JP2004326084A - Photosensitive element, resist pattern forming method using the same and method for manufacturing printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive element capable of ensuring satisfactory sensitivity and resolution and capable of obtaining a good resist shape, when light having a wavelength of 400-450 nm is used as exposure light. <P>SOLUTION: The photosensitive element comprises a support film X and a photosensitive resin composition layer Z. A photosensitive resin composition as the material of the layer Z contains a binder polymer A, a photopolymerizable compound B having at least one polymerizable ethylenically unsaturated bond and a photopolymerization initiator C, wherein at least a 4,4'-bis(dialkylamino)benzophenone and/or a 4,4'-bis(alkylamino)benzophenone is contained as a constituent in the initiator C, and a thickness Q [μm] of the layer Z, gross mass Wa [g] of the polymer A in the layer Z, gross mass Wb [g] of the compound B in the layer Z and mass Wc [g] of the above benzophenone in the layer Z are regulated so as to simultaneously satisfy conditions represented by the expressions (1): P=äWc/(Wa+Wb)}×100, (2): P×Q=R, (3): 6.5≤R≤17.5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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

  In the field of manufacturing printed wiring boards, a photosensitive resin composition or a layer made of the photosensitive resin composition (hereinafter, referred to as a “photosensitive resin composition layer”) is used as a resist material used for etching, plating, and the like. 2. Description of the Related Art Photosensitive elements (laminates) formed on a support film and having a structure in which a protective film is disposed on a photosensitive resin composition layer are widely used.

  Conventionally, a printed wiring board has been manufactured using the photosensitive element according to, for example, the following procedure. That is, first, the photosensitive resin composition layer of the photosensitive element is laminated on a circuit-forming substrate such as a copper-clad laminate. At this time, the surface of the photosensitive resin composition layer opposite to the surface in contact with the support film (hereinafter referred to as the “lower surface” of the photosensitive resin composition layer) (hereinafter, the “upper surface of the photosensitive resin composition layer”) ") Is in close contact with the surface of the circuit forming substrate on which the circuit is to be formed. Therefore, when the protective film is disposed on the upper surface of the photosensitive resin composition layer, this laminating operation is performed while removing the protective film. Next, the photosensitive resin composition layer is heat-pressed to the underlying circuit-forming substrate (normal pressure lamination method).

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

  Here, the etching treatment is a method in which a metal surface that is not covered with a cured resist formed after development is removed by etching, and then the resist is removed. On the other hand, the plating treatment is a method in which a metal surface not covered with a cured resist formed after development is subjected to a plating treatment such as copper and solder, and then the resist is removed and the metal surface covered with the resist is etched. .

  Conventionally, a mercury lamp has been mainly used as a light source for the above pattern exposure. However, the light of the mercury lamp contains ultraviolet rays (light having a wavelength of 400 nm or less) which are harmful to the human body, and there is a problem in work safety. There is also an exposure method using a visible light laser as a light source, but this method required a resist sensitive to visible light, and this resist had to be handled in a dark room or under a red lamp.

  In consideration of the above points, there has been proposed a technique of using, for pattern exposure, active light obtained by cutting light having a wavelength of 365 nm or less out of light emitted from a mercury lamp light source by 99.5% or more using a filter.

  In recent years, a long-life, high-output gallium nitride-based blue laser light source that oscillates light having a wavelength of 405 nm has become available at a low cost, and a technique for using this as a light source for pattern exposure has been proposed.

In recent years, a direct drawing method called a digital light processing (DLP) exposure method has been proposed (for example, see Non-Patent Document 1). Also in this exposure method, an actinic ray obtained by cutting light having a wavelength of 365 nm or less out of light emitted from a mercury lamp light source by 99.5% or more using a filter, or a blue laser light source may be used.
Electronics Packaging Technology June 2002 (p.74-79)

  However, since the conventional photosensitive element is designed so as to exhibit optimal photosensitive characteristics for full-wavelength exposure of a mercury lamp light source centered on light having a wavelength of 365 nm, light having a wavelength of 400 to 450 nm (mercury lamp light source) is used. Of the light emitted from the semiconductor light having a wavelength of 365 nm or less, which is cut by 99.5% or more by using a filter, and the exposure light by the light having a wavelength of 405 nm of a semiconductor laser including those described in Non-Patent Document 1. ) Is intended to perform pattern exposure, the sensitivity of the photosensitive element to the light having a wavelength of 400 to 450 nm is low, so that the throughput is low, and sufficient resolution and a good resist shape can be obtained. could not.

  The present invention has been made in view of the above problems, and can provide sufficient sensitivity and resolution when using light having a wavelength of 400 to 450 nm as exposure light, and can obtain a good resist shape. It is an object of the present invention to provide a photosensitive element that can be used. Another object of the present invention is to provide a method for forming a resist pattern using such a photosensitive element. Furthermore, the present invention provides a method for manufacturing a printed wiring board which uses such a photosensitive element and can manufacture a high-density printed wiring board with high throughput when using light having a wavelength of 400 to 450 nm as exposure light. The purpose is to provide.

  The present inventors have found that one of the major reasons that the above-described conventional photosensitive element has low sensitivity to light having a wavelength of 400 to 450 nm is one of the major reasons for the optical density (hereinafter referred to as “O”) of the photosensitive element in the above wavelength region. .D. Value) is too small to absorb light in the above-mentioned wavelength range sufficiently, and the photopolymerization of the component (B) (photopolymerizable compound) in the photosensitive element has not been started. I found that.

  The present inventors have further studied, and by adding a compound having a large light absorption property to light having a wavelength of 400 to 450 nm as a photopolymerization initiator component to the photosensitive resin composition layer, the above-described sensitivity shortage is caused. It was found that when the intention was to eliminate the problem, the storage stability under yellow light (light having a wavelength of 580 to 600 nm) was reduced, although the sensitivity was high.

  Further, the present inventors, while sufficiently ensuring the storage stability under yellow light, in order to improve the sensitivity to light having a wavelength of 400 to 450 nm, the storage stability under yellow light. And a compound having an appropriate light absorption property for light having a wavelength of 400 to 450 nm may be added in a larger amount than the amount contained in the photosensitive resin composition layer of the conventional photosensitive element. Found to be effective.

  The present inventors have made intensive studies and as a result, the above object can be achieved by forming a photosensitive element using a photosensitive resin composition layer containing a specific amount of a specific photopolymerization initiator component. And arrived at the present invention.

That is, the present invention is a photosensitive element having a support film and a photosensitive resin composition layer disposed on the support film,
The photosensitive resin composition layer contains a photosensitive resin composition,
The photosensitive resin composition contains (A) a binder polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond, and (C) a photopolymerization initiator,
The (C) photopolymerization initiator contains at least 4,4′-bis (dialkylamino) benzophenone and / or 4,4′-bis (alkylamino) benzophenone as a component,
The layer thickness Q [μm] of the photosensitive resin composition layer, the total mass Wa [g] of the binder polymer (A) in the photosensitive resin composition layer, and the total weight Wa [g] of the photosensitive resin composition layer (B) the total mass Wb [g] of the photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond, and the 4,4′-bis (dialkylamino) benzophenone in the photosensitive resin composition layer And / or the mass Wc [g] of 4,4′-bis (alkylamino) benzophenone is adjusted so as to simultaneously satisfy the conditions represented by the following formulas (1) to (3);
It is characterized by.
P = {Wc / (Wa + Wb)} × 100 (1)
P × Q = R (2)
6.5 ≦ R ≦ 17.5 (3)

  The photosensitive resin composition serving as the constituent material of the photosensitive resin composition layer of the photosensitive element of the present invention comprises (C) 4,4′-bis (dialkylamino) benzophenone and / or 4,4'-bis (alkylamino) benzophenone. The above-mentioned benzophenone has relatively large light absorption characteristics with respect to light having a wavelength of 400 to 450 nm, and has good storage stability under yellow light. Then, by adjusting the content so as to simultaneously satisfy the conditions of the above expressions (1) to (3), sufficient sensitivity and resolution can be obtained when light having a wavelength of 400 to 450 nm is used as exposure light. And a good resist shape can be obtained.

  When the thickness of the photosensitive resin composition layer is constant, if the blending amount of the benzophenone is too large (R exceeds 17.8) in order to increase the sensitivity to light having a wavelength of 400 to 450 nm, the photosensitivity increases. Value of the photosensitive resin composition layer increases, and the sensitivity to light having a wavelength of 400 to 450 nm increases, but since the light hardly reaches the bottom of the photosensitive element, the curability of the bottom becomes insufficient. In addition, the shape of the resist after development is inverted trapezoidal, or the resolution becomes insufficient.

  On the other hand, when the thickness of the photosensitive resin composition layer is constant, if the amount of the benzophenone is too small (R is less than 6.5), sufficient sensitivity to light having a wavelength of 400 to 450 nm is obtained. Can not be.

  Furthermore, the sensitivity of the photosensitive resin composition layer to light having a wavelength of 400 to 450 nm and the storage stability under yellow light depend not only on the amount of the benzophenone but also on the thickness of the photosensitive resin composition layer. In view of the above, the present inventors have found the conditions of the above-described equations (1) to (3).

  In the present invention, the 4,4'-bis (dialkylamino) benzophenone is 4,4'-bis (diethylamino) benzophenone, 4,4'-bis (dimethylamino) benzophenone, or 4,4'- Bis (methylethylamino) benzophenone is preferred. These benzophenone compounds have storage stability under yellow light and have appropriate light absorption characteristics for light having a wavelength of 400 to 450 nm.

In the present invention, R preferably satisfies the condition represented by the following formula (4), and more preferably satisfies the condition represented by the following formula (5).
7.2 ≦ R ≦ 16.8 (4)
9.6 ≦ R ≦ 14.4 (5)

  The photosensitive element may be (i) a photosensitive element exposed to light having a wavelength of 400 to 450 nm or (ii) a photosensitive element exposed to light having a wavelength of 400 to 415 nm. Further, the photosensitive element is (iii) a photosensitive element exposed by light emitted from a blue laser or (iv) by arranging a plurality of mirrors, by changing the angle of each mirror as necessary, It is further preferable that the photosensitive element is a photosensitive element that is exposed by a direct drawing method (more preferably, a digital light processing exposure method) in which the exposure light becomes an image. Furthermore, it is further preferable that the photosensitive element has a property that the photosensitive resin composition contained in the photosensitive resin composition layer is exposed and polymerized as described above. In a more preferred embodiment, the light having a wavelength of 400 to 415 nm is laser light (preferably light emitted from a semiconductor laser diode, more preferably light emitted from a gallium nitride-based semiconductor laser) and emitted from the blue laser. The light to be emitted is light having a wavelength of 400 to 415 nm emitted from a gallium nitride blue laser, and the exposure by the direct drawing method is performed by light having a wavelength of 400 to 415 nm.

  It is preferable that the photosensitive element is (v) a photosensitive element that is exposed to an actinic ray obtained by cutting light having a wavelength of 365 nm or less by 90% or more. Furthermore, it is further preferable that the photosensitive element has a property that the photosensitive resin composition contained in the photosensitive resin composition layer is exposed and polymerized as described above. In this case, the light having a wavelength of 365 nm or less is more preferably cut by 99.0%, particularly preferably cut by 99.5% or more.

  The photosensitive element is also (vi) a photosensitive element exposed to light having an area integrated intensity a at a wavelength of 400 nm to 450 nm in an oscillation spectrum of a light source of 10 times or more of an area integrated intensity b having a wavelength of 300 nm or more and less than 400 nm. It is good.

  By adopting the preferred embodiment of the photosensitive element, sensitivity and resolution can be further improved, and a good resist shape can be surely obtained.

Further, in the present invention, the surface of the photosensitive element of the present invention described above, which is opposite to the surface in contact with the support film in the photosensitive resin composition layer, should form a circuit of a circuit-forming substrate. A first step of laminating the photosensitive resin composition layer on the circuit forming substrate by bringing the photosensitive resin composition layer into close contact with a surface;
A second step of irradiating a predetermined portion of the photosensitive resin composition layer to be exposed with actinic rays to form an exposed portion;
Next, a third step of removing unexposed portions other than the exposed portions,
Contains at least
And a method for forming a resist pattern.

  The present invention also provides a method for manufacturing a printed wiring board, characterized by etching or plating a circuit-forming substrate on which a resist pattern has been formed by the above-described method for forming a resist pattern of the present invention.

  Since the method of forming a resist pattern of the present invention and the method of manufacturing a printed wiring board of the present invention use the above-described photosensitive element of the present invention, light having a wavelength of 400 to 450 nm is used as exposure light for the photosensitive element. Even in this case, a sufficient sensitivity and resolution can be obtained, a resist pattern capable of obtaining a good resist shape can be obtained, and a dense printed wiring board can be manufactured with high throughput. be able to.

Further, the present invention is a photosensitive element having a support film, a protective film made of a synthetic resin, and a photosensitive resin composition layer disposed between the support film and the protective film,
The photosensitive resin composition layer contains a photosensitive resin composition,
The photosensitive resin composition contains (A) a binder polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond, and (C) a photopolymerization initiator,
(C) The photopolymerization initiator contains at least 4,4′-bis (dialkylamino) benzophenone and / or 4,4′-bis (alkylamino) benzophenone as a component,
The layer thickness Q [μm] of the photosensitive resin composition layer, the total mass Wa [g] of the (A) binder polymer in the photosensitive resin composition layer, and the (B) at least 1 in the photosensitive resin composition layer The total mass Wb [g] of the photopolymerizable compound having two polymerizable ethylenically unsaturated bonds, and 4,4′-bis (dialkylamino) benzophenone and / or 4,4 ′ in the photosensitive resin composition layer The mass Wc [g] of -bis (alkylamino) benzophenone is adjusted so as to simultaneously satisfy the conditions represented by the following formulas (1) to (3);
A photosensitive element is provided.
P = {Wc / (Wa + Wb)} × 100 (1)
P × Q = R (2)
6.5 ≦ R ≦ 17.5 (3)

Further, the present invention, the protective film of the photosensitive element of the present invention described above is gradually peeled from the photosensitive resin composition layer, simultaneously with the surface portion of the photosensitive resin composition layer gradually exposed at the same time. A first step of laminating a photosensitive resin composition layer on the circuit forming substrate by adhering to the surface of the circuit forming substrate on which the circuit is to be formed;
A second step of irradiating a predetermined portion of the photosensitive resin composition layer to be exposed with actinic rays to form an exposed portion;
Next, a third step of removing unexposed portions other than the exposed portions;
Contains at least
And a method for forming a resist pattern.

  The present invention also provides a method for manufacturing a printed wiring board, characterized by etching or plating a circuit-forming substrate on which a resist pattern has been formed by the above-described method for forming a resist pattern of the present invention.

  According to the present invention, it is possible to provide a photosensitive element that can obtain sufficient sensitivity and resolution when light having a wavelength of 400 to 450 nm is used as exposure light and can obtain a good resist shape. It becomes possible.

  Further, according to the present invention, it is possible to provide a method for forming a resist pattern using such a photosensitive element and a method for manufacturing a printed wiring board. More specifically, it is possible to provide a method for forming a resist pattern which can obtain sufficient sensitivity and resolution when light having a wavelength of 400 to 450 nm is used as exposure light, and can obtain a good resist shape. It becomes possible. Further, it is possible to provide a method for manufacturing a printed wiring board that can manufacture a high-density printed wiring board with high throughput when light having a wavelength of 400 to 450 nm is used as exposure light.

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

(Photosensitive resin composition)
First, the photosensitive resin composition which is a constituent material of the photosensitive resin composition layer of the photosensitive element of the present invention will be described. This photosensitive resin composition is a photosensitive resin composition to be a constituent material of a photosensitive resin composition layer of a photosensitive element having at least a support film and a photosensitive resin composition layer disposed on the support film. Wherein (A) a binder polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond, and (C) a photopolymerization initiator.

  First, the binder polymer as the component (A) will be described.

  From the viewpoint of improving both the adhesion and the peeling property of the photosensitive resin composition layer containing the photosensitive resin composition to the circuit forming substrate, the (A) binder polymer has styrene or styrene in its molecule. It preferably contains at least a repeating unit based on a derivative. Further, the content of the repeating unit based on styrene or a styrene derivative is preferably 3 to 30% by mass, more preferably 4 to 28% by mass, and more preferably 5 to 27% by mass based on the total mass of the molecule. It is particularly preferred that there is. When the content is less than 3% by mass, the adhesion tends to be inferior. When the content exceeds 30% by mass, the peeled pieces tend to be large and the peeling time tends to be long. Further, from the viewpoint of the adhesiveness and the peeling property, the binder polymer (A) preferably contains a repeating unit based on methacrylic acid as a component.

  In the present invention, the “styrene derivative” refers to a styrene derivative in which a hydrogen atom has been substituted with a substituent (an organic group such as an alkyl group, a halogen atom, or the like).

  When a photosensitive resin composition layer is formed using this binder polymer, one type of binder polymer may be used alone, or two or more types of binder polymers may be used in any combination. When two or more binder polymers are used in combination, examples of the binder polymer include two or more binder polymers composed of different copolymer components (including different repeating units as constituent components), and two or more binder polymers having different weight average molecular weights. Polymers, two or more kinds of binder polymers having different dispersities, and the like. Further, a polymer having a multi-mode molecular weight distribution described in JP-A-11-327137 can also be used.

  The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the binder polymer can be measured by gel permeation chromatography (GPC) (converted by a calibration curve using standard polystyrene).

  According to this measuring method, the Mw of the binder polymer is preferably 5,000 to 300,000, more preferably 40,000 to 150,000. When Mw is less than 5000, the developer resistance tends to decrease, and when it exceeds 300,000, the development time tends to be long.

  The binder polymer (A) preferably has a dispersity (Mw / Mn) of 1.0 to 3.0, more preferably 1.0 to 2.0. If the degree of dispersion exceeds 3.0, the adhesion and the resolution tend to decrease.

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

  The (A) binder polymer can be produced, for example, by radically polymerizing a polymerizable monomer. As the polymerizable monomer, for example, a polymerizable styrene derivative substituted at the α-position or an aromatic ring such as styrene, vinyltoluene, and α-methylstyrene is included as an essential copolymerization component. Other components include acrylamide such as diacetone acrylamide, esters of vinyl alcohol such as acrylonitrile and vinyl-n-butyl ether, alkyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and dimethyl (meth) acrylate. Aminoethyl ester, diethylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, 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 , Monomethyl maleate, male Ynoic acid monoethyl maleate monoesters such as maleic acid monoisopropyl, fumaric acid, cinnamic acid, alpha-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid. These may be used alone or in any combination of two or more.

Examples of the alkyl (meth) acrylate include compounds represented by the following general formula (I), and compounds in which an alkyl group of these compounds is substituted with a hydroxyl group, an epoxy group, a halogen group, or the like. However, in the following general formula (I), R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents an alkyl group having 1 to 12 carbon atoms.

CH ₂ ＣC (R ³ ) —COOR ⁴ (I)

Examples of the alkyl group having 1 to 12 carbon atoms represented by R ⁴ in the general formula (I) 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, Examples include a nonyl group, a decyl group, an undecyl group, a dodecyl group, and structural isomers thereof. Examples of the monomer represented by the general formula (I) include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid butyl ester, Pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, Examples include decyl (meth) acrylate, undecyl (meth) acrylate, and dodecyl (meth) acrylate. These can be used alone or in any combination of two or more.

  It is preferable that the binder polymer (A) in the present invention is composed of one or more polymers having a carboxyl group from the viewpoint of developability when performing alkali development using an alkali solution. Such a binder polymer (A) can be produced, for example, by radically polymerizing a polymerizable monomer having a carboxyl group and another polymerizable monomer.

  (A) The acid value of the binder polymer is preferably from 30 to 200 mgKOH / g, more preferably from 45 to 150 mgKOH / g. If the acid value is less than 30 mgKOH / g, the developing time tends to be long, and if it exceeds 200 mgKOH / g, the developing solution resistance of the photocured resist tends to decrease. When solvent development is performed as a development step, it is preferable to prepare a small amount of a polymerizable monomer having a carboxyl group.

  Further, the binder polymer (A) may have a characteristic group having photosensitivity to light having a wavelength of 400 to 450 nm in the molecule thereof, if necessary.

  Next, the photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond (hereinafter, referred to as “photopolymerizable compound”), which is the component (B), will be described.

  (B) As the photopolymerizable compound, for example, a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol, a bisphenol A (meth) acrylate compound, and a glycidyl group-containing compound with α, β- Compounds obtained by reacting unsaturated carboxylic acids, urethane monomers such as (meth) acrylate compounds having a urethane bond in the molecule, nonylphenoxypolyethyleneoxyacrylate, phthalic acid compounds, alkyl (meth) acrylates, and the like. Can be These are used alone or in combination of two or more. From the viewpoints of plating resistance and adhesion, it is preferable that a bisphenol A (meth) acrylate compound or a (meth) acrylate compound having a urethane bond in a molecule is an essential component. Also, a photopolymerizable unsaturated compound having one polymerizable ethylenically unsaturated bond in the molecule and a photopolymerizable unsaturated compound having two or more polymerizable ethylenically unsaturated bonds in the molecule It is preferable to use them in combination from the viewpoint of more surely obtaining the effects of the present invention.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups. 14, polypropylene glycol di (meth) acrylate, a polyethylene / polypropylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di (meth) acrylate, Trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO, PO-modified trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate (T) acrylate, tetramethylolmethanetetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like. These are used alone or in combination of two or more. Here, “EO” indicates ethylene oxide, and the EO-modified compound has a block structure of an ethylene oxide group. “PO” indicates propylene oxide, and a PO-modified compound indicates a compound having a block structure of a propylene oxide group.

  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. Can be Examples of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include, for example, 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2 -Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meta ) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) Propane, 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxynona Toxi) phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, , 2-Bis (4-((meth) acryloxydodecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4- ((Meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy) Hexadecaethoxy) phenyl) propane and the like.

  2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is commercially available as BPE-500 (product name, manufactured by Shin-Nakamura Chemical Co., Ltd.), and 2,2-bis ( 4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name). The number of ethylene oxide groups in one molecule of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane is preferably from 4 to 20, more preferably from 8 to 15. . These may be used alone or in any combination of two or more.

  Examples of the (meth) acrylate compound having a urethane bond in the molecule include a (meth) acryl monomer having an OH group at the β-position and a diisocyanate compound (isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate). , 1,6-hexamethylene diisocyanate), tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, EO, PO-modified urethane di (meth) acrylate And the like. Examples of the EO-modified urethane di (meth) acrylate include UA-11 (product name, manufactured by Shin-Nakamura Chemical Co., Ltd.). Examples of the EO, PO-modified urethane di (meth) acrylate include UA-13 (product name, manufactured by Shin-Nakamura Chemical Co., Ltd.). These are used alone or in combination of two or more.

  Examples of the nonylphenoxypolyethyleneoxyacrylate include nonylphenoxytetraethyleneoxyacrylate, nonylphenoxypentaethyleneoxyacrylate, nonylphenoxyhexaethyleneoxyacrylate, nonylphenoxyheptaethyleneoxyacrylate, nonylphenoxyoctaethyleneoxyacrylate, and nonylphenoxynonaethylene. Oxyacrylate, nonylphenoxydecaethyleneoxyacrylate, nonylphenoxyundecaethyleneoxyacrylate are exemplified. These may be used alone or in any combination of two or more.

  Examples of the phthalic acid-based compound include γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate and β-hydroxyalkyl-β ′-(meth) acryloloxyalkyl-o-phthalate. And the like. These may be used alone or in any combination of two or more.

  Next, the photopolymerization initiator as the component (C) will be described. (C) The photopolymerization initiator contains at least 4,4'-bis (dialkylamino) benzophenone and / or 4,4'-bis (alkylamino) benzophenone as a component. Here, 4,4'-bis (dialkylamino) benzophenone is 4,4'-bis (diethylamino) benzophenone, 4,4'-bis (dimethylamino) benzophenone, or 4,4'-bis (methylethylamino). ) Benzophenone is preferred. It is more preferable that the photopolymerization initiator (C) contains at least 4,4′-bis (diethylamino) benzophenone as a component. And the compounding quantity (content) of 4,4'-bis (dialkylamino) benzophenone and / or 4,4'-bis (alkylamino) benzophenone in the photosensitive resin composition layer should satisfy the following conditions. Has been adjusted to.

That is, the layer thickness Q [μm] of the photosensitive resin composition layer, the total mass Wa [g] of the (A) binder polymer in the photosensitive resin composition layer, and the (B) in the photosensitive resin composition layer The total weight Wb [g] of the photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond, and 4,4′-bis (dialkylamino) benzophenone and / or 4,4 ′ in the photosensitive resin composition layer The mass Wc [g] of 4′-bis (alkylamino) benzophenone is adjusted so as to simultaneously satisfy the conditions represented by the following formulas (1) to (3).
P = {Wc / (Wa + Wb)} × 100 (1)
P × Q = R (2)
6.5 ≦ R ≦ 17.5 (3)

  Here, if R is less than 6.5, the OD value with respect to light having a wavelength of 400 to 450 nm is small and the light cannot be sufficiently absorbed, so that the sensitivity becomes low. Further, when R exceeds 17.5, the OD value is high and the sensitivity can be increased, but the light hardly reaches the bottom of the photosensitive element, so that the curability of the bottom deteriorates, and the resist after development is deteriorated. The shape becomes an inverted trapezoidal shape or the resolution becomes insufficient.

Further, the above R preferably satisfies the condition represented by the following formula (4), and more preferably satisfies the condition represented by the following formula (5).
7.2 ≦ R ≦ 16.8 (4)
9.6 ≦ R ≦ 14.4 (5)

  As the other photopolymerization initiator component (C), for example, benzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl-1- [4- ( Aromatic ketones such as methylthio) phenyl] -2-morpholino-propanone-1, quinones such as alkylanthraquinone, benzoin ether compounds such as benzoin alkyl ether, benzoin compounds such as benzoin and alkylbenzoin, and benzyl derivatives such as benzyldimethylketal 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl)- 4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) Nyl) -4,5-diphenylimidazole dimer, 2,4,5-triarylimidazole dimer such as 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer, 9-phenylacridine And acridine derivatives such as 1,7-bis (9,9'-acridinyl) heptane, N-phenylglycine, N-phenylglycine derivatives, and coumarin-based compounds.

  Further, the substituents of the aryl groups of the two 2,4,5-triarylimidazoles may be the same to give a target compound, or different asymmetric compounds may be given. From the viewpoints of adhesion and sensitivity, 2,4,5-triarylimidazole dimer is more preferable. These are used alone or in combination of two or more.

  The photosensitive resin composition may contain, as necessary, a photopolymerizable compound (oxetane compound or the like) having at least one cationically polymerizable cyclic ether group in the molecule, a cationic polymerization initiator, a dye such as malachite green, Photochromic agents such as bromophenylsulfone and leucocrystal violet, thermal coloring inhibitors, plasticizers such as p-toluenesulfonamide, pigments, fillers, defoamers, flame retardants, stabilizers, adhesion promoters, leveling agents , About 0.01 to 20 parts by mass of a release accelerator, an antioxidant, a fragrance, an imaging agent, a thermal crosslinking agent, etc. based on 100 parts by mass of the total amount of the components (A) and (B). . These are used alone or in combination of two or more.

  Further, the photosensitive resin composition of the present invention is dissolved in a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether or a mixed solvent thereof. And a solution having a solid content of about 30 to 60% by mass. This solution can be used as a coating solution for forming a photosensitive resin composition layer of a photosensitive element.

  Further, the above coating liquid may be used to form a photosensitive resin composition layer of the photosensitive element by coating and drying on a support film described below, for example, the surface of a metal plate, for example, Copper, copper-based alloy, nickel, chromium, iron, iron-based alloys such as stainless steel, preferably copper, copper-based alloy, on the surface of the iron-based alloy, applied as a liquid resist and dried, then coated with a protective film May be used.

  The thickness Q of the photosensitive resin composition layer varies depending on the use of the photosensitive element, but is preferably about 1 to 100 μm as a thickness after drying. When the above liquid resist is used by covering it with a protective film, examples of the protective film include polymer films such as polyethylene and polypropylene.

(Photosensitive element)
Next, the photosensitive element of the present invention will be described. The photosensitive element of the present invention has at least a support film and a photosensitive resin composition layer disposed on the support film. The photosensitive element of the present invention may further include a protective film on the surface of the photosensitive resin composition layer opposite to the surface in contact with the support film.

  As the support film, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used. Further, the thickness of the support film (polymer film) is preferably 1 to 100 μm. If the thickness is less than 5 μm, the support film tends to be broken when the support film is peeled off before development, and if it exceeds 25 μm, the resolution tends to decrease. The polymer film is used by laminating one on both sides of the photosensitive resin composition layer as a support for the photosensitive resin composition layer and the other as a protective film of the photosensitive resin composition layer. Is also good.

  The protective film preferably has a smaller adhesive force between the photosensitive resin composition layer and the protective film than the adhesive force between the photosensitive resin composition layer and the support, and a film having a low fish eye is preferred. In addition, “fish eye” means that when a material is hot-melted, kneaded, extruded, biaxially stretched, or produced by a casting method, a foreign material, undissolved matter, oxidized degraded material, etc. of the material are contained in the film. It was taken in.

  As the protective film, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used. Examples of commercially available products include polypropylene films such as Oji Paper's Alphan MA-410 and E-200C, manufactured by Shin-Etsu Film Co., Ltd., and polyethylene terephthalate films such as PS series such as Teijin's PS-25. It is not limited to this.

  The protective film preferably has a thickness of 1 to 100 μm, more preferably 5 to 50 μm, further preferably 5 to 30 μm, and particularly preferably 15 to 30 μm. If the thickness is less than 1 μm, the protective film tends to be broken during lamination, and if it exceeds 100 μm, the cost tends to be poor.

  The photosensitive resin composition layer is formed by dissolving the photosensitive resin composition of the present invention in the solvent described above to obtain a solution (coating solution) having a solid content of about 30 to 60% by mass, and then applying the solution (coating solution). Liquid) is preferably applied to a support film and dried. The coating can be performed by a known method such as a roll coater, a comma coater, a gravure coater, an air knife coater, a die coater, and a bar coater. Drying can be performed at 70 to 150 ° C. for about 5 to 30 minutes. Further, the amount of the residual organic solvent in the photosensitive resin composition is preferably 2% by mass or less from the viewpoint of preventing the diffusion of the organic solvent in a later step.

  The thickness of the photosensitive resin composition layer varies depending on the application, but is preferably from 1 to 100 μm, more preferably from 1 to 50 μm as a thickness after drying. If the thickness is less than 1 μm, coating tends to be difficult industrially, and if it exceeds 100 μm, the effect of the present invention tends to be small, and the adhesive strength and the resolution tend to be reduced.

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

  The photosensitive resin composition layer formed by the above method has an O.D. D. Those having a value of 0.20 to 0.70 are preferable, and those having a value of 0.25 to 0.65 are more preferable. O. of the photosensitive resin composition layer D. When the value is within the above range, the photosensitive resin composition layer can obtain sufficient sensitivity and resolution when light having a wavelength of 400 to 450 nm is used as exposure light, and obtains a good resist shape. Can do. O. D. If the value is less than 0.20, sufficient light for performing the polymerization reaction cannot be absorbed, so that the sensitivity tends to be low. On the other hand, the above O.D. D. When the value exceeds 0.65, although the sensitivity is high, the light hardly reaches the bottom, so that the curability of the bottom is deteriorated, and the resist shape after development becomes an inverted trapezoid shape or the resolution is deteriorated. Tend.

  The photosensitive element of the present invention may further have an intermediate layer such as a cushion layer, an adhesive layer, a light absorbing layer, and a gas barrier layer. The obtained photosensitive element can be stored in a sheet form or wound up in a roll form around a core. At this time, it is preferable that the support is wound up so that it is the outermost side. An end face separator is preferably provided 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 provided from the viewpoint of edge fusion resistance. In addition, as a packing method, it is preferable to wrap in a black sheet with low moisture permeability. Examples of the core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

(Method of forming resist pattern)
Next, a method for forming a resist pattern according to the present invention will be described. In the method of forming a resist pattern of the present invention, when the above-described photosensitive element of the present invention includes a protective film, the protective film is gradually peeled off from the photosensitive resin composition layer, and at the same time, gradually. The first part of laminating the photosensitive resin composition layer on the circuit forming substrate is brought into close contact with the exposed surface of the photosensitive resin composition layer on the surface of the circuit forming substrate on which the circuit is to be formed. Step, a second step of irradiating a predetermined portion of the photosensitive resin composition layer to be exposed with active light rays to form an exposed portion, and then a third step of removing an unexposed portion other than the exposed portion. At least inclusive. Note that the “circuit formation substrate” refers to a substrate including an insulating layer and a conductor layer formed over the insulating layer.

As a method of laminating the photosensitive resin composition layer on the circuit forming substrate in the first step, the photosensitive resin composition layer is formed by removing the protective film and heating the photosensitive resin composition layer while forming the circuit. There is a method of laminating by pressing the substrate. Note that, in this operation, it is preferable to perform lamination under reduced pressure from the viewpoint of adhesion and followability. The lamination of the photosensitive elements is preferably performed by heating the photosensitive resin composition layer and / or the substrate for circuit formation to 70 to 130 ° C., and the pressing pressure is about 0.1 to 1.0 MPa (1 to 10 kgf / cm ^{About 2} ), but these conditions are not particularly limited. In addition, if the photosensitive resin composition layer is heated to 70 to 130 ° C. as described above, it is not necessary to pre-heat the circuit forming substrate in advance. Preheating of the substrate can also be performed.

  As a method of forming an exposed portion in the second step, there is a method of irradiating an actinic ray on an image through a negative or positive mask pattern called an artwork (mask exposure method). At this time, when the support film present on the photosensitive resin composition layer is transparent to actinic light, the actinic light can be irradiated through the support film, and when the support film is light-shielding, After the support film is removed, the photosensitive resin composition layer is irradiated with actinic rays. In addition, the active light beam can be generated by a direct drawing method such as a laser direct drawing exposure method or a direct drawing method in which a plurality of mirrors are arranged and the angle of each mirror is changed as necessary, so that the exposure light becomes image-like. A method of irradiating an image may be employed.

  By arranging a plurality of mirrors and changing the angle of each mirror as necessary, as a direct drawing method in which the exposure light becomes image-like, for example, a mirror having a size of about 13 to 17 μm square is 480,000 to 800,000. There is a direct drawing method in which exposure light is formed into an image by arranging about mirrors and changing the angle of each mirror as necessary. More specifically, for example, “Digital Light Processing” exposure method (DLP (Digital Light Processing)) of Texas Instruments, “Data Direct Imaging System” of Pentax, “Maskless Lithography System” of BALL Connector (Maskless Lithography System) ”and the like. The arranged mirrors that perform the core function of the direct writing method are called, for example, a “micromirror array”, a “two-dimensional display element”, a “DMD (Digital Mirror Device)”, and the like.

  As a light source of the actinic ray, a known light source, a known light source, for example, a carbon arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, a xenon lamp, an ultraviolet ray such as an Ar ion laser, a semiconductor laser, or the like, is effectively emitted. Things are used. In the present invention, an active ray having a wavelength of 365 nm or less of a mercury lamp light source cut by 90% (more preferably 99.0%, more preferably 99.5%) or more by using a filter, a wavelength of 400 to 450 nm ( More preferably, light (active light) of 400 to 415 nm) or light (active light) of a semiconductor laser having a wavelength of 405 nm is used. As a filter for cutting light having a wavelength of 365 nm or less, for example, a sharp cut filter SCF-100S-39L manufactured by Sigma Koki Co., Ltd. can be used. As a light source, a laser (more preferably, a semiconductor laser diode, more preferably, a gallium nitride-based semiconductor laser) or a blue laser (more preferably, a gallium nitride-based blue laser) is preferably used. It is preferable to irradiate light (active rays) of from 450 to 450 nm (more preferably, from 400 to 415 nm).

  In the present embodiment, as the light from the light source, light having a wavelength of 400 to 450 nm is preferably applied, and light having a wavelength of 400 to 415 nm is more preferable. When a light source that emits a large amount of light having a wavelength of 365 nm or less, such as a mercury lamp, is used as exposure light, it is preferable that the light having a wavelength of 365 nm or less be cut by 90% or more using a filter and irradiated with light, and 99.0% or more be used. It is more preferable to cut, and it is particularly preferable to cut 99.5% or more. As a filter that cuts light having a wavelength of 365 nm or less, for example, a sharp cut filter SCF-100S-39L manufactured by Sigma Koki Co., Ltd. can be used. As a light source, a laser is preferably used, a semiconductor laser diode is more preferably used, and a gallium nitride based semiconductor laser and a blue laser are particularly preferable. As the blue laser, a gallium nitride blue laser is preferable. Furthermore, when using a laser light source as exposure light, it is preferable to irradiate light having a wavelength of 400 to 450 nm, more preferably light having a wavelength of 400 to 415 nm, and particularly preferably light having a wavelength of 405 nm. Further, a method of arranging about 480,000 to 800,000 mirrors each having a size of about 13 to 17 μm square and changing the angle of each mirror as necessary to expose the exposure light by an image-forming direct drawing method is known. It is preferably performed with light having a wavelength of 400 to 450 nm, more preferably light having a wavelength of 400 to 415 nm, and particularly preferably light having a wavelength of 400 to 410 nm.

  In addition, it is also preferable to irradiate, as the light of the light source exemplified above, light whose area integrated intensity a at a wavelength of 400 nm to 450 nm in the oscillation spectrum of the light source is 10 times or more the area integrated intensity b at a wavelength of 300 nm or more and less than 400 nm. . FIG. 1 is an oscillation spectrum diagram of a mercury lamp light source. When exposed as it is using a mercury lamp as a light source, the wavelength range of light emitted as shown in FIG. 1 is wide, and light having a wavelength of less than 400 nm, which is harmful to the human body, is centered on light (i-line) having a wavelength of 365 nm. Irradiated. Therefore, using a cut filter as shown in FIG. 2, the area integrated intensity of an oscillation spectrum having a wavelength of 300 nm or more and less than 400 nm, which is ultraviolet light harmful to the human body, is set to b, and the area integrated intensity of the emitted light having a wavelength of 400 to 450 nm is set to b. When a is set, it is preferable to cut so that a becomes 10 times or more of b. Here, FIG. 2 is an oscillation spectrum diagram of a mercury lamp light source using a filter.

  Then, after the exposure, as a method of removing the portion other than the exposed portion in the third step, first, if a support film is present on the photosensitive resin composition layer, the support film is removed, A method of removing a portion other than the exposed portion by wet development, dry development, or the like to perform development. As a result, a resist pattern is formed.

  For example, in the case of wet development, an alkaline aqueous solution, an aqueous developer, a developer corresponding to a photosensitive resin composition such as an organic solvent developer, for example, spraying, rocking immersion, brushing, scraping and the like Develop by a known method.

  As the developing solution, a safe and stable one having good operability, such as an alkaline aqueous solution, is used. As the base of the alkaline aqueous solution, for example, alkali hydroxides such as lithium, sodium or potassium hydroxide, alkali carbonates such as lithium, sodium, potassium or ammonium carbonate or bicarbonate, potassium phosphate, phosphoric acid Alkali metal phosphates such as sodium and alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate are used.

  Examples of the alkaline aqueous solution used for development include a dilute solution of 0.1 to 5% by mass of sodium carbonate, a dilute solution of 0.1 to 5% by mass of potassium carbonate, a dilute solution of 0.1 to 5% by mass of sodium hydroxide, A dilute solution of 0.1 to 5% by mass of sodium tetraborate is preferred. The pH of the alkaline aqueous solution used for development 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, a small amount of an organic solvent for promoting development, and the like may be mixed in the alkaline aqueous solution.

  Examples of the aqueous developer include a developer comprising water or an aqueous alkaline 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-1,3 -Propanediol, 1,3-diaminopropanol-2, morpholine and the like. The pH of the developing solution is preferably as low as possible within a range where the development of the resist can be sufficiently performed, and is preferably from 8 to 12, more preferably from 9 to 10.

  Examples of the organic solvent include triacetone alcohol, acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monoethyl ether. Butyl ether and the like. These are used alone or in combination of two or more. The concentration of the organic solvent is usually preferably from 2 to 90% by mass, and the temperature can be adjusted according to the developing property. Further, a small amount of a surfactant, an antifoaming agent or the like can be mixed in the aqueous developer. Examples of the organic solvent-based developer used alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, γ-butyrolactone, and the like.

  It is preferable to add water to these organic solvents in a range of 1 to 20% by mass to prevent ignition. If necessary, two or more developing methods may be used in combination. Development methods include a dip method, a battle method, a spray method, brushing, and slapping, and a high-pressure spray method is most suitable for improving resolution.

Examples of the developing method include a dip method, a spray method, brushing, and slapping. As a treatment after development, the resist pattern may be further cured by heating at about 60 to 250 ° C. or exposing at about 0.2 to 10 J / cm ² as necessary. Further, for the etching of the metal surface performed after the development, for example, a cupric chloride solution, a ferric chloride solution, an alkali etching solution, or the like can be used.

(Method of manufacturing printed wiring boards)
Next, a method for manufacturing a printed wiring board of the present invention will be described. In the method for manufacturing a printed wiring board according to the present invention, the circuit-forming substrate on which the resist pattern is formed is etched or plated by the above-described method for forming a resist pattern according to the present invention.

  The etching and plating of the circuit forming substrate are performed on the conductor layer and the like of the circuit forming substrate using the formed resist pattern as a mask. Examples of the etching solution for performing the etching include a cupric chloride solution, a ferric chloride solution, an alkali etching solution, and a hydrogen peroxide etching solution. Preferably, an iron solution is used. Examples of plating methods for plating include, for example, copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-throw solder plating, Watt bath (nickel sulfate-nickel chloride) plating, nickel sulfamate and the like. Gold plating such as nickel plating, hard gold plating, and soft gold plating.

  After the completion of the etching or plating, the resist pattern can be peeled off, for example, with a more alkaline aqueous solution than the alkaline aqueous solution used for development. As the strong alkaline aqueous solution, for example, a 1 to 10% by mass aqueous sodium hydroxide solution, a 1 to 10% by mass aqueous potassium hydroxide solution, or the like is used. Examples of the peeling method include an immersion method and a spray method. The immersion method and the spray method may be used alone or in combination. 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. Thus, a printed wiring board is obtained.

  Hereinafter, preferred embodiments of the present invention will be described in more detail, but the present invention is not limited to these embodiments.

  First, the components shown in Tables 1 and 2 were blended to obtain solutions of the photosensitive resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2.

  Next, a solution of the obtained photosensitive resin composition (Examples 1 to 3, and Comparative Examples 1 and 2) was applied to a 16 μm-thick polyethylene terephthalate film (trade name: GS-16, manufactured by Teijin Limited). The photosensitive element (Examples 1 to 3, and Comparative Examples 1 and 2) was uniformly coated on the top and dried for 10 minutes with a hot air convection dryer at 100 ° C. The dried film thickness of the photosensitive resin composition layer of each photosensitive element was 24 μm.

  Next, using a UV spectrometer (trade name: “U-3310 spectrophotometer” manufactured by Hitachi, Ltd.), each photosensitive element (Examples 1 to 3, and Comparative Examples 1 and 2) was used. ) Of the photosensitive resin composition layer of Example 1) with respect to the exposure wavelength was measured. The OD value was determined by first placing each photosensitive element comprising a support film and a photosensitive resin composition layer on the measurement side, placing the support film on the reference side, and continuously measuring from 550 to 300 nm in the absorbance mode. , 405 nm. The results are shown in Table 3 below.

On the other hand, a copper-clad laminate (manufactured by Hitachi Chemical Co., Ltd., product name: MCL-E-67), which is a glass epoxy material having copper foil (thickness: 35 μm) laminated on both sides, is brushed with a brush equivalent to # 600. It was polished using a polishing machine (manufactured by Sankei Co., Ltd.), washed with water, and dried in an air stream to obtain a copper-clad laminate (substrate). Next, after the copper-clad laminate was heated to 80 ° C., the protective film of each photosensitive element (Examples 1 to 3, and Comparative Examples 1 and 2) was removed on the copper-clad laminate. Then, lamination (lamination) was performed at 120 ° C. under a pressure of 4 kgf / cm ² so that each photosensitive resin composition layer was in close contact with the surface of the copper-clad laminate.

  Next, when the copper-clad laminate on which the photosensitive elements were laminated was cooled to 23 ° C., the polyethylene terephthalate surface had a density range of 0.00 to 2.00, a density step of 0.05, and a tablet size. A photo tool having a 41-step tablet with a size of 20 mm × 187 mm and each step size of 3 mm × 12 mm, and a wiring having a line width / space width of 6/6 to 35/35 (unit: μm) as a negative for resolution evaluation A photo tool having a pattern was brought into close contact. Next, a sharp cut filter SCF-100S-39L manufactured by Sigma Koki Co., Ltd. was placed thereon to cut 99.5% or more of light having a wavelength of 365 nm or less, and parallel light exposure using a 5 kW short arc lamp as a light source. Exposure was performed using a machine (manufactured by Oak Manufacturing Co., Ltd., product name EXM-1201) at an exposure amount such that the number of remaining steps after development of the 41-step tablet was 14, 17, and 20 steps.

  The exposure amount at which the number of remaining steps after development of the 41-step tablet was 17 was determined as the sensitivity. The illuminance was measured using an ultraviolet illuminometer (product name: “UIT-101” manufactured by Ushio Inc.) using a 405 nm-compatible probe for the light transmitted through the sharp cut filter. Amount.

  Next, the polyethylene terephthalate film was peeled off, and a 1% by mass aqueous sodium carbonate solution was sprayed at 30 ° C. for 24 seconds to remove unexposed portions. Thereafter, the photosensitivity of the photosensitive resin composition was evaluated by measuring the number of steps of the step tablet of the photocured film formed on the copper-clad laminate. The results are shown in Table 3 below. The light sensitivity is indicated by the number of steps of the step tablet. The higher the number of steps of the step tablet, the higher the light sensitivity.

  The resolution was evaluated based on the smallest value of the space width between the line widths generated without removing the unexposed portions by the development processing and without generating meandering or chipping of the lines. In both the evaluation of the sensitivity and the resolution, the smaller the numerical value, the better the value. The results are shown in Table 3 below.

  The resist shape after development was observed using a Hitachi scanning electron microscope S-500A. Desirably, the resist shape is close to a rectangle. The results are shown in Table 3 below.

It is an oscillation spectrum figure of a mercury lamp light source. FIG. 3 is an oscillation spectrum diagram of a mercury lamp light source using a filter.

Claims (20)

Support film, a photosensitive element having a photosensitive resin composition layer disposed on the support film,
The photosensitive resin composition layer contains a photosensitive resin composition,
The photosensitive resin composition contains (A) a binder polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond, and (C) a photopolymerization initiator,
The (C) photopolymerization initiator contains at least 4,4′-bis (dialkylamino) benzophenone and / or 4,4′-bis (alkylamino) benzophenone as a component,
The layer thickness Q [μm] of the photosensitive resin composition layer, the total weight Wa [g] of the (A) binder polymer in the photosensitive resin composition layer, and the total weight Wa [g] of the photosensitive resin composition layer. (B) the total mass Wb [g] of the photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond, and the 4,4′-bis (dialkylamino) benzophenone in the photosensitive resin composition layer And / or the mass Wc [g] of 4,4′-bis (alkylamino) benzophenone is adjusted so as to simultaneously satisfy the conditions represented by the following formulas (1) to (3);
A photosensitive element characterized by the following.
P = {Wc / (Wa + Wb)} × 100 (1)
P × Q = R (2)
6.5 ≦ R ≦ 17.5 (3)   The 4,4'-bis (dialkylamino) benzophenone is 4,4'-bis (diethylamino) benzophenone, 4,4'-bis (dimethylamino) benzophenone, or 4,4'-bis (methylethylamino) benzophenone The photosensitive element according to claim 1, wherein 3. The photosensitive element according to claim 1, wherein R satisfies a condition represented by the following formula (4).
7.2 ≦ R ≦ 16.8 (4) The photosensitive element according to any one of claims 1 to 3, wherein R satisfies a condition represented by the following formula (5).
9.6 ≦ R ≦ 14.4 (5)   The photosensitive element according to any one of claims 1 to 4, wherein the photosensitive element is exposed to light having a wavelength of 400 to 450 nm.   The photosensitive element according to claim 5, wherein the photosensitive resin composition of the photosensitive element has a property of being exposed to the light having the wavelength of 400 to 450 nm and being polymerized.   The photosensitive element according to any one of claims 1 to 4, wherein the photosensitive element is exposed to light having a wavelength of 400 to 415 nm.   The photosensitive element according to claim 7, wherein the photosensitive resin composition of the photosensitive element has a property of being exposed to the light having the wavelength of 400 to 415 nm and being polymerized.   9. The photosensitive element according to claim 1, wherein the photosensitive element is exposed by light emitted from a blue laser.   The photosensitive element according to any one of claims 1 to 8, wherein the photosensitive element is exposed to light emitted from a gallium nitride based semiconductor laser.   The photosensitive element according to any one of claims 1 to 10, wherein a plurality of mirrors are arranged, and an angle of each of the mirrors is changed as necessary, whereby the exposure light becomes image-like. A photosensitive element exposed by a drawing method.   The photosensitive element according to any one of claims 1 to 10, wherein the photosensitive element is exposed by a digital light processing exposure method.   The photosensitive element according to any one of claims 1 to 4, wherein the photosensitive element is exposed to an actinic ray obtained by cutting light having a wavelength of 365 nm or less by 90% or more.   The photosensitive resin composition of the photosensitive element has a property of being exposed to an actinic ray obtained by cutting the light having a wavelength of 365 nm or less by 90% or more and polymerizing the same. Photosensitive element.   5. The photosensitive element according to claim 1, wherein the integrated area intensity a at a wavelength of 400 nm to 450 nm in the oscillation spectrum of the light source is at least 10 times the integrated area intensity b at a wavelength of 300 nm or more and less than 400 nm. A photosensitive element that is exposed to light. The portion of the photosensitive element according to any one of claims 1 to 15 opposite to the surface of the photosensitive resin composition layer which is in contact with the support film, and is provided on a circuit of a circuit forming substrate. A first step of laminating the photosensitive resin composition layer on the circuit-forming substrate,
A second step of irradiating a predetermined portion of the photosensitive resin composition layer to be exposed with actinic rays to form an exposed portion;
Next, a third step of removing unexposed portions other than the exposed portions;
Contains at least
A method for forming a resist pattern.   A method for manufacturing a printed wiring board, comprising etching or plating a circuit-forming substrate on which a resist pattern has been formed by the method for forming a resist pattern according to claim 16. Support film, a protective film made of a synthetic resin, a photosensitive element having a photosensitive resin composition layer disposed between the support film and the protective film,
The photosensitive resin composition layer contains a photosensitive resin composition,
The photosensitive resin composition contains (A) a binder polymer, (B) a photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond, and (C) a photopolymerization initiator,
The (C) photopolymerization initiator contains at least 4,4′-bis (dialkylamino) benzophenone and / or 4,4′-bis (alkylamino) benzophenone as a component,
The layer thickness Q [μm] of the photosensitive resin composition layer, the total weight Wa [g] of the (A) binder polymer in the photosensitive resin composition layer, and the total weight Wa [g] of the photosensitive resin composition layer. (B) the total mass Wb [g] of the photopolymerizable compound having at least one polymerizable ethylenically unsaturated bond, and the 4,4′-bis (dialkylamino) benzophenone in the photosensitive resin composition layer And / or the mass Wc [g] of 4,4′-bis (alkylamino) benzophenone is adjusted so as to simultaneously satisfy the conditions represented by the following formulas (1) to (3);
A photosensitive element characterized by the following.
P = {Wc / (Wa + Wb)} × 100 (1)
P × Q = R (2)
6.5 ≦ R ≦ 17.5 (3) 19. The photosensitive element according to claim 18, wherein the protective film is gradually peeled off from the photosensitive resin composition layer, and at the same time, a portion of the surface of the photosensitive resin composition layer which is gradually exposed is formed as a circuit. A first step of laminating the photosensitive resin composition layer on the circuit forming substrate by bringing the photosensitive resin composition layer into close contact with a surface of the forming substrate on which a circuit is to be formed;
A second step of irradiating a predetermined portion of the photosensitive resin composition layer to be exposed with actinic rays to form an exposed portion;
Next, a third step of removing unexposed portions other than the exposed portions;
Contains at least
A method for forming a resist pattern. A method for manufacturing a printed wiring board, comprising etching or plating a circuit-forming substrate on which a resist pattern has been formed by the method for forming a resist pattern according to claim 19.

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