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

Abstract

According to one embodiment of the present invention, a photosensitive element is provided with: a support film containing a lubricant; and a photosensitive layer formed on a first surface of the support film, in which the amount of a lubricant having a particle diameter of 0.8 [mu] m or more contained in a second surface of the support film on the opposite side from the first surface is 80 or less per 0.0225 mm2.

Description

Technical Field

[0001] The present invention relates to a photosensitive element, a method for forming a resist pattern, and a method for manufacturing a printed wiring board. Background Art

[0002] In the field of printed wiring board production, photosensitive elements including a layer (hereinafter also referred to as "photosensitive layer") formed on a support film using a photosensitive resin composition are widely used as resist materials used in etching processes, plating processes, and the like.

[0003] Regarding printed wiring boards, a photosensitive element is used, for example, to manufacture the printed wiring board by the following process. That is, first, the photosensitive layer of the photosensitive element is laminated on a circuit forming substrate such as a copper-clad laminate. Then, the photosensitive layer is exposed through a mask film to form a photocured portion. At this time, the support film is peeled off before or after exposure. Then, the area of ​​the photosensitive layer other than the photocured portion is removed with a developer to form a resist pattern. Then, the resist pattern is used as a resist, and an etching process or a plating process is performed to form a conductor pattern, and finally the photocured portion (resist pattern) of the photosensitive layer is peeled off (removed).

[0004] As a support film used for a photosensitive element, a support film having a specific haze value, a support film having a specific lubricant particle size, and the like are known (for example, see Patent Documents 1 and 2).

[0005] Previous technical literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-13681

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2014-74764 Summary of the Invention

[0009] Technical issues to be solved by the invention

[0010] In recent years, with the increasing demand for higher-resolution circuit formation, there has been a demand for miniaturized conductor patterns, and this has also led to a demand for miniaturized resist patterns used to form these patterns. However, lubricants contained in support films can sometimes scatter light during exposure, which can cause roughness (jitter) in the resist pattern's profile. Lubricants with large particle sizes, in particular, spread the light over a wider range, making the resist pattern's profile more likely to become coarse.

[0011] An object of the present invention is to provide a photosensitive element having excellent formability of a fine resist pattern, a method for forming a resist pattern using the photosensitive element, and a method for producing a printed wiring board.

[0012] Means for solving technical problems

[0013] One embodiment of the present invention relates to the following photosensitive element, resist pattern forming method, and printed wiring board manufacturing method.

[0014] [1] A photosensitive element comprising: a support film containing a lubricant; and a photosensitive layer formed on a first surface of the support film.

[0015] The amount of lubricant with a particle size of 0.8 μm or more contained in the second surface of the support film opposite to the first surface is 0.0225 mm 2 Below 80.

[0016] [2] The photosensitive element according to [1] above, wherein

[0017] The total amount of lubricant contained in the second surface is per 0.0225mm 2 Below 2000.

[0018] [3] The photosensitive element according to [1] or [2] above, wherein

[0019] The value obtained by dividing the number of lubricants having a particle size of 0.8 μm or more contained in the second surface by the total number of lubricants contained in the second surface is 0.20 or less.

[0020] [4] The photosensitive element according to any one of [1] to [3] above, wherein

[0021] The amount of lubricant with a particle size of 0.8 μm or more contained in the first surface is per 0.0225 mm 2 Below 200.

[0022] [5] The photosensitive element according to any one of [1] to [4] above, wherein

[0023] The average particle size of the lubricant contained in the first surface and the second surface is 0.3 μm or more and 1.0 μm or less.

[0024] [6] The photosensitive element according to any one of [1] to [5] above, wherein

[0025] The support film is a biaxially oriented polyester film.

[0026] [7] The photosensitive element according to any one of [1] to [6] above, wherein

[0027] The support film does not contain a lubricant with a particle size exceeding 3.0 μm.

[0028] [8] A method for forming a resist pattern, comprising: a lamination step of laminating the photosensitive element described in any one of [1] to [7] on a substrate in the order of a photosensitive layer and a support film; an exposure step of irradiating a predetermined portion of the photosensitive layer with active light through the support film to form a photocured portion; and a development step of removing the region of the photosensitive layer other than the photocured portion.

[0029] [9] A method for manufacturing a printed wiring board, comprising the step of forming a conductor pattern by etching or plating a substrate having a resist pattern formed by the resist pattern forming method described in [8] above.

[0030] Effects of the Invention

[0031] According to the present invention, a photosensitive element having excellent formability of a fine resist pattern, a method for forming a resist pattern using the photosensitive element, and a method for producing a printed wiring board can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic cross-sectional view showing one embodiment of a photosensitive element. DETAILED DESCRIPTION

[0033] Hereinafter, the embodiment for implementing the present invention will be described in detail. However, the present invention is not limited to the following embodiment.

[0034] In this specification, the numerical range represented by "~" means a range that includes the numerical values ​​recorded before and after "~" as the minimum value and the maximum value, respectively. "A above" in a numerical range refers to the range of A and above. "A below" in a numerical range refers to the range of A and below A. Within the numerical ranges recorded in stages in this specification, the upper limit or lower limit of the numerical range of a certain stage can be arbitrarily combined with the upper limit or lower limit of the numerical range of other stages. Within the numerical ranges recorded in this specification, the upper limit or lower limit of the numerical range can be replaced with the value shown in the examples.

[0035] In this specification, "A or B" includes either A or B, and may also include both. Unless otherwise specified, the materials exemplified in this specification can be used alone or in combination of two or more. Regarding the content of each component in the composition, when there are multiple substances equivalent to each component in the composition, unless otherwise specified, it refers to the total amount of the multiple substances present in the composition. Regarding the terms "layer" and "film", when observed as a top view, in addition to the structure of the shape formed on the entire surface, it also includes the structure of the shape formed on a part. The term "process" not only includes independent processes, but also includes processes that cannot be clearly distinguished from other processes as long as the intended effect of the process is achieved.

[0036] In this specification, "(meth)acrylate" refers to at least one of acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acrylic acid". "EO" means ethylene oxide, and an "EO-modified" compound means a compound having an ethylene oxide group. "PO" means propylene oxide, and a "PO-modified" compound means a compound having an ethylene oxide group. "Solid content" means the non-volatile components contained in the photosensitive resin composition except for volatile substances such as water and solvents, and means the components that do not volatilize and remain when the resin composition is dried, and also includes components that are liquid, sugary and waxy at room temperature of about 25°C.

[0037] [Photosensitive element]

[0038] The photosensitive element according to this embodiment comprises: a support film containing a lubricant; and a photosensitive layer formed on a first surface of the support film, wherein the amount of the lubricant having a particle size of 0.8 μm or more contained on a second surface of the support film opposite to the first surface is 0.0225 mm 2 Below 80.

[0039] Figure 1 1 is a schematic cross-sectional view showing an embodiment of a photosensitive element. Figure 1 The support film 10 and the photosensitive layer 20 are shown. The photosensitive layer 20 is provided on the first surface 10a of the support film 10. The support film 10 has a second surface 10b on the opposite side to the first surface 10a.

[0040] To improve lubricity, a lubricant is added to the support film 10, and the lubricant is applied to both surfaces of the support film. By reducing the amount of lubricant particles with a diameter of 0.8 μm or larger contained in the second surface 10b of the support film that does not contact the photosensitive layer, the roughness of the resist pattern profile can be reduced.

[0041] The lubricant is not particularly limited as long as it is a component that does not hinder the light transmittance of the support film and is used to make the polyester film, and may be an inorganic lubricant or an organic lubricant. Examples of inorganic lubricants include inorganic particles containing silicon dioxide, calcium carbonate, aluminum oxide, aluminum silicate, mica, clay, talc, wollastonite, kaolin, zinc oxide, barium sulfate, calcium phosphate, calcium, magnesium, barium, zinc, manganese, etc. as inorganic components. Examples of organic lubricants include cross-linked polymers such as polystyrene, polymethyl methacrylate, polyimide, polyolefin, modified polyolefin, and silicone resin.

[0042] From the viewpoint of further reducing the roughness of the resist pattern profile, the amount of the lubricant having a particle size of 0.8 μm or more contained in the second surface 10 b of the support film is 0.0225 mm. 2 It may be 75 or less, 70 or less, 65 or less, or 60 or less. The amount of lubricant involved in this embodiment is 0.0225 mm per unit area of ​​the support film. 2 The average value of (0.150 mm x 0.150 mm) is shown in Table 1. In addition, the lubricant with a particle size of 0.8 μm or more also includes aggregates of lubricants with a particle size of 0.8 μm or less.

[0043] The support film involved in this embodiment may contain a lubricant with a particle size of less than 0.8 μm. From the perspective of further improving the lubricity of the support film, the total number of lubricants contained in the second surface 10b (the number of lubricants with a particle size of 0.8 μm or more and the number of lubricants with a particle size of less than 0.8 μm) may be 0.0225 mm 2 It is 2500 or less, 2200 or less, 2000 or less, or 1800 or less, and may be 10 to 1800, 20 to 1600, 30 to 1400, or 40 to 1200.

[0044] From the perspective of further improving the lubricity of the support film, the value obtained by dividing the number of lubricants with a particle size of 0.8 μm or more contained in the second surface 10 b by the total number of lubricants contained in the second surface 10 b can be less than 0.20, less than 0.18, less than 0.16, less than 0.14 or less than 0.12.

[0045] The amount of lubricant with a particle size of 0.8 μm or more contained in the second surface 10b is preferably less than the amount of lubricant with a particle size of 0.8 μm or more contained in the first surface 10a. From the viewpoint of suppressing resist defects, the amount of lubricant with a particle size of 0.8 μm or more contained in the first surface 10a may be less than the amount of lubricant with a particle size of 0.8 μm or more contained in the second surface 10b. 2 It is 400 or less, 300 or less, 200 or less, or 180 or less, and may be 10-400, 15-300, 20-200, or 25-180.

[0046] From the viewpoint of further improving the lubricity of the support film, the total amount of lubricant contained in the first surface 10a may be 0.0225 mm 2 It is 100-1600, 150-1500, 155-1400 or 160-1200.

[0047] From the perspective of suppressing resist defects, the support film involved in this embodiment preferably does not contain a lubricant with a particle size exceeding 3.0 μm. The upper limit of the size of the lubricant with a particle size of 0.8 μm or more contained in the first surface 10a and the second surface 10b can be 3.0 μm or less, 2.5 μm or less, 2.0 μm or less, or 1.5 μm or less. From the perspective of improving operability, the lower limit of the size of the lubricant with a particle size of 0.8 μm or more contained in the first surface 10a and the second surface 10b can be 0.8 μm or more, 0.9 μm or more, 1.0 μm or more, or 1.1 μm or more.

[0048] From the perspective of improving operability, the average particle size of the lubricant contained in the first surface 10a and the second surface 10b can be greater than 0.2μm, greater than 0.3μm or greater than 0.4μm, and from the perspective of suppressing corrosion resistance defects, it can be less than 1.0μm, less than 0.8μm or less than 0.6μm.

[0049] The size and amount of the lubricant contained in the support film can be measured using a confocal microscope. As a confocal microscope, a hybrid laser microscope OPTELICS HYBRID (Lasertec Corporation, product name) or the like can be used. Observation using a confocal microscope is a measurement method in which the light reflected from the observation object is detected by a light receiving portion. When the observation object is in focus (in focus), the reflected light can be strongly obtained, and the intensity of the light can be strongly observed (mostly in the case of observation in white). When the observation object is not in focus (out of focus), the intensity of the light observed is weak (mostly in the case of observation in black).

[0050] From the perspective of facilitating high-precision and efficient observation, the numerical aperture (Na) of the objective lens used for observation can be 0.8. When the numerical aperture is 0.8, compared to when the numerical aperture exceeds 0.8, it is easier to prevent the lens from contacting the observed object and causing contamination of the microscope, and it is also possible to prevent excessively high magnification, thereby easily preventing a decrease in the amount of light in the field of view and a reduction in the detection level. Furthermore, when the numerical aperture (Na) is 0.8, compared to when the numerical aperture is less than 0.8, it is less likely to introduce errors in the dimensional detection of the observed object due to the reduced resolution, making it easier to perform high-precision measurements.

[0051] During observation using a conjugate focus microscope, the measurement magnification can be 50x, and the digital zoom on the software can be set to 2x. At 50x, the decrease in light intensity in the field of view is reduced compared to when the magnification exceeds 50x, making it easier to suppress a decrease in detection performance and more accurate measurement of defects compared to when the magnification is less than 50x. At 2x, the decrease in light intensity in the field of view is reduced compared to when the digital zoom is set to the same magnification (not set), making it easier to suppress a decrease in detection performance.

[0052] Examples of the structural material of the support film include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene 2,6-naphthalate (PEN); and polyolefins such as polypropylene and polyethylene. To prevent resist defects, the support film can be a polyester film or a PET film. The support film is a light-transmitting film, such as a transparent resin film.

[0053] The support film can be a multilayer film having a lubricant layer. The support film may comprise a polyester film and a lubricant layer disposed on at least one surface of the polyester film. The lubricant layer can be formed using known methods such as a roll coater, flow coater, spray coater, curtain coater, dip coater, or slot die coater. A biaxially oriented polyester film having a two- or three-layer structure is preferably used as the support film, and a three-layer biaxially oriented PET film is more preferably used.

[0054] From the perspective of improving the operability when laminating the photosensitive element on the substrate and the operability when forming the photosensitive layer on the support film, the haze value of the support film can be 0.01% or more, 0.05% or more, 0.1% or more, 0.3% or more, 0.5% or more, or 0.7% or more. From the perspective of easily obtaining good sensitivity and resolution, the haze value of the support film can be 3.0% or less, 1.5% or less, 0.8% or less, or 0.7% or less. From these perspectives, the haze value of the support film can be 0.01-3.0%, 0.01-1.5%, 0.01-0.8%, or 0.01-0.7%. "Haze value" refers to haze. The haze value of the support film can be measured in accordance with the method specified in JIS K7105 using a commercially available haze meter (for example, a turbidity meter, product name “NDH-5000” manufactured by NIPPON DENSHOKU INDUSTRIES Co., Ltd.).

[0055] The light transmittance of the support film (for example, the light transmittance over the entire range of wavelengths of 380 to 780 nm) may be within the following ranges. The light transmittance of the support film may be 80% or more, 85% or more, 87% or more, 88% or more, or 89% or more. The light transmittance of the support film may be 95% or less, 93% or less, 90% or less, or 89% or less. From these viewpoints, the light transmittance of the support film may be 80 to 95%. The light transmittance of the support film can be measured using a commercially available haze meter (for example, product name "NDH-5000" manufactured by NIPPON DENSHOKU INDUSTRIES Co., Ltd.).

[0056] The thickness of the support film or the thickness of the polyester film may be within the following ranges. From the perspective of preventing the support film from being easily broken when peeled from the photosensitive element, the thickness may be 5 μm or more, 10 μm or more, 11 μm or more, 12 μm or more, 15 μm or more, or 16 μm or more. From the perspective of easily ensuring a focus margin during exposure, the thickness may be 200 μm or less, 100 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, or 18 μm or less. From these perspectives, the thickness may be 5 to 200 μm, 11 to 100 μm, 12 to 50 μm, or 15 to 40 μm.

[0057] The photosensitive layer 20 is a layer formed of a photosensitive resin composition. The photosensitive resin composition used to form the photosensitive layer 20 may contain (A) a binder polymer (component (A)), (B) a photopolymerizable compound (component (B)), and (C) a photopolymerization initiator (component (C)).

[0058] As the structural material of the component (A), i.e., the binder polymer, for example, acrylic resins, styrene resins, epoxy resins, amide resins, amide epoxy resins, alkyd resins, and phenolic resins can be mentioned. From the viewpoint of easily obtaining good alkali developability, the component (A) may include an acrylic resin. As the component (A), the binder polymer used in the conventional photosensitive resin composition can be used.

[0059] (A) Component can be produced by, for example, radical polymerization of a polymerizable monomer. Examples of the polymerizable monomer include styrene or styrene derivatives, acrylamides such as diacetone acrylamide, acrylonitrile, ethers of vinyl alcohol such as vinyl n-butyl ether, alkyl (meth)acrylates, benzyl (meth)acrylate, hydroxyalkyl (meth)acrylates, tetrahydrofuran methyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, (meth)acrylic acid, α-bromoacrylic acid, α-chloroacrylic acid, β-furyl (meth)acrylate, β-styryl (meth)acrylate, maleic acid, maleic anhydride, maleic acid monoesters such as monomethyl maleate, monoethyl maleate, and monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic acid, itaconic acid, crotonic acid, and propiolic acid. The polymerizable monomers can be used alone or in combination of two or more.

[0060] From the perspective of alkali developability, component (A) may have a carboxyl group. Component (A) having a carboxyl group can be produced, for example, by free radical polymerization of a polymerizable monomer having a carboxyl group and another polymerizable monomer. The polymerizable monomer having a carboxyl group may be (meth)acrylic acid or methacrylic acid.

[0061] From the perspective of improving alkali developability and alkali resistance in a balanced manner, the content of the structural unit based on the polymerizable monomer having a carboxyl group can be 10 to 50% by mass, 15 to 40% by mass, or 20 to 35% by mass based on the total amount of component (A). When the carboxyl group content is 10% by mass or more, there is a tendency for alkali developability to be improved, and when the carboxyl group content is 50% by mass or less, there is a tendency for excellent alkali resistance to be achieved.

[0062] From the perspective of adhesion and peeling properties, component (A) may have a structural unit based on styrene or a styrene derivative. Styrene derivatives are polymerizable compounds in which hydrogen atoms in the α position or aromatic ring of styrene such as vinyltoluene and α-methylstyrene are substituted. The content of the structural unit based on styrene or a styrene derivative in component (A) may be 10 to 60% by mass, 15 to 50% by mass, 35 to 50% by mass, or 40 to 50% by mass. If the content is 10% by mass or more, there is a tendency for improved adhesion. If it is 60% by mass or less, there is a tendency to suppress the enlargement of the peeling piece during development and to suppress the prolonged time required for peeling.

[0063] From the viewpoint of improving resolution, component (A) may have a structural unit derived from benzyl (meth)acrylate. The content of the structural unit derived from benzyl (meth)acrylate in component (A) may be 10 to 40% by mass, 15 to 35% by mass, or 20 to 30% by mass.

[0064] From the viewpoint of improving plasticity, component (A) may have a structural unit based on an alkyl (meth)acrylate. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, and dodecyl (meth)acrylate.

[0065] From the perspective of further improving resolution and adhesion, component (A) may have a structural unit based on a hydroxyalkyl (meth)acrylate. Examples of the hydroxyalkyl (meth)acrylate include hydroxymethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, and hydroxyhexyl (meth)acrylate. Furthermore, in the hydroxyalkyl (meth)acrylate unit, when the alkyl portion has 3 or more carbon atoms, it may have a branched structure.

[0066] From the perspective of excellent adhesion of the resist pattern, the weight average molecular weight (Mw) of component (A) may be 10,000 or more, 15,000 or more, 20,000 or more, or 25,000 or more. From the perspective of enabling appropriate development, it may be 100,000 or less, 80,000 or less, 70,000 or less, or 60,000 or less. The dispersion degree (Mw / Mn) of component (A) may be, for example, 1.0 or more, 1.5 or more, or 1.8 or more. From the perspective of further improving adhesion and resolution, it may be 3.0 or less, 2.5 or less, or 2.0 or less.

[0067] The weight average molecular weight (Mw) and the dispersion degree (Mw / Mn) in this specification can be measured by gel permeation chromatography (GPC) and obtained by conversion using a calibration curve of standard polystyrene.

[0068] From the perspective of enabling optimal development, the acid value of component (A) may be 60 mgKOH / g or more, 80 mgKOH / g or more, 90 mgKOH / g or more, or 100 mgKOH / g or more. From the perspective of improving the adhesion (developer resistance) of the resist pattern, the acid value may be 250 mgKOH / g or less, 230 mgKOH / g or less, 210 mgKOH / g or less, or 200 mgKOH / g or less. The acid value of component (A) can be adjusted by adjusting the content of the structural units of component (A) (e.g., structural units derived from (meth)acrylic acid).

[0069] Component (A) can be used alone or in combination of two or more. When two or more components (A) are used in combination, for example, two or more binder polymers composed of different polymerizable monomers, two or more binder polymers with different Mw, and two or more binder polymers with different dispersities can be cited.

[0070] The content of component (A) can be 30 to 80 parts by mass, 40 to 75 parts by mass, 50 to 70 parts by mass, or 50 to 60 parts by mass relative to 100 parts by mass of the total amount of component (A) and component (B) described below. When the content of component (A) is within this range, the strength of the photocured portion of the photosensitive layer is further improved.

[0071] As the photopolymerizable compound of the component (B), a compound having at least one ethylenically unsaturated bond in the molecule can be used. The component (B) can be used alone or in combination of two or more.

[0072] The ethylenically unsaturated bond possessed by the (B) component is not particularly limited as long as it can be photopolymerized. Examples of the ethylenically unsaturated bond include α,β-unsaturated carbonyl groups such as (meth)acryloyl groups. Examples of photopolymerizable compounds having an α,β-unsaturated carbonyl group include α,β-unsaturated carboxylic acid esters of polyols, bisphenol-type (meth)acrylates, α,β-unsaturated carboxylic acid adducts of glycidyl-containing compounds, (meth)acrylates having a carbamate bond, nonylphenoxy polyethyleneoxyacrylates, (meth)acrylates having a phthalic acid skeleton, and (meth)acrylate alkyl esters.

[0073] Examples of the α,β-unsaturated carboxylic acid esters of polyols include polyethylene glycol di(meth)acrylate having 2 to 14 ethylene groups, polypropylene glycol di(meth)acrylate having 2 to 14 propylene groups, polyethylene-polypropylene glycol di(meth)acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, EO,PO-modified trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, and (meth)acrylate compounds having a skeleton derived from dipentaerythritol or pentaerythritol. "EO modification" refers to a block structure having an ethylene oxide (EO) group, and "PO modification" refers to a block structure having a propylene oxide (PO) group.

[0074] From the viewpoint of improving the flexibility of resist pattern, (B) component can include polyalkylene glycol di(meth)acrylate.Polyalkylene glycol di(meth)acrylate can have at least one of EO group and PO group, or can have both EO group and PO group.In polyalkylene glycol di(meth)acrylate with both EO group and PO group, EO group and PO group can be respectively continuous and block existence, or can be random existence.And, PO group can be any one of oxy-n-propylene or oxy-isopropylene.In addition, in (poly)oxy-isopropylene, the secondary carbon of propylene can be bonded to oxygen atom, or primary carbon can be bonded to oxygen atom.

[0075] Examples of commercially available products of polyalkylene glycol di(meth)acrylate include FA-023M (manufactured by Resonac Holdings Corporation), FA-024M (manufactured by Resonac Holdings Corporation), and NK ester HEMA-9P (manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0076] From the perspective of improving the flexibility of the resist pattern, component (B) may include a (meth)acrylate having a urethane bond. Examples of (meth)acrylates having a urethane bond include addition reaction products of a (meth)acrylic monomer having an OH group at the β-position and a diisocyanate (such as isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, and 1,6-hexamethylene diisocyanate), tris((meth)acryloyloxytetraethylene glycol isocyanate)hexamethylene isocyanurate, EO-modified urethane di(meth)acrylate, and EO,PO-modified urethane di(meth)acrylate.

[0077] Examples of commercially available products of EO-modified urethane di(meth)acrylates include "UA-11" and "UA-21EB" (manufactured by Shin-Nakamura Chemical Co., Ltd.). Examples of commercially available products of EO,PO-modified urethane di(meth)acrylates include "UA-13" (manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0078] From the perspective of easily forming a thick resist pattern and achieving balanced improvements in resolution and adhesion, component (B) may include a (meth)acrylate compound having a skeleton derived from dipentaerythritol or pentaerythritol. The (meth)acrylate compound having a skeleton derived from dipentaerythritol or pentaerythritol preferably has four or more (meth)acryloyl groups and may be dipentaerythritol penta(meth)acrylate or dipentaerythritol hexa(meth)acrylate.

[0079] As component (B), a multifunctional (meth)acrylate compound obtained by reacting an α,β-unsaturated carboxylic acid with a polyol may be contained. The multifunctional (meth)acrylate compound may have at least one of an EO group and a PO group, or may have both an EO group and a PO group. As such a compound, dipentaerythritol (meth)acrylate having an EO group may be used. Commercially available products of dipentaerythritol (meth)acrylate having an EO group include, for example, DPEA-12 (manufactured by Nippon Kayaku Co., Ltd.).

[0080] From the perspective of improving resolution and peeling properties after curing, component (B) may include bisphenol (meth)acrylate or, among bisphenol (meth)acrylates, bisphenol A (meth)acrylate. Examples of bisphenol A (meth)acrylate include 2,2-bis(4-((meth)acryloyloxypolyethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolypropoxy)phenyl)propane, 2,2-bis(4-((meth)acryloyloxypolybutoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloyloxypolyethoxypolypropoxy)phenyl)propane.

[0081] Commercially available substances include, for example, BPE-200 (manufactured by Shin-Nakamura Chemical Co., Ltd.) for 2,2-bis(4-((meth)acryloyloxydiethoxy)phenyl)propane, and BPE-500 (manufactured by Shin-Nakamura Chemical Co., Ltd.) and FA-321M (manufactured by Resonac Holdings Corporation) for 2,2-bis(4-(methacryloyloxypentaethoxy)phenyl)propane.

[0082] Examples of the nonylphenoxy polyethyleneoxy acrylate include nonylphenoxy tetraethyleneoxy acrylate, nonylphenoxy pentaethyleneoxy acrylate, nonylphenoxy hexaethyleneoxy acrylate, nonylphenoxy heptaethyleneoxy acrylate, nonylphenoxy octaethyleneoxy acrylate, nonylphenoxy nonaethyleneoxy acrylate, nonylphenoxy decaethyleneoxy acrylate, and nonylphenoxy undecethyleneoxy acrylate.

[0083] Examples of (meth)acrylates having a phthalic acid skeleton include γ-chloro-β-hydroxypropyl-β'-(meth)acryloyloxyethyl phthalate, β-hydroxyethyl-β'-(meth)acryloyloxyethyl phthalate, and β-hydroxypropyl-β'-(meth)acryloyloxyethyl phthalate. γ-Chloro-β-hydroxypropyl-β'-methacryloyloxyethyl phthalate is commercially available as FA-MECH (manufactured by Resonac Holdings Corporation).

[0084] The photopolymerization initiator (C) is not particularly limited as long as it can polymerize the component (B), and can be appropriately selected from commonly used photopolymerization initiators. Component (C) can be used alone or in combination of two or more.

[0085] Examples of the component (C) include imidazole compounds, aromatic ketones (excluding compounds corresponding to benzophenone compounds), quinone compounds, benzoin compounds, acridine compounds, N-phenylglycine compounds, and benzyl derivatives.

[0086] Examples of the imidazole compound include 2-(o-chlorophenyl)-4,5-diphenylbiimidazole, 2,2',5-tris-(o-chlorophenyl)-4-(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',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.

[0087] Examples of the acridine compound include 9-phenylacridine, 9-(p-methylphenyl)acridine, 9-(m-methylphenyl)acridine, 9-(p-chlorophenyl)acridine, 9-(m-chlorophenyl)acridine, 9-aminoacridine, 9-dimethylaminoacridine, 9-diethylaminoacridine, 9-pentylaminoacridine, 1,2-bis(9-acridyl)ethane, 1,4-bis(9-acridyl)butane, 1,6-bis(9-acridyl)hexane, 1,8-bis(9-acridyl)octane, 1,1 Bis(9-acridyl)alkanes such as 1,0-bis(9-acridyl)decane, 1,12-bis(9-acridyl)dodecane, 1,14-bis(9-acridyl)tetradecane, 1,16-bis(9-acridyl)hexadecane, 1,18-bis(9-acridyl)octadecane, 1,20-bis(9-acridyl)eicosane, 1,3-bis(9-acridyl)-2-oxapropane, 1,3-bis(9-acridyl)-2-thiapropane, and 1,5-bis(9-acridyl)-3-thiapentane.

[0088] Examples of N-phenylglycine compounds include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine. Examples of aromatic ketones include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propanone-1. Examples of quinone compounds include alkyl anthraquinones. Examples of benzoin compounds include benzoin, alkyl benzoin, and benzoin ether compounds (benzoin alkyl ether, etc.). Examples of benzyl derivatives include benzyl dimethyl ketal.

[0089] The content of component (C) can be 0.1 to 10 parts by mass, 1 to 5 parts by mass, or 2 to 4.5 parts by mass relative to 100 parts by mass of the total amount of components (A) and (B). When the content of component (C) is 0.1 parts by mass or more, photosensitivity, resolution, and adhesion tend to be improved, while when the content of component (C) is 10 parts by mass or less, resist pattern formability tends to be further improved.

[0090] The photosensitive resin composition according to this embodiment may further contain a photosensitizer as component (D). By containing component (D), the absorption wavelength of the active light used for exposure can be effectively utilized. Component (D) can be used alone or in combination of two or more.

[0091] Examples of component (D) include pyrazoline compounds, benzophenone compounds, anthracene compounds, coumarin compounds, xanthone compounds, thioxanthone compounds, oxazole compounds, benzoxazole compounds, thiazole compounds, benzothiazole compounds, triazole compounds, stilbene compounds, triazine compounds, thiophene compounds, naphthalimide compounds, triarylamine compounds, and aminoacridine compounds. From the perspectives of easily suppressing the occurrence of resist defects, easily shortening the minimum development time, and easily achieving good sensitivity, resolution, and adhesion, the sensitizer may include at least one selected from the group consisting of pyrazoline compounds, benzophenone compounds, anthracene compounds, and coumarin compounds.

[0092] Examples of the pyrazoline compound include 1-(4-methoxyphenyl)-3-styrene-5-phenyl-pyrazoline, 1-phenyl-3-(4-methoxystyrene)-5-(4-methoxyphenyl)-pyrazoline, 1,5-bis-(4-methoxyphenyl)-3-(4-methoxystyrene)-pyrazoline, 1-(4-isopropylphenyl)-3-styrene-5-phenyl-pyrazoline, 1-phenyl-3-(4-isopropylstyrene)-5-(4-isopropylphenyl)-pyrazoline, 1,5-bis-(4-isopropylphenyl)-3-(4-isopropylstyrene)-pyrazoline, 1-(4-methoxyphenyl)-3-(4-tert-butylstyrene)-5-(4-tert-butylphenyl)-pyrazoline, and 1-(4-methoxyphenyl)-3-(4-tert-butylstyrene)-5-(4-tert-butylphenyl)-pyrazoline. 4-tert-butyl-phenyl)-3-(4-methoxystyrene)-5-(4-methoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(4-tert-butyl-styrene)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(4-isopropyl-styrene)-5-(4-isopropyl-phenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(4-isopropylstyrene)-5-(4-isopropylphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(4-methoxystyrene)-5-(4-methoxyphenyl)-pyrazoline, 1-phenyl-3-(3,5-dimethoxystyrene)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(3,4-dimethoxystyrene)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,6-dimethoxystyrene)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,5-dimethoxystyrene)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,3-dimethoxystyrene)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,4-dimethoxystyrene)-5-(2,4-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(3,5-dimethoxystyrene)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-( 4-methoxyphenyl)-3-(3,4-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,6-dimethoxyphenyl)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,5-dimethoxyphenyl)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,3-dimethoxyphenyl)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-(4-methoxyphenyl)-3-(2,4-dimethoxyphenyl)-5-(2,4-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(3,5-dimethoxystyrene)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(3,4-dimethoxystyrene)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,6-dimethoxystyrene)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,5-dimethoxystyrene)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,3-dimethoxystyrene)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-(4-tert-butyl-phenyl)-3-(2,4-dimethoxystyrene)-5-(2,4-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl- phenyl)-3-(3,5-dimethoxystyrene)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(3,4-dimethoxystyrene)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(2,6-dimethoxystyrene)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(2,5-dimethoxystyrene)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-(4-isopropyl-phenyl)-3-(2,3-dimethoxystyrene)-5-(2,3-dimethoxyphenyl)-pyrazoline, and 1-(4-isopropyl-phenyl)-3-(2,4-dimethoxystyrene)-5-(2,4-dimethoxyphenyl)-pyrazoline. From the perspective of easily obtaining good resolution and adhesion, the sensitizer may contain 1-phenyl-3-(4-methoxyphenyl)-5-(4-methoxyphenyl)-pyrazoline.

[0093] Examples of benzophenone compounds include benzophenone; N,N,N',N'-tetramethyl-4,4'-diaminobenzophenone (also known as Michler's ketone) and N,N,N',N'-tetraethyl-4,4'-diaminobenzophenone, as well as dialkylaminobenzophenones such as 4-methoxy-4'-dimethylaminobenzophenone. From the perspective of achieving good resolution and adhesion, the sensitizer may contain N,N,N',N'-tetraalkyl-4,4'-diaminobenzophenone.

[0094] Examples of the anthracene compound include 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-dibutoxyanthracene, and 9,10-dipentyloxyanthracene. From the viewpoint of easily obtaining good sensitivity, the sensitizer may contain 9,10-dialkoxyanthracene.

[0095] Examples of the coumarin compound include 7-amino-4-methylcoumarin, 7-dimethylamino-4-methylcoumarin, 7-diethylamino-4-methylcoumarin, 7-methylamino-4-methylcoumarin, 7-ethylamino-4-methylcoumarin, 7-aminocyclopenta[c]coumarin, 7-dimethylaminocyclopenta[c]coumarin, 7-diethylaminocyclopenta[c]coumarin, 4,6-dimethyl-7-dimethylaminocoumarin, 4,6-dimethyl-7-ethylaminocoumarin, The sensitizer may include 2,3,6,7-tetrahydro-9-methyl-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one from the viewpoint of easily obtaining good sensitivity.

[0096] From the viewpoint of improving photosensitivity and resolution, the content of component (D) may be 0.01 to 5 parts by mass, 0.01 to 1 part by mass, or 0.01 to 0.2 parts by mass relative to 100 parts by mass of the total amount of components (A) and (B).

[0097] The photosensitive resin composition according to the present embodiment may further contain additives such as dyes, photochromic agents, thermochromic inhibitors, plasticizers, pigments, fillers, defoamers, flame retardants, adhesion-imparting agents, leveling agents, release accelerators, antioxidants, fragrances, developers, thermal crosslinking agents, and polymerization inhibitors, as needed. These additives may be used alone or in combination of two or more.

[0098] Examples of dyes include malachite green, Victoria blue, brilliant green, and methyl violet. Examples of photochromic agents include tribromophenylsulfone, leuco crystal violet, diphenylamine, benzylamine, triphenylamine, diethylaniline, and o-chloroaniline. Examples of plasticizers include p-toluenesulfonamide.

[0099] If necessary, the photosensitive resin composition can be dissolved in a solvent such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, propylene glycol monomethyl ether, or a mixed solvent thereof to prepare a solution having a solid content of about 30 to 60% by mass.

[0100] The thickness of the photosensitive layer 20 may be 1 to 200 μm, 5 to 100 μm, 10 to 50 μm, or 10 to 30 μm.

[0101] The photosensitive element of this embodiment may include a protective film (not shown) on the side of the photosensitive layer 20 opposite to the support film 10 (on the second surface 10b side). The protective film is preferably a film in which the adhesive strength between the photosensitive layer 20 and the protective film is smaller than the adhesive strength between the photosensitive layer 20 and the support film 10. Polyolefin films such as polyethylene and polypropylene can be used as the protective film. The protective film may be a polyethylene film.

[0102] The thickness of the protective film may be 5 to 100 μm, 5 to 70 μm, 10 to 60 μm, 10 to 50 μm, 15 to 40 μm, or 15 to 30 μm.

[0103] The photosensitive element of this embodiment may include an intermediate layer (not shown) between the support film and the photosensitive layer. The adhesive strength between the support film and the intermediate layer may be smaller than the adhesive strength between the intermediate layer and the photosensitive layer. The intermediate layer may be water-soluble or soluble in a developer. The intermediate layer is formed using the intermediate layer-forming resin composition described below.

[0104] The resin composition for forming the intermediate layer may contain a water-soluble resin. There is a tendency that the solubility of the intermediate layer formed is improved by containing a water-soluble resin. In addition, since it is easy to maintain the separation of the intermediate layer and the photosensitive layer for a long time, there is a tendency for the stability to be improved. Examples of water-soluble resins include polyvinyl alcohol and polyvinyl pyrrolidone. From the perspective of having a low oxygen permeability and being able to further suppress the deactivation of free radicals generated by the active light used for exposure, the resin composition for forming the intermediate layer may contain polyvinyl alcohol. Regarding polyvinyl alcohol, for example, it can be obtained by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate. The degree of saponification of the polyvinyl alcohol used in this embodiment may be 50 mol% or more, 70 mol% or more, or 80 mol% or more. By using polyvinyl alcohol having a saponification degree of 50 mol% or more, there is a tendency that the gas barrier properties of the intermediate layer can be further improved, thereby being able to further improve the resolution of the formed resist pattern. In addition, the "saponification degree" in this specification refers to the value measured according to JIS K 6726 (1994) (Testing methods for polyvinyl alcohol) specified in Japanese Industrial Standards. The upper limit of the saponification degree can be 100 mol%.

[0105] The average degree of polymerization of polyvinyl alcohol may be 300 to 3500, 300 to 2500, or 300 to 1000. Furthermore, the average degree of polymerization of polyvinyl pyrrolidone may be 10,000 to 100,000, or 10,000 to 50,000. Two or more polyvinyl alcohols having different saponification degrees, viscosities, polymerization degrees, and types of modifications may be used in combination.

[0106] The resin composition for forming the intermediate layer may contain a resin soluble in a developer. The resin soluble in a developer may include, for example, component (A) used in the photosensitive resin composition, or component (B). The inclusion of a resin soluble in a developer tends to improve the adhesion between the formed intermediate layer and the photosensitive layer, and also facilitates the formation of a photosensitive layer on the formed intermediate layer.

[0107] In order to improve the handling properties of the resin composition, or to adjust the viscosity and storage stability, the resin composition for forming the intermediate layer may contain at least one solvent as needed. Examples of the solvent include water and organic solvents. Examples of the organic solvent include methanol, acetone, toluene, or mixed solvents thereof. Methanol may be included from the perspective of improving the drying efficiency when forming the intermediate layer. Furthermore, when the resin composition for forming the intermediate layer contains a water-soluble resin, water, and methanol, the content of methanol may be 1 to 100 parts by mass, 10 to 80 parts by mass, or 20 to 60 parts by mass relative to 100 parts by mass of water from the perspective of solubility of the water-soluble resin. The content of the water-soluble resin may be 1 to 50 parts by mass, 5 to 40 parts by mass, or 10 to 30 parts by mass relative to 100 parts by mass of water.

[0108] The resin composition for forming the intermediate layer can be formulated with known additives such as surfactants, plasticizers, and leveling agents. As the leveling agent, for example, a silicone leveling agent can be mentioned. As a commercially available product of a silicone leveling agent, for example, Polyflow KL-401 (made by KYOEISHA CHEMICAL Co., LTD.) can be mentioned. When containing a leveling agent, from the perspective of the ease of forming the intermediate layer, the content of the leveling agent can be 0.01 to 2.0 parts by mass, 0.03 to 1.5 parts by mass, or 0.05 to 1.0 parts by mass relative to 100 parts by mass of the resin composition for forming the intermediate layer.

[0109] From the perspective of improving the peelability from the support film, as a surfactant, a silicone surfactant or a fluorine-based surfactant can be included. These surfactants can be used alone or in combination of two or more. In the case of containing a surfactant, from the perspective of the ease of forming the intermediate layer, the content of the surfactant can be 0.01 to 1.0 parts by mass, 0.05 to 0.5 parts by mass, or 0.1 to 0.3 parts by mass relative to 100 parts by mass of the resin composition for forming the intermediate layer.

[0110] For example, to facilitate the formation of the intermediate layer, a polyol compound may be included as a plasticizer. Examples of plasticizers include glycerols such as glycerol, diglycerol, and triglycerol; (poly)alkylene glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, and polypropylene glycol; and trimethylolpropane. These plasticizers may be used alone or in combination of two or more.

[0111] The thickness of the intermediate layer is not particularly limited, but from the perspective of developability, it may be 12 μm or less, 10 μm or less, or 8 μm or less. Furthermore, from the perspective of ease of formation and resolvability of the intermediate layer, the thickness of the intermediate layer may be 1.0 μm or more, 1.5 μm or more, or 2.0 μm or more.

[0112] [Method for Forming Resist Pattern]

[0113] The method for forming a resist pattern involved in this embodiment includes: a stacking process, in which the photosensitive layer 20 of the photosensitive element 1 is stacked on the substrate in the order of the photosensitive layer and the support film; an exposure process, in which active light is irradiated to a specified portion of the photosensitive layer 20 through the support film 10 to form a photocured portion; and a development process, in which the area other than the photocured portion in the photosensitive layer 20 is removed.

[0114] In the lamination process, for example, the photosensitive layer and the support film of the photosensitive element are sequentially laminated on the substrate. In the lamination process, as a method for laminating the photosensitive layer 20 on the substrate, for example, the following method can be cited: when there is a protective film on the photosensitive layer 20, after removing the protective film, the photosensitive layer 20 is heated to about 70 to 130°C and pressed onto the substrate with a pressure of about 0.1 to 1 MPa, thereby laminating. In the lamination process, lamination can also be performed under reduced pressure. In addition, the surface of the substrate on which the photosensitive layer 20 is laminated is usually a metal surface, but there is no particular limitation. In addition, in order to further improve the lamination properties, the substrate can be preheated.

[0115] Next, in the exposure step, for example, active light is irradiated onto a predetermined portion of the photosensitive layer 20 through the support film 10, thereby forming a photocured portion on the photosensitive layer 20. Examples of the exposure method include a method of irradiating active light in an image-like manner through a negative or positive photomask pattern called an original image (photomask exposure method), a method of irradiating active light in an image-like manner by a projection exposure method, and a method of irradiating active light in an image-like manner by a direct drawing exposure method such as an LDI (Laser Direct Imaging) exposure method or a DLP (Digital Light Processing) exposure method.

[0116] As the light source of the active light, a known light source can be used, for example, a carbon arc lamp, a mercury vapor arc lamp, a high-pressure mercury lamp, a xenon lamp, a gas laser such as an argon laser, a solid laser such as a YAG laser, an ultraviolet light such as a semiconductor laser, or a light source that efficiently radiates visible light.

[0117] From the perspective of improving adhesion, post-exposure baking (PEB) can be performed after exposure and before development. The temperature during PEB can be 50-100°C. As a heating machine, a hot plate, a box dryer, a heating roller, etc. can be used.

[0118] In the development step, at least a portion of the photosensitive layer excluding the photocured portion is removed from the substrate, thereby forming a resist pattern on the substrate.

[0119] In the development step, after the support film 10 is peeled off from the photosensitive layer 20, the region of the photosensitive layer other than the photocured portion is removed. In the development step, the unexposed portion (unphotocured portion) of the photosensitive layer 20 is removed and developed by, for example, wet development or dry development using a developer such as an alkaline aqueous solution, an aqueous developer, or an organic solvent, thereby producing a resist pattern.

[0120] Examples of the alkaline aqueous solution include 0.1-5% by mass sodium carbonate solution, 0.1-5% by mass potassium carbonate solution, and 0.1-5% by mass sodium hydroxide solution. The pH of the alkaline aqueous solution is preferably in the range of 9-11. The temperature of the alkaline aqueous solution is adjusted according to the developability of the photosensitive layer 20. The alkaline aqueous solution may also contain a surfactant, a defoaming agent, an organic solvent, and the like. Examples of the developing method include immersion, spraying, brushing, and scrubbing.

[0121] As a treatment after the development step, heating at about 60 to 250° C. or 0.2 to 10 J / cm 2 The resist pattern is further cured by exposure of about 100 Å.

[0122] [Manufacturing method of printed wiring board]

[0123] The method for manufacturing a printed wiring board according to this embodiment includes a step of forming a conductor pattern by etching or plating a substrate having a resist pattern formed by the resist pattern forming method described above. The etching or plating of the substrate can be performed by etching or plating the surface of the substrate using a known method, using the resist pattern as a photomask.

[0124] Examples of etching solutions include copper chloride solutions, ferric chloride solutions, and alkaline etching solutions. Examples of plating methods include copper plating, solder plating, nickel plating, and gold plating.

[0125] After etching or plating, the resist pattern can be stripped using, for example, an aqueous solution that is more alkaline than the alkaline aqueous solution used for development. Examples of such highly alkaline aqueous solutions include 1-10% by mass sodium hydroxide aqueous solutions and 1-10% by mass potassium hydroxide aqueous solutions. Examples of stripping methods include immersion and spraying. Furthermore, the printed wiring board on which the resist pattern is formed can be a multilayer printed wiring board and can also have small-diameter through-holes.

[0126] When plating a substrate having an insulating layer and a conductive layer formed thereon, it is necessary to remove the conductive layer except for the resist pattern. Examples of such removal methods include a method of removing the resist pattern followed by light etching; a method of removing the resist pattern after solder plating, etc., to photomask the wiring portion with solder, and then treating with an etching solution that etches only the portion of the conductive layer not masked with solder.

[0127] Example

[0128] Hereinafter, the present invention will be described in further detail using Examples and Comparative Examples, but the present invention is not limited to the Examples.

[0129] [Photosensitive resin composition]

[0130] A photosensitive resin composition was prepared by mixing the components in the amounts (parts by mass) shown in Table 1. Details of the components shown in Table 1 are as follows.

[0131] (Binder polymer)

[0132] A-1: Ethylene glycol monomethyl ether / toluene solution (solid content: 40% by mass) of a copolymer of methacrylic acid / styrene / benzyl methacrylate / 2-hydroxyethyl methacrylate (mass ratio: 27 / 50 / 20 / 3, Mw: 35,000, acid value: 176 mgKOH / g)

[0133] The Mw of the binder polymer was measured by gel permeation chromatography (GPC) under the following conditions and was calculated by conversion using a calibration curve of standard polystyrene.

[0134] Pump: L-2130 (manufactured by Hitachi High-Tech Corporation)

[0135] Detector: L-2490 RI (manufactured by Hitachi High-Tech Corporation)

[0136] Column oven: L-2350 (manufactured by Hitachi High-Tech Corporation)

[0137] Column: Gelpack GL-R440 + Gelpack GL-R450 + Gelpack GL-R400M (3 pieces in total) (manufactured by Resonac Holdings Corporation)

[0138] Column size: 10.7mm I.D × 300mm

[0139] Eluent: tetrahydrofuran

[0140] Sample concentration: 10mg / 2mL

[0141] Injection volume: 200 μL

[0142] Flow rate: 2.05mL / min

[0143] Measurement temperature: 25°C

[0144] The acid value of the binder polymer was measured using the following procedure. First, the binder polymer was weighed in an Erlenmeyer flask. A mixed solvent (mass ratio: toluene / methanol = 70 / 30) was then added to dissolve the binder polymer. A phenolphthalein solution was then added as an indicator. The acid value was then determined by titration using a 0.1 mol / L (N / 10) potassium hydroxide solution (in ethanol).

[0145] (Photopolymerizable compound)

[0146] FA-321M: EO-modified bisphenol A dimethacrylate (manufactured by Resonac Holdings Corporation, number of EO groups: 10 (average value))

[0147] FA-024M: Polyalkylene glycol dimethacrylate (manufactured by Resonac Holdings Corporation, number of EO groups: 12 (average value), number of PO groups: 4 (average value))

[0148] BP-2EM: 2,2-bis(4-(methacryloyloxydiethoxy)phenyl)propane (manufactured by KYOEISHA CHEMICAL Co., LTD.)

[0149] (Photopolymerization initiator)

[0150] B-CIM: 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole (manufactured by Hodogaya Chemical Co., Ltd.)

[0151] (Sensitizer)

[0152] PZ-501D: 1-phenyl-3-(4-methoxystyrene)-5-(4-methoxyphenyl)-pyrazoline (manufactured by Nippon Chemical Industry Co., Ltd.)

[0153] (Polymerization Inhibitor)

[0154] TBC: 4-tert-butylcatechol (manufactured by DIC Corporation)

[0155] LA-7RD: 4-Hydroxy-2,2,6,6-tetramethylpiperidinyl-N-oxyl (manufactured by ADEKA CORPORATION)

[0156] (dye)

[0157] MKG: Malachite green (manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD.)

[0158] (Developer)

[0159] LCV: Colorless crystal violet (manufactured by YAMADA CHEMICAL CO., LTD.)

[0160] [Table 1]

[0161]

[0162] [Support film]

[0163] As a support film for the photosensitive element, biaxially oriented PET films (thickness 16 μm) S1 to S12 were prepared. Using a conjugate focus microscope (manufactured by Lasertec Corporation, product name "Hybrid Laser Microscope OPTELICS HYBRID"), the 0.0225 mm diameter of the first and second surfaces of the support film was measured. 2 The amount of lubricant contained in an area (0.150 mm x 0.150 mm). Images were acquired under the conditions shown in Table 2 below, using a lens aperture (Na) of 0.8, a magnification of 50x, and a digital zoom of 2x. The size and amount of lubricant were calculated based on the pixels in the images. The results for S1 to S7 are shown in Table 3, and the results for S8 to S12 are shown in Table 4. Lubricant particles with a diameter of 2.0 μm or less were contained in S1 to S12.

[0164] [Table 2]

[0165]

[0166] [Photosensitive element]

[0167] A solution of the photosensitive resin composition was evenly applied to the first layer of the support film using a notched wheel coater. This was then dried in a hot air convection dryer at 100°C for 2 minutes to form a 15 μm thick photosensitive layer. A PE film (manufactured by Tamapoly Co., Ltd., product name "NF-15A," thickness: 28 μm) was then laminated on the photosensitive layer as a protective film to produce a photosensitive element.

[0168] [evaluate]

[0169] (Production of Laminated Body)

[0170] Substrate a was prepared on a PET film (manufactured by TOYOBO CO., LTD., trade name "Cosmoshine A4160," thickness: 125 μm) with titanium sputtered to 10 nm and copper sputtered to 100 nm. After heating this substrate a to 80°C, the protective film of the photosensitive element was removed and the photosensitive element was laminated with the photosensitive layer in contact with the copper layer. This produced a laminate comprising substrate a, the photosensitive layer, and the support film in that order in the lamination direction. Lamination was performed using a heated roller at 110°C, with a pressure of 0.4 MPa and a roller speed of 1.5 m / min.

[0171] (Formation of Resist Pattern)

[0172] The photosensitive layer of the laminate was exposed using an optical fixture with a 41-step scale, a glass chrome optical fixture with a wiring pattern of 20 / 20 to 1.0 / 1.0 (unit: μm) as a negative film for adhesion evaluation, and a high-resolution projection exposure system (manufactured by USHIO Inc., product name "UX-2240") equipped with a high-pressure mercury lamp. Exposure was performed at an irradiation energy level sufficient to achieve 11 steps remaining after development of the 41-step scale. Subsequently, the support film was peeled off, and a 1% by mass sodium carbonate aqueous solution was spray-developed at 30°C to remove the unexposed areas, forming a resist pattern with a line / space width of 5.0 / 5.0 (unit: μm).

[0173] Using NEXIV VMZ-R4540 (trade name, manufactured by Nikon Corporation), an area of ​​73μm×55μm of a substrate on which a resist pattern was formed was imaged. In the scanning measurement of NEXIV VMZ-R4540, the contour of the formed resist pattern was determined, and the coordinates of the contour of the resist pattern were measured for the 6 lines of the resist pattern. In the coordinate measurement, the coordinates of 260 points with a length of 52μm divided by 0.2μm scale were measured for the contour on one side of the line and the contour on the other side. Moreover, these measurements were performed at 3 locations for each of the 6 lines. Thus, a total of 9360 coordinates were measured. Based on the measured 9360 coordinates, the deviation (3σ) of the contour of the resist pattern was calculated. The 3σ of the contour is also called LER (LineEdgeRoughness). The smaller the value, the finer the resist pattern is formed.

[0174] [Table 3]

[0175]

[0176] [Table 4]

[0177]

[0178] Explanation of symbols

[0179] 1- photosensitive element, 10- supporting film, 10a- first surface, 10b- second surface, 20- photosensitive layer.

Claims

1. A photosensitive element comprising: a support film containing a lubricant; and a photosensitive layer formed on a first surface of the support film. The amount of the lubricant having a particle size of 0.8 μm or more contained in the second surface of the support film opposite to the first surface is 0.0225 mm 2 Below 80.

2. The photosensitive element according to claim 1, wherein The total amount of lubricant contained in the second surface is per 0.0225 mm 2 Below 2000.

3. The photosensitive element according to claim 1, wherein A value obtained by dividing the number of lubricants with a particle size of 0.8 μm or larger contained in the second surface by the total number of lubricants contained in the second surface is 0.20 or less.

4. The photosensitive element according to claim 1, wherein The amount of lubricant with a particle size of 0.8 μm or more contained in the first surface is per 0.0225 mm 2 Below 200.

5. The photosensitive element according to claim 1, wherein The average particle size of the lubricant contained in the first surface and the second surface is 0.3 μm or more and 1.0 μm or less.

6. The photosensitive element according to claim 1, wherein The support film is a biaxially oriented polyester film.

7. The photosensitive element according to claim 1, wherein The support film does not contain a lubricant with a particle size exceeding 3.0 μm.

8. A method for forming a resist pattern, comprising: a lamination step of laminating the photosensitive element according to any one of claims 1 to 7 on a substrate in the order of a photosensitive layer and a support film; an exposure step of irradiating a predetermined portion of the photosensitive layer with active light through the support film to form a photocured portion; and The developing step removes the region of the photosensitive layer except the photocured portion. 9 . A method for producing a printed wiring board, comprising the step of forming a conductor pattern by etching or plating a substrate having a resist pattern formed by the resist pattern forming method according to claim 8 .

Images