Photosensitive element, production method therefor, resist pattern production method, and conductive pattern production method

Abstract

The present disclosure relates to a photosensitive element and a production method therefor, the photosensitive element comprising: a support film; a positive photosensitive resin film that is disposed on the support film; and a protective film that is disposed on the photosensitive resin film, wherein the average thickness of the photosensitive resin film is 80 µm or greater, the photosensitive resin film contains an organic solvent, and the organic solvent content is not less than 7.0 mass% but less than 18.0 mass% with respect to the total amount of the photosensitive resin film.

Description

Photosensitive Element, Method for Producing the Same, Method for Producing a Resist Pattern, and Method for Producing a Conductor Pattern

[0001] The present disclosure relates to a photosensitive element, a method for producing the same, a method for producing a resist pattern, a method for producing a conductor pattern, and the like.

[0002] In the production of a wiring board or the like, a resist pattern is formed in order to obtain a desired conductor pattern (for example, a wiring pattern). For example, the resist pattern can be formed by disposing a photosensitive resin film on a substrate using a photosensitive element including the photosensitive resin film and then exposing and developing the photosensitive resin film. Such a photosensitive element can be stored with the photosensitive resin film sandwiched between two films (for example, a support film and a protective film) (see Patent Document 1 below).

[0003] Japanese Patent Application Laid-Open No. 2017-126023 Japanese Patent Application Laid-Open No. 2022-129979 Japanese Patent Application Laid-Open No. 2020-76871 Japanese Patent Application Laid-Open No. 2017-198919

[0004] For the photosensitive element, there may be a case where it is required to include a thick photosensitive resin film (for example, a photosensitive resin film of 80 μm or more) in order to obtain a thick conductor pattern. However, a positive-type photosensitive resin film may crack during handling or wrinkle during storage at room temperature.

[0005] One aspect of the present disclosure aims to provide a photosensitive element including a positive-type photosensitive resin film excellent in handling properties and storage stability. Another aspect of the present disclosure aims to provide a method for producing such a photosensitive element. Another aspect of the present disclosure aims to provide a method for producing a resist pattern using such a photosensitive element. Another aspect of the present disclosure aims to provide a method for producing a conductor pattern using such a method for producing a resist pattern.

[0006] This disclosure relates to the following [1] to

[14] etc. [1] A photosensitive element comprising a support film, a positive-type photosensitive resin film disposed on the support film, and a protective film disposed on the photosensitive resin film, wherein the average thickness of the photosensitive resin film is 80 μm or more, the photosensitive resin film contains an organic solvent, and the content of the organic solvent is 7.0% by mass or more and less than 18.0% by mass based on the total amount of the photosensitive resin film. [2] The photosensitive element according to [1], wherein the organic solvent comprises an organic solvent having a boiling point of less than 150°C and an organic solvent having a boiling point of 150°C or higher. [3] The photosensitive element according to [1] or [2], wherein the organic solvent comprises alkylene glycol monoalkyl ether acetate and alkoxyalkyl acetate. [4] The photosensitive element according to any one of [1] to [3], wherein the content of the organic solvent is 9.0 to 17.5% by mass based on the total amount of the photosensitive resin film. [5] The photosensitive element according to any one of [1] to [3], wherein the content of the organic solvent is 9.5 to 15.0% by mass based on the total amount of the photosensitive resin film. [6] A method for manufacturing a resist pattern, comprising, in this order: a placement step of placing the photosensitive resin film of the photosensitive element according to any one of [1] to [5] on the substrate with the protective film removed and the photosensitive resin film positioned on the substrate side with respect to the support film; an exposure step of exposing a part of the photosensitive resin film; and a developing step of removing at least a part of the exposed portion of the photosensitive resin film to form a resist pattern. [7] The method for manufacturing a resist pattern according to [6], further comprising a step of heating the photosensitive resin film with the support film removed between the placement step and the exposure step. [8] The method for manufacturing a resist pattern according to [6] or [7], further comprising a step of heating the photosensitive resin film between the exposure step and the developing step. A method for manufacturing a conductor pattern, comprising the step of forming a conductor pattern using a resist pattern obtained by any one of the methods for manufacturing a resist pattern described in [9], [6], to [8] as a mask.

[10] A method for producing a photosensitive element, comprising the steps of: forming a photosensitive resin film with an average thickness of 80 μm or more by coating a positive-type photosensitive resin composition onto a support film and then drying the photosensitive resin composition; and arranging a protective film on the photosensitive resin film, wherein the photosensitive resin film contains an organic solvent, and the content of the organic solvent is 7.0% by mass or more and less than 18.0% by mass based on the total amount of the photosensitive resin film.

[11] The method for producing a photosensitive element according to

[10] , wherein the organic solvent comprises an organic solvent having a boiling point of less than 150°C and an organic solvent having a boiling point of 150°C or higher.

[12] The method for producing a photosensitive element according to

[10] , wherein the organic solvent comprises an alkylene glycol monoalkyl ether acetate and an alkoxyalkyl acetate.

[13] The method for producing a photosensitive element according to any one of

[10] to

[12] , wherein the content of the organic solvent is 9.0 to 17.5% by mass based on the total amount of the photosensitive resin film.

[14] A method for producing a photosensitive element according to any one of

[10] to

[12] , wherein the content of the organic solvent is 9.5 to 15.0% by mass based on the total amount of the photosensitive resin film.

[0007] According to one aspect of this disclosure, a photosensitive element comprising a positive-type photosensitive resin film with excellent handling and storage stability can be provided. According to another aspect of this disclosure, a method for manufacturing such a photosensitive element can be provided. According to yet another aspect of this disclosure, a method for manufacturing a resist pattern using such a photosensitive element can be provided. According to yet another aspect of this disclosure, a method for manufacturing a conductor pattern using such a resist pattern manufacturing method can be provided.

[0008] This is a schematic cross-sectional view showing an example of a photosensitive element. This is a schematic cross-sectional view showing an example of a resist pattern manufacturing method. This is a schematic cross-sectional view showing an example of a resist pattern manufacturing method. This is a schematic cross-sectional view showing an example of a conductor pattern manufacturing method.

[0009] The embodiments of this disclosure will be described in detail below. However, this disclosure is not limited to the embodiments described below.

[0010] In this specification, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. "A or greater" in a numerical range means A and the range greater than A. "A or less" in a numerical range means A and the range less than A. In numerical ranges described stepwise in this specification, the upper or lower limit of a numerical range in one step can be arbitrarily combined with the upper or lower limit of a numerical range in another step. In numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. "A or B" means that either A or B may be included, or both may be included. Unless otherwise specified, the materials exemplified in this specification may be used individually or in combination of two or more. The content of each component in a composition means the total amount (sum) of the multiple substances corresponding to each component present in the composition, unless otherwise specified. The term "layer" includes not only structures formed across the entire surface when observed as a plan view, but also structures formed in only a portion of it. The term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from others, as long as the intended function of the process is achieved. "Room temperature" means around 25°C. "(Meth)acrylic" means at least one of acrylic and its corresponding methacrylic. Unless otherwise specified, alkyl groups may be linear, branched, or cyclic.

[0011] The photosensitive element according to this embodiment comprises a support film, a positive-type photosensitive resin film disposed on the support film, and a protective film disposed on the photosensitive resin film, wherein the average thickness of the photosensitive resin film is 80 μm or more, the photosensitive resin film contains an organic solvent, and the content of the organic solvent is 7.0% by mass or more and less than 18.0% by mass, based on the total amount of the photosensitive resin film.

[0012] According to the inventors' findings, positive-type photosensitive resin films have inferior handling properties and storage stability compared to negative-type photosensitive resin films, making it difficult to increase their thickness to 80 μm or more. In contrast, the photosensitive element according to this embodiment can be made to have excellent handling properties and storage stability by adjusting the solvent content contained in the positive-type photosensitive resin film. The photosensitive element according to this embodiment can be used in the manufacture of resist patterns, in the manufacture of conductor patterns, and in the manufacture of wiring boards.

[0013] The photosensitive element according to this embodiment comprises a support film, a positive-type photosensitive resin film (photosensitive layer) disposed on the support film, and a protective film disposed on the photosensitive resin film. That is, the photosensitive element according to this embodiment comprises a support film, a photosensitive resin film, and a protective film in this order. Furthermore, the photosensitive element according to this embodiment comprises a support film, a protective film, and a photosensitive resin film disposed between the support film and the protective film. The support film can come into contact with the photosensitive resin film. The protective film can come into contact with the photosensitive resin film.

[0014] Examples of support films and protective films include polyolefin films such as polyethylene (PE) film and polypropylene (PP) film; and polyester films such as polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, and polyethylene-2,6-naphthalate (PEN) film. The support film and protective film may be the same type of film or different types of films. The support film may be a polyethylene terephthalate film, and the protective film may be a polypropylene film.

[0015] The average thickness of the support film may be 1 μm or more, 5 μm or more, 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, 40 μm or more, 45 μm or more, or 50 μm or more, from the viewpoint of easily suppressing damage to the support film when peeling the support film from the photosensitive element. The average thickness of the support film may be 300 μm or less, 250 μm or less, 200 μm or less, 180 μm or less, 150 μm or less, 120 μm or less, 110 μm or less, 100 μm or less, 95 μm or less, 90 μm or less, 85 μm or less, 80 μm or less, 75 μm or less, 70 μm or less, 65 μm or less, 60 μm or less, 55 μm or less, or 50 μm or less, from the viewpoint of processability (damage to the blade when slitting, difficulty in winding onto the core). From these perspectives, the average thickness of the support film may be 1 to 300 μm, 5 to 150 μm, 10 to 100 μm, 20 to 90 μm, 30 to 80 μm, 35 to 70 μm, or 40 to 60 μm. The average thickness of the support film can be measured by the measurement method described in the examples below.

[0016] The average thickness of the protective film may be 1 μm or more, 5 μm or more, 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 35 μm or more, or 40 μm or more, from the viewpoint of easily suppressing damage to the protective film when peeling it from the photosensitive element. The average thickness of the protective film may be 300 μm or less, 250 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, or 40 μm or less, from the viewpoint of processability (damage to the blade when slitting, difficulty in winding onto the core). From these perspectives, the average thickness of the protective film may be 1 to 300 μm, 5 to 150 μm, 10 to 100 μm, 20 to 80 μm, 35 to 70 μm, 30 to 60 μm, or 35 to 50 μm. The average thickness of the protective film can be measured by the measurement method described in the examples below.

[0017] The photosensitive resin film according to this embodiment contains an organic solvent in an amount of 7.0% by mass or more and less than 18.0% by mass, based on the total amount of the photosensitive resin film. The organic solvent content in the photosensitive resin film may be 7.0% by mass or more, 7.5% by mass or more, 8.0% by mass or more, 8.5% by mass or more, 9.0% by mass or more, or 9.5% by mass or more, based on the total amount of the photosensitive resin film, from the viewpoint of easily suppressing the occurrence of cracks in the photosensitive resin film. The organic solvent content may be less than 18.0% by mass, 17.5% by mass or less, 17.0% by mass or less, 16.5% by mass or less, 16.0% by mass or less, 15.5% by mass or less, or 15.0% by mass or less, based on the total amount of the photosensitive resin film, from the viewpoint of easily suppressing the occurrence of wrinkles in the photosensitive resin film during storage. From these perspectives, the organic solvent content may be 7.0 to 17.5% by mass, 7.5 to 17.5% by mass, 8.0 to 17.5% by mass, 8.5 to 17.5% by mass, 9.0 to 17.5% by mass, 9.0 to 17.0% by mass, 9.0 to 16.5% by mass, 9.0 to 16.0% by mass, 9.0 to 15.5% by mass, or 9.5 to 15.0% by mass, based on the total amount of the photosensitive resin film.

[0018] The photosensitive resin film has positive-type photosensitivity. The photosensitive resin film is a film containing a positive-type photosensitive resin composition, and may be a film made of a positive-type photosensitive resin composition. The organic solvent contained in the photosensitive resin film is derived from the organic solvent contained in the photosensitive resin composition.

[0019] The photosensitive resin composition contains an organic solvent. Examples of organic solvents include acetate solvents, ether solvents, ester solvents, alcohol solvents, sulfoxide solvents, formamide solvents, acetamide solvents, pyrrolidone solvents, and aromatic hydrocarbon solvents. The organic solvent can be used individually or in combination of two or more.

[0020] The photosensitive resin composition may contain an acetate-based solvent, from the viewpoint of easily adjusting the organic solvent content in the photosensitive resin film by drying the photosensitive resin composition. Examples of acetate-based solvents include alkylene glycol monoalkyl ether acetate, dialkylene glycol alkyl ether acetate, alkoxyalkyl acetate (for example, alkoxybutyl acetate such as 3-methoxybutyl acetate (MBA)), 3-methoxy-3-methylbutyl acetate, propylene glycol diacetate, 1,3-butylene glycol diacetate, 1,4-butanediol diacetate, 1,6-hexanediol diacetate, cyclohexanol acetate, and butyl acetate. Examples of alkylene glycol monoalkyl ether acetates include propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, and other propylene glycol monoalkyl ether acetates; and ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate. Examples of dialkylene glycol alkyl ether acetates include dipropylene glycol monoalkyl ether acetates such as dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, and dipropylene glycol monobutyl ether acetate; and diethylene glycol monoalkyl ether acetates such as diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate.

[0021] The photosensitive resin composition may contain at least one selected from the group consisting of alkylene glycol monoalkyl ether acetate and alkoxyalkyl acetate, and may also contain at least one selected from the group consisting of propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate, from the viewpoint of easily adjusting the content of organic solvents in the photosensitive resin film formed from the photosensitive resin composition. The photosensitive resin composition may contain alkylene glycol monoalkyl ether acetate and alkoxyalkyl acetate, and may also contain propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate, from the viewpoint of easily improving the uniformity of the thickness of the photosensitive resin film, or from the viewpoint of easily adjusting the content of organic solvents in the photosensitive resin film formed from the photosensitive resin composition. It is presumed that by using these organic solvents in combination, the volatilization of the organic solvent can be adjusted, making it easier to produce a film with uniform thickness. However, the factors are not limited to the above.

[0022] The organic solvent contained in the photosensitive resin film may include at least one selected from the group consisting of alkylene glycol monoalkyl ether acetate and alkoxyalkyl acetate, and may also include at least one selected from the group consisting of propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate, from the viewpoint of preventing excessive evaporation from the dry surface of the photosensitive resin film. In the photosensitive element according to this embodiment, from the viewpoint of sufficiently evaporating the organic solvent from the photosensitive resin film, the photosensitive resin film may contain propylene glycol monomethyl ether acetate as the alkylene glycol monoalkyl ether acetate.

[0023] The photosensitive resin composition may contain an organic solvent with a boiling point (at atmospheric pressure) of less than 150°C (first solvent) and an organic solvent with a boiling point (at atmospheric pressure) of 150°C or higher (second solvent), from the viewpoint of easily adjusting the content of organic solvents in the photosensitive resin film by drying the photosensitive resin composition. In the photosensitive element according to this embodiment, the photosensitive resin film may contain an organic solvent with a boiling point of less than 150°C (first solvent) and an organic solvent with a boiling point of 150°C or higher (second solvent), from the viewpoint of easily adjusting the content of organic solvents in the photosensitive resin film. The type and content of organic solvents contained in the photosensitive resin film can be confirmed by gas chromatography.

[0024] The boiling point of the first organic solvent may be 100°C or higher, 110°C or higher, 120°C or higher, 130°C or higher, 140°C or higher, or 144°C or higher. The boiling point of the first organic solvent may be less than 150°C, 149°C or lower, 148°C or lower, or 147°C or lower. From these viewpoints, the boiling point of the first organic solvent may be 100°C or higher but less than 150°C, 110°C or higher but less than 150°C, 120 to 149°C, 130 to 149°C, 140 to 148°C, or 144 to 147°C.

[0025] The boiling point of the second organic solvent may be 150°C or higher, 155°C or higher, 160°C or higher, 165°C or higher, or 170°C or higher. The boiling point of the second organic solvent may be 200°C or lower, 195°C or lower, 190°C or lower, 185°C or lower, 180°C or lower, or 175°C or lower. From these viewpoints, the boiling point of the second organic solvent may be 150-200°C, 155-200°C, 160-190°C, 160-185°C, 160-180°C, 165-180°C, or 170-175°C.

[0026] The content of the first organic solvent in the photosensitive element may be 2.3% by mass or more, 2.5% by mass or more, 2.7% by mass or more, or 3.0% by mass or more, based on the total amount of the photosensitive resin film, and may be 6.0% by mass or less, 5.8% by mass or less, 5.7% by mass or less, or 5.5% by mass or less.

[0027] Photosensitive resin compositions and photosensitive resin films may contain a resin having an acid-dissociable group. The resin having an acid-dissociable group is not particularly limited as long as it is a resin used in positive-type photosensitive resin compositions. Examples of resins having an acid-dissociable group include novolac resins having an acid-dissociable group, hydroxystyrene resins having an acid-dissociable group, and (meth)acrylic resins having an acid-dissociable group. The resins having an acid-dissociable group can be used individually or in combination of two or more.

[0028] Acid-dissociable groups can generate alkali-soluble groups (carboxyl groups, phenolic hydroxyl groups, etc.) through the action of acid. Examples of acid-dissociable groups include alkyl groups, alkoxyalkyl groups, alkoxycarbonyl groups, vinyloxyethyl groups, tetrahydropyranyl groups, tetrahydrofuranyl groups, and trialkylsilyl groups.

[0029] Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, cyclopentyl, and cyclohexyl groups. Examples of alkoxyalkyl groups include methoxyethyl, ethoxyethyl, n-propoxyethyl, isopropoxyethyl, n-butoxyethyl, isobutoxyethyl, tert-butoxyethyl, cyclohexyloxyethyl, methoxypropyl, ethoxypropyl, and 1-methoxy-1-methylmethoxyethyl. Examples of alkoxycarbonyl groups include tert-butoxycarbonyl and tert-butoxycarbonylmethyl groups. Examples of trialkylsilyl groups include trimethylsilyl and tri-tert-butyldimethylsilyl groups.

[0030] Resins having acid-dissociable groups may include resins described in the above-mentioned Patent Documents 2 to 4, etc. (for example, resins whose solubility in alkalis increases due to the action of acid).

[0031] The photosensitive resin composition and the photosensitive resin film may contain a photoacid generator. The photoacid generator comprises one or more compounds that generate acid upon exposure to light (e.g., ultraviolet light) and functions as a photosensitive agent in the photosensitive resin composition. The acid generated from the photoacid generator upon absorption of light selectively increases the solubility of the photosensitive resin film in an alkaline aqueous solution in the portion exposed to light.

[0032] The photoacid generator is not particularly limited as long as it is a compound that generates acid directly or indirectly upon exposure to light. The compounds constituting the photoacid generator may be selected from compounds commonly used as photoacid generators. Examples of photoacid generators include onium salt compounds, halogen-containing triazine compounds, diazoketone compounds, sulfonic acid compounds, sulfonimide compounds, and diazomethane compounds. The photoacid generator can be used individually or in combination of two or more.

[0033] Examples of onium salt compounds include iodonium salt compounds such as diaryliodonium salts, sulfonium salt compounds such as triarylsulfonium salts, diazonium salt compounds such as aryldiazonium salts, phosphonium salt compounds, and pyridinium salt compounds.

[0034] Examples of halogen-containing triazine compounds include s-triazine derivatives such as phenyl-bis(trichloromethyl)-s-triazine, 4-methoxyphenyl-bis(trichloromethyl)-s-triazine, styryl-bis(trichloromethyl)-s-triazine, and naphthyl-bis(trichloromethyl)-s-triazine.

[0035] Examples of diazoketone compounds include 1,3-diketo-2-diazo compounds, diazobenzoquinone compounds, and diazonaphthoquinone compounds.

[0036] Examples of sulfonic acid compounds include benzoin p-toluenesulfonate, pyrogallol trifluoromethanesulfonate, o-nitrobenzyl trifluoromethanesulfonate, and o-nitrobenzyl p-toluenesulfonate.

[0037] Examples of sulfonimide compounds include N-(trifluoromethylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(trifluoromethylsulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, N-(trifluoromethylsulfonyloxy)naphthalimide, N-(p-toluenesulfonyloxy)-1,8-naphthalimide, and N-(10-camphorsulfonyloxy)-1,8-naphthalimide.

[0038] Examples of diazomethane compounds include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, and bis(phenylsulfonyl)diazomethane.

[0039] The photoacid generator may include compounds described in the above-mentioned Patent Documents 2 to 4, etc. (for example, compounds that generate acid upon irradiation with active light or radiation).

[0040] The content of the photoacid generator may be within the following ranges per 100 parts by mass of the resin having an acid-dissociable group. The content of the photoacid generator may be 0.01 parts by mass or more, 0.05 parts by mass or more, 0.1 parts by mass or more, or 0.2 parts by mass or more. The content of the photoacid generator may be 1.0 part by mass or less, 0.9 parts by mass or less, or 0.8 parts by mass or less. From these viewpoints, the content of the photoacid generator may be 0.01 to 1.0 parts by mass, 0.05 to 0.9 parts by mass, 0.1 to 0.9 parts by mass, or 0.2 to 0.8 parts by mass.

[0041] The photosensitive resin composition and photosensitive resin film may further contain an alkali-soluble resin, an acid diffusion inhibitor, etc. The alkali-soluble resin is not particularly limited as long as it is a resin having alkali-soluble groups (carboxyl groups, phenolic hydroxyl groups, etc.). Examples of alkali-soluble resins include novolac resins, hydroxystyrene resins, (meth)acrylic resins, etc. The alkali-soluble resin can be used alone or in combination of two or more. Examples of acid diffusion inhibitors include hindered amine compounds, pyridine compounds, etc.

[0042] From the viewpoint of facilitating the formation of thick conductor patterns, the average thickness of the photosensitive resin film may be 80 μm or more, 85 μm or more, 90 μm or more, 95 μm or more, 100 μm or more, more than 100 μm, 105 μm or more, 110 μm or more, 115 μm or more, 120 μm or more, 125 μm or more, 130 μm or more, 135 μm or more, 140 μm or more, or 145 μm or more. The average thickness of the photosensitive resin film may be 300 μm or less, 250 μm or less, 200 μm or less, 190 μm or less, 180 μm or less, 175 μm or less, 170 μm or less, 165 μm or less, 160 μm or less, 155 μm or less, 150 μm or less, or 145 μm or less. From these viewpoints, the average thickness of the photosensitive resin film may be 80 to 300 μm, 80 to 200 μm, 80 to 150 μm, 100 to 300 μm, 100 to 200 μm, 100 to 150 μm, 120 to 300 μm, 120 to 200 μm, or 120 to 150 μm. The average thickness of the photosensitive resin film can be measured by the measurement method in [Examples] described later.

[0043] The photosensitive element according to the present embodiment may include a support layer (support film), a protective layer (protective film), a cushion layer, an adhesive layer, a light absorption layer, a gas barrier layer, and the like. The photosensitive element according to the present embodiment may include the above-described layers as films other than the support film and the protective film.

[0044] FIG. 1 is a schematic cross-sectional view showing an example of a photosensitive element. The photosensitive element 10 in FIG. 1 includes a support film 12, a positive photosensitive resin film 14 disposed on the support film 12, and a protective film 16 disposed on the photosensitive resin film 14, and the average thickness of the photosensitive resin film 14 is 80 μm or more. Each of the support film 12 and the protective film 16 is in contact with the photosensitive resin film 14. That is, the photosensitive element 10 includes the photosensitive resin film 14, the support film 12 in contact with one surface of the photosensitive resin film 14, and the protective film 16 in contact with the other surface of the photosensitive resin film 14.

[0045] The method for manufacturing a photosensitive element according to this embodiment is a method for obtaining a photosensitive element according to this embodiment. The method for manufacturing a photosensitive element according to this embodiment comprises the steps of forming a photosensitive resin film with an average thickness of 80 μm or more by coating a positive-type photosensitive resin composition onto a support film and then drying the photosensitive resin composition, and placing a protective film on the photosensitive resin film. By drying the photosensitive resin composition, at least a portion of the organic solvent can be removed. According to the method for manufacturing a photosensitive element according to this embodiment, a photosensitive element according to this embodiment can be obtained.

[0046] The drying temperature of the photosensitive resin composition may be 70°C or higher, 80°C or higher, 90°C or higher, or 100°C or higher from the viewpoint of reducing drying time, and may be 150°C or lower, 140°C or lower, 130°C or lower, 120°C or lower, or 110°C or lower from the viewpoint of easily adjusting the amount of residual solvent. From these viewpoints, the drying temperature of the photosensitive resin composition may be 70 to 150°C, 80 to 140°C, 90 to 130°C, 100 to 120°C, or 100 to 110°C. The drying time of the photosensitive resin composition can be adjusted by the drying temperature. From the viewpoint of storage stability of the photosensitive resin film, the drying time may be 6 minutes or more, 10 minutes or more, 12 minutes or more, or 14 minutes or more, and from the viewpoint of handlingability of the photosensitive resin film, it may be 80 minutes or less, 70 minutes or less, 60 minutes or less, 55 minutes or less, or 50 minutes or less. From these perspectives, the drying time may be 6-80 minutes, 8-70 minutes, 10-60 minutes, 12-55 minutes, or 14-50 minutes.

[0047] The method for manufacturing a resist pattern according to this embodiment comprises, in this order: an arrangement step of arranging the photosensitive resin film of the photosensitive element according to this embodiment on a substrate with one of the support film and protective film removed and the photosensitive resin film positioned on the substrate side relative to the other of the support film and protective film; an exposure step of exposing a part of the photosensitive resin film; and a developing step of removing at least a part (part or all) of the exposed portion of the photosensitive resin film to form a resist pattern.

[0048] In the placement step, while the protective film is removed and the photosensitive resin film of the photosensitive element according to the present embodiment is positioned on the substrate with the photosensitive resin film on the support film on the substrate side, the photosensitive resin film of the photosensitive element is placed on the substrate.

[0049] In the placement step, the photosensitive resin film can be placed on the substrate with the photosensitive resin film in contact with the substrate. When placing the photosensitive resin film on the substrate, the photosensitive resin film may be pressure-bonded to the substrate while heating the photosensitive resin film. The heating temperature during pressure bonding may be, for example, 70 to 130°C, and the pressure during pressure bonding may be, for example, 0.1 to 1.0 MPa (1 to 10 kgf / cm ２ ), but these conditions can be appropriately selected as needed. The placement step may be performed under reduced pressure.

[0050] The substrate may include a conductor layer, and may include an insulating layer and a conductor layer disposed on the insulating layer. The substrate is not particularly limited, and examples include a circuit forming substrate including an insulating layer and a conductor layer disposed on the insulating layer; a die pad (substrate for lead frame) such as an alloy substrate.

[0051] In the exposure step, a part of the photosensitive resin film is exposed. In the exposure step, the photosensitive resin film can be exposed by actinic rays. In the exposure step, the photosensitive resin film may be exposed in a state where the support film is removed, or the photosensitive resin film may be exposed by actinic rays through the support film.

[0052] As the exposure method, a known exposure method can be used without particular limitation, such as a method of irradiating actinic rays in an image shape through a positive mask pattern called an artwork (mask exposure method), an LDI (Laser Direct Imaging) exposure method, a method of irradiating actinic rays with an image of a photomask projected through a lens in an image shape (projection exposure method), and the like.

[0053] As a light source for the active ray, any known light source can be used without particular restrictions, and a light source that emits ultraviolet light can be used. Examples of light sources that emit ultraviolet light include carbon arc lamps, mercury vapor arc lamps, high-pressure mercury lamps, xenon lamps, gas lasers (argon lasers, etc.), solid-state lasers (YAG lasers, etc.), and semiconductor lasers (gallium nitride-based blue-violet lasers, etc.).

[0054] In the development process, at least a portion of the exposed area of ​​the photosensitive resin film is removed to form a resist pattern. If a support film is placed on the photosensitive resin film during the exposure process, the development process may be performed after removing the support film. The development method may be wet development or dry development.

[0055] In the case of wet development, the photosensitive resin film can be developed using a developer solution appropriate to its composition and a known wet development method. Examples of wet development methods include the dip method, paddle method, high-pressure spray method, brushing, scrubbing, and agitation immersion method. One wet development method may be used alone or in combination of two or more methods.

[0056] The developer can be appropriately selected depending on the composition of the photosensitive resin film. Examples of developers include alkaline aqueous solutions and organic solvent developers.

[0057] Examples of bases in alkaline aqueous solutions 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; sodium borate; sodium metasilicate; tetramethylammonium hydroxide; ethanolamine; ethylenediamine; diethylenetriamine; 2-amino-2-hydroxymethyl-1,3-propanediol; 1,3-diamino-2-propanol; and morpholine.

[0058] Examples of organic solvents used in organic solvent developers include 1,1,1-trichloroethane, N-methyl-2-pyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone.

[0059] The method for manufacturing a resist pattern according to this embodiment may include a step of obtaining a photosensitive element by the method for manufacturing a photosensitive element according to this embodiment, prior to the arrangement step.

[0060] The resist pattern manufacturing method according to this embodiment may include a step of removing (peeling off) a protective film from the photosensitive element before the placement step. The resist pattern manufacturing method according to this embodiment may include a step of removing (peeling off) a support film from the photosensitive element between the placement step and the exposure step, or between the exposure step and the development step.

[0061] The method for manufacturing a resist pattern according to this embodiment may include a heating step (hereinafter referred to as the "first heating step") between the arrangement step and the exposure step, in order to reduce the residual solvent in the photosensitive resin film, and may also include a step of heating the photosensitive resin film with the support film removed.

[0062] The heating temperature in the first heating step may be 50°C or higher, 60°C or higher, 70°C or higher, 80°C or higher, 90°C or higher, or 100°C or higher. The heating temperature may be 200°C or lower, 190°C or lower, 180°C or lower, 170°C or lower, 160°C or lower, or 150°C or lower. From these viewpoints, the heating temperature may be 50 to 200°C, 60 to 180°C, or 80 to 160°C. The first heating step may have multiple steps with different heating temperatures.

[0063] The method for manufacturing a resist pattern according to this embodiment may include a heating step (hereinafter referred to as the "second heating step") between the exposure step and the development step, in order to improve adhesion to the substrate.

[0064] The heating temperature in the second heating step may be 50°C or higher, 60°C or higher, 70°C or higher, 80°C or higher, 90°C or higher, or 100°C or higher. The heating temperature may be 250°C or lower, 230°C or lower, 210°C or lower, 200°C or lower, 190°C or lower, or 180°C or lower. From these viewpoints, the heating temperature may be 50 to 250°C, 60 to 200°C, or 80 to 180°C. The second heating step may have multiple steps with different heating temperatures.

[0065] The method for manufacturing a resist pattern according to this embodiment may include a step of heating or exposing the resist pattern after the development step.

[0066] Figures 2 and 3 are schematic cross-sectional views showing an example of a resist pattern manufacturing method, and are schematic cross-sectional views showing an example of a resist pattern manufacturing method using a positive-type photosensitive photosensitive resin film. In Figure 2(a), a substrate 20 is prepared. The substrate 20 comprises an insulating layer 22 and a conductive layer 24 disposed on the insulating layer 22. The conductive layer 24 is, for example, a copper layer. In Figure 2(b), after removing the protective film 16 of the photosensitive element 10 in Figure 1, the photosensitive resin film 14 and support film 12 of the photosensitive element 10 are laminated on the substrate 20. In Figure 2(c), after removing the support film 12, the photosensitive resin film 14 is heated. In Figure 3(a), an exposed area 14a is formed on the photosensitive resin film 14 by irradiating the photosensitive resin film 14 with an active light L onto which the image of the photomask is projected (exposure by projection exposure method). In Figure 3(b), a resist pattern 14b is formed on the substrate 20 by removing the exposed portion 14a of the photosensitive resin film 14 from the substrate 20.

[0067] The method for manufacturing a conductor pattern according to this embodiment includes a step of forming a conductor pattern using a resist pattern obtained by the resist pattern manufacturing method according to this embodiment as a mask. In the method for manufacturing a conductor pattern according to this embodiment, the conductor pattern may be formed by performing a plating treatment or etching treatment using the resist pattern obtained by the resist pattern manufacturing method according to this embodiment as a mask, or the conductor pattern may be formed by performing a plating treatment or etching treatment on a substrate on which the resist pattern obtained by the resist pattern manufacturing method according to this embodiment has been formed. Examples of constituent materials for the conductor pattern include copper, solder, nickel, and gold.

[0068] In the method for manufacturing a conductor pattern according to the first embodiment, a resist pattern obtained by the resist pattern manufacturing method according to this embodiment is used as a mask, and a conductor pattern is formed by applying a plating treatment to at least a part (or all) of the portion of the substrate where the resist pattern is not formed. In the method for manufacturing a conductor pattern according to the first embodiment, the substrate has a conductor layer, and the resist pattern obtained by the resist pattern manufacturing method according to this embodiment is formed on the conductor layer. The resist pattern is used as a mask, and a conductor pattern is formed by applying a plating treatment to at least a part (or all) of the portion of the substrate's conductor layer where the resist pattern is not formed. The materials of the substrate's conductor layer and the plating layer (conductor layer) formed by the plating treatment may be the same or different. If the materials of the substrate's conductor layer and the plating layer (conductor layer) formed by the plating treatment are the same, the conductor layer and the plating layer may be integrated. The plating treatment may be electrolytic plating or electroless plating. Examples of plating treatments include copper plating, solder plating, nickel plating, gold plating, etc.

[0069] In the method for manufacturing a conductor pattern according to the second embodiment, the substrate comprises a conductor layer, and a resist pattern obtained by the method for manufacturing a resist pattern according to this embodiment is formed on the conductor layer. Using the resist pattern as a mask, a conductor pattern covered by the resist pattern is formed by etching away at least a portion (part or all) of the conductor layer not covered by the resist pattern. The etching method is appropriately selected according to the conductor layer to be removed.

[0070] The method for manufacturing a conductor pattern according to this embodiment may include a step of removing the resist pattern on the substrate after plating or etching. The resist pattern can be removed, for example, with an aqueous solution that is more strongly alkaline than the alkaline aqueous solution used in the developing step.

[0071] In the method for manufacturing a conductor pattern according to the first embodiment, if the substrate has a conductor layer, after removing the resist pattern, the portion of the conductor layer of the substrate that was covered by the resist pattern may be removed by etching (for example, flash etching). The etching method is appropriately selected depending on the conductor layer to be removed.

[0072] One embodiment of the method for manufacturing a conductor pattern according to this embodiment is a method for manufacturing a wiring substrate (for example, a method for manufacturing a printed circuit board), and the method for manufacturing a wiring substrate according to this embodiment includes a step of forming a wiring pattern (for example, a circuit) as a conductor pattern using a resist pattern obtained by the method for manufacturing a resist pattern according to this embodiment as a mask. The wiring substrate according to this embodiment can be obtained by the method for manufacturing a wiring substrate according to this embodiment. The wiring substrate according to this embodiment may be a single-layer printed circuit board, a multilayer printed circuit board, or a printed circuit board having small-diameter through-holes.

[0073] Figure 4 is a schematic cross-sectional view showing an example of a method for manufacturing a conductor pattern, and is a schematic cross-sectional view showing an example of a method for manufacturing a conductor pattern using the resist pattern 14b in Figure 3. In Figure 4(a), a plating layer 30 is formed on the conductor layer 24 that is not covered by the resist pattern 14b on the substrate 20 by a plating process using the resist pattern 14b as a mask. In Figure 4(b), after removing the resist pattern 14b, a conductor layer 24a is formed by removing the portion of the conductor layer 24 that was covered by the resist pattern 14b. As a result, a conductor pattern 40 composed of the conductor layer 24a and the plating layer 30 is formed.

[0074] The present disclosure will be further described below with reference to examples, but the present disclosure is not limited to the following examples.

[0075] [Preparation of Photosensitive Element] (Example 1) A polyethylene terephthalate film with an average thickness of 50 μm (manufactured by Toyobo Co., Ltd., product name "A-5300", width: 590 mm) was prepared as a support film. Next, a positive-type photosensitive resin composition (PGMEA:MBA = 3:2 (mass ratio), non-volatile content: 50% by mass) containing propylene glycol monomethyl ether acetate (PGMEA) and 3-methoxybutyl acetate (MBA) as organic solvents was prepared using "PMER P-BZ4000" manufactured by Tokyo Ohka Kogyo Co., Ltd. After applying the positive-type photosensitive resin composition onto the support film in a direction perpendicular to the width direction of the support film, a photosensitive resin film (average thickness after drying: 145 μm) was formed by drying at 100°C for 55 minutes using a hot air convection dryer. Next, a biaxially oriented polypropylene film with an average thickness of 35 μm (manufactured by Oji F-Tex Co., Ltd., product name "MA-420") was laminated to the photosensitive resin film as a protective film, thereby creating a photosensitive element in which the support film, photosensitive resin film, and protective film were laminated in this order.

[0076] (Examples 2-6) Photosensitive elements were fabricated in the same manner as in Example 1, except that the drying conditions for forming the photosensitive resin film on the support film were changed to the conditions shown in Table 1.

[0077] (Comparative Examples 1-2) Photosensitive elements were fabricated in the same manner as in Example 1, except that the drying conditions for forming the photosensitive resin film on the support film were changed to the conditions shown in Table 2.

[0078] (Comparative Examples 3-4) A positive-type photosensitive resin composition (non-volatile content: 50% by mass) was prepared by changing the organic solvent to 3-methoxybutyl acetate (MBA) only, and a photosensitive element was fabricated in the same manner as in Example 1, except that the drying conditions when forming the photosensitive resin film on the support film were changed to the conditions shown in Table 2.

[0079] <Measurement of Average Thickness> The average thickness of the support film, photosensitive resin film, and protective film was measured using the following procedure. First, a test piece measuring 50 mm in length and 320 mm in width (horizontal direction = width direction of the support film) was obtained by cutting the photosensitive element. Marks were made on the surface of the support film and protective film at the center of this test piece, at two positions located 60 mm apart from the center in the horizontal direction, and at two positions located 120 mm apart from the center in the horizontal direction. The average thickness of the photosensitive element was obtained by measuring the thickness of these five positions (marked positions) on the photosensitive element using a contact-type film thickness gauge (manufactured by Mitutoyo Corporation, product name "VL-50"). After peeling off the protective film, the average thickness of the protective film was obtained by measuring the thickness of the five positions (marked positions) on the protective film using the same contact-type film thickness gauge. After peeling off the support film, the average thickness of the support film was obtained by measuring the thickness of the five positions (marked positions) on the support film using the same contact-type film thickness gauge. The average thickness of the photosensitive resin film was obtained by subtracting the average thickness of the protective film and the average thickness of the support film from the average thickness of the photosensitive elements.

[0080] <Measurement of Solvent Amount> Calibration curves for PGMEA and MBA were created by gas chromatography under the following conditions. Next, the photosensitive resin film, from which the support film and protective film had been removed from the photosensitive element, was dissolved in acetone, and the content of organic solvents (total amount of PGMEA and MBA) contained in the photosensitive resin film was measured by gas chromatography. The results are shown in Tables 1 and 2. Apparatus: Agilent 7890B GC (manufactured by Agilent Technologies, Inc.) Carrier gas: Nitrogen gas (5.0 mL / min) Column: DB-WAX polyethylene glycol (inner diameter 0.53 mm, length 30 m, film thickness 1.0 μm) Oven temperature: Heating at 60°C for 5 minutes, then increasing to 200°C at 20°C / min. Detector: Flame ionization detector (FID)

[0081] <Handling> A test specimen measuring 300 mm in length and 400 mm in width was obtained by cutting the photosensitive element. After bending the test specimen along a 3-inch diameter core, the occurrence of cracks in the photosensitive resin film was observed. If no cracks occurred in the photosensitive resin film, it was judged as "A", if a crack occurred in one place, it was judged as "B", and if multiple cracks occurred, it was judged as "C". The results are shown in Tables 1 and 2.

[0082] <Storage Stability> A photosensitive element roll was prepared by winding 25 m of photosensitive element onto a 3-inch diameter core. Side plates were attached to both ends of the photosensitive element roll, and it was stored horizontally in a cleanroom at a temperature of 22°C and a humidity of 60% RH. The occurrence of wrinkles in the photosensitive resin film was observed by visually inspecting the photosensitive element roll. If no wrinkles occurred after 7 days, it was judged as "A", if wrinkles were observed after 2 to 6 days, it was judged as "B", and if wrinkles were observed within 1 day, it was judged as "C". The results are shown in Tables 1 and 2.

[0083] <Removability of Protective Film> A test piece measuring 200 mm in length and 20 mm in width was obtained by cutting the photosensitive element. After leaving the test piece in an environment with a temperature of approximately 22°C and a humidity of approximately 50% RH for 20 minutes, the protective film was peeled off from the photosensitive resin film. The photosensitive resin film was visually inspected, and if no peeling marks of the protective film remained on the photosensitive resin film, it was judged as "A," and if peeling marks of the protective film remained on the photosensitive resin film, it was judged as "B." The results are shown in Tables 1 and 2.

[0084]

[0085]

[0086] 10...Photosensitive element, 12...Support film, 14...Photosensitive resin film, 14a...Exposure area, 14b...Resist pattern, 16...Protective film, 20...Substrate, 22...Insulating layer, 24, 24a...Conducting layer, 30...Plating layer, 40...Conducting pattern, L...Activating light.

Claims

1. A photosensitive element comprising a support film, a positive-type photosensitive resin film disposed on the support film, and a protective film disposed on the photosensitive resin film, wherein the average thickness of the photosensitive resin film is 80 μm or more, and the photosensitive resin film contains an organic solvent, with the content of the organic solvent being 7.0% by mass or more and less than 18.0% by mass, based on the total amount of the photosensitive resin film.

2. The photosensitive element according to claim 1, wherein the organic solvent comprises an organic solvent having a boiling point of less than 150°C and an organic solvent having a boiling point of 150°C or higher.

3. The photosensitive element according to claim 1, wherein the organic solvent comprises an alkylene glycol monoalkyl ether acetate and an alkoxyalkyl acetate.

4. The photosensitive element according to claim 1, wherein the content of the organic solvent is 9.0 to 17.5% by mass based on the total amount of the photosensitive resin film.

5. The photosensitive element according to claim 1, wherein the content of the organic solvent is 9.5 to 15.0% by mass based on the total amount of the photosensitive resin film.

6. A method for manufacturing a resist pattern, comprising, in this order: an arrangement step of arranging the photosensitive resin film of the photosensitive element according to any one of claims 1 to 5 on the substrate with the protective film removed and the photosensitive resin film positioned on the substrate side relative to the support film; an exposure step of exposing a part of the photosensitive resin film; and a developing step of removing at least a part of the exposed portion of the photosensitive resin film to form a resist pattern.

7. The method for manufacturing a resist pattern according to claim 6, further comprising the step of heating the photosensitive resin film with the support film removed between the arrangement step and the exposure step.

8. The method for manufacturing a resist pattern according to claim 6, further comprising a step of heating the photosensitive resin film between the exposure step and the development step.

9. A method for manufacturing a conductor pattern, comprising the step of forming a conductor pattern using a resist pattern obtained by the method for manufacturing a resist pattern described in claim 6 as a mask.

10. A method for producing a photosensitive element, comprising the steps of: forming a photosensitive resin film with an average thickness of 80 μm or more by applying a positive-type photosensitive resin composition onto a support film and then drying the photosensitive resin composition; and placing a protective film on the photosensitive resin film, wherein the photosensitive resin film contains an organic solvent, and the content of the organic solvent is 7.0% by mass or more and less than 18.0% by mass based on the total amount of the photosensitive resin film.

11. The method for producing a photosensitive element according to claim 10, wherein the organic solvent comprises an organic solvent having a boiling point of less than 150°C and an organic solvent having a boiling point of 150°C or higher.

12. The method for producing a photosensitive element according to claim 10, wherein the organic solvent comprises an alkylene glycol monoalkyl ether acetate and an alkoxyalkyl acetate.

13. A method for producing a photosensitive element according to any one of claims 10 to 12, wherein the content of the organic solvent is 9.0 to 17.5% by mass based on the total amount of the photosensitive resin film.

14. A method for producing a photosensitive element according to any one of claims 10 to 12, wherein the content of the organic solvent is 9.5 to 15.0% by mass based on the total amount of the photosensitive resin film.

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