JP2010085605A - Photosensitive resin composition, photosensitive element using same, method of forming resist pattern, and method of manufacturing printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition capable of forming a resist pattern superior in sensitivity, resolution, adhesion and resist shape and having satisfactory peelability, a photosensitive element using the same, a method of forming resist pattern, and a method of manufacturing printed wiring board. <P>SOLUTION: The photosensitive resin composition includes: (A) a binder polymer containing an alkali soluble group; (B) a photopolymerizable compound; and (C) a photopolymerization initiator, wherein an amount of variation of vibration frequency at 60 seconds after immersion is -80 Hz or more and -20 Hz or less per 1 μm of film thickness of a cured film, where the cured film of the photosensitive resin composition formed on the crystal oscillator is immersed in one mass% sodium carbonate aqueous solution at 25°C and an indication value of a crystal oscillator microbalance (QCM) immediately after the immersion is defined as 0 Hz. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  In the field of manufacturing printed wiring boards, as a resist material used for etching, plating, etc., a photosensitive resin composition or a layer made of this photosensitive resin composition (hereinafter referred to as “photosensitive resin composition layer”). ) Is formed on a support film, and a photosensitive element (laminate) having a structure in which a protective film is disposed on a photosensitive resin composition 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 composition 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 photosensitive resin composition layer) opposite to the surface in contact with the support film of the photosensitive resin composition layer (hereinafter referred to as the “lower surface” of the photosensitive resin composition layer). (Referred to as the “upper surface”) is in close contact with the surface of the circuit forming substrate on which the circuit is formed. Therefore, when the protective film is arrange | positioned on the upper surface of the photosensitive resin composition layer, this lamination operation is performed while peeling off the protective film. Lamination is performed by thermocompression bonding the photosensitive resin composition layer to the underlying circuit-forming substrate (normal pressure laminating method).

Next, the photosensitive resin composition 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 is dissolved or dispersed and removed with a developer to form a resist pattern. The circuit forming substrate on which the resist pattern is formed is subjected to an etching process or a plating process to form a circuit pattern, and finally the hardened portion is peeled and removed.
Here, the etching treatment is a method of removing the cured resist after etching away the metal surface not covered with the cured resist formed after development. On the other hand, the plating process refers to a metal surface not coated with a hardened resist formed after development, after plating with copper and solder, etc., and then removing the hardened resist to remove the metal surface covered with this resist. This is a method of etching.

  By the way, as a pattern exposure technique described above, conventionally, a technique of exposing via a photomask using a mercury lamp as a light source has been used. In recent years, as a new exposure technique, a direct drawing exposure method called DLP (Digital Light Processing), which directly draws digital data of a pattern on a photosensitive resin composition layer, has been proposed. This direct drawing exposure method has been introduced for the production of a high-density package substrate because it has better alignment accuracy than a photomask exposure and provides a fine pattern.

  In the pattern exposure process, it is necessary to shorten the exposure time as much as possible in order to improve the production throughput. In the above-described direct drawing exposure method, if a photosensitive resin composition used in an exposure method through a conventional photomask is used, generally a lot of exposure time is required. Therefore, it is necessary to increase the illuminance on the exposure apparatus side and to increase the sensitivity of the photosensitive resin composition.

In addition to the sensitivity described above, it is important that the photosensitive resin composition is excellent in resolution, adhesion, resist shape, and resist peeling characteristics.
In particular, in recent high-density package substrates, the width of the circuit pattern is required to be narrower than 10 μm pitch (line width / space width = 10/10 (unit: μm)). Accordingly, a resist pattern used for producing a circuit pattern is also required to have a resolution adhesion of 10 μm pitch or less.

  Further, in a high-density package substrate, since the width between circuits is narrow, it is also important that the resist shape is excellent. If the cross-sectional shape of the resist is trapezoidal or inverted trapezoidal, or if there is a tailing of the resist, there is a possibility that a short circuit or disconnection may occur in the circuit formed by the subsequent etching process or plating process. Therefore, it is desired that the resist shape is rectangular and that there is no bottoming of the resist.

  However, in the case of an alkali-developable photosensitive resin composition, since an alkaline aqueous solution is generally used for both the developer and the stripper, when the resolution adhesion, that is, the resistance to the alkali developer is improved, the stripping characteristics deteriorate. There is a problem of doing. If the resist stripping time is long, the resist pattern formation efficiency will decrease, and if the resist strip size is large, the spray nozzle of the stripper will become clogged and the resist stripping will remain, resulting in the production yield of the printed wiring board. descend. Therefore, there is a demand for a photosensitive resin composition that can achieve a balance between resolution adhesion and resist peeling characteristics.

However, when the conventional photosensitive resin composition is applied to the direct drawing exposure method, the above-described sensitivity, resolution adhesion, resist shape, and resist peeling characteristics are not sufficient. In response to such demands, photosensitive resin compositions using specific binder polymers, photopolymerization initiators, and the like have been studied (see, for example, Patent Documents 1 and 2).
JP 2006-234959 A JP 2005-122123 A

However, in the photosensitive resin compositions described in Patent Documents 1 and 2, as the pitch becomes narrower, swell and collapse of the resist line occur, and it is difficult to form a 10 μm pitch resist pattern. In addition, there is a problem that the bottom of the resist is generated.
That is, even when the conventional photosensitive resin composition is used, the sensitivity, resolution adhesion, and resist shape are not sufficiently satisfied while maintaining good resist release characteristics.

  The present invention is a photosensitive resin composition capable of forming a resist pattern that is excellent in sensitivity, resolution, adhesion, and resist shape and sufficiently satisfies the peeling characteristics, a photosensitive element using the same, and formation of a resist pattern It is an object to provide a method and a printed wiring board manufacturing method.

The present invention relates to the following.
(1) A photosensitive resin composition containing (A) an alkali-soluble group-containing binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator, which is formed on a crystal resonator When the cured film of the photosensitive resin composition is immersed in a 1% by mass sodium carbonate aqueous solution at 25 ° C., and the indicated value of the quartz crystal microbalance (QCM) immediately after the immersion is 0 Hz, the frequency at 60 seconds after the immersion The photosensitive resin composition whose change amount is -80 Hz or more and -20 Hz or less per 1 micrometer of film thickness of a cured film.
The natural frequency of the crystal resonator is 5 MHz, and the gold electrode area is 1.37 cm ² .
(2) The photosensitive resin composition according to item (1), wherein (A) the alkali-soluble group-containing binder polymer contains (meth) acrylic acid as a copolymerization component.
(3) The photosensitive resin composition according to item (1) or (2), wherein (A) the alkali-soluble group-containing binder polymer contains styrene or a styrene derivative as a copolymerization component.
(4) In any one of items (1) to (3), (A) the alkali-soluble group-containing binder polymer is (meth) acrylic acid benzyl ester, (meth) acrylic acid t-butyl ester, (meth) acrylic acid Photosensitive resin composition containing, as a copolymerization component, one or more selected from the group consisting of n-butyl ester, (meth) acrylic acid cyclohexyl ester, (meth) acrylic acid adamantyl ester, and (meth) acrylic acid tetrahydrofurfuryl ester object.
(5) The photosensitive resin composition according to any one of items (1) to (4), wherein (A) the acid value of the alkali-soluble group-containing binder polymer is 50 to 300 mgKOH / g.
(6) The photosensitive resin composition according to any one of items (1) to (5), wherein the weight average molecular weight of the (A) alkali-soluble group-containing binder polymer is 5000 to 150,000.
(7) A photosensitive element comprising a support film and a photosensitive resin composition layer having the photosensitive resin composition according to any one of Items (1) to (6) formed on the support film.
(8) A lamination step of laminating a photosensitive resin composition layer having the photosensitive resin composition according to any one of Items (1) to (6) on a circuit forming substrate, and the photosensitive resin composition An exposure step of irradiating a predetermined portion of the layer with actinic rays to photocure the exposed portion, and a developing step of removing a portion other than the exposed portion of the photosensitive resin composition layer from the circuit forming substrate. A method for forming a resist pattern.
(9) The method for forming a resist pattern according to item (8), wherein the exposure step is a step of directly drawing and exposing the photosensitive resin composition layer with a laser beam to photocur the exposed portion.
(10) A method for producing a printed wiring board, comprising etching or plating a circuit-forming substrate on which a resist pattern is formed by the method for forming a resist pattern described in (8) or (9).

The photosensitive resin composition of the present invention can form a resist pattern that has excellent sensitivity, in particular, resolution, adhesion, and resist shape, and good resist release characteristics, by having the above-described configuration. It becomes possible.
The reason why this effect is achieved is not necessarily clear, but the present inventors speculate as follows. The present inventors have found that the swelling and shrinkage of the resist in the development process contributes to the deterioration of the resolution, adhesion and resist shape. That is, when the hardened resist swells, it is considered that the developer hardly penetrates into the unexposed portion that is the dissolved portion, and a development residue (bottoming) occurs at the bottom of the resist. Further, it is considered that the resist is swelled and collapsed due to the stress caused by the resist shrinkage during the development and the subsequent drying process, and the resolution and adhesion are deteriorated.

  However, if the swelling of the resist is suppressed, alkali developability and peeling characteristics are deteriorated. Therefore, as a result of intensive studies, it was found that by adjusting the mass change due to swelling of the resist in the developer to the above range, both resolution, adhesion, resist shape, and peeling characteristics can be improved in a balanced manner. It is a thing.

  Moreover, it is preferable that (A) alkali-soluble group containing binder polymer contains (meth) acrylic acid as a copolymerization component, and this further improves the alkali developability of the photosensitive resin composition.

  In addition, (A) the alkali-soluble group-containing binder polymer preferably contains styrene or a styrene derivative as a copolymerization component, whereby the resolution, adhesion and resist shape of the photosensitive resin composition, and the resist peeling. Good balance with characteristics.

  Moreover, (A) alkali-soluble group containing binder polymer is (meth) acrylic acid benzyl ester, (meth) acrylic acid t-butyl ester, (meth) acrylic acid n-butyl ester, (meth) acrylic acid cyclohexyl ester, ( It is preferable that one or more selected from the group consisting of (meth) acrylic acid adamantyl ester and (meth) acrylic acid tetrahydrofurfuryl ester is included as a copolymerization component, whereby the resolution and adhesion of the photosensitive resin composition The balance between the properties and the resist shape and the resist peeling characteristics is further improved.

  Moreover, it is preferable that the acid value of (A) alkali-soluble group containing binder polymer is 50-300 mgKOH / g, and, thereby, the alkali developability of a photosensitive resin composition, resolution, adhesiveness, and resist The balance with the peeling characteristics is further improved.

  Moreover, it is preferable that the weight average molecular weight of (A) alkali-soluble group containing binder polymer is 5000-150,000, and, thereby, the alkali developability, resolution, and adhesiveness of the photosensitive resin composition are further improved. .

  The photosensitive element of the present invention comprises a photosensitive resin composition layer comprising the above-described photosensitive resin composition of the present invention, so that it has excellent sensitivity, particularly resolution, adhesion and resist shape, and resist stripping characteristics. However, it is possible to form a resist pattern with good.

  According to the resist pattern forming method of the present invention, since the resist pattern is formed using the photosensitive resin composition of the present invention, sufficient sensitivity and resolution can be obtained even when the laser direct writing method is used. A resist pattern having excellent properties and adhesion and having an excellent resist shape can be formed efficiently.

  According to the method for forming a resist pattern of the present invention, exposure is performed by a laser direct drawing method while using the photosensitive resin composition of the present invention, so that it has sufficient sensitivity, resolution, and adhesion. In addition, a resist pattern having an excellent resist shape can be formed more efficiently.

  According to the method for producing a printed wiring board of the present invention, since the resist pattern is formed by the resist pattern forming method of the present invention, the printed wiring board can be efficiently produced and the density of the wiring is high. Can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the photosensitive resin composition which can form the resist pattern which is excellent in a sensitivity, resolution, adhesiveness, and resist shape, and can fully satisfy peeling characteristics, a photosensitive element using this, and a resist pattern And a method for producing a printed wiring board can be provided.

  Hereinafter, preferred 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 a corresponding methacrylate, and (meth) acryloyl group means acryloyl group or The corresponding methacryloyl group is meant.

(Photosensitive resin composition)
The photosensitive resin composition of the present invention contains (A) an alkali-soluble group-containing binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator.
Further, the photosensitive resin composition of the present invention comprises a cured crystal film of the photosensitive resin composition formed on a crystal resonator, which is immersed in a 1% by mass sodium carbonate aqueous solution at 25 ° C. When the indication value of micro balance (QCM) is 0 Hz, the amount of change in the frequency after 60 seconds of immersion is -80 Hz or more and -20 Hz or less per 1 μm of film thickness of the cured film. However, the natural frequency of the crystal resonator is 5 MHz, and the gold electrode area is 1.37 cm ² .

First, a quartz crystal micro balance (hereinafter referred to as “QCM”) will be described.
The crystal resonator has a structure in which a crystal piece is sandwiched between two electrodes. When a voltage is applied to the crystal of the crystal, deformation occurs due to the piezoelectric effect, and the operation is performed at a value close to the natural frequency. The quartz crystal microbalance is a device that can measure a change in mass in real time by using a change in the frequency of the quartz crystal.

The QCM measurement method in the present embodiment is as follows.
First, a photosensitive resin composition solution is applied on the surface of a crystal resonator having a natural frequency of 5 MHz and a gold electrode area of 1.37 cm ² , and then dried to form a photosensitive resin composition layer. Alternatively, a photosensitive element obtained by previously forming a photosensitive resin composition layer on a support is laminated on the surface of the quartz vibrator to form a photosensitive resin composition layer. The film thickness of the photosensitive resin composition layer is preferably 50 μm or less. When the film thickness of the photosensitive resin composition layer exceeds 50 μm, the photosensitive resin composition layer tends to be peeled off from the crystal oscillator during the QCM measurement, and the measurement accuracy tends to decrease.

  Next, the quartz resonator on which the photosensitive resin composition layer is formed is irradiated with light to form a cured film. The light irradiation conditions are not limited as long as the photosensitive resin composition layer can be completely photocured, and the exposure energy amount and the like are appropriately adjusted depending on the composition of the photosensitive resin composition layer.

Thereafter, the crystal resonator on which the cured film is formed is immersed in a 3% by mass sodium carbonate aqueous solution at 25 ° C., and an instruction of QCM immediately after immersion is performed using a QCM apparatus (manufactured by MAXTEK Corporation, product name: PM-700). The value is set to 0 Hz, and the amount of change in frequency is measured 60 seconds after immersion.
If the frequency increases compared to immediately after immersion, the mass is reduced. This means that the cured film is dissolved in the alkaline developer. On the contrary, if the frequency decreases, the mass increases, which indicates that the cured film is swollen by absorbing the alkali developer.

  In the photosensitive resin composition of the present invention, the frequency variation is −80 Hz or more and −20 Hz or less per 1 μm of the thickness of the cured film, but the resolution, adhesion, resist shape, and resist peeling characteristics From the viewpoint of further improving the balance, it is preferably −80 Hz or more and −30 Hz or less, more preferably −80 Hz or more and −40 Hz or less, and further preferably −80 Hz or more and −50 Hz or less. Preferably, it is -76 Hz or more and -52 Hz or less.

(Alkali-soluble group-containing binder polymer)
Next, the alkali-soluble group-containing binder polymer as component (A) will be described.
(A) The alkali-soluble group-containing binder polymer is not particularly limited as long as it has an alkali-soluble group in the molecule, and examples thereof include acrylic resins, styrene resins, epoxy resins, amide resins, Examples include amide epoxy resins, alkyd resins, phenol resins, and the like. From the viewpoint of alkali developability, an acrylic resin is preferable. These can be used alone or in combination of two or more.

  Examples of the alkali-soluble group include a carboxyl group, a hydroxyl group, and a sulfonic acid group. From the viewpoint of alkali developability, a carboxyl group is preferred. These can be used alone or in combination of two or more.

  The (A) alkali-soluble group-containing binder polymer of the present invention can be produced, for example, by radical polymerization of a polymerizable monomer having an alkali-soluble group and another polymerizable monomer. Examples of the polymerizable monomer include styrene derivatives such as styrene, α-methylstyrene, methylstyrene, ethylstyrene, hydroxystyrene, butoxystyrene, chlorostyrene, bromostyrene, aminostyrene, and 4-t-butylstyrene. Aromatic ring-containing (meth) acrylic acid benzyl esters such as benzyl (meth) acrylate, cyclohexyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate (Meth) acrylic acid cycloalkyl esters, (meth) acrylic acid alkyl esters, (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid furfuryl ester, (meth) acrylic acid tetrahydropyranyl ester, diacetate Acrylamides such as acrylamide, esters of vinyl alcohol such as acrylonitrile and vinyl-n-butyl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester and other (meth) acrylic acid alkylamino esters , (Meth) acrylic acid glycidyl ester, (meth) acrylic acid, α-bromo (meth) acrylic acid, α-chloro (meth) acrylic acid, β-furyl (meth) acrylic acid, β-styryl (meth) acrylic acid , Maleic acid, maleic anhydride, maleic acid monoester such as monomethyl maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, propiolic acid, etc. Is mentioned. These may be used alone or in any combination of two or more.

  Examples of alkyl (meth) acrylates include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, T-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and structures thereof Examples include isomers. These can be used alone or in combination of two or more.

  (A) The alkali-soluble group-containing binder polymer component preferably contains (meth) acrylic acid as a copolymer component from the viewpoint of alkali developability. (A) When the alkali-soluble group-containing binder polymer component contains (meth) acrylic acid as a copolymerization component, the content is preferably 10 to 50% by mass based on the total mass of the molecule, and is 15 to 45% by mass. More preferably, it is more preferably 20 to 35% by mass. When the content is less than 10% by mass, the alkali developability tends to gradually decrease, and when it exceeds 50% by mass, the alkali developer resistance gradually decreases, and the resolution and adhesion tend to decrease. There is.

  Moreover, it is preferable that (A) alkali-soluble group containing binder polymer component contains styrene or a styrene derivative as a copolymerization component from a viewpoint of making adhesiveness and a peeling characteristic favorable. (A) The content when the alkali-soluble group-containing binder polymer component contains styrene or a styrene derivative as a copolymerization component is preferably 3 to 65% by mass based on the total mass of the molecule, and 5 to 60% by mass. % Is more preferable, and 10 to 55% by mass is even more preferable. When the content is less than 3% by mass, the adhesion tends to be inferior. When the content exceeds 65% by mass, the peel piece tends to be large and the peeling time tends to be long. In the present invention, the “styrene derivative” refers to one in which the α-position in styrene or the hydrogen atom of the benzene ring is substituted with a substituent (an organic group such as an alkyl group or a halogen atom).

In addition, (A) the alkali-soluble group-containing binder polymer component is a (meth) acrylic acid benzyl ester, (meta) from the viewpoint of further improving the balance between the resolution, adhesion, resist shape, and resist release characteristics. ) Acrylic acid t-butyl ester, (meth) acrylic acid n-butyl ester, (meth) acrylic acid cyclohexyl ester, (meth) acrylic acid adamantyl ester, and (meth) acrylic acid tetrahydrofurfuryl ester It is preferable to include one or more as a copolymerization component. (A) When the alkali-soluble group-containing binder polymer component contains these as copolymerization components, the content is preferably 3 to 50% by mass, and 5 to 45% by mass, based on the total mass of the molecule. It is more preferable, and it is especially preferable that it is 10-40 mass%. When the content is less than 3% by mass, the adhesion tends to be gradually deteriorated. When the content exceeds 50% by mass, the peel piece tends to be large and the peeling time tends to be long.
When forming the photosensitive resin composition layer using the binder polymer, one kind of binder polymer may be used alone, or two or more kinds of binder polymers may be used in any combination. As a binder polymer in the case of using two or more types in combination, for example, two or more types of binder polymers comprising different copolymerization components (including different repeating units as constituent components), two or more types of binders having different weight average molecular weights Examples thereof include polymers and two or more types of binder polymers having different degrees of dispersion. In addition, a polymer having a multimode molecular weight distribution described in JP-A No. 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 weight average molecular weight of the (A) alkali-soluble group-containing binder polymer component is preferably 5000 to 150,000, more preferably 10,000 to 100,000, and further preferably 20,000 to 80,000. Preferably, it is 30000-60000. When the weight average molecular weight is less than 5000, the resistance to alkaline developer of the resist gradually decreases and resolution and adhesion tend to decrease. When the weight average molecular weight exceeds 150,000, the development time tends to gradually increase.

  (A) The dispersity (Mw / Mn) of the alkali-soluble group-containing binder polymer component is preferably 1.0 to 3.0, and more preferably 1.0 to 2.0. When the degree of dispersion exceeds 3.0, the resolution and adhesion tend to gradually decrease.

  Moreover, the acid value of the (A) alkali-soluble group-containing binder polymer component is preferably 50 to 300 mgKOH / g, more preferably 100 to 250 mgKOH / g, and further preferably 150 to 200 mgKOH / g. preferable. When the acid value is less than 50 mgKOH / g, the development time tends to be gradually increased. When the acid value exceeds 300 mgKOH / g, the resistance to alkaline developer of the resist gradually decreases, and the resolution and adhesion tend to decrease. There is.

  Moreover, (A) alkali-soluble group containing binder polymer may have the characteristic group which has photosensitivity in the molecule | numerator as needed.

  The content of the (A) alkali-soluble group-containing binder polymer is 30 to 70 parts by mass with respect to 100 parts by mass of the total amount of (A) the alkali-soluble group-containing binder polymer component and (B) the photopolymerizable compound component. It is preferably 35 to 65 parts by mass, particularly preferably 40 to 60 parts by mass. If this content is less than 30 parts by mass, a good shape tends to be not obtained, and if it exceeds 70 parts by mass, good sensitivity and resolution tend not to be obtained.

(Photopolymerizable compound)
Next, the photopolymerizable compound as the component (B) will be described.
(B) As a photopolymerizable compound, for example, a compound obtained by reacting an α, β-unsaturated carboxylic acid with a polyhydric alcohol, a bisphenol A-based (meth) acrylate compound, 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, (meth) acrylic acid alkyl esters, etc. It is done. These may be used alone or in combination of two or more.
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 propylene groups. Polypropylene glycol di (meth) acrylate that is 2-14, the number of ethylene groups is 2-14, and the number of propylene groups is 2-14. Polyethylene polypropylene glycol di (meth) acrylate, 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, tetramethylol Methanate Examples include li (meth) 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” represents ethylene oxide, and the EO-modified compound has an ethylene oxide group block structure. “PO” represents propylene oxide, and a PO-modified compound has a propylene oxide group block structure.

Examples of bisphenol A-based (meth) acrylate compounds include 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane and 2,2-bis (4-((meth) acryloxypolypropoxy) phenyl. ) Propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane and the like. .
Examples of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2 -Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meta ) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) Propane, 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxynonane) Xyl) phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, 2 , 2-bis (4-((meth) acryloxydodecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4- ((Meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy) Hexadecaethoxy) phenyl) propane and the like.

  2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is either BPE-500 (Shin-Nakamura Chemical Co., Ltd., product name) or FA-321M (Hitachi Chemical Industry Co., Ltd., product name). 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is commercially available as BPE-1300 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name). Is possible. The number of ethylene oxide groups in one molecule of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane is preferably 4-20, and preferably 8-15. More preferred. 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) acrylic 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) addition reaction product, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, EO, PO-modified urethane di (meth) An acrylate etc. are mentioned. Examples of the EO-modified urethane di (meth) acrylate include UA-11 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name). Examples of EO and PO-modified urethane di (meth) acrylate include UA-13 (manufactured by Shin-Nakamura Chemical Co., Ltd., product name). These may be used alone or in combination of two or more.

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

  Examples of the phthalic acid compounds include γ-chloro-β-hydroxypropyl-β ′-(meth) acryloyloxyethyl-o-phthalate, β-hydroxyalkyl-β ′-(meth) acryloloxyalkyl-o-phthalate. Etc. These may be used alone or in combination of two or more.

  (B) The photopolymerizable compound component preferably contains a bisphenol A-based (meth) acrylate compound from the viewpoint of improving sensitivity and resolution, and 2,2-bis (4-((meth) acryloxypolyethoxy) More preferably, it includes phenyl) propane.

  Moreover, it is preferable that (B) photopolymerizable compound component contains the (meth) acrylate compound which has a urethane bond in a molecule | numerator from a viewpoint of improving the mechanical strength of a film.

  Moreover, it is preferable that (B) photopolymerizable compound component contains the compound which has one ethylenically unsaturated group in a molecule | numerator from a viewpoint which can shorten peeling time. As the compound having one ethylenically unsaturated group in the molecule, the above nonylphenoxypolyethyleneoxyacrylate or the above phthalic acid compound is preferable.

  The (B) photopolymerizable compound component preferably contains polyalkylene glycol di (meth) acrylate having both an ethylene glycol chain and a propylene glycol chain in the molecule from the viewpoint of improving the flexibility of the cured film. . This (meth) acrylate is not particularly limited as long as it has both an ethylene glycol chain and a propylene glycol chain (n-propylene glycol chain or isopropylene glycol chain) as alkylene glycol chains in the molecule. In addition, this (meth) acrylate further includes an n-butylene glycol chain, an isobutylene glycol chain, an n-pentylene glycol chain, a hexylene glycol chain, an alkylene glycol chain having about 4 to 6 carbon atoms such as a structural isomer thereof. You may have.

When there are a plurality of ethylene glycol chains and propylene glycol chains, the plurality of ethylene glycol chains and propylene glycol chains need not be continuously present in blocks, and may be present randomly. In the isopropylene glycol chain, the secondary carbon of the propylene group may be bonded to an oxygen atom, or the primary carbon may be bonded to an oxygen atom.
Intramolecular of polyalkylene glycol di (meth) acrylate having at least one polymerizable ethylenically unsaturated bond in these components (B) and having both ethylene glycol chain and propylene glycol chain in the molecule Examples of the alkylene glycol chain include compounds represented by the following general formula (1), general formula (2), and general formula (3). These may be used alone or in combination of two or more.

As a C1-C3 alkyl group in the said General formula (1), General formula (2), and General formula (3), a methyl group, an ethyl group, n-propyl group, an isopropyl group etc. are mentioned, for example.
The total number (m ₁ + m ₂ , m ₃ and m ₄ ) of ethylene glycol chain repeats in the above general formula (1), general formula (2) and general formula (3) is an integer of 1 to 30 each independently. It is preferably an integer of 1 to 10, more preferably an integer of 4 to 9, and particularly preferably an integer of 5 to 8. If the number of repetitions exceeds 30, the tent reliability and the resist shape tend to deteriorate.
The total number of repeating propylene glycol chains (n ₁ , n ₂ + n ₃ and n ₄ ) in the above general formula (1), general formula (2) and general formula (3) is an integer of 1 to 30 each independently. It is preferably an integer of 5 to 20, more preferably an integer of 8 to 16, and particularly preferably an integer of 10 to 14. If the number of repetitions exceeds 30, the resolution tends to deteriorate and sludge tends to occur.

Specific examples of the compound represented by the general formula (1) include, for example, R = methyl group, m ₁ + m ₂ = 4 (average value), and n ₁ = 12 (average value) vinyl compound (Hitachi Chemical Industry) And trade name FA-023M). Specific examples of the compound represented by the general formula (2) include, for example, R = methyl group, m ₃ = 6 (average value), n ₂ + n ₃ = 12 (average value) vinyl compound (Hitachi Chemical Industry) Product name FA-024M), etc. Specific examples of the compound represented by the general formula (3) include, for example, a vinyl compound (Shin Nakamura Chemical Co., Ltd.) in which R = hydrogen atom, m ₄ = 1 (average value), and n ₄ = 9 (average value). The company name, sample name NK ester HEMA-9P), etc. are mentioned. These are used alone or in combination of two or more.

  (B) As content of the photopolymerizable compound of a photopolymerizable compound component, with respect to 100 mass parts of total amounts of (A) alkali-soluble group containing binder polymer component and (B) photopolymerizable compound component, 30- The amount is preferably 70 parts by mass, more preferably 35 to 65 parts by mass, and particularly preferably 40 to 60 parts by mass. If this content is less than 30 parts by mass, good sensitivity, resolution and adhesion tend not to be obtained, and if it exceeds 70 parts by mass, a good resist shape tends to be not obtained.

(Photopolymerization initiator)
Next, the photopolymerization initiator which is the component (C) will be described.
(C) As the photopolymerization initiator, for example, 4,4′-bis (diethylamino) benzophenone, benzophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-methyl Aromatic ketones such as -1- [4- (methylthio) phenyl] -2-morpholino-propanone-1, quinones such as alkyl anthraquinones, benzoin ether compounds such as benzoin alkyl ether, benzoin compounds such as benzoin and alkylbenzoin, Benzyl derivatives such as benzyldimethyl ketal, 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (methoxyphenyl) imidazole dimer, 2- (O-Fluorophenyl) -4,5-diphenylimidazole 2,4,5- such as dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) -4,5-diphenylimidazole dimer And acridine derivatives such as triarylimidazole dimer, 9-phenylacridine, 1,7-bis (9,9′-acridinyl) heptane, and the like.
From the viewpoint of adhesion and sensitivity, 2,4,5-triarylimidazole dimer is more preferable. The substituents of the aryl groups of two 2,4,5-triarylimidazoles may give the same and interesting compound or differently give asymmetric compounds. These are used alone or in combination of two or more.

  As content of the photoinitiator of (C) component, it is 0.1-10 mass with respect to 100 mass parts of total amounts of (A) alkali-soluble group containing binder polymer component and (B) photopolymerizable compound component. Part, preferably 1 to 8 parts by weight, more preferably 2 to 6 parts by weight. If this content is less than 0.1 parts by mass, good sensitivity and adhesion tend not to be obtained, and if it exceeds 10 parts by mass, good resolution and resist shape tend not to be obtained.

(Sensitizing dye)
The photosensitive resin composition of the present invention preferably further contains a sensitizing dye as the component (D). (D) The sensitizing dye can effectively utilize the absorption wavelength of the active light to be used. As the sensitizing dye, a compound having a maximum absorption wavelength of 370 nm to 420 nm is preferable.
In the present invention, by using such a sensitizing dye, it becomes possible to have a sufficiently high sensitivity to the exposure light of the direct drawing exposure method. When the maximum absorption wavelength of the sensitizing dye is less than 370 nm, the sensitivity to direct drawing exposure light tends to be lowered, and when it exceeds 420 nm, stability in a yellow light environment tends to be lowered.

  (D) Examples of the sensitizing dye include pyrazolines, anthracenes, coumarins, xanthones, oxazoles, benzoxazoles, thiazoles, benzothiazoles, triazoles, stilbenes, triazines, thiophenes, Examples thereof include phthalimides, and among them, anthracene is preferable. These are used alone or in combination of two or more.

  When the photosensitive resin composition contains (D) a sensitizing dye, the content of (A) the alkali-soluble group-containing binder polymer component and (B) the photopolymerizable compound component is 100 parts by mass in total. It is preferable to set it as 0.01-10 mass parts, It is more preferable to set it as 0.05-5 mass parts, It is especially preferable to set it as 0.1-2 mass parts. If the blending amount is less than 0.01 parts by mass, good sensitivity and resolution tend not to be obtained, and if it exceeds 10 parts by mass, a good resist shape tends not to be obtained.

The photosensitive resin composition of the present invention preferably further contains an amine compound as the component (E). Examples of (E) amine compounds include bis [4- (dimethylamino) phenyl] methane, bis [4- (diethylamino) phenyl] methane, and leucocrystal violet. These are used alone or in combination of two or more.
When the photosensitive resin composition contains (E) an amine compound, the content of (A) the alkali-soluble group-containing binder polymer component and (B) the photopolymerizable compound component is 100 parts by mass in total. It is preferable to set it as 0.01-10 mass parts, It is more preferable to set it as 0.05-5 mass parts, It is especially preferable to set it as 0.1-2 mass parts. If the blending amount is less than 0.01 parts by mass, good sensitivity tends not to be obtained, and if it exceeds 10 parts by mass, it tends to precipitate as foreign matter after the formation of the photosensitive element.

  In the photosensitive resin composition, if necessary, at least one cationically polymerizable photopolymerizable compound having a cyclic ether group (such as an oxetane compound), a cationic polymerization initiator, a dye such as malachite green, Photochromic agents such as tribromophenylsulfone and leucocrystal violet, thermochromic inhibitors, plasticizers such as p-toluenesulfonamide, pigments, fillers, antifoaming agents, flame retardants, stabilizers, adhesion promoters, leveling Agent, exfoliation accelerator, antioxidant, fragrance, imaging agent, thermal crosslinking agent, etc., with respect to 100 parts by mass in total of (A) alkali-soluble group-containing binder polymer component and (B) photopolymerizable compound component. Each can be contained in an amount of about 0.01 to 20 parts by mass. These are used alone or in combination of two or more.

The photosensitive resin composition of the present invention is soluble in a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N, N-dimethylformamide, propylene glycol monomethyl ether, or a mixed solvent thereof. And it is good also as a solution of solid content: about 30-60 mass%. This solution can be used as a coating solution for forming the photosensitive resin composition layer of the photosensitive element.
In addition, the above coating solution may be used for forming a photosensitive resin composition layer of a photosensitive element by applying and drying on a support film described later, for example, the surface of a metal plate, for example, On the surface of copper, copper alloy, nickel, chromium, iron, stainless steel, etc., preferably copper, copper alloy, iron alloy, apply as a liquid resist and dry, and then coat the protective film May be used.

(Photosensitive element)
Next, the photosensitive element of the present invention will be described. The photosensitive element of this invention is equipped with the support body and the photosensitive resin composition layer which has the photosensitive resin composition of this invention formed on this support body.

  As the support, for example, a polymer film having heat resistance and solvent resistance such as polyethylene terephthalate, polypropylene, polyethylene, and polyester can be used. Moreover, it is preferable that the thickness of a support body (polymer film) is 5-50 micrometers, and it is more preferable that it is 10-30 micrometers. If the thickness is less than 5 μm, the support tends to be broken when the support is peeled off before development, and if it exceeds 50 μm, the resolution tends to decrease. One polymer film is used as a support for the photosensitive resin composition layer and the other is used as a protective film for the photosensitive resin composition, laminated on both sides of the photosensitive resin composition layer. May be.

The protective film preferably has a smaller adhesive strength between the photosensitive resin composition layer and the protective film than the adhesive strength between the photosensitive resin composition layer and the support, and is preferably a low fisheye film. “Fish eye” means that when a material is melted by heat, kneaded, extruded, biaxially stretched, casting method, etc., foreign materials, undissolved materials, oxidized degradation products, etc. It is 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 Alfan MA-410 (product name), E-200C (product name), and Shin-Etsu Film Co., Ltd. manufactured by Oji Paper Co., Ltd., and PS-25 (product name) manufactured by Teijin Limited. Polyethylene terephthalate film such as PS series, etc.) may be mentioned, but not limited thereto.
The thickness of the protective film is preferably 1 to 100 μm, more preferably 5 to 50 μm, still more preferably 5 to 30 μm, and particularly preferably 15 to 30 μm. If this 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 inferior.

The photosensitive resin composition layer is prepared by dissolving the photosensitive resin composition of the present invention in a solvent as described above to obtain a solution (coating solution) having a solid content of about 30 to 60% by mass, The coating liquid is preferably formed by coating on a support film and drying.
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, or a bar coater. Drying can be performed at 70 to 150 ° C. for about 5 to 30 minutes. Moreover, it is preferable that the amount of the residual organic solvent in the photosensitive resin composition shall be 2 mass% or less from the point which prevents the spreading | diffusion of the organic solvent in a next process.

  Moreover, although the thickness of the photosensitive resin composition layer changes with uses, it is preferable that it is 1-100 micrometers in thickness after drying, it is more preferable that it is 1-50 micrometers, and it is further 10-35 micrometers. preferable. If the thickness is less than 1 μm, there is a tendency that it is difficult to apply industrially, and if it exceeds 100 μm, the effect of the present invention is reduced, and the sensitivity and resolution tend to decrease.

  The photosensitive resin composition layer preferably has a transmittance for ultraviolet rays having a wavelength of 405 nm of 5 to 75%, more preferably 10 to 65%, and particularly preferably 15 to 55%. . When the transmittance is less than 5%, the adhesion tends to be inferior, and when it exceeds 75%, the resolution tends to be inferior. The transmittance can be measured by a UV spectrometer, and examples of the UV spectrometer include a 228A type W beam spectrophotometer (product name) manufactured by Hitachi, Ltd.

  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, and a gas barrier layer. Moreover, the obtained photosensitive element can be wound up and stored in a sheet form or a roll around a core. At this time, it is preferable that the support is wound so that it is the outermost side. From the viewpoint of protecting the end face, it is preferable to install an end face separator on the end face of the roll-shaped photosensitive element roll, and it is preferable to install a moisture-proof end face separator from the viewpoint of edge fusion resistance. Moreover, as a packing method, it is preferable to wrap and package in a black sheet with low moisture permeability. Examples of the winding core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

(Method for forming resist pattern)
Next, the resist pattern forming method of the present invention will be described. The method for forming a resist pattern of the present invention is a method in which the above-described protective film of the photosensitive element of the present invention is gradually peeled off from the photosensitive resin composition layer and simultaneously exposed to the photosensitive resin composition layer. A first step of laminating the photosensitive resin composition layer on the circuit forming substrate by bringing the surface portion into close contact with the surface of the circuit forming substrate on which the circuit is to be formed, and the photosensitive resin composition layer A second step of irradiating a predetermined portion to be exposed with actinic rays to form an exposed portion, and then a third step of removing an unexposed portion other than the exposed portion. The “circuit forming substrate” refers to a substrate including an insulating layer and a conductor layer formed on the insulating layer.

As a method for laminating the photosensitive resin composition layer on the circuit forming substrate in the first step, the protective resin is removed, and then the photosensitive resin composition layer is heated while the photosensitive resin composition layer is heated. The method of laminating | stacking is mentioned by crimping | bonding to the formation board | substrate. In addition, it is preferable to laminate | stack this operation under reduced pressure from the viewpoint of adhesiveness and followability. In the lamination of the photosensitive elements, it is preferable to heat the photosensitive resin composition layer and / or the circuit forming substrate to 70 to 130 ° C., and the pressure bonding pressure is about 0.1 to 1.0 MPa (1 to 10 kgf / it is preferable that the cm order of ^2), but not particularly limited to these conditions. Further, 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. A pre-heat treatment of the forming substrate can also be performed.

Examples of the method for forming the exposed portion in the second step include a method of irradiating an image with active light through a negative or positive mask pattern called an artwork (mask exposure method). In this case, when the support film present on the photosensitive resin composition layer is transparent to the active light, the active light can be irradiated through the support film, and the support film is light-shielding. For this, after removing the support film, the photosensitive resin composition layer is irradiated with actinic rays. Further, it is preferable to irradiate the laser beam in an image form by a direct drawing method such as a laser direct drawing exposure method or a DLP (Digital Light Processing) exposure method.
Examples of the active light source include known light sources such as carbon arc lamps, mercury vapor arc lamps, high pressure mercury lamps, xenon lamps, gas lasers such as argon lasers, solid state lasers such as YAG lasers, ultraviolet rays such as semiconductor lasers, and visible light. That effectively radiate are used.

Next, after exposure, as a method of removing the portion other than the exposed portion in the third step, first, when the support film is present on the photosensitive resin composition layer, the support film is removed, and then And a method of developing by removing portions other than the exposed portion by wet development, dry development, or the like. Thereby, a resist pattern is formed.
For example, in the case of wet development, using a developer corresponding to a photosensitive resin composition such as an alkaline aqueous solution, an aqueous developer, an organic solvent developer, etc., for example, spraying, rocking immersion, brushing, scraping, etc. Development is performed by a known method.

As the developer, a safe and stable developer having good operability such as an alkaline aqueous solution is used. 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, and phosphoric acid. Alkali metal phosphates such as sodium and alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate are used.
Moreover, as alkaline aqueous solution used for image development, 0.1-5 mass% dilute solution of sodium carbonate, 0.1-5 mass% dilute solution of potassium carbonate, 0.1-5 mass% dilute solution of sodium hydroxide, A dilute solution of 0.1 to 5% by mass sodium tetraborate is preferred. From the viewpoint of obtaining the effect of the present invention more reliably, it is more preferable to use a 3 mass% sodium carbonate aqueous solution. 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. 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.

  Examples of the aqueous developer include a developer having 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, 3 -Propanediol, 1,3-diaminopropanol-2, morpholine and the like. The pH of the developer is preferably as low as possible within the range where the resist can be sufficiently developed, preferably pH 8-12, and more preferably pH 9-10.

Examples of the organic solvent include acetone, ethyl acetate, alkoxyethanol having an alkoxy group having 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and the like. It is done. These are used alone or in combination of two or more. The concentration of the organic solvent is usually preferably 2 to 90% by mass, and the temperature can be adjusted according to the developability.
Further, a small amount of a surfactant, an antifoaming agent or the like can be mixed in the aqueous developer. Examples of the organic solvent developer used alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N, N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone.
These organic solvents are preferably added with water in the range of 1 to 20% by mass in order to prevent ignition. Moreover, you may use together 2 or more types of image development methods as needed. Development methods include a dip method, a battle method, a spray method, brushing, and slapping, and the high pressure spray method is most suitable for improving the resolution.

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

(Printed wiring board manufacturing method)
Next, the manufacturing method of the printed wiring board of this invention is demonstrated. The method for producing a printed wiring board of the present invention comprises etching or plating a circuit forming substrate on which a resist pattern is formed by the above-described resist pattern forming method of the present invention.
Etching and plating of the circuit forming substrate is performed on a conductor layer or the like of the circuit forming substrate using the formed resist pattern as a mask. Etching solutions for etching include cupric chloride solution, ferric chloride solution, alkaline etching solution, and hydrogen peroxide etching solution. Among these, from the viewpoint of good etch factor, It is preferable to use a diiron solution. Moreover, as a plating method in the case of plating, 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, etc. And nickel plating, hard gold plating, and gold plating such as soft gold plating.

After completion of etching or plating, the resist pattern can be peeled off with a strong alkaline aqueous solution, for example, further than the alkaline aqueous solution used for development. As this strongly alkaline aqueous solution, for example, a 1 to 10% by mass sodium hydroxide aqueous solution, a 1 to 10% by mass potassium hydroxide aqueous solution and the like are used. Examples of the peeling method include a dipping method and a spray method, and the dipping method and the spray method may be used alone or in combination.
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. A printed wiring board is obtained as described above.

Hereinafter, preferred examples of the present invention will be described in more detail, but the present invention is not limited to these examples.
[Synthesis of Binder Polymer (A-1)]
To a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen gas inlet tube, 450 g of a mixture of 1-methoxy-2-propanol and toluene having a mass ratio of 3: 2 was added, and nitrogen gas was added. Stirring while blowing and heating to 80 ° C. On the other hand, as a comonomer, methacrylic acid: 150 g, methyl methacrylate: 100 g, benzyl methacrylate: 100 g, and styrene: 150 g were mixed with azobisisobutyronitrile: 9.0 g (hereinafter referred to as “solution”). a)), the solution a was added dropwise over 4 hours to the above mixture of methyl cellosolve and toluene having a mass ratio of 3: 2 heated to 80 ° C., and then stirred at 80 ° C. for 2 hours. Keep warm. Further, a solution in which 1.2 g of azobisisobutyronitrile was dissolved in 100 g of a mixture of 1-methoxy-2-propanol and toluene having a mass ratio of 3: 2 was dropped into the flask over 10 minutes. The solution after dropping was kept at 80 ° C. for 3 hours while stirring, and then heated to 90 ° C. over 30 minutes. The mixture was kept at 90 ° C. for 2 hours and then cooled to obtain a binder polymer A-1.
The binder polymer (A-1) had a non-volatile content (solid content) of 48.3 mass% and a weight average molecular weight of 45,000. 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 (three in total) (above, manufactured by Hitachi Chemical Co., Ltd., trade name)
Eluent: Tetrahydrofuran Measurement temperature: 40 ° C
Flow rate: 2.05 mL / min Detector: Hitachi L-3300 type RI [manufactured by Hitachi, Ltd.]

[Synthesis of Binder Polymers (A-2) to (A-12)]
The binder polymers A-2 to A-12 were synthesized in the same manner as A-1 with the composition of the comonomer shown in Table 1 below.

(Preparation of photosensitive resin composition)
The above binder polymers (A-1) to (A-12) and the following materials are blended in the mass ratio shown in the following Table 2 (the component (A) is a solid content), and Examples 1 to 5 and Comparison Solutions of the photosensitive resin compositions of Examples 1-8 were prepared.

<(B) Photopolymerizable compound>
(B-1): FA-321M (manufactured by Hitachi Chemical Co., Ltd., trade name); 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane)
(B-2): FA-024M (trade name, manufactured by Hitachi Chemical Co., Ltd.); in the compound represented by the general formula (1), R = methyl group, m ₃ = 6 (average value), n ₂ + N ₃ = 12 (average value)
(B-3): M-114 (trade name, manufactured by Toagosei Co., Ltd .; 4-normalnonylphenoxyoctaethylene glycol acrylate)
(B-4): UA-13 (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.); a dimethacrylate compound having a urethane bond represented by the following chemical formula (4)

<(C) Photopolymerization initiator>
(C-1): BCIM (trade name, manufactured by Hampford, Inc.); 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbisimidazole <(D) sensitizing dye >
(D-1): DBA (trade name, manufactured by Kawasaki Kasei Kogyo Co., Ltd.); 9,10-dibutoxyanthracene <(E) Color former (amine compound)>
(E-1): leuco crystal violet

  Next, the photosensitive resin composition solution was uniformly applied onto a 16 μm thick polyethylene terephthalate film (product name “HTF-01” manufactured by Teijin Limited), and a hot air convection dryer at 70 ° C. and 110 ° C. And a photosensitive resin composition layer having a film thickness after drying of 25 μm was formed. Subsequently, a protective film (manufactured by Tamapoly Co., Ltd., product name “NF-15”) is laminated on the photosensitive resin composition layer by roll pressurization, and the photosensitivity according to each of Examples 1 to 5 and Comparative Examples 1 to 8. A sex element was obtained.

(Measurement of frequency change)
Each photosensitive resin composition layer adheres to the surface of the crystal unit while removing the protective film of each photosensitive element on the crystal unit having a natural frequency of 5 MHz and a gold electrode area of 1.37 cm ^2. In this manner, lamination was performed at 110 ° C. under a pressure of 0.4 MPa (4 kgf / cm ² ) at a lamination speed of 1.5 m / min.
Made by Hitachi Via Mechanics Co., Ltd., using a 405 nm blue-violet laser diode as a light source on a photosensitive resin composition layer of a quartz resonator in which each photosensitive element is laminated; Direct drawing machine “DE-1AH” (trade name) Was used and exposed through a polyethylene terephthalate film with an energy amount of 100 mJ / cm ² to form a cured film. The illuminance was measured using an ultraviolet illuminometer (trade name: UIT-150, manufactured by Ushio Inc.) to which a 405 nm probe was applied. Thereafter, the polyethylene terephthalate film on the cured film was peeled off, and the sensor on which the crystal resonator was installed was immersed in a 1% by mass sodium carbonate aqueous solution at 25 ° C., and QCM (manufactured by MAXTEK Corporation, PM-700) was used. Then, the amount of change in the frequency after 60 seconds from immediately after the immersion was measured. The results are shown in Table 3.

(Preparation of test piece)
On the other hand, the copper surface of a copper clad laminate (made by Hitachi Chemical Co., Ltd., trade name: MCL-E-67), which is a glass epoxy material in which copper foil (thickness 35 mm) is laminated on both sides, is a brush equivalent to # 600. Polishing was performed using a polishing machine (manufactured by Sankei Co., Ltd.), washed with water, and dried with an air flow to obtain a copper-clad laminate (substrate). After heating the copper clad laminate to 80 ° C., each photosensitive resin composition layer is placed on the surface of the copper clad laminate while removing the protective film of each photosensitive element on the copper clad laminate. A test piece was prepared by laminating (lamination) at 110 ° C. under a pressure of 0.4 MPa (4 kgf / cm ² ) and a lamination speed of 1.5 m / min.

(Characteristic evaluation)
<Sensitivity>
Next, the copper-clad laminate on which each photosensitive element is laminated is allowed to cool, and when the temperature reaches 23 ° C., on polyethylene terephthalate, concentration range: 0.00 to 2.00, concentration step: 0.05. The size of the tablet: 20 mm × 187 mm, and a phototool having a 41-step tablet with a step size of 3 mm × 12 mm was brought into close contact.
Using a direct drawing machine “DE-1AH” (trade name) manufactured by Hitachi Via Mechanics Co., Ltd., which uses a 405 nm blue-violet laser diode as a light source, with a photo tool and a polyethylene terephthalate film at an energy amount of 50 mJ / cm ^2. Then, the photosensitive resin composition layer was exposed (drawn). The illuminance was measured using an ultraviolet illuminometer (trade name: UIT-150, manufactured by Ushio Inc.) to which a 405 nm probe was applied.
Next, the polyethylene terephthalate film was peeled off, and a 1% by mass sodium carbonate aqueous solution was sprayed at 30 ° C. for 24 seconds to remove unexposed portions. Then, 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 above. The photosensitivity is indicated by the number of steps of the step tablet, and the higher the number of steps of the step tablet, the higher the photosensitivity.

<Resolution and adhesion>
Using a drawing pattern having a line width / space width of 3/3 to 30/30 (unit: μm) for the test piece, the number of steps of the 41-step tablet is 12 steps, and the support film Then, the photosensitive resin composition layer was exposed (drawn).
Thereafter, the unexposed portion can be removed cleanly by development processing, and the line is formed without meandering and chipping. The line width and the space width are equal, and the line width / space width is the smallest value. Thus, resolution and adhesion were evaluated. The smaller the numerical value, the better the resolution and adhesion. The results are shown in Table 3 above.

<Peeling characteristics>
A photosensitive resin composition layer according to each example and comparative example was formed on a copper clad laminate, and the photosensitive resin composition layer was exposed and developed under the conditions shown in Table 4 below. A photocured film having a size of 50 mm was prepared. And it peeled off using 3 mass% sodium hydroxide aqueous solution. The peeling characteristics were evaluated by the peeling time and the peeling piece size. The peeling time was the time when the peeling liquid was sprayed and the photocured film was completely peeled off from the copper clad laminate. Moreover, the size of the peeling piece after peeling was observed visually, and the peeling piece size was evaluated according to the criteria shown in Table 4. Table 4 shows the obtained results.

<Resist shape>
In the evaluation of the resolution and adhesion, the developed resist shape (line width: 10 μm) was observed using a Hitachi scanning electron microscope S-500A and evaluated according to the following criteria. The results are shown in Table 3 above. If the cross-sectional shape of the resist is trapezoidal or inverted trapezoidal, or if there is a tailing of the resist, there is a possibility that a short circuit or disconnection may occur in a circuit formed by subsequent etching or plating. Accordingly, it is desirable that the resist has a rectangular cross-sectional shape and no tailing.
A: The cross-sectional shape of the resist is rectangular and there is no bottoming B: The cross-sectional shape of the resist is rectangular and has a bottoming C: The cross-sectional shape of the resist is not rectangular and there is no bottoming D: The cross-sectional shape of the resist is There is a skirt rather than a rectangle

As is clear from the results shown in Table 3, in Examples 1 to 5, the sensitivity and the resist shape are excellent, in particular, the resolution and adhesion (L / S) are excellent as 9 μm, and the peeling time is moderate. In addition, the peel piece size was small, and the balance of all characteristics was good.
On the other hand, in Comparative Examples 1-3, 4-5, and 7, the peeling properties were good, but the resolution and adhesion were insufficient. Furthermore, in Comparative Examples 6 and 8, a development residue was generated after the resist pattern was formed, and pattern formation was impossible.

Claims (10)

  (A) A photosensitive resin composition containing an alkali-soluble group-containing binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator, wherein the photosensitive resin is formed on a crystal resonator When the cured film of the composition is immersed in a 1% by mass sodium carbonate aqueous solution at 25 ° C., and the indicated value of the crystal resonator microbalance (QCM) immediately after immersion is 0 Hz, the amount of change in frequency in 60 seconds after immersion is The photosensitive resin composition which is -80 Hz or more and -20 Hz or less per 1 micrometer of film thickness of a cured film.   The photosensitive resin composition according to claim 1, wherein (A) the alkali-soluble group-containing binder polymer contains (meth) acrylic acid as a copolymerization component.   3. The photosensitive resin composition according to claim 1, wherein (A) the alkali-soluble group-containing binder polymer contains styrene or a styrene derivative as a copolymerization component.   In any one of Claim 1 thru | or 3, (A) alkali-soluble group containing binder polymer is (meth) acrylic-acid benzyl ester, (meth) acrylic-acid t-butyl ester, (meth) acrylic-acid n-butyl ester, ( A photosensitive resin composition comprising, as a copolymerization component, one or more selected from the group consisting of (meth) acrylic acid cyclohexyl ester, (meth) acrylic acid adamantyl ester, and (meth) acrylic acid tetrahydrofurfuryl ester.   5. The photosensitive resin composition according to claim 1, wherein (A) the acid value of the alkali-soluble group-containing binder polymer is 50 to 300 mgKOH / g.   The photosensitive resin composition in any one of Claims 1 thru | or 5 whose weight average molecular weights of (A) alkali-soluble group containing binder polymer are 5000-150,000.   A photosensitive element provided with a support film and the photosensitive resin composition layer which has the photosensitive resin composition in any one of Claims 1 thru | or 6 formed on this support film.   A laminating step of laminating a photosensitive resin composition layer having the photosensitive resin composition according to any one of claims 1 to 6 on a circuit forming substrate, and active in a predetermined portion of the photosensitive resin composition layer A method for forming a resist pattern, comprising: an exposure step of irradiating light to photocure an exposed portion; and a developing step of removing a portion other than the exposed portion of the photosensitive resin composition layer from the circuit forming substrate.   9. The method of forming a resist pattern according to claim 8, wherein the exposure step is a step of directly drawing and exposing the photosensitive resin composition layer with a laser beam to photocure the exposed portion.   A method for manufacturing a printed wiring board, comprising: etching or plating a circuit forming substrate on which a resist pattern is formed by the method for forming a resist pattern according to claim 8.