliability, adhesion And it showed excellent characteristics in resolution. On the other hand, Comparative Example 2 using a sensitizing dye that does not correspond to a pyrazoline compound was not only inferior in photosensitivity but also inferior in tent reliability.

[Examples 10 to 13]
A photosensitive resin composition and a photosensitive element were prepared in the same manner as in Example 2 except that the type of the photopolymerizable compound (B) in Example 2 was changed as shown in Table 4 below. The above method was used for evaluation. The results are shown in Table 4.

Each component in the above table represents the following.
* 13: (B-2)
In general formula (I), n = 1, AO = ethylene oxide group, and R ⁴ is a methyl group.
* 14: (B-3)
In general formula (I), n = 5, AO = ethylene oxide group, and R ⁴ is a methyl group.
* 15: (B-4)
In general formula (I), n = 1, AO = propylene oxide group, and R ⁴ is a methyl group.
* 16: (B-5)
In general formula (I), n = 5, AO = propylene oxide group, and R ⁴ is a methyl group.

  As shown in Table 4, in the case of a (meth) acrylate compound having a skeleton derived from dipentaerythritol (particularly a compound corresponding to the general formula (I)) even if the type of the photopolymerizable compound (B) is changed. Showed excellent characteristics in photosensitivity, tent reliability, adhesion and resolution.

2 Support 4 Photosensitive resin layer 6 Protective film 10 Photosensitive element

Claims (5)

(A) component: binder polymer, (B) component: photopolymerizable compound having at least one ethylenically unsaturated bond, (C) component: photopolymerization initiator, and (D) component: sensitizing dye and, wherein the (B) component comprises a Metaku Relate compound having a skeleton derived from dipentaerythritol, wherein component (D), 1-phenyl-3- (4-methoxyphenyl) -5- (4-methoxyphenyl) A photosensitive resin composition comprising at least one pyrazoline compound selected from the group consisting of -pyrazoline and 1-phenyl-3- (4-isopropylstyryl) -5- (4-isopropylphenyl) -pyrazoline. A support;
A photosensitive resin layer derived from the photosensitive resin composition according to claim 1 formed on the support;
A photosensitive element. A photosensitive resin layer forming step of forming a photosensitive resin layer derived from the photosensitive resin composition according to claim 1 on a substrate;
An exposure step of irradiating at least a part of the photosensitive resin layer with actinic rays and photocuring an exposed portion;
A development step of removing the uncured portion of the photosensitive resin layer from the substrate by development;
The manufacturing method of the resist pattern which has this.   A printed wiring board manufacturing method comprising a step of forming a conductor pattern by etching or plating a substrate on which a resist pattern is formed by the method for manufacturing a resist pattern according to claim 3.   A lead frame manufacturing method comprising a step of forming a conductor pattern by plating a substrate on which a resist pattern is formed by the resist pattern forming method according to claim 3.