Photosensitive resin composition, photosensitive element, method for forming resist pattern, and method for manufacturing printed wiring board

Abstract

To provide a photosensitive resin composition which can shorten development time without impairing excellent resolution and adhesion.SOLUTION: A photosensitive resin composition contains (A) a binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator represented by the following general formula (I), wherein (C) the photopolymerization initiator contains at least a first photopolymerization initiator which does not have an alkoxy group and is represented by the following general formula (I), and a second photopolymerization initiator which has an alkoxy group and is represented by the following general formula (I). The absorbance to light with a wavelength of 365 nm per 1 μm thickness of the photosensitive resin composition is 0.0030 to 0.0119. In the formula (I), Z1 and Z2 each independently represent a monovalent group represented by general formula (II) or (III).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for producing a printed wiring board. [Background technology]

[0002] In the field of printed wiring board production, photosensitive resin compositions and photosensitive elements (laminates) having a structure in which a layer containing this photosensitive resin composition (hereinafter referred to as a "photosensitive layer") is formed on a support and a protective film is disposed on the photosensitive layer are widely used as resist materials used in etching, plating, and the like.

[0003] When a printed wiring board is manufactured using a photosensitive element, first, the photosensitive layer of the photosensitive element is laminated on a circuit-forming substrate. Next, a predetermined portion of the photosensitive layer is irradiated with active light rays to harden the exposed portion. After that, the support is peeled off and removed, and the unexposed portion of the photosensitive layer is removed with a developer to form a resist pattern on the substrate. Next, using this resist pattern as a mask, the substrate on which the resist pattern is formed is subjected to an etching process or a plating process to form a circuit pattern on the substrate, and finally, the hardened portion of the photosensitive layer (resist pattern) is peeled off and removed from the substrate.

[0004] The exposure method involves exposing the photosensitive layer to a pattern through a mask film or the like. In recent years, the projection exposure method has come into use, in which the photosensitive layer is exposed by irradiating it with active light projected from an image of a photomask through a lens. Ultra-high pressure mercury lamps are used as the light source for the projection exposure method. Generally, exposure machines that use monochromatic i-line light (365 nm) as the exposure wavelength are widely used, but monochromatic h-line light (405 nm) and IHG mixed line exposure wavelengths may also be used.

[0005] The projection exposure method is an exposure method that can ensure high resolution and high alignment compared to the contact exposure method, and therefore has attracted much attention in the current situation where there is a demand for finer circuit formation on printed wiring boards.

[0006] With the recent trend toward high density printed wiring boards, there is an increasing demand for photosensitive resin compositions with excellent resolution and adhesion. In particular, in the manufacture of package substrates, there is a demand for photosensitive resin compositions capable of forming resist patterns with a line width / space width of 10 / 10 (unit: μm) or less. For example, Patent Document 1 discusses the use of a specific photopolymerizable compound to improve resolution and adhesion. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2013-195712 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, photosensitive resin compositions having excellent resolution and adhesion have a problem in that the development time of the photosensitive layer tends to be long, and it is desirable to shorten the development time as much as possible in order to improve production throughput.

[0009] Therefore, an object of the present disclosure is to provide a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for producing a printed wiring board, which are capable of shortening the development time without impairing excellent resolution and adhesion. [Means for solving the problem]

[0010] In order to solve the above problems, the present inventors have conducted extensive research focusing on photopolymerization initiators. As a result, they have found that a photosensitive resin composition that is sufficiently effective in shortening the development time without impairing excellent resolution and adhesion can be obtained by using two or more specific photopolymerization initiators in combination and setting the absorbance within a specific range, and have completed the present invention. That is, the present invention provides the following photosensitive resin composition, photosensitive element, method for forming a resist pattern, and method for producing a printed wiring board.

[0011] [1] A photosensitive resin composition comprising (A) a binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator represented by the following general formula (I), wherein the (C) photopolymerization initiator comprises at least a first photopolymerization initiator represented by the following general formula (I) having no alkoxy group, and a second photopolymerization initiator represented by the following general formula (I) having an alkoxy group, and wherein the absorbance of the photosensitive resin composition for light having a wavelength of 365 nm per 1 μm of thickness is 0.0030 to 0.0119. [ka] [In formula (I), Z 1 and Z 2 each independently represents a monovalent group represented by the following general formula (II) or (III). [ka] [ka] [In formula (II) and formula (III), R 1 ~R 30 each independently represents a hydrogen atom, a halogen atom, or an alkoxy group having 1 to 5 carbon atoms, and R 1 ~R 30 When multiple are present, they may be the same or different. [2] The photosensitive resin composition according to the above [1], wherein the second photopolymerization initiator has at least one methoxy group. [3] The photosensitive resin composition according to the above [1] or [2], wherein the content of the (C) photopolymerization initiator is 1 to 5 mass % based on the total solid content of the photosensitive resin composition. [4] The photosensitive resin composition according to any one of the above [1] to [3], wherein the binder polymer (A) comprises a binder polymer having a divalent group represented by the following general formula (IV): [ka] [In formula (IV), R 31 represents a hydrogen atom or a methyl group, R 32 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom, and multiple R 32 may be the same or different.] [5] The photosensitive resin composition according to any one of the above [1] to [4], wherein the binder polymer (A) comprises a binder polymer having a divalent group represented by the following general formula (V): [ka] [In formula (V), R 33 represents a hydrogen atom or a methyl group. [6] The photosensitive resin composition according to any one of the above [1] to [5], wherein the (A) binder polymer comprises a binder polymer having a divalent group represented by the following general formula (VI): [ka] [In formula (VI), R 34 represents a hydrogen atom or a methyl group, R 35 represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom; m represents an integer of 0 to 5; 35 may be the same or different.] [7] The photosensitive resin composition according to any one of the above [1] to [6], wherein the binder polymer (A) comprises a binder polymer having a divalent group represented by the following general formula (VII): [ka] [In formula (VII), R 36 represents a hydrogen atom or a methyl group, R 37 represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom; n represents an integer of 0 to 5; 37 may be the same or different.] [8] The photosensitive resin composition according to any one of the above [1] to [7], wherein the (A) binder polymer includes a binder polymer having a weight average molecular weight of 20,000 to 50,000. [9] The photosensitive resin composition according to any one of the above [1] to [8], further comprising a heterocyclic compound.

[10] The photosensitive resin composition according to any one of the above [1] to [9], further comprising a hydrogen donor compound.

[11] The photosensitive resin composition according to any one of the above [1] to

[10] , further comprising a polymerization inhibitor.

[12] The photosensitive resin composition according to any one of the above [1] to

[11] , further comprising a dye.

[13] The photosensitive resin composition according to any one of the above [1] to

[12] , wherein the content of the sensitizer is 0.065 mass % or less based on the total solid content of the photosensitive resin composition.

[14] A photosensitive element comprising a support and a photosensitive layer formed on the support, the photosensitive layer comprising the photosensitive resin composition according to any one of [1] to

[13] above.

[15] A method for forming a resist pattern, comprising: a photosensitive layer forming step of laminating a photosensitive layer containing the photosensitive resin composition according to any one of the above [1] to

[13] or a photosensitive layer of the photosensitive element according to the above

[14] on a substrate; an exposure step of irradiating predetermined portions of the photosensitive layer with active light to form photocured portions; and a development step of removing areas of the photosensitive layer other than the predetermined portions from the substrate.

[16] The method for forming a resist pattern according to the above

[15] , wherein the wavelength of the actinic radiation is within the range of 340 to 430 nm.

[17] A method for producing a printed wiring board, comprising the step of etching or plating a substrate on which a resist pattern has been formed by the method for forming a resist pattern according to

[15] or

[16] above, to form a conductor pattern.

[0012] The photosensitive resin composition described in [1] above is composed of a combination of the specific components as described above, and therefore, even when a resist pattern is formed by a projection exposure method, it is possible to form a resist pattern with sufficient resolution and adhesion, and the development time can be sufficiently shortened. In addition, by adjusting the absorbance of the photosensitive resin composition to 0.0030 or more for light with a wavelength of 365 nm per 1 μm thickness, the decrease in resolution can be suppressed. In addition, by adjusting the absorbance of the photosensitive resin composition to 0.0119 or less for light with a wavelength of 365 nm per 1 μm thickness, the resolution and adhesion can be improved. Furthermore, the present inventors believe that by combining two or more specific initiators such as the above component (C), the development time of the photosensitive layer can be shortened without decreasing the resolution and adhesion. In addition, the photosensitive resin composition can also shorten the peeling time of the resist pattern.

[0013] According to the photosensitive resin composition described in the above item [2], the adhesion of the photosensitive resin composition is further improved, and the developing time and the peeling time can be further shortened.

[0014] In the photosensitive resin composition described in [3] above, if the content of the (C) photopolymerization initiator is 1% by mass or more, the resolution and adhesion of the photosensitive resin composition are further improved. If the content of the (C) photopolymerization initiator is 5% by mass or less, the development time and peeling time can be further shortened. If the content of the (C) photopolymerization initiator is within the above range, the occurrence of cracks in the photosensitive layer after exposure can be suppressed in a bending resistance test performed using a cylindrical mandrel with a diameter of 6 μm according to the cylindrical mandrel method (JIS K5600-5-1:1999).

[0015] According to the photosensitive resin composition described in the above [4], the resolution and adhesion of the photosensitive resin composition are further improved.

[0016] According to the photosensitive resin composition described in the above item [5], the resolution and adhesion of the photosensitive resin composition are further improved, and the developing time and the peeling time can be further shortened.

[0017] According to the photosensitive resin composition described in the above item [6], the resolution and adhesion of the photosensitive resin composition are further improved.

[0018] According to the photosensitive resin composition described in the above item [7], the resolution and adhesion of the photosensitive resin composition are further improved, and the developing time and the peeling time can be further shortened.

[0019] According to the photosensitive resin composition described in the above item [8], the resolution and adhesion of the photosensitive resin composition can be further improved, and the developing time and the peeling time can be further shortened.

[0020] According to the photosensitive resin composition described in the above [9], the adhesion of the photosensitive resin composition can be further improved.

[0021] According to the photosensitive resin composition described in the above item

[10] , the sensitivity, resolution and adhesion of the photosensitive resin composition can be further improved.

[0022] According to the photosensitive resin composition described in the above item

[11] , unintended curing reactions in areas other than exposed areas of the photosensitive layer can be suppressed, thereby improving resolution and stability.

[0023] According to the photosensitive resin composition described in the above item

[12] , the adhesion of the photosensitive resin composition can be further improved, and the developing time and the peeling time can be further shortened.

[0024] According to the photosensitive resin composition described in the above item

[13] , the absorbance of the photosensitive resin composition for light with a wavelength of 365 nm is not too high, and the resolution and adhesion can be further improved.

[0025] The photosensitive element described in

[14] above has a photosensitive layer containing the photosensitive resin composition. Therefore, even when a resist pattern is formed by exposure using a projection exposure method, it is possible to form a resist pattern with sufficient resolution and adhesion, and is also effective in shortening the developing time and peeling time.

[0026] According to the method for forming a resist pattern described in

[15] above, a resist pattern is formed using a photosensitive layer containing the above-mentioned photosensitive resin composition, so that a resist pattern with sufficient resolution and adhesion can be formed.

[0027] The curing reaction of the photosensitive resin composition proceeds efficiently within the exposure wavelength range specified in the method for forming a resist pattern described in

[16] above, and therefore the method for forming a resist pattern described in

[16] above can form a resist pattern with more sufficient resolution and adhesion.

[0028] According to the method for producing a printed wiring board described in

[17] above, a circuit-forming substrate on which a resist pattern has been formed by the above-mentioned resist pattern forming method is used, so that high-density wiring can be formed and high-throughput production is possible by shortening the development time and peeling time. Effect of the Invention

[0029] According to the present disclosure, it is possible to provide a photosensitive resin composition, a photosensitive element, a method for forming a resist pattern, and a method for producing a printed wiring board, which are capable of shortening the development time without impairing excellent resolution and adhesion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments.

[0031] In this specification, the term "step" includes not only an independent step, but also a step that cannot be clearly distinguished from other steps, as long as the intended effect of the step is achieved. In this specification, the term "layer" includes a structure having a shape formed on the entire surface as well as a structure having a shape formed on a part of the surface when observed in a plan view. In this specification, "(meth)acrylic acid" means at least one of "acrylic acid" and the corresponding "methacrylic acid". The same applies to other similar expressions such as (meth)acrylate.

[0032] In this specification, a numerical range indicated using "~" indicates a range including the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper limit or lower limit of a certain numerical range may be replaced with the upper limit or lower limit of a numerical range of another stage. In addition, in the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with a value shown in the examples.

[0033] In this specification, when referring to the amount of each component in a composition, if multiple substances corresponding to each component are present in the composition, the amount refers to the total amount of those multiple substances present in the composition, unless otherwise specified.

[0034] [Photosensitive resin composition] The photosensitive resin composition of the present embodiment contains component (A): a binder polymer, component (B): a photopolymerizable compound, and component (C): a photopolymerization initiator represented by the following general formula (I). The component (C) contains at least a first photopolymerization initiator represented by the following general formula (I) that does not have an alkoxy group, and a second photopolymerization initiator represented by the following general formula (I) that has an alkoxy group. The photosensitive resin composition has an absorbance of 0.0030 to 0.0119 for light with a wavelength of 365 nm per 1 μm of thickness. [ka] [In formula (I), Z 1 and Z2 each independently represents a monovalent group represented by the following general formula (II) or (III). [ka] [ka] [In formula (II) and formula (III), R 1 ~R 30 each independently represents a hydrogen atom, a halogen atom, or an alkoxy group having 1 to 5 carbon atoms, and R 1 ~R 30 When multiple are present, they may be the same or different.

[0035] The photosensitive resin composition of the present embodiment contains the above components (A) to (C) as essential components, and has an absorbance of 0.0030 to 0.0119 for light of wavelength 365 nm per 1 μm of thickness, thereby making it possible to form a resist pattern with excellent resolution and adhesion, and to shorten the developing time of the photosensitive layer. Furthermore, the photosensitive resin composition of the present embodiment also makes it possible to shorten the peeling time of the resist pattern.

[0036] The photosensitive resin composition of the present embodiment may further contain a hydrogen donor or other components, as necessary. Each component used in the photosensitive resin composition of the present embodiment will be described in more detail below.

[0037] (Component (A): Binder polymer) The photosensitive resin composition of the present embodiment can have improved resolution and adhesion by containing a binder polymer.

[0038] The component (A) may contain a binder polymer having at least one of a divalent group represented by the following general formula (IV), a divalent group represented by the following general formula (V), a divalent group represented by the following general formula (VI), and a divalent group represented by the following general formula (VII). This further improves the resolution and adhesion of the photosensitive resin composition. Furthermore, the development time and peeling time can be further shortened.

[0039] [ka] In formula (IV), R 31 represents a hydrogen atom or a methyl group, R 32 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom, and multiple R 32 may be the same or different from each other.

[0040] [ka] In formula (V), R 33 represents a hydrogen atom or a methyl group.

[0041] [ka] In formula (VI), R 34 represents a hydrogen atom or a methyl group, R 35 represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom; m represents an integer of 0 to 5; 35 may be the same or different from each other.

[0042] [ka] In formula (VII), R 36 represents a hydrogen atom or a methyl group, R 37represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom; n represents an integer of 0 to 5; 37 may be the same or different from each other.

[0043] The weight average molecular weight (Mw) of the (A) component may be 8000 to 100000, 10000 to 80000, 15000 to 70000, or 20000 to 50000. When Mw is 100000 or less, the resolution and developability tend to improve, and when Mw is 8000 or more, the flexibility of the cured film improves, and chipping and peeling of the resist pattern tend to be less likely to occur. The dispersity (Mw / Mn) of the (A) component may be 1.0 to 3.0, 1.2 to 2.5, 1.4 to 2.3, or 1.5 to 2.0. When the dispersity is smaller, the resolution tends to improve. The weight average molecular weight of the binder polymer is measured by gel permeation chromatography (GPC) (converted by a calibration curve using standard polystyrene).

[0044] In the photosensitive resin composition of the present embodiment, the component (A) may be one type of binder polymer used alone, or two or more types of binder polymers may be used in any combination. Examples of the binder polymers used in combination of two or more types include two or more types of binder polymers made of different copolymerization components (containing different monomer units as copolymerization components), and two or more types of binder polymers with different Mw.

[0045] The acid value of component (A) may be 100 to 250 mgKOH / g, 120 to 240 mgKOH / g, 140 to 230 mgKOH / g, or 150 to 230 mgKOH / g. When the acid value of component (A) is 100 mgKOH / g or more, it is possible to sufficiently prevent the development time from becoming long, and when it is 250 mgKOH / g or less, it is easy to improve the developer resistance (adhesion) of the cured product of the photosensitive resin composition.

[0046] The acid value of component (A) can be measured as follows. First, 1 g of the binder polymer to be measured for acid value is precisely weighed out. 30 g of acetone is added to the precisely weighed binder polymer and dissolved uniformly. Next, an appropriate amount of phenolphthalein as an indicator is added to the solution, and titration is performed using a 0.1 N aqueous potassium hydroxide (KOH) solution. The acid value is obtained by calculating the number of mg of KOH required to neutralize the acetone solution of the binder polymer to be measured. When the solution to be measured is a mixture of the binder polymer with a synthesis solvent, dilution solvent, etc., the acid value is calculated using the following formula. Acid value = 0.1 x Vf x 56.1 / (Wp x I / 100) In the formula, Vf represents the titration amount (mL) of the KOH aqueous solution, Wp represents the mass (g) of the measured solution containing the binder polymer, and I represents the proportion (mass%) of the non-volatile content in the measured solution containing the binder polymer. In addition, when the binder polymer is mixed with a volatile matter such as a synthesis solvent or a dilution solvent and then blended, the acid value can be measured after removing the volatile matter by heating the mixture at a temperature 10°C or more higher than the boiling point of the volatile matter for 1 to 4 hours before weighing.

[0047] The content of the component (A) in the photosensitive resin composition of this embodiment may be 20 to 90 mass%, 30 to 80 mass%, or 40 to 65 mass% based on the total solid content of the photosensitive resin composition. When the content of the component (A) is 20 mass% or more, the film tends to have excellent formability, and when it is 90 mass% or less, the sensitivity and resolution tend to be excellent.

[0048] ((B) component: photopolymerizable compound) The (B) component is not particularly limited as long as it has at least one ethylenically unsaturated bond and is a photopolymerizable compound. From the viewpoint of improving the alkali developability, resolution, and peeling properties after curing, the (B) component preferably contains at least one bisphenol type (meth)acrylate, and among the bisphenol type (meth)acrylates, it is more preferable to contain bisphenol A type (meth)acrylate. Examples of the bisphenol A type (meth)acrylate include 2,2-bis(4-((meth)acryloxypolyethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloxypolyethoxypolypropoxy)phenyl)propane. Among these, from the viewpoint of further improving the resolution and peeling properties, 2,2-bis(4-((meth)acryloxypolyethoxy)phenyl)propane is preferred.

[0049] Examples of commercially available bisphenol A type (meth)acrylates include 2,2-bis(4-((meth)acryloxydipropoxy)phenyl)propane, such as BPE-200 (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name), ethoxylated bisphenol A dimethacrylate, such as BP-2EM (manufactured by Kyoeisha Chemical Co., Ltd., trade name), and 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane, such as BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name), and FA-321M (manufactured by Showa Denko Materials Co., Ltd., trade name). These bisphenol A type (meth)acrylates may be used alone or in combination of two or more.

[0050] The content of the bisphenol type (meth)acrylate may be 40 to 98 mass%, 50 to 97 mass%, 60 to 95 mass%, or 70 to 90 mass% based on the total amount of the (B) component. If the content is 40 mass% or more, the resolution, adhesion, and suppression of the occurrence of resist tailing will be better, and if it is 98 mass% or less, the development time will be appropriately shortened and the occurrence of development residue will be more unlikely.

[0051] As the (B) component other than the bisphenol type (meth)acrylate, from the viewpoint of improving the flexibility of the cured product (cured film), at least one of polyalkylene glycol di(meth)acrylate having at least one of a (poly)oxyethylene chain and a (poly)oxypropylene chain in the molecule may be further included, and polyalkylene glycol di(meth)acrylate having both a (poly)oxyethylene chain and a (poly)oxypropylene chain in the molecule may be further included. Examples of the polyalkylene glycol di(meth)acrylate include FA-023M (manufactured by Showa Denko Materials Co., Ltd., trade name), FA-024M (manufactured by Showa Denko Materials Co., Ltd., trade name), and NK Ester HEMA-9P (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name). These may be used alone or in combination of two or more.

[0052] The content of the polyalkylene glycol di(meth)acrylate may be 2 to 40 mass %, 3 to 30 mass %, or 5 to 20 mass % based on the total amount of the component (B).

[0053] Other (B) components may include nonylphenoxy polyethyleneoxy acrylate, phthalic acid compounds, (meth)acrylic acid polyol esters, (meth)acrylic acid alkyl esters, etc. Among them, from the viewpoint of improving the resolution, adhesion, resist shape, and peeling properties after curing in a well-balanced manner, the (B) component may contain at least one selected from nonylphenoxy polyethyleneoxy acrylate and phthalic acid compounds. However, since the refractive index of these compounds is relatively low, from the viewpoint of improving the resolution, the content thereof may be 5 to 50 mass%, 5 to 40 mass%, or 10 to 30 mass% based on the total amount of the (B) component.

[0054] Examples of nonylphenoxy polyethyleneoxyacrylates include nonylphenoxy triethyleneoxyacrylate, nonylphenoxy tetraethyleneoxyacrylate, nonylphenoxy pentaethyleneoxyacrylate, nonylphenoxy hexaethyleneoxyacrylate, nonylphenoxy heptaethyleneoxyacrylate, nonylphenoxy octaethyleneoxyacrylate, nonylphenoxy nonaethyleneoxyacrylate, nonylphenoxy decaethyleneoxyacrylate, and nonylphenoxy undecaethyleneoxyacrylate.

[0055] Examples of the phthalic acid compound include γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, β-hydroxyethyl-β'-(meth)acryloyloxyethyl-o-phthalate, and β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate, and among them, γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl-o-phthalate may be used. γ-Chloro-β-hydroxypropyl-β'-methacryloyloxyethyl-o-phthalate is commercially available as FA-MECH (trade name, manufactured by Showa Denko Materials Co., Ltd.).

[0056] From the viewpoint of improving sensitivity and reducing tailing, the component (B) may contain a (meth)acrylic polyol. Examples of the (meth)acrylic polyol ester include trimethylolpropane polyethoxy tri(meth)acrylate, trimethylolpropane polypropoxy tri(meth)acrylate, trimethylolpropane polybutoxy tri(meth)acrylate, trimethylolpropane polyethoxy polypropoxy tri(meth)acrylate, trimethylolethane polyethoxy tri(meth)acrylate, trimethylolethane polypropoxy tri(meth)acrylate, trimethylolethane polybut ... Examples of the polyethoxypolypropoxytri(meth)acrylate include pentaerythritol polyethoxytri(meth)acrylate, pentaerythritol polypropoxytri(meth)acrylate, pentaerythritol polybutoxytri(meth)acrylate, pentaerythritol polyethoxypolypropoxytri(meth)acrylate, glyceryl polyethoxytri(meth)acrylate, glyceryl polypropoxytri(meth)acrylate, glyceryl polybutoxytri(meth)acrylate, and glyceryl polyethoxypolypropoxytri(meth)acrylate.

[0057] The content of component (B) is preferably 20 to 60 parts by mass, more preferably 30 to 55 parts by mass, and even more preferably 35 to 50 parts by mass, relative to 100 parts by mass of the total amount of components (A) and (B). When the content of component (B) is within this range, the photosensitive resin composition exhibits better photosensitivity and coating properties in addition to improved resolution, adhesion, and resist tail generation.

[0058] (Component (C): Photopolymerization initiator) As the component (C), two or more types of hexaarylbiimidazole derivatives represented by the following general formula (I) are used.

[0059] [ka] [In formula (I), Z1 and Z 2 each independently represents a monovalent group represented by the following general formula (II) or (III). [ka] [ka] [In formula (II) and formula (III), R 1 ~R 30 each independently represents a hydrogen atom, a halogen atom, or an alkoxy group having 1 to 5 carbon atoms, and R 1 ~R 30 When multiple are present, they may be the same or different.

[0060] Examples of the hexaarylbiimidazole derivative represented by the above general formula (I) include 2-(o-chlorophenyl)-4,5-diphenylbiimidazole, 2,2',4-tris-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-4',5'-diphenylbiimidazole, 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole, 2,4,5-tris-(o-chlorophenyl)-diphenylbiimidazole, 2-(o-chlorophenyl)-bis-4,5-(3,4-dimethoxyphenyl)-biimidazole, 2,2'-bis-(2-fluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3-difluoromethylphenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,4-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, and 2,2'-bis-(2,5-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole. Among them, from the viewpoint of resolution and adhesion, 2-(o-chlorophenyl)-4,5-diphenylbiimidazole, 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylbiimidazole, and 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole are preferred. Also, from the viewpoint of shortening the development time and stripping time, 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylbiimidazole and 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole are more preferred. 2-(o-chlorophenyl)-4,5-diphenylbiimidazole is commercially available under the trade name "B-CIM" from Hodogaya Chemical Industry Co., Ltd., and 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylbiimidazole is commercially available under the trade name "TR-HABI-102" from Changzhou Strong Electronic New Materials Co., Ltd.

[0061] The component (C) does not have an alkoxy group (i.e., R 1 ~R 30 a first photopolymerization initiator represented by the above general formula (I) having an alkoxy group (i.e., R 1 ~R 30 and a second photopolymerization initiator represented by the above general formula (I), at least one of which is an alkoxy group having 1 to 5 carbon atoms. By using these two types of photopolymerization initiators in combination, the photosensitive resin composition can reduce the developing time of the photosensitive layer and the peeling time of the resist pattern without impairing the excellent resolution and adhesion.

[0062] From the viewpoint of improving resolution and adhesion, the second photopolymerization initiator may have at least one methoxy group as the alkoxy group. The number of alkoxy groups in the second photopolymerization initiator is 1 or more, but from the viewpoint of shortening the development time and the peeling time, it may be 2 or more or 3 or more, and from the viewpoint of suppressing the decrease in resolution and adhesion, it may be 5 or less.

[0063] The first photopolymerization initiator and the second photopolymerization initiator may have at least one halogen atom from the viewpoint of improving resolution and adhesion. The number of halogen atoms that the first photopolymerization initiator and the second photopolymerization initiator have may be 1 or more, 2 or more, or 3 or more from the viewpoint of improving resolution and adhesion, and may be 4 or less from the viewpoint of suppressing extension of development time and peeling time.

[0064] The first photopolymerization initiator may be used alone or in combination of two or more kinds, and the second photopolymerization initiator may be used alone or in combination of two or more kinds.

[0065] The content of the (C) component may be 0.5 to 10 parts by mass, 1 to 8 parts by mass, or 1.5 to 5 parts by mass, based on 100 parts by mass of the total amount of the (A) component and the (B) component. When the content of the (C) component is within this range, it is easy to improve both the photosensitivity and the resolution in a well-balanced manner. When the content of the (C) component is 1% by mass or more of the photosensitive resin composition, the resolution and adhesion can be increased, and when the content is 5% by mass or less of the photosensitive resin composition, the development time and the peeling time can be sufficiently shortened. When the content of the (C) component is adjusted so that the absorbance of the photosensitive resin composition at a wavelength of 365 nm per 1 μm of thickness is 0.0030 or more, the deterioration of the resolution can be suppressed, and when the absorbance of the photosensitive resin composition at a wavelength of 365 nm per 1 μm of thickness is 0.0119 or less, the resolution and adhesion can be increased.

[0066] In the component (C), the contents of the first photopolymerization initiator and the second photopolymerization initiator are not particularly limited as long as they are adjusted so that the absorbance of the photosensitive resin composition per 1 μm thickness for light with a wavelength of 365 nm is 0.0030 or more and 0.0119 or less. However, since this makes it easy to shorten the developing time of the photosensitive layer and the peeling time of the resist pattern without impairing excellent resolution and adhesion, the content of the first photopolymerization initiator may be 40 to 97 mass%, 50 to 95 mass%, or 60 to 93 mass% based on the total amount of solids in the component (C) (the total amount of the first photopolymerization initiator and the second photopolymerization initiator).

[0067] The photosensitive resin composition of the present embodiment may contain a photopolymerization initiator other than the component (C), i.e., a photopolymerization initiator other than the photopolymerization initiator represented by the general formula (I), within a range that satisfies the above absorbance condition. The content of the other photopolymerization initiator may be 0 to 0.5 parts by mass, or 0 to 0.1 parts by mass, relative to 100 parts by mass of the total amount of the components (A) and (B).

[0068] (sensitizer) The photosensitive resin composition of the present embodiment can reduce the content of the sensitizer by using the component (C). By reducing the content of the sensitizer, the development time of the photosensitive layer and the peeling time of the resist pattern can be further shortened. From this viewpoint, the content of the sensitizer in the photosensitive resin composition may be 0.065 mass% or less, 0.030 mass% or less, or 0 mass% based on the total solid content of the photosensitive resin composition.

[0069] Examples of the sensitizer include dialkylaminobenzophenone compounds, pyrazoline compounds, anthracene compounds, coumarin compounds, xanthone compounds, stilbene compounds, and triarylamine compounds.

[0070] Examples of pyrazoline compounds include 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)pyrazoline, 1-phenyl-3-(4-tert-butylstyryl)-5-(4-tert-butylphenyl)pyrazoline, and 1-phenyl-3-biphenyl-5-(4-tert-butylphenyl)pyrazoline. Examples of anthracene compounds include 9,10-dibutoxyanthracene and 9,10-diphenylanthracene. Examples of coumarin compounds include 3-benzoyl-7-diethylaminocoumarin, 7-diethylamino-4-methylcoumarin, 3,3'-carbonylbis(7-diethylaminocoumarin), and 2,3,6,7-tetrahydro-9-methyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]kyrolidin-11-one.

[0071] (Heterocyclic compounds) The photosensitive resin composition of the present embodiment may further contain a heterocyclic compound. This can further improve the resolution and adhesion of the photosensitive resin composition. Examples of the heterocyclic compound include 5-carboxybenzotriazole and 5-amino-1H-tetrazole. These compounds may be used alone or in combination of two or more.

[0072] When the photosensitive resin composition contains a heterocyclic compound, the content thereof may be 0.01 to 5.0 mass%, 0.03 to 3.0 mass%, or 0.1 to 1.5 mass% based on the total solid content of the photosensitive resin composition. When the content of the heterocyclic compound is 0.01 mass% or more, the resolution and adhesion tend to be improved, and when it is 5.0 mass% or less, the developing time and peeling time of the photosensitive layer tend to be shortened.

[0073] (Hydrogen donor) The photosensitive resin composition of the present embodiment may further contain a hydrogen donor (hydrogen-donating compound). This further improves the sensitivity, resolution, and adhesion of the photosensitive resin composition. Examples of hydrogen donors include bis[4-(dimethylamino)phenyl]methane, bis[4-(diethylamino)phenyl]methane, N-phenylglycine, and leuco crystal violet. These may be used alone or in combination of two or more.

[0074] When the photosensitive resin composition contains a hydrogen donor, the content thereof may be 0.01 to 10 mass%, 0.05 to 5 mass%, or 0.1 to 2 mass% based on the total solid content of the photosensitive resin composition. When the hydrogen donor content is 0.01 mass% or more, the sensitivity can be further improved, and when it is 10 mass% or less, the excessive hydrogen donor is prevented from precipitating as a foreign matter after film formation.

[0075] (Polymerization inhibitor) The photosensitive resin composition of the present embodiment may further contain a polymerization inhibitor. This improves the resolution of the photosensitive resin composition. In addition, the temperature stability of the film is improved. Examples of the polymerization inhibitor include tert-butylcatechol and 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl. These are used alone or in combination of two or more.

[0076] When the photosensitive resin composition contains a polymerization inhibitor, the content thereof may be 0.001 to 1.0 mass%, 0.005 to 0.5 mass%, or 0.01 to 0.1 mass% based on the total solid content of the photosensitive resin composition. When the content of the polymerization inhibitor is 0.001 mass% or more, the resolution can be further improved, and when it is 1.0 mass% or less, the sensitivity can be further improved.

[0077] (dye) The photosensitive resin composition of the present embodiment may further contain a dye. This further improves the adhesion of the photosensitive resin composition, and shortens the development time and peeling time. Examples of dyes include malachite green and diamond green. These may be used alone or in combination of two or more.

[0078] When the photosensitive resin composition contains a dye, the content thereof may be 0.001 to 1.0 mass%, 0.005 to 0.5 mass%, or 0.01 to 0.1 mass% based on the total solid content of the photosensitive resin composition. When the content of the dye is 0.001 mass% or more, the development time and the peeling time can be further shortened, and when it is 1.0 mass% or less, the resolution and adhesion can be further improved.

[0079] (Other Ingredients) The photosensitive resin composition may further contain other components as necessary. Examples of the other components include a photopolymerizable compound (such as an oxetane compound) having at least one cationic polymerizable cyclic ether group in the molecule, a cationic polymerization initiator, tribromophenyl sulfone, a photocoloring agent, a thermal coloring inhibitor, a plasticizer (such as p-toluenesulfonamide), a silane coupling agent, a pigment, a filler, a defoaming agent, a flame retardant, a stabilizer, an adhesion imparting agent, a leveling agent, a peeling promoter, an antioxidant, a fragrance, an imaging agent, and a thermal crosslinking agent. These are used alone or in combination of two or more. The content of each of the other components may be about 0.01 to 20% by mass.

[0080] The photosensitive resin composition may contain at least one organic solvent in order to improve the handling property of the photosensitive composition and adjust the viscosity and storage stability. As the organic solvent, any organic solvent that is commonly used may be used without any particular limitation. Examples of the organic solvent include methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, propylene glycol monomethyl ether, and mixed solvents thereof. For example, the (A) component, the (B) component, and the (C) component may be dissolved in an organic solvent to form a solution having a solid content of about 30 to 60 mass% (hereinafter referred to as a "coating liquid"). The solid content means the remaining components obtained by removing volatile components from the solution of the photosensitive resin composition.

[0081] (absorbance) The photosensitive resin composition of the present embodiment has an absorbance of 0.0030 to 0.0119 per 1 μm of thickness for light having a wavelength of 365 nm. When the absorbance is 0.0030 or more, the decrease in resolution can be suppressed. When the absorbance is 0.0119 or less, the resolution and adhesion are improved. From the viewpoint of further suppressing the decrease in resolution, the absorbance may be 0.0040 or more, 0.0050 or more, or 0.0055 or more, and from the viewpoint of further improving the resolution and adhesion, the absorbance may be 0.0100 or less, 0.0090 or less, or 0.0080 or less.

[0082] The absorbance of the photosensitive resin composition can be appropriately adjusted by the types and contents of the above-mentioned (B) photopolymerizable compound, (C) photopolymerization initiator, sensitizer, and other components.

[0083] The absorbance of the photosensitive resin composition can be measured by forming a photosensitive layer by forming the photosensitive resin composition into a film, and measuring the absorbance of this photosensitive layer with respect to light having a wavelength of 365 nm using, for example, a UV-visible spectrophotometer such as a U-3310 spectrophotometer (manufactured by Hitachi High-Tech Science Co., Ltd.) and a slide glass as a reference. The absorbance per 1 μm of thickness of the photosensitive resin composition can be calculated by dividing the absorbance measured for the photosensitive layer by the thickness (unit: μm) of the photosensitive layer.

[0084] [Photosensitive element] The photosensitive element of the present embodiment includes a support and a photosensitive layer containing the above-mentioned photosensitive resin composition formed on the support. When using the photosensitive element of the present embodiment, the photosensitive layer may be laminated on a substrate and then exposed to light without peeling off the support.

[0085] (Support) The support may be a polymer film (support film) having heat resistance and solvent resistance, such as polyesters such as polyethylene terephthalate (PET), polyolefins such as polypropylene and polyethylene, etc. Among them, a PET film may be used because it is easily available and has excellent handleability (particularly heat resistance, heat shrinkage rate, and breaking strength) in the manufacturing process.

[0086] The haze of the support may be 0.01 to 1.0%, or 0.01 to 0.5%. When the haze of the support is 0.01% or more, the support itself tends to be easily manufactured, and when it is 1.0% or less, micro defects that may occur in the resist pattern tend to be reduced. Here, "haze" means cloudiness. The haze in the present disclosure refers to a value measured using a commercially available haze meter (turbidity meter) in accordance with the method specified in JIS K 7105. The haze can be measured, for example, using a commercially available turbidity meter such as NDH-5000 (manufactured by Nippon Denshoku Industries Co., Ltd.).

[0087] The number of particles with a diameter of 5 μm or more contained in the support is 5 / mm 2The support may be a support containing particles. This improves the slipperiness of the support surface, and can improve the resolution and adhesion by well-balanced suppression of light scattering during exposure. The average particle size of the particles may be 5 μm or less, 1 μm or less, or 0.1 μm or less. The lower limit of the average particle size is not particularly limited, but may be 0.001 μm or more.

[0088] Commercially available examples of such supports include three-layer biaxially oriented PET films containing particles in the outermost layer, such as "QS48" (Toray Industries, Inc.), "FB40" (Toray Industries, Inc.), "FS31" (Toray Industries, Inc.), "R705G" (Mitsubishi Chemical Corporation), and "HTF-01" (Teijin Film Solutions Limited), as well as a two-layer biaxially oriented PET film "A-1517" (Toyobo Co., Ltd.), which has a particle-containing layer on one side.

[0089] The thickness of the support may be 1 to 100 μm, 5 to 50 μm, or 5 to 30 μm. When the thickness is 1 μm or more, the support can be prevented from being broken when peeled off, and when the thickness is 100 μm or less, the resolution can be prevented from decreasing.

[0090] (Middle class) The photosensitive element may further include an intermediate layer between the support and the photosensitive layer. The intermediate layer may be a layer containing a water-soluble resin. Examples of the water-soluble resin include a resin containing polyvinyl alcohol as a main component.

[0091] (protective layer) The photosensitive element may further include a protective layer as necessary. As the protective layer, a film may be used in which the adhesive strength between the photosensitive layer and the protective layer is smaller than the adhesive strength between the photosensitive layer and the support, or a film with low fisheyes may be used. Specifically, for example, the above-mentioned films that can be used as the support may be used. From the viewpoint of peelability from the photosensitive layer, a polyethylene film may be used. The thickness of the protective layer may be about 1 to 100 μm, depending on the application.

[0092] [Method of manufacturing photosensitive element] The photosensitive element can be manufactured, for example, as follows. The photosensitive element can be manufactured by a manufacturing method including preparing the above-mentioned coating liquid, applying the coating liquid onto a support to form a coating layer, and drying the coating layer to form a photosensitive layer. The coating liquid can be applied onto the support by a known method such as roll coating, comma coating, gravure coating, air knife coating, die coating, bar coating, etc.

[0093] The drying of the coating layer is not particularly limited as long as at least a part of the organic solvent can be removed from the coating layer. For example, the drying may be performed at 70 to 150° C. for about 5 to 30 minutes. After drying, the amount of the organic solvent remaining in the photosensitive layer may be 2% by mass or less from the viewpoint of preventing the diffusion of the organic solvent in the subsequent steps.

[0094] The thickness of the photosensitive layer in the photosensitive element can be appropriately selected depending on the application, and may be 1 to 100 μm, 3 to 50 μm, 5 to 40 μm, or 10 to 30 μm after drying. When the photosensitive layer has a thickness of 1 μm or more, industrial coating becomes easy and productivity improves, and when the thickness is 100 μm or less, adhesion and resolution are further improved.

[0095] Since the photosensitive layer in the photosensitive element is a layer formed using the photosensitive resin composition, the absorbance of the layer per 1 μm of thickness for light having a wavelength of 365 nm may be 0.0030 to 0.0119. When the absorbance is 0.0030 or more, the resolution can be suppressed from decreasing. When the absorbance is 0.0119 or less, the resolution and adhesion are improved. From the viewpoint of further suppressing the resolution from decreasing, the absorbance may be 0.0040 or more, 0.0050 or more, or 0.0055 or more, and from the viewpoint of further improving the resolution and adhesion, the absorbance may be 0.0100 or less, 0.0090 or less, or 0.0080 or less. The method for measuring the absorbance of the photosensitive layer is as described above.

[0096] The photosensitive element can be suitably used, for example, in the method for forming a resist pattern described below. In particular, from the viewpoint of resolution, it is suitable for application to a manufacturing method for forming a conductor pattern by plating treatment.

[0097] [Method of forming resist pattern] The method for forming a resist pattern of this embodiment includes a photosensitive layer forming step of laminating a photosensitive layer containing the photosensitive resin composition or a photosensitive layer of the photosensitive element on a substrate, an exposure step of irradiating a predetermined portion of the photosensitive layer with active light to form a photocured portion, and a development step of removing an area of ​​the photosensitive layer other than the predetermined portion from the substrate. The method for forming a resist pattern may include other steps as necessary. The resist pattern may be a photocured product pattern of the photosensitive resin composition or a relief pattern. The method for forming a resist pattern may also be a method for producing a substrate with a resist pattern.

[0098] (Photosensitive layer formation process) The method of forming the photosensitive layer on the substrate may be, for example, coating and drying a photosensitive resin composition, or removing a protective layer from a photosensitive element, and then heating and pressing the photosensitive layer of the photosensitive element onto the substrate. When a photosensitive element is used, a laminate consisting of a substrate, a photosensitive layer, and a support, which are laminated in order, is obtained. The substrate is not particularly limited, but typically includes a circuit-forming substrate having an insulating layer and a conductor layer formed on the insulating layer, a metal substrate for manufacturing a metal mask, or a die pad (substrate for lead frame) such as an alloy substrate.

[0099] From the viewpoint of further improving the resolution, the surface roughness (Ra) of the substrate may be 10 to 200 nm, 30 to 100 nm, or 40 to 100 nm. By setting Ra to 40 to 100 nm, halation caused by unevenness on the substrate surface can be suppressed, and the resolution is further improved.

[0100] When a photosensitive element is used, it is preferable to carry out the bonding under reduced pressure from the viewpoint of adhesion and followability. The photosensitive layer and / or the substrate may be heated at a temperature of 70 to 130° C. The bonding is carried out under a pressure of about 0.1 to 1.0 MPa (1 to 10 kgf / cm 2 The pressure may be about 100 MPa (about 100 MPa), but these conditions are appropriately selected according to need. If the photosensitive layer is heated to 70 to 130° C., it is not necessary to preheat the substrate in advance, but the substrate can be preheated in order to further improve the adhesion and conformability.

[0101] (Exposure process) In the exposure step, at least a part of the photosensitive layer formed on the substrate is irradiated with active light rays, whereby the part irradiated with the active light rays is photocured to form a latent image. In this case, if the support present on the photosensitive layer is transparent to the active light rays, the active light rays can be irradiated through the support, but if the support is light-shielding, the support is removed before the photosensitive layer is irradiated with the active light rays.

[0102] The exposure method includes a method of irradiating an active light beam imagewise through a negative or positive mask pattern called artwork (mask exposure method). Alternatively, a method of irradiating an active light beam imagewise by a projection exposure method may be used.

[0103] As the light source of the actinic ray, a known light source can be used, for example, a carbon arc lamp, a mercury vapor arc lamp, a high pressure mercury lamp, an extra-high pressure mercury lamp, a xenon lamp, a gas laser such as an argon laser, a solid-state laser such as a YAG laser, a semiconductor laser, etc. that effectively emits ultraviolet light and visible light can be used. The wavelength of the actinic ray may be within the range of 340 nm to 430 nm.

[0104] (Development process) In the development process, at least a part of the photosensitive layer other than the photocured portion is removed from the substrate, thereby forming a resist pattern on the substrate. If a support is present on the photosensitive layer, the support is removed, and then the area other than the photocured portion (which may also be called the unexposed portion) is removed (developed). There are two development methods, wet development and dry development, and wet development is widely used.

[0105] In the case of wet development, a developer corresponding to the photosensitive resin composition is used, and development is performed by a known development method. Examples of the development method include a dip method, a paddle method, a spray method, a brushing method, a slapping method, a scrubbing method, a swinging immersion method, etc., and from the viewpoint of improving the resolution, a high-pressure spray method may be used. Development may be performed by combining two or more of these methods.

[0106] The composition of the developer is appropriately selected depending on the composition of the photosensitive resin composition, and examples thereof include an alkaline aqueous solution and an organic solvent developer.

[0107] From the viewpoint of safety, stability, and good operability, an alkaline aqueous solution may be used as the developer. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium, or potassium hydroxides; alkali carbonates such as lithium, sodium, potassium, or ammonium carbonates or bicarbonates; alkali metal phosphates such as potassium phosphate and sodium phosphate; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; borax, sodium metasilicate, tetramethylammonium hydroxide, ethanolamine, ethylenediamine, diethylenetriamine, 2-amino-2-hydroxymethyl-1,3-propanediol, 1,3-diaminopropanol-2, and morpholine.

[0108] The alkaline aqueous solution used for development may be a dilute solution of 0.1 to 5 mass % sodium carbonate, a dilute solution of 0.1 to 5 mass % potassium carbonate, a dilute solution of 0.1 to 5 mass % sodium hydroxide, a dilute solution of 0.1 to 5 mass % sodium tetraborate, etc. The pH of the alkaline aqueous solution used for development may be in the range of 9 to 11, and the temperature can be adjusted according to the alkaline developability of the photosensitive layer.

[0109] The alkaline aqueous solution may contain, for example, a surfactant, an antifoaming agent, a small amount of an organic solvent for promoting development, etc. Examples of the organic solvent used in the alkaline aqueous solution include acetone, ethyl acetate, an 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 monobutyl ether.

[0110] Examples of organic solvents used in the organic solvent developer include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone. To prevent ignition, water may be added to these organic solvents in an amount of 1 to 20% by mass to prepare the organic solvent developer.

[0111] In the method for forming a resist pattern in this embodiment, after removing the uncured portion in the development step, heating at about 60 to 250° C. or applying 0.2 to 10 J / cm 2 is performed as necessary. 2 The method may further include a step of hardening the resist pattern by exposure to light of about 1000 nm.

[0112] [Printed wiring board manufacturing method] The method for producing a printed wiring board according to the present embodiment includes a step of forming a conductor pattern by etching or plating a substrate on which a resist pattern has been formed by the above-described method for forming a resist pattern. The method for producing a printed wiring board may include other steps, such as a resist pattern removal step, as necessary.

[0113] In the plating process, the conductive layer provided on the substrate is plated using the resist pattern formed on the substrate as a mask. After the plating process, the resist is removed by removing the resist pattern as described below, and the conductive layer covered by the resist may be etched to form a conductive pattern.

[0114] The plating method may be electrolytic plating or electroless plating, or may be electroless plating. In the etching process, the conductor layer provided on the substrate is etched away using a resist pattern formed on the substrate as a mask to form a conductor pattern. The etching method is appropriately selected depending on the conductor layer to be removed. Examples of the etching solution include a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, and a hydrogen peroxide-based etching solution.

[0115] After the etching or plating process, the resist pattern on the substrate may be removed. The resist pattern can be removed by, for example, using an aqueous solution that is more strongly alkaline than the aqueous solution used in the development process. As the aqueous solution, for example, an amine-based stripping solution (15% by volume R-100S+8% by volume R-101 aqueous solution (manufactured by Mitsubishi Gas Chemical Co., Ltd.)) is used. As the aqueous solution, a 1-10% by mass sodium hydroxide aqueous solution, a 1-10% by mass potassium hydroxide aqueous solution, or the like may be used.

[0116] When the resist pattern is removed after the plating process, the conductor layer covered with the resist is etched by an etching process to form a conductor pattern, thereby manufacturing a desired printed wiring board. The method of the etching process is appropriately selected depending on the conductor layer to be removed. For example, the above-mentioned etching solution can be used.

[0117] The method for manufacturing a printed wiring board according to this embodiment can be applied to the manufacture of not only single-layer printed wiring boards but also multi-layer printed wiring boards, and can also be applied to the manufacture of printed wiring boards having small diameter through holes. EXAMPLES

[0118] [Examples 1 to 3 and Comparative Examples 1 to 2] <Preparation of Photosensitive Resin Composition> Photosensitive resin compositions of the examples and comparative examples were prepared by mixing (A) binder polymer with (B) photopolymerizable compound, (C) photopolymerization initiator, sensitizer, other components, and solvent in the amounts (parts by mass) shown in Table 2 below. The amounts of components other than the solvent shown in Table 2 are the mass of nonvolatile matter (solid content). The results of the evaluations described below are also shown in Table 2.

[0119] ((A) Binder polymer) A-1: Methylpropylene glycol / toluene solution of a copolymer of methacrylic acid / styrene / 2-hydroxyethyl methacrylate / benzyl methacrylate (mass ratio: 27 / 50 / 3 / 20, weight average molecular weight: 35,000)

[0120] ((B) Photopolymerizable compound) B-1: 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane (manufactured by Showa Denko Materials Co., Ltd., product name: FA-321M, number of EO groups: 10 (average value)) B-2: Ethoxylated bisphenol A dimethacrylate (number of EO groups: 2.6 (average value)) (manufactured by Kyoeisha Chemical Co., Ltd., product name: BP-2EM) B-3: (PO)(EO)(PO) modified polyethylene glycol dimethacrylate (manufactured by Showa Denko Materials Co., Ltd., product name: FA-024M, number of EO groups: 6 (average value), number of PO groups: 12 (average value))

[0121] ((C) Photopolymerization initiator) C-1: 2-(o-chlorophenyl)-4,5-diphenylbiimidazole (manufactured by Changzhou Strong Electronic New Materials Co., Ltd., a compound represented by the following formula (IX)) C-2: A mixture of 2-(o-chlorophenyl)-4,5-diphenylbiimidazole (manufactured by Changzhou Powerful New Electronic Materials Co., Ltd., a compound represented by the following formula (IX)), 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylbiimidazole (manufactured by Changzhou Powerful New Electronic Materials Co., Ltd., a compound represented by the following formula (X)), and 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole (manufactured by Changzhou Powerful New Electronic Materials Co., Ltd., a compound represented by the following formula (XI)). The compositions of C-1 and C-2 are shown in Table 1. Table 1 also shows the chemical formulas of the compounds contained in C-1 and C-2, and the Z value when expressed by the general formula (I). 1 and Z 2 The content shown in Table 1 indicates the content of each compound based on the total amount of C-1 or C-2.

[0122] [Table 1]

[0123] [ka] [ka] [ka]

[0124] (sensitizer) D-1: 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)pyrazoline (manufactured by Nippon Chemical Industry Co., Ltd.)

[0125] (Other Ingredients) E-1: Leuco Crystal Violet (Yamada Chemical Co., Ltd.) (hydrogen donor) E-2: Malachite Green (Osaka Organic Chemical Industry Co., Ltd.) (dye) E-3: tert-butylcatechol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (polymerization inhibitor) E-4: Benzotriazole derivative (manufactured by Sanwa Chemical Industries, Ltd., product name: SF-808H (heterocyclic compound) E-5: 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl (manufactured by ADEKA Corporation) (polymerization inhibitor)

[0126] <Measurement of Mw of binder polymer> The weight average molecular weight Mw of the binder polymer was measured by gel permeation chromatography (GPC) and calculated using a calibration curve of standard polystyrene. The GPC conditions are shown below.

[0127] (GPC conditions) Columns: Gelpack GL-R440, Gelpack GL-R450 and Gelpack GL-R400M (all manufactured by Showa Denko Materials Co., Ltd.) Eluent: Tetrahydrofuran Measurement temperature: 40℃ Flow rate: 2.05mL / min Concentration: 5mg / mL Injection volume: 200μL Detector: Hitachi L-2490 type RI (manufactured by Hitachi, Ltd.)

[0128] <Preparation of Photosensitive Element> The solution of the photosensitive resin composition was uniformly applied onto a 16 μm-thick polyethylene terephthalate film (manufactured by Toray Industries, Inc., product name "FS-31") serving as a support. The film was then dried for 10 minutes in a hot air convection dryer at 90° C. to form a photosensitive layer having a film thickness of 25 μm after drying. Subsequently, a polyethylene film (manufactured by Tamapoly Co., Ltd., product name "NF-15A") was laminated as a protective layer on the photosensitive layer to obtain a photosensitive element.

[0129] <Measurement of absorbance> A photosensitive element was laminated (laminated) on the surface of a slide glass (Matsunami Glass Industry Co., Ltd., white slide glass cut No. 1 S1126). The lamination was performed by peeling off the protective layer, so that the photosensitive layer of the photosensitive element was in contact with the surface of the slide glass, using a heat roll at 110°C, with a pressure of 0.4 MPa and a roll speed of 1.0 m / min. After the photosensitive layer was laminated on the slide glass, the support was peeled off. The absorbance of the photosensitive layer was measured using a U-3310 spectrophotometer (Hitachi High-Tech Science Co., Ltd.) under the measurement conditions of a wavelength range of 330 to 700 nm, a scan speed of 300 nm / min, and a scan interval of 0.50 nm. A baseline measurement was performed using untreated slide glass as a reference and a sample. From the obtained measurement spectrum, the absorbance A at the exposure wavelength (365 nm) was recorded and used as the absorbance of the photosensitive layer. The absorbance per 1 μm of thickness was calculated by dividing the absorbance of the photosensitive layer by the thickness of the photosensitive layer (25 μm).

[0130] <Preparation of Laminate> A substrate in which copper was sputtered onto a polyethylene terephthalate film was heated to 80°C, and a photosensitive element was laminated onto the copper surface of the substrate. The lamination was performed using a heat roll at 110°C, with the photosensitive layer of the photosensitive element in contact with the copper surface of the copper substrate while peeling off the protective layer, at a pressure of 0.4 MPa and a roll speed of 1.0 m / min. This resulted in a laminate in which the substrate, photosensitive layer, and support were laminated in this order. The resulting laminate was used as a test piece for the following test.

[0131] <Measurement of minimum development time> The support was peeled off from the test piece to expose the photosensitive layer, and a 1% by mass aqueous solution of sodium carbonate at 30° C. was sprayed on it. The time until the photosensitive layer was completely removed was measured and taken as the minimum development time.

[0132] <Evaluation of resolution and adhesion> On the support of the test piece, a glass chrome type phototool (resolution negative: one having a wiring pattern with a line width / space width of 3x / x (x: 1 to 10, unit: μm), adhesion negative: one having a wiring pattern with a line width / space width of x / 3x (x: 1 to 18, unit: μm)) was used as a negative for evaluating resolution and adhesion, and the photosensitive layer was exposed with a predetermined amount of energy using a projection exposure device (manufactured by Ushio Inc., product name "UX-2240-SM-XJ01") with an ultra-high pressure mercury lamp (365 nm) as a light source. After exposure, the support was peeled off to expose the photosensitive layer, and a 1% by mass sodium carbonate aqueous solution at 30°C was sprayed for twice the minimum development time to remove the unexposed parts (development process).

[0133] After development, the space portion (unexposed portion) was completely removed, and the line portion (exposed portion) was formed without twisting, meandering, or chipping. The smallest line width / space width value was used to evaluate the resolution and adhesion. At this time, the exposure dose at which the resist line width of the adhesion negative pattern (line width / space width=10 μm / 10 μm) becomes 10.0 μm was evaluated as the above-mentioned predetermined energy amount, and the line width / space width value was recorded as the resolution and adhesion. The smaller this value, the better the resolution and adhesion.

[0134] <Evaluation of peeling time> A glass chrome type phototool (having a flat pattern of 50 mm x 40 mm) was used as a negative for evaluating the peel test on the support of the test piece, and the photosensitive layer was exposed to the above-mentioned predetermined energy amount using a projection exposure device (manufactured by Ushio Inc., product name "UX-2240-SM-XJ01") with an ultra-high pressure mercury lamp (365 nm) as a light source. After exposure, the support was peeled off to expose the photosensitive layer, and a 1% by mass aqueous solution of sodium carbonate at 30°C was sprayed for twice the minimum development time to remove the unexposed portion.

[0135] After the development process, the substrate was immersed in an amine-based stripping solution (aqueous solution of 15% by volume R-100S + 8% by volume R-101, manufactured by Mitsubishi Gas Chemical Co., Inc.) heated to 50° C. The time until the photosensitive layer was completely removed was measured and taken as the stripping time.

[0136] <Mandrel test> A glass chrome type phototool (having a strip pattern of 5 mm x 50 mm) was used as a negative for evaluating the peel test on the support of the test piece, and the photosensitive layer was exposed with the above-mentioned predetermined energy amount using a projection exposure device (manufactured by Ushio Inc., product name "UX-2240-SM-XJ01") with an ultra-high pressure mercury lamp (365 nm) as a light source. After exposure, the support was peeled off to expose the photosensitive layer, and a 1% by mass aqueous solution of sodium carbonate at 30°C was sprayed for twice the shortest development time to remove the unexposed portion.

[0137] After development, the exposed photosensitive layer was checked for cracks in a bending resistance test using a cylindrical mandrel with a diameter of 6 μm according to the cylindrical mandrel method (JIS K5600-5-1:1999). No cracks were rated as "A" and cracks were rated as "B".

[0138] [Table 2]

Claims

1. A photosensitive resin composition comprising (A) a binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator represented by the following general formula (I): the (C) photopolymerization initiator includes at least a first photopolymerization initiator represented by the following general formula (I) having no alkoxy group, and a second photopolymerization initiator represented by the following general formula (I) having an alkoxy group, each of the first photopolymerization initiator and the second photopolymerization initiator has at least one chlorine atom; The content of the first photopolymerization initiator based on the total amount of the first photopolymerization initiator and the second photopolymerization initiator is 60 to 97 mass %, The photosensitive resin composition has an absorbance of 0.0030 to 0.0119 for light having a wavelength of 365 nm per 1 μm of thickness. 【Chemistry 1】 [In formula (I), Z １ represents a monovalent group represented by the following general formula (II), Z ２ represents a monovalent group represented by the following general formula (III). 【Chemistry 2】 【Chemistry 3】 [In formula (II) and formula (III), R １ ~R ３０ each independently represents a hydrogen atom, a halogen atom, or an alkoxy group having 1 to 5 carbon atoms; １ ~R ３０ When multiple are present, they may be the same or different.

2. The photosensitive resin composition according to claim 1 , wherein the second photopolymerization initiator has at least one methoxy group.

3. 2. The photosensitive resin composition according to claim 1, wherein the content of the photopolymerization initiator (C) is 1 to 5 mass % based on the total solid content of the photosensitive resin composition.

4. The photosensitive resin composition according to claim 1 , wherein the binder polymer (A) comprises a binder polymer having a divalent group represented by the following general formula (IV): 【Chemistry 4】 [In formula (IV), R ３１ represents a hydrogen atom or a methyl group, R ３２ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom; ３２ may be the same or different.

5. The photosensitive resin composition according to claim 1 , wherein the binder polymer (A) comprises a binder polymer having a divalent group represented by the following general formula (V): 【Chemistry 5】 [In formula (V), R ３３ represents a hydrogen atom or a methyl group.

6. The photosensitive resin composition according to claim 1 , wherein the binder polymer (A) comprises a binder polymer having a divalent group represented by the following general formula (VI): 【Chemistry 6】 [In formula (VI), R ３４ represents a hydrogen atom or a methyl group, R ３５ represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom; m represents an integer of 0 to 5; ３５ may be the same or different.

7. The photosensitive resin composition according to claim 1 , wherein the binder polymer (A) comprises a binder polymer having a divalent group represented by the following general formula (VII): 【Chemistry 7】 [In formula (VII), R ３６ represents a hydrogen atom or a methyl group, R ３７ represents an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, a hydroxyl group, or a halogen atom; n represents an integer of 0 to 5; ３７ may be the same or different.

8. 2. The photosensitive resin composition according to claim 1, wherein the binder polymer (A) comprises a binder polymer having a weight average molecular weight of 20,000 to 50,000.

9. 2. The photosensitive resin composition according to claim 1, further comprising at least one of 5-carboxybenzotriazole and 5-amino-1H-tetrazole.

10. The photosensitive resin composition according to claim 1 , further comprising a hydrogen donor compound.

11. The photosensitive resin composition according to claim 1 , further comprising a polymerization inhibitor.

12. The photosensitive resin composition according to claim 1 , further comprising a dye.

13. 2. The photosensitive resin composition according to claim 1, wherein the content of the sensitizer is 0.065 mass % or less based on the total solid content of the photosensitive resin composition.

14. A photosensitive element comprising a support and a photosensitive layer formed on the support, the photosensitive layer comprising the photosensitive resin composition according to claim 1.

15. A photosensitive layer forming step of laminating a photosensitive layer containing the photosensitive resin composition according to claim 1 or a photosensitive layer of the photosensitive element according to claim 14 on a substrate; an exposure step of irradiating a predetermined portion of the photosensitive layer with active light to form a photocured portion; a developing step of removing an area of ​​the photosensitive layer other than the predetermined portion from the substrate; The method for forming a resist pattern comprises the steps of:

16. 16. The method for forming a resist pattern according to claim 15, wherein the wavelength of the actinic light is within the range of 340 to 430 nm.

17. A method for producing a printed wiring board, comprising the step of etching or plating a substrate on which a resist pattern has been formed by the method for forming a resist pattern according to claim 15 to form a conductor pattern.

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